| 1 | #include <windows.h> |
| 2 | #include <stdio.h> |
| 3 | #include <stdlib.h> |
| 4 | #include <stdarg.h> |
| 5 | #include <assert.h> |
| 6 | |
| 7 | #include "putty.h" |
| 8 | #include "tree234.h" |
| 9 | #include "ssh.h" |
| 10 | |
| 11 | #ifndef FALSE |
| 12 | #define FALSE 0 |
| 13 | #endif |
| 14 | #ifndef TRUE |
| 15 | #define TRUE 1 |
| 16 | #endif |
| 17 | |
| 18 | #define logevent(s) { logevent(s); \ |
| 19 | if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ |
| 20 | { fprintf(stderr, "%s\n", s); fflush(stderr); } } |
| 21 | |
| 22 | /* logevent, only printf-formatted. */ |
| 23 | void logeventf(char *fmt, ...) |
| 24 | { |
| 25 | va_list ap; |
| 26 | char stuff[200]; |
| 27 | |
| 28 | va_start(ap, fmt); |
| 29 | vsprintf(stuff, fmt, ap); |
| 30 | va_end(ap); |
| 31 | logevent(stuff); |
| 32 | } |
| 33 | |
| 34 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ |
| 35 | (s ? sk_close(s), s = NULL : 0), \ |
| 36 | logeventf msg, connection_fatal msg ) |
| 37 | |
| 38 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
| 39 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
| 40 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
| 41 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
| 42 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
| 43 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
| 44 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
| 45 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
| 46 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
| 47 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
| 48 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
| 49 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
| 50 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
| 51 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
| 52 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
| 53 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
| 54 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
| 55 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
| 56 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
| 57 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
| 58 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
| 59 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
| 60 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
| 61 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
| 62 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
| 63 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
| 64 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
| 65 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
| 66 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
| 67 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
| 68 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
| 69 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
| 70 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
| 71 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
| 72 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
| 73 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
| 74 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
| 75 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
| 76 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
| 77 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
| 78 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
| 79 | |
| 80 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
| 81 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
| 82 | |
| 83 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
| 84 | /* Mask for protoflags we will echo back to server if seen */ |
| 85 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
| 86 | |
| 87 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
| 88 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
| 89 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
| 90 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
| 91 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
| 92 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
| 93 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
| 94 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
| 95 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
| 96 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
| 97 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
| 98 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
| 99 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
| 100 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
| 101 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
| 102 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
| 103 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
| 104 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
| 105 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
| 106 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
| 107 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ |
| 108 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ |
| 109 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
| 110 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
| 111 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
| 112 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
| 113 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
| 114 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
| 115 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
| 116 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
| 117 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
| 118 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
| 119 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
| 120 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
| 121 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
| 122 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
| 123 | |
| 124 | /* |
| 125 | * Packet type contexts, so that ssh2_pkt_type can correctly decode |
| 126 | * the ambiguous type numbers back into the correct type strings. |
| 127 | */ |
| 128 | #define SSH2_PKTCTX_DHGROUP1 0x0001 |
| 129 | #define SSH2_PKTCTX_DHGEX 0x0002 |
| 130 | #define SSH2_PKTCTX_PUBLICKEY 0x0010 |
| 131 | #define SSH2_PKTCTX_PASSWORD 0x0020 |
| 132 | #define SSH2_PKTCTX_KBDINTER 0x0040 |
| 133 | #define SSH2_PKTCTX_AUTH_MASK 0x00F0 |
| 134 | |
| 135 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
| 136 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
| 137 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
| 138 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
| 139 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
| 140 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
| 141 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
| 142 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
| 143 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
| 144 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
| 145 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
| 146 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
| 147 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
| 148 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
| 149 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
| 150 | |
| 151 | static const char *const ssh2_disconnect_reasons[] = { |
| 152 | NULL, |
| 153 | "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", |
| 154 | "SSH_DISCONNECT_PROTOCOL_ERROR", |
| 155 | "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", |
| 156 | "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", |
| 157 | "SSH_DISCONNECT_MAC_ERROR", |
| 158 | "SSH_DISCONNECT_COMPRESSION_ERROR", |
| 159 | "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", |
| 160 | "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", |
| 161 | "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", |
| 162 | "SSH_DISCONNECT_CONNECTION_LOST", |
| 163 | "SSH_DISCONNECT_BY_APPLICATION", |
| 164 | "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", |
| 165 | "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", |
| 166 | "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", |
| 167 | "SSH_DISCONNECT_ILLEGAL_USER_NAME", |
| 168 | }; |
| 169 | |
| 170 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
| 171 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
| 172 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
| 173 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
| 174 | |
| 175 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
| 176 | |
| 177 | /* |
| 178 | * Various remote-bug flags. |
| 179 | */ |
| 180 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
| 181 | #define BUG_SSH2_HMAC 2 |
| 182 | #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 |
| 183 | #define BUG_CHOKES_ON_RSA 8 |
| 184 | |
| 185 | static int ssh_pkt_ctx = 0; |
| 186 | |
| 187 | #define translate(x) if (type == x) return #x |
| 188 | #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x |
| 189 | char *ssh1_pkt_type(int type) |
| 190 | { |
| 191 | translate(SSH1_MSG_DISCONNECT); |
| 192 | translate(SSH1_SMSG_PUBLIC_KEY); |
| 193 | translate(SSH1_CMSG_SESSION_KEY); |
| 194 | translate(SSH1_CMSG_USER); |
| 195 | translate(SSH1_CMSG_AUTH_RSA); |
| 196 | translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); |
| 197 | translate(SSH1_CMSG_AUTH_RSA_RESPONSE); |
| 198 | translate(SSH1_CMSG_AUTH_PASSWORD); |
| 199 | translate(SSH1_CMSG_REQUEST_PTY); |
| 200 | translate(SSH1_CMSG_WINDOW_SIZE); |
| 201 | translate(SSH1_CMSG_EXEC_SHELL); |
| 202 | translate(SSH1_CMSG_EXEC_CMD); |
| 203 | translate(SSH1_SMSG_SUCCESS); |
| 204 | translate(SSH1_SMSG_FAILURE); |
| 205 | translate(SSH1_CMSG_STDIN_DATA); |
| 206 | translate(SSH1_SMSG_STDOUT_DATA); |
| 207 | translate(SSH1_SMSG_STDERR_DATA); |
| 208 | translate(SSH1_CMSG_EOF); |
| 209 | translate(SSH1_SMSG_EXIT_STATUS); |
| 210 | translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 211 | translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); |
| 212 | translate(SSH1_MSG_CHANNEL_DATA); |
| 213 | translate(SSH1_MSG_CHANNEL_CLOSE); |
| 214 | translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); |
| 215 | translate(SSH1_SMSG_X11_OPEN); |
| 216 | translate(SSH1_CMSG_PORT_FORWARD_REQUEST); |
| 217 | translate(SSH1_MSG_PORT_OPEN); |
| 218 | translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); |
| 219 | translate(SSH1_SMSG_AGENT_OPEN); |
| 220 | translate(SSH1_MSG_IGNORE); |
| 221 | translate(SSH1_CMSG_EXIT_CONFIRMATION); |
| 222 | translate(SSH1_CMSG_X11_REQUEST_FORWARDING); |
| 223 | translate(SSH1_CMSG_AUTH_RHOSTS_RSA); |
| 224 | translate(SSH1_MSG_DEBUG); |
| 225 | translate(SSH1_CMSG_REQUEST_COMPRESSION); |
| 226 | translate(SSH1_CMSG_AUTH_TIS); |
| 227 | translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); |
| 228 | translate(SSH1_CMSG_AUTH_TIS_RESPONSE); |
| 229 | translate(SSH1_CMSG_AUTH_CCARD); |
| 230 | translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); |
| 231 | translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); |
| 232 | return "unknown"; |
| 233 | } |
| 234 | char *ssh2_pkt_type(int type) |
| 235 | { |
| 236 | translate(SSH2_MSG_DISCONNECT); |
| 237 | translate(SSH2_MSG_IGNORE); |
| 238 | translate(SSH2_MSG_UNIMPLEMENTED); |
| 239 | translate(SSH2_MSG_DEBUG); |
| 240 | translate(SSH2_MSG_SERVICE_REQUEST); |
| 241 | translate(SSH2_MSG_SERVICE_ACCEPT); |
| 242 | translate(SSH2_MSG_KEXINIT); |
| 243 | translate(SSH2_MSG_NEWKEYS); |
| 244 | translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1); |
| 245 | translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1); |
| 246 | translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); |
| 247 | translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); |
| 248 | translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); |
| 249 | translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); |
| 250 | translate(SSH2_MSG_USERAUTH_REQUEST); |
| 251 | translate(SSH2_MSG_USERAUTH_FAILURE); |
| 252 | translate(SSH2_MSG_USERAUTH_SUCCESS); |
| 253 | translate(SSH2_MSG_USERAUTH_BANNER); |
| 254 | translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); |
| 255 | translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); |
| 256 | translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); |
| 257 | translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); |
| 258 | translate(SSH2_MSG_GLOBAL_REQUEST); |
| 259 | translate(SSH2_MSG_REQUEST_SUCCESS); |
| 260 | translate(SSH2_MSG_REQUEST_FAILURE); |
| 261 | translate(SSH2_MSG_CHANNEL_OPEN); |
| 262 | translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 263 | translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 264 | translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 265 | translate(SSH2_MSG_CHANNEL_DATA); |
| 266 | translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); |
| 267 | translate(SSH2_MSG_CHANNEL_EOF); |
| 268 | translate(SSH2_MSG_CHANNEL_CLOSE); |
| 269 | translate(SSH2_MSG_CHANNEL_REQUEST); |
| 270 | translate(SSH2_MSG_CHANNEL_SUCCESS); |
| 271 | translate(SSH2_MSG_CHANNEL_FAILURE); |
| 272 | return "unknown"; |
| 273 | } |
| 274 | #undef translate |
| 275 | #undef translatec |
| 276 | |
| 277 | #define GET_32BIT(cp) \ |
| 278 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
| 279 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 280 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 281 | ((unsigned long)(unsigned char)(cp)[3])) |
| 282 | |
| 283 | #define PUT_32BIT(cp, value) { \ |
| 284 | (cp)[0] = (unsigned char)((value) >> 24); \ |
| 285 | (cp)[1] = (unsigned char)((value) >> 16); \ |
| 286 | (cp)[2] = (unsigned char)((value) >> 8); \ |
| 287 | (cp)[3] = (unsigned char)(value); } |
| 288 | |
| 289 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
| 290 | |
| 291 | /* Coroutine mechanics for the sillier bits of the code */ |
| 292 | #define crBegin1 static int crLine = 0; |
| 293 | #define crBegin2 switch(crLine) { case 0:; |
| 294 | #define crBegin crBegin1; crBegin2; |
| 295 | #define crFinish(z) } crLine = 0; return (z) |
| 296 | #define crFinishV } crLine = 0; return |
| 297 | #define crReturn(z) \ |
| 298 | do {\ |
| 299 | crLine=__LINE__; return (z); case __LINE__:;\ |
| 300 | } while (0) |
| 301 | #define crReturnV \ |
| 302 | do {\ |
| 303 | crLine=__LINE__; return; case __LINE__:;\ |
| 304 | } while (0) |
| 305 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
| 306 | #define crStopV do{ crLine = 0; return; }while(0) |
| 307 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 308 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 309 | |
| 310 | extern char *x11_init(Socket *, char *, void *); |
| 311 | extern void x11_close(Socket); |
| 312 | extern int x11_send(Socket, char *, int); |
| 313 | extern void x11_invent_auth(char *, int, char *, int); |
| 314 | extern void x11_unthrottle(Socket s); |
| 315 | extern void x11_override_throttle(Socket s, int enable); |
| 316 | |
| 317 | extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c); |
| 318 | extern char *pfd_addforward(char *desthost, int destport, int port); |
| 319 | extern void pfd_close(Socket s); |
| 320 | extern int pfd_send(Socket s, char *data, int len); |
| 321 | extern void pfd_confirm(Socket s); |
| 322 | extern void pfd_unthrottle(Socket s); |
| 323 | extern void pfd_override_throttle(Socket s, int enable); |
| 324 | |
| 325 | static void ssh2_pkt_init(int pkt_type); |
| 326 | static void ssh2_pkt_addbool(unsigned char value); |
| 327 | static void ssh2_pkt_adduint32(unsigned long value); |
| 328 | static void ssh2_pkt_addstring_start(void); |
| 329 | static void ssh2_pkt_addstring_str(char *data); |
| 330 | static void ssh2_pkt_addstring_data(char *data, int len); |
| 331 | static void ssh2_pkt_addstring(char *data); |
| 332 | static char *ssh2_mpint_fmt(Bignum b, int *len); |
| 333 | static void ssh2_pkt_addmp(Bignum b); |
| 334 | static int ssh2_pkt_construct(void); |
| 335 | static void ssh2_pkt_send(void); |
| 336 | |
| 337 | /* |
| 338 | * Buffer management constants. There are several of these for |
| 339 | * various different purposes: |
| 340 | * |
| 341 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up |
| 342 | * on a local data stream before we throttle the whole SSH |
| 343 | * connection (in SSH1 only). Throttling the whole connection is |
| 344 | * pretty drastic so we set this high in the hope it won't |
| 345 | * happen very often. |
| 346 | * |
| 347 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up |
| 348 | * on the SSH connection itself before we defensively throttle |
| 349 | * _all_ local data streams. This is pretty drastic too (though |
| 350 | * thankfully unlikely in SSH2 since the window mechanism should |
| 351 | * ensure that the server never has any need to throttle its end |
| 352 | * of the connection), so we set this high as well. |
| 353 | * |
| 354 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 |
| 355 | * channels. |
| 356 | */ |
| 357 | |
| 358 | #define SSH1_BUFFER_LIMIT 32768 |
| 359 | #define SSH_MAX_BACKLOG 32768 |
| 360 | #define OUR_V2_WINSIZE 16384 |
| 361 | |
| 362 | const static struct ssh_kex *kex_algs[] = { |
| 363 | &ssh_diffiehellman_gex, |
| 364 | &ssh_diffiehellman |
| 365 | }; |
| 366 | |
| 367 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
| 368 | |
| 369 | static void nullmac_key(unsigned char *key) |
| 370 | { |
| 371 | } |
| 372 | static void nullmac_generate(unsigned char *blk, int len, |
| 373 | unsigned long seq) |
| 374 | { |
| 375 | } |
| 376 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) |
| 377 | { |
| 378 | return 1; |
| 379 | } |
| 380 | const static struct ssh_mac ssh_mac_none = { |
| 381 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
| 382 | }; |
| 383 | const static struct ssh_mac *macs[] = { |
| 384 | &ssh_sha1, &ssh_md5, &ssh_mac_none |
| 385 | }; |
| 386 | const static struct ssh_mac *buggymacs[] = { |
| 387 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none |
| 388 | }; |
| 389 | |
| 390 | static void ssh_comp_none_init(void) |
| 391 | { |
| 392 | } |
| 393 | static int ssh_comp_none_block(unsigned char *block, int len, |
| 394 | unsigned char **outblock, int *outlen) |
| 395 | { |
| 396 | return 0; |
| 397 | } |
| 398 | static int ssh_comp_none_disable(void) |
| 399 | { |
| 400 | return 0; |
| 401 | } |
| 402 | const static struct ssh_compress ssh_comp_none = { |
| 403 | "none", |
| 404 | ssh_comp_none_init, ssh_comp_none_block, |
| 405 | ssh_comp_none_init, ssh_comp_none_block, |
| 406 | ssh_comp_none_disable |
| 407 | }; |
| 408 | extern const struct ssh_compress ssh_zlib; |
| 409 | const static struct ssh_compress *compressions[] = { |
| 410 | &ssh_zlib, &ssh_comp_none |
| 411 | }; |
| 412 | |
| 413 | enum { /* channel types */ |
| 414 | CHAN_MAINSESSION, |
| 415 | CHAN_X11, |
| 416 | CHAN_AGENT, |
| 417 | CHAN_SOCKDATA, |
| 418 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ |
| 419 | }; |
| 420 | |
| 421 | /* |
| 422 | * 2-3-4 tree storing channels. |
| 423 | */ |
| 424 | struct ssh_channel { |
| 425 | unsigned remoteid, localid; |
| 426 | int type; |
| 427 | int closes; |
| 428 | union { |
| 429 | struct ssh1_data_channel { |
| 430 | int throttling; |
| 431 | } v1; |
| 432 | struct ssh2_data_channel { |
| 433 | bufchain outbuffer; |
| 434 | unsigned remwindow, remmaxpkt; |
| 435 | unsigned locwindow; |
| 436 | } v2; |
| 437 | } v; |
| 438 | union { |
| 439 | struct ssh_agent_channel { |
| 440 | unsigned char *message; |
| 441 | unsigned char msglen[4]; |
| 442 | int lensofar, totallen; |
| 443 | } a; |
| 444 | struct ssh_x11_channel { |
| 445 | Socket s; |
| 446 | } x11; |
| 447 | struct ssh_pfd_channel { |
| 448 | Socket s; |
| 449 | } pfd; |
| 450 | } u; |
| 451 | }; |
| 452 | |
| 453 | /* |
| 454 | * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH |
| 455 | * 2 use this structure in different ways, reflecting SSH 2's |
| 456 | * altogether saner approach to port forwarding. |
| 457 | * |
| 458 | * In SSH 1, you arrange a remote forwarding by sending the server |
| 459 | * the remote port number, and the local destination host:port. |
| 460 | * When a connection comes in, the server sends you back that |
| 461 | * host:port pair, and you connect to it. This is a ready-made |
| 462 | * security hole if you're not on the ball: a malicious server |
| 463 | * could send you back _any_ host:port pair, so if you trustingly |
| 464 | * connect to the address it gives you then you've just opened the |
| 465 | * entire inside of your corporate network just by connecting |
| 466 | * through it to a dodgy SSH server. Hence, we must store a list of |
| 467 | * host:port pairs we _are_ trying to forward to, and reject a |
| 468 | * connection request from the server if it's not in the list. |
| 469 | * |
| 470 | * In SSH 2, each side of the connection minds its own business and |
| 471 | * doesn't send unnecessary information to the other. You arrange a |
| 472 | * remote forwarding by sending the server just the remote port |
| 473 | * number. When a connection comes in, the server tells you which |
| 474 | * of its ports was connected to; and _you_ have to remember what |
| 475 | * local host:port pair went with that port number. |
| 476 | * |
| 477 | * Hence: in SSH 1 this structure stores host:port pairs we intend |
| 478 | * to allow connections to, and is indexed by those host:port |
| 479 | * pairs. In SSH 2 it stores a mapping from source port to |
| 480 | * destination host:port pair, and is indexed by source port. |
| 481 | */ |
| 482 | struct ssh_rportfwd { |
| 483 | unsigned sport, dport; |
| 484 | char dhost[256]; |
| 485 | }; |
| 486 | |
| 487 | struct Packet { |
| 488 | long length; |
| 489 | int type; |
| 490 | unsigned char *data; |
| 491 | unsigned char *body; |
| 492 | long savedpos; |
| 493 | long maxlen; |
| 494 | }; |
| 495 | |
| 496 | static SHA_State exhash, exhashbase; |
| 497 | |
| 498 | static Socket s = NULL; |
| 499 | |
| 500 | static unsigned char session_key[32]; |
| 501 | static int ssh1_compressing; |
| 502 | static int ssh1_remote_protoflags; |
| 503 | static int ssh1_local_protoflags; |
| 504 | static int ssh_agentfwd_enabled; |
| 505 | static int ssh_X11_fwd_enabled; |
| 506 | static int ssh_remote_bugs; |
| 507 | static const struct ssh_cipher *cipher = NULL; |
| 508 | static const struct ssh2_cipher *cscipher = NULL; |
| 509 | static const struct ssh2_cipher *sccipher = NULL; |
| 510 | static const struct ssh_mac *csmac = NULL; |
| 511 | static const struct ssh_mac *scmac = NULL; |
| 512 | static const struct ssh_compress *cscomp = NULL; |
| 513 | static const struct ssh_compress *sccomp = NULL; |
| 514 | static const struct ssh_kex *kex = NULL; |
| 515 | static const struct ssh_signkey *hostkey = NULL; |
| 516 | static unsigned char ssh2_session_id[20]; |
| 517 | int (*ssh_get_line) (const char *prompt, char *str, int maxlen, |
| 518 | int is_pw) = NULL; |
| 519 | |
| 520 | static char *savedhost; |
| 521 | static int savedport; |
| 522 | static int ssh_send_ok; |
| 523 | static int ssh_echoing, ssh_editing; |
| 524 | |
| 525 | static tree234 *ssh_channels; /* indexed by local id */ |
| 526 | static struct ssh_channel *mainchan; /* primary session channel */ |
| 527 | static int ssh_exitcode = -1; |
| 528 | |
| 529 | static tree234 *ssh_rportfwds; |
| 530 | |
| 531 | static enum { |
| 532 | SSH_STATE_PREPACKET, |
| 533 | SSH_STATE_BEFORE_SIZE, |
| 534 | SSH_STATE_INTERMED, |
| 535 | SSH_STATE_SESSION, |
| 536 | SSH_STATE_CLOSED |
| 537 | } ssh_state = SSH_STATE_PREPACKET; |
| 538 | |
| 539 | static int size_needed = FALSE, eof_needed = FALSE; |
| 540 | |
| 541 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
| 542 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
| 543 | static unsigned char *deferred_send_data = NULL; |
| 544 | static int deferred_len = 0, deferred_size = 0; |
| 545 | |
| 546 | /* |
| 547 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if |
| 548 | * that fails. This variable is the means by which scp.c can reach |
| 549 | * into the SSH code and find out which one it got. |
| 550 | */ |
| 551 | int ssh_fallback_cmd = 0; |
| 552 | |
| 553 | static int ssh_version; |
| 554 | static int ssh1_throttle_count; |
| 555 | static int ssh_overall_bufsize; |
| 556 | static int ssh_throttled_all; |
| 557 | static int ssh1_stdout_throttling; |
| 558 | static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt); |
| 559 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
| 560 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
| 561 | static void ssh_size(void); |
| 562 | static void ssh_special(Telnet_Special); |
| 563 | static int ssh2_try_send(struct ssh_channel *c); |
| 564 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
| 565 | int len); |
| 566 | static void ssh_throttle_all(int enable, int bufsize); |
| 567 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); |
| 568 | static int (*s_rdpkt) (unsigned char **data, int *datalen); |
| 569 | static int ssh_sendbuffer(void); |
| 570 | |
| 571 | static struct rdpkt1_state_tag { |
| 572 | long len, pad, biglen, to_read; |
| 573 | unsigned long realcrc, gotcrc; |
| 574 | unsigned char *p; |
| 575 | int i; |
| 576 | int chunk; |
| 577 | } rdpkt1_state; |
| 578 | |
| 579 | static struct rdpkt2_state_tag { |
| 580 | long len, pad, payload, packetlen, maclen; |
| 581 | int i; |
| 582 | int cipherblk; |
| 583 | unsigned long incoming_sequence; |
| 584 | } rdpkt2_state; |
| 585 | |
