| 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <stdarg.h> |
| 4 | #include <assert.h> |
| 5 | #include <winsock.h> |
| 6 | |
| 7 | #include "putty.h" |
| 8 | #include "ssh.h" |
| 9 | #include "scp.h" |
| 10 | |
| 11 | #ifndef FALSE |
| 12 | #define FALSE 0 |
| 13 | #endif |
| 14 | #ifndef TRUE |
| 15 | #define TRUE 1 |
| 16 | #endif |
| 17 | |
| 18 | #define logevent(s) { logevent(s); \ |
| 19 | if (!(flags & FLAG_CONNECTION) && (flags & FLAG_VERBOSE)) \ |
| 20 | fprintf(stderr, "%s\n", s); } |
| 21 | |
| 22 | #define SSH1_MSG_DISCONNECT 1 |
| 23 | #define SSH1_SMSG_PUBLIC_KEY 2 |
| 24 | #define SSH1_CMSG_SESSION_KEY 3 |
| 25 | #define SSH1_CMSG_USER 4 |
| 26 | #define SSH1_CMSG_AUTH_RSA 6 |
| 27 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 |
| 28 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 |
| 29 | #define SSH1_CMSG_AUTH_PASSWORD 9 |
| 30 | #define SSH1_CMSG_REQUEST_PTY 10 |
| 31 | #define SSH1_CMSG_WINDOW_SIZE 11 |
| 32 | #define SSH1_CMSG_EXEC_SHELL 12 |
| 33 | #define SSH1_CMSG_EXEC_CMD 13 |
| 34 | #define SSH1_SMSG_SUCCESS 14 |
| 35 | #define SSH1_SMSG_FAILURE 15 |
| 36 | #define SSH1_CMSG_STDIN_DATA 16 |
| 37 | #define SSH1_SMSG_STDOUT_DATA 17 |
| 38 | #define SSH1_SMSG_STDERR_DATA 18 |
| 39 | #define SSH1_CMSG_EOF 19 |
| 40 | #define SSH1_SMSG_EXIT_STATUS 20 |
| 41 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 |
| 42 | #define SSH1_MSG_IGNORE 32 |
| 43 | #define SSH1_MSG_DEBUG 36 |
| 44 | #define SSH1_CMSG_AUTH_TIS 39 |
| 45 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 |
| 46 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 |
| 47 | |
| 48 | #define SSH1_AUTH_TIS 5 |
| 49 | |
| 50 | #define SSH2_MSG_DISCONNECT 1 |
| 51 | #define SSH2_MSG_IGNORE 2 |
| 52 | #define SSH2_MSG_UNIMPLEMENTED 3 |
| 53 | #define SSH2_MSG_DEBUG 4 |
| 54 | #define SSH2_MSG_SERVICE_REQUEST 5 |
| 55 | #define SSH2_MSG_SERVICE_ACCEPT 6 |
| 56 | #define SSH2_MSG_KEXINIT 20 |
| 57 | #define SSH2_MSG_NEWKEYS 21 |
| 58 | #define SSH2_MSG_KEXDH_INIT 30 |
| 59 | #define SSH2_MSG_KEXDH_REPLY 31 |
| 60 | #define SSH2_MSG_USERAUTH_REQUEST 50 |
| 61 | #define SSH2_MSG_USERAUTH_FAILURE 51 |
| 62 | #define SSH2_MSG_USERAUTH_SUCCESS 52 |
| 63 | #define SSH2_MSG_USERAUTH_BANNER 53 |
| 64 | #define SSH2_MSG_USERAUTH_PK_OK 60 |
| 65 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 |
| 66 | #define SSH2_MSG_GLOBAL_REQUEST 80 |
| 67 | #define SSH2_MSG_REQUEST_SUCCESS 81 |
| 68 | #define SSH2_MSG_REQUEST_FAILURE 82 |
| 69 | #define SSH2_MSG_CHANNEL_OPEN 90 |
| 70 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 |
| 71 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 |
| 72 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 |
| 73 | #define SSH2_MSG_CHANNEL_DATA 94 |
| 74 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 |
| 75 | #define SSH2_MSG_CHANNEL_EOF 96 |
| 76 | #define SSH2_MSG_CHANNEL_CLOSE 97 |
| 77 | #define SSH2_MSG_CHANNEL_REQUEST 98 |
| 78 | #define SSH2_MSG_CHANNEL_SUCCESS 99 |
| 79 | #define SSH2_MSG_CHANNEL_FAILURE 100 |
| 80 | |
| 81 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 |
| 82 | #define SSH2_OPEN_CONNECT_FAILED 2 |
| 83 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 |
| 84 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 |
| 85 | #define SSH2_EXTENDED_DATA_STDERR 1 |
| 86 | |
| 87 | #define GET_32BIT(cp) \ |
| 88 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
| 89 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 90 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 91 | ((unsigned long)(unsigned char)(cp)[3])) |
| 92 | |
| 93 | #define PUT_32BIT(cp, value) { \ |
| 94 | (cp)[0] = (unsigned char)((value) >> 24); \ |
| 95 | (cp)[1] = (unsigned char)((value) >> 16); \ |
| 96 | (cp)[2] = (unsigned char)((value) >> 8); \ |
| 97 | (cp)[3] = (unsigned char)(value); } |
| 98 | |
| 99 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
| 100 | |
| 101 | /* Coroutine mechanics for the sillier bits of the code */ |
| 102 | #define crBegin1 static int crLine = 0; |
| 103 | #define crBegin2 switch(crLine) { case 0:; |
| 104 | #define crBegin crBegin1; crBegin2; |
| 105 | #define crFinish(z) } crLine = 0; return (z) |
| 106 | #define crFinishV } crLine = 0; return |
| 107 | #define crReturn(z) \ |
| 108 | do {\ |
| 109 | crLine=__LINE__; return (z); case __LINE__:;\ |
| 110 | } while (0) |
| 111 | #define crReturnV \ |
| 112 | do {\ |
| 113 | crLine=__LINE__; return; case __LINE__:;\ |
| 114 | } while (0) |
| 115 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
| 116 | #define crStopV do{ crLine = 0; return; }while(0) |
| 117 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 118 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 119 | |
| 120 | extern struct ssh_cipher ssh_3des; |
| 121 | extern struct ssh_cipher ssh_3des_ssh2; |
| 122 | extern struct ssh_cipher ssh_des; |
| 123 | extern struct ssh_cipher ssh_blowfish; |
| 124 | |
| 125 | /* for ssh 2; we miss out single-DES because it isn't supported */ |
| 126 | struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish }; |
| 127 | |
| 128 | extern struct ssh_kex ssh_diffiehellman; |
| 129 | struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; |
| 130 | |
| 131 | extern struct ssh_hostkey ssh_dss; |
| 132 | struct ssh_hostkey *hostkey_algs[] = { &ssh_dss }; |
| 133 | |
| 134 | extern struct ssh_mac ssh_sha1; |
| 135 | |
| 136 | SHA_State exhash; |
| 137 | |
| 138 | static void nullmac_key(unsigned char *key) { } |
| 139 | static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } |
| 140 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } |
| 141 | struct ssh_mac ssh_mac_none = { |
| 142 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
| 143 | }; |
| 144 | struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none }; |
| 145 | |
| 146 | struct ssh_compress ssh_comp_none = { |
| 147 | "none" |
| 148 | }; |
| 149 | struct ssh_compress *compressions[] = { &ssh_comp_none }; |
| 150 | |
| 151 | static SOCKET s = INVALID_SOCKET; |
| 152 | |
| 153 | static unsigned char session_key[32]; |
| 154 | static struct ssh_cipher *cipher = NULL; |
| 155 | static struct ssh_cipher *cscipher = NULL; |
| 156 | static struct ssh_cipher *sccipher = NULL; |
| 157 | static struct ssh_mac *csmac = NULL; |
| 158 | static struct ssh_mac *scmac = NULL; |
| 159 | static struct ssh_compress *cscomp = NULL; |
| 160 | static struct ssh_compress *sccomp = NULL; |
| 161 | static struct ssh_kex *kex = NULL; |
| 162 | static struct ssh_hostkey *hostkey = NULL; |
| 163 | int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL; |
| 164 | |
| 165 | static char *savedhost; |
| 166 | static int ssh_send_ok; |
| 167 | |
| 168 | static enum { |
| 169 | SSH_STATE_BEFORE_SIZE, |
| 170 | SSH_STATE_INTERMED, |
| 171 | SSH_STATE_SESSION, |
| 172 | SSH_STATE_CLOSED |
| 173 | } ssh_state = SSH_STATE_BEFORE_SIZE; |
| 174 | |
| 175 | static int size_needed = FALSE; |
| 176 | |
| 177 | static void s_write (char *buf, int len) { |
| 178 | while (len > 0) { |
| 179 | int i = send (s, buf, len, 0); |
| 180 | noise_ultralight(i); |
| 181 | if (i <= 0) |
| 182 | fatalbox("Lost connection while sending"); |
| 183 | if (i > 0) |
| 184 | len -= i, buf += i; |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | static int s_read (char *buf, int len) { |
| 189 | int ret = 0; |
| 190 | while (len > 0) { |
| 191 | int i = recv (s, buf, len, 0); |
| 192 | noise_ultralight(i); |
| 193 | if (i > 0) |
| 194 | len -= i, buf += i, ret += i; |
| 195 | else |
| 196 | return i; |
| 197 | } |
| 198 | return ret; |
| 199 | } |
| 200 | |
| 201 | static void c_write (char *buf, int len) { |
| 202 | if (!(flags & FLAG_CONNECTION)) { |
| 203 | int i; |
| 204 | for (i = 0; i < len; i++) |
| 205 | if (buf[i] != '\r') |
| 206 | fputc(buf[i], stderr); |
| 207 | return; |
| 208 | } |
| 209 | while (len--) |
| 210 | c_write1(*buf++); |
| 211 | } |
| 212 | |
| 213 | struct Packet { |
| 214 | long length; |
| 215 | int type; |
| 216 | unsigned char *data; |
| 217 | unsigned char *body; |
| 218 | long savedpos; |
| 219 | long maxlen; |
| 220 | }; |
| 221 | |
| 222 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
| 223 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
| 224 | |
| 225 | static int ssh_version; |
| 226 | static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt); |
| 227 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
| 228 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
| 229 | static void ssh_size(void); |
| 230 | |
| 231 | static int (*s_rdpkt)(unsigned char **data, int *datalen); |
| 232 | |
| 233 | /* |
| 234 | * Collect incoming data in the incoming packet buffer. |
| 235 | * Decipher and verify the packet when it is completely read. |
| 236 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 237 | * Update the *data and *datalen variables. |
| 238 | * Return the additional nr of bytes needed, or 0 when |
| 239 | * a complete packet is available. |
| 240 | */ |
| 241 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
| 242 | { |
| 243 | static long len, pad, biglen, to_read; |
| 244 | static unsigned long realcrc, gotcrc; |
| 245 | static unsigned char *p; |
| 246 | static int i; |
| 247 | |
| 248 | crBegin; |
| 249 | |
| 250 | next_packet: |
| 251 | |
| 252 | pktin.type = 0; |
| 253 | pktin.length = 0; |
| 254 | |
| 255 | for (i = len = 0; i < 4; i++) { |
| 256 | while ((*datalen) == 0) |
| 257 | crReturn(4-i); |
| 258 | len = (len << 8) + **data; |
| 259 | (*data)++, (*datalen)--; |
| 260 | } |
| 261 | |
| 262 | #ifdef FWHACK |
| 263 | if (len == 0x52656d6f) { /* "Remo"te server has closed ... */ |
| 264 | len = 0x300; /* big enough to carry to end */ |
| 265 | } |
| 266 | #endif |
| 267 | |
| 268 | pad = 8 - (len % 8); |
| 269 | biglen = len + pad; |
| 270 | pktin.length = len - 5; |
| 271 | |
| 272 | if (pktin.maxlen < biglen) { |
| 273 | pktin.maxlen = biglen; |
| 274 | pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) : |
| 275 | realloc(pktin.data, biglen+APIEXTRA)); |
| 276 | if (!pktin.data) |
| 277 | fatalbox("Out of memory"); |
| 278 | } |
| 279 | |
| 280 | to_read = biglen; |
| 281 | p = pktin.data; |
| 282 | while (to_read > 0) { |
| 283 | static int chunk; |
| 284 | chunk = to_read; |
| 285 | while ((*datalen) == 0) |
| 286 | crReturn(to_read); |
| 287 | if (chunk > (*datalen)) |
| 288 | chunk = (*datalen); |
| 289 | memcpy(p, *data, chunk); |
| 290 | *data += chunk; |
| 291 | *datalen -= chunk; |
| 292 | p += chunk; |
| 293 | to_read -= chunk; |
| 294 | } |
| 295 | |
| 296 | if (cipher) |
| 297 | cipher->decrypt(pktin.data, biglen); |
| 298 | |
| 299 | pktin.type = pktin.data[pad]; |
| 300 | pktin.body = pktin.data + pad + 1; |
| 301 | |
| 302 | realcrc = crc32(pktin.data, biglen-4); |
| 303 | gotcrc = GET_32BIT(pktin.data+biglen-4); |
| 304 | if (gotcrc != realcrc) { |
| 305 | fatalbox("Incorrect CRC received on packet"); |
| 306 | } |
| 307 | |
| 308 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 309 | pktin.type == SSH1_SMSG_STDERR_DATA || |
| 310 | pktin.type == SSH1_MSG_DEBUG || |
| 311 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 312 | long strlen = GET_32BIT(pktin.body); |
| 313 | if (strlen + 4 != pktin.length) |
| 314 | fatalbox("Received data packet with bogus string length"); |
| 315 | } |
| 316 | |
| 317 | if (pktin.type == SSH1_MSG_DEBUG) { |
| 318 | /* log debug message */ |
| 319 | char buf[80]; |
| 320 | int strlen = GET_32BIT(pktin.body); |
| 321 | strcpy(buf, "Remote: "); |
| 322 | if (strlen > 70) strlen = 70; |
| 323 | memcpy(buf+8, pktin.body+4, strlen); |
| 324 | buf[8+strlen] = '\0'; |
| 325 | logevent(buf); |
| 326 | goto next_packet; |
| 327 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
| 328 | /* do nothing */ |
| 329 | goto next_packet; |
| 330 | } |
| 331 | |
| 332 | crFinish(0); |
| 333 | } |
| 334 | |
| 335 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
| 336 | { |
| 337 | static long len, pad, payload, packetlen, maclen; |
| 338 | static int i; |
| 339 | static int cipherblk; |
| 340 | static unsigned long incoming_sequence = 0; |
| 341 | |
| 342 | crBegin; |
| 343 | |
| 344 | next_packet: |
| 345 | |
| 346 | pktin.type = 0; |
| 347 | pktin.length = 0; |
| 348 | |
| 349 | if (cipher) |
| 350 | cipherblk = cipher->blksize; |
| 351 | else |
| 352 | cipherblk = 8; |
| 353 | if (cipherblk < 8) |
| 354 | cipherblk = 8; |
| 355 | |
| 356 | if (pktin.maxlen < cipherblk) { |
| 357 | pktin.maxlen = cipherblk; |
| 358 | pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) : |
| 359 | realloc(pktin.data, cipherblk+APIEXTRA)); |
| 360 | if (!pktin.data) |
| 361 | fatalbox("Out of memory"); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * Acquire and decrypt the first block of the packet. This will |
| 366 | * contain the length and padding details. |
| 367 | */ |
| 368 | for (i = len = 0; i < cipherblk; i++) { |
| 369 | while ((*datalen) == 0) |
| 370 | crReturn(cipherblk-i); |
| 371 | pktin.data[i] = *(*data)++; |
| 372 | (*datalen)--; |
| 373 | } |
| 374 | #ifdef FWHACK |
| 375 | if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */ |
| 376 | /* FIXME */ |
| 377 | } |
| 378 | #endif |
| 379 | if (sccipher) |
| 380 | sccipher->decrypt(pktin.data, cipherblk); |
| 381 | |
| 382 | /* |
| 383 | * Now get the length and padding figures. |
| 384 | */ |
| 385 | len = GET_32BIT(pktin.data); |
| 386 | pad = pktin.data[4]; |
| 387 | |
| 388 | /* |
| 389 | * This enables us to deduce the payload length. |
| 390 | */ |
| 391 | payload = len - pad - 1; |
| 392 | |
| 393 | pktin.length = payload + 5; |
| 394 | |
| 395 | /* |
| 396 | * So now we can work out the total packet length. |
| 397 | */ |
| 398 | packetlen = len + 4; |
| 399 | maclen = scmac ? scmac->len : 0; |
| 400 | |
| 401 | /* |
| 402 | * Adjust memory allocation if packet is too big. |
| 403 | */ |
| 404 | if (pktin.maxlen < packetlen) { |
| 405 | pktin.maxlen = packetlen; |
| 406 | pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) : |
| 407 | realloc(pktin.data, packetlen+APIEXTRA)); |
| 408 | if (!pktin.data) |
| 409 | fatalbox("Out of memory"); |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * Read and decrypt the remainder of the packet. |
| 414 | */ |
| 415 | for (i = cipherblk; i < packetlen + maclen; i++) { |
| 416 | while ((*datalen) == 0) |
| 417 | crReturn(packetlen + maclen - i); |
| 418 | pktin.data[i] = *(*data)++; |
| 419 | (*datalen)--; |
| 420 | } |
| 421 | /* Decrypt everything _except_ the MAC. */ |
| 422 | if (sccipher) |
| 423 | sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk); |
| 424 | |
| 425 | #if 0 |
| 426 | debug(("Got packet len=%d pad=%d\r\n", len, pad)); |
| 427 | for (i = 0; i < packetlen; i++) |
| 428 | debug((" %02x", (unsigned char)pktin.data[i])); |
| 429 | debug(("\r\n")); |
| 430 | #endif |
| 431 | |
| 432 | /* |
| 433 | * Check the MAC. |
| 434 | */ |
| 435 | if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence)) |
| 436 | fatalbox("Incorrect MAC received on packet"); |
| 437 | incoming_sequence++; /* whether or not we MACed */ |
| 438 | |
| 439 | pktin.savedpos = 6; |
| 440 | pktin.type = pktin.data[5]; |
| 441 | |
| 442 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
| 443 | goto next_packet; /* FIXME: print DEBUG message */ |
| 444 | |
| 445 | crFinish(0); |
| 446 | } |
| 447 | |
| 448 | static void ssh_gotdata(unsigned char *data, int datalen) |
| 449 | { |
| 450 | while (datalen > 0) { |
| 451 | if ( s_rdpkt(&data, &datalen) == 0 ) { |
| 452 | ssh_protocol(NULL, 0, 1); |
| 453 | if (ssh_state == SSH_STATE_CLOSED) { |
| 454 | return; |
| 455 | } |
| 456 | } |
| 457 | } |
| 458 | } |
| 459 | |
| 460 | |
| 461 | static void s_wrpkt_start(int type, int len) { |
| 462 | int pad, biglen; |
| 463 | |
| 464 | len += 5; /* type and CRC */ |
| 465 | pad = 8 - (len%8); |
| 466 | biglen = len + pad; |
| 467 | |
| 468 | pktout.length = len-5; |
| 469 | if (pktout.maxlen < biglen) { |
| 470 | pktout.maxlen = biglen; |
| 471 | #ifdef MSCRYPTOAPI |
| 472 | /* Allocate enough buffer space for extra block |
| 473 | * for MS CryptEncrypt() */ |
| 474 | pktout.data = (pktout.data == NULL ? malloc(biglen+12) : |
| 475 | realloc(pktout.data, biglen+12)); |
| 476 | #else |
| 477 | pktout.data = (pktout.data == NULL ? malloc(biglen+4) : |
| 478 | realloc(pktout.data, biglen+4)); |
| 479 | #endif |
| 480 | if (!pktout.data) |
| 481 | fatalbox("Out of memory"); |
| 482 | } |
| 483 | |
| 484 | pktout.type = type; |
| 485 | pktout.body = pktout.data+4+pad+1; |
| 486 | } |
| 487 | |
| 488 | static void s_wrpkt(void) { |
| 489 | int pad, len, biglen, i; |
| 490 | unsigned long crc; |
| 491 | |
| 492 | len = pktout.length + 5; /* type and CRC */ |
| 493 | pad = 8 - (len%8); |
| 494 | biglen = len + pad; |
| 495 | |
| 496 | pktout.body[-1] = pktout.type; |
| 497 | for (i=0; i<pad; i++) |
| 498 | pktout.data[i+4] = random_byte(); |
| 499 | crc = crc32(pktout.data+4, biglen-4); |
| 500 | PUT_32BIT(pktout.data+biglen, crc); |
| 501 | PUT_32BIT(pktout.data, len); |
| 502 | |
| 503 | if (cipher) |
| 504 | cipher->encrypt(pktout.data+4, biglen); |
| 505 | |
| 506 | s_write(pktout.data, biglen+4); |
| 507 | } |
| 508 | |
| 509 | /* |
| 510 | * Construct a packet with the specified contents and |
| 511 | * send it to the server. |
| 512 | */ |
| 513 | static void send_packet(int pkttype, ...) |
| 514 | { |
| 515 | va_list args; |
| 516 | unsigned char *p, *argp, argchar; |
| 517 | unsigned long argint; |
| 518 | int pktlen, argtype, arglen; |
| 519 | Bignum bn; |
| 520 | int i; |
| 521 | |
| 522 | pktlen = 0; |
| 523 | va_start(args, pkttype); |
| 524 | while ((argtype = va_arg(args, int)) != PKT_END) { |
| 525 | switch (argtype) { |
| 526 | case PKT_INT: |
| 527 | (void) va_arg(args, int); |
| 528 | pktlen += 4; |
| 529 | break; |
| 530 | case PKT_CHAR: |
| 531 | (void) va_arg(args, char); |
| 532 | pktlen++; |
| 533 | break; |
| 534 | case PKT_DATA: |
| 535 | (void) va_arg(args, unsigned char *); |
| 536 | arglen = va_arg(args, int); |
| 537 | pktlen += arglen; |
| 538 | break; |
| 539 | case PKT_STR: |
| 540 | argp = va_arg(args, unsigned char *); |
| 541 | arglen = strlen(argp); |
| 542 | pktlen += 4 + arglen; |
| 543 | break; |
| 544 | case PKT_BIGNUM: |
| 545 | bn = va_arg(args, Bignum); |
| 546 | i = 16 * bn[0] - 1; |
| 547 | while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 ) |
| 548 | i--; |
| 549 | pktlen += 2 + (i+7)/8; |
| 550 | break; |
| 551 | default: |
| 552 | assert(0); |
| 553 | } |
| 554 | } |
| 555 | va_end(args); |
| 556 | |
| 557 | s_wrpkt_start(pkttype, pktlen); |
| 558 | p = pktout.body; |
| 559 | |
| 560 | va_start(args, pkttype); |
| 561 | while ((argtype = va_arg(args, int)) != PKT_END) { |
| 562 | switch (argtype) { |
| 563 | case PKT_INT: |
| 564 | argint = va_arg(args, int); |
| 565 | PUT_32BIT(p, argint); |
| 566 | p += 4; |
| 567 | break; |
| 568 | case PKT_CHAR: |
| 569 | argchar = va_arg(args, unsigned char); |
| 570 | *p = argchar; |
| 571 | p++; |
| 572 | break; |
| 573 | case PKT_DATA: |
| 574 | argp = va_arg(args, unsigned char *); |
| 575 | arglen = va_arg(args, int); |
| 576 | memcpy(p, argp, arglen); |
| 577 | p += arglen; |
| 578 | break; |
| 579 | case PKT_STR: |
| 580 | argp = va_arg(args, unsigned char *); |
| 581 | arglen = strlen(argp); |
| 582 | PUT_32BIT(p, arglen); |
| 583 | memcpy(p + 4, argp, arglen); |
| 584 | p += 4 + arglen; |
| 585 | break; |
| 586 | case PKT_BIGNUM: |
| 587 | bn = va_arg(args, Bignum); |
| 588 | i = 16 * bn[0] - 1; |
| 589 | while ( i > 0 && (bn[i/16+1] >> (i%16)) == 0 ) |
| 590 | i--; |
| 591 | *p++ = (i >> 8) & 0xFF; |
| 592 | *p++ = i & 0xFF; |
| 593 | i = (i + 7) / 8; |
| 594 | while (i-- > 0) { |
| 595 | if (i % 2) |
| 596 | *p++ = bn[i/2+1] >> 8; |
| 597 | else |
| 598 | *p++ = bn[i/2+1] & 0xFF; |
| 599 | } |
| 600 | break; |
| 601 | } |
| 602 | } |
| 603 | va_end(args); |
| 604 | |
| 605 | s_wrpkt(); |
| 606 | } |
| 607 | |
| 608 | |
| 609 | /* |
| 610 | * Connect to specified host and port. |
| 611 | * Returns an error message, or NULL on success. |
| 612 | * Also places the canonical host name into `realhost'. |
| 613 | */ |
| 614 | static char *connect_to_host(char *host, int port, char **realhost) |
| 615 | { |
| 616 | SOCKADDR_IN addr; |
| 617 | struct hostent *h; |
| 618 | unsigned long a; |
| 619 | #ifdef FWHACK |
| 620 | char *FWhost; |
| 621 | int FWport; |
| 622 | #endif |
| 623 | |
| 624 | savedhost = malloc(1+strlen(host)); |
| 625 | if (!savedhost) |
| 626 | fatalbox("Out of memory"); |
| 627 | strcpy(savedhost, host); |
| 628 | |
| 629 | if (port < 0) |
| 630 | port = 22; /* default ssh port */ |
| 631 | |
| 632 | #ifdef FWHACK |
| 633 | FWhost = host; |
| 634 | FWport = port; |
| 635 | host = FWSTR; |
| 636 | port = 23; |
| 637 | #endif |
| 638 | |
| 639 | /* |
| 640 | * Try to find host. |
| 641 | */ |
| 642 | if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) { |
| 643 | if ( (h = gethostbyname(host)) == NULL) |
| 644 | switch (WSAGetLastError()) { |
| 645 | case WSAENETDOWN: return "Network is down"; |
| 646 | case WSAHOST_NOT_FOUND: case WSANO_DATA: |
| 647 | return "Host does not exist"; |
| 648 | case WSATRY_AGAIN: return "Host not found"; |
| 649 | default: return "gethostbyname: unknown error"; |
| 650 | } |
| 651 | memcpy (&a, h->h_addr, sizeof(a)); |
| 652 | *realhost = h->h_name; |
| 653 | } else |
| 654 | *realhost = host; |
| 655 | #ifdef FWHACK |
| 656 | *realhost = FWhost; |
| 657 | #endif |
| 658 | a = ntohl(a); |
| 659 | |
| 660 | /* |
| 661 | * Open socket. |
| 662 | */ |
| 663 | s = socket(AF_INET, SOCK_STREAM, 0); |
| 664 | if (s == INVALID_SOCKET) |
| 665 | switch (WSAGetLastError()) { |
| 666 | case WSAENETDOWN: return "Network is down"; |
| 667 | case WSAEAFNOSUPPORT: return "TCP/IP support not present"; |
| 668 | default: return "socket(): unknown error"; |
| 669 | } |
| 670 | |
| 671 | /* |
| 672 | * Bind to local address. |
| 673 | */ |
| 674 | addr.sin_family = AF_INET; |
| 675 | addr.sin_addr.s_addr = htonl(INADDR_ANY); |
| 676 | addr.sin_port = htons(0); |
| 677 | if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR) |
| 678 | switch (WSAGetLastError()) { |
| 679 | case WSAENETDOWN: return "Network is down"; |
| 680 | default: return "bind(): unknown error"; |
| 681 | } |
| 682 | |
| 683 | /* |
| 684 | * Connect to remote address. |
| 685 | */ |
| 686 | addr.sin_addr.s_addr = htonl(a); |
| 687 | addr.sin_port = htons((short)port); |
| 688 | if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR) |
| 689 | switch (WSAGetLastError()) { |
| 690 | case WSAENETDOWN: return "Network is down"; |
| 691 | case WSAECONNREFUSED: return "Connection refused"; |
| 692 | case WSAENETUNREACH: return "Network is unreachable"; |
| 693 | case WSAEHOSTUNREACH: return "No route to host"; |
| 694 | default: return "connect(): unknown error"; |
| 695 | } |
| 696 | |
| 697 | #ifdef FWHACK |
| 698 | send(s, "connect ", 8, 0); |
| 699 | send(s, FWhost, strlen(FWhost), 0); |
| 700 | { |
| 701 | char buf[20]; |
| 702 | sprintf(buf, " %d\n", FWport); |
| 703 | send (s, buf, strlen(buf), 0); |
| 704 | } |
| 705 | #endif |
| 706 | |
| 707 | return NULL; |
| 708 | } |
| 709 | |
| 710 | static int ssh_versioncmp(char *a, char *b) { |
| 711 | char *ae, *be; |
| 712 | unsigned long av, bv; |
| 713 | |
| 714 | av = strtoul(a, &ae, 10); |
| 715 | bv = strtoul(b, &be, 10); |
| 716 | if (av != bv) return (av < bv ? -1 : +1); |
| 717 | if (*ae == '.') ae++; |
| 718 | if (*be == '.') be++; |
| 719 | av = strtoul(ae, &ae, 10); |
| 720 | bv = strtoul(be, &be, 10); |
| 721 | if (av != bv) return (av < bv ? -1 : +1); |
| 722 | return 0; |
| 723 | } |
| 724 | |
| 725 | |
| 726 | /* |
| 727 | * Utility routine for putting an SSH-protocol `string' into a SHA |
| 728 | * state. |
| 729 | */ |
| 730 | #include <stdio.h> |
| 731 | void sha_string(SHA_State *s, void *str, int len) { |
| 732 | unsigned char lenblk[4]; |
| 733 | static FILE *fp; |
| 734 | PUT_32BIT(lenblk, len); |
| 735 | if (!fp) fp = fopen("h:\\statham\\windows\\putty\\data","wb"); |
| 736 | fwrite(lenblk, 4, 1, fp); |
| 737 | SHA_Bytes(s, lenblk, 4); |
| 738 | fwrite(str, len, 1, fp); |
| 739 | fflush(fp); |
| 740 | SHA_Bytes(s, str, len); |
| 741 | } |
| 742 | |
| 743 | /* |
| 744 | * SSH2 packet construction functions. |
| 745 | */ |
| 746 | void ssh2_pkt_adddata(void *data, int len) { |
| 747 | pktout.length += len; |
| 748 | if (pktout.maxlen < pktout.length) { |
| 749 | pktout.maxlen = pktout.length + 256; |
| 750 | pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) : |
| 751 | realloc(pktout.data, pktout.maxlen+APIEXTRA)); |
| 752 | if (!pktout.data) |
| 753 | fatalbox("Out of memory"); |
| 754 | } |
| 755 | memcpy(pktout.data+pktout.length-len, data, len); |
| 756 | } |
| 757 | void ssh2_pkt_addbyte(unsigned char byte) { |
| 758 | ssh2_pkt_adddata(&byte, 1); |
| 759 | } |
| 760 | void ssh2_pkt_init(int pkt_type) { |
| 761 | pktout.length = 5; |
| 762 | ssh2_pkt_addbyte((unsigned char)pkt_type); |
| 763 | } |
| 764 | void ssh2_pkt_addbool(unsigned char value) { |
| 765 | ssh2_pkt_adddata(&value, 1); |
| 766 | } |
| 767 | void ssh2_pkt_adduint32(unsigned long value) { |
| 768 | unsigned char x[4]; |
| 769 | PUT_32BIT(x, value); |
| 770 | ssh2_pkt_adddata(x, 4); |
| 771 | } |
| 772 | void ssh2_pkt_addstring_start(void) { |
| 773 | ssh2_pkt_adduint32(0); |
| 774 | pktout.savedpos = pktout.length; |
| 775 | } |
| 776 | void ssh2_pkt_addstring_str(char *data) { |
| 777 | ssh2_pkt_adddata(data, strlen(data)); |
| 778 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 779 | pktout.length - pktout.savedpos); |
| 780 | } |
| 781 | void ssh2_pkt_addstring_data(char *data, int len) { |
| 782 | ssh2_pkt_adddata(data, len); |
| 783 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 784 | pktout.length - pktout.savedpos); |
| 785 | } |
| 786 | void ssh2_pkt_addstring(char *data) { |
| 787 | ssh2_pkt_addstring_start(); |
| 788 | ssh2_pkt_addstring_str(data); |
| 789 | } |
| 790 | char *ssh2_mpint_fmt(Bignum b, int *len) { |
| 791 | unsigned char *p; |
| 792 | int i, n = b[0]; |
| 793 | p = malloc(n * 2 + 1); |
| 794 | if (!p) |
| 795 | fatalbox("out of memory"); |
| 796 | p[0] = 0; |
| 797 | for (i = 0; i < n; i++) { |
| 798 | p[i*2+1] = (b[n-i] >> 8) & 0xFF; |
| 799 | p[i*2+2] = (b[n-i] ) & 0xFF; |
| 800 | } |
| 801 | i = 0; |
| 802 | while (p[i] == 0 && (p[i+1] & 0x80) == 0) |
| 803 | i++; |
| 804 | memmove(p, p+i, n*2+1-i); |
| 805 | *len = n*2+1-i; |
| 806 | return p; |
| 807 | } |
| 808 | void ssh2_pkt_addmp(Bignum b) { |
| 809 | unsigned char *p; |
| 810 | int len; |
| 811 | p = ssh2_mpint_fmt(b, &len); |
| 812 | ssh2_pkt_addstring_start(); |
| 813 | ssh2_pkt_addstring_data(p, len); |
| 814 | free(p); |
| 815 | } |
| 816 | void ssh2_pkt_send(void) { |
| 817 | int cipherblk, maclen, padding, i; |
| 818 | static unsigned long outgoing_sequence = 0; |
| 819 | |
| 820 | /* |
| 821 | * Add padding. At least four bytes, and must also bring total |
| 822 | * length (minus MAC) up to a multiple of the block size. |
| 823 | */ |
| 824 | cipherblk = cipher ? cipher->blksize : 8; /* block size */ |
| 825 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 826 | padding = 4; |
| 827 | padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
| 828 | pktout.data[4] = padding; |
| 829 | for (i = 0; i < padding; i++) |
| 830 | pktout.data[pktout.length + i] = random_byte(); |
| 831 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
| 832 | if (csmac) |
| 833 | csmac->generate(pktout.data, pktout.length + padding, |
| 834 | outgoing_sequence); |
| 835 | outgoing_sequence++; /* whether or not we MACed */ |
| 836 | |
| 837 | #if 0 |
| 838 | debug(("Sending packet len=%d\r\n", pktout.length+padding)); |
| 839 | for (i = 0; i < pktout.length+padding; i++) |
| 840 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 841 | debug(("\r\n")); |
| 842 | #endif |
| 843 | |
| 844 | if (cscipher) |
| 845 | cscipher->encrypt(pktout.data, pktout.length + padding); |
| 846 | maclen = csmac ? csmac->len : 0; |
| 847 | |
| 848 | s_write(pktout.data, pktout.length + padding + maclen); |
| 849 | } |
| 850 | |
| 851 | #if 0 |
| 852 | void bndebug(char *string, Bignum b) { |
| 853 | unsigned char *p; |
| 854 | int i, len; |
| 855 | p = ssh2_mpint_fmt(b, &len); |
| 856 | debug(("%s", string)); |
| 857 | for (i = 0; i < len; i++) |
| 858 | debug((" %02x", p[i])); |
| 859 | debug(("\r\n")); |
| 860 | free(p); |
| 861 | } |
| 862 | #endif |
| 863 | |
| 864 | void sha_mpint(SHA_State *s, Bignum b) { |
| 865 | unsigned char *p; |
| 866 | int len; |
| 867 | p = ssh2_mpint_fmt(b, &len); |
| 868 | sha_string(s, p, len); |
| 869 | free(p); |
| 870 | } |
| 871 | |
| 872 | /* |
| 873 | * SSH2 packet decode functions. |
| 874 | */ |
| 875 | unsigned long ssh2_pkt_getuint32(void) { |
| 876 | unsigned long value; |
| 877 | if (pktin.length - pktin.savedpos < 4) |
| 878 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 879 | value = GET_32BIT(pktin.data+pktin.savedpos); |
| 880 | pktin.savedpos += 4; |
| 881 | return value; |
| 882 | } |
| 883 | void ssh2_pkt_getstring(char **p, int *length) { |
| 884 | *p = NULL; |
| 885 | if (pktin.length - pktin.savedpos < 4) |
| 886 | return; |
| 887 | *length = GET_32BIT(pktin.data+pktin.savedpos); |
| 888 | pktin.savedpos += 4; |
| 889 | if (pktin.length - pktin.savedpos < *length) |
| 890 | return; |
| 891 | *p = pktin.data+pktin.savedpos; |
| 892 | pktin.savedpos += *length; |
| 893 | } |
| 894 | Bignum ssh2_pkt_getmp(void) { |
| 895 | char *p; |
| 896 | int i, j, length; |
| 897 | Bignum b; |
| 898 | |
| 899 | ssh2_pkt_getstring(&p, &length); |
| 900 | if (!p) |
| 901 | return NULL; |
| 902 | if (p[0] & 0x80) |
| 903 | fatalbox("internal error: Can't handle negative mpints"); |
| 904 | b = newbn((length+1)/2); |
| 905 | for (i = 0; i < length; i++) { |
| 906 | j = length - 1 - i; |
| 907 | if (j & 1) |
| 908 | b[j/2+1] |= ((unsigned char)p[i]) << 8; |
| 909 | else |
| 910 | b[j/2+1] |= ((unsigned char)p[i]); |
| 911 | } |
| 912 | return b; |
| 913 | } |
| 914 | |
| 915 | static int do_ssh_init(void) { |
| 916 | char c, *vsp; |
| 917 | char version[10]; |
| 918 | char vstring[80]; |
| 919 | char vlog[sizeof(vstring)+20]; |
| 920 | int i; |
| 921 | |
| 922 | #ifdef FWHACK |
| 923 | i = 0; |
| 924 | while (s_read(&c, 1) == 1) { |
| 925 | if (c == 'S' && i < 2) i++; |
| 926 | else if (c == 'S' && i == 2) i = 2; |
| 927 | else if (c == 'H' && i == 2) break; |
| 928 | else i = 0; |
| 929 | } |
| 930 | #else |
| 931 | if (s_read(&c,1) != 1 || c != 'S') return 0; |
| 932 | if (s_read(&c,1) != 1 || c != 'S') return 0; |
| 933 | if (s_read(&c,1) != 1 || c != 'H') return 0; |
| 934 | #endif |
| 935 | strcpy(vstring, "SSH-"); |
| 936 | vsp = vstring+4; |
| 937 | if (s_read(&c,1) != 1 || c != '-') return 0; |
| 938 | i = 0; |
| 939 | while (1) { |
| 940 | if (s_read(&c,1) != 1) |
| 941 | return 0; |
| 942 | if (vsp < vstring+sizeof(vstring)-1) |
| 943 | *vsp++ = c; |
| 944 | if (i >= 0) { |
| 945 | if (c == '-') { |
| 946 | version[i] = '\0'; |
| 947 | i = -1; |
| 948 | } else if (i < sizeof(version)-1) |
| 949 | version[i++] = c; |
| 950 | } |
| 951 | else if (c == '\n') |
| 952 | break; |
| 953 | } |
| 954 | |
| 955 | *vsp = 0; |
| 956 | sprintf(vlog, "Server version: %s", vstring); |
| 957 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 958 | logevent(vlog); |
| 959 | |
| 960 | if (ssh_versioncmp(version, "2.0" /* FIXME: "1.99" */ ) >= 0) { |
| 961 | /* |
| 962 | * This is a v2 server. Begin v2 protocol. |
| 963 | */ |
| 964 | char *verstring = "SSH-2.0-PuTTY"; |
| 965 | SHA_Init(&exhash); |
| 966 | /* |
| 967 | * Hash our version string and their version string. |
| 968 | */ |
| 969 | sha_string(&exhash, verstring, strlen(verstring)); |
| 970 | sha_string(&exhash, vstring, strcspn(vstring, "\r\n")); |
| 971 | sprintf(vstring, "%s\n", verstring); |
| 972 | sprintf(vlog, "We claim version: %s", verstring); |
| 973 | logevent(vlog); |
| 974 | logevent("Using SSH protocol version 2"); |
| 975 | s_write(vstring, strlen(vstring)); |
| 976 | ssh_protocol = ssh2_protocol; |
| 977 | ssh_version = 2; |
| 978 | s_rdpkt = ssh2_rdpkt; |
| 979 | } else { |
| 980 | /* |
| 981 | * This is a v1 server. Begin v1 protocol. |
| 982 | */ |
| 983 | sprintf(vstring, "SSH-%s-PuTTY\n", |
| 984 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5")); |
| 985 | sprintf(vlog, "We claim version: %s", vstring); |
| 986 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 987 | logevent(vlog); |
| 988 | logevent("Using SSH protocol version 1"); |
| 989 | s_write(vstring, strlen(vstring)); |
| 990 | ssh_protocol = ssh1_protocol; |
| 991 | ssh_version = 1; |
| 992 | s_rdpkt = ssh1_rdpkt; |
| 993 | } |
| 994 | ssh_send_ok = 0; |
| 995 | return 1; |
| 996 | } |
| 997 | |
| 998 | /* |
| 999 | * Handle the key exchange and user authentication phases. |
| 1000 | */ |
| 1001 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
| 1002 | { |
| 1003 | int i, j, len; |
| 1004 | unsigned char *rsabuf, *keystr1, *keystr2; |
| 1005 | unsigned char cookie[8]; |
| 1006 | struct RSAKey servkey, hostkey; |
| 1007 | struct MD5Context md5c; |
| 1008 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
| 1009 | static int tried_publickey; |
| 1010 | static unsigned char session_id[16]; |
| 1011 | int cipher_type; |
| 1012 | |
| 1013 | crBegin; |
| 1014 | |
| 1015 | if (!ispkt) crWaitUntil(ispkt); |
| 1016 | |
| 1017 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) |
| 1018 | fatalbox("Public key packet not received"); |
| 1019 | |
| 1020 | logevent("Received public keys"); |
| 1021 | |
| 1022 | memcpy(cookie, pktin.body, 8); |
| 1023 | |
| 1024 | i = makekey(pktin.body+8, &servkey, &keystr1, 0); |
| 1025 | j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); |
| 1026 | |
| 1027 | /* |
| 1028 | * Hash the host key and print the hash in the log box. Just as |
| 1029 | * a last resort in case the registry's host key checking is |
| 1030 | * compromised, we'll allow the user some ability to verify |
| 1031 | * host keys by eye. |
| 1032 | */ |
| 1033 | MD5Init(&md5c); |
| 1034 | MD5Update(&md5c, keystr2, hostkey.bytes); |
| 1035 | MD5Final(session_id, &md5c); |
| 1036 | { |
| 1037 | char logmsg[80]; |
| 1038 | int i; |
| 1039 | logevent("Host key MD5 is:"); |
| 1040 | strcpy(logmsg, " "); |
| 1041 | for (i = 0; i < 16; i++) |
| 1042 | sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]); |
| 1043 | logevent(logmsg); |
| 1044 | } |
| 1045 | |
| 1046 | supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); |
| 1047 | supported_auths_mask = GET_32BIT(pktin.body+16+i+j); |
| 1048 | |
| 1049 | MD5Init(&md5c); |
| 1050 | MD5Update(&md5c, keystr2, hostkey.bytes); |
| 1051 | MD5Update(&md5c, keystr1, servkey.bytes); |
| 1052 | MD5Update(&md5c, pktin.body, 8); |
| 1053 | MD5Final(session_id, &md5c); |
| 1054 | |
| 1055 | for (i=0; i<32; i++) |
| 1056 | session_key[i] = random_byte(); |
| 1057 | |
| 1058 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 1059 | |
| 1060 | rsabuf = malloc(len); |
| 1061 | if (!rsabuf) |
| 1062 | fatalbox("Out of memory"); |
| 1063 | |
| 1064 | /* |
| 1065 | * Verify the host key. |
| 1066 | */ |
| 1067 | { |
| 1068 | /* |
| 1069 | * First format the key into a string. |
| 1070 | */ |
| 1071 | int len = rsastr_len(&hostkey); |
| 1072 | char *keystr = malloc(len); |
| 1073 | if (!keystr) |
| 1074 | fatalbox("Out of memory"); |
| 1075 | rsastr_fmt(keystr, &hostkey); |
| 1076 | verify_ssh_host_key(savedhost, keystr); |
| 1077 | free(keystr); |
| 1078 | } |
| 1079 | |
| 1080 | for (i=0; i<32; i++) { |
| 1081 | rsabuf[i] = session_key[i]; |
| 1082 | if (i < 16) |
| 1083 | rsabuf[i] ^= session_id[i]; |
| 1084 | } |
| 1085 | |
| 1086 | if (hostkey.bytes > servkey.bytes) { |
| 1087 | rsaencrypt(rsabuf, 32, &servkey); |
| 1088 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
| 1089 | } else { |
| 1090 | rsaencrypt(rsabuf, 32, &hostkey); |
| 1091 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
| 1092 | } |
| 1093 | |
| 1094 | logevent("Encrypted session key"); |
| 1095 | |
| 1096 | cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH : |
| 1097 | cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES : |
| 1098 | SSH_CIPHER_3DES; |
| 1099 | if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { |
| 1100 | c_write("Selected cipher not supported, falling back to 3DES\r\n", 53); |
| 1101 | cipher_type = SSH_CIPHER_3DES; |
| 1102 | } |
| 1103 | switch (cipher_type) { |
| 1104 | case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; |
| 1105 | case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; |
| 1106 | case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; |
| 1107 | } |
| 1108 | |
| 1109 | send_packet(SSH1_CMSG_SESSION_KEY, |
| 1110 | PKT_CHAR, cipher_type, |
| 1111 | PKT_DATA, cookie, 8, |
| 1112 | PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, |
| 1113 | PKT_DATA, rsabuf, len, |
| 1114 | PKT_INT, 0, |
| 1115 | PKT_END); |
| 1116 | |
| 1117 | logevent("Trying to enable encryption..."); |
| 1118 | |
| 1119 | free(rsabuf); |
| 1120 | |
| 1121 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish : |
| 1122 | cipher_type == SSH_CIPHER_DES ? &ssh_des : |
| 1123 | &ssh_3des; |
| 1124 | cipher->sesskey(session_key); |
| 1125 | |
| 1126 | crWaitUntil(ispkt); |
| 1127 | |
| 1128 | if (pktin.type != SSH1_SMSG_SUCCESS) |
| 1129 | fatalbox("Encryption not successfully enabled"); |
| 1130 | |
| 1131 | logevent("Successfully started encryption"); |
| 1132 | |
| 1133 | fflush(stdout); |
| 1134 | { |
| 1135 | static char username[100]; |
| 1136 | static int pos = 0; |
| 1137 | static char c; |
| 1138 | if (!(flags & FLAG_CONNECTION) && !*cfg.username) { |
| 1139 | c_write("login as: ", 10); |
| 1140 | while (pos >= 0) { |
| 1141 | crWaitUntil(!ispkt); |
| 1142 | while (inlen--) switch (c = *in++) { |
| 1143 | case 10: case 13: |
| 1144 | username[pos] = 0; |
| 1145 | pos = -1; |
| 1146 | break; |
| 1147 | case 8: case 127: |
| 1148 | if (pos > 0) { |
| 1149 | c_write("\b \b", 3); |
| 1150 | pos--; |
| 1151 | } |
| 1152 | break; |
| 1153 | case 21: case 27: |
| 1154 | while (pos > 0) { |
| 1155 | c_write("\b \b", 3); |
| 1156 | pos--; |
| 1157 | } |
| 1158 | break; |
| 1159 | case 3: case 4: |
| 1160 | random_save_seed(); |
| 1161 | exit(0); |
| 1162 | break; |
| 1163 | default: |
| 1164 | if (((c >= ' ' && c <= '~') || |
| 1165 | ((unsigned char)c >= 160)) && pos < 40) { |
| 1166 | username[pos++] = c; |
| 1167 | c_write(&c, 1); |
| 1168 | } |
| 1169 | break; |
| 1170 | } |
| 1171 | } |
| 1172 | c_write("\r\n", 2); |
| 1173 | username[strcspn(username, "\n\r")] = '\0'; |
| 1174 | } else { |
| 1175 | char stuff[200]; |
| 1176 | strncpy(username, cfg.username, 99); |
| 1177 | username[99] = '\0'; |
| 1178 | if (flags & FLAG_VERBOSE) { |
| 1179 | sprintf(stuff, "Sent username \"%s\".\r\n", username); |
| 1180 | c_write(stuff, strlen(stuff)); |
| 1181 | } |
| 1182 | } |
| 1183 | |
| 1184 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
| 1185 | { |
| 1186 | char userlog[20+sizeof(username)]; |
| 1187 | sprintf(userlog, "Sent username \"%s\"", username); |
| 1188 | logevent(userlog); |
| 1189 | } |
| 1190 | } |
| 1191 | |
| 1192 | crWaitUntil(ispkt); |
| 1193 | |
| 1194 | tried_publickey = 0; |
| 1195 | |
| 1196 | while (pktin.type == SSH1_SMSG_FAILURE) { |
| 1197 | static char password[100]; |
| 1198 | static int pos; |
| 1199 | static char c; |
| 1200 | static int pwpkt_type; |
| 1201 | /* |
| 1202 | * Show password prompt, