| 1 | /* |
| 2 | * SSH backend. |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <stdarg.h> |
| 8 | #include <assert.h> |
| 9 | #include <limits.h> |
| 10 | #include <signal.h> |
| 11 | |
| 12 | #include "putty.h" |
| 13 | #include "tree234.h" |
| 14 | #include "ssh.h" |
| 15 | #ifndef NO_GSSAPI |
| 16 | #include "sshgssc.h" |
| 17 | #include "sshgss.h" |
| 18 | #endif |
| 19 | |
| 20 | #ifndef FALSE |
| 21 | #define FALSE 0 |
| 22 | #endif |
| 23 | #ifndef TRUE |
| 24 | #define TRUE 1 |
| 25 | #endif |
| 26 | |
| 27 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
| 28 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
| 29 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
| 30 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
| 31 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
| 32 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
| 33 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
| 34 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
| 35 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
| 36 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
| 37 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
| 38 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
| 39 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
| 40 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
| 41 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
| 42 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
| 43 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
| 44 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
| 45 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
| 46 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
| 47 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
| 48 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
| 49 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
| 50 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
| 51 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
| 52 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
| 53 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
| 54 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
| 55 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
| 56 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
| 57 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
| 58 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
| 59 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
| 60 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
| 61 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
| 62 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
| 63 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
| 64 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
| 65 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
| 66 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
| 67 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
| 68 | |
| 69 | #define SSH1_AUTH_RHOSTS 1 /* 0x1 */ |
| 70 | #define SSH1_AUTH_RSA 2 /* 0x2 */ |
| 71 | #define SSH1_AUTH_PASSWORD 3 /* 0x3 */ |
| 72 | #define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */ |
| 73 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
| 74 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
| 75 | |
| 76 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
| 77 | /* Mask for protoflags we will echo back to server if seen */ |
| 78 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
| 79 | |
| 80 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
| 81 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
| 82 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
| 83 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
| 84 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
| 85 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
| 86 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
| 87 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
| 88 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
| 89 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
| 90 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
| 91 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
| 92 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
| 93 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
| 94 | #define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */ |
| 95 | #define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */ |
| 96 | #define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */ |
| 97 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
| 98 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
| 99 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
| 100 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
| 101 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
| 102 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
| 103 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ |
| 104 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ |
| 105 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
| 106 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
| 107 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
| 108 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
| 109 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
| 110 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
| 111 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
| 112 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
| 113 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
| 114 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
| 115 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
| 116 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
| 117 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
| 118 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
| 119 | #define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60 |
| 120 | #define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61 |
| 121 | #define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63 |
| 122 | #define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64 |
| 123 | #define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65 |
| 124 | #define SSH2_MSG_USERAUTH_GSSAPI_MIC 66 |
| 125 | |
| 126 | /* |
| 127 | * Packet type contexts, so that ssh2_pkt_type can correctly decode |
| 128 | * the ambiguous type numbers back into the correct type strings. |
| 129 | */ |
| 130 | typedef enum { |
| 131 | SSH2_PKTCTX_NOKEX, |
| 132 | SSH2_PKTCTX_DHGROUP, |
| 133 | SSH2_PKTCTX_DHGEX, |
| 134 | SSH2_PKTCTX_RSAKEX |
| 135 | } Pkt_KCtx; |
| 136 | typedef enum { |
| 137 | SSH2_PKTCTX_NOAUTH, |
| 138 | SSH2_PKTCTX_PUBLICKEY, |
| 139 | SSH2_PKTCTX_PASSWORD, |
| 140 | SSH2_PKTCTX_GSSAPI, |
| 141 | SSH2_PKTCTX_KBDINTER |
| 142 | } Pkt_ACtx; |
| 143 | |
| 144 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
| 145 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
| 146 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
| 147 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
| 148 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
| 149 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
| 150 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
| 151 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
| 152 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
| 153 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
| 154 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
| 155 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
| 156 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
| 157 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
| 158 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
| 159 | |
| 160 | static const char *const ssh2_disconnect_reasons[] = { |
| 161 | NULL, |
| 162 | "host not allowed to connect", |
| 163 | "protocol error", |
| 164 | "key exchange failed", |
| 165 | "host authentication failed", |
| 166 | "MAC error", |
| 167 | "compression error", |
| 168 | "service not available", |
| 169 | "protocol version not supported", |
| 170 | "host key not verifiable", |
| 171 | "connection lost", |
| 172 | "by application", |
| 173 | "too many connections", |
| 174 | "auth cancelled by user", |
| 175 | "no more auth methods available", |
| 176 | "illegal user name", |
| 177 | }; |
| 178 | |
| 179 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
| 180 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
| 181 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
| 182 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
| 183 | |
| 184 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
| 185 | |
| 186 | /* |
| 187 | * Various remote-bug flags. |
| 188 | */ |
| 189 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
| 190 | #define BUG_SSH2_HMAC 2 |
| 191 | #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 |
| 192 | #define BUG_CHOKES_ON_RSA 8 |
| 193 | #define BUG_SSH2_RSA_PADDING 16 |
| 194 | #define BUG_SSH2_DERIVEKEY 32 |
| 195 | #define BUG_SSH2_REKEY 64 |
| 196 | #define BUG_SSH2_PK_SESSIONID 128 |
| 197 | #define BUG_SSH2_MAXPKT 256 |
| 198 | #define BUG_CHOKES_ON_SSH2_IGNORE 512 |
| 199 | |
| 200 | /* |
| 201 | * Codes for terminal modes. |
| 202 | * Most of these are the same in SSH-1 and SSH-2. |
| 203 | * This list is derived from RFC 4254 and |
| 204 | * SSH-1 RFC-1.2.31. |
| 205 | */ |
| 206 | static const struct { |
| 207 | const char* const mode; |
| 208 | int opcode; |
| 209 | enum { TTY_OP_CHAR, TTY_OP_BOOL } type; |
| 210 | } ssh_ttymodes[] = { |
| 211 | /* "V" prefix discarded for special characters relative to SSH specs */ |
| 212 | { "INTR", 1, TTY_OP_CHAR }, |
| 213 | { "QUIT", 2, TTY_OP_CHAR }, |
| 214 | { "ERASE", 3, TTY_OP_CHAR }, |
| 215 | { "KILL", 4, TTY_OP_CHAR }, |
| 216 | { "EOF", 5, TTY_OP_CHAR }, |
| 217 | { "EOL", 6, TTY_OP_CHAR }, |
| 218 | { "EOL2", 7, TTY_OP_CHAR }, |
| 219 | { "START", 8, TTY_OP_CHAR }, |
| 220 | { "STOP", 9, TTY_OP_CHAR }, |
| 221 | { "SUSP", 10, TTY_OP_CHAR }, |
| 222 | { "DSUSP", 11, TTY_OP_CHAR }, |
| 223 | { "REPRINT", 12, TTY_OP_CHAR }, |
| 224 | { "WERASE", 13, TTY_OP_CHAR }, |
| 225 | { "LNEXT", 14, TTY_OP_CHAR }, |
| 226 | { "FLUSH", 15, TTY_OP_CHAR }, |
| 227 | { "SWTCH", 16, TTY_OP_CHAR }, |
| 228 | { "STATUS", 17, TTY_OP_CHAR }, |
| 229 | { "DISCARD", 18, TTY_OP_CHAR }, |
| 230 | { "IGNPAR", 30, TTY_OP_BOOL }, |
| 231 | { "PARMRK", 31, TTY_OP_BOOL }, |
| 232 | { "INPCK", 32, TTY_OP_BOOL }, |
| 233 | { "ISTRIP", 33, TTY_OP_BOOL }, |
| 234 | { "INLCR", 34, TTY_OP_BOOL }, |
| 235 | { "IGNCR", 35, TTY_OP_BOOL }, |
| 236 | { "ICRNL", 36, TTY_OP_BOOL }, |
| 237 | { "IUCLC", 37, TTY_OP_BOOL }, |
| 238 | { "IXON", 38, TTY_OP_BOOL }, |
| 239 | { "IXANY", 39, TTY_OP_BOOL }, |
| 240 | { "IXOFF", 40, TTY_OP_BOOL }, |
| 241 | { "IMAXBEL", 41, TTY_OP_BOOL }, |
| 242 | { "ISIG", 50, TTY_OP_BOOL }, |
| 243 | { "ICANON", 51, TTY_OP_BOOL }, |
| 244 | { "XCASE", 52, TTY_OP_BOOL }, |
| 245 | { "ECHO", 53, TTY_OP_BOOL }, |
| 246 | { "ECHOE", 54, TTY_OP_BOOL }, |
| 247 | { "ECHOK", 55, TTY_OP_BOOL }, |
| 248 | { "ECHONL", 56, TTY_OP_BOOL }, |
| 249 | { "NOFLSH", 57, TTY_OP_BOOL }, |
| 250 | { "TOSTOP", 58, TTY_OP_BOOL }, |
| 251 | { "IEXTEN", 59, TTY_OP_BOOL }, |
| 252 | { "ECHOCTL", 60, TTY_OP_BOOL }, |
| 253 | { "ECHOKE", 61, TTY_OP_BOOL }, |
| 254 | { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */ |
| 255 | { "OPOST", 70, TTY_OP_BOOL }, |
| 256 | { "OLCUC", 71, TTY_OP_BOOL }, |
| 257 | { "ONLCR", 72, TTY_OP_BOOL }, |
| 258 | { "OCRNL", 73, TTY_OP_BOOL }, |
| 259 | { "ONOCR", 74, TTY_OP_BOOL }, |
| 260 | { "ONLRET", 75, TTY_OP_BOOL }, |
| 261 | { "CS7", 90, TTY_OP_BOOL }, |
| 262 | { "CS8", 91, TTY_OP_BOOL }, |
| 263 | { "PARENB", 92, TTY_OP_BOOL }, |
| 264 | { "PARODD", 93, TTY_OP_BOOL } |
| 265 | }; |
| 266 | |
| 267 | /* Miscellaneous other tty-related constants. */ |
| 268 | #define SSH_TTY_OP_END 0 |
| 269 | /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */ |
| 270 | #define SSH1_TTY_OP_ISPEED 192 |
| 271 | #define SSH1_TTY_OP_OSPEED 193 |
| 272 | #define SSH2_TTY_OP_ISPEED 128 |
| 273 | #define SSH2_TTY_OP_OSPEED 129 |
| 274 | |
| 275 | /* Helper functions for parsing tty-related config. */ |
| 276 | static unsigned int ssh_tty_parse_specchar(char *s) |
| 277 | { |
| 278 | unsigned int ret; |
| 279 | if (*s) { |
| 280 | char *next = NULL; |
| 281 | ret = ctrlparse(s, &next); |
| 282 | if (!next) ret = s[0]; |
| 283 | } else { |
| 284 | ret = 255; /* special value meaning "don't set" */ |
| 285 | } |
| 286 | return ret; |
| 287 | } |
| 288 | static unsigned int ssh_tty_parse_boolean(char *s) |
| 289 | { |
| 290 | if (stricmp(s, "yes") == 0 || |
| 291 | stricmp(s, "on") == 0 || |
| 292 | stricmp(s, "true") == 0 || |
| 293 | stricmp(s, "+") == 0) |
| 294 | return 1; /* true */ |
| 295 | else if (stricmp(s, "no") == 0 || |
| 296 | stricmp(s, "off") == 0 || |
| 297 | stricmp(s, "false") == 0 || |
| 298 | stricmp(s, "-") == 0) |
| 299 | return 0; /* false */ |
| 300 | else |
| 301 | return (atoi(s) != 0); |
| 302 | } |
| 303 | |
| 304 | #define translate(x) if (type == x) return #x |
| 305 | #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x |
| 306 | #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x |
| 307 | static char *ssh1_pkt_type(int type) |
| 308 | { |
| 309 | translate(SSH1_MSG_DISCONNECT); |
| 310 | translate(SSH1_SMSG_PUBLIC_KEY); |
| 311 | translate(SSH1_CMSG_SESSION_KEY); |
| 312 | translate(SSH1_CMSG_USER); |
| 313 | translate(SSH1_CMSG_AUTH_RSA); |
| 314 | translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); |
| 315 | translate(SSH1_CMSG_AUTH_RSA_RESPONSE); |
| 316 | translate(SSH1_CMSG_AUTH_PASSWORD); |
| 317 | translate(SSH1_CMSG_REQUEST_PTY); |
| 318 | translate(SSH1_CMSG_WINDOW_SIZE); |
| 319 | translate(SSH1_CMSG_EXEC_SHELL); |
| 320 | translate(SSH1_CMSG_EXEC_CMD); |
| 321 | translate(SSH1_SMSG_SUCCESS); |
| 322 | translate(SSH1_SMSG_FAILURE); |
| 323 | translate(SSH1_CMSG_STDIN_DATA); |
| 324 | translate(SSH1_SMSG_STDOUT_DATA); |
| 325 | translate(SSH1_SMSG_STDERR_DATA); |
| 326 | translate(SSH1_CMSG_EOF); |
| 327 | translate(SSH1_SMSG_EXIT_STATUS); |
| 328 | translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 329 | translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); |
| 330 | translate(SSH1_MSG_CHANNEL_DATA); |
| 331 | translate(SSH1_MSG_CHANNEL_CLOSE); |
| 332 | translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); |
| 333 | translate(SSH1_SMSG_X11_OPEN); |
| 334 | translate(SSH1_CMSG_PORT_FORWARD_REQUEST); |
| 335 | translate(SSH1_MSG_PORT_OPEN); |
| 336 | translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); |
| 337 | translate(SSH1_SMSG_AGENT_OPEN); |
| 338 | translate(SSH1_MSG_IGNORE); |
| 339 | translate(SSH1_CMSG_EXIT_CONFIRMATION); |
| 340 | translate(SSH1_CMSG_X11_REQUEST_FORWARDING); |
| 341 | translate(SSH1_CMSG_AUTH_RHOSTS_RSA); |
| 342 | translate(SSH1_MSG_DEBUG); |
| 343 | translate(SSH1_CMSG_REQUEST_COMPRESSION); |
| 344 | translate(SSH1_CMSG_AUTH_TIS); |
| 345 | translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); |
| 346 | translate(SSH1_CMSG_AUTH_TIS_RESPONSE); |
| 347 | translate(SSH1_CMSG_AUTH_CCARD); |
| 348 | translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); |
| 349 | translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); |
| 350 | return "unknown"; |
| 351 | } |
| 352 | static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) |
| 353 | { |
| 354 | translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI); |
| 355 | translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI); |
| 356 | translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI); |
| 357 | translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI); |
| 358 | translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI); |
| 359 | translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI); |
| 360 | translate(SSH2_MSG_DISCONNECT); |
| 361 | translate(SSH2_MSG_IGNORE); |
| 362 | translate(SSH2_MSG_UNIMPLEMENTED); |
| 363 | translate(SSH2_MSG_DEBUG); |
| 364 | translate(SSH2_MSG_SERVICE_REQUEST); |
| 365 | translate(SSH2_MSG_SERVICE_ACCEPT); |
| 366 | translate(SSH2_MSG_KEXINIT); |
| 367 | translate(SSH2_MSG_NEWKEYS); |
| 368 | translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP); |
| 369 | translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP); |
| 370 | translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); |
| 371 | translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); |
| 372 | translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); |
| 373 | translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); |
| 374 | translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX); |
| 375 | translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX); |
| 376 | translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX); |
| 377 | translate(SSH2_MSG_USERAUTH_REQUEST); |
| 378 | translate(SSH2_MSG_USERAUTH_FAILURE); |
| 379 | translate(SSH2_MSG_USERAUTH_SUCCESS); |
| 380 | translate(SSH2_MSG_USERAUTH_BANNER); |
| 381 | translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); |
| 382 | translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); |
| 383 | translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); |
| 384 | translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); |
| 385 | translate(SSH2_MSG_GLOBAL_REQUEST); |
| 386 | translate(SSH2_MSG_REQUEST_SUCCESS); |
| 387 | translate(SSH2_MSG_REQUEST_FAILURE); |
| 388 | translate(SSH2_MSG_CHANNEL_OPEN); |
| 389 | translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 390 | translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 391 | translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 392 | translate(SSH2_MSG_CHANNEL_DATA); |
| 393 | translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); |
| 394 | translate(SSH2_MSG_CHANNEL_EOF); |
| 395 | translate(SSH2_MSG_CHANNEL_CLOSE); |
| 396 | translate(SSH2_MSG_CHANNEL_REQUEST); |
| 397 | translate(SSH2_MSG_CHANNEL_SUCCESS); |
| 398 | translate(SSH2_MSG_CHANNEL_FAILURE); |
| 399 | return "unknown"; |
| 400 | } |
| 401 | #undef translate |
| 402 | #undef translatec |
| 403 | |
| 404 | /* Enumeration values for fields in SSH-1 packets */ |
| 405 | enum { |
| 406 | PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, |
| 407 | /* These values are for communicating relevant semantics of |
| 408 | * fields to the packet logging code. */ |
| 409 | PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA |
| 410 | }; |
| 411 | |
| 412 | /* |
| 413 | * Coroutine mechanics for the sillier bits of the code. If these |
| 414 | * macros look impenetrable to you, you might find it helpful to |
| 415 | * read |
| 416 | * |
| 417 | * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html |
| 418 | * |
| 419 | * which explains the theory behind these macros. |
| 420 | * |
| 421 | * In particular, if you are getting `case expression not constant' |
| 422 | * errors when building with MS Visual Studio, this is because MS's |
| 423 | * Edit and Continue debugging feature causes their compiler to |
| 424 | * violate ANSI C. To disable Edit and Continue debugging: |
| 425 | * |
| 426 | * - right-click ssh.c in the FileView |
| 427 | * - click Settings |
| 428 | * - select the C/C++ tab and the General category |
| 429 | * - under `Debug info:', select anything _other_ than `Program |
| 430 | * Database for Edit and Continue'. |
| 431 | */ |
| 432 | #define crBegin(v) { int *crLine = &v; switch(v) { case 0:; |
| 433 | #define crState(t) \ |
| 434 | struct t *s; \ |
| 435 | if (!ssh->t) ssh->t = snew(struct t); \ |
| 436 | s = ssh->t; |
| 437 | #define crFinish(z) } *crLine = 0; return (z); } |
| 438 | #define crFinishV } *crLine = 0; return; } |
| 439 | #define crReturn(z) \ |
| 440 | do {\ |
| 441 | *crLine =__LINE__; return (z); case __LINE__:;\ |
| 442 | } while (0) |
| 443 | #define crReturnV \ |
| 444 | do {\ |
| 445 | *crLine=__LINE__; return; case __LINE__:;\ |
| 446 | } while (0) |
| 447 | #define crStop(z) do{ *crLine = 0; return (z); }while(0) |
| 448 | #define crStopV do{ *crLine = 0; return; }while(0) |
| 449 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 450 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 451 | |
| 452 | typedef struct ssh_tag *Ssh; |
| 453 | struct Packet; |
| 454 | |
| 455 | static struct Packet *ssh1_pkt_init(int pkt_type); |
| 456 | static struct Packet *ssh2_pkt_init(int pkt_type); |
| 457 | static void ssh_pkt_ensure(struct Packet *, int length); |
| 458 | static void ssh_pkt_adddata(struct Packet *, void *data, int len); |
| 459 | static void ssh_pkt_addbyte(struct Packet *, unsigned char value); |
| 460 | static void ssh2_pkt_addbool(struct Packet *, unsigned char value); |
| 461 | static void ssh_pkt_adduint32(struct Packet *, unsigned long value); |
| 462 | static void ssh_pkt_addstring_start(struct Packet *); |
| 463 | static void ssh_pkt_addstring_str(struct Packet *, char *data); |
| 464 | static void ssh_pkt_addstring_data(struct Packet *, char *data, int len); |
| 465 | static void ssh_pkt_addstring(struct Packet *, char *data); |
| 466 | static unsigned char *ssh2_mpint_fmt(Bignum b, int *len); |
| 467 | static void ssh1_pkt_addmp(struct Packet *, Bignum b); |
| 468 | static void ssh2_pkt_addmp(struct Packet *, Bignum b); |
| 469 | static int ssh2_pkt_construct(Ssh, struct Packet *); |
| 470 | static void ssh2_pkt_send(Ssh, struct Packet *); |
| 471 | static void ssh2_pkt_send_noqueue(Ssh, struct Packet *); |
| 472 | static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, |
| 473 | struct Packet *pktin); |
| 474 | static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, |
| 475 | struct Packet *pktin); |
| 476 | static void ssh2_channel_check_close(struct ssh_channel *c); |
| 477 | static void ssh_channel_destroy(struct ssh_channel *c); |
| 478 | |
| 479 | /* |
| 480 | * Buffer management constants. There are several of these for |
| 481 | * various different purposes: |
| 482 | * |
| 483 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up |
| 484 | * on a local data stream before we throttle the whole SSH |
| 485 | * connection (in SSH-1 only). Throttling the whole connection is |
| 486 | * pretty drastic so we set this high in the hope it won't |
| 487 | * happen very often. |
| 488 | * |
| 489 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up |
| 490 | * on the SSH connection itself before we defensively throttle |
| 491 | * _all_ local data streams. This is pretty drastic too (though |
| 492 | * thankfully unlikely in SSH-2 since the window mechanism should |
| 493 | * ensure that the server never has any need to throttle its end |
| 494 | * of the connection), so we set this high as well. |
| 495 | * |
| 496 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 |
| 497 | * channels. |
| 498 | * |
| 499 | * - OUR_V2_BIGWIN is the window size we advertise for the only |
| 500 | * channel in a simple connection. It must be <= INT_MAX. |
| 501 | * |
| 502 | * - OUR_V2_MAXPKT is the official "maximum packet size" we send |
| 503 | * to the remote side. This actually has nothing to do with the |
| 504 | * size of the _packet_, but is instead a limit on the amount |
| 505 | * of data we're willing to receive in a single SSH2 channel |
| 506 | * data message. |
| 507 | * |
| 508 | * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH |
| 509 | * _packet_ we're prepared to cope with. It must be a multiple |
| 510 | * of the cipher block size, and must be at least 35000. |
| 511 | */ |
| 512 | |
| 513 | #define SSH1_BUFFER_LIMIT 32768 |
| 514 | #define SSH_MAX_BACKLOG 32768 |
| 515 | #define OUR_V2_WINSIZE 16384 |
| 516 | #define OUR_V2_BIGWIN 0x7fffffff |
| 517 | #define OUR_V2_MAXPKT 0x4000UL |
| 518 | #define OUR_V2_PACKETLIMIT 0x9000UL |
| 519 | |
| 520 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
| 521 | |
| 522 | const static struct ssh_mac *macs[] = { |
| 523 | &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 |
| 524 | }; |
| 525 | const static struct ssh_mac *buggymacs[] = { |
| 526 | &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5 |
| 527 | }; |
| 528 | |
| 529 | static void *ssh_comp_none_init(void) |
| 530 | { |
| 531 | return NULL; |
| 532 | } |
| 533 | static void ssh_comp_none_cleanup(void *handle) |
| 534 | { |
| 535 | } |
| 536 | static int ssh_comp_none_block(void *handle, unsigned char *block, int len, |
| 537 | unsigned char **outblock, int *outlen) |
| 538 | { |
| 539 | return 0; |
| 540 | } |
| 541 | static int ssh_comp_none_disable(void *handle) |
| 542 | { |
| 543 | return 0; |
| 544 | } |
| 545 | const static struct ssh_compress ssh_comp_none = { |
| 546 | "none", NULL, |
| 547 | ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, |
| 548 | ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, |
| 549 | ssh_comp_none_disable, NULL |
| 550 | }; |
| 551 | extern const struct ssh_compress ssh_zlib; |
| 552 | const static struct ssh_compress *compressions[] = { |
| 553 | &ssh_zlib, &ssh_comp_none |
| 554 | }; |
| 555 | |
| 556 | enum { /* channel types */ |
| 557 | CHAN_MAINSESSION, |
| 558 | CHAN_X11, |
| 559 | CHAN_AGENT, |
| 560 | CHAN_SOCKDATA, |
| 561 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ |
| 562 | }; |
| 563 | |
| 564 | /* |
| 565 | * little structure to keep track of outstanding WINDOW_ADJUSTs |
| 566 | */ |
| 567 | struct winadj { |
| 568 | struct winadj *next; |
| 569 | unsigned size; |
| 570 | }; |
| 571 | |
| 572 | /* |
| 573 | * 2-3-4 tree storing channels. |
| 574 | */ |
| 575 | struct ssh_channel { |
| 576 | Ssh ssh; /* pointer back to main context */ |
| 577 | unsigned remoteid, localid; |
| 578 | int type; |
| 579 | /* True if we opened this channel but server hasn't confirmed. */ |
| 580 | int halfopen; |
| 581 | /* |
| 582 | * In SSH-1, this value contains four bits: |
| 583 | * |
| 584 | * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. |
| 585 | * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. |
| 586 | * 4 We have received SSH1_MSG_CHANNEL_CLOSE. |
| 587 | * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. |
| 588 | * |
| 589 | * A channel is completely finished with when all four bits are set. |
| 590 | * |
| 591 | * In SSH-2, the four bits mean: |
| 592 | * |
| 593 | * 1 We have sent SSH2_MSG_CHANNEL_EOF. |
| 594 | * 2 We have sent SSH2_MSG_CHANNEL_CLOSE. |
| 595 | * 4 We have received SSH2_MSG_CHANNEL_EOF. |
| 596 | * 8 We have received SSH2_MSG_CHANNEL_CLOSE. |
| 597 | * |
| 598 | * A channel is completely finished with when we have both sent |
| 599 | * and received CLOSE. |
| 600 | * |
| 601 | * The symbolic constants below use the SSH-2 terminology, which |
| 602 | * is a bit confusing in SSH-1, but we have to use _something_. |
| 603 | */ |
| 604 | #define CLOSES_SENT_EOF 1 |
| 605 | #define CLOSES_SENT_CLOSE 2 |
| 606 | #define CLOSES_RCVD_EOF 4 |
| 607 | #define CLOSES_RCVD_CLOSE 8 |
| 608 | int closes; |
| 609 | |
| 610 | /* |
| 611 | * This flag indicates that an EOF is pending on the outgoing side |
| 612 | * of the channel: that is, wherever we're getting the data for |
| 613 | * this channel has sent us some data followed by EOF. We can't |
| 614 | * actually send the EOF until we've finished sending the data, so |
| 615 | * we set this flag instead to remind us to do so once our buffer |
| 616 | * is clear. |
| 617 | */ |
| 618 | int pending_eof; |
| 619 | |
| 620 | /* |
| 621 | * True if this channel is causing the underlying connection to be |
| 622 | * throttled. |
| 623 | */ |
| 624 | int throttling_conn; |
| 625 | union { |
| 626 | struct ssh2_data_channel { |
| 627 | bufchain outbuffer; |
| 628 | unsigned remwindow, remmaxpkt; |
| 629 | /* locwindow is signed so we can cope with excess data. */ |
| 630 | int locwindow, locmaxwin; |
| 631 | /* |
| 632 | * remlocwin is the amount of local window that we think |
| 633 | * the remote end had available to it after it sent the |
| 634 | * last data packet or window adjust ack. |
| 635 | */ |
| 636 | int remlocwin; |
| 637 | /* |
| 638 | * These store the list of window adjusts that haven't |
| 639 | * been acked. |
| 640 | */ |
| 641 | struct winadj *winadj_head, *winadj_tail; |
| 642 | enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state; |
| 643 | } v2; |
| 644 | } v; |
| 645 | union { |
| 646 | struct ssh_agent_channel { |
| 647 | unsigned char *message; |
| 648 | unsigned char msglen[4]; |
| 649 | unsigned lensofar, totallen; |
| 650 | } a; |
| 651 | struct ssh_x11_channel { |
| 652 | Socket s; |
| 653 | } x11; |
| 654 | struct ssh_pfd_channel { |
| 655 | Socket s; |
| 656 | } pfd; |
| 657 | } u; |
| 658 | }; |
| 659 | |
| 660 | /* |
| 661 | * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2 |
| 662 | * use this structure in different ways, reflecting SSH-2's |
| 663 | * altogether saner approach to port forwarding. |
| 664 | * |
| 665 | * In SSH-1, you arrange a remote forwarding by sending the server |
| 666 | * the remote port number, and the local destination host:port. |
| 667 | * When a connection comes in, the server sends you back that |
| 668 | * host:port pair, and you connect to it. This is a ready-made |
| 669 | * security hole if you're not on the ball: a malicious server |
| 670 | * could send you back _any_ host:port pair, so if you trustingly |
| 671 | * connect to the address it gives you then you've just opened the |
| 672 | * entire inside of your corporate network just by connecting |
| 673 | * through it to a dodgy SSH server. Hence, we must store a list of |
| 674 | * host:port pairs we _are_ trying to forward to, and reject a |
| 675 | * connection request from the server if it's not in the list. |
| 676 | * |
| 677 | * In SSH-2, each side of the connection minds its own business and |
| 678 | * doesn't send unnecessary information to the other. You arrange a |
| 679 | * remote forwarding by sending the server just the remote port |
| 680 | * number. When a connection comes in, the server tells you which |
| 681 | * of its ports was connected to; and _you_ have to remember what |
| 682 | * local host:port pair went with that port number. |
| 683 | * |
| 684 | * Hence, in SSH-1 this structure is indexed by destination |
| 685 | * host:port pair, whereas in SSH-2 it is indexed by source port. |
| 686 | */ |
| 687 | struct ssh_portfwd; /* forward declaration */ |
| 688 | |
| 689 | struct ssh_rportfwd { |
| 690 | unsigned sport, dport; |
| 691 | char dhost[256]; |
| 692 | char *sportdesc; |
| 693 | struct ssh_portfwd *pfrec; |
| 694 | }; |
| 695 | #define free_rportfwd(pf) ( \ |
| 696 | ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) ) |
| 697 | |
| 698 | /* |
| 699 | * Separately to the rportfwd tree (which is for looking up port |
| 700 | * open requests from the server), a tree of _these_ structures is |
| 701 | * used to keep track of all the currently open port forwardings, |
| 702 | * so that we can reconfigure in mid-session if the user requests |
| 703 | * it. |
| 704 | */ |
| 705 | struct ssh_portfwd { |
| 706 | enum { DESTROY, KEEP, CREATE } status; |
| 707 | int type; |
| 708 | unsigned sport, dport; |
| 709 | char *saddr, *daddr; |
| 710 | char *sserv, *dserv; |
| 711 | struct ssh_rportfwd *remote; |
| 712 | int addressfamily; |
| 713 | void *local; |
| 714 | }; |
| 715 | #define free_portfwd(pf) ( \ |
| 716 | ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \ |
| 717 | sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) ) |
| 718 | |
| 719 | struct Packet { |
| 720 | long length; /* length of `data' actually used */ |
| 721 | long forcepad; /* SSH-2: force padding to at least this length */ |
| 722 | int type; /* only used for incoming packets */ |
| 723 | unsigned long sequence; /* SSH-2 incoming sequence number */ |
| 724 | unsigned char *data; /* allocated storage */ |
| 725 | unsigned char *body; /* offset of payload within `data' */ |
| 726 | long savedpos; /* temporary index into `data' (for strings) */ |
| 727 | long maxlen; /* amount of storage allocated for `data' */ |
| 728 | long encrypted_len; /* for SSH-2 total-size counting */ |
| 729 | |
| 730 | /* |
| 731 | * State associated with packet logging |
| 732 | */ |
| 733 | int logmode; |
| 734 | int nblanks; |
| 735 | struct logblank_t *blanks; |
| 736 | }; |
| 737 | |
| 738 | static void ssh1_protocol(Ssh ssh, void *vin, int inlen, |
| 739 | struct Packet *pktin); |
| 740 | static void ssh2_protocol(Ssh ssh, void *vin, int inlen, |
| 741 | struct Packet *pktin); |
| 742 | static void ssh1_protocol_setup(Ssh ssh); |
| 743 | static void ssh2_protocol_setup(Ssh ssh); |
| 744 | static void ssh_size(void *handle, int width, int height); |
| 745 | static void ssh_special(void *handle, Telnet_Special); |
| 746 | static int ssh2_try_send(struct ssh_channel *c); |
| 747 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); |
| 748 | static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); |
| 749 | static void ssh2_set_window(struct ssh_channel *c, int newwin); |
| 750 | static int ssh_sendbuffer(void *handle); |
| 751 | static int ssh_do_close(Ssh ssh, int notify_exit); |
| 752 | static unsigned long ssh_pkt_getuint32(struct Packet *pkt); |
| 753 | static int ssh2_pkt_getbool(struct Packet *pkt); |
| 754 | static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length); |
| 755 | static void ssh2_timer(void *ctx, long now); |
| 756 | static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, |
| 757 | struct Packet *pktin); |
| 758 | |
| 759 | struct rdpkt1_state_tag { |
| 760 | long len, pad, biglen, to_read; |
| 761 | unsigned long realcrc, gotcrc; |
| 762 | unsigned char *p; |
| 763 | int i; |
| 764 | int chunk; |
| 765 | struct Packet *pktin; |
| 766 | }; |
| 767 | |
| 768 | struct rdpkt2_state_tag { |
| 769 | long len, pad, payload, packetlen, maclen; |
| 770 | int i; |
| 771 | int cipherblk; |
| 772 | unsigned long incoming_sequence; |
| 773 | struct Packet *pktin; |
| 774 | }; |
| 775 | |
| 776 | typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin); |
| 777 | typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx); |
| 778 | |
| 779 | struct queued_handler; |
| 780 | struct queued_handler { |
| 781 | int msg1, msg2; |
| 782 | chandler_fn_t handler; |
| 783 | void *ctx; |
| 784 | struct queued_handler *next; |
| 785 | }; |
| 786 | |
| 787 | struct ssh_tag { |
| 788 | const struct plug_function_table *fn; |
| 789 | /* the above field _must_ be first in the structure */ |
| 790 | |
| 791 | char *v_c, *v_s; |
| 792 | void *exhash; |
| 793 | |
| 794 | Socket s; |
| 795 | |
| 796 | void *ldisc; |
| 797 | void *logctx; |
| 798 | |
| 799 | unsigned char session_key[32]; |
| 800 | int v1_compressing; |
| 801 | int v1_remote_protoflags; |
| 802 | int v1_local_protoflags; |
| 803 | int agentfwd_enabled; |
| 804 | int X11_fwd_enabled; |
| 805 | int remote_bugs; |
| 806 | const struct ssh_cipher *cipher; |
| 807 | void *v1_cipher_ctx; |
| 808 | void *crcda_ctx; |
| 809 | const struct ssh2_cipher *cscipher, *sccipher; |
| 810 | void *cs_cipher_ctx, *sc_cipher_ctx; |
| 811 | const struct ssh_mac *csmac, *scmac; |
| 812 | void *cs_mac_ctx, *sc_mac_ctx; |
| 813 | const struct ssh_compress *cscomp, *sccomp; |
| 814 | void *cs_comp_ctx, *sc_comp_ctx; |
| 815 | const struct ssh_kex *kex; |
| 816 | const struct ssh_signkey *hostkey; |
| 817 | unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN]; |
| 818 | int v2_session_id_len; |
| 819 | void *kex_ctx; |
| 820 | |
| 821 | char *savedhost; |
| 822 | int savedport; |
| 823 | int send_ok; |
| 824 | int echoing, editing; |
| 825 | |
| 826 | void *frontend; |
| 827 | |
| 828 | int ospeed, ispeed; /* temporaries */ |
| 829 | int term_width, term_height; |
| 830 | |
| 831 | tree234 *channels; /* indexed by local id */ |
| 832 | struct ssh_channel *mainchan; /* primary session channel */ |
| 833 | int ncmode; /* is primary channel direct-tcpip? */ |
| 834 | int exitcode; |
| 835 | int close_expected; |
| 836 | int clean_exit; |
| 837 | |
| 838 | tree234 *rportfwds, *portfwds; |
| 839 | |
| 840 | enum { |
| 841 | SSH_STATE_PREPACKET, |
| 842 | SSH_STATE_BEFORE_SIZE, |
| 843 | SSH_STATE_INTERMED, |
| 844 | SSH_STATE_SESSION, |
| 845 | SSH_STATE_CLOSED |
| 846 | } state; |
| 847 | |
| 848 | int size_needed, eof_needed; |
| 849 | int sent_console_eof; |
| 850 | int got_pty; /* affects EOF behaviour on main channel */ |
| 851 | |
| 852 | struct Packet **queue; |
| 853 | int queuelen, queuesize; |
| 854 | int queueing; |
| 855 | unsigned char *deferred_send_data; |
| 856 | int deferred_len, deferred_size; |
| 857 | |
| 858 | /* |
| 859 | * Gross hack: pscp will try to start SFTP but fall back to |
| 860 | * scp1 if that fails. This variable is the means by which |
| 861 | * scp.c can reach into the SSH code and find out which one it |
| 862 | * got. |
| 863 | */ |
| 864 | int fallback_cmd; |
| 865 | |
| 866 | bufchain banner; /* accumulates banners during do_ssh2_authconn */ |
| 867 | |
| 868 | Pkt_KCtx pkt_kctx; |
| 869 | Pkt_ACtx pkt_actx; |
| 870 | |
| 871 | struct X11Display *x11disp; |
| 872 | |
| 873 | int version; |
| 874 | int conn_throttle_count; |
| 875 | int overall_bufsize; |
| 876 | int throttled_all; |
| 877 | int v1_stdout_throttling; |
| 878 | unsigned long v2_outgoing_sequence; |
| 879 | |
| 880 | int ssh1_rdpkt_crstate; |
| 881 | int ssh2_rdpkt_crstate; |
| 882 | int do_ssh_init_crstate; |
| 883 | int ssh_gotdata_crstate; |
| 884 | int do_ssh1_login_crstate; |
| 885 | int do_ssh1_connection_crstate; |
| 886 | int do_ssh2_transport_crstate; |
| 887 | int do_ssh2_authconn_crstate; |
| 888 | |
| 889 | void *do_ssh_init_state; |
| 890 | void *do_ssh1_login_state; |
| 891 | void *do_ssh2_transport_state; |
| 892 | void *do_ssh2_authconn_state; |
| 893 | |
| 894 | struct rdpkt1_state_tag rdpkt1_state; |
| 895 | struct rdpkt2_state_tag rdpkt2_state; |
| 896 | |
| 897 | /* SSH-1 and SSH-2 use this for different things, but both use it */ |
| 898 | int protocol_initial_phase_done; |
| 899 | |
| 900 | void (*protocol) (Ssh ssh, void *vin, int inlen, |
| 901 | struct Packet *pkt); |
| 902 | struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); |
| 903 | |
| 904 | /* |
| 905 | * We maintain our own copy of a Conf structure here. That way, |
| 906 | * when we're passed a new one for reconfiguration, we can check |
| 907 | * the differences and potentially reconfigure port forwardings |
| 908 | * etc in mid-session. |
| 909 | */ |
| 910 | Conf *conf; |
| 911 | |
| 912 | /* |
| 913 | * Values cached out of conf so as to avoid the tree234 lookup |
| 914 | * cost every time they're used. |
| 915 | */ |
| 916 | int logomitdata; |
| 917 | |
| 918 | /* |
| 919 | * Dynamically allocated username string created during SSH |
| 920 | * login. Stored in here rather than in the coroutine state so |
| 921 | * that it'll be reliably freed if we shut down the SSH session |
| 922 | * at some unexpected moment. |
| 923 | */ |
| 924 | char *username; |
| 925 | |
| 926 | /* |
| 927 | * Used to transfer data back from async callbacks. |
| 928 | */ |
| 929 | void *agent_response; |
| 930 | int agent_response_len; |
| 931 | int user_response; |
| 932 | |
| 933 | /* |
| 934 | * The SSH connection can be set as `frozen', meaning we are |
| 935 | * not currently accepting incoming data from the network. This |
| 936 | * is slightly more serious than setting the _socket_ as |
| 937 | * frozen, because we may already have had data passed to us |
| 938 | * from the network which we need to delay processing until |
| 939 | * after the freeze is lifted, so we also need a bufchain to |
| 940 | * store that data. |
| 941 | */ |
| 942 | int frozen; |
| 943 | bufchain queued_incoming_data; |
| 944 | |
| 945 | /* |
| 946 | * Dispatch table for packet types that we may have to deal |
| 947 | * with at any time. |
| 948 | */ |
| 949 | handler_fn_t packet_dispatch[256]; |
| 950 | |
| 951 | /* |
| 952 | * Queues of one-off handler functions for success/failure |
| 953 | * indications from a request. |
| 954 | */ |
| 955 | struct queued_handler *qhead, *qtail; |
| 956 | |
| 957 | /* |
| 958 | * This module deals with sending keepalives. |
| 959 | */ |
| 960 | Pinger pinger; |
| 961 | |
| 962 | /* |
| 963 | * Track incoming and outgoing data sizes and time, for |
| 964 | * size-based rekeys. |
| 965 | */ |
| 966 | unsigned long incoming_data_size, outgoing_data_size, deferred_data_size; |
| 967 | unsigned long max_data_size; |
| 968 | int kex_in_progress; |
| 969 | long next_rekey, last_rekey; |
| 970 | char *deferred_rekey_reason; /* points to STATIC string; don't free */ |
| 971 | |
| 972 | /* |
| 973 | * Fully qualified host name, which we need if doing GSSAPI. |
| 974 | */ |
| 975 | char *fullhostname; |
| 976 | |
| 977 | #ifndef NO_GSSAPI |
| 978 | /* |
| 979 | * GSSAPI libraries for this session. |
| 980 | */ |
| 981 | struct ssh_gss_liblist *gsslibs; |
| 982 | #endif |
| 983 | }; |
| 984 | |
| 985 | #define logevent(s) logevent(ssh->frontend, s) |
| 986 | |
| 987 | /* logevent, only printf-formatted. */ |
| 988 | static void logeventf(Ssh ssh, const char *fmt, ...) |
| 989 | { |
| 990 | va_list ap; |
| 991 | char *buf; |
| 992 | |
| 993 | va_start(ap, fmt); |
| 994 | buf = dupvprintf(fmt, ap); |
| 995 | va_end(ap); |
| 996 | logevent(buf); |
| 997 | sfree(buf); |
| 998 | } |
| 999 | |
| 1000 | #define bombout(msg) \ |
| 1001 | do { \ |
| 1002 | char *text = dupprintf msg; \ |
| 1003 | ssh_do_close(ssh, FALSE); \ |
| 1004 | logevent(text); \ |
| 1005 | connection_fatal(ssh->frontend, "%s", text); \ |
| 1006 | sfree(text); \ |
| 1007 | } while (0) |
| 1008 | |
| 1009 | /* Functions to leave bits out of the SSH packet log file. */ |
| 1010 | |
| 1011 | static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype) |
| 1012 | { |
| 1013 | if (conf_get_int(ssh->conf, CONF_logomitpass)) |
| 1014 | pkt->logmode = blanktype; |
| 1015 | } |
| 1016 | |
| 1017 | static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype) |
| 1018 | { |
| 1019 | if (ssh->logomitdata) |
| 1020 | pkt->logmode = blanktype; |
| 1021 | } |
| 1022 | |
| 1023 | static void end_log_omission(Ssh ssh, struct Packet *pkt) |
| 1024 | { |
| 1025 | pkt->logmode = PKTLOG_EMIT; |
| 1026 | } |
| 1027 | |
| 1028 | /* Helper function for common bits of parsing ttymodes. */ |
| 1029 | static void parse_ttymodes(Ssh ssh, |
| 1030 | void (*do_mode)(void *data, char *mode, char *val), |
| 1031 | void *data) |
| 1032 | { |
| 1033 | char *key, *val; |
| 1034 | |
| 1035 | for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key); |
| 1036 | val != NULL; |
| 1037 | val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) { |
| 1038 | /* |
| 1039 | * val[0] is either 'V', indicating that an explicit value |
| 1040 | * follows it, or 'A' indicating that we should pass the |
| 1041 | * value through from the local environment via get_ttymode. |
| 1042 | */ |
| 1043 | if (val[0] == 'A') |
| 1044 | val = get_ttymode(ssh->frontend, key); |
| 1045 | else |
| 1046 | val++; /* skip the 'V' */ |
| 1047 | if (val) |
| 1048 | do_mode(data, key, val); |
| 1049 | } |
| 1050 | } |
| 1051 | |
| 1052 | static int ssh_channelcmp(void *av, void *bv) |
| 1053 | { |
| 1054 | struct ssh_channel *a = (struct ssh_channel *) av; |
| 1055 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 1056 | if (a->localid < b->localid) |
| 1057 | return -1; |
| 1058 | if (a->localid > b->localid) |
| 1059 | return +1; |
| 1060 | return 0; |
| 1061 | } |
| 1062 | static int ssh_channelfind(void *av, void *bv) |
| 1063 | { |
| 1064 | unsigned *a = (unsigned *) av; |
| 1065 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 1066 | if (*a < b->localid) |
| 1067 | return -1; |
| 1068 | if (*a > b->localid) |
| 1069 | return +1; |
| 1070 | return 0; |
| 1071 | } |
| 1072 | |
| 1073 | static int ssh_rportcmp_ssh1(void *av, void *bv) |
| 1074 | { |
| 1075 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 1076 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 1077 | int i; |
| 1078 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) |
| 1079 | return i < 0 ? -1 : +1; |
| 1080 | if (a->dport > b->dport) |
| 1081 | return +1; |
| 1082 | if (a->dport < b->dport) |
| 1083 | return -1; |
| 1084 | return 0; |
| 1085 | } |
| 1086 | |
| 1087 | static int ssh_rportcmp_ssh2(void *av, void *bv) |
| 1088 | { |
| 1089 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 1090 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 1091 | |
| 1092 | if (a->sport > b->sport) |
| 1093 | return +1; |
| 1094 | if (a->sport < b->sport) |
| 1095 | return -1; |
| 1096 | return 0; |
| 1097 | } |
| 1098 | |
| 1099 | /* |
| 1100 | * Special form of strcmp which can cope with NULL inputs. NULL is |
| 1101 | * defined to sort before even the empty string. |
| 1102 | */ |
| 1103 | static int nullstrcmp(const char *a, const char *b) |
| 1104 | { |
| 1105 | if (a == NULL && b == NULL) |
| 1106 | return 0; |
| 1107 | if (a == NULL) |
| 1108 | return -1; |
| 1109 | if (b == NULL) |
| 1110 | return +1; |
| 1111 | return strcmp(a, b); |
| 1112 | } |
| 1113 | |
| 1114 | static int ssh_portcmp(void *av, void *bv) |
| 1115 | { |
| 1116 | struct ssh_portfwd *a = (struct ssh_portfwd *) av; |
| 1117 | struct ssh_portfwd *b = (struct ssh_portfwd *) bv; |
| 1118 | int i; |
| 1119 | if (a->type > b->type) |
| 1120 | return +1; |
| 1121 | if (a->type < b->type) |
| 1122 | return -1; |
| 1123 | if (a->addressfamily > b->addressfamily) |
| 1124 | return +1; |
| 1125 | if (a->addressfamily < b->addressfamily) |
| 1126 | return -1; |
| 1127 | if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0) |
| 1128 | return i < 0 ? -1 : +1; |
| 1129 | if (a->sport > b->sport) |
| 1130 | return +1; |
| 1131 | if (a->sport < b->sport) |
| 1132 | return -1; |
| 1133 | if (a->type != 'D') { |
| 1134 | if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0) |
| 1135 | return i < 0 ? -1 : +1; |
| 1136 | if (a->dport > b->dport) |
| 1137 | return +1; |
| 1138 | if (a->dport < b->dport) |
| 1139 | return -1; |
| 1140 | } |
| 1141 | return 0; |
| 1142 | } |
| 1143 | |
| 1144 | static int alloc_channel_id(Ssh ssh) |
| 1145 | { |
| 1146 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
| 1147 | unsigned low, high, mid; |
| 1148 | int tsize; |
| 1149 | struct ssh_channel *c; |
| 1150 | |
| 1151 | /* |
| 1152 | * First-fit allocation of channel numbers: always pick the |
| 1153 | * lowest unused one. To do this, binary-search using the |
| 1154 | * counted B-tree to find the largest channel ID which is in a |
| 1155 | * contiguous sequence from the beginning. (Precisely |
| 1156 | * everything in that sequence must have ID equal to its tree |
| 1157 | * index plus CHANNEL_NUMBER_OFFSET.) |
| 1158 | */ |
| 1159 | tsize = count234(ssh->channels); |
| 1160 | |
| 1161 | low = -1; |
| 1162 | high = tsize; |
| 1163 | while (high - low > 1) { |
| 1164 | mid = (high + low) / 2; |
| 1165 | c = index234(ssh->channels, mid); |
| 1166 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
| 1167 | low = mid; /* this one is fine */ |
| 1168 | else |
| 1169 | high = mid; /* this one is past it */ |
| 1170 | } |
| 1171 | /* |
| 1172 | * Now low points to either -1, or the tree index of the |
| 1173 | * largest ID in the initial sequence. |
| 1174 | */ |
| 1175 | { |
| 1176 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
| 1177 | assert(NULL == find234(ssh->channels, &i, ssh_channelfind)); |
| 1178 | } |