| 586 | static int ssh_channelcmp(void *av, void *bv) |
| 587 | { |
| 588 | struct ssh_channel *a = (struct ssh_channel *) av; |
| 589 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 590 | if (a->localid < b->localid) |
| 591 | return -1; |
| 592 | if (a->localid > b->localid) |
| 593 | return +1; |
| 594 | return 0; |
| 595 | } |
| 596 | static int ssh_channelfind(void *av, void *bv) |
| 597 | { |
| 598 | unsigned *a = (unsigned *) av; |
| 599 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 600 | if (*a < b->localid) |
| 601 | return -1; |
| 602 | if (*a > b->localid) |
| 603 | return +1; |
| 604 | return 0; |
| 605 | } |
| 606 | |
| 607 | static int ssh_rportcmp_ssh1(void *av, void *bv) |
| 608 | { |
| 609 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 610 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 611 | int i; |
| 612 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) |
| 613 | return i < 0 ? -1 : +1; |
| 614 | if (a->dport > b->dport) |
| 615 | return +1; |
| 616 | if (a->dport < b->dport) |
| 617 | return -1; |
| 618 | return 0; |
| 619 | } |
| 620 | |
| 621 | static int ssh_rportcmp_ssh2(void *av, void *bv) |
| 622 | { |
| 623 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 624 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 625 | |
| 626 | if (a->sport > b->sport) |
| 627 | return +1; |
| 628 | if (a->sport < b->sport) |
| 629 | return -1; |
| 630 | return 0; |
| 631 | } |
| 632 | |
| 633 | static int alloc_channel_id(void) |
| 634 | { |
| 635 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
| 636 | unsigned low, high, mid; |
| 637 | int tsize; |
| 638 | struct ssh_channel *c; |
| 639 | |
| 640 | /* |
| 641 | * First-fit allocation of channel numbers: always pick the |
| 642 | * lowest unused one. To do this, binary-search using the |
| 643 | * counted B-tree to find the largest channel ID which is in a |
| 644 | * contiguous sequence from the beginning. (Precisely |
| 645 | * everything in that sequence must have ID equal to its tree |
| 646 | * index plus CHANNEL_NUMBER_OFFSET.) |
| 647 | */ |
| 648 | tsize = count234(ssh_channels); |
| 649 | |
| 650 | low = -1; |
| 651 | high = tsize; |
| 652 | while (high - low > 1) { |
| 653 | mid = (high + low) / 2; |
| 654 | c = index234(ssh_channels, mid); |
| 655 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
| 656 | low = mid; /* this one is fine */ |
| 657 | else |
| 658 | high = mid; /* this one is past it */ |
| 659 | } |
| 660 | /* |
| 661 | * Now low points to either -1, or the tree index of the |
| 662 | * largest ID in the initial sequence. |
| 663 | */ |
| 664 | { |
| 665 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
| 666 | assert(NULL == find234(ssh_channels, &i, ssh_channelfind)); |
| 667 | } |
| 668 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
| 669 | } |
| 670 | |
| 671 | static void c_write(char *buf, int len) |
| 672 | { |
| 673 | if ((flags & FLAG_STDERR)) { |
| 674 | int i; |
| 675 | for (i = 0; i < len; i++) |
| 676 | if (buf[i] != '\r') |
| 677 | fputc(buf[i], stderr); |
| 678 | return; |
| 679 | } |
| 680 | from_backend(1, buf, len); |
| 681 | } |
| 682 | |
| 683 | static void c_write_untrusted(char *buf, int len) |
| 684 | { |
| 685 | int i; |
| 686 | for (i = 0; i < len; i++) { |
| 687 | if (buf[i] == '\n') |
| 688 | c_write("\r\n", 2); |
| 689 | else if ((buf[i] & 0x60) || (buf[i] == '\r')) |
| 690 | c_write(buf + i, 1); |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | static void c_write_str(char *buf) |
| 695 | { |
| 696 | c_write(buf, strlen(buf)); |
| 697 | } |
| 698 | |
| 699 | /* |
| 700 | * Collect incoming data in the incoming packet buffer. |
| 701 | * Decipher and verify the packet when it is completely read. |
| 702 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 703 | * Update the *data and *datalen variables. |
| 704 | * Return the additional nr of bytes needed, or 0 when |
| 705 | * a complete packet is available. |
| 706 | */ |
| 707 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
| 708 | { |
| 709 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
| 710 | |
| 711 | crBegin; |
| 712 | |
| 713 | next_packet: |
| 714 | |
| 715 | pktin.type = 0; |
| 716 | pktin.length = 0; |
| 717 | |
| 718 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
| 719 | while ((*datalen) == 0) |
| 720 | crReturn(4 - st->i); |
| 721 | st->len = (st->len << 8) + **data; |
| 722 | (*data)++, (*datalen)--; |
| 723 | } |
| 724 | |
| 725 | st->pad = 8 - (st->len % 8); |
| 726 | st->biglen = st->len + st->pad; |
| 727 | pktin.length = st->len - 5; |
| 728 | |
| 729 | if (pktin.maxlen < st->biglen) { |
| 730 | pktin.maxlen = st->biglen; |
| 731 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) : |
| 732 | srealloc(pktin.data, st->biglen + APIEXTRA)); |
| 733 | if (!pktin.data) |
| 734 | fatalbox("Out of memory"); |
| 735 | } |
| 736 | |
| 737 | st->to_read = st->biglen; |
| 738 | st->p = pktin.data; |
| 739 | while (st->to_read > 0) { |
| 740 | st->chunk = st->to_read; |
| 741 | while ((*datalen) == 0) |
| 742 | crReturn(st->to_read); |
| 743 | if (st->chunk > (*datalen)) |
| 744 | st->chunk = (*datalen); |
| 745 | memcpy(st->p, *data, st->chunk); |
| 746 | *data += st->chunk; |
| 747 | *datalen -= st->chunk; |
| 748 | st->p += st->chunk; |
| 749 | st->to_read -= st->chunk; |
| 750 | } |
| 751 | |
| 752 | if (cipher && detect_attack(pktin.data, st->biglen, NULL)) { |
| 753 | bombout(("Network attack (CRC compensation) detected!")); |
| 754 | crReturn(0); |
| 755 | } |
| 756 | |
| 757 | if (cipher) |
| 758 | cipher->decrypt(pktin.data, st->biglen); |
| 759 | |
| 760 | st->realcrc = crc32(pktin.data, st->biglen - 4); |
| 761 | st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4); |
| 762 | if (st->gotcrc != st->realcrc) { |
| 763 | bombout(("Incorrect CRC received on packet")); |
| 764 | crReturn(0); |
| 765 | } |
| 766 | |
| 767 | pktin.body = pktin.data + st->pad + 1; |
| 768 | |
| 769 | if (ssh1_compressing) { |
| 770 | unsigned char *decompblk; |
| 771 | int decomplen; |
| 772 | zlib_decompress_block(pktin.body - 1, pktin.length + 1, |
| 773 | &decompblk, &decomplen); |
| 774 | |
| 775 | if (pktin.maxlen < st->pad + decomplen) { |
| 776 | pktin.maxlen = st->pad + decomplen; |
| 777 | pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA); |
| 778 | pktin.body = pktin.data + st->pad + 1; |
| 779 | if (!pktin.data) |
| 780 | fatalbox("Out of memory"); |
| 781 | } |
| 782 | |
| 783 | memcpy(pktin.body - 1, decompblk, decomplen); |
| 784 | sfree(decompblk); |
| 785 | pktin.length = decomplen - 1; |
| 786 | } |
| 787 | |
| 788 | pktin.type = pktin.body[-1]; |
| 789 | |
| 790 | log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type), |
| 791 | pktin.body, pktin.length); |
| 792 | |
| 793 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 794 | pktin.type == SSH1_SMSG_STDERR_DATA || |
| 795 | pktin.type == SSH1_MSG_DEBUG || |
| 796 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
| 797 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 798 | long stringlen = GET_32BIT(pktin.body); |
| 799 | if (stringlen + 4 != pktin.length) { |
| 800 | bombout(("Received data packet with bogus string length")); |
| 801 | crReturn(0); |
| 802 | } |
| 803 | } |
| 804 | |
| 805 | if (pktin.type == SSH1_MSG_DEBUG) { |
| 806 | /* log debug message */ |
| 807 | char buf[80]; |
| 808 | int stringlen = GET_32BIT(pktin.body); |
| 809 | strcpy(buf, "Remote: "); |
| 810 | if (stringlen > 70) |
| 811 | stringlen = 70; |
| 812 | memcpy(buf + 8, pktin.body + 4, stringlen); |
| 813 | buf[8 + stringlen] = '\0'; |
| 814 | logevent(buf); |
| 815 | goto next_packet; |
| 816 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
| 817 | /* do nothing */ |
| 818 | goto next_packet; |
| 819 | } |
| 820 | |
| 821 | if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 822 | /* log reason code in disconnect message */ |
| 823 | char buf[256]; |
| 824 | unsigned msglen = GET_32BIT(pktin.body); |
| 825 | unsigned nowlen; |
| 826 | strcpy(buf, "Remote sent disconnect: "); |
| 827 | nowlen = strlen(buf); |
| 828 | if (msglen > sizeof(buf) - nowlen - 1) |
| 829 | msglen = sizeof(buf) - nowlen - 1; |
| 830 | memcpy(buf + nowlen, pktin.body + 4, msglen); |
| 831 | buf[nowlen + msglen] = '\0'; |
| 832 | /* logevent(buf); (this is now done within the bombout macro) */ |
| 833 | bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen)); |
| 834 | crReturn(0); |
| 835 | } |
| 836 | |
| 837 | crFinish(0); |
| 838 | } |
| 839 | |
| 840 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
| 841 | { |
| 842 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
| 843 | |
| 844 | crBegin; |
| 845 | |
| 846 | next_packet: |
| 847 | pktin.type = 0; |
| 848 | pktin.length = 0; |
| 849 | if (sccipher) |
| 850 | st->cipherblk = sccipher->blksize; |
| 851 | else |
| 852 | st->cipherblk = 8; |
| 853 | if (st->cipherblk < 8) |
| 854 | st->cipherblk = 8; |
| 855 | |
| 856 | if (pktin.maxlen < st->cipherblk) { |
| 857 | pktin.maxlen = st->cipherblk; |
| 858 | pktin.data = |
| 859 | (pktin.data == |
| 860 | NULL ? smalloc(st->cipherblk + |
| 861 | APIEXTRA) : srealloc(pktin.data, |
| 862 | st->cipherblk + |
| 863 | APIEXTRA)); |
| 864 | if (!pktin.data) |
| 865 | fatalbox("Out of memory"); |
| 866 | } |
| 867 | |
| 868 | /* |
| 869 | * Acquire and decrypt the first block of the packet. This will |
| 870 | * contain the length and padding details. |
| 871 | */ |
| 872 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
| 873 | while ((*datalen) == 0) |
| 874 | crReturn(st->cipherblk - st->i); |
| 875 | pktin.data[st->i] = *(*data)++; |
| 876 | (*datalen)--; |
| 877 | } |
| 878 | |
| 879 | if (sccipher) |
| 880 | sccipher->decrypt(pktin.data, st->cipherblk); |
| 881 | |
| 882 | /* |
| 883 | * Now get the length and padding figures. |
| 884 | */ |
| 885 | st->len = GET_32BIT(pktin.data); |
| 886 | st->pad = pktin.data[4]; |
| 887 | |
| 888 | /* |
| 889 | * This enables us to deduce the payload length. |
| 890 | */ |
| 891 | st->payload = st->len - st->pad - 1; |
| 892 | |
| 893 | pktin.length = st->payload + 5; |
| 894 | |
| 895 | /* |
| 896 | * So now we can work out the total packet length. |
| 897 | */ |
| 898 | st->packetlen = st->len + 4; |
| 899 | st->maclen = scmac ? scmac->len : 0; |
| 900 | |
| 901 | /* |
| 902 | * Adjust memory allocation if packet is too big. |
| 903 | */ |
| 904 | if (pktin.maxlen < st->packetlen + st->maclen) { |
| 905 | pktin.maxlen = st->packetlen + st->maclen; |
| 906 | pktin.data = |
| 907 | (pktin.data == |
| 908 | NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data, |
| 909 | pktin.maxlen |
| 910 | + |
| 911 | APIEXTRA)); |
| 912 | if (!pktin.data) |
| 913 | fatalbox("Out of memory"); |
| 914 | } |
| 915 | |
| 916 | /* |
| 917 | * Read and decrypt the remainder of the packet. |
| 918 | */ |
| 919 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; |
| 920 | st->i++) { |
| 921 | while ((*datalen) == 0) |
| 922 | crReturn(st->packetlen + st->maclen - st->i); |
| 923 | pktin.data[st->i] = *(*data)++; |
| 924 | (*datalen)--; |
| 925 | } |
| 926 | /* Decrypt everything _except_ the MAC. */ |
| 927 | if (sccipher) |
| 928 | sccipher->decrypt(pktin.data + st->cipherblk, |
| 929 | st->packetlen - st->cipherblk); |
| 930 | |
| 931 | /* |
| 932 | * Check the MAC. |
| 933 | */ |
| 934 | if (scmac |
| 935 | && !scmac->verify(pktin.data, st->len + 4, |
| 936 | st->incoming_sequence)) { |
| 937 | bombout(("Incorrect MAC received on packet")); |
| 938 | crReturn(0); |
| 939 | } |
| 940 | st->incoming_sequence++; /* whether or not we MACed */ |
| 941 | |
| 942 | /* |
| 943 | * Decompress packet payload. |
| 944 | */ |
| 945 | { |
| 946 | unsigned char *newpayload; |
| 947 | int newlen; |
| 948 | if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5, |
| 949 | &newpayload, &newlen)) { |
| 950 | if (pktin.maxlen < newlen + 5) { |
| 951 | pktin.maxlen = newlen + 5; |
| 952 | pktin.data = |
| 953 | (pktin.data == |
| 954 | NULL ? smalloc(pktin.maxlen + |
| 955 | APIEXTRA) : srealloc(pktin.data, |
| 956 | pktin.maxlen + |
| 957 | APIEXTRA)); |
| 958 | if (!pktin.data) |
| 959 | fatalbox("Out of memory"); |
| 960 | } |
| 961 | pktin.length = 5 + newlen; |
| 962 | memcpy(pktin.data + 5, newpayload, newlen); |
| 963 | sfree(newpayload); |
| 964 | } |
| 965 | } |
| 966 | |
| 967 | pktin.savedpos = 6; |
| 968 | pktin.type = pktin.data[5]; |
| 969 | |
| 970 | log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type), |
| 971 | pktin.data+6, pktin.length-6); |
| 972 | |
| 973 | switch (pktin.type) { |
| 974 | /* |
| 975 | * These packets we must handle instantly. |
| 976 | */ |
| 977 | case SSH2_MSG_DISCONNECT: |
| 978 | { |
| 979 | /* log reason code in disconnect message */ |
| 980 | char buf[256]; |
| 981 | int reason = GET_32BIT(pktin.data + 6); |
| 982 | unsigned msglen = GET_32BIT(pktin.data + 10); |
| 983 | unsigned nowlen; |
| 984 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
| 985 | sprintf(buf, "Received disconnect message (%s)", |
| 986 | ssh2_disconnect_reasons[reason]); |
| 987 | } else { |
| 988 | sprintf(buf, "Received disconnect message (unknown type %d)", |
| 989 | reason); |
| 990 | } |
| 991 | logevent(buf); |
| 992 | strcpy(buf, "Disconnection message text: "); |
| 993 | nowlen = strlen(buf); |
| 994 | if (msglen > sizeof(buf) - nowlen - 1) |
| 995 | msglen = sizeof(buf) - nowlen - 1; |
| 996 | memcpy(buf + nowlen, pktin.data + 14, msglen); |
| 997 | buf[nowlen + msglen] = '\0'; |
| 998 | logevent(buf); |
| 999 | bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"", |
| 1000 | reason, |
| 1001 | (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? |
| 1002 | ssh2_disconnect_reasons[reason] : "unknown", |
| 1003 | buf+nowlen)); |
| 1004 | crReturn(0); |
| 1005 | } |
| 1006 | break; |
| 1007 | case SSH2_MSG_IGNORE: |
| 1008 | goto next_packet; |
| 1009 | case SSH2_MSG_DEBUG: |
| 1010 | { |
| 1011 | /* log the debug message */ |
| 1012 | char buf[512]; |
| 1013 | /* int display = pktin.body[6]; */ |
| 1014 | int stringlen = GET_32BIT(pktin.data+7); |
| 1015 | int prefix; |
| 1016 | strcpy(buf, "Remote debug message: "); |
| 1017 | prefix = strlen(buf); |
| 1018 | if (stringlen > sizeof(buf)-prefix-1) |
| 1019 | stringlen = sizeof(buf)-prefix-1; |
| 1020 | memcpy(buf + prefix, pktin.data + 11, stringlen); |
| 1021 | buf[prefix + stringlen] = '\0'; |
| 1022 | logevent(buf); |
| 1023 | } |
| 1024 | goto next_packet; /* FIXME: print the debug message */ |
| 1025 | |
| 1026 | /* |
| 1027 | * These packets we need do nothing about here. |
| 1028 | */ |
| 1029 | case SSH2_MSG_UNIMPLEMENTED: |
| 1030 | case SSH2_MSG_SERVICE_REQUEST: |
| 1031 | case SSH2_MSG_SERVICE_ACCEPT: |
| 1032 | case SSH2_MSG_KEXINIT: |
| 1033 | case SSH2_MSG_NEWKEYS: |
| 1034 | case SSH2_MSG_KEXDH_INIT: |
| 1035 | case SSH2_MSG_KEXDH_REPLY: |
| 1036 | /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */ |
| 1037 | /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */ |
| 1038 | case SSH2_MSG_KEX_DH_GEX_INIT: |
| 1039 | case SSH2_MSG_KEX_DH_GEX_REPLY: |
| 1040 | case SSH2_MSG_USERAUTH_REQUEST: |
| 1041 | case SSH2_MSG_USERAUTH_FAILURE: |
| 1042 | case SSH2_MSG_USERAUTH_SUCCESS: |
| 1043 | case SSH2_MSG_USERAUTH_BANNER: |
| 1044 | case SSH2_MSG_USERAUTH_PK_OK: |
| 1045 | /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */ |
| 1046 | /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */ |
| 1047 | case SSH2_MSG_USERAUTH_INFO_RESPONSE: |
| 1048 | case SSH2_MSG_GLOBAL_REQUEST: |
| 1049 | case SSH2_MSG_REQUEST_SUCCESS: |
| 1050 | case SSH2_MSG_REQUEST_FAILURE: |
| 1051 | case SSH2_MSG_CHANNEL_OPEN: |
| 1052 | case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION: |
| 1053 | case SSH2_MSG_CHANNEL_OPEN_FAILURE: |
| 1054 | case SSH2_MSG_CHANNEL_WINDOW_ADJUST: |
| 1055 | case SSH2_MSG_CHANNEL_DATA: |
| 1056 | case SSH2_MSG_CHANNEL_EXTENDED_DATA: |
| 1057 | case SSH2_MSG_CHANNEL_EOF: |
| 1058 | case SSH2_MSG_CHANNEL_CLOSE: |
| 1059 | case SSH2_MSG_CHANNEL_REQUEST: |
| 1060 | case SSH2_MSG_CHANNEL_SUCCESS: |
| 1061 | case SSH2_MSG_CHANNEL_FAILURE: |
| 1062 | break; |
| 1063 | |
| 1064 | /* |
| 1065 | * For anything else we send SSH2_MSG_UNIMPLEMENTED. |
| 1066 | */ |
| 1067 | default: |
| 1068 | ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); |
| 1069 | ssh2_pkt_adduint32(st->incoming_sequence - 1); |
| 1070 | ssh2_pkt_send(); |
| 1071 | break; |
| 1072 | } |
| 1073 | |
| 1074 | crFinish(0); |
| 1075 | } |
| 1076 | |
| 1077 | static void ssh1_pktout_size(int len) |
| 1078 | { |
| 1079 | int pad, biglen; |
| 1080 | |
| 1081 | len += 5; /* type and CRC */ |
| 1082 | pad = 8 - (len % 8); |
| 1083 | biglen = len + pad; |
| 1084 | |
| 1085 | pktout.length = len - 5; |
| 1086 | if (pktout.maxlen < biglen) { |
| 1087 | pktout.maxlen = biglen; |
| 1088 | #ifdef MSCRYPTOAPI |
| 1089 | /* Allocate enough buffer space for extra block |
| 1090 | * for MS CryptEncrypt() */ |
| 1091 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) : |
| 1092 | srealloc(pktout.data, biglen + 12)); |
| 1093 | #else |
| 1094 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) : |
| 1095 | srealloc(pktout.data, biglen + 4)); |
| 1096 | #endif |
| 1097 | if (!pktout.data) |
| 1098 | fatalbox("Out of memory"); |
| 1099 | } |
| 1100 | pktout.body = pktout.data + 4 + pad + 1; |
| 1101 | } |
| 1102 | |
| 1103 | static void s_wrpkt_start(int type, int len) |
| 1104 | { |
| 1105 | ssh1_pktout_size(len); |
| 1106 | pktout.type = type; |
| 1107 | } |
| 1108 | |
| 1109 | static int s_wrpkt_prepare(void) |
| 1110 | { |
| 1111 | int pad, len, biglen, i; |
| 1112 | unsigned long crc; |
| 1113 | |
| 1114 | pktout.body[-1] = pktout.type; |
| 1115 | |
| 1116 | log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type), |
| 1117 | pktout.body, pktout.length); |
| 1118 | |
| 1119 | if (ssh1_compressing) { |
| 1120 | unsigned char *compblk; |
| 1121 | int complen; |
| 1122 | zlib_compress_block(pktout.body - 1, pktout.length + 1, |
| 1123 | &compblk, &complen); |
| 1124 | ssh1_pktout_size(complen - 1); |
| 1125 | memcpy(pktout.body - 1, compblk, complen); |
| 1126 | sfree(compblk); |
| 1127 | } |
| 1128 | |
| 1129 | len = pktout.length + 5; /* type and CRC */ |
| 1130 | pad = 8 - (len % 8); |
| 1131 | biglen = len + pad; |
| 1132 | |
| 1133 | for (i = 0; i < pad; i++) |
| 1134 | pktout.data[i + 4] = random_byte(); |
| 1135 | crc = crc32(pktout.data + 4, biglen - 4); |
| 1136 | PUT_32BIT(pktout.data + biglen, crc); |
| 1137 | PUT_32BIT(pktout.data, len); |
| 1138 | |
| 1139 | if (cipher) |
| 1140 | cipher->encrypt(pktout.data + 4, biglen); |
| 1141 | |
| 1142 | return biglen + 4; |
| 1143 | } |
| 1144 | |
| 1145 | static void s_wrpkt(void) |
| 1146 | { |
| 1147 | int len, backlog; |
| 1148 | len = s_wrpkt_prepare(); |
| 1149 | backlog = sk_write(s, pktout.data, len); |
| 1150 | if (backlog > SSH_MAX_BACKLOG) |
| 1151 | ssh_throttle_all(1, backlog); |
| 1152 | } |
| 1153 | |
| 1154 | static void s_wrpkt_defer(void) |
| 1155 | { |
| 1156 | int len; |
| 1157 | len = s_wrpkt_prepare(); |
| 1158 | if (deferred_len + len > deferred_size) { |
| 1159 | deferred_size = deferred_len + len + 128; |
| 1160 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
| 1161 | } |
| 1162 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
| 1163 | deferred_len += len; |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * Construct a packet with the specified contents. |
| 1168 | */ |
| 1169 | static void construct_packet(int pkttype, va_list ap1, va_list ap2) |
| 1170 | { |
| 1171 | unsigned char *p, *argp, argchar; |
| 1172 | unsigned long argint; |
| 1173 | int pktlen, argtype, arglen; |
| 1174 | Bignum bn; |
| 1175 | |
| 1176 | pktlen = 0; |
| 1177 | while ((argtype = va_arg(ap1, int)) != PKT_END) { |
| 1178 | switch (argtype) { |
| 1179 | case PKT_INT: |
| 1180 | (void) va_arg(ap1, int); |
| 1181 | pktlen += 4; |
| 1182 | break; |
| 1183 | case PKT_CHAR: |
| 1184 | (void) va_arg(ap1, char); |
| 1185 | pktlen++; |
| 1186 | break; |
| 1187 | case PKT_DATA: |
| 1188 | (void) va_arg(ap1, unsigned char *); |
| 1189 | arglen = va_arg(ap1, int); |
| 1190 | pktlen += arglen; |
| 1191 | break; |
| 1192 | case PKT_STR: |
| 1193 | argp = va_arg(ap1, unsigned char *); |
| 1194 | arglen = strlen(argp); |
| 1195 | pktlen += 4 + arglen; |
| 1196 | break; |
| 1197 | case PKT_BIGNUM: |
| 1198 | bn = va_arg(ap1, Bignum); |
| 1199 | pktlen += ssh1_bignum_length(bn); |
| 1200 | break; |
| 1201 | default: |
| 1202 | assert(0); |
| 1203 | } |
| 1204 | } |
| 1205 | |
| 1206 | s_wrpkt_start(pkttype, pktlen); |
| 1207 | p = pktout.body; |
| 1208 | |
| 1209 | while ((argtype = va_arg(ap2, int)) != PKT_END) { |
| 1210 | switch (argtype) { |
| 1211 | case PKT_INT: |
| 1212 | argint = va_arg(ap2, int); |
| 1213 | PUT_32BIT(p, argint); |
| 1214 | p += 4; |
| 1215 | break; |
| 1216 | case PKT_CHAR: |
| 1217 | argchar = va_arg(ap2, unsigned char); |
| 1218 | *p = argchar; |
| 1219 | p++; |
| 1220 | break; |
| 1221 | case PKT_DATA: |
| 1222 | argp = va_arg(ap2, unsigned char *); |
| 1223 | arglen = va_arg(ap2, int); |
| 1224 | memcpy(p, argp, arglen); |
| 1225 | p += arglen; |
| 1226 | break; |
| 1227 | case PKT_STR: |
| 1228 | argp = va_arg(ap2, unsigned char *); |
| 1229 | arglen = strlen(argp); |
| 1230 | PUT_32BIT(p, arglen); |
| 1231 | memcpy(p + 4, argp, arglen); |
| 1232 | p += 4 + arglen; |
| 1233 | break; |
| 1234 | case PKT_BIGNUM: |
| 1235 | bn = va_arg(ap2, Bignum); |
| 1236 | p += ssh1_write_bignum(p, bn); |
| 1237 | break; |
| 1238 | } |
| 1239 | } |
| 1240 | } |
| 1241 | |
| 1242 | static void send_packet(int pkttype, ...) |
| 1243 | { |
| 1244 | va_list ap1, ap2; |
| 1245 | va_start(ap1, pkttype); |
| 1246 | va_start(ap2, pkttype); |
| 1247 | construct_packet(pkttype, ap1, ap2); |
| 1248 | s_wrpkt(); |
| 1249 | } |
| 1250 | |
| 1251 | static void defer_packet(int pkttype, ...) |
| 1252 | { |
| 1253 | va_list ap1, ap2; |
| 1254 | va_start(ap1, pkttype); |
| 1255 | va_start(ap2, pkttype); |
| 1256 | construct_packet(pkttype, ap1, ap2); |
| 1257 | s_wrpkt_defer(); |
| 1258 | } |
| 1259 | |
| 1260 | static int ssh_versioncmp(char *a, char *b) |
| 1261 | { |
| 1262 | char *ae, *be; |
| 1263 | unsigned long av, bv; |
| 1264 | |
| 1265 | av = strtoul(a, &ae, 10); |
| 1266 | bv = strtoul(b, &be, 10); |
| 1267 | if (av != bv) |
| 1268 | return (av < bv ? -1 : +1); |
| 1269 | if (*ae == '.') |
| 1270 | ae++; |
| 1271 | if (*be == '.') |
| 1272 | be++; |
| 1273 | av = strtoul(ae, &ae, 10); |
| 1274 | bv = strtoul(be, &be, 10); |
| 1275 | if (av != bv) |
| 1276 | return (av < bv ? -1 : +1); |
| 1277 | return 0; |
| 1278 | } |
| 1279 | |
| 1280 | |
| 1281 | /* |
| 1282 | * Utility routines for putting an SSH-protocol `string' and |
| 1283 | * `uint32' into a SHA state. |
| 1284 | */ |
| 1285 | #include <stdio.h> |
| 1286 | static void sha_string(SHA_State * s, void *str, int len) |
| 1287 | { |
| 1288 | unsigned char lenblk[4]; |
| 1289 | PUT_32BIT(lenblk, len); |
| 1290 | SHA_Bytes(s, lenblk, 4); |
| 1291 | SHA_Bytes(s, str, len); |
| 1292 | } |
| 1293 | |
| 1294 | static void sha_uint32(SHA_State * s, unsigned i) |
| 1295 | { |
| 1296 | unsigned char intblk[4]; |
| 1297 | PUT_32BIT(intblk, i); |
| 1298 | SHA_Bytes(s, intblk, 4); |
| 1299 | } |
| 1300 | |
| 1301 | /* |
| 1302 | * SSH2 packet construction functions. |
| 1303 | */ |
| 1304 | static void ssh2_pkt_ensure(int length) |
| 1305 | { |
| 1306 | if (pktout.maxlen < length) { |
| 1307 | pktout.maxlen = length + 256; |
| 1308 | pktout.data = |
| 1309 | (pktout.data == |
| 1310 | NULL ? smalloc(pktout.maxlen + |
| 1311 | APIEXTRA) : srealloc(pktout.data, |
| 1312 | pktout.maxlen + |
| 1313 | APIEXTRA)); |
| 1314 | if (!pktout.data) |
| 1315 | fatalbox("Out of memory"); |
| 1316 | } |
| 1317 | } |
| 1318 | static void ssh2_pkt_adddata(void *data, int len) |
| 1319 | { |
| 1320 | pktout.length += len; |
| 1321 | ssh2_pkt_ensure(pktout.length); |
| 1322 | memcpy(pktout.data + pktout.length - len, data, len); |
| 1323 | } |
| 1324 | static void ssh2_pkt_addbyte(unsigned char byte) |
| 1325 | { |
| 1326 | ssh2_pkt_adddata(&byte, 1); |
| 1327 | } |
| 1328 | static void ssh2_pkt_init(int pkt_type) |
| 1329 | { |
| 1330 | pktout.length = 5; |
| 1331 | ssh2_pkt_addbyte((unsigned char) pkt_type); |
| 1332 | } |
| 1333 | static void ssh2_pkt_addbool(unsigned char value) |
| 1334 | { |
| 1335 | ssh2_pkt_adddata(&value, 1); |
| 1336 | } |
| 1337 | static void ssh2_pkt_adduint32(unsigned long value) |
| 1338 | { |
| 1339 | unsigned char x[4]; |
| 1340 | PUT_32BIT(x, value); |
| 1341 | ssh2_pkt_adddata(x, 4); |
| 1342 | } |
| 1343 | static void ssh2_pkt_addstring_start(void) |
| 1344 | { |
| 1345 | ssh2_pkt_adduint32(0); |
| 1346 | pktout.savedpos = pktout.length; |
| 1347 | } |
| 1348 | static void ssh2_pkt_addstring_str(char *data) |
| 1349 | { |
| 1350 | ssh2_pkt_adddata(data, strlen(data)); |
| 1351 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 1352 | pktout.length - pktout.savedpos); |
| 1353 | } |
| 1354 | static void ssh2_pkt_addstring_data(char *data, int len) |
| 1355 | { |
| 1356 | ssh2_pkt_adddata(data, len); |
| 1357 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 1358 | pktout.length - pktout.savedpos); |
| 1359 | } |
| 1360 | static void ssh2_pkt_addstring(char *data) |
| 1361 | { |
| 1362 | ssh2_pkt_addstring_start(); |
| 1363 | ssh2_pkt_addstring_str(data); |
| 1364 | } |
| 1365 | static char *ssh2_mpint_fmt(Bignum b, int *len) |
| 1366 | { |
| 1367 | unsigned char *p; |
| 1368 | int i, n = (bignum_bitcount(b) + 7) / 8; |
| 1369 | p = smalloc(n + 1); |
| 1370 | if (!p) |
| 1371 | fatalbox("out of memory"); |
| 1372 | p[0] = 0; |
| 1373 | for (i = 1; i <= n; i++) |
| 1374 | p[i] = bignum_byte(b, n - i); |
| 1375 | i = 0; |
| 1376 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) |
| 1377 | i++; |
| 1378 | memmove(p, p + i, n + 1 - i); |
| 1379 | *len = n + 1 - i; |
| 1380 | return p; |
| 1381 | } |
| 1382 | static void ssh2_pkt_addmp(Bignum b) |
| 1383 | { |
| 1384 | unsigned char *p; |
| 1385 | int len; |
| 1386 | p = ssh2_mpint_fmt(b, &len); |
| 1387 | ssh2_pkt_addstring_start(); |
| 1388 | ssh2_pkt_addstring_data(p, len); |
| 1389 | sfree(p); |
| 1390 | } |
| 1391 | |
| 1392 | /* |
| 1393 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
| 1394 | * put the MAC on it. Final packet, ready to be sent, is stored in |
| 1395 | * pktout.data. Total length is returned. |
| 1396 | */ |
| 1397 | static int ssh2_pkt_construct(void) |
| 1398 | { |
| 1399 | int cipherblk, maclen, padding, i; |
| 1400 | static unsigned long outgoing_sequence = 0; |
| 1401 | |
| 1402 | log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]), |
| 1403 | pktout.data + 6, pktout.length - 6); |
| 1404 | |
| 1405 | /* |
| 1406 | * Compress packet payload. |
| 1407 | */ |
| 1408 | { |
| 1409 | unsigned char *newpayload; |
| 1410 | int newlen; |
| 1411 | if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5, |
| 1412 | &newpayload, &newlen)) { |
| 1413 | pktout.length = 5; |
| 1414 | ssh2_pkt_adddata(newpayload, newlen); |
| 1415 | sfree(newpayload); |
| 1416 | } |
| 1417 | } |
| 1418 | |
| 1419 | /* |
| 1420 | * Add padding. At least four bytes, and must also bring total |
| 1421 | * length (minus MAC) up to a multiple of the block size. |
| 1422 | */ |
| 1423 | cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ |
| 1424 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 1425 | padding = 4; |
| 1426 | padding += |
| 1427 | (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
| 1428 | maclen = csmac ? csmac->len : 0; |
| 1429 | ssh2_pkt_ensure(pktout.length + padding + maclen); |
| 1430 | pktout.data[4] = padding; |
| 1431 | for (i = 0; i < padding; i++) |
| 1432 | pktout.data[pktout.length + i] = random_byte(); |
| 1433 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
| 1434 | if (csmac) |
| 1435 | csmac->generate(pktout.data, pktout.length + padding, |
| 1436 | outgoing_sequence); |
| 1437 | outgoing_sequence++; /* whether or not we MACed */ |
| 1438 | |
| 1439 | if (cscipher) |
| 1440 | cscipher->encrypt(pktout.data, pktout.length + padding); |
| 1441 | |
| 1442 | /* Ready-to-send packet starts at pktout.data. We return length. */ |
| 1443 | return pktout.length + padding + maclen; |
| 1444 | } |
| 1445 | |
| 1446 | /* |
| 1447 | * Construct and send an SSH2 packet immediately. |
| 1448 | */ |
| 1449 | static void ssh2_pkt_send(void) |
| 1450 | { |
| 1451 | int len; |
| 1452 | int backlog; |
| 1453 | len = ssh2_pkt_construct(); |
| 1454 | backlog = sk_write(s, pktout.data, len); |
| 1455 | if (backlog > SSH_MAX_BACKLOG) |
| 1456 | ssh_throttle_all(1, backlog); |
| 1457 | } |
| 1458 | |
| 1459 | /* |
| 1460 | * Construct an SSH2 packet and add it to a deferred data block. |
| 1461 | * Useful for sending multiple packets in a single sk_write() call, |
| 1462 | * to prevent a traffic-analysing listener from being able to work |
| 1463 | * out the length of any particular packet (such as the password |
| 1464 | * packet). |
| 1465 | * |
| 1466 | * Note that because SSH2 sequence-numbers its packets, this can |
| 1467 | * NOT be used as an m4-style `defer' allowing packets to be |
| 1468 | * constructed in one order and sent in another. |
| 1469 | */ |
| 1470 | static void ssh2_pkt_defer(void) |
| 1471 | { |
| 1472 | int len = ssh2_pkt_construct(); |
| 1473 | if (deferred_len + len > deferred_size) { |
| 1474 | deferred_size = deferred_len + len + 128; |
| 1475 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
| 1476 | } |
| 1477 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
| 1478 | deferred_len += len; |
| 1479 | } |
| 1480 | |
| 1481 | /* |
| 1482 | * Send the whole deferred data block constructed by |
| 1483 | * ssh2_pkt_defer() or SSH1's defer_packet(). |
| 1484 | */ |
| 1485 | static void ssh_pkt_defersend(void) |
| 1486 | { |
| 1487 | int backlog; |
| 1488 | backlog = sk_write(s, deferred_send_data, deferred_len); |
| 1489 | deferred_len = deferred_size = 0; |
| 1490 | sfree(deferred_send_data); |
| 1491 | deferred_send_data = NULL; |
| 1492 | if (backlog > SSH_MAX_BACKLOG) |
| 1493 | ssh_throttle_all(1, backlog); |
| 1494 | } |
| 1495 | |
| 1496 | #if 0 |
| 1497 | void bndebug(char *string, Bignum b) |
| 1498 | { |
| 1499 | unsigned char *p; |
| 1500 | int i, len; |
| 1501 | p = ssh2_mpint_fmt(b, &len); |
| 1502 | debug(("%s", string)); |
| 1503 | for (i = 0; i < len; i++) |
| 1504 | debug((" %02x", p[i])); |
| 1505 | debug(("\n")); |
| 1506 | sfree(p); |
| 1507 | } |
| 1508 | #endif |
| 1509 | |
| 1510 | static void sha_mpint(SHA_State * s, Bignum b) |
| 1511 | { |
| 1512 | unsigned char *p; |
| 1513 | int len; |
| 1514 | p = ssh2_mpint_fmt(b, &len); |
| 1515 | sha_string(s, p, len); |
| 1516 | sfree(p); |
| 1517 | } |
| 1518 | |
| 1519 | /* |
| 1520 | * SSH2 packet decode functions. |
| 1521 | */ |
| 1522 | static unsigned long ssh2_pkt_getuint32(void) |
| 1523 | { |
| 1524 | unsigned long value; |
| 1525 | if (pktin.length - pktin.savedpos < 4) |
| 1526 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1527 | value = GET_32BIT(pktin.data + pktin.savedpos); |
| 1528 | pktin.savedpos += 4; |
| 1529 | return value; |
| 1530 | } |
| 1531 | static int ssh2_pkt_getbool(void) |
| 1532 | { |
| 1533 | unsigned long value; |
| 1534 | if (pktin.length - pktin.savedpos < 1) |
| 1535 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1536 | value = pktin.data[pktin.savedpos] != 0; |
| 1537 | pktin.savedpos++; |
| 1538 | return value; |
| 1539 | } |
| 1540 | static void ssh2_pkt_getstring(char **p, int *length) |
| 1541 | { |
| 1542 | *p = NULL; |
| 1543 | if (pktin.length - pktin.savedpos < 4) |
| 1544 | return; |
| 1545 | *length = GET_32BIT(pktin.data + pktin.savedpos); |
| 1546 | pktin.savedpos += 4; |
| 1547 | if (pktin.length - pktin.savedpos < *length) |
| 1548 | return; |
| 1549 | *p = pktin.data + pktin.savedpos; |
| 1550 | pktin.savedpos += *length; |
| 1551 | } |
| 1552 | static Bignum ssh2_pkt_getmp(void) |
| 1553 | { |
| 1554 | char *p; |
| 1555 | int length; |
| 1556 | Bignum b; |
| 1557 | |
| 1558 | ssh2_pkt_getstring(&p, &length); |
| 1559 | if (!p) |
| 1560 | return NULL; |
| 1561 | if (p[0] & 0x80) { |
| 1562 | bombout(("internal error: Can't handle negative mpints")); |
| 1563 | return NULL; |
| 1564 | } |
| 1565 | b = bignum_from_bytes(p, length); |
| 1566 | return b; |
| 1567 | } |
| 1568 | |
| 1569 | /* |
| 1570 | * Examine the remote side's version string and compare it against |
| 1571 | * a list of known buggy implementations. |
| 1572 | */ |
| 1573 | static void ssh_detect_bugs(char *vstring) |
| 1574 | { |
| 1575 | char *imp; /* pointer to implementation part */ |
| 1576 | imp = vstring; |
| 1577 | imp += strcspn(imp, "-"); |
| 1578 | if (*imp) imp++; |
| 1579 | imp += strcspn(imp, "-"); |
| 1580 | if (*imp) imp++; |
| 1581 | |
| 1582 | ssh_remote_bugs = 0; |
| 1583 | |
| 1584 | if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
| 1585 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
| 1586 | !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) { |
| 1587 | /* |
| 1588 | * These versions don't support SSH1_MSG_IGNORE, so we have |
| 1589 | * to use a different defence against password length |
| 1590 | * sniffing. |
| 1591 | */ |
| 1592 | ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
| 1593 | logevent("We believe remote version has SSH1 ignore bug"); |
| 1594 | } |
| 1595 | |
| 1596 | if (!strcmp(imp, "Cisco-1.25")) { |
| 1597 | /* |
| 1598 | * These versions need a plain password sent; they can't |
| 1599 | * handle having a null and a random length of data after |
| 1600 | * the password. |
| 1601 | */ |
| 1602 | ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; |
| 1603 | logevent("We believe remote version needs a plain SSH1 password"); |
| 1604 | } |
| 1605 | |
| 1606 | if (!strcmp(imp, "Cisco-1.25")) { |
| 1607 | /* |
| 1608 | * These versions apparently have no clue whatever about |
| 1609 | * RSA authentication and will panic and die if they see |
| 1610 | * an AUTH_RSA message. |
| 1611 | */ |
| 1612 | ssh_remote_bugs |= BUG_CHOKES_ON_RSA; |
| 1613 | logevent("We believe remote version can't handle RSA authentication"); |
| 1614 | } |
| 1615 | |
| 1616 | if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || |
| 1617 | !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || |
| 1618 | !strncmp(imp, "2.1 ", 4)) { |
| 1619 | /* |
| 1620 | * These versions have the HMAC bug. |
| 1621 | */ |
| 1622 | ssh_remote_bugs |= BUG_SSH2_HMAC; |
| 1623 | logevent("We believe remote version has SSH2 HMAC bug"); |
| 1624 | } |
| 1625 | } |
| 1626 | |
| 1627 | static int do_ssh_init(unsigned char c) |
| 1628 | { |
| 1629 | static int vslen; |
| 1630 | static char version[10]; |
| 1631 | static char *vstring; |
| 1632 | static int vstrsize; |
| 1633 | static char *vlog; |
| 1634 | static int i; |
| 1635 | |
| 1636 | crBegin; |
| 1637 | |
| 1638 | /* Search for the string "SSH-" in the input. */ |
| 1639 | i = 0; |
| 1640 | while (1) { |
| 1641 | static const int transS[] = { 1, 2, 2, 1 }; |
| 1642 | static const int transH[] = { 0, 0, 3, 0 }; |
| 1643 | static const int transminus[] = { 0, 0, 0, -1 }; |
| 1644 | if (c == 'S') |
| 1645 | i = transS[i]; |
| 1646 | else if (c == 'H') |
| 1647 | i = transH[i]; |
| 1648 | else if (c == '-') |
| 1649 | i = transminus[i]; |
| 1650 | else |
| 1651 | i = 0; |
| 1652 | if (i < 0) |
| 1653 | break; |
| 1654 | crReturn(1); /* get another character */ |
| 1655 | } |
| 1656 | |
| 1657 | vstrsize = 16; |
| 1658 | vstring = smalloc(vstrsize); |
| 1659 | strcpy(vstring, "SSH-"); |
| 1660 | vslen = 4; |
| 1661 | i = 0; |
| 1662 | while (1) { |
| 1663 | crReturn(1); /* get another char */ |
| 1664 | if (vslen >= vstrsize - 1) { |
| 1665 | vstrsize += 16; |
| 1666 | vstring = srealloc(vstring, vstrsize); |
| 1667 | } |
| 1668 | vstring[vslen++] = c; |
| 1669 | if (i >= 0) { |
| 1670 | if (c == '-') { |
| 1671 | version[i] = '\0'; |
| 1672 | i = -1; |
| 1673 | } else if (i < sizeof(version) - 1) |
| 1674 | version[i++] = c; |
| 1675 | } else if (c == '\n') |
| 1676 | break; |
| 1677 | } |
| 1678 | |
| 1679 | ssh_agentfwd_enabled = FALSE; |
| 1680 | rdpkt2_state.incoming_sequence = 0; |
| 1681 | |
| 1682 | vstring[vslen] = 0; |
| 1683 | vlog = smalloc(20 + vslen); |
| 1684 | vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */ |
| 1685 | sprintf(vlog, "Server version: %s", vstring); |
| 1686 | logevent(vlog); |
| 1687 | ssh_detect_bugs(vstring); |
| 1688 | sfree(vlog); |
| 1689 | |
| 1690 | /* |
| 1691 | * Server version "1.99" means we can choose whether we use v1 |
| 1692 | * or v2 protocol. Choice is based on cfg.sshprot. |
| 1693 | */ |
| 1694 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
| 1695 | /* |
| 1696 | * This is a v2 server. Begin v2 protocol. |
| 1697 | */ |
| 1698 | char verstring[80], vlog[100]; |
| 1699 | sprintf(verstring, "SSH-2.0-%s", sshver); |
| 1700 | SHA_Init(&exhashbase); |
| 1701 | /* |
| 1702 | * Hash our version string and their version string. |
| 1703 | */ |
| 1704 | sha_string(&exhashbase, verstring, strlen(verstring)); |
| 1705 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
| 1706 | sprintf(vlog, "We claim version: %s", verstring); |
| 1707 | logevent(vlog); |
| 1708 | strcat(verstring, "\n"); |
| 1709 | logevent("Using SSH protocol version 2"); |
| 1710 | sk_write(s, verstring, strlen(verstring)); |
| 1711 | ssh_protocol = ssh2_protocol; |
| 1712 | ssh_version = 2; |
| 1713 | s_rdpkt = ssh2_rdpkt; |
| 1714 | } else { |
| 1715 | /* |
| 1716 | * This is a v1 server. Begin v1 protocol. |
| 1717 | */ |
| 1718 | char verstring[80], vlog[100]; |
| 1719 | sprintf(verstring, "SSH-%s-%s", |
| 1720 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"), |
| 1721 | sshver); |
| 1722 | sprintf(vlog, "We claim version: %s", verstring); |
| 1723 | logevent(vlog); |
| 1724 | strcat(verstring, "\n"); |
| 1725 | logevent("Using SSH protocol version 1"); |
| 1726 | sk_write(s, verstring, strlen(verstring)); |
| 1727 | ssh_protocol = ssh1_protocol; |
| 1728 | ssh_version = 1; |
| 1729 | s_rdpkt = ssh1_rdpkt; |
| 1730 | } |
| 1731 | ssh_state = SSH_STATE_BEFORE_SIZE; |
| 1732 | |
| 1733 | sfree(vstring); |
| 1734 | |
| 1735 | crFinish(0); |
| 1736 | } |
| 1737 | |
| 1738 | static void ssh_gotdata(unsigned char *data, int datalen) |
| 1739 | { |
| 1740 | crBegin; |
| 1741 | |
| 1742 | /* |
| 1743 | * To begin with, feed the characters one by one to the |
| 1744 | * protocol initialisation / selection function do_ssh_init(). |
| 1745 | * When that returns 0, we're done with the initial greeting |
| 1746 | * exchange and can move on to packet discipline. |
| 1747 | */ |
| 1748 | while (1) { |
| 1749 | int ret; |
| 1750 | if (datalen == 0) |
| 1751 | crReturnV; /* more data please */ |
| 1752 | ret = do_ssh_init(*data); |
| 1753 | data++; |
| 1754 | datalen--; |
| 1755 | if (ret == 0) |
| 1756 | break; |
| 1757 | } |
| 1758 | |
| 1759 | /* |
| 1760 | * We emerge from that loop when the initial negotiation is |
| 1761 | * over and we have selected an s_rdpkt function. Now pass |
| 1762 | * everything to s_rdpkt, and then pass the resulting packets |
| 1763 | * to the proper protocol handler. |
| 1764 | */ |
| 1765 | if (datalen == 0) |
| 1766 | crReturnV; |
| 1767 | while (1) { |
| 1768 | while (datalen > 0) { |
| 1769 | if (s_rdpkt(&data, &datalen) == 0) { |
| 1770 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1771 | return; |
| 1772 | } |
| 1773 | ssh_protocol(NULL, 0, 1); |
| 1774 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1775 | return; |
| 1776 | } |
| 1777 | } |
| 1778 | } |
| 1779 | crReturnV; |
| 1780 | } |
| 1781 | crFinishV; |
| 1782 | } |
| 1783 | |
| 1784 | static int ssh_closing(Plug plug, char *error_msg, int error_code, |
| 1785 | int calling_back) |
| 1786 | { |
| 1787 | ssh_state = SSH_STATE_CLOSED; |
| 1788 | if (s) { |
| 1789 | sk_close(s); |
| 1790 | s = NULL; |
| 1791 | } |
| 1792 | if (error_msg) { |
| 1793 | /* A socket error has occurred. */ |
| 1794 | logevent(error_msg); |
| 1795 | connection_fatal(error_msg); |
| 1796 | } else { |
| 1797 | /* Otherwise, the remote side closed the connection normally. */ |
| 1798 | } |
| 1799 | return 0; |
| 1800 | } |
| 1801 | |
| 1802 | static int ssh_receive(Plug plug, int urgent, char *data, int len) |
| 1803 | { |
| 1804 | ssh_gotdata(data, len); |
| 1805 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1806 | if (s) { |
| 1807 | sk_close(s); |
| 1808 | s = NULL; |
| 1809 | } |
| 1810 | return 0; |
| 1811 | } |
| 1812 | return 1; |
| 1813 | } |
| 1814 | |
| 1815 | static void ssh_sent(Plug plug, int bufsize) |
| 1816 | { |
| 1817 | /* |
| 1818 | * If the send backlog on the SSH socket itself clears, we |
| 1819 | * should unthrottle the whole world if it was throttled. |
| 1820 | */ |
| 1821 | if (bufsize < SSH_MAX_BACKLOG) |
| 1822 | ssh_throttle_all(0, bufsize); |
| 1823 | } |
| 1824 | |
| 1825 | /* |
| 1826 | * Connect to specified host and port. |
| 1827 | * Returns an error message, or NULL on success. |
| 1828 | * Also places the canonical host name into `realhost'. It must be |
| 1829 | * freed by the caller. |
| 1830 | */ |
| 1831 | static char *connect_to_host(char *host, int port, char **realhost, int nodelay) |
| 1832 | { |
| 1833 | static struct plug_function_table fn_table = { |
| 1834 | ssh_closing, |
| 1835 | ssh_receive, |
| 1836 | ssh_sent, |
| 1837 | NULL |
| 1838 | }, *fn_table_ptr = &fn_table; |
| 1839 | |
| 1840 | SockAddr addr; |
| 1841 | char *err; |
| 1842 | #ifdef FWHACK |
| 1843 | char *FWhost; |
| 1844 | int FWport; |
| 1845 | #endif |
| 1846 | |
| 1847 | savedhost = smalloc(1 + strlen(host)); |
| 1848 | if (!savedhost) |
| 1849 | fatalbox("Out of memory"); |
| 1850 | strcpy(savedhost, host); |
| 1851 | |
| 1852 | if (port < 0) |
| 1853 | port = 22; /* default ssh port */ |
| 1854 | savedport = port; |
| 1855 | |
| 1856 | #ifdef FWHACK |
| 1857 | FWhost = host; |
| 1858 | FWport = port; |
| 1859 | host = FWSTR; |
| 1860 | port = 23; |
| 1861 | #endif |
| 1862 | |
| 1863 | /* |
| 1864 | * Try to find host. |
| 1865 | */ |
| 1866 | { |
| 1867 | char buf[200]; |
| 1868 | sprintf(buf, "Looking up host \"%.170s\"", host); |
| 1869 | logevent(buf); |
| 1870 | } |
| 1871 | addr = sk_namelookup(host, realhost); |
| 1872 | if ((err = sk_addr_error(addr))) |
| 1873 | return err; |
| 1874 | |
| 1875 | #ifdef FWHACK |
| 1876 | *realhost = strdup(FWhost); |
| 1877 | #endif |
| 1878 | |
| 1879 | /* |
| 1880 | * Open socket. |
| 1881 | */ |
| 1882 | { |
| 1883 | char buf[200], addrbuf[100]; |
| 1884 | sk_getaddr(addr, addrbuf, 100); |
| 1885 | sprintf(buf, "Connecting to %.100s port %d", addrbuf, port); |
| 1886 | logevent(buf); |
| 1887 | } |
| 1888 | s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr); |
| 1889 | if ((err = sk_socket_error(s))) { |
| 1890 | s = NULL; |
| 1891 | return err; |
| 1892 | } |
| 1893 | |
| 1894 | #ifdef FWHACK |
| 1895 | sk_write(s, "connect ", 8); |
| 1896 | sk_write(s, FWhost, strlen(FWhost)); |
| 1897 | { |
| 1898 | char buf[20]; |
| 1899 | sprintf(buf, " %d\n", FWport); |
| 1900 | sk_write(s, buf, strlen(buf)); |
| 1901 | } |
| 1902 | #endif |
| 1903 | |
| 1904 | return NULL; |
| 1905 | } |
| 1906 | |
| 1907 | /* |
| 1908 | * Throttle or unthrottle the SSH connection. |
| 1909 | */ |
| 1910 | static void ssh1_throttle(int adjust) |
| 1911 | { |
| 1912 | int old_count = ssh1_throttle_count; |
| 1913 | ssh1_throttle_count += adjust; |
| 1914 | assert(ssh1_throttle_count >= 0); |
| 1915 | if (ssh1_throttle_count && !old_count) { |
| 1916 | sk_set_frozen(s, 1); |
| 1917 | } else if (!ssh1_throttle_count && old_count) { |
| 1918 | sk_set_frozen(s, 0); |
| 1919 | } |
| 1920 | } |
| 1921 | |
| 1922 | /* |
| 1923 | * Throttle or unthrottle _all_ local data streams (for when sends |
| 1924 | * on the SSH connection itself back up). |
| 1925 | */ |
| 1926 | static void ssh_throttle_all(int enable, int bufsize) |
| 1927 | { |
| 1928 | int i; |
| 1929 | struct ssh_channel *c; |
| 1930 | |
| 1931 | if (enable == ssh_throttled_all) |
| 1932 | return; |
| 1933 | ssh_throttled_all = enable; |
| 1934 | ssh_overall_bufsize = bufsize; |
| 1935 | if (!ssh_channels) |
| 1936 | return; |
| 1937 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
| 1938 | switch (c->type) { |
| 1939 | case CHAN_MAINSESSION: |
| 1940 | /* |
| 1941 | * This is treated separately, outside the switch. |
| 1942 | */ |
| 1943 | break; |
| 1944 | case CHAN_X11: |
| 1945 | x11_override_throttle(c->u.x11.s, enable); |
| 1946 | break; |
| 1947 | case CHAN_AGENT: |
| 1948 | /* Agent channels require no buffer management. */ |
| 1949 | break; |
| 1950 | case CHAN_SOCKDATA: |
| 1951 | pfd_override_throttle(c->u.x11.s, enable); |
| 1952 | break; |
| 1953 | } |
| 1954 | } |
| 1955 | } |
| 1956 | |
| 1957 | /* |
| 1958 | * Handle the key exchange and user authentication phases. |
| 1959 | */ |
| 1960 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
| 1961 | { |
| 1962 | int i, j; |
| 1963 | static int len; |
| 1964 | static unsigned char *rsabuf, *keystr1, *keystr2; |
| 1965 | unsigned char cookie[8]; |
| 1966 | struct RSAKey servkey, hostkey; |
| 1967 | struct MD5Context md5c; |
| 1968 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
| 1969 | static int tried_publickey, tried_agent; |
| 1970 | static int tis_auth_refused, ccard_auth_refused; |
| 1971 | static unsigned char session_id[16]; |
| 1972 | static int cipher_type; |
| 1973 | static char username[100]; |
| 1974 | static void *publickey_blob; |
| 1975 | int publickey_bloblen; |
| 1976 | |
| 1977 | crBegin; |
| 1978 | |
| 1979 | if (!ispkt) |
| 1980 | crWaitUntil(ispkt); |
| 1981 | |
| 1982 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
| 1983 | bombout(("Public key packet not received")); |
| 1984 | crReturn(0); |
| 1985 | } |
| 1986 | |
| 1987 | logevent("Received public keys"); |
| 1988 | |
| 1989 | memcpy(cookie, pktin.body, 8); |
| 1990 | |
| 1991 | i = makekey(pktin.body + 8, &servkey, &keystr1, 0); |
| 1992 | j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0); |
| 1993 | |
| 1994 | /* |
| 1995 | * Log the host key fingerprint. |
| 1996 | */ |
| 1997 | { |
| 1998 | char logmsg[80]; |
| 1999 | logevent("Host key fingerprint is:"); |
| 2000 | strcpy(logmsg, " "); |
| 2001 | hostkey.comment = NULL; |
| 2002 | rsa_fingerprint(logmsg + strlen(logmsg), |
| 2003 | sizeof(logmsg) - strlen(logmsg), &hostkey); |
| 2004 | logevent(logmsg); |
| 2005 | } |
| 2006 | |
| 2007 | ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j); |
| 2008 | supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j); |
| 2009 | supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j); |
| 2010 | |
| 2011 | ssh1_local_protoflags = |
| 2012 | ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
| 2013 | ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
| 2014 | |
| 2015 | MD5Init(&md5c); |
| 2016 | MD5Update(&md5c, keystr2, hostkey.bytes); |
| 2017 | MD5Update(&md5c, keystr1, servkey.bytes); |
| 2018 | MD5Update(&md5c, pktin.body, 8); |
| 2019 | MD5Final(session_id, &md5c); |
| 2020 | |
| 2021 | for (i = 0; i < 32; i++) |
| 2022 | session_key[i] = random_byte(); |
| 2023 | |
| 2024 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 2025 | |
| 2026 | rsabuf = smalloc(len); |
| 2027 | if (!rsabuf) |
| 2028 | fatalbox("Out of memory"); |
| 2029 | |
| 2030 | /* |
| 2031 | * Verify the host key. |
| 2032 | */ |
| 2033 | { |
| 2034 | /* |
| 2035 | * First format the key into a string. |
| 2036 | */ |
| 2037 | int len = rsastr_len(&hostkey); |
| 2038 | char fingerprint[100]; |
| 2039 | char *keystr = smalloc(len); |
| 2040 | if (!keystr) |
| 2041 | fatalbox("Out of memory"); |
| 2042 | rsastr_fmt(keystr, &hostkey); |
| 2043 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
| 2044 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, |
| 2045 | fingerprint); |
| 2046 | sfree(keystr); |
| 2047 | } |
| 2048 | |
| 2049 | for (i = 0; i < 32; i++) { |
| 2050 | rsabuf[i] = session_key[i]; |
| 2051 | if (i < 16) |
| 2052 | rsabuf[i] ^= session_id[i]; |
| 2053 | } |
| 2054 | |
| 2055 | if (hostkey.bytes > servkey.bytes) { |
| 2056 | rsaencrypt(rsabuf, 32, &servkey); |
| 2057 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
| 2058 | } else { |
| 2059 | rsaencrypt(rsabuf, 32, &hostkey); |
| 2060 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
| 2061 | } |
| 2062 | |
| 2063 | logevent("Encrypted session key"); |
| 2064 | |
| 2065 | { |
| 2066 | int cipher_chosen = 0, warn = 0; |
| 2067 | char *cipher_string = NULL; |
| 2068 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { |
| 2069 | int next_cipher = cfg.ssh_cipherlist[i]; |
| 2070 | if (next_cipher == CIPHER_WARN) { |
| 2071 | /* If/when we choose a cipher, warn about it */ |
| 2072 | warn = 1; |
| 2073 | } else if (next_cipher == CIPHER_AES) { |
| 2074 | /* XXX Probably don't need to mention this. */ |
| 2075 | logevent("AES not supported in SSH1, skipping"); |
| 2076 | } else { |
| 2077 | switch (next_cipher) { |
| 2078 | case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; |
| 2079 | cipher_string = "3DES"; break; |
| 2080 | case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; |
| 2081 | cipher_string = "Blowfish"; break; |
| 2082 | case CIPHER_DES: cipher_type = SSH_CIPHER_DES; |
| 2083 | cipher_string = "single-DES"; break; |
| 2084 | } |
| 2085 | if (supported_ciphers_mask & (1 << cipher_type)) |
| 2086 | cipher_chosen = 1; |
| 2087 | } |
| 2088 | } |
| 2089 | if (!cipher_chosen) { |
| 2090 | if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) |
| 2091 | bombout(("Server violates SSH 1 protocol by not " |
| 2092 | "supporting 3DES encryption")); |
| 2093 | else |
| 2094 | /* shouldn't happen */ |
| 2095 | bombout(("No supported ciphers found")); |
| 2096 | crReturn(0); |
| 2097 | } |
| 2098 | |
| 2099 | /* Warn about chosen cipher if necessary. */ |
| 2100 | if (warn) |
| 2101 | askcipher(cipher_string, 0); |
| 2102 | } |
| 2103 | |
| 2104 | switch (cipher_type) { |
| 2105 | case SSH_CIPHER_3DES: |
| 2106 | logevent("Using 3DES encryption"); |
| 2107 | break; |
| 2108 | case SSH_CIPHER_DES: |
| 2109 | logevent("Using single-DES encryption"); |
| 2110 | break; |
| 2111 | case SSH_CIPHER_BLOWFISH: |
| 2112 | logevent("Using Blowfish encryption"); |
| 2113 | break; |
| 2114 | } |
| 2115 | |
| 2116 | send_packet(SSH1_CMSG_SESSION_KEY, |
| 2117 | PKT_CHAR, cipher_type, |
| 2118 | PKT_DATA, cookie, 8, |
| 2119 | PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF, |
| 2120 | PKT_DATA, rsabuf, len, |
| 2121 | PKT_INT, ssh1_local_protoflags, PKT_END); |
| 2122 | |
| 2123 | logevent("Trying to enable encryption..."); |
| 2124 | |
| 2125 | sfree(rsabuf); |
| 2126 | |
| 2127 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
| 2128 | cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des; |
| 2129 | cipher->sesskey(session_key); |
| 2130 | |
| 2131 | crWaitUntil(ispkt); |
| 2132 | |
| 2133 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 2134 | bombout(("Encryption not successfully enabled")); |
| 2135 | crReturn(0); |
| 2136 | } |
| 2137 | |
| 2138 | logevent("Successfully started encryption"); |
