| 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <stdarg.h> |
| 4 | #include <assert.h> |
| 5 | |
| 6 | #include "putty.h" |
| 7 | #include "tree234.h" |
| 8 | #include "ssh.h" |
| 9 | |
| 10 | #ifndef FALSE |
| 11 | #define FALSE 0 |
| 12 | #endif |
| 13 | #ifndef TRUE |
| 14 | #define TRUE 1 |
| 15 | #endif |
| 16 | |
| 17 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
| 18 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
| 19 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
| 20 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
| 21 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
| 22 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
| 23 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
| 24 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
| 25 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
| 26 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
| 27 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
| 28 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
| 29 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
| 30 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
| 31 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
| 32 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
| 33 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
| 34 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
| 35 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
| 36 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
| 37 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
| 38 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
| 39 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
| 40 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
| 41 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
| 42 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
| 43 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
| 44 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
| 45 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
| 46 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
| 47 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
| 48 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
| 49 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
| 50 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
| 51 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
| 52 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
| 53 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
| 54 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
| 55 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
| 56 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
| 57 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
| 58 | |
| 59 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
| 60 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
| 61 | |
| 62 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
| 63 | /* Mask for protoflags we will echo back to server if seen */ |
| 64 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
| 65 | |
| 66 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
| 67 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
| 68 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
| 69 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
| 70 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
| 71 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
| 72 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
| 73 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
| 74 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
| 75 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
| 76 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
| 77 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
| 78 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
| 79 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
| 80 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
| 81 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
| 82 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
| 83 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
| 84 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
| 85 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
| 86 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ |
| 87 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ |
| 88 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
| 89 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
| 90 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
| 91 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
| 92 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
| 93 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
| 94 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
| 95 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
| 96 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
| 97 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
| 98 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
| 99 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
| 100 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
| 101 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
| 102 | |
| 103 | /* |
| 104 | * Packet type contexts, so that ssh2_pkt_type can correctly decode |
| 105 | * the ambiguous type numbers back into the correct type strings. |
| 106 | */ |
| 107 | #define SSH2_PKTCTX_DHGROUP1 0x0001 |
| 108 | #define SSH2_PKTCTX_DHGEX 0x0002 |
| 109 | #define SSH2_PKTCTX_PUBLICKEY 0x0010 |
| 110 | #define SSH2_PKTCTX_PASSWORD 0x0020 |
| 111 | #define SSH2_PKTCTX_KBDINTER 0x0040 |
| 112 | #define SSH2_PKTCTX_AUTH_MASK 0x00F0 |
| 113 | |
| 114 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
| 115 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
| 116 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
| 117 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
| 118 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
| 119 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
| 120 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
| 121 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
| 122 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
| 123 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
| 124 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
| 125 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
| 126 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
| 127 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
| 128 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
| 129 | |
| 130 | static const char *const ssh2_disconnect_reasons[] = { |
| 131 | NULL, |
| 132 | "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", |
| 133 | "SSH_DISCONNECT_PROTOCOL_ERROR", |
| 134 | "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", |
| 135 | "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", |
| 136 | "SSH_DISCONNECT_MAC_ERROR", |
| 137 | "SSH_DISCONNECT_COMPRESSION_ERROR", |
| 138 | "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", |
| 139 | "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", |
| 140 | "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", |
| 141 | "SSH_DISCONNECT_CONNECTION_LOST", |
| 142 | "SSH_DISCONNECT_BY_APPLICATION", |
| 143 | "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", |
| 144 | "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", |
| 145 | "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", |
| 146 | "SSH_DISCONNECT_ILLEGAL_USER_NAME", |
| 147 | }; |
| 148 | |
| 149 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
| 150 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
| 151 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
| 152 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
| 153 | |
| 154 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
| 155 | |
| 156 | /* |
| 157 | * Various remote-bug flags. |
| 158 | */ |
| 159 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
| 160 | #define BUG_SSH2_HMAC 2 |
| 161 | #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 |
| 162 | #define BUG_CHOKES_ON_RSA 8 |
| 163 | #define BUG_SSH2_RSA_PADDING 16 |
| 164 | #define BUG_SSH2_DERIVEKEY 32 |
| 165 | #define BUG_SSH2_DH_GEX 64 |
| 166 | #define BUG_SSH2_PK_SESSIONID 128 |
| 167 | |
| 168 | #define translate(x) if (type == x) return #x |
| 169 | #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x |
| 170 | static char *ssh1_pkt_type(int type) |
| 171 | { |
| 172 | translate(SSH1_MSG_DISCONNECT); |
| 173 | translate(SSH1_SMSG_PUBLIC_KEY); |
| 174 | translate(SSH1_CMSG_SESSION_KEY); |
| 175 | translate(SSH1_CMSG_USER); |
| 176 | translate(SSH1_CMSG_AUTH_RSA); |
| 177 | translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); |
| 178 | translate(SSH1_CMSG_AUTH_RSA_RESPONSE); |
| 179 | translate(SSH1_CMSG_AUTH_PASSWORD); |
| 180 | translate(SSH1_CMSG_REQUEST_PTY); |
| 181 | translate(SSH1_CMSG_WINDOW_SIZE); |
| 182 | translate(SSH1_CMSG_EXEC_SHELL); |
| 183 | translate(SSH1_CMSG_EXEC_CMD); |
| 184 | translate(SSH1_SMSG_SUCCESS); |
| 185 | translate(SSH1_SMSG_FAILURE); |
| 186 | translate(SSH1_CMSG_STDIN_DATA); |
| 187 | translate(SSH1_SMSG_STDOUT_DATA); |
| 188 | translate(SSH1_SMSG_STDERR_DATA); |
| 189 | translate(SSH1_CMSG_EOF); |
| 190 | translate(SSH1_SMSG_EXIT_STATUS); |
| 191 | translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 192 | translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); |
| 193 | translate(SSH1_MSG_CHANNEL_DATA); |
| 194 | translate(SSH1_MSG_CHANNEL_CLOSE); |
| 195 | translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); |
| 196 | translate(SSH1_SMSG_X11_OPEN); |
| 197 | translate(SSH1_CMSG_PORT_FORWARD_REQUEST); |
| 198 | translate(SSH1_MSG_PORT_OPEN); |
| 199 | translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); |
| 200 | translate(SSH1_SMSG_AGENT_OPEN); |
| 201 | translate(SSH1_MSG_IGNORE); |
| 202 | translate(SSH1_CMSG_EXIT_CONFIRMATION); |
| 203 | translate(SSH1_CMSG_X11_REQUEST_FORWARDING); |
| 204 | translate(SSH1_CMSG_AUTH_RHOSTS_RSA); |
| 205 | translate(SSH1_MSG_DEBUG); |
| 206 | translate(SSH1_CMSG_REQUEST_COMPRESSION); |
| 207 | translate(SSH1_CMSG_AUTH_TIS); |
| 208 | translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); |
| 209 | translate(SSH1_CMSG_AUTH_TIS_RESPONSE); |
| 210 | translate(SSH1_CMSG_AUTH_CCARD); |
| 211 | translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); |
| 212 | translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); |
| 213 | return "unknown"; |
| 214 | } |
| 215 | static char *ssh2_pkt_type(int pkt_ctx, int type) |
| 216 | { |
| 217 | translate(SSH2_MSG_DISCONNECT); |
| 218 | translate(SSH2_MSG_IGNORE); |
| 219 | translate(SSH2_MSG_UNIMPLEMENTED); |
| 220 | translate(SSH2_MSG_DEBUG); |
| 221 | translate(SSH2_MSG_SERVICE_REQUEST); |
| 222 | translate(SSH2_MSG_SERVICE_ACCEPT); |
| 223 | translate(SSH2_MSG_KEXINIT); |
| 224 | translate(SSH2_MSG_NEWKEYS); |
| 225 | translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1); |
| 226 | translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1); |
| 227 | translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); |
| 228 | translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); |
| 229 | translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); |
| 230 | translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); |
| 231 | translate(SSH2_MSG_USERAUTH_REQUEST); |
| 232 | translate(SSH2_MSG_USERAUTH_FAILURE); |
| 233 | translate(SSH2_MSG_USERAUTH_SUCCESS); |
| 234 | translate(SSH2_MSG_USERAUTH_BANNER); |
| 235 | translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); |
| 236 | translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); |
| 237 | translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); |
| 238 | translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); |
| 239 | translate(SSH2_MSG_GLOBAL_REQUEST); |
| 240 | translate(SSH2_MSG_REQUEST_SUCCESS); |
| 241 | translate(SSH2_MSG_REQUEST_FAILURE); |
| 242 | translate(SSH2_MSG_CHANNEL_OPEN); |
| 243 | translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 244 | translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 245 | translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 246 | translate(SSH2_MSG_CHANNEL_DATA); |
| 247 | translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); |
| 248 | translate(SSH2_MSG_CHANNEL_EOF); |
| 249 | translate(SSH2_MSG_CHANNEL_CLOSE); |
| 250 | translate(SSH2_MSG_CHANNEL_REQUEST); |
| 251 | translate(SSH2_MSG_CHANNEL_SUCCESS); |
| 252 | translate(SSH2_MSG_CHANNEL_FAILURE); |
| 253 | return "unknown"; |
| 254 | } |
| 255 | #undef translate |
| 256 | #undef translatec |
| 257 | |
| 258 | #define GET_32BIT(cp) \ |
| 259 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
| 260 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 261 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 262 | ((unsigned long)(unsigned char)(cp)[3])) |
| 263 | |
| 264 | #define PUT_32BIT(cp, value) { \ |
| 265 | (cp)[0] = (unsigned char)((value) >> 24); \ |
| 266 | (cp)[1] = (unsigned char)((value) >> 16); \ |
| 267 | (cp)[2] = (unsigned char)((value) >> 8); \ |
| 268 | (cp)[3] = (unsigned char)(value); } |
| 269 | |
| 270 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
| 271 | |
| 272 | /* |
| 273 | * Coroutine mechanics for the sillier bits of the code. If these |
| 274 | * macros look impenetrable to you, you might find it helpful to |
| 275 | * read |
| 276 | * |
| 277 | * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html |
| 278 | * |
| 279 | * which explains the theory behind these macros. |
| 280 | * |
| 281 | * In particular, if you are getting `case expression not constant' |
| 282 | * errors when building with MS Visual Studio, this is because MS's |
| 283 | * Edit and Continue debugging feature causes their compiler to |
| 284 | * violate ANSI C. To disable Edit and Continue debugging: |
| 285 | * |
| 286 | * - right-click ssh.c in the FileView |
| 287 | * - click Settings |
| 288 | * - select the C/C++ tab and the General category |
| 289 | * - under `Debug info:', select anything _other_ than `Program |
| 290 | * Database for Edit and Continue'. |
| 291 | */ |
| 292 | #define crBegin(v) { int *crLine = &v; switch(v) { case 0:; |
| 293 | #define crState(t) \ |
| 294 | struct t *s; \ |
| 295 | if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \ |
| 296 | s = ssh->t; |
| 297 | #define crFinish(z) } *crLine = 0; return (z); } |
| 298 | #define crFinishV } *crLine = 0; return; } |
| 299 | #define crReturn(z) \ |
| 300 | do {\ |
| 301 | *crLine =__LINE__; return (z); case __LINE__:;\ |
| 302 | } while (0) |
| 303 | #define crReturnV \ |
| 304 | do {\ |
| 305 | *crLine=__LINE__; return; case __LINE__:;\ |
| 306 | } while (0) |
| 307 | #define crStop(z) do{ *crLine = 0; return (z); }while(0) |
| 308 | #define crStopV do{ *crLine = 0; return; }while(0) |
| 309 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 310 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 311 | |
| 312 | typedef struct ssh_tag *Ssh; |
| 313 | |
| 314 | static void ssh2_pkt_init(Ssh, int pkt_type); |
| 315 | static void ssh2_pkt_addbool(Ssh, unsigned char value); |
| 316 | static void ssh2_pkt_adduint32(Ssh, unsigned long value); |
| 317 | static void ssh2_pkt_addstring_start(Ssh); |
| 318 | static void ssh2_pkt_addstring_str(Ssh, char *data); |
| 319 | static void ssh2_pkt_addstring_data(Ssh, char *data, int len); |
| 320 | static void ssh2_pkt_addstring(Ssh, char *data); |
| 321 | static unsigned char *ssh2_mpint_fmt(Bignum b, int *len); |
| 322 | static void ssh2_pkt_addmp(Ssh, Bignum b); |
| 323 | static int ssh2_pkt_construct(Ssh); |
| 324 | static void ssh2_pkt_send(Ssh); |
| 325 | |
| 326 | /* |
| 327 | * Buffer management constants. There are several of these for |
| 328 | * various different purposes: |
| 329 | * |
| 330 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up |
| 331 | * on a local data stream before we throttle the whole SSH |
| 332 | * connection (in SSH1 only). Throttling the whole connection is |
| 333 | * pretty drastic so we set this high in the hope it won't |
| 334 | * happen very often. |
| 335 | * |
| 336 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up |
| 337 | * on the SSH connection itself before we defensively throttle |
| 338 | * _all_ local data streams. This is pretty drastic too (though |
| 339 | * thankfully unlikely in SSH2 since the window mechanism should |
| 340 | * ensure that the server never has any need to throttle its end |
| 341 | * of the connection), so we set this high as well. |
| 342 | * |
| 343 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 |
| 344 | * channels. |
| 345 | */ |
| 346 | |
| 347 | #define SSH1_BUFFER_LIMIT 32768 |
| 348 | #define SSH_MAX_BACKLOG 32768 |
| 349 | #define OUR_V2_WINSIZE 16384 |
| 350 | |
| 351 | const static struct ssh_kex *kex_algs[] = { |
| 352 | &ssh_diffiehellman_gex, |
| 353 | &ssh_diffiehellman |
| 354 | }; |
| 355 | |
| 356 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
| 357 | |
| 358 | static void *nullmac_make_context(void) |
| 359 | { |
| 360 | return NULL; |
| 361 | } |
| 362 | static void nullmac_free_context(void *handle) |
| 363 | { |
| 364 | } |
| 365 | static void nullmac_key(void *handle, unsigned char *key) |
| 366 | { |
| 367 | } |
| 368 | static void nullmac_generate(void *handle, unsigned char *blk, int len, |
| 369 | unsigned long seq) |
| 370 | { |
| 371 | } |
| 372 | static int nullmac_verify(void *handle, unsigned char *blk, int len, |
| 373 | unsigned long seq) |
| 374 | { |
| 375 | return 1; |
| 376 | } |
| 377 | const static struct ssh_mac ssh_mac_none = { |
| 378 | nullmac_make_context, nullmac_free_context, nullmac_key, |
| 379 | nullmac_generate, nullmac_verify, "none", 0 |
| 380 | }; |
| 381 | const static struct ssh_mac *macs[] = { |
| 382 | &ssh_sha1, &ssh_md5, &ssh_mac_none |
| 383 | }; |
| 384 | const static struct ssh_mac *buggymacs[] = { |
| 385 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none |
| 386 | }; |
| 387 | |
| 388 | static void *ssh_comp_none_init(void) |
| 389 | { |
| 390 | return NULL; |
| 391 | } |
| 392 | static void ssh_comp_none_cleanup(void *handle) |
| 393 | { |
| 394 | } |
| 395 | static int ssh_comp_none_block(void *handle, unsigned char *block, int len, |
| 396 | unsigned char **outblock, int *outlen) |
| 397 | { |
| 398 | return 0; |
| 399 | } |
| 400 | static int ssh_comp_none_disable(void *handle) |
| 401 | { |
| 402 | return 0; |
| 403 | } |
| 404 | const static struct ssh_compress ssh_comp_none = { |
| 405 | "none", |
| 406 | ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, |
| 407 | ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, |
| 408 | ssh_comp_none_disable, NULL |
| 409 | }; |
| 410 | extern const struct ssh_compress ssh_zlib; |
| 411 | const static struct ssh_compress *compressions[] = { |
| 412 | &ssh_zlib, &ssh_comp_none |
| 413 | }; |
| 414 | |
| 415 | enum { /* channel types */ |
| 416 | CHAN_MAINSESSION, |
| 417 | CHAN_X11, |
| 418 | CHAN_AGENT, |
| 419 | CHAN_SOCKDATA, |
| 420 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ |
| 421 | }; |
| 422 | |
| 423 | /* |
| 424 | * 2-3-4 tree storing channels. |
| 425 | */ |
| 426 | struct ssh_channel { |
| 427 | Ssh ssh; /* pointer back to main context */ |
| 428 | unsigned remoteid, localid; |
| 429 | int type; |
| 430 | /* |
| 431 | * In SSH1, this value contains four bits: |
| 432 | * |
| 433 | * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. |
| 434 | * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. |
| 435 | * 4 We have received SSH1_MSG_CHANNEL_CLOSE. |
| 436 | * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. |
| 437 | * |
| 438 | * A channel is completely finished with when all four bits are set. |
| 439 | */ |
| 440 | int closes; |
| 441 | union { |
| 442 | struct ssh1_data_channel { |
| 443 | int throttling; |
| 444 | } v1; |
| 445 | struct ssh2_data_channel { |
| 446 | bufchain outbuffer; |
| 447 | unsigned remwindow, remmaxpkt; |
| 448 | unsigned locwindow; |
| 449 | } v2; |
| 450 | } v; |
| 451 | union { |
| 452 | struct ssh_agent_channel { |
| 453 | unsigned char *message; |
| 454 | unsigned char msglen[4]; |
| 455 | int lensofar, totallen; |
| 456 | } a; |
| 457 | struct ssh_x11_channel { |
| 458 | Socket s; |
| 459 | } x11; |
| 460 | struct ssh_pfd_channel { |
| 461 | Socket s; |
| 462 | } pfd; |
| 463 | } u; |
| 464 | }; |
| 465 | |
| 466 | /* |
| 467 | * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH |
| 468 | * 2 use this structure in different ways, reflecting SSH 2's |
| 469 | * altogether saner approach to port forwarding. |
| 470 | * |
| 471 | * In SSH 1, you arrange a remote forwarding by sending the server |
| 472 | * the remote port number, and the local destination host:port. |
| 473 | * When a connection comes in, the server sends you back that |
| 474 | * host:port pair, and you connect to it. This is a ready-made |
| 475 | * security hole if you're not on the ball: a malicious server |
| 476 | * could send you back _any_ host:port pair, so if you trustingly |
| 477 | * connect to the address it gives you then you've just opened the |
| 478 | * entire inside of your corporate network just by connecting |
| 479 | * through it to a dodgy SSH server. Hence, we must store a list of |
| 480 | * host:port pairs we _are_ trying to forward to, and reject a |
| 481 | * connection request from the server if it's not in the list. |
| 482 | * |
| 483 | * In SSH 2, each side of the connection minds its own business and |
| 484 | * doesn't send unnecessary information to the other. You arrange a |
| 485 | * remote forwarding by sending the server just the remote port |
| 486 | * number. When a connection comes in, the server tells you which |
| 487 | * of its ports was connected to; and _you_ have to remember what |
| 488 | * local host:port pair went with that port number. |
| 489 | * |
| 490 | * Hence: in SSH 1 this structure stores host:port pairs we intend |
| 491 | * to allow connections to, and is indexed by those host:port |
| 492 | * pairs. In SSH 2 it stores a mapping from source port to |
| 493 | * destination host:port pair, and is indexed by source port. |
| 494 | */ |
| 495 | struct ssh_rportfwd { |
| 496 | unsigned sport, dport; |
| 497 | char dhost[256]; |
| 498 | }; |
| 499 | |
| 500 | struct Packet { |
| 501 | long length; |
| 502 | int type; |
| 503 | unsigned char *data; |
| 504 | unsigned char *body; |
| 505 | long savedpos; |
| 506 | long maxlen; |
| 507 | }; |
| 508 | |
| 509 | static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt); |
| 510 | static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt); |
| 511 | static void ssh_size(void *handle, int width, int height); |
| 512 | static void ssh_special(void *handle, Telnet_Special); |
| 513 | static int ssh2_try_send(struct ssh_channel *c); |
| 514 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); |
| 515 | static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); |
| 516 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); |
| 517 | static int ssh_sendbuffer(void *handle); |
| 518 | |
| 519 | struct rdpkt1_state_tag { |
| 520 | long len, pad, biglen, to_read; |
| 521 | unsigned long realcrc, gotcrc; |
| 522 | unsigned char *p; |
| 523 | int i; |
| 524 | int chunk; |
| 525 | }; |
| 526 | |
| 527 | struct rdpkt2_state_tag { |
| 528 | long len, pad, payload, packetlen, maclen; |
| 529 | int i; |
| 530 | int cipherblk; |
| 531 | unsigned long incoming_sequence; |
| 532 | }; |
| 533 | |
| 534 | struct ssh_tag { |
| 535 | const struct plug_function_table *fn; |
| 536 | /* the above field _must_ be first in the structure */ |
| 537 | |
| 538 | SHA_State exhash, exhashbase; |
| 539 | |
| 540 | Socket s; |
| 541 | |
| 542 | void *ldisc; |
| 543 | void *logctx; |
| 544 | |
| 545 | unsigned char session_key[32]; |
| 546 | int v1_compressing; |
| 547 | int v1_remote_protoflags; |
| 548 | int v1_local_protoflags; |
| 549 | int agentfwd_enabled; |
| 550 | int X11_fwd_enabled; |
| 551 | int remote_bugs; |
| 552 | const struct ssh_cipher *cipher; |
| 553 | void *v1_cipher_ctx; |
| 554 | void *crcda_ctx; |
| 555 | const struct ssh2_cipher *cscipher, *sccipher; |
| 556 | void *cs_cipher_ctx, *sc_cipher_ctx; |
| 557 | const struct ssh_mac *csmac, *scmac; |
| 558 | void *cs_mac_ctx, *sc_mac_ctx; |
| 559 | const struct ssh_compress *cscomp, *sccomp; |
| 560 | void *cs_comp_ctx, *sc_comp_ctx; |
| 561 | const struct ssh_kex *kex; |
| 562 | const struct ssh_signkey *hostkey; |
| 563 | unsigned char v2_session_id[20]; |
| 564 | void *kex_ctx; |
| 565 | |
| 566 | char *savedhost; |
| 567 | int savedport; |
| 568 | int send_ok; |
| 569 | int echoing, editing; |
| 570 | |
| 571 | void *frontend; |
| 572 | |
| 573 | int term_width, term_height; |
| 574 | |
| 575 | tree234 *channels; /* indexed by local id */ |
| 576 | struct ssh_channel *mainchan; /* primary session channel */ |
| 577 | int exitcode; |
| 578 | |
| 579 | tree234 *rportfwds; |
| 580 | |
| 581 | enum { |
| 582 | SSH_STATE_PREPACKET, |
| 583 | SSH_STATE_BEFORE_SIZE, |
| 584 | SSH_STATE_INTERMED, |
| 585 | SSH_STATE_SESSION, |
| 586 | SSH_STATE_CLOSED |
| 587 | } state; |
| 588 | |
| 589 | int size_needed, eof_needed; |
| 590 | |
| 591 | struct Packet pktin; |
| 592 | struct Packet pktout; |
| 593 | unsigned char *deferred_send_data; |
| 594 | int deferred_len, deferred_size; |
| 595 | |
| 596 | /* |
| 597 | * Gross hack: pscp will try to start SFTP but fall back to |
| 598 | * scp1 if that fails. This variable is the means by which |
| 599 | * scp.c can reach into the SSH code and find out which one it |
| 600 | * got. |
| 601 | */ |
| 602 | int fallback_cmd; |
| 603 | |
| 604 | /* |
| 605 | * Used for username and password input. |
| 606 | */ |
| 607 | char *userpass_input_buffer; |
| 608 | int userpass_input_buflen; |
| 609 | int userpass_input_bufpos; |
| 610 | int userpass_input_echo; |
| 611 | |
| 612 | char *portfwd_strptr; |
| 613 | int pkt_ctx; |
| 614 | |
| 615 | void *x11auth; |
| 616 | |
| 617 | int version; |
| 618 | int v1_throttle_count; |
| 619 | int overall_bufsize; |
| 620 | int throttled_all; |
| 621 | int v1_stdout_throttling; |
| 622 | int v2_outgoing_sequence; |
| 623 | |
| 624 | int ssh1_rdpkt_crstate; |
| 625 | int ssh2_rdpkt_crstate; |
| 626 | int do_ssh_init_crstate; |
| 627 | int ssh_gotdata_crstate; |
| 628 | int ssh1_protocol_crstate; |
| 629 | int do_ssh1_login_crstate; |
| 630 | int do_ssh2_transport_crstate; |
| 631 | int do_ssh2_authconn_crstate; |
| 632 | |
| 633 | void *do_ssh_init_state; |
| 634 | void *do_ssh1_login_state; |
| 635 | void *do_ssh2_transport_state; |
| 636 | void *do_ssh2_authconn_state; |
| 637 | |
| 638 | struct rdpkt1_state_tag rdpkt1_state; |
| 639 | struct rdpkt2_state_tag rdpkt2_state; |
| 640 | |
| 641 | void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt); |
| 642 | int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); |
| 643 | |
| 644 | /* |
| 645 | * We maintain a full _copy_ of a Config structure here, not |
| 646 | * merely a pointer to it. That way, when we're passed a new |
| 647 | * one for reconfiguration, we can check the differences and |
| 648 | * potentially reconfigure port forwardings etc in mid-session. |
| 649 | */ |
| 650 | Config cfg; |
| 651 | }; |
| 652 | |
| 653 | #define logevent(s) logevent(ssh->frontend, s) |
| 654 | |
| 655 | /* logevent, only printf-formatted. */ |
| 656 | static void logeventf(Ssh ssh, char *fmt, ...) |
| 657 | { |
| 658 | va_list ap; |
| 659 | char *buf; |
| 660 | |
| 661 | va_start(ap, fmt); |
| 662 | buf = dupvprintf(fmt, ap); |
| 663 | va_end(ap); |
| 664 | logevent(buf); |
| 665 | sfree(buf); |
| 666 | } |
| 667 | |
| 668 | #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \ |
| 669 | (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \ |
| 670 | logeventf msg, connection_fatal msg ) |
| 671 | |
| 672 | static int ssh_channelcmp(void *av, void *bv) |
| 673 | { |
| 674 | struct ssh_channel *a = (struct ssh_channel *) av; |
| 675 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 676 | if (a->localid < b->localid) |
| 677 | return -1; |
| 678 | if (a->localid > b->localid) |
| 679 | return +1; |
| 680 | return 0; |
| 681 | } |
| 682 | static int ssh_channelfind(void *av, void *bv) |
| 683 | { |
| 684 | unsigned *a = (unsigned *) av; |
| 685 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 686 | if (*a < b->localid) |
| 687 | return -1; |
| 688 | if (*a > b->localid) |
| 689 | return +1; |
| 690 | return 0; |
| 691 | } |
| 692 | |
| 693 | static int ssh_rportcmp_ssh1(void *av, void *bv) |
| 694 | { |
| 695 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 696 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 697 | int i; |
| 698 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) |
| 699 | return i < 0 ? -1 : +1; |
| 700 | if (a->dport > b->dport) |
| 701 | return +1; |
| 702 | if (a->dport < b->dport) |
| 703 | return -1; |
| 704 | return 0; |
| 705 | } |
| 706 | |
| 707 | static int ssh_rportcmp_ssh2(void *av, void *bv) |
| 708 | { |
| 709 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 710 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 711 | |
| 712 | if (a->sport > b->sport) |
| 713 | return +1; |
| 714 | if (a->sport < b->sport) |
| 715 | return -1; |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | static int alloc_channel_id(Ssh ssh) |
| 720 | { |
| 721 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
| 722 | unsigned low, high, mid; |
| 723 | int tsize; |
| 724 | struct ssh_channel *c; |
| 725 | |
| 726 | /* |