| 1179 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
| 1180 | } |
| 1181 | |
| 1182 | static void c_write_stderr(int trusted, const char *buf, int len) |
| 1183 | { |
| 1184 | int i; |
| 1185 | for (i = 0; i < len; i++) |
| 1186 | if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60))) |
| 1187 | fputc(buf[i], stderr); |
| 1188 | } |
| 1189 | |
| 1190 | static void c_write(Ssh ssh, const char *buf, int len) |
| 1191 | { |
| 1192 | if (flags & FLAG_STDERR) |
| 1193 | c_write_stderr(1, buf, len); |
| 1194 | else |
| 1195 | from_backend(ssh->frontend, 1, buf, len); |
| 1196 | } |
| 1197 | |
| 1198 | static void c_write_untrusted(Ssh ssh, const char *buf, int len) |
| 1199 | { |
| 1200 | if (flags & FLAG_STDERR) |
| 1201 | c_write_stderr(0, buf, len); |
| 1202 | else |
| 1203 | from_backend_untrusted(ssh->frontend, buf, len); |
| 1204 | } |
| 1205 | |
| 1206 | static void c_write_str(Ssh ssh, const char *buf) |
| 1207 | { |
| 1208 | c_write(ssh, buf, strlen(buf)); |
| 1209 | } |
| 1210 | |
| 1211 | static void ssh_free_packet(struct Packet *pkt) |
| 1212 | { |
| 1213 | sfree(pkt->data); |
| 1214 | sfree(pkt); |
| 1215 | } |
| 1216 | static struct Packet *ssh_new_packet(void) |
| 1217 | { |
| 1218 | struct Packet *pkt = snew(struct Packet); |
| 1219 | |
| 1220 | pkt->body = pkt->data = NULL; |
| 1221 | pkt->maxlen = 0; |
| 1222 | pkt->logmode = PKTLOG_EMIT; |
| 1223 | pkt->nblanks = 0; |
| 1224 | pkt->blanks = NULL; |
| 1225 | |
| 1226 | return pkt; |
| 1227 | } |
| 1228 | |
| 1229 | /* |
| 1230 | * Collect incoming data in the incoming packet buffer. |
| 1231 | * Decipher and verify the packet when it is completely read. |
| 1232 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 1233 | * Update the *data and *datalen variables. |
| 1234 | * Return a Packet structure when a packet is completed. |
| 1235 | */ |
| 1236 | static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) |
| 1237 | { |
| 1238 | struct rdpkt1_state_tag *st = &ssh->rdpkt1_state; |
| 1239 | |
| 1240 | crBegin(ssh->ssh1_rdpkt_crstate); |
| 1241 | |
| 1242 | st->pktin = ssh_new_packet(); |
| 1243 | |
| 1244 | st->pktin->type = 0; |
| 1245 | st->pktin->length = 0; |
| 1246 | |
| 1247 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
| 1248 | while ((*datalen) == 0) |
| 1249 | crReturn(NULL); |
| 1250 | st->len = (st->len << 8) + **data; |
| 1251 | (*data)++, (*datalen)--; |
| 1252 | } |
| 1253 | |
| 1254 | st->pad = 8 - (st->len % 8); |
| 1255 | st->biglen = st->len + st->pad; |
| 1256 | st->pktin->length = st->len - 5; |
| 1257 | |
| 1258 | if (st->biglen < 0) { |
| 1259 | bombout(("Extremely large packet length from server suggests" |
| 1260 | " data stream corruption")); |
| 1261 | ssh_free_packet(st->pktin); |
| 1262 | crStop(NULL); |
| 1263 | } |
| 1264 | |
| 1265 | st->pktin->maxlen = st->biglen; |
| 1266 | st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char); |
| 1267 | |
| 1268 | st->to_read = st->biglen; |
| 1269 | st->p = st->pktin->data; |
| 1270 | while (st->to_read > 0) { |
| 1271 | st->chunk = st->to_read; |
| 1272 | while ((*datalen) == 0) |
| 1273 | crReturn(NULL); |
| 1274 | if (st->chunk > (*datalen)) |
| 1275 | st->chunk = (*datalen); |
| 1276 | memcpy(st->p, *data, st->chunk); |
| 1277 | *data += st->chunk; |
| 1278 | *datalen -= st->chunk; |
| 1279 | st->p += st->chunk; |
| 1280 | st->to_read -= st->chunk; |
| 1281 | } |
| 1282 | |
| 1283 | if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data, |
| 1284 | st->biglen, NULL)) { |
| 1285 | bombout(("Network attack (CRC compensation) detected!")); |
| 1286 | ssh_free_packet(st->pktin); |
| 1287 | crStop(NULL); |
| 1288 | } |
| 1289 | |
| 1290 | if (ssh->cipher) |
| 1291 | ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen); |
| 1292 | |
| 1293 | st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4); |
| 1294 | st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4); |
| 1295 | if (st->gotcrc != st->realcrc) { |
| 1296 | bombout(("Incorrect CRC received on packet")); |
| 1297 | ssh_free_packet(st->pktin); |
| 1298 | crStop(NULL); |
| 1299 | } |
| 1300 | |
| 1301 | st->pktin->body = st->pktin->data + st->pad + 1; |
| 1302 | st->pktin->savedpos = 0; |
| 1303 | |
| 1304 | if (ssh->v1_compressing) { |
| 1305 | unsigned char *decompblk; |
| 1306 | int decomplen; |
| 1307 | if (!zlib_decompress_block(ssh->sc_comp_ctx, |
| 1308 | st->pktin->body - 1, st->pktin->length + 1, |
| 1309 | &decompblk, &decomplen)) { |
| 1310 | bombout(("Zlib decompression encountered invalid data")); |
| 1311 | ssh_free_packet(st->pktin); |
| 1312 | crStop(NULL); |
| 1313 | } |
| 1314 | |
| 1315 | if (st->pktin->maxlen < st->pad + decomplen) { |
| 1316 | st->pktin->maxlen = st->pad + decomplen; |
| 1317 | st->pktin->data = sresize(st->pktin->data, |
| 1318 | st->pktin->maxlen + APIEXTRA, |
| 1319 | unsigned char); |
| 1320 | st->pktin->body = st->pktin->data + st->pad + 1; |
| 1321 | } |
| 1322 | |
| 1323 | memcpy(st->pktin->body - 1, decompblk, decomplen); |
| 1324 | sfree(decompblk); |
| 1325 | st->pktin->length = decomplen - 1; |
| 1326 | } |
| 1327 | |
| 1328 | st->pktin->type = st->pktin->body[-1]; |
| 1329 | |
| 1330 | /* |
| 1331 | * Log incoming packet, possibly omitting sensitive fields. |
| 1332 | */ |
| 1333 | if (ssh->logctx) { |
| 1334 | int nblanks = 0; |
| 1335 | struct logblank_t blank; |
| 1336 | if (ssh->logomitdata) { |
| 1337 | int do_blank = FALSE, blank_prefix = 0; |
| 1338 | /* "Session data" packets - omit the data field */ |
| 1339 | if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) || |
| 1340 | (st->pktin->type == SSH1_SMSG_STDERR_DATA)) { |
| 1341 | do_blank = TRUE; blank_prefix = 4; |
| 1342 | } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) { |
| 1343 | do_blank = TRUE; blank_prefix = 8; |
| 1344 | } |
| 1345 | if (do_blank) { |
| 1346 | blank.offset = blank_prefix; |
| 1347 | blank.len = st->pktin->length; |
| 1348 | blank.type = PKTLOG_OMIT; |
| 1349 | nblanks = 1; |
| 1350 | } |
| 1351 | } |
| 1352 | log_packet(ssh->logctx, |
| 1353 | PKT_INCOMING, st->pktin->type, |
| 1354 | ssh1_pkt_type(st->pktin->type), |
| 1355 | st->pktin->body, st->pktin->length, |
| 1356 | nblanks, &blank, NULL); |
| 1357 | } |
| 1358 | |
| 1359 | crFinish(st->pktin); |
| 1360 | } |
| 1361 | |
| 1362 | static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) |
| 1363 | { |
| 1364 | struct rdpkt2_state_tag *st = &ssh->rdpkt2_state; |
| 1365 | |
| 1366 | crBegin(ssh->ssh2_rdpkt_crstate); |
| 1367 | |
| 1368 | st->pktin = ssh_new_packet(); |
| 1369 | |
| 1370 | st->pktin->type = 0; |
| 1371 | st->pktin->length = 0; |
| 1372 | if (ssh->sccipher) |
| 1373 | st->cipherblk = ssh->sccipher->blksize; |
| 1374 | else |
| 1375 | st->cipherblk = 8; |
| 1376 | if (st->cipherblk < 8) |
| 1377 | st->cipherblk = 8; |
| 1378 | st->maclen = ssh->scmac ? ssh->scmac->len : 0; |
| 1379 | |
| 1380 | if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) && |
| 1381 | ssh->scmac) { |
| 1382 | /* |
| 1383 | * When dealing with a CBC-mode cipher, we want to avoid the |
| 1384 | * possibility of an attacker's tweaking the ciphertext stream |
| 1385 | * so as to cause us to feed the same block to the block |
| 1386 | * cipher more than once and thus leak information |
| 1387 | * (VU#958563). The way we do this is not to take any |
| 1388 | * decisions on the basis of anything we've decrypted until |
| 1389 | * we've verified it with a MAC. That includes the packet |
| 1390 | * length, so we just read data and check the MAC repeatedly, |
| 1391 | * and when the MAC passes, see if the length we've got is |
| 1392 | * plausible. |
| 1393 | */ |
| 1394 | |
| 1395 | /* May as well allocate the whole lot now. */ |
| 1396 | st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA, |
| 1397 | unsigned char); |
| 1398 | |
| 1399 | /* Read an amount corresponding to the MAC. */ |
| 1400 | for (st->i = 0; st->i < st->maclen; st->i++) { |
| 1401 | while ((*datalen) == 0) |
| 1402 | crReturn(NULL); |
| 1403 | st->pktin->data[st->i] = *(*data)++; |
| 1404 | (*datalen)--; |
| 1405 | } |
| 1406 | |
| 1407 | st->packetlen = 0; |
| 1408 | { |
| 1409 | unsigned char seq[4]; |
| 1410 | ssh->scmac->start(ssh->sc_mac_ctx); |
| 1411 | PUT_32BIT(seq, st->incoming_sequence); |
| 1412 | ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4); |
| 1413 | } |
| 1414 | |
| 1415 | for (;;) { /* Once around this loop per cipher block. */ |
| 1416 | /* Read another cipher-block's worth, and tack it onto the end. */ |
| 1417 | for (st->i = 0; st->i < st->cipherblk; st->i++) { |
| 1418 | while ((*datalen) == 0) |
| 1419 | crReturn(NULL); |
| 1420 | st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++; |
| 1421 | (*datalen)--; |
| 1422 | } |
| 1423 | /* Decrypt one more block (a little further back in the stream). */ |
| 1424 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, |
| 1425 | st->pktin->data + st->packetlen, |
| 1426 | st->cipherblk); |
| 1427 | /* Feed that block to the MAC. */ |
| 1428 | ssh->scmac->bytes(ssh->sc_mac_ctx, |
| 1429 | st->pktin->data + st->packetlen, st->cipherblk); |
| 1430 | st->packetlen += st->cipherblk; |
| 1431 | /* See if that gives us a valid packet. */ |
| 1432 | if (ssh->scmac->verresult(ssh->sc_mac_ctx, |
| 1433 | st->pktin->data + st->packetlen) && |
| 1434 | (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen) |
| 1435 | break; |
| 1436 | if (st->packetlen >= OUR_V2_PACKETLIMIT) { |
| 1437 | bombout(("No valid incoming packet found")); |
| 1438 | ssh_free_packet(st->pktin); |
| 1439 | crStop(NULL); |
| 1440 | } |
| 1441 | } |
| 1442 | st->pktin->maxlen = st->packetlen + st->maclen; |
| 1443 | st->pktin->data = sresize(st->pktin->data, |
| 1444 | st->pktin->maxlen + APIEXTRA, |
| 1445 | unsigned char); |
| 1446 | } else { |
| 1447 | st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char); |
| 1448 | |
| 1449 | /* |
| 1450 | * Acquire and decrypt the first block of the packet. This will |
| 1451 | * contain the length and padding details. |
| 1452 | */ |
| 1453 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
| 1454 | while ((*datalen) == 0) |
| 1455 | crReturn(NULL); |
| 1456 | st->pktin->data[st->i] = *(*data)++; |
| 1457 | (*datalen)--; |
| 1458 | } |
| 1459 | |
| 1460 | if (ssh->sccipher) |
| 1461 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, |
| 1462 | st->pktin->data, st->cipherblk); |
| 1463 | |
| 1464 | /* |
| 1465 | * Now get the length figure. |
| 1466 | */ |
| 1467 | st->len = GET_32BIT(st->pktin->data); |
| 1468 | |
| 1469 | /* |
| 1470 | * _Completely_ silly lengths should be stomped on before they |
| 1471 | * do us any more damage. |
| 1472 | */ |
| 1473 | if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT || |
| 1474 | (st->len + 4) % st->cipherblk != 0) { |
| 1475 | bombout(("Incoming packet was garbled on decryption")); |
| 1476 | ssh_free_packet(st->pktin); |
| 1477 | crStop(NULL); |
| 1478 | } |
| 1479 | |
| 1480 | /* |
| 1481 | * So now we can work out the total packet length. |
| 1482 | */ |
| 1483 | st->packetlen = st->len + 4; |
| 1484 | |
| 1485 | /* |
| 1486 | * Allocate memory for the rest of the packet. |
| 1487 | */ |
| 1488 | st->pktin->maxlen = st->packetlen + st->maclen; |
| 1489 | st->pktin->data = sresize(st->pktin->data, |
| 1490 | st->pktin->maxlen + APIEXTRA, |
| 1491 | unsigned char); |
| 1492 | |
| 1493 | /* |
| 1494 | * Read and decrypt the remainder of the packet. |
| 1495 | */ |
| 1496 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; |
| 1497 | st->i++) { |
| 1498 | while ((*datalen) == 0) |
| 1499 | crReturn(NULL); |
| 1500 | st->pktin->data[st->i] = *(*data)++; |
| 1501 | (*datalen)--; |
| 1502 | } |
| 1503 | /* Decrypt everything _except_ the MAC. */ |
| 1504 | if (ssh->sccipher) |
| 1505 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, |
| 1506 | st->pktin->data + st->cipherblk, |
| 1507 | st->packetlen - st->cipherblk); |
| 1508 | |
| 1509 | /* |
| 1510 | * Check the MAC. |
| 1511 | */ |
| 1512 | if (ssh->scmac |
| 1513 | && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, |
| 1514 | st->len + 4, st->incoming_sequence)) { |
| 1515 | bombout(("Incorrect MAC received on packet")); |
| 1516 | ssh_free_packet(st->pktin); |
| 1517 | crStop(NULL); |
| 1518 | } |
| 1519 | } |
| 1520 | /* Get and sanity-check the amount of random padding. */ |
| 1521 | st->pad = st->pktin->data[4]; |
| 1522 | if (st->pad < 4 || st->len - st->pad < 1) { |
| 1523 | bombout(("Invalid padding length on received packet")); |
| 1524 | ssh_free_packet(st->pktin); |
| 1525 | crStop(NULL); |
| 1526 | } |
| 1527 | /* |
| 1528 | * This enables us to deduce the payload length. |
| 1529 | */ |
| 1530 | st->payload = st->len - st->pad - 1; |
| 1531 | |
| 1532 | st->pktin->length = st->payload + 5; |
| 1533 | st->pktin->encrypted_len = st->packetlen; |
| 1534 | |
| 1535 | st->pktin->sequence = st->incoming_sequence++; |
| 1536 | |
| 1537 | /* |
| 1538 | * Decompress packet payload. |
| 1539 | */ |
| 1540 | { |
| 1541 | unsigned char *newpayload; |
| 1542 | int newlen; |
| 1543 | if (ssh->sccomp && |
| 1544 | ssh->sccomp->decompress(ssh->sc_comp_ctx, |
| 1545 | st->pktin->data + 5, st->pktin->length - 5, |
| 1546 | &newpayload, &newlen)) { |
| 1547 | if (st->pktin->maxlen < newlen + 5) { |
| 1548 | st->pktin->maxlen = newlen + 5; |
| 1549 | st->pktin->data = sresize(st->pktin->data, |
| 1550 | st->pktin->maxlen + APIEXTRA, |
| 1551 | unsigned char); |
| 1552 | } |
| 1553 | st->pktin->length = 5 + newlen; |
| 1554 | memcpy(st->pktin->data + 5, newpayload, newlen); |
| 1555 | sfree(newpayload); |
| 1556 | } |
| 1557 | } |
| 1558 | |
| 1559 | st->pktin->savedpos = 6; |
| 1560 | st->pktin->body = st->pktin->data; |
| 1561 | st->pktin->type = st->pktin->data[5]; |
| 1562 | |
| 1563 | /* |
| 1564 | * Log incoming packet, possibly omitting sensitive fields. |
| 1565 | */ |
| 1566 | if (ssh->logctx) { |
| 1567 | int nblanks = 0; |
| 1568 | struct logblank_t blank; |
| 1569 | if (ssh->logomitdata) { |
| 1570 | int do_blank = FALSE, blank_prefix = 0; |
| 1571 | /* "Session data" packets - omit the data field */ |
| 1572 | if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) { |
| 1573 | do_blank = TRUE; blank_prefix = 8; |
| 1574 | } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 1575 | do_blank = TRUE; blank_prefix = 12; |
| 1576 | } |
| 1577 | if (do_blank) { |
| 1578 | blank.offset = blank_prefix; |
| 1579 | blank.len = (st->pktin->length-6) - blank_prefix; |
| 1580 | blank.type = PKTLOG_OMIT; |
| 1581 | nblanks = 1; |
| 1582 | } |
| 1583 | } |
| 1584 | log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type, |
| 1585 | ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, |
| 1586 | st->pktin->type), |
| 1587 | st->pktin->data+6, st->pktin->length-6, |
| 1588 | nblanks, &blank, &st->pktin->sequence); |
| 1589 | } |
| 1590 | |
| 1591 | crFinish(st->pktin); |
| 1592 | } |
| 1593 | |
| 1594 | static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p) |
| 1595 | { |
| 1596 | int pad, biglen, i, pktoffs; |
| 1597 | unsigned long crc; |
| 1598 | #ifdef __SC__ |
| 1599 | /* |
| 1600 | * XXX various versions of SC (including 8.8.4) screw up the |
| 1601 | * register allocation in this function and use the same register |
| 1602 | * (D6) for len and as a temporary, with predictable results. The |
| 1603 | * following sledgehammer prevents this. |
| 1604 | */ |
| 1605 | volatile |
| 1606 | #endif |
| 1607 | int len; |
| 1608 | |
| 1609 | if (ssh->logctx) |
| 1610 | log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12], |
| 1611 | ssh1_pkt_type(pkt->data[12]), |
| 1612 | pkt->body, pkt->length - (pkt->body - pkt->data), |
| 1613 | pkt->nblanks, pkt->blanks, NULL); |
| 1614 | sfree(pkt->blanks); pkt->blanks = NULL; |
| 1615 | pkt->nblanks = 0; |
| 1616 | |
| 1617 | if (ssh->v1_compressing) { |
| 1618 | unsigned char *compblk; |
| 1619 | int complen; |
| 1620 | zlib_compress_block(ssh->cs_comp_ctx, |
| 1621 | pkt->data + 12, pkt->length - 12, |
| 1622 | &compblk, &complen); |
| 1623 | ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */ |
| 1624 | memcpy(pkt->data + 12, compblk, complen); |
| 1625 | sfree(compblk); |
| 1626 | pkt->length = complen + 12; |
| 1627 | } |
| 1628 | |
| 1629 | ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */ |
| 1630 | pkt->length += 4; |
| 1631 | len = pkt->length - 4 - 8; /* len(type+data+CRC) */ |
| 1632 | pad = 8 - (len % 8); |
| 1633 | pktoffs = 8 - pad; |
| 1634 | biglen = len + pad; /* len(padding+type+data+CRC) */ |
| 1635 | |
| 1636 | for (i = pktoffs; i < 4+8; i++) |
| 1637 | pkt->data[i] = random_byte(); |
| 1638 | crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */ |
| 1639 | PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc); |
| 1640 | PUT_32BIT(pkt->data + pktoffs, len); |
| 1641 | |
| 1642 | if (ssh->cipher) |
| 1643 | ssh->cipher->encrypt(ssh->v1_cipher_ctx, |
| 1644 | pkt->data + pktoffs + 4, biglen); |
| 1645 | |
| 1646 | if (offset_p) *offset_p = pktoffs; |
| 1647 | return biglen + 4; /* len(length+padding+type+data+CRC) */ |
| 1648 | } |
| 1649 | |
| 1650 | static int s_write(Ssh ssh, void *data, int len) |
| 1651 | { |
| 1652 | if (ssh->logctx) |
| 1653 | log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, |
| 1654 | 0, NULL, NULL); |
| 1655 | return sk_write(ssh->s, (char *)data, len); |
| 1656 | } |
| 1657 | |
| 1658 | static void s_wrpkt(Ssh ssh, struct Packet *pkt) |
| 1659 | { |
| 1660 | int len, backlog, offset; |
| 1661 | len = s_wrpkt_prepare(ssh, pkt, &offset); |
| 1662 | backlog = s_write(ssh, pkt->data + offset, len); |
| 1663 | if (backlog > SSH_MAX_BACKLOG) |
| 1664 | ssh_throttle_all(ssh, 1, backlog); |
| 1665 | ssh_free_packet(pkt); |
| 1666 | } |
| 1667 | |
| 1668 | static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt) |
| 1669 | { |
| 1670 | int len, offset; |
| 1671 | len = s_wrpkt_prepare(ssh, pkt, &offset); |
| 1672 | if (ssh->deferred_len + len > ssh->deferred_size) { |
| 1673 | ssh->deferred_size = ssh->deferred_len + len + 128; |
| 1674 | ssh->deferred_send_data = sresize(ssh->deferred_send_data, |
| 1675 | ssh->deferred_size, |
| 1676 | unsigned char); |
| 1677 | } |
| 1678 | memcpy(ssh->deferred_send_data + ssh->deferred_len, |
| 1679 | pkt->data + offset, len); |
| 1680 | ssh->deferred_len += len; |
| 1681 | ssh_free_packet(pkt); |
| 1682 | } |
| 1683 | |
| 1684 | /* |
| 1685 | * Construct a SSH-1 packet with the specified contents. |
| 1686 | * (This all-at-once interface used to be the only one, but now SSH-1 |
| 1687 | * packets can also be constructed incrementally.) |
| 1688 | */ |
| 1689 | static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap) |
| 1690 | { |
| 1691 | int argtype; |
| 1692 | Bignum bn; |
| 1693 | struct Packet *pkt; |
| 1694 | |
| 1695 | pkt = ssh1_pkt_init(pkttype); |
| 1696 | |
| 1697 | while ((argtype = va_arg(ap, int)) != PKT_END) { |
| 1698 | unsigned char *argp, argchar; |
| 1699 | char *sargp; |
| 1700 | unsigned long argint; |
| 1701 | int arglen; |
| 1702 | switch (argtype) { |
| 1703 | /* Actual fields in the packet */ |
| 1704 | case PKT_INT: |
| 1705 | argint = va_arg(ap, int); |
| 1706 | ssh_pkt_adduint32(pkt, argint); |
| 1707 | break; |
| 1708 | case PKT_CHAR: |
| 1709 | argchar = (unsigned char) va_arg(ap, int); |
| 1710 | ssh_pkt_addbyte(pkt, argchar); |
| 1711 | break; |
| 1712 | case PKT_DATA: |
| 1713 | argp = va_arg(ap, unsigned char *); |
| 1714 | arglen = va_arg(ap, int); |
| 1715 | ssh_pkt_adddata(pkt, argp, arglen); |
| 1716 | break; |
| 1717 | case PKT_STR: |
| 1718 | sargp = va_arg(ap, char *); |
| 1719 | ssh_pkt_addstring(pkt, sargp); |
| 1720 | break; |
| 1721 | case PKT_BIGNUM: |
| 1722 | bn = va_arg(ap, Bignum); |
| 1723 | ssh1_pkt_addmp(pkt, bn); |
| 1724 | break; |
| 1725 | /* Tokens for modifications to packet logging */ |
| 1726 | case PKTT_PASSWORD: |
| 1727 | dont_log_password(ssh, pkt, PKTLOG_BLANK); |
| 1728 | break; |
| 1729 | case PKTT_DATA: |
| 1730 | dont_log_data(ssh, pkt, PKTLOG_OMIT); |
| 1731 | break; |
| 1732 | case PKTT_OTHER: |
| 1733 | end_log_omission(ssh, pkt); |
| 1734 | break; |
| 1735 | } |
| 1736 | } |
| 1737 | |
| 1738 | return pkt; |
| 1739 | } |
| 1740 | |
| 1741 | static void send_packet(Ssh ssh, int pkttype, ...) |
| 1742 | { |
| 1743 | struct Packet *pkt; |
| 1744 | va_list ap; |
| 1745 | va_start(ap, pkttype); |
| 1746 | pkt = construct_packet(ssh, pkttype, ap); |
| 1747 | va_end(ap); |
| 1748 | s_wrpkt(ssh, pkt); |
| 1749 | } |
| 1750 | |
| 1751 | static void defer_packet(Ssh ssh, int pkttype, ...) |
| 1752 | { |
| 1753 | struct Packet *pkt; |
| 1754 | va_list ap; |
| 1755 | va_start(ap, pkttype); |
| 1756 | pkt = construct_packet(ssh, pkttype, ap); |
| 1757 | va_end(ap); |
| 1758 | s_wrpkt_defer(ssh, pkt); |
| 1759 | } |
| 1760 | |
| 1761 | static int ssh_versioncmp(char *a, char *b) |
| 1762 | { |
| 1763 | char *ae, *be; |
| 1764 | unsigned long av, bv; |
| 1765 | |
| 1766 | av = strtoul(a, &ae, 10); |
| 1767 | bv = strtoul(b, &be, 10); |
| 1768 | if (av != bv) |
| 1769 | return (av < bv ? -1 : +1); |
| 1770 | if (*ae == '.') |
| 1771 | ae++; |
| 1772 | if (*be == '.') |
| 1773 | be++; |
| 1774 | av = strtoul(ae, &ae, 10); |
| 1775 | bv = strtoul(be, &be, 10); |
| 1776 | if (av != bv) |
| 1777 | return (av < bv ? -1 : +1); |
| 1778 | return 0; |
| 1779 | } |
| 1780 | |
| 1781 | /* |
| 1782 | * Utility routines for putting an SSH-protocol `string' and |
| 1783 | * `uint32' into a hash state. |
| 1784 | */ |
| 1785 | static void hash_string(const struct ssh_hash *h, void *s, void *str, int len) |
| 1786 | { |
| 1787 | unsigned char lenblk[4]; |
| 1788 | PUT_32BIT(lenblk, len); |
| 1789 | h->bytes(s, lenblk, 4); |
| 1790 | h->bytes(s, str, len); |
| 1791 | } |
| 1792 | |
| 1793 | static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i) |
| 1794 | { |
| 1795 | unsigned char intblk[4]; |
| 1796 | PUT_32BIT(intblk, i); |
| 1797 | h->bytes(s, intblk, 4); |
| 1798 | } |
| 1799 | |
| 1800 | /* |
| 1801 | * Packet construction functions. Mostly shared between SSH-1 and SSH-2. |
| 1802 | */ |
| 1803 | static void ssh_pkt_ensure(struct Packet *pkt, int length) |
| 1804 | { |
| 1805 | if (pkt->maxlen < length) { |
| 1806 | unsigned char *body = pkt->body; |
| 1807 | int offset = body ? body - pkt->data : 0; |
| 1808 | pkt->maxlen = length + 256; |
| 1809 | pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char); |
| 1810 | if (body) pkt->body = pkt->data + offset; |
| 1811 | } |
| 1812 | } |
| 1813 | static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len) |
| 1814 | { |
| 1815 | if (pkt->logmode != PKTLOG_EMIT) { |
| 1816 | pkt->nblanks++; |
| 1817 | pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t); |
| 1818 | assert(pkt->body); |
| 1819 | pkt->blanks[pkt->nblanks-1].offset = pkt->length - |
| 1820 | (pkt->body - pkt->data); |
| 1821 | pkt->blanks[pkt->nblanks-1].len = len; |
| 1822 | pkt->blanks[pkt->nblanks-1].type = pkt->logmode; |
| 1823 | } |
| 1824 | pkt->length += len; |
| 1825 | ssh_pkt_ensure(pkt, pkt->length); |
| 1826 | memcpy(pkt->data + pkt->length - len, data, len); |
| 1827 | } |
| 1828 | static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte) |
| 1829 | { |
| 1830 | ssh_pkt_adddata(pkt, &byte, 1); |
| 1831 | } |
| 1832 | static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value) |
| 1833 | { |
| 1834 | ssh_pkt_adddata(pkt, &value, 1); |
| 1835 | } |
| 1836 | static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value) |
| 1837 | { |
| 1838 | unsigned char x[4]; |
| 1839 | PUT_32BIT(x, value); |
| 1840 | ssh_pkt_adddata(pkt, x, 4); |
| 1841 | } |
| 1842 | static void ssh_pkt_addstring_start(struct Packet *pkt) |
| 1843 | { |
| 1844 | ssh_pkt_adduint32(pkt, 0); |
| 1845 | pkt->savedpos = pkt->length; |
| 1846 | } |
| 1847 | static void ssh_pkt_addstring_str(struct Packet *pkt, char *data) |
| 1848 | { |
| 1849 | ssh_pkt_adddata(pkt, data, strlen(data)); |
| 1850 | PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); |
| 1851 | } |
| 1852 | static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len) |
| 1853 | { |
| 1854 | ssh_pkt_adddata(pkt, data, len); |
| 1855 | PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); |
| 1856 | } |
| 1857 | static void ssh_pkt_addstring(struct Packet *pkt, char *data) |
| 1858 | { |
| 1859 | ssh_pkt_addstring_start(pkt); |
| 1860 | ssh_pkt_addstring_str(pkt, data); |
| 1861 | } |
| 1862 | static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b) |
| 1863 | { |
| 1864 | int len = ssh1_bignum_length(b); |
| 1865 | unsigned char *data = snewn(len, unsigned char); |
| 1866 | (void) ssh1_write_bignum(data, b); |
| 1867 | ssh_pkt_adddata(pkt, data, len); |
| 1868 | sfree(data); |
| 1869 | } |
| 1870 | static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) |
| 1871 | { |
| 1872 | unsigned char *p; |
| 1873 | int i, n = (bignum_bitcount(b) + 7) / 8; |
| 1874 | p = snewn(n + 1, unsigned char); |
| 1875 | p[0] = 0; |
| 1876 | for (i = 1; i <= n; i++) |
| 1877 | p[i] = bignum_byte(b, n - i); |
| 1878 | i = 0; |
| 1879 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) |
| 1880 | i++; |
| 1881 | memmove(p, p + i, n + 1 - i); |
| 1882 | *len = n + 1 - i; |
| 1883 | return p; |
| 1884 | } |
| 1885 | static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b) |
| 1886 | { |
| 1887 | unsigned char *p; |
| 1888 | int len; |
| 1889 | p = ssh2_mpint_fmt(b, &len); |
| 1890 | ssh_pkt_addstring_start(pkt); |
| 1891 | ssh_pkt_addstring_data(pkt, (char *)p, len); |
| 1892 | sfree(p); |
| 1893 | } |
| 1894 | |
| 1895 | static struct Packet *ssh1_pkt_init(int pkt_type) |
| 1896 | { |
| 1897 | struct Packet *pkt = ssh_new_packet(); |
| 1898 | pkt->length = 4 + 8; /* space for length + max padding */ |
| 1899 | ssh_pkt_addbyte(pkt, pkt_type); |
| 1900 | pkt->body = pkt->data + pkt->length; |
| 1901 | return pkt; |
| 1902 | } |
| 1903 | |
| 1904 | /* For legacy code (SSH-1 and -2 packet construction used to be separate) */ |
| 1905 | #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length) |
| 1906 | #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len) |
| 1907 | #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte) |
| 1908 | #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value) |
| 1909 | #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt) |
| 1910 | #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data) |
| 1911 | #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len) |
| 1912 | #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data) |
| 1913 | |
| 1914 | static struct Packet *ssh2_pkt_init(int pkt_type) |
| 1915 | { |
| 1916 | struct Packet *pkt = ssh_new_packet(); |
| 1917 | pkt->length = 5; /* space for packet length + padding length */ |
| 1918 | pkt->forcepad = 0; |
| 1919 | ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); |
| 1920 | pkt->body = pkt->data + pkt->length; /* after packet type */ |
| 1921 | return pkt; |
| 1922 | } |
| 1923 | |
| 1924 | /* |
| 1925 | * Construct an SSH-2 final-form packet: compress it, encrypt it, |
| 1926 | * put the MAC on it. Final packet, ready to be sent, is stored in |
| 1927 | * pkt->data. Total length is returned. |
| 1928 | */ |
| 1929 | static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) |
| 1930 | { |
| 1931 | int cipherblk, maclen, padding, i; |
| 1932 | |
| 1933 | if (ssh->logctx) |
| 1934 | log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], |
| 1935 | ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]), |
| 1936 | pkt->body, pkt->length - (pkt->body - pkt->data), |
| 1937 | pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence); |
| 1938 | sfree(pkt->blanks); pkt->blanks = NULL; |
| 1939 | pkt->nblanks = 0; |
| 1940 | |
| 1941 | /* |
| 1942 | * Compress packet payload. |
| 1943 | */ |
| 1944 | { |
| 1945 | unsigned char *newpayload; |
| 1946 | int newlen; |
| 1947 | if (ssh->cscomp && |
| 1948 | ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5, |
| 1949 | pkt->length - 5, |
| 1950 | &newpayload, &newlen)) { |
| 1951 | pkt->length = 5; |
| 1952 | ssh2_pkt_adddata(pkt, newpayload, newlen); |
| 1953 | sfree(newpayload); |
| 1954 | } |
| 1955 | } |
| 1956 | |
| 1957 | /* |
| 1958 | * Add padding. At least four bytes, and must also bring total |
| 1959 | * length (minus MAC) up to a multiple of the block size. |
| 1960 | * If pkt->forcepad is set, make sure the packet is at least that size |
| 1961 | * after padding. |
| 1962 | */ |
| 1963 | cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ |
| 1964 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 1965 | padding = 4; |
| 1966 | if (pkt->length + padding < pkt->forcepad) |
| 1967 | padding = pkt->forcepad - pkt->length; |
| 1968 | padding += |
| 1969 | (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk; |
| 1970 | assert(padding <= 255); |
| 1971 | maclen = ssh->csmac ? ssh->csmac->len : 0; |
| 1972 | ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); |
| 1973 | pkt->data[4] = padding; |
| 1974 | for (i = 0; i < padding; i++) |
| 1975 | pkt->data[pkt->length + i] = random_byte(); |
| 1976 | PUT_32BIT(pkt->data, pkt->length + padding - 4); |
| 1977 | if (ssh->csmac) |
| 1978 | ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, |
| 1979 | pkt->length + padding, |
| 1980 | ssh->v2_outgoing_sequence); |
| 1981 | ssh->v2_outgoing_sequence++; /* whether or not we MACed */ |
| 1982 | |
| 1983 | if (ssh->cscipher) |
| 1984 | ssh->cscipher->encrypt(ssh->cs_cipher_ctx, |
| 1985 | pkt->data, pkt->length + padding); |
| 1986 | |
| 1987 | pkt->encrypted_len = pkt->length + padding; |
| 1988 | |
| 1989 | /* Ready-to-send packet starts at pkt->data. We return length. */ |
| 1990 | return pkt->length + padding + maclen; |
| 1991 | } |
| 1992 | |
| 1993 | /* |
| 1994 | * Routines called from the main SSH code to send packets. There |
| 1995 | * are quite a few of these, because we have two separate |
| 1996 | * mechanisms for delaying the sending of packets: |
| 1997 | * |
| 1998 | * - In order to send an IGNORE message and a password message in |
| 1999 | * a single fixed-length blob, we require the ability to |
| 2000 | * concatenate the encrypted forms of those two packets _into_ a |
| 2001 | * single blob and then pass it to our <network.h> transport |
| 2002 | * layer in one go. Hence, there's a deferment mechanism which |
| 2003 | * works after packet encryption. |
| 2004 | * |
| 2005 | * - In order to avoid sending any connection-layer messages |
| 2006 | * during repeat key exchange, we have to queue up any such |
| 2007 | * outgoing messages _before_ they are encrypted (and in |
| 2008 | * particular before they're allocated sequence numbers), and |
| 2009 | * then send them once we've finished. |
| 2010 | * |
| 2011 | * I call these mechanisms `defer' and `queue' respectively, so as |
| 2012 | * to distinguish them reasonably easily. |
| 2013 | * |
| 2014 | * The functions send_noqueue() and defer_noqueue() free the packet |
| 2015 | * structure they are passed. Every outgoing packet goes through |
| 2016 | * precisely one of these functions in its life; packets passed to |
| 2017 | * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of |
| 2018 | * these or get queued, and then when the queue is later emptied |
| 2019 | * the packets are all passed to defer_noqueue(). |
| 2020 | * |
| 2021 | * When using a CBC-mode cipher, it's necessary to ensure that an |
| 2022 | * attacker can't provide data to be encrypted using an IV that they |
| 2023 | * know. We ensure this by prefixing each packet that might contain |
| 2024 | * user data with an SSH_MSG_IGNORE. This is done using the deferral |
| 2025 | * mechanism, so in this case send_noqueue() ends up redirecting to |
| 2026 | * defer_noqueue(). If you don't like this inefficiency, don't use |
| 2027 | * CBC. |
| 2028 | */ |
| 2029 | |
| 2030 | static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int); |
| 2031 | static void ssh_pkt_defersend(Ssh); |
| 2032 | |
| 2033 | /* |
| 2034 | * Send an SSH-2 packet immediately, without queuing or deferring. |
| 2035 | */ |
| 2036 | static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) |
| 2037 | { |
| 2038 | int len; |
| 2039 | int backlog; |
| 2040 | if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) { |
| 2041 | /* We need to send two packets, so use the deferral mechanism. */ |
| 2042 | ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); |
| 2043 | ssh_pkt_defersend(ssh); |
| 2044 | return; |
| 2045 | } |
| 2046 | len = ssh2_pkt_construct(ssh, pkt); |
| 2047 | backlog = s_write(ssh, pkt->data, len); |
| 2048 | if (backlog > SSH_MAX_BACKLOG) |
| 2049 | ssh_throttle_all(ssh, 1, backlog); |
| 2050 | |
| 2051 | ssh->outgoing_data_size += pkt->encrypted_len; |
| 2052 | if (!ssh->kex_in_progress && |
| 2053 | ssh->max_data_size != 0 && |
| 2054 | ssh->outgoing_data_size > ssh->max_data_size) |
| 2055 | do_ssh2_transport(ssh, "too much data sent", -1, NULL); |
| 2056 | |
| 2057 | ssh_free_packet(pkt); |
| 2058 | } |
| 2059 | |
| 2060 | /* |
| 2061 | * Defer an SSH-2 packet. |
| 2062 | */ |
| 2063 | static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) |
| 2064 | { |
| 2065 | int len; |
| 2066 | if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) && |
| 2067 | ssh->deferred_len == 0 && !noignore && |
| 2068 | !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { |
| 2069 | /* |
| 2070 | * Interpose an SSH_MSG_IGNORE to ensure that user data don't |
| 2071 | * get encrypted with a known IV. |
| 2072 | */ |
| 2073 | struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 2074 | ssh2_pkt_addstring_start(ipkt); |
| 2075 | ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE); |
| 2076 | } |
| 2077 | len = ssh2_pkt_construct(ssh, pkt); |
| 2078 | if (ssh->deferred_len + len > ssh->deferred_size) { |
| 2079 | ssh->deferred_size = ssh->deferred_len + len + 128; |
| 2080 | ssh->deferred_send_data = sresize(ssh->deferred_send_data, |
| 2081 | ssh->deferred_size, |
| 2082 | unsigned char); |
| 2083 | } |
| 2084 | memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len); |
| 2085 | ssh->deferred_len += len; |
| 2086 | ssh->deferred_data_size += pkt->encrypted_len; |
| 2087 | ssh_free_packet(pkt); |
| 2088 | } |
| 2089 | |
| 2090 | /* |
| 2091 | * Queue an SSH-2 packet. |
| 2092 | */ |
| 2093 | static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) |
| 2094 | { |
| 2095 | assert(ssh->queueing); |
| 2096 | |
| 2097 | if (ssh->queuelen >= ssh->queuesize) { |
| 2098 | ssh->queuesize = ssh->queuelen + 32; |
| 2099 | ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *); |
| 2100 | } |
| 2101 | |
| 2102 | ssh->queue[ssh->queuelen++] = pkt; |
| 2103 | } |
| 2104 | |
| 2105 | /* |
| 2106 | * Either queue or send a packet, depending on whether queueing is |
| 2107 | * set. |
| 2108 | */ |
| 2109 | static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt) |
| 2110 | { |
| 2111 | if (ssh->queueing) |
| 2112 | ssh2_pkt_queue(ssh, pkt); |
| 2113 | else |
| 2114 | ssh2_pkt_send_noqueue(ssh, pkt); |
| 2115 | } |
| 2116 | |
| 2117 | /* |
| 2118 | * Either queue or defer a packet, depending on whether queueing is |
| 2119 | * set. |
| 2120 | */ |
| 2121 | static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt) |
| 2122 | { |
| 2123 | if (ssh->queueing) |
| 2124 | ssh2_pkt_queue(ssh, pkt); |
| 2125 | else |
| 2126 | ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); |
| 2127 | } |
| 2128 | |
| 2129 | /* |
| 2130 | * Send the whole deferred data block constructed by |
| 2131 | * ssh2_pkt_defer() or SSH-1's defer_packet(). |
| 2132 | * |
| 2133 | * The expected use of the defer mechanism is that you call |
| 2134 | * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If |
| 2135 | * not currently queueing, this simply sets up deferred_send_data |
| 2136 | * and then sends it. If we _are_ currently queueing, the calls to |
| 2137 | * ssh2_pkt_defer() put the deferred packets on to the queue |
| 2138 | * instead, and therefore ssh_pkt_defersend() has no deferred data |
| 2139 | * to send. Hence, there's no need to make it conditional on |
| 2140 | * ssh->queueing. |
| 2141 | */ |
| 2142 | static void ssh_pkt_defersend(Ssh ssh) |
| 2143 | { |
| 2144 | int backlog; |
| 2145 | backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len); |
| 2146 | ssh->deferred_len = ssh->deferred_size = 0; |
| 2147 | sfree(ssh->deferred_send_data); |
| 2148 | ssh->deferred_send_data = NULL; |
| 2149 | if (backlog > SSH_MAX_BACKLOG) |
| 2150 | ssh_throttle_all(ssh, 1, backlog); |
| 2151 | |
| 2152 | ssh->outgoing_data_size += ssh->deferred_data_size; |
| 2153 | if (!ssh->kex_in_progress && |
| 2154 | ssh->max_data_size != 0 && |
| 2155 | ssh->outgoing_data_size > ssh->max_data_size) |
| 2156 | do_ssh2_transport(ssh, "too much data sent", -1, NULL); |
| 2157 | ssh->deferred_data_size = 0; |
| 2158 | } |
| 2159 | |
| 2160 | /* |
| 2161 | * Send a packet whose length needs to be disguised (typically |
| 2162 | * passwords or keyboard-interactive responses). |
| 2163 | */ |
| 2164 | static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt, |
| 2165 | int padsize) |
| 2166 | { |
| 2167 | #if 0 |
| 2168 | if (0) { |
| 2169 | /* |
| 2170 | * The simplest way to do this is to adjust the |
| 2171 | * variable-length padding field in the outgoing packet. |
| 2172 | * |
| 2173 | * Currently compiled out, because some Cisco SSH servers |
| 2174 | * don't like excessively padded packets (bah, why's it |
| 2175 | * always Cisco?) |
| 2176 | */ |
| 2177 | pkt->forcepad = padsize; |
| 2178 | ssh2_pkt_send(ssh, pkt); |
| 2179 | } else |
| 2180 | #endif |
| 2181 | { |
| 2182 | /* |
| 2183 | * If we can't do that, however, an alternative approach is |
| 2184 | * to use the pkt_defer mechanism to bundle the packet |
| 2185 | * tightly together with an SSH_MSG_IGNORE such that their |
| 2186 | * combined length is a constant. So first we construct the |
| 2187 | * final form of this packet and defer its sending. |
| 2188 | */ |
| 2189 | ssh2_pkt_defer(ssh, pkt); |
| 2190 | |
| 2191 | /* |
| 2192 | * Now construct an SSH_MSG_IGNORE which includes a string |
| 2193 | * that's an exact multiple of the cipher block size. (If |
| 2194 | * the cipher is NULL so that the block size is |
| 2195 | * unavailable, we don't do this trick at all, because we |
| 2196 | * gain nothing by it.) |
| 2197 | */ |
| 2198 | if (ssh->cscipher && |
| 2199 | !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { |
| 2200 | int stringlen, i; |
| 2201 | |
| 2202 | stringlen = (256 - ssh->deferred_len); |
| 2203 | stringlen += ssh->cscipher->blksize - 1; |
| 2204 | stringlen -= (stringlen % ssh->cscipher->blksize); |
| 2205 | if (ssh->cscomp) { |
| 2206 | /* |
| 2207 | * Temporarily disable actual compression, so we |
| 2208 | * can guarantee to get this string exactly the |
| 2209 | * length we want it. The compression-disabling |
| 2210 | * routine should return an integer indicating how |
| 2211 | * many bytes we should adjust our string length |
| 2212 | * by. |
| 2213 | */ |
| 2214 | stringlen -= |
| 2215 | ssh->cscomp->disable_compression(ssh->cs_comp_ctx); |
| 2216 | } |
| 2217 | pkt = ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 2218 | ssh2_pkt_addstring_start(pkt); |
| 2219 | for (i = 0; i < stringlen; i++) { |
| 2220 | char c = (char) random_byte(); |
| 2221 | ssh2_pkt_addstring_data(pkt, &c, 1); |
| 2222 | } |
| 2223 | ssh2_pkt_defer(ssh, pkt); |
| 2224 | } |
| 2225 | ssh_pkt_defersend(ssh); |
| 2226 | } |
| 2227 | } |
| 2228 | |
| 2229 | /* |
| 2230 | * Send all queued SSH-2 packets. We send them by means of |
| 2231 | * ssh2_pkt_defer_noqueue(), in case they included a pair of |
| 2232 | * packets that needed to be lumped together. |
| 2233 | */ |
| 2234 | static void ssh2_pkt_queuesend(Ssh ssh) |
| 2235 | { |
| 2236 | int i; |
| 2237 | |
| 2238 | assert(!ssh->queueing); |
| 2239 | |
| 2240 | for (i = 0; i < ssh->queuelen; i++) |
| 2241 | ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE); |
| 2242 | ssh->queuelen = 0; |
| 2243 | |
| 2244 | ssh_pkt_defersend(ssh); |
| 2245 | } |
| 2246 | |
| 2247 | #if 0 |
| 2248 | void bndebug(char *string, Bignum b) |
| 2249 | { |
| 2250 | unsigned char *p; |
| 2251 | int i, len; |
| 2252 | p = ssh2_mpint_fmt(b, &len); |
| 2253 | debug(("%s", string)); |
| 2254 | for (i = 0; i < len; i++) |
| 2255 | debug((" %02x", p[i])); |
| 2256 | debug(("\n")); |
| 2257 | sfree(p); |
| 2258 | } |
| 2259 | #endif |
| 2260 | |
| 2261 | static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b) |
| 2262 | { |
| 2263 | unsigned char *p; |
| 2264 | int len; |
| 2265 | p = ssh2_mpint_fmt(b, &len); |
| 2266 | hash_string(h, s, p, len); |
| 2267 | sfree(p); |
| 2268 | } |
| 2269 | |
| 2270 | /* |
| 2271 | * Packet decode functions for both SSH-1 and SSH-2. |
| 2272 | */ |
| 2273 | static unsigned long ssh_pkt_getuint32(struct Packet *pkt) |
| 2274 | { |
| 2275 | unsigned long value; |
| 2276 | if (pkt->length - pkt->savedpos < 4) |
| 2277 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 2278 | value = GET_32BIT(pkt->body + pkt->savedpos); |
| 2279 | pkt->savedpos += 4; |
| 2280 | return value; |
| 2281 | } |
| 2282 | static int ssh2_pkt_getbool(struct Packet *pkt) |
| 2283 | { |
| 2284 | unsigned long value; |
| 2285 | if (pkt->length - pkt->savedpos < 1) |
| 2286 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 2287 | value = pkt->body[pkt->savedpos] != 0; |
| 2288 | pkt->savedpos++; |
| 2289 | return value; |
| 2290 | } |
| 2291 | static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length) |
| 2292 | { |
| 2293 | int len; |
| 2294 | *p = NULL; |
| 2295 | *length = 0; |
| 2296 | if (pkt->length - pkt->savedpos < 4) |
| 2297 | return; |
| 2298 | len = GET_32BIT(pkt->body + pkt->savedpos); |
| 2299 | if (len < 0) |
| 2300 | return; |
| 2301 | *length = len; |
| 2302 | pkt->savedpos += 4; |
| 2303 | if (pkt->length - pkt->savedpos < *length) |
| 2304 | return; |
| 2305 | *p = (char *)(pkt->body + pkt->savedpos); |
| 2306 | pkt->savedpos += *length; |
| 2307 | } |
| 2308 | static void *ssh_pkt_getdata(struct Packet *pkt, int length) |
| 2309 | { |
| 2310 | if (pkt->length - pkt->savedpos < length) |
| 2311 | return NULL; |
| 2312 | pkt->savedpos += length; |
| 2313 | return pkt->body + (pkt->savedpos - length); |
| 2314 | } |
| 2315 | static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key, |
| 2316 | unsigned char **keystr) |
| 2317 | { |
| 2318 | int j; |
| 2319 | |
| 2320 | j = makekey(pkt->body + pkt->savedpos, |
| 2321 | pkt->length - pkt->savedpos, |
| 2322 | key, keystr, 0); |
| 2323 | |
| 2324 | if (j < 0) |
| 2325 | return FALSE; |
| 2326 | |
| 2327 | pkt->savedpos += j; |
| 2328 | assert(pkt->savedpos < pkt->length); |
| 2329 | |
| 2330 | return TRUE; |
| 2331 | } |
| 2332 | static Bignum ssh1_pkt_getmp(struct Packet *pkt) |
| 2333 | { |
| 2334 | int j; |
| 2335 | Bignum b; |
| 2336 | |
| 2337 | j = ssh1_read_bignum(pkt->body + pkt->savedpos, |
| 2338 | pkt->length - pkt->savedpos, &b); |
| 2339 | |
| 2340 | if (j < 0) |
| 2341 | return NULL; |
| 2342 | |
| 2343 | pkt->savedpos += j; |
| 2344 | return b; |
| 2345 | } |
| 2346 | static Bignum ssh2_pkt_getmp(struct Packet *pkt) |
| 2347 | { |
| 2348 | char *p; |
| 2349 | int length; |
| 2350 | Bignum b; |
| 2351 | |
| 2352 | ssh_pkt_getstring(pkt, &p, &length); |
| 2353 | if (!p) |
| 2354 | return NULL; |
| 2355 | if (p[0] & 0x80) |
| 2356 | return NULL; |
| 2357 | b = bignum_from_bytes((unsigned char *)p, length); |
| 2358 | return b; |
| 2359 | } |
| 2360 | |
| 2361 | /* |
| 2362 | * Helper function to add an SSH-2 signature blob to a packet. |
| 2363 | * Expects to be shown the public key blob as well as the signature |
| 2364 | * blob. Normally works just like ssh2_pkt_addstring, but will |
| 2365 | * fiddle with the signature packet if necessary for |
| 2366 | * BUG_SSH2_RSA_PADDING. |
| 2367 | */ |
| 2368 | static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, |
| 2369 | void *pkblob_v, int pkblob_len, |
| 2370 | void *sigblob_v, int sigblob_len) |
| 2371 | { |
| 2372 | unsigned char *pkblob = (unsigned char *)pkblob_v; |
| 2373 | unsigned char *sigblob = (unsigned char *)sigblob_v; |
| 2374 | |
| 2375 | /* dmemdump(pkblob, pkblob_len); */ |
| 2376 | /* dmemdump(sigblob, sigblob_len); */ |
| 2377 | |
| 2378 | /* |
| 2379 | * See if this is in fact an ssh-rsa signature and a buggy |
| 2380 | * server; otherwise we can just do this the easy way. |
| 2381 | */ |
| 2382 | if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && |
| 2383 | (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { |
| 2384 | int pos, len, siglen; |
| 2385 | |
| 2386 | /* |
| 2387 | * Find the byte length of the modulus. |
| 2388 | */ |
| 2389 | |
| 2390 | pos = 4+7; /* skip over "ssh-rsa" */ |
| 2391 | pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */ |
| 2392 | len = GET_32BIT(pkblob+pos); /* find length of modulus */ |
| 2393 | pos += 4; /* find modulus itself */ |
| 2394 | while (len > 0 && pkblob[pos] == 0) |
| 2395 | len--, pos++; |
| 2396 | /* debug(("modulus length is %d\n", len)); */ |
| 2397 | |
| 2398 | /* |
| 2399 | * Now find the signature integer. |
| 2400 | */ |
| 2401 | pos = 4+7; /* skip over "ssh-rsa" */ |
| 2402 | siglen = GET_32BIT(sigblob+pos); |
| 2403 | /* debug(("signature length is %d\n", siglen)); */ |
| 2404 | |
| 2405 | if (len != siglen) { |
| 2406 | unsigned char newlen[4]; |
| 2407 | ssh2_pkt_addstring_start(pkt); |
| 2408 | ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos); |
| 2409 | /* dmemdump(sigblob, pos); */ |
| 2410 | pos += 4; /* point to start of actual sig */ |
| 2411 | PUT_32BIT(newlen, len); |
| 2412 | ssh2_pkt_addstring_data(pkt, (char *)newlen, 4); |
| 2413 | /* dmemdump(newlen, 4); */ |
| 2414 | newlen[0] = 0; |
| 2415 | while (len-- > siglen) { |
| 2416 | ssh2_pkt_addstring_data(pkt, (char *)newlen, 1); |
| 2417 | /* dmemdump(newlen, 1); */ |
| 2418 | } |
| 2419 | ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen); |
| 2420 | /* dmemdump(sigblob+pos, siglen); */ |
| 2421 | return; |
| 2422 | } |
| 2423 | |
| 2424 | /* Otherwise fall through and do it the easy way. */ |
| 2425 | } |
| 2426 | |
| 2427 | ssh2_pkt_addstring_start(pkt); |
| 2428 | ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len); |
| 2429 | } |
| 2430 | |
| 2431 | /* |
| 2432 | * Examine the remote side's version string and compare it against |
| 2433 | * a list of known buggy implementations. |
| 2434 | */ |
| 2435 | static void ssh_detect_bugs(Ssh ssh, char *vstring) |
| 2436 | { |
| 2437 | char *imp; /* pointer to implementation part */ |
| 2438 | imp = vstring; |
| 2439 | imp += strcspn(imp, "-"); |
| 2440 | if (*imp) imp++; |
| 2441 | imp += strcspn(imp, "-"); |
| 2442 | if (*imp) imp++; |
| 2443 | |
| 2444 | ssh->remote_bugs = 0; |
| 2445 | |
| 2446 | /* |
| 2447 | * General notes on server version strings: |
| 2448 | * - Not all servers reporting "Cisco-1.25" have all the bugs listed |
| 2449 | * here -- in particular, we've heard of one that's perfectly happy |
| 2450 | * with SSH1_MSG_IGNOREs -- but this string never seems to change, |
| 2451 | * so we can't distinguish them. |
| 2452 | */ |
| 2453 | if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON || |
| 2454 | (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO && |
| 2455 | (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
| 2456 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
| 2457 | !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") || |
| 2458 | !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) { |
| 2459 | /* |
| 2460 | * These versions don't support SSH1_MSG_IGNORE, so we have |
| 2461 | * to use a different defence against password length |
| 2462 | * sniffing. |
| 2463 | */ |
| 2464 | ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
| 2465 | logevent("We believe remote version has SSH-1 ignore bug"); |
| 2466 | } |
| 2467 | |
| 2468 | if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON || |
| 2469 | (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO && |
| 2470 | (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) { |
| 2471 | /* |
| 2472 | * These versions need a plain password sent; they can't |
| 2473 | * handle having a null and a random length of data after |
| 2474 | * the password. |
| 2475 | */ |
| 2476 | ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; |
| 2477 | logevent("We believe remote version needs a plain SSH-1 password"); |
| 2478 | } |
| 2479 | |
| 2480 | if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON || |
| 2481 | (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO && |
| 2482 | (!strcmp(imp, "Cisco-1.25")))) { |
| 2483 | /* |
| 2484 | * These versions apparently have no clue whatever about |
| 2485 | * RSA authentication and will panic and die if they see |
| 2486 | * an AUTH_RSA message. |
| 2487 | */ |
| 2488 | ssh->remote_bugs |= BUG_CHOKES_ON_RSA; |
| 2489 | logevent("We believe remote version can't handle SSH-1 RSA authentication"); |
| 2490 | } |
| 2491 | |
| 2492 | if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON || |
| 2493 | (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO && |
| 2494 | !wc_match("* VShell", imp) && |
| 2495 | (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) || |
| 2496 | wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) || |
| 2497 | wc_match("2.1 *", imp)))) { |
| 2498 | /* |
| 2499 | * These versions have the HMAC bug. |
| 2500 | */ |
| 2501 | ssh->remote_bugs |= BUG_SSH2_HMAC; |
| 2502 | logevent("We believe remote version has SSH-2 HMAC bug"); |
| 2503 | } |
| 2504 | |
| 2505 | if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON || |
| 2506 | (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO && |
| 2507 | !wc_match("* VShell", imp) && |
| 2508 | (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) { |
| 2509 | /* |
| 2510 | * These versions have the key-derivation bug (failing to |
| 2511 | * include the literal shared secret in the hashes that |
| 2512 | * generate the keys). |
| 2513 | */ |
| 2514 | ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; |
| 2515 | logevent("We believe remote version has SSH-2 key-derivation bug"); |
| 2516 | } |
| 2517 | |
| 2518 | if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON || |
| 2519 | (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO && |
| 2520 | (wc_match("OpenSSH_2.[5-9]*", imp) || |
| 2521 | wc_match("OpenSSH_3.[0-2]*", imp)))) { |
| 2522 | /* |
| 2523 | * These versions have the SSH-2 RSA padding bug. |
| 2524 | */ |
| 2525 | ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; |
| 2526 | logevent("We believe remote version has SSH-2 RSA padding bug"); |
| 2527 | } |
| 2528 | |
| 2529 | if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON || |
| 2530 | (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO && |
| 2531 | wc_match("OpenSSH_2.[0-2]*", imp))) { |
| 2532 | /* |
| 2533 | * These versions have the SSH-2 session-ID bug in |
| 2534 | * public-key authentication. |
| 2535 | */ |
| 2536 | ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; |
| 2537 | logevent("We believe remote version has SSH-2 public-key-session-ID bug"); |
| 2538 | } |
| 2539 | |
| 2540 | if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON || |
| 2541 | (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO && |
| 2542 | (wc_match("DigiSSH_2.0", imp) || |
| 2543 | wc_match("OpenSSH_2.[0-4]*", imp) || |
| 2544 | wc_match("OpenSSH_2.5.[0-3]*", imp) || |
| 2545 | wc_match("Sun_SSH_1.0", imp) || |
| 2546 | wc_match("Sun_SSH_1.0.1", imp) || |
| 2547 | /* All versions <= 1.2.6 (they changed their format in 1.2.7) */ |
| 2548 | wc_match("WeOnlyDo-*", imp)))) { |
| 2549 | /* |
| 2550 | * These versions have the SSH-2 rekey bug. |
| 2551 | */ |
| 2552 | ssh->remote_bugs |= BUG_SSH2_REKEY; |
| 2553 | logevent("We believe remote version has SSH-2 rekey bug"); |
| 2554 | } |
| 2555 | |
| 2556 | if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON || |
| 2557 | (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO && |
| 2558 | (wc_match("1.36_sshlib GlobalSCAPE", imp) || |
| 2559 | wc_match("1.36 sshlib: GlobalScape", imp)))) { |
| 2560 | /* |
| 2561 | * This version ignores our makpkt and needs to be throttled. |
| 2562 | */ |
| 2563 | ssh->remote_bugs |= BUG_SSH2_MAXPKT; |
| 2564 | logevent("We believe remote version ignores SSH-2 maximum packet size"); |
| 2565 | } |
| 2566 | |
| 2567 | if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) { |
| 2568 | /* |
| 2569 | * Servers that don't support SSH2_MSG_IGNORE. Currently, |
| 2570 | * none detected automatically. |
| 2571 | */ |
| 2572 | ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE; |
| 2573 | logevent("We believe remote version has SSH-2 ignore bug"); |
| 2574 | } |
| 2575 | } |
| 2576 | |
| 2577 | /* |
| 2578 | * The `software version' part of an SSH version string is required |
| 2579 | * to contain no spaces or minus signs. |
| 2580 | */ |
| 2581 | static void ssh_fix_verstring(char *str) |
| 2582 | { |
| 2583 | /* Eat "SSH-<protoversion>-". */ |
| 2584 | assert(*str == 'S'); str++; |
| 2585 | assert(*str == 'S'); str++; |
| 2586 | assert(*str == 'H'); str++; |
| 2587 | assert(*str == '-'); str++; |
| 2588 | while (*str && *str != '-') str++; |
| 2589 | assert(*str == '-'); str++; |
| 2590 | |
| 2591 | /* Convert minus signs and spaces in the remaining string into |
| 2592 | * underscores. */ |
| 2593 | while (*str) { |
| 2594 | if (*str == '-' || *str == ' ') |
| 2595 | *str = '_'; |
| 2596 | str++; |
| 2597 | } |
| 2598 | } |
| 2599 | |
| 2600 | /* |
| 2601 | * Send an appropriate SSH version string. |
| 2602 | */ |
| 2603 | static void ssh_send_verstring(Ssh ssh, char *svers) |
| 2604 | { |
| 2605 | char *verstring; |
| 2606 | |
| 2607 | if (ssh->version == 2) { |
| 2608 | /* |
| 2609 | * Construct a v2 version string. |
| 2610 | */ |
| 2611 | verstring = dupprintf("SSH-2.0-%s\015\012", sshver); |
| 2612 | } else { |
| 2613 | /* |
| 2614 | * Construct a v1 version string. |
| 2615 | */ |
| 2616 | verstring = dupprintf("SSH-%s-%s\012", |
| 2617 | (ssh_versioncmp(svers, "1.5") <= 0 ? |
| 2618 | svers : "1.5"), |
| 2619 | sshver); |
| 2620 | } |
| 2621 | |
| 2622 | ssh_fix_verstring(verstring); |
| 2623 | |
| 2624 | if (ssh->version == 2) { |
| 2625 | size_t len; |
| 2626 | /* |
| 2627 | * Record our version string. |
| 2628 | */ |
| 2629 | len = strcspn(verstring, "\015\012"); |
| 2630 | ssh->v_c = snewn(len + 1, char); |
| 2631 | memcpy(ssh->v_c, verstring, len); |
| 2632 | ssh->v_c[len] = 0; |
| 2633 | } |
| 2634 | |
| 2635 | logeventf(ssh, "We claim version: %.*s", |
| 2636 | strcspn(verstring, "\015\012"), verstring); |
| 2637 | s_write(ssh, verstring, strlen(verstring)); |
| 2638 | sfree(verstring); |
| 2639 | } |
| 2640 | |
| 2641 | static int do_ssh_init(Ssh ssh, unsigned char c) |
| 2642 | { |
| 2643 | struct do_ssh_init_state { |
| 2644 | int vslen; |
| 2645 | char version[10]; |
| 2646 | char *vstring; |
| 2647 | int vstrsize; |
| 2648 | int i; |
| 2649 | int proto1, proto2; |
| 2650 | }; |
| 2651 | crState(do_ssh_init_state); |
| 2652 | |
| 2653 | crBegin(ssh->do_ssh_init_crstate); |
| 2654 | |
| 2655 | /* Search for a line beginning with the string "SSH-" in the input. */ |
| 2656 | for (;;) { |
| 2657 | if (c != 'S') goto no; |
| 2658 | crReturn(1); |
| 2659 | if (c != 'S') goto no; |
| 2660 | crReturn(1); |
| 2661 | if (c != 'H') goto no; |
| 2662 | crReturn(1); |
| 2663 | if (c != '-') goto no; |
| 2664 | break; |
| 2665 | no: |
| 2666 | while (c != '\012') |
| 2667 | crReturn(1); |
| 2668 | crReturn(1); |
| 2669 | } |
| 2670 | |
| 2671 | s->vstrsize = 16; |
| 2672 | s->vstring = snewn(s->vstrsize, char); |
| 2673 | strcpy(s->vstring, "SSH-"); |
| 2674 | s->vslen = 4; |
| 2675 | s->i = 0; |
| 2676 | while (1) { |
| 2677 | crReturn(1); /* get another char */ |
| 2678 | if (s->vslen >= s->vstrsize - 1) { |
| 2679 | s->vstrsize += 16; |
| 2680 | s->vstring = sresize(s->vstring, s->vstrsize, char); |
| 2681 | } |
| 2682 | s->vstring[s->vslen++] = c; |
| 2683 | if (s->i >= 0) { |
| 2684 | if (c == '-') { |
| 2685 | s->version[s->i] = '\0'; |
| 2686 | s->i = -1; |
| 2687 | } else if (s->i < sizeof(s->version) - 1) |
| 2688 | s->version[s->i++] = c; |
| 2689 | } else if (c == '\012') |
| 2690 | break; |
| 2691 | } |
| 2692 | |
| 2693 | ssh->agentfwd_enabled = FALSE; |
| 2694 | ssh->rdpkt2_state.incoming_sequence = 0; |
| 2695 | |
| 2696 | s->vstring[s->vslen] = 0; |
| 2697 | s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ |
| 2698 | logeventf(ssh, "Server version: %s", s->vstring); |
| 2699 | ssh_detect_bugs(ssh, s->vstring); |
| 2700 | |
| 2701 | /* |
| 2702 | * Decide which SSH protocol version to support. |
| 2703 | */ |
| 2704 | |
| 2705 | /* Anything strictly below "2.0" means protocol 1 is supported. */ |
| 2706 | s->proto1 = ssh_versioncmp(s->version, "2.0") < 0; |
| 2707 | /* Anything greater or equal to "1.99" means protocol 2 is supported. */ |
| 2708 | s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0; |
| 2709 | |
| 2710 | if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) { |
| 2711 | bombout(("SSH protocol version 1 required by user but not provided by server")); |
| 2712 | crStop(0); |
| 2713 | } |
| 2714 | if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) { |
| 2715 | bombout(("SSH protocol version 2 required by user but not provided by server")); |
| 2716 | crStop(0); |
| 2717 | } |
| 2718 | |
| 2719 | if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1)) |
| 2720 | ssh->version = 2; |
| 2721 | else |
| 2722 | ssh->version = 1; |
| 2723 | |
| 2724 | logeventf(ssh, "Using SSH protocol version %d", ssh->version); |
| 2725 | |
| 2726 | /* Send the version string, if we haven't already */ |
| 2727 | if (conf_get_int(ssh->conf, CONF_sshprot) != 3) |
| 2728 | ssh_send_verstring(ssh, s->version); |
| 2729 | |
| 2730 | if (ssh->version == 2) { |
| 2731 | size_t len; |
| 2732 | /* |
| 2733 | * Record their version string. |
| 2734 | */ |
| 2735 | len = strcspn(s->vstring, "\015\012"); |
| 2736 | ssh->v_s = snewn(len + 1, char); |
| 2737 | memcpy(ssh->v_s, s->vstring, len); |
| 2738 | ssh->v_s[len] = 0; |
| 2739 | |
| 2740 | /* |
| 2741 | * Initialise SSH-2 protocol. |
| 2742 | */ |
| 2743 | ssh->protocol = ssh2_protocol; |
| 2744 | ssh2_protocol_setup(ssh); |
| 2745 | ssh->s_rdpkt = ssh2_rdpkt; |
| 2746 | } else { |
| 2747 | /* |
| 2748 | * Initialise SSH-1 protocol. |
| 2749 | */ |
| 2750 | ssh->protocol = ssh1_protocol; |
| 2751 | ssh1_protocol_setup(ssh); |
| 2752 | ssh->s_rdpkt = ssh1_rdpkt; |
| 2753 | } |
| 2754 | if (ssh->version == 2) |
| 2755 | do_ssh2_transport(ssh, NULL, -1, NULL); |
| 2756 | |
| 2757 | update_specials_menu(ssh->frontend); |
| 2758 | ssh->state = SSH_STATE_BEFORE_SIZE; |
| 2759 | ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh); |
| 2760 | |
| 2761 | sfree(s->vstring); |
| 2762 | |
| 2763 | crFinish(0); |
| 2764 | } |
| 2765 | |
| 2766 | static void ssh_process_incoming_data(Ssh ssh, |
| 2767 | unsigned char **data, int *datalen) |
| 2768 | { |
| 2769 | struct Packet *pktin; |
| 2770 | |
| 2771 | pktin = ssh->s_rdpkt(ssh, data, datalen); |
| 2772 | if (pktin) { |
| 2773 | ssh->protocol(ssh, NULL, 0, pktin); |
| 2774 | ssh_free_packet(pktin); |
| 2775 | } |
| 2776 | } |
| 2777 | |
| 2778 | static void ssh_queue_incoming_data(Ssh ssh, |
| 2779 | unsigned char **data, int *datalen) |
| 2780 | { |
| 2781 | bufchain_add(&ssh->queued_incoming_data, *data, *datalen); |
| 2782 | *data += *datalen; |
| 2783 | *datalen = 0; |
| 2784 | } |
| 2785 | |
| 2786 | static void ssh_process_queued_incoming_data(Ssh ssh) |
| 2787 | { |
| 2788 | void *vdata; |
| 2789 | unsigned char *data; |
| 2790 | int len, origlen; |
| 2791 | |
| 2792 | while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { |
| 2793 | bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len); |
| 2794 | data = vdata; |
| 2795 | origlen = len; |
| 2796 | |
| 2797 | while (!ssh->frozen && len > 0) |
| 2798 | ssh_process_incoming_data(ssh, &data, &len); |
| 2799 | |
| 2800 | if (origlen > len) |
| 2801 | bufchain_consume(&ssh->queued_incoming_data, origlen - len); |
| 2802 | } |
| 2803 | } |
| 2804 | |
| 2805 | static void ssh_set_frozen(Ssh ssh, int frozen) |
| 2806 | { |
| 2807 | if (ssh->s) |
| 2808 | sk_set_frozen(ssh->s, frozen); |
| 2809 | ssh->frozen = frozen; |
| 2810 | } |
| 2811 | |
| 2812 | static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) |
| 2813 | { |
| 2814 | /* Log raw data, if we're in that mode. */ |
| 2815 | if (ssh->logctx) |
| 2816 | log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen, |
| 2817 | 0, NULL, NULL); |
| 2818 | |
| 2819 | crBegin(ssh->ssh_gotdata_crstate); |
| 2820 | |
| 2821 | /* |
| 2822 | * To begin with, feed the characters one by one to the |
| 2823 | * protocol initialisation / selection function do_ssh_init(). |
| 2824 | * When that returns 0, we're done with the initial greeting |
| 2825 | * exchange and can move on to packet discipline. |
| 2826 | */ |
| 2827 | while (1) { |
| 2828 | int ret; /* need not be kept across crReturn */ |
| 2829 | if (datalen == 0) |
| 2830 | crReturnV; /* more data please */ |
| 2831 | ret = do_ssh_init(ssh, *data); |
| 2832 | data++; |
| 2833 | datalen--; |
| 2834 | if (ret == 0) |
| 2835 | break; |
| 2836 | } |
| 2837 | |
| 2838 | /* |
| 2839 | * We emerge from that loop when the initial negotiation is |
| 2840 | * over and we have selected an s_rdpkt function. Now pass |
| 2841 | * everything to s_rdpkt, and then pass the resulting packets |
| 2842 | * to the proper protocol handler. |
| 2843 | */ |
| 2844 | |
| 2845 | while (1) { |
| 2846 | while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) { |
| 2847 | if (ssh->frozen) { |
| 2848 | ssh_queue_incoming_data(ssh, &data, &datalen); |
| 2849 | /* This uses up all data and cannot cause anything interesting |
| 2850 | * to happen; indeed, for anything to happen at all, we must |
| 2851 | * return, so break out. */ |
| 2852 | break; |
| 2853 | } else if (bufchain_size(&ssh->queued_incoming_data) > 0) { |
| 2854 | /* This uses up some or all data, and may freeze the |
| 2855 | * session. */ |
| 2856 | ssh_process_queued_incoming_data(ssh); |
| 2857 | } else { |
| 2858 | /* This uses up some or all data, and may freeze the |
| 2859 | * session. */ |
| 2860 | ssh_process_incoming_data(ssh, &data, &datalen); |
| 2861 | } |
| 2862 | /* FIXME this is probably EBW. */ |
| 2863 | if (ssh->state == SSH_STATE_CLOSED) |
| 2864 | return; |
| 2865 | } |
| 2866 | /* We're out of data. Go and get some more. */ |
| 2867 | crReturnV; |
| 2868 | } |
| 2869 | crFinishV; |
| 2870 | } |
| 2871 | |
| 2872 | static int ssh_do_close(Ssh ssh, int notify_exit) |
| 2873 | { |
| 2874 | int ret = 0; |
| 2875 | struct ssh_channel *c; |
| 2876 | |
| 2877 | ssh->state = SSH_STATE_CLOSED; |
| 2878 | expire_timer_context(ssh); |
| 2879 | if (ssh->s) { |
| 2880 | sk_close(ssh->s); |
| 2881 | ssh->s = NULL; |
| 2882 | if (notify_exit) |
| 2883 | notify_remote_exit(ssh->frontend); |
| 2884 | else |
| 2885 | ret = 1; |
| 2886 | } |
| 2887 | /* |
| 2888 | * Now we must shut down any port- and X-forwarded channels going |
| 2889 | * through this connection. |
| 2890 | */ |
| 2891 | if (ssh->channels) { |
| 2892 | while (NULL != (c = index234(ssh->channels, 0))) { |
| 2893 | switch (c->type) { |
| 2894 | case CHAN_X11: |
| 2895 | x11_close(c->u.x11.s); |
| 2896 | break; |
| 2897 | case CHAN_SOCKDATA: |
| 2898 | case CHAN_SOCKDATA_DORMANT: |
| 2899 | pfd_close(c->u.pfd.s); |
| 2900 | break; |
| 2901 | } |
| 2902 | del234(ssh->channels, c); /* moving next one to index 0 */ |
| 2903 | if (ssh->version == 2) |
| 2904 | bufchain_clear(&c->v.v2.outbuffer); |
| 2905 | sfree(c); |
| 2906 | } |
| 2907 | } |
| 2908 | /* |
| 2909 | * Go through port-forwardings, and close any associated |
| 2910 | * listening sockets. |
| 2911 | */ |
| 2912 | if (ssh->portfwds) { |
| 2913 | struct ssh_portfwd *pf; |
| 2914 | while (NULL != (pf = index234(ssh->portfwds, 0))) { |
| 2915 | /* Dispose of any listening socket. */ |
| 2916 | if (pf->local) |
| 2917 | pfd_terminate(pf->local); |
| 2918 | del234(ssh->portfwds, pf); /* moving next one to index 0 */ |
| 2919 | free_portfwd(pf); |
| 2920 | } |
| 2921 | freetree234(ssh->portfwds); |
| 2922 | ssh->portfwds = NULL; |
| 2923 | } |
| 2924 | |
| 2925 | return ret; |
| 2926 | } |
| 2927 | |
| 2928 | static void ssh_log(Plug plug, int type, SockAddr addr, int port, |
| 2929 | const char *error_msg, int error_code) |
| 2930 | { |
| 2931 | Ssh ssh = (Ssh) plug; |
| 2932 | char addrbuf[256], *msg; |
| 2933 | |
| 2934 | sk_getaddr(addr, addrbuf, lenof(addrbuf)); |
| 2935 | |
| 2936 | if (type == 0) |
| 2937 | msg = dupprintf("Connecting to %s port %d", addrbuf, port); |
| 2938 | else |
| 2939 | msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); |
| 2940 | |
| 2941 | logevent(msg); |
| 2942 | sfree(msg); |
| 2943 | } |
| 2944 | |
| 2945 | static int ssh_closing(Plug plug, const char *error_msg, int error_code, |
| 2946 | int calling_back) |
| 2947 | { |
| 2948 | Ssh ssh = (Ssh) plug; |
| 2949 | int need_notify = ssh_do_close(ssh, FALSE); |
| 2950 | |
| 2951 | if (!error_msg) { |
| 2952 | if (!ssh->close_expected) |
| 2953 | error_msg = "Server unexpectedly closed network connection"; |
| 2954 | else |
| 2955 | error_msg = "Server closed network connection"; |
| 2956 | } |
| 2957 | |
| 2958 | if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0) |
| 2959 | ssh->exitcode = 0; |
| 2960 | |
| 2961 | if (need_notify) |
| 2962 | notify_remote_exit(ssh->frontend); |
| 2963 | |
| 2964 | if (error_msg) |
| 2965 | logevent(error_msg); |
| 2966 | if (!ssh->close_expected || !ssh->clean_exit) |
| 2967 | connection_fatal(ssh->frontend, "%s", error_msg); |
| 2968 | return 0; |
| 2969 | } |
| 2970 | |
| 2971 | static int ssh_receive(Plug plug, int urgent, char *data, int len) |
| 2972 | { |
| 2973 | Ssh ssh = (Ssh) plug; |
| 2974 | ssh_gotdata(ssh, (unsigned char *)data, len); |
| 2975 | if (ssh->state == SSH_STATE_CLOSED) { |
| 2976 | ssh_do_close(ssh, TRUE); |
| 2977 | return 0; |
| 2978 | } |
| 2979 | return 1; |
| 2980 | } |
| 2981 | |
| 2982 | static void ssh_sent(Plug plug, int bufsize) |
| 2983 | { |
| 2984 | Ssh ssh = (Ssh) plug; |
| 2985 | /* |
| 2986 | * If the send backlog on the SSH socket itself clears, we |
| 2987 | * should unthrottle the whole world if it was throttled. |
| 2988 | */ |
| 2989 | if (bufsize < SSH_MAX_BACKLOG) |
| 2990 | ssh_throttle_all(ssh, 0, bufsize); |
| 2991 | } |
| 2992 | |
| 2993 | /* |
| 2994 | * Connect to specified host and port. |
| 2995 | * Returns an error message, or NULL on success. |
| 2996 | * Also places the canonical host name into `realhost'. It must be |
| 2997 | * freed by the caller. |
| 2998 | */ |
| 2999 | static const char *connect_to_host(Ssh ssh, char *host, int port, |
| 3000 | char **realhost, int nodelay, int keepalive) |
| 3001 | { |
| 3002 | static const struct plug_function_table fn_table = { |
| 3003 | ssh_log, |
| 3004 | ssh_closing, |
| 3005 | ssh_receive, |
| 3006 | ssh_sent, |
| 3007 | NULL |
| 3008 | }; |
| 3009 | |
| 3010 | SockAddr addr; |
| 3011 | const char *err; |
| 3012 | char *loghost; |
| 3013 | int addressfamily, sshprot; |
| 3014 | |
| 3015 | loghost = conf_get_str(ssh->conf, CONF_loghost); |
| 3016 | if (*loghost) { |
| 3017 | char *colon; |
| 3018 | |
| 3019 | ssh->savedhost = dupstr(loghost); |
| 3020 | ssh->savedport = 22; /* default ssh port */ |
| 3021 | |
| 3022 | /* |
| 3023 | * A colon suffix on savedhost also lets us affect |
| 3024 | * savedport. |
| 3025 | * |
| 3026 | * (FIXME: do something about IPv6 address literals here.) |
| 3027 | */ |
| 3028 | colon = strrchr(ssh->savedhost, ':'); |
| 3029 | if (colon) { |
| 3030 | *colon++ = '\0'; |
| 3031 | if (*colon) |
| 3032 | ssh->savedport = atoi(colon); |
| 3033 | } |
| 3034 | } else { |
| 3035 | ssh->savedhost = dupstr(host); |
| 3036 | if (port < 0) |
| 3037 | port = 22; /* default ssh port */ |
| 3038 | ssh->savedport = port; |
| 3039 | } |
| 3040 | |
| 3041 | /* |
| 3042 | * Try to find host. |
| 3043 | */ |
| 3044 | addressfamily = conf_get_int(ssh->conf, CONF_addressfamily); |
| 3045 | logeventf(ssh, "Looking up host \"%s\"%s", host, |
| 3046 | (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : |
| 3047 | (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); |
| 3048 | addr = name_lookup(host, port, realhost, ssh->conf, addressfamily); |
| 3049 | if ((err = sk_addr_error(addr)) != NULL) { |
| 3050 | sk_addr_free(addr); |
| 3051 | return err; |
| 3052 | } |
| 3053 | ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */ |
| 3054 | |
| 3055 | /* |
| 3056 | * Open socket. |
| 3057 | */ |
| 3058 | ssh->fn = &fn_table; |
| 3059 | ssh->s = new_connection(addr, *realhost, port, |
| 3060 | 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf); |
| 3061 | if ((err = sk_socket_error(ssh->s)) != NULL) { |
| 3062 | ssh->s = NULL; |
| 3063 | notify_remote_exit(ssh->frontend); |
| 3064 | return err; |
| 3065 | } |
| 3066 | |
| 3067 | /* |
| 3068 | * If the SSH version number's fixed, set it now, and if it's SSH-2, |
| 3069 | * send the version string too. |
| 3070 | */ |
| 3071 | sshprot = conf_get_int(ssh->conf, CONF_sshprot); |
| 3072 | if (sshprot == 0) |
| 3073 | ssh->version = 1; |
| 3074 | if (sshprot == 3) { |
| 3075 | ssh->version = 2; |
| 3076 | ssh_send_verstring(ssh, NULL); |
| 3077 | } |
| 3078 | |
| 3079 | /* |
| 3080 | * loghost, if configured, overrides realhost. |
| 3081 | */ |
| 3082 | if (*loghost) { |
| 3083 | sfree(*realhost); |
| 3084 | *realhost = dupstr(loghost); |
| 3085 | } |
| 3086 | |
| 3087 | return NULL; |
| 3088 | } |
| 3089 | |
| 3090 | /* |
| 3091 | * Throttle or unthrottle the SSH connection. |
| 3092 | */ |
| 3093 | static void ssh_throttle_conn(Ssh ssh, int adjust) |
| 3094 | { |
| 3095 | int old_count = ssh->conn_throttle_count; |
| 3096 | ssh->conn_throttle_count += adjust; |
| 3097 | assert(ssh->conn_throttle_count >= 0); |
| 3098 | if (ssh->conn_throttle_count && !old_count) { |
| 3099 | ssh_set_frozen(ssh, 1); |
| 3100 | } else if (!ssh->conn_throttle_count && old_count) { |
| 3101 | ssh_set_frozen(ssh, 0); |
| 3102 | } |
| 3103 | } |
| 3104 | |
| 3105 | /* |
| 3106 | * Throttle or unthrottle _all_ local data streams (for when sends |
| 3107 | * on the SSH connection itself back up). |
| 3108 | */ |
| 3109 | static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) |
| 3110 | { |
| 3111 | int i; |
| 3112 | struct ssh_channel *c; |
| 3113 | |
| 3114 | if (enable == ssh->throttled_all) |
| 3115 | return; |
| 3116 | ssh->throttled_all = enable; |
| 3117 | ssh->overall_bufsize = bufsize; |
| 3118 | if (!ssh->channels) |
| 3119 | return; |
| 3120 | for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { |
| 3121 | switch (c->type) { |
| 3122 | case CHAN_MAINSESSION: |
| 3123 | /* |
| 3124 | * This is treated separately, outside the switch. |
| 3125 | */ |
| 3126 | break; |
| 3127 | case CHAN_X11: |
| 3128 | x11_override_throttle(c->u.x11.s, enable); |
| 3129 | break; |
| 3130 | case CHAN_AGENT: |
| 3131 | /* Agent channels require no buffer management. */ |
| 3132 | break; |
| 3133 | case CHAN_SOCKDATA: |
| 3134 | pfd_override_throttle(c->u.pfd.s, enable); |
| 3135 | break; |
| 3136 | } |
| 3137 | } |
| 3138 | } |
| 3139 | |
| 3140 | static void ssh_agent_callback(void *sshv, void *reply, int replylen) |
| 3141 | { |
| 3142 | Ssh ssh = (Ssh) sshv; |
| 3143 | |
| 3144 | ssh->agent_response = reply; |
| 3145 | ssh->agent_response_len = replylen; |
| 3146 | |
| 3147 | if (ssh->version == 1) |
| 3148 | do_ssh1_login(ssh, NULL, -1, NULL); |
| 3149 | else |
| 3150 | do_ssh2_authconn(ssh, NULL, -1, NULL); |
| 3151 | } |
| 3152 | |
| 3153 | static void ssh_dialog_callback(void *sshv, int ret) |
| 3154 | { |
| 3155 | Ssh ssh = (Ssh) sshv; |
| 3156 | |
| 3157 | ssh->user_response = ret; |
| 3158 | |
| 3159 | if (ssh->version == 1) |
| 3160 | do_ssh1_login(ssh, NULL, -1, NULL); |
| 3161 | else |
| 3162 | do_ssh2_transport(ssh, NULL, -1, NULL); |
| 3163 | |
| 3164 | /* |
| 3165 | * This may have unfrozen the SSH connection, so do a |
| 3166 | * queued-data run. |
| 3167 | */ |
| 3168 | ssh_process_queued_incoming_data(ssh); |
| 3169 | } |
| 3170 | |
| 3171 | static void ssh_agentf_callback(void *cv, void *reply, int replylen) |
| 3172 | { |
| 3173 | struct ssh_channel *c = (struct ssh_channel *)cv; |
| 3174 | Ssh ssh = c->ssh; |
| 3175 | void *sentreply = reply; |
| 3176 | |
| 3177 | if (!sentreply) { |
| 3178 | /* Fake SSH_AGENT_FAILURE. */ |
| 3179 | sentreply = "\0\0\0\1\5"; |
| 3180 | replylen = 5; |
| 3181 | } |
| 3182 | if (ssh->version == 2) { |
| 3183 | ssh2_add_channel_data(c, sentreply, replylen); |
| 3184 | ssh2_try_send(c); |
| 3185 | } else { |
| 3186 | send_packet(ssh, SSH1_MSG_CHANNEL_DATA, |
| 3187 | PKT_INT, c->remoteid, |
| 3188 | PKT_INT, replylen, |
| 3189 | PKTT_DATA, |
| 3190 | PKT_DATA, sentreply, replylen, |
| 3191 | PKTT_OTHER, |
| 3192 | PKT_END); |
| 3193 | } |
| 3194 | if (reply) |
| 3195 | sfree(reply); |
| 3196 | } |
| 3197 | |
| 3198 | /* |
| 3199 | * Client-initiated disconnection. Send a DISCONNECT if `wire_reason' |
| 3200 | * non-NULL, otherwise just close the connection. `client_reason' == NULL |
| 3201 | * => log `wire_reason'. |
| 3202 | */ |
| 3203 | static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, |
| 3204 | int code, int clean_exit) |
| 3205 | { |
| 3206 | char *error; |
| 3207 | if (!client_reason) |
| 3208 | client_reason = wire_reason; |
| 3209 | if (client_reason) |
| 3210 | error = dupprintf("Disconnected: %s", client_reason); |
| 3211 | else |
| 3212 | error = dupstr("Disconnected"); |
| 3213 | if (wire_reason) { |
| 3214 | if (ssh->version == 1) { |
| 3215 | send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason, |
| 3216 | PKT_END); |
| 3217 | } else if (ssh->version == 2) { |
| 3218 | struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 3219 | ssh2_pkt_adduint32(pktout, code); |
| 3220 | ssh2_pkt_addstring(pktout, wire_reason); |
| 3221 | ssh2_pkt_addstring(pktout, "en"); /* language tag */ |
| 3222 | ssh2_pkt_send_noqueue(ssh, pktout); |
| 3223 | } |
| 3224 | } |
| 3225 | ssh->close_expected = TRUE; |
| 3226 | ssh->clean_exit = clean_exit; |
| 3227 | ssh_closing((Plug)ssh, error, 0, 0); |
| 3228 | sfree(error); |
| 3229 | } |
| 3230 | |
| 3231 | /* |
| 3232 | * Handle the key exchange and user authentication phases. |
| 3233 | */ |
| 3234 | static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, |
| 3235 | struct Packet *pktin) |
| 3236 | { |
| 3237 | int i, j, ret; |
| 3238 | unsigned char cookie[8], *ptr; |
| 3239 | struct RSAKey servkey, hostkey; |
| 3240 | struct MD5Context md5c; |
| 3241 | struct do_ssh1_login_state { |
| 3242 | int len; |
| 3243 | unsigned char *rsabuf, *keystr1, *keystr2; |
| 3244 | unsigned long supported_ciphers_mask, supported_auths_mask; |
| 3245 | int tried_publickey, tried_agent; |
| 3246 | int tis_auth_refused, ccard_auth_refused; |
| 3247 | unsigned char session_id[16]; |
| 3248 | int cipher_type; |
| 3249 | void *publickey_blob; |
| 3250 | int publickey_bloblen; |
| 3251 | char *publickey_comment; |
| 3252 | int publickey_encrypted; |
| 3253 | prompts_t *cur_prompt; |
| 3254 | char c; |
| 3255 | int pwpkt_type; |
| 3256 | unsigned char request[5], *response, *p; |
| 3257 | int responselen; |
| 3258 | int keyi, nkeys; |
| 3259 | int authed; |
| 3260 | struct RSAKey key; |
| 3261 | Bignum challenge; |
| 3262 | char *commentp; |
| 3263 | int commentlen; |
| 3264 | int dlgret; |
| 3265 | Filename *keyfile; |
| 3266 | }; |
| 3267 | crState(do_ssh1_login_state); |
| 3268 | |
| 3269 | crBegin(ssh->do_ssh1_login_crstate); |
| 3270 | |
| 3271 | if (!pktin) |
| 3272 | crWaitUntil(pktin); |
| 3273 | |
| 3274 | if (pktin->type != SSH1_SMSG_PUBLIC_KEY) { |
| 3275 | bombout(("Public key packet not received")); |
| 3276 | crStop(0); |
| 3277 | } |
| 3278 | |
| 3279 | logevent("Received public keys"); |
| 3280 | |
| 3281 | ptr = ssh_pkt_getdata(pktin, 8); |
| 3282 | if (!ptr) { |
| 3283 | bombout(("SSH-1 public key packet stopped before random cookie")); |
| 3284 | crStop(0); |
| 3285 | } |
| 3286 | memcpy(cookie, ptr, 8); |
| 3287 | |
| 3288 | if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) || |
| 3289 | !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) { |
| 3290 | bombout(("Failed to read SSH-1 public keys from public key packet")); |
| 3291 | crStop(0); |
| 3292 | } |
| 3293 | |
| 3294 | /* |
| 3295 | * Log the host key fingerprint. |
| 3296 | */ |
| 3297 | { |
| 3298 | char logmsg[80]; |
| 3299 | logevent("Host key fingerprint is:"); |
| 3300 | strcpy(logmsg, " "); |
| 3301 | hostkey.comment = NULL; |
| 3302 | rsa_fingerprint(logmsg + strlen(logmsg), |
| 3303 | sizeof(logmsg) - strlen(logmsg), &hostkey); |
| 3304 | logevent(logmsg); |
| 3305 | } |
| 3306 | |
| 3307 | ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin); |
| 3308 | s->supported_ciphers_mask = ssh_pkt_getuint32(pktin); |
| 3309 | s->supported_auths_mask = ssh_pkt_getuint32(pktin); |
| 3310 | if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) |
| 3311 | s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA); |
| 3312 | |
| 3313 | ssh->v1_local_protoflags = |
| 3314 | ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
| 3315 | ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
| 3316 | |
| 3317 | MD5Init(&md5c); |
| 3318 | MD5Update(&md5c, s->keystr2, hostkey.bytes); |
| 3319 | MD5Update(&md5c, s->keystr1, servkey.bytes); |
| 3320 | MD5Update(&md5c, cookie, 8); |
| 3321 | MD5Final(s->session_id, &md5c); |
| 3322 | |
| 3323 | for (i = 0; i < 32; i++) |
| 3324 | ssh->session_key[i] = random_byte(); |
| 3325 | |
| 3326 | /* |
| 3327 | * Verify that the `bits' and `bytes' parameters match. |
| 3328 | */ |
| 3329 | if (hostkey.bits > hostkey.bytes * 8 || |
| 3330 | servkey.bits > servkey.bytes * 8) { |
| 3331 | bombout(("SSH-1 public keys were badly formatted")); |
| 3332 | crStop(0); |
| 3333 | } |
| 3334 | |
| 3335 | s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 3336 | |
| 3337 | s->rsabuf = snewn(s->len, unsigned char); |
| 3338 | |
| 3339 | /* |
| 3340 | * Verify the host key. |
| 3341 | */ |
| 3342 | { |
| 3343 | /* |
| 3344 | * First format the key into a string. |
| 3345 | */ |
| 3346 | int len = rsastr_len(&hostkey); |
| 3347 | char fingerprint[100]; |
| 3348 | char *keystr = snewn(len, char); |
| 3349 | rsastr_fmt(keystr, &hostkey); |
| 3350 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
| 3351 | |
| 3352 | ssh_set_frozen(ssh, 1); |
| 3353 | s->dlgret = verify_ssh_host_key(ssh->frontend, |
| 3354 | ssh->savedhost, ssh->savedport, |
| 3355 | "rsa", keystr, fingerprint, |
| 3356 | ssh_dialog_callback, ssh); |
| 3357 | sfree(keystr); |
| 3358 | if (s->dlgret < 0) { |
| 3359 | do { |
| 3360 | crReturn(0); |
| 3361 | if (pktin) { |
| 3362 | bombout(("Unexpected data from server while waiting" |
| 3363 | " for user host key response")); |
| 3364 | crStop(0); |
| 3365 | } |
| 3366 | } while (pktin || inlen > 0); |
| 3367 | s->dlgret = ssh->user_response; |
| 3368 | } |
| 3369 | ssh_set_frozen(ssh, 0); |
| 3370 | |
| 3371 | if (s->dlgret == 0) { |
| 3372 | ssh_disconnect(ssh, "User aborted at host key verification", |
| 3373 | NULL, 0, TRUE); |
| 3374 | crStop(0); |
| 3375 | } |
| 3376 | } |
| 3377 | |
| 3378 | for (i = 0; i < 32; i++) { |
| 3379 | s->rsabuf[i] = ssh->session_key[i]; |
| 3380 | if (i < 16) |
| 3381 | s->rsabuf[i] ^= s->session_id[i]; |
| 3382 | } |
| 3383 | |
| 3384 | if (hostkey.bytes > servkey.bytes) { |
| 3385 | ret = rsaencrypt(s->rsabuf, 32, &servkey); |
| 3386 | if (ret) |
| 3387 | ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey); |
| 3388 | } else { |
| 3389 | ret = rsaencrypt(s->rsabuf, 32, &hostkey); |
| 3390 | if (ret) |
| 3391 | ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); |
| 3392 | } |
| 3393 | if (!ret) { |
| 3394 | bombout(("SSH-1 public key encryptions failed due to bad formatting")); |
| 3395 | crStop(0); |
| 3396 | } |
| 3397 | |
| 3398 | logevent("Encrypted session key"); |
| 3399 | |
| 3400 | { |
| 3401 | int cipher_chosen = 0, warn = 0; |
| 3402 | char *cipher_string = NULL; |
| 3403 | int i; |
| 3404 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { |
| 3405 | int next_cipher = conf_get_int_int(ssh->conf, |
| 3406 | CONF_ssh_cipherlist, i); |
| 3407 | if (next_cipher == CIPHER_WARN) { |
| 3408 | /* If/when we choose a cipher, warn about it */ |
| 3409 | warn = 1; |
| 3410 | } else if (next_cipher == CIPHER_AES) { |
| 3411 | /* XXX Probably don't need to mention this. */ |
| 3412 | logevent("AES not supported in SSH-1, skipping"); |
| 3413 | } else { |
| 3414 | switch (next_cipher) { |
| 3415 | case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; |
| 3416 | cipher_string = "3DES"; break; |
| 3417 | case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH; |
| 3418 | cipher_string = "Blowfish"; break; |
| 3419 | case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES; |
| 3420 | cipher_string = "single-DES"; break; |
| 3421 | } |
| 3422 | if (s->supported_ciphers_mask & (1 << s->cipher_type)) |
| 3423 | cipher_chosen = 1; |
| 3424 | } |
| 3425 | } |
| 3426 | if (!cipher_chosen) { |
| 3427 | if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) |
| 3428 | bombout(("Server violates SSH-1 protocol by not " |
| 3429 | "supporting 3DES encryption")); |
| 3430 | else |
| 3431 | /* shouldn't happen */ |
| 3432 | bombout(("No supported ciphers found")); |
| 3433 | crStop(0); |
| 3434 | } |
| 3435 | |
| 3436 | /* Warn about chosen cipher if necessary. */ |
| 3437 | if (warn) { |
| 3438 | ssh_set_frozen(ssh, 1); |
| 3439 | s->dlgret = askalg(ssh->frontend, "cipher", cipher_string, |
| 3440 | ssh_dialog_callback, ssh); |
| 3441 | if (s->dlgret < 0) { |
| 3442 | do { |
| 3443 | crReturn(0); |
| 3444 | if (pktin) { |
| 3445 | bombout(("Unexpected data from server while waiting" |
| 3446 | " for user response")); |
| 3447 | crStop(0); |
| 3448 | } |
| 3449 | } while (pktin || inlen > 0); |
| 3450 | s->dlgret = ssh->user_response; |
| 3451 | } |
| 3452 | ssh_set_frozen(ssh, 0); |
| 3453 | if (s->dlgret == 0) { |
| 3454 | ssh_disconnect(ssh, "User aborted at cipher warning", NULL, |
| 3455 | 0, TRUE); |
| 3456 | crStop(0); |
| 3457 | } |
| 3458 | } |
| 3459 | } |
| 3460 | |
| 3461 | switch (s->cipher_type) { |
| 3462 | case SSH_CIPHER_3DES: |
| 3463 | logevent("Using 3DES encryption"); |
| 3464 | break; |
| 3465 | case SSH_CIPHER_DES: |
| 3466 | logevent("Using single-DES encryption"); |
| 3467 | break; |
| 3468 | case SSH_CIPHER_BLOWFISH: |
| 3469 | logevent("Using Blowfish encryption"); |
| 3470 | break; |
| 3471 | } |
| 3472 | |
| 3473 | send_packet(ssh, SSH1_CMSG_SESSION_KEY, |
| 3474 | PKT_CHAR, s->cipher_type, |
| 3475 | PKT_DATA, cookie, 8, |
| 3476 | PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF, |
| 3477 | PKT_DATA, s->rsabuf, s->len, |
| 3478 | PKT_INT, ssh->v1_local_protoflags, PKT_END); |
| 3479 | |
| 3480 | logevent("Trying to enable encryption..."); |
| 3481 | |
| 3482 | sfree(s->rsabuf); |
| 3483 | |
| 3484 | ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
| 3485 | s->cipher_type == SSH_CIPHER_DES ? &ssh_des : |
| 3486 | &ssh_3des); |
| 3487 | ssh->v1_cipher_ctx = ssh->cipher->make_context(); |
| 3488 | ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key); |
| 3489 | logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name); |
| 3490 | |
| 3491 | ssh->crcda_ctx = crcda_make_context(); |
| 3492 | logevent("Installing CRC compensation attack detector"); |
| 3493 | |
| 3494 | if (servkey.modulus) { |
| 3495 | sfree(servkey.modulus); |
| 3496 | servkey.modulus = NULL; |
| 3497 | } |
| 3498 | if (servkey.exponent) { |
| 3499 | sfree(servkey.exponent); |
| 3500 | servkey.exponent = NULL; |
| 3501 | } |
| 3502 | if (hostkey.modulus) { |
| 3503 | sfree(hostkey.modulus); |
| 3504 | hostkey.modulus = NULL; |
| 3505 | } |
| 3506 | if (hostkey.exponent) { |
| 3507 | sfree(hostkey.exponent); |
| 3508 | hostkey.exponent = NULL; |
| 3509 | } |
| 3510 | crWaitUntil(pktin); |
| 3511 | |
| 3512 | if (pktin->type != SSH1_SMSG_SUCCESS) { |
| 3513 | bombout(("Encryption not successfully enabled")); |
| 3514 | crStop(0); |
| 3515 | } |
| 3516 | |
| 3517 | logevent("Successfully started encryption"); |
| 3518 | |
| 3519 | fflush(stdout); /* FIXME eh? */ |
| 3520 | { |
| 3521 | if ((ssh->username = get_remote_username(ssh->conf)) == NULL) { |
| 3522 | int ret; /* need not be kept over crReturn */ |
| 3523 | s->cur_prompt = new_prompts(ssh->frontend); |
| 3524 | s->cur_prompt->to_server = TRUE; |
| 3525 | s->cur_prompt->name = dupstr("SSH login name"); |
| 3526 | add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); |
| 3527 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 3528 | while (ret < 0) { |
| 3529 | ssh->send_ok = 1; |
| 3530 | crWaitUntil(!pktin); |
| 3531 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 3532 | ssh->send_ok = 0; |
| 3533 | } |
| 3534 | if (!ret) { |
| 3535 | /* |
| 3536 | * Failed to get a username. Terminate. |
| 3537 | */ |
| 3538 | free_prompts(s->cur_prompt); |
| 3539 | ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); |
| 3540 | crStop(0); |
| 3541 | } |
| 3542 | ssh->username = dupstr(s->cur_prompt->prompts[0]->result); |
| 3543 | free_prompts(s->cur_prompt); |
| 3544 | } |
| 3545 | |
| 3546 | send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END); |
| 3547 | { |
| 3548 | char *userlog = dupprintf("Sent username \"%s\"", ssh->username); |
| 3549 | logevent(userlog); |
| 3550 | if (flags & FLAG_INTERACTIVE && |
| 3551 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
| 3552 | c_write_str(ssh, userlog); |
| 3553 | c_write_str(ssh, "\r\n"); |
| 3554 | } |
| 3555 | sfree(userlog); |
| 3556 | } |
| 3557 | } |
| 3558 | |
| 3559 | crWaitUntil(pktin); |
| 3560 | |
| 3561 | if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) { |
| 3562 | /* We must not attempt PK auth. Pretend we've already tried it. */ |
| 3563 | s->tried_publickey = s->tried_agent = 1; |
| 3564 | } else { |
| 3565 | s->tried_publickey = s->tried_agent = 0; |
| 3566 | } |
| 3567 | s->tis_auth_refused = s->ccard_auth_refused = 0; |
| 3568 | /* |
| 3569 | * Load the public half of any configured keyfile for later use. |
| 3570 | */ |
| 3571 | s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); |
| 3572 | if (!filename_is_null(s->keyfile)) { |
| 3573 | int keytype; |
| 3574 | logeventf(ssh, "Reading private key file \"%.150s\"", |
| 3575 | filename_to_str(s->keyfile)); |
| 3576 | keytype = key_type(s->keyfile); |
| 3577 | if (keytype == SSH_KEYTYPE_SSH1) { |
| 3578 | const char *error; |
| 3579 | if (rsakey_pubblob(s->keyfile, |
| 3580 | &s->publickey_blob, &s->publickey_bloblen, |
| 3581 | &s->publickey_comment, &error)) { |
| 3582 | s->publickey_encrypted = rsakey_encrypted(s->keyfile, |
| 3583 | NULL); |
| 3584 | } else { |
| 3585 | char *msgbuf; |
| 3586 | logeventf(ssh, "Unable to load private key (%s)", error); |
| 3587 | msgbuf = dupprintf("Unable to load private key file " |
| 3588 | "\"%.150s\" (%s)\r\n", |
| 3589 | filename_to_str(s->keyfile), |
| 3590 | error); |
| 3591 | c_write_str(ssh, msgbuf); |
| 3592 | sfree(msgbuf); |
| 3593 | s->publickey_blob = NULL; |
| 3594 | } |
| 3595 | } else { |
| 3596 | char *msgbuf; |
| 3597 | logeventf(ssh, "Unable to use this key file (%s)", |
| 3598 | key_type_to_str(keytype)); |
| 3599 | msgbuf = dupprintf("Unable to use key file \"%.150s\"" |
| 3600 | " (%s)\r\n", |
| 3601 | filename_to_str(s->keyfile), |
| 3602 | key_type_to_str(keytype)); |
| 3603 | c_write_str(ssh, msgbuf); |
| 3604 | sfree(msgbuf); |
| 3605 | s->publickey_blob = NULL; |
| 3606 | } |
| 3607 | } else |
| 3608 | s->publickey_blob = NULL; |
| 3609 | |
| 3610 | while (pktin->type == SSH1_SMSG_FAILURE) { |
| 3611 | s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 3612 | |
| 3613 | if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) { |
| 3614 | /* |
| 3615 | * Attempt RSA authentication using Pageant. |
| 3616 | */ |
| 3617 | void *r; |
| 3618 | |
| 3619 | s->authed = FALSE; |
| 3620 | s->tried_agent = 1; |
| 3621 | logevent("Pageant is running. Requesting keys."); |
| 3622 | |
| 3623 | /* Request the keys held by the agent. */ |
| 3624 | PUT_32BIT(s->request, 1); |
| 3625 | s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
| 3626 | if (!agent_query(s->request, 5, &r, &s->responselen, |
| 3627 | ssh_agent_callback, ssh)) { |
| 3628 | do { |
| 3629 | crReturn(0); |
| 3630 | if (pktin) { |
| 3631 | bombout(("Unexpected data from server while waiting" |
| 3632 | " for agent response")); |
| 3633 | crStop(0); |
| 3634 | } |
| 3635 | } while (pktin || inlen > 0); |
| 3636 | r = ssh->agent_response; |
| 3637 | s->responselen = ssh->agent_response_len; |
| 3638 | } |
| 3639 | s->response = (unsigned char *) r; |
| 3640 | if (s->response && s->responselen >= 5 && |
| 3641 | s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
| 3642 | s->p = s->response + 5; |
| 3643 | s->nkeys = GET_32BIT(s->p); |
| 3644 | s->p += 4; |
| 3645 | logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); |
| 3646 | for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { |
| 3647 | unsigned char *pkblob = s->p; |
| 3648 | s->p += 4; |
| 3649 | { |
| 3650 | int n, ok = FALSE; |
| 3651 | do { /* do while (0) to make breaking easy */ |
| 3652 | n = ssh1_read_bignum |
| 3653 | (s->p, s->responselen-(s->p-s->response), |
| 3654 | &s->key.exponent); |
| 3655 | if (n < 0) |
| 3656 | break; |
| 3657 | s->p += n; |
| 3658 | n = ssh1_read_bignum |
| 3659 | (s->p, s->responselen-(s->p-s->response), |
| 3660 | &s->key.modulus); |
| 3661 | if (n < 0) |
| 3662 | break; |
| 3663 | s->p += n; |
| 3664 | if (s->responselen - (s->p-s->response) < 4) |
| 3665 | break; |
| 3666 | s->commentlen = GET_32BIT(s->p); |
| 3667 | s->p += 4; |
| 3668 | if (s->responselen - (s->p-s->response) < |
| 3669 | s->commentlen) |
| 3670 | break; |
| 3671 | s->commentp = (char *)s->p; |
| 3672 | s->p += s->commentlen; |
| 3673 | ok = TRUE; |
| 3674 | } while (0); |
| 3675 | if (!ok) { |
| 3676 | logevent("Pageant key list packet was truncated"); |
| 3677 | break; |
| 3678 | } |
| 3679 | } |
| 3680 | if (s->publickey_blob) { |
| 3681 | if (!memcmp(pkblob, s->publickey_blob, |
| 3682 | s->publickey_bloblen)) { |
| 3683 | logeventf(ssh, "Pageant key #%d matches " |
| 3684 | "configured key file", s->keyi); |
| 3685 | s->tried_publickey = 1; |
| 3686 | } else |
| 3687 | /* Skip non-configured key */ |
| 3688 | continue; |
| 3689 | } |
| 3690 | logeventf(ssh, "Trying Pageant key #%d", s->keyi); |
| 3691 | send_packet(ssh, SSH1_CMSG_AUTH_RSA, |
| 3692 | PKT_BIGNUM, s->key.modulus, PKT_END); |
| 3693 | crWaitUntil(pktin); |
| 3694 | if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 3695 | logevent("Key refused"); |
| 3696 | continue; |
| 3697 | } |
| 3698 | logevent("Received RSA challenge"); |
| 3699 | if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) { |
| 3700 | bombout(("Server's RSA challenge was badly formatted")); |
| 3701 | crStop(0); |
| 3702 | } |
| 3703 | |
| 3704 | { |
| 3705 | char *agentreq, *q, *ret; |
| 3706 | void *vret; |
| 3707 | int len, retlen; |
| 3708 | len = 1 + 4; /* message type, bit count */ |
| 3709 | len += ssh1_bignum_length(s->key.exponent); |
| 3710 | len += ssh1_bignum_length(s->key.modulus); |
| 3711 | len += ssh1_bignum_length(s->challenge); |
| 3712 | len += 16; /* session id */ |
| 3713 | len += 4; /* response format */ |
| 3714 | agentreq = snewn(4 + len, char); |
| 3715 | PUT_32BIT(agentreq, len); |
| 3716 | q = agentreq + 4; |
| 3717 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
| 3718 | PUT_32BIT(q, bignum_bitcount(s->key.modulus)); |
| 3719 | q += 4; |
| 3720 | q += ssh1_write_bignum(q, s->key.exponent); |
| 3721 | q += ssh1_write_bignum(q, s->key.modulus); |
| 3722 | q += ssh1_write_bignum(q, s->challenge); |
| 3723 | memcpy(q, s->session_id, 16); |
| 3724 | q += 16; |
| 3725 | PUT_32BIT(q, 1); /* response format */ |
| 3726 | if (!agent_query(agentreq, len + 4, &vret, &retlen, |
| 3727 | ssh_agent_callback, ssh)) { |
| 3728 | sfree(agentreq); |
| 3729 | do { |
| 3730 | crReturn(0); |
| 3731 | if (pktin) { |
| 3732 | bombout(("Unexpected data from server" |
| 3733 | " while waiting for agent" |
| 3734 | " response")); |
| 3735 | crStop(0); |
| 3736 | } |
| 3737 | } while (pktin || inlen > 0); |
| 3738 | vret = ssh->agent_response; |
| 3739 | retlen = ssh->agent_response_len; |
| 3740 | } else |
| 3741 | sfree(agentreq); |
| 3742 | ret = vret; |
| 3743 | if (ret) { |
| 3744 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
| 3745 | logevent("Sending Pageant's response"); |
| 3746 | send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 3747 | PKT_DATA, ret + 5, 16, |
| 3748 | PKT_END); |
| 3749 | sfree(ret); |
| 3750 | crWaitUntil(pktin); |
| 3751 | if (pktin->type == SSH1_SMSG_SUCCESS) { |
| 3752 | logevent |
| 3753 | ("Pageant's response accepted"); |
| 3754 | if (flags & FLAG_VERBOSE) { |
| 3755 | c_write_str(ssh, "Authenticated using" |
| 3756 | " RSA key \""); |
| 3757 | c_write(ssh, s->commentp, |
| 3758 | s->commentlen); |
| 3759 | c_write_str(ssh, "\" from agent\r\n"); |
| 3760 | } |
| 3761 | s->authed = TRUE; |
| 3762 | } else |
| 3763 | logevent |
| 3764 | ("Pageant's response not accepted"); |
| 3765 | } else { |
| 3766 | logevent |
| 3767 | ("Pageant failed to answer challenge"); |
| 3768 | sfree(ret); |
| 3769 | } |
| 3770 | } else { |
| 3771 | logevent("No reply received from Pageant"); |
| 3772 | } |
| 3773 | } |
| 3774 | freebn(s->key.exponent); |
| 3775 | freebn(s->key.modulus); |
| 3776 | freebn(s->challenge); |
| 3777 | if (s->authed) |
| 3778 | break; |
| 3779 | } |
| 3780 | sfree(s->response); |
| 3781 | if (s->publickey_blob && !s->tried_publickey) |
| 3782 | logevent("Configured key file not in Pageant"); |
| 3783 | } else { |
| 3784 | logevent("Failed to get reply from Pageant"); |
| 3785 | } |
| 3786 | if (s->authed) |
| 3787 | break; |
| 3788 | } |
| 3789 | if (s->publickey_blob && !s->tried_publickey) { |
| 3790 | /* |
| 3791 | * Try public key authentication with the specified |
| 3792 | * key file. |
| 3793 | */ |
| 3794 | int got_passphrase; /* need not be kept over crReturn */ |
| 3795 | if (flags & FLAG_VERBOSE) |
| 3796 | c_write_str(ssh, "Trying public key authentication.\r\n"); |
| 3797 | s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); |
| 3798 | logeventf(ssh, "Trying public key \"%s\"", |
| 3799 | filename_to_str(s->keyfile)); |
| 3800 | s->tried_publickey = 1; |
| 3801 | got_passphrase = FALSE; |
| 3802 | while (!got_passphrase) { |
| 3803 | /* |
| 3804 | * Get a passphrase, if necessary. |
| 3805 | */ |
| 3806 | char *passphrase = NULL; /* only written after crReturn */ |
| 3807 | const char *error; |
| 3808 | if (!s->publickey_encrypted) { |
| 3809 | if (flags & FLAG_VERBOSE) |
| 3810 | c_write_str(ssh, "No passphrase required.\r\n"); |
| 3811 | passphrase = NULL; |
| 3812 | } else { |
| 3813 | int ret; /* need not be kept over crReturn */ |
| 3814 | s->cur_prompt = new_prompts(ssh->frontend); |
| 3815 | s->cur_prompt->to_server = FALSE; |
| 3816 | s->cur_prompt->name = dupstr("SSH key passphrase"); |
| 3817 | add_prompt(s->cur_prompt, |
| 3818 | dupprintf("Passphrase for key \"%.100s\": ", |
| 3819 | s->publickey_comment), FALSE); |
| 3820 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 3821 | while (ret < 0) { |
| 3822 | ssh->send_ok = 1; |
| 3823 | crWaitUntil(!pktin); |
| 3824 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 3825 | ssh->send_ok = 0; |
| 3826 | } |
| 3827 | if (!ret) { |
| 3828 | /* Failed to get a passphrase. Terminate. */ |
| 3829 | free_prompts(s->cur_prompt); |
| 3830 | ssh_disconnect(ssh, NULL, "Unable to authenticate", |
| 3831 | 0, TRUE); |
| 3832 | crStop(0); |
| 3833 | } |
| 3834 | passphrase = dupstr(s->cur_prompt->prompts[0]->result); |
| 3835 | free_prompts(s->cur_prompt); |
| 3836 | } |
| 3837 | /* |
| 3838 | * Try decrypting key with passphrase. |
| 3839 | */ |
| 3840 | s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); |
| 3841 | ret = loadrsakey(s->keyfile, &s->key, passphrase, |
| 3842 | &error); |
| 3843 | if (passphrase) { |
| 3844 | memset(passphrase, 0, strlen(passphrase)); |
| 3845 | sfree(passphrase); |
| 3846 | } |
| 3847 | if (ret == 1) { |
| 3848 | /* Correct passphrase. */ |
| 3849 | got_passphrase = TRUE; |
| 3850 | } else if (ret == 0) { |
| 3851 | c_write_str(ssh, "Couldn't load private key from "); |
| 3852 | c_write_str(ssh, filename_to_str(s->keyfile)); |
| 3853 | c_write_str(ssh, " ("); |
| 3854 | c_write_str(ssh, error); |
| 3855 | c_write_str(ssh, ").\r\n"); |
| 3856 | got_passphrase = FALSE; |
| 3857 | break; /* go and try something else */ |
| 3858 | } else if (ret == -1) { |
| 3859 | c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */ |
| 3860 | got_passphrase = FALSE; |
| 3861 | /* and try again */ |
| 3862 | } else { |
| 3863 | assert(0 && "unexpected return from loadrsakey()"); |
| 3864 | got_passphrase = FALSE; /* placate optimisers */ |
| 3865 | } |
| 3866 | } |
| 3867 | |
| 3868 | if (got_passphrase) { |
| 3869 | |
| 3870 | /* |
| 3871 | * Send a public key attempt. |
| 3872 | */ |
| 3873 | send_packet(ssh, SSH1_CMSG_AUTH_RSA, |
| 3874 | PKT_BIGNUM, s->key.modulus, PKT_END); |
| 3875 | |
| 3876 | crWaitUntil(pktin); |
| 3877 | if (pktin->type == SSH1_SMSG_FAILURE) { |
| 3878 | c_write_str(ssh, "Server refused our public key.\r\n"); |
| 3879 | continue; /* go and try something else */ |
| 3880 | } |
| 3881 | if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 3882 | bombout(("Bizarre response to offer of public key")); |
| 3883 | crStop(0); |
| 3884 | } |
| 3885 | |
| 3886 | { |
| 3887 | int i; |
| 3888 | unsigned char buffer[32]; |
| 3889 | Bignum challenge, response; |
| 3890 | |
| 3891 | if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) { |
| 3892 | bombout(("Server's RSA challenge was badly formatted")); |
| 3893 | crStop(0); |
| 3894 | } |
| 3895 | response = rsadecrypt(challenge, &s->key); |
| 3896 | freebn(s->key.private_exponent);/* burn the evidence */ |
| 3897 | |
| 3898 | for (i = 0; i < 32; i++) { |
| 3899 | buffer[i] = bignum_byte(response, 31 - i); |
| 3900 | } |
| 3901 | |
| 3902 | MD5Init(&md5c); |
| 3903 | MD5Update(&md5c, buffer, 32); |
| 3904 | MD5Update(&md5c, s->session_id, 16); |
| 3905 | MD5Final(buffer, &md5c); |
| 3906 | |
| 3907 | send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 3908 | PKT_DATA, buffer, 16, PKT_END); |
| 3909 | |
| 3910 | freebn(challenge); |
| 3911 | freebn(response); |
| 3912 | } |
| 3913 | |
| 3914 | crWaitUntil(pktin); |
| 3915 | if (pktin->type == SSH1_SMSG_FAILURE) { |
| 3916 | if (flags & FLAG_VERBOSE) |
| 3917 | c_write_str(ssh, "Failed to authenticate with" |
| 3918 | " our public key.\r\n"); |
| 3919 | continue; /* go and try something else */ |
| 3920 | } else if (pktin->type != SSH1_SMSG_SUCCESS) { |
| 3921 | bombout(("Bizarre response to RSA authentication response")); |
| 3922 | crStop(0); |
| 3923 | } |
| 3924 | |
| 3925 | break; /* we're through! */ |
| 3926 | } |
| 3927 | |
| 3928 | } |
| 3929 | |
| 3930 | /* |
| 3931 | * Otherwise, try various forms of password-like authentication. |
| 3932 | */ |
| 3933 | s->cur_prompt = new_prompts(ssh->frontend); |
| 3934 | |
| 3935 | if (conf_get_int(ssh->conf, CONF_try_tis_auth) && |
| 3936 | (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) && |
| 3937 | !s->tis_auth_refused) { |
| 3938 | s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 3939 | logevent("Requested TIS authentication"); |
| 3940 | send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END); |
| 3941 | crWaitUntil(pktin); |
| 3942 | if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 3943 | logevent("TIS authentication declined"); |
| 3944 | if (flags & FLAG_INTERACTIVE) |
| 3945 | c_write_str(ssh, "TIS authentication refused.\r\n"); |
| 3946 | s->tis_auth_refused = 1; |
| 3947 | continue; |
| 3948 | } else { |
| 3949 | char *challenge; |
| 3950 | int challengelen; |
| 3951 | char *instr_suf, *prompt; |
| 3952 | |
| 3953 | ssh_pkt_getstring(pktin, &challenge, &challengelen); |
| 3954 | if (!challenge) { |
| 3955 | bombout(("TIS challenge packet was badly formed")); |
| 3956 | crStop(0); |
| 3957 | } |
| 3958 | logevent("Received TIS challenge"); |
| 3959 | s->cur_prompt->to_server = TRUE; |
| 3960 | s->cur_prompt->name = dupstr("SSH TIS authentication"); |
| 3961 | /* Prompt heuristic comes from OpenSSH */ |
| 3962 | if (memchr(challenge, '\n', challengelen)) { |
| 3963 | instr_suf = dupstr(""); |
| 3964 | prompt = dupprintf("%.*s", challengelen, challenge); |
| 3965 | } else { |
| 3966 | instr_suf = dupprintf("%.*s", challengelen, challenge); |
| 3967 | prompt = dupstr("Response: "); |
| 3968 | } |
| 3969 | s->cur_prompt->instruction = |
| 3970 | dupprintf("Using TIS authentication.%s%s", |
| 3971 | (*instr_suf) ? "\n" : "", |
| 3972 | instr_suf); |
| 3973 | s->cur_prompt->instr_reqd = TRUE; |
| 3974 | add_prompt(s->cur_prompt, prompt, FALSE); |
| 3975 | sfree(instr_suf); |
| 3976 | } |
| 3977 | } |
| 3978 | if (conf_get_int(ssh->conf, CONF_try_tis_auth) && |
| 3979 | (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && |
| 3980 | !s->ccard_auth_refused) { |
| 3981 | s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
| 3982 | logevent("Requested CryptoCard authentication"); |
| 3983 | send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END); |
| 3984 | crWaitUntil(pktin); |
| 3985 | if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 3986 | logevent("CryptoCard authentication declined"); |
| 3987 | c_write_str(ssh, "CryptoCard authentication refused.\r\n"); |
| 3988 | s->ccard_auth_refused = 1; |
| 3989 | continue; |
| 3990 | } else { |
| 3991 | char *challenge; |
| 3992 | int challengelen; |
| 3993 | char *instr_suf, *prompt; |
| 3994 | |
| 3995 | ssh_pkt_getstring(pktin, &challenge, &challengelen); |
| 3996 | if (!challenge) { |
| 3997 | bombout(("CryptoCard challenge packet was badly formed")); |
| 3998 | crStop(0); |
| 3999 | } |
| 4000 | logevent("Received CryptoCard challenge"); |
| 4001 | s->cur_prompt->to_server = TRUE; |
| 4002 | s->cur_prompt->name = dupstr("SSH CryptoCard authentication"); |
| 4003 | s->cur_prompt->name_reqd = FALSE; |
| 4004 | /* Prompt heuristic comes from OpenSSH */ |
| 4005 | if (memchr(challenge, '\n', challengelen)) { |
| 4006 | instr_suf = dupstr(""); |
| 4007 | prompt = dupprintf("%.*s", challengelen, challenge); |
| 4008 | } else { |
| 4009 | instr_suf = dupprintf("%.*s", challengelen, challenge); |
| 4010 | prompt = dupstr("Response: "); |
| 4011 | } |
| 4012 | s->cur_prompt->instruction = |
| 4013 | dupprintf("Using CryptoCard authentication.%s%s", |
| 4014 | (*instr_suf) ? "\n" : "", |
| 4015 | instr_suf); |
| 4016 | s->cur_prompt->instr_reqd = TRUE; |
| 4017 | add_prompt(s->cur_prompt, prompt, FALSE); |
| 4018 | sfree(instr_suf); |
| 4019 | } |
| 4020 | } |
| 4021 | if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 4022 | if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) { |
| 4023 | bombout(("No supported authentication methods available")); |
| 4024 | crStop(0); |
| 4025 | } |
| 4026 | s->cur_prompt->to_server = TRUE; |
| 4027 | s->cur_prompt->name = dupstr("SSH password"); |
| 4028 | add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", |
| 4029 | ssh->username, ssh->savedhost), |
| 4030 | FALSE); |
| 4031 | } |
| 4032 | |
| 4033 | /* |
| 4034 | * Show password prompt, having first obtained it via a TIS |
| 4035 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
| 4036 | * authentication. |
| 4037 | */ |
| 4038 | { |
| 4039 | int ret; /* need not be kept over crReturn */ |
| 4040 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 4041 | while (ret < 0) { |
| 4042 | ssh->send_ok = 1; |
| 4043 | crWaitUntil(!pktin); |
| 4044 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 4045 | ssh->send_ok = 0; |
| 4046 | } |
| 4047 | if (!ret) { |
| 4048 | /* |
| 4049 | * Failed to get a password (for example |
| 4050 | * because one was supplied on the command line |
| 4051 | * which has already failed to work). Terminate. |
| 4052 | */ |
| 4053 | free_prompts(s->cur_prompt); |
| 4054 | ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE); |
| 4055 | crStop(0); |
| 4056 | } |
| 4057 | } |
| 4058 | |
| 4059 | if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 4060 | /* |
| 4061 | * Defence against traffic analysis: we send a |
| 4062 | * whole bunch of packets containing strings of |
| 4063 | * different lengths. One of these strings is the |
| 4064 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
| 4065 | * The others are all random data in |
| 4066 | * SSH1_MSG_IGNORE packets. This way a passive |
| 4067 | * listener can't tell which is the password, and |
| 4068 | * hence can't deduce the password length. |
| 4069 | * |
| 4070 | * Anybody with a password length greater than 16 |
| 4071 | * bytes is going to have enough entropy in their |
| 4072 | * password that a listener won't find it _that_ |
| 4073 | * much help to know how long it is. So what we'll |
| 4074 | * do is: |
| 4075 | * |
| 4076 | * - if password length < 16, we send 15 packets |
| 4077 | * containing string lengths 1 through 15 |
| 4078 | * |
| 4079 | * - otherwise, we let N be the nearest multiple |
| 4080 | * of 8 below the password length, and send 8 |
| 4081 | * packets containing string lengths N through |
| 4082 | * N+7. This won't obscure the order of |
| 4083 | * magnitude of the password length, but it will |
| 4084 | * introduce a bit of extra uncertainty. |
| 4085 | * |
| 4086 | * A few servers can't deal with SSH1_MSG_IGNORE, at |
| 4087 | * least in this context. For these servers, we need |
| 4088 | * an alternative defence. We make use of the fact |
| 4089 | * that the password is interpreted as a C string: |
| 4090 | * so we can append a NUL, then some random data. |
| 4091 | * |
| 4092 | * A few servers can deal with neither SSH1_MSG_IGNORE |
| 4093 | * here _nor_ a padded password string. |
| 4094 | * For these servers we are left with no defences |
| 4095 | * against password length sniffing. |
| 4096 | */ |
| 4097 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) && |
| 4098 | !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { |
| 4099 | /* |
| 4100 | * The server can deal with SSH1_MSG_IGNORE, so |
| 4101 | * we can use the primary defence. |
| 4102 | */ |
| 4103 | int bottom, top, pwlen, i; |
| 4104 | char *randomstr; |
| 4105 | |
| 4106 | pwlen = strlen(s->cur_prompt->prompts[0]->result); |
| 4107 | if (pwlen < 16) { |
| 4108 | bottom = 0; /* zero length passwords are OK! :-) */ |
| 4109 | top = 15; |
| 4110 | } else { |
| 4111 | bottom = pwlen & ~7; |
| 4112 | top = bottom + 7; |
| 4113 | } |
| 4114 | |
| 4115 | assert(pwlen >= bottom && pwlen <= top); |
| 4116 | |
| 4117 | randomstr = snewn(top + 1, char); |
| 4118 | |
| 4119 | for (i = bottom; i <= top; i++) { |
| 4120 | if (i == pwlen) { |
| 4121 | defer_packet(ssh, s->pwpkt_type, |
| 4122 | PKTT_PASSWORD, PKT_STR, |
| 4123 | s->cur_prompt->prompts[0]->result, |
| 4124 | PKTT_OTHER, PKT_END); |
| 4125 | } else { |
| 4126 | for (j = 0; j < i; j++) { |
| 4127 | do { |
| 4128 | randomstr[j] = random_byte(); |
| 4129 | } while (randomstr[j] == '\0'); |
| 4130 | } |
| 4131 | randomstr[i] = '\0'; |
| 4132 | defer_packet(ssh, SSH1_MSG_IGNORE, |
| 4133 | PKT_STR, randomstr, PKT_END); |
| 4134 | } |
| 4135 | } |
| 4136 | logevent("Sending password with camouflage packets"); |
| 4137 | ssh_pkt_defersend(ssh); |
| 4138 | sfree(randomstr); |
| 4139 | } |
| 4140 | else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { |
| 4141 | /* |
| 4142 | * The server can't deal with SSH1_MSG_IGNORE |
| 4143 | * but can deal with padded passwords, so we |
| 4144 | * can use the secondary defence. |
| 4145 | */ |
| 4146 | char string[64]; |
| 4147 | char *ss; |
| 4148 | int len; |
| 4149 | |
| 4150 | len = strlen(s->cur_prompt->prompts[0]->result); |
| 4151 | if (len < sizeof(string)) { |
| 4152 | ss = string; |
| 4153 | strcpy(string, s->cur_prompt->prompts[0]->result); |
| 4154 | len++; /* cover the zero byte */ |
| 4155 | while (len < sizeof(string)) { |
| 4156 | string[len++] = (char) random_byte(); |
| 4157 | } |
| 4158 | } else { |
| 4159 | ss = s->cur_prompt->prompts[0]->result; |
| 4160 | } |
| 4161 | logevent("Sending length-padded password"); |
| 4162 | send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, |
| 4163 | PKT_INT, len, PKT_DATA, ss, len, |
| 4164 | PKTT_OTHER, PKT_END); |
| 4165 | } else { |
| 4166 | /* |
| 4167 | * The server is believed unable to cope with |
| 4168 | * any of our password camouflage methods. |
| 4169 | */ |
| 4170 | int len; |
| 4171 | len = strlen(s->cur_prompt->prompts[0]->result); |
| 4172 | logevent("Sending unpadded password"); |
| 4173 | send_packet(ssh, s->pwpkt_type, |
| 4174 | PKTT_PASSWORD, PKT_INT, len, |
| 4175 | PKT_DATA, s->cur_prompt->prompts[0]->result, len, |
| 4176 | PKTT_OTHER, PKT_END); |
| 4177 | } |
| 4178 | } else { |
| 4179 | send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, |
| 4180 | PKT_STR, s->cur_prompt->prompts[0]->result, |
| 4181 | PKTT_OTHER, PKT_END); |
| 4182 | } |
| 4183 | logevent("Sent password"); |
| 4184 | free_prompts(s->cur_prompt); |
| 4185 | crWaitUntil(pktin); |
| 4186 | if (pktin->type == SSH1_SMSG_FAILURE) { |
| 4187 | if (flags & FLAG_VERBOSE) |
| 4188 | c_write_str(ssh, "Access denied\r\n"); |
| 4189 | logevent("Authentication refused"); |
| 4190 | } else if (pktin->type != SSH1_SMSG_SUCCESS) { |
| 4191 | bombout(("Strange packet received, type %d", pktin->type)); |
| 4192 | crStop(0); |
| 4193 | } |
| 4194 | } |
| 4195 | |
| 4196 | /* Clear up */ |
| 4197 | if (s->publickey_blob) { |
| 4198 | sfree(s->publickey_blob); |
| 4199 | sfree(s->publickey_comment); |
| 4200 | } |
| 4201 | |
| 4202 | logevent("Authentication successful"); |
| 4203 | |
| 4204 | crFinish(1); |
| 4205 | } |
| 4206 | |
| 4207 | static void ssh_channel_try_eof(struct ssh_channel *c) |
| 4208 | { |
| 4209 | Ssh ssh = c->ssh; |
| 4210 | assert(c->pending_eof); /* precondition for calling us */ |
| 4211 | if (c->halfopen) |
| 4212 | return; /* can't close: not even opened yet */ |
| 4213 | if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0) |
| 4214 | return; /* can't send EOF: pending outgoing data */ |
| 4215 | |
| 4216 | if (ssh->version == 1) { |
| 4217 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
| 4218 | PKT_END); |
| 4219 | c->closes |= CLOSES_SENT_EOF; |
| 4220 | } else { |
| 4221 | struct Packet *pktout; |
| 4222 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
| 4223 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 4224 | ssh2_pkt_send(ssh, pktout); |
| 4225 | c->closes |= CLOSES_SENT_EOF; |
| 4226 | if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes)) { |
| 4227 | /* |
| 4228 | * Also send MSG_CLOSE. |
| 4229 | */ |
| 4230 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 4231 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 4232 | ssh2_pkt_send(ssh, pktout); |
| 4233 | c->closes |= CLOSES_SENT_CLOSE; |
| 4234 | } |
| 4235 | } |
| 4236 | c->pending_eof = FALSE; /* we've sent it now */ |
| 4237 | } |
| 4238 | |
| 4239 | void sshfwd_write_eof(struct ssh_channel *c) |
| 4240 | { |
| 4241 | Ssh ssh = c->ssh; |
| 4242 | |
| 4243 | if (ssh->state == SSH_STATE_CLOSED) |
| 4244 | return; |
| 4245 | |
| 4246 | if (c->closes & CLOSES_SENT_EOF) |
| 4247 | return; |
| 4248 | |
| 4249 | c->pending_eof = TRUE; |
| 4250 | ssh_channel_try_eof(c); |
| 4251 | } |
| 4252 | |
| 4253 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) |
| 4254 | { |
| 4255 | Ssh ssh = c->ssh; |
| 4256 | |
| 4257 | if (ssh->state == SSH_STATE_CLOSED) |
| 4258 | return 0; |
| 4259 | |
| 4260 | if (ssh->version == 1) { |
| 4261 | send_packet(ssh, SSH1_MSG_CHANNEL_DATA, |
| 4262 | PKT_INT, c->remoteid, |
| 4263 | PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len, |
| 4264 | PKTT_OTHER, PKT_END); |
| 4265 | /* |
| 4266 | * In SSH-1 we can return 0 here - implying that forwarded |
| 4267 | * connections are never individually throttled - because |
| 4268 | * the only circumstance that can cause throttling will be |
| 4269 | * the whole SSH connection backing up, in which case |
| 4270 | * _everything_ will be throttled as a whole. |
| 4271 | */ |
| 4272 | return 0; |
| 4273 | } else { |
| 4274 | ssh2_add_channel_data(c, buf, len); |
| 4275 | return ssh2_try_send(c); |
| 4276 | } |
| 4277 | } |
| 4278 | |
| 4279 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) |
| 4280 | { |
| 4281 | Ssh ssh = c->ssh; |
| 4282 | int buflimit; |
| 4283 | |
| 4284 | if (ssh->state == SSH_STATE_CLOSED) |
| 4285 | return; |
| 4286 | |
| 4287 | if (ssh->version == 1) { |
| 4288 | buflimit = SSH1_BUFFER_LIMIT; |
| 4289 | } else { |
| 4290 | buflimit = c->v.v2.locmaxwin; |
| 4291 | ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0); |
| 4292 | } |
| 4293 | if (c->throttling_conn && bufsize <= buflimit) { |
| 4294 | c->throttling_conn = 0; |
| 4295 | ssh_throttle_conn(ssh, -1); |
| 4296 | } |
| 4297 | } |
| 4298 | |
| 4299 | static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) |
| 4300 | { |
| 4301 | struct queued_handler *qh = ssh->qhead; |
| 4302 | |
| 4303 | assert(qh != NULL); |
| 4304 | |
| 4305 | assert(pktin->type == qh->msg1 || pktin->type == qh->msg2); |
| 4306 | |
| 4307 | if (qh->msg1 > 0) { |
| 4308 | assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler); |
| 4309 | ssh->packet_dispatch[qh->msg1] = NULL; |
| 4310 | } |
| 4311 | if (qh->msg2 > 0) { |
| 4312 | assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler); |
| 4313 | ssh->packet_dispatch[qh->msg2] = NULL; |
| 4314 | } |
| 4315 | |
| 4316 | if (qh->next) { |
| 4317 | ssh->qhead = qh->next; |
| 4318 | |
| 4319 | if (ssh->qhead->msg1 > 0) { |
| 4320 | assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL); |
| 4321 | ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler; |
| 4322 | } |
| 4323 | if (ssh->qhead->msg2 > 0) { |
| 4324 | assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL); |
| 4325 | ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler; |
| 4326 | } |
| 4327 | } else { |
| 4328 | ssh->qhead = ssh->qtail = NULL; |
| 4329 | ssh->packet_dispatch[pktin->type] = NULL; |
| 4330 | } |
| 4331 | |
| 4332 | qh->handler(ssh, pktin, qh->ctx); |
| 4333 | |
| 4334 | sfree(qh); |
| 4335 | } |
| 4336 | |
| 4337 | static void ssh_queue_handler(Ssh ssh, int msg1, int msg2, |
| 4338 | chandler_fn_t handler, void *ctx) |
| 4339 | { |
| 4340 | struct queued_handler *qh; |
| 4341 | |
| 4342 | qh = snew(struct queued_handler); |
| 4343 | qh->msg1 = msg1; |
| 4344 | qh->msg2 = msg2; |
| 4345 | qh->handler = handler; |
| 4346 | qh->ctx = ctx; |
| 4347 | qh->next = NULL; |
| 4348 | |
| 4349 | if (ssh->qtail == NULL) { |
| 4350 | ssh->qhead = qh; |
| 4351 | |
| 4352 | if (qh->msg1 > 0) { |
| 4353 | assert(ssh->packet_dispatch[qh->msg1] == NULL); |
| 4354 | ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler; |
| 4355 | } |
| 4356 | if (qh->msg2 > 0) { |
| 4357 | assert(ssh->packet_dispatch[qh->msg2] == NULL); |
| 4358 | ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler; |
| 4359 | } |
| 4360 | } else { |
| 4361 | ssh->qtail->next = qh; |
| 4362 | } |
| 4363 | ssh->qtail = qh; |
| 4364 | } |
| 4365 | |
| 4366 | static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) |
| 4367 | { |
| 4368 | struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx; |
| 4369 | |
| 4370 | if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS : |
| 4371 | SSH2_MSG_REQUEST_SUCCESS)) { |
| 4372 | logeventf(ssh, "Remote port forwarding from %s enabled", |
| 4373 | pf->sportdesc); |
| 4374 | } else { |
| 4375 | logeventf(ssh, "Remote port forwarding from %s refused", |
| 4376 | pf->sportdesc); |
| 4377 | |
| 4378 | rpf = del234(ssh->rportfwds, pf); |
| 4379 | assert(rpf == pf); |
| 4380 | pf->pfrec->remote = NULL; |
| 4381 | free_rportfwd(pf); |
| 4382 | } |
| 4383 | } |
| 4384 | |
| 4385 | static void ssh_setup_portfwd(Ssh ssh, Conf *conf) |
| 4386 | { |
| 4387 | struct ssh_portfwd *epf; |
| 4388 | int i; |
| 4389 | char *key, *val; |
| 4390 | |
| 4391 | if (!ssh->portfwds) { |
| 4392 | ssh->portfwds = newtree234(ssh_portcmp); |
| 4393 | } else { |
| 4394 | /* |
| 4395 | * Go through the existing port forwardings and tag them |
| 4396 | * with status==DESTROY. Any that we want to keep will be |
| 4397 | * re-enabled (status==KEEP) as we go through the |
| 4398 | * configuration and find out which bits are the same as |
| 4399 | * they were before. |
| 4400 | */ |
| 4401 | struct ssh_portfwd *epf; |
| 4402 | int i; |
| 4403 | for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) |
| 4404 | epf->status = DESTROY; |
| 4405 | } |
| 4406 | |
| 4407 | for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key); |
| 4408 | val != NULL; |
| 4409 | val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) { |
| 4410 | char *kp, *kp2, *vp, *vp2; |
| 4411 | char address_family, type; |
| 4412 | int sport,dport,sserv,dserv; |
| 4413 | char *sports, *dports, *saddr, *host; |
| 4414 | |
| 4415 | kp = key; |
| 4416 | |
| 4417 | address_family = 'A'; |
| 4418 | type = 'L'; |
| 4419 | if (*kp == 'A' || *kp == '4' || *kp == '6') |
| 4420 | address_family = *kp++; |
| 4421 | if (*kp == 'L' || *kp == 'R') |
| 4422 | type = *kp++; |
| 4423 | |
| 4424 | if ((kp2 = strchr(kp, ':')) != NULL) { |
| 4425 | /* |
| 4426 | * There's a colon in the middle of the source port |
| 4427 | * string, which means that the part before it is |
| 4428 | * actually a source address. |
| 4429 | */ |
| 4430 | saddr = dupprintf("%.*s", (int)(kp2 - kp), kp); |
| 4431 | sports = kp2+1; |
| 4432 | } else { |
| 4433 | saddr = NULL; |
| 4434 | sports = kp; |
| 4435 | } |
| 4436 | sport = atoi(sports); |
| 4437 | sserv = 0; |
| 4438 | if (sport == 0) { |
| 4439 | sserv = 1; |
| 4440 | sport = net_service_lookup(sports); |
| 4441 | if (!sport) { |
| 4442 | logeventf(ssh, "Service lookup failed for source" |
| 4443 | " port \"%s\"", sports); |
| 4444 | } |
| 4445 | } |
| 4446 | |
| 4447 | if (type == 'L' && !strcmp(val, "D")) { |
| 4448 | /* dynamic forwarding */ |
| 4449 | host = NULL; |
| 4450 | dports = NULL; |
| 4451 | dport = -1; |
| 4452 | dserv = 0; |
| 4453 | type = 'D'; |
| 4454 | } else { |
| 4455 | /* ordinary forwarding */ |
| 4456 | vp = val; |
| 4457 | vp2 = vp + strcspn(vp, ":"); |
| 4458 | host = dupprintf("%.*s", (int)(vp2 - vp), vp); |
| 4459 | if (vp2) |
| 4460 | vp2++; |
| 4461 | dports = vp2; |
| 4462 | dport = atoi(dports); |
| 4463 | dserv = 0; |
| 4464 | if (dport == 0) { |
| 4465 | dserv = 1; |
| 4466 | dport = net_service_lookup(dports); |
| 4467 | if (!dport) { |
| 4468 | logeventf(ssh, "Service lookup failed for destination" |
| 4469 | " port \"%s\"", dports); |
| 4470 | } |
| 4471 | } |
| 4472 | } |
| 4473 | |
| 4474 | if (sport && dport) { |
| 4475 | /* Set up a description of the source port. */ |
| 4476 | struct ssh_portfwd *pfrec, *epfrec; |
| 4477 | |
| 4478 | pfrec = snew(struct ssh_portfwd); |
| 4479 | pfrec->type = type; |
| 4480 | pfrec->saddr = saddr; |
| 4481 | pfrec->sserv = sserv ? dupstr(sports) : NULL; |
| 4482 | pfrec->sport = sport; |
| 4483 | pfrec->daddr = host; |
| 4484 | pfrec->dserv = dserv ? dupstr(dports) : NULL; |
| 4485 | pfrec->dport = dport; |
| 4486 | pfrec->local = NULL; |
| 4487 | pfrec->remote = NULL; |
| 4488 | pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 : |
| 4489 | address_family == '6' ? ADDRTYPE_IPV6 : |
| 4490 | ADDRTYPE_UNSPEC); |
| 4491 | |
| 4492 | epfrec = add234(ssh->portfwds, pfrec); |
| 4493 | if (epfrec != pfrec) { |
| 4494 | if (epfrec->status == DESTROY) { |
| 4495 | /* |
| 4496 | * We already have a port forwarding up and running |
| 4497 | * with precisely these parameters. Hence, no need |
| 4498 | * to do anything; simply re-tag the existing one |
| 4499 | * as KEEP. |
| 4500 | */ |
| 4501 | epfrec->status = KEEP; |
| 4502 | } |
| 4503 | /* |
| 4504 | * Anything else indicates that there was a duplicate |
| 4505 | * in our input, which we'll silently ignore. |
| 4506 | */ |
| 4507 | free_portfwd(pfrec); |
| 4508 | } else { |
| 4509 | pfrec->status = CREATE; |
| 4510 | } |
| 4511 | } else { |
| 4512 | sfree(saddr); |
| 4513 | sfree(host); |
| 4514 | } |
| 4515 | } |
| 4516 | |
| 4517 | /* |
| 4518 | * Now go through and destroy any port forwardings which were |
| 4519 | * not re-enabled. |
| 4520 | */ |
| 4521 | for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) |
| 4522 | if (epf->status == DESTROY) { |
| 4523 | char *message; |
| 4524 | |
| 4525 | message = dupprintf("%s port forwarding from %s%s%d", |
| 4526 | epf->type == 'L' ? "local" : |
| 4527 | epf->type == 'R' ? "remote" : "dynamic", |
| 4528 | epf->saddr ? epf->saddr : "", |
| 4529 | epf->saddr ? ":" : "", |
| 4530 | epf->sport); |
| 4531 | |
| 4532 | if (epf->type != 'D') { |
| 4533 | char *msg2 = dupprintf("%s to %s:%d", message, |
| 4534 | epf->daddr, epf->dport); |
| 4535 | sfree(message); |
| 4536 | message = msg2; |
| 4537 | } |
| 4538 | |
| 4539 | logeventf(ssh, "Cancelling %s", message); |
| 4540 | sfree(message); |
| 4541 | |
| 4542 | /* epf->remote or epf->local may be NULL if setting up a |
| 4543 | * forwarding failed. */ |
| 4544 | if (epf->remote) { |
| 4545 | struct ssh_rportfwd *rpf = epf->remote; |
| 4546 | struct Packet *pktout; |
| 4547 | |
| 4548 | /* |
| 4549 | * Cancel the port forwarding at the server |
| 4550 | * end. |
| 4551 | */ |
| 4552 | if (ssh->version == 1) { |
| 4553 | /* |
| 4554 | * We cannot cancel listening ports on the |
| 4555 | * server side in SSH-1! There's no message |
| 4556 | * to support it. Instead, we simply remove |
| 4557 | * the rportfwd record from the local end |
| 4558 | * so that any connections the server tries |
| 4559 | * to make on it are rejected. |
| 4560 | */ |
| 4561 | } else { |
| 4562 | pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); |
| 4563 | ssh2_pkt_addstring(pktout, "cancel-tcpip-forward"); |
| 4564 | ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */ |
| 4565 | if (epf->saddr) { |
| 4566 | ssh2_pkt_addstring(pktout, epf->saddr); |
| 4567 | } else if (conf_get_int(conf, CONF_rport_acceptall)) { |
| 4568 | /* XXX: rport_acceptall may not represent |
| 4569 | * what was used to open the original connection, |
| 4570 | * since it's reconfigurable. */ |
| 4571 | ssh2_pkt_addstring(pktout, "0.0.0.0"); |
| 4572 | } else { |
| 4573 | ssh2_pkt_addstring(pktout, "127.0.0.1"); |
| 4574 | } |
| 4575 | ssh2_pkt_adduint32(pktout, epf->sport); |
| 4576 | ssh2_pkt_send(ssh, pktout); |
| 4577 | } |
| 4578 | |
| 4579 | del234(ssh->rportfwds, rpf); |
| 4580 | free_rportfwd(rpf); |
| 4581 | } else if (epf->local) { |
| 4582 | pfd_terminate(epf->local); |
| 4583 | } |
| 4584 | |
| 4585 | delpos234(ssh->portfwds, i); |
| 4586 | free_portfwd(epf); |
| 4587 | i--; /* so we don't skip one in the list */ |
| 4588 | } |
| 4589 | |
| 4590 | /* |
| 4591 | * And finally, set up any new port forwardings (status==CREATE). |
| 4592 | */ |
| 4593 | for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) |
| 4594 | if (epf->status == CREATE) { |
| 4595 | char *sportdesc, *dportdesc; |
| 4596 | sportdesc = dupprintf("%s%s%s%s%d%s", |
| 4597 | epf->saddr ? epf->saddr : "", |
| 4598 | epf->saddr ? ":" : "", |
| 4599 | epf->sserv ? epf->sserv : "", |
| 4600 | epf->sserv ? "(" : "", |
| 4601 | epf->sport, |
| 4602 | epf->sserv ? ")" : ""); |
| 4603 | if (epf->type == 'D') { |
| 4604 | dportdesc = NULL; |
| 4605 | } else { |
| 4606 | dportdesc = dupprintf("%s:%s%s%d%s", |
| 4607 | epf->daddr, |
| 4608 | epf->dserv ? epf->dserv : "", |
| 4609 | epf->dserv ? "(" : "", |
| 4610 | epf->dport, |
| 4611 | epf->dserv ? ")" : ""); |
| 4612 | } |
| 4613 | |
| 4614 | if (epf->type == 'L') { |
| 4615 | const char *err = pfd_addforward(epf->daddr, epf->dport, |
| 4616 | epf->saddr, epf->sport, |
| 4617 | ssh, conf, |
| 4618 | &epf->local, |
| 4619 | epf->addressfamily); |
| 4620 | |
| 4621 | logeventf(ssh, "Local %sport %s forwarding to %s%s%s", |
| 4622 | epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : |
| 4623 | epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", |
| 4624 | sportdesc, dportdesc, |
| 4625 | err ? " failed: " : "", err ? err : ""); |
| 4626 | } else if (epf->type == 'D') { |
| 4627 | const char *err = pfd_addforward(NULL, -1, |
| 4628 | epf->saddr, epf->sport, |
| 4629 | ssh, conf, |
| 4630 | &epf->local, |
| 4631 | epf->addressfamily); |
| 4632 | |
| 4633 | logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s", |
| 4634 | epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : |
| 4635 | epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", |
| 4636 | sportdesc, |
| 4637 | err ? " failed: " : "", err ? err : ""); |
| 4638 | } else { |
| 4639 | struct ssh_rportfwd *pf; |
| 4640 | |
| 4641 | /* |
| 4642 | * Ensure the remote port forwardings tree exists. |
| 4643 | */ |
| 4644 | if (!ssh->rportfwds) { |
| 4645 | if (ssh->version == 1) |
| 4646 | ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); |
| 4647 | else |
| 4648 | ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); |
| 4649 | } |
| 4650 | |
| 4651 | pf = snew(struct ssh_rportfwd); |
| 4652 | strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1); |
| 4653 | pf->dhost[lenof(pf->dhost)-1] = '\0'; |
| 4654 | pf->dport = epf->dport; |
| 4655 | pf->sport = epf->sport; |
| 4656 | if (add234(ssh->rportfwds, pf) != pf) { |
| 4657 | logeventf(ssh, "Duplicate remote port forwarding to %s:%d", |
| 4658 | epf->daddr, epf->dport); |
| 4659 | sfree(pf); |
| 4660 | } else { |
| 4661 | logeventf(ssh, "Requesting remote port %s" |
| 4662 | " forward to %s", sportdesc, dportdesc); |
| 4663 | |
| 4664 | pf->sportdesc = sportdesc; |
| 4665 | sportdesc = NULL; |
| 4666 | epf->remote = pf; |
| 4667 | pf->pfrec = epf; |
| 4668 | |
| 4669 | if (ssh->version == 1) { |
| 4670 | send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, |
| 4671 | PKT_INT, epf->sport, |
| 4672 | PKT_STR, epf->daddr, |
| 4673 | PKT_INT, epf->dport, |
| 4674 | PKT_END); |
| 4675 | ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS, |
| 4676 | SSH1_SMSG_FAILURE, |
| 4677 | ssh_rportfwd_succfail, pf); |
| 4678 | } else { |
| 4679 | struct Packet *pktout; |
| 4680 | pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); |
| 4681 | ssh2_pkt_addstring(pktout, "tcpip-forward"); |
| 4682 | ssh2_pkt_addbool(pktout, 1);/* want reply */ |
| 4683 | if (epf->saddr) { |
| 4684 | ssh2_pkt_addstring(pktout, epf->saddr); |
| 4685 | } else if (conf_get_int(conf, CONF_rport_acceptall)) { |
| 4686 | ssh2_pkt_addstring(pktout, "0.0.0.0"); |
| 4687 | } else { |
| 4688 | ssh2_pkt_addstring(pktout, "127.0.0.1"); |
| 4689 | } |
| 4690 | ssh2_pkt_adduint32(pktout, epf->sport); |
| 4691 | ssh2_pkt_send(ssh, pktout); |
| 4692 | |
| 4693 | ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, |
| 4694 | SSH2_MSG_REQUEST_FAILURE, |
| 4695 | ssh_rportfwd_succfail, pf); |
| 4696 | } |
| 4697 | } |
| 4698 | } |
| 4699 | sfree(sportdesc); |
| 4700 | sfree(dportdesc); |
| 4701 | } |
| 4702 | } |
| 4703 | |
| 4704 | static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin) |
| 4705 | { |
| 4706 | char *string; |
| 4707 | int stringlen, bufsize; |
| 4708 | |
| 4709 | ssh_pkt_getstring(pktin, &string, &stringlen); |
| 4710 | if (string == NULL) { |
| 4711 | bombout(("Incoming terminal data packet was badly formed")); |
| 4712 | return; |
| 4713 | } |
| 4714 | |
| 4715 | bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA, |
| 4716 | string, stringlen); |
| 4717 | if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 4718 | ssh->v1_stdout_throttling = 1; |
| 4719 | ssh_throttle_conn(ssh, +1); |
| 4720 | } |
| 4721 | } |
| 4722 | |
| 4723 | static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) |
| 4724 | { |
| 4725 | /* Remote side is trying to open a channel to talk to our |
| 4726 | * X-Server. Give them back a local channel number. */ |
| 4727 | struct ssh_channel *c; |
| 4728 | int remoteid = ssh_pkt_getuint32(pktin); |
| 4729 | |
| 4730 | logevent("Received X11 connect request"); |
| 4731 | /* Refuse if X11 forwarding is disabled. */ |
| 4732 | if (!ssh->X11_fwd_enabled) { |
| 4733 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 4734 | PKT_INT, remoteid, PKT_END); |
| 4735 | logevent("Rejected X11 connect request"); |
| 4736 | } else { |
| 4737 | c = snew(struct ssh_channel); |
| 4738 | c->ssh = ssh; |
| 4739 | |
| 4740 | if (x11_init(&c->u.x11.s, ssh->x11disp, c, |
| 4741 | NULL, -1, ssh->conf) != NULL) { |
| 4742 | logevent("Opening X11 forward connection failed"); |
| 4743 | sfree(c); |
| 4744 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 4745 | PKT_INT, remoteid, PKT_END); |
| 4746 | } else { |
| 4747 | logevent |
| 4748 | ("Opening X11 forward connection succeeded"); |
| 4749 | c->remoteid = remoteid; |
| 4750 | c->halfopen = FALSE; |
| 4751 | c->localid = alloc_channel_id(ssh); |
| 4752 | c->closes = 0; |
| 4753 | c->pending_eof = FALSE; |
| 4754 | c->throttling_conn = 0; |
| 4755 | c->type = CHAN_X11; /* identify channel type */ |
| 4756 | add234(ssh->channels, c); |
| 4757 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 4758 | PKT_INT, c->remoteid, PKT_INT, |
| 4759 | c->localid, PKT_END); |
| 4760 | logevent("Opened X11 forward channel"); |
| 4761 | } |
| 4762 | } |
| 4763 | } |
| 4764 | |
| 4765 | static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) |
| 4766 | { |
| 4767 | /* Remote side is trying to open a channel to talk to our |
| 4768 | * agent. Give them back a local channel number. */ |
| 4769 | struct ssh_channel *c; |
| 4770 | int remoteid = ssh_pkt_getuint32(pktin); |
| 4771 | |
| 4772 | /* Refuse if agent forwarding is disabled. */ |
| 4773 | if (!ssh->agentfwd_enabled) { |
| 4774 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 4775 | PKT_INT, remoteid, PKT_END); |
| 4776 | } else { |
| 4777 | c = snew(struct ssh_channel); |
| 4778 | c->ssh = ssh; |
| 4779 | c->remoteid = remoteid; |
| 4780 | c->halfopen = FALSE; |
| 4781 | c->localid = alloc_channel_id(ssh); |
| 4782 | c->closes = 0; |
| 4783 | c->pending_eof = FALSE; |
| 4784 | c->throttling_conn = 0; |
| 4785 | c->type = CHAN_AGENT; /* identify channel type */ |
| 4786 | c->u.a.lensofar = 0; |
| 4787 | c->u.a.message = NULL; |
| 4788 | add234(ssh->channels, c); |
| 4789 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 4790 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 4791 | PKT_END); |
| 4792 | } |
| 4793 | } |
| 4794 | |
| 4795 | static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) |
| 4796 | { |
| 4797 | /* Remote side is trying to open a channel to talk to a |
| 4798 | * forwarded port. Give them back a local channel number. */ |
| 4799 | struct ssh_channel *c; |
| 4800 | struct ssh_rportfwd pf, *pfp; |
| 4801 | int remoteid; |
| 4802 | int hostsize, port; |
| 4803 | char *host; |
| 4804 | const char *e; |
| 4805 | c = snew(struct ssh_channel); |
| 4806 | c->ssh = ssh; |
| 4807 | |
| 4808 | remoteid = ssh_pkt_getuint32(pktin); |
| 4809 | ssh_pkt_getstring(pktin, &host, &hostsize); |
| 4810 | port = ssh_pkt_getuint32(pktin); |
| 4811 | |
| 4812 | if (hostsize >= lenof(pf.dhost)) |
| 4813 | hostsize = lenof(pf.dhost)-1; |
| 4814 | memcpy(pf.dhost, host, hostsize); |
| 4815 | pf.dhost[hostsize] = '\0'; |
| 4816 | pf.dport = port; |
| 4817 | pfp = find234(ssh->rportfwds, &pf, NULL); |
| 4818 | |
| 4819 | if (pfp == NULL) { |
| 4820 | logeventf(ssh, "Rejected remote port open request for %s:%d", |
| 4821 | pf.dhost, port); |
| 4822 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 4823 | PKT_INT, remoteid, PKT_END); |
| 4824 | } else { |
| 4825 | logeventf(ssh, "Received remote port open request for %s:%d", |
| 4826 | pf.dhost, port); |
| 4827 | e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port, |
| 4828 | c, ssh->conf, pfp->pfrec->addressfamily); |
| 4829 | if (e != NULL) { |
| 4830 | logeventf(ssh, "Port open failed: %s", e); |
| 4831 | sfree(c); |
| 4832 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 4833 | PKT_INT, remoteid, PKT_END); |
| 4834 | } else { |
| 4835 | c->remoteid = remoteid; |
| 4836 | c->halfopen = FALSE; |
| 4837 | c->localid = alloc_channel_id(ssh); |
| 4838 | c->closes = 0; |
| 4839 | c->pending_eof = FALSE; |
| 4840 | c->throttling_conn = 0; |
| 4841 | c->type = CHAN_SOCKDATA; /* identify channel type */ |
| 4842 | add234(ssh->channels, c); |
| 4843 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 4844 | PKT_INT, c->remoteid, PKT_INT, |
| 4845 | c->localid, PKT_END); |
| 4846 | logevent("Forwarded port opened successfully"); |
| 4847 | } |
| 4848 | } |
| 4849 | } |
| 4850 | |
| 4851 | static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) |
| 4852 | { |
| 4853 | unsigned int remoteid = ssh_pkt_getuint32(pktin); |
| 4854 | unsigned int localid = ssh_pkt_getuint32(pktin); |
| 4855 | struct ssh_channel *c; |
| 4856 | |
| 4857 | c = find234(ssh->channels, &remoteid, ssh_channelfind); |
| 4858 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 4859 | c->remoteid = localid; |
| 4860 | c->halfopen = FALSE; |
| 4861 | c->type = CHAN_SOCKDATA; |
| 4862 | c->throttling_conn = 0; |
| 4863 | pfd_confirm(c->u.pfd.s); |
| 4864 | } |
| 4865 | |
| 4866 | if (c && c->pending_eof) { |
| 4867 | /* |
| 4868 | * We have a pending close on this channel, |
| 4869 | * which we decided on before the server acked |
| 4870 | * the channel open. So now we know the |
| 4871 | * remoteid, we can close it again. |
| 4872 | */ |
| 4873 | ssh_channel_try_eof(c); |
| 4874 | } |
| 4875 | } |
| 4876 | |
| 4877 | static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) |
| 4878 | { |
| 4879 | unsigned int remoteid = ssh_pkt_getuint32(pktin); |
| 4880 | struct ssh_channel *c; |
| 4881 | |
| 4882 | c = find234(ssh->channels, &remoteid, ssh_channelfind); |
| 4883 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 4884 | logevent("Forwarded connection refused by server"); |
| 4885 | pfd_close(c->u.pfd.s); |
| 4886 | del234(ssh->channels, c); |
| 4887 | sfree(c); |
| 4888 | } |
| 4889 | } |
| 4890 | |
| 4891 | static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) |
| 4892 | { |
| 4893 | /* Remote side closes a channel. */ |
| 4894 | unsigned i = ssh_pkt_getuint32(pktin); |
| 4895 | struct ssh_channel *c; |
| 4896 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 4897 | if (c && !c->halfopen) { |
| 4898 | |
| 4899 | if (pktin->type == SSH1_MSG_CHANNEL_CLOSE && |
| 4900 | !(c->closes & CLOSES_RCVD_EOF)) { |
| 4901 | /* |
| 4902 | * Received CHANNEL_CLOSE, which we translate into |
| 4903 | * outgoing EOF. |
| 4904 | */ |
| 4905 | int send_close = FALSE; |
| 4906 | |
| 4907 | c->closes |= CLOSES_RCVD_EOF; |
| 4908 | |
| 4909 | switch (c->type) { |
| 4910 | case CHAN_X11: |
| 4911 | if (c->u.x11.s) |
| 4912 | x11_send_eof(c->u.x11.s); |
| 4913 | else |
| 4914 | send_close = TRUE; |
| 4915 | case CHAN_SOCKDATA: |
| 4916 | if (c->u.pfd.s) |
| 4917 | x11_send_eof(c->u.pfd.s); |
| 4918 | else |
| 4919 | send_close = TRUE; |
| 4920 | case CHAN_AGENT: |
| 4921 | send_close = TRUE; |
| 4922 | } |
| 4923 | |
| 4924 | if (send_close && !(c->closes & CLOSES_SENT_EOF)) { |
| 4925 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
| 4926 | PKT_END); |
| 4927 | c->closes |= CLOSES_SENT_EOF; |
| 4928 | } |
| 4929 | } |
| 4930 | |
| 4931 | if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION && |
| 4932 | !(c->closes & CLOSES_RCVD_CLOSE)) { |
| 4933 | |
| 4934 | if (!(c->closes & CLOSES_SENT_EOF)) { |
| 4935 | bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d" |
| 4936 | " for which we never sent CHANNEL_CLOSE\n", i)); |
| 4937 | } |
| 4938 | |
| 4939 | c->closes |= CLOSES_RCVD_CLOSE; |
| 4940 | } |
| 4941 | |
| 4942 | if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) && |
| 4943 | !(c->closes & CLOSES_SENT_CLOSE)) { |
| 4944 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION, |
| 4945 | PKT_INT, c->remoteid, PKT_END); |
| 4946 | c->closes |= CLOSES_SENT_CLOSE; |
| 4947 | } |
| 4948 | |
| 4949 | if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) |
| 4950 | ssh_channel_destroy(c); |
| 4951 | } else { |
| 4952 | bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", |
| 4953 | pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" : |
| 4954 | "_CONFIRMATION", c ? "half-open" : "nonexistent", |
| 4955 | i)); |
| 4956 | } |
| 4957 | } |
| 4958 | |
| 4959 | static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) |
| 4960 | { |
| 4961 | /* Data sent down one of our channels. */ |
| 4962 | int i = ssh_pkt_getuint32(pktin); |
| 4963 | char *p; |
| 4964 | int len; |
| 4965 | struct ssh_channel *c; |
| 4966 | |
| 4967 | ssh_pkt_getstring(pktin, &p, &len); |
| 4968 | |
| 4969 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 4970 | if (c) { |
| 4971 | int bufsize = 0; |
| 4972 | switch (c->type) { |
| 4973 | case CHAN_X11: |
| 4974 | bufsize = x11_send(c->u.x11.s, p, len); |
| 4975 | break; |
| 4976 | case CHAN_SOCKDATA: |
| 4977 | bufsize = pfd_send(c->u.pfd.s, p, len); |
| 4978 | break; |
| 4979 | case CHAN_AGENT: |
| 4980 | /* Data for an agent message. Buffer it. */ |
| 4981 | while (len > 0) { |
| 4982 | if (c->u.a.lensofar < 4) { |
| 4983 | unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len); |
| 4984 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, |
| 4985 | l); |
| 4986 | p += l; |
| 4987 | len -= l; |
| 4988 | c->u.a.lensofar += l; |
| 4989 | } |
| 4990 | if (c->u.a.lensofar == 4) { |
| 4991 | c->u.a.totallen = |
| 4992 | 4 + GET_32BIT(c->u.a.msglen); |
| 4993 | c->u.a.message = snewn(c->u.a.totallen, |
| 4994 | unsigned char); |
| 4995 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 4996 | } |
| 4997 | if (c->u.a.lensofar >= 4 && len > 0) { |
| 4998 | unsigned int l = |
| 4999 | min(c->u.a.totallen - c->u.a.lensofar, |
| 5000 | (unsigned)len); |
| 5001 | memcpy(c->u.a.message + c->u.a.lensofar, p, |
| 5002 | l); |
| 5003 | p += l; |
| 5004 | len -= l; |
| 5005 | c->u.a.lensofar += l; |
| 5006 | } |
| 5007 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 5008 | void *reply; |
| 5009 | int replylen; |
| 5010 | if (agent_query(c->u.a.message, |
| 5011 | c->u.a.totallen, |
| 5012 | &reply, &replylen, |
| 5013 | ssh_agentf_callback, c)) |
| 5014 | ssh_agentf_callback(c, reply, replylen); |
| 5015 | sfree(c->u.a.message); |
| 5016 | c->u.a.lensofar = 0; |
| 5017 | } |
| 5018 | } |
| 5019 | bufsize = 0; /* agent channels never back up */ |
| 5020 | break; |
| 5021 | } |
| 5022 | if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) { |
| 5023 | c->throttling_conn = 1; |
| 5024 | ssh_throttle_conn(ssh, +1); |
| 5025 | } |
| 5026 | } |
| 5027 | } |
| 5028 | |
| 5029 | static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) |
| 5030 | { |
| 5031 | ssh->exitcode = ssh_pkt_getuint32(pktin); |
| 5032 | logeventf(ssh, "Server sent command exit status %d", ssh->exitcode); |
| 5033 | send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 5034 | /* |
| 5035 | * In case `helpful' firewalls or proxies tack |
| 5036 | * extra human-readable text on the end of the |
| 5037 | * session which we might mistake for another |
| 5038 | * encrypted packet, we close the session once |
| 5039 | * we've sent EXIT_CONFIRMATION. |
| 5040 | */ |
| 5041 | ssh_disconnect(ssh, NULL, NULL, 0, TRUE); |
| 5042 | } |
| 5043 | |
| 5044 | /* Helper function to deal with sending tty modes for REQUEST_PTY */ |
| 5045 | static void ssh1_send_ttymode(void *data, char *mode, char *val) |
| 5046 | { |
| 5047 | struct Packet *pktout = (struct Packet *)data; |
| 5048 | int i = 0; |
| 5049 | unsigned int arg = 0; |
| 5050 | while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; |
| 5051 | if (i == lenof(ssh_ttymodes)) return; |
| 5052 | switch (ssh_ttymodes[i].type) { |
| 5053 | case TTY_OP_CHAR: |
| 5054 | arg = ssh_tty_parse_specchar(val); |
| 5055 | break; |
| 5056 | case TTY_OP_BOOL: |
| 5057 | arg = ssh_tty_parse_boolean(val); |
| 5058 | break; |
| 5059 | } |
| 5060 | ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); |
| 5061 | ssh2_pkt_addbyte(pktout, arg); |
| 5062 | } |
| 5063 | |
| 5064 | |
| 5065 | static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, |
| 5066 | struct Packet *pktin) |
| 5067 | { |
| 5068 | crBegin(ssh->do_ssh1_connection_crstate); |
| 5069 | |
| 5070 | ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] = |
| 5071 | ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] = |
| 5072 | ssh1_smsg_stdout_stderr_data; |
| 5073 | |
| 5074 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] = |
| 5075 | ssh1_msg_channel_open_confirmation; |
| 5076 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] = |
| 5077 | ssh1_msg_channel_open_failure; |
| 5078 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] = |
| 5079 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] = |
| 5080 | ssh1_msg_channel_close; |
| 5081 | ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data; |
| 5082 | ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status; |
| 5083 | |
| 5084 | if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) { |
| 5085 | logevent("Requesting agent forwarding"); |
| 5086 | send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
| 5087 | do { |
| 5088 | crReturnV; |
| 5089 | } while (!pktin); |
| 5090 | if (pktin->type != SSH1_SMSG_SUCCESS |
| 5091 | && pktin->type != SSH1_SMSG_FAILURE) { |
| 5092 | bombout(("Protocol confusion")); |
| 5093 | crStopV; |
| 5094 | } else if (pktin->type == SSH1_SMSG_FAILURE) { |
| 5095 | logevent("Agent forwarding refused"); |
| 5096 | } else { |
| 5097 | logevent("Agent forwarding enabled"); |
| 5098 | ssh->agentfwd_enabled = TRUE; |
| 5099 | ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open; |
| 5100 | } |
| 5101 | } |
| 5102 | |
| 5103 | if (conf_get_int(ssh->conf, CONF_x11_forward) && |
| 5104 | (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), |
| 5105 | conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) { |
| 5106 | logevent("Requesting X11 forwarding"); |
| 5107 | /* |
| 5108 | * Note that while we blank the X authentication data here, we don't |
| 5109 | * take any special action to blank the start of an X11 channel, |
| 5110 | * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection |
| 5111 | * without having session blanking enabled is likely to leak your |
| 5112 | * cookie into the log. |
| 5113 | */ |
| 5114 | if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
| 5115 | send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 5116 | PKT_STR, ssh->x11disp->remoteauthprotoname, |
| 5117 | PKTT_PASSWORD, |
| 5118 | PKT_STR, ssh->x11disp->remoteauthdatastring, |
| 5119 | PKTT_OTHER, |
| 5120 | PKT_INT, ssh->x11disp->screennum, |
| 5121 | PKT_END); |
| 5122 | } else { |
| 5123 | send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 5124 | PKT_STR, ssh->x11disp->remoteauthprotoname, |
| 5125 | PKTT_PASSWORD, |
| 5126 | PKT_STR, ssh->x11disp->remoteauthdatastring, |
| 5127 | PKTT_OTHER, |
| 5128 | PKT_END); |
| 5129 | } |
| 5130 | do { |
| 5131 | crReturnV; |
| 5132 | } while (!pktin); |
| 5133 | if (pktin->type != SSH1_SMSG_SUCCESS |
| 5134 | && pktin->type != SSH1_SMSG_FAILURE) { |
| 5135 | bombout(("Protocol confusion")); |
| 5136 | crStopV; |
| 5137 | } else if (pktin->type == SSH1_SMSG_FAILURE) { |
| 5138 | logevent("X11 forwarding refused"); |
| 5139 | } else { |
| 5140 | logevent("X11 forwarding enabled"); |
| 5141 | ssh->X11_fwd_enabled = TRUE; |
| 5142 | ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open; |
| 5143 | } |
| 5144 | } |
| 5145 | |
| 5146 | ssh_setup_portfwd(ssh, ssh->conf); |
| 5147 | ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open; |
| 5148 | |
| 5149 | if (!conf_get_int(ssh->conf, CONF_nopty)) { |
| 5150 | struct Packet *pkt; |
| 5151 | /* Unpick the terminal-speed string. */ |
| 5152 | /* XXX perhaps we should allow no speeds to be sent. */ |
| 5153 | ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ |
| 5154 | sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); |
| 5155 | /* Send the pty request. */ |
| 5156 | pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY); |
| 5157 | ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype)); |
| 5158 | ssh_pkt_adduint32(pkt, ssh->term_height); |
| 5159 | ssh_pkt_adduint32(pkt, ssh->term_width); |
| 5160 | ssh_pkt_adduint32(pkt, 0); /* width in pixels */ |
| 5161 | ssh_pkt_adduint32(pkt, 0); /* height in pixels */ |
| 5162 | parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt); |
| 5163 | ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED); |
| 5164 | ssh_pkt_adduint32(pkt, ssh->ispeed); |
| 5165 | ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED); |
| 5166 | ssh_pkt_adduint32(pkt, ssh->ospeed); |
| 5167 | ssh_pkt_addbyte(pkt, SSH_TTY_OP_END); |
| 5168 | s_wrpkt(ssh, pkt); |
| 5169 | ssh->state = SSH_STATE_INTERMED; |
| 5170 | do { |
| 5171 | crReturnV; |
| 5172 | } while (!pktin); |
| 5173 | if (pktin->type != SSH1_SMSG_SUCCESS |
| 5174 | && pktin->type != SSH1_SMSG_FAILURE) { |
| 5175 | bombout(("Protocol confusion")); |
| 5176 | crStopV; |
| 5177 | } else if (pktin->type == SSH1_SMSG_FAILURE) { |
| 5178 | c_write_str(ssh, "Server refused to allocate pty\r\n"); |
| 5179 | ssh->editing = ssh->echoing = 1; |
| 5180 | } else { |
| 5181 | logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", |
| 5182 | ssh->ospeed, ssh->ispeed); |
| 5183 | ssh->got_pty = TRUE; |
| 5184 | } |
| 5185 | } else { |
| 5186 | ssh->editing = ssh->echoing = 1; |
| 5187 | } |
| 5188 | |
| 5189 | if (conf_get_int(ssh->conf, CONF_compression)) { |
| 5190 | send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
| 5191 | do { |
| 5192 | crReturnV; |
| 5193 | } while (!pktin); |
| 5194 | if (pktin->type != SSH1_SMSG_SUCCESS |
| 5195 | && pktin->type != SSH1_SMSG_FAILURE) { |
| 5196 | bombout(("Protocol confusion")); |
| 5197 | crStopV; |
| 5198 | } else if (pktin->type == SSH1_SMSG_FAILURE) { |
| 5199 | c_write_str(ssh, "Server refused to compress\r\n"); |
| 5200 | } |
| 5201 | logevent("Started compression"); |
| 5202 | ssh->v1_compressing = TRUE; |
| 5203 | ssh->cs_comp_ctx = zlib_compress_init(); |
| 5204 | logevent("Initialised zlib (RFC1950) compression"); |
| 5205 | ssh->sc_comp_ctx = zlib_decompress_init(); |
| 5206 | logevent("Initialised zlib (RFC1950) decompression"); |
| 5207 | } |
| 5208 | |
| 5209 | /* |
| 5210 | * Start the shell or command. |
| 5211 | * |
| 5212 | * Special case: if the first-choice command is an SSH-2 |
| 5213 | * subsystem (hence not usable here) and the second choice |
| 5214 | * exists, we fall straight back to that. |
| 5215 | */ |
| 5216 | { |
| 5217 | char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd); |
| 5218 | |
| 5219 | if (conf_get_int(ssh->conf, CONF_ssh_subsys) && |
| 5220 | conf_get_str(ssh->conf, CONF_remote_cmd2)) { |
| 5221 | cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); |
| 5222 | ssh->fallback_cmd = TRUE; |
| 5223 | } |
| 5224 | if (*cmd) |
| 5225 | send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
| 5226 | else |
| 5227 | send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 5228 | logevent("Started session"); |
| 5229 | } |
| 5230 | |
| 5231 | ssh->state = SSH_STATE_SESSION; |
| 5232 | if (ssh->size_needed) |
| 5233 | ssh_size(ssh, ssh->term_width, ssh->term_height); |
| 5234 | if (ssh->eof_needed) |
| 5235 | ssh_special(ssh, TS_EOF); |
| 5236 | |
| 5237 | if (ssh->ldisc) |
| 5238 | ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ |
| 5239 | ssh->send_ok = 1; |
| 5240 | ssh->channels = newtree234(ssh_channelcmp); |
| 5241 | while (1) { |
| 5242 | |
| 5243 | /* |
| 5244 | * By this point, most incoming packets are already being |
| 5245 | * handled by the dispatch table, and we need only pay |
| 5246 | * attention to the unusual ones. |
| 5247 | */ |
| 5248 | |
| 5249 | crReturnV; |
| 5250 | if (pktin) { |
| 5251 | if (pktin->type == SSH1_SMSG_SUCCESS) { |
| 5252 | /* may be from EXEC_SHELL on some servers */ |
| 5253 | } else if (pktin->type == SSH1_SMSG_FAILURE) { |
| 5254 | /* may be from EXEC_SHELL on some servers |
| 5255 | * if no pty is available or in other odd cases. Ignore */ |
| 5256 | } else { |
| 5257 | bombout(("Strange packet received: type %d", pktin->type)); |
| 5258 | crStopV; |
| 5259 | } |
| 5260 | } else { |
| 5261 | while (inlen > 0) { |
| 5262 | int len = min(inlen, 512); |
| 5263 | send_packet(ssh, SSH1_CMSG_STDIN_DATA, |
| 5264 | PKT_INT, len, PKTT_DATA, PKT_DATA, in, len, |
| 5265 | PKTT_OTHER, PKT_END); |
| 5266 | in += len; |
| 5267 | inlen -= len; |
| 5268 | } |
| 5269 | } |
| 5270 | } |
| 5271 | |
| 5272 | crFinishV; |
| 5273 | } |
| 5274 | |
| 5275 | /* |
| 5276 | * Handle the top-level SSH-2 protocol. |
| 5277 | */ |
| 5278 | static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) |
| 5279 | { |
| 5280 | char *msg; |
| 5281 | int msglen; |
| 5282 | |
| 5283 | ssh_pkt_getstring(pktin, &msg, &msglen); |
| 5284 | logeventf(ssh, "Remote debug message: %.*s", msglen, msg); |
| 5285 | } |
| 5286 | |
| 5287 | static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) |
| 5288 | { |
| 5289 | /* log reason code in disconnect message */ |
| 5290 | char *msg; |
| 5291 | int msglen; |
| 5292 | |
| 5293 | ssh_pkt_getstring(pktin, &msg, &msglen); |
| 5294 | bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); |
| 5295 | } |
| 5296 | |
| 5297 | static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) |
| 5298 | { |
| 5299 | /* Do nothing, because we're ignoring it! Duhh. */ |
| 5300 | } |
| 5301 | |
| 5302 | static void ssh1_protocol_setup(Ssh ssh) |
| 5303 | { |
| 5304 | int i; |
| 5305 | |
| 5306 | /* |
| 5307 | * Most messages are handled by the coroutines. |
| 5308 | */ |
| 5309 | for (i = 0; i < 256; i++) |
| 5310 | ssh->packet_dispatch[i] = NULL; |
| 5311 | |
| 5312 | /* |
| 5313 | * These special message types we install handlers for. |
| 5314 | */ |
| 5315 | ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect; |
| 5316 | ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore; |
| 5317 | ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; |
| 5318 | } |
| 5319 | |
| 5320 | static void ssh1_protocol(Ssh ssh, void *vin, int inlen, |
| 5321 | struct Packet *pktin) |
| 5322 | { |
| 5323 | unsigned char *in=(unsigned char*)vin; |
| 5324 | if (ssh->state == SSH_STATE_CLOSED) |
| 5325 | return; |
| 5326 | |
| 5327 | if (pktin && ssh->packet_dispatch[pktin->type]) { |
| 5328 | ssh->packet_dispatch[pktin->type](ssh, pktin); |
| 5329 | return; |
| 5330 | } |
| 5331 | |
| 5332 | if (!ssh->protocol_initial_phase_done) { |
| 5333 | if (do_ssh1_login(ssh, in, inlen, pktin)) |
| 5334 | ssh->protocol_initial_phase_done = TRUE; |
| 5335 | else |
| 5336 | return; |
| 5337 | } |
| 5338 | |
| 5339 | do_ssh1_connection(ssh, in, inlen, pktin); |
| 5340 | } |
| 5341 | |
| 5342 | /* |
| 5343 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 5344 | */ |
| 5345 | static int in_commasep_string(char *needle, char *haystack, int haylen) |
| 5346 | { |
| 5347 | int needlen; |
| 5348 | if (!needle || !haystack) /* protect against null pointers */ |
| 5349 | return 0; |
| 5350 | needlen = strlen(needle); |
| 5351 | while (1) { |
| 5352 | /* |
| 5353 | * Is it at the start of the string? |
| 5354 | */ |
| 5355 | if (haylen >= needlen && /* haystack is long enough */ |
| 5356 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 5357 | (haylen == needlen || haystack[needlen] == ',') |
| 5358 | /* either , or EOS follows */ |
| 5359 | ) |
| 5360 | return 1; |
| 5361 | /* |
| 5362 | * If not, search for the next comma and resume after that. |
| 5363 | * If no comma found, terminate. |
| 5364 | */ |
| 5365 | while (haylen > 0 && *haystack != ',') |
| 5366 | haylen--, haystack++; |
| 5367 | if (haylen == 0) |
| 5368 | return 0; |
| 5369 | haylen--, haystack++; /* skip over comma itself */ |
| 5370 | } |
| 5371 | } |
| 5372 | |
| 5373 | /* |
| 5374 | * Similar routine for checking whether we have the first string in a list. |
| 5375 | */ |
| 5376 | static int first_in_commasep_string(char *needle, char *haystack, int haylen) |
| 5377 | { |
| 5378 | int needlen; |
| 5379 | if (!needle || !haystack) /* protect against null pointers */ |
| 5380 | return 0; |
| 5381 | needlen = strlen(needle); |
| 5382 | /* |
| 5383 | * Is it at the start of the string? |
| 5384 | */ |
| 5385 | if (haylen >= needlen && /* haystack is long enough */ |
| 5386 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 5387 | (haylen == needlen || haystack[needlen] == ',') |
| 5388 | /* either , or EOS follows */ |
| 5389 | ) |
| 5390 | return 1; |
| 5391 | return 0; |
| 5392 | } |
| 5393 | |
| 5394 | |
| 5395 | /* |
| 5396 | * SSH-2 key creation method. |
| 5397 | * (Currently assumes 2 lots of any hash are sufficient to generate |
| 5398 | * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.) |
| 5399 | */ |
| 5400 | #define SSH2_MKKEY_ITERS (2) |
| 5401 | static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, |
| 5402 | unsigned char *keyspace) |
| 5403 | { |
| 5404 | const struct ssh_hash *h = ssh->kex->hash; |
| 5405 | void *s; |
| 5406 | /* First hlen bytes. */ |
| 5407 | s = h->init(); |
| 5408 | if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) |
| 5409 | hash_mpint(h, s, K); |
| 5410 | h->bytes(s, H, h->hlen); |
| 5411 | h->bytes(s, &chr, 1); |
| 5412 | h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len); |
| 5413 | h->final(s, keyspace); |
| 5414 | /* Next hlen bytes. */ |
| 5415 | s = h->init(); |
| 5416 | if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) |
| 5417 | hash_mpint(h, s, K); |
| 5418 | h->bytes(s, H, h->hlen); |
| 5419 | h->bytes(s, keyspace, h->hlen); |
| 5420 | h->final(s, keyspace + h->hlen); |
| 5421 | } |
| 5422 | |
| 5423 | /* |
| 5424 | * Handle the SSH-2 transport layer. |
| 5425 | */ |
| 5426 | static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, |
| 5427 | struct Packet *pktin) |
| 5428 | { |
| 5429 | unsigned char *in = (unsigned char *)vin; |
| 5430 | struct do_ssh2_transport_state { |
| 5431 | int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; |
| 5432 | Bignum p, g, e, f, K; |
| 5433 | void *our_kexinit; |
| 5434 | int our_kexinitlen; |
| 5435 | int kex_init_value, kex_reply_value; |
| 5436 | const struct ssh_mac **maclist; |
| 5437 | int nmacs; |
| 5438 | const struct ssh2_cipher *cscipher_tobe; |
| 5439 | const struct ssh2_cipher *sccipher_tobe; |
| 5440 | const struct ssh_mac *csmac_tobe; |
| 5441 | const struct ssh_mac *scmac_tobe; |
| 5442 | const struct ssh_compress *cscomp_tobe; |
| 5443 | const struct ssh_compress *sccomp_tobe; |
| 5444 | char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint; |
| 5445 | int hostkeylen, siglen, rsakeylen; |
| 5446 | void *hkey; /* actual host key */ |
| 5447 | void *rsakey; /* for RSA kex */ |
| 5448 | unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN]; |
| 5449 | int n_preferred_kex; |
| 5450 | const struct ssh_kexes *preferred_kex[KEX_MAX]; |
| 5451 | int n_preferred_ciphers; |
| 5452 | const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; |
| 5453 | const struct ssh_compress *preferred_comp; |
| 5454 | int userauth_succeeded; /* for delayed compression */ |
| 5455 | int pending_compression; |
| 5456 | int got_session_id, activated_authconn; |
| 5457 | struct Packet *pktout; |
| 5458 | int dlgret; |
| 5459 | int guessok; |
| 5460 | int ignorepkt; |
| 5461 | }; |
| 5462 | crState(do_ssh2_transport_state); |
| 5463 | |
| 5464 | crBegin(ssh->do_ssh2_transport_crstate); |
| 5465 | |
| 5466 | s->cscipher_tobe = s->sccipher_tobe = NULL; |
| 5467 | s->csmac_tobe = s->scmac_tobe = NULL; |
| 5468 | s->cscomp_tobe = s->sccomp_tobe = NULL; |
| 5469 | |
| 5470 | s->got_session_id = s->activated_authconn = FALSE; |
| 5471 | s->userauth_succeeded = FALSE; |
| 5472 | s->pending_compression = FALSE; |
| 5473 | |
| 5474 | /* |
| 5475 | * Be prepared to work around the buggy MAC problem. |
| 5476 | */ |
| 5477 | if (ssh->remote_bugs & BUG_SSH2_HMAC) |
| 5478 | s->maclist = buggymacs, s->nmacs = lenof(buggymacs); |
| 5479 | else |
| 5480 | s->maclist = macs, s->nmacs = lenof(macs); |
| 5481 | |
| 5482 | begin_key_exchange: |
| 5483 | ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; |
| 5484 | { |
| 5485 | int i, j, commalist_started; |
| 5486 | |
| 5487 | /* |
| 5488 | * Set up the preferred key exchange. (NULL => warn below here) |
| 5489 | */ |
| 5490 | s->n_preferred_kex = 0; |
| 5491 | for (i = 0; i < KEX_MAX; i++) { |
| 5492 | switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) { |
| 5493 | case KEX_DHGEX: |
| 5494 | s->preferred_kex[s->n_preferred_kex++] = |
| 5495 | &ssh_diffiehellman_gex; |
| 5496 | break; |
| 5497 | case KEX_DHGROUP14: |
| 5498 | s->preferred_kex[s->n_preferred_kex++] = |
| 5499 | &ssh_diffiehellman_group14; |
| 5500 | break; |
| 5501 | case KEX_DHGROUP1: |
| 5502 | s->preferred_kex[s->n_preferred_kex++] = |
| 5503 | &ssh_diffiehellman_group1; |
| 5504 | break; |
| 5505 | case KEX_RSA: |
| 5506 | s->preferred_kex[s->n_preferred_kex++] = |
| 5507 | &ssh_rsa_kex; |
| 5508 | break; |
| 5509 | case KEX_WARN: |
| 5510 | /* Flag for later. Don't bother if it's the last in |
| 5511 | * the list. */ |
| 5512 | if (i < KEX_MAX - 1) { |
| 5513 | s->preferred_kex[s->n_preferred_kex++] = NULL; |
| 5514 | } |
| 5515 | break; |
| 5516 | } |
| 5517 | } |
| 5518 | |
| 5519 | /* |
| 5520 | * Set up the preferred ciphers. (NULL => warn below here) |
| 5521 | */ |
| 5522 | s->n_preferred_ciphers = 0; |
| 5523 | for (i = 0; i < CIPHER_MAX; i++) { |
| 5524 | switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) { |
| 5525 | case CIPHER_BLOWFISH: |
| 5526 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish; |
| 5527 | break; |
| 5528 | case CIPHER_DES: |
| 5529 | if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) { |
| 5530 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des; |
| 5531 | } |
| 5532 | break; |
| 5533 | case CIPHER_3DES: |
| 5534 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des; |
| 5535 | break; |
| 5536 | case CIPHER_AES: |
| 5537 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes; |
| 5538 | break; |
| 5539 | case CIPHER_ARCFOUR: |
| 5540 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour; |
| 5541 | break; |
| 5542 | case CIPHER_WARN: |
| 5543 | /* Flag for later. Don't bother if it's the last in |
| 5544 | * the list. */ |
| 5545 | if (i < CIPHER_MAX - 1) { |
| 5546 | s->preferred_ciphers[s->n_preferred_ciphers++] = NULL; |
| 5547 | } |
| 5548 | break; |
| 5549 | } |
| 5550 | } |
| 5551 | |
| 5552 | /* |
| 5553 | * Set up preferred compression. |
| 5554 | */ |
| 5555 | if (conf_get_int(ssh->conf, CONF_compression)) |
| 5556 | s->preferred_comp = &ssh_zlib; |
| 5557 | else |
| 5558 | s->preferred_comp = &ssh_comp_none; |
| 5559 | |
| 5560 | /* |
| 5561 | * Enable queueing of outgoing auth- or connection-layer |
| 5562 | * packets while we are in the middle of a key exchange. |
| 5563 | */ |
| 5564 | ssh->queueing = TRUE; |
| 5565 | |
| 5566 | /* |
| 5567 | * Flag that KEX is in progress. |
| 5568 | */ |
| 5569 | ssh->kex_in_progress = TRUE; |
| 5570 | |
| 5571 | /* |
| 5572 | * Construct and send our key exchange packet. |
| 5573 | */ |
| 5574 | s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); |
| 5575 | for (i = 0; i < 16; i++) |
| 5576 | ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); |
| 5577 | /* List key exchange algorithms. */ |
| 5578 | ssh2_pkt_addstring_start(s->pktout); |
| 5579 | commalist_started = 0; |
| 5580 | for (i = 0; i < s->n_preferred_kex; i++) { |
| 5581 | const struct ssh_kexes *k = s->preferred_kex[i]; |
| 5582 | if (!k) continue; /* warning flag */ |
| 5583 | for (j = 0; j < k->nkexes; j++) { |
| 5584 | if (commalist_started) |
| 5585 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5586 | ssh2_pkt_addstring_str(s->pktout, k->list[j]->name); |
| 5587 | commalist_started = 1; |
| 5588 | } |
| 5589 | } |
| 5590 | /* List server host key algorithms. */ |
| 5591 | ssh2_pkt_addstring_start(s->pktout); |
| 5592 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 5593 | ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name); |
| 5594 | if (i < lenof(hostkey_algs) - 1) |
| 5595 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5596 | } |
| 5597 | /* List client->server encryption algorithms. */ |
| 5598 | ssh2_pkt_addstring_start(s->pktout); |
| 5599 | commalist_started = 0; |
| 5600 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 5601 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 5602 | if (!c) continue; /* warning flag */ |
| 5603 | for (j = 0; j < c->nciphers; j++) { |
| 5604 | if (commalist_started) |
| 5605 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5606 | ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); |
| 5607 | commalist_started = 1; |
| 5608 | } |
| 5609 | } |
| 5610 | /* List server->client encryption algorithms. */ |
| 5611 | ssh2_pkt_addstring_start(s->pktout); |
| 5612 | commalist_started = 0; |
| 5613 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 5614 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 5615 | if (!c) continue; /* warning flag */ |
| 5616 | for (j = 0; j < c->nciphers; j++) { |
| 5617 | if (commalist_started) |
| 5618 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5619 | ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); |
| 5620 | commalist_started = 1; |
| 5621 | } |
| 5622 | } |
| 5623 | /* List client->server MAC algorithms. */ |
| 5624 | ssh2_pkt_addstring_start(s->pktout); |
| 5625 | for (i = 0; i < s->nmacs; i++) { |
| 5626 | ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); |
| 5627 | if (i < s->nmacs - 1) |
| 5628 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5629 | } |
| 5630 | /* List server->client MAC algorithms. */ |
| 5631 | ssh2_pkt_addstring_start(s->pktout); |
| 5632 | for (i = 0; i < s->nmacs; i++) { |
| 5633 | ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); |
| 5634 | if (i < s->nmacs - 1) |
| 5635 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5636 | } |
| 5637 | /* List client->server compression algorithms, |
| 5638 | * then server->client compression algorithms. (We use the |
| 5639 | * same set twice.) */ |
| 5640 | for (j = 0; j < 2; j++) { |
| 5641 | ssh2_pkt_addstring_start(s->pktout); |
| 5642 | assert(lenof(compressions) > 1); |
| 5643 | /* Prefer non-delayed versions */ |
| 5644 | ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name); |
| 5645 | /* We don't even list delayed versions of algorithms until |
| 5646 | * they're allowed to be used, to avoid a race. See the end of |
| 5647 | * this function. */ |
| 5648 | if (s->userauth_succeeded && s->preferred_comp->delayed_name) { |
| 5649 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5650 | ssh2_pkt_addstring_str(s->pktout, |
| 5651 | s->preferred_comp->delayed_name); |
| 5652 | } |
| 5653 | for (i = 0; i < lenof(compressions); i++) { |
| 5654 | const struct ssh_compress *c = compressions[i]; |
| 5655 | if (c != s->preferred_comp) { |
| 5656 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5657 | ssh2_pkt_addstring_str(s->pktout, c->name); |
| 5658 | if (s->userauth_succeeded && c->delayed_name) { |
| 5659 | ssh2_pkt_addstring_str(s->pktout, ","); |
| 5660 | ssh2_pkt_addstring_str(s->pktout, c->delayed_name); |
| 5661 | } |
| 5662 | } |
| 5663 | } |
| 5664 | } |
| 5665 | /* List client->server languages. Empty list. */ |
| 5666 | ssh2_pkt_addstring_start(s->pktout); |
| 5667 | /* List server->client languages. Empty list. */ |
| 5668 | ssh2_pkt_addstring_start(s->pktout); |
| 5669 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 5670 | ssh2_pkt_addbool(s->pktout, FALSE); |
| 5671 | /* Reserved. */ |
| 5672 | ssh2_pkt_adduint32(s->pktout, 0); |
| 5673 | } |
| 5674 | |
| 5675 | s->our_kexinitlen = s->pktout->length - 5; |
| 5676 | s->our_kexinit = snewn(s->our_kexinitlen, unsigned char); |
| 5677 | memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen); |
| 5678 | |
| 5679 | ssh2_pkt_send_noqueue(ssh, s->pktout); |
| 5680 | |
| 5681 | if (!pktin) |
| 5682 | crWaitUntil(pktin); |
| 5683 | |
| 5684 | /* |
| 5685 | * Now examine the other side's KEXINIT to see what we're up |
| 5686 | * to. |
| 5687 | */ |
| 5688 | { |
| 5689 | char *str, *preferred; |
| 5690 | int i, j, len; |
| 5691 | |
| 5692 | if (pktin->type != SSH2_MSG_KEXINIT) { |
| 5693 | bombout(("expected key exchange packet from server")); |
| 5694 | crStop(0); |
| 5695 | } |
| 5696 | ssh->kex = NULL; |
| 5697 | ssh->hostkey = NULL; |
| 5698 | s->cscipher_tobe = NULL; |
| 5699 | s->sccipher_tobe = NULL; |
| 5700 | s->csmac_tobe = NULL; |
| 5701 | s->scmac_tobe = NULL; |
| 5702 | s->cscomp_tobe = NULL; |
| 5703 | s->sccomp_tobe = NULL; |
| 5704 | s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; |
| 5705 | |
| 5706 | pktin->savedpos += 16; /* skip garbage cookie */ |
| 5707 | ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */ |
| 5708 | |
| 5709 | preferred = NULL; |
| 5710 | for (i = 0; i < s->n_preferred_kex; i++) { |
| 5711 | const struct ssh_kexes *k = s->preferred_kex[i]; |
| 5712 | if (!k) { |
| 5713 | s->warn_kex = TRUE; |
| 5714 | } else { |
| 5715 | for (j = 0; j < k->nkexes; j++) { |
| 5716 | if (!preferred) preferred = k->list[j]->name; |
| 5717 | if (in_commasep_string(k->list[j]->name, str, len)) { |
| 5718 | ssh->kex = k->list[j]; |
| 5719 | break; |
| 5720 | } |
| 5721 | } |
| 5722 | } |
| 5723 | if (ssh->kex) |
| 5724 | break; |
| 5725 | } |
| 5726 | if (!ssh->kex) { |
| 5727 | bombout(("Couldn't agree a key exchange algorithm (available: %s)", |
| 5728 | str ? str : "(null)")); |
| 5729 | crStop(0); |
| 5730 | } |
| 5731 | /* |
| 5732 | * Note that the server's guess is considered wrong if it doesn't match |
| 5733 | * the first algorithm in our list, even if it's still the algorithm |
| 5734 | * we end up using. |
| 5735 | */ |
| 5736 | s->guessok = first_in_commasep_string(preferred, str, len); |
| 5737 | ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */ |
| 5738 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 5739 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 5740 | ssh->hostkey = hostkey_algs[i]; |
| 5741 | break; |
| 5742 | } |
| 5743 | } |
| 5744 | s->guessok = s->guessok && |
| 5745 | first_in_commasep_string(hostkey_algs[0]->name, str, len); |
| 5746 | ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ |
| 5747 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 5748 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 5749 | if (!c) { |
| 5750 | s->warn_cscipher = TRUE; |
| 5751 | } else { |
| 5752 | for (j = 0; j < c->nciphers; j++) { |
| 5753 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 5754 | s->cscipher_tobe = c->list[j]; |
| 5755 | break; |
| 5756 | } |
| 5757 | } |
| 5758 | } |
| 5759 | if (s->cscipher_tobe) |
| 5760 | break; |
| 5761 | } |
| 5762 | if (!s->cscipher_tobe) { |
| 5763 | bombout(("Couldn't agree a client-to-server cipher (available: %s)", |
| 5764 | str ? str : "(null)")); |
| 5765 | crStop(0); |
| 5766 | } |
| 5767 | |
| 5768 | ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ |
| 5769 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 5770 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 5771 | if (!c) { |
| 5772 | s->warn_sccipher = TRUE; |
| 5773 | } else { |
| 5774 | for (j = 0; j < c->nciphers; j++) { |
| 5775 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 5776 | s->sccipher_tobe = c->list[j]; |
| 5777 | break; |
| 5778 | } |
| 5779 | } |
| 5780 | } |
| 5781 | if (s->sccipher_tobe) |
| 5782 | break; |
| 5783 | } |
| 5784 | if (!s->sccipher_tobe) { |
| 5785 | bombout(("Couldn't agree a server-to-client cipher (available: %s)", |
| 5786 | str ? str : "(null)")); |
| 5787 | crStop(0); |
| 5788 | } |
| 5789 | |
| 5790 | ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */ |
| 5791 | for (i = 0; i < s->nmacs; i++) { |
| 5792 | if (in_commasep_string(s->maclist[i]->name, str, len)) { |
| 5793 | s->csmac_tobe = s->maclist[i]; |
| 5794 | break; |
| 5795 | } |
| 5796 | } |
| 5797 | ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */ |
| 5798 | for (i = 0; i < s->nmacs; i++) { |
| 5799 | if (in_commasep_string(s->maclist[i]->name, str, len)) { |
| 5800 | s->scmac_tobe = s->maclist[i]; |
| 5801 | break; |
| 5802 | } |
| 5803 | } |
| 5804 | ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */ |
| 5805 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 5806 | const struct ssh_compress *c = |
| 5807 | i == 0 ? s->preferred_comp : compressions[i - 1]; |
| 5808 | if (in_commasep_string(c->name, str, len)) { |
| 5809 | s->cscomp_tobe = c; |
| 5810 | break; |
| 5811 | } else if (in_commasep_string(c->delayed_name, str, len)) { |
| 5812 | if (s->userauth_succeeded) { |
| 5813 | s->cscomp_tobe = c; |
| 5814 | break; |
| 5815 | } else { |
| 5816 | s->pending_compression = TRUE; /* try this later */ |
| 5817 | } |
| 5818 | } |
| 5819 | } |
| 5820 | ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */ |
| 5821 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 5822 | const struct ssh_compress *c = |
| 5823 | i == 0 ? s->preferred_comp : compressions[i - 1]; |
| 5824 | if (in_commasep_string(c->name, str, len)) { |
| 5825 | s->sccomp_tobe = c; |
| 5826 | break; |
| 5827 | } else if (in_commasep_string(c->delayed_name, str, len)) { |
| 5828 | if (s->userauth_succeeded) { |
| 5829 | s->sccomp_tobe = c; |
| 5830 | break; |
| 5831 | } else { |
| 5832 | s->pending_compression = TRUE; /* try this later */ |
| 5833 | } |
| 5834 | } |
| 5835 | } |
| 5836 | if (s->pending_compression) { |
| 5837 | logevent("Server supports delayed compression; " |
| 5838 | "will try this later"); |
| 5839 | } |
| 5840 | ssh_pkt_getstring(pktin, &str, &len); /* client->server language */ |
| 5841 | ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ |
| 5842 | s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; |
| 5843 | |
| 5844 | if (s->warn_kex) { |
| 5845 | ssh_set_frozen(ssh, 1); |
| 5846 | s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", |
| 5847 | ssh->kex->name, |
| 5848 | ssh_dialog_callback, ssh); |
| 5849 | if (s->dlgret < 0) { |
| 5850 | do { |
| 5851 | crReturn(0); |
| 5852 | if (pktin) { |
| 5853 | bombout(("Unexpected data from server while" |
| 5854 | " waiting for user response")); |
| 5855 | crStop(0); |
| 5856 | } |
| 5857 | } while (pktin || inlen > 0); |
| 5858 | s->dlgret = ssh->user_response; |
| 5859 | } |
| 5860 | ssh_set_frozen(ssh, 0); |
| 5861 | if (s->dlgret == 0) { |
| 5862 | ssh_disconnect(ssh, "User aborted at kex warning", NULL, |
| 5863 | 0, TRUE); |
| 5864 | crStop(0); |
| 5865 | } |
| 5866 | } |
| 5867 | |
| 5868 | if (s->warn_cscipher) { |
| 5869 | ssh_set_frozen(ssh, 1); |
| 5870 | s->dlgret = askalg(ssh->frontend, |
| 5871 | "client-to-server cipher", |
| 5872 | s->cscipher_tobe->name, |
| 5873 | ssh_dialog_callback, ssh); |
| 5874 | if (s->dlgret < 0) { |
| 5875 | do { |
| 5876 | crReturn(0); |
| 5877 | if (pktin) { |
| 5878 | bombout(("Unexpected data from server while" |
| 5879 | " waiting for user response")); |
| 5880 | crStop(0); |
| 5881 | } |
| 5882 | } while (pktin || inlen > 0); |
| 5883 | s->dlgret = ssh->user_response; |
| 5884 | } |
| 5885 | ssh_set_frozen(ssh, 0); |
| 5886 | if (s->dlgret == 0) { |
| 5887 | ssh_disconnect(ssh, "User aborted at cipher warning", NULL, |
| 5888 | 0, TRUE); |
| 5889 | crStop(0); |
| 5890 | } |
| 5891 | } |
| 5892 | |
| 5893 | if (s->warn_sccipher) { |
| 5894 | ssh_set_frozen(ssh, 1); |
| 5895 | s->dlgret = askalg(ssh->frontend, |
| 5896 | "server-to-client cipher", |
| 5897 | s->sccipher_tobe->name, |
| 5898 | ssh_dialog_callback, ssh); |
| 5899 | if (s->dlgret < 0) { |
| 5900 | do { |
| 5901 | crReturn(0); |
| 5902 | if (pktin) { |
| 5903 | bombout(("Unexpected data from server while" |
| 5904 | " waiting for user response")); |
| 5905 | crStop(0); |
| 5906 | } |
| 5907 | } while (pktin || inlen > 0); |
| 5908 | s->dlgret = ssh->user_response; |
| 5909 | } |
| 5910 | ssh_set_frozen(ssh, 0); |
| 5911 | if (s->dlgret == 0) { |
| 5912 | ssh_disconnect(ssh, "User aborted at cipher warning", NULL, |
| 5913 | 0, TRUE); |
| 5914 | crStop(0); |
| 5915 | } |
| 5916 | } |
| 5917 | |
| 5918 | ssh->exhash = ssh->kex->hash->init(); |
| 5919 | hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); |
| 5920 | hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); |
| 5921 | hash_string(ssh->kex->hash, ssh->exhash, |
| 5922 | s->our_kexinit, s->our_kexinitlen); |
| 5923 | sfree(s->our_kexinit); |
| 5924 | if (pktin->length > 5) |
| 5925 | hash_string(ssh->kex->hash, ssh->exhash, |
| 5926 | pktin->data + 5, pktin->length - 5); |
| 5927 | |
| 5928 | if (s->ignorepkt) /* first_kex_packet_follows */ |
| 5929 | crWaitUntil(pktin); /* Ignore packet */ |
| 5930 | } |
| 5931 | |
| 5932 | if (ssh->kex->main_type == KEXTYPE_DH) { |
| 5933 | /* |
| 5934 | * Work out the number of bits of key we will need from the |
| 5935 | * key exchange. We start with the maximum key length of |
| 5936 | * either cipher... |
| 5937 | */ |
| 5938 | { |
| 5939 | int csbits, scbits; |
| 5940 | |
| 5941 | csbits = s->cscipher_tobe->keylen; |
| 5942 | scbits = s->sccipher_tobe->keylen; |
| 5943 | s->nbits = (csbits > scbits ? csbits : scbits); |
| 5944 | } |
| 5945 | /* The keys only have hlen-bit entropy, since they're based on |
| 5946 | * a hash. So cap the key size at hlen bits. */ |
| 5947 | if (s->nbits > ssh->kex->hash->hlen * 8) |
| 5948 | s->nbits = ssh->kex->hash->hlen * 8; |
| 5949 | |
| 5950 | /* |
| 5951 | * If we're doing Diffie-Hellman group exchange, start by |
| 5952 | * requesting a group. |
| 5953 | */ |
| 5954 | if (!ssh->kex->pdata) { |
| 5955 | logevent("Doing Diffie-Hellman group exchange"); |
| 5956 | ssh->pkt_kctx = SSH2_PKTCTX_DHGEX; |
| 5957 | /* |
| 5958 | * Work out how big a DH group we will need to allow that |
| 5959 | * much data. |
| 5960 | */ |
| 5961 | s->pbits = 512 << ((s->nbits - 1) / 64); |
| 5962 | s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
| 5963 | ssh2_pkt_adduint32(s->pktout, s->pbits); |
| 5964 | ssh2_pkt_send_noqueue(ssh, s->pktout); |
| 5965 | |
| 5966 | crWaitUntil(pktin); |
| 5967 | if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
| 5968 | bombout(("expected key exchange group packet from server")); |
| 5969 | crStop(0); |
| 5970 | } |
| 5971 | s->p = ssh2_pkt_getmp(pktin); |
| 5972 | s->g = ssh2_pkt_getmp(pktin); |
| 5973 | if (!s->p || !s->g) { |
| 5974 | bombout(("unable to read mp-ints from incoming group packet")); |
| 5975 | crStop(0); |
| 5976 | } |
| 5977 | ssh->kex_ctx = dh_setup_gex(s->p, s->g); |
| 5978 | s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
| 5979 | s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
| 5980 | } else { |
| 5981 | ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP; |
| 5982 | ssh->kex_ctx = dh_setup_group(ssh->kex); |
| 5983 | s->kex_init_value = SSH2_MSG_KEXDH_INIT; |
| 5984 | s->kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
| 5985 | logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"", |
| 5986 | ssh->kex->groupname); |
| 5987 | } |
| 5988 | |
| 5989 | logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s", |
| 5990 | ssh->kex->hash->text_name); |
| 5991 | /* |
| 5992 | * Now generate and send e for Diffie-Hellman. |
| 5993 | */ |
| 5994 | set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */ |
| 5995 | s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); |
| 5996 | s->pktout = ssh2_pkt_init(s->kex_init_value); |
| 5997 | ssh2_pkt_addmp(s->pktout, s->e); |
| 5998 | ssh2_pkt_send_noqueue(ssh, s->pktout); |
| 5999 | |
| 6000 | set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */ |
| 6001 | crWaitUntil(pktin); |
| 6002 | if (pktin->type != s->kex_reply_value) { |
| 6003 | bombout(("expected key exchange reply packet from server")); |
| 6004 | crStop(0); |
| 6005 | } |
| 6006 | set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ |
| 6007 | ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); |
| 6008 | s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); |
| 6009 | s->f = ssh2_pkt_getmp(pktin); |
| 6010 | if (!s->f) { |
| 6011 | bombout(("unable to parse key exchange reply packet")); |
| 6012 | crStop(0); |
| 6013 | } |
| 6014 | ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); |
| 6015 | |
| 6016 | s->K = dh_find_K(ssh->kex_ctx, s->f); |
| 6017 | |
| 6018 | /* We assume everything from now on will be quick, and it might |
| 6019 | * involve user interaction. */ |
| 6020 | set_busy_status(ssh->frontend, BUSY_NOT); |
| 6021 | |
| 6022 | hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); |
| 6023 | if (!ssh->kex->pdata) { |
| 6024 | hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits); |
| 6025 | hash_mpint(ssh->kex->hash, ssh->exhash, s->p); |
| 6026 | hash_mpint(ssh->kex->hash, ssh->exhash, s->g); |
| 6027 | } |
| 6028 | hash_mpint(ssh->kex->hash, ssh->exhash, s->e); |
| 6029 | hash_mpint(ssh->kex->hash, ssh->exhash, s->f); |
| 6030 | |
| 6031 | dh_cleanup(ssh->kex_ctx); |
| 6032 | freebn(s->f); |
| 6033 | if (!ssh->kex->pdata) { |
| 6034 | freebn(s->g); |
| 6035 | freebn(s->p); |
| 6036 | } |
| 6037 | } else { |
| 6038 | logeventf(ssh, "Doing RSA key exchange with hash %s", |
| 6039 | ssh->kex->hash->text_name); |
| 6040 | ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX; |
| 6041 | /* |
| 6042 | * RSA key exchange. First expect a KEXRSA_PUBKEY packet |
| 6043 | * from the server. |
| 6044 | */ |
| 6045 | crWaitUntil(pktin); |
| 6046 | if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) { |
| 6047 | bombout(("expected RSA public key packet from server")); |
| 6048 | crStop(0); |
| 6049 | } |
| 6050 | |
| 6051 | ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); |
| 6052 | hash_string(ssh->kex->hash, ssh->exhash, |
| 6053 | s->hostkeydata, s->hostkeylen); |
| 6054 | s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); |
| 6055 | |
| 6056 | { |
| 6057 | char *keydata; |
| 6058 | ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen); |
| 6059 | s->rsakeydata = snewn(s->rsakeylen, char); |
| 6060 | memcpy(s->rsakeydata, keydata, s->rsakeylen); |
| 6061 | } |
| 6062 | |
| 6063 | s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen); |
| 6064 | if (!s->rsakey) { |
| 6065 | sfree(s->rsakeydata); |
| 6066 | bombout(("unable to parse RSA public key from server")); |
| 6067 | crStop(0); |
| 6068 | } |
| 6069 | |
| 6070 | hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen); |
| 6071 | |
| 6072 | /* |
| 6073 | * Next, set up a shared secret K, of precisely KLEN - |
| 6074 | * 2*HLEN - 49 bits, where KLEN is the bit length of the |
| 6075 | * RSA key modulus and HLEN is the bit length of the hash |
| 6076 | * we're using. |
| 6077 | */ |
| 6078 | { |
| 6079 | int klen = ssh_rsakex_klen(s->rsakey); |
| 6080 | int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49); |
| 6081 | int i, byte = 0; |
| 6082 | unsigned char *kstr1, *kstr2, *outstr; |
| 6083 | int kstr1len, kstr2len, outstrlen; |
| 6084 | |
| 6085 | s->K = bn_power_2(nbits - 1); |
| 6086 | |
| 6087 | for (i = 0; i < nbits; i++) { |
| 6088 | if ((i & 7) == 0) { |
| 6089 | byte = random_byte(); |
| 6090 | } |
| 6091 | bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1); |
| 6092 | } |
| 6093 | |
| 6094 | /* |
| 6095 | * Encode this as an mpint. |
| 6096 | */ |
| 6097 | kstr1 = ssh2_mpint_fmt(s->K, &kstr1len); |
| 6098 | kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char); |
| 6099 | PUT_32BIT(kstr2, kstr1len); |
| 6100 | memcpy(kstr2 + 4, kstr1, kstr1len); |
| 6101 | |
| 6102 | /* |
| 6103 | * Encrypt it with the given RSA key. |
| 6104 | */ |
| 6105 | outstrlen = (klen + 7) / 8; |
| 6106 | outstr = snewn(outstrlen, unsigned char); |
| 6107 | ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len, |
| 6108 | outstr, outstrlen, s->rsakey); |
| 6109 | |
| 6110 | /* |
| 6111 | * And send it off in a return packet. |
| 6112 | */ |
| 6113 | s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET); |
| 6114 | ssh2_pkt_addstring_start(s->pktout); |
| 6115 | ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen); |
| 6116 | ssh2_pkt_send_noqueue(ssh, s->pktout); |
| 6117 | |
| 6118 | hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen); |
| 6119 | |
| 6120 | sfree(kstr2); |
| 6121 | sfree(kstr1); |
| 6122 | sfree(outstr); |
| 6123 | } |
| 6124 | |
| 6125 | ssh_rsakex_freekey(s->rsakey); |
| 6126 | |
| 6127 | crWaitUntil(pktin); |
| 6128 | if (pktin->type != SSH2_MSG_KEXRSA_DONE) { |
| 6129 | sfree(s->rsakeydata); |
| 6130 | bombout(("expected signature packet from server")); |
| 6131 | crStop(0); |
| 6132 | } |
| 6133 | |
| 6134 | ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); |
| 6135 | |
| 6136 | sfree(s->rsakeydata); |
| 6137 | } |
| 6138 | |
| 6139 | hash_mpint(ssh->kex->hash, ssh->exhash, s->K); |
| 6140 | assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash)); |
| 6141 | ssh->kex->hash->final(ssh->exhash, s->exchange_hash); |
| 6142 | |
| 6143 | ssh->kex_ctx = NULL; |
| 6144 | |
| 6145 | #if 0 |
| 6146 | debug(("Exchange hash is:\n")); |
| 6147 | dmemdump(s->exchange_hash, ssh->kex->hash->hlen); |
| 6148 | #endif |
| 6149 | |
| 6150 | if (!s->hkey || |
| 6151 | !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, |
| 6152 | (char *)s->exchange_hash, |
| 6153 | ssh->kex->hash->hlen)) { |
| 6154 | bombout(("Server's host key did not match the signature supplied")); |
| 6155 | crStop(0); |
| 6156 | } |
| 6157 | |
| 6158 | /* |
| 6159 | * Authenticate remote host: verify host key. (We've already |
| 6160 | * checked the signature of the exchange hash.) |
| 6161 | */ |
| 6162 | s->keystr = ssh->hostkey->fmtkey(s->hkey); |
| 6163 | s->fingerprint = ssh->hostkey->fingerprint(s->hkey); |
| 6164 | ssh_set_frozen(ssh, 1); |
| 6165 | s->dlgret = verify_ssh_host_key(ssh->frontend, |
| 6166 | ssh->savedhost, ssh->savedport, |
| 6167 | ssh->hostkey->keytype, s->keystr, |
| 6168 | s->fingerprint, |
| 6169 | ssh_dialog_callback, ssh); |
| 6170 | if (s->dlgret < 0) { |
| 6171 | do { |
| 6172 | crReturn(0); |
| 6173 | if (pktin) { |
| 6174 | bombout(("Unexpected data from server while waiting" |
| 6175 | " for user host key response")); |
| 6176 | crStop(0); |
| 6177 | } |
| 6178 | } while (pktin || inlen > 0); |
| 6179 | s->dlgret = ssh->user_response; |
| 6180 | } |
| 6181 | ssh_set_frozen(ssh, 0); |
| 6182 | if (s->dlgret == 0) { |
| 6183 | ssh_disconnect(ssh, "User aborted at host key verification", NULL, |
| 6184 | 0, TRUE); |
| 6185 | crStop(0); |
| 6186 | } |
| 6187 | if (!s->got_session_id) { /* don't bother logging this in rekeys */ |
| 6188 | logevent("Host key fingerprint is:"); |
| 6189 | logevent(s->fingerprint); |
| 6190 | } |
| 6191 | sfree(s->fingerprint); |
| 6192 | sfree(s->keystr); |
| 6193 | ssh->hostkey->freekey(s->hkey); |
| 6194 | |
| 6195 | /* |
| 6196 | * The exchange hash from the very first key exchange is also |
| 6197 | * the session id, used in session key construction and |
| 6198 | * authentication. |
| 6199 | */ |
| 6200 | if (!s->got_session_id) { |
| 6201 | assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id)); |
| 6202 | memcpy(ssh->v2_session_id, s->exchange_hash, |
| 6203 | sizeof(s->exchange_hash)); |
| 6204 | ssh->v2_session_id_len = ssh->kex->hash->hlen; |
| 6205 | assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id)); |
| 6206 | s->got_session_id = TRUE; |
| 6207 | } |
| 6208 | |
| 6209 | /* |
| 6210 | * Send SSH2_MSG_NEWKEYS. |
| 6211 | */ |
| 6212 | s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
| 6213 | ssh2_pkt_send_noqueue(ssh, s->pktout); |
| 6214 | ssh->outgoing_data_size = 0; /* start counting from here */ |
| 6215 | |
| 6216 | /* |
| 6217 | * We've sent client NEWKEYS, so create and initialise |
| 6218 | * client-to-server session keys. |
| 6219 | */ |
| 6220 | if (ssh->cs_cipher_ctx) |
| 6221 | ssh->cscipher->free_context(ssh->cs_cipher_ctx); |
| 6222 | ssh->cscipher = s->cscipher_tobe; |
| 6223 | ssh->cs_cipher_ctx = ssh->cscipher->make_context(); |
| 6224 | |
| 6225 | if (ssh->cs_mac_ctx) |
| 6226 | ssh->csmac->free_context(ssh->cs_mac_ctx); |
| 6227 | ssh->csmac = s->csmac_tobe; |
| 6228 | ssh->cs_mac_ctx = ssh->csmac->make_context(); |
| 6229 | |
| 6230 | if (ssh->cs_comp_ctx) |
| 6231 | ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); |
| 6232 | ssh->cscomp = s->cscomp_tobe; |
| 6233 | ssh->cs_comp_ctx = ssh->cscomp->compress_init(); |
| 6234 | |
| 6235 | /* |
| 6236 | * Set IVs on client-to-server keys. Here we use the exchange |
| 6237 | * hash from the _first_ key exchange. |
| 6238 | */ |
| 6239 | { |
| 6240 | unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; |
| 6241 | assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6242 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); |
| 6243 | assert((ssh->cscipher->keylen+7) / 8 <= |
| 6244 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6245 | ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); |
| 6246 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); |
| 6247 | assert(ssh->cscipher->blksize <= |
| 6248 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6249 | ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); |
| 6250 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); |
| 6251 | assert(ssh->csmac->len <= |
| 6252 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6253 | ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); |
| 6254 | memset(keyspace, 0, sizeof(keyspace)); |
| 6255 | } |
| 6256 | |
| 6257 | logeventf(ssh, "Initialised %.200s client->server encryption", |
| 6258 | ssh->cscipher->text_name); |
| 6259 | logeventf(ssh, "Initialised %.200s client->server MAC algorithm", |
| 6260 | ssh->csmac->text_name); |
| 6261 | if (ssh->cscomp->text_name) |
| 6262 | logeventf(ssh, "Initialised %s compression", |
| 6263 | ssh->cscomp->text_name); |
| 6264 | |
| 6265 | /* |
| 6266 | * Now our end of the key exchange is complete, we can send all |
| 6267 | * our queued higher-layer packets. |
| 6268 | */ |
| 6269 | ssh->queueing = FALSE; |
| 6270 | ssh2_pkt_queuesend(ssh); |
| 6271 | |
| 6272 | /* |
| 6273 | * Expect SSH2_MSG_NEWKEYS from server. |
| 6274 | */ |
| 6275 | crWaitUntil(pktin); |
| 6276 | if (pktin->type != SSH2_MSG_NEWKEYS) { |
| 6277 | bombout(("expected new-keys packet from server")); |
| 6278 | crStop(0); |
| 6279 | } |
| 6280 | ssh->incoming_data_size = 0; /* start counting from here */ |
| 6281 | |
| 6282 | /* |
| 6283 | * We've seen server NEWKEYS, so create and initialise |
| 6284 | * server-to-client session keys. |
| 6285 | */ |
| 6286 | if (ssh->sc_cipher_ctx) |
| 6287 | ssh->sccipher->free_context(ssh->sc_cipher_ctx); |
| 6288 | ssh->sccipher = s->sccipher_tobe; |
| 6289 | ssh->sc_cipher_ctx = ssh->sccipher->make_context(); |
| 6290 | |
| 6291 | if (ssh->sc_mac_ctx) |
| 6292 | ssh->scmac->free_context(ssh->sc_mac_ctx); |
| 6293 | ssh->scmac = s->scmac_tobe; |
| 6294 | ssh->sc_mac_ctx = ssh->scmac->make_context(); |
| 6295 | |
| 6296 | if (ssh->sc_comp_ctx) |
| 6297 | ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); |
| 6298 | ssh->sccomp = s->sccomp_tobe; |
| 6299 | ssh->sc_comp_ctx = ssh->sccomp->decompress_init(); |
| 6300 | |
| 6301 | /* |
| 6302 | * Set IVs on server-to-client keys. Here we use the exchange |
| 6303 | * hash from the _first_ key exchange. |
| 6304 | */ |
| 6305 | { |
| 6306 | unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; |
| 6307 | assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6308 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace); |
| 6309 | assert((ssh->sccipher->keylen+7) / 8 <= |
| 6310 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6311 | ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); |
| 6312 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace); |
| 6313 | assert(ssh->sccipher->blksize <= |
| 6314 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6315 | ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); |
| 6316 | ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); |
| 6317 | assert(ssh->scmac->len <= |
| 6318 | ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); |
| 6319 | ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); |
| 6320 | memset(keyspace, 0, sizeof(keyspace)); |
| 6321 | } |
| 6322 | logeventf(ssh, "Initialised %.200s server->client encryption", |
| 6323 | ssh->sccipher->text_name); |
| 6324 | logeventf(ssh, "Initialised %.200s server->client MAC algorithm", |
| 6325 | ssh->scmac->text_name); |
| 6326 | if (ssh->sccomp->text_name) |
| 6327 | logeventf(ssh, "Initialised %s decompression", |
| 6328 | ssh->sccomp->text_name); |
| 6329 | |
| 6330 | /* |
| 6331 | * Free shared secret. |
| 6332 | */ |
| 6333 | freebn(s->K); |
| 6334 | |
| 6335 | /* |
| 6336 | * Key exchange is over. Loop straight back round if we have a |
| 6337 | * deferred rekey reason. |
| 6338 | */ |
| 6339 | if (ssh->deferred_rekey_reason) { |
| 6340 | logevent(ssh->deferred_rekey_reason); |
| 6341 | pktin = NULL; |
| 6342 | ssh->deferred_rekey_reason = NULL; |
| 6343 | goto begin_key_exchange; |
| 6344 | } |
| 6345 | |
| 6346 | /* |
| 6347 | * Otherwise, schedule a timer for our next rekey. |
| 6348 | */ |
| 6349 | ssh->kex_in_progress = FALSE; |
| 6350 | ssh->last_rekey = GETTICKCOUNT(); |
| 6351 | if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) |
| 6352 | ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC, |
| 6353 | ssh2_timer, ssh); |
| 6354 | |
| 6355 | /* |
| 6356 | * If this is the first key exchange phase, we must pass the |
| 6357 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
| 6358 | * wants to see it but because it will need time to initialise |
| 6359 | * itself before it sees an actual packet. In subsequent key |
| 6360 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
| 6361 | * it would only confuse the layer above. |
| 6362 | */ |
| 6363 | if (s->activated_authconn) { |
| 6364 | crReturn(0); |
| 6365 | } |
| 6366 | s->activated_authconn = TRUE; |
| 6367 | |
| 6368 | /* |
| 6369 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 6370 | * function so that other things can run on top of the |
| 6371 | * transport. If we ever see a KEXINIT, we must go back to the |
| 6372 | * start. |
| 6373 | * |
| 6374 | * We _also_ go back to the start if we see pktin==NULL and |
| 6375 | * inlen negative, because this is a special signal meaning |
| 6376 | * `initiate client-driven rekey', and `in' contains a message |
| 6377 | * giving the reason for the rekey. |
| 6378 | * |
| 6379 | * inlen==-1 means always initiate a rekey; |
| 6380 | * inlen==-2 means that userauth has completed successfully and |
| 6381 | * we should consider rekeying (for delayed compression). |
| 6382 | */ |
| 6383 | while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) || |
| 6384 | (!pktin && inlen < 0))) { |
| 6385 | wait_for_rekey: |
| 6386 | crReturn(1); |
| 6387 | } |
| 6388 | if (pktin) { |
| 6389 | logevent("Server initiated key re-exchange"); |
| 6390 | } else { |
| 6391 | if (inlen == -2) { |
| 6392 | /* |
| 6393 | * authconn has seen a USERAUTH_SUCCEEDED. Time to enable |
| 6394 | * delayed compression, if it's available. |
| 6395 | * |
| 6396 | * draft-miller-secsh-compression-delayed-00 says that you |
| 6397 | * negotiate delayed compression in the first key exchange, and |
| 6398 | * both sides start compressing when the server has sent |
| 6399 | * USERAUTH_SUCCESS. This has a race condition -- the server |
| 6400 | * can't know when the client has seen it, and thus which incoming |
| 6401 | * packets it should treat as compressed. |
| 6402 | * |
| 6403 | * Instead, we do the initial key exchange without offering the |
| 6404 | * delayed methods, but note if the server offers them; when we |
| 6405 | * get here, if a delayed method was available that was higher |
| 6406 | * on our list than what we got, we initiate a rekey in which we |
| 6407 | * _do_ list the delayed methods (and hopefully get it as a |
| 6408 | * result). Subsequent rekeys will do the same. |
| 6409 | */ |
| 6410 | assert(!s->userauth_succeeded); /* should only happen once */ |
| 6411 | s->userauth_succeeded = TRUE; |
| 6412 | if (!s->pending_compression) |
| 6413 | /* Can't see any point rekeying. */ |
| 6414 | goto wait_for_rekey; /* this is utterly horrid */ |
| 6415 | /* else fall through to rekey... */ |
| 6416 | s->pending_compression = FALSE; |
| 6417 | } |
| 6418 | /* |
| 6419 | * Now we've decided to rekey. |
| 6420 | * |
| 6421 | * Special case: if the server bug is set that doesn't |
| 6422 | * allow rekeying, we give a different log message and |
| 6423 | * continue waiting. (If such a server _initiates_ a rekey, |
| 6424 | * we process it anyway!) |
| 6425 | */ |
| 6426 | if ((ssh->remote_bugs & BUG_SSH2_REKEY)) { |
| 6427 | logeventf(ssh, "Server bug prevents key re-exchange (%s)", |
| 6428 | (char *)in); |
| 6429 | /* Reset the counters, so that at least this message doesn't |
| 6430 | * hit the event log _too_ often. */ |
| 6431 | ssh->outgoing_data_size = 0; |
| 6432 | ssh->incoming_data_size = 0; |
| 6433 | if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) { |
| 6434 | ssh->next_rekey = |
| 6435 | schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC, |
| 6436 | ssh2_timer, ssh); |
| 6437 | } |
| 6438 | goto wait_for_rekey; /* this is still utterly horrid */ |
| 6439 | } else { |
| 6440 | logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in); |
| 6441 | } |
| 6442 | } |
| 6443 | goto begin_key_exchange; |
| 6444 | |
| 6445 | crFinish(1); |
| 6446 | } |
| 6447 | |
| 6448 | /* |
| 6449 | * Add data to an SSH-2 channel output buffer. |
| 6450 | */ |
| 6451 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
| 6452 | int len) |
| 6453 | { |
| 6454 | bufchain_add(&c->v.v2.outbuffer, buf, len); |
| 6455 | } |
| 6456 | |
| 6457 | /* |
| 6458 | * Attempt to send data on an SSH-2 channel. |
| 6459 | */ |
| 6460 | static int ssh2_try_send(struct ssh_channel *c) |
| 6461 | { |
| 6462 | Ssh ssh = c->ssh; |
| 6463 | struct Packet *pktout; |
| 6464 | int ret; |
| 6465 | |
| 6466 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { |
| 6467 | int len; |
| 6468 | void *data; |
| 6469 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); |
| 6470 | if ((unsigned)len > c->v.v2.remwindow) |
| 6471 | len = c->v.v2.remwindow; |
| 6472 | if ((unsigned)len > c->v.v2.remmaxpkt) |
| 6473 | len = c->v.v2.remmaxpkt; |
| 6474 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
| 6475 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 6476 | ssh2_pkt_addstring_start(pktout); |
| 6477 | dont_log_data(ssh, pktout, PKTLOG_OMIT); |
| 6478 | ssh2_pkt_addstring_data(pktout, data, len); |
| 6479 | end_log_omission(ssh, pktout); |
| 6480 | ssh2_pkt_send(ssh, pktout); |
| 6481 | bufchain_consume(&c->v.v2.outbuffer, len); |
| 6482 | c->v.v2.remwindow -= len; |
| 6483 | } |
| 6484 | |
| 6485 | /* |
| 6486 | * After having sent as much data as we can, return the amount |
| 6487 | * still buffered. |
| 6488 | */ |
| 6489 | ret = bufchain_size(&c->v.v2.outbuffer); |
| 6490 | |
| 6491 | /* |
| 6492 | * And if there's no data pending but we need to send an EOF, send |
| 6493 | * it. |
| 6494 | */ |
| 6495 | if (!ret && c->pending_eof) |
| 6496 | ssh_channel_try_eof(c); |
| 6497 | |
| 6498 | return ret; |
| 6499 | } |
| 6500 | |
| 6501 | static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c) |
| 6502 | { |
| 6503 | int bufsize; |
| 6504 | if (c->closes & CLOSES_SENT_EOF) |
| 6505 | return; /* don't send on channels we've EOFed */ |
| 6506 | bufsize = ssh2_try_send(c); |
| 6507 | if (bufsize == 0) { |
| 6508 | switch (c->type) { |
| 6509 | case CHAN_MAINSESSION: |
| 6510 | /* stdin need not receive an unthrottle |
| 6511 | * notification since it will be polled */ |
| 6512 | break; |
| 6513 | case CHAN_X11: |
| 6514 | x11_unthrottle(c->u.x11.s); |
| 6515 | break; |
| 6516 | case CHAN_AGENT: |
| 6517 | /* agent sockets are request/response and need no |
| 6518 | * buffer management */ |
| 6519 | break; |
| 6520 | case CHAN_SOCKDATA: |
| 6521 | pfd_unthrottle(c->u.pfd.s); |
| 6522 | break; |
| 6523 | } |
| 6524 | } |
| 6525 | } |
| 6526 | |
| 6527 | /* |
| 6528 | * Set up most of a new ssh_channel for SSH-2. |
| 6529 | */ |
| 6530 | static void ssh2_channel_init(struct ssh_channel *c) |
| 6531 | { |
| 6532 | Ssh ssh = c->ssh; |
| 6533 | c->localid = alloc_channel_id(ssh); |
| 6534 | c->closes = 0; |
| 6535 | c->pending_eof = FALSE; |
| 6536 | c->throttling_conn = FALSE; |
| 6537 | c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = |
| 6538 | conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; |
| 6539 | c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL; |
| 6540 | c->v.v2.throttle_state = UNTHROTTLED; |
| 6541 | bufchain_init(&c->v.v2.outbuffer); |
| 6542 | } |
| 6543 | |
| 6544 | /* |
| 6545 | * Potentially enlarge the window on an SSH-2 channel. |
| 6546 | */ |
| 6547 | static void ssh2_set_window(struct ssh_channel *c, int newwin) |
| 6548 | { |
| 6549 | Ssh ssh = c->ssh; |
| 6550 | |
| 6551 | /* |
| 6552 | * Never send WINDOW_ADJUST for a channel that the remote side has |
| 6553 | * already sent EOF on; there's no point, since it won't be |
| 6554 | * sending any more data anyway. |
| 6555 | */ |
| 6556 | if (c->closes & CLOSES_RCVD_EOF) |
| 6557 | return; |
| 6558 | |
| 6559 | /* |
| 6560 | * If the remote end has a habit of ignoring maxpkt, limit the |
| 6561 | * window so that it has no choice (assuming it doesn't ignore the |
| 6562 | * window as well). |
| 6563 | */ |
| 6564 | if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT) |
| 6565 | newwin = OUR_V2_MAXPKT; |
| 6566 | |
| 6567 | |
| 6568 | /* |
| 6569 | * Only send a WINDOW_ADJUST if there's significantly more window |
| 6570 | * available than the other end thinks there is. This saves us |
| 6571 | * sending a WINDOW_ADJUST for every character in a shell session. |
| 6572 | * |
| 6573 | * "Significant" is arbitrarily defined as half the window size. |
| 6574 | */ |
| 6575 | if (newwin / 2 >= c->v.v2.locwindow) { |
| 6576 | struct Packet *pktout; |
| 6577 | struct winadj *wa; |
| 6578 | |
| 6579 | /* |
| 6580 | * In order to keep track of how much window the client |
| 6581 | * actually has available, we'd like it to acknowledge each |
| 6582 | * WINDOW_ADJUST. We can't do that directly, so we accompany |
| 6583 | * it with a CHANNEL_REQUEST that has to be acknowledged. |
| 6584 | * |
| 6585 | * This is only necessary if we're opening the window wide. |
| 6586 | * If we're not, then throughput is being constrained by |
| 6587 | * something other than the maximum window size anyway. |
| 6588 | * |
| 6589 | * We also only send this if the main channel has finished its |
| 6590 | * initial CHANNEL_REQUESTs and installed the default |
| 6591 | * CHANNEL_FAILURE handler, so as not to risk giving it |
| 6592 | * unexpected CHANNEL_FAILUREs. |
| 6593 | */ |
| 6594 | if (newwin == c->v.v2.locmaxwin && |
| 6595 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) { |
| 6596 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 6597 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 6598 | ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org"); |
| 6599 | ssh2_pkt_addbool(pktout, TRUE); |
| 6600 | ssh2_pkt_send(ssh, pktout); |
| 6601 | |
| 6602 | /* |
| 6603 | * CHANNEL_FAILURE doesn't come with any indication of |
| 6604 | * what message caused it, so we have to keep track of the |
| 6605 | * outstanding CHANNEL_REQUESTs ourselves. |
| 6606 | */ |
| 6607 | wa = snew(struct winadj); |
| 6608 | wa->size = newwin - c->v.v2.locwindow; |
| 6609 | wa->next = NULL; |
| 6610 | if (!c->v.v2.winadj_head) |
| 6611 | c->v.v2.winadj_head = wa; |
| 6612 | else |
| 6613 | c->v.v2.winadj_tail->next = wa; |
| 6614 | c->v.v2.winadj_tail = wa; |
| 6615 | if (c->v.v2.throttle_state != UNTHROTTLED) |
| 6616 | c->v.v2.throttle_state = UNTHROTTLING; |
| 6617 | } else { |
| 6618 | /* Pretend the WINDOW_ADJUST was acked immediately. */ |
| 6619 | c->v.v2.remlocwin = newwin; |
| 6620 | c->v.v2.throttle_state = THROTTLED; |
| 6621 | } |
| 6622 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 6623 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 6624 | ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow); |
| 6625 | ssh2_pkt_send(ssh, pktout); |
| 6626 | c->v.v2.locwindow = newwin; |
| 6627 | } |
| 6628 | } |
| 6629 | |
| 6630 | /* |
| 6631 | * Find the channel associated with a message. If there's no channel, |
| 6632 | * or it's not properly open, make a noise about it and return NULL. |
| 6633 | */ |
| 6634 | static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin) |
| 6635 | { |
| 6636 | unsigned localid = ssh_pkt_getuint32(pktin); |
| 6637 | struct ssh_channel *c; |
| 6638 | |
| 6639 | c = find234(ssh->channels, &localid, ssh_channelfind); |
| 6640 | if (!c || |
| 6641 | (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION && |
| 6642 | pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) { |
| 6643 | char *buf = dupprintf("Received %s for %s channel %u", |
| 6644 | ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, |
| 6645 | pktin->type), |
| 6646 | c ? "half-open" : "nonexistent", localid); |
| 6647 | ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); |
| 6648 | sfree(buf); |
| 6649 | return NULL; |
| 6650 | } |
| 6651 | return c; |
| 6652 | } |
| 6653 | |
| 6654 | static int ssh2_handle_winadj_response(struct ssh_channel *c) |
| 6655 | { |
| 6656 | struct winadj *wa = c->v.v2.winadj_head; |
| 6657 | if (!wa) |
| 6658 | return FALSE; |
| 6659 | c->v.v2.winadj_head = wa->next; |
| 6660 | c->v.v2.remlocwin += wa->size; |
| 6661 | sfree(wa); |
| 6662 | /* |
| 6663 | * winadj messages are only sent when the window is fully open, so |
| 6664 | * if we get an ack of one, we know any pending unthrottle is |
| 6665 | * complete. |
| 6666 | */ |
| 6667 | if (c->v.v2.throttle_state == UNTHROTTLING) |
| 6668 | c->v.v2.throttle_state = UNTHROTTLED; |
| 6669 | /* |
| 6670 | * We may now initiate channel-closing procedures, if that winadj |
| 6671 | * was the last thing outstanding before we send CHANNEL_CLOSE. |
| 6672 | */ |
| 6673 | ssh2_channel_check_close(c); |
| 6674 | return TRUE; |
| 6675 | } |
| 6676 | |
| 6677 | static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin) |
| 6678 | { |
| 6679 | /* |
| 6680 | * This should never get called. All channel requests are either |
| 6681 | * sent with want_reply false, are sent before this handler gets |
| 6682 | * installed, or are "winadj@putty" requests, which servers should |
| 6683 | * never respond to with success. |
| 6684 | * |
| 6685 | * However, at least one server ("boks_sshd") is known to return |
| 6686 | * SUCCESS for channel requests it's never heard of, such as |
| 6687 | * "winadj@putty". Raised with foxt.com as bug 090916-090424, but |
| 6688 | * for the sake of a quiet life, we handle it just the same as the |
| 6689 | * expected FAILURE. |
| 6690 | */ |
| 6691 | struct ssh_channel *c; |
| 6692 | |
| 6693 | c = ssh2_channel_msg(ssh, pktin); |
| 6694 | if (!c) |
| 6695 | return; |
| 6696 | if (!ssh2_handle_winadj_response(c)) |
| 6697 | ssh_disconnect(ssh, NULL, |
| 6698 | "Received unsolicited SSH_MSG_CHANNEL_SUCCESS", |
| 6699 | SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); |
| 6700 | } |
| 6701 | |
| 6702 | static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin) |
| 6703 | { |
| 6704 | /* |
| 6705 | * The only time this should get called is for "winadj@putty" |
| 6706 | * messages sent above. All other channel requests are either |
| 6707 | * sent with want_reply false or are sent before this handler gets |
| 6708 | * installed. |
| 6709 | */ |
| 6710 | struct ssh_channel *c; |
| 6711 | |
| 6712 | c = ssh2_channel_msg(ssh, pktin); |
| 6713 | if (!c) |
| 6714 | return; |
| 6715 | if (!ssh2_handle_winadj_response(c)) |
| 6716 | ssh_disconnect(ssh, NULL, |
| 6717 | "Received unsolicited SSH_MSG_CHANNEL_FAILURE", |
| 6718 | SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); |
| 6719 | } |
| 6720 | |
| 6721 | static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) |
| 6722 | { |
| 6723 | struct ssh_channel *c; |
| 6724 | c = ssh2_channel_msg(ssh, pktin); |
| 6725 | if (!c) |
| 6726 | return; |
| 6727 | if (!(c->closes & CLOSES_SENT_EOF)) { |
| 6728 | c->v.v2.remwindow += ssh_pkt_getuint32(pktin); |
| 6729 | ssh2_try_send_and_unthrottle(ssh, c); |
| 6730 | } |
| 6731 | } |
| 6732 | |
| 6733 | static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) |
| 6734 | { |
| 6735 | char *data; |
| 6736 | int length; |
| 6737 | struct ssh_channel *c; |
| 6738 | c = ssh2_channel_msg(ssh, pktin); |
| 6739 | if (!c) |
| 6740 | return; |
| 6741 | if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 6742 | ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) |
| 6743 | return; /* extended but not stderr */ |
| 6744 | ssh_pkt_getstring(pktin, &data, &length); |
| 6745 | if (data) { |
| 6746 | int bufsize = 0; |
| 6747 | c->v.v2.locwindow -= length; |
| 6748 | c->v.v2.remlocwin -= length; |
| 6749 | switch (c->type) { |
| 6750 | case CHAN_MAINSESSION: |
| 6751 | bufsize = |
| 6752 | from_backend(ssh->frontend, pktin->type == |
| 6753 | SSH2_MSG_CHANNEL_EXTENDED_DATA, |
| 6754 | data, length); |
| 6755 | break; |
| 6756 | case CHAN_X11: |
| 6757 | bufsize = x11_send(c->u.x11.s, data, length); |
| 6758 | break; |
| 6759 | case CHAN_SOCKDATA: |
| 6760 | bufsize = pfd_send(c->u.pfd.s, data, length); |
| 6761 | break; |
| 6762 | case CHAN_AGENT: |
| 6763 | while (length > 0) { |
| 6764 | if (c->u.a.lensofar < 4) { |
| 6765 | unsigned int l = min(4 - c->u.a.lensofar, |
| 6766 | (unsigned)length); |
| 6767 | memcpy(c->u.a.msglen + c->u.a.lensofar, |
| 6768 | data, l); |
| 6769 | data += l; |
| 6770 | length -= l; |
| 6771 | c->u.a.lensofar += l; |
| 6772 | } |
| 6773 | if (c->u.a.lensofar == 4) { |
| 6774 | c->u.a.totallen = |
| 6775 | 4 + GET_32BIT(c->u.a.msglen); |
| 6776 | c->u.a.message = snewn(c->u.a.totallen, |
| 6777 | unsigned char); |
| 6778 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 6779 | } |
| 6780 | if (c->u.a.lensofar >= 4 && length > 0) { |
| 6781 | unsigned int l = |
| 6782 | min(c->u.a.totallen - c->u.a.lensofar, |
| 6783 | (unsigned)length); |
| 6784 | memcpy(c->u.a.message + c->u.a.lensofar, |
| 6785 | data, l); |
| 6786 | data += l; |
| 6787 | length -= l; |
| 6788 | c->u.a.lensofar += l; |
| 6789 | } |
| 6790 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 6791 | void *reply; |
| 6792 | int replylen; |
| 6793 | if (agent_query(c->u.a.message, |
| 6794 | c->u.a.totallen, |
| 6795 | &reply, &replylen, |
| 6796 | ssh_agentf_callback, c)) |
| 6797 | ssh_agentf_callback(c, reply, replylen); |
| 6798 | sfree(c->u.a.message); |
| 6799 | c->u.a.message = NULL; |
| 6800 | c->u.a.lensofar = 0; |
| 6801 | } |
| 6802 | } |
| 6803 | bufsize = 0; |
| 6804 | break; |
| 6805 | } |
| 6806 | /* |
| 6807 | * If it looks like the remote end hit the end of its window, |
| 6808 | * and we didn't want it to do that, think about using a |
| 6809 | * larger window. |
| 6810 | */ |
| 6811 | if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED && |
| 6812 | c->v.v2.locmaxwin < 0x40000000) |
| 6813 | c->v.v2.locmaxwin += OUR_V2_WINSIZE; |
| 6814 | /* |
| 6815 | * If we are not buffering too much data, |
| 6816 | * enlarge the window again at the remote side. |
| 6817 | * If we are buffering too much, we may still |
| 6818 | * need to adjust the window if the server's |
| 6819 | * sent excess data. |
| 6820 | */ |
| 6821 | ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ? |
| 6822 | c->v.v2.locmaxwin - bufsize : 0); |
| 6823 | /* |
| 6824 | * If we're either buffering way too much data, or if we're |
| 6825 | * buffering anything at all and we're in "simple" mode, |
| 6826 | * throttle the whole channel. |
| 6827 | */ |
| 6828 | if ((bufsize > c->v.v2.locmaxwin || |
| 6829 | (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) && |
| 6830 | !c->throttling_conn) { |
| 6831 | c->throttling_conn = 1; |
| 6832 | ssh_throttle_conn(ssh, +1); |
| 6833 | } |
| 6834 | } |
| 6835 | } |
| 6836 | |
| 6837 | static void ssh_channel_destroy(struct ssh_channel *c) |
| 6838 | { |
| 6839 | Ssh ssh = c->ssh; |
| 6840 | |
| 6841 | switch (c->type) { |
| 6842 | case CHAN_MAINSESSION: |
| 6843 | ssh->mainchan = NULL; |
| 6844 | update_specials_menu(ssh->frontend); |
| 6845 | break; |
| 6846 | case CHAN_X11: |
| 6847 | if (c->u.x11.s != NULL) |
| 6848 | x11_close(c->u.x11.s); |
| 6849 | logevent("Forwarded X11 connection terminated"); |
| 6850 | break; |
| 6851 | case CHAN_AGENT: |
| 6852 | sfree(c->u.a.message); |
| 6853 | break; |
| 6854 | case CHAN_SOCKDATA: |
| 6855 | if (c->u.pfd.s != NULL) |
| 6856 | pfd_close(c->u.pfd.s); |
| 6857 | logevent("Forwarded port closed"); |
| 6858 | break; |
| 6859 | } |
| 6860 | |
| 6861 | del234(ssh->channels, c); |
| 6862 | if (ssh->version == 2) |
| 6863 | bufchain_clear(&c->v.v2.outbuffer); |
| 6864 | sfree(c); |
| 6865 | |
| 6866 | /* |
| 6867 | * See if that was the last channel left open. |
| 6868 | * (This is only our termination condition if we're |
| 6869 | * not running in -N mode.) |
| 6870 | */ |
| 6871 | if (ssh->version == 2 && |
| 6872 | !conf_get_int(ssh->conf, CONF_ssh_no_shell) && |
| 6873 | count234(ssh->channels) == 0) { |
| 6874 | /* |
| 6875 | * We used to send SSH_MSG_DISCONNECT here, |
| 6876 | * because I'd believed that _every_ conforming |
| 6877 | * SSH-2 connection had to end with a disconnect |
| 6878 | * being sent by at least one side; apparently |
| 6879 | * I was wrong and it's perfectly OK to |
| 6880 | * unceremoniously slam the connection shut |
| 6881 | * when you're done, and indeed OpenSSH feels |
| 6882 | * this is more polite than sending a |
| 6883 | * DISCONNECT. So now we don't. |
| 6884 | */ |
| 6885 | ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); |
| 6886 | } |
| 6887 | } |
| 6888 | |
| 6889 | static void ssh2_channel_check_close(struct ssh_channel *c) |
| 6890 | { |
| 6891 | Ssh ssh = c->ssh; |
| 6892 | struct Packet *pktout; |
| 6893 | |
| 6894 | if ((c->closes & (CLOSES_SENT_EOF | CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE)) |
| 6895 | == (CLOSES_SENT_EOF | CLOSES_RCVD_EOF) && !c->v.v2.winadj_head) { |
| 6896 | /* |
| 6897 | * We have both sent and received EOF, and we have no |
| 6898 | * outstanding winadj channel requests, which means the |
| 6899 | * channel is in final wind-up. But we haven't sent CLOSE, so |
| 6900 | * let's do so now. |
| 6901 | */ |
| 6902 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 6903 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 6904 | ssh2_pkt_send(ssh, pktout); |
| 6905 | c->closes |= CLOSES_SENT_CLOSE; |
| 6906 | } |
| 6907 | |
| 6908 | if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) { |
| 6909 | /* |
| 6910 | * We have both sent and received CLOSE, which means we're |
| 6911 | * completely done with the channel. |
| 6912 | */ |
| 6913 | ssh_channel_destroy(c); |
| 6914 | } |
| 6915 | } |
| 6916 | |
| 6917 | static void ssh2_channel_got_eof(struct ssh_channel *c) |
| 6918 | { |
| 6919 | if (c->closes & CLOSES_RCVD_EOF) |
| 6920 | return; /* already seen EOF */ |
| 6921 | c->closes |= CLOSES_RCVD_EOF; |
| 6922 | |
| 6923 | if (c->type == CHAN_X11) { |
| 6924 | x11_send_eof(c->u.x11.s); |
| 6925 | } else if (c->type == CHAN_AGENT) { |
| 6926 | /* Manufacture an outgoing EOF in response to the incoming one. */ |
| 6927 | sshfwd_write_eof(c); |
| 6928 | } else if (c->type == CHAN_SOCKDATA) { |
| 6929 | pfd_send_eof(c->u.pfd.s); |
| 6930 | } else if (c->type == CHAN_MAINSESSION) { |
| 6931 | Ssh ssh = c->ssh; |
| 6932 | |
| 6933 | if (!ssh->sent_console_eof && |
| 6934 | (from_backend_eof(ssh->frontend) || ssh->got_pty)) { |
| 6935 | /* |
| 6936 | * Either from_backend_eof told us that the front end |
| 6937 | * wants us to close the outgoing side of the connection |
| 6938 | * as soon as we see EOF from the far end, or else we've |
| 6939 | * unilaterally decided to do that because we've allocated |
| 6940 | * a remote pty and hence EOF isn't a particularly |
| 6941 | * meaningful concept. |
| 6942 | */ |
| 6943 | sshfwd_write_eof(c); |
| 6944 | } |
| 6945 | ssh->sent_console_eof = TRUE; |
| 6946 | } |
| 6947 | |
| 6948 | ssh2_channel_check_close(c); |
| 6949 | } |
| 6950 | |
| 6951 | static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) |
| 6952 | { |
| 6953 | struct ssh_channel *c; |
| 6954 | |
| 6955 | c = ssh2_channel_msg(ssh, pktin); |
| 6956 | if (!c) |
| 6957 | return; |
| 6958 | ssh2_channel_got_eof(c); |
| 6959 | } |
| 6960 | |
| 6961 | static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) |
| 6962 | { |
| 6963 | struct ssh_channel *c; |
| 6964 | |
| 6965 | c = ssh2_channel_msg(ssh, pktin); |
| 6966 | if (!c) |
| 6967 | return; |
| 6968 | |
| 6969 | /* |
| 6970 | * When we receive CLOSE on a channel, we assume it comes with an |
| 6971 | * implied EOF if we haven't seen EOF yet. |
| 6972 | */ |
| 6973 | ssh2_channel_got_eof(c); |
| 6974 | |
| 6975 | /* |
| 6976 | * And we also send an outgoing EOF, if we haven't already, on the |
| 6977 | * assumption that CLOSE is a pretty forceful announcement that |
| 6978 | * the remote side is doing away with the entire channel. (If it |
| 6979 | * had wanted to send us EOF and continue receiving data from us, |
| 6980 | * it would have just sent CHANNEL_EOF.) |
| 6981 | */ |
| 6982 | if (!(c->closes & CLOSES_SENT_EOF)) { |
| 6983 | /* |
| 6984 | * Make sure we don't read any more from whatever our local |
| 6985 | * data source is for this channel. |
| 6986 | */ |
| 6987 | switch (c->type) { |
| 6988 | case CHAN_MAINSESSION: |
| 6989 | ssh->send_ok = 0; /* stop trying to read from stdin */ |
| 6990 | break; |
| 6991 | case CHAN_X11: |
| 6992 | x11_override_throttle(c->u.x11.s, 1); |
| 6993 | break; |
| 6994 | case CHAN_SOCKDATA: |
| 6995 | pfd_override_throttle(c->u.pfd.s, 1); |
| 6996 | break; |
| 6997 | } |
| 6998 | |
| 6999 | /* |
| 7000 | * Send outgoing EOF. |
| 7001 | */ |
| 7002 | sshfwd_write_eof(ssh->mainchan); |
| 7003 | } |
| 7004 | |
| 7005 | /* |
| 7006 | * Now process the actual close. |
| 7007 | */ |
| 7008 | if (!(c->closes & CLOSES_RCVD_CLOSE)) { |
| 7009 | c->closes |= CLOSES_RCVD_CLOSE; |
| 7010 | ssh2_channel_check_close(c); |
| 7011 | } |
| 7012 | } |
| 7013 | |
| 7014 | static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) |
| 7015 | { |
| 7016 | struct ssh_channel *c; |
| 7017 | |
| 7018 | c = ssh2_channel_msg(ssh, pktin); |
| 7019 | if (!c) |
| 7020 | return; |
| 7021 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 7022 | return; /* dunno why they're confirming this */ |
| 7023 | c->remoteid = ssh_pkt_getuint32(pktin); |
| 7024 | c->halfopen = FALSE; |
| 7025 | c->type = CHAN_SOCKDATA; |
| 7026 | c->v.v2.remwindow = ssh_pkt_getuint32(pktin); |
| 7027 | c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); |
| 7028 | if (c->u.pfd.s) |
| 7029 | pfd_confirm(c->u.pfd.s); |
| 7030 | if (c->pending_eof) |
| 7031 | ssh_channel_try_eof(c); |
| 7032 | } |
| 7033 | |
| 7034 | static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) |
| 7035 | { |
| 7036 | static const char *const reasons[] = { |
| 7037 | "<unknown reason code>", |
| 7038 | "Administratively prohibited", |
| 7039 | "Connect failed", |
| 7040 | "Unknown channel type", |
| 7041 | "Resource shortage", |
| 7042 | }; |
| 7043 | unsigned reason_code; |
| 7044 | char *reason_string; |
| 7045 | int reason_length; |
| 7046 | struct ssh_channel *c; |
| 7047 | c = ssh2_channel_msg(ssh, pktin); |
| 7048 | if (!c) |
| 7049 | return; |
| 7050 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 7051 | return; /* dunno why they're failing this */ |
| 7052 | |
| 7053 | reason_code = ssh_pkt_getuint32(pktin); |
| 7054 | if (reason_code >= lenof(reasons)) |
| 7055 | reason_code = 0; /* ensure reasons[reason_code] in range */ |
| 7056 | ssh_pkt_getstring(pktin, &reason_string, &reason_length); |
| 7057 | logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", |
| 7058 | reasons[reason_code], reason_length, reason_string); |
| 7059 | |
| 7060 | pfd_close(c->u.pfd.s); |
| 7061 | |
| 7062 | del234(ssh->channels, c); |
| 7063 | sfree(c); |
| 7064 | } |
| 7065 | |
| 7066 | static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) |
| 7067 | { |
| 7068 | char *type; |
| 7069 | int typelen, want_reply; |
| 7070 | int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ |
| 7071 | struct ssh_channel *c; |
| 7072 | struct Packet *pktout; |
| 7073 | |
| 7074 | c = ssh2_channel_msg(ssh, pktin); |
| 7075 | if (!c) |
| 7076 | return; |
| 7077 | ssh_pkt_getstring(pktin, &type, &typelen); |
| 7078 | want_reply = ssh2_pkt_getbool(pktin); |
| 7079 | |
| 7080 | /* |
| 7081 | * Having got the channel number, we now look at |
| 7082 | * the request type string to see if it's something |
| 7083 | * we recognise. |
| 7084 | */ |
| 7085 | if (c == ssh->mainchan) { |
| 7086 | /* |
| 7087 | * We recognise "exit-status" and "exit-signal" on |
| 7088 | * the primary channel. |
| 7089 | */ |
| 7090 | if (typelen == 11 && |
| 7091 | !memcmp(type, "exit-status", 11)) { |
| 7092 | |
| 7093 | ssh->exitcode = ssh_pkt_getuint32(pktin); |
| 7094 | logeventf(ssh, "Server sent command exit status %d", |
| 7095 | ssh->exitcode); |
| 7096 | reply = SSH2_MSG_CHANNEL_SUCCESS; |
| 7097 | |
| 7098 | } else if (typelen == 11 && |
| 7099 | !memcmp(type, "exit-signal", 11)) { |
| 7100 | |
| 7101 | int is_plausible = TRUE, is_int = FALSE; |
| 7102 | char *fmt_sig = "", *fmt_msg = ""; |
| 7103 | char *msg; |
| 7104 | int msglen = 0, core = FALSE; |
| 7105 | /* ICK: older versions of OpenSSH (e.g. 3.4p1) |
| 7106 | * provide an `int' for the signal, despite its |
| 7107 | * having been a `string' in the drafts of RFC 4254 since at |
| 7108 | * least 2001. (Fixed in session.c 1.147.) Try to |
| 7109 | * infer which we can safely parse it as. */ |
| 7110 | { |
| 7111 | unsigned char *p = pktin->body + |
| 7112 | pktin->savedpos; |
| 7113 | long len = pktin->length - pktin->savedpos; |
| 7114 | unsigned long num = GET_32BIT(p); /* what is it? */ |
| 7115 | /* If it's 0, it hardly matters; assume string */ |
| 7116 | if (num == 0) { |
| 7117 | is_int = FALSE; |
| 7118 | } else { |
| 7119 | int maybe_int = FALSE, maybe_str = FALSE; |
| 7120 | #define CHECK_HYPOTHESIS(offset, result) \ |
| 7121 | do { \ |
| 7122 | long q = offset; \ |
| 7123 | if (q >= 0 && q+4 <= len) { \ |
| 7124 | q = q + 4 + GET_32BIT(p+q); \ |
| 7125 | if (q >= 0 && q+4 <= len && \ |
| 7126 | ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \ |
| 7127 | result = TRUE; \ |
| 7128 | } \ |
| 7129 | } while(0) |
| 7130 | CHECK_HYPOTHESIS(4+1, maybe_int); |
| 7131 | CHECK_HYPOTHESIS(4+num+1, maybe_str); |
| 7132 | #undef CHECK_HYPOTHESIS |
| 7133 | if (maybe_int && !maybe_str) |
| 7134 | is_int = TRUE; |
| 7135 | else if (!maybe_int && maybe_str) |
| 7136 | is_int = FALSE; |
| 7137 | else |
| 7138 | /* Crikey. Either or neither. Panic. */ |
| 7139 | is_plausible = FALSE; |
| 7140 | } |
| 7141 | } |
| 7142 | ssh->exitcode = 128; /* means `unknown signal' */ |
| 7143 | if (is_plausible) { |
| 7144 | if (is_int) { |
| 7145 | /* Old non-standard OpenSSH. */ |
| 7146 | int signum = ssh_pkt_getuint32(pktin); |
| 7147 | fmt_sig = dupprintf(" %d", signum); |
| 7148 | ssh->exitcode = 128 + signum; |
| 7149 | } else { |
| 7150 | /* As per RFC 4254. */ |
| 7151 | char *sig; |
| 7152 | int siglen; |
| 7153 | ssh_pkt_getstring(pktin, &sig, &siglen); |
| 7154 | /* Signal name isn't supposed to be blank, but |
| 7155 | * let's cope gracefully if it is. */ |
| 7156 | if (siglen) { |
| 7157 | fmt_sig = dupprintf(" \"%.*s\"", |
| 7158 | siglen, sig); |
| 7159 | } |
| 7160 | |
| 7161 | /* |
| 7162 | * Really hideous method of translating the |
| 7163 | * signal description back into a locally |
| 7164 | * meaningful number. |
| 7165 | */ |
| 7166 | |
| 7167 | if (0) |
| 7168 | ; |
| 7169 | #define TRANSLATE_SIGNAL(s) \ |
| 7170 | else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \ |
| 7171 | ssh->exitcode = 128 + SIG ## s |
| 7172 | #ifdef SIGABRT |
| 7173 | TRANSLATE_SIGNAL(ABRT); |
| 7174 | #endif |
| 7175 | #ifdef SIGALRM |
| 7176 | TRANSLATE_SIGNAL(ALRM); |
| 7177 | #endif |
| 7178 | #ifdef SIGFPE |
| 7179 | TRANSLATE_SIGNAL(FPE); |
| 7180 | #endif |
| 7181 | #ifdef SIGHUP |
| 7182 | TRANSLATE_SIGNAL(HUP); |
| 7183 | #endif |
| 7184 | #ifdef SIGILL |
| 7185 | TRANSLATE_SIGNAL(ILL); |
| 7186 | #endif |
| 7187 | #ifdef SIGINT |
| 7188 | TRANSLATE_SIGNAL(INT); |
| 7189 | #endif |
| 7190 | #ifdef SIGKILL |
| 7191 | TRANSLATE_SIGNAL(KILL); |
| 7192 | #endif |
| 7193 | #ifdef SIGPIPE |
| 7194 | TRANSLATE_SIGNAL(PIPE); |
| 7195 | #endif |
| 7196 | #ifdef SIGQUIT |
| 7197 | TRANSLATE_SIGNAL(QUIT); |
| 7198 | #endif |
| 7199 | #ifdef SIGSEGV |
| 7200 | TRANSLATE_SIGNAL(SEGV); |
| 7201 | #endif |
| 7202 | #ifdef SIGTERM |
| 7203 | TRANSLATE_SIGNAL(TERM); |
| 7204 | #endif |
| 7205 | #ifdef SIGUSR1 |
| 7206 | TRANSLATE_SIGNAL(USR1); |
| 7207 | #endif |
| 7208 | #ifdef SIGUSR2 |
| 7209 | TRANSLATE_SIGNAL(USR2); |
| 7210 | #endif |
| 7211 | #undef TRANSLATE_SIGNAL |
| 7212 | else |
| 7213 | ssh->exitcode = 128; |
| 7214 | } |
| 7215 | core = ssh2_pkt_getbool(pktin); |
| 7216 | ssh_pkt_getstring(pktin, &msg, &msglen); |
| 7217 | if (msglen) { |
| 7218 | fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg); |
| 7219 | } |
| 7220 | /* ignore lang tag */ |
| 7221 | } /* else don't attempt to parse */ |
| 7222 | logeventf(ssh, "Server exited on signal%s%s%s", |
| 7223 | fmt_sig, core ? " (core dumped)" : "", |
| 7224 | fmt_msg); |
| 7225 | if (*fmt_sig) sfree(fmt_sig); |
| 7226 | if (*fmt_msg) sfree(fmt_msg); |
| 7227 | reply = SSH2_MSG_CHANNEL_SUCCESS; |
| 7228 | |
| 7229 | } |
| 7230 | } else { |
| 7231 | /* |
| 7232 | * This is a channel request we don't know |
| 7233 | * about, so we now either ignore the request |
| 7234 | * or respond with CHANNEL_FAILURE, depending |
| 7235 | * on want_reply. |
| 7236 | */ |
| 7237 | reply = SSH2_MSG_CHANNEL_FAILURE; |
| 7238 | } |
| 7239 | if (want_reply) { |
| 7240 | pktout = ssh2_pkt_init(reply); |
| 7241 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 7242 | ssh2_pkt_send(ssh, pktout); |
| 7243 | } |
| 7244 | } |
| 7245 | |
| 7246 | static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin) |
| 7247 | { |
| 7248 | char *type; |
| 7249 | int typelen, want_reply; |
| 7250 | struct Packet *pktout; |
| 7251 | |
| 7252 | ssh_pkt_getstring(pktin, &type, &typelen); |
| 7253 | want_reply = ssh2_pkt_getbool(pktin); |
| 7254 | |
| 7255 | /* |
| 7256 | * We currently don't support any global requests |
| 7257 | * at all, so we either ignore the request or |
| 7258 | * respond with REQUEST_FAILURE, depending on |
| 7259 | * want_reply. |
| 7260 | */ |
| 7261 | if (want_reply) { |
| 7262 | pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); |
| 7263 | ssh2_pkt_send(ssh, pktout); |
| 7264 | } |
| 7265 | } |
| 7266 | |
| 7267 | static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) |
| 7268 | { |
| 7269 | char *type; |
| 7270 | int typelen; |
| 7271 | char *peeraddr; |
| 7272 | int peeraddrlen; |
| 7273 | int peerport; |
| 7274 | char *error = NULL; |
| 7275 | struct ssh_channel *c; |
| 7276 | unsigned remid, winsize, pktsize; |
| 7277 | struct Packet *pktout; |
| 7278 | |
| 7279 | ssh_pkt_getstring(pktin, &type, &typelen); |
| 7280 | c = snew(struct ssh_channel); |
| 7281 | c->ssh = ssh; |
| 7282 | |
| 7283 | remid = ssh_pkt_getuint32(pktin); |
| 7284 | winsize = ssh_pkt_getuint32(pktin); |
| 7285 | pktsize = ssh_pkt_getuint32(pktin); |
| 7286 | |
| 7287 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
| 7288 | char *addrstr; |
| 7289 | const char *x11err; |
| 7290 | |
| 7291 | ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); |
| 7292 | addrstr = snewn(peeraddrlen+1, char); |
| 7293 | memcpy(addrstr, peeraddr, peeraddrlen); |
| 7294 | addrstr[peeraddrlen] = '\0'; |
| 7295 | peerport = ssh_pkt_getuint32(pktin); |
| 7296 | |
| 7297 | logeventf(ssh, "Received X11 connect request from %s:%d", |
| 7298 | addrstr, peerport); |
| 7299 | |
| 7300 | if (!ssh->X11_fwd_enabled) |
| 7301 | error = "X11 forwarding is not enabled"; |
| 7302 | else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c, |
| 7303 | addrstr, peerport, ssh->conf)) != NULL) { |
| 7304 | logeventf(ssh, "Local X11 connection failed: %s", x11err); |
| 7305 | error = "Unable to open an X11 connection"; |
| 7306 | } else { |
| 7307 | logevent("Opening X11 forward connection succeeded"); |
| 7308 | c->type = CHAN_X11; |
| 7309 | } |
| 7310 | |
| 7311 | sfree(addrstr); |
| 7312 | } else if (typelen == 15 && |
| 7313 | !memcmp(type, "forwarded-tcpip", 15)) { |
| 7314 | struct ssh_rportfwd pf, *realpf; |
| 7315 | char *dummy; |
| 7316 | int dummylen; |
| 7317 | ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */ |
| 7318 | pf.sport = ssh_pkt_getuint32(pktin); |
| 7319 | ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); |
| 7320 | peerport = ssh_pkt_getuint32(pktin); |
| 7321 | realpf = find234(ssh->rportfwds, &pf, NULL); |
| 7322 | logeventf(ssh, "Received remote port %d open request " |
| 7323 | "from %s:%d", pf.sport, peeraddr, peerport); |
| 7324 | if (realpf == NULL) { |
| 7325 | error = "Remote port is not recognised"; |
| 7326 | } else { |
| 7327 | const char *e = pfd_newconnect(&c->u.pfd.s, |
| 7328 | realpf->dhost, |
| 7329 | realpf->dport, c, |
| 7330 | ssh->conf, |
| 7331 | realpf->pfrec->addressfamily); |
| 7332 | logeventf(ssh, "Attempting to forward remote port to " |
| 7333 | "%s:%d", realpf->dhost, realpf->dport); |
| 7334 | if (e != NULL) { |
| 7335 | logeventf(ssh, "Port open failed: %s", e); |
| 7336 | error = "Port open failed"; |
| 7337 | } else { |
| 7338 | logevent("Forwarded port opened successfully"); |
| 7339 | c->type = CHAN_SOCKDATA; |
| 7340 | } |
| 7341 | } |
| 7342 | } else if (typelen == 22 && |
| 7343 | !memcmp(type, "auth-agent@openssh.com", 22)) { |
| 7344 | if (!ssh->agentfwd_enabled) |
| 7345 | error = "Agent forwarding is not enabled"; |
| 7346 | else { |
| 7347 | c->type = CHAN_AGENT; /* identify channel type */ |
| 7348 | c->u.a.lensofar = 0; |
| 7349 | } |
| 7350 | } else { |
| 7351 | error = "Unsupported channel type requested"; |
| 7352 | } |
| 7353 | |
| 7354 | c->remoteid = remid; |
| 7355 | c->halfopen = FALSE; |
| 7356 | if (error) { |
| 7357 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 7358 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 7359 | ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED); |
| 7360 | ssh2_pkt_addstring(pktout, error); |
| 7361 | ssh2_pkt_addstring(pktout, "en"); /* language tag */ |
| 7362 | ssh2_pkt_send(ssh, pktout); |
| 7363 | logeventf(ssh, "Rejected channel open: %s", error); |
| 7364 | sfree(c); |
| 7365 | } else { |
| 7366 | ssh2_channel_init(c); |
| 7367 | c->v.v2.remwindow = winsize; |
| 7368 | c->v.v2.remmaxpkt = pktsize; |
| 7369 | add234(ssh->channels, c); |
| 7370 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 7371 | ssh2_pkt_adduint32(pktout, c->remoteid); |
| 7372 | ssh2_pkt_adduint32(pktout, c->localid); |
| 7373 | ssh2_pkt_adduint32(pktout, c->v.v2.locwindow); |
| 7374 | ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ |
| 7375 | ssh2_pkt_send(ssh, pktout); |
| 7376 | } |
| 7377 | } |
| 7378 | |
| 7379 | /* |
| 7380 | * Buffer banner messages for later display at some convenient point, |
| 7381 | * if we're going to display them. |
| 7382 | */ |
| 7383 | static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin) |
| 7384 | { |
| 7385 | /* Arbitrary limit to prevent unbounded inflation of buffer */ |
| 7386 | if (conf_get_int(ssh->conf, CONF_ssh_show_banner) && |
| 7387 | bufchain_size(&ssh->banner) <= 131072) { |
| 7388 | char *banner = NULL; |
| 7389 | int size = 0; |
| 7390 | ssh_pkt_getstring(pktin, &banner, &size); |
| 7391 | if (banner) |
| 7392 | bufchain_add(&ssh->banner, banner, size); |
| 7393 | } |
| 7394 | } |
| 7395 | |
| 7396 | /* Helper function to deal with sending tty modes for "pty-req" */ |
| 7397 | static void ssh2_send_ttymode(void *data, char *mode, char *val) |
| 7398 | { |
| 7399 | struct Packet *pktout = (struct Packet *)data; |
| 7400 | int i = 0; |
| 7401 | unsigned int arg = 0; |
| 7402 | while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; |
| 7403 | if (i == lenof(ssh_ttymodes)) return; |
| 7404 | switch (ssh_ttymodes[i].type) { |
| 7405 | case TTY_OP_CHAR: |
| 7406 | arg = ssh_tty_parse_specchar(val); |
| 7407 | break; |
| 7408 | case TTY_OP_BOOL: |
| 7409 | arg = ssh_tty_parse_boolean(val); |
| 7410 | break; |
| 7411 | } |
| 7412 | ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); |
| 7413 | ssh2_pkt_adduint32(pktout, arg); |
| 7414 | } |
| 7415 | |
| 7416 | /* |
| 7417 | * Handle the SSH-2 userauth and connection layers. |
| 7418 | */ |
| 7419 | static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, |
| 7420 | struct Packet *pktin) |
| 7421 | { |
| 7422 | struct do_ssh2_authconn_state { |
| 7423 | enum { |
| 7424 | AUTH_TYPE_NONE, |
| 7425 | AUTH_TYPE_PUBLICKEY, |
| 7426 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
| 7427 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
| 7428 | AUTH_TYPE_PASSWORD, |
| 7429 | AUTH_TYPE_GSSAPI, /* always QUIET */ |
| 7430 | AUTH_TYPE_KEYBOARD_INTERACTIVE, |
| 7431 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET |
| 7432 | } type; |
| 7433 | int done_service_req; |
| 7434 | int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; |
| 7435 | int tried_pubkey_config, done_agent; |
| 7436 | #ifndef NO_GSSAPI |
| 7437 | int can_gssapi; |
| 7438 | int tried_gssapi; |
| 7439 | #endif |
| 7440 | int kbd_inter_refused; |
| 7441 | int we_are_in, userauth_success; |
| 7442 | prompts_t *cur_prompt; |
| 7443 | int num_prompts; |
| 7444 | char *username; |
| 7445 | char *password; |
| 7446 | int got_username; |
| 7447 | void *publickey_blob; |
| 7448 | int publickey_bloblen; |
| 7449 | int publickey_encrypted; |
| 7450 | char *publickey_algorithm; |
| 7451 | char *publickey_comment; |
| 7452 | unsigned char agent_request[5], *agent_response, *agentp; |
| 7453 | int agent_responselen; |
| 7454 | unsigned char *pkblob_in_agent; |
| 7455 | int keyi, nkeys; |
| 7456 | char *pkblob, *alg, *commentp; |
| 7457 | int pklen, alglen, commentlen; |
| 7458 | int siglen, retlen, len; |
| 7459 | char *q, *agentreq, *ret; |
| 7460 | int try_send; |
| 7461 | int num_env, env_left, env_ok; |
| 7462 | struct Packet *pktout; |
| 7463 | Filename *keyfile; |
| 7464 | #ifndef NO_GSSAPI |
| 7465 | struct ssh_gss_library *gsslib; |
| 7466 | Ssh_gss_ctx gss_ctx; |
| 7467 | Ssh_gss_buf gss_buf; |
| 7468 | Ssh_gss_buf gss_rcvtok, gss_sndtok; |
| 7469 | Ssh_gss_name gss_srv_name; |
| 7470 | Ssh_gss_stat gss_stat; |
| 7471 | #endif |
| 7472 | }; |
| 7473 | crState(do_ssh2_authconn_state); |
| 7474 | |
| 7475 | crBegin(ssh->do_ssh2_authconn_crstate); |
| 7476 | |
| 7477 | s->done_service_req = FALSE; |
| 7478 | s->we_are_in = s->userauth_success = FALSE; |
| 7479 | #ifndef NO_GSSAPI |
| 7480 | s->tried_gssapi = FALSE; |
| 7481 | #endif |
| 7482 | |
| 7483 | if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) { |
| 7484 | /* |
| 7485 | * Request userauth protocol, and await a response to it. |
| 7486 | */ |
| 7487 | s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 7488 | ssh2_pkt_addstring(s->pktout, "ssh-userauth"); |
| 7489 | ssh2_pkt_send(ssh, s->pktout); |
| 7490 | crWaitUntilV(pktin); |
| 7491 | if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) |
| 7492 | s->done_service_req = TRUE; |
| 7493 | } |
| 7494 | if (!s->done_service_req) { |
| 7495 | /* |
| 7496 | * Request connection protocol directly, without authentication. |
| 7497 | */ |
| 7498 | s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 7499 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 7500 | ssh2_pkt_send(ssh, s->pktout); |
| 7501 | crWaitUntilV(pktin); |
| 7502 | if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) { |
| 7503 | s->we_are_in = TRUE; /* no auth required */ |
| 7504 | } else { |
| 7505 | bombout(("Server refused service request")); |
| 7506 | crStopV; |
| 7507 | } |
| 7508 | } |
| 7509 | |
| 7510 | /* Arrange to be able to deal with any BANNERs that come in. |
| 7511 | * (We do this now as packets may come in during the next bit.) */ |
| 7512 | bufchain_init(&ssh->banner); |
| 7513 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = |
| 7514 | ssh2_msg_userauth_banner; |
| 7515 | |
| 7516 | /* |
| 7517 | * Misc one-time setup for authentication. |
| 7518 | */ |
| 7519 | s->publickey_blob = NULL; |
| 7520 | if (!s->we_are_in) { |
| 7521 | |
| 7522 | /* |
| 7523 | * Load the public half of any configured public key file |
| 7524 | * for later use. |
| 7525 | */ |
| 7526 | s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); |
| 7527 | if (!filename_is_null(s->keyfile)) { |
| 7528 | int keytype; |
| 7529 | logeventf(ssh, "Reading private key file \"%.150s\"", |
| 7530 | filename_to_str(s->keyfile)); |
| 7531 | keytype = key_type(s->keyfile); |
| 7532 | if (keytype == SSH_KEYTYPE_SSH2) { |
| 7533 | const char *error; |
| 7534 | s->publickey_blob = |
| 7535 | ssh2_userkey_loadpub(s->keyfile, |
| 7536 | &s->publickey_algorithm, |
| 7537 | &s->publickey_bloblen, |
| 7538 | &s->publickey_comment, &error); |
| 7539 | if (s->publickey_blob) { |
| 7540 | s->publickey_encrypted = |
| 7541 | ssh2_userkey_encrypted(s->keyfile, NULL); |
| 7542 | } else { |
| 7543 | char *msgbuf; |
| 7544 | logeventf(ssh, "Unable to load private key (%s)", |
| 7545 | error); |
| 7546 | msgbuf = dupprintf("Unable to load private key file " |
| 7547 | "\"%.150s\" (%s)\r\n", |
| 7548 | filename_to_str(s->keyfile), |
| 7549 | error); |
| 7550 | c_write_str(ssh, msgbuf); |
| 7551 | sfree(msgbuf); |
| 7552 | } |
| 7553 | } else { |
| 7554 | char *msgbuf; |
| 7555 | logeventf(ssh, "Unable to use this key file (%s)", |
| 7556 | key_type_to_str(keytype)); |
| 7557 | msgbuf = dupprintf("Unable to use key file \"%.150s\"" |
| 7558 | " (%s)\r\n", |
| 7559 | filename_to_str(s->keyfile), |
| 7560 | key_type_to_str(keytype)); |
| 7561 | c_write_str(ssh, msgbuf); |
| 7562 | sfree(msgbuf); |
| 7563 | s->publickey_blob = NULL; |
| 7564 | } |
| 7565 | } |
| 7566 | |
| 7567 | /* |
| 7568 | * Find out about any keys Pageant has (but if there's a |
| 7569 | * public key configured, filter out all others). |
| 7570 | */ |
| 7571 | s->nkeys = 0; |
| 7572 | s->agent_response = NULL; |
| 7573 | s->pkblob_in_agent = NULL; |
| 7574 | if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) { |
| 7575 | |
| 7576 | void *r; |
| 7577 | |
| 7578 | logevent("Pageant is running. Requesting keys."); |
| 7579 | |
| 7580 | /* Request the keys held by the agent. */ |
| 7581 | PUT_32BIT(s->agent_request, 1); |
| 7582 | s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
| 7583 | if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen, |
| 7584 | ssh_agent_callback, ssh)) { |
| 7585 | do { |
| 7586 | crReturnV; |
| 7587 | if (pktin) { |
| 7588 | bombout(("Unexpected data from server while" |
| 7589 | " waiting for agent response")); |
| 7590 | crStopV; |
| 7591 | } |
| 7592 | } while (pktin || inlen > 0); |
| 7593 | r = ssh->agent_response; |
| 7594 | s->agent_responselen = ssh->agent_response_len; |
| 7595 | } |
| 7596 | s->agent_response = (unsigned char *) r; |
| 7597 | if (s->agent_response && s->agent_responselen >= 5 && |
| 7598 | s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
| 7599 | int keyi; |
| 7600 | unsigned char *p; |
| 7601 | p = s->agent_response + 5; |
| 7602 | s->nkeys = GET_32BIT(p); |
| 7603 | p += 4; |
| 7604 | logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); |
| 7605 | if (s->publickey_blob) { |
| 7606 | /* See if configured key is in agent. */ |
| 7607 | for (keyi = 0; keyi < s->nkeys; keyi++) { |
| 7608 | s->pklen = GET_32BIT(p); |
| 7609 | if (s->pklen == s->publickey_bloblen && |
| 7610 | !memcmp(p+4, s->publickey_blob, |
| 7611 | s->publickey_bloblen)) { |
| 7612 | logeventf(ssh, "Pageant key #%d matches " |
| 7613 | "configured key file", keyi); |
| 7614 | s->keyi = keyi; |
| 7615 | s->pkblob_in_agent = p; |
| 7616 | break; |
| 7617 | } |
| 7618 | p += 4 + s->pklen; |
| 7619 | p += GET_32BIT(p) + 4; /* comment */ |
| 7620 | } |
| 7621 | if (!s->pkblob_in_agent) { |
| 7622 | logevent("Configured key file not in Pageant"); |
| 7623 | s->nkeys = 0; |
| 7624 | } |
| 7625 | } |
| 7626 | } else { |
| 7627 | logevent("Failed to get reply from Pageant"); |
| 7628 | } |
| 7629 | } |
| 7630 | |
| 7631 | } |
| 7632 | |
| 7633 | /* |
| 7634 | * We repeat this whole loop, including the username prompt, |
| 7635 | * until we manage a successful authentication. If the user |
| 7636 | * types the wrong _password_, they can be sent back to the |
| 7637 | * beginning to try another username, if this is configured on. |
| 7638 | * (If they specify a username in the config, they are never |
| 7639 | * asked, even if they do give a wrong password.) |
| 7640 | * |
| 7641 | * I think this best serves the needs of |
| 7642 | * |
| 7643 | * - the people who have no configuration, no keys, and just |
| 7644 | * want to try repeated (username,password) pairs until they |
| 7645 | * type both correctly |
| 7646 | * |
| 7647 | * - people who have keys and configuration but occasionally |
| 7648 | * need to fall back to passwords |
| 7649 | * |
| 7650 | * - people with a key held in Pageant, who might not have |
| 7651 | * logged in to a particular machine before; so they want to |
| 7652 | * type a username, and then _either_ their key will be |
| 7653 | * accepted, _or_ they will type a password. If they mistype |
| 7654 | * the username they will want to be able to get back and |
| 7655 | * retype it! |
| 7656 | */ |
| 7657 | s->got_username = FALSE; |
| 7658 | while (!s->we_are_in) { |
| 7659 | /* |
| 7660 | * Get a username. |
| 7661 | */ |
| 7662 | if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) { |
| 7663 | /* |
| 7664 | * We got a username last time round this loop, and |
| 7665 | * with change_username turned off we don't try to get |
| 7666 | * it again. |
| 7667 | */ |
| 7668 | } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) { |
| 7669 | int ret; /* need not be kept over crReturn */ |
| 7670 | s->cur_prompt = new_prompts(ssh->frontend); |
| 7671 | s->cur_prompt->to_server = TRUE; |
| 7672 | s->cur_prompt->name = dupstr("SSH login name"); |
| 7673 | add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); |
| 7674 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 7675 | while (ret < 0) { |
| 7676 | ssh->send_ok = 1; |
| 7677 | crWaitUntilV(!pktin); |
| 7678 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 7679 | ssh->send_ok = 0; |
| 7680 | } |
| 7681 | if (!ret) { |
| 7682 | /* |
| 7683 | * get_userpass_input() failed to get a username. |
| 7684 | * Terminate. |
| 7685 | */ |
| 7686 | free_prompts(s->cur_prompt); |
| 7687 | ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); |
| 7688 | crStopV; |
| 7689 | } |
| 7690 | ssh->username = dupstr(s->cur_prompt->prompts[0]->result); |
| 7691 | free_prompts(s->cur_prompt); |
| 7692 | } else { |
| 7693 | char *stuff; |
| 7694 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
| 7695 | stuff = dupprintf("Using username \"%s\".\r\n", ssh->username); |
| 7696 | c_write_str(ssh, stuff); |
| 7697 | sfree(stuff); |
| 7698 | } |
| 7699 | } |
| 7700 | s->got_username = TRUE; |
| 7701 | |
| 7702 | /* |
| 7703 | * Send an authentication request using method "none": (a) |
| 7704 | * just in case it succeeds, and (b) so that we know what |
| 7705 | * authentication methods we can usefully try next. |
| 7706 | */ |
| 7707 | ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; |
| 7708 | |
| 7709 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 7710 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 7711 | ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */ |
| 7712 | ssh2_pkt_addstring(s->pktout, "none"); /* method */ |
| 7713 | ssh2_pkt_send(ssh, s->pktout); |
| 7714 | s->type = AUTH_TYPE_NONE; |
| 7715 | s->gotit = FALSE; |
| 7716 | s->we_are_in = FALSE; |
| 7717 | |
| 7718 | s->tried_pubkey_config = FALSE; |
| 7719 | s->kbd_inter_refused = FALSE; |
| 7720 | |
| 7721 | /* Reset agent request state. */ |
| 7722 | s->done_agent = FALSE; |
| 7723 | if (s->agent_response) { |
| 7724 | if (s->pkblob_in_agent) { |
| 7725 | s->agentp = s->pkblob_in_agent; |
| 7726 | } else { |
| 7727 | s->agentp = s->agent_response + 5 + 4; |
| 7728 | s->keyi = 0; |
| 7729 | } |
| 7730 | } |
| 7731 | |
| 7732 | while (1) { |
| 7733 | char *methods = NULL; |
| 7734 | int methlen = 0; |
| 7735 | |
| 7736 | /* |
| 7737 | * Wait for the result of the last authentication request. |
| 7738 | */ |
| 7739 | if (!s->gotit) |
| 7740 | crWaitUntilV(pktin); |
| 7741 | /* |
| 7742 | * Now is a convenient point to spew any banner material |
| 7743 | * that we've accumulated. (This should ensure that when |
| 7744 | * we exit the auth loop, we haven't any left to deal |
| 7745 | * with.) |
| 7746 | */ |
| 7747 | { |
| 7748 | int size = bufchain_size(&ssh->banner); |
| 7749 | /* |
| 7750 | * Don't show the banner if we're operating in |
| 7751 | * non-verbose non-interactive mode. (It's probably |
| 7752 | * a script, which means nobody will read the |
| 7753 | * banner _anyway_, and moreover the printing of |
| 7754 | * the banner will screw up processing on the |
| 7755 | * output of (say) plink.) |
| 7756 | */ |
| 7757 | if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) { |
| 7758 | char *banner = snewn(size, char); |
| 7759 | bufchain_fetch(&ssh->banner, banner, size); |
| 7760 | c_write_untrusted(ssh, banner, size); |
| 7761 | sfree(banner); |
| 7762 | } |
| 7763 | bufchain_clear(&ssh->banner); |
| 7764 | } |
| 7765 | if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) { |
| 7766 | logevent("Access granted"); |
| 7767 | s->we_are_in = s->userauth_success = TRUE; |
| 7768 | break; |
| 7769 | } |
| 7770 | |
| 7771 | if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) { |
| 7772 | bombout(("Strange packet received during authentication: " |
| 7773 | "type %d", pktin->type)); |
| 7774 | crStopV; |
| 7775 | } |
| 7776 | |
| 7777 | s->gotit = FALSE; |
| 7778 | |
| 7779 | /* |
| 7780 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
| 7781 | * we can look at the string in it and know what we can |
| 7782 | * helpfully try next. |
| 7783 | */ |
| 7784 | if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) { |
| 7785 | ssh_pkt_getstring(pktin, &methods, &methlen); |
| 7786 | if (!ssh2_pkt_getbool(pktin)) { |
| 7787 | /* |
| 7788 | * We have received an unequivocal Access |
| 7789 | * Denied. This can translate to a variety of |
| 7790 | * messages, or no message at all. |
| 7791 | * |
| 7792 | * For forms of authentication which are attempted |
| 7793 | * implicitly, by which I mean without printing |
| 7794 | * anything in the window indicating that we're |
| 7795 | * trying them, we should never print 'Access |
| 7796 | * denied'. |
| 7797 | * |
| 7798 | * If we do print a message saying that we're |
| 7799 | * attempting some kind of authentication, it's OK |
| 7800 | * to print a followup message saying it failed - |
| 7801 | * but the message may sometimes be more specific |
| 7802 | * than simply 'Access denied'. |
| 7803 | * |
| 7804 | * Additionally, if we'd just tried password |
| 7805 | * authentication, we should break out of this |
| 7806 | * whole loop so as to go back to the username |
| 7807 | * prompt (iff we're configured to allow |
| 7808 | * username change attempts). |
| 7809 | */ |
| 7810 | if (s->type == AUTH_TYPE_NONE) { |
| 7811 | /* do nothing */ |
| 7812 | } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
| 7813 | s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
| 7814 | if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
| 7815 | c_write_str(ssh, "Server refused our key\r\n"); |
| 7816 | logevent("Server refused our key"); |
| 7817 | } else if (s->type == AUTH_TYPE_PUBLICKEY) { |
| 7818 | /* This _shouldn't_ happen except by a |
| 7819 | * protocol bug causing client and server to |
| 7820 | * disagree on what is a correct signature. */ |
| 7821 | c_write_str(ssh, "Server refused public-key signature" |
| 7822 | " despite accepting key!\r\n"); |
| 7823 | logevent("Server refused public-key signature" |
| 7824 | " despite accepting key!"); |
| 7825 | } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { |
| 7826 | /* quiet, so no c_write */ |
| 7827 | logevent("Server refused keyboard-interactive authentication"); |
| 7828 | } else if (s->type==AUTH_TYPE_GSSAPI) { |
| 7829 | /* always quiet, so no c_write */ |
| 7830 | /* also, the code down in the GSSAPI block has |
| 7831 | * already logged this in the Event Log */ |
| 7832 | } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) { |
| 7833 | logevent("Keyboard-interactive authentication failed"); |
| 7834 | c_write_str(ssh, "Access denied\r\n"); |
| 7835 | } else { |
| 7836 | assert(s->type == AUTH_TYPE_PASSWORD); |
| 7837 | logevent("Password authentication failed"); |
| 7838 | c_write_str(ssh, "Access denied\r\n"); |
| 7839 | |
| 7840 | if (conf_get_int(ssh->conf, CONF_change_username)) { |
| 7841 | /* XXX perhaps we should allow |
| 7842 | * keyboard-interactive to do this too? */ |
| 7843 | s->we_are_in = FALSE; |
| 7844 | break; |
| 7845 | } |
| 7846 | } |
| 7847 | } else { |
| 7848 | c_write_str(ssh, "Further authentication required\r\n"); |
| 7849 | logevent("Further authentication required"); |
| 7850 | } |
| 7851 | |
| 7852 | s->can_pubkey = |
| 7853 | in_commasep_string("publickey", methods, methlen); |
| 7854 | s->can_passwd = |
| 7855 | in_commasep_string("password", methods, methlen); |
| 7856 | s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) && |
| 7857 | in_commasep_string("keyboard-interactive", methods, methlen); |
| 7858 | #ifndef NO_GSSAPI |
| 7859 | if (!ssh->gsslibs) |
| 7860 | ssh->gsslibs = ssh_gss_setup(ssh->conf); |
| 7861 | s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) && |
| 7862 | in_commasep_string("gssapi-with-mic", methods, methlen) && |
| 7863 | ssh->gsslibs->nlibraries > 0; |
| 7864 | #endif |
| 7865 | } |
| 7866 | |
| 7867 | ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; |
| 7868 | |
| 7869 | if (s->can_pubkey && !s->done_agent && s->nkeys) { |
| 7870 | |
| 7871 | /* |
| 7872 | * Attempt public-key authentication using a key from Pageant. |
| 7873 | */ |
| 7874 | |
| 7875 | ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; |
| 7876 | |
| 7877 | logeventf(ssh, "Trying Pageant key #%d", s->keyi); |
| 7878 | |
| 7879 | /* Unpack key from agent response */ |
| 7880 | s->pklen = GET_32BIT(s->agentp); |
| 7881 | s->agentp += 4; |
| 7882 | s->pkblob = (char *)s->agentp; |
| 7883 | s->agentp += s->pklen; |
| 7884 | s->alglen = GET_32BIT(s->pkblob); |
| 7885 | s->alg = s->pkblob + 4; |
| 7886 | s->commentlen = GET_32BIT(s->agentp); |
| 7887 | s->agentp += 4; |
| 7888 | s->commentp = (char *)s->agentp; |
| 7889 | s->agentp += s->commentlen; |
| 7890 | /* s->agentp now points at next key, if any */ |
| 7891 | |
| 7892 | /* See if server will accept it */ |
| 7893 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 7894 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 7895 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 7896 | /* service requested */ |
| 7897 | ssh2_pkt_addstring(s->pktout, "publickey"); |
| 7898 | /* method */ |
| 7899 | ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ |
| 7900 | ssh2_pkt_addstring_start(s->pktout); |
| 7901 | ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); |
| 7902 | ssh2_pkt_addstring_start(s->pktout); |
| 7903 | ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); |
| 7904 | ssh2_pkt_send(ssh, s->pktout); |
| 7905 | s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET; |
| 7906 | |
| 7907 | crWaitUntilV(pktin); |
| 7908 | if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { |
| 7909 | |
| 7910 | /* Offer of key refused. */ |
| 7911 | s->gotit = TRUE; |
| 7912 | |
| 7913 | } else { |
| 7914 | |
| 7915 | void *vret; |
| 7916 | |
| 7917 | if (flags & FLAG_VERBOSE) { |
| 7918 | c_write_str(ssh, "Authenticating with " |
| 7919 | "public key \""); |
| 7920 | c_write(ssh, s->commentp, s->commentlen); |
| 7921 | c_write_str(ssh, "\" from agent\r\n"); |
| 7922 | } |
| 7923 | |
| 7924 | /* |
| 7925 | * Server is willing to accept the key. |
| 7926 | * Construct a SIGN_REQUEST. |
| 7927 | */ |
| 7928 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 7929 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 7930 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 7931 | /* service requested */ |
| 7932 | ssh2_pkt_addstring(s->pktout, "publickey"); |
| 7933 | /* method */ |
| 7934 | ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */ |
| 7935 | ssh2_pkt_addstring_start(s->pktout); |
| 7936 | ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); |
| 7937 | ssh2_pkt_addstring_start(s->pktout); |
| 7938 | ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); |
| 7939 | |
| 7940 | /* Ask agent for signature. */ |
| 7941 | s->siglen = s->pktout->length - 5 + 4 + |
| 7942 | ssh->v2_session_id_len; |
| 7943 | if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) |
| 7944 | s->siglen -= 4; |
| 7945 | s->len = 1; /* message type */ |
| 7946 | s->len += 4 + s->pklen; /* key blob */ |
| 7947 | s->len += 4 + s->siglen; /* data to sign */ |
| 7948 | s->len += 4; /* flags */ |
| 7949 | s->agentreq = snewn(4 + s->len, char); |
| 7950 | PUT_32BIT(s->agentreq, s->len); |
| 7951 | s->q = s->agentreq + 4; |
| 7952 | *s->q++ = SSH2_AGENTC_SIGN_REQUEST; |
| 7953 | PUT_32BIT(s->q, s->pklen); |
| 7954 | s->q += 4; |
| 7955 | memcpy(s->q, s->pkblob, s->pklen); |
| 7956 | s->q += s->pklen; |
| 7957 | PUT_32BIT(s->q, s->siglen); |
| 7958 | s->q += 4; |
| 7959 | /* Now the data to be signed... */ |
| 7960 | if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { |
| 7961 | PUT_32BIT(s->q, ssh->v2_session_id_len); |
| 7962 | s->q += 4; |
| 7963 | } |
| 7964 | memcpy(s->q, ssh->v2_session_id, |
| 7965 | ssh->v2_session_id_len); |
| 7966 | s->q += ssh->v2_session_id_len; |
| 7967 | memcpy(s->q, s->pktout->data + 5, |
| 7968 | s->pktout->length - 5); |
| 7969 | s->q += s->pktout->length - 5; |
| 7970 | /* And finally the (zero) flags word. */ |
| 7971 | PUT_32BIT(s->q, 0); |
| 7972 | if (!agent_query(s->agentreq, s->len + 4, |
| 7973 | &vret, &s->retlen, |
| 7974 | ssh_agent_callback, ssh)) { |
| 7975 | do { |
| 7976 | crReturnV; |
| 7977 | if (pktin) { |
| 7978 | bombout(("Unexpected data from server" |
| 7979 | " while waiting for agent" |
| 7980 | " response")); |
| 7981 | crStopV; |
| 7982 | } |
| 7983 | } while (pktin || inlen > 0); |
| 7984 | vret = ssh->agent_response; |
| 7985 | s->retlen = ssh->agent_response_len; |
| 7986 | } |
| 7987 | s->ret = vret; |
| 7988 | sfree(s->agentreq); |
| 7989 | if (s->ret) { |
| 7990 | if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
| 7991 | logevent("Sending Pageant's response"); |
| 7992 | ssh2_add_sigblob(ssh, s->pktout, |
| 7993 | s->pkblob, s->pklen, |
| 7994 | s->ret + 9, |
| 7995 | GET_32BIT(s->ret + 5)); |
| 7996 | ssh2_pkt_send(ssh, s->pktout); |
| 7997 | s->type = AUTH_TYPE_PUBLICKEY; |
| 7998 | } else { |
| 7999 | /* FIXME: less drastic response */ |
| 8000 | bombout(("Pageant failed to answer challenge")); |
| 8001 | crStopV; |
| 8002 | } |
| 8003 | } |
| 8004 | } |
| 8005 | |
| 8006 | /* Do we have any keys left to try? */ |
| 8007 | if (s->pkblob_in_agent) { |
| 8008 | s->done_agent = TRUE; |
| 8009 | s->tried_pubkey_config = TRUE; |
| 8010 | } else { |
| 8011 | s->keyi++; |
| 8012 | if (s->keyi >= s->nkeys) |
| 8013 | s->done_agent = TRUE; |
| 8014 | } |
| 8015 | |
| 8016 | } else if (s->can_pubkey && s->publickey_blob && |
| 8017 | !s->tried_pubkey_config) { |
| 8018 | |
| 8019 | struct ssh2_userkey *key; /* not live over crReturn */ |
| 8020 | char *passphrase; /* not live over crReturn */ |
| 8021 | |
| 8022 | ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; |
| 8023 | |
| 8024 | s->tried_pubkey_config = TRUE; |
| 8025 | |
| 8026 | /* |
| 8027 | * Try the public key supplied in the configuration. |
| 8028 | * |
| 8029 | * First, offer the public blob to see if the server is |
| 8030 | * willing to accept it. |
| 8031 | */ |
| 8032 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 8033 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 8034 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 8035 | /* service requested */ |
| 8036 | ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ |
| 8037 | ssh2_pkt_addbool(s->pktout, FALSE); |
| 8038 | /* no signature included */ |
| 8039 | ssh2_pkt_addstring(s->pktout, s->publickey_algorithm); |
| 8040 | ssh2_pkt_addstring_start(s->pktout); |
| 8041 | ssh2_pkt_addstring_data(s->pktout, |
| 8042 | (char *)s->publickey_blob, |
| 8043 | s->publickey_bloblen); |
| 8044 | ssh2_pkt_send(ssh, s->pktout); |
| 8045 | logevent("Offered public key"); |
| 8046 | |
| 8047 | crWaitUntilV(pktin); |
| 8048 | if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { |
| 8049 | /* Key refused. Give up. */ |
| 8050 | s->gotit = TRUE; /* reconsider message next loop */ |
| 8051 | s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
| 8052 | continue; /* process this new message */ |
| 8053 | } |
| 8054 | logevent("Offer of public key accepted"); |
| 8055 | |
| 8056 | /* |
| 8057 | * Actually attempt a serious authentication using |
| 8058 | * the key. |
| 8059 | */ |
| 8060 | if (flags & FLAG_VERBOSE) { |
| 8061 | c_write_str(ssh, "Authenticating with public key \""); |
| 8062 | c_write_str(ssh, s->publickey_comment); |
| 8063 | c_write_str(ssh, "\"\r\n"); |
| 8064 | } |
| 8065 | key = NULL; |
| 8066 | while (!key) { |
| 8067 | const char *error; /* not live over crReturn */ |
| 8068 | if (s->publickey_encrypted) { |
| 8069 | /* |
| 8070 | * Get a passphrase from the user. |
| 8071 | */ |
| 8072 | int ret; /* need not be kept over crReturn */ |
| 8073 | s->cur_prompt = new_prompts(ssh->frontend); |
| 8074 | s->cur_prompt->to_server = FALSE; |
| 8075 | s->cur_prompt->name = dupstr("SSH key passphrase"); |
| 8076 | add_prompt(s->cur_prompt, |
| 8077 | dupprintf("Passphrase for key \"%.100s\": ", |
| 8078 | s->publickey_comment), |
| 8079 | FALSE); |
| 8080 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 8081 | while (ret < 0) { |
| 8082 | ssh->send_ok = 1; |
| 8083 | crWaitUntilV(!pktin); |
| 8084 | ret = get_userpass_input(s->cur_prompt, |
| 8085 | in, inlen); |
| 8086 | ssh->send_ok = 0; |
| 8087 | } |
| 8088 | if (!ret) { |
| 8089 | /* Failed to get a passphrase. Terminate. */ |
| 8090 | free_prompts(s->cur_prompt); |
| 8091 | ssh_disconnect(ssh, NULL, |
| 8092 | "Unable to authenticate", |
| 8093 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, |
| 8094 | TRUE); |
| 8095 | crStopV; |
| 8096 | } |
| 8097 | passphrase = |
| 8098 | dupstr(s->cur_prompt->prompts[0]->result); |
| 8099 | free_prompts(s->cur_prompt); |
| 8100 | } else { |
| 8101 | passphrase = NULL; /* no passphrase needed */ |
| 8102 | } |
| 8103 | |
| 8104 | /* |
| 8105 | * Try decrypting the key. |
| 8106 | */ |
| 8107 | s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); |
| 8108 | key = ssh2_load_userkey(s->keyfile, passphrase, &error); |
| 8109 | if (passphrase) { |
| 8110 | /* burn the evidence */ |
| 8111 | memset(passphrase, 0, strlen(passphrase)); |
| 8112 | sfree(passphrase); |
| 8113 | } |
| 8114 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
| 8115 | if (passphrase && |
| 8116 | (key == SSH2_WRONG_PASSPHRASE)) { |
| 8117 | c_write_str(ssh, "Wrong passphrase\r\n"); |
| 8118 | key = NULL; |
| 8119 | /* and loop again */ |
| 8120 | } else { |
| 8121 | c_write_str(ssh, "Unable to load private key ("); |
| 8122 | c_write_str(ssh, error); |
| 8123 | c_write_str(ssh, ")\r\n"); |
| 8124 | key = NULL; |
| 8125 | break; /* try something else */ |
| 8126 | } |
| 8127 | } |
| 8128 | } |
| 8129 | |
| 8130 | if (key) { |
| 8131 | unsigned char *pkblob, *sigblob, *sigdata; |
| 8132 | int pkblob_len, sigblob_len, sigdata_len; |
| 8133 | int p; |
| 8134 | |
| 8135 | /* |
| 8136 | * We have loaded the private key and the server |
| 8137 | * has announced that it's willing to accept it. |
| 8138 | * Hallelujah. Generate a signature and send it. |
| 8139 | */ |
| 8140 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 8141 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 8142 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 8143 | /* service requested */ |
| 8144 | ssh2_pkt_addstring(s->pktout, "publickey"); |
| 8145 | /* method */ |
| 8146 | ssh2_pkt_addbool(s->pktout, TRUE); |
| 8147 | /* signature follows */ |
| 8148 | ssh2_pkt_addstring(s->pktout, key->alg->name); |
| 8149 | pkblob = key->alg->public_blob(key->data, |
| 8150 | &pkblob_len); |
| 8151 | ssh2_pkt_addstring_start(s->pktout); |
| 8152 | ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, |
| 8153 | pkblob_len); |
| 8154 | |
| 8155 | /* |
| 8156 | * The data to be signed is: |
| 8157 | * |
| 8158 | * string session-id |
| 8159 | * |
| 8160 | * followed by everything so far placed in the |
| 8161 | * outgoing packet. |
| 8162 | */ |
| 8163 | sigdata_len = s->pktout->length - 5 + 4 + |
| 8164 | ssh->v2_session_id_len; |
| 8165 | if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) |
| 8166 | sigdata_len -= 4; |
| 8167 | sigdata = snewn(sigdata_len, unsigned char); |
| 8168 | p = 0; |
| 8169 | if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { |
| 8170 | PUT_32BIT(sigdata+p, ssh->v2_session_id_len); |
| 8171 | p += 4; |
| 8172 | } |
| 8173 | memcpy(sigdata+p, ssh->v2_session_id, |
| 8174 | ssh->v2_session_id_len); |
| 8175 | p += ssh->v2_session_id_len; |
| 8176 | memcpy(sigdata+p, s->pktout->data + 5, |
| 8177 | s->pktout->length - 5); |
| 8178 | p += s->pktout->length - 5; |
| 8179 | assert(p == sigdata_len); |
| 8180 | sigblob = key->alg->sign(key->data, (char *)sigdata, |
| 8181 | sigdata_len, &sigblob_len); |
| 8182 | ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len, |
| 8183 | sigblob, sigblob_len); |
| 8184 | sfree(pkblob); |
| 8185 | sfree(sigblob); |
| 8186 | sfree(sigdata); |
| 8187 | |
| 8188 | ssh2_pkt_send(ssh, s->pktout); |
| 8189 | logevent("Sent public key signature"); |
| 8190 | s->type = AUTH_TYPE_PUBLICKEY; |
| 8191 | key->alg->freekey(key->data); |
| 8192 | } |
| 8193 | |
| 8194 | #ifndef NO_GSSAPI |
| 8195 | } else if (s->can_gssapi && !s->tried_gssapi) { |
| 8196 | |
| 8197 | /* GSSAPI Authentication */ |
| 8198 | |
| 8199 | int micoffset, len; |
| 8200 | char *data; |
| 8201 | Ssh_gss_buf mic; |
| 8202 | s->type = AUTH_TYPE_GSSAPI; |
| 8203 | s->tried_gssapi = TRUE; |
| 8204 | s->gotit = TRUE; |
| 8205 | ssh->pkt_actx = SSH2_PKTCTX_GSSAPI; |
| 8206 | |
| 8207 | /* |
| 8208 | * Pick the highest GSS library on the preference |
| 8209 | * list. |
| 8210 | */ |
| 8211 | { |
| 8212 | int i, j; |
| 8213 | s->gsslib = NULL; |
| 8214 | for (i = 0; i < ngsslibs; i++) { |
| 8215 | int want_id = conf_get_int_int(ssh->conf, |
| 8216 | CONF_ssh_gsslist, i); |
| 8217 | for (j = 0; j < ssh->gsslibs->nlibraries; j++) |
| 8218 | if (ssh->gsslibs->libraries[j].id == want_id) { |
| 8219 | s->gsslib = &ssh->gsslibs->libraries[j]; |
| 8220 | goto got_gsslib; /* double break */ |
| 8221 | } |
| 8222 | } |
| 8223 | got_gsslib: |
| 8224 | /* |
| 8225 | * We always expect to have found something in |
| 8226 | * the above loop: we only came here if there |
| 8227 | * was at least one viable GSS library, and the |
| 8228 | * preference list should always mention |
| 8229 | * everything and only change the order. |
| 8230 | */ |
| 8231 | assert(s->gsslib); |
| 8232 | } |
| 8233 | |
| 8234 | if (s->gsslib->gsslogmsg) |
| 8235 | logevent(s->gsslib->gsslogmsg); |
| 8236 | |
| 8237 | /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */ |
| 8238 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 8239 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 8240 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 8241 | ssh2_pkt_addstring(s->pktout, "gssapi-with-mic"); |
| 8242 | logevent("Attempting GSSAPI authentication"); |
| 8243 | |
| 8244 | /* add mechanism info */ |
| 8245 | s->gsslib->indicate_mech(s->gsslib, &s->gss_buf); |
| 8246 | |
| 8247 | /* number of GSSAPI mechanisms */ |
| 8248 | ssh2_pkt_adduint32(s->pktout,1); |
| 8249 | |
| 8250 | /* length of OID + 2 */ |
| 8251 | ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2); |
| 8252 | ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE); |
| 8253 | |
| 8254 | /* length of OID */ |
| 8255 | ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length); |
| 8256 | |
| 8257 | ssh_pkt_adddata(s->pktout, s->gss_buf.value, |
| 8258 | s->gss_buf.length); |
| 8259 | ssh2_pkt_send(ssh, s->pktout); |
| 8260 | crWaitUntilV(pktin); |
| 8261 | if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) { |
| 8262 | logevent("GSSAPI authentication request refused"); |
| 8263 | continue; |
| 8264 | } |
| 8265 | |
| 8266 | /* check returned packet ... */ |
| 8267 | |
| 8268 | ssh_pkt_getstring(pktin, &data, &len); |
| 8269 | s->gss_rcvtok.value = data; |
| 8270 | s->gss_rcvtok.length = len; |
| 8271 | if (s->gss_rcvtok.length != s->gss_buf.length + 2 || |
| 8272 | ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE || |
| 8273 | ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length || |
| 8274 | memcmp((char *)s->gss_rcvtok.value + 2, |
| 8275 | s->gss_buf.value,s->gss_buf.length) ) { |
| 8276 | logevent("GSSAPI authentication - wrong response from server"); |
| 8277 | continue; |
| 8278 | } |
| 8279 | |
| 8280 | /* now start running */ |
| 8281 | s->gss_stat = s->gsslib->import_name(s->gsslib, |
| 8282 | ssh->fullhostname, |
| 8283 | &s->gss_srv_name); |
| 8284 | if (s->gss_stat != SSH_GSS_OK) { |
| 8285 | if (s->gss_stat == SSH_GSS_BAD_HOST_NAME) |
| 8286 | logevent("GSSAPI import name failed - Bad service name"); |
| 8287 | else |
| 8288 | logevent("GSSAPI import name failed"); |
| 8289 | continue; |
| 8290 | } |
| 8291 | |
| 8292 | /* fetch TGT into GSS engine */ |
| 8293 | s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx); |
| 8294 | |
| 8295 | if (s->gss_stat != SSH_GSS_OK) { |
| 8296 | logevent("GSSAPI authentication failed to get credentials"); |
| 8297 | s->gsslib->release_name(s->gsslib, &s->gss_srv_name); |
| 8298 | continue; |
| 8299 | } |
| 8300 | |
| 8301 | /* initial tokens are empty */ |
| 8302 | SSH_GSS_CLEAR_BUF(&s->gss_rcvtok); |
| 8303 | SSH_GSS_CLEAR_BUF(&s->gss_sndtok); |
| 8304 | |
| 8305 | /* now enter the loop */ |
| 8306 | do { |
| 8307 | s->gss_stat = s->gsslib->init_sec_context |
| 8308 | (s->gsslib, |
| 8309 | &s->gss_ctx, |
| 8310 | s->gss_srv_name, |
| 8311 | conf_get_int(ssh->conf, CONF_gssapifwd), |
| 8312 | &s->gss_rcvtok, |
| 8313 | &s->gss_sndtok); |
| 8314 | |
| 8315 | if (s->gss_stat!=SSH_GSS_S_COMPLETE && |
| 8316 | s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) { |
| 8317 | logevent("GSSAPI authentication initialisation failed"); |
| 8318 | |
| 8319 | if (s->gsslib->display_status(s->gsslib, s->gss_ctx, |
| 8320 | &s->gss_buf) == SSH_GSS_OK) { |
| 8321 | logevent(s->gss_buf.value); |
| 8322 | sfree(s->gss_buf.value); |
| 8323 | } |
| 8324 | |
| 8325 | break; |
| 8326 | } |
| 8327 | logevent("GSSAPI authentication initialised"); |
| 8328 | |
| 8329 | /* Client and server now exchange tokens until GSSAPI |
| 8330 | * no longer says CONTINUE_NEEDED */ |
| 8331 | |
| 8332 | if (s->gss_sndtok.length != 0) { |
| 8333 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); |
| 8334 | ssh_pkt_addstring_start(s->pktout); |
| 8335 | ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length); |
| 8336 | ssh2_pkt_send(ssh, s->pktout); |
| 8337 | s->gsslib->free_tok(s->gsslib, &s->gss_sndtok); |
| 8338 | } |
| 8339 | |
| 8340 | if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) { |
| 8341 | crWaitUntilV(pktin); |
| 8342 | if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) { |
| 8343 | logevent("GSSAPI authentication - bad server response"); |
| 8344 | s->gss_stat = SSH_GSS_FAILURE; |
| 8345 | break; |
| 8346 | } |
| 8347 | ssh_pkt_getstring(pktin, &data, &len); |
| 8348 | s->gss_rcvtok.value = data; |
| 8349 | s->gss_rcvtok.length = len; |
| 8350 | } |
| 8351 | } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED); |
| 8352 | |
| 8353 | if (s->gss_stat != SSH_GSS_OK) { |
| 8354 | s->gsslib->release_name(s->gsslib, &s->gss_srv_name); |
| 8355 | s->gsslib->release_cred(s->gsslib, &s->gss_ctx); |
| 8356 | continue; |
| 8357 | } |
| 8358 | logevent("GSSAPI authentication loop finished OK"); |
| 8359 | |
| 8360 | /* Now send the MIC */ |
| 8361 | |
| 8362 | s->pktout = ssh2_pkt_init(0); |
| 8363 | micoffset = s->pktout->length; |
| 8364 | ssh_pkt_addstring_start(s->pktout); |
| 8365 | ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len); |
| 8366 | ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST); |
| 8367 | ssh_pkt_addstring(s->pktout, ssh->username); |
| 8368 | ssh_pkt_addstring(s->pktout, "ssh-connection"); |
| 8369 | ssh_pkt_addstring(s->pktout, "gssapi-with-mic"); |
| 8370 | |
| 8371 | s->gss_buf.value = (char *)s->pktout->data + micoffset; |
| 8372 | s->gss_buf.length = s->pktout->length - micoffset; |
| 8373 | |
| 8374 | s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic); |
| 8375 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC); |
| 8376 | ssh_pkt_addstring_start(s->pktout); |
| 8377 | ssh_pkt_addstring_data(s->pktout, mic.value, mic.length); |
| 8378 | ssh2_pkt_send(ssh, s->pktout); |
| 8379 | s->gsslib->free_mic(s->gsslib, &mic); |
| 8380 | |
| 8381 | s->gotit = FALSE; |
| 8382 | |
| 8383 | s->gsslib->release_name(s->gsslib, &s->gss_srv_name); |
| 8384 | s->gsslib->release_cred(s->gsslib, &s->gss_ctx); |
| 8385 | continue; |
| 8386 | #endif |
| 8387 | } else if (s->can_keyb_inter && !s->kbd_inter_refused) { |
| 8388 | |
| 8389 | /* |
| 8390 | * Keyboard-interactive authentication. |
| 8391 | */ |
| 8392 | |
| 8393 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 8394 | |
| 8395 | ssh->pkt_actx = SSH2_PKTCTX_KBDINTER; |
| 8396 | |
| 8397 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 8398 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 8399 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 8400 | /* service requested */ |
| 8401 | ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); |
| 8402 | /* method */ |
| 8403 | ssh2_pkt_addstring(s->pktout, ""); /* lang */ |
| 8404 | ssh2_pkt_addstring(s->pktout, ""); /* submethods */ |
| 8405 | ssh2_pkt_send(ssh, s->pktout); |
| 8406 | |
| 8407 | logevent("Attempting keyboard-interactive authentication"); |
| 8408 | |
| 8409 | crWaitUntilV(pktin); |
| 8410 | if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 8411 | /* Server is not willing to do keyboard-interactive |
| 8412 | * at all (or, bizarrely but legally, accepts the |
| 8413 | * user without actually issuing any prompts). |
| 8414 | * Give up on it entirely. */ |
| 8415 | s->gotit = TRUE; |
| 8416 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; |
| 8417 | s->kbd_inter_refused = TRUE; /* don't try it again */ |
| 8418 | continue; |
| 8419 | } |
| 8420 | |
| 8421 | /* |
| 8422 | * Loop while the server continues to send INFO_REQUESTs. |
| 8423 | */ |
| 8424 | while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 8425 | |
| 8426 | char *name, *inst, *lang; |
| 8427 | int name_len, inst_len, lang_len; |
| 8428 | int i; |
| 8429 | |
| 8430 | /* |
| 8431 | * We've got a fresh USERAUTH_INFO_REQUEST. |
| 8432 | * Get the preamble and start building a prompt. |
| 8433 | */ |
| 8434 | ssh_pkt_getstring(pktin, &name, &name_len); |
| 8435 | ssh_pkt_getstring(pktin, &inst, &inst_len); |
| 8436 | ssh_pkt_getstring(pktin, &lang, &lang_len); |
| 8437 | s->cur_prompt = new_prompts(ssh->frontend); |
| 8438 | s->cur_prompt->to_server = TRUE; |
| 8439 | |
| 8440 | /* |
| 8441 | * Get any prompt(s) from the packet. |
| 8442 | */ |
| 8443 | s->num_prompts = ssh_pkt_getuint32(pktin); |
| 8444 | for (i = 0; i < s->num_prompts; i++) { |
| 8445 | char *prompt; |
| 8446 | int prompt_len; |
| 8447 | int echo; |
| 8448 | static char noprompt[] = |
| 8449 | "<server failed to send prompt>: "; |
| 8450 | |
| 8451 | ssh_pkt_getstring(pktin, &prompt, &prompt_len); |
| 8452 | echo = ssh2_pkt_getbool(pktin); |
| 8453 | if (!prompt_len) { |
| 8454 | prompt = noprompt; |
| 8455 | prompt_len = lenof(noprompt)-1; |
| 8456 | } |
| 8457 | add_prompt(s->cur_prompt, |
| 8458 | dupprintf("%.*s", prompt_len, prompt), |
| 8459 | echo); |
| 8460 | } |
| 8461 | |
| 8462 | if (name_len) { |
| 8463 | /* FIXME: better prefix to distinguish from |
| 8464 | * local prompts? */ |
| 8465 | s->cur_prompt->name = |
| 8466 | dupprintf("SSH server: %.*s", name_len, name); |
| 8467 | s->cur_prompt->name_reqd = TRUE; |
| 8468 | } else { |
| 8469 | s->cur_prompt->name = |
| 8470 | dupstr("SSH server authentication"); |
| 8471 | s->cur_prompt->name_reqd = FALSE; |
| 8472 | } |
| 8473 | /* We add a prefix to try to make it clear that a prompt |
| 8474 | * has come from the server. |
| 8475 | * FIXME: ugly to print "Using..." in prompt _every_ |
| 8476 | * time round. Can this be done more subtly? */ |
| 8477 | /* Special case: for reasons best known to themselves, |
| 8478 | * some servers send k-i requests with no prompts and |
| 8479 | * nothing to display. Keep quiet in this case. */ |
| 8480 | if (s->num_prompts || name_len || inst_len) { |
| 8481 | s->cur_prompt->instruction = |
| 8482 | dupprintf("Using keyboard-interactive authentication.%s%.*s", |
| 8483 | inst_len ? "\n" : "", inst_len, inst); |
| 8484 | s->cur_prompt->instr_reqd = TRUE; |
| 8485 | } else { |
| 8486 | s->cur_prompt->instr_reqd = FALSE; |
| 8487 | } |
| 8488 | |
| 8489 | /* |
| 8490 | * Display any instructions, and get the user's |
| 8491 | * response(s). |
| 8492 | */ |
| 8493 | { |
| 8494 | int ret; /* not live over crReturn */ |
| 8495 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 8496 | while (ret < 0) { |
| 8497 | ssh->send_ok = 1; |
| 8498 | crWaitUntilV(!pktin); |
| 8499 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 8500 | ssh->send_ok = 0; |
| 8501 | } |
| 8502 | if (!ret) { |
| 8503 | /* |
| 8504 | * Failed to get responses. Terminate. |
| 8505 | */ |
| 8506 | free_prompts(s->cur_prompt); |
| 8507 | ssh_disconnect(ssh, NULL, "Unable to authenticate", |
| 8508 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, |
| 8509 | TRUE); |
| 8510 | crStopV; |
| 8511 | } |
| 8512 | } |
| 8513 | |
| 8514 | /* |
| 8515 | * Send the response(s) to the server. |
| 8516 | */ |
| 8517 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
| 8518 | ssh2_pkt_adduint32(s->pktout, s->num_prompts); |
| 8519 | for (i=0; i < s->num_prompts; i++) { |
| 8520 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); |
| 8521 | ssh2_pkt_addstring(s->pktout, |
| 8522 | s->cur_prompt->prompts[i]->result); |
| 8523 | end_log_omission(ssh, s->pktout); |
| 8524 | } |
| 8525 | ssh2_pkt_send_with_padding(ssh, s->pktout, 256); |
| 8526 | |
| 8527 | /* |
| 8528 | * Free the prompts structure from this iteration. |
| 8529 | * If there's another, a new one will be allocated |
| 8530 | * when we return to the top of this while loop. |
| 8531 | */ |
| 8532 | free_prompts(s->cur_prompt); |
| 8533 | |
| 8534 | /* |
| 8535 | * Get the next packet in case it's another |
| 8536 | * INFO_REQUEST. |
| 8537 | */ |
| 8538 | crWaitUntilV(pktin); |
| 8539 | |
| 8540 | } |
| 8541 | |
| 8542 | /* |
| 8543 | * We should have SUCCESS or FAILURE now. |
| 8544 | */ |
| 8545 | s->gotit = TRUE; |
| 8546 | |
| 8547 | } else if (s->can_passwd) { |
| 8548 | |
| 8549 | /* |
| 8550 | * Plain old password authentication. |
| 8551 | */ |
| 8552 | int ret; /* not live over crReturn */ |
| 8553 | int changereq_first_time; /* not live over crReturn */ |
| 8554 | |
| 8555 | ssh->pkt_actx = SSH2_PKTCTX_PASSWORD; |
| 8556 | |
| 8557 | s->cur_prompt = new_prompts(ssh->frontend); |
| 8558 | s->cur_prompt->to_server = TRUE; |
| 8559 | s->cur_prompt->name = dupstr("SSH password"); |
| 8560 | add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", |
| 8561 | ssh->username, |
| 8562 | ssh->savedhost), |
| 8563 | FALSE); |
| 8564 | |
| 8565 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 8566 | while (ret < 0) { |
| 8567 | ssh->send_ok = 1; |
| 8568 | crWaitUntilV(!pktin); |
| 8569 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 8570 | ssh->send_ok = 0; |
| 8571 | } |
| 8572 | if (!ret) { |
| 8573 | /* |
| 8574 | * Failed to get responses. Terminate. |
| 8575 | */ |
| 8576 | free_prompts(s->cur_prompt); |
| 8577 | ssh_disconnect(ssh, NULL, "Unable to authenticate", |
| 8578 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, |
| 8579 | TRUE); |
| 8580 | crStopV; |
| 8581 | } |
| 8582 | /* |
| 8583 | * Squirrel away the password. (We may need it later if |
| 8584 | * asked to change it.) |
| 8585 | */ |
| 8586 | s->password = dupstr(s->cur_prompt->prompts[0]->result); |
| 8587 | free_prompts(s->cur_prompt); |
| 8588 | |
| 8589 | /* |
| 8590 | * Send the password packet. |
| 8591 | * |
| 8592 | * We pad out the password packet to 256 bytes to make |
| 8593 | * it harder for an attacker to find the length of the |
| 8594 | * user's password. |
| 8595 | * |
| 8596 | * Anyone using a password longer than 256 bytes |
| 8597 | * probably doesn't have much to worry about from |
| 8598 | * people who find out how long their password is! |
| 8599 | */ |
| 8600 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 8601 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 8602 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 8603 | /* service requested */ |
| 8604 | ssh2_pkt_addstring(s->pktout, "password"); |
| 8605 | ssh2_pkt_addbool(s->pktout, FALSE); |
| 8606 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); |
| 8607 | ssh2_pkt_addstring(s->pktout, s->password); |
| 8608 | end_log_omission(ssh, s->pktout); |
| 8609 | ssh2_pkt_send_with_padding(ssh, s->pktout, 256); |
| 8610 | logevent("Sent password"); |
| 8611 | s->type = AUTH_TYPE_PASSWORD; |
| 8612 | |
| 8613 | /* |
| 8614 | * Wait for next packet, in case it's a password change |
| 8615 | * request. |
| 8616 | */ |
| 8617 | crWaitUntilV(pktin); |
| 8618 | changereq_first_time = TRUE; |
| 8619 | |
| 8620 | while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { |
| 8621 | |
| 8622 | /* |
| 8623 | * We're being asked for a new password |
| 8624 | * (perhaps not for the first time). |
| 8625 | * Loop until the server accepts it. |
| 8626 | */ |
| 8627 | |
| 8628 | int got_new = FALSE; /* not live over crReturn */ |
| 8629 | char *prompt; /* not live over crReturn */ |
| 8630 | int prompt_len; /* not live over crReturn */ |
| 8631 | |
| 8632 | { |
| 8633 | char *msg; |
| 8634 | if (changereq_first_time) |
| 8635 | msg = "Server requested password change"; |
| 8636 | else |
| 8637 | msg = "Server rejected new password"; |
| 8638 | logevent(msg); |
| 8639 | c_write_str(ssh, msg); |
| 8640 | c_write_str(ssh, "\r\n"); |
| 8641 | } |
| 8642 | |
| 8643 | ssh_pkt_getstring(pktin, &prompt, &prompt_len); |
| 8644 | |
| 8645 | s->cur_prompt = new_prompts(ssh->frontend); |
| 8646 | s->cur_prompt->to_server = TRUE; |
| 8647 | s->cur_prompt->name = dupstr("New SSH password"); |
| 8648 | s->cur_prompt->instruction = |
| 8649 | dupprintf("%.*s", prompt_len, prompt); |
| 8650 | s->cur_prompt->instr_reqd = TRUE; |
| 8651 | /* |
| 8652 | * There's no explicit requirement in the protocol |
| 8653 | * for the "old" passwords in the original and |
| 8654 | * password-change messages to be the same, and |
| 8655 | * apparently some Cisco kit supports password change |
| 8656 | * by the user entering a blank password originally |
| 8657 | * and the real password subsequently, so, |
| 8658 | * reluctantly, we prompt for the old password again. |
| 8659 | * |
| 8660 | * (On the other hand, some servers don't even bother |
| 8661 | * to check this field.) |
| 8662 | */ |
| 8663 | add_prompt(s->cur_prompt, |
| 8664 | dupstr("Current password (blank for previously entered password): "), |
| 8665 | FALSE); |
| 8666 | add_prompt(s->cur_prompt, dupstr("Enter new password: "), |
| 8667 | FALSE); |
| 8668 | add_prompt(s->cur_prompt, dupstr("Confirm new password: "), |
| 8669 | FALSE); |
| 8670 | |
| 8671 | /* |
| 8672 | * Loop until the user manages to enter the same |
| 8673 | * password twice. |
| 8674 | */ |
| 8675 | while (!got_new) { |
| 8676 | |
| 8677 | ret = get_userpass_input(s->cur_prompt, NULL, 0); |
| 8678 | while (ret < 0) { |
| 8679 | ssh->send_ok = 1; |
| 8680 | crWaitUntilV(!pktin); |
| 8681 | ret = get_userpass_input(s->cur_prompt, in, inlen); |
| 8682 | ssh->send_ok = 0; |
| 8683 | } |
| 8684 | if (!ret) { |
| 8685 | /* |
| 8686 | * Failed to get responses. Terminate. |
| 8687 | */ |
| 8688 | /* burn the evidence */ |
| 8689 | free_prompts(s->cur_prompt); |
| 8690 | memset(s->password, 0, strlen(s->password)); |
| 8691 | sfree(s->password); |
| 8692 | ssh_disconnect(ssh, NULL, "Unable to authenticate", |
| 8693 | SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, |
| 8694 | TRUE); |
| 8695 | crStopV; |
| 8696 | } |
| 8697 | |
| 8698 | /* |
| 8699 | * If the user specified a new original password |
| 8700 | * (IYSWIM), overwrite any previously specified |
| 8701 | * one. |
| 8702 | * (A side effect is that the user doesn't have to |
| 8703 | * re-enter it if they louse up the new password.) |
| 8704 | */ |
| 8705 | if (s->cur_prompt->prompts[0]->result[0]) { |
| 8706 | memset(s->password, 0, strlen(s->password)); |
| 8707 | /* burn the evidence */ |
| 8708 | sfree(s->password); |
| 8709 | s->password = |
| 8710 | dupstr(s->cur_prompt->prompts[0]->result); |
| 8711 | } |
| 8712 | |
| 8713 | /* |
| 8714 | * Check the two new passwords match. |
| 8715 | */ |
| 8716 | got_new = (strcmp(s->cur_prompt->prompts[1]->result, |
| 8717 | s->cur_prompt->prompts[2]->result) |
| 8718 | == 0); |
| 8719 | if (!got_new) |
| 8720 | /* They don't. Silly user. */ |
| 8721 | c_write_str(ssh, "Passwords do not match\r\n"); |
| 8722 | |
| 8723 | } |
| 8724 | |
| 8725 | /* |
| 8726 | * Send the new password (along with the old one). |
| 8727 | * (see above for padding rationale) |
| 8728 | */ |
| 8729 | s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 8730 | ssh2_pkt_addstring(s->pktout, ssh->username); |
| 8731 | ssh2_pkt_addstring(s->pktout, "ssh-connection"); |
| 8732 | /* service requested */ |
| 8733 | ssh2_pkt_addstring(s->pktout, "password"); |
| 8734 | ssh2_pkt_addbool(s->pktout, TRUE); |
| 8735 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); |
| 8736 | ssh2_pkt_addstring(s->pktout, s->password); |
| 8737 | ssh2_pkt_addstring(s->pktout, |
| 8738 | s->cur_prompt->prompts[1]->result); |
| 8739 | free_prompts(s->cur_prompt); |
| 8740 | end_log_omission(ssh, s->pktout); |
| 8741 | ssh2_pkt_send_with_padding(ssh, s->pktout, 256); |
| 8742 | logevent("Sent new password"); |
| 8743 | |
| 8744 | /* |
| 8745 | * Now see what the server has to say about it. |
| 8746 | * (If it's CHANGEREQ again, it's not happy with the |
| 8747 | * new password.) |
| 8748 | */ |
| 8749 | crWaitUntilV(pktin); |
| 8750 | changereq_first_time = FALSE; |
| 8751 | |
| 8752 | } |
| 8753 | |
| 8754 | /* |
| 8755 | * We need to reexamine the current pktin at the top |
| 8756 | * of the loop. Either: |
| 8757 | * - we weren't asked to change password at all, in |
| 8758 | * which case it's a SUCCESS or FAILURE with the |
| 8759 | * usual meaning |
| 8760 | * - we sent a new password, and the server was |
| 8761 | * either OK with it (SUCCESS or FAILURE w/partial |
| 8762 | * success) or unhappy with the _old_ password |
| 8763 | * (FAILURE w/o partial success) |
| 8764 | * In any of these cases, we go back to the top of |
| 8765 | * the loop and start again. |
| 8766 | */ |
| 8767 | s->gotit = TRUE; |
| 8768 | |
| 8769 | /* |
| 8770 | * We don't need the old password any more, in any |
| 8771 | * case. Burn the evidence. |
| 8772 | */ |
| 8773 | memset(s->password, 0, strlen(s->password)); |
| 8774 | sfree(s->password); |
| 8775 | |
| 8776 | } else { |
| 8777 | char *str = dupprintf("No supported authentication methods available" |
| 8778 | " (server sent: %.*s)", |
| 8779 | methlen, methods); |
| 8780 | |
| 8781 | ssh_disconnect(ssh, str, |
| 8782 | "No supported authentication methods available", |
| 8783 | SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, |
| 8784 | FALSE); |
| 8785 | sfree(str); |
| 8786 | |
| 8787 | crStopV; |
| 8788 | |
| 8789 | } |
| 8790 | |
| 8791 | } |
| 8792 | } |
| 8793 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; |
| 8794 | |
| 8795 | /* Clear up various bits and pieces from authentication. */ |
| 8796 | if (s->publickey_blob) { |
| 8797 | sfree(s->publickey_blob); |
| 8798 | sfree(s->publickey_comment); |
| 8799 | } |
| 8800 | if (s->agent_response) |
| 8801 | sfree(s->agent_response); |
| 8802 | |
| 8803 | if (s->userauth_success) { |
| 8804 | /* |
| 8805 | * We've just received USERAUTH_SUCCESS, and we haven't sent any |
| 8806 | * packets since. Signal the transport layer to consider enacting |
| 8807 | * delayed compression. |
| 8808 | * |
| 8809 | * (Relying on we_are_in is not sufficient, as |
| 8810 | * draft-miller-secsh-compression-delayed is quite clear that it |
| 8811 | * triggers on USERAUTH_SUCCESS specifically, and we_are_in can |
| 8812 | * become set for other reasons.) |
| 8813 | */ |
| 8814 | do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL); |
| 8815 | } |
| 8816 | |
| 8817 | /* |
| 8818 | * Now the connection protocol has started, one way or another. |
| 8819 | */ |
| 8820 | |
| 8821 | ssh->channels = newtree234(ssh_channelcmp); |
| 8822 | |
| 8823 | /* |
| 8824 | * Set up handlers for some connection protocol messages, so we |
| 8825 | * don't have to handle them repeatedly in this coroutine. |
| 8826 | */ |
| 8827 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = |
| 8828 | ssh2_msg_channel_window_adjust; |
| 8829 | ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = |
| 8830 | ssh2_msg_global_request; |
| 8831 | |
| 8832 | /* |
| 8833 | * Create the main session channel. |
| 8834 | */ |
| 8835 | if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) { |
| 8836 | ssh->mainchan = NULL; |
| 8837 | } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) { |
| 8838 | /* |
| 8839 | * Just start a direct-tcpip channel and use it as the main |
| 8840 | * channel. |
| 8841 | */ |
| 8842 | ssh->mainchan = snew(struct ssh_channel); |
| 8843 | ssh->mainchan->ssh = ssh; |
| 8844 | ssh2_channel_init(ssh->mainchan); |
| 8845 | logeventf(ssh, |
| 8846 | "Opening direct-tcpip channel to %s:%d in place of session", |
| 8847 | conf_get_str(ssh->conf, CONF_ssh_nc_host), |
| 8848 | conf_get_int(ssh->conf, CONF_ssh_nc_port)); |
| 8849 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 8850 | ssh2_pkt_addstring(s->pktout, "direct-tcpip"); |
| 8851 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); |
| 8852 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ |
| 8853 | ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ |
| 8854 | ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host)); |
| 8855 | ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port)); |
| 8856 | /* |
| 8857 | * There's nothing meaningful to put in the originator |
| 8858 | * fields, but some servers insist on syntactically correct |
| 8859 | * information. |
| 8860 | */ |
| 8861 | ssh2_pkt_addstring(s->pktout, "0.0.0.0"); |
| 8862 | ssh2_pkt_adduint32(s->pktout, 0); |
| 8863 | ssh2_pkt_send(ssh, s->pktout); |
| 8864 | |
| 8865 | crWaitUntilV(pktin); |
| 8866 | if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 8867 | bombout(("Server refused to open a direct-tcpip channel")); |
| 8868 | crStopV; |
| 8869 | /* FIXME: error data comes back in FAILURE packet */ |
| 8870 | } |
| 8871 | if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { |
| 8872 | bombout(("Server's channel confirmation cited wrong channel")); |
| 8873 | crStopV; |
| 8874 | } |
| 8875 | ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); |
| 8876 | ssh->mainchan->halfopen = FALSE; |
| 8877 | ssh->mainchan->type = CHAN_MAINSESSION; |
| 8878 | ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); |
| 8879 | ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); |
| 8880 | add234(ssh->channels, ssh->mainchan); |
| 8881 | update_specials_menu(ssh->frontend); |
| 8882 | logevent("Opened direct-tcpip channel"); |
| 8883 | ssh->ncmode = TRUE; |
| 8884 | } else { |
| 8885 | ssh->mainchan = snew(struct ssh_channel); |
| 8886 | ssh->mainchan->ssh = ssh; |
| 8887 | ssh2_channel_init(ssh->mainchan); |
| 8888 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 8889 | ssh2_pkt_addstring(s->pktout, "session"); |
| 8890 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); |
| 8891 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ |
| 8892 | ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ |
| 8893 | ssh2_pkt_send(ssh, s->pktout); |
| 8894 | crWaitUntilV(pktin); |
| 8895 | if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 8896 | bombout(("Server refused to open a session")); |
| 8897 | crStopV; |
| 8898 | /* FIXME: error data comes back in FAILURE packet */ |
| 8899 | } |
| 8900 | if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { |
| 8901 | bombout(("Server's channel confirmation cited wrong channel")); |
| 8902 | crStopV; |
| 8903 | } |
| 8904 | ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); |
| 8905 | ssh->mainchan->halfopen = FALSE; |
| 8906 | ssh->mainchan->type = CHAN_MAINSESSION; |
| 8907 | ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); |
| 8908 | ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); |
| 8909 | add234(ssh->channels, ssh->mainchan); |
| 8910 | update_specials_menu(ssh->frontend); |
| 8911 | logevent("Opened channel for session"); |
| 8912 | ssh->ncmode = FALSE; |
| 8913 | } |
| 8914 | |
| 8915 | /* |
| 8916 | * Now we have a channel, make dispatch table entries for |
| 8917 | * general channel-based messages. |
| 8918 | */ |
| 8919 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = |
| 8920 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = |
| 8921 | ssh2_msg_channel_data; |
| 8922 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof; |
| 8923 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close; |
| 8924 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = |
| 8925 | ssh2_msg_channel_open_confirmation; |
| 8926 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = |
| 8927 | ssh2_msg_channel_open_failure; |
| 8928 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = |
| 8929 | ssh2_msg_channel_request; |
| 8930 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = |
| 8931 | ssh2_msg_channel_open; |
| 8932 | |
| 8933 | if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) { |
| 8934 | /* |
| 8935 | * This message indicates to the server that we promise |
| 8936 | * not to try to run any other channel in parallel with |
| 8937 | * this one, so it's safe for it to advertise a very large |
| 8938 | * window and leave the flow control to TCP. |
| 8939 | */ |
| 8940 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 8941 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); |
| 8942 | ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org"); |
| 8943 | ssh2_pkt_addbool(s->pktout, 0); /* no reply */ |
| 8944 | ssh2_pkt_send(ssh, s->pktout); |
| 8945 | } |
| 8946 | |
| 8947 | /* |
| 8948 | * Potentially enable X11 forwarding. |
| 8949 | */ |
| 8950 | if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) && |
| 8951 | (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), |
| 8952 | conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) { |
| 8953 | logevent("Requesting X11 forwarding"); |
| 8954 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 8955 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); |
| 8956 | ssh2_pkt_addstring(s->pktout, "x11-req"); |
| 8957 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 8958 | ssh2_pkt_addbool(s->pktout, 0); /* many connections */ |
| 8959 | ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname); |
| 8960 | /* |
| 8961 | * Note that while we blank the X authentication data here, we don't |
| 8962 | * take any special action to blank the start of an X11 channel, |
| 8963 | * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection |
| 8964 | * without having session blanking enabled is likely to leak your |
| 8965 | * cookie into the log. |
| 8966 | */ |
| 8967 | dont_log_password(ssh, s->pktout, PKTLOG_BLANK); |
| 8968 | ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring); |
| 8969 | end_log_omission(ssh, s->pktout); |
| 8970 | ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum); |
| 8971 | ssh2_pkt_send(ssh, s->pktout); |
| 8972 | |
| 8973 | crWaitUntilV(pktin); |
| 8974 | |
| 8975 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 8976 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { |
| 8977 | bombout(("Unexpected response to X11 forwarding request:" |
| 8978 | " packet type %d", pktin->type)); |
| 8979 | crStopV; |
| 8980 | } |
| 8981 | logevent("X11 forwarding refused"); |
| 8982 | } else { |
| 8983 | logevent("X11 forwarding enabled"); |
| 8984 | ssh->X11_fwd_enabled = TRUE; |
| 8985 | } |
| 8986 | } |
| 8987 | |
| 8988 | /* |
| 8989 | * Enable port forwardings. |
| 8990 | */ |
| 8991 | ssh_setup_portfwd(ssh, ssh->conf); |
| 8992 | |
| 8993 | /* |
| 8994 | * Potentially enable agent forwarding. |
| 8995 | */ |
| 8996 | if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) { |
| 8997 | logevent("Requesting OpenSSH-style agent forwarding"); |
| 8998 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 8999 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); |
| 9000 | ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com"); |
| 9001 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 9002 | ssh2_pkt_send(ssh, s->pktout); |
| 9003 | |
| 9004 | crWaitUntilV(pktin); |
| 9005 | |
| 9006 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 9007 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { |
| 9008 | bombout(("Unexpected response to agent forwarding request:" |
| 9009 | " packet type %d", pktin->type)); |
| 9010 | crStopV; |
| 9011 | } |
| 9012 | logevent("Agent forwarding refused"); |
| 9013 | } else { |
| 9014 | logevent("Agent forwarding enabled"); |
| 9015 | ssh->agentfwd_enabled = TRUE; |
| 9016 | } |
| 9017 | } |
| 9018 | |
| 9019 | /* |
| 9020 | * Now allocate a pty for the session. |
| 9021 | */ |
| 9022 | if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) { |
| 9023 | /* Unpick the terminal-speed string. */ |
| 9024 | /* XXX perhaps we should allow no speeds to be sent. */ |
| 9025 | ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ |
| 9026 | sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); |
| 9027 | /* Build the pty request. */ |
| 9028 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 9029 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */ |
| 9030 | ssh2_pkt_addstring(s->pktout, "pty-req"); |
| 9031 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 9032 | ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_termtype)); |
| 9033 | ssh2_pkt_adduint32(s->pktout, ssh->term_width); |
| 9034 | ssh2_pkt_adduint32(s->pktout, ssh->term_height); |
| 9035 | ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */ |
| 9036 | ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */ |
| 9037 | ssh2_pkt_addstring_start(s->pktout); |
| 9038 | parse_ttymodes(ssh, ssh2_send_ttymode, (void *)s->pktout); |
| 9039 | ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED); |
| 9040 | ssh2_pkt_adduint32(s->pktout, ssh->ispeed); |
| 9041 | ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED); |
| 9042 | ssh2_pkt_adduint32(s->pktout, ssh->ospeed); |
| 9043 | ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */ |
| 9044 | ssh2_pkt_send(ssh, s->pktout); |
| 9045 | ssh->state = SSH_STATE_INTERMED; |
| 9046 | |
| 9047 | crWaitUntilV(pktin); |
| 9048 | |
| 9049 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 9050 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { |
| 9051 | bombout(("Unexpected response to pty request:" |
| 9052 | " packet type %d", pktin->type)); |
| 9053 | crStopV; |
| 9054 | } |
| 9055 | c_write_str(ssh, "Server refused to allocate pty\r\n"); |
| 9056 | ssh->editing = ssh->echoing = 1; |
| 9057 | } else { |
| 9058 | logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", |
| 9059 | ssh->ospeed, ssh->ispeed); |
| 9060 | ssh->got_pty = TRUE; |
| 9061 | } |
| 9062 | } else { |
| 9063 | ssh->editing = ssh->echoing = 1; |
| 9064 | } |
| 9065 | |
| 9066 | /* |
| 9067 | * Send environment variables. |
| 9068 | * |
| 9069 | * Simplest thing here is to send all the requests at once, and |
| 9070 | * then wait for a whole bunch of successes or failures. |
| 9071 | */ |
| 9072 | if (ssh->mainchan && !ssh->ncmode) { |
| 9073 | char *key, *val; |
| 9074 | |
| 9075 | s->num_env = 0; |
| 9076 | |
| 9077 | for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key); |
| 9078 | val != NULL; |
| 9079 | val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) { |
| 9080 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 9081 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); |
| 9082 | ssh2_pkt_addstring(s->pktout, "env"); |
| 9083 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 9084 | ssh2_pkt_addstring(s->pktout, key); |
| 9085 | ssh2_pkt_addstring(s->pktout, val); |
| 9086 | ssh2_pkt_send(ssh, s->pktout); |
| 9087 | |
| 9088 | s->num_env++; |
| 9089 | } |
| 9090 | |
| 9091 | if (s->num_env) { |
| 9092 | logeventf(ssh, "Sent %d environment variables", s->num_env); |
| 9093 | |
| 9094 | s->env_ok = 0; |
| 9095 | s->env_left = s->num_env; |
| 9096 | |
| 9097 | while (s->env_left > 0) { |
| 9098 | crWaitUntilV(pktin); |
| 9099 | |
| 9100 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 9101 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { |
| 9102 | bombout(("Unexpected response to environment request:" |
| 9103 | " packet type %d", pktin->type)); |
| 9104 | crStopV; |
| 9105 | } |
| 9106 | } else { |
| 9107 | s->env_ok++; |
| 9108 | } |
| 9109 | |
| 9110 | s->env_left--; |
| 9111 | } |
| 9112 | |
| 9113 | if (s->env_ok == s->num_env) { |
| 9114 | logevent("All environment variables successfully set"); |
| 9115 | } else if (s->env_ok == 0) { |
| 9116 | logevent("All environment variables refused"); |
| 9117 | c_write_str(ssh, "Server refused to set environment variables\r\n"); |
| 9118 | } else { |
| 9119 | logeventf(ssh, "%d environment variables refused", |
| 9120 | s->num_env - s->env_ok); |
| 9121 | c_write_str(ssh, "Server refused to set all environment variables\r\n"); |
| 9122 | } |
| 9123 | } |
| 9124 | } |
| 9125 | |
| 9126 | /* |
| 9127 | * Start a shell or a remote command. We may have to attempt |
| 9128 | * this twice if the config data has provided a second choice |
| 9129 | * of command. |
| 9130 | */ |
| 9131 | if (ssh->mainchan && !ssh->ncmode) while (1) { |
| 9132 | int subsys; |
| 9133 | char *cmd; |
| 9134 | |
| 9135 | if (ssh->fallback_cmd) { |
| 9136 | subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2); |
| 9137 | cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); |
| 9138 | } else { |
| 9139 | subsys = conf_get_int(ssh->conf, CONF_ssh_subsys); |
| 9140 | cmd = conf_get_str(ssh->conf, CONF_remote_cmd); |
| 9141 | } |
| 9142 | |
| 9143 | s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 9144 | ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */ |
| 9145 | if (subsys) { |
| 9146 | ssh2_pkt_addstring(s->pktout, "subsystem"); |
| 9147 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 9148 | ssh2_pkt_addstring(s->pktout, cmd); |
| 9149 | } else if (*cmd) { |
| 9150 | ssh2_pkt_addstring(s->pktout, "exec"); |
| 9151 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 9152 | ssh2_pkt_addstring(s->pktout, cmd); |
| 9153 | } else { |
| 9154 | ssh2_pkt_addstring(s->pktout, "shell"); |
| 9155 | ssh2_pkt_addbool(s->pktout, 1); /* want reply */ |
| 9156 | } |
| 9157 | ssh2_pkt_send(ssh, s->pktout); |
| 9158 | |
| 9159 | crWaitUntilV(pktin); |
| 9160 | |
| 9161 | if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 9162 | if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { |
| 9163 | bombout(("Unexpected response to shell/command request:" |
| 9164 | " packet type %d", pktin->type)); |
| 9165 | crStopV; |
| 9166 | } |
| 9167 | /* |
| 9168 | * We failed to start the command. If this is the |
| 9169 | * fallback command, we really are finished; if it's |
| 9170 | * not, and if the fallback command exists, try falling |
| 9171 | * back to it before complaining. |
| 9172 | */ |
| 9173 | if (!ssh->fallback_cmd && |
| 9174 | *conf_get_str(ssh->conf, CONF_remote_cmd2)) { |
| 9175 | logevent("Primary command failed; attempting fallback"); |
| 9176 | ssh->fallback_cmd = TRUE; |
| 9177 | continue; |
| 9178 | } |
| 9179 | bombout(("Server refused to start a shell/command")); |
| 9180 | crStopV; |
| 9181 | } else { |
| 9182 | logevent("Started a shell/command"); |
| 9183 | } |
| 9184 | break; |
| 9185 | } |
| 9186 | |
| 9187 | ssh->state = SSH_STATE_SESSION; |
| 9188 | if (ssh->size_needed) |
| 9189 | ssh_size(ssh, ssh->term_width, ssh->term_height); |
| 9190 | if (ssh->eof_needed) |
| 9191 | ssh_special(ssh, TS_EOF); |
| 9192 | |
| 9193 | /* |
| 9194 | * All the initial channel requests are done, so install the default |
| 9195 | * failure handler. |
| 9196 | */ |
| 9197 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success; |
| 9198 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure; |
| 9199 | |
| 9200 | /* |
| 9201 | * Transfer data! |
| 9202 | */ |
| 9203 | if (ssh->ldisc) |
| 9204 | ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ |
| 9205 | if (ssh->mainchan) |
| 9206 | ssh->send_ok = 1; |
| 9207 | while (1) { |
| 9208 | crReturnV; |
| 9209 | s->try_send = FALSE; |
| 9210 | if (pktin) { |
| 9211 | |
| 9212 | /* |
| 9213 | * _All_ the connection-layer packets we expect to |
| 9214 | * receive are now handled by the dispatch table. |
| 9215 | * Anything that reaches here must be bogus. |
| 9216 | */ |
| 9217 | |
| 9218 | bombout(("Strange packet received: type %d", pktin->type)); |
| 9219 | crStopV; |
| 9220 | } else if (ssh->mainchan) { |
| 9221 | /* |
| 9222 | * We have spare data. Add it to the channel buffer. |
| 9223 | */ |
| 9224 | ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen); |
| 9225 | s->try_send = TRUE; |
| 9226 | } |
| 9227 | if (s->try_send) { |
| 9228 | int i; |
| 9229 | struct ssh_channel *c; |
| 9230 | /* |
| 9231 | * Try to send data on all channels if we can. |
| 9232 | */ |
| 9233 | for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) |
| 9234 | ssh2_try_send_and_unthrottle(ssh, c); |
| 9235 | } |
| 9236 | } |
| 9237 | |
| 9238 | crFinishV; |
| 9239 | } |
| 9240 | |
| 9241 | /* |
| 9242 | * Handlers for SSH-2 messages that might arrive at any moment. |
| 9243 | */ |
| 9244 | static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) |
| 9245 | { |
| 9246 | /* log reason code in disconnect message */ |
| 9247 | char *buf, *msg; |
| 9248 | int reason, msglen; |
| 9249 | |
| 9250 | reason = ssh_pkt_getuint32(pktin); |
| 9251 | ssh_pkt_getstring(pktin, &msg, &msglen); |
| 9252 | |
| 9253 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
| 9254 | buf = dupprintf("Received disconnect message (%s)", |
| 9255 | ssh2_disconnect_reasons[reason]); |
| 9256 | } else { |
| 9257 | buf = dupprintf("Received disconnect message (unknown" |
| 9258 | " type %d)", reason); |
| 9259 | } |
| 9260 | logevent(buf); |
| 9261 | sfree(buf); |
| 9262 | buf = dupprintf("Disconnection message text: %.*s", |
| 9263 | msglen, msg); |
| 9264 | logevent(buf); |
| 9265 | bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"", |
| 9266 | reason, |
| 9267 | (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? |
| 9268 | ssh2_disconnect_reasons[reason] : "unknown", |
| 9269 | msglen, msg)); |
| 9270 | sfree(buf); |
| 9271 | } |
| 9272 | |
| 9273 | static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) |
| 9274 | { |
| 9275 | /* log the debug message */ |
| 9276 | char *msg; |
| 9277 | int msglen; |
| 9278 | |
| 9279 | /* XXX maybe we should actually take notice of the return value */ |
| 9280 | ssh2_pkt_getbool(pktin); |
| 9281 | ssh_pkt_getstring(pktin, &msg, &msglen); |
| 9282 | |
| 9283 | logeventf(ssh, "Remote debug message: %.*s", msglen, msg); |
| 9284 | } |
| 9285 | |
| 9286 | static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) |
| 9287 | { |
| 9288 | struct Packet *pktout; |
| 9289 | pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); |
| 9290 | ssh2_pkt_adduint32(pktout, pktin->sequence); |
| 9291 | /* |
| 9292 | * UNIMPLEMENTED messages MUST appear in the same order as the |
| 9293 | * messages they respond to. Hence, never queue them. |
| 9294 | */ |
| 9295 | ssh2_pkt_send_noqueue(ssh, pktout); |
| 9296 | } |
| 9297 | |
| 9298 | /* |
| 9299 | * Handle the top-level SSH-2 protocol. |
| 9300 | */ |
| 9301 | static void ssh2_protocol_setup(Ssh ssh) |
| 9302 | { |
| 9303 | int i; |
| 9304 | |
| 9305 | /* |
| 9306 | * Most messages cause SSH2_MSG_UNIMPLEMENTED. |
| 9307 | */ |
| 9308 | for (i = 0; i < 256; i++) |
| 9309 | ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented; |
| 9310 | |
| 9311 | /* |
| 9312 | * Any message we actually understand, we set to NULL so that |
| 9313 | * the coroutines will get it. |
| 9314 | */ |
| 9315 | ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL; |
| 9316 | ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL; |
| 9317 | ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL; |
| 9318 | ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL; |
| 9319 | ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL; |
| 9320 | ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL; |
| 9321 | ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL; |
| 9322 | /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */ |
| 9323 | /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */ |
| 9324 | ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL; |
| 9325 | ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL; |
| 9326 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL; |
| 9327 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL; |
| 9328 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL; |
| 9329 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; |
| 9330 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL; |
| 9331 | /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */ |
| 9332 | /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */ |
| 9333 | ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL; |
| 9334 | ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL; |
| 9335 | ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL; |
| 9336 | ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL; |
| 9337 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL; |
| 9338 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL; |
| 9339 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL; |
| 9340 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL; |
| 9341 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL; |
| 9342 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL; |
| 9343 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL; |
| 9344 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL; |
| 9345 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL; |
| 9346 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL; |
| 9347 | ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL; |
| 9348 | |
| 9349 | /* |
| 9350 | * These special message types we install handlers for. |
| 9351 | */ |
| 9352 | ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; |
| 9353 | ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */ |
| 9354 | ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; |
| 9355 | } |
| 9356 | |
| 9357 | static void ssh2_timer(void *ctx, long now) |
| 9358 | { |
| 9359 | Ssh ssh = (Ssh)ctx; |
| 9360 | |
| 9361 | if (ssh->state == SSH_STATE_CLOSED) |
| 9362 | return; |
| 9363 | |
| 9364 | if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 && |
| 9365 | now - ssh->next_rekey >= 0) { |
| 9366 | do_ssh2_transport(ssh, "timeout", -1, NULL); |
| 9367 | } |
| 9368 | } |
| 9369 | |
| 9370 | static void ssh2_protocol(Ssh ssh, void *vin, int inlen, |
| 9371 | struct Packet *pktin) |
| 9372 | { |
| 9373 | unsigned char *in = (unsigned char *)vin; |
| 9374 | if (ssh->state == SSH_STATE_CLOSED) |
| 9375 | return; |
| 9376 | |
| 9377 | if (pktin) { |
| 9378 | ssh->incoming_data_size += pktin->encrypted_len; |
| 9379 | if (!ssh->kex_in_progress && |
| 9380 | ssh->max_data_size != 0 && |
| 9381 | ssh->incoming_data_size > ssh->max_data_size) |
| 9382 | do_ssh2_transport(ssh, "too much data received", -1, NULL); |
| 9383 | } |
| 9384 | |
| 9385 | if (pktin && ssh->packet_dispatch[pktin->type]) { |
| 9386 | ssh->packet_dispatch[pktin->type](ssh, pktin); |
| 9387 | return; |
| 9388 | } |
| 9389 | |
| 9390 | if (!ssh->protocol_initial_phase_done || |
| 9391 | (pktin && pktin->type >= 20 && pktin->type < 50)) { |
| 9392 | if (do_ssh2_transport(ssh, in, inlen, pktin) && |
| 9393 | !ssh->protocol_initial_phase_done) { |
| 9394 | ssh->protocol_initial_phase_done = TRUE; |
| 9395 | /* |
| 9396 | * Allow authconn to initialise itself. |
| 9397 | */ |
| 9398 | do_ssh2_authconn(ssh, NULL, 0, NULL); |
| 9399 | } |
| 9400 | } else { |
| 9401 | do_ssh2_authconn(ssh, in, inlen, pktin); |
| 9402 | } |
| 9403 | } |
| 9404 | |
| 9405 | static void ssh_cache_conf_values(Ssh ssh) |
| 9406 | { |
| 9407 | ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata); |
| 9408 | } |
| 9409 | |
| 9410 | /* |
| 9411 | * Called to set up the connection. |
| 9412 | * |
| 9413 | * Returns an error message, or NULL on success. |
| 9414 | */ |
| 9415 | static const char *ssh_init(void *frontend_handle, void **backend_handle, |
| 9416 | Conf *conf, char *host, int port, char **realhost, |
| 9417 | int nodelay, int keepalive) |
| 9418 | { |
| 9419 | const char *p; |
| 9420 | Ssh ssh; |
| 9421 | |
| 9422 | ssh = snew(struct ssh_tag); |
| 9423 | ssh->conf = conf_copy(conf); |
| 9424 | ssh_cache_conf_values(ssh); |
| 9425 | ssh->version = 0; /* when not ready yet */ |
| 9426 | ssh->s = NULL; |
| 9427 | ssh->cipher = NULL; |
| 9428 | ssh->v1_cipher_ctx = NULL; |
| 9429 | ssh->crcda_ctx = NULL; |
| 9430 | ssh->cscipher = NULL; |
| 9431 | ssh->cs_cipher_ctx = NULL; |
| 9432 | ssh->sccipher = NULL; |
| 9433 | ssh->sc_cipher_ctx = NULL; |
| 9434 | ssh->csmac = NULL; |
| 9435 | ssh->cs_mac_ctx = NULL; |
| 9436 | ssh->scmac = NULL; |
| 9437 | ssh->sc_mac_ctx = NULL; |
| 9438 | ssh->cscomp = NULL; |
| 9439 | ssh->cs_comp_ctx = NULL; |
| 9440 | ssh->sccomp = NULL; |
| 9441 | ssh->sc_comp_ctx = NULL; |
| 9442 | ssh->kex = NULL; |
| 9443 | ssh->kex_ctx = NULL; |
| 9444 | ssh->hostkey = NULL; |
| 9445 | ssh->exitcode = -1; |
| 9446 | ssh->close_expected = FALSE; |
| 9447 | ssh->clean_exit = FALSE; |
| 9448 | ssh->state = SSH_STATE_PREPACKET; |
| 9449 | ssh->size_needed = FALSE; |
| 9450 | ssh->eof_needed = FALSE; |
| 9451 | ssh->ldisc = NULL; |
| 9452 | ssh->logctx = NULL; |
| 9453 | ssh->deferred_send_data = NULL; |
| 9454 | ssh->deferred_len = 0; |
| 9455 | ssh->deferred_size = 0; |
| 9456 | ssh->fallback_cmd = 0; |
| 9457 | ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; |
| 9458 | ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; |
| 9459 | ssh->x11disp = NULL; |
| 9460 | ssh->v1_compressing = FALSE; |
| 9461 | ssh->v2_outgoing_sequence = 0; |
| 9462 | ssh->ssh1_rdpkt_crstate = 0; |
| 9463 | ssh->ssh2_rdpkt_crstate = 0; |
| 9464 | ssh->do_ssh_init_crstate = 0; |
| 9465 | ssh->ssh_gotdata_crstate = 0; |
| 9466 | ssh->do_ssh1_connection_crstate = 0; |
| 9467 | ssh->do_ssh1_login_crstate = 0; |
| 9468 | ssh->do_ssh2_transport_crstate = 0; |
| 9469 | ssh->do_ssh2_authconn_crstate = 0; |
| 9470 | ssh->do_ssh_init_state = NULL; |
| 9471 | ssh->do_ssh1_login_state = NULL; |
| 9472 | ssh->do_ssh2_transport_state = NULL; |
| 9473 | ssh->do_ssh2_authconn_state = NULL; |
| 9474 | ssh->v_c = NULL; |
| 9475 | ssh->v_s = NULL; |
| 9476 | ssh->mainchan = NULL; |
| 9477 | ssh->throttled_all = 0; |
| 9478 | ssh->v1_stdout_throttling = 0; |
| 9479 | ssh->queue = NULL; |
| 9480 | ssh->queuelen = ssh->queuesize = 0; |
| 9481 | ssh->queueing = FALSE; |
| 9482 | ssh->qhead = ssh->qtail = NULL; |
| 9483 | ssh->deferred_rekey_reason = NULL; |
| 9484 | bufchain_init(&ssh->queued_incoming_data); |
| 9485 | ssh->frozen = FALSE; |
| 9486 | ssh->username = NULL; |
| 9487 | ssh->sent_console_eof = FALSE; |
| 9488 | ssh->got_pty = FALSE; |
| 9489 | |
| 9490 | *backend_handle = ssh; |
| 9491 | |
| 9492 | #ifdef MSCRYPTOAPI |
| 9493 | if (crypto_startup() == 0) |
| 9494 | return "Microsoft high encryption pack not installed!"; |
| 9495 | #endif |
| 9496 | |
| 9497 | ssh->frontend = frontend_handle; |
| 9498 | ssh->term_width = conf_get_int(ssh->conf, CONF_width); |
| 9499 | ssh->term_height = conf_get_int(ssh->conf, CONF_height); |
| 9500 | |
| 9501 | ssh->channels = NULL; |
| 9502 | ssh->rportfwds = NULL; |
| 9503 | ssh->portfwds = NULL; |
| 9504 | |
| 9505 | ssh->send_ok = 0; |
| 9506 | ssh->editing = 0; |
| 9507 | ssh->echoing = 0; |
| 9508 | ssh->conn_throttle_count = 0; |
| 9509 | ssh->overall_bufsize = 0; |
| 9510 | ssh->fallback_cmd = 0; |
| 9511 | |
| 9512 | ssh->protocol = NULL; |
| 9513 | |
| 9514 | ssh->protocol_initial_phase_done = FALSE; |
| 9515 | |
| 9516 | ssh->pinger = NULL; |
| 9517 | |
| 9518 | ssh->incoming_data_size = ssh->outgoing_data_size = |
| 9519 | ssh->deferred_data_size = 0L; |
| 9520 | ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf, |
| 9521 | CONF_ssh_rekey_data)); |
| 9522 | ssh->kex_in_progress = FALSE; |
| 9523 | |
| 9524 | #ifndef NO_GSSAPI |
| 9525 | ssh->gsslibs = NULL; |
| 9526 | #endif |
| 9527 | |
| 9528 | p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); |
| 9529 | if (p != NULL) |
| 9530 | return p; |
| 9531 | |
| 9532 | random_ref(); |
| 9533 | |
| 9534 | return NULL; |
| 9535 | } |
| 9536 | |
| 9537 | static void ssh_free(void *handle) |
| 9538 | { |
| 9539 | Ssh ssh = (Ssh) handle; |
| 9540 | struct ssh_channel *c; |
| 9541 | struct ssh_rportfwd *pf; |
| 9542 | |
| 9543 | if (ssh->v1_cipher_ctx) |
| 9544 | ssh->cipher->free_context(ssh->v1_cipher_ctx); |
| 9545 | if (ssh->cs_cipher_ctx) |
| 9546 | ssh->cscipher->free_context(ssh->cs_cipher_ctx); |
| 9547 | if (ssh->sc_cipher_ctx) |
| 9548 | ssh->sccipher->free_context(ssh->sc_cipher_ctx); |
| 9549 | if (ssh->cs_mac_ctx) |
| 9550 | ssh->csmac->free_context(ssh->cs_mac_ctx); |
| 9551 | if (ssh->sc_mac_ctx) |
| 9552 | ssh->scmac->free_context(ssh->sc_mac_ctx); |
| 9553 | if (ssh->cs_comp_ctx) { |
| 9554 | if (ssh->cscomp) |
| 9555 | ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); |
| 9556 | else |
| 9557 | zlib_compress_cleanup(ssh->cs_comp_ctx); |
| 9558 | } |
| 9559 | if (ssh->sc_comp_ctx) { |
| 9560 | if (ssh->sccomp) |
| 9561 | ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); |
| 9562 | else |
| 9563 | zlib_decompress_cleanup(ssh->sc_comp_ctx); |
| 9564 | } |
| 9565 | if (ssh->kex_ctx) |
| 9566 | dh_cleanup(ssh->kex_ctx); |
| 9567 | sfree(ssh->savedhost); |
| 9568 | |
| 9569 | while (ssh->queuelen-- > 0) |
| 9570 | ssh_free_packet(ssh->queue[ssh->queuelen]); |
| 9571 | sfree(ssh->queue); |
| 9572 | |
| 9573 | while (ssh->qhead) { |
| 9574 | struct queued_handler *qh = ssh->qhead; |
| 9575 | ssh->qhead = qh->next; |
| 9576 | sfree(ssh->qhead); |
| 9577 | } |
| 9578 | ssh->qhead = ssh->qtail = NULL; |
| 9579 | |
| 9580 | if (ssh->channels) { |
| 9581 | while ((c = delpos234(ssh->channels, 0)) != NULL) { |
| 9582 | switch (c->type) { |
| 9583 | case CHAN_X11: |
| 9584 | if (c->u.x11.s != NULL) |
| 9585 | x11_close(c->u.x11.s); |
| 9586 | break; |
| 9587 | case CHAN_SOCKDATA: |
| 9588 | case CHAN_SOCKDATA_DORMANT: |
| 9589 | if (c->u.pfd.s != NULL) |
| 9590 | pfd_close(c->u.pfd.s); |
| 9591 | break; |
| 9592 | } |
| 9593 | sfree(c); |
| 9594 | } |
| 9595 | freetree234(ssh->channels); |
| 9596 | ssh->channels = NULL; |
| 9597 | } |
| 9598 | |
| 9599 | if (ssh->rportfwds) { |
| 9600 | while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) |
| 9601 | free_rportfwd(pf); |
| 9602 | freetree234(ssh->rportfwds); |
| 9603 | ssh->rportfwds = NULL; |
| 9604 | } |
| 9605 | sfree(ssh->deferred_send_data); |
| 9606 | if (ssh->x11disp) |
| 9607 | x11_free_display(ssh->x11disp); |
| 9608 | sfree(ssh->do_ssh_init_state); |
| 9609 | sfree(ssh->do_ssh1_login_state); |
| 9610 | sfree(ssh->do_ssh2_transport_state); |
| 9611 | sfree(ssh->do_ssh2_authconn_state); |
| 9612 | sfree(ssh->v_c); |
| 9613 | sfree(ssh->v_s); |
| 9614 | sfree(ssh->fullhostname); |
| 9615 | if (ssh->crcda_ctx) { |
| 9616 | crcda_free_context(ssh->crcda_ctx); |
| 9617 | ssh->crcda_ctx = NULL; |
| 9618 | } |
| 9619 | if (ssh->s) |
| 9620 | ssh_do_close(ssh, TRUE); |
| 9621 | expire_timer_context(ssh); |
| 9622 | if (ssh->pinger) |
| 9623 | pinger_free(ssh->pinger); |
| 9624 | bufchain_clear(&ssh->queued_incoming_data); |
| 9625 | sfree(ssh->username); |
| 9626 | conf_free(ssh->conf); |
| 9627 | #ifndef NO_GSSAPI |
| 9628 | if (ssh->gsslibs) |
| 9629 | ssh_gss_cleanup(ssh->gsslibs); |
| 9630 | #endif |
| 9631 | sfree(ssh); |
| 9632 | |
| 9633 | random_unref(); |
| 9634 | } |
| 9635 | |
| 9636 | /* |
| 9637 | * Reconfigure the SSH backend. |
| 9638 | */ |
| 9639 | static void ssh_reconfig(void *handle, Conf *conf) |
| 9640 | { |
| 9641 | Ssh ssh = (Ssh) handle; |
| 9642 | char *rekeying = NULL, rekey_mandatory = FALSE; |
| 9643 | unsigned long old_max_data_size; |
| 9644 | int i, rekey_time; |
| 9645 | |
| 9646 | pinger_reconfig(ssh->pinger, ssh->conf, conf); |
| 9647 | if (ssh->portfwds) |
| 9648 | ssh_setup_portfwd(ssh, conf); |
| 9649 | |
| 9650 | rekey_time = conf_get_int(conf, CONF_ssh_rekey_time); |
| 9651 | if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time && |
| 9652 | rekey_time != 0) { |
| 9653 | long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC; |
| 9654 | long now = GETTICKCOUNT(); |
| 9655 | |
| 9656 | if (new_next - now < 0) { |
| 9657 | rekeying = "timeout shortened"; |
| 9658 | } else { |
| 9659 | ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh); |
| 9660 | } |
| 9661 | } |
| 9662 | |
| 9663 | old_max_data_size = ssh->max_data_size; |
| 9664 | ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf, |
| 9665 | CONF_ssh_rekey_data)); |
| 9666 | if (old_max_data_size != ssh->max_data_size && |
| 9667 | ssh->max_data_size != 0) { |
| 9668 | if (ssh->outgoing_data_size > ssh->max_data_size || |
| 9669 | ssh->incoming_data_size > ssh->max_data_size) |
| 9670 | rekeying = "data limit lowered"; |
| 9671 | } |
| 9672 | |
| 9673 | if (conf_get_int(ssh->conf, CONF_compression) != |
| 9674 | conf_get_int(conf, CONF_compression)) { |
| 9675 | rekeying = "compression setting changed"; |
| 9676 | rekey_mandatory = TRUE; |
| 9677 | } |
| 9678 | |
| 9679 | for (i = 0; i < CIPHER_MAX; i++) |
| 9680 | if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) != |
| 9681 | conf_get_int_int(conf, CONF_ssh_cipherlist, i)) { |
| 9682 | rekeying = "cipher settings changed"; |
| 9683 | rekey_mandatory = TRUE; |
| 9684 | } |
| 9685 | if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) != |
| 9686 | conf_get_int(conf, CONF_ssh2_des_cbc)) { |
| 9687 | rekeying = "cipher settings changed"; |
| 9688 | rekey_mandatory = TRUE; |
| 9689 | } |
| 9690 | |
| 9691 | conf_free(ssh->conf); |
| 9692 | ssh->conf = conf_copy(conf); |
| 9693 | ssh_cache_conf_values(ssh); |
| 9694 | |
| 9695 | if (rekeying) { |
| 9696 | if (!ssh->kex_in_progress) { |
| 9697 | do_ssh2_transport(ssh, rekeying, -1, NULL); |
| 9698 | } else if (rekey_mandatory) { |
| 9699 | ssh->deferred_rekey_reason = rekeying; |
| 9700 | } |
| 9701 | } |
| 9702 | } |
| 9703 | |
| 9704 | /* |
| 9705 | * Called to send data down the SSH connection. |
| 9706 | */ |
| 9707 | static int ssh_send(void *handle, char *buf, int len) |
| 9708 | { |
| 9709 | Ssh ssh = (Ssh) handle; |
| 9710 | |
| 9711 | if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) |
| 9712 | return 0; |
| 9713 | |
| 9714 | ssh->protocol(ssh, (unsigned char *)buf, len, 0); |
| 9715 | |
| 9716 | return ssh_sendbuffer(ssh); |
| 9717 | } |
| 9718 | |
| 9719 | /* |
| 9720 | * Called to query the current amount of buffered stdin data. |
| 9721 | */ |
| 9722 | static int ssh_sendbuffer(void *handle) |
| 9723 | { |
| 9724 | Ssh ssh = (Ssh) handle; |
| 9725 | int override_value; |
| 9726 | |
| 9727 | if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) |
| 9728 | return 0; |
| 9729 | |
| 9730 | /* |
| 9731 | * If the SSH socket itself has backed up, add the total backup |
| 9732 | * size on that to any individual buffer on the stdin channel. |
| 9733 | */ |
| 9734 | override_value = 0; |
| 9735 | if (ssh->throttled_all) |
| 9736 | override_value = ssh->overall_bufsize; |
| 9737 | |
| 9738 | if (ssh->version == 1) { |
| 9739 | return override_value; |
| 9740 | } else if (ssh->version == 2) { |
| 9741 | if (!ssh->mainchan) |
| 9742 | return override_value; |
| 9743 | else |
| 9744 | return (override_value + |
| 9745 | bufchain_size(&ssh->mainchan->v.v2.outbuffer)); |
| 9746 | } |
| 9747 | |
| 9748 | return 0; |
| 9749 | } |
| 9750 | |
| 9751 | /* |
| 9752 | * Called to set the size of the window from SSH's POV. |
| 9753 | */ |
| 9754 | static void ssh_size(void *handle, int width, int height) |
| 9755 | { |
| 9756 | Ssh ssh = (Ssh) handle; |
| 9757 | struct Packet *pktout; |
| 9758 | |
| 9759 | ssh->term_width = width; |
| 9760 | ssh->term_height = height; |
| 9761 | |
| 9762 | switch (ssh->state) { |
| 9763 | case SSH_STATE_BEFORE_SIZE: |
| 9764 | case SSH_STATE_PREPACKET: |
| 9765 | case SSH_STATE_CLOSED: |
| 9766 | break; /* do nothing */ |
| 9767 | case SSH_STATE_INTERMED: |
| 9768 | ssh->size_needed = TRUE; /* buffer for later */ |
| 9769 | break; |
| 9770 | case SSH_STATE_SESSION: |
| 9771 | if (!conf_get_int(ssh->conf, CONF_nopty)) { |
| 9772 | if (ssh->version == 1) { |
| 9773 | send_packet(ssh, SSH1_CMSG_WINDOW_SIZE, |
| 9774 | PKT_INT, ssh->term_height, |
| 9775 | PKT_INT, ssh->term_width, |
| 9776 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 9777 | } else if (ssh->mainchan) { |
| 9778 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 9779 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); |
| 9780 | ssh2_pkt_addstring(pktout, "window-change"); |
| 9781 | ssh2_pkt_addbool(pktout, 0); |
| 9782 | ssh2_pkt_adduint32(pktout, ssh->term_width); |
| 9783 | ssh2_pkt_adduint32(pktout, ssh->term_height); |
| 9784 | ssh2_pkt_adduint32(pktout, 0); |
| 9785 | ssh2_pkt_adduint32(pktout, 0); |
| 9786 | ssh2_pkt_send(ssh, pktout); |
| 9787 | } |
| 9788 | } |
| 9789 | break; |
| 9790 | } |
| 9791 | } |
| 9792 | |
| 9793 | /* |
| 9794 | * Return a list of the special codes that make sense in this |
| 9795 | * protocol. |
| 9796 | */ |
| 9797 | static const struct telnet_special *ssh_get_specials(void *handle) |
| 9798 | { |
| 9799 | static const struct telnet_special ssh1_ignore_special[] = { |
| 9800 | {"IGNORE message", TS_NOP} |
| 9801 | }; |
| 9802 | static const struct telnet_special ssh2_ignore_special[] = { |
| 9803 | {"IGNORE message", TS_NOP}, |
| 9804 | }; |
| 9805 | static const struct telnet_special ssh2_rekey_special[] = { |
| 9806 | {"Repeat key exchange", TS_REKEY}, |
| 9807 | }; |
| 9808 | static const struct telnet_special ssh2_session_specials[] = { |
| 9809 | {NULL, TS_SEP}, |
| 9810 | {"Break", TS_BRK}, |
| 9811 | /* These are the signal names defined by RFC 4254. |
| 9812 | * They include all the ISO C signals, but are a subset of the POSIX |
| 9813 | * required signals. */ |
| 9814 | {"SIGINT (Interrupt)", TS_SIGINT}, |
| 9815 | {"SIGTERM (Terminate)", TS_SIGTERM}, |
| 9816 | {"SIGKILL (Kill)", TS_SIGKILL}, |
| 9817 | {"SIGQUIT (Quit)", TS_SIGQUIT}, |
| 9818 | {"SIGHUP (Hangup)", TS_SIGHUP}, |
| 9819 | {"More signals", TS_SUBMENU}, |
| 9820 | {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM}, |
| 9821 | {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL}, |
| 9822 | {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV}, |
| 9823 | {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2}, |
| 9824 | {NULL, TS_EXITMENU} |
| 9825 | }; |
| 9826 | static const struct telnet_special specials_end[] = { |
| 9827 | {NULL, TS_EXITMENU} |
| 9828 | }; |
| 9829 | /* XXX review this length for any changes: */ |
| 9830 | static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) + |
| 9831 | lenof(ssh2_rekey_special) + |
| 9832 | lenof(ssh2_session_specials) + |
| 9833 | lenof(specials_end)]; |
| 9834 | Ssh ssh = (Ssh) handle; |
| 9835 | int i = 0; |
| 9836 | #define ADD_SPECIALS(name) \ |
| 9837 | do { \ |
| 9838 | assert((i + lenof(name)) <= lenof(ssh_specials)); \ |
| 9839 | memcpy(&ssh_specials[i], name, sizeof name); \ |
| 9840 | i += lenof(name); \ |
| 9841 | } while(0) |
| 9842 | |
| 9843 | if (ssh->version == 1) { |
| 9844 | /* Don't bother offering IGNORE if we've decided the remote |
| 9845 | * won't cope with it, since we wouldn't bother sending it if |
| 9846 | * asked anyway. */ |
| 9847 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) |
| 9848 | ADD_SPECIALS(ssh1_ignore_special); |
| 9849 | } else if (ssh->version == 2) { |
| 9850 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) |
| 9851 | ADD_SPECIALS(ssh2_ignore_special); |
| 9852 | if (!(ssh->remote_bugs & BUG_SSH2_REKEY)) |
| 9853 | ADD_SPECIALS(ssh2_rekey_special); |
| 9854 | if (ssh->mainchan) |
| 9855 | ADD_SPECIALS(ssh2_session_specials); |
| 9856 | } /* else we're not ready yet */ |
| 9857 | |
| 9858 | if (i) { |
| 9859 | ADD_SPECIALS(specials_end); |
| 9860 | return ssh_specials; |
| 9861 | } else { |
| 9862 | return NULL; |
| 9863 | } |
| 9864 | #undef ADD_SPECIALS |
| 9865 | } |
| 9866 | |
| 9867 | /* |
| 9868 | * Send special codes. TS_EOF is useful for `plink', so you |
| 9869 | * can send an EOF and collect resulting output (e.g. `plink |
| 9870 | * hostname sort'). |
| 9871 | */ |
| 9872 | static void ssh_special(void *handle, Telnet_Special code) |
| 9873 | { |
| 9874 | Ssh ssh = (Ssh) handle; |
| 9875 | struct Packet *pktout; |
| 9876 | |
| 9877 | if (code == TS_EOF) { |
| 9878 | if (ssh->state != SSH_STATE_SESSION) { |
| 9879 | /* |
| 9880 | * Buffer the EOF in case we are pre-SESSION, so we can |
| 9881 | * send it as soon as we reach SESSION. |
| 9882 | */ |
| 9883 | if (code == TS_EOF) |
| 9884 | ssh->eof_needed = TRUE; |
| 9885 | return; |
| 9886 | } |
| 9887 | if (ssh->version == 1) { |
| 9888 | send_packet(ssh, SSH1_CMSG_EOF, PKT_END); |
| 9889 | } else if (ssh->mainchan) { |
| 9890 | sshfwd_write_eof(ssh->mainchan); |
| 9891 | ssh->send_ok = 0; /* now stop trying to read from stdin */ |
| 9892 | } |
| 9893 | logevent("Sent EOF message"); |
| 9894 | } else if (code == TS_PING || code == TS_NOP) { |
| 9895 | if (ssh->state == SSH_STATE_CLOSED |
| 9896 | || ssh->state == SSH_STATE_PREPACKET) return; |
| 9897 | if (ssh->version == 1) { |
| 9898 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) |
| 9899 | send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
| 9900 | } else { |
| 9901 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { |
| 9902 | pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 9903 | ssh2_pkt_addstring_start(pktout); |
| 9904 | ssh2_pkt_send_noqueue(ssh, pktout); |
| 9905 | } |
| 9906 | } |
| 9907 | } else if (code == TS_REKEY) { |
| 9908 | if (!ssh->kex_in_progress && ssh->version == 2) { |
| 9909 | do_ssh2_transport(ssh, "at user request", -1, NULL); |
| 9910 | } |
| 9911 | } else if (code == TS_BRK) { |
| 9912 | if (ssh->state == SSH_STATE_CLOSED |
| 9913 | || ssh->state == SSH_STATE_PREPACKET) return; |
| 9914 | if (ssh->version == 1) { |
| 9915 | logevent("Unable to send BREAK signal in SSH-1"); |
| 9916 | } else if (ssh->mainchan) { |
| 9917 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 9918 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); |
| 9919 | ssh2_pkt_addstring(pktout, "break"); |
| 9920 | ssh2_pkt_addbool(pktout, 0); |
| 9921 | ssh2_pkt_adduint32(pktout, 0); /* default break length */ |
| 9922 | ssh2_pkt_send(ssh, pktout); |
| 9923 | } |
| 9924 | } else { |
| 9925 | /* Is is a POSIX signal? */ |
| 9926 | char *signame = NULL; |
| 9927 | if (code == TS_SIGABRT) signame = "ABRT"; |
| 9928 | if (code == TS_SIGALRM) signame = "ALRM"; |
| 9929 | if (code == TS_SIGFPE) signame = "FPE"; |
| 9930 | if (code == TS_SIGHUP) signame = "HUP"; |
| 9931 | if (code == TS_SIGILL) signame = "ILL"; |
| 9932 | if (code == TS_SIGINT) signame = "INT"; |
| 9933 | if (code == TS_SIGKILL) signame = "KILL"; |
| 9934 | if (code == TS_SIGPIPE) signame = "PIPE"; |
| 9935 | if (code == TS_SIGQUIT) signame = "QUIT"; |
| 9936 | if (code == TS_SIGSEGV) signame = "SEGV"; |
| 9937 | if (code == TS_SIGTERM) signame = "TERM"; |
| 9938 | if (code == TS_SIGUSR1) signame = "USR1"; |
| 9939 | if (code == TS_SIGUSR2) signame = "USR2"; |
| 9940 | /* The SSH-2 protocol does in principle support arbitrary named |
| 9941 | * signals, including signame@domain, but we don't support those. */ |
| 9942 | if (signame) { |
| 9943 | /* It's a signal. */ |
| 9944 | if (ssh->version == 2 && ssh->mainchan) { |
| 9945 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 9946 | ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); |
| 9947 | ssh2_pkt_addstring(pktout, "signal"); |
| 9948 | ssh2_pkt_addbool(pktout, 0); |
| 9949 | ssh2_pkt_addstring(pktout, signame); |
| 9950 | ssh2_pkt_send(ssh, pktout); |
| 9951 | logeventf(ssh, "Sent signal SIG%s", signame); |
| 9952 | } |
| 9953 | } else { |
| 9954 | /* Never heard of it. Do nothing */ |
| 9955 | } |
| 9956 | } |
| 9957 | } |
| 9958 | |
| 9959 | void *new_sock_channel(void *handle, Socket s) |
| 9960 | { |
| 9961 | Ssh ssh = (Ssh) handle; |
| 9962 | struct ssh_channel *c; |
| 9963 | c = snew(struct ssh_channel); |
| 9964 | |
| 9965 | c->ssh = ssh; |
| 9966 | ssh2_channel_init(c); |
| 9967 | c->halfopen = TRUE; |
| 9968 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ |
| 9969 | c->u.pfd.s = s; |
| 9970 | add234(ssh->channels, c); |
| 9971 | return c; |
| 9972 | } |
| 9973 | |
| 9974 | /* |
| 9975 | * This is called when stdout/stderr (the entity to which |
| 9976 | * from_backend sends data) manages to clear some backlog. |
| 9977 | */ |
| 9978 | static void ssh_unthrottle(void *handle, int bufsize) |
| 9979 | { |
| 9980 | Ssh ssh = (Ssh) handle; |
| 9981 | int buflimit; |
| 9982 | |
| 9983 | if (ssh->version == 1) { |
| 9984 | if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 9985 | ssh->v1_stdout_throttling = 0; |
| 9986 | ssh_throttle_conn(ssh, -1); |
| 9987 | } |
| 9988 | } else { |
| 9989 | if (ssh->mainchan) { |
| 9990 | ssh2_set_window(ssh->mainchan, |
| 9991 | bufsize < ssh->mainchan->v.v2.locmaxwin ? |
| 9992 | ssh->mainchan->v.v2.locmaxwin - bufsize : 0); |
| 9993 | if (conf_get_int(ssh->conf, CONF_ssh_simple)) |
| 9994 | buflimit = 0; |
| 9995 | else |
| 9996 | buflimit = ssh->mainchan->v.v2.locmaxwin; |
| 9997 | if (ssh->mainchan->throttling_conn && bufsize <= buflimit) { |
| 9998 | ssh->mainchan->throttling_conn = 0; |
| 9999 | ssh_throttle_conn(ssh, -1); |
| 10000 | } |
| 10001 | } |
| 10002 | } |
| 10003 | } |
| 10004 | |
| 10005 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) |
| 10006 | { |
| 10007 | struct ssh_channel *c = (struct ssh_channel *)channel; |
| 10008 | Ssh ssh = c->ssh; |
| 10009 | struct Packet *pktout; |
| 10010 | |
| 10011 | logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port); |
| 10012 | |
| 10013 | if (ssh->version == 1) { |
| 10014 | send_packet(ssh, SSH1_MSG_PORT_OPEN, |
| 10015 | PKT_INT, c->localid, |
| 10016 | PKT_STR, hostname, |
| 10017 | PKT_INT, port, |
| 10018 | /* PKT_STR, <org:orgport>, */ |
| 10019 | PKT_END); |
| 10020 | } else { |
| 10021 | pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 10022 | ssh2_pkt_addstring(pktout, "direct-tcpip"); |
| 10023 | ssh2_pkt_adduint32(pktout, c->localid); |
| 10024 | ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ |
| 10025 | ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ |
| 10026 | ssh2_pkt_addstring(pktout, hostname); |
| 10027 | ssh2_pkt_adduint32(pktout, port); |
| 10028 | /* |
| 10029 | * We make up values for the originator data; partly it's |
| 10030 | * too much hassle to keep track, and partly I'm not |
| 10031 | * convinced the server should be told details like that |
| 10032 | * about my local network configuration. |
| 10033 | * The "originator IP address" is syntactically a numeric |
| 10034 | * IP address, and some servers (e.g., Tectia) get upset |
| 10035 | * if it doesn't match this syntax. |
| 10036 | */ |
| 10037 | ssh2_pkt_addstring(pktout, "0.0.0.0"); |
| 10038 | ssh2_pkt_adduint32(pktout, 0); |
| 10039 | ssh2_pkt_send(ssh, pktout); |
| 10040 | } |
| 10041 | } |
| 10042 | |
| 10043 | static int ssh_connected(void *handle) |
| 10044 | { |
| 10045 | Ssh ssh = (Ssh) handle; |
| 10046 | return ssh->s != NULL; |
| 10047 | } |
| 10048 | |
| 10049 | static int ssh_sendok(void *handle) |
| 10050 | { |
| 10051 | Ssh ssh = (Ssh) handle; |
| 10052 | return ssh->send_ok; |
| 10053 | } |
| 10054 | |
| 10055 | static int ssh_ldisc(void *handle, int option) |
| 10056 | { |
| 10057 | Ssh ssh = (Ssh) handle; |
| 10058 | if (option == LD_ECHO) |
| 10059 | return ssh->echoing; |
| 10060 | if (option == LD_EDIT) |
| 10061 | return ssh->editing; |
| 10062 | return FALSE; |
| 10063 | } |
| 10064 | |
| 10065 | static void ssh_provide_ldisc(void *handle, void *ldisc) |
| 10066 | { |
| 10067 | Ssh ssh = (Ssh) handle; |
| 10068 | ssh->ldisc = ldisc; |
| 10069 | } |
| 10070 | |
| 10071 | static void ssh_provide_logctx(void *handle, void *logctx) |
| 10072 | { |
| 10073 | Ssh ssh = (Ssh) handle; |
| 10074 | ssh->logctx = logctx; |
| 10075 | } |
| 10076 | |
| 10077 | static int ssh_return_exitcode(void *handle) |
| 10078 | { |
| 10079 | Ssh ssh = (Ssh) handle; |
| 10080 | if (ssh->s != NULL) |
| 10081 | return -1; |
| 10082 | else |
| 10083 | return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX); |
| 10084 | } |
| 10085 | |
| 10086 | /* |
| 10087 | * cfg_info for SSH is the currently running version of the |
| 10088 | * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.) |
| 10089 | */ |
| 10090 | static int ssh_cfg_info(void *handle) |
| 10091 | { |
| 10092 | Ssh ssh = (Ssh) handle; |
| 10093 | return ssh->version; |
| 10094 | } |
| 10095 | |
| 10096 | /* |
| 10097 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if |
| 10098 | * that fails. This variable is the means by which scp.c can reach |
| 10099 | * into the SSH code and find out which one it got. |
| 10100 | */ |
| 10101 | extern int ssh_fallback_cmd(void *handle) |
| 10102 | { |
| 10103 | Ssh ssh = (Ssh) handle; |
| 10104 | return ssh->fallback_cmd; |
| 10105 | } |
| 10106 | |
| 10107 | Backend ssh_backend = { |
| 10108 | ssh_init, |
| 10109 | ssh_free, |
| 10110 | ssh_reconfig, |
| 10111 | ssh_send, |
| 10112 | ssh_sendbuffer, |
| 10113 | ssh_size, |
| 10114 | ssh_special, |
| 10115 | ssh_get_specials, |
| 10116 | ssh_connected, |
| 10117 | ssh_return_exitcode, |
| 10118 | ssh_sendok, |
| 10119 | ssh_ldisc, |
| 10120 | ssh_provide_ldisc, |
| 10121 | ssh_provide_logctx, |
| 10122 | ssh_unthrottle, |
| 10123 | ssh_cfg_info, |
| 10124 | "ssh", |
| 10125 | PROT_SSH, |
| 10126 | 22 |
| 10127 | }; |