| 2139 | |
| 2140 | fflush(stdout); |
| 2141 | { |
| 2142 | static int pos = 0; |
| 2143 | static char c; |
| 2144 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 2145 | if (ssh_get_line) { |
| 2146 | if (!ssh_get_line("login as: ", |
| 2147 | username, sizeof(username), FALSE)) { |
| 2148 | /* |
| 2149 | * get_line failed to get a username. |
| 2150 | * Terminate. |
| 2151 | */ |
| 2152 | logevent("No username provided. Abandoning session."); |
| 2153 | ssh_state = SSH_STATE_CLOSED; |
| 2154 | crReturn(1); |
| 2155 | } |
| 2156 | } else { |
| 2157 | c_write_str("login as: "); |
| 2158 | ssh_send_ok = 1; |
| 2159 | while (pos >= 0) { |
| 2160 | crWaitUntil(!ispkt); |
| 2161 | while (inlen--) |
| 2162 | switch (c = *in++) { |
| 2163 | case 10: |
| 2164 | case 13: |
| 2165 | username[pos] = 0; |
| 2166 | pos = -1; |
| 2167 | break; |
| 2168 | case 8: |
| 2169 | case 127: |
| 2170 | if (pos > 0) { |
| 2171 | c_write_str("\b \b"); |
| 2172 | pos--; |
| 2173 | } |
| 2174 | break; |
| 2175 | case 21: |
| 2176 | case 27: |
| 2177 | while (pos > 0) { |
| 2178 | c_write_str("\b \b"); |
| 2179 | pos--; |
| 2180 | } |
| 2181 | break; |
| 2182 | case 3: |
| 2183 | case 4: |
| 2184 | cleanup_exit(0); |
| 2185 | break; |
| 2186 | default: |
| 2187 | if (((c >= ' ' && c <= '~') || |
| 2188 | ((unsigned char) c >= 160)) |
| 2189 | && pos < sizeof(username)-1) { |
| 2190 | username[pos++] = c; |
| 2191 | c_write(&c, 1); |
| 2192 | } |
| 2193 | break; |
| 2194 | } |
| 2195 | } |
| 2196 | c_write_str("\r\n"); |
| 2197 | username[strcspn(username, "\n\r")] = '\0'; |
| 2198 | } |
| 2199 | } else { |
| 2200 | strncpy(username, cfg.username, 99); |
| 2201 | username[99] = '\0'; |
| 2202 | } |
| 2203 | |
| 2204 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
| 2205 | { |
| 2206 | char userlog[22 + sizeof(username)]; |
| 2207 | sprintf(userlog, "Sent username \"%s\"", username); |
| 2208 | logevent(userlog); |
| 2209 | if (flags & FLAG_INTERACTIVE && |
| 2210 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
| 2211 | strcat(userlog, "\r\n"); |
| 2212 | c_write_str(userlog); |
| 2213 | } |
| 2214 | } |
| 2215 | } |
| 2216 | |
| 2217 | crWaitUntil(ispkt); |
| 2218 | |
| 2219 | if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) { |
| 2220 | /* We must not attempt PK auth. Pretend we've already tried it. */ |
| 2221 | tried_publickey = tried_agent = 1; |
| 2222 | } else { |
| 2223 | tried_publickey = tried_agent = 0; |
| 2224 | } |
| 2225 | tis_auth_refused = ccard_auth_refused = 0; |
| 2226 | /* Load the public half of cfg.keyfile so we notice if it's in Pageant */ |
| 2227 | if (*cfg.keyfile) { |
| 2228 | if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen)) |
| 2229 | publickey_blob = NULL; |
| 2230 | } else |
| 2231 | publickey_blob = NULL; |
| 2232 | |
| 2233 | while (pktin.type == SSH1_SMSG_FAILURE) { |
| 2234 | static char password[100]; |
| 2235 | static char prompt[200]; |
| 2236 | static int pos; |
| 2237 | static char c; |
| 2238 | static int pwpkt_type; |
| 2239 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 2240 | |
| 2241 | if (agent_exists() && !tried_agent) { |
| 2242 | /* |
| 2243 | * Attempt RSA authentication using Pageant. |
| 2244 | */ |
| 2245 | static unsigned char request[5], *response, *p; |
| 2246 | static int responselen; |
| 2247 | static int i, nkeys; |
| 2248 | static int authed = FALSE; |
| 2249 | void *r; |
| 2250 | |
| 2251 | tried_agent = 1; |
| 2252 | logevent("Pageant is running. Requesting keys."); |
| 2253 | |
| 2254 | /* Request the keys held by the agent. */ |
| 2255 | PUT_32BIT(request, 1); |
| 2256 | request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
| 2257 | agent_query(request, 5, &r, &responselen); |
| 2258 | response = (unsigned char *) r; |
| 2259 | if (response && responselen >= 5 && |
| 2260 | response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
| 2261 | p = response + 5; |
| 2262 | nkeys = GET_32BIT(p); |
| 2263 | p += 4; |
| 2264 | { |
| 2265 | char buf[64]; |
| 2266 | sprintf(buf, "Pageant has %d SSH1 keys", nkeys); |
| 2267 | logevent(buf); |
| 2268 | } |
| 2269 | for (i = 0; i < nkeys; i++) { |
| 2270 | static struct RSAKey key; |
| 2271 | static Bignum challenge; |
| 2272 | static char *commentp; |
| 2273 | static int commentlen; |
| 2274 | |
| 2275 | { |
| 2276 | char buf[64]; |
| 2277 | sprintf(buf, "Trying Pageant key #%d", i); |
| 2278 | logevent(buf); |
| 2279 | } |
| 2280 | if (publickey_blob && |
| 2281 | !memcmp(p, publickey_blob, publickey_bloblen)) { |
| 2282 | logevent("This key matches configured key file"); |
| 2283 | tried_publickey = 1; |
| 2284 | } |
| 2285 | p += 4; |
| 2286 | p += ssh1_read_bignum(p, &key.exponent); |
| 2287 | p += ssh1_read_bignum(p, &key.modulus); |
| 2288 | commentlen = GET_32BIT(p); |
| 2289 | p += 4; |
| 2290 | commentp = p; |
| 2291 | p += commentlen; |
| 2292 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 2293 | PKT_BIGNUM, key.modulus, PKT_END); |
| 2294 | crWaitUntil(ispkt); |
| 2295 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 2296 | logevent("Key refused"); |
| 2297 | continue; |
| 2298 | } |
| 2299 | logevent("Received RSA challenge"); |
| 2300 | ssh1_read_bignum(pktin.body, &challenge); |
| 2301 | { |
| 2302 | char *agentreq, *q, *ret; |
| 2303 | void *vret; |
| 2304 | int len, retlen; |
| 2305 | len = 1 + 4; /* message type, bit count */ |
| 2306 | len += ssh1_bignum_length(key.exponent); |
| 2307 | len += ssh1_bignum_length(key.modulus); |
| 2308 | len += ssh1_bignum_length(challenge); |
| 2309 | len += 16; /* session id */ |
| 2310 | len += 4; /* response format */ |
| 2311 | agentreq = smalloc(4 + len); |
| 2312 | PUT_32BIT(agentreq, len); |
| 2313 | q = agentreq + 4; |
| 2314 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
| 2315 | PUT_32BIT(q, bignum_bitcount(key.modulus)); |
| 2316 | q += 4; |
| 2317 | q += ssh1_write_bignum(q, key.exponent); |
| 2318 | q += ssh1_write_bignum(q, key.modulus); |
| 2319 | q += ssh1_write_bignum(q, challenge); |
| 2320 | memcpy(q, session_id, 16); |
| 2321 | q += 16; |
| 2322 | PUT_32BIT(q, 1); /* response format */ |
| 2323 | agent_query(agentreq, len + 4, &vret, &retlen); |
| 2324 | ret = vret; |
| 2325 | sfree(agentreq); |
| 2326 | if (ret) { |
| 2327 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
| 2328 | logevent("Sending Pageant's response"); |
| 2329 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 2330 | PKT_DATA, ret + 5, 16, |
| 2331 | PKT_END); |
| 2332 | sfree(ret); |
| 2333 | crWaitUntil(ispkt); |
| 2334 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 2335 | logevent |
| 2336 | ("Pageant's response accepted"); |
| 2337 | if (flags & FLAG_VERBOSE) { |
| 2338 | c_write_str |
| 2339 | ("Authenticated using RSA key \""); |
| 2340 | c_write(commentp, commentlen); |
| 2341 | c_write_str("\" from agent\r\n"); |
| 2342 | } |
| 2343 | authed = TRUE; |
| 2344 | } else |
| 2345 | logevent |
| 2346 | ("Pageant's response not accepted"); |
| 2347 | } else { |
| 2348 | logevent |
| 2349 | ("Pageant failed to answer challenge"); |
| 2350 | sfree(ret); |
| 2351 | } |
| 2352 | } else { |
| 2353 | logevent("No reply received from Pageant"); |
| 2354 | } |
| 2355 | } |
| 2356 | freebn(key.exponent); |
| 2357 | freebn(key.modulus); |
| 2358 | freebn(challenge); |
| 2359 | if (authed) |
| 2360 | break; |
| 2361 | } |
| 2362 | } |
| 2363 | if (authed) |
| 2364 | break; |
| 2365 | } |
| 2366 | if (*cfg.keyfile && !tried_publickey) |
| 2367 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
| 2368 | |
| 2369 | if (cfg.try_tis_auth && |
| 2370 | (supported_auths_mask & (1 << SSH1_AUTH_TIS)) && |
| 2371 | !tis_auth_refused) { |
| 2372 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 2373 | logevent("Requested TIS authentication"); |
| 2374 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
| 2375 | crWaitUntil(ispkt); |
| 2376 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 2377 | logevent("TIS authentication declined"); |
| 2378 | if (flags & FLAG_INTERACTIVE) |
| 2379 | c_write_str("TIS authentication refused.\r\n"); |
| 2380 | tis_auth_refused = 1; |
| 2381 | continue; |
| 2382 | } else { |
| 2383 | int challengelen = ((pktin.body[0] << 24) | |
| 2384 | (pktin.body[1] << 16) | |
| 2385 | (pktin.body[2] << 8) | |
| 2386 | (pktin.body[3])); |
| 2387 | logevent("Received TIS challenge"); |
| 2388 | if (challengelen > sizeof(prompt) - 1) |
| 2389 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
| 2390 | memcpy(prompt, pktin.body + 4, challengelen); |
| 2391 | /* Prompt heuristic comes from OpenSSH */ |
| 2392 | strncpy(prompt + challengelen, |
| 2393 | memchr(prompt, '\n', challengelen) ? |
| 2394 | "": "\r\nResponse: ", |
| 2395 | (sizeof prompt) - challengelen); |
| 2396 | prompt[(sizeof prompt) - 1] = '\0'; |
| 2397 | } |
| 2398 | } |
| 2399 | if (cfg.try_tis_auth && |
| 2400 | (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && |
| 2401 | !ccard_auth_refused) { |
| 2402 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
| 2403 | logevent("Requested CryptoCard authentication"); |
| 2404 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
| 2405 | crWaitUntil(ispkt); |
| 2406 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 2407 | logevent("CryptoCard authentication declined"); |
| 2408 | c_write_str("CryptoCard authentication refused.\r\n"); |
| 2409 | ccard_auth_refused = 1; |
| 2410 | continue; |
| 2411 | } else { |
| 2412 | int challengelen = ((pktin.body[0] << 24) | |
| 2413 | (pktin.body[1] << 16) | |
| 2414 | (pktin.body[2] << 8) | |
| 2415 | (pktin.body[3])); |
| 2416 | logevent("Received CryptoCard challenge"); |
| 2417 | if (challengelen > sizeof(prompt) - 1) |
| 2418 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
| 2419 | memcpy(prompt, pktin.body + 4, challengelen); |
| 2420 | strncpy(prompt + challengelen, |
| 2421 | memchr(prompt, '\n', challengelen) ? |
| 2422 | "" : "\r\nResponse: ", |
| 2423 | sizeof(prompt) - challengelen); |
| 2424 | prompt[sizeof(prompt) - 1] = '\0'; |
| 2425 | } |
| 2426 | } |
| 2427 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 2428 | sprintf(prompt, "%.90s@%.90s's password: ", |
| 2429 | username, savedhost); |
| 2430 | } |
| 2431 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 2432 | char *comment = NULL; |
| 2433 | if (flags & FLAG_VERBOSE) |
| 2434 | c_write_str("Trying public key authentication.\r\n"); |
| 2435 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
| 2436 | if (flags & FLAG_VERBOSE) |
| 2437 | c_write_str("No passphrase required.\r\n"); |
| 2438 | goto tryauth; |
| 2439 | } |
| 2440 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
| 2441 | sfree(comment); |
| 2442 | } |
| 2443 | |
| 2444 | /* |
| 2445 | * Show password prompt, having first obtained it via a TIS |
| 2446 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
| 2447 | * authentication. |
| 2448 | */ |
| 2449 | if (ssh_get_line) { |
| 2450 | if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { |
| 2451 | /* |
| 2452 | * get_line failed to get a password (for example |
| 2453 | * because one was supplied on the command line |
| 2454 | * which has already failed to work). Terminate. |
| 2455 | */ |
| 2456 | send_packet(SSH1_MSG_DISCONNECT, |
| 2457 | PKT_STR, "No more passwords available to try", |
| 2458 | PKT_END); |
| 2459 | logevent("Unable to authenticate"); |
| 2460 | connection_fatal("Unable to authenticate"); |
| 2461 | ssh_state = SSH_STATE_CLOSED; |
| 2462 | crReturn(1); |
| 2463 | } |
| 2464 | } else { |
| 2465 | /* Prompt may have come from server. We've munged it a bit, so |
| 2466 | * we know it to be zero-terminated at least once. */ |
| 2467 | c_write_untrusted(prompt, strlen(prompt)); |
| 2468 | pos = 0; |
| 2469 | ssh_send_ok = 1; |
| 2470 | while (pos >= 0) { |
| 2471 | crWaitUntil(!ispkt); |
| 2472 | while (inlen--) |
| 2473 | switch (c = *in++) { |
| 2474 | case 10: |
| 2475 | case 13: |
| 2476 | password[pos] = 0; |
| 2477 | pos = -1; |
| 2478 | break; |
| 2479 | case 8: |
| 2480 | case 127: |
| 2481 | if (pos > 0) |
| 2482 | pos--; |
| 2483 | break; |
| 2484 | case 21: |
| 2485 | case 27: |
| 2486 | pos = 0; |
| 2487 | break; |
| 2488 | case 3: |
| 2489 | case 4: |
| 2490 | cleanup_exit(0); |
| 2491 | break; |
| 2492 | default: |
| 2493 | if (pos < sizeof(password)-1) |
| 2494 | password[pos++] = c; |
| 2495 | break; |
| 2496 | } |
| 2497 | } |
| 2498 | c_write_str("\r\n"); |
| 2499 | } |
| 2500 | |
| 2501 | tryauth: |
| 2502 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 2503 | /* |
| 2504 | * Try public key authentication with the specified |
| 2505 | * key file. |
| 2506 | */ |
| 2507 | static struct RSAKey pubkey; |
| 2508 | static Bignum challenge, response; |
| 2509 | static int i; |
| 2510 | static unsigned char buffer[32]; |
| 2511 | |
| 2512 | tried_publickey = 1; |
| 2513 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
| 2514 | if (i == 0) { |
| 2515 | c_write_str("Couldn't load private key from "); |
| 2516 | c_write_str(cfg.keyfile); |
| 2517 | c_write_str(".\r\n"); |
| 2518 | continue; /* go and try password */ |
| 2519 | } |
| 2520 | if (i == -1) { |
| 2521 | c_write_str("Wrong passphrase.\r\n"); |
| 2522 | tried_publickey = 0; |
| 2523 | continue; /* try again */ |
| 2524 | } |
| 2525 | |
| 2526 | /* |
| 2527 | * Send a public key attempt. |
| 2528 | */ |
| 2529 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 2530 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
| 2531 | |
| 2532 | crWaitUntil(ispkt); |
| 2533 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2534 | c_write_str("Server refused our public key.\r\n"); |
| 2535 | continue; /* go and try password */ |
| 2536 | } |
| 2537 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 2538 | bombout(("Bizarre response to offer of public key")); |
| 2539 | crReturn(0); |
| 2540 | } |
| 2541 | ssh1_read_bignum(pktin.body, &challenge); |
| 2542 | response = rsadecrypt(challenge, &pubkey); |
| 2543 | freebn(pubkey.private_exponent); /* burn the evidence */ |
| 2544 | |
| 2545 | for (i = 0; i < 32; i++) { |
| 2546 | buffer[i] = bignum_byte(response, 31 - i); |
| 2547 | } |
| 2548 | |
| 2549 | MD5Init(&md5c); |
| 2550 | MD5Update(&md5c, buffer, 32); |
| 2551 | MD5Update(&md5c, session_id, 16); |
| 2552 | MD5Final(buffer, &md5c); |
| 2553 | |
| 2554 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 2555 | PKT_DATA, buffer, 16, PKT_END); |
| 2556 | |
| 2557 | crWaitUntil(ispkt); |
| 2558 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2559 | if (flags & FLAG_VERBOSE) |
| 2560 | c_write_str |
| 2561 | ("Failed to authenticate with our public key.\r\n"); |
| 2562 | continue; /* go and try password */ |
| 2563 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 2564 | bombout( |
| 2565 | ("Bizarre response to RSA authentication response")); |
| 2566 | crReturn(0); |
| 2567 | } |
| 2568 | |
| 2569 | break; /* we're through! */ |
| 2570 | } else { |
| 2571 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 2572 | /* |
| 2573 | * Defence against traffic analysis: we send a |
| 2574 | * whole bunch of packets containing strings of |
| 2575 | * different lengths. One of these strings is the |
| 2576 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
| 2577 | * The others are all random data in |
| 2578 | * SSH1_MSG_IGNORE packets. This way a passive |
| 2579 | * listener can't tell which is the password, and |
| 2580 | * hence can't deduce the password length. |
| 2581 | * |
| 2582 | * Anybody with a password length greater than 16 |
| 2583 | * bytes is going to have enough entropy in their |
| 2584 | * password that a listener won't find it _that_ |
| 2585 | * much help to know how long it is. So what we'll |
| 2586 | * do is: |
| 2587 | * |
| 2588 | * - if password length < 16, we send 15 packets |
| 2589 | * containing string lengths 1 through 15 |
| 2590 | * |
| 2591 | * - otherwise, we let N be the nearest multiple |
| 2592 | * of 8 below the password length, and send 8 |
| 2593 | * packets containing string lengths N through |
| 2594 | * N+7. This won't obscure the order of |
| 2595 | * magnitude of the password length, but it will |
| 2596 | * introduce a bit of extra uncertainty. |
| 2597 | * |
| 2598 | * A few servers (the old 1.2.18 through 1.2.22) |
| 2599 | * can't deal with SSH1_MSG_IGNORE. For these |
| 2600 | * servers, we need an alternative defence. We make |
| 2601 | * use of the fact that the password is interpreted |
| 2602 | * as a C string: so we can append a NUL, then some |
| 2603 | * random data. |
| 2604 | * |
| 2605 | * One server (a Cisco one) can deal with neither |
| 2606 | * SSH1_MSG_IGNORE _nor_ a padded password string. |
| 2607 | * For this server we are left with no defences |
| 2608 | * against password length sniffing. |
| 2609 | */ |
| 2610 | if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { |
| 2611 | /* |
| 2612 | * The server can deal with SSH1_MSG_IGNORE, so |
| 2613 | * we can use the primary defence. |
| 2614 | */ |
| 2615 | int bottom, top, pwlen, i; |
| 2616 | char *randomstr; |
| 2617 | |
| 2618 | pwlen = strlen(password); |
| 2619 | if (pwlen < 16) { |
| 2620 | bottom = 0; /* zero length passwords are OK! :-) */ |
| 2621 | top = 15; |
| 2622 | } else { |
| 2623 | bottom = pwlen & ~7; |
| 2624 | top = bottom + 7; |
| 2625 | } |
| 2626 | |
| 2627 | assert(pwlen >= bottom && pwlen <= top); |
| 2628 | |
| 2629 | randomstr = smalloc(top + 1); |
| 2630 | |
| 2631 | for (i = bottom; i <= top; i++) { |
| 2632 | if (i == pwlen) |
| 2633 | defer_packet(pwpkt_type, PKT_STR, password, |
| 2634 | PKT_END); |
| 2635 | else { |
| 2636 | for (j = 0; j < i; j++) { |
| 2637 | do { |
| 2638 | randomstr[j] = random_byte(); |
| 2639 | } while (randomstr[j] == '\0'); |
| 2640 | } |
| 2641 | randomstr[i] = '\0'; |
| 2642 | defer_packet(SSH1_MSG_IGNORE, |
| 2643 | PKT_STR, randomstr, PKT_END); |
| 2644 | } |
| 2645 | } |
| 2646 | logevent("Sending password with camouflage packets"); |
| 2647 | ssh_pkt_defersend(); |
| 2648 | } |
| 2649 | else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { |
| 2650 | /* |
| 2651 | * The server can't deal with SSH1_MSG_IGNORE |
| 2652 | * but can deal with padded passwords, so we |
| 2653 | * can use the secondary defence. |
| 2654 | */ |
| 2655 | char string[64]; |
| 2656 | char *s; |
| 2657 | int len; |
| 2658 | |
| 2659 | len = strlen(password); |
| 2660 | if (len < sizeof(string)) { |
| 2661 | s = string; |
| 2662 | strcpy(string, password); |
| 2663 | len++; /* cover the zero byte */ |
| 2664 | while (len < sizeof(string)) { |
| 2665 | string[len++] = (char) random_byte(); |
| 2666 | } |
| 2667 | } else { |
| 2668 | s = password; |
| 2669 | } |
| 2670 | logevent("Sending length-padded password"); |
| 2671 | send_packet(pwpkt_type, PKT_INT, len, |
| 2672 | PKT_DATA, s, len, PKT_END); |
| 2673 | } else { |
| 2674 | /* |
| 2675 | * The server has _both_ |
| 2676 | * BUG_CHOKES_ON_SSH1_IGNORE and |
| 2677 | * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is |
| 2678 | * therefore nothing we can do. |
| 2679 | */ |
| 2680 | int len; |
| 2681 | len = strlen(password); |
| 2682 | logevent("Sending unpadded password"); |
| 2683 | send_packet(pwpkt_type, PKT_INT, len, |
| 2684 | PKT_DATA, password, len, PKT_END); |
| 2685 | } |
| 2686 | } else { |
| 2687 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
| 2688 | } |
| 2689 | } |
| 2690 | logevent("Sent password"); |
| 2691 | memset(password, 0, strlen(password)); |
| 2692 | crWaitUntil(ispkt); |
| 2693 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2694 | if (flags & FLAG_VERBOSE) |
| 2695 | c_write_str("Access denied\r\n"); |
| 2696 | logevent("Authentication refused"); |
| 2697 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 2698 | logevent("Received disconnect request"); |
| 2699 | ssh_state = SSH_STATE_CLOSED; |
| 2700 | crReturn(1); |
| 2701 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 2702 | bombout(("Strange packet received, type %d", pktin.type)); |
| 2703 | crReturn(0); |
| 2704 | } |
| 2705 | } |
| 2706 | |
| 2707 | logevent("Authentication successful"); |
| 2708 | |
| 2709 | crFinish(1); |
| 2710 | } |
| 2711 | |
| 2712 | void sshfwd_close(struct ssh_channel *c) |
| 2713 | { |
| 2714 | if (c && !c->closes) { |
| 2715 | /* |
| 2716 | * If the channel's remoteid is -1, we have sent |
| 2717 | * CHANNEL_OPEN for this channel, but it hasn't even been |
| 2718 | * acknowledged by the server. So we must set a close flag |
| 2719 | * on it now, and then when the server acks the channel |
| 2720 | * open, we can close it then. |
| 2721 | */ |
| 2722 | if (c->remoteid != -1) { |
| 2723 | if (ssh_version == 1) { |
| 2724 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
| 2725 | PKT_END); |
| 2726 | } else { |
| 2727 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 2728 | ssh2_pkt_adduint32(c->remoteid); |
| 2729 | ssh2_pkt_send(); |
| 2730 | } |
| 2731 | } |
| 2732 | c->closes = 1; |
| 2733 | if (c->type == CHAN_X11) { |
| 2734 | c->u.x11.s = NULL; |
| 2735 | logevent("Forwarded X11 connection terminated"); |
| 2736 | } else if (c->type == CHAN_SOCKDATA || |
| 2737 | c->type == CHAN_SOCKDATA_DORMANT) { |
| 2738 | c->u.pfd.s = NULL; |
| 2739 | logevent("Forwarded port closed"); |
| 2740 | } |
| 2741 | } |
| 2742 | } |
| 2743 | |
| 2744 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) |
| 2745 | { |
| 2746 | if (ssh_version == 1) { |
| 2747 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 2748 | PKT_INT, c->remoteid, |
| 2749 | PKT_INT, len, PKT_DATA, buf, len, PKT_END); |
| 2750 | /* |
| 2751 | * In SSH1 we can return 0 here - implying that forwarded |
| 2752 | * connections are never individually throttled - because |
| 2753 | * the only circumstance that can cause throttling will be |
| 2754 | * the whole SSH connection backing up, in which case |
| 2755 | * _everything_ will be throttled as a whole. |
| 2756 | */ |
| 2757 | return 0; |
| 2758 | } else { |
| 2759 | ssh2_add_channel_data(c, buf, len); |
| 2760 | return ssh2_try_send(c); |
| 2761 | } |
| 2762 | } |
| 2763 | |
| 2764 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) |
| 2765 | { |
| 2766 | if (ssh_version == 1) { |
| 2767 | if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 2768 | c->v.v1.throttling = 0; |
| 2769 | ssh1_throttle(-1); |
| 2770 | } |
| 2771 | } else { |
| 2772 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
| 2773 | } |
| 2774 | } |
| 2775 | |
| 2776 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) |
| 2777 | { |
| 2778 | crBegin; |
| 2779 | |
| 2780 | random_init(); |
| 2781 | |
| 2782 | while (!do_ssh1_login(in, inlen, ispkt)) { |
| 2783 | crReturnV; |
| 2784 | } |
| 2785 | if (ssh_state == SSH_STATE_CLOSED) |
| 2786 | crReturnV; |
| 2787 | |
| 2788 | if (cfg.agentfwd && agent_exists()) { |
| 2789 | logevent("Requesting agent forwarding"); |
| 2790 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
| 2791 | do { |
| 2792 | crReturnV; |
| 2793 | } while (!ispkt); |
| 2794 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2795 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2796 | bombout(("Protocol confusion")); |
| 2797 | crReturnV; |
| 2798 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2799 | logevent("Agent forwarding refused"); |
| 2800 | } else { |
| 2801 | logevent("Agent forwarding enabled"); |
| 2802 | ssh_agentfwd_enabled = TRUE; |
| 2803 | } |
| 2804 | } |
| 2805 | |
| 2806 | if (cfg.x11_forward) { |
| 2807 | char proto[20], data[64]; |
| 2808 | logevent("Requesting X11 forwarding"); |
| 2809 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
| 2810 | if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
| 2811 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 2812 | PKT_STR, proto, PKT_STR, data, |
| 2813 | PKT_INT, 0, PKT_END); |
| 2814 | } else { |
| 2815 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 2816 | PKT_STR, proto, PKT_STR, data, PKT_END); |
| 2817 | } |
| 2818 | do { |
| 2819 | crReturnV; |
| 2820 | } while (!ispkt); |
| 2821 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2822 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2823 | bombout(("Protocol confusion")); |
| 2824 | crReturnV; |
| 2825 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2826 | logevent("X11 forwarding refused"); |
| 2827 | } else { |
| 2828 | logevent("X11 forwarding enabled"); |
| 2829 | ssh_X11_fwd_enabled = TRUE; |
| 2830 | } |
| 2831 | } |
| 2832 | |
| 2833 | { |
| 2834 | char type; |
| 2835 | static char *e; |
| 2836 | int n; |
| 2837 | int sport,dport,sserv,dserv; |
| 2838 | char sports[256], dports[256], host[256]; |
| 2839 | char buf[1024]; |
| 2840 | struct servent *se; |
| 2841 | |
| 2842 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh1); |
| 2843 | /* Add port forwardings. */ |
| 2844 | e = cfg.portfwd; |
| 2845 | while (*e) { |
| 2846 | type = *e++; |
| 2847 | n = 0; |
| 2848 | while (*e && *e != '\t') |
| 2849 | sports[n++] = *e++; |
| 2850 | sports[n] = 0; |
| 2851 | if (*e == '\t') |
| 2852 | e++; |
| 2853 | n = 0; |
| 2854 | while (*e && *e != ':') |
| 2855 | host[n++] = *e++; |
| 2856 | host[n] = 0; |
| 2857 | if (*e == ':') |
| 2858 | e++; |
| 2859 | n = 0; |
| 2860 | while (*e) |
| 2861 | dports[n++] = *e++; |
| 2862 | dports[n] = 0; |
| 2863 | e++; |
| 2864 | dport = atoi(dports); |
| 2865 | dserv = 0; |
| 2866 | if (dport == 0) { |
| 2867 | dserv = 1; |
| 2868 | se = getservbyname(dports, NULL); |
| 2869 | if (se != NULL) { |
| 2870 | dport = ntohs(se->s_port); |
| 2871 | } else { |
| 2872 | sprintf(buf, |
| 2873 | "Service lookup failed for destination port \"%s\"", |
| 2874 | dports); |
| 2875 | logevent(buf); |
| 2876 | } |
| 2877 | } |
| 2878 | sport = atoi(sports); |
| 2879 | sserv = 0; |
| 2880 | if (sport == 0) { |
| 2881 | sserv = 1; |
| 2882 | se = getservbyname(sports, NULL); |
| 2883 | if (se != NULL) { |
| 2884 | sport = ntohs(se->s_port); |
| 2885 | } else { |
| 2886 | sprintf(buf, |
| 2887 | "Service lookup failed for source port \"%s\"", |
| 2888 | sports); |
| 2889 | logevent(buf); |
| 2890 | } |
| 2891 | } |
| 2892 | if (sport && dport) { |
| 2893 | if (type == 'L') { |
| 2894 | pfd_addforward(host, dport, sport); |
| 2895 | sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to" |
| 2896 | " %s:%.*s%.*s%d%.*s", |
| 2897 | sserv ? strlen(sports) : 0, sports, |
| 2898 | sserv, "(", sport, sserv, ")", |
| 2899 | host, |
| 2900 | dserv ? strlen(dports) : 0, dports, |
| 2901 | dserv, "(", dport, dserv, ")"); |
| 2902 | logevent(buf); |
| 2903 | } else { |
| 2904 | struct ssh_rportfwd *pf; |
| 2905 | pf = smalloc(sizeof(*pf)); |
| 2906 | strcpy(pf->dhost, host); |
| 2907 | pf->dport = dport; |
| 2908 | if (add234(ssh_rportfwds, pf) != pf) { |
| 2909 | sprintf(buf, |
| 2910 | "Duplicate remote port forwarding to %s:%d", |
| 2911 | host, dport); |
| 2912 | logevent(buf); |
| 2913 | sfree(pf); |
| 2914 | } else { |
| 2915 | sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s" |
| 2916 | " forward to %s:%.*s%.*s%d%.*s", |
| 2917 | sserv ? strlen(sports) : 0, sports, |
| 2918 | sserv, "(", sport, sserv, ")", |
| 2919 | host, |
| 2920 | dserv ? strlen(dports) : 0, dports, |
| 2921 | dserv, "(", dport, dserv, ")"); |
| 2922 | logevent(buf); |
| 2923 | send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST, |
| 2924 | PKT_INT, sport, |
| 2925 | PKT_STR, host, |
| 2926 | PKT_INT, dport, |
| 2927 | PKT_END); |
| 2928 | do { |
| 2929 | crReturnV; |
| 2930 | } while (!ispkt); |
| 2931 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2932 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2933 | bombout(("Protocol confusion")); |
| 2934 | crReturnV; |
| 2935 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2936 | c_write_str("Server refused port forwarding\r\n"); |
| 2937 | ssh_editing = ssh_echoing = 1; |
| 2938 | } |
| 2939 | logevent("Remote port forwarding enabled"); |
| 2940 | } |
| 2941 | } |
| 2942 | } |
| 2943 | } |
| 2944 | } |
| 2945 | |
| 2946 | if (!cfg.nopty) { |
| 2947 | send_packet(SSH1_CMSG_REQUEST_PTY, |
| 2948 | PKT_STR, cfg.termtype, |
| 2949 | PKT_INT, rows, PKT_INT, cols, |
| 2950 | PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END); |
| 2951 | ssh_state = SSH_STATE_INTERMED; |
| 2952 | do { |
| 2953 | crReturnV; |
| 2954 | } while (!ispkt); |
| 2955 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2956 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2957 | bombout(("Protocol confusion")); |
| 2958 | crReturnV; |
| 2959 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2960 | c_write_str("Server refused to allocate pty\r\n"); |
| 2961 | ssh_editing = ssh_echoing = 1; |
| 2962 | } |
| 2963 | logevent("Allocated pty"); |
| 2964 | } else { |
| 2965 | ssh_editing = ssh_echoing = 1; |
| 2966 | } |
| 2967 | |
| 2968 | if (cfg.compression) { |
| 2969 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
| 2970 | do { |
| 2971 | crReturnV; |
| 2972 | } while (!ispkt); |
| 2973 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2974 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2975 | bombout(("Protocol confusion")); |
| 2976 | crReturnV; |
| 2977 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2978 | c_write_str("Server refused to compress\r\n"); |
| 2979 | } |
| 2980 | logevent("Started compression"); |
| 2981 | ssh1_compressing = TRUE; |
| 2982 | zlib_compress_init(); |
| 2983 | zlib_decompress_init(); |
| 2984 | } |
| 2985 | |
| 2986 | /* |
| 2987 | * Start the shell or command. |
| 2988 | * |
| 2989 | * Special case: if the first-choice command is an SSH2 |
| 2990 | * subsystem (hence not usable here) and the second choice |
| 2991 | * exists, we fall straight back to that. |
| 2992 | */ |
| 2993 | { |
| 2994 | char *cmd = cfg.remote_cmd_ptr; |
| 2995 | |
| 2996 | if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) { |
| 2997 | cmd = cfg.remote_cmd_ptr2; |
| 2998 | ssh_fallback_cmd = TRUE; |
| 2999 | } |
| 3000 | if (*cmd) |
| 3001 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
| 3002 | else |
| 3003 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 3004 | logevent("Started session"); |
| 3005 | } |
| 3006 | |
| 3007 | ssh_state = SSH_STATE_SESSION; |
| 3008 | if (size_needed) |
| 3009 | ssh_size(); |
| 3010 | if (eof_needed) |
| 3011 | ssh_special(TS_EOF); |
| 3012 | |
| 3013 | ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ |
| 3014 | ssh_send_ok = 1; |
| 3015 | ssh_channels = newtree234(ssh_channelcmp); |
| 3016 | while (1) { |
| 3017 | crReturnV; |
| 3018 | if (ispkt) { |
| 3019 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 3020 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 3021 | long len = GET_32BIT(pktin.body); |
| 3022 | int bufsize = |
| 3023 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
| 3024 | pktin.body + 4, len); |
| 3025 | if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 3026 | ssh1_stdout_throttling = 1; |
| 3027 | ssh1_throttle(+1); |
| 3028 | } |
| 3029 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 3030 | ssh_state = SSH_STATE_CLOSED; |
| 3031 | logevent("Received disconnect request"); |
| 3032 | crReturnV; |
| 3033 | } else if (pktin.type == SSH1_SMSG_X11_OPEN) { |
| 3034 | /* Remote side is trying to open a channel to talk to our |
| 3035 | * X-Server. Give them back a local channel number. */ |
| 3036 | struct ssh_channel *c; |
| 3037 | |
| 3038 | logevent("Received X11 connect request"); |
| 3039 | /* Refuse if X11 forwarding is disabled. */ |
| 3040 | if (!ssh_X11_fwd_enabled) { |
| 3041 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3042 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
| 3043 | logevent("Rejected X11 connect request"); |
| 3044 | } else { |
| 3045 | c = smalloc(sizeof(struct ssh_channel)); |
| 3046 | |
| 3047 | if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) { |
| 3048 | logevent("opening X11 forward connection failed"); |
| 3049 | sfree(c); |
| 3050 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3051 | PKT_INT, GET_32BIT(pktin.body), |
| 3052 | PKT_END); |
| 3053 | } else { |
| 3054 | logevent |
| 3055 | ("opening X11 forward connection succeeded"); |
| 3056 | c->remoteid = GET_32BIT(pktin.body); |
| 3057 | c->localid = alloc_channel_id(); |
| 3058 | c->closes = 0; |
| 3059 | c->v.v1.throttling = 0; |
| 3060 | c->type = CHAN_X11; /* identify channel type */ |
| 3061 | add234(ssh_channels, c); |
| 3062 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 3063 | PKT_INT, c->remoteid, PKT_INT, |
| 3064 | c->localid, PKT_END); |
| 3065 | logevent("Opened X11 forward channel"); |
| 3066 | } |
| 3067 | } |
| 3068 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
| 3069 | /* Remote side is trying to open a channel to talk to our |
| 3070 | * agent. Give them back a local channel number. */ |
| 3071 | struct ssh_channel *c; |
| 3072 | |
| 3073 | /* Refuse if agent forwarding is disabled. */ |
| 3074 | if (!ssh_agentfwd_enabled) { |
| 3075 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3076 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
| 3077 | } else { |
| 3078 | c = smalloc(sizeof(struct ssh_channel)); |
| 3079 | c->remoteid = GET_32BIT(pktin.body); |
| 3080 | c->localid = alloc_channel_id(); |
| 3081 | c->closes = 0; |
| 3082 | c->v.v1.throttling = 0; |
| 3083 | c->type = CHAN_AGENT; /* identify channel type */ |
| 3084 | c->u.a.lensofar = 0; |
| 3085 | add234(ssh_channels, c); |
| 3086 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 3087 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 3088 | PKT_END); |
| 3089 | } |
| 3090 | } else if (pktin.type == SSH1_MSG_PORT_OPEN) { |
| 3091 | /* Remote side is trying to open a channel to talk to a |
| 3092 | * forwarded port. Give them back a local channel number. */ |
| 3093 | struct ssh_channel *c; |
| 3094 | struct ssh_rportfwd pf; |
| 3095 | int hostsize, port; |
| 3096 | char host[256], buf[1024]; |
| 3097 | char *p, *h, *e; |
| 3098 | c = smalloc(sizeof(struct ssh_channel)); |
| 3099 | |
| 3100 | hostsize = GET_32BIT(pktin.body+4); |
| 3101 | for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) { |
| 3102 | if (h+1 < host+sizeof(host)) |
| 3103 | *h++ = *p; |
| 3104 | p++; |
| 3105 | } |
| 3106 | *h = 0; |
| 3107 | port = GET_32BIT(p); |
| 3108 | |
| 3109 | strcpy(pf.dhost, host); |
| 3110 | pf.dport = port; |
| 3111 | |
| 3112 | if (find234(ssh_rportfwds, &pf, NULL) == NULL) { |
| 3113 | sprintf(buf, "Rejected remote port open request for %s:%d", |
| 3114 | host, port); |
| 3115 | logevent(buf); |
| 3116 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3117 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
| 3118 | } else { |
| 3119 | sprintf(buf, "Received remote port open request for %s:%d", |
| 3120 | host, port); |
| 3121 | logevent(buf); |
| 3122 | e = pfd_newconnect(&c->u.pfd.s, host, port, c); |
| 3123 | if (e != NULL) { |
| 3124 | char buf[256]; |
| 3125 | sprintf(buf, "Port open failed: %s", e); |
| 3126 | logevent(buf); |
| 3127 | sfree(c); |
| 3128 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3129 | PKT_INT, GET_32BIT(pktin.body), |
| 3130 | PKT_END); |
| 3131 | } else { |
| 3132 | c->remoteid = GET_32BIT(pktin.body); |
| 3133 | c->localid = alloc_channel_id(); |
| 3134 | c->closes = 0; |
| 3135 | c->v.v1.throttling = 0; |
| 3136 | c->type = CHAN_SOCKDATA; /* identify channel type */ |
| 3137 | add234(ssh_channels, c); |
| 3138 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 3139 | PKT_INT, c->remoteid, PKT_INT, |
| 3140 | c->localid, PKT_END); |
| 3141 | logevent("Forwarded port opened successfully"); |
| 3142 | } |
| 3143 | } |
| 3144 | |
| 3145 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 3146 | unsigned int remoteid = GET_32BIT(pktin.body); |
| 3147 | unsigned int localid = GET_32BIT(pktin.body+4); |
| 3148 | struct ssh_channel *c; |
| 3149 | |
| 3150 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
| 3151 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 3152 | c->remoteid = localid; |
| 3153 | c->type = CHAN_SOCKDATA; |
| 3154 | c->v.v1.throttling = 0; |
| 3155 | pfd_confirm(c->u.pfd.s); |
| 3156 | } |
| 3157 | |
| 3158 | if (c && c->closes) { |
| 3159 | /* |
| 3160 | * We have a pending close on this channel, |
| 3161 | * which we decided on before the server acked |
| 3162 | * the channel open. So now we know the |
| 3163 | * remoteid, we can close it again. |
| 3164 | */ |
| 3165 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
| 3166 | PKT_END); |
| 3167 | } |
| 3168 | |
| 3169 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { |
| 3170 | unsigned int remoteid = GET_32BIT(pktin.body); |
| 3171 | unsigned int localid = GET_32BIT(pktin.body+4); |
| 3172 | struct ssh_channel *c; |
| 3173 | |
| 3174 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
| 3175 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 3176 | logevent("Forwarded connection refused by server"); |
| 3177 | pfd_close(c->u.pfd.s); |
| 3178 | del234(ssh_channels, c); |
| 3179 | sfree(c); |
| 3180 | } |
| 3181 | |
| 3182 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
| 3183 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
| 3184 | /* Remote side closes a channel. */ |
| 3185 | unsigned i = GET_32BIT(pktin.body); |
| 3186 | struct ssh_channel *c; |
| 3187 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3188 | if (c) { |
| 3189 | int closetype; |
| 3190 | closetype = |
| 3191 | (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
| 3192 | if (!(c->closes & closetype)) |
| 3193 | send_packet(pktin.type, PKT_INT, c->remoteid, |
| 3194 | PKT_END); |
| 3195 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
| 3196 | logevent("Forwarded X11 connection terminated"); |
| 3197 | assert(c->u.x11.s != NULL); |
| 3198 | x11_close(c->u.x11.s); |
| 3199 | c->u.x11.s = NULL; |
| 3200 | } |
| 3201 | if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { |
| 3202 | logevent("Forwarded port closed"); |
| 3203 | assert(c->u.pfd.s != NULL); |
| 3204 | pfd_close(c->u.pfd.s); |
| 3205 | c->u.pfd.s = NULL; |
| 3206 | } |
| 3207 | c->closes |= closetype; |
| 3208 | if (c->closes == 3) { |
| 3209 | del234(ssh_channels, c); |
| 3210 | sfree(c); |
| 3211 | } |
| 3212 | } |
| 3213 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
| 3214 | /* Data sent down one of our channels. */ |
| 3215 | int i = GET_32BIT(pktin.body); |
| 3216 | int len = GET_32BIT(pktin.body + 4); |
| 3217 | unsigned char *p = pktin.body + 8; |
| 3218 | struct ssh_channel *c; |
| 3219 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3220 | if (c) { |
| 3221 | int bufsize; |
| 3222 | switch (c->type) { |
| 3223 | case CHAN_X11: |
| 3224 | bufsize = x11_send(c->u.x11.s, p, len); |
| 3225 | break; |
| 3226 | case CHAN_SOCKDATA: |
| 3227 | bufsize = pfd_send(c->u.pfd.s, p, len); |
| 3228 | break; |
| 3229 | case CHAN_AGENT: |
| 3230 | /* Data for an agent message. Buffer it. */ |
| 3231 | while (len > 0) { |
| 3232 | if (c->u.a.lensofar < 4) { |
| 3233 | int l = min(4 - c->u.a.lensofar, len); |
| 3234 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, |
| 3235 | l); |
| 3236 | p += l; |
| 3237 | len -= l; |
| 3238 | c->u.a.lensofar += l; |
| 3239 | } |
| 3240 | if (c->u.a.lensofar == 4) { |
| 3241 | c->u.a.totallen = |
| 3242 | 4 + GET_32BIT(c->u.a.msglen); |
| 3243 | c->u.a.message = smalloc(c->u.a.totallen); |
| 3244 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 3245 | } |
| 3246 | if (c->u.a.lensofar >= 4 && len > 0) { |
| 3247 | int l = |
| 3248 | min(c->u.a.totallen - c->u.a.lensofar, |
| 3249 | len); |
| 3250 | memcpy(c->u.a.message + c->u.a.lensofar, p, |
| 3251 | l); |
| 3252 | p += l; |
| 3253 | len -= l; |
| 3254 | c->u.a.lensofar += l; |
| 3255 | } |
| 3256 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 3257 | void *reply, *sentreply; |
| 3258 | int replylen; |
| 3259 | agent_query(c->u.a.message, |
| 3260 | c->u.a.totallen, &reply, |
| 3261 | &replylen); |
| 3262 | if (reply) |
| 3263 | sentreply = reply; |
| 3264 | else { |
| 3265 | /* Fake SSH_AGENT_FAILURE. */ |
| 3266 | sentreply = "\0\0\0\1\5"; |
| 3267 | replylen = 5; |
| 3268 | } |
| 3269 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 3270 | PKT_INT, c->remoteid, |
| 3271 | PKT_INT, replylen, |
| 3272 | PKT_DATA, sentreply, replylen, |
| 3273 | PKT_END); |
| 3274 | if (reply) |
| 3275 | sfree(reply); |
| 3276 | sfree(c->u.a.message); |
| 3277 | c->u.a.lensofar = 0; |
| 3278 | } |
| 3279 | } |
| 3280 | bufsize = 0; /* agent channels never back up */ |
| 3281 | break; |
| 3282 | } |
| 3283 | if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 3284 | c->v.v1.throttling = 1; |
| 3285 | ssh1_throttle(+1); |
| 3286 | } |
| 3287 | } |
| 3288 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 3289 | /* may be from EXEC_SHELL on some servers */ |
| 3290 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 3291 | /* may be from EXEC_SHELL on some servers |
| 3292 | * if no pty is available or in other odd cases. Ignore */ |
| 3293 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 3294 | char buf[100]; |
| 3295 | ssh_exitcode = GET_32BIT(pktin.body); |
| 3296 | sprintf(buf, "Server sent command exit status %d", |
| 3297 | ssh_exitcode); |
| 3298 | logevent(buf); |
| 3299 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 3300 | /* |
| 3301 | * In case `helpful' firewalls or proxies tack |
| 3302 | * extra human-readable text on the end of the |
| 3303 | * session which we might mistake for another |
| 3304 | * encrypted packet, we close the session once |
| 3305 | * we've sent EXIT_CONFIRMATION. |
| 3306 | */ |
| 3307 | ssh_state = SSH_STATE_CLOSED; |
| 3308 | crReturnV; |
| 3309 | } else { |
| 3310 | bombout(("Strange packet received: type %d", pktin.type)); |
| 3311 | crReturnV; |
| 3312 | } |
| 3313 | } else { |
| 3314 | while (inlen > 0) { |
| 3315 | int len = min(inlen, 512); |
| 3316 | send_packet(SSH1_CMSG_STDIN_DATA, |
| 3317 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
| 3318 | in += len; |
| 3319 | inlen -= len; |
| 3320 | } |
| 3321 | } |
| 3322 | } |
| 3323 | |
| 3324 | crFinishV; |
| 3325 | } |
| 3326 | |
| 3327 | /* |
| 3328 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 3329 | */ |
| 3330 | static int in_commasep_string(char *needle, char *haystack, int haylen) |
| 3331 | { |
| 3332 | int needlen = strlen(needle); |
| 3333 | while (1) { |
| 3334 | /* |
| 3335 | * Is it at the start of the string? |
| 3336 | */ |
| 3337 | if (haylen >= needlen && /* haystack is long enough */ |
| 3338 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 3339 | (haylen == needlen || haystack[needlen] == ',') |
| 3340 | /* either , or EOS follows */ |
| 3341 | ) |
| 3342 | return 1; |
| 3343 | /* |
| 3344 | * If not, search for the next comma and resume after that. |
| 3345 | * If no comma found, terminate. |
| 3346 | */ |
| 3347 | while (haylen > 0 && *haystack != ',') |
| 3348 | haylen--, haystack++; |
| 3349 | if (haylen == 0) |
| 3350 | return 0; |
| 3351 | haylen--, haystack++; /* skip over comma itself */ |
| 3352 | } |
| 3353 | } |
| 3354 | |
| 3355 | /* |
| 3356 | * SSH2 key creation method. |
| 3357 | */ |
| 3358 | static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, |
| 3359 | char *keyspace) |
| 3360 | { |
| 3361 | SHA_State s; |
| 3362 | /* First 20 bytes. */ |
| 3363 | SHA_Init(&s); |
| 3364 | sha_mpint(&s, K); |
| 3365 | SHA_Bytes(&s, H, 20); |
| 3366 | SHA_Bytes(&s, &chr, 1); |
| 3367 | SHA_Bytes(&s, sessid, 20); |
| 3368 | SHA_Final(&s, keyspace); |
| 3369 | /* Next 20 bytes. */ |
| 3370 | SHA_Init(&s); |
| 3371 | sha_mpint(&s, K); |
| 3372 | SHA_Bytes(&s, H, 20); |
| 3373 | SHA_Bytes(&s, keyspace, 20); |
| 3374 | SHA_Final(&s, keyspace + 20); |
| 3375 | } |
| 3376 | |
| 3377 | /* |
| 3378 | * Handle the SSH2 transport layer. |
| 3379 | */ |
| 3380 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
| 3381 | { |
| 3382 | static int i, j, len, nbits, pbits, warn; |
| 3383 | static char *str; |
| 3384 | static Bignum p, g, e, f, K; |
| 3385 | static int kex_init_value, kex_reply_value; |
| 3386 | static const struct ssh_mac **maclist; |
| 3387 | static int nmacs; |
| 3388 | static const struct ssh2_cipher *cscipher_tobe = NULL; |
| 3389 | static const struct ssh2_cipher *sccipher_tobe = NULL; |
| 3390 | static const struct ssh_mac *csmac_tobe = NULL; |
| 3391 | static const struct ssh_mac *scmac_tobe = NULL; |
| 3392 | static const struct ssh_compress *cscomp_tobe = NULL; |
| 3393 | static const struct ssh_compress *sccomp_tobe = NULL; |
| 3394 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
| 3395 | static int hostkeylen, siglen; |
| 3396 | static void *hkey; /* actual host key */ |
| 3397 | static unsigned char exchange_hash[20]; |
| 3398 | static unsigned char keyspace[40]; |
| 3399 | static int n_preferred_ciphers; |
| 3400 | static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; |
| 3401 | static const struct ssh_compress *preferred_comp; |
| 3402 | static int cipherstr_started; |
| 3403 | static int first_kex; |
| 3404 | |
| 3405 | crBegin; |
| 3406 | random_init(); |
| 3407 | first_kex = 1; |
| 3408 | |
| 3409 | /* |
| 3410 | * Set up the preferred ciphers. (NULL => warn below here) |
| 3411 | */ |
| 3412 | n_preferred_ciphers = 0; |
| 3413 | for (i = 0; i < CIPHER_MAX; i++) { |
| 3414 | switch (cfg.ssh_cipherlist[i]) { |
| 3415 | case CIPHER_BLOWFISH: |
| 3416 | preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish; |
| 3417 | n_preferred_ciphers++; |
| 3418 | break; |
| 3419 | case CIPHER_DES: |
| 3420 | if (cfg.ssh2_des_cbc) { |
| 3421 | preferred_ciphers[n_preferred_ciphers] = &ssh2_des; |
| 3422 | n_preferred_ciphers++; |
| 3423 | } |
| 3424 | break; |
| 3425 | case CIPHER_3DES: |
| 3426 | preferred_ciphers[n_preferred_ciphers] = &ssh2_3des; |
| 3427 | n_preferred_ciphers++; |
| 3428 | break; |
| 3429 | case CIPHER_AES: |
| 3430 | preferred_ciphers[n_preferred_ciphers] = &ssh2_aes; |
| 3431 | n_preferred_ciphers++; |
| 3432 | break; |
| 3433 | case CIPHER_WARN: |
| 3434 | /* Flag for later. Don't bother if it's the last in |
| 3435 | * the list. */ |
| 3436 | if (i < CIPHER_MAX - 1) { |
| 3437 | preferred_ciphers[n_preferred_ciphers] = NULL; |
| 3438 | n_preferred_ciphers++; |
| 3439 | } |
| 3440 | break; |
| 3441 | } |
| 3442 | } |
| 3443 | |
| 3444 | /* |
| 3445 | * Set up preferred compression. |
| 3446 | */ |
| 3447 | if (cfg.compression) |
| 3448 | preferred_comp = &ssh_zlib; |
| 3449 | else |
| 3450 | preferred_comp = &ssh_comp_none; |
| 3451 | |
| 3452 | /* |
| 3453 | * Be prepared to work around the buggy MAC problem. |
| 3454 | */ |
| 3455 | if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC)) |
| 3456 | maclist = buggymacs, nmacs = lenof(buggymacs); |
| 3457 | else |
| 3458 | maclist = macs, nmacs = lenof(macs); |
| 3459 | |
| 3460 | begin_key_exchange: |
| 3461 | /* |
| 3462 | * Construct and send our key exchange packet. |
| 3463 | */ |
| 3464 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
| 3465 | for (i = 0; i < 16; i++) |
| 3466 | ssh2_pkt_addbyte((unsigned char) random_byte()); |
| 3467 | /* List key exchange algorithms. */ |
| 3468 | ssh2_pkt_addstring_start(); |
| 3469 | for (i = 0; i < lenof(kex_algs); i++) { |
| 3470 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
| 3471 | if (i < lenof(kex_algs) - 1) |
| 3472 | ssh2_pkt_addstring_str(","); |
| 3473 | } |
| 3474 | /* List server host key algorithms. */ |
| 3475 | ssh2_pkt_addstring_start(); |
| 3476 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 3477 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
| 3478 | if (i < lenof(hostkey_algs) - 1) |
| 3479 | ssh2_pkt_addstring_str(","); |
| 3480 | } |
| 3481 | /* List client->server encryption algorithms. */ |
| 3482 | ssh2_pkt_addstring_start(); |
| 3483 | cipherstr_started = 0; |
| 3484 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3485 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3486 | if (!c) continue; /* warning flag */ |
| 3487 | for (j = 0; j < c->nciphers; j++) { |
| 3488 | if (cipherstr_started) |
| 3489 | ssh2_pkt_addstring_str(","); |
| 3490 | ssh2_pkt_addstring_str(c->list[j]->name); |
| 3491 | cipherstr_started = 1; |
| 3492 | } |
| 3493 | } |
| 3494 | /* List server->client encryption algorithms. */ |
| 3495 | ssh2_pkt_addstring_start(); |
| 3496 | cipherstr_started = 0; |
| 3497 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3498 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3499 | if (!c) continue; /* warning flag */ |
| 3500 | for (j = 0; j < c->nciphers; j++) { |
| 3501 | if (cipherstr_started) |
| 3502 | ssh2_pkt_addstring_str(","); |
| 3503 | ssh2_pkt_addstring_str(c->list[j]->name); |
| 3504 | cipherstr_started = 1; |
| 3505 | } |
| 3506 | } |
| 3507 | /* List client->server MAC algorithms. */ |
| 3508 | ssh2_pkt_addstring_start(); |
| 3509 | for (i = 0; i < nmacs; i++) { |
| 3510 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 3511 | if (i < nmacs - 1) |
| 3512 | ssh2_pkt_addstring_str(","); |
| 3513 | } |
| 3514 | /* List server->client MAC algorithms. */ |
| 3515 | ssh2_pkt_addstring_start(); |
| 3516 | for (i = 0; i < nmacs; i++) { |
| 3517 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 3518 | if (i < nmacs - 1) |
| 3519 | ssh2_pkt_addstring_str(","); |
| 3520 | } |
| 3521 | /* List client->server compression algorithms. */ |
| 3522 | ssh2_pkt_addstring_start(); |
| 3523 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3524 | const struct ssh_compress *c = |
| 3525 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3526 | ssh2_pkt_addstring_str(c->name); |
| 3527 | if (i < lenof(compressions)) |
| 3528 | ssh2_pkt_addstring_str(","); |
| 3529 | } |
| 3530 | /* List server->client compression algorithms. */ |
| 3531 | ssh2_pkt_addstring_start(); |
| 3532 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3533 | const struct ssh_compress *c = |
| 3534 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3535 | ssh2_pkt_addstring_str(c->name); |
| 3536 | if (i < lenof(compressions)) |
| 3537 | ssh2_pkt_addstring_str(","); |
| 3538 | } |
| 3539 | /* List client->server languages. Empty list. */ |
| 3540 | ssh2_pkt_addstring_start(); |
| 3541 | /* List server->client languages. Empty list. */ |
| 3542 | ssh2_pkt_addstring_start(); |
| 3543 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 3544 | ssh2_pkt_addbool(FALSE); |
| 3545 | /* Reserved. */ |
| 3546 | ssh2_pkt_adduint32(0); |
| 3547 | |
| 3548 | exhash = exhashbase; |
| 3549 | sha_string(&exhash, pktout.data + 5, pktout.length - 5); |
| 3550 | |
| 3551 | ssh2_pkt_send(); |
| 3552 | |
| 3553 | if (!ispkt) |
| 3554 | crWaitUntil(ispkt); |
| 3555 | sha_string(&exhash, pktin.data + 5, pktin.length - 5); |
| 3556 | |
| 3557 | /* |
| 3558 | * Now examine the other side's KEXINIT to see what we're up |
| 3559 | * to. |
| 3560 | */ |
| 3561 | if (pktin.type != SSH2_MSG_KEXINIT) { |
| 3562 | bombout(("expected key exchange packet from server")); |
| 3563 | crReturn(0); |
| 3564 | } |
| 3565 | kex = NULL; |
| 3566 | hostkey = NULL; |
| 3567 | cscipher_tobe = NULL; |
| 3568 | sccipher_tobe = NULL; |
| 3569 | csmac_tobe = NULL; |
| 3570 | scmac_tobe = NULL; |
| 3571 | cscomp_tobe = NULL; |
| 3572 | sccomp_tobe = NULL; |
| 3573 | pktin.savedpos += 16; /* skip garbage cookie */ |
| 3574 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
| 3575 | for (i = 0; i < lenof(kex_algs); i++) { |
| 3576 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
| 3577 | kex = kex_algs[i]; |
| 3578 | break; |
| 3579 | } |
| 3580 | } |
| 3581 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
| 3582 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 3583 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 3584 | hostkey = hostkey_algs[i]; |
| 3585 | break; |
| 3586 | } |
| 3587 | } |
| 3588 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
| 3589 | warn = 0; |
| 3590 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3591 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3592 | if (!c) { |
| 3593 | warn = 1; |
| 3594 | } else { |
| 3595 | for (j = 0; j < c->nciphers; j++) { |
| 3596 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 3597 | cscipher_tobe = c->list[j]; |
| 3598 | break; |
| 3599 | } |
| 3600 | } |
| 3601 | } |
| 3602 | if (cscipher_tobe) { |
| 3603 | if (warn) |
| 3604 | askcipher(cscipher_tobe->name, 1); |
| 3605 | break; |
| 3606 | } |
| 3607 | } |
| 3608 | if (!cscipher_tobe) { |
| 3609 | bombout(("Couldn't agree a client-to-server cipher (available: %s)", str)); |
| 3610 | crReturn(0); |
| 3611 | } |
| 3612 | |
| 3613 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
| 3614 | warn = 0; |
| 3615 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3616 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3617 | if (!c) { |
| 3618 | warn = 1; |
| 3619 | } else { |
| 3620 | for (j = 0; j < c->nciphers; j++) { |
| 3621 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 3622 | sccipher_tobe = c->list[j]; |
| 3623 | break; |
| 3624 | } |
| 3625 | } |
| 3626 | } |
| 3627 | if (sccipher_tobe) { |
| 3628 | if (warn) |
| 3629 | askcipher(sccipher_tobe->name, 2); |
| 3630 | break; |
| 3631 | } |
| 3632 | } |
| 3633 | if (!sccipher_tobe) { |
| 3634 | bombout(("Couldn't agree a server-to-client cipher (available: %s)", str)); |
| 3635 | crReturn(0); |
| 3636 | } |
| 3637 | |
| 3638 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
| 3639 | for (i = 0; i < nmacs; i++) { |
| 3640 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 3641 | csmac_tobe = maclist[i]; |
| 3642 | break; |
| 3643 | } |
| 3644 | } |
| 3645 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
| 3646 | for (i = 0; i < nmacs; i++) { |
| 3647 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 3648 | scmac_tobe = maclist[i]; |
| 3649 | break; |
| 3650 | } |
| 3651 | } |
| 3652 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
| 3653 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3654 | const struct ssh_compress *c = |
| 3655 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3656 | if (in_commasep_string(c->name, str, len)) { |
| 3657 | cscomp_tobe = c; |
| 3658 | break; |
| 3659 | } |
| 3660 | } |
| 3661 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
| 3662 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3663 | const struct ssh_compress *c = |
| 3664 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3665 | if (in_commasep_string(c->name, str, len)) { |
| 3666 | sccomp_tobe = c; |
| 3667 | break; |
| 3668 | } |
| 3669 | } |
| 3670 | |
| 3671 | /* |
| 3672 | * Work out the number of bits of key we will need from the key |
| 3673 | * exchange. We start with the maximum key length of either |
| 3674 | * cipher... |
| 3675 | */ |
| 3676 | { |
| 3677 | int csbits, scbits; |
| 3678 | |
| 3679 | csbits = cscipher_tobe->keylen; |
| 3680 | scbits = sccipher_tobe->keylen; |
| 3681 | nbits = (csbits > scbits ? csbits : scbits); |
| 3682 | } |
| 3683 | /* The keys only have 160-bit entropy, since they're based on |
| 3684 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
| 3685 | if (nbits > 160) |
| 3686 | nbits = 160; |
| 3687 | |
| 3688 | /* |
| 3689 | * If we're doing Diffie-Hellman group exchange, start by |
| 3690 | * requesting a group. |
| 3691 | */ |
| 3692 | if (kex == &ssh_diffiehellman_gex) { |
| 3693 | logevent("Doing Diffie-Hellman group exchange"); |
| 3694 | ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX; |
| 3695 | /* |
| 3696 | * Work out how big a DH group we will need to allow that |
| 3697 | * much data. |
| 3698 | */ |
| 3699 | pbits = 512 << ((nbits - 1) / 64); |
| 3700 | ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
| 3701 | ssh2_pkt_adduint32(pbits); |
| 3702 | ssh2_pkt_send(); |
| 3703 | |
| 3704 | crWaitUntil(ispkt); |
| 3705 | if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
| 3706 | bombout(("expected key exchange group packet from server")); |
| 3707 | crReturn(0); |
| 3708 | } |
| 3709 | p = ssh2_pkt_getmp(); |
| 3710 | g = ssh2_pkt_getmp(); |
| 3711 | dh_setup_group(p, g); |
| 3712 | kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
| 3713 | kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
| 3714 | } else { |
| 3715 | ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1; |
| 3716 | dh_setup_group1(); |
| 3717 | kex_init_value = SSH2_MSG_KEXDH_INIT; |
| 3718 | kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
| 3719 | } |
| 3720 | |
| 3721 | logevent("Doing Diffie-Hellman key exchange"); |
| 3722 | /* |
| 3723 | * Now generate and send e for Diffie-Hellman. |
| 3724 | */ |
| 3725 | e = dh_create_e(nbits * 2); |
| 3726 | ssh2_pkt_init(kex_init_value); |
| 3727 | ssh2_pkt_addmp(e); |
| 3728 | ssh2_pkt_send(); |
| 3729 | |
| 3730 | crWaitUntil(ispkt); |
| 3731 | if (pktin.type != kex_reply_value) { |
| 3732 | bombout(("expected key exchange reply packet from server")); |
| 3733 | crReturn(0); |
| 3734 | } |
| 3735 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
| 3736 | f = ssh2_pkt_getmp(); |
| 3737 | ssh2_pkt_getstring(&sigdata, &siglen); |
| 3738 | |
| 3739 | K = dh_find_K(f); |
| 3740 | |
| 3741 | sha_string(&exhash, hostkeydata, hostkeylen); |
| 3742 | if (kex == &ssh_diffiehellman_gex) { |
| 3743 | sha_uint32(&exhash, pbits); |
| 3744 | sha_mpint(&exhash, p); |
| 3745 | sha_mpint(&exhash, g); |
| 3746 | } |
| 3747 | sha_mpint(&exhash, e); |
| 3748 | sha_mpint(&exhash, f); |
| 3749 | sha_mpint(&exhash, K); |
| 3750 | SHA_Final(&exhash, exchange_hash); |
| 3751 | |
| 3752 | dh_cleanup(); |
| 3753 | |
| 3754 | #if 0 |
| 3755 | debug(("Exchange hash is:\n")); |
| 3756 | dmemdump(exchange_hash, 20); |
| 3757 | #endif |
| 3758 | |
| 3759 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
| 3760 | if (!hkey || |
| 3761 | !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
| 3762 | bombout(("Server's host key did not match the signature supplied")); |
| 3763 | crReturn(0); |
| 3764 | } |
| 3765 | |
| 3766 | /* |
| 3767 | * Authenticate remote host: verify host key. (We've already |
| 3768 | * checked the signature of the exchange hash.) |
| 3769 | */ |
| 3770 | keystr = hostkey->fmtkey(hkey); |
| 3771 | fingerprint = hostkey->fingerprint(hkey); |
| 3772 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
| 3773 | keystr, fingerprint); |
| 3774 | if (first_kex) { /* don't bother logging this in rekeys */ |
| 3775 | logevent("Host key fingerprint is:"); |
| 3776 | logevent(fingerprint); |
| 3777 | } |
| 3778 | sfree(fingerprint); |
| 3779 | sfree(keystr); |
| 3780 | hostkey->freekey(hkey); |
| 3781 | |
| 3782 | /* |
| 3783 | * Send SSH2_MSG_NEWKEYS. |
| 3784 | */ |
| 3785 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
| 3786 | ssh2_pkt_send(); |
| 3787 | |
| 3788 | /* |
| 3789 | * Expect SSH2_MSG_NEWKEYS from server. |
| 3790 | */ |
| 3791 | crWaitUntil(ispkt); |
| 3792 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
| 3793 | bombout(("expected new-keys packet from server")); |
| 3794 | crReturn(0); |
| 3795 | } |
| 3796 | |
| 3797 | /* |
| 3798 | * Create and initialise session keys. |
| 3799 | */ |
| 3800 | cscipher = cscipher_tobe; |
| 3801 | sccipher = sccipher_tobe; |
| 3802 | csmac = csmac_tobe; |
| 3803 | scmac = scmac_tobe; |
| 3804 | cscomp = cscomp_tobe; |
| 3805 | sccomp = sccomp_tobe; |
| 3806 | cscomp->compress_init(); |
| 3807 | sccomp->decompress_init(); |
| 3808 | /* |
| 3809 | * Set IVs after keys. Here we use the exchange hash from the |
| 3810 | * _first_ key exchange. |
| 3811 | */ |
| 3812 | if (first_kex) |
| 3813 | memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); |
| 3814 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); |
| 3815 | cscipher->setcskey(keyspace); |
| 3816 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); |
| 3817 | sccipher->setsckey(keyspace); |
| 3818 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); |
| 3819 | cscipher->setcsiv(keyspace); |
| 3820 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); |
| 3821 | sccipher->setsciv(keyspace); |
| 3822 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); |
| 3823 | csmac->setcskey(keyspace); |
| 3824 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); |
| 3825 | scmac->setsckey(keyspace); |
| 3826 | |
| 3827 | /* |
| 3828 | * If this is the first key exchange phase, we must pass the |
| 3829 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
| 3830 | * wants to see it but because it will need time to initialise |
| 3831 | * itself before it sees an actual packet. In subsequent key |
| 3832 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
| 3833 | * it would only confuse the layer above. |
| 3834 | */ |
| 3835 | if (!first_kex) { |
| 3836 | crReturn(0); |
| 3837 | } |
| 3838 | first_kex = 0; |
| 3839 | |
| 3840 | /* |
| 3841 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 3842 | * function so that other things can run on top of the |
| 3843 | * transport. If we ever see a KEXINIT, we must go back to the |
| 3844 | * start. |
| 3845 | */ |
| 3846 | while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { |
| 3847 | crReturn(1); |
| 3848 | } |
| 3849 | logevent("Server initiated key re-exchange"); |
| 3850 | goto begin_key_exchange; |
| 3851 | |
| 3852 | crFinish(1); |
| 3853 | } |
| 3854 | |
| 3855 | /* |
| 3856 | * Add data to an SSH2 channel output buffer. |
| 3857 | */ |
| 3858 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
| 3859 | int len) |
| 3860 | { |
| 3861 | bufchain_add(&c->v.v2.outbuffer, buf, len); |
| 3862 | } |
| 3863 | |
| 3864 | /* |
| 3865 | * Attempt to send data on an SSH2 channel. |
| 3866 | */ |
| 3867 | static int ssh2_try_send(struct ssh_channel *c) |
| 3868 | { |
| 3869 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { |
| 3870 | int len; |
| 3871 | void *data; |
| 3872 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); |
| 3873 | if ((unsigned)len > c->v.v2.remwindow) |
| 3874 | len = c->v.v2.remwindow; |
| 3875 | if ((unsigned)len > c->v.v2.remmaxpkt) |
| 3876 | len = c->v.v2.remmaxpkt; |
| 3877 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
| 3878 | ssh2_pkt_adduint32(c->remoteid); |
| 3879 | ssh2_pkt_addstring_start(); |
| 3880 | ssh2_pkt_addstring_data(data, len); |
| 3881 | ssh2_pkt_send(); |
| 3882 | bufchain_consume(&c->v.v2.outbuffer, len); |
| 3883 | c->v.v2.remwindow -= len; |
| 3884 | } |
| 3885 | |
| 3886 | /* |
| 3887 | * After having sent as much data as we can, return the amount |
| 3888 | * still buffered. |
| 3889 | */ |
| 3890 | return bufchain_size(&c->v.v2.outbuffer); |
| 3891 | } |
| 3892 | |
| 3893 | /* |
| 3894 | * Potentially enlarge the window on an SSH2 channel. |
| 3895 | */ |
| 3896 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) |
| 3897 | { |
| 3898 | /* |
| 3899 | * Never send WINDOW_ADJUST for a channel that the remote side |
| 3900 | * already thinks it's closed; there's no point, since it won't |
| 3901 | * be sending any more data anyway. |
| 3902 | */ |
| 3903 | if (c->closes != 0) |
| 3904 | return; |
| 3905 | |
| 3906 | if (newwin > c->v.v2.locwindow) { |
| 3907 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 3908 | ssh2_pkt_adduint32(c->remoteid); |
| 3909 | ssh2_pkt_adduint32(newwin - c->v.v2.locwindow); |
| 3910 | ssh2_pkt_send(); |
| 3911 | c->v.v2.locwindow = newwin; |
| 3912 | } |
| 3913 | } |
| 3914 | |
| 3915 | /* |
| 3916 | * Handle the SSH2 userauth and connection layers. |
| 3917 | */ |
| 3918 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
| 3919 | { |
| 3920 | static enum { |
| 3921 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, |
| 3922 | AUTH_PASSWORD, |
| 3923 | AUTH_KEYBOARD_INTERACTIVE |
| 3924 | } method; |
| 3925 | static enum { |
| 3926 | AUTH_TYPE_NONE, |
| 3927 | AUTH_TYPE_PUBLICKEY, |
| 3928 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
| 3929 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
| 3930 | AUTH_TYPE_PASSWORD, |
| 3931 | AUTH_TYPE_KEYBOARD_INTERACTIVE, |
| 3932 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET |
| 3933 | } type; |
| 3934 | static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; |
| 3935 | static int tried_pubkey_config, tried_agent, tried_keyb_inter; |
| 3936 | static int kbd_inter_running; |
| 3937 | static int we_are_in; |
| 3938 | static int num_prompts, echo; |
| 3939 | static char username[100]; |
| 3940 | static int got_username; |
| 3941 | static char pwprompt[200]; |
| 3942 | static char password[100]; |
| 3943 | static void *publickey_blob; |
| 3944 | static int publickey_bloblen; |
| 3945 | |
| 3946 | crBegin; |
| 3947 | |
| 3948 | /* |
| 3949 | * Request userauth protocol, and await a response to it. |
| 3950 | */ |
| 3951 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 3952 | ssh2_pkt_addstring("ssh-userauth"); |
| 3953 | ssh2_pkt_send(); |
| 3954 | crWaitUntilV(ispkt); |
| 3955 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
| 3956 | bombout(("Server refused user authentication protocol")); |
| 3957 | crReturnV; |
| 3958 | } |
| 3959 | |
| 3960 | /* |
| 3961 | * We repeat this whole loop, including the username prompt, |
| 3962 | * until we manage a successful authentication. If the user |
| 3963 | * types the wrong _password_, they are sent back to the |
| 3964 | * beginning to try another username. (If they specify a |
| 3965 | * username in the config, they are never asked, even if they |
| 3966 | * do give a wrong password.) |
| 3967 | * |
| 3968 | * I think this best serves the needs of |
| 3969 | * |
| 3970 | * - the people who have no configuration, no keys, and just |
| 3971 | * want to try repeated (username,password) pairs until they |
| 3972 | * type both correctly |
| 3973 | * |
| 3974 | * - people who have keys and configuration but occasionally |
| 3975 | * need to fall back to passwords |
| 3976 | * |
| 3977 | * - people with a key held in Pageant, who might not have |
| 3978 | * logged in to a particular machine before; so they want to |
| 3979 | * type a username, and then _either_ their key will be |
| 3980 | * accepted, _or_ they will type a password. If they mistype |
| 3981 | * the username they will want to be able to get back and |
| 3982 | * retype it! |
| 3983 | */ |
| 3984 | username[0] = '\0'; |
| 3985 | got_username = FALSE; |
| 3986 | do { |
| 3987 | static int pos; |
| 3988 | static char c; |
| 3989 | |
| 3990 | /* |
| 3991 | * Get a username. |
| 3992 | */ |
| 3993 | pos = 0; |
| 3994 | if (got_username && !cfg.change_username) { |
| 3995 | /* |
| 3996 | * We got a username last time round this loop, and |
| 3997 | * with change_username turned off we don't try to get |
| 3998 | * it again. |
| 3999 | */ |
| 4000 | } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 4001 | if (ssh_get_line) { |
| 4002 | if (!ssh_get_line("login as: ", |
| 4003 | username, sizeof(username), FALSE)) { |
| 4004 | /* |
| 4005 | * get_line failed to get a username. |
| 4006 | * Terminate. |
| 4007 | */ |
| 4008 | logevent("No username provided. Abandoning session."); |
| 4009 | ssh_state = SSH_STATE_CLOSED; |
| 4010 | crReturnV; |
| 4011 | } |
| 4012 | } else { |
| 4013 | c_write_str("login as: "); |
| 4014 | ssh_send_ok = 1; |
| 4015 | while (pos >= 0) { |
| 4016 | crWaitUntilV(!ispkt); |
| 4017 | while (inlen--) |
| 4018 | switch (c = *in++) { |
| 4019 | case 10: |
| 4020 | case 13: |
| 4021 | username[pos] = 0; |
| 4022 | pos = -1; |
| 4023 | break; |
| 4024 | case 8: |
| 4025 | case 127: |
| 4026 | if (pos > 0) { |
| 4027 | c_write_str("\b \b"); |
| 4028 | pos--; |
| 4029 | } |
| 4030 | break; |
| 4031 | case 21: |
| 4032 | case 27: |
| 4033 | while (pos > 0) { |
| 4034 | c_write_str("\b \b"); |
| 4035 | pos--; |
| 4036 | } |
| 4037 | break; |
| 4038 | case 3: |
| 4039 | case 4: |
| 4040 | cleanup_exit(0); |
| 4041 | break; |
| 4042 | default: |
| 4043 | if (((c >= ' ' && c <= '~') || |
| 4044 | ((unsigned char) c >= 160)) |
| 4045 | && pos < sizeof(username)-1) { |
| 4046 | username[pos++] = c; |
| 4047 | c_write(&c, 1); |
| 4048 | } |
| 4049 | break; |
| 4050 | } |
| 4051 | } |
| 4052 | } |
| 4053 | c_write_str("\r\n"); |
| 4054 | username[strcspn(username, "\n\r")] = '\0'; |
| 4055 | } else { |
| 4056 | char stuff[200]; |
| 4057 | strncpy(username, cfg.username, 99); |
| 4058 | username[99] = '\0'; |
| 4059 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
| 4060 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
| 4061 | c_write_str(stuff); |
| 4062 | } |
| 4063 | } |
| 4064 | got_username = TRUE; |
| 4065 | |
| 4066 | /* |
| 4067 | * Send an authentication request using method "none": (a) |
| 4068 | * just in case it succeeds, and (b) so that we know what |
| 4069 | * authentication methods we can usefully try next. |
| 4070 | */ |
| 4071 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4072 | |
| 4073 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4074 | ssh2_pkt_addstring(username); |
| 4075 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4076 | ssh2_pkt_addstring("none"); /* method */ |
| 4077 | ssh2_pkt_send(); |
| 4078 | type = AUTH_TYPE_NONE; |
| 4079 | gotit = FALSE; |
| 4080 | we_are_in = FALSE; |
| 4081 | |
| 4082 | tried_pubkey_config = FALSE; |
| 4083 | tried_agent = FALSE; |
| 4084 | tried_keyb_inter = FALSE; |
| 4085 | kbd_inter_running = FALSE; |
| 4086 | /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */ |
| 4087 | if (*cfg.keyfile) { |
| 4088 | publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL, |
| 4089 | &publickey_bloblen); |
| 4090 | } else |
| 4091 | publickey_blob = NULL; |
| 4092 | |
| 4093 | while (1) { |
| 4094 | /* |
| 4095 | * Wait for the result of the last authentication request. |
| 4096 | */ |
| 4097 | if (!gotit) |
| 4098 | crWaitUntilV(ispkt); |
| 4099 | while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
| 4100 | char *banner; |
| 4101 | int size; |
| 4102 | /* |
| 4103 | * Don't show the banner if we're operating in |
| 4104 | * non-verbose non-interactive mode. (It's probably |
| 4105 | * a script, which means nobody will read the |
| 4106 | * banner _anyway_, and moreover the printing of |
| 4107 | * the banner will screw up processing on the |
| 4108 | * output of (say) plink.) |
| 4109 | */ |
| 4110 | if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { |
| 4111 | ssh2_pkt_getstring(&banner, &size); |
| 4112 | if (banner) |
| 4113 | c_write_untrusted(banner, size); |
| 4114 | } |
| 4115 | crWaitUntilV(ispkt); |
| 4116 | } |
| 4117 | if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
| 4118 | logevent("Access granted"); |
| 4119 | we_are_in = TRUE; |
| 4120 | break; |
| 4121 | } |
| 4122 | |
| 4123 | if (kbd_inter_running && |
| 4124 | pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 4125 | /* |
| 4126 | * This is a further prompt in keyboard-interactive |
| 4127 | * authentication. Do nothing. |
| 4128 | */ |
| 4129 | } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
| 4130 | bombout(("Strange packet received during authentication: type %d", |
| 4131 | pktin.type)); |
| 4132 | crReturnV; |
| 4133 | } |
| 4134 | |
| 4135 | gotit = FALSE; |
| 4136 | |
| 4137 | /* |
| 4138 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
| 4139 | * we can look at the string in it and know what we can |
| 4140 | * helpfully try next. |
| 4141 | */ |
| 4142 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) { |
| 4143 | char *methods; |
| 4144 | int methlen; |
| 4145 | ssh2_pkt_getstring(&methods, &methlen); |
| 4146 | kbd_inter_running = FALSE; |
| 4147 | if (!ssh2_pkt_getbool()) { |
| 4148 | /* |
| 4149 | * We have received an unequivocal Access |
| 4150 | * Denied. This can translate to a variety of |
| 4151 | * messages: |
| 4152 | * |
| 4153 | * - if we'd just tried "none" authentication, |
| 4154 | * it's not worth printing anything at all |
| 4155 | * |
| 4156 | * - if we'd just tried a public key _offer_, |
| 4157 | * the message should be "Server refused our |
| 4158 | * key" (or no message at all if the key |
| 4159 | * came from Pageant) |
| 4160 | * |
| 4161 | * - if we'd just tried anything else, the |
| 4162 | * message really should be "Access denied". |
| 4163 | * |
| 4164 | * Additionally, if we'd just tried password |
| 4165 | * authentication, we should break out of this |
| 4166 | * whole loop so as to go back to the username |
| 4167 | * prompt. |
| 4168 | */ |
| 4169 | if (type == AUTH_TYPE_NONE) { |
| 4170 | /* do nothing */ |
| 4171 | } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
| 4172 | type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
| 4173 | if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
| 4174 | c_write_str("Server refused our key\r\n"); |
| 4175 | logevent("Server refused public key"); |
| 4176 | } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { |
| 4177 | /* server declined keyboard-interactive; ignore */ |
| 4178 | } else { |
| 4179 | c_write_str("Access denied\r\n"); |
| 4180 | logevent("Access denied"); |
| 4181 | if (type == AUTH_TYPE_PASSWORD) { |
| 4182 | we_are_in = FALSE; |
| 4183 | break; |
| 4184 | } |
| 4185 | } |
| 4186 | } else { |
| 4187 | c_write_str("Further authentication required\r\n"); |
| 4188 | logevent("Further authentication required"); |
| 4189 | } |
| 4190 | |
| 4191 | can_pubkey = |
| 4192 | in_commasep_string("publickey", methods, methlen); |
| 4193 | can_passwd = |
| 4194 | in_commasep_string("password", methods, methlen); |
| 4195 | can_keyb_inter = cfg.try_ki_auth && |
| 4196 | in_commasep_string("keyboard-interactive", methods, methlen); |
| 4197 | } |
| 4198 | |
| 4199 | method = 0; |
| 4200 | ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4201 | |
| 4202 | if (!method && can_pubkey && agent_exists() && !tried_agent) { |
| 4203 | /* |
| 4204 | * Attempt public-key authentication using Pageant. |
| 4205 | */ |
| 4206 | static unsigned char request[5], *response, *p; |
| 4207 | static int responselen; |
| 4208 | static int i, nkeys; |
| 4209 | static int authed = FALSE; |
| 4210 | void *r; |
| 4211 | |
| 4212 | ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
| 4213 | |
| 4214 | tried_agent = TRUE; |
| 4215 | |
| 4216 | logevent("Pageant is running. Requesting keys."); |
| 4217 | |
| 4218 | /* Request the keys held by the agent. */ |
| 4219 | PUT_32BIT(request, 1); |
| 4220 | request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
| 4221 | agent_query(request, 5, &r, &responselen); |
| 4222 | response = (unsigned char *) r; |
| 4223 | if (response && responselen >= 5 && |
| 4224 | response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
| 4225 | p = response + 5; |
| 4226 | nkeys = GET_32BIT(p); |
| 4227 | p += 4; |
| 4228 | { |
| 4229 | char buf[64]; |
| 4230 | sprintf(buf, "Pageant has %d SSH2 keys", nkeys); |
| 4231 | logevent(buf); |
| 4232 | } |
| 4233 | for (i = 0; i < nkeys; i++) { |
| 4234 | static char *pkblob, *alg, *commentp; |
| 4235 | static int pklen, alglen, commentlen; |
| 4236 | static int siglen, retlen, len; |
| 4237 | static char *q, *agentreq, *ret; |
| 4238 | void *vret; |
| 4239 | |
| 4240 | { |
| 4241 | char buf[64]; |
| 4242 | sprintf(buf, "Trying Pageant key #%d", i); |
| 4243 | logevent(buf); |
| 4244 | } |
| 4245 | pklen = GET_32BIT(p); |
| 4246 | p += 4; |
| 4247 | if (publickey_blob && |
| 4248 | pklen == publickey_bloblen && |
| 4249 | !memcmp(p, publickey_blob, publickey_bloblen)) { |
| 4250 | logevent("This key matches configured key file"); |
| 4251 | tried_pubkey_config = 1; |
| 4252 | } |
| 4253 | pkblob = p; |
| 4254 | p += pklen; |
| 4255 | alglen = GET_32BIT(pkblob); |
| 4256 | alg = pkblob + 4; |
| 4257 | commentlen = GET_32BIT(p); |
| 4258 | p += 4; |
| 4259 | commentp = p; |
| 4260 | p += commentlen; |
| 4261 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4262 | ssh2_pkt_addstring(username); |
| 4263 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4264 | ssh2_pkt_addstring("publickey"); /* method */ |
| 4265 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
| 4266 | ssh2_pkt_addstring_start(); |
| 4267 | ssh2_pkt_addstring_data(alg, alglen); |
| 4268 | ssh2_pkt_addstring_start(); |
| 4269 | ssh2_pkt_addstring_data(pkblob, pklen); |
| 4270 | ssh2_pkt_send(); |
| 4271 | |
| 4272 | crWaitUntilV(ispkt); |
| 4273 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 4274 | logevent("Key refused"); |
| 4275 | continue; |
| 4276 | } |
| 4277 | |
| 4278 | if (flags & FLAG_VERBOSE) { |
| 4279 | c_write_str |
| 4280 | ("Authenticating with public key \""); |
| 4281 | c_write(commentp, commentlen); |
| 4282 | c_write_str("\" from agent\r\n"); |
| 4283 | } |
| 4284 | |
| 4285 | /* |
| 4286 | * Server is willing to accept the key. |
| 4287 | * Construct a SIGN_REQUEST. |
| 4288 | */ |
| 4289 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4290 | ssh2_pkt_addstring(username); |
| 4291 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4292 | ssh2_pkt_addstring("publickey"); /* method */ |
| 4293 | ssh2_pkt_addbool(TRUE); |
| 4294 | ssh2_pkt_addstring_start(); |
| 4295 | ssh2_pkt_addstring_data(alg, alglen); |
| 4296 | ssh2_pkt_addstring_start(); |
| 4297 | ssh2_pkt_addstring_data(pkblob, pklen); |
| 4298 | |
| 4299 | siglen = pktout.length - 5 + 4 + 20; |
| 4300 | len = 1; /* message type */ |
| 4301 | len += 4 + pklen; /* key blob */ |
| 4302 | len += 4 + siglen; /* data to sign */ |
| 4303 | len += 4; /* flags */ |
| 4304 | agentreq = smalloc(4 + len); |
| 4305 | PUT_32BIT(agentreq, len); |
| 4306 | q = agentreq + 4; |
| 4307 | *q++ = SSH2_AGENTC_SIGN_REQUEST; |
| 4308 | PUT_32BIT(q, pklen); |
| 4309 | q += 4; |
| 4310 | memcpy(q, pkblob, pklen); |
| 4311 | q += pklen; |
| 4312 | PUT_32BIT(q, siglen); |
| 4313 | q += 4; |
| 4314 | /* Now the data to be signed... */ |
| 4315 | PUT_32BIT(q, 20); |
| 4316 | q += 4; |
| 4317 | memcpy(q, ssh2_session_id, 20); |
| 4318 | q += 20; |
| 4319 | memcpy(q, pktout.data + 5, pktout.length - 5); |
| 4320 | q += pktout.length - 5; |
| 4321 | /* And finally the (zero) flags word. */ |
| 4322 | PUT_32BIT(q, 0); |
| 4323 | agent_query(agentreq, len + 4, &vret, &retlen); |
| 4324 | ret = vret; |
| 4325 | sfree(agentreq); |
| 4326 | if (ret) { |
| 4327 | if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
| 4328 | logevent("Sending Pageant's response"); |
| 4329 | ssh2_pkt_addstring_start(); |
| 4330 | ssh2_pkt_addstring_data(ret + 9, |
| 4331 | GET_32BIT(ret + |
| 4332 | 5)); |
| 4333 | ssh2_pkt_send(); |
| 4334 | authed = TRUE; |
| 4335 | break; |
| 4336 | } else { |
| 4337 | logevent |
| 4338 | ("Pageant failed to answer challenge"); |
| 4339 | sfree(ret); |
| 4340 | } |
| 4341 | } |
| 4342 | } |
| 4343 | if (authed) |
| 4344 | continue; |
| 4345 | } |
| 4346 | } |
| 4347 | |
| 4348 | if (!method && can_pubkey && *cfg.keyfile |
| 4349 | && !tried_pubkey_config) { |
| 4350 | unsigned char *pub_blob; |
| 4351 | char *algorithm, *comment; |
| 4352 | int pub_blob_len; |
| 4353 | |
| 4354 | tried_pubkey_config = TRUE; |
| 4355 | |
| 4356 | ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
| 4357 | |
| 4358 | /* |
| 4359 | * Try the public key supplied in the configuration. |
| 4360 | * |
| 4361 | * First, offer the public blob to see if the server is |
| 4362 | * willing to accept it. |
| 4363 | */ |
| 4364 | pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, |
| 4365 | &pub_blob_len); |
| 4366 | if (pub_blob) { |
| 4367 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4368 | ssh2_pkt_addstring(username); |
| 4369 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4370 | ssh2_pkt_addstring("publickey"); /* method */ |
| 4371 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
| 4372 | ssh2_pkt_addstring(algorithm); |
| 4373 | ssh2_pkt_addstring_start(); |
| 4374 | ssh2_pkt_addstring_data(pub_blob, pub_blob_len); |
| 4375 | ssh2_pkt_send(); |
| 4376 | logevent("Offered public key"); /* FIXME */ |
| 4377 | |
| 4378 | crWaitUntilV(ispkt); |
| 4379 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 4380 | gotit = TRUE; |
| 4381 | type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
| 4382 | continue; /* key refused; give up on it */ |
| 4383 | } |
| 4384 | |
| 4385 | logevent("Offer of public key accepted"); |
| 4386 | /* |
| 4387 | * Actually attempt a serious authentication using |
| 4388 | * the key. |
| 4389 | */ |
| 4390 | if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { |
| 4391 | sprintf(pwprompt, |
| 4392 | "Passphrase for key \"%.100s\": ", |
| 4393 | comment); |
| 4394 | need_pw = TRUE; |
| 4395 | } else { |
| 4396 | need_pw = FALSE; |
| 4397 | } |
| 4398 | c_write_str("Authenticating with public key \""); |
| 4399 | c_write_str(comment); |
| 4400 | c_write_str("\"\r\n"); |
| 4401 | method = AUTH_PUBLICKEY_FILE; |
| 4402 | } |
| 4403 | } |
| 4404 | |
| 4405 | if (!method && can_keyb_inter && !tried_keyb_inter) { |
| 4406 | method = AUTH_KEYBOARD_INTERACTIVE; |
| 4407 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4408 | tried_keyb_inter = TRUE; |
| 4409 | |
| 4410 | ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
| 4411 | |
| 4412 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4413 | ssh2_pkt_addstring(username); |
| 4414 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4415 | ssh2_pkt_addstring("keyboard-interactive"); /* method */ |
| 4416 | ssh2_pkt_addstring(""); /* lang */ |
| 4417 | ssh2_pkt_addstring(""); |
| 4418 | ssh2_pkt_send(); |
| 4419 | |
| 4420 | crWaitUntilV(ispkt); |
| 4421 | if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 4422 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) |
| 4423 | gotit = TRUE; |
| 4424 | logevent("Keyboard-interactive authentication refused"); |
| 4425 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; |
| 4426 | continue; |
| 4427 | } |
| 4428 | |
| 4429 | kbd_inter_running = TRUE; |
| 4430 | } |
| 4431 | |
| 4432 | if (kbd_inter_running) { |
| 4433 | method = AUTH_KEYBOARD_INTERACTIVE; |
| 4434 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4435 | tried_keyb_inter = TRUE; |
| 4436 | |
| 4437 | ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
| 4438 | |
| 4439 | /* We've got packet with that "interactive" info |
| 4440 | dump banners, and set its prompt as ours */ |
| 4441 | { |
| 4442 | char *name, *inst, *lang, *prompt; |
| 4443 | int name_len, inst_len, lang_len, prompt_len; |
| 4444 | ssh2_pkt_getstring(&name, &name_len); |
| 4445 | ssh2_pkt_getstring(&inst, &inst_len); |
| 4446 | ssh2_pkt_getstring(&lang, &lang_len); |
| 4447 | if (name_len > 0) |
| 4448 | c_write_untrusted(name, name_len); |
| 4449 | if (inst_len > 0) |
| 4450 | c_write_untrusted(inst, inst_len); |
| 4451 | num_prompts = ssh2_pkt_getuint32(); |
| 4452 | |
| 4453 | ssh2_pkt_getstring(&prompt, &prompt_len); |
| 4454 | strncpy(pwprompt, prompt, sizeof(pwprompt)); |
| 4455 | pwprompt[prompt_len < sizeof(pwprompt) ? |
| 4456 | prompt_len : sizeof(pwprompt)-1] = '\0'; |
| 4457 | need_pw = TRUE; |
| 4458 | |
| 4459 | echo = ssh2_pkt_getbool(); |
| 4460 | } |
| 4461 | } |
| 4462 | |
| 4463 | if (!method && can_passwd) { |
| 4464 | method = AUTH_PASSWORD; |
| 4465 | ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD; |
| 4466 | sprintf(pwprompt, "%.90s@%.90s's password: ", username, |
| 4467 | savedhost); |
| 4468 | need_pw = TRUE; |
| 4469 | } |
| 4470 | |
| 4471 | if (need_pw) { |
| 4472 | if (ssh_get_line) { |
| 4473 | if (!ssh_get_line(pwprompt, password, |
| 4474 | sizeof(password), TRUE)) { |
| 4475 | /* |
| 4476 | * get_line failed to get a password (for |
| 4477 | * example because one was supplied on the |
| 4478 | * command line which has already failed to |
| 4479 | * work). Terminate. |
| 4480 | */ |
| 4481 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 4482 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 4483 | ssh2_pkt_addstring |
| 4484 | ("No more passwords available to try"); |
| 4485 | ssh2_pkt_addstring("en"); /* language tag */ |
| 4486 | ssh2_pkt_send(); |
| 4487 | logevent("Unable to authenticate"); |
| 4488 | connection_fatal("Unable to authenticate"); |
| 4489 | ssh_state = SSH_STATE_CLOSED; |
| 4490 | crReturnV; |
| 4491 | } |
| 4492 | } else { |
| 4493 | static int pos = 0; |
| 4494 | static char c; |
| 4495 | |
| 4496 | c_write_untrusted(pwprompt, strlen(pwprompt)); |
| 4497 | ssh_send_ok = 1; |
| 4498 | |
| 4499 | pos = 0; |
| 4500 | while (pos >= 0) { |
| 4501 | crWaitUntilV(!ispkt); |
| 4502 | while (inlen--) |
| 4503 | switch (c = *in++) { |
| 4504 | case 10: |
| 4505 | case 13: |
| 4506 | password[pos] = 0; |
| 4507 | pos = -1; |
| 4508 | break; |
| 4509 | case 8: |
| 4510 | case 127: |
| 4511 | if (pos > 0) |
| 4512 | pos--; |
| 4513 | break; |
| 4514 | case 21: |
| 4515 | case 27: |
| 4516 | pos = 0; |
| 4517 | break; |
| 4518 | case 3: |
| 4519 | case 4: |
| 4520 | cleanup_exit(0); |
| 4521 | break; |
| 4522 | default: |
| 4523 | if (pos < sizeof(password)-1) |
| 4524 | password[pos++] = c; |
| 4525 | break; |
| 4526 | } |
| 4527 | } |
| 4528 | c_write_str("\r\n"); |
| 4529 | } |
| 4530 | } |
| 4531 | |
| 4532 | if (method == AUTH_PUBLICKEY_FILE) { |
| 4533 | /* |
| 4534 | * We have our passphrase. Now try the actual authentication. |
| 4535 | */ |
| 4536 | struct ssh2_userkey *key; |
| 4537 | |
| 4538 | key = ssh2_load_userkey(cfg.keyfile, password); |
| 4539 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
| 4540 | if (key == SSH2_WRONG_PASSPHRASE) { |
| 4541 | c_write_str("Wrong passphrase\r\n"); |
| 4542 | tried_pubkey_config = FALSE; |
| 4543 | } else { |
| 4544 | c_write_str("Unable to load private key\r\n"); |
| 4545 | tried_pubkey_config = TRUE; |
| 4546 | } |
| 4547 | /* Send a spurious AUTH_NONE to return to the top. */ |
| 4548 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4549 | ssh2_pkt_addstring(username); |
| 4550 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4551 | ssh2_pkt_addstring("none"); /* method */ |
| 4552 | ssh2_pkt_send(); |
| 4553 | type = AUTH_TYPE_NONE; |
| 4554 | } else { |
| 4555 | unsigned char *blob, *sigdata; |
| 4556 | int blob_len, sigdata_len; |
| 4557 | |
| 4558 | /* |
| 4559 | * We have loaded the private key and the server |
| 4560 | * has announced that it's willing to accept it. |
| 4561 | * Hallelujah. Generate a signature and send it. |
| 4562 | */ |
| 4563 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4564 | ssh2_pkt_addstring(username); |
| 4565 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4566 | ssh2_pkt_addstring("publickey"); /* method */ |
| 4567 | ssh2_pkt_addbool(TRUE); |
| 4568 | ssh2_pkt_addstring(key->alg->name); |
| 4569 | blob = key->alg->public_blob(key->data, &blob_len); |
| 4570 | ssh2_pkt_addstring_start(); |
| 4571 | ssh2_pkt_addstring_data(blob, blob_len); |
| 4572 | sfree(blob); |
| 4573 | |
| 4574 | /* |
| 4575 | * The data to be signed is: |
| 4576 | * |
| 4577 | * string session-id |
| 4578 | * |
| 4579 | * followed by everything so far placed in the |
| 4580 | * outgoing packet. |
| 4581 | */ |
| 4582 | sigdata_len = pktout.length - 5 + 4 + 20; |
| 4583 | sigdata = smalloc(sigdata_len); |
| 4584 | PUT_32BIT(sigdata, 20); |
| 4585 | memcpy(sigdata + 4, ssh2_session_id, 20); |
| 4586 | memcpy(sigdata + 24, pktout.data + 5, |
| 4587 | pktout.length - 5); |
| 4588 | blob = |
| 4589 | key->alg->sign(key->data, sigdata, sigdata_len, |
| 4590 | &blob_len); |
| 4591 | ssh2_pkt_addstring_start(); |
| 4592 | ssh2_pkt_addstring_data(blob, blob_len); |
| 4593 | sfree(blob); |
| 4594 | sfree(sigdata); |
| 4595 | |
| 4596 | ssh2_pkt_send(); |
| 4597 | type = AUTH_TYPE_PUBLICKEY; |
| 4598 | } |
| 4599 | } else if (method == AUTH_PASSWORD) { |
| 4600 | /* |
| 4601 | * We send the password packet lumped tightly together with |
| 4602 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
| 4603 | * string long enough to make the total length of the two |
| 4604 | * packets constant. This should ensure that a passive |
| 4605 | * listener doing traffic analyis can't work out the length |
| 4606 | * of the password. |
| 4607 | * |
| 4608 | * For this to work, we need an assumption about the |
| 4609 | * maximum length of the password packet. I think 256 is |
| 4610 | * pretty conservative. Anyone using a password longer than |
| 4611 | * that probably doesn't have much to worry about from |
| 4612 | * people who find out how long their password is! |
| 4613 | */ |
| 4614 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4615 | ssh2_pkt_addstring(username); |
| 4616 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4617 | ssh2_pkt_addstring("password"); |
| 4618 | ssh2_pkt_addbool(FALSE); |
| 4619 | ssh2_pkt_addstring(password); |
| 4620 | ssh2_pkt_defer(); |
| 4621 | /* |
| 4622 | * We'll include a string that's an exact multiple of the |
| 4623 | * cipher block size. If the cipher is NULL for some |
| 4624 | * reason, we don't do this trick at all because we gain |
| 4625 | * nothing by it. |
| 4626 | */ |
| 4627 | if (cscipher) { |
| 4628 | int stringlen, i; |
| 4629 | |
| 4630 | stringlen = (256 - deferred_len); |
| 4631 | stringlen += cscipher->blksize - 1; |
| 4632 | stringlen -= (stringlen % cscipher->blksize); |
| 4633 | if (cscomp) { |
| 4634 | /* |
| 4635 | * Temporarily disable actual compression, |
| 4636 | * so we can guarantee to get this string |
| 4637 | * exactly the length we want it. The |
| 4638 | * compression-disabling routine should |
| 4639 | * return an integer indicating how many |
| 4640 | * bytes we should adjust our string length |
| 4641 | * by. |
| 4642 | */ |
| 4643 | stringlen -= cscomp->disable_compression(); |
| 4644 | } |
| 4645 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 4646 | ssh2_pkt_addstring_start(); |
| 4647 | for (i = 0; i < stringlen; i++) { |
| 4648 | char c = (char) random_byte(); |
| 4649 | ssh2_pkt_addstring_data(&c, 1); |
| 4650 | } |
| 4651 | ssh2_pkt_defer(); |
| 4652 | } |
| 4653 | ssh_pkt_defersend(); |
| 4654 | logevent("Sent password"); |
| 4655 | type = AUTH_TYPE_PASSWORD; |
| 4656 | } else if (method == AUTH_KEYBOARD_INTERACTIVE) { |
| 4657 | ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
| 4658 | ssh2_pkt_adduint32(num_prompts); |
| 4659 | ssh2_pkt_addstring(password); |
| 4660 | memset(password, 0, sizeof(password)); |
| 4661 | ssh2_pkt_send(); |
| 4662 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4663 | } else { |
| 4664 | c_write_str |
| 4665 | ("No supported authentication methods left to try!\r\n"); |
| 4666 | logevent |
| 4667 | ("No supported authentications offered. Disconnecting"); |
| 4668 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 4669 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 4670 | ssh2_pkt_addstring |
| 4671 | ("No supported authentication methods available"); |
| 4672 | ssh2_pkt_addstring("en"); /* language tag */ |
| 4673 | ssh2_pkt_send(); |
| 4674 | ssh_state = SSH_STATE_CLOSED; |
| 4675 | crReturnV; |
| 4676 | } |
| 4677 | } |
| 4678 | } while (!we_are_in); |
| 4679 | |
| 4680 | /* |
| 4681 | * Now we're authenticated for the connection protocol. The |
| 4682 | * connection protocol will automatically have started at this |
| 4683 | * point; there's no need to send SERVICE_REQUEST. |
| 4684 | */ |
| 4685 | |
| 4686 | /* |
| 4687 | * So now create a channel with a session in it. |
| 4688 | */ |
| 4689 | ssh_channels = newtree234(ssh_channelcmp); |
| 4690 | mainchan = smalloc(sizeof(struct ssh_channel)); |
| 4691 | mainchan->localid = alloc_channel_id(); |
| 4692 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 4693 | ssh2_pkt_addstring("session"); |
| 4694 | ssh2_pkt_adduint32(mainchan->localid); |
| 4695 | mainchan->v.v2.locwindow = OUR_V2_WINSIZE; |
| 4696 | ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */ |
| 4697 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 4698 | ssh2_pkt_send(); |
| 4699 | crWaitUntilV(ispkt); |
| 4700 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 4701 | bombout(("Server refused to open a session")); |
| 4702 | crReturnV; |
| 4703 | /* FIXME: error data comes back in FAILURE packet */ |
| 4704 | } |
| 4705 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
| 4706 | bombout(("Server's channel confirmation cited wrong channel")); |
| 4707 | crReturnV; |
| 4708 | } |
| 4709 | mainchan->remoteid = ssh2_pkt_getuint32(); |
| 4710 | mainchan->type = CHAN_MAINSESSION; |
| 4711 | mainchan->closes = 0; |
| 4712 | mainchan->v.v2.remwindow = ssh2_pkt_getuint32(); |
| 4713 | mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 4714 | bufchain_init(&mainchan->v.v2.outbuffer); |
| 4715 | add234(ssh_channels, mainchan); |
| 4716 | logevent("Opened channel for session"); |
| 4717 | |
| 4718 | /* |
| 4719 | * Potentially enable X11 forwarding. |
| 4720 | */ |
| 4721 | if (cfg.x11_forward) { |
| 4722 | char proto[20], data[64]; |
| 4723 | logevent("Requesting X11 forwarding"); |
| 4724 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
| 4725 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4726 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 4727 | ssh2_pkt_addstring("x11-req"); |
| 4728 | ssh2_pkt_addbool(1); /* want reply */ |
| 4729 | ssh2_pkt_addbool(0); /* many connections */ |
| 4730 | ssh2_pkt_addstring(proto); |
| 4731 | ssh2_pkt_addstring(data); |
| 4732 | ssh2_pkt_adduint32(0); /* screen number */ |
| 4733 | ssh2_pkt_send(); |
| 4734 | |
| 4735 | do { |
| 4736 | crWaitUntilV(ispkt); |
| 4737 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4738 | unsigned i = ssh2_pkt_getuint32(); |
| 4739 | struct ssh_channel *c; |
| 4740 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4741 | if (!c) |
| 4742 | continue; /* nonexistent channel */ |
| 4743 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4744 | } |
| 4745 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4746 | |
| 4747 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4748 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4749 | bombout(("Unexpected response to X11 forwarding request:" |
| 4750 | " packet type %d", pktin.type)); |
| 4751 | crReturnV; |
| 4752 | } |
| 4753 | logevent("X11 forwarding refused"); |
| 4754 | } else { |
| 4755 | logevent("X11 forwarding enabled"); |
| 4756 | ssh_X11_fwd_enabled = TRUE; |
| 4757 | } |
| 4758 | } |
| 4759 | |
| 4760 | /* |
| 4761 | * Enable port forwardings. |
| 4762 | */ |
| 4763 | { |
| 4764 | static char *e; /* preserve across crReturn */ |
| 4765 | char type; |
| 4766 | int n; |
| 4767 | int sport,dport,sserv,dserv; |
| 4768 | char sports[256], dports[256], host[256]; |
| 4769 | char buf[1024]; |
| 4770 | struct servent *se; |
| 4771 | |
| 4772 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh2); |
| 4773 | /* Add port forwardings. */ |
| 4774 | e = cfg.portfwd; |
| 4775 | while (*e) { |
| 4776 | type = *e++; |
| 4777 | n = 0; |
| 4778 | while (*e && *e != '\t') |
| 4779 | sports[n++] = *e++; |
| 4780 | sports[n] = 0; |
| 4781 | if (*e == '\t') |
| 4782 | e++; |
| 4783 | n = 0; |
| 4784 | while (*e && *e != ':') |
| 4785 | host[n++] = *e++; |
| 4786 | host[n] = 0; |
| 4787 | if (*e == ':') |
| 4788 | e++; |
| 4789 | n = 0; |
| 4790 | while (*e) |
| 4791 | dports[n++] = *e++; |
| 4792 | dports[n] = 0; |
| 4793 | e++; |
| 4794 | dport = atoi(dports); |
| 4795 | dserv = 0; |
| 4796 | if (dport == 0) { |
| 4797 | dserv = 1; |
| 4798 | se = getservbyname(dports, NULL); |
| 4799 | if (se != NULL) { |
| 4800 | dport = ntohs(se->s_port); |
| 4801 | } else { |
| 4802 | sprintf(buf, |
| 4803 | "Service lookup failed for destination port \"%s\"", |
| 4804 | dports); |
| 4805 | logevent(buf); |
| 4806 | } |
| 4807 | } |
| 4808 | sport = atoi(sports); |
| 4809 | sserv = 0; |
| 4810 | if (sport == 0) { |
| 4811 | sserv = 1; |
| 4812 | se = getservbyname(sports, NULL); |
| 4813 | if (se != NULL) { |
| 4814 | sport = ntohs(se->s_port); |
| 4815 | } else { |
| 4816 | sprintf(buf, |
| 4817 | "Service lookup failed for source port \"%s\"", |
| 4818 | sports); |
| 4819 | logevent(buf); |
| 4820 | } |
| 4821 | } |
| 4822 | if (sport && dport) { |
| 4823 | if (type == 'L') { |
| 4824 | pfd_addforward(host, dport, sport); |
| 4825 | sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to" |
| 4826 | " %s:%.*s%.*s%d%.*s", |
| 4827 | sserv ? strlen(sports) : 0, sports, |
| 4828 | sserv, "(", sport, sserv, ")", |
| 4829 | host, |
| 4830 | dserv ? strlen(dports) : 0, dports, |
| 4831 | dserv, "(", dport, dserv, ")"); |
| 4832 | logevent(buf); |
| 4833 | } else { |
| 4834 | struct ssh_rportfwd *pf; |
| 4835 | pf = smalloc(sizeof(*pf)); |
| 4836 | strcpy(pf->dhost, host); |
| 4837 | pf->dport = dport; |
| 4838 | pf->sport = sport; |
| 4839 | if (add234(ssh_rportfwds, pf) != pf) { |
| 4840 | sprintf(buf, |
| 4841 | "Duplicate remote port forwarding to %s:%d", |
| 4842 | host, dport); |
| 4843 | logevent(buf); |
| 4844 | sfree(pf); |
| 4845 | } else { |
| 4846 | sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s" |
| 4847 | " forward to %s:%.*s%.*s%d%.*s", |
| 4848 | sserv ? strlen(sports) : 0, sports, |
| 4849 | sserv, "(", sport, sserv, ")", |
| 4850 | host, |
| 4851 | dserv ? strlen(dports) : 0, dports, |
| 4852 | dserv, "(", dport, dserv, ")"); |
| 4853 | logevent(buf); |
| 4854 | ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); |
| 4855 | ssh2_pkt_addstring("tcpip-forward"); |
| 4856 | ssh2_pkt_addbool(1);/* want reply */ |
| 4857 | if (cfg.rport_acceptall) |
| 4858 | ssh2_pkt_addstring("0.0.0.0"); |
| 4859 | else |
| 4860 | ssh2_pkt_addstring("127.0.0.1"); |
| 4861 | ssh2_pkt_adduint32(sport); |
| 4862 | ssh2_pkt_send(); |
| 4863 | |
| 4864 | do { |
| 4865 | crWaitUntilV(ispkt); |
| 4866 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4867 | unsigned i = ssh2_pkt_getuint32(); |
| 4868 | struct ssh_channel *c; |
| 4869 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4870 | if (!c) |
| 4871 | continue;/* nonexistent channel */ |
| 4872 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4873 | } |
| 4874 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4875 | |
| 4876 | if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) { |
| 4877 | if (pktin.type != SSH2_MSG_REQUEST_FAILURE) { |
| 4878 | bombout(("Unexpected response to port " |
| 4879 | "forwarding request: packet type %d", |
| 4880 | pktin.type)); |
| 4881 | crReturnV; |
| 4882 | } |
| 4883 | logevent("Server refused this port forwarding"); |
| 4884 | } else { |
| 4885 | logevent("Remote port forwarding enabled"); |
| 4886 | } |
| 4887 | } |
| 4888 | } |
| 4889 | } |
| 4890 | } |
| 4891 | } |
| 4892 | |
| 4893 | /* |
| 4894 | * Potentially enable agent forwarding. |
| 4895 | */ |
| 4896 | if (cfg.agentfwd && agent_exists()) { |
| 4897 | logevent("Requesting OpenSSH-style agent forwarding"); |
| 4898 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4899 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 4900 | ssh2_pkt_addstring("auth-agent-req@openssh.com"); |
| 4901 | ssh2_pkt_addbool(1); /* want reply */ |
| 4902 | ssh2_pkt_send(); |
| 4903 | |
| 4904 | do { |
| 4905 | crWaitUntilV(ispkt); |
| 4906 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4907 | unsigned i = ssh2_pkt_getuint32(); |
| 4908 | struct ssh_channel *c; |
| 4909 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4910 | if (!c) |
| 4911 | continue; /* nonexistent channel */ |
| 4912 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4913 | } |
| 4914 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4915 | |
| 4916 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4917 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4918 | bombout(("Unexpected response to agent forwarding request:" |
| 4919 | " packet type %d", pktin.type)); |
| 4920 | crReturnV; |
| 4921 | } |
| 4922 | logevent("Agent forwarding refused"); |
| 4923 | } else { |
| 4924 | logevent("Agent forwarding enabled"); |
| 4925 | ssh_agentfwd_enabled = TRUE; |
| 4926 | } |
| 4927 | } |
| 4928 | |
| 4929 | /* |
| 4930 | * Now allocate a pty for the session. |
| 4931 | */ |
| 4932 | if (!cfg.nopty) { |
| 4933 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4934 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 4935 | ssh2_pkt_addstring("pty-req"); |
| 4936 | ssh2_pkt_addbool(1); /* want reply */ |
| 4937 | ssh2_pkt_addstring(cfg.termtype); |
| 4938 | ssh2_pkt_adduint32(cols); |
| 4939 | ssh2_pkt_adduint32(rows); |
| 4940 | ssh2_pkt_adduint32(0); /* pixel width */ |
| 4941 | ssh2_pkt_adduint32(0); /* pixel height */ |
| 4942 | ssh2_pkt_addstring_start(); |
| 4943 | ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */ |
| 4944 | ssh2_pkt_send(); |
| 4945 | ssh_state = SSH_STATE_INTERMED; |
| 4946 | |
| 4947 | do { |
| 4948 | crWaitUntilV(ispkt); |
| 4949 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4950 | unsigned i = ssh2_pkt_getuint32(); |
| 4951 | struct ssh_channel *c; |
| 4952 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4953 | if (!c) |
| 4954 | continue; /* nonexistent channel */ |
| 4955 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4956 | } |
| 4957 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4958 | |
| 4959 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4960 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4961 | bombout(("Unexpected response to pty request:" |
| 4962 | " packet type %d", pktin.type)); |
| 4963 | crReturnV; |
| 4964 | } |
| 4965 | c_write_str("Server refused to allocate pty\r\n"); |
| 4966 | ssh_editing = ssh_echoing = 1; |
| 4967 | } else { |
| 4968 | logevent("Allocated pty"); |
| 4969 | } |
| 4970 | } else { |
| 4971 | ssh_editing = ssh_echoing = 1; |
| 4972 | } |
| 4973 | |
| 4974 | /* |
| 4975 | * Start a shell or a remote command. We may have to attempt |
| 4976 | * this twice if the config data has provided a second choice |
| 4977 | * of command. |
| 4978 | */ |
| 4979 | while (1) { |
| 4980 | int subsys; |
| 4981 | char *cmd; |
| 4982 | |
| 4983 | if (ssh_fallback_cmd) { |
| 4984 | subsys = cfg.ssh_subsys2; |
| 4985 | cmd = cfg.remote_cmd_ptr2; |
| 4986 | } else { |
| 4987 | subsys = cfg.ssh_subsys; |
| 4988 | cmd = cfg.remote_cmd_ptr; |
| 4989 | } |
| 4990 | |
| 4991 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4992 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 4993 | if (subsys) { |
| 4994 | ssh2_pkt_addstring("subsystem"); |
| 4995 | ssh2_pkt_addbool(1); /* want reply */ |
| 4996 | ssh2_pkt_addstring(cmd); |
| 4997 | } else if (*cmd) { |
| 4998 | ssh2_pkt_addstring("exec"); |
| 4999 | ssh2_pkt_addbool(1); /* want reply */ |
| 5000 | ssh2_pkt_addstring(cmd); |
| 5001 | } else { |
| 5002 | ssh2_pkt_addstring("shell"); |
| 5003 | ssh2_pkt_addbool(1); /* want reply */ |
| 5004 | } |
| 5005 | ssh2_pkt_send(); |
| 5006 | do { |
| 5007 | crWaitUntilV(ispkt); |
| 5008 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5009 | unsigned i = ssh2_pkt_getuint32(); |
| 5010 | struct ssh_channel *c; |
| 5011 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5012 | if (!c) |
| 5013 | continue; /* nonexistent channel */ |
| 5014 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 5015 | } |
| 5016 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 5017 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 5018 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 5019 | bombout(("Unexpected response to shell/command request:" |
| 5020 | " packet type %d", pktin.type)); |
| 5021 | crReturnV; |
| 5022 | } |
| 5023 | /* |
| 5024 | * We failed to start the command. If this is the |
| 5025 | * fallback command, we really are finished; if it's |
| 5026 | * not, and if the fallback command exists, try falling |
| 5027 | * back to it before complaining. |
| 5028 | */ |
| 5029 | if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) { |
| 5030 | logevent("Primary command failed; attempting fallback"); |
| 5031 | ssh_fallback_cmd = TRUE; |
| 5032 | continue; |
| 5033 | } |
| 5034 | bombout(("Server refused to start a shell/command")); |
| 5035 | crReturnV; |
| 5036 | } else { |
| 5037 | logevent("Started a shell/command"); |
| 5038 | } |
| 5039 | break; |
| 5040 | } |
| 5041 | |
| 5042 | ssh_state = SSH_STATE_SESSION; |
| 5043 | if (size_needed) |
| 5044 | ssh_size(); |
| 5045 | if (eof_needed) |
| 5046 | ssh_special(TS_EOF); |
| 5047 | |
| 5048 | /* |
| 5049 | * Transfer data! |
| 5050 | */ |
| 5051 | ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ |
| 5052 | ssh_send_ok = 1; |
| 5053 | while (1) { |
| 5054 | static int try_send; |
| 5055 | crReturnV; |
| 5056 | try_send = FALSE; |
| 5057 | if (ispkt) { |
| 5058 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
| 5059 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 5060 | char *data; |
| 5061 | int length; |
| 5062 | unsigned i = ssh2_pkt_getuint32(); |
| 5063 | struct ssh_channel *c; |
| 5064 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5065 | if (!c) |
| 5066 | continue; /* nonexistent channel */ |
| 5067 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 5068 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
| 5069 | continue; /* extended but not stderr */ |
| 5070 | ssh2_pkt_getstring(&data, &length); |
| 5071 | if (data) { |
| 5072 | int bufsize; |
| 5073 | c->v.v2.locwindow -= length; |
| 5074 | switch (c->type) { |
| 5075 | case CHAN_MAINSESSION: |
| 5076 | bufsize = |
| 5077 | from_backend(pktin.type == |
| 5078 | SSH2_MSG_CHANNEL_EXTENDED_DATA, |
| 5079 | data, length); |
| 5080 | break; |
| 5081 | case CHAN_X11: |
| 5082 | bufsize = x11_send(c->u.x11.s, data, length); |
| 5083 | break; |
| 5084 | case CHAN_SOCKDATA: |
| 5085 | bufsize = pfd_send(c->u.pfd.s, data, length); |
| 5086 | break; |
| 5087 | case CHAN_AGENT: |
| 5088 | while (length > 0) { |
| 5089 | if (c->u.a.lensofar < 4) { |
| 5090 | int l = min(4 - c->u.a.lensofar, length); |
| 5091 | memcpy(c->u.a.msglen + c->u.a.lensofar, |
| 5092 | data, l); |
| 5093 | data += l; |
| 5094 | length -= l; |
| 5095 | c->u.a.lensofar += l; |
| 5096 | } |
| 5097 | if (c->u.a.lensofar == 4) { |
| 5098 | c->u.a.totallen = |
| 5099 | 4 + GET_32BIT(c->u.a.msglen); |
| 5100 | c->u.a.message = smalloc(c->u.a.totallen); |
| 5101 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 5102 | } |
| 5103 | if (c->u.a.lensofar >= 4 && length > 0) { |
| 5104 | int l = |
| 5105 | min(c->u.a.totallen - c->u.a.lensofar, |
| 5106 | length); |
| 5107 | memcpy(c->u.a.message + c->u.a.lensofar, |
| 5108 | data, l); |
| 5109 | data += l; |
| 5110 | length -= l; |
| 5111 | c->u.a.lensofar += l; |
| 5112 | } |
| 5113 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 5114 | void *reply, *sentreply; |
| 5115 | int replylen; |
| 5116 | agent_query(c->u.a.message, |
| 5117 | c->u.a.totallen, &reply, |
| 5118 | &replylen); |
| 5119 | if (reply) |
| 5120 | sentreply = reply; |
| 5121 | else { |
| 5122 | /* Fake SSH_AGENT_FAILURE. */ |
| 5123 | sentreply = "\0\0\0\1\5"; |
| 5124 | replylen = 5; |
| 5125 | } |
| 5126 | ssh2_add_channel_data(c, sentreply, |
| 5127 | replylen); |
| 5128 | try_send = TRUE; |
| 5129 | if (reply) |
| 5130 | sfree(reply); |
| 5131 | sfree(c->u.a.message); |
| 5132 | c->u.a.lensofar = 0; |
| 5133 | } |
| 5134 | } |
| 5135 | bufsize = 0; |
| 5136 | break; |
| 5137 | } |
| 5138 | /* |
| 5139 | * If we are not buffering too much data, |
| 5140 | * enlarge the window again at the remote side. |
| 5141 | */ |
| 5142 | if (bufsize < OUR_V2_WINSIZE) |
| 5143 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
| 5144 | } |
| 5145 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
| 5146 | ssh_state = SSH_STATE_CLOSED; |
| 5147 | logevent("Received disconnect message"); |
| 5148 | crReturnV; |
| 5149 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
| 5150 | unsigned i = ssh2_pkt_getuint32(); |
| 5151 | struct ssh_channel *c; |
| 5152 | |
| 5153 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5154 | if (!c) |
| 5155 | continue; /* nonexistent channel */ |
| 5156 | |
| 5157 | if (c->type == CHAN_X11) { |
| 5158 | /* |
| 5159 | * Remote EOF on an X11 channel means we should |
| 5160 | * wrap up and close the channel ourselves. |
| 5161 | */ |
| 5162 | x11_close(c->u.x11.s); |
| 5163 | sshfwd_close(c); |
| 5164 | } else if (c->type == CHAN_AGENT) { |
| 5165 | sshfwd_close(c); |
| 5166 | } else if (c->type == CHAN_SOCKDATA) { |
| 5167 | pfd_close(c->u.pfd.s); |
| 5168 | sshfwd_close(c); |
| 5169 | } |
| 5170 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
| 5171 | unsigned i = ssh2_pkt_getuint32(); |
| 5172 | struct ssh_channel *c; |
| 5173 | |
| 5174 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5175 | if (!c) |
| 5176 | continue; /* nonexistent channel */ |
| 5177 | /* Do pre-close processing on the channel. */ |
| 5178 | switch (c->type) { |
| 5179 | case CHAN_MAINSESSION: |
| 5180 | break; /* nothing to see here, move along */ |
| 5181 | case CHAN_X11: |
| 5182 | if (c->u.x11.s != NULL) |
| 5183 | x11_close(c->u.x11.s); |
| 5184 | sshfwd_close(c); |
| 5185 | break; |
| 5186 | case CHAN_AGENT: |
| 5187 | sshfwd_close(c); |
| 5188 | break; |
| 5189 | case CHAN_SOCKDATA: |
| 5190 | if (c->u.pfd.s != NULL) |
| 5191 | pfd_close(c->u.pfd.s); |
| 5192 | sshfwd_close(c); |
| 5193 | break; |
| 5194 | } |
| 5195 | if (c->closes == 0) { |
| 5196 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 5197 | ssh2_pkt_adduint32(c->remoteid); |
| 5198 | ssh2_pkt_send(); |
| 5199 | } |
| 5200 | del234(ssh_channels, c); |
| 5201 | bufchain_clear(&c->v.v2.outbuffer); |
| 5202 | sfree(c); |
| 5203 | |
| 5204 | /* |
| 5205 | * See if that was the last channel left open. |
| 5206 | */ |
| 5207 | if (count234(ssh_channels) == 0) { |
| 5208 | #if 0 |
| 5209 | /* |
| 5210 | * We used to send SSH_MSG_DISCONNECT here, |
| 5211 | * because I'd believed that _every_ conforming |
| 5212 | * SSH2 connection had to end with a disconnect |
| 5213 | * being sent by at least one side; apparently |
| 5214 | * I was wrong and it's perfectly OK to |
| 5215 | * unceremoniously slam the connection shut |
| 5216 | * when you're done, and indeed OpenSSH feels |
| 5217 | * this is more polite than sending a |
| 5218 | * DISCONNECT. So now we don't. |
| 5219 | */ |
| 5220 | logevent("All channels closed. Disconnecting"); |
| 5221 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 5222 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 5223 | ssh2_pkt_addstring("All open channels closed"); |
| 5224 | ssh2_pkt_addstring("en"); /* language tag */ |
| 5225 | ssh2_pkt_send(); |
| 5226 | #endif |
| 5227 | ssh_state = SSH_STATE_CLOSED; |
| 5228 | crReturnV; |
| 5229 | } |
| 5230 | continue; /* remote sends close; ignore (FIXME) */ |
| 5231 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5232 | unsigned i = ssh2_pkt_getuint32(); |
| 5233 | struct ssh_channel *c; |
| 5234 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5235 | if (!c) |
| 5236 | continue; /* nonexistent channel */ |
| 5237 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 5238 | try_send = TRUE; |
| 5239 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 5240 | unsigned i = ssh2_pkt_getuint32(); |
| 5241 | struct ssh_channel *c; |
| 5242 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5243 | if (!c) |
| 5244 | continue; /* nonexistent channel */ |
| 5245 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 5246 | continue; /* dunno why they're confirming this */ |
| 5247 | c->remoteid = ssh2_pkt_getuint32(); |
| 5248 | c->type = CHAN_SOCKDATA; |
| 5249 | c->v.v2.remwindow = ssh2_pkt_getuint32(); |
| 5250 | c->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 5251 | bufchain_init(&c->v.v2.outbuffer); |
| 5252 | if (c->u.pfd.s) |
| 5253 | pfd_confirm(c->u.pfd.s); |
| 5254 | if (c->closes) { |
| 5255 | /* |
| 5256 | * We have a pending close on this channel, |
| 5257 | * which we decided on before the server acked |
| 5258 | * the channel open. So now we know the |
| 5259 | * remoteid, we can close it again. |
| 5260 | */ |
| 5261 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 5262 | ssh2_pkt_adduint32(c->remoteid); |
| 5263 | ssh2_pkt_send(); |
| 5264 | } |
| 5265 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { |
| 5266 | unsigned i = ssh2_pkt_getuint32(); |
| 5267 | struct ssh_channel *c; |
| 5268 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 5269 | if (!c) |
| 5270 | continue; /* nonexistent channel */ |
| 5271 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 5272 | continue; /* dunno why they're failing this */ |
| 5273 | |
| 5274 | logevent("Forwarded connection refused by server"); |
| 5275 | |
| 5276 | pfd_close(c->u.pfd.s); |
| 5277 | |
| 5278 | del234(ssh_channels, c); |
| 5279 | sfree(c); |
| 5280 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
| 5281 | unsigned localid; |
| 5282 | char *type; |
| 5283 | int typelen, want_reply; |
| 5284 | struct ssh_channel *c; |
| 5285 | |
| 5286 | localid = ssh2_pkt_getuint32(); |
| 5287 | ssh2_pkt_getstring(&type, &typelen); |
| 5288 | want_reply = ssh2_pkt_getbool(); |
| 5289 | |
| 5290 | /* |
| 5291 | * First, check that the channel exists. Otherwise, |
| 5292 | * we can instantly disconnect with a rude message. |
| 5293 | */ |
| 5294 | c = find234(ssh_channels, &localid, ssh_channelfind); |
| 5295 | if (!c) { |
| 5296 | char buf[80]; |
| 5297 | sprintf(buf, "Received channel request for nonexistent" |
| 5298 | " channel %d", localid); |
| 5299 | logevent(buf); |
| 5300 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 5301 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 5302 | ssh2_pkt_addstring(buf); |
| 5303 | ssh2_pkt_addstring("en"); /* language tag */ |
| 5304 | ssh2_pkt_send(); |
| 5305 | connection_fatal("%s", buf); |
| 5306 | ssh_state = SSH_STATE_CLOSED; |
| 5307 | crReturnV; |
| 5308 | } |
| 5309 | |
| 5310 | /* |
| 5311 | * Having got the channel number, we now look at |
| 5312 | * the request type string to see if it's something |
| 5313 | * we recognise. |
| 5314 | */ |
| 5315 | if (typelen == 11 && !memcmp(type, "exit-status", 11) && |
| 5316 | c == mainchan) { |
| 5317 | /* We recognise "exit-status" on the primary channel. */ |
| 5318 | char buf[100]; |
| 5319 | ssh_exitcode = ssh2_pkt_getuint32(); |
| 5320 | sprintf(buf, "Server sent command exit status %d", |
| 5321 | ssh_exitcode); |
| 5322 | logevent(buf); |
| 5323 | if (want_reply) { |
| 5324 | ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS); |
| 5325 | ssh2_pkt_adduint32(c->remoteid); |
| 5326 | ssh2_pkt_send(); |
| 5327 | } |
| 5328 | } else { |
| 5329 | /* |
| 5330 | * This is a channel request we don't know |
| 5331 | * about, so we now either ignore the request |
| 5332 | * or respond with CHANNEL_FAILURE, depending |
| 5333 | * on want_reply. |
| 5334 | */ |
| 5335 | if (want_reply) { |
| 5336 | ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE); |
| 5337 | ssh2_pkt_adduint32(c->remoteid); |
| 5338 | ssh2_pkt_send(); |
| 5339 | } |
| 5340 | } |
| 5341 | } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) { |
| 5342 | char *type; |
| 5343 | int typelen, want_reply; |
| 5344 | |
| 5345 | ssh2_pkt_getstring(&type, &typelen); |
| 5346 | want_reply = ssh2_pkt_getbool(); |
| 5347 | |
| 5348 | /* |
| 5349 | * We currently don't support any global requests |
| 5350 | * at all, so we either ignore the request or |
| 5351 | * respond with REQUEST_FAILURE, depending on |
| 5352 | * want_reply. |
| 5353 | */ |
| 5354 | if (want_reply) { |
| 5355 | ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); |
| 5356 | ssh2_pkt_send(); |
| 5357 | } |
| 5358 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
| 5359 | char *type; |
| 5360 | int typelen; |
| 5361 | char *error = NULL; |
| 5362 | struct ssh_channel *c; |
| 5363 | unsigned remid, winsize, pktsize; |
| 5364 | ssh2_pkt_getstring(&type, &typelen); |
| 5365 | c = smalloc(sizeof(struct ssh_channel)); |
| 5366 | |
| 5367 | remid = ssh2_pkt_getuint32(); |
| 5368 | winsize = ssh2_pkt_getuint32(); |
| 5369 | pktsize = ssh2_pkt_getuint32(); |
| 5370 | |
| 5371 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
| 5372 | if (!ssh_X11_fwd_enabled) |
| 5373 | error = "X11 forwarding is not enabled"; |
| 5374 | else if (x11_init(&c->u.x11.s, cfg.x11_display, c) != |
| 5375 | NULL) { |
| 5376 | error = "Unable to open an X11 connection"; |
| 5377 | } else { |
| 5378 | c->type = CHAN_X11; |
| 5379 | } |
| 5380 | } else if (typelen == 15 && |
| 5381 | !memcmp(type, "forwarded-tcpip", 15)) { |
| 5382 | struct ssh_rportfwd pf, *realpf; |
| 5383 | char *dummy; |
| 5384 | int dummylen; |
| 5385 | ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */ |
| 5386 | pf.sport = ssh2_pkt_getuint32(); |
| 5387 | realpf = find234(ssh_rportfwds, &pf, NULL); |
| 5388 | if (realpf == NULL) { |
| 5389 | error = "Remote port is not recognised"; |
| 5390 | } else { |
| 5391 | char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost, |
| 5392 | realpf->dport, c); |
| 5393 | char buf[1024]; |
| 5394 | sprintf(buf, "Received remote port open request for %s:%d", |
| 5395 | realpf->dhost, realpf->dport); |
| 5396 | logevent(buf); |
| 5397 | if (e != NULL) { |
| 5398 | sprintf(buf, "Port open failed: %s", e); |
| 5399 | logevent(buf); |
| 5400 | error = "Port open failed"; |
| 5401 | } else { |
| 5402 | logevent("Forwarded port opened successfully"); |
| 5403 | c->type = CHAN_SOCKDATA; |
| 5404 | } |
| 5405 | } |
| 5406 | } else if (typelen == 22 && |
| 5407 | !memcmp(type, "auth-agent@openssh.com", 3)) { |
| 5408 | if (!ssh_agentfwd_enabled) |
| 5409 | error = "Agent forwarding is not enabled"; |
| 5410 | else { |
| 5411 | c->type = CHAN_AGENT; /* identify channel type */ |
| 5412 | c->u.a.lensofar = 0; |
| 5413 | } |
| 5414 | } else { |
| 5415 | error = "Unsupported channel type requested"; |
| 5416 | } |
| 5417 | |
| 5418 | c->remoteid = remid; |
| 5419 | if (error) { |
| 5420 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 5421 | ssh2_pkt_adduint32(c->remoteid); |
| 5422 | ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); |
| 5423 | ssh2_pkt_addstring(error); |
| 5424 | ssh2_pkt_addstring("en"); /* language tag */ |
| 5425 | ssh2_pkt_send(); |
| 5426 | sfree(c); |
| 5427 | } else { |
| 5428 | c->localid = alloc_channel_id(); |
| 5429 | c->closes = 0; |
| 5430 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
| 5431 | c->v.v2.remwindow = winsize; |
| 5432 | c->v.v2.remmaxpkt = pktsize; |
| 5433 | bufchain_init(&c->v.v2.outbuffer); |
| 5434 | add234(ssh_channels, c); |
| 5435 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 5436 | ssh2_pkt_adduint32(c->remoteid); |
| 5437 | ssh2_pkt_adduint32(c->localid); |
| 5438 | ssh2_pkt_adduint32(c->v.v2.locwindow); |
| 5439 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 5440 | ssh2_pkt_send(); |
| 5441 | } |
| 5442 | } else { |
| 5443 | bombout(("Strange packet received: type %d", pktin.type)); |
| 5444 | crReturnV; |
| 5445 | } |
| 5446 | } else { |
| 5447 | /* |
| 5448 | * We have spare data. Add it to the channel buffer. |
| 5449 | */ |
| 5450 | ssh2_add_channel_data(mainchan, in, inlen); |
| 5451 | try_send = TRUE; |
| 5452 | } |
| 5453 | if (try_send) { |
| 5454 | int i; |
| 5455 | struct ssh_channel *c; |
| 5456 | /* |
| 5457 | * Try to send data on all channels if we can. |
| 5458 | */ |
| 5459 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
| 5460 | int bufsize = ssh2_try_send(c); |
| 5461 | if (bufsize == 0) { |
| 5462 | switch (c->type) { |
| 5463 | case CHAN_MAINSESSION: |
| 5464 | /* stdin need not receive an unthrottle |
| 5465 | * notification since it will be polled */ |
| 5466 | break; |
| 5467 | case CHAN_X11: |
| 5468 | x11_unthrottle(c->u.x11.s); |
| 5469 | break; |
| 5470 | case CHAN_AGENT: |
| 5471 | /* agent sockets are request/response and need no |
| 5472 | * buffer management */ |
| 5473 | break; |
| 5474 | case CHAN_SOCKDATA: |
| 5475 | pfd_unthrottle(c->u.pfd.s); |
| 5476 | break; |
| 5477 | } |
| 5478 | } |
| 5479 | } |
| 5480 | } |
| 5481 | } |
| 5482 | |
| 5483 | crFinishV; |
| 5484 | } |
| 5485 | |
| 5486 | /* |
| 5487 | * Handle the top-level SSH2 protocol. |
| 5488 | */ |
| 5489 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
| 5490 | { |
| 5491 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
| 5492 | return; |
| 5493 | do_ssh2_authconn(in, inlen, ispkt); |
| 5494 | } |
| 5495 | |
| 5496 | /* |
| 5497 | * Called to set up the connection. |
| 5498 | * |
| 5499 | * Returns an error message, or NULL on success. |
| 5500 | */ |
| 5501 | static char *ssh_init(char *host, int port, char **realhost, int nodelay) |
| 5502 | { |
| 5503 | char *p; |
| 5504 | |
| 5505 | #ifdef MSCRYPTOAPI |
| 5506 | if (crypto_startup() == 0) |
| 5507 | return "Microsoft high encryption pack not installed!"; |
| 5508 | #endif |
| 5509 | |
| 5510 | ssh_send_ok = 0; |
| 5511 | ssh_editing = 0; |
| 5512 | ssh_echoing = 0; |
| 5513 | ssh1_throttle_count = 0; |
| 5514 | ssh_overall_bufsize = 0; |
| 5515 | ssh_fallback_cmd = 0; |
| 5516 | |
| 5517 | p = connect_to_host(host, port, realhost, nodelay); |
| 5518 | if (p != NULL) |
| 5519 | return p; |
| 5520 | |
| 5521 | return NULL; |
| 5522 | } |
| 5523 | |
| 5524 | /* |
| 5525 | * Called to send data down the Telnet connection. |
| 5526 | */ |
| 5527 | static int ssh_send(char *buf, int len) |
| 5528 | { |
| 5529 | if (s == NULL || ssh_protocol == NULL) |
| 5530 | return 0; |
| 5531 | |
| 5532 | ssh_protocol(buf, len, 0); |
| 5533 | |
| 5534 | return ssh_sendbuffer(); |
| 5535 | } |
| 5536 | |
| 5537 | /* |
| 5538 | * Called to query the current amount of buffered stdin data. |
| 5539 | */ |
| 5540 | static int ssh_sendbuffer(void) |
| 5541 | { |
| 5542 | int override_value; |
| 5543 | |
| 5544 | if (s == NULL || ssh_protocol == NULL) |
| 5545 | return 0; |
| 5546 | |
| 5547 | /* |
| 5548 | * If the SSH socket itself has backed up, add the total backup |
| 5549 | * size on that to any individual buffer on the stdin channel. |
| 5550 | */ |
| 5551 | override_value = 0; |
| 5552 | if (ssh_throttled_all) |
| 5553 | override_value = ssh_overall_bufsize; |
| 5554 | |
| 5555 | if (ssh_version == 1) { |
| 5556 | return override_value; |
| 5557 | } else if (ssh_version == 2) { |
| 5558 | if (!mainchan || mainchan->closes > 0) |
| 5559 | return override_value; |
| 5560 | else |
| 5561 | return override_value + bufchain_size(&mainchan->v.v2.outbuffer); |
| 5562 | } |
| 5563 | |
| 5564 | return 0; |
| 5565 | } |
| 5566 | |
| 5567 | /* |
| 5568 | * Called to set the size of the window from SSH's POV. |
| 5569 | */ |
| 5570 | static void ssh_size(void) |
| 5571 | { |
| 5572 | switch (ssh_state) { |
| 5573 | case SSH_STATE_BEFORE_SIZE: |
| 5574 | case SSH_STATE_PREPACKET: |
| 5575 | case SSH_STATE_CLOSED: |
| 5576 | break; /* do nothing */ |
| 5577 | case SSH_STATE_INTERMED: |
| 5578 | size_needed = TRUE; /* buffer for later */ |
| 5579 | break; |
| 5580 | case SSH_STATE_SESSION: |
| 5581 | if (!cfg.nopty) { |
| 5582 | if (ssh_version == 1) { |
| 5583 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
| 5584 | PKT_INT, rows, PKT_INT, cols, |
| 5585 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 5586 | } else { |
| 5587 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 5588 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 5589 | ssh2_pkt_addstring("window-change"); |
| 5590 | ssh2_pkt_addbool(0); |
| 5591 | ssh2_pkt_adduint32(cols); |
| 5592 | ssh2_pkt_adduint32(rows); |
| 5593 | ssh2_pkt_adduint32(0); |
| 5594 | ssh2_pkt_adduint32(0); |
| 5595 | ssh2_pkt_send(); |
| 5596 | } |
| 5597 | } |
| 5598 | break; |
| 5599 | } |
| 5600 | } |
| 5601 | |
| 5602 | /* |
| 5603 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
| 5604 | * can send an EOF and collect resulting output (e.g. `plink |
| 5605 | * hostname sort'). |
| 5606 | */ |
| 5607 | static void ssh_special(Telnet_Special code) |
| 5608 | { |
| 5609 | if (code == TS_EOF) { |
| 5610 | if (ssh_state != SSH_STATE_SESSION) { |
| 5611 | /* |
| 5612 | * Buffer the EOF in case we are pre-SESSION, so we can |
| 5613 | * send it as soon as we reach SESSION. |
| 5614 | */ |
| 5615 | if (code == TS_EOF) |
| 5616 | eof_needed = TRUE; |
| 5617 | return; |
| 5618 | } |
| 5619 | if (ssh_version == 1) { |
| 5620 | send_packet(SSH1_CMSG_EOF, PKT_END); |
| 5621 | } else { |
| 5622 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
| 5623 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 5624 | ssh2_pkt_send(); |
| 5625 | } |
| 5626 | logevent("Sent EOF message"); |
| 5627 | } else if (code == TS_PING) { |
| 5628 | if (ssh_state == SSH_STATE_CLOSED |
| 5629 | || ssh_state == SSH_STATE_PREPACKET) return; |
| 5630 | if (ssh_version == 1) { |
| 5631 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
| 5632 | } else { |
| 5633 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 5634 | ssh2_pkt_addstring_start(); |
| 5635 | ssh2_pkt_send(); |
| 5636 | } |
| 5637 | } else { |
| 5638 | /* do nothing */ |
| 5639 | } |
| 5640 | } |
| 5641 | |
| 5642 | void *new_sock_channel(Socket s) |
| 5643 | { |
| 5644 | struct ssh_channel *c; |
| 5645 | c = smalloc(sizeof(struct ssh_channel)); |
| 5646 | |
| 5647 | if (c) { |
| 5648 | c->remoteid = -1; /* to be set when open confirmed */ |
| 5649 | c->localid = alloc_channel_id(); |
| 5650 | c->closes = 0; |
| 5651 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ |
| 5652 | c->u.pfd.s = s; |
| 5653 | add234(ssh_channels, c); |
| 5654 | } |
| 5655 | return c; |
| 5656 | } |
| 5657 | |
| 5658 | /* |
| 5659 | * This is called when stdout/stderr (the entity to which |
| 5660 | * from_backend sends data) manages to clear some backlog. |
| 5661 | */ |
| 5662 | void ssh_unthrottle(int bufsize) |
| 5663 | { |
| 5664 | if (ssh_version == 1) { |
| 5665 | if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 5666 | ssh1_stdout_throttling = 0; |
| 5667 | ssh1_throttle(-1); |
| 5668 | } |
| 5669 | } else { |
| 5670 | if (mainchan && mainchan->closes == 0) |
| 5671 | ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize); |
| 5672 | } |
| 5673 | } |
| 5674 | |
| 5675 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) |
| 5676 | { |
| 5677 | struct ssh_channel *c = (struct ssh_channel *)channel; |
| 5678 | char buf[1024]; |
| 5679 | |
| 5680 | sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port); |
| 5681 | logevent(buf); |
| 5682 | |
| 5683 | if (ssh_version == 1) { |
| 5684 | send_packet(SSH1_MSG_PORT_OPEN, |
| 5685 | PKT_INT, c->localid, |
| 5686 | PKT_STR, hostname, |
| 5687 | PKT_INT, port, |
| 5688 | //PKT_STR, <org:orgport>, |
| 5689 | PKT_END); |
| 5690 | } else { |
| 5691 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 5692 | ssh2_pkt_addstring("direct-tcpip"); |
| 5693 | ssh2_pkt_adduint32(c->localid); |
| 5694 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
| 5695 | ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */ |
| 5696 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 5697 | ssh2_pkt_addstring(hostname); |
| 5698 | ssh2_pkt_adduint32(port); |
| 5699 | /* |
| 5700 | * We make up values for the originator data; partly it's |
| 5701 | * too much hassle to keep track, and partly I'm not |
| 5702 | * convinced the server should be told details like that |
| 5703 | * about my local network configuration. |
| 5704 | */ |
| 5705 | ssh2_pkt_addstring("client-side-connection"); |
| 5706 | ssh2_pkt_adduint32(0); |
| 5707 | ssh2_pkt_send(); |
| 5708 | } |
| 5709 | } |
| 5710 | |
| 5711 | |
| 5712 | static Socket ssh_socket(void) |
| 5713 | { |
| 5714 | return s; |
| 5715 | } |
| 5716 | |
| 5717 | static int ssh_sendok(void) |
| 5718 | { |
| 5719 | return ssh_send_ok; |
| 5720 | } |
| 5721 | |
| 5722 | static int ssh_ldisc(int option) |
| 5723 | { |
| 5724 | if (option == LD_ECHO) |
| 5725 | return ssh_echoing; |
| 5726 | if (option == LD_EDIT) |
| 5727 | return ssh_editing; |
| 5728 | return FALSE; |
| 5729 | } |
| 5730 | |
| 5731 | static int ssh_return_exitcode(void) |
| 5732 | { |
| 5733 | return ssh_exitcode; |
| 5734 | } |
| 5735 | |
| 5736 | Backend ssh_backend = { |
| 5737 | ssh_init, |
| 5738 | ssh_send, |
| 5739 | ssh_sendbuffer, |
| 5740 | ssh_size, |
| 5741 | ssh_special, |
| 5742 | ssh_socket, |
| 5743 | ssh_return_exitcode, |
| 5744 | ssh_sendok, |
| 5745 | ssh_ldisc, |
| 5746 | ssh_unthrottle, |
| 5747 | 22 |
| 5748 | }; |