| 727 | * First-fit allocation of channel numbers: always pick the |
| 728 | * lowest unused one. To do this, binary-search using the |
| 729 | * counted B-tree to find the largest channel ID which is in a |
| 730 | * contiguous sequence from the beginning. (Precisely |
| 731 | * everything in that sequence must have ID equal to its tree |
| 732 | * index plus CHANNEL_NUMBER_OFFSET.) |
| 733 | */ |
| 734 | tsize = count234(ssh->channels); |
| 735 | |
| 736 | low = -1; |
| 737 | high = tsize; |
| 738 | while (high - low > 1) { |
| 739 | mid = (high + low) / 2; |
| 740 | c = index234(ssh->channels, mid); |
| 741 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
| 742 | low = mid; /* this one is fine */ |
| 743 | else |
| 744 | high = mid; /* this one is past it */ |
| 745 | } |
| 746 | /* |
| 747 | * Now low points to either -1, or the tree index of the |
| 748 | * largest ID in the initial sequence. |
| 749 | */ |
| 750 | { |
| 751 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
| 752 | assert(NULL == find234(ssh->channels, &i, ssh_channelfind)); |
| 753 | } |
| 754 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
| 755 | } |
| 756 | |
| 757 | static void c_write(Ssh ssh, const char *buf, int len) |
| 758 | { |
| 759 | if ((flags & FLAG_STDERR)) { |
| 760 | int i; |
| 761 | for (i = 0; i < len; i++) |
| 762 | if (buf[i] != '\r') |
| 763 | fputc(buf[i], stderr); |
| 764 | return; |
| 765 | } |
| 766 | from_backend(ssh->frontend, 1, buf, len); |
| 767 | } |
| 768 | |
| 769 | static void c_write_untrusted(Ssh ssh, const char *buf, int len) |
| 770 | { |
| 771 | int i; |
| 772 | for (i = 0; i < len; i++) { |
| 773 | if (buf[i] == '\n') |
| 774 | c_write(ssh, "\r\n", 2); |
| 775 | else if ((buf[i] & 0x60) || (buf[i] == '\r')) |
| 776 | c_write(ssh, buf + i, 1); |
| 777 | } |
| 778 | } |
| 779 | |
| 780 | static void c_write_str(Ssh ssh, const char *buf) |
| 781 | { |
| 782 | c_write(ssh, buf, strlen(buf)); |
| 783 | } |
| 784 | |
| 785 | /* |
| 786 | * Collect incoming data in the incoming packet buffer. |
| 787 | * Decipher and verify the packet when it is completely read. |
| 788 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 789 | * Update the *data and *datalen variables. |
| 790 | * Return the additional nr of bytes needed, or 0 when |
| 791 | * a complete packet is available. |
| 792 | */ |
| 793 | static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) |
| 794 | { |
| 795 | struct rdpkt1_state_tag *st = &ssh->rdpkt1_state; |
| 796 | |
| 797 | crBegin(ssh->ssh1_rdpkt_crstate); |
| 798 | |
| 799 | next_packet: |
| 800 | |
| 801 | ssh->pktin.type = 0; |
| 802 | ssh->pktin.length = 0; |
| 803 | |
| 804 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
| 805 | while ((*datalen) == 0) |
| 806 | crReturn(4 - st->i); |
| 807 | st->len = (st->len << 8) + **data; |
| 808 | (*data)++, (*datalen)--; |
| 809 | } |
| 810 | |
| 811 | st->pad = 8 - (st->len % 8); |
| 812 | st->biglen = st->len + st->pad; |
| 813 | ssh->pktin.length = st->len - 5; |
| 814 | |
| 815 | if (ssh->pktin.maxlen < st->biglen) { |
| 816 | ssh->pktin.maxlen = st->biglen; |
| 817 | ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA); |
| 818 | } |
| 819 | |
| 820 | st->to_read = st->biglen; |
| 821 | st->p = ssh->pktin.data; |
| 822 | while (st->to_read > 0) { |
| 823 | st->chunk = st->to_read; |
| 824 | while ((*datalen) == 0) |
| 825 | crReturn(st->to_read); |
| 826 | if (st->chunk > (*datalen)) |
| 827 | st->chunk = (*datalen); |
| 828 | memcpy(st->p, *data, st->chunk); |
| 829 | *data += st->chunk; |
| 830 | *datalen -= st->chunk; |
| 831 | st->p += st->chunk; |
| 832 | st->to_read -= st->chunk; |
| 833 | } |
| 834 | |
| 835 | if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data, |
| 836 | st->biglen, NULL)) { |
| 837 | bombout((ssh,"Network attack (CRC compensation) detected!")); |
| 838 | crReturn(0); |
| 839 | } |
| 840 | |
| 841 | if (ssh->cipher) |
| 842 | ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen); |
| 843 | |
| 844 | st->realcrc = crc32(ssh->pktin.data, st->biglen - 4); |
| 845 | st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4); |
| 846 | if (st->gotcrc != st->realcrc) { |
| 847 | bombout((ssh,"Incorrect CRC received on packet")); |
| 848 | crReturn(0); |
| 849 | } |
| 850 | |
| 851 | ssh->pktin.body = ssh->pktin.data + st->pad + 1; |
| 852 | |
| 853 | if (ssh->v1_compressing) { |
| 854 | unsigned char *decompblk; |
| 855 | int decomplen; |
| 856 | zlib_decompress_block(ssh->sc_comp_ctx, |
| 857 | ssh->pktin.body - 1, ssh->pktin.length + 1, |
| 858 | &decompblk, &decomplen); |
| 859 | |
| 860 | if (ssh->pktin.maxlen < st->pad + decomplen) { |
| 861 | ssh->pktin.maxlen = st->pad + decomplen; |
| 862 | ssh->pktin.data = srealloc(ssh->pktin.data, |
| 863 | ssh->pktin.maxlen + APIEXTRA); |
| 864 | ssh->pktin.body = ssh->pktin.data + st->pad + 1; |
| 865 | } |
| 866 | |
| 867 | memcpy(ssh->pktin.body - 1, decompblk, decomplen); |
| 868 | sfree(decompblk); |
| 869 | ssh->pktin.length = decomplen - 1; |
| 870 | } |
| 871 | |
| 872 | ssh->pktin.type = ssh->pktin.body[-1]; |
| 873 | |
| 874 | if (ssh->logctx) |
| 875 | log_packet(ssh->logctx, |
| 876 | PKT_INCOMING, ssh->pktin.type, |
| 877 | ssh1_pkt_type(ssh->pktin.type), |
| 878 | ssh->pktin.body, ssh->pktin.length); |
| 879 | |
| 880 | if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 881 | ssh->pktin.type == SSH1_SMSG_STDERR_DATA || |
| 882 | ssh->pktin.type == SSH1_MSG_DEBUG || |
| 883 | ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
| 884 | ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 885 | long stringlen = GET_32BIT(ssh->pktin.body); |
| 886 | if (stringlen + 4 != ssh->pktin.length) { |
| 887 | bombout((ssh,"Received data packet with bogus string length")); |
| 888 | crReturn(0); |
| 889 | } |
| 890 | } |
| 891 | |
| 892 | if (ssh->pktin.type == SSH1_MSG_DEBUG) { |
| 893 | /* log debug message */ |
| 894 | char buf[512]; |
| 895 | int stringlen = GET_32BIT(ssh->pktin.body); |
| 896 | strcpy(buf, "Remote debug message: "); |
| 897 | if (stringlen > 480) |
| 898 | stringlen = 480; |
| 899 | memcpy(buf + 8, ssh->pktin.body + 4, stringlen); |
| 900 | buf[8 + stringlen] = '\0'; |
| 901 | logevent(buf); |
| 902 | goto next_packet; |
| 903 | } else if (ssh->pktin.type == SSH1_MSG_IGNORE) { |
| 904 | /* do nothing */ |
| 905 | goto next_packet; |
| 906 | } |
| 907 | |
| 908 | if (ssh->pktin.type == SSH1_MSG_DISCONNECT) { |
| 909 | /* log reason code in disconnect message */ |
| 910 | char buf[256]; |
| 911 | unsigned msglen = GET_32BIT(ssh->pktin.body); |
| 912 | unsigned nowlen; |
| 913 | strcpy(buf, "Remote sent disconnect: "); |
| 914 | nowlen = strlen(buf); |
| 915 | if (msglen > sizeof(buf) - nowlen - 1) |
| 916 | msglen = sizeof(buf) - nowlen - 1; |
| 917 | memcpy(buf + nowlen, ssh->pktin.body + 4, msglen); |
| 918 | buf[nowlen + msglen] = '\0'; |
| 919 | /* logevent(buf); (this is now done within the bombout macro) */ |
| 920 | bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen)); |
| 921 | crReturn(0); |
| 922 | } |
| 923 | |
| 924 | crFinish(0); |
| 925 | } |
| 926 | |
| 927 | static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) |
| 928 | { |
| 929 | struct rdpkt2_state_tag *st = &ssh->rdpkt2_state; |
| 930 | |
| 931 | crBegin(ssh->ssh2_rdpkt_crstate); |
| 932 | |
| 933 | next_packet: |
| 934 | ssh->pktin.type = 0; |
| 935 | ssh->pktin.length = 0; |
| 936 | if (ssh->sccipher) |
| 937 | st->cipherblk = ssh->sccipher->blksize; |
| 938 | else |
| 939 | st->cipherblk = 8; |
| 940 | if (st->cipherblk < 8) |
| 941 | st->cipherblk = 8; |
| 942 | |
| 943 | if (ssh->pktin.maxlen < st->cipherblk) { |
| 944 | ssh->pktin.maxlen = st->cipherblk; |
| 945 | ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA); |
| 946 | } |
| 947 | |
| 948 | /* |
| 949 | * Acquire and decrypt the first block of the packet. This will |
| 950 | * contain the length and padding details. |
| 951 | */ |
| 952 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
| 953 | while ((*datalen) == 0) |
| 954 | crReturn(st->cipherblk - st->i); |
| 955 | ssh->pktin.data[st->i] = *(*data)++; |
| 956 | (*datalen)--; |
| 957 | } |
| 958 | |
| 959 | if (ssh->sccipher) |
| 960 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, |
| 961 | ssh->pktin.data, st->cipherblk); |
| 962 | |
| 963 | /* |
| 964 | * Now get the length and padding figures. |
| 965 | */ |
| 966 | st->len = GET_32BIT(ssh->pktin.data); |
| 967 | st->pad = ssh->pktin.data[4]; |
| 968 | |
| 969 | /* |
| 970 | * _Completely_ silly lengths should be stomped on before they |
| 971 | * do us any more damage. |
| 972 | */ |
| 973 | if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) { |
| 974 | bombout((ssh,"Incoming packet was garbled on decryption")); |
| 975 | crReturn(0); |
| 976 | } |
| 977 | |
| 978 | /* |
| 979 | * This enables us to deduce the payload length. |
| 980 | */ |
| 981 | st->payload = st->len - st->pad - 1; |
| 982 | |
| 983 | ssh->pktin.length = st->payload + 5; |
| 984 | |
| 985 | /* |
| 986 | * So now we can work out the total packet length. |
| 987 | */ |
| 988 | st->packetlen = st->len + 4; |
| 989 | st->maclen = ssh->scmac ? ssh->scmac->len : 0; |
| 990 | |
| 991 | /* |
| 992 | * Adjust memory allocation if packet is too big. |
| 993 | */ |
| 994 | if (ssh->pktin.maxlen < st->packetlen + st->maclen) { |
| 995 | ssh->pktin.maxlen = st->packetlen + st->maclen; |
| 996 | ssh->pktin.data = srealloc(ssh->pktin.data, |
| 997 | ssh->pktin.maxlen + APIEXTRA); |
| 998 | } |
| 999 | |
| 1000 | /* |
| 1001 | * Read and decrypt the remainder of the packet. |
| 1002 | */ |
| 1003 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; |
| 1004 | st->i++) { |
| 1005 | while ((*datalen) == 0) |
| 1006 | crReturn(st->packetlen + st->maclen - st->i); |
| 1007 | ssh->pktin.data[st->i] = *(*data)++; |
| 1008 | (*datalen)--; |
| 1009 | } |
| 1010 | /* Decrypt everything _except_ the MAC. */ |
| 1011 | if (ssh->sccipher) |
| 1012 | ssh->sccipher->decrypt(ssh->sc_cipher_ctx, |
| 1013 | ssh->pktin.data + st->cipherblk, |
| 1014 | st->packetlen - st->cipherblk); |
| 1015 | |
| 1016 | /* |
| 1017 | * Check the MAC. |
| 1018 | */ |
| 1019 | if (ssh->scmac |
| 1020 | && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4, |
| 1021 | st->incoming_sequence)) { |
| 1022 | bombout((ssh,"Incorrect MAC received on packet")); |
| 1023 | crReturn(0); |
| 1024 | } |
| 1025 | st->incoming_sequence++; /* whether or not we MACed */ |
| 1026 | |
| 1027 | /* |
| 1028 | * Decompress packet payload. |
| 1029 | */ |
| 1030 | { |
| 1031 | unsigned char *newpayload; |
| 1032 | int newlen; |
| 1033 | if (ssh->sccomp && |
| 1034 | ssh->sccomp->decompress(ssh->sc_comp_ctx, |
| 1035 | ssh->pktin.data + 5, ssh->pktin.length - 5, |
| 1036 | &newpayload, &newlen)) { |
| 1037 | if (ssh->pktin.maxlen < newlen + 5) { |
| 1038 | ssh->pktin.maxlen = newlen + 5; |
| 1039 | ssh->pktin.data = srealloc(ssh->pktin.data, |
| 1040 | ssh->pktin.maxlen + APIEXTRA); |
| 1041 | } |
| 1042 | ssh->pktin.length = 5 + newlen; |
| 1043 | memcpy(ssh->pktin.data + 5, newpayload, newlen); |
| 1044 | sfree(newpayload); |
| 1045 | } |
| 1046 | } |
| 1047 | |
| 1048 | ssh->pktin.savedpos = 6; |
| 1049 | ssh->pktin.type = ssh->pktin.data[5]; |
| 1050 | |
| 1051 | if (ssh->logctx) |
| 1052 | log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type, |
| 1053 | ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type), |
| 1054 | ssh->pktin.data+6, ssh->pktin.length-6); |
| 1055 | |
| 1056 | switch (ssh->pktin.type) { |
| 1057 | /* |
| 1058 | * These packets we must handle instantly. |
| 1059 | */ |
| 1060 | case SSH2_MSG_DISCONNECT: |
| 1061 | { |
| 1062 | /* log reason code in disconnect message */ |
| 1063 | char *buf; |
| 1064 | int nowlen; |
| 1065 | int reason = GET_32BIT(ssh->pktin.data + 6); |
| 1066 | unsigned msglen = GET_32BIT(ssh->pktin.data + 10); |
| 1067 | |
| 1068 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
| 1069 | buf = dupprintf("Received disconnect message (%s)", |
| 1070 | ssh2_disconnect_reasons[reason]); |
| 1071 | } else { |
| 1072 | buf = dupprintf("Received disconnect message (unknown" |
| 1073 | " type %d)", reason); |
| 1074 | } |
| 1075 | logevent(buf); |
| 1076 | sfree(buf); |
| 1077 | buf = dupprintf("Disconnection message text: %n%.*s", |
| 1078 | &nowlen, msglen, ssh->pktin.data + 14); |
| 1079 | logevent(buf); |
| 1080 | bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"", |
| 1081 | reason, |
| 1082 | (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? |
| 1083 | ssh2_disconnect_reasons[reason] : "unknown", |
| 1084 | buf+nowlen)); |
| 1085 | sfree(buf); |
| 1086 | crReturn(0); |
| 1087 | } |
| 1088 | break; |
| 1089 | case SSH2_MSG_IGNORE: |
| 1090 | goto next_packet; |
| 1091 | case SSH2_MSG_DEBUG: |
| 1092 | { |
| 1093 | /* log the debug message */ |
| 1094 | char buf[512]; |
| 1095 | /* int display = ssh->pktin.body[6]; */ |
| 1096 | int stringlen = GET_32BIT(ssh->pktin.data+7); |
| 1097 | int prefix; |
| 1098 | strcpy(buf, "Remote debug message: "); |
| 1099 | prefix = strlen(buf); |
| 1100 | if (stringlen > (int)(sizeof(buf)-prefix-1)) |
| 1101 | stringlen = sizeof(buf)-prefix-1; |
| 1102 | memcpy(buf + prefix, ssh->pktin.data + 11, stringlen); |
| 1103 | buf[prefix + stringlen] = '\0'; |
| 1104 | logevent(buf); |
| 1105 | } |
| 1106 | goto next_packet; /* FIXME: print the debug message */ |
| 1107 | |
| 1108 | /* |
| 1109 | * These packets we need do nothing about here. |
| 1110 | */ |
| 1111 | case SSH2_MSG_UNIMPLEMENTED: |
| 1112 | case SSH2_MSG_SERVICE_REQUEST: |
| 1113 | case SSH2_MSG_SERVICE_ACCEPT: |
| 1114 | case SSH2_MSG_KEXINIT: |
| 1115 | case SSH2_MSG_NEWKEYS: |
| 1116 | case SSH2_MSG_KEXDH_INIT: |
| 1117 | case SSH2_MSG_KEXDH_REPLY: |
| 1118 | /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */ |
| 1119 | /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */ |
| 1120 | case SSH2_MSG_KEX_DH_GEX_INIT: |
| 1121 | case SSH2_MSG_KEX_DH_GEX_REPLY: |
| 1122 | case SSH2_MSG_USERAUTH_REQUEST: |
| 1123 | case SSH2_MSG_USERAUTH_FAILURE: |
| 1124 | case SSH2_MSG_USERAUTH_SUCCESS: |
| 1125 | case SSH2_MSG_USERAUTH_BANNER: |
| 1126 | case SSH2_MSG_USERAUTH_PK_OK: |
| 1127 | /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */ |
| 1128 | /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */ |
| 1129 | case SSH2_MSG_USERAUTH_INFO_RESPONSE: |
| 1130 | case SSH2_MSG_GLOBAL_REQUEST: |
| 1131 | case SSH2_MSG_REQUEST_SUCCESS: |
| 1132 | case SSH2_MSG_REQUEST_FAILURE: |
| 1133 | case SSH2_MSG_CHANNEL_OPEN: |
| 1134 | case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION: |
| 1135 | case SSH2_MSG_CHANNEL_OPEN_FAILURE: |
| 1136 | case SSH2_MSG_CHANNEL_WINDOW_ADJUST: |
| 1137 | case SSH2_MSG_CHANNEL_DATA: |
| 1138 | case SSH2_MSG_CHANNEL_EXTENDED_DATA: |
| 1139 | case SSH2_MSG_CHANNEL_EOF: |
| 1140 | case SSH2_MSG_CHANNEL_CLOSE: |
| 1141 | case SSH2_MSG_CHANNEL_REQUEST: |
| 1142 | case SSH2_MSG_CHANNEL_SUCCESS: |
| 1143 | case SSH2_MSG_CHANNEL_FAILURE: |
| 1144 | break; |
| 1145 | |
| 1146 | /* |
| 1147 | * For anything else we send SSH2_MSG_UNIMPLEMENTED. |
| 1148 | */ |
| 1149 | default: |
| 1150 | ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED); |
| 1151 | ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1); |
| 1152 | ssh2_pkt_send(ssh); |
| 1153 | break; |
| 1154 | } |
| 1155 | |
| 1156 | crFinish(0); |
| 1157 | } |
| 1158 | |
| 1159 | static void ssh1_pktout_size(Ssh ssh, int len) |
| 1160 | { |
| 1161 | int pad, biglen; |
| 1162 | |
| 1163 | len += 5; /* type and CRC */ |
| 1164 | pad = 8 - (len % 8); |
| 1165 | biglen = len + pad; |
| 1166 | |
| 1167 | ssh->pktout.length = len - 5; |
| 1168 | if (ssh->pktout.maxlen < biglen) { |
| 1169 | ssh->pktout.maxlen = biglen; |
| 1170 | #ifdef MSCRYPTOAPI |
| 1171 | /* Allocate enough buffer space for extra block |
| 1172 | * for MS CryptEncrypt() */ |
| 1173 | ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12); |
| 1174 | #else |
| 1175 | ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4); |
| 1176 | #endif |
| 1177 | } |
| 1178 | ssh->pktout.body = ssh->pktout.data + 4 + pad + 1; |
| 1179 | } |
| 1180 | |
| 1181 | static void s_wrpkt_start(Ssh ssh, int type, int len) |
| 1182 | { |
| 1183 | ssh1_pktout_size(ssh, len); |
| 1184 | ssh->pktout.type = type; |
| 1185 | } |
| 1186 | |
| 1187 | static int s_wrpkt_prepare(Ssh ssh) |
| 1188 | { |
| 1189 | int pad, biglen, i; |
| 1190 | unsigned long crc; |
| 1191 | #ifdef __SC__ |
| 1192 | /* |
| 1193 | * XXX various versions of SC (including 8.8.4) screw up the |
| 1194 | * register allocation in this function and use the same register |
| 1195 | * (D6) for len and as a temporary, with predictable results. The |
| 1196 | * following sledgehammer prevents this. |
| 1197 | */ |
| 1198 | volatile |
| 1199 | #endif |
| 1200 | int len; |
| 1201 | |
| 1202 | ssh->pktout.body[-1] = ssh->pktout.type; |
| 1203 | |
| 1204 | if (ssh->logctx) |
| 1205 | log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type, |
| 1206 | ssh1_pkt_type(ssh->pktout.type), |
| 1207 | ssh->pktout.body, ssh->pktout.length); |
| 1208 | |
| 1209 | if (ssh->v1_compressing) { |
| 1210 | unsigned char *compblk; |
| 1211 | int complen; |
| 1212 | zlib_compress_block(ssh->cs_comp_ctx, |
| 1213 | ssh->pktout.body - 1, ssh->pktout.length + 1, |
| 1214 | &compblk, &complen); |
| 1215 | ssh1_pktout_size(ssh, complen - 1); |
| 1216 | memcpy(ssh->pktout.body - 1, compblk, complen); |
| 1217 | sfree(compblk); |
| 1218 | } |
| 1219 | |
| 1220 | len = ssh->pktout.length + 5; /* type and CRC */ |
| 1221 | pad = 8 - (len % 8); |
| 1222 | biglen = len + pad; |
| 1223 | |
| 1224 | for (i = 0; i < pad; i++) |
| 1225 | ssh->pktout.data[i + 4] = random_byte(); |
| 1226 | crc = crc32(ssh->pktout.data + 4, biglen - 4); |
| 1227 | PUT_32BIT(ssh->pktout.data + biglen, crc); |
| 1228 | PUT_32BIT(ssh->pktout.data, len); |
| 1229 | |
| 1230 | if (ssh->cipher) |
| 1231 | ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen); |
| 1232 | |
| 1233 | return biglen + 4; |
| 1234 | } |
| 1235 | |
| 1236 | static void s_wrpkt(Ssh ssh) |
| 1237 | { |
| 1238 | int len, backlog; |
| 1239 | len = s_wrpkt_prepare(ssh); |
| 1240 | backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len); |
| 1241 | if (backlog > SSH_MAX_BACKLOG) |
| 1242 | ssh_throttle_all(ssh, 1, backlog); |
| 1243 | } |
| 1244 | |
| 1245 | static void s_wrpkt_defer(Ssh ssh) |
| 1246 | { |
| 1247 | int len; |
| 1248 | len = s_wrpkt_prepare(ssh); |
| 1249 | if (ssh->deferred_len + len > ssh->deferred_size) { |
| 1250 | ssh->deferred_size = ssh->deferred_len + len + 128; |
| 1251 | ssh->deferred_send_data = srealloc(ssh->deferred_send_data, |
| 1252 | ssh->deferred_size); |
| 1253 | } |
| 1254 | memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len); |
| 1255 | ssh->deferred_len += len; |
| 1256 | } |
| 1257 | |
| 1258 | /* |
| 1259 | * Construct a packet with the specified contents. |
| 1260 | */ |
| 1261 | static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2) |
| 1262 | { |
| 1263 | unsigned char *p, *argp, argchar; |
| 1264 | unsigned long argint; |
| 1265 | int pktlen, argtype, arglen; |
| 1266 | Bignum bn; |
| 1267 | |
| 1268 | pktlen = 0; |
| 1269 | while ((argtype = va_arg(ap1, int)) != PKT_END) { |
| 1270 | switch (argtype) { |
| 1271 | case PKT_INT: |
| 1272 | (void) va_arg(ap1, int); |
| 1273 | pktlen += 4; |
| 1274 | break; |
| 1275 | case PKT_CHAR: |
| 1276 | (void) va_arg(ap1, int); |
| 1277 | pktlen++; |
| 1278 | break; |
| 1279 | case PKT_DATA: |
| 1280 | (void) va_arg(ap1, unsigned char *); |
| 1281 | arglen = va_arg(ap1, int); |
| 1282 | pktlen += arglen; |
| 1283 | break; |
| 1284 | case PKT_STR: |
| 1285 | argp = va_arg(ap1, unsigned char *); |
| 1286 | arglen = strlen((char *)argp); |
| 1287 | pktlen += 4 + arglen; |
| 1288 | break; |
| 1289 | case PKT_BIGNUM: |
| 1290 | bn = va_arg(ap1, Bignum); |
| 1291 | pktlen += ssh1_bignum_length(bn); |
| 1292 | break; |
| 1293 | default: |
| 1294 | assert(0); |
| 1295 | } |
| 1296 | } |
| 1297 | |
| 1298 | s_wrpkt_start(ssh, pkttype, pktlen); |
| 1299 | p = ssh->pktout.body; |
| 1300 | |
| 1301 | while ((argtype = va_arg(ap2, int)) != PKT_END) { |
| 1302 | switch (argtype) { |
| 1303 | case PKT_INT: |
| 1304 | argint = va_arg(ap2, int); |
| 1305 | PUT_32BIT(p, argint); |
| 1306 | p += 4; |
| 1307 | break; |
| 1308 | case PKT_CHAR: |
| 1309 | argchar = (unsigned char) va_arg(ap2, int); |
| 1310 | *p = argchar; |
| 1311 | p++; |
| 1312 | break; |
| 1313 | case PKT_DATA: |
| 1314 | argp = va_arg(ap2, unsigned char *); |
| 1315 | arglen = va_arg(ap2, int); |
| 1316 | memcpy(p, argp, arglen); |
| 1317 | p += arglen; |
| 1318 | break; |
| 1319 | case PKT_STR: |
| 1320 | argp = va_arg(ap2, unsigned char *); |
| 1321 | arglen = strlen((char *)argp); |
| 1322 | PUT_32BIT(p, arglen); |
| 1323 | memcpy(p + 4, argp, arglen); |
| 1324 | p += 4 + arglen; |
| 1325 | break; |
| 1326 | case PKT_BIGNUM: |
| 1327 | bn = va_arg(ap2, Bignum); |
| 1328 | p += ssh1_write_bignum(p, bn); |
| 1329 | break; |
| 1330 | } |
| 1331 | } |
| 1332 | } |
| 1333 | |
| 1334 | static void send_packet(Ssh ssh, int pkttype, ...) |
| 1335 | { |
| 1336 | va_list ap1, ap2; |
| 1337 | va_start(ap1, pkttype); |
| 1338 | va_start(ap2, pkttype); |
| 1339 | construct_packet(ssh, pkttype, ap1, ap2); |
| 1340 | s_wrpkt(ssh); |
| 1341 | } |
| 1342 | |
| 1343 | static void defer_packet(Ssh ssh, int pkttype, ...) |
| 1344 | { |
| 1345 | va_list ap1, ap2; |
| 1346 | va_start(ap1, pkttype); |
| 1347 | va_start(ap2, pkttype); |
| 1348 | construct_packet(ssh, pkttype, ap1, ap2); |
| 1349 | s_wrpkt_defer(ssh); |
| 1350 | } |
| 1351 | |
| 1352 | static int ssh_versioncmp(char *a, char *b) |
| 1353 | { |
| 1354 | char *ae, *be; |
| 1355 | unsigned long av, bv; |
| 1356 | |
| 1357 | av = strtoul(a, &ae, 10); |
| 1358 | bv = strtoul(b, &be, 10); |
| 1359 | if (av != bv) |
| 1360 | return (av < bv ? -1 : +1); |
| 1361 | if (*ae == '.') |
| 1362 | ae++; |
| 1363 | if (*be == '.') |
| 1364 | be++; |
| 1365 | av = strtoul(ae, &ae, 10); |
| 1366 | bv = strtoul(be, &be, 10); |
| 1367 | if (av != bv) |
| 1368 | return (av < bv ? -1 : +1); |
| 1369 | return 0; |
| 1370 | } |
| 1371 | |
| 1372 | /* |
| 1373 | * Utility routines for putting an SSH-protocol `string' and |
| 1374 | * `uint32' into a SHA state. |
| 1375 | */ |
| 1376 | #include <stdio.h> |
| 1377 | static void sha_string(SHA_State * s, void *str, int len) |
| 1378 | { |
| 1379 | unsigned char lenblk[4]; |
| 1380 | PUT_32BIT(lenblk, len); |
| 1381 | SHA_Bytes(s, lenblk, 4); |
| 1382 | SHA_Bytes(s, str, len); |
| 1383 | } |
| 1384 | |
| 1385 | static void sha_uint32(SHA_State * s, unsigned i) |
| 1386 | { |
| 1387 | unsigned char intblk[4]; |
| 1388 | PUT_32BIT(intblk, i); |
| 1389 | SHA_Bytes(s, intblk, 4); |
| 1390 | } |
| 1391 | |
| 1392 | /* |
| 1393 | * SSH2 packet construction functions. |
| 1394 | */ |
| 1395 | static void ssh2_pkt_ensure(Ssh ssh, int length) |
| 1396 | { |
| 1397 | if (ssh->pktout.maxlen < length) { |
| 1398 | ssh->pktout.maxlen = length + 256; |
| 1399 | ssh->pktout.data = srealloc(ssh->pktout.data, |
| 1400 | ssh->pktout.maxlen + APIEXTRA); |
| 1401 | if (!ssh->pktout.data) |
| 1402 | fatalbox("Out of memory"); |
| 1403 | } |
| 1404 | } |
| 1405 | static void ssh2_pkt_adddata(Ssh ssh, void *data, int len) |
| 1406 | { |
| 1407 | ssh->pktout.length += len; |
| 1408 | ssh2_pkt_ensure(ssh, ssh->pktout.length); |
| 1409 | memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len); |
| 1410 | } |
| 1411 | static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte) |
| 1412 | { |
| 1413 | ssh2_pkt_adddata(ssh, &byte, 1); |
| 1414 | } |
| 1415 | static void ssh2_pkt_init(Ssh ssh, int pkt_type) |
| 1416 | { |
| 1417 | ssh->pktout.length = 5; |
| 1418 | ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type); |
| 1419 | } |
| 1420 | static void ssh2_pkt_addbool(Ssh ssh, unsigned char value) |
| 1421 | { |
| 1422 | ssh2_pkt_adddata(ssh, &value, 1); |
| 1423 | } |
| 1424 | static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value) |
| 1425 | { |
| 1426 | unsigned char x[4]; |
| 1427 | PUT_32BIT(x, value); |
| 1428 | ssh2_pkt_adddata(ssh, x, 4); |
| 1429 | } |
| 1430 | static void ssh2_pkt_addstring_start(Ssh ssh) |
| 1431 | { |
| 1432 | ssh2_pkt_adduint32(ssh, 0); |
| 1433 | ssh->pktout.savedpos = ssh->pktout.length; |
| 1434 | } |
| 1435 | static void ssh2_pkt_addstring_str(Ssh ssh, char *data) |
| 1436 | { |
| 1437 | ssh2_pkt_adddata(ssh, data, strlen(data)); |
| 1438 | PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4, |
| 1439 | ssh->pktout.length - ssh->pktout.savedpos); |
| 1440 | } |
| 1441 | static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len) |
| 1442 | { |
| 1443 | ssh2_pkt_adddata(ssh, data, len); |
| 1444 | PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4, |
| 1445 | ssh->pktout.length - ssh->pktout.savedpos); |
| 1446 | } |
| 1447 | static void ssh2_pkt_addstring(Ssh ssh, char *data) |
| 1448 | { |
| 1449 | ssh2_pkt_addstring_start(ssh); |
| 1450 | ssh2_pkt_addstring_str(ssh, data); |
| 1451 | } |
| 1452 | static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) |
| 1453 | { |
| 1454 | unsigned char *p; |
| 1455 | int i, n = (bignum_bitcount(b) + 7) / 8; |
| 1456 | p = smalloc(n + 1); |
| 1457 | if (!p) |
| 1458 | fatalbox("out of memory"); |
| 1459 | p[0] = 0; |
| 1460 | for (i = 1; i <= n; i++) |
| 1461 | p[i] = bignum_byte(b, n - i); |
| 1462 | i = 0; |
| 1463 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) |
| 1464 | i++; |
| 1465 | memmove(p, p + i, n + 1 - i); |
| 1466 | *len = n + 1 - i; |
| 1467 | return p; |
| 1468 | } |
| 1469 | static void ssh2_pkt_addmp(Ssh ssh, Bignum b) |
| 1470 | { |
| 1471 | unsigned char *p; |
| 1472 | int len; |
| 1473 | p = ssh2_mpint_fmt(b, &len); |
| 1474 | ssh2_pkt_addstring_start(ssh); |
| 1475 | ssh2_pkt_addstring_data(ssh, (char *)p, len); |
| 1476 | sfree(p); |
| 1477 | } |
| 1478 | |
| 1479 | /* |
| 1480 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
| 1481 | * put the MAC on it. Final packet, ready to be sent, is stored in |
| 1482 | * ssh->pktout.data. Total length is returned. |
| 1483 | */ |
| 1484 | static int ssh2_pkt_construct(Ssh ssh) |
| 1485 | { |
| 1486 | int cipherblk, maclen, padding, i; |
| 1487 | |
| 1488 | if (ssh->logctx) |
| 1489 | log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5], |
| 1490 | ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]), |
| 1491 | ssh->pktout.data + 6, ssh->pktout.length - 6); |
| 1492 | |
| 1493 | /* |
| 1494 | * Compress packet payload. |
| 1495 | */ |
| 1496 | { |
| 1497 | unsigned char *newpayload; |
| 1498 | int newlen; |
| 1499 | if (ssh->cscomp && |
| 1500 | ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5, |
| 1501 | ssh->pktout.length - 5, |
| 1502 | &newpayload, &newlen)) { |
| 1503 | ssh->pktout.length = 5; |
| 1504 | ssh2_pkt_adddata(ssh, newpayload, newlen); |
| 1505 | sfree(newpayload); |
| 1506 | } |
| 1507 | } |
| 1508 | |
| 1509 | /* |
| 1510 | * Add padding. At least four bytes, and must also bring total |
| 1511 | * length (minus MAC) up to a multiple of the block size. |
| 1512 | */ |
| 1513 | cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ |
| 1514 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 1515 | padding = 4; |
| 1516 | padding += |
| 1517 | (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk; |
| 1518 | maclen = ssh->csmac ? ssh->csmac->len : 0; |
| 1519 | ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen); |
| 1520 | ssh->pktout.data[4] = padding; |
| 1521 | for (i = 0; i < padding; i++) |
| 1522 | ssh->pktout.data[ssh->pktout.length + i] = random_byte(); |
| 1523 | PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4); |
| 1524 | if (ssh->csmac) |
| 1525 | ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data, |
| 1526 | ssh->pktout.length + padding, |
| 1527 | ssh->v2_outgoing_sequence); |
| 1528 | ssh->v2_outgoing_sequence++; /* whether or not we MACed */ |
| 1529 | |
| 1530 | if (ssh->cscipher) |
| 1531 | ssh->cscipher->encrypt(ssh->cs_cipher_ctx, |
| 1532 | ssh->pktout.data, ssh->pktout.length + padding); |
| 1533 | |
| 1534 | /* Ready-to-send packet starts at ssh->pktout.data. We return length. */ |
| 1535 | return ssh->pktout.length + padding + maclen; |
| 1536 | } |
| 1537 | |
| 1538 | /* |
| 1539 | * Construct and send an SSH2 packet immediately. |
| 1540 | */ |
| 1541 | static void ssh2_pkt_send(Ssh ssh) |
| 1542 | { |
| 1543 | int len; |
| 1544 | int backlog; |
| 1545 | len = ssh2_pkt_construct(ssh); |
| 1546 | backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len); |
| 1547 | if (backlog > SSH_MAX_BACKLOG) |
| 1548 | ssh_throttle_all(ssh, 1, backlog); |
| 1549 | } |
| 1550 | |
| 1551 | /* |
| 1552 | * Construct an SSH2 packet and add it to a deferred data block. |
| 1553 | * Useful for sending multiple packets in a single sk_write() call, |
| 1554 | * to prevent a traffic-analysing listener from being able to work |
| 1555 | * out the length of any particular packet (such as the password |
| 1556 | * packet). |
| 1557 | * |
| 1558 | * Note that because SSH2 sequence-numbers its packets, this can |
| 1559 | * NOT be used as an m4-style `defer' allowing packets to be |
| 1560 | * constructed in one order and sent in another. |
| 1561 | */ |
| 1562 | static void ssh2_pkt_defer(Ssh ssh) |
| 1563 | { |
| 1564 | int len = ssh2_pkt_construct(ssh); |
| 1565 | if (ssh->deferred_len + len > ssh->deferred_size) { |
| 1566 | ssh->deferred_size = ssh->deferred_len + len + 128; |
| 1567 | ssh->deferred_send_data = srealloc(ssh->deferred_send_data, |
| 1568 | ssh->deferred_size); |
| 1569 | } |
| 1570 | memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len); |
| 1571 | ssh->deferred_len += len; |
| 1572 | } |
| 1573 | |
| 1574 | /* |
| 1575 | * Send the whole deferred data block constructed by |
| 1576 | * ssh2_pkt_defer() or SSH1's defer_packet(). |
| 1577 | */ |
| 1578 | static void ssh_pkt_defersend(Ssh ssh) |
| 1579 | { |
| 1580 | int backlog; |
| 1581 | backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data, |
| 1582 | ssh->deferred_len); |
| 1583 | ssh->deferred_len = ssh->deferred_size = 0; |
| 1584 | sfree(ssh->deferred_send_data); |
| 1585 | ssh->deferred_send_data = NULL; |
| 1586 | if (backlog > SSH_MAX_BACKLOG) |
| 1587 | ssh_throttle_all(ssh, 1, backlog); |
| 1588 | } |
| 1589 | |
| 1590 | #if 0 |
| 1591 | void bndebug(char *string, Bignum b) |
| 1592 | { |
| 1593 | unsigned char *p; |
| 1594 | int i, len; |
| 1595 | p = ssh2_mpint_fmt(b, &len); |
| 1596 | debug(("%s", string)); |
| 1597 | for (i = 0; i < len; i++) |
| 1598 | debug((" %02x", p[i])); |
| 1599 | debug(("\n")); |
| 1600 | sfree(p); |
| 1601 | } |
| 1602 | #endif |
| 1603 | |
| 1604 | static void sha_mpint(SHA_State * s, Bignum b) |
| 1605 | { |
| 1606 | unsigned char *p; |
| 1607 | int len; |
| 1608 | p = ssh2_mpint_fmt(b, &len); |
| 1609 | sha_string(s, p, len); |
| 1610 | sfree(p); |
| 1611 | } |
| 1612 | |
| 1613 | /* |
| 1614 | * SSH2 packet decode functions. |
| 1615 | */ |
| 1616 | static unsigned long ssh2_pkt_getuint32(Ssh ssh) |
| 1617 | { |
| 1618 | unsigned long value; |
| 1619 | if (ssh->pktin.length - ssh->pktin.savedpos < 4) |
| 1620 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1621 | value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos); |
| 1622 | ssh->pktin.savedpos += 4; |
| 1623 | return value; |
| 1624 | } |
| 1625 | static int ssh2_pkt_getbool(Ssh ssh) |
| 1626 | { |
| 1627 | unsigned long value; |
| 1628 | if (ssh->pktin.length - ssh->pktin.savedpos < 1) |
| 1629 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1630 | value = ssh->pktin.data[ssh->pktin.savedpos] != 0; |
| 1631 | ssh->pktin.savedpos++; |
| 1632 | return value; |
| 1633 | } |
| 1634 | static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length) |
| 1635 | { |
| 1636 | int len; |
| 1637 | *p = NULL; |
| 1638 | *length = 0; |
| 1639 | if (ssh->pktin.length - ssh->pktin.savedpos < 4) |
| 1640 | return; |
| 1641 | len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos); |
| 1642 | if (len < 0) |
| 1643 | return; |
| 1644 | *length = len; |
| 1645 | ssh->pktin.savedpos += 4; |
| 1646 | if (ssh->pktin.length - ssh->pktin.savedpos < *length) |
| 1647 | return; |
| 1648 | *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos); |
| 1649 | ssh->pktin.savedpos += *length; |
| 1650 | } |
| 1651 | static Bignum ssh2_pkt_getmp(Ssh ssh) |
| 1652 | { |
| 1653 | char *p; |
| 1654 | int length; |
| 1655 | Bignum b; |
| 1656 | |
| 1657 | ssh2_pkt_getstring(ssh, &p, &length); |
| 1658 | if (!p) |
| 1659 | return NULL; |
| 1660 | if (p[0] & 0x80) { |
| 1661 | bombout((ssh,"internal error: Can't handle negative mpints")); |
| 1662 | return NULL; |
| 1663 | } |
| 1664 | b = bignum_from_bytes((unsigned char *)p, length); |
| 1665 | return b; |
| 1666 | } |
| 1667 | |
| 1668 | /* |
| 1669 | * Helper function to add an SSH2 signature blob to a packet. |
| 1670 | * Expects to be shown the public key blob as well as the signature |
| 1671 | * blob. Normally works just like ssh2_pkt_addstring, but will |
| 1672 | * fiddle with the signature packet if necessary for |
| 1673 | * BUG_SSH2_RSA_PADDING. |
| 1674 | */ |
| 1675 | static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len, |
| 1676 | void *sigblob_v, int sigblob_len) |
| 1677 | { |
| 1678 | unsigned char *pkblob = (unsigned char *)pkblob_v; |
| 1679 | unsigned char *sigblob = (unsigned char *)sigblob_v; |
| 1680 | |
| 1681 | /* dmemdump(pkblob, pkblob_len); */ |
| 1682 | /* dmemdump(sigblob, sigblob_len); */ |
| 1683 | |
| 1684 | /* |
| 1685 | * See if this is in fact an ssh-rsa signature and a buggy |
| 1686 | * server; otherwise we can just do this the easy way. |
| 1687 | */ |
| 1688 | if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && |
| 1689 | (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { |
| 1690 | int pos, len, siglen; |
| 1691 | |
| 1692 | /* |
| 1693 | * Find the byte length of the modulus. |
| 1694 | */ |
| 1695 | |
| 1696 | pos = 4+7; /* skip over "ssh-rsa" */ |
| 1697 | pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */ |
| 1698 | len = GET_32BIT(pkblob+pos); /* find length of modulus */ |
| 1699 | pos += 4; /* find modulus itself */ |
| 1700 | while (len > 0 && pkblob[pos] == 0) |
| 1701 | len--, pos++; |
| 1702 | /* debug(("modulus length is %d\n", len)); */ |
| 1703 | |
| 1704 | /* |
| 1705 | * Now find the signature integer. |
| 1706 | */ |
| 1707 | pos = 4+7; /* skip over "ssh-rsa" */ |
| 1708 | siglen = GET_32BIT(sigblob+pos); |
| 1709 | /* debug(("signature length is %d\n", siglen)); */ |
| 1710 | |
| 1711 | if (len != siglen) { |
| 1712 | unsigned char newlen[4]; |
| 1713 | ssh2_pkt_addstring_start(ssh); |
| 1714 | ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos); |
| 1715 | /* dmemdump(sigblob, pos); */ |
| 1716 | pos += 4; /* point to start of actual sig */ |
| 1717 | PUT_32BIT(newlen, len); |
| 1718 | ssh2_pkt_addstring_data(ssh, (char *)newlen, 4); |
| 1719 | /* dmemdump(newlen, 4); */ |
| 1720 | newlen[0] = 0; |
| 1721 | while (len-- > siglen) { |
| 1722 | ssh2_pkt_addstring_data(ssh, (char *)newlen, 1); |
| 1723 | /* dmemdump(newlen, 1); */ |
| 1724 | } |
| 1725 | ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen); |
| 1726 | /* dmemdump(sigblob+pos, siglen); */ |
| 1727 | return; |
| 1728 | } |
| 1729 | |
| 1730 | /* Otherwise fall through and do it the easy way. */ |
| 1731 | } |
| 1732 | |
| 1733 | ssh2_pkt_addstring_start(ssh); |
| 1734 | ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len); |
| 1735 | } |
| 1736 | |
| 1737 | /* |
| 1738 | * Examine the remote side's version string and compare it against |
| 1739 | * a list of known buggy implementations. |
| 1740 | */ |
| 1741 | static void ssh_detect_bugs(Ssh ssh, char *vstring) |
| 1742 | { |
| 1743 | char *imp; /* pointer to implementation part */ |
| 1744 | imp = vstring; |
| 1745 | imp += strcspn(imp, "-"); |
| 1746 | if (*imp) imp++; |
| 1747 | imp += strcspn(imp, "-"); |
| 1748 | if (*imp) imp++; |
| 1749 | |
| 1750 | ssh->remote_bugs = 0; |
| 1751 | |
| 1752 | if (ssh->cfg.sshbug_ignore1 == FORCE_ON || |
| 1753 | (ssh->cfg.sshbug_ignore1 == AUTO && |
| 1754 | (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
| 1755 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
| 1756 | !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) { |
| 1757 | /* |
| 1758 | * These versions don't support SSH1_MSG_IGNORE, so we have |
| 1759 | * to use a different defence against password length |
| 1760 | * sniffing. |
| 1761 | */ |
| 1762 | ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
| 1763 | logevent("We believe remote version has SSH1 ignore bug"); |
| 1764 | } |
| 1765 | |
| 1766 | if (ssh->cfg.sshbug_plainpw1 == FORCE_ON || |
| 1767 | (ssh->cfg.sshbug_plainpw1 == AUTO && |
| 1768 | (!strcmp(imp, "Cisco-1.25")))) { |
| 1769 | /* |
| 1770 | * These versions need a plain password sent; they can't |
| 1771 | * handle having a null and a random length of data after |
| 1772 | * the password. |
| 1773 | */ |
| 1774 | ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; |
| 1775 | logevent("We believe remote version needs a plain SSH1 password"); |
| 1776 | } |
| 1777 | |
| 1778 | if (ssh->cfg.sshbug_rsa1 == FORCE_ON || |
| 1779 | (ssh->cfg.sshbug_rsa1 == AUTO && |
| 1780 | (!strcmp(imp, "Cisco-1.25")))) { |
| 1781 | /* |
| 1782 | * These versions apparently have no clue whatever about |
| 1783 | * RSA authentication and will panic and die if they see |
| 1784 | * an AUTH_RSA message. |
| 1785 | */ |
| 1786 | ssh->remote_bugs |= BUG_CHOKES_ON_RSA; |
| 1787 | logevent("We believe remote version can't handle RSA authentication"); |
| 1788 | } |
| 1789 | |
| 1790 | if (ssh->cfg.sshbug_hmac2 == FORCE_ON || |
| 1791 | (ssh->cfg.sshbug_hmac2 == AUTO && |
| 1792 | (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) || |
| 1793 | wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) || |
| 1794 | wc_match("2.1 *", imp)))) { |
| 1795 | /* |
| 1796 | * These versions have the HMAC bug. |
| 1797 | */ |
| 1798 | ssh->remote_bugs |= BUG_SSH2_HMAC; |
| 1799 | logevent("We believe remote version has SSH2 HMAC bug"); |
| 1800 | } |
| 1801 | |
| 1802 | if (ssh->cfg.sshbug_derivekey2 == FORCE_ON || |
| 1803 | (ssh->cfg.sshbug_derivekey2 == AUTO && |
| 1804 | (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) { |
| 1805 | /* |
| 1806 | * These versions have the key-derivation bug (failing to |
| 1807 | * include the literal shared secret in the hashes that |
| 1808 | * generate the keys). |
| 1809 | */ |
| 1810 | ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; |
| 1811 | logevent("We believe remote version has SSH2 key-derivation bug"); |
| 1812 | } |
| 1813 | |
| 1814 | if (ssh->cfg.sshbug_rsapad2 == FORCE_ON || |
| 1815 | (ssh->cfg.sshbug_rsapad2 == AUTO && |
| 1816 | (wc_match("OpenSSH_2.[5-9]*", imp) || |
| 1817 | wc_match("OpenSSH_3.[0-2]*", imp)))) { |
| 1818 | /* |
| 1819 | * These versions have the SSH2 RSA padding bug. |
| 1820 | */ |
| 1821 | ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; |
| 1822 | logevent("We believe remote version has SSH2 RSA padding bug"); |
| 1823 | } |
| 1824 | |
| 1825 | if (ssh->cfg.sshbug_pksessid2 == FORCE_ON || |
| 1826 | (ssh->cfg.sshbug_pksessid2 == AUTO && |
| 1827 | wc_match("OpenSSH_2.[0-2]*", imp))) { |
| 1828 | /* |
| 1829 | * These versions have the SSH2 session-ID bug in |
| 1830 | * public-key authentication. |
| 1831 | */ |
| 1832 | ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; |
| 1833 | logevent("We believe remote version has SSH2 public-key-session-ID bug"); |
| 1834 | } |
| 1835 | |
| 1836 | if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) { |
| 1837 | /* |
| 1838 | * User specified the SSH2 DH GEX bug. |
| 1839 | */ |
| 1840 | ssh->remote_bugs |= BUG_SSH2_DH_GEX; |
| 1841 | logevent("We believe remote version has SSH2 DH group exchange bug"); |
| 1842 | } |
| 1843 | } |
| 1844 | |
| 1845 | static int do_ssh_init(Ssh ssh, unsigned char c) |
| 1846 | { |
| 1847 | struct do_ssh_init_state { |
| 1848 | int vslen; |
| 1849 | char version[10]; |
| 1850 | char *vstring; |
| 1851 | int vstrsize; |
| 1852 | int i; |
| 1853 | int proto1, proto2; |
| 1854 | }; |
| 1855 | crState(do_ssh_init_state); |
| 1856 | |
| 1857 | crBegin(ssh->do_ssh_init_crstate); |
| 1858 | |
| 1859 | /* Search for the string "SSH-" in the input. */ |
| 1860 | s->i = 0; |
| 1861 | while (1) { |
| 1862 | static const int transS[] = { 1, 2, 2, 1 }; |
| 1863 | static const int transH[] = { 0, 0, 3, 0 }; |
| 1864 | static const int transminus[] = { 0, 0, 0, -1 }; |
| 1865 | if (c == 'S') |
| 1866 | s->i = transS[s->i]; |
| 1867 | else if (c == 'H') |
| 1868 | s->i = transH[s->i]; |
| 1869 | else if (c == '-') |
| 1870 | s->i = transminus[s->i]; |
| 1871 | else |
| 1872 | s->i = 0; |
| 1873 | if (s->i < 0) |
| 1874 | break; |
| 1875 | crReturn(1); /* get another character */ |
| 1876 | } |
| 1877 | |
| 1878 | s->vstrsize = 16; |
| 1879 | s->vstring = smalloc(s->vstrsize); |
| 1880 | strcpy(s->vstring, "SSH-"); |
| 1881 | s->vslen = 4; |
| 1882 | s->i = 0; |
| 1883 | while (1) { |
| 1884 | crReturn(1); /* get another char */ |
| 1885 | if (s->vslen >= s->vstrsize - 1) { |
| 1886 | s->vstrsize += 16; |
| 1887 | s->vstring = srealloc(s->vstring, s->vstrsize); |
| 1888 | } |
| 1889 | s->vstring[s->vslen++] = c; |
| 1890 | if (s->i >= 0) { |
| 1891 | if (c == '-') { |
| 1892 | s->version[s->i] = '\0'; |
| 1893 | s->i = -1; |
| 1894 | } else if (s->i < sizeof(s->version) - 1) |
| 1895 | s->version[s->i++] = c; |
| 1896 | } else if (c == '\012') |
| 1897 | break; |
| 1898 | } |
| 1899 | |
| 1900 | ssh->agentfwd_enabled = FALSE; |
| 1901 | ssh->rdpkt2_state.incoming_sequence = 0; |
| 1902 | |
| 1903 | s->vstring[s->vslen] = 0; |
| 1904 | s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */ |
| 1905 | { |
| 1906 | char *vlog; |
| 1907 | vlog = smalloc(20 + s->vslen); |
| 1908 | sprintf(vlog, "Server version: %s", s->vstring); |
| 1909 | logevent(vlog); |
| 1910 | sfree(vlog); |
| 1911 | } |
| 1912 | ssh_detect_bugs(ssh, s->vstring); |
| 1913 | |
| 1914 | /* |
| 1915 | * Decide which SSH protocol version to support. |
| 1916 | */ |
| 1917 | |
| 1918 | /* Anything strictly below "2.0" means protocol 1 is supported. */ |
| 1919 | s->proto1 = ssh_versioncmp(s->version, "2.0") < 0; |
| 1920 | /* Anything greater or equal to "1.99" means protocol 2 is supported. */ |
| 1921 | s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0; |
| 1922 | |
| 1923 | if (ssh->cfg.sshprot == 0 && !s->proto1) { |
| 1924 | bombout((ssh,"SSH protocol version 1 required by user but not provided by server")); |
| 1925 | crReturn(0); |
| 1926 | } |
| 1927 | if (ssh->cfg.sshprot == 3 && !s->proto2) { |
| 1928 | bombout((ssh,"SSH protocol version 2 required by user but not provided by server")); |
| 1929 | crReturn(0); |
| 1930 | } |
| 1931 | |
| 1932 | if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) { |
| 1933 | /* |
| 1934 | * Use v2 protocol. |
| 1935 | */ |
| 1936 | char verstring[80], vlog[100]; |
| 1937 | sprintf(verstring, "SSH-2.0-%s", sshver); |
| 1938 | SHA_Init(&ssh->exhashbase); |
| 1939 | /* |
| 1940 | * Hash our version string and their version string. |
| 1941 | */ |
| 1942 | sha_string(&ssh->exhashbase, verstring, strlen(verstring)); |
| 1943 | sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n")); |
| 1944 | sprintf(vlog, "We claim version: %s", verstring); |
| 1945 | logevent(vlog); |
| 1946 | strcat(verstring, "\012"); |
| 1947 | logevent("Using SSH protocol version 2"); |
| 1948 | sk_write(ssh->s, verstring, strlen(verstring)); |
| 1949 | ssh->protocol = ssh2_protocol; |
| 1950 | ssh->version = 2; |
| 1951 | ssh->s_rdpkt = ssh2_rdpkt; |
| 1952 | } else { |
| 1953 | /* |
| 1954 | * Use v1 protocol. |
| 1955 | */ |
| 1956 | char verstring[80], vlog[100]; |
| 1957 | sprintf(verstring, "SSH-%s-%s", |
| 1958 | (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"), |
| 1959 | sshver); |
| 1960 | sprintf(vlog, "We claim version: %s", verstring); |
| 1961 | logevent(vlog); |
| 1962 | strcat(verstring, "\012"); |
| 1963 | |
| 1964 | logevent("Using SSH protocol version 1"); |
| 1965 | sk_write(ssh->s, verstring, strlen(verstring)); |
| 1966 | ssh->protocol = ssh1_protocol; |
| 1967 | ssh->version = 1; |
| 1968 | ssh->s_rdpkt = ssh1_rdpkt; |
| 1969 | } |
| 1970 | ssh->state = SSH_STATE_BEFORE_SIZE; |
| 1971 | |
| 1972 | sfree(s->vstring); |
| 1973 | |
| 1974 | crFinish(0); |
| 1975 | } |
| 1976 | |
| 1977 | static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) |
| 1978 | { |
| 1979 | crBegin(ssh->ssh_gotdata_crstate); |
| 1980 | |
| 1981 | /* |
| 1982 | * To begin with, feed the characters one by one to the |
| 1983 | * protocol initialisation / selection function do_ssh_init(). |
| 1984 | * When that returns 0, we're done with the initial greeting |
| 1985 | * exchange and can move on to packet discipline. |
| 1986 | */ |
| 1987 | while (1) { |
| 1988 | int ret; /* need not be kept across crReturn */ |
| 1989 | if (datalen == 0) |
| 1990 | crReturnV; /* more data please */ |
| 1991 | ret = do_ssh_init(ssh, *data); |
| 1992 | data++; |
| 1993 | datalen--; |
| 1994 | if (ret == 0) |
| 1995 | break; |
| 1996 | } |
| 1997 | |
| 1998 | /* |
| 1999 | * We emerge from that loop when the initial negotiation is |
| 2000 | * over and we have selected an s_rdpkt function. Now pass |
| 2001 | * everything to s_rdpkt, and then pass the resulting packets |
| 2002 | * to the proper protocol handler. |
| 2003 | */ |
| 2004 | if (datalen == 0) |
| 2005 | crReturnV; |
| 2006 | while (1) { |
| 2007 | while (datalen > 0) { |
| 2008 | if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) { |
| 2009 | if (ssh->state == SSH_STATE_CLOSED) { |
| 2010 | return; |
| 2011 | } |
| 2012 | ssh->protocol(ssh, NULL, 0, 1); |
| 2013 | if (ssh->state == SSH_STATE_CLOSED) { |
| 2014 | return; |
| 2015 | } |
| 2016 | } |
| 2017 | } |
| 2018 | crReturnV; |
| 2019 | } |
| 2020 | crFinishV; |
| 2021 | } |
| 2022 | |
| 2023 | static int ssh_closing(Plug plug, char *error_msg, int error_code, |
| 2024 | int calling_back) |
| 2025 | { |
| 2026 | Ssh ssh = (Ssh) plug; |
| 2027 | ssh->state = SSH_STATE_CLOSED; |
| 2028 | if (ssh->s) { |
| 2029 | sk_close(ssh->s); |
| 2030 | ssh->s = NULL; |
| 2031 | } |
| 2032 | if (error_msg) { |
| 2033 | /* A socket error has occurred. */ |
| 2034 | logevent(error_msg); |
| 2035 | connection_fatal(ssh->frontend, error_msg); |
| 2036 | } else { |
| 2037 | /* Otherwise, the remote side closed the connection normally. */ |
| 2038 | } |
| 2039 | return 0; |
| 2040 | } |
| 2041 | |
| 2042 | static int ssh_receive(Plug plug, int urgent, char *data, int len) |
| 2043 | { |
| 2044 | Ssh ssh = (Ssh) plug; |
| 2045 | ssh_gotdata(ssh, (unsigned char *)data, len); |
| 2046 | if (ssh->state == SSH_STATE_CLOSED) { |
| 2047 | if (ssh->s) { |
| 2048 | sk_close(ssh->s); |
| 2049 | ssh->s = NULL; |
| 2050 | } |
| 2051 | return 0; |
| 2052 | } |
| 2053 | return 1; |
| 2054 | } |
| 2055 | |
| 2056 | static void ssh_sent(Plug plug, int bufsize) |
| 2057 | { |
| 2058 | Ssh ssh = (Ssh) plug; |
| 2059 | /* |
| 2060 | * If the send backlog on the SSH socket itself clears, we |
| 2061 | * should unthrottle the whole world if it was throttled. |
| 2062 | */ |
| 2063 | if (bufsize < SSH_MAX_BACKLOG) |
| 2064 | ssh_throttle_all(ssh, 0, bufsize); |
| 2065 | } |
| 2066 | |
| 2067 | /* |
| 2068 | * Connect to specified host and port. |
| 2069 | * Returns an error message, or NULL on success. |
| 2070 | * Also places the canonical host name into `realhost'. It must be |
| 2071 | * freed by the caller. |
| 2072 | */ |
| 2073 | static char *connect_to_host(Ssh ssh, char *host, int port, |
| 2074 | char **realhost, int nodelay) |
| 2075 | { |
| 2076 | static const struct plug_function_table fn_table = { |
| 2077 | ssh_closing, |
| 2078 | ssh_receive, |
| 2079 | ssh_sent, |
| 2080 | NULL |
| 2081 | }; |
| 2082 | |
| 2083 | SockAddr addr; |
| 2084 | char *err; |
| 2085 | |
| 2086 | ssh->savedhost = smalloc(1 + strlen(host)); |
| 2087 | if (!ssh->savedhost) |
| 2088 | fatalbox("Out of memory"); |
| 2089 | strcpy(ssh->savedhost, host); |
| 2090 | |
| 2091 | if (port < 0) |
| 2092 | port = 22; /* default ssh port */ |
| 2093 | ssh->savedport = port; |
| 2094 | |
| 2095 | /* |
| 2096 | * Try to find host. |
| 2097 | */ |
| 2098 | logeventf(ssh, "Looking up host \"%s\"", host); |
| 2099 | addr = name_lookup(host, port, realhost, &ssh->cfg); |
| 2100 | if ((err = sk_addr_error(addr)) != NULL) |
| 2101 | return err; |
| 2102 | |
| 2103 | /* |
| 2104 | * Open socket. |
| 2105 | */ |
| 2106 | { |
| 2107 | char addrbuf[100]; |
| 2108 | sk_getaddr(addr, addrbuf, 100); |
| 2109 | logeventf(ssh, "Connecting to %s port %d", addrbuf, port); |
| 2110 | } |
| 2111 | ssh->fn = &fn_table; |
| 2112 | ssh->s = new_connection(addr, *realhost, port, |
| 2113 | 0, 1, nodelay, (Plug) ssh, &ssh->cfg); |
| 2114 | if ((err = sk_socket_error(ssh->s)) != NULL) { |
| 2115 | ssh->s = NULL; |
| 2116 | return err; |
| 2117 | } |
| 2118 | |
| 2119 | return NULL; |
| 2120 | } |
| 2121 | |
| 2122 | /* |
| 2123 | * Throttle or unthrottle the SSH connection. |
| 2124 | */ |
| 2125 | static void ssh1_throttle(Ssh ssh, int adjust) |
| 2126 | { |
| 2127 | int old_count = ssh->v1_throttle_count; |
| 2128 | ssh->v1_throttle_count += adjust; |
| 2129 | assert(ssh->v1_throttle_count >= 0); |
| 2130 | if (ssh->v1_throttle_count && !old_count) { |
| 2131 | sk_set_frozen(ssh->s, 1); |
| 2132 | } else if (!ssh->v1_throttle_count && old_count) { |
| 2133 | sk_set_frozen(ssh->s, 0); |
| 2134 | } |
| 2135 | } |
| 2136 | |
| 2137 | /* |
| 2138 | * Throttle or unthrottle _all_ local data streams (for when sends |
| 2139 | * on the SSH connection itself back up). |
| 2140 | */ |
| 2141 | static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) |
| 2142 | { |
| 2143 | int i; |
| 2144 | struct ssh_channel *c; |
| 2145 | |
| 2146 | if (enable == ssh->throttled_all) |
| 2147 | return; |
| 2148 | ssh->throttled_all = enable; |
| 2149 | ssh->overall_bufsize = bufsize; |
| 2150 | if (!ssh->channels) |
| 2151 | return; |
| 2152 | for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { |
| 2153 | switch (c->type) { |
| 2154 | case CHAN_MAINSESSION: |
| 2155 | /* |
| 2156 | * This is treated separately, outside the switch. |
| 2157 | */ |
| 2158 | break; |
| 2159 | case CHAN_X11: |
| 2160 | x11_override_throttle(c->u.x11.s, enable); |
| 2161 | break; |
| 2162 | case CHAN_AGENT: |
| 2163 | /* Agent channels require no buffer management. */ |
| 2164 | break; |
| 2165 | case CHAN_SOCKDATA: |
| 2166 | pfd_override_throttle(c->u.x11.s, enable); |
| 2167 | break; |
| 2168 | } |
| 2169 | } |
| 2170 | } |
| 2171 | |
| 2172 | /* |
| 2173 | * Username and password input, abstracted off into routines |
| 2174 | * reusable in several places - even between SSH1 and SSH2. |
| 2175 | */ |
| 2176 | |
| 2177 | /* Set up a username or password input loop on a given buffer. */ |
| 2178 | static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo) |
| 2179 | { |
| 2180 | ssh->userpass_input_buffer = buffer; |
| 2181 | ssh->userpass_input_buflen = buflen; |
| 2182 | ssh->userpass_input_bufpos = 0; |
| 2183 | ssh->userpass_input_echo = echo; |
| 2184 | } |
| 2185 | |
| 2186 | /* |
| 2187 | * Process some terminal data in the course of username/password |
| 2188 | * input. Returns >0 for success (line of input returned in |
| 2189 | * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0 |
| 2190 | * for inconclusive (keep waiting for more input please). |
| 2191 | */ |
| 2192 | static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen) |
| 2193 | { |
| 2194 | char c; |
| 2195 | |
| 2196 | while (inlen--) { |
| 2197 | switch (c = *in++) { |
| 2198 | case 10: |
| 2199 | case 13: |
| 2200 | ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0; |
| 2201 | ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0; |
| 2202 | return +1; |
| 2203 | break; |
| 2204 | case 8: |
| 2205 | case 127: |
| 2206 | if (ssh->userpass_input_bufpos > 0) { |
| 2207 | if (ssh->userpass_input_echo) |
| 2208 | c_write_str(ssh, "\b \b"); |
| 2209 | ssh->userpass_input_bufpos--; |
| 2210 | } |
| 2211 | break; |
| 2212 | case 21: |
| 2213 | case 27: |
| 2214 | while (ssh->userpass_input_bufpos > 0) { |
| 2215 | if (ssh->userpass_input_echo) |
| 2216 | c_write_str(ssh, "\b \b"); |
| 2217 | ssh->userpass_input_bufpos--; |
| 2218 | } |
| 2219 | break; |
| 2220 | case 3: |
| 2221 | case 4: |
| 2222 | return -1; |
| 2223 | break; |
| 2224 | default: |
| 2225 | /* |
| 2226 | * This simplistic check for printability is disabled |
| 2227 | * when we're doing password input, because some people |
| 2228 | * have control characters in their passwords.o |
| 2229 | */ |
| 2230 | if ((!ssh->userpass_input_echo || |
| 2231 | (c >= ' ' && c <= '~') || |
| 2232 | ((unsigned char) c >= 160)) |
| 2233 | && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) { |
| 2234 | ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c; |
| 2235 | if (ssh->userpass_input_echo) |
| 2236 | c_write(ssh, &c, 1); |
| 2237 | } |
| 2238 | break; |
| 2239 | } |
| 2240 | } |
| 2241 | return 0; |
| 2242 | } |
| 2243 | |
| 2244 | /* |
| 2245 | * Handle the key exchange and user authentication phases. |
| 2246 | */ |
| 2247 | static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt) |
| 2248 | { |
| 2249 | int i, j; |
| 2250 | unsigned char cookie[8]; |
| 2251 | struct RSAKey servkey, hostkey; |
| 2252 | struct MD5Context md5c; |
| 2253 | struct do_ssh1_login_state { |
| 2254 | int len; |
| 2255 | unsigned char *rsabuf, *keystr1, *keystr2; |
| 2256 | unsigned long supported_ciphers_mask, supported_auths_mask; |
| 2257 | int tried_publickey, tried_agent; |
| 2258 | int tis_auth_refused, ccard_auth_refused; |
| 2259 | unsigned char session_id[16]; |
| 2260 | int cipher_type; |
| 2261 | char username[100]; |
| 2262 | void *publickey_blob; |
| 2263 | int publickey_bloblen; |
| 2264 | char password[100]; |
| 2265 | char prompt[200]; |
| 2266 | int pos; |
| 2267 | char c; |
| 2268 | int pwpkt_type; |
| 2269 | unsigned char request[5], *response, *p; |
| 2270 | int responselen; |
| 2271 | int keyi, nkeys; |
| 2272 | int authed; |
| 2273 | struct RSAKey key; |
| 2274 | Bignum challenge; |
| 2275 | char *commentp; |
| 2276 | int commentlen; |
| 2277 | }; |
| 2278 | crState(do_ssh1_login_state); |
| 2279 | |
| 2280 | crBegin(ssh->do_ssh1_login_crstate); |
| 2281 | |
| 2282 | if (!ispkt) |
| 2283 | crWaitUntil(ispkt); |
| 2284 | |
| 2285 | if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
| 2286 | bombout((ssh,"Public key packet not received")); |
| 2287 | crReturn(0); |
| 2288 | } |
| 2289 | |
| 2290 | logevent("Received public keys"); |
| 2291 | |
| 2292 | memcpy(cookie, ssh->pktin.body, 8); |
| 2293 | |
| 2294 | i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0); |
| 2295 | j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0); |
| 2296 | |
| 2297 | /* |
| 2298 | * Log the host key fingerprint. |
| 2299 | */ |
| 2300 | { |
| 2301 | char logmsg[80]; |
| 2302 | logevent("Host key fingerprint is:"); |
| 2303 | strcpy(logmsg, " "); |
| 2304 | hostkey.comment = NULL; |
| 2305 | rsa_fingerprint(logmsg + strlen(logmsg), |
| 2306 | sizeof(logmsg) - strlen(logmsg), &hostkey); |
| 2307 | logevent(logmsg); |
| 2308 | } |
| 2309 | |
| 2310 | ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j); |
| 2311 | s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j); |
| 2312 | s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j); |
| 2313 | |
| 2314 | ssh->v1_local_protoflags = |
| 2315 | ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
| 2316 | ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
| 2317 | |
| 2318 | MD5Init(&md5c); |
| 2319 | MD5Update(&md5c, s->keystr2, hostkey.bytes); |
| 2320 | MD5Update(&md5c, s->keystr1, servkey.bytes); |
| 2321 | MD5Update(&md5c, ssh->pktin.body, 8); |
| 2322 | MD5Final(s->session_id, &md5c); |
| 2323 | |
| 2324 | for (i = 0; i < 32; i++) |
| 2325 | ssh->session_key[i] = random_byte(); |
| 2326 | |
| 2327 | s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 2328 | |
| 2329 | s->rsabuf = smalloc(s->len); |
| 2330 | if (!s->rsabuf) |
| 2331 | fatalbox("Out of memory"); |
| 2332 | |
| 2333 | /* |
| 2334 | * Verify the host key. |
| 2335 | */ |
| 2336 | { |
| 2337 | /* |
| 2338 | * First format the key into a string. |
| 2339 | */ |
| 2340 | int len = rsastr_len(&hostkey); |
| 2341 | char fingerprint[100]; |
| 2342 | char *keystr = smalloc(len); |
| 2343 | if (!keystr) |
| 2344 | fatalbox("Out of memory"); |
| 2345 | rsastr_fmt(keystr, &hostkey); |
| 2346 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
| 2347 | verify_ssh_host_key(ssh->frontend, |
| 2348 | ssh->savedhost, ssh->savedport, "rsa", keystr, |
| 2349 | fingerprint); |
| 2350 | sfree(keystr); |
| 2351 | } |
| 2352 | |
| 2353 | for (i = 0; i < 32; i++) { |
| 2354 | s->rsabuf[i] = ssh->session_key[i]; |
| 2355 | if (i < 16) |
| 2356 | s->rsabuf[i] ^= s->session_id[i]; |
| 2357 | } |
| 2358 | |
| 2359 | if (hostkey.bytes > servkey.bytes) { |
| 2360 | rsaencrypt(s->rsabuf, 32, &servkey); |
| 2361 | rsaencrypt(s->rsabuf, servkey.bytes, &hostkey); |
| 2362 | } else { |
| 2363 | rsaencrypt(s->rsabuf, 32, &hostkey); |
| 2364 | rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); |
| 2365 | } |
| 2366 | |
| 2367 | logevent("Encrypted session key"); |
| 2368 | |
| 2369 | { |
| 2370 | int cipher_chosen = 0, warn = 0; |
| 2371 | char *cipher_string = NULL; |
| 2372 | int i; |
| 2373 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { |
| 2374 | int next_cipher = ssh->cfg.ssh_cipherlist[i]; |
| 2375 | if (next_cipher == CIPHER_WARN) { |
| 2376 | /* If/when we choose a cipher, warn about it */ |
| 2377 | warn = 1; |
| 2378 | } else if (next_cipher == CIPHER_AES) { |
| 2379 | /* XXX Probably don't need to mention this. */ |
| 2380 | logevent("AES not supported in SSH1, skipping"); |
| 2381 | } else { |
| 2382 | switch (next_cipher) { |
| 2383 | case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; |
| 2384 | cipher_string = "3DES"; break; |
| 2385 | case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH; |
| 2386 | cipher_string = "Blowfish"; break; |
| 2387 | case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES; |
| 2388 | cipher_string = "single-DES"; break; |
| 2389 | } |
| 2390 | if (s->supported_ciphers_mask & (1 << s->cipher_type)) |
| 2391 | cipher_chosen = 1; |
| 2392 | } |
| 2393 | } |
| 2394 | if (!cipher_chosen) { |
| 2395 | if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) |
| 2396 | bombout((ssh,"Server violates SSH 1 protocol by not " |
| 2397 | "supporting 3DES encryption")); |
| 2398 | else |
| 2399 | /* shouldn't happen */ |
| 2400 | bombout((ssh,"No supported ciphers found")); |
| 2401 | crReturn(0); |
| 2402 | } |
| 2403 | |
| 2404 | /* Warn about chosen cipher if necessary. */ |
| 2405 | if (warn) |
| 2406 | askcipher(ssh->frontend, cipher_string, 0); |
| 2407 | } |
| 2408 | |
| 2409 | switch (s->cipher_type) { |
| 2410 | case SSH_CIPHER_3DES: |
| 2411 | logevent("Using 3DES encryption"); |
| 2412 | break; |
| 2413 | case SSH_CIPHER_DES: |
| 2414 | logevent("Using single-DES encryption"); |
| 2415 | break; |
| 2416 | case SSH_CIPHER_BLOWFISH: |
| 2417 | logevent("Using Blowfish encryption"); |
| 2418 | break; |
| 2419 | } |
| 2420 | |
| 2421 | send_packet(ssh, SSH1_CMSG_SESSION_KEY, |
| 2422 | PKT_CHAR, s->cipher_type, |
| 2423 | PKT_DATA, cookie, 8, |
| 2424 | PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF, |
| 2425 | PKT_DATA, s->rsabuf, s->len, |
| 2426 | PKT_INT, ssh->v1_local_protoflags, PKT_END); |
| 2427 | |
| 2428 | logevent("Trying to enable encryption..."); |
| 2429 | |
| 2430 | sfree(s->rsabuf); |
| 2431 | |
| 2432 | ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
| 2433 | s->cipher_type == SSH_CIPHER_DES ? &ssh_des : |
| 2434 | &ssh_3des); |
| 2435 | ssh->v1_cipher_ctx = ssh->cipher->make_context(); |
| 2436 | ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key); |
| 2437 | logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name); |
| 2438 | |
| 2439 | ssh->crcda_ctx = crcda_make_context(); |
| 2440 | logevent("Installing CRC compensation attack detector"); |
| 2441 | |
| 2442 | crWaitUntil(ispkt); |
| 2443 | |
| 2444 | if (ssh->pktin.type != SSH1_SMSG_SUCCESS) { |
| 2445 | bombout((ssh,"Encryption not successfully enabled")); |
| 2446 | crReturn(0); |
| 2447 | } |
| 2448 | |
| 2449 | logevent("Successfully started encryption"); |
| 2450 | |
| 2451 | fflush(stdout); |
| 2452 | { |
| 2453 | if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) { |
| 2454 | if (ssh_get_line && !ssh_getline_pw_only) { |
| 2455 | if (!ssh_get_line("login as: ", |
| 2456 | s->username, sizeof(s->username), FALSE)) { |
| 2457 | /* |
| 2458 | * get_line failed to get a username. |
| 2459 | * Terminate. |
| 2460 | */ |
| 2461 | logevent("No username provided. Abandoning session."); |
| 2462 | ssh->state = SSH_STATE_CLOSED; |
| 2463 | crReturn(1); |
| 2464 | } |
| 2465 | } else { |
| 2466 | int ret; /* need not be kept over crReturn */ |
| 2467 | c_write_str(ssh, "login as: "); |
| 2468 | ssh->send_ok = 1; |
| 2469 | |
| 2470 | setup_userpass_input(ssh, s->username, sizeof(s->username), 1); |
| 2471 | do { |
| 2472 | crWaitUntil(!ispkt); |
| 2473 | ret = process_userpass_input(ssh, in, inlen); |
| 2474 | } while (ret == 0); |
| 2475 | if (ret < 0) |
| 2476 | cleanup_exit(0); |
| 2477 | c_write_str(ssh, "\r\n"); |
| 2478 | } |
| 2479 | } else { |
| 2480 | strncpy(s->username, ssh->cfg.username, sizeof(s->username)); |
| 2481 | s->username[sizeof(s->username)-1] = '\0'; |
| 2482 | } |
| 2483 | |
| 2484 | send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END); |
| 2485 | { |
| 2486 | char userlog[22 + sizeof(s->username)]; |
| 2487 | sprintf(userlog, "Sent username \"%s\"", s->username); |
| 2488 | logevent(userlog); |
| 2489 | if (flags & FLAG_INTERACTIVE && |
| 2490 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
| 2491 | strcat(userlog, "\r\n"); |
| 2492 | c_write_str(ssh, userlog); |
| 2493 | } |
| 2494 | } |
| 2495 | } |
| 2496 | |
| 2497 | crWaitUntil(ispkt); |
| 2498 | |
| 2499 | if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) { |
| 2500 | /* We must not attempt PK auth. Pretend we've already tried it. */ |
| 2501 | s->tried_publickey = s->tried_agent = 1; |
| 2502 | } else { |
| 2503 | s->tried_publickey = s->tried_agent = 0; |
| 2504 | } |
| 2505 | s->tis_auth_refused = s->ccard_auth_refused = 0; |
| 2506 | /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */ |
| 2507 | if (!filename_is_null(ssh->cfg.keyfile)) { |
| 2508 | if (!rsakey_pubblob(&ssh->cfg.keyfile, |
| 2509 | &s->publickey_blob, &s->publickey_bloblen)) |
| 2510 | s->publickey_blob = NULL; |
| 2511 | } else |
| 2512 | s->publickey_blob = NULL; |
| 2513 | |
| 2514 | while (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 2515 | s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 2516 | |
| 2517 | if (agent_exists() && !s->tried_agent) { |
| 2518 | /* |
| 2519 | * Attempt RSA authentication using Pageant. |
| 2520 | */ |
| 2521 | void *r; |
| 2522 | |
| 2523 | s->authed = FALSE; |
| 2524 | s->tried_agent = 1; |
| 2525 | logevent("Pageant is running. Requesting keys."); |
| 2526 | |
| 2527 | /* Request the keys held by the agent. */ |
| 2528 | PUT_32BIT(s->request, 1); |
| 2529 | s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
| 2530 | agent_query(s->request, 5, &r, &s->responselen); |
| 2531 | s->response = (unsigned char *) r; |
| 2532 | if (s->response && s->responselen >= 5 && |
| 2533 | s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
| 2534 | s->p = s->response + 5; |
| 2535 | s->nkeys = GET_32BIT(s->p); |
| 2536 | s->p += 4; |
| 2537 | { |
| 2538 | char buf[64]; |
| 2539 | sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys); |
| 2540 | logevent(buf); |
| 2541 | } |
| 2542 | for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { |
| 2543 | { |
| 2544 | char buf[64]; |
| 2545 | sprintf(buf, "Trying Pageant key #%d", s->keyi); |
| 2546 | logevent(buf); |
| 2547 | } |
| 2548 | if (s->publickey_blob && |
| 2549 | !memcmp(s->p, s->publickey_blob, |
| 2550 | s->publickey_bloblen)) { |
| 2551 | logevent("This key matches configured key file"); |
| 2552 | s->tried_publickey = 1; |
| 2553 | } |
| 2554 | s->p += 4; |
| 2555 | s->p += ssh1_read_bignum(s->p, &s->key.exponent); |
| 2556 | s->p += ssh1_read_bignum(s->p, &s->key.modulus); |
| 2557 | s->commentlen = GET_32BIT(s->p); |
| 2558 | s->p += 4; |
| 2559 | s->commentp = (char *)s->p; |
| 2560 | s->p += s->commentlen; |
| 2561 | send_packet(ssh, SSH1_CMSG_AUTH_RSA, |
| 2562 | PKT_BIGNUM, s->key.modulus, PKT_END); |
| 2563 | crWaitUntil(ispkt); |
| 2564 | if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 2565 | logevent("Key refused"); |
| 2566 | continue; |
| 2567 | } |
| 2568 | logevent("Received RSA challenge"); |
| 2569 | ssh1_read_bignum(ssh->pktin.body, &s->challenge); |
| 2570 | { |
| 2571 | char *agentreq, *q, *ret; |
| 2572 | void *vret; |
| 2573 | int len, retlen; |
| 2574 | len = 1 + 4; /* message type, bit count */ |
| 2575 | len += ssh1_bignum_length(s->key.exponent); |
| 2576 | len += ssh1_bignum_length(s->key.modulus); |
| 2577 | len += ssh1_bignum_length(s->challenge); |
| 2578 | len += 16; /* session id */ |
| 2579 | len += 4; /* response format */ |
| 2580 | agentreq = smalloc(4 + len); |
| 2581 | PUT_32BIT(agentreq, len); |
| 2582 | q = agentreq + 4; |
| 2583 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
| 2584 | PUT_32BIT(q, bignum_bitcount(s->key.modulus)); |
| 2585 | q += 4; |
| 2586 | q += ssh1_write_bignum(q, s->key.exponent); |
| 2587 | q += ssh1_write_bignum(q, s->key.modulus); |
| 2588 | q += ssh1_write_bignum(q, s->challenge); |
| 2589 | memcpy(q, s->session_id, 16); |
| 2590 | q += 16; |
| 2591 | PUT_32BIT(q, 1); /* response format */ |
| 2592 | agent_query(agentreq, len + 4, &vret, &retlen); |
| 2593 | ret = vret; |
| 2594 | sfree(agentreq); |
| 2595 | if (ret) { |
| 2596 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
| 2597 | logevent("Sending Pageant's response"); |
| 2598 | send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 2599 | PKT_DATA, ret + 5, 16, |
| 2600 | PKT_END); |
| 2601 | sfree(ret); |
| 2602 | crWaitUntil(ispkt); |
| 2603 | if (ssh->pktin.type == SSH1_SMSG_SUCCESS) { |
| 2604 | logevent |
| 2605 | ("Pageant's response accepted"); |
| 2606 | if (flags & FLAG_VERBOSE) { |
| 2607 | c_write_str(ssh, "Authenticated using" |
| 2608 | " RSA key \""); |
| 2609 | c_write(ssh, s->commentp, |
| 2610 | s->commentlen); |
| 2611 | c_write_str(ssh, "\" from agent\r\n"); |
| 2612 | } |
| 2613 | s->authed = TRUE; |
| 2614 | } else |
| 2615 | logevent |
| 2616 | ("Pageant's response not accepted"); |
| 2617 | } else { |
| 2618 | logevent |
| 2619 | ("Pageant failed to answer challenge"); |
| 2620 | sfree(ret); |
| 2621 | } |
| 2622 | } else { |
| 2623 | logevent("No reply received from Pageant"); |
| 2624 | } |
| 2625 | } |
| 2626 | freebn(s->key.exponent); |
| 2627 | freebn(s->key.modulus); |
| 2628 | freebn(s->challenge); |
| 2629 | if (s->authed) |
| 2630 | break; |
| 2631 | } |
| 2632 | } |
| 2633 | if (s->authed) |
| 2634 | break; |
| 2635 | } |
| 2636 | if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey) |
| 2637 | s->pwpkt_type = SSH1_CMSG_AUTH_RSA; |
| 2638 | |
| 2639 | if (ssh->cfg.try_tis_auth && |
| 2640 | (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) && |
| 2641 | !s->tis_auth_refused) { |
| 2642 | s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 2643 | logevent("Requested TIS authentication"); |
| 2644 | send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END); |
| 2645 | crWaitUntil(ispkt); |
| 2646 | if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 2647 | logevent("TIS authentication declined"); |
| 2648 | if (flags & FLAG_INTERACTIVE) |
| 2649 | c_write_str(ssh, "TIS authentication refused.\r\n"); |
| 2650 | s->tis_auth_refused = 1; |
| 2651 | continue; |
| 2652 | } else { |
| 2653 | int challengelen = GET_32BIT(ssh->pktin.body); |
| 2654 | logevent("Received TIS challenge"); |
| 2655 | if (challengelen > sizeof(s->prompt) - 1) |
| 2656 | challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ |
| 2657 | memcpy(s->prompt, ssh->pktin.body + 4, challengelen); |
| 2658 | /* Prompt heuristic comes from OpenSSH */ |
| 2659 | strncpy(s->prompt + challengelen, |
| 2660 | memchr(s->prompt, '\n', challengelen) ? |
| 2661 | "": "\r\nResponse: ", |
| 2662 | (sizeof s->prompt) - challengelen); |
| 2663 | s->prompt[(sizeof s->prompt) - 1] = '\0'; |
| 2664 | } |
| 2665 | } |
| 2666 | if (ssh->cfg.try_tis_auth && |
| 2667 | (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && |
| 2668 | !s->ccard_auth_refused) { |
| 2669 | s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
| 2670 | logevent("Requested CryptoCard authentication"); |
| 2671 | send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END); |
| 2672 | crWaitUntil(ispkt); |
| 2673 | if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 2674 | logevent("CryptoCard authentication declined"); |
| 2675 | c_write_str(ssh, "CryptoCard authentication refused.\r\n"); |
| 2676 | s->ccard_auth_refused = 1; |
| 2677 | continue; |
| 2678 | } else { |
| 2679 | int challengelen = GET_32BIT(ssh->pktin.body); |
| 2680 | logevent("Received CryptoCard challenge"); |
| 2681 | if (challengelen > sizeof(s->prompt) - 1) |
| 2682 | challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ |
| 2683 | memcpy(s->prompt, ssh->pktin.body + 4, challengelen); |
| 2684 | strncpy(s->prompt + challengelen, |
| 2685 | memchr(s->prompt, '\n', challengelen) ? |
| 2686 | "" : "\r\nResponse: ", |
| 2687 | sizeof(s->prompt) - challengelen); |
| 2688 | s->prompt[sizeof(s->prompt) - 1] = '\0'; |
| 2689 | } |
| 2690 | } |
| 2691 | if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 2692 | sprintf(s->prompt, "%.90s@%.90s's password: ", |
| 2693 | s->username, ssh->savedhost); |
| 2694 | } |
| 2695 | if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 2696 | char *comment = NULL; |
| 2697 | int type; |
| 2698 | char msgbuf[256]; |
| 2699 | if (flags & FLAG_VERBOSE) |
| 2700 | c_write_str(ssh, "Trying public key authentication.\r\n"); |
| 2701 | logeventf(ssh, "Trying public key \"%s\"", |
| 2702 | filename_to_str(&ssh->cfg.keyfile)); |
| 2703 | type = key_type(&ssh->cfg.keyfile); |
| 2704 | if (type != SSH_KEYTYPE_SSH1) { |
| 2705 | sprintf(msgbuf, "Key is of wrong type (%s)", |
| 2706 | key_type_to_str(type)); |
| 2707 | logevent(msgbuf); |
| 2708 | c_write_str(ssh, msgbuf); |
| 2709 | c_write_str(ssh, "\r\n"); |
| 2710 | s->tried_publickey = 1; |
| 2711 | continue; |
| 2712 | } |
| 2713 | if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) { |
| 2714 | if (flags & FLAG_VERBOSE) |
| 2715 | c_write_str(ssh, "No passphrase required.\r\n"); |
| 2716 | goto tryauth; |
| 2717 | } |
| 2718 | sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment); |
| 2719 | sfree(comment); |
| 2720 | } |
| 2721 | |
| 2722 | /* |
| 2723 | * Show password prompt, having first obtained it via a TIS |
| 2724 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
| 2725 | * authentication. |
| 2726 | */ |
| 2727 | if (ssh_get_line) { |
| 2728 | if (!ssh_get_line(s->prompt, s->password, |
| 2729 | sizeof(s->password), TRUE)) { |
| 2730 | /* |
| 2731 | * get_line failed to get a password (for example |
| 2732 | * because one was supplied on the command line |
| 2733 | * which has already failed to work). Terminate. |
| 2734 | */ |
| 2735 | send_packet(ssh, SSH1_MSG_DISCONNECT, |
| 2736 | PKT_STR, "No more passwords available to try", |
| 2737 | PKT_END); |
| 2738 | logevent("Unable to authenticate"); |
| 2739 | connection_fatal(ssh->frontend, "Unable to authenticate"); |
| 2740 | ssh->state = SSH_STATE_CLOSED; |
| 2741 | crReturn(1); |
| 2742 | } |
| 2743 | } else { |
| 2744 | /* Prompt may have come from server. We've munged it a bit, so |
| 2745 | * we know it to be zero-terminated at least once. */ |
| 2746 | int ret; /* need not be saved over crReturn */ |
| 2747 | c_write_untrusted(ssh, s->prompt, strlen(s->prompt)); |
| 2748 | s->pos = 0; |
| 2749 | |
| 2750 | setup_userpass_input(ssh, s->password, sizeof(s->password), 0); |
| 2751 | do { |
| 2752 | crWaitUntil(!ispkt); |
| 2753 | ret = process_userpass_input(ssh, in, inlen); |
| 2754 | } while (ret == 0); |
| 2755 | if (ret < 0) |
| 2756 | cleanup_exit(0); |
| 2757 | c_write_str(ssh, "\r\n"); |
| 2758 | } |
| 2759 | |
| 2760 | tryauth: |
| 2761 | if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 2762 | /* |
| 2763 | * Try public key authentication with the specified |
| 2764 | * key file. |
| 2765 | */ |
| 2766 | s->tried_publickey = 1; |
| 2767 | |
| 2768 | { |
| 2769 | int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password); |
| 2770 | if (ret == 0) { |
| 2771 | c_write_str(ssh, "Couldn't load private key from "); |
| 2772 | c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile)); |
| 2773 | c_write_str(ssh, ".\r\n"); |
| 2774 | continue; /* go and try password */ |
| 2775 | } |
| 2776 | if (ret == -1) { |
| 2777 | c_write_str(ssh, "Wrong passphrase.\r\n"); |
| 2778 | s->tried_publickey = 0; |
| 2779 | continue; /* try again */ |
| 2780 | } |
| 2781 | } |
| 2782 | |
| 2783 | /* |
| 2784 | * Send a public key attempt. |
| 2785 | */ |
| 2786 | send_packet(ssh, SSH1_CMSG_AUTH_RSA, |
| 2787 | PKT_BIGNUM, s->key.modulus, PKT_END); |
| 2788 | |
| 2789 | crWaitUntil(ispkt); |
| 2790 | if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 2791 | c_write_str(ssh, "Server refused our public key.\r\n"); |
| 2792 | continue; /* go and try password */ |
| 2793 | } |
| 2794 | if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 2795 | bombout((ssh,"Bizarre response to offer of public key")); |
| 2796 | crReturn(0); |
| 2797 | } |
| 2798 | |
| 2799 | { |
| 2800 | int i; |
| 2801 | unsigned char buffer[32]; |
| 2802 | Bignum challenge, response; |
| 2803 | |
| 2804 | ssh1_read_bignum(ssh->pktin.body, &challenge); |
| 2805 | response = rsadecrypt(challenge, &s->key); |
| 2806 | freebn(s->key.private_exponent);/* burn the evidence */ |
| 2807 | |
| 2808 | for (i = 0; i < 32; i++) { |
| 2809 | buffer[i] = bignum_byte(response, 31 - i); |
| 2810 | } |
| 2811 | |
| 2812 | MD5Init(&md5c); |
| 2813 | MD5Update(&md5c, buffer, 32); |
| 2814 | MD5Update(&md5c, s->session_id, 16); |
| 2815 | MD5Final(buffer, &md5c); |
| 2816 | |
| 2817 | send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 2818 | PKT_DATA, buffer, 16, PKT_END); |
| 2819 | |
| 2820 | freebn(challenge); |
| 2821 | freebn(response); |
| 2822 | } |
| 2823 | |
| 2824 | crWaitUntil(ispkt); |
| 2825 | if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 2826 | if (flags & FLAG_VERBOSE) |
| 2827 | c_write_str(ssh, "Failed to authenticate with" |
| 2828 | " our public key.\r\n"); |
| 2829 | continue; /* go and try password */ |
| 2830 | } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) { |
| 2831 | bombout((ssh,"Bizarre response to RSA authentication response")); |
| 2832 | crReturn(0); |
| 2833 | } |
| 2834 | |
| 2835 | break; /* we're through! */ |
| 2836 | } else { |
| 2837 | if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 2838 | /* |
| 2839 | * Defence against traffic analysis: we send a |
| 2840 | * whole bunch of packets containing strings of |
| 2841 | * different lengths. One of these strings is the |
| 2842 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
| 2843 | * The others are all random data in |
| 2844 | * SSH1_MSG_IGNORE packets. This way a passive |
| 2845 | * listener can't tell which is the password, and |
| 2846 | * hence can't deduce the password length. |
| 2847 | * |
| 2848 | * Anybody with a password length greater than 16 |
| 2849 | * bytes is going to have enough entropy in their |
| 2850 | * password that a listener won't find it _that_ |
| 2851 | * much help to know how long it is. So what we'll |
| 2852 | * do is: |
| 2853 | * |
| 2854 | * - if password length < 16, we send 15 packets |
| 2855 | * containing string lengths 1 through 15 |
| 2856 | * |
| 2857 | * - otherwise, we let N be the nearest multiple |
| 2858 | * of 8 below the password length, and send 8 |
| 2859 | * packets containing string lengths N through |
| 2860 | * N+7. This won't obscure the order of |
| 2861 | * magnitude of the password length, but it will |
| 2862 | * introduce a bit of extra uncertainty. |
| 2863 | * |
| 2864 | * A few servers (the old 1.2.18 through 1.2.22) |
| 2865 | * can't deal with SSH1_MSG_IGNORE. For these |
| 2866 | * servers, we need an alternative defence. We make |
| 2867 | * use of the fact that the password is interpreted |
| 2868 | * as a C string: so we can append a NUL, then some |
| 2869 | * random data. |
| 2870 | * |
| 2871 | * One server (a Cisco one) can deal with neither |
| 2872 | * SSH1_MSG_IGNORE _nor_ a padded password string. |
| 2873 | * For this server we are left with no defences |
| 2874 | * against password length sniffing. |
| 2875 | */ |
| 2876 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { |
| 2877 | /* |
| 2878 | * The server can deal with SSH1_MSG_IGNORE, so |
| 2879 | * we can use the primary defence. |
| 2880 | */ |
| 2881 | int bottom, top, pwlen, i; |
| 2882 | char *randomstr; |
| 2883 | |
| 2884 | pwlen = strlen(s->password); |
| 2885 | if (pwlen < 16) { |
| 2886 | bottom = 0; /* zero length passwords are OK! :-) */ |
| 2887 | top = 15; |
| 2888 | } else { |
| 2889 | bottom = pwlen & ~7; |
| 2890 | top = bottom + 7; |
| 2891 | } |
| 2892 | |
| 2893 | assert(pwlen >= bottom && pwlen <= top); |
| 2894 | |
| 2895 | randomstr = smalloc(top + 1); |
| 2896 | |
| 2897 | for (i = bottom; i <= top; i++) { |
| 2898 | if (i == pwlen) |
| 2899 | defer_packet(ssh, s->pwpkt_type, |
| 2900 | PKT_STR, s->password, PKT_END); |
| 2901 | else { |
| 2902 | for (j = 0; j < i; j++) { |
| 2903 | do { |
| 2904 | randomstr[j] = random_byte(); |
| 2905 | } while (randomstr[j] == '\0'); |
| 2906 | } |
| 2907 | randomstr[i] = '\0'; |
| 2908 | defer_packet(ssh, SSH1_MSG_IGNORE, |
| 2909 | PKT_STR, randomstr, PKT_END); |
| 2910 | } |
| 2911 | } |
| 2912 | logevent("Sending password with camouflage packets"); |
| 2913 | ssh_pkt_defersend(ssh); |
| 2914 | } |
| 2915 | else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { |
| 2916 | /* |
| 2917 | * The server can't deal with SSH1_MSG_IGNORE |
| 2918 | * but can deal with padded passwords, so we |
| 2919 | * can use the secondary defence. |
| 2920 | */ |
| 2921 | char string[64]; |
| 2922 | char *ss; |
| 2923 | int len; |
| 2924 | |
| 2925 | len = strlen(s->password); |
| 2926 | if (len < sizeof(string)) { |
| 2927 | ss = string; |
| 2928 | strcpy(string, s->password); |
| 2929 | len++; /* cover the zero byte */ |
| 2930 | while (len < sizeof(string)) { |
| 2931 | string[len++] = (char) random_byte(); |
| 2932 | } |
| 2933 | } else { |
| 2934 | ss = s->password; |
| 2935 | } |
| 2936 | logevent("Sending length-padded password"); |
| 2937 | send_packet(ssh, s->pwpkt_type, PKT_INT, len, |
| 2938 | PKT_DATA, ss, len, PKT_END); |
| 2939 | } else { |
| 2940 | /* |
| 2941 | * The server has _both_ |
| 2942 | * BUG_CHOKES_ON_SSH1_IGNORE and |
| 2943 | * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is |
| 2944 | * therefore nothing we can do. |
| 2945 | */ |
| 2946 | int len; |
| 2947 | len = strlen(s->password); |
| 2948 | logevent("Sending unpadded password"); |
| 2949 | send_packet(ssh, s->pwpkt_type, PKT_INT, len, |
| 2950 | PKT_DATA, s->password, len, PKT_END); |
| 2951 | } |
| 2952 | } else { |
| 2953 | send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END); |
| 2954 | } |
| 2955 | } |
| 2956 | logevent("Sent password"); |
| 2957 | memset(s->password, 0, strlen(s->password)); |
| 2958 | crWaitUntil(ispkt); |
| 2959 | if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 2960 | if (flags & FLAG_VERBOSE) |
| 2961 | c_write_str(ssh, "Access denied\r\n"); |
| 2962 | logevent("Authentication refused"); |
| 2963 | } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) { |
| 2964 | bombout((ssh,"Strange packet received, type %d", ssh->pktin.type)); |
| 2965 | crReturn(0); |
| 2966 | } |
| 2967 | } |
| 2968 | |
| 2969 | logevent("Authentication successful"); |
| 2970 | |
| 2971 | crFinish(1); |
| 2972 | } |
| 2973 | |
| 2974 | void sshfwd_close(struct ssh_channel *c) |
| 2975 | { |
| 2976 | Ssh ssh = c->ssh; |
| 2977 | |
| 2978 | if (c && !c->closes) { |
| 2979 | /* |
| 2980 | * If the channel's remoteid is -1, we have sent |
| 2981 | * CHANNEL_OPEN for this channel, but it hasn't even been |
| 2982 | * acknowledged by the server. So we must set a close flag |
| 2983 | * on it now, and then when the server acks the channel |
| 2984 | * open, we can close it then. |
| 2985 | */ |
| 2986 | if (((int)c->remoteid) != -1) { |
| 2987 | if (ssh->version == 1) { |
| 2988 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
| 2989 | PKT_END); |
| 2990 | } else { |
| 2991 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE); |
| 2992 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 2993 | ssh2_pkt_send(ssh); |
| 2994 | } |
| 2995 | } |
| 2996 | c->closes = 1; /* sent MSG_CLOSE */ |
| 2997 | if (c->type == CHAN_X11) { |
| 2998 | c->u.x11.s = NULL; |
| 2999 | logevent("Forwarded X11 connection terminated"); |
| 3000 | } else if (c->type == CHAN_SOCKDATA || |
| 3001 | c->type == CHAN_SOCKDATA_DORMANT) { |
| 3002 | c->u.pfd.s = NULL; |
| 3003 | logevent("Forwarded port closed"); |
| 3004 | } |
| 3005 | } |
| 3006 | } |
| 3007 | |
| 3008 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) |
| 3009 | { |
| 3010 | Ssh ssh = c->ssh; |
| 3011 | |
| 3012 | if (ssh->version == 1) { |
| 3013 | send_packet(ssh, SSH1_MSG_CHANNEL_DATA, |
| 3014 | PKT_INT, c->remoteid, |
| 3015 | PKT_INT, len, PKT_DATA, buf, len, PKT_END); |
| 3016 | /* |
| 3017 | * In SSH1 we can return 0 here - implying that forwarded |
| 3018 | * connections are never individually throttled - because |
| 3019 | * the only circumstance that can cause throttling will be |
| 3020 | * the whole SSH connection backing up, in which case |
| 3021 | * _everything_ will be throttled as a whole. |
| 3022 | */ |
| 3023 | return 0; |
| 3024 | } else { |
| 3025 | ssh2_add_channel_data(c, buf, len); |
| 3026 | return ssh2_try_send(c); |
| 3027 | } |
| 3028 | } |
| 3029 | |
| 3030 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) |
| 3031 | { |
| 3032 | Ssh ssh = c->ssh; |
| 3033 | |
| 3034 | if (ssh->version == 1) { |
| 3035 | if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 3036 | c->v.v1.throttling = 0; |
| 3037 | ssh1_throttle(ssh, -1); |
| 3038 | } |
| 3039 | } else { |
| 3040 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
| 3041 | } |
| 3042 | } |
| 3043 | |
| 3044 | static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt) |
| 3045 | { |
| 3046 | crBegin(ssh->ssh1_protocol_crstate); |
| 3047 | |
| 3048 | random_init(); |
| 3049 | |
| 3050 | while (!do_ssh1_login(ssh, in, inlen, ispkt)) { |
| 3051 | crReturnV; |
| 3052 | } |
| 3053 | if (ssh->state == SSH_STATE_CLOSED) |
| 3054 | crReturnV; |
| 3055 | |
| 3056 | if (ssh->cfg.agentfwd && agent_exists()) { |
| 3057 | logevent("Requesting agent forwarding"); |
| 3058 | send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
| 3059 | do { |
| 3060 | crReturnV; |
| 3061 | } while (!ispkt); |
| 3062 | if (ssh->pktin.type != SSH1_SMSG_SUCCESS |
| 3063 | && ssh->pktin.type != SSH1_SMSG_FAILURE) { |
| 3064 | bombout((ssh,"Protocol confusion")); |
| 3065 | crReturnV; |
| 3066 | } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 3067 | logevent("Agent forwarding refused"); |
| 3068 | } else { |
| 3069 | logevent("Agent forwarding enabled"); |
| 3070 | ssh->agentfwd_enabled = TRUE; |
| 3071 | } |
| 3072 | } |
| 3073 | |
| 3074 | if (ssh->cfg.x11_forward) { |
| 3075 | char proto[20], data[64]; |
| 3076 | logevent("Requesting X11 forwarding"); |
| 3077 | ssh->x11auth = x11_invent_auth(proto, sizeof(proto), |
| 3078 | data, sizeof(data), ssh->cfg.x11_auth); |
| 3079 | x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display); |
| 3080 | if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
| 3081 | send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 3082 | PKT_STR, proto, PKT_STR, data, |
| 3083 | PKT_INT, x11_get_screen_number(ssh->cfg.x11_display), |
| 3084 | PKT_END); |
| 3085 | } else { |
| 3086 | send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 3087 | PKT_STR, proto, PKT_STR, data, PKT_END); |
| 3088 | } |
| 3089 | do { |
| 3090 | crReturnV; |
| 3091 | } while (!ispkt); |
| 3092 | if (ssh->pktin.type != SSH1_SMSG_SUCCESS |
| 3093 | && ssh->pktin.type != SSH1_SMSG_FAILURE) { |
| 3094 | bombout((ssh,"Protocol confusion")); |
| 3095 | crReturnV; |
| 3096 | } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 3097 | logevent("X11 forwarding refused"); |
| 3098 | } else { |
| 3099 | logevent("X11 forwarding enabled"); |
| 3100 | ssh->X11_fwd_enabled = TRUE; |
| 3101 | } |
| 3102 | } |
| 3103 | |
| 3104 | { |
| 3105 | char type; |
| 3106 | int n; |
| 3107 | int sport,dport,sserv,dserv; |
| 3108 | char sports[256], dports[256], saddr[256], host[256]; |
| 3109 | |
| 3110 | ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); |
| 3111 | /* Add port forwardings. */ |
| 3112 | ssh->portfwd_strptr = ssh->cfg.portfwd; |
| 3113 | while (*ssh->portfwd_strptr) { |
| 3114 | type = *ssh->portfwd_strptr++; |
| 3115 | saddr[0] = '\0'; |
| 3116 | n = 0; |
| 3117 | while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') { |
| 3118 | if (*ssh->portfwd_strptr == ':') { |
| 3119 | /* |
| 3120 | * We've seen a colon in the middle of the |
| 3121 | * source port number. This means that |
| 3122 | * everything we've seen until now is the |
| 3123 | * source _address_, so we'll move it into |
| 3124 | * saddr and start sports from the beginning |
| 3125 | * again. |
| 3126 | */ |
| 3127 | ssh->portfwd_strptr++; |
| 3128 | sports[n] = '\0'; |
| 3129 | strcpy(saddr, sports); |
| 3130 | n = 0; |
| 3131 | } |
| 3132 | if (n < 255) sports[n++] = *ssh->portfwd_strptr++; |
| 3133 | } |
| 3134 | sports[n] = 0; |
| 3135 | if (*ssh->portfwd_strptr == '\t') |
| 3136 | ssh->portfwd_strptr++; |
| 3137 | n = 0; |
| 3138 | while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') { |
| 3139 | if (n < 255) host[n++] = *ssh->portfwd_strptr++; |
| 3140 | } |
| 3141 | host[n] = 0; |
| 3142 | if (*ssh->portfwd_strptr == ':') |
| 3143 | ssh->portfwd_strptr++; |
| 3144 | n = 0; |
| 3145 | while (*ssh->portfwd_strptr) { |
| 3146 | if (n < 255) dports[n++] = *ssh->portfwd_strptr++; |
| 3147 | } |
| 3148 | dports[n] = 0; |
| 3149 | ssh->portfwd_strptr++; |
| 3150 | dport = atoi(dports); |
| 3151 | dserv = 0; |
| 3152 | if (dport == 0) { |
| 3153 | dserv = 1; |
| 3154 | dport = net_service_lookup(dports); |
| 3155 | if (!dport) { |
| 3156 | logeventf(ssh, "Service lookup failed for" |
| 3157 | " destination port \"%s\"", dports); |
| 3158 | } |
| 3159 | } |
| 3160 | sport = atoi(sports); |
| 3161 | sserv = 0; |
| 3162 | if (sport == 0) { |
| 3163 | sserv = 1; |
| 3164 | sport = net_service_lookup(sports); |
| 3165 | if (!sport) { |
| 3166 | logeventf(ssh, "Service lookup failed for source" |
| 3167 | " port \"%s\"", sports); |
| 3168 | } |
| 3169 | } |
| 3170 | if (sport && dport) { |
| 3171 | if (type == 'L') { |
| 3172 | pfd_addforward(host, dport, *saddr ? saddr : NULL, |
| 3173 | sport, ssh, &ssh->cfg); |
| 3174 | logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s" |
| 3175 | " forwarding to %s:%.*s%.*s%d%.*s", |
| 3176 | (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, |
| 3177 | (int)(*saddr?1:0), ":", |
| 3178 | (int)(sserv ? strlen(sports) : 0), sports, |
| 3179 | sserv, "(", sport, sserv, ")", |
| 3180 | host, |
| 3181 | (int)(dserv ? strlen(dports) : 0), dports, |
| 3182 | dserv, "(", dport, dserv, ")"); |
| 3183 | } else { |
| 3184 | struct ssh_rportfwd *pf; |
| 3185 | pf = smalloc(sizeof(*pf)); |
| 3186 | strcpy(pf->dhost, host); |
| 3187 | pf->dport = dport; |
| 3188 | if (saddr) { |
| 3189 | logeventf(ssh, |
| 3190 | "SSH1 cannot handle source address spec \"%s:%d\"; ignoring", |
| 3191 | saddr, sport); |
| 3192 | } |
| 3193 | if (add234(ssh->rportfwds, pf) != pf) { |
| 3194 | logeventf(ssh, |
| 3195 | "Duplicate remote port forwarding to %s:%d", |
| 3196 | host, dport); |
| 3197 | sfree(pf); |
| 3198 | } else { |
| 3199 | logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s" |
| 3200 | " forward to %s:%.*s%.*s%d%.*s", |
| 3201 | (int)(sserv ? strlen(sports) : 0), sports, |
| 3202 | sserv, "(", sport, sserv, ")", |
| 3203 | host, |
| 3204 | (int)(dserv ? strlen(dports) : 0), dports, |
| 3205 | dserv, "(", dport, dserv, ")"); |
| 3206 | send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, |
| 3207 | PKT_INT, sport, |
| 3208 | PKT_STR, host, |
| 3209 | PKT_INT, dport, |
| 3210 | PKT_END); |
| 3211 | do { |
| 3212 | crReturnV; |
| 3213 | } while (!ispkt); |
| 3214 | if (ssh->pktin.type != SSH1_SMSG_SUCCESS |
| 3215 | && ssh->pktin.type != SSH1_SMSG_FAILURE) { |
| 3216 | bombout((ssh,"Protocol confusion")); |
| 3217 | crReturnV; |
| 3218 | } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 3219 | c_write_str(ssh, "Server refused port" |
| 3220 | " forwarding\r\n"); |
| 3221 | } |
| 3222 | logevent("Remote port forwarding enabled"); |
| 3223 | } |
| 3224 | } |
| 3225 | } |
| 3226 | } |
| 3227 | } |
| 3228 | |
| 3229 | if (!ssh->cfg.nopty) { |
| 3230 | send_packet(ssh, SSH1_CMSG_REQUEST_PTY, |
| 3231 | PKT_STR, ssh->cfg.termtype, |
| 3232 | PKT_INT, ssh->term_height, |
| 3233 | PKT_INT, ssh->term_width, |
| 3234 | PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END); |
| 3235 | ssh->state = SSH_STATE_INTERMED; |
| 3236 | do { |
| 3237 | crReturnV; |
| 3238 | } while (!ispkt); |
| 3239 | if (ssh->pktin.type != SSH1_SMSG_SUCCESS |
| 3240 | && ssh->pktin.type != SSH1_SMSG_FAILURE) { |
| 3241 | bombout((ssh,"Protocol confusion")); |
| 3242 | crReturnV; |
| 3243 | } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 3244 | c_write_str(ssh, "Server refused to allocate pty\r\n"); |
| 3245 | ssh->editing = ssh->echoing = 1; |
| 3246 | } |
| 3247 | logevent("Allocated pty"); |
| 3248 | } else { |
| 3249 | ssh->editing = ssh->echoing = 1; |
| 3250 | } |
| 3251 | |
| 3252 | if (ssh->cfg.compression) { |
| 3253 | send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
| 3254 | do { |
| 3255 | crReturnV; |
| 3256 | } while (!ispkt); |
| 3257 | if (ssh->pktin.type != SSH1_SMSG_SUCCESS |
| 3258 | && ssh->pktin.type != SSH1_SMSG_FAILURE) { |
| 3259 | bombout((ssh,"Protocol confusion")); |
| 3260 | crReturnV; |
| 3261 | } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 3262 | c_write_str(ssh, "Server refused to compress\r\n"); |
| 3263 | } |
| 3264 | logevent("Started compression"); |
| 3265 | ssh->v1_compressing = TRUE; |
| 3266 | ssh->cs_comp_ctx = zlib_compress_init(); |
| 3267 | logevent("Initialised zlib (RFC1950) compression"); |
| 3268 | ssh->sc_comp_ctx = zlib_decompress_init(); |
| 3269 | logevent("Initialised zlib (RFC1950) decompression"); |
| 3270 | } |
| 3271 | |
| 3272 | /* |
| 3273 | * Start the shell or command. |
| 3274 | * |
| 3275 | * Special case: if the first-choice command is an SSH2 |
| 3276 | * subsystem (hence not usable here) and the second choice |
| 3277 | * exists, we fall straight back to that. |
| 3278 | */ |
| 3279 | { |
| 3280 | char *cmd = ssh->cfg.remote_cmd_ptr; |
| 3281 | |
| 3282 | if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) { |
| 3283 | cmd = ssh->cfg.remote_cmd_ptr2; |
| 3284 | ssh->fallback_cmd = TRUE; |
| 3285 | } |
| 3286 | if (*cmd) |
| 3287 | send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
| 3288 | else |
| 3289 | send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 3290 | logevent("Started session"); |
| 3291 | } |
| 3292 | |
| 3293 | ssh->state = SSH_STATE_SESSION; |
| 3294 | if (ssh->size_needed) |
| 3295 | ssh_size(ssh, ssh->term_width, ssh->term_height); |
| 3296 | if (ssh->eof_needed) |
| 3297 | ssh_special(ssh, TS_EOF); |
| 3298 | |
| 3299 | if (ssh->ldisc) |
| 3300 | ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ |
| 3301 | ssh->send_ok = 1; |
| 3302 | ssh->channels = newtree234(ssh_channelcmp); |
| 3303 | while (1) { |
| 3304 | crReturnV; |
| 3305 | if (ispkt) { |
| 3306 | if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 3307 | ssh->pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 3308 | long len = GET_32BIT(ssh->pktin.body); |
| 3309 | int bufsize = |
| 3310 | from_backend(ssh->frontend, |
| 3311 | ssh->pktin.type == SSH1_SMSG_STDERR_DATA, |
| 3312 | (char *)(ssh->pktin.body) + 4, len); |
| 3313 | if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 3314 | ssh->v1_stdout_throttling = 1; |
| 3315 | ssh1_throttle(ssh, +1); |
| 3316 | } |
| 3317 | } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) { |
| 3318 | ssh->state = SSH_STATE_CLOSED; |
| 3319 | logevent("Received disconnect request"); |
| 3320 | crReturnV; |
| 3321 | } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) { |
| 3322 | /* Remote side is trying to open a channel to talk to our |
| 3323 | * X-Server. Give them back a local channel number. */ |
| 3324 | struct ssh_channel *c; |
| 3325 | |
| 3326 | logevent("Received X11 connect request"); |
| 3327 | /* Refuse if X11 forwarding is disabled. */ |
| 3328 | if (!ssh->X11_fwd_enabled) { |
| 3329 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3330 | PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END); |
| 3331 | logevent("Rejected X11 connect request"); |
| 3332 | } else { |
| 3333 | c = smalloc(sizeof(struct ssh_channel)); |
| 3334 | c->ssh = ssh; |
| 3335 | |
| 3336 | if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c, |
| 3337 | ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) { |
| 3338 | logevent("opening X11 forward connection failed"); |
| 3339 | sfree(c); |
| 3340 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3341 | PKT_INT, GET_32BIT(ssh->pktin.body), |
| 3342 | PKT_END); |
| 3343 | } else { |
| 3344 | logevent |
| 3345 | ("opening X11 forward connection succeeded"); |
| 3346 | c->remoteid = GET_32BIT(ssh->pktin.body); |
| 3347 | c->localid = alloc_channel_id(ssh); |
| 3348 | c->closes = 0; |
| 3349 | c->v.v1.throttling = 0; |
| 3350 | c->type = CHAN_X11; /* identify channel type */ |
| 3351 | add234(ssh->channels, c); |
| 3352 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 3353 | PKT_INT, c->remoteid, PKT_INT, |
| 3354 | c->localid, PKT_END); |
| 3355 | logevent("Opened X11 forward channel"); |
| 3356 | } |
| 3357 | } |
| 3358 | } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) { |
| 3359 | /* Remote side is trying to open a channel to talk to our |
| 3360 | * agent. Give them back a local channel number. */ |
| 3361 | struct ssh_channel *c; |
| 3362 | |
| 3363 | /* Refuse if agent forwarding is disabled. */ |
| 3364 | if (!ssh->agentfwd_enabled) { |
| 3365 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3366 | PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END); |
| 3367 | } else { |
| 3368 | c = smalloc(sizeof(struct ssh_channel)); |
| 3369 | c->ssh = ssh; |
| 3370 | c->remoteid = GET_32BIT(ssh->pktin.body); |
| 3371 | c->localid = alloc_channel_id(ssh); |
| 3372 | c->closes = 0; |
| 3373 | c->v.v1.throttling = 0; |
| 3374 | c->type = CHAN_AGENT; /* identify channel type */ |
| 3375 | c->u.a.lensofar = 0; |
| 3376 | add234(ssh->channels, c); |
| 3377 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 3378 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 3379 | PKT_END); |
| 3380 | } |
| 3381 | } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) { |
| 3382 | /* Remote side is trying to open a channel to talk to a |
| 3383 | * forwarded port. Give them back a local channel number. */ |
| 3384 | struct ssh_channel *c; |
| 3385 | struct ssh_rportfwd pf; |
| 3386 | int hostsize, port; |
| 3387 | char host[256], buf[1024]; |
| 3388 | char *p, *h, *e; |
| 3389 | c = smalloc(sizeof(struct ssh_channel)); |
| 3390 | c->ssh = ssh; |
| 3391 | |
| 3392 | hostsize = GET_32BIT(ssh->pktin.body+4); |
| 3393 | for (h = host, p = (char *)(ssh->pktin.body+8); |
| 3394 | hostsize != 0; hostsize--) { |
| 3395 | if (h+1 < host+sizeof(host)) |
| 3396 | *h++ = *p; |
| 3397 | p++; |
| 3398 | } |
| 3399 | *h = 0; |
| 3400 | port = GET_32BIT(p); |
| 3401 | |
| 3402 | strcpy(pf.dhost, host); |
| 3403 | pf.dport = port; |
| 3404 | |
| 3405 | if (find234(ssh->rportfwds, &pf, NULL) == NULL) { |
| 3406 | sprintf(buf, "Rejected remote port open request for %s:%d", |
| 3407 | host, port); |
| 3408 | logevent(buf); |
| 3409 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3410 | PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END); |
| 3411 | } else { |
| 3412 | sprintf(buf, "Received remote port open request for %s:%d", |
| 3413 | host, port); |
| 3414 | logevent(buf); |
| 3415 | e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg); |
| 3416 | if (e != NULL) { |
| 3417 | char buf[256]; |
| 3418 | sprintf(buf, "Port open failed: %s", e); |
| 3419 | logevent(buf); |
| 3420 | sfree(c); |
| 3421 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 3422 | PKT_INT, GET_32BIT(ssh->pktin.body), |
| 3423 | PKT_END); |
| 3424 | } else { |
| 3425 | c->remoteid = GET_32BIT(ssh->pktin.body); |
| 3426 | c->localid = alloc_channel_id(ssh); |
| 3427 | c->closes = 0; |
| 3428 | c->v.v1.throttling = 0; |
| 3429 | c->type = CHAN_SOCKDATA; /* identify channel type */ |
| 3430 | add234(ssh->channels, c); |
| 3431 | send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 3432 | PKT_INT, c->remoteid, PKT_INT, |
| 3433 | c->localid, PKT_END); |
| 3434 | logevent("Forwarded port opened successfully"); |
| 3435 | } |
| 3436 | } |
| 3437 | |
| 3438 | } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 3439 | unsigned int remoteid = GET_32BIT(ssh->pktin.body); |
| 3440 | unsigned int localid = GET_32BIT(ssh->pktin.body+4); |
| 3441 | struct ssh_channel *c; |
| 3442 | |
| 3443 | c = find234(ssh->channels, &remoteid, ssh_channelfind); |
| 3444 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 3445 | c->remoteid = localid; |
| 3446 | c->type = CHAN_SOCKDATA; |
| 3447 | c->v.v1.throttling = 0; |
| 3448 | pfd_confirm(c->u.pfd.s); |
| 3449 | } |
| 3450 | |
| 3451 | if (c && c->closes) { |
| 3452 | /* |
| 3453 | * We have a pending close on this channel, |
| 3454 | * which we decided on before the server acked |
| 3455 | * the channel open. So now we know the |
| 3456 | * remoteid, we can close it again. |
| 3457 | */ |
| 3458 | send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, |
| 3459 | PKT_INT, c->remoteid, PKT_END); |
| 3460 | } |
| 3461 | |
| 3462 | } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { |
| 3463 | unsigned int remoteid = GET_32BIT(ssh->pktin.body); |
| 3464 | struct ssh_channel *c; |
| 3465 | |
| 3466 | c = find234(ssh->channels, &remoteid, ssh_channelfind); |
| 3467 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 3468 | logevent("Forwarded connection refused by server"); |
| 3469 | pfd_close(c->u.pfd.s); |
| 3470 | del234(ssh->channels, c); |
| 3471 | sfree(c); |
| 3472 | } |
| 3473 | |
| 3474 | } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
| 3475 | ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
| 3476 | /* Remote side closes a channel. */ |
| 3477 | unsigned i = GET_32BIT(ssh->pktin.body); |
| 3478 | struct ssh_channel *c; |
| 3479 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 3480 | if (c && ((int)c->remoteid) != -1) { |
| 3481 | int closetype; |
| 3482 | closetype = |
| 3483 | (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
| 3484 | |
| 3485 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
| 3486 | logevent("Forwarded X11 connection terminated"); |
| 3487 | assert(c->u.x11.s != NULL); |
| 3488 | x11_close(c->u.x11.s); |
| 3489 | c->u.x11.s = NULL; |
| 3490 | } |
| 3491 | if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { |
| 3492 | logevent("Forwarded port closed"); |
| 3493 | assert(c->u.pfd.s != NULL); |
| 3494 | pfd_close(c->u.pfd.s); |
| 3495 | c->u.pfd.s = NULL; |
| 3496 | } |
| 3497 | |
| 3498 | c->closes |= (closetype << 2); /* seen this message */ |
| 3499 | if (!(c->closes & closetype)) { |
| 3500 | send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid, |
| 3501 | PKT_END); |
| 3502 | c->closes |= closetype; /* sent it too */ |
| 3503 | } |
| 3504 | |
| 3505 | if (c->closes == 15) { |
| 3506 | del234(ssh->channels, c); |
| 3507 | sfree(c); |
| 3508 | } |
| 3509 | } else { |
| 3510 | bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n", |
| 3511 | ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" : |
| 3512 | "_CONFIRMATION", c ? "half-open" : "nonexistent", |
| 3513 | i)); |
| 3514 | } |
| 3515 | } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) { |
| 3516 | /* Data sent down one of our channels. */ |
| 3517 | int i = GET_32BIT(ssh->pktin.body); |
| 3518 | int len = GET_32BIT(ssh->pktin.body + 4); |
| 3519 | unsigned char *p = ssh->pktin.body + 8; |
| 3520 | struct ssh_channel *c; |
| 3521 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 3522 | if (c) { |
| 3523 | int bufsize; |
| 3524 | switch (c->type) { |
| 3525 | case CHAN_X11: |
| 3526 | bufsize = x11_send(c->u.x11.s, (char *)p, len); |
| 3527 | break; |
| 3528 | case CHAN_SOCKDATA: |
| 3529 | bufsize = pfd_send(c->u.pfd.s, (char *)p, len); |
| 3530 | break; |
| 3531 | case CHAN_AGENT: |
| 3532 | /* Data for an agent message. Buffer it. */ |
| 3533 | while (len > 0) { |
| 3534 | if (c->u.a.lensofar < 4) { |
| 3535 | int l = min(4 - c->u.a.lensofar, len); |
| 3536 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, |
| 3537 | l); |
| 3538 | p += l; |
| 3539 | len -= l; |
| 3540 | c->u.a.lensofar += l; |
| 3541 | } |
| 3542 | if (c->u.a.lensofar == 4) { |
| 3543 | c->u.a.totallen = |
| 3544 | 4 + GET_32BIT(c->u.a.msglen); |
| 3545 | c->u.a.message = smalloc(c->u.a.totallen); |
| 3546 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 3547 | } |
| 3548 | if (c->u.a.lensofar >= 4 && len > 0) { |
| 3549 | int l = |
| 3550 | min(c->u.a.totallen - c->u.a.lensofar, |
| 3551 | len); |
| 3552 | memcpy(c->u.a.message + c->u.a.lensofar, p, |
| 3553 | l); |
| 3554 | p += l; |
| 3555 | len -= l; |
| 3556 | c->u.a.lensofar += l; |
| 3557 | } |
| 3558 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 3559 | void *reply, *sentreply; |
| 3560 | int replylen; |
| 3561 | agent_query(c->u.a.message, |
| 3562 | c->u.a.totallen, &reply, |
| 3563 | &replylen); |
| 3564 | if (reply) |
| 3565 | sentreply = reply; |
| 3566 | else { |
| 3567 | /* Fake SSH_AGENT_FAILURE. */ |
| 3568 | sentreply = "\0\0\0\1\5"; |
| 3569 | replylen = 5; |
| 3570 | } |
| 3571 | send_packet(ssh, SSH1_MSG_CHANNEL_DATA, |
| 3572 | PKT_INT, c->remoteid, |
| 3573 | PKT_INT, replylen, |
| 3574 | PKT_DATA, sentreply, replylen, |
| 3575 | PKT_END); |
| 3576 | if (reply) |
| 3577 | sfree(reply); |
| 3578 | sfree(c->u.a.message); |
| 3579 | c->u.a.lensofar = 0; |
| 3580 | } |
| 3581 | } |
| 3582 | bufsize = 0; /* agent channels never back up */ |
| 3583 | break; |
| 3584 | } |
| 3585 | if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 3586 | c->v.v1.throttling = 1; |
| 3587 | ssh1_throttle(ssh, +1); |
| 3588 | } |
| 3589 | } |
| 3590 | } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) { |
| 3591 | /* may be from EXEC_SHELL on some servers */ |
| 3592 | } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) { |
| 3593 | /* may be from EXEC_SHELL on some servers |
| 3594 | * if no pty is available or in other odd cases. Ignore */ |
| 3595 | } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 3596 | char buf[100]; |
| 3597 | ssh->exitcode = GET_32BIT(ssh->pktin.body); |
| 3598 | sprintf(buf, "Server sent command exit status %d", |
| 3599 | ssh->exitcode); |
| 3600 | logevent(buf); |
| 3601 | send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 3602 | /* |
| 3603 | * In case `helpful' firewalls or proxies tack |
| 3604 | * extra human-readable text on the end of the |
| 3605 | * session which we might mistake for another |
| 3606 | * encrypted packet, we close the session once |
| 3607 | * we've sent EXIT_CONFIRMATION. |
| 3608 | */ |
| 3609 | ssh->state = SSH_STATE_CLOSED; |
| 3610 | crReturnV; |
| 3611 | } else { |
| 3612 | bombout((ssh,"Strange packet received: type %d", ssh->pktin.type)); |
| 3613 | crReturnV; |
| 3614 | } |
| 3615 | } else { |
| 3616 | while (inlen > 0) { |
| 3617 | int len = min(inlen, 512); |
| 3618 | send_packet(ssh, SSH1_CMSG_STDIN_DATA, |
| 3619 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
| 3620 | in += len; |
| 3621 | inlen -= len; |
| 3622 | } |
| 3623 | } |
| 3624 | } |
| 3625 | |
| 3626 | crFinishV; |
| 3627 | } |
| 3628 | |
| 3629 | /* |
| 3630 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 3631 | */ |
| 3632 | static int in_commasep_string(char *needle, char *haystack, int haylen) |
| 3633 | { |
| 3634 | int needlen; |
| 3635 | if (!needle || !haystack) /* protect against null pointers */ |
| 3636 | return 0; |
| 3637 | needlen = strlen(needle); |
| 3638 | while (1) { |
| 3639 | /* |
| 3640 | * Is it at the start of the string? |
| 3641 | */ |
| 3642 | if (haylen >= needlen && /* haystack is long enough */ |
| 3643 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 3644 | (haylen == needlen || haystack[needlen] == ',') |
| 3645 | /* either , or EOS follows */ |
| 3646 | ) |
| 3647 | return 1; |
| 3648 | /* |
| 3649 | * If not, search for the next comma and resume after that. |
| 3650 | * If no comma found, terminate. |
| 3651 | */ |
| 3652 | while (haylen > 0 && *haystack != ',') |
| 3653 | haylen--, haystack++; |
| 3654 | if (haylen == 0) |
| 3655 | return 0; |
| 3656 | haylen--, haystack++; /* skip over comma itself */ |
| 3657 | } |
| 3658 | } |
| 3659 | |
| 3660 | /* |
| 3661 | * SSH2 key creation method. |
| 3662 | */ |
| 3663 | static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, |
| 3664 | unsigned char *sessid, char chr, |
| 3665 | unsigned char *keyspace) |
| 3666 | { |
| 3667 | SHA_State s; |
| 3668 | /* First 20 bytes. */ |
| 3669 | SHA_Init(&s); |
| 3670 | if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) |
| 3671 | sha_mpint(&s, K); |
| 3672 | SHA_Bytes(&s, H, 20); |
| 3673 | SHA_Bytes(&s, &chr, 1); |
| 3674 | SHA_Bytes(&s, sessid, 20); |
| 3675 | SHA_Final(&s, keyspace); |
| 3676 | /* Next 20 bytes. */ |
| 3677 | SHA_Init(&s); |
| 3678 | if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) |
| 3679 | sha_mpint(&s, K); |
| 3680 | SHA_Bytes(&s, H, 20); |
| 3681 | SHA_Bytes(&s, keyspace, 20); |
| 3682 | SHA_Final(&s, keyspace + 20); |
| 3683 | } |
| 3684 | |
| 3685 | /* |
| 3686 | * Handle the SSH2 transport layer. |
| 3687 | */ |
| 3688 | static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt) |
| 3689 | { |
| 3690 | struct do_ssh2_transport_state { |
| 3691 | int nbits, pbits, warn; |
| 3692 | Bignum p, g, e, f, K; |
| 3693 | int kex_init_value, kex_reply_value; |
| 3694 | const struct ssh_mac **maclist; |
| 3695 | int nmacs; |
| 3696 | const struct ssh2_cipher *cscipher_tobe; |
| 3697 | const struct ssh2_cipher *sccipher_tobe; |
| 3698 | const struct ssh_mac *csmac_tobe; |
| 3699 | const struct ssh_mac *scmac_tobe; |
| 3700 | const struct ssh_compress *cscomp_tobe; |
| 3701 | const struct ssh_compress *sccomp_tobe; |
| 3702 | char *hostkeydata, *sigdata, *keystr, *fingerprint; |
| 3703 | int hostkeylen, siglen; |
| 3704 | void *hkey; /* actual host key */ |
| 3705 | unsigned char exchange_hash[20]; |
| 3706 | int n_preferred_ciphers; |
| 3707 | const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; |
| 3708 | const struct ssh_compress *preferred_comp; |
| 3709 | int first_kex; |
| 3710 | }; |
| 3711 | crState(do_ssh2_transport_state); |
| 3712 | |
| 3713 | crBegin(ssh->do_ssh2_transport_crstate); |
| 3714 | |
| 3715 | s->cscipher_tobe = s->sccipher_tobe = NULL; |
| 3716 | s->csmac_tobe = s->scmac_tobe = NULL; |
| 3717 | s->cscomp_tobe = s->sccomp_tobe = NULL; |
| 3718 | |
| 3719 | random_init(); |
| 3720 | s->first_kex = 1; |
| 3721 | |
| 3722 | { |
| 3723 | int i; |
| 3724 | /* |
| 3725 | * Set up the preferred ciphers. (NULL => warn below here) |
| 3726 | */ |
| 3727 | s->n_preferred_ciphers = 0; |
| 3728 | for (i = 0; i < CIPHER_MAX; i++) { |
| 3729 | switch (ssh->cfg.ssh_cipherlist[i]) { |
| 3730 | case CIPHER_BLOWFISH: |
| 3731 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish; |
| 3732 | break; |
| 3733 | case CIPHER_DES: |
| 3734 | if (ssh->cfg.ssh2_des_cbc) { |
| 3735 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des; |
| 3736 | } |
| 3737 | break; |
| 3738 | case CIPHER_3DES: |
| 3739 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des; |
| 3740 | break; |
| 3741 | case CIPHER_AES: |
| 3742 | s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes; |
| 3743 | break; |
| 3744 | case CIPHER_WARN: |
| 3745 | /* Flag for later. Don't bother if it's the last in |
| 3746 | * the list. */ |
| 3747 | if (i < CIPHER_MAX - 1) { |
| 3748 | s->preferred_ciphers[s->n_preferred_ciphers++] = NULL; |
| 3749 | } |
| 3750 | break; |
| 3751 | } |
| 3752 | } |
| 3753 | } |
| 3754 | |
| 3755 | /* |
| 3756 | * Set up preferred compression. |
| 3757 | */ |
| 3758 | if (ssh->cfg.compression) |
| 3759 | s->preferred_comp = &ssh_zlib; |
| 3760 | else |
| 3761 | s->preferred_comp = &ssh_comp_none; |
| 3762 | |
| 3763 | /* |
| 3764 | * Be prepared to work around the buggy MAC problem. |
| 3765 | */ |
| 3766 | if (ssh->remote_bugs & BUG_SSH2_HMAC) |
| 3767 | s->maclist = buggymacs, s->nmacs = lenof(buggymacs); |
| 3768 | else |
| 3769 | s->maclist = macs, s->nmacs = lenof(macs); |
| 3770 | |
| 3771 | begin_key_exchange: |
| 3772 | { |
| 3773 | int i, j, cipherstr_started; |
| 3774 | |
| 3775 | /* |
| 3776 | * Construct and send our key exchange packet. |
| 3777 | */ |
| 3778 | ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT); |
| 3779 | for (i = 0; i < 16; i++) |
| 3780 | ssh2_pkt_addbyte(ssh, (unsigned char) random_byte()); |
| 3781 | /* List key exchange algorithms. */ |
| 3782 | ssh2_pkt_addstring_start(ssh); |
| 3783 | for (i = 0; i < lenof(kex_algs); i++) { |
| 3784 | if (kex_algs[i] == &ssh_diffiehellman_gex && |
| 3785 | (ssh->remote_bugs & BUG_SSH2_DH_GEX)) |
| 3786 | continue; |
| 3787 | ssh2_pkt_addstring_str(ssh, kex_algs[i]->name); |
| 3788 | if (i < lenof(kex_algs) - 1) |
| 3789 | ssh2_pkt_addstring_str(ssh, ","); |
| 3790 | } |
| 3791 | /* List server host key algorithms. */ |
| 3792 | ssh2_pkt_addstring_start(ssh); |
| 3793 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 3794 | ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name); |
| 3795 | if (i < lenof(hostkey_algs) - 1) |
| 3796 | ssh2_pkt_addstring_str(ssh, ","); |
| 3797 | } |
| 3798 | /* List client->server encryption algorithms. */ |
| 3799 | ssh2_pkt_addstring_start(ssh); |
| 3800 | cipherstr_started = 0; |
| 3801 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 3802 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 3803 | if (!c) continue; /* warning flag */ |
| 3804 | for (j = 0; j < c->nciphers; j++) { |
| 3805 | if (cipherstr_started) |
| 3806 | ssh2_pkt_addstring_str(ssh, ","); |
| 3807 | ssh2_pkt_addstring_str(ssh, c->list[j]->name); |
| 3808 | cipherstr_started = 1; |
| 3809 | } |
| 3810 | } |
| 3811 | /* List server->client encryption algorithms. */ |
| 3812 | ssh2_pkt_addstring_start(ssh); |
| 3813 | cipherstr_started = 0; |
| 3814 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 3815 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 3816 | if (!c) continue; /* warning flag */ |
| 3817 | for (j = 0; j < c->nciphers; j++) { |
| 3818 | if (cipherstr_started) |
| 3819 | ssh2_pkt_addstring_str(ssh, ","); |
| 3820 | ssh2_pkt_addstring_str(ssh, c->list[j]->name); |
| 3821 | cipherstr_started = 1; |
| 3822 | } |
| 3823 | } |
| 3824 | /* List client->server MAC algorithms. */ |
| 3825 | ssh2_pkt_addstring_start(ssh); |
| 3826 | for (i = 0; i < s->nmacs; i++) { |
| 3827 | ssh2_pkt_addstring_str(ssh, s->maclist[i]->name); |
| 3828 | if (i < s->nmacs - 1) |
| 3829 | ssh2_pkt_addstring_str(ssh, ","); |
| 3830 | } |
| 3831 | /* List server->client MAC algorithms. */ |
| 3832 | ssh2_pkt_addstring_start(ssh); |
| 3833 | for (i = 0; i < s->nmacs; i++) { |
| 3834 | ssh2_pkt_addstring_str(ssh, s->maclist[i]->name); |
| 3835 | if (i < s->nmacs - 1) |
| 3836 | ssh2_pkt_addstring_str(ssh, ","); |
| 3837 | } |
| 3838 | /* List client->server compression algorithms. */ |
| 3839 | ssh2_pkt_addstring_start(ssh); |
| 3840 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3841 | const struct ssh_compress *c = |
| 3842 | i == 0 ? s->preferred_comp : compressions[i - 1]; |
| 3843 | ssh2_pkt_addstring_str(ssh, c->name); |
| 3844 | if (i < lenof(compressions)) |
| 3845 | ssh2_pkt_addstring_str(ssh, ","); |
| 3846 | } |
| 3847 | /* List server->client compression algorithms. */ |
| 3848 | ssh2_pkt_addstring_start(ssh); |
| 3849 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3850 | const struct ssh_compress *c = |
| 3851 | i == 0 ? s->preferred_comp : compressions[i - 1]; |
| 3852 | ssh2_pkt_addstring_str(ssh, c->name); |
| 3853 | if (i < lenof(compressions)) |
| 3854 | ssh2_pkt_addstring_str(ssh, ","); |
| 3855 | } |
| 3856 | /* List client->server languages. Empty list. */ |
| 3857 | ssh2_pkt_addstring_start(ssh); |
| 3858 | /* List server->client languages. Empty list. */ |
| 3859 | ssh2_pkt_addstring_start(ssh); |
| 3860 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 3861 | ssh2_pkt_addbool(ssh, FALSE); |
| 3862 | /* Reserved. */ |
| 3863 | ssh2_pkt_adduint32(ssh, 0); |
| 3864 | } |
| 3865 | |
| 3866 | ssh->exhash = ssh->exhashbase; |
| 3867 | sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5); |
| 3868 | |
| 3869 | ssh2_pkt_send(ssh); |
| 3870 | |
| 3871 | if (!ispkt) |
| 3872 | crWaitUntil(ispkt); |
| 3873 | if (ssh->pktin.length > 5) |
| 3874 | sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5); |
| 3875 | |
| 3876 | /* |
| 3877 | * Now examine the other side's KEXINIT to see what we're up |
| 3878 | * to. |
| 3879 | */ |
| 3880 | { |
| 3881 | char *str; |
| 3882 | int i, j, len; |
| 3883 | |
| 3884 | if (ssh->pktin.type != SSH2_MSG_KEXINIT) { |
| 3885 | bombout((ssh,"expected key exchange packet from server")); |
| 3886 | crReturn(0); |
| 3887 | } |
| 3888 | ssh->kex = NULL; |
| 3889 | ssh->hostkey = NULL; |
| 3890 | s->cscipher_tobe = NULL; |
| 3891 | s->sccipher_tobe = NULL; |
| 3892 | s->csmac_tobe = NULL; |
| 3893 | s->scmac_tobe = NULL; |
| 3894 | s->cscomp_tobe = NULL; |
| 3895 | s->sccomp_tobe = NULL; |
| 3896 | ssh->pktin.savedpos += 16; /* skip garbage cookie */ |
| 3897 | ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */ |
| 3898 | for (i = 0; i < lenof(kex_algs); i++) { |
| 3899 | if (kex_algs[i] == &ssh_diffiehellman_gex && |
| 3900 | (ssh->remote_bugs & BUG_SSH2_DH_GEX)) |
| 3901 | continue; |
| 3902 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
| 3903 | ssh->kex = kex_algs[i]; |
| 3904 | break; |
| 3905 | } |
| 3906 | } |
| 3907 | ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */ |
| 3908 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 3909 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 3910 | ssh->hostkey = hostkey_algs[i]; |
| 3911 | break; |
| 3912 | } |
| 3913 | } |
| 3914 | ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */ |
| 3915 | s->warn = 0; |
| 3916 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 3917 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 3918 | if (!c) { |
| 3919 | s->warn = 1; |
| 3920 | } else { |
| 3921 | for (j = 0; j < c->nciphers; j++) { |
| 3922 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 3923 | s->cscipher_tobe = c->list[j]; |
| 3924 | break; |
| 3925 | } |
| 3926 | } |
| 3927 | } |
| 3928 | if (s->cscipher_tobe) { |
| 3929 | if (s->warn) |
| 3930 | askcipher(ssh->frontend, s->cscipher_tobe->name, 1); |
| 3931 | break; |
| 3932 | } |
| 3933 | } |
| 3934 | if (!s->cscipher_tobe) { |
| 3935 | bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)", |
| 3936 | str ? str : "(null)")); |
| 3937 | crReturn(0); |
| 3938 | } |
| 3939 | |
| 3940 | ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */ |
| 3941 | s->warn = 0; |
| 3942 | for (i = 0; i < s->n_preferred_ciphers; i++) { |
| 3943 | const struct ssh2_ciphers *c = s->preferred_ciphers[i]; |
| 3944 | if (!c) { |
| 3945 | s->warn = 1; |
| 3946 | } else { |
| 3947 | for (j = 0; j < c->nciphers; j++) { |
| 3948 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 3949 | s->sccipher_tobe = c->list[j]; |
| 3950 | break; |
| 3951 | } |
| 3952 | } |
| 3953 | } |
| 3954 | if (s->sccipher_tobe) { |
| 3955 | if (s->warn) |
| 3956 | askcipher(ssh->frontend, s->sccipher_tobe->name, 2); |
| 3957 | break; |
| 3958 | } |
| 3959 | } |
| 3960 | if (!s->sccipher_tobe) { |
| 3961 | bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)", |
| 3962 | str ? str : "(null)")); |
| 3963 | crReturn(0); |
| 3964 | } |
| 3965 | |
| 3966 | ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */ |
| 3967 | for (i = 0; i < s->nmacs; i++) { |
| 3968 | if (in_commasep_string(s->maclist[i]->name, str, len)) { |
| 3969 | s->csmac_tobe = s->maclist[i]; |
| 3970 | break; |
| 3971 | } |
| 3972 | } |
| 3973 | ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */ |
| 3974 | for (i = 0; i < s->nmacs; i++) { |
| 3975 | if (in_commasep_string(s->maclist[i]->name, str, len)) { |
| 3976 | s->scmac_tobe = s->maclist[i]; |
| 3977 | break; |
| 3978 | } |
| 3979 | } |
| 3980 | ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */ |
| 3981 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3982 | const struct ssh_compress *c = |
| 3983 | i == 0 ? s->preferred_comp : compressions[i - 1]; |
| 3984 | if (in_commasep_string(c->name, str, len)) { |
| 3985 | s->cscomp_tobe = c; |
| 3986 | break; |
| 3987 | } |
| 3988 | } |
| 3989 | ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */ |
| 3990 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3991 | const struct ssh_compress *c = |
| 3992 | i == 0 ? s->preferred_comp : compressions[i - 1]; |
| 3993 | if (in_commasep_string(c->name, str, len)) { |
| 3994 | s->sccomp_tobe = c; |
| 3995 | break; |
| 3996 | } |
| 3997 | } |
| 3998 | } |
| 3999 | |
| 4000 | /* |
| 4001 | * Work out the number of bits of key we will need from the key |
| 4002 | * exchange. We start with the maximum key length of either |
| 4003 | * cipher... |
| 4004 | */ |
| 4005 | { |
| 4006 | int csbits, scbits; |
| 4007 | |
| 4008 | csbits = s->cscipher_tobe->keylen; |
| 4009 | scbits = s->sccipher_tobe->keylen; |
| 4010 | s->nbits = (csbits > scbits ? csbits : scbits); |
| 4011 | } |
| 4012 | /* The keys only have 160-bit entropy, since they're based on |
| 4013 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
| 4014 | if (s->nbits > 160) |
| 4015 | s->nbits = 160; |
| 4016 | |
| 4017 | /* |
| 4018 | * If we're doing Diffie-Hellman group exchange, start by |
| 4019 | * requesting a group. |
| 4020 | */ |
| 4021 | if (ssh->kex == &ssh_diffiehellman_gex) { |
| 4022 | logevent("Doing Diffie-Hellman group exchange"); |
| 4023 | ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX; |
| 4024 | /* |
| 4025 | * Work out how big a DH group we will need to allow that |
| 4026 | * much data. |
| 4027 | */ |
| 4028 | s->pbits = 512 << ((s->nbits - 1) / 64); |
| 4029 | ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST); |
| 4030 | ssh2_pkt_adduint32(ssh, s->pbits); |
| 4031 | ssh2_pkt_send(ssh); |
| 4032 | |
| 4033 | crWaitUntil(ispkt); |
| 4034 | if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
| 4035 | bombout((ssh,"expected key exchange group packet from server")); |
| 4036 | crReturn(0); |
| 4037 | } |
| 4038 | s->p = ssh2_pkt_getmp(ssh); |
| 4039 | s->g = ssh2_pkt_getmp(ssh); |
| 4040 | ssh->kex_ctx = dh_setup_group(s->p, s->g); |
| 4041 | s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
| 4042 | s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
| 4043 | } else { |
| 4044 | ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1; |
| 4045 | ssh->kex_ctx = dh_setup_group1(); |
| 4046 | s->kex_init_value = SSH2_MSG_KEXDH_INIT; |
| 4047 | s->kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
| 4048 | } |
| 4049 | |
| 4050 | logevent("Doing Diffie-Hellman key exchange"); |
| 4051 | /* |
| 4052 | * Now generate and send e for Diffie-Hellman. |
| 4053 | */ |
| 4054 | s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); |
| 4055 | ssh2_pkt_init(ssh, s->kex_init_value); |
| 4056 | ssh2_pkt_addmp(ssh, s->e); |
| 4057 | ssh2_pkt_send(ssh); |
| 4058 | |
| 4059 | crWaitUntil(ispkt); |
| 4060 | if (ssh->pktin.type != s->kex_reply_value) { |
| 4061 | bombout((ssh,"expected key exchange reply packet from server")); |
| 4062 | crReturn(0); |
| 4063 | } |
| 4064 | ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen); |
| 4065 | s->f = ssh2_pkt_getmp(ssh); |
| 4066 | ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen); |
| 4067 | |
| 4068 | s->K = dh_find_K(ssh->kex_ctx, s->f); |
| 4069 | |
| 4070 | sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen); |
| 4071 | if (ssh->kex == &ssh_diffiehellman_gex) { |
| 4072 | sha_uint32(&ssh->exhash, s->pbits); |
| 4073 | sha_mpint(&ssh->exhash, s->p); |
| 4074 | sha_mpint(&ssh->exhash, s->g); |
| 4075 | } |
| 4076 | sha_mpint(&ssh->exhash, s->e); |
| 4077 | sha_mpint(&ssh->exhash, s->f); |
| 4078 | sha_mpint(&ssh->exhash, s->K); |
| 4079 | SHA_Final(&ssh->exhash, s->exchange_hash); |
| 4080 | |
| 4081 | dh_cleanup(ssh->kex_ctx); |
| 4082 | ssh->kex_ctx = NULL; |
| 4083 | |
| 4084 | #if 0 |
| 4085 | debug(("Exchange hash is:\n")); |
| 4086 | dmemdump(s->exchange_hash, 20); |
| 4087 | #endif |
| 4088 | |
| 4089 | s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); |
| 4090 | if (!s->hkey || |
| 4091 | !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, |
| 4092 | (char *)s->exchange_hash, 20)) { |
| 4093 | bombout((ssh,"Server's host key did not match the signature supplied")); |
| 4094 | crReturn(0); |
| 4095 | } |
| 4096 | |
| 4097 | /* |
| 4098 | * Authenticate remote host: verify host key. (We've already |
| 4099 | * checked the signature of the exchange hash.) |
| 4100 | */ |
| 4101 | s->keystr = ssh->hostkey->fmtkey(s->hkey); |
| 4102 | s->fingerprint = ssh->hostkey->fingerprint(s->hkey); |
| 4103 | verify_ssh_host_key(ssh->frontend, |
| 4104 | ssh->savedhost, ssh->savedport, ssh->hostkey->keytype, |
| 4105 | s->keystr, s->fingerprint); |
| 4106 | if (s->first_kex) { /* don't bother logging this in rekeys */ |
| 4107 | logevent("Host key fingerprint is:"); |
| 4108 | logevent(s->fingerprint); |
| 4109 | } |
| 4110 | sfree(s->fingerprint); |
| 4111 | sfree(s->keystr); |
| 4112 | ssh->hostkey->freekey(s->hkey); |
| 4113 | |
| 4114 | /* |
| 4115 | * Send SSH2_MSG_NEWKEYS. |
| 4116 | */ |
| 4117 | ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS); |
| 4118 | ssh2_pkt_send(ssh); |
| 4119 | |
| 4120 | /* |
| 4121 | * Expect SSH2_MSG_NEWKEYS from server. |
| 4122 | */ |
| 4123 | crWaitUntil(ispkt); |
| 4124 | if (ssh->pktin.type != SSH2_MSG_NEWKEYS) { |
| 4125 | bombout((ssh,"expected new-keys packet from server")); |
| 4126 | crReturn(0); |
| 4127 | } |
| 4128 | |
| 4129 | /* |
| 4130 | * Create and initialise session keys. |
| 4131 | */ |
| 4132 | if (ssh->cs_cipher_ctx) |
| 4133 | ssh->cscipher->free_context(ssh->cs_cipher_ctx); |
| 4134 | ssh->cscipher = s->cscipher_tobe; |
| 4135 | ssh->cs_cipher_ctx = ssh->cscipher->make_context(); |
| 4136 | |
| 4137 | if (ssh->sc_cipher_ctx) |
| 4138 | ssh->sccipher->free_context(ssh->sc_cipher_ctx); |
| 4139 | ssh->sccipher = s->sccipher_tobe; |
| 4140 | ssh->sc_cipher_ctx = ssh->sccipher->make_context(); |
| 4141 | |
| 4142 | if (ssh->cs_mac_ctx) |
| 4143 | ssh->csmac->free_context(ssh->cs_mac_ctx); |
| 4144 | ssh->csmac = s->csmac_tobe; |
| 4145 | ssh->cs_mac_ctx = ssh->csmac->make_context(); |
| 4146 | |
| 4147 | if (ssh->sc_mac_ctx) |
| 4148 | ssh->scmac->free_context(ssh->sc_mac_ctx); |
| 4149 | ssh->scmac = s->scmac_tobe; |
| 4150 | ssh->sc_mac_ctx = ssh->scmac->make_context(); |
| 4151 | |
| 4152 | if (ssh->cs_comp_ctx) |
| 4153 | ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); |
| 4154 | ssh->cscomp = s->cscomp_tobe; |
| 4155 | ssh->cs_comp_ctx = ssh->cscomp->compress_init(); |
| 4156 | |
| 4157 | if (ssh->sc_comp_ctx) |
| 4158 | ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); |
| 4159 | ssh->sccomp = s->sccomp_tobe; |
| 4160 | ssh->sc_comp_ctx = ssh->sccomp->decompress_init(); |
| 4161 | |
| 4162 | /* |
| 4163 | * Set IVs after keys. Here we use the exchange hash from the |
| 4164 | * _first_ key exchange. |
| 4165 | */ |
| 4166 | { |
| 4167 | unsigned char keyspace[40]; |
| 4168 | if (s->first_kex) |
| 4169 | memcpy(ssh->v2_session_id, s->exchange_hash, |
| 4170 | sizeof(s->exchange_hash)); |
| 4171 | ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace); |
| 4172 | ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); |
| 4173 | ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace); |
| 4174 | ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); |
| 4175 | ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace); |
| 4176 | ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); |
| 4177 | ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace); |
| 4178 | ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); |
| 4179 | ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace); |
| 4180 | ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); |
| 4181 | ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace); |
| 4182 | ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); |
| 4183 | } |
| 4184 | logeventf(ssh, "Initialised %.200s client->server encryption", |
| 4185 | ssh->cscipher->text_name); |
| 4186 | logeventf(ssh, "Initialised %.200s server->client encryption", |
| 4187 | ssh->sccipher->text_name); |
| 4188 | if (ssh->cscomp->text_name) |
| 4189 | logeventf(ssh, "Initialised %s compression", |
| 4190 | ssh->cscomp->text_name); |
| 4191 | if (ssh->sccomp->text_name) |
| 4192 | logeventf(ssh, "Initialised %s decompression", |
| 4193 | ssh->sccomp->text_name); |
| 4194 | |
| 4195 | /* |
| 4196 | * If this is the first key exchange phase, we must pass the |
| 4197 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
| 4198 | * wants to see it but because it will need time to initialise |
| 4199 | * itself before it sees an actual packet. In subsequent key |
| 4200 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
| 4201 | * it would only confuse the layer above. |
| 4202 | */ |
| 4203 | if (!s->first_kex) { |
| 4204 | crReturn(0); |
| 4205 | } |
| 4206 | s->first_kex = 0; |
| 4207 | |
| 4208 | /* |
| 4209 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 4210 | * function so that other things can run on top of the |
| 4211 | * transport. If we ever see a KEXINIT, we must go back to the |
| 4212 | * start. |
| 4213 | */ |
| 4214 | while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) { |
| 4215 | crReturn(1); |
| 4216 | } |
| 4217 | logevent("Server initiated key re-exchange"); |
| 4218 | goto begin_key_exchange; |
| 4219 | |
| 4220 | crFinish(1); |
| 4221 | } |
| 4222 | |
| 4223 | /* |
| 4224 | * Add data to an SSH2 channel output buffer. |
| 4225 | */ |
| 4226 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
| 4227 | int len) |
| 4228 | { |
| 4229 | bufchain_add(&c->v.v2.outbuffer, buf, len); |
| 4230 | } |
| 4231 | |
| 4232 | /* |
| 4233 | * Attempt to send data on an SSH2 channel. |
| 4234 | */ |
| 4235 | static int ssh2_try_send(struct ssh_channel *c) |
| 4236 | { |
| 4237 | Ssh ssh = c->ssh; |
| 4238 | |
| 4239 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { |
| 4240 | int len; |
| 4241 | void *data; |
| 4242 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); |
| 4243 | if ((unsigned)len > c->v.v2.remwindow) |
| 4244 | len = c->v.v2.remwindow; |
| 4245 | if ((unsigned)len > c->v.v2.remmaxpkt) |
| 4246 | len = c->v.v2.remmaxpkt; |
| 4247 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA); |
| 4248 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 4249 | ssh2_pkt_addstring_start(ssh); |
| 4250 | ssh2_pkt_addstring_data(ssh, data, len); |
| 4251 | ssh2_pkt_send(ssh); |
| 4252 | bufchain_consume(&c->v.v2.outbuffer, len); |
| 4253 | c->v.v2.remwindow -= len; |
| 4254 | } |
| 4255 | |
| 4256 | /* |
| 4257 | * After having sent as much data as we can, return the amount |
| 4258 | * still buffered. |
| 4259 | */ |
| 4260 | return bufchain_size(&c->v.v2.outbuffer); |
| 4261 | } |
| 4262 | |
| 4263 | /* |
| 4264 | * Potentially enlarge the window on an SSH2 channel. |
| 4265 | */ |
| 4266 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) |
| 4267 | { |
| 4268 | Ssh ssh = c->ssh; |
| 4269 | |
| 4270 | /* |
| 4271 | * Never send WINDOW_ADJUST for a channel that the remote side |
| 4272 | * already thinks it's closed; there's no point, since it won't |
| 4273 | * be sending any more data anyway. |
| 4274 | */ |
| 4275 | if (c->closes != 0) |
| 4276 | return; |
| 4277 | |
| 4278 | if (newwin > c->v.v2.locwindow) { |
| 4279 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4280 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 4281 | ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow); |
| 4282 | ssh2_pkt_send(ssh); |
| 4283 | c->v.v2.locwindow = newwin; |
| 4284 | } |
| 4285 | } |
| 4286 | |
| 4287 | /* |
| 4288 | * Handle the SSH2 userauth and connection layers. |
| 4289 | */ |
| 4290 | static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt) |
| 4291 | { |
| 4292 | struct do_ssh2_authconn_state { |
| 4293 | enum { |
| 4294 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, |
| 4295 | AUTH_PASSWORD, |
| 4296 | AUTH_KEYBOARD_INTERACTIVE |
| 4297 | } method; |
| 4298 | enum { |
| 4299 | AUTH_TYPE_NONE, |
| 4300 | AUTH_TYPE_PUBLICKEY, |
| 4301 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
| 4302 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
| 4303 | AUTH_TYPE_PASSWORD, |
| 4304 | AUTH_TYPE_KEYBOARD_INTERACTIVE, |
| 4305 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET |
| 4306 | } type; |
| 4307 | int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; |
| 4308 | int tried_pubkey_config, tried_agent, tried_keyb_inter; |
| 4309 | int kbd_inter_running; |
| 4310 | int we_are_in; |
| 4311 | int num_prompts, curr_prompt, echo; |
| 4312 | char username[100]; |
| 4313 | int got_username; |
| 4314 | char pwprompt[200]; |
| 4315 | char password[100]; |
| 4316 | void *publickey_blob; |
| 4317 | int publickey_bloblen; |
| 4318 | unsigned char request[5], *response, *p; |
| 4319 | int responselen; |
| 4320 | int keyi, nkeys; |
| 4321 | int authed; |
| 4322 | char *pkblob, *alg, *commentp; |
| 4323 | int pklen, alglen, commentlen; |
| 4324 | int siglen, retlen, len; |
| 4325 | char *q, *agentreq, *ret; |
| 4326 | int try_send; |
| 4327 | }; |
| 4328 | crState(do_ssh2_authconn_state); |
| 4329 | |
| 4330 | crBegin(ssh->do_ssh2_authconn_crstate); |
| 4331 | |
| 4332 | /* |
| 4333 | * Request userauth protocol, and await a response to it. |
| 4334 | */ |
| 4335 | ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST); |
| 4336 | ssh2_pkt_addstring(ssh, "ssh-userauth"); |
| 4337 | ssh2_pkt_send(ssh); |
| 4338 | crWaitUntilV(ispkt); |
| 4339 | if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
| 4340 | bombout((ssh,"Server refused user authentication protocol")); |
| 4341 | crReturnV; |
| 4342 | } |
| 4343 | |
| 4344 | /* |
| 4345 | * We repeat this whole loop, including the username prompt, |
| 4346 | * until we manage a successful authentication. If the user |
| 4347 | * types the wrong _password_, they can be sent back to the |
| 4348 | * beginning to try another username, if this is configured on. |
| 4349 | * (If they specify a username in the config, they are never |
| 4350 | * asked, even if they do give a wrong password.) |
| 4351 | * |
| 4352 | * I think this best serves the needs of |
| 4353 | * |
| 4354 | * - the people who have no configuration, no keys, and just |
| 4355 | * want to try repeated (username,password) pairs until they |
| 4356 | * type both correctly |
| 4357 | * |
| 4358 | * - people who have keys and configuration but occasionally |
| 4359 | * need to fall back to passwords |
| 4360 | * |
| 4361 | * - people with a key held in Pageant, who might not have |
| 4362 | * logged in to a particular machine before; so they want to |
| 4363 | * type a username, and then _either_ their key will be |
| 4364 | * accepted, _or_ they will type a password. If they mistype |
| 4365 | * the username they will want to be able to get back and |
| 4366 | * retype it! |
| 4367 | */ |
| 4368 | s->username[0] = '\0'; |
| 4369 | s->got_username = FALSE; |
| 4370 | do { |
| 4371 | /* |
| 4372 | * Get a username. |
| 4373 | */ |
| 4374 | if (s->got_username && !ssh->cfg.change_username) { |
| 4375 | /* |
| 4376 | * We got a username last time round this loop, and |
| 4377 | * with change_username turned off we don't try to get |
| 4378 | * it again. |
| 4379 | */ |
| 4380 | } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) { |
| 4381 | if (ssh_get_line && !ssh_getline_pw_only) { |
| 4382 | if (!ssh_get_line("login as: ", |
| 4383 | s->username, sizeof(s->username), FALSE)) { |
| 4384 | /* |
| 4385 | * get_line failed to get a username. |
| 4386 | * Terminate. |
| 4387 | */ |
| 4388 | logevent("No username provided. Abandoning session."); |
| 4389 | ssh->state = SSH_STATE_CLOSED; |
| 4390 | crReturnV; |
| 4391 | } |
| 4392 | } else { |
| 4393 | int ret; /* need not be saved across crReturn */ |
| 4394 | c_write_str(ssh, "login as: "); |
| 4395 | ssh->send_ok = 1; |
| 4396 | setup_userpass_input(ssh, s->username, sizeof(s->username), 1); |
| 4397 | do { |
| 4398 | crWaitUntilV(!ispkt); |
| 4399 | ret = process_userpass_input(ssh, in, inlen); |
| 4400 | } while (ret == 0); |
| 4401 | if (ret < 0) |
| 4402 | cleanup_exit(0); |
| 4403 | c_write_str(ssh, "\r\n"); |
| 4404 | } |
| 4405 | s->username[strcspn(s->username, "\n\r")] = '\0'; |
| 4406 | } else { |
| 4407 | char *stuff; |
| 4408 | strncpy(s->username, ssh->cfg.username, sizeof(s->username)); |
| 4409 | s->username[sizeof(s->username)-1] = '\0'; |
| 4410 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
| 4411 | stuff = dupprintf("Using username \"%s\".\r\n", s->username); |
| 4412 | c_write_str(ssh, stuff); |
| 4413 | sfree(stuff); |
| 4414 | } |
| 4415 | } |
| 4416 | s->got_username = TRUE; |
| 4417 | |
| 4418 | /* |
| 4419 | * Send an authentication request using method "none": (a) |
| 4420 | * just in case it succeeds, and (b) so that we know what |
| 4421 | * authentication methods we can usefully try next. |
| 4422 | */ |
| 4423 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4424 | |
| 4425 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4426 | ssh2_pkt_addstring(ssh, s->username); |
| 4427 | ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */ |
| 4428 | ssh2_pkt_addstring(ssh, "none"); /* method */ |
| 4429 | ssh2_pkt_send(ssh); |
| 4430 | s->type = AUTH_TYPE_NONE; |
| 4431 | s->gotit = FALSE; |
| 4432 | s->we_are_in = FALSE; |
| 4433 | |
| 4434 | s->tried_pubkey_config = FALSE; |
| 4435 | s->tried_agent = FALSE; |
| 4436 | s->tried_keyb_inter = FALSE; |
| 4437 | s->kbd_inter_running = FALSE; |
| 4438 | /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */ |
| 4439 | if (!filename_is_null(ssh->cfg.keyfile)) { |
| 4440 | int keytype; |
| 4441 | logeventf(ssh, "Reading private key file \"%.150s\"", |
| 4442 | filename_to_str(&ssh->cfg.keyfile)); |
| 4443 | keytype = key_type(&ssh->cfg.keyfile); |
| 4444 | if (keytype == SSH_KEYTYPE_SSH2) { |
| 4445 | s->publickey_blob = |
| 4446 | ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL, |
| 4447 | &s->publickey_bloblen); |
| 4448 | } else { |
| 4449 | char *msgbuf; |
| 4450 | logeventf(ssh, "Unable to use this key file (%s)", |
| 4451 | key_type_to_str(keytype)); |
| 4452 | msgbuf = dupprintf("Unable to use key file \"%.150s\"" |
| 4453 | " (%s)\r\n", |
| 4454 | filename_to_str(&ssh->cfg.keyfile), |
| 4455 | key_type_to_str(keytype)); |
| 4456 | c_write_str(ssh, msgbuf); |
| 4457 | sfree(msgbuf); |
| 4458 | s->publickey_blob = NULL; |
| 4459 | } |
| 4460 | } else |
| 4461 | s->publickey_blob = NULL; |
| 4462 | |
| 4463 | while (1) { |
| 4464 | /* |
| 4465 | * Wait for the result of the last authentication request. |
| 4466 | */ |
| 4467 | if (!s->gotit) |
| 4468 | crWaitUntilV(ispkt); |
| 4469 | while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
| 4470 | char *banner; |
| 4471 | int size; |
| 4472 | /* |
| 4473 | * Don't show the banner if we're operating in |
| 4474 | * non-verbose non-interactive mode. (It's probably |
| 4475 | * a script, which means nobody will read the |
| 4476 | * banner _anyway_, and moreover the printing of |
| 4477 | * the banner will screw up processing on the |
| 4478 | * output of (say) plink.) |
| 4479 | */ |
| 4480 | if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { |
| 4481 | ssh2_pkt_getstring(ssh, &banner, &size); |
| 4482 | if (banner) |
| 4483 | c_write_untrusted(ssh, banner, size); |
| 4484 | } |
| 4485 | crWaitUntilV(ispkt); |
| 4486 | } |
| 4487 | if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
| 4488 | logevent("Access granted"); |
| 4489 | s->we_are_in = TRUE; |
| 4490 | break; |
| 4491 | } |
| 4492 | |
| 4493 | if (s->kbd_inter_running && |
| 4494 | ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 4495 | /* |
| 4496 | * This is either a further set-of-prompts packet |
| 4497 | * in keyboard-interactive authentication, or it's |
| 4498 | * the same one and we came back here with `gotit' |
| 4499 | * set. In the former case, we must reset the |
| 4500 | * curr_prompt variable. |
| 4501 | */ |
| 4502 | if (!s->gotit) |
| 4503 | s->curr_prompt = 0; |
| 4504 | } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
| 4505 | bombout((ssh,"Strange packet received during authentication: type %d", |
| 4506 | ssh->pktin.type)); |
| 4507 | crReturnV; |
| 4508 | } |
| 4509 | |
| 4510 | s->gotit = FALSE; |
| 4511 | |
| 4512 | /* |
| 4513 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
| 4514 | * we can look at the string in it and know what we can |
| 4515 | * helpfully try next. |
| 4516 | */ |
| 4517 | if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) { |
| 4518 | char *methods; |
| 4519 | int methlen; |
| 4520 | ssh2_pkt_getstring(ssh, &methods, &methlen); |
| 4521 | s->kbd_inter_running = FALSE; |
| 4522 | if (!ssh2_pkt_getbool(ssh)) { |
| 4523 | /* |
| 4524 | * We have received an unequivocal Access |
| 4525 | * Denied. This can translate to a variety of |
| 4526 | * messages: |
| 4527 | * |
| 4528 | * - if we'd just tried "none" authentication, |
| 4529 | * it's not worth printing anything at all |
| 4530 | * |
| 4531 | * - if we'd just tried a public key _offer_, |
| 4532 | * the message should be "Server refused our |
| 4533 | * key" (or no message at all if the key |
| 4534 | * came from Pageant) |
| 4535 | * |
| 4536 | * - if we'd just tried anything else, the |
| 4537 | * message really should be "Access denied". |
| 4538 | * |
| 4539 | * Additionally, if we'd just tried password |
| 4540 | * authentication, we should break out of this |
| 4541 | * whole loop so as to go back to the username |
| 4542 | * prompt. |
| 4543 | */ |
| 4544 | if (s->type == AUTH_TYPE_NONE) { |
| 4545 | /* do nothing */ |
| 4546 | } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
| 4547 | s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
| 4548 | if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
| 4549 | c_write_str(ssh, "Server refused our key\r\n"); |
| 4550 | logevent("Server refused public key"); |
| 4551 | } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { |
| 4552 | /* server declined keyboard-interactive; ignore */ |
| 4553 | } else { |
| 4554 | c_write_str(ssh, "Access denied\r\n"); |
| 4555 | logevent("Access denied"); |
| 4556 | if (s->type == AUTH_TYPE_PASSWORD) { |
| 4557 | s->we_are_in = FALSE; |
| 4558 | break; |
| 4559 | } |
| 4560 | } |
| 4561 | } else { |
| 4562 | c_write_str(ssh, "Further authentication required\r\n"); |
| 4563 | logevent("Further authentication required"); |
| 4564 | } |
| 4565 | |
| 4566 | s->can_pubkey = |
| 4567 | in_commasep_string("publickey", methods, methlen); |
| 4568 | s->can_passwd = |
| 4569 | in_commasep_string("password", methods, methlen); |
| 4570 | s->can_keyb_inter = ssh->cfg.try_ki_auth && |
| 4571 | in_commasep_string("keyboard-interactive", methods, methlen); |
| 4572 | } |
| 4573 | |
| 4574 | s->method = 0; |
| 4575 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4576 | |
| 4577 | /* |
| 4578 | * Most password/passphrase prompts will be |
| 4579 | * non-echoing, so we set this to 0 by default. |
| 4580 | * Exception is that some keyboard-interactive prompts |
| 4581 | * can be echoing, in which case we'll set this to 1. |
| 4582 | */ |
| 4583 | s->echo = 0; |
| 4584 | |
| 4585 | if (!s->method && s->can_pubkey && |
| 4586 | agent_exists() && !s->tried_agent) { |
| 4587 | /* |
| 4588 | * Attempt public-key authentication using Pageant. |
| 4589 | */ |
| 4590 | void *r; |
| 4591 | s->authed = FALSE; |
| 4592 | |
| 4593 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4594 | ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
| 4595 | |
| 4596 | s->tried_agent = TRUE; |
| 4597 | |
| 4598 | logevent("Pageant is running. Requesting keys."); |
| 4599 | |
| 4600 | /* Request the keys held by the agent. */ |
| 4601 | PUT_32BIT(s->request, 1); |
| 4602 | s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
| 4603 | agent_query(s->request, 5, &r, &s->responselen); |
| 4604 | s->response = (unsigned char *) r; |
| 4605 | if (s->response && s->responselen >= 5 && |
| 4606 | s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
| 4607 | s->p = s->response + 5; |
| 4608 | s->nkeys = GET_32BIT(s->p); |
| 4609 | s->p += 4; |
| 4610 | { |
| 4611 | char buf[64]; |
| 4612 | sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys); |
| 4613 | logevent(buf); |
| 4614 | } |
| 4615 | for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { |
| 4616 | void *vret; |
| 4617 | |
| 4618 | { |
| 4619 | char buf[64]; |
| 4620 | sprintf(buf, "Trying Pageant key #%d", s->keyi); |
| 4621 | logevent(buf); |
| 4622 | } |
| 4623 | s->pklen = GET_32BIT(s->p); |
| 4624 | s->p += 4; |
| 4625 | if (s->publickey_blob && |
| 4626 | s->pklen == s->publickey_bloblen && |
| 4627 | !memcmp(s->p, s->publickey_blob, |
| 4628 | s->publickey_bloblen)) { |
| 4629 | logevent("This key matches configured key file"); |
| 4630 | s->tried_pubkey_config = 1; |
| 4631 | } |
| 4632 | s->pkblob = (char *)s->p; |
| 4633 | s->p += s->pklen; |
| 4634 | s->alglen = GET_32BIT(s->pkblob); |
| 4635 | s->alg = s->pkblob + 4; |
| 4636 | s->commentlen = GET_32BIT(s->p); |
| 4637 | s->p += 4; |
| 4638 | s->commentp = (char *)s->p; |
| 4639 | s->p += s->commentlen; |
| 4640 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4641 | ssh2_pkt_addstring(ssh, s->username); |
| 4642 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 4643 | ssh2_pkt_addstring(ssh, "publickey"); /* method */ |
| 4644 | ssh2_pkt_addbool(ssh, FALSE); /* no signature included */ |
| 4645 | ssh2_pkt_addstring_start(ssh); |
| 4646 | ssh2_pkt_addstring_data(ssh, s->alg, s->alglen); |
| 4647 | ssh2_pkt_addstring_start(ssh); |
| 4648 | ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen); |
| 4649 | ssh2_pkt_send(ssh); |
| 4650 | |
| 4651 | crWaitUntilV(ispkt); |
| 4652 | if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 4653 | logevent("Key refused"); |
| 4654 | continue; |
| 4655 | } |
| 4656 | |
| 4657 | if (flags & FLAG_VERBOSE) { |
| 4658 | c_write_str(ssh, "Authenticating with " |
| 4659 | "public key \""); |
| 4660 | c_write(ssh, s->commentp, s->commentlen); |
| 4661 | c_write_str(ssh, "\" from agent\r\n"); |
| 4662 | } |
| 4663 | |
| 4664 | /* |
| 4665 | * Server is willing to accept the key. |
| 4666 | * Construct a SIGN_REQUEST. |
| 4667 | */ |
| 4668 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4669 | ssh2_pkt_addstring(ssh, s->username); |
| 4670 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 4671 | ssh2_pkt_addstring(ssh, "publickey"); /* method */ |
| 4672 | ssh2_pkt_addbool(ssh, TRUE); |
| 4673 | ssh2_pkt_addstring_start(ssh); |
| 4674 | ssh2_pkt_addstring_data(ssh, s->alg, s->alglen); |
| 4675 | ssh2_pkt_addstring_start(ssh); |
| 4676 | ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen); |
| 4677 | |
| 4678 | s->siglen = ssh->pktout.length - 5 + 4 + 20; |
| 4679 | if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) |
| 4680 | s->siglen -= 4; |
| 4681 | s->len = 1; /* message type */ |
| 4682 | s->len += 4 + s->pklen; /* key blob */ |
| 4683 | s->len += 4 + s->siglen; /* data to sign */ |
| 4684 | s->len += 4; /* flags */ |
| 4685 | s->agentreq = smalloc(4 + s->len); |
| 4686 | PUT_32BIT(s->agentreq, s->len); |
| 4687 | s->q = s->agentreq + 4; |
| 4688 | *s->q++ = SSH2_AGENTC_SIGN_REQUEST; |
| 4689 | PUT_32BIT(s->q, s->pklen); |
| 4690 | s->q += 4; |
| 4691 | memcpy(s->q, s->pkblob, s->pklen); |
| 4692 | s->q += s->pklen; |
| 4693 | PUT_32BIT(s->q, s->siglen); |
| 4694 | s->q += 4; |
| 4695 | /* Now the data to be signed... */ |
| 4696 | if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { |
| 4697 | PUT_32BIT(s->q, 20); |
| 4698 | s->q += 4; |
| 4699 | } |
| 4700 | memcpy(s->q, ssh->v2_session_id, 20); |
| 4701 | s->q += 20; |
| 4702 | memcpy(s->q, ssh->pktout.data + 5, |
| 4703 | ssh->pktout.length - 5); |
| 4704 | s->q += ssh->pktout.length - 5; |
| 4705 | /* And finally the (zero) flags word. */ |
| 4706 | PUT_32BIT(s->q, 0); |
| 4707 | agent_query(s->agentreq, s->len + 4, &vret, &s->retlen); |
| 4708 | s->ret = vret; |
| 4709 | sfree(s->agentreq); |
| 4710 | if (s->ret) { |
| 4711 | if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
| 4712 | logevent("Sending Pageant's response"); |
| 4713 | ssh2_add_sigblob(ssh, s->pkblob, s->pklen, |
| 4714 | s->ret + 9, |
| 4715 | GET_32BIT(s->ret + 5)); |
| 4716 | ssh2_pkt_send(ssh); |
| 4717 | s->authed = TRUE; |
| 4718 | break; |
| 4719 | } else { |
| 4720 | logevent |
| 4721 | ("Pageant failed to answer challenge"); |
| 4722 | sfree(s->ret); |
| 4723 | } |
| 4724 | } |
| 4725 | } |
| 4726 | if (s->authed) |
| 4727 | continue; |
| 4728 | } |
| 4729 | } |
| 4730 | |
| 4731 | if (!s->method && s->can_pubkey && s->publickey_blob |
| 4732 | && !s->tried_pubkey_config) { |
| 4733 | unsigned char *pub_blob; |
| 4734 | char *algorithm, *comment; |
| 4735 | int pub_blob_len; |
| 4736 | |
| 4737 | s->tried_pubkey_config = TRUE; |
| 4738 | |
| 4739 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4740 | ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; |
| 4741 | |
| 4742 | /* |
| 4743 | * Try the public key supplied in the configuration. |
| 4744 | * |
| 4745 | * First, offer the public blob to see if the server is |
| 4746 | * willing to accept it. |
| 4747 | */ |
| 4748 | pub_blob = |
| 4749 | (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile, |
| 4750 | &algorithm, |
| 4751 | &pub_blob_len); |
| 4752 | if (pub_blob) { |
| 4753 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4754 | ssh2_pkt_addstring(ssh, s->username); |
| 4755 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 4756 | ssh2_pkt_addstring(ssh, "publickey"); /* method */ |
| 4757 | ssh2_pkt_addbool(ssh, FALSE); /* no signature included */ |
| 4758 | ssh2_pkt_addstring(ssh, algorithm); |
| 4759 | ssh2_pkt_addstring_start(ssh); |
| 4760 | ssh2_pkt_addstring_data(ssh, (char *)pub_blob, |
| 4761 | pub_blob_len); |
| 4762 | ssh2_pkt_send(ssh); |
| 4763 | logevent("Offered public key"); /* FIXME */ |
| 4764 | |
| 4765 | crWaitUntilV(ispkt); |
| 4766 | if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 4767 | s->gotit = TRUE; |
| 4768 | s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
| 4769 | continue; /* key refused; give up on it */ |
| 4770 | } |
| 4771 | |
| 4772 | logevent("Offer of public key accepted"); |
| 4773 | /* |
| 4774 | * Actually attempt a serious authentication using |
| 4775 | * the key. |
| 4776 | */ |
| 4777 | if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) { |
| 4778 | sprintf(s->pwprompt, |
| 4779 | "Passphrase for key \"%.100s\": ", |
| 4780 | comment); |
| 4781 | s->need_pw = TRUE; |
| 4782 | } else { |
| 4783 | s->need_pw = FALSE; |
| 4784 | } |
| 4785 | c_write_str(ssh, "Authenticating with public key \""); |
| 4786 | c_write_str(ssh, comment); |
| 4787 | c_write_str(ssh, "\"\r\n"); |
| 4788 | s->method = AUTH_PUBLICKEY_FILE; |
| 4789 | } |
| 4790 | } |
| 4791 | |
| 4792 | if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) { |
| 4793 | s->method = AUTH_KEYBOARD_INTERACTIVE; |
| 4794 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4795 | s->tried_keyb_inter = TRUE; |
| 4796 | |
| 4797 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4798 | ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
| 4799 | |
| 4800 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4801 | ssh2_pkt_addstring(ssh, s->username); |
| 4802 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 4803 | ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */ |
| 4804 | ssh2_pkt_addstring(ssh, ""); /* lang */ |
| 4805 | ssh2_pkt_addstring(ssh, ""); |
| 4806 | ssh2_pkt_send(ssh); |
| 4807 | |
| 4808 | crWaitUntilV(ispkt); |
| 4809 | if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 4810 | if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) |
| 4811 | s->gotit = TRUE; |
| 4812 | logevent("Keyboard-interactive authentication refused"); |
| 4813 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; |
| 4814 | continue; |
| 4815 | } |
| 4816 | |
| 4817 | s->kbd_inter_running = TRUE; |
| 4818 | s->curr_prompt = 0; |
| 4819 | } |
| 4820 | |
| 4821 | if (s->kbd_inter_running) { |
| 4822 | s->method = AUTH_KEYBOARD_INTERACTIVE; |
| 4823 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4824 | s->tried_keyb_inter = TRUE; |
| 4825 | |
| 4826 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4827 | ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; |
| 4828 | |
| 4829 | if (s->curr_prompt == 0) { |
| 4830 | /* |
| 4831 | * We've got a fresh USERAUTH_INFO_REQUEST. |
| 4832 | * Display header data, and start going through |
| 4833 | * the prompts. |
| 4834 | */ |
| 4835 | char *name, *inst, *lang; |
| 4836 | int name_len, inst_len, lang_len; |
| 4837 | |
| 4838 | ssh2_pkt_getstring(ssh, &name, &name_len); |
| 4839 | ssh2_pkt_getstring(ssh, &inst, &inst_len); |
| 4840 | ssh2_pkt_getstring(ssh, &lang, &lang_len); |
| 4841 | if (name_len > 0) { |
| 4842 | c_write_untrusted(ssh, name, name_len); |
| 4843 | c_write_str(ssh, "\r\n"); |
| 4844 | } |
| 4845 | if (inst_len > 0) { |
| 4846 | c_write_untrusted(ssh, inst, inst_len); |
| 4847 | c_write_str(ssh, "\r\n"); |
| 4848 | } |
| 4849 | s->num_prompts = ssh2_pkt_getuint32(ssh); |
| 4850 | } |
| 4851 | |
| 4852 | /* |
| 4853 | * If there are prompts remaining in the packet, |
| 4854 | * display one and get a response. |
| 4855 | */ |
| 4856 | if (s->curr_prompt < s->num_prompts) { |
| 4857 | char *prompt; |
| 4858 | int prompt_len; |
| 4859 | |
| 4860 | ssh2_pkt_getstring(ssh, &prompt, &prompt_len); |
| 4861 | if (prompt_len > 0) { |
| 4862 | strncpy(s->pwprompt, prompt, sizeof(s->pwprompt)); |
| 4863 | s->pwprompt[prompt_len < sizeof(s->pwprompt) ? |
| 4864 | prompt_len : sizeof(s->pwprompt)-1] = '\0'; |
| 4865 | } else { |
| 4866 | strcpy(s->pwprompt, |
| 4867 | "<server failed to send prompt>: "); |
| 4868 | } |
| 4869 | s->echo = ssh2_pkt_getbool(ssh); |
| 4870 | s->need_pw = TRUE; |
| 4871 | } else |
| 4872 | s->need_pw = FALSE; |
| 4873 | } |
| 4874 | |
| 4875 | if (!s->method && s->can_passwd) { |
| 4876 | s->method = AUTH_PASSWORD; |
| 4877 | ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; |
| 4878 | ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD; |
| 4879 | sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username, |
| 4880 | ssh->savedhost); |
| 4881 | s->need_pw = TRUE; |
| 4882 | } |
| 4883 | |
| 4884 | if (s->need_pw) { |
| 4885 | if (ssh_get_line) { |
| 4886 | if (!ssh_get_line(s->pwprompt, s->password, |
| 4887 | sizeof(s->password), TRUE)) { |
| 4888 | /* |
| 4889 | * get_line failed to get a password (for |
| 4890 | * example because one was supplied on the |
| 4891 | * command line which has already failed to |
| 4892 | * work). Terminate. |
| 4893 | */ |
| 4894 | ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); |
| 4895 | ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION); |
| 4896 | ssh2_pkt_addstring(ssh, "No more passwords available" |
| 4897 | " to try"); |
| 4898 | ssh2_pkt_addstring(ssh, "en"); /* language tag */ |
| 4899 | ssh2_pkt_send(ssh); |
| 4900 | logevent("Unable to authenticate"); |
| 4901 | connection_fatal(ssh->frontend, |
| 4902 | "Unable to authenticate"); |
| 4903 | ssh->state = SSH_STATE_CLOSED; |
| 4904 | crReturnV; |
| 4905 | } |
| 4906 | } else { |
| 4907 | int ret; /* need not be saved across crReturn */ |
| 4908 | c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt)); |
| 4909 | ssh->send_ok = 1; |
| 4910 | |
| 4911 | setup_userpass_input(ssh, s->password, |
| 4912 | sizeof(s->password), s->echo); |
| 4913 | do { |
| 4914 | crWaitUntilV(!ispkt); |
| 4915 | ret = process_userpass_input(ssh, in, inlen); |
| 4916 | } while (ret == 0); |
| 4917 | if (ret < 0) |
| 4918 | cleanup_exit(0); |
| 4919 | c_write_str(ssh, "\r\n"); |
| 4920 | } |
| 4921 | } |
| 4922 | |
| 4923 | if (s->method == AUTH_PUBLICKEY_FILE) { |
| 4924 | /* |
| 4925 | * We have our passphrase. Now try the actual authentication. |
| 4926 | */ |
| 4927 | struct ssh2_userkey *key; |
| 4928 | |
| 4929 | key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password); |
| 4930 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
| 4931 | if (key == SSH2_WRONG_PASSPHRASE) { |
| 4932 | c_write_str(ssh, "Wrong passphrase\r\n"); |
| 4933 | s->tried_pubkey_config = FALSE; |
| 4934 | } else { |
| 4935 | c_write_str(ssh, "Unable to load private key\r\n"); |
| 4936 | s->tried_pubkey_config = TRUE; |
| 4937 | } |
| 4938 | /* Send a spurious AUTH_NONE to return to the top. */ |
| 4939 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4940 | ssh2_pkt_addstring(ssh, s->username); |
| 4941 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 4942 | ssh2_pkt_addstring(ssh, "none"); /* method */ |
| 4943 | ssh2_pkt_send(ssh); |
| 4944 | s->type = AUTH_TYPE_NONE; |
| 4945 | } else { |
| 4946 | unsigned char *pkblob, *sigblob, *sigdata; |
| 4947 | int pkblob_len, sigblob_len, sigdata_len; |
| 4948 | int p; |
| 4949 | |
| 4950 | /* |
| 4951 | * We have loaded the private key and the server |
| 4952 | * has announced that it's willing to accept it. |
| 4953 | * Hallelujah. Generate a signature and send it. |
| 4954 | */ |
| 4955 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 4956 | ssh2_pkt_addstring(ssh, s->username); |
| 4957 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 4958 | ssh2_pkt_addstring(ssh, "publickey"); /* method */ |
| 4959 | ssh2_pkt_addbool(ssh, TRUE); |
| 4960 | ssh2_pkt_addstring(ssh, key->alg->name); |
| 4961 | pkblob = key->alg->public_blob(key->data, &pkblob_len); |
| 4962 | ssh2_pkt_addstring_start(ssh); |
| 4963 | ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len); |
| 4964 | |
| 4965 | /* |
| 4966 | * The data to be signed is: |
| 4967 | * |
| 4968 | * string session-id |
| 4969 | * |
| 4970 | * followed by everything so far placed in the |
| 4971 | * outgoing packet. |
| 4972 | */ |
| 4973 | sigdata_len = ssh->pktout.length - 5 + 4 + 20; |
| 4974 | if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) |
| 4975 | sigdata_len -= 4; |
| 4976 | sigdata = smalloc(sigdata_len); |
| 4977 | p = 0; |
| 4978 | if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { |
| 4979 | PUT_32BIT(sigdata+p, 20); |
| 4980 | p += 4; |
| 4981 | } |
| 4982 | memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20; |
| 4983 | memcpy(sigdata+p, ssh->pktout.data + 5, |
| 4984 | ssh->pktout.length - 5); |
| 4985 | p += ssh->pktout.length - 5; |
| 4986 | assert(p == sigdata_len); |
| 4987 | sigblob = key->alg->sign(key->data, (char *)sigdata, |
| 4988 | sigdata_len, &sigblob_len); |
| 4989 | ssh2_add_sigblob(ssh, pkblob, pkblob_len, |
| 4990 | sigblob, sigblob_len); |
| 4991 | sfree(pkblob); |
| 4992 | sfree(sigblob); |
| 4993 | sfree(sigdata); |
| 4994 | |
| 4995 | ssh2_pkt_send(ssh); |
| 4996 | s->type = AUTH_TYPE_PUBLICKEY; |
| 4997 | } |
| 4998 | } else if (s->method == AUTH_PASSWORD) { |
| 4999 | /* |
| 5000 | * We send the password packet lumped tightly together with |
| 5001 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
| 5002 | * string long enough to make the total length of the two |
| 5003 | * packets constant. This should ensure that a passive |
| 5004 | * listener doing traffic analyis can't work out the length |
| 5005 | * of the password. |
| 5006 | * |
| 5007 | * For this to work, we need an assumption about the |
| 5008 | * maximum length of the password packet. I think 256 is |
| 5009 | * pretty conservative. Anyone using a password longer than |
| 5010 | * that probably doesn't have much to worry about from |
| 5011 | * people who find out how long their password is! |
| 5012 | */ |
| 5013 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST); |
| 5014 | ssh2_pkt_addstring(ssh, s->username); |
| 5015 | ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */ |
| 5016 | ssh2_pkt_addstring(ssh, "password"); |
| 5017 | ssh2_pkt_addbool(ssh, FALSE); |
| 5018 | ssh2_pkt_addstring(ssh, s->password); |
| 5019 | memset(s->password, 0, sizeof(s->password)); |
| 5020 | ssh2_pkt_defer(ssh); |
| 5021 | /* |
| 5022 | * We'll include a string that's an exact multiple of the |
| 5023 | * cipher block size. If the cipher is NULL for some |
| 5024 | * reason, we don't do this trick at all because we gain |
| 5025 | * nothing by it. |
| 5026 | */ |
| 5027 | if (ssh->cscipher) { |
| 5028 | int stringlen, i; |
| 5029 | |
| 5030 | stringlen = (256 - ssh->deferred_len); |
| 5031 | stringlen += ssh->cscipher->blksize - 1; |
| 5032 | stringlen -= (stringlen % ssh->cscipher->blksize); |
| 5033 | if (ssh->cscomp) { |
| 5034 | /* |
| 5035 | * Temporarily disable actual compression, |
| 5036 | * so we can guarantee to get this string |
| 5037 | * exactly the length we want it. The |
| 5038 | * compression-disabling routine should |
| 5039 | * return an integer indicating how many |
| 5040 | * bytes we should adjust our string length |
| 5041 | * by. |
| 5042 | */ |
| 5043 | stringlen -= |
| 5044 | ssh->cscomp->disable_compression(ssh->cs_comp_ctx); |
| 5045 | } |
| 5046 | ssh2_pkt_init(ssh, SSH2_MSG_IGNORE); |
| 5047 | ssh2_pkt_addstring_start(ssh); |
| 5048 | for (i = 0; i < stringlen; i++) { |
| 5049 | char c = (char) random_byte(); |
| 5050 | ssh2_pkt_addstring_data(ssh, &c, 1); |
| 5051 | } |
| 5052 | ssh2_pkt_defer(ssh); |
| 5053 | } |
| 5054 | ssh_pkt_defersend(ssh); |
| 5055 | logevent("Sent password"); |
| 5056 | s->type = AUTH_TYPE_PASSWORD; |
| 5057 | } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) { |
| 5058 | if (s->curr_prompt == 0) { |
| 5059 | ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE); |
| 5060 | ssh2_pkt_adduint32(ssh, s->num_prompts); |
| 5061 | } |
| 5062 | if (s->need_pw) { /* only add pw if we just got one! */ |
| 5063 | ssh2_pkt_addstring(ssh, s->password); |
| 5064 | memset(s->password, 0, sizeof(s->password)); |
| 5065 | s->curr_prompt++; |
| 5066 | } |
| 5067 | if (s->curr_prompt >= s->num_prompts) { |
| 5068 | ssh2_pkt_send(ssh); |
| 5069 | } else { |
| 5070 | /* |
| 5071 | * If there are prompts remaining, we set |
| 5072 | * `gotit' so that we won't attempt to get |
| 5073 | * another packet. Then we go back round the |
| 5074 | * loop and will end up retrieving another |
| 5075 | * prompt out of the existing packet. Funky or |
| 5076 | * what? |
| 5077 | */ |
| 5078 | s->gotit = TRUE; |
| 5079 | } |
| 5080 | s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 5081 | } else { |
| 5082 | c_write_str(ssh, "No supported authentication methods" |
| 5083 | " left to try!\r\n"); |
| 5084 | logevent("No supported authentications offered." |
| 5085 | " Disconnecting"); |
| 5086 | ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); |
| 5087 | ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION); |
| 5088 | ssh2_pkt_addstring(ssh, "No supported authentication" |
| 5089 | " methods available"); |
| 5090 | ssh2_pkt_addstring(ssh, "en"); /* language tag */ |
| 5091 | ssh2_pkt_send(ssh); |
| 5092 | ssh->state = SSH_STATE_CLOSED; |
| 5093 | crReturnV; |
| 5094 | } |
| 5095 | } |
| 5096 | } while (!s->we_are_in); |
| 5097 | |
| 5098 | /* |
| 5099 | * Now we're authenticated for the connection protocol. The |
| 5100 | * connection protocol will automatically have started at this |
| 5101 | * point; there's no need to send SERVICE_REQUEST. |
| 5102 | */ |
| 5103 | |
| 5104 | /* |
| 5105 | * So now create a channel with a session in it. |
| 5106 | */ |
| 5107 | ssh->channels = newtree234(ssh_channelcmp); |
| 5108 | ssh->mainchan = smalloc(sizeof(struct ssh_channel)); |
| 5109 | ssh->mainchan->ssh = ssh; |
| 5110 | ssh->mainchan->localid = alloc_channel_id(ssh); |
| 5111 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN); |
| 5112 | ssh2_pkt_addstring(ssh, "session"); |
| 5113 | ssh2_pkt_adduint32(ssh, ssh->mainchan->localid); |
| 5114 | ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE; |
| 5115 | ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */ |
| 5116 | ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */ |
| 5117 | ssh2_pkt_send(ssh); |
| 5118 | crWaitUntilV(ispkt); |
| 5119 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 5120 | bombout((ssh,"Server refused to open a session")); |
| 5121 | crReturnV; |
| 5122 | /* FIXME: error data comes back in FAILURE packet */ |
| 5123 | } |
| 5124 | if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) { |
| 5125 | bombout((ssh,"Server's channel confirmation cited wrong channel")); |
| 5126 | crReturnV; |
| 5127 | } |
| 5128 | ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh); |
| 5129 | ssh->mainchan->type = CHAN_MAINSESSION; |
| 5130 | ssh->mainchan->closes = 0; |
| 5131 | ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh); |
| 5132 | ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh); |
| 5133 | bufchain_init(&ssh->mainchan->v.v2.outbuffer); |
| 5134 | add234(ssh->channels, ssh->mainchan); |
| 5135 | logevent("Opened channel for session"); |
| 5136 | |
| 5137 | /* |
| 5138 | * Potentially enable X11 forwarding. |
| 5139 | */ |
| 5140 | if (ssh->cfg.x11_forward) { |
| 5141 | char proto[20], data[64]; |
| 5142 | logevent("Requesting X11 forwarding"); |
| 5143 | ssh->x11auth = x11_invent_auth(proto, sizeof(proto), |
| 5144 | data, sizeof(data), ssh->cfg.x11_auth); |
| 5145 | x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display); |
| 5146 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); |
| 5147 | ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); |
| 5148 | ssh2_pkt_addstring(ssh, "x11-req"); |
| 5149 | ssh2_pkt_addbool(ssh, 1); /* want reply */ |
| 5150 | ssh2_pkt_addbool(ssh, 0); /* many connections */ |
| 5151 | ssh2_pkt_addstring(ssh, proto); |
| 5152 | ssh2_pkt_addstring(ssh, data); |
| 5153 | ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display)); |
| 5154 | ssh2_pkt_send(ssh); |
| 5155 | |
| 5156 | do { |
| 5157 | crWaitUntilV(ispkt); |
| 5158 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5159 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5160 | struct ssh_channel *c; |
| 5161 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5162 | if (!c) |
| 5163 | continue; /* nonexistent channel */ |
| 5164 | c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); |
| 5165 | } |
| 5166 | } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 5167 | |
| 5168 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 5169 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 5170 | bombout((ssh,"Unexpected response to X11 forwarding request:" |
| 5171 | " packet type %d", ssh->pktin.type)); |
| 5172 | crReturnV; |
| 5173 | } |
| 5174 | logevent("X11 forwarding refused"); |
| 5175 | } else { |
| 5176 | logevent("X11 forwarding enabled"); |
| 5177 | ssh->X11_fwd_enabled = TRUE; |
| 5178 | } |
| 5179 | } |
| 5180 | |
| 5181 | /* |
| 5182 | * Enable port forwardings. |
| 5183 | */ |
| 5184 | { |
| 5185 | char type; |
| 5186 | int n; |
| 5187 | int sport,dport,sserv,dserv; |
| 5188 | char sports[256], dports[256], saddr[256], host[256]; |
| 5189 | |
| 5190 | ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); |
| 5191 | /* Add port forwardings. */ |
| 5192 | ssh->portfwd_strptr = ssh->cfg.portfwd; |
| 5193 | while (*ssh->portfwd_strptr) { |
| 5194 | type = *ssh->portfwd_strptr++; |
| 5195 | saddr[0] = '\0'; |
| 5196 | n = 0; |
| 5197 | while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') { |
| 5198 | if (*ssh->portfwd_strptr == ':') { |
| 5199 | /* |
| 5200 | * We've seen a colon in the middle of the |
| 5201 | * source port number. This means that |
| 5202 | * everything we've seen until now is the |
| 5203 | * source _address_, so we'll move it into |
| 5204 | * saddr and start sports from the beginning |
| 5205 | * again. |
| 5206 | */ |
| 5207 | ssh->portfwd_strptr++; |
| 5208 | sports[n] = '\0'; |
| 5209 | strcpy(saddr, sports); |
| 5210 | n = 0; |
| 5211 | } |
| 5212 | if (n < 255) sports[n++] = *ssh->portfwd_strptr++; |
| 5213 | } |
| 5214 | sports[n] = 0; |
| 5215 | if (*ssh->portfwd_strptr == '\t') |
| 5216 | ssh->portfwd_strptr++; |
| 5217 | n = 0; |
| 5218 | while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') { |
| 5219 | if (n < 255) host[n++] = *ssh->portfwd_strptr++; |
| 5220 | } |
| 5221 | host[n] = 0; |
| 5222 | if (*ssh->portfwd_strptr == ':') |
| 5223 | ssh->portfwd_strptr++; |
| 5224 | n = 0; |
| 5225 | while (*ssh->portfwd_strptr) { |
| 5226 | if (n < 255) dports[n++] = *ssh->portfwd_strptr++; |
| 5227 | } |
| 5228 | dports[n] = 0; |
| 5229 | ssh->portfwd_strptr++; |
| 5230 | dport = atoi(dports); |
| 5231 | dserv = 0; |
| 5232 | if (dport == 0) { |
| 5233 | dserv = 1; |
| 5234 | dport = net_service_lookup(dports); |
| 5235 | if (!dport) { |
| 5236 | logeventf(ssh, "Service lookup failed for destination" |
| 5237 | " port \"%s\"", dports); |
| 5238 | } |
| 5239 | } |
| 5240 | sport = atoi(sports); |
| 5241 | sserv = 0; |
| 5242 | if (sport == 0) { |
| 5243 | sserv = 1; |
| 5244 | sport = net_service_lookup(sports); |
| 5245 | if (!sport) { |
| 5246 | logeventf(ssh, "Service lookup failed for source" |
| 5247 | " port \"%s\"", sports); |
| 5248 | } |
| 5249 | } |
| 5250 | if (sport && dport) { |
| 5251 | if (type == 'L') { |
| 5252 | pfd_addforward(host, dport, *saddr ? saddr : NULL, |
| 5253 | sport, ssh, &ssh->cfg); |
| 5254 | logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s" |
| 5255 | " forwarding to %s:%.*s%.*s%d%.*s", |
| 5256 | (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, |
| 5257 | (int)(*saddr?1:0), ":", |
| 5258 | (int)(sserv ? strlen(sports) : 0), sports, |
| 5259 | sserv, "(", sport, sserv, ")", |
| 5260 | host, |
| 5261 | (int)(dserv ? strlen(dports) : 0), dports, |
| 5262 | dserv, "(", dport, dserv, ")"); |
| 5263 | } else { |
| 5264 | struct ssh_rportfwd *pf; |
| 5265 | pf = smalloc(sizeof(*pf)); |
| 5266 | strcpy(pf->dhost, host); |
| 5267 | pf->dport = dport; |
| 5268 | pf->sport = sport; |
| 5269 | if (add234(ssh->rportfwds, pf) != pf) { |
| 5270 | logeventf(ssh, "Duplicate remote port forwarding" |
| 5271 | " to %s:%d", host, dport); |
| 5272 | sfree(pf); |
| 5273 | } else { |
| 5274 | logeventf(ssh, "Requesting remote port " |
| 5275 | "%.*s%.*s%.*s%.*s%d%.*s" |
| 5276 | " forward to %s:%.*s%.*s%d%.*s", |
| 5277 | (int)(*saddr?strlen(saddr):0), |
| 5278 | *saddr?saddr:NULL, |
| 5279 | (int)(*saddr?1:0), ":", |
| 5280 | (int)(sserv ? strlen(sports) : 0), sports, |
| 5281 | sserv, "(", sport, sserv, ")", |
| 5282 | host, |
| 5283 | (int)(dserv ? strlen(dports) : 0), dports, |
| 5284 | dserv, "(", dport, dserv, ")"); |
| 5285 | ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST); |
| 5286 | ssh2_pkt_addstring(ssh, "tcpip-forward"); |
| 5287 | ssh2_pkt_addbool(ssh, 1);/* want reply */ |
| 5288 | if (*saddr) |
| 5289 | ssh2_pkt_addstring(ssh, saddr); |
| 5290 | if (ssh->cfg.rport_acceptall) |
| 5291 | ssh2_pkt_addstring(ssh, "0.0.0.0"); |
| 5292 | else |
| 5293 | ssh2_pkt_addstring(ssh, "127.0.0.1"); |
| 5294 | ssh2_pkt_adduint32(ssh, sport); |
| 5295 | ssh2_pkt_send(ssh); |
| 5296 | |
| 5297 | do { |
| 5298 | crWaitUntilV(ispkt); |
| 5299 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5300 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5301 | struct ssh_channel *c; |
| 5302 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5303 | if (!c) |
| 5304 | continue;/* nonexistent channel */ |
| 5305 | c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); |
| 5306 | } |
| 5307 | } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 5308 | |
| 5309 | if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) { |
| 5310 | if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) { |
| 5311 | bombout((ssh,"Unexpected response to port " |
| 5312 | "forwarding request: packet type %d", |
| 5313 | ssh->pktin.type)); |
| 5314 | crReturnV; |
| 5315 | } |
| 5316 | logevent("Server refused this port forwarding"); |
| 5317 | } else { |
| 5318 | logevent("Remote port forwarding enabled"); |
| 5319 | } |
| 5320 | } |
| 5321 | } |
| 5322 | } |
| 5323 | } |
| 5324 | } |
| 5325 | |
| 5326 | /* |
| 5327 | * Potentially enable agent forwarding. |
| 5328 | */ |
| 5329 | if (ssh->cfg.agentfwd && agent_exists()) { |
| 5330 | logevent("Requesting OpenSSH-style agent forwarding"); |
| 5331 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); |
| 5332 | ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); |
| 5333 | ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com"); |
| 5334 | ssh2_pkt_addbool(ssh, 1); /* want reply */ |
| 5335 | ssh2_pkt_send(ssh); |
| 5336 | |
| 5337 | do { |
| 5338 | crWaitUntilV(ispkt); |
| 5339 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5340 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5341 | struct ssh_channel *c; |
| 5342 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5343 | if (!c) |
| 5344 | continue; /* nonexistent channel */ |
| 5345 | c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); |
| 5346 | } |
| 5347 | } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 5348 | |
| 5349 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 5350 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 5351 | bombout((ssh,"Unexpected response to agent forwarding request:" |
| 5352 | " packet type %d", ssh->pktin.type)); |
| 5353 | crReturnV; |
| 5354 | } |
| 5355 | logevent("Agent forwarding refused"); |
| 5356 | } else { |
| 5357 | logevent("Agent forwarding enabled"); |
| 5358 | ssh->agentfwd_enabled = TRUE; |
| 5359 | } |
| 5360 | } |
| 5361 | |
| 5362 | /* |
| 5363 | * Now allocate a pty for the session. |
| 5364 | */ |
| 5365 | if (!ssh->cfg.nopty) { |
| 5366 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); |
| 5367 | ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */ |
| 5368 | ssh2_pkt_addstring(ssh, "pty-req"); |
| 5369 | ssh2_pkt_addbool(ssh, 1); /* want reply */ |
| 5370 | ssh2_pkt_addstring(ssh, ssh->cfg.termtype); |
| 5371 | ssh2_pkt_adduint32(ssh, ssh->term_width); |
| 5372 | ssh2_pkt_adduint32(ssh, ssh->term_height); |
| 5373 | ssh2_pkt_adduint32(ssh, 0); /* pixel width */ |
| 5374 | ssh2_pkt_adduint32(ssh, 0); /* pixel height */ |
| 5375 | ssh2_pkt_addstring_start(ssh); |
| 5376 | ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */ |
| 5377 | ssh2_pkt_send(ssh); |
| 5378 | ssh->state = SSH_STATE_INTERMED; |
| 5379 | |
| 5380 | do { |
| 5381 | crWaitUntilV(ispkt); |
| 5382 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5383 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5384 | struct ssh_channel *c; |
| 5385 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5386 | if (!c) |
| 5387 | continue; /* nonexistent channel */ |
| 5388 | c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); |
| 5389 | } |
| 5390 | } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 5391 | |
| 5392 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 5393 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 5394 | bombout((ssh,"Unexpected response to pty request:" |
| 5395 | " packet type %d", ssh->pktin.type)); |
| 5396 | crReturnV; |
| 5397 | } |
| 5398 | c_write_str(ssh, "Server refused to allocate pty\r\n"); |
| 5399 | ssh->editing = ssh->echoing = 1; |
| 5400 | } else { |
| 5401 | logevent("Allocated pty"); |
| 5402 | } |
| 5403 | } else { |
| 5404 | ssh->editing = ssh->echoing = 1; |
| 5405 | } |
| 5406 | |
| 5407 | /* |
| 5408 | * Start a shell or a remote command. We may have to attempt |
| 5409 | * this twice if the config data has provided a second choice |
| 5410 | * of command. |
| 5411 | */ |
| 5412 | while (1) { |
| 5413 | int subsys; |
| 5414 | char *cmd; |
| 5415 | |
| 5416 | if (ssh->fallback_cmd) { |
| 5417 | subsys = ssh->cfg.ssh_subsys2; |
| 5418 | cmd = ssh->cfg.remote_cmd_ptr2; |
| 5419 | } else { |
| 5420 | subsys = ssh->cfg.ssh_subsys; |
| 5421 | cmd = ssh->cfg.remote_cmd_ptr; |
| 5422 | } |
| 5423 | |
| 5424 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); |
| 5425 | ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */ |
| 5426 | if (subsys) { |
| 5427 | ssh2_pkt_addstring(ssh, "subsystem"); |
| 5428 | ssh2_pkt_addbool(ssh, 1); /* want reply */ |
| 5429 | ssh2_pkt_addstring(ssh, cmd); |
| 5430 | } else if (*cmd) { |
| 5431 | ssh2_pkt_addstring(ssh, "exec"); |
| 5432 | ssh2_pkt_addbool(ssh, 1); /* want reply */ |
| 5433 | ssh2_pkt_addstring(ssh, cmd); |
| 5434 | } else { |
| 5435 | ssh2_pkt_addstring(ssh, "shell"); |
| 5436 | ssh2_pkt_addbool(ssh, 1); /* want reply */ |
| 5437 | } |
| 5438 | ssh2_pkt_send(ssh); |
| 5439 | do { |
| 5440 | crWaitUntilV(ispkt); |
| 5441 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5442 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5443 | struct ssh_channel *c; |
| 5444 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5445 | if (!c) |
| 5446 | continue; /* nonexistent channel */ |
| 5447 | c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); |
| 5448 | } |
| 5449 | } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 5450 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 5451 | if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 5452 | bombout((ssh,"Unexpected response to shell/command request:" |
| 5453 | " packet type %d", ssh->pktin.type)); |
| 5454 | crReturnV; |
| 5455 | } |
| 5456 | /* |
| 5457 | * We failed to start the command. If this is the |
| 5458 | * fallback command, we really are finished; if it's |
| 5459 | * not, and if the fallback command exists, try falling |
| 5460 | * back to it before complaining. |
| 5461 | */ |
| 5462 | if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) { |
| 5463 | logevent("Primary command failed; attempting fallback"); |
| 5464 | ssh->fallback_cmd = TRUE; |
| 5465 | continue; |
| 5466 | } |
| 5467 | bombout((ssh,"Server refused to start a shell/command")); |
| 5468 | crReturnV; |
| 5469 | } else { |
| 5470 | logevent("Started a shell/command"); |
| 5471 | } |
| 5472 | break; |
| 5473 | } |
| 5474 | |
| 5475 | ssh->state = SSH_STATE_SESSION; |
| 5476 | if (ssh->size_needed) |
| 5477 | ssh_size(ssh, ssh->term_width, ssh->term_height); |
| 5478 | if (ssh->eof_needed) |
| 5479 | ssh_special(ssh, TS_EOF); |
| 5480 | |
| 5481 | /* |
| 5482 | * Transfer data! |
| 5483 | */ |
| 5484 | if (ssh->ldisc) |
| 5485 | ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ |
| 5486 | ssh->send_ok = 1; |
| 5487 | while (1) { |
| 5488 | crReturnV; |
| 5489 | s->try_send = FALSE; |
| 5490 | if (ispkt) { |
| 5491 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA || |
| 5492 | ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 5493 | char *data; |
| 5494 | int length; |
| 5495 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5496 | struct ssh_channel *c; |
| 5497 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5498 | if (!c) |
| 5499 | continue; /* nonexistent channel */ |
| 5500 | if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 5501 | ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR) |
| 5502 | continue; /* extended but not stderr */ |
| 5503 | ssh2_pkt_getstring(ssh, &data, &length); |
| 5504 | if (data) { |
| 5505 | int bufsize; |
| 5506 | c->v.v2.locwindow -= length; |
| 5507 | switch (c->type) { |
| 5508 | case CHAN_MAINSESSION: |
| 5509 | bufsize = |
| 5510 | from_backend(ssh->frontend, ssh->pktin.type == |
| 5511 | SSH2_MSG_CHANNEL_EXTENDED_DATA, |
| 5512 | data, length); |
| 5513 | break; |
| 5514 | case CHAN_X11: |
| 5515 | bufsize = x11_send(c->u.x11.s, data, length); |
| 5516 | break; |
| 5517 | case CHAN_SOCKDATA: |
| 5518 | bufsize = pfd_send(c->u.pfd.s, data, length); |
| 5519 | break; |
| 5520 | case CHAN_AGENT: |
| 5521 | while (length > 0) { |
| 5522 | if (c->u.a.lensofar < 4) { |
| 5523 | int l = min(4 - c->u.a.lensofar, length); |
| 5524 | memcpy(c->u.a.msglen + c->u.a.lensofar, |
| 5525 | data, l); |
| 5526 | data += l; |
| 5527 | length -= l; |
| 5528 | c->u.a.lensofar += l; |
| 5529 | } |
| 5530 | if (c->u.a.lensofar == 4) { |
| 5531 | c->u.a.totallen = |
| 5532 | 4 + GET_32BIT(c->u.a.msglen); |
| 5533 | c->u.a.message = smalloc(c->u.a.totallen); |
| 5534 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 5535 | } |
| 5536 | if (c->u.a.lensofar >= 4 && length > 0) { |
| 5537 | int l = |
| 5538 | min(c->u.a.totallen - c->u.a.lensofar, |
| 5539 | length); |
| 5540 | memcpy(c->u.a.message + c->u.a.lensofar, |
| 5541 | data, l); |
| 5542 | data += l; |
| 5543 | length -= l; |
| 5544 | c->u.a.lensofar += l; |
| 5545 | } |
| 5546 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 5547 | void *reply, *sentreply; |
| 5548 | int replylen; |
| 5549 | agent_query(c->u.a.message, |
| 5550 | c->u.a.totallen, &reply, |
| 5551 | &replylen); |
| 5552 | if (reply) |
| 5553 | sentreply = reply; |
| 5554 | else { |
| 5555 | /* Fake SSH_AGENT_FAILURE. */ |
| 5556 | sentreply = "\0\0\0\1\5"; |
| 5557 | replylen = 5; |
| 5558 | } |
| 5559 | ssh2_add_channel_data(c, sentreply, replylen); |
| 5560 | s->try_send = TRUE; |
| 5561 | if (reply) |
| 5562 | sfree(reply); |
| 5563 | sfree(c->u.a.message); |
| 5564 | c->u.a.lensofar = 0; |
| 5565 | } |
| 5566 | } |
| 5567 | bufsize = 0; |
| 5568 | break; |
| 5569 | } |
| 5570 | /* |
| 5571 | * If we are not buffering too much data, |
| 5572 | * enlarge the window again at the remote side. |
| 5573 | */ |
| 5574 | if (bufsize < OUR_V2_WINSIZE) |
| 5575 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
| 5576 | } |
| 5577 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) { |
| 5578 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5579 | struct ssh_channel *c; |
| 5580 | |
| 5581 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5582 | if (!c) |
| 5583 | continue; /* nonexistent channel */ |
| 5584 | |
| 5585 | if (c->type == CHAN_X11) { |
| 5586 | /* |
| 5587 | * Remote EOF on an X11 channel means we should |
| 5588 | * wrap up and close the channel ourselves. |
| 5589 | */ |
| 5590 | x11_close(c->u.x11.s); |
| 5591 | sshfwd_close(c); |
| 5592 | } else if (c->type == CHAN_AGENT) { |
| 5593 | sshfwd_close(c); |
| 5594 | } else if (c->type == CHAN_SOCKDATA) { |
| 5595 | pfd_close(c->u.pfd.s); |
| 5596 | sshfwd_close(c); |
| 5597 | } |
| 5598 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
| 5599 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5600 | struct ssh_channel *c; |
| 5601 | |
| 5602 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5603 | if (!c || ((int)c->remoteid) == -1) { |
| 5604 | bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n", |
| 5605 | c ? "half-open" : "nonexistent", i)); |
| 5606 | } |
| 5607 | /* Do pre-close processing on the channel. */ |
| 5608 | switch (c->type) { |
| 5609 | case CHAN_MAINSESSION: |
| 5610 | break; /* nothing to see here, move along */ |
| 5611 | case CHAN_X11: |
| 5612 | if (c->u.x11.s != NULL) |
| 5613 | x11_close(c->u.x11.s); |
| 5614 | sshfwd_close(c); |
| 5615 | break; |
| 5616 | case CHAN_AGENT: |
| 5617 | sshfwd_close(c); |
| 5618 | break; |
| 5619 | case CHAN_SOCKDATA: |
| 5620 | if (c->u.pfd.s != NULL) |
| 5621 | pfd_close(c->u.pfd.s); |
| 5622 | sshfwd_close(c); |
| 5623 | break; |
| 5624 | } |
| 5625 | if (c->closes == 0) { |
| 5626 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE); |
| 5627 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 5628 | ssh2_pkt_send(ssh); |
| 5629 | } |
| 5630 | del234(ssh->channels, c); |
| 5631 | bufchain_clear(&c->v.v2.outbuffer); |
| 5632 | sfree(c); |
| 5633 | |
| 5634 | /* |
| 5635 | * See if that was the last channel left open. |
| 5636 | */ |
| 5637 | if (count234(ssh->channels) == 0) { |
| 5638 | #if 0 |
| 5639 | /* |
| 5640 | * We used to send SSH_MSG_DISCONNECT here, |
| 5641 | * because I'd believed that _every_ conforming |
| 5642 | * SSH2 connection had to end with a disconnect |
| 5643 | * being sent by at least one side; apparently |
| 5644 | * I was wrong and it's perfectly OK to |
| 5645 | * unceremoniously slam the connection shut |
| 5646 | * when you're done, and indeed OpenSSH feels |
| 5647 | * this is more polite than sending a |
| 5648 | * DISCONNECT. So now we don't. |
| 5649 | */ |
| 5650 | logevent("All channels closed. Disconnecting"); |
| 5651 | ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); |
| 5652 | ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION); |
| 5653 | ssh2_pkt_addstring(ssh, "All open channels closed"); |
| 5654 | ssh2_pkt_addstring(ssh, "en"); /* language tag */ |
| 5655 | ssh2_pkt_send(ssh); |
| 5656 | #endif |
| 5657 | ssh->state = SSH_STATE_CLOSED; |
| 5658 | crReturnV; |
| 5659 | } |
| 5660 | continue; /* remote sends close; ignore (FIXME) */ |
| 5661 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 5662 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5663 | struct ssh_channel *c; |
| 5664 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5665 | if (!c || c->closes) |
| 5666 | continue; /* nonexistent or closing channel */ |
| 5667 | c->v.v2.remwindow += ssh2_pkt_getuint32(ssh); |
| 5668 | s->try_send = TRUE; |
| 5669 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 5670 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5671 | struct ssh_channel *c; |
| 5672 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5673 | if (!c) |
| 5674 | continue; /* nonexistent channel */ |
| 5675 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 5676 | continue; /* dunno why they're confirming this */ |
| 5677 | c->remoteid = ssh2_pkt_getuint32(ssh); |
| 5678 | c->type = CHAN_SOCKDATA; |
| 5679 | c->v.v2.remwindow = ssh2_pkt_getuint32(ssh); |
| 5680 | c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh); |
| 5681 | if (c->u.pfd.s) |
| 5682 | pfd_confirm(c->u.pfd.s); |
| 5683 | if (c->closes) { |
| 5684 | /* |
| 5685 | * We have a pending close on this channel, |
| 5686 | * which we decided on before the server acked |
| 5687 | * the channel open. So now we know the |
| 5688 | * remoteid, we can close it again. |
| 5689 | */ |
| 5690 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE); |
| 5691 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 5692 | ssh2_pkt_send(ssh); |
| 5693 | } |
| 5694 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { |
| 5695 | unsigned i = ssh2_pkt_getuint32(ssh); |
| 5696 | struct ssh_channel *c; |
| 5697 | c = find234(ssh->channels, &i, ssh_channelfind); |
| 5698 | if (!c) |
| 5699 | continue; /* nonexistent channel */ |
| 5700 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 5701 | continue; /* dunno why they're failing this */ |
| 5702 | |
| 5703 | logevent("Forwarded connection refused by server"); |
| 5704 | |
| 5705 | pfd_close(c->u.pfd.s); |
| 5706 | |
| 5707 | del234(ssh->channels, c); |
| 5708 | sfree(c); |
| 5709 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
| 5710 | unsigned localid; |
| 5711 | char *type; |
| 5712 | int typelen, want_reply; |
| 5713 | struct ssh_channel *c; |
| 5714 | |
| 5715 | localid = ssh2_pkt_getuint32(ssh); |
| 5716 | ssh2_pkt_getstring(ssh, &type, &typelen); |
| 5717 | want_reply = ssh2_pkt_getbool(ssh); |
| 5718 | |
| 5719 | /* |
| 5720 | * First, check that the channel exists. Otherwise, |
| 5721 | * we can instantly disconnect with a rude message. |
| 5722 | */ |
| 5723 | c = find234(ssh->channels, &localid, ssh_channelfind); |
| 5724 | if (!c) { |
| 5725 | char buf[80]; |
| 5726 | sprintf(buf, "Received channel request for nonexistent" |
| 5727 | " channel %d", localid); |
| 5728 | logevent(buf); |
| 5729 | ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT); |
| 5730 | ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION); |
| 5731 | ssh2_pkt_addstring(ssh, buf); |
| 5732 | ssh2_pkt_addstring(ssh, "en"); /* language tag */ |
| 5733 | ssh2_pkt_send(ssh); |
| 5734 | connection_fatal("%s", buf); |
| 5735 | ssh->state = SSH_STATE_CLOSED; |
| 5736 | crReturnV; |
| 5737 | } |
| 5738 | |
| 5739 | /* |
| 5740 | * Having got the channel number, we now look at |
| 5741 | * the request type string to see if it's something |
| 5742 | * we recognise. |
| 5743 | */ |
| 5744 | if (typelen == 11 && !memcmp(type, "exit-status", 11) && |
| 5745 | c == ssh->mainchan) { |
| 5746 | /* We recognise "exit-status" on the primary channel. */ |
| 5747 | char buf[100]; |
| 5748 | ssh->exitcode = ssh2_pkt_getuint32(ssh); |
| 5749 | sprintf(buf, "Server sent command exit status %d", |
| 5750 | ssh->exitcode); |
| 5751 | logevent(buf); |
| 5752 | if (want_reply) { |
| 5753 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS); |
| 5754 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 5755 | ssh2_pkt_send(ssh); |
| 5756 | } |
| 5757 | } else { |
| 5758 | /* |
| 5759 | * This is a channel request we don't know |
| 5760 | * about, so we now either ignore the request |
| 5761 | * or respond with CHANNEL_FAILURE, depending |
| 5762 | * on want_reply. |
| 5763 | */ |
| 5764 | if (want_reply) { |
| 5765 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE); |
| 5766 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 5767 | ssh2_pkt_send(ssh); |
| 5768 | } |
| 5769 | } |
| 5770 | } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) { |
| 5771 | char *type; |
| 5772 | int typelen, want_reply; |
| 5773 | |
| 5774 | ssh2_pkt_getstring(ssh, &type, &typelen); |
| 5775 | want_reply = ssh2_pkt_getbool(ssh); |
| 5776 | |
| 5777 | /* |
| 5778 | * We currently don't support any global requests |
| 5779 | * at all, so we either ignore the request or |
| 5780 | * respond with REQUEST_FAILURE, depending on |
| 5781 | * want_reply. |
| 5782 | */ |
| 5783 | if (want_reply) { |
| 5784 | ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE); |
| 5785 | ssh2_pkt_send(ssh); |
| 5786 | } |
| 5787 | } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
| 5788 | char *type; |
| 5789 | int typelen; |
| 5790 | char *peeraddr; |
| 5791 | int peeraddrlen; |
| 5792 | int port; |
| 5793 | char *error = NULL; |
| 5794 | struct ssh_channel *c; |
| 5795 | unsigned remid, winsize, pktsize; |
| 5796 | ssh2_pkt_getstring(ssh, &type, &typelen); |
| 5797 | c = smalloc(sizeof(struct ssh_channel)); |
| 5798 | c->ssh = ssh; |
| 5799 | |
| 5800 | remid = ssh2_pkt_getuint32(ssh); |
| 5801 | winsize = ssh2_pkt_getuint32(ssh); |
| 5802 | pktsize = ssh2_pkt_getuint32(ssh); |
| 5803 | ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen); |
| 5804 | port = ssh2_pkt_getuint32(ssh); |
| 5805 | |
| 5806 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
| 5807 | char *addrstr = smalloc(peeraddrlen+1); |
| 5808 | memcpy(addrstr, peeraddr, peeraddrlen); |
| 5809 | peeraddr[peeraddrlen] = '\0'; |
| 5810 | |
| 5811 | if (!ssh->X11_fwd_enabled) |
| 5812 | error = "X11 forwarding is not enabled"; |
| 5813 | else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c, |
| 5814 | ssh->x11auth, addrstr, port, |
| 5815 | &ssh->cfg) != NULL) { |
| 5816 | error = "Unable to open an X11 connection"; |
| 5817 | } else { |
| 5818 | c->type = CHAN_X11; |
| 5819 | } |
| 5820 | |
| 5821 | sfree(addrstr); |
| 5822 | } else if (typelen == 15 && |
| 5823 | !memcmp(type, "forwarded-tcpip", 15)) { |
| 5824 | struct ssh_rportfwd pf, *realpf; |
| 5825 | char *dummy; |
| 5826 | int dummylen; |
| 5827 | ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */ |
| 5828 | pf.sport = ssh2_pkt_getuint32(ssh); |
| 5829 | realpf = find234(ssh->rportfwds, &pf, NULL); |
| 5830 | if (realpf == NULL) { |
| 5831 | error = "Remote port is not recognised"; |
| 5832 | } else { |
| 5833 | char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost, |
| 5834 | realpf->dport, c, &ssh->cfg); |
| 5835 | logeventf(ssh, "Received remote port open request" |
| 5836 | " for %s:%d", realpf->dhost, realpf->dport); |
| 5837 | if (e != NULL) { |
| 5838 | logeventf(ssh, "Port open failed: %s", e); |
| 5839 | error = "Port open failed"; |
| 5840 | } else { |
| 5841 | logevent("Forwarded port opened successfully"); |
| 5842 | c->type = CHAN_SOCKDATA; |
| 5843 | } |
| 5844 | } |
| 5845 | } else if (typelen == 22 && |
| 5846 | !memcmp(type, "auth-agent@openssh.com", 3)) { |
| 5847 | if (!ssh->agentfwd_enabled) |
| 5848 | error = "Agent forwarding is not enabled"; |
| 5849 | else { |
| 5850 | c->type = CHAN_AGENT; /* identify channel type */ |
| 5851 | c->u.a.lensofar = 0; |
| 5852 | } |
| 5853 | } else { |
| 5854 | error = "Unsupported channel type requested"; |
| 5855 | } |
| 5856 | |
| 5857 | c->remoteid = remid; |
| 5858 | if (error) { |
| 5859 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 5860 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 5861 | ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED); |
| 5862 | ssh2_pkt_addstring(ssh, error); |
| 5863 | ssh2_pkt_addstring(ssh, "en"); /* language tag */ |
| 5864 | ssh2_pkt_send(ssh); |
| 5865 | sfree(c); |
| 5866 | } else { |
| 5867 | c->localid = alloc_channel_id(ssh); |
| 5868 | c->closes = 0; |
| 5869 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
| 5870 | c->v.v2.remwindow = winsize; |
| 5871 | c->v.v2.remmaxpkt = pktsize; |
| 5872 | bufchain_init(&c->v.v2.outbuffer); |
| 5873 | add234(ssh->channels, c); |
| 5874 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 5875 | ssh2_pkt_adduint32(ssh, c->remoteid); |
| 5876 | ssh2_pkt_adduint32(ssh, c->localid); |
| 5877 | ssh2_pkt_adduint32(ssh, c->v.v2.locwindow); |
| 5878 | ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */ |
| 5879 | ssh2_pkt_send(ssh); |
| 5880 | } |
| 5881 | } else { |
| 5882 | bombout((ssh,"Strange packet received: type %d", ssh->pktin.type)); |
| 5883 | crReturnV; |
| 5884 | } |
| 5885 | } else { |
| 5886 | /* |
| 5887 | * We have spare data. Add it to the channel buffer. |
| 5888 | */ |
| 5889 | ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen); |
| 5890 | s->try_send = TRUE; |
| 5891 | } |
| 5892 | if (s->try_send) { |
| 5893 | int i; |
| 5894 | struct ssh_channel *c; |
| 5895 | /* |
| 5896 | * Try to send data on all channels if we can. |
| 5897 | */ |
| 5898 | for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { |
| 5899 | int bufsize; |
| 5900 | if (c->closes) |
| 5901 | continue; /* don't send on closing channels */ |
| 5902 | bufsize = ssh2_try_send(c); |
| 5903 | if (bufsize == 0) { |
| 5904 | switch (c->type) { |
| 5905 | case CHAN_MAINSESSION: |
| 5906 | /* stdin need not receive an unthrottle |
| 5907 | * notification since it will be polled */ |
| 5908 | break; |
| 5909 | case CHAN_X11: |
| 5910 | x11_unthrottle(c->u.x11.s); |
| 5911 | break; |
| 5912 | case CHAN_AGENT: |
| 5913 | /* agent sockets are request/response and need no |
| 5914 | * buffer management */ |
| 5915 | break; |
| 5916 | case CHAN_SOCKDATA: |
| 5917 | pfd_unthrottle(c->u.pfd.s); |
| 5918 | break; |
| 5919 | } |
| 5920 | } |
| 5921 | } |
| 5922 | } |
| 5923 | } |
| 5924 | |
| 5925 | crFinishV; |
| 5926 | } |
| 5927 | |
| 5928 | /* |
| 5929 | * Handle the top-level SSH2 protocol. |
| 5930 | */ |
| 5931 | static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt) |
| 5932 | { |
| 5933 | if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0) |
| 5934 | return; |
| 5935 | do_ssh2_authconn(ssh, in, inlen, ispkt); |
| 5936 | } |
| 5937 | |
| 5938 | /* |
| 5939 | * Called to set up the connection. |
| 5940 | * |
| 5941 | * Returns an error message, or NULL on success. |
| 5942 | */ |
| 5943 | static char *ssh_init(void *frontend_handle, void **backend_handle, |
| 5944 | Config *cfg, |
| 5945 | char *host, int port, char **realhost, int nodelay) |
| 5946 | { |
| 5947 | char *p; |
| 5948 | Ssh ssh; |
| 5949 | |
| 5950 | ssh = smalloc(sizeof(*ssh)); |
| 5951 | ssh->cfg = *cfg; /* STRUCTURE COPY */ |
| 5952 | ssh->s = NULL; |
| 5953 | ssh->cipher = NULL; |
| 5954 | ssh->v1_cipher_ctx = NULL; |
| 5955 | ssh->crcda_ctx = NULL; |
| 5956 | ssh->cscipher = NULL; |
| 5957 | ssh->cs_cipher_ctx = NULL; |
| 5958 | ssh->sccipher = NULL; |
| 5959 | ssh->sc_cipher_ctx = NULL; |
| 5960 | ssh->csmac = NULL; |
| 5961 | ssh->cs_mac_ctx = NULL; |
| 5962 | ssh->scmac = NULL; |
| 5963 | ssh->sc_mac_ctx = NULL; |
| 5964 | ssh->cscomp = NULL; |
| 5965 | ssh->cs_comp_ctx = NULL; |
| 5966 | ssh->sccomp = NULL; |
| 5967 | ssh->sc_comp_ctx = NULL; |
| 5968 | ssh->kex = NULL; |
| 5969 | ssh->kex_ctx = NULL; |
| 5970 | ssh->hostkey = NULL; |
| 5971 | ssh->exitcode = -1; |
| 5972 | ssh->state = SSH_STATE_PREPACKET; |
| 5973 | ssh->size_needed = FALSE; |
| 5974 | ssh->eof_needed = FALSE; |
| 5975 | ssh->ldisc = NULL; |
| 5976 | ssh->logctx = NULL; |
| 5977 | { |
| 5978 | static const struct Packet empty = { 0, 0, NULL, NULL, 0 }; |
| 5979 | ssh->pktin = ssh->pktout = empty; |
| 5980 | } |
| 5981 | ssh->deferred_send_data = NULL; |
| 5982 | ssh->deferred_len = 0; |
| 5983 | ssh->deferred_size = 0; |
| 5984 | ssh->fallback_cmd = 0; |
| 5985 | ssh->pkt_ctx = 0; |
| 5986 | ssh->x11auth = NULL; |
| 5987 | ssh->v1_compressing = FALSE; |
| 5988 | ssh->v2_outgoing_sequence = 0; |
| 5989 | ssh->ssh1_rdpkt_crstate = 0; |
| 5990 | ssh->ssh2_rdpkt_crstate = 0; |
| 5991 | ssh->do_ssh_init_crstate = 0; |
| 5992 | ssh->ssh_gotdata_crstate = 0; |
| 5993 | ssh->ssh1_protocol_crstate = 0; |
| 5994 | ssh->do_ssh1_login_crstate = 0; |
| 5995 | ssh->do_ssh2_transport_crstate = 0; |
| 5996 | ssh->do_ssh2_authconn_crstate = 0; |
| 5997 | ssh->do_ssh_init_state = NULL; |
| 5998 | ssh->do_ssh1_login_state = NULL; |
| 5999 | ssh->do_ssh2_transport_state = NULL; |
| 6000 | ssh->do_ssh2_authconn_state = NULL; |
| 6001 | ssh->mainchan = NULL; |
| 6002 | ssh->throttled_all = 0; |
| 6003 | ssh->v1_stdout_throttling = 0; |
| 6004 | |
| 6005 | *backend_handle = ssh; |
| 6006 | |
| 6007 | #ifdef MSCRYPTOAPI |
| 6008 | if (crypto_startup() == 0) |
| 6009 | return "Microsoft high encryption pack not installed!"; |
| 6010 | #endif |
| 6011 | |
| 6012 | ssh->frontend = frontend_handle; |
| 6013 | ssh->term_width = ssh->cfg.width; |
| 6014 | ssh->term_height = ssh->cfg.height; |
| 6015 | |
| 6016 | ssh->channels = NULL; |
| 6017 | ssh->rportfwds = NULL; |
| 6018 | |
| 6019 | ssh->send_ok = 0; |
| 6020 | ssh->editing = 0; |
| 6021 | ssh->echoing = 0; |
| 6022 | ssh->v1_throttle_count = 0; |
| 6023 | ssh->overall_bufsize = 0; |
| 6024 | ssh->fallback_cmd = 0; |
| 6025 | |
| 6026 | ssh->protocol = NULL; |
| 6027 | |
| 6028 | p = connect_to_host(ssh, host, port, realhost, nodelay); |
| 6029 | if (p != NULL) |
| 6030 | return p; |
| 6031 | |
| 6032 | return NULL; |
| 6033 | } |
| 6034 | |
| 6035 | static void ssh_free(void *handle) |
| 6036 | { |
| 6037 | Ssh ssh = (Ssh) handle; |
| 6038 | struct ssh_channel *c; |
| 6039 | struct ssh_rportfwd *pf; |
| 6040 | |
| 6041 | if (ssh->v1_cipher_ctx) |
| 6042 | ssh->cipher->free_context(ssh->v1_cipher_ctx); |
| 6043 | if (ssh->cs_cipher_ctx) |
| 6044 | ssh->cscipher->free_context(ssh->cs_cipher_ctx); |
| 6045 | if (ssh->sc_cipher_ctx) |
| 6046 | ssh->sccipher->free_context(ssh->sc_cipher_ctx); |
| 6047 | if (ssh->cs_mac_ctx) |
| 6048 | ssh->csmac->free_context(ssh->cs_mac_ctx); |
| 6049 | if (ssh->sc_mac_ctx) |
| 6050 | ssh->scmac->free_context(ssh->sc_mac_ctx); |
| 6051 | if (ssh->cs_comp_ctx) |
| 6052 | ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); |
| 6053 | if (ssh->sc_comp_ctx) |
| 6054 | ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx); |
| 6055 | if (ssh->kex_ctx) |
| 6056 | dh_cleanup(ssh->kex_ctx); |
| 6057 | sfree(ssh->savedhost); |
| 6058 | |
| 6059 | if (ssh->channels) { |
| 6060 | while ((c = delpos234(ssh->channels, 0)) != NULL) { |
| 6061 | switch (c->type) { |
| 6062 | case CHAN_X11: |
| 6063 | if (c->u.x11.s != NULL) |
| 6064 | x11_close(c->u.x11.s); |
| 6065 | break; |
| 6066 | case CHAN_SOCKDATA: |
| 6067 | if (c->u.pfd.s != NULL) |
| 6068 | pfd_close(c->u.pfd.s); |
| 6069 | break; |
| 6070 | } |
| 6071 | sfree(c); |
| 6072 | } |
| 6073 | freetree234(ssh->channels); |
| 6074 | } |
| 6075 | |
| 6076 | if (ssh->rportfwds) { |
| 6077 | while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) |
| 6078 | sfree(pf); |
| 6079 | freetree234(ssh->rportfwds); |
| 6080 | } |
| 6081 | sfree(ssh->deferred_send_data); |
| 6082 | if (ssh->x11auth) |
| 6083 | x11_free_auth(ssh->x11auth); |
| 6084 | sfree(ssh->do_ssh_init_state); |
| 6085 | sfree(ssh->do_ssh1_login_state); |
| 6086 | sfree(ssh->do_ssh2_transport_state); |
| 6087 | sfree(ssh->do_ssh2_authconn_state); |
| 6088 | |
| 6089 | if (ssh->s) |
| 6090 | sk_close(ssh->s); |
| 6091 | sfree(ssh); |
| 6092 | } |
| 6093 | |
| 6094 | /* |
| 6095 | * Reconfigure the SSH backend. |
| 6096 | * |
| 6097 | * Currently, this function does nothing very useful. In future, |
| 6098 | * however, we could do some handy things with it. For example, we |
| 6099 | * could make the port forwarding configurer active in the Change |
| 6100 | * Settings box, and this routine could close down existing |
| 6101 | * forwardings and open up new ones in response to changes. |
| 6102 | */ |
| 6103 | static void ssh_reconfig(void *handle, Config *cfg) |
| 6104 | { |
| 6105 | Ssh ssh = (Ssh) handle; |
| 6106 | ssh->cfg = *cfg; /* STRUCTURE COPY */ |
| 6107 | } |
| 6108 | |
| 6109 | /* |
| 6110 | * Called to send data down the Telnet connection. |
| 6111 | */ |
| 6112 | static int ssh_send(void *handle, char *buf, int len) |
| 6113 | { |
| 6114 | Ssh ssh = (Ssh) handle; |
| 6115 | |
| 6116 | if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) |
| 6117 | return 0; |
| 6118 | |
| 6119 | ssh->protocol(ssh, (unsigned char *)buf, len, 0); |
| 6120 | |
| 6121 | return ssh_sendbuffer(ssh); |
| 6122 | } |
| 6123 | |
| 6124 | /* |
| 6125 | * Called to query the current amount of buffered stdin data. |
| 6126 | */ |
| 6127 | static int ssh_sendbuffer(void *handle) |
| 6128 | { |
| 6129 | Ssh ssh = (Ssh) handle; |
| 6130 | int override_value; |
| 6131 | |
| 6132 | if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) |
| 6133 | return 0; |
| 6134 | |
| 6135 | /* |
| 6136 | * If the SSH socket itself has backed up, add the total backup |
| 6137 | * size on that to any individual buffer on the stdin channel. |
| 6138 | */ |
| 6139 | override_value = 0; |
| 6140 | if (ssh->throttled_all) |
| 6141 | override_value = ssh->overall_bufsize; |
| 6142 | |
| 6143 | if (ssh->version == 1) { |
| 6144 | return override_value; |
| 6145 | } else if (ssh->version == 2) { |
| 6146 | if (!ssh->mainchan || ssh->mainchan->closes > 0) |
| 6147 | return override_value; |
| 6148 | else |
| 6149 | return (override_value + |
| 6150 | bufchain_size(&ssh->mainchan->v.v2.outbuffer)); |
| 6151 | } |
| 6152 | |
| 6153 | return 0; |
| 6154 | } |
| 6155 | |
| 6156 | /* |
| 6157 | * Called to set the size of the window from SSH's POV. |
| 6158 | */ |
| 6159 | static void ssh_size(void *handle, int width, int height) |
| 6160 | { |
| 6161 | Ssh ssh = (Ssh) handle; |
| 6162 | |
| 6163 | ssh->term_width = width; |
| 6164 | ssh->term_height = height; |
| 6165 | |
| 6166 | switch (ssh->state) { |
| 6167 | case SSH_STATE_BEFORE_SIZE: |
| 6168 | case SSH_STATE_PREPACKET: |
| 6169 | case SSH_STATE_CLOSED: |
| 6170 | break; /* do nothing */ |
| 6171 | case SSH_STATE_INTERMED: |
| 6172 | ssh->size_needed = TRUE; /* buffer for later */ |
| 6173 | break; |
| 6174 | case SSH_STATE_SESSION: |
| 6175 | if (!ssh->cfg.nopty) { |
| 6176 | if (ssh->version == 1) { |
| 6177 | send_packet(ssh, SSH1_CMSG_WINDOW_SIZE, |
| 6178 | PKT_INT, ssh->term_height, |
| 6179 | PKT_INT, ssh->term_width, |
| 6180 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 6181 | } else { |
| 6182 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST); |
| 6183 | ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); |
| 6184 | ssh2_pkt_addstring(ssh, "window-change"); |
| 6185 | ssh2_pkt_addbool(ssh, 0); |
| 6186 | ssh2_pkt_adduint32(ssh, ssh->term_width); |
| 6187 | ssh2_pkt_adduint32(ssh, ssh->term_height); |
| 6188 | ssh2_pkt_adduint32(ssh, 0); |
| 6189 | ssh2_pkt_adduint32(ssh, 0); |
| 6190 | ssh2_pkt_send(ssh); |
| 6191 | } |
| 6192 | } |
| 6193 | break; |
| 6194 | } |
| 6195 | } |
| 6196 | |
| 6197 | /* |
| 6198 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
| 6199 | * can send an EOF and collect resulting output (e.g. `plink |
| 6200 | * hostname sort'). |
| 6201 | */ |
| 6202 | static void ssh_special(void *handle, Telnet_Special code) |
| 6203 | { |
| 6204 | Ssh ssh = (Ssh) handle; |
| 6205 | |
| 6206 | if (code == TS_EOF) { |
| 6207 | if (ssh->state != SSH_STATE_SESSION) { |
| 6208 | /* |
| 6209 | * Buffer the EOF in case we are pre-SESSION, so we can |
| 6210 | * send it as soon as we reach SESSION. |
| 6211 | */ |
| 6212 | if (code == TS_EOF) |
| 6213 | ssh->eof_needed = TRUE; |
| 6214 | return; |
| 6215 | } |
| 6216 | if (ssh->version == 1) { |
| 6217 | send_packet(ssh, SSH1_CMSG_EOF, PKT_END); |
| 6218 | } else { |
| 6219 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF); |
| 6220 | ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); |
| 6221 | ssh2_pkt_send(ssh); |
| 6222 | } |
| 6223 | logevent("Sent EOF message"); |
| 6224 | } else if (code == TS_PING) { |
| 6225 | if (ssh->state == SSH_STATE_CLOSED |
| 6226 | || ssh->state == SSH_STATE_PREPACKET) return; |
| 6227 | if (ssh->version == 1) { |
| 6228 | if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) |
| 6229 | send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
| 6230 | } else { |
| 6231 | ssh2_pkt_init(ssh, SSH2_MSG_IGNORE); |
| 6232 | ssh2_pkt_addstring_start(ssh); |
| 6233 | ssh2_pkt_send(ssh); |
| 6234 | } |
| 6235 | } else { |
| 6236 | /* do nothing */ |
| 6237 | } |
| 6238 | } |
| 6239 | |
| 6240 | void *new_sock_channel(void *handle, Socket s) |
| 6241 | { |
| 6242 | Ssh ssh = (Ssh) handle; |
| 6243 | struct ssh_channel *c; |
| 6244 | c = smalloc(sizeof(struct ssh_channel)); |
| 6245 | c->ssh = ssh; |
| 6246 | |
| 6247 | if (c) { |
| 6248 | c->remoteid = -1; /* to be set when open confirmed */ |
| 6249 | c->localid = alloc_channel_id(ssh); |
| 6250 | c->closes = 0; |
| 6251 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ |
| 6252 | c->u.pfd.s = s; |
| 6253 | bufchain_init(&c->v.v2.outbuffer); |
| 6254 | add234(ssh->channels, c); |
| 6255 | } |
| 6256 | return c; |
| 6257 | } |
| 6258 | |
| 6259 | /* |
| 6260 | * This is called when stdout/stderr (the entity to which |
| 6261 | * from_backend sends data) manages to clear some backlog. |
| 6262 | */ |
| 6263 | static void ssh_unthrottle(void *handle, int bufsize) |
| 6264 | { |
| 6265 | Ssh ssh = (Ssh) handle; |
| 6266 | if (ssh->version == 1) { |
| 6267 | if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 6268 | ssh->v1_stdout_throttling = 0; |
| 6269 | ssh1_throttle(ssh, -1); |
| 6270 | } |
| 6271 | } else { |
| 6272 | if (ssh->mainchan && ssh->mainchan->closes == 0) |
| 6273 | ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize); |
| 6274 | } |
| 6275 | } |
| 6276 | |
| 6277 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) |
| 6278 | { |
| 6279 | struct ssh_channel *c = (struct ssh_channel *)channel; |
| 6280 | Ssh ssh = c->ssh; |
| 6281 | |
| 6282 | logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port); |
| 6283 | |
| 6284 | if (ssh->version == 1) { |
| 6285 | send_packet(ssh, SSH1_MSG_PORT_OPEN, |
| 6286 | PKT_INT, c->localid, |
| 6287 | PKT_STR, hostname, |
| 6288 | PKT_INT, port, |
| 6289 | //PKT_STR, <org:orgport>, |
| 6290 | PKT_END); |
| 6291 | } else { |
| 6292 | ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN); |
| 6293 | ssh2_pkt_addstring(ssh, "direct-tcpip"); |
| 6294 | ssh2_pkt_adduint32(ssh, c->localid); |
| 6295 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
| 6296 | ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */ |
| 6297 | ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */ |
| 6298 | ssh2_pkt_addstring(ssh, hostname); |
| 6299 | ssh2_pkt_adduint32(ssh, port); |
| 6300 | /* |
| 6301 | * We make up values for the originator data; partly it's |
| 6302 | * too much hassle to keep track, and partly I'm not |
| 6303 | * convinced the server should be told details like that |
| 6304 | * about my local network configuration. |
| 6305 | */ |
| 6306 | ssh2_pkt_addstring(ssh, "client-side-connection"); |
| 6307 | ssh2_pkt_adduint32(ssh, 0); |
| 6308 | ssh2_pkt_send(ssh); |
| 6309 | } |
| 6310 | } |
| 6311 | |
| 6312 | |
| 6313 | static Socket ssh_socket(void *handle) |
| 6314 | { |
| 6315 | Ssh ssh = (Ssh) handle; |
| 6316 | return ssh->s; |
| 6317 | } |
| 6318 | |
| 6319 | static int ssh_sendok(void *handle) |
| 6320 | { |
| 6321 | Ssh ssh = (Ssh) handle; |
| 6322 | return ssh->send_ok; |
| 6323 | } |
| 6324 | |
| 6325 | static int ssh_ldisc(void *handle, int option) |
| 6326 | { |
| 6327 | Ssh ssh = (Ssh) handle; |
| 6328 | if (option == LD_ECHO) |
| 6329 | return ssh->echoing; |
| 6330 | if (option == LD_EDIT) |
| 6331 | return ssh->editing; |
| 6332 | return FALSE; |
| 6333 | } |
| 6334 | |
| 6335 | static void ssh_provide_ldisc(void *handle, void *ldisc) |
| 6336 | { |
| 6337 | Ssh ssh = (Ssh) handle; |
| 6338 | ssh->ldisc = ldisc; |
| 6339 | } |
| 6340 | |
| 6341 | static void ssh_provide_logctx(void *handle, void *logctx) |
| 6342 | { |
| 6343 | Ssh ssh = (Ssh) handle; |
| 6344 | ssh->logctx = logctx; |
| 6345 | } |
| 6346 | |
| 6347 | static int ssh_return_exitcode(void *handle) |
| 6348 | { |
| 6349 | Ssh ssh = (Ssh) handle; |
| 6350 | return ssh->exitcode; |
| 6351 | } |
| 6352 | |
| 6353 | /* |
| 6354 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if |
| 6355 | * that fails. This variable is the means by which scp.c can reach |
| 6356 | * into the SSH code and find out which one it got. |
| 6357 | */ |
| 6358 | extern int ssh_fallback_cmd(void *handle) |
| 6359 | { |
| 6360 | Ssh ssh = (Ssh) handle; |
| 6361 | return ssh->fallback_cmd; |
| 6362 | } |
| 6363 | |
| 6364 | Backend ssh_backend = { |
| 6365 | ssh_init, |
| 6366 | ssh_free, |
| 6367 | ssh_reconfig, |
| 6368 | ssh_send, |
| 6369 | ssh_sendbuffer, |
| 6370 | ssh_size, |
| 6371 | ssh_special, |
| 6372 | ssh_socket, |
| 6373 | ssh_return_exitcode, |
| 6374 | ssh_sendok, |
| 6375 | ssh_ldisc, |
| 6376 | ssh_provide_ldisc, |
| 6377 | ssh_provide_logctx, |
| 6378 | ssh_unthrottle, |
| 6379 | 22 |
| 6380 | }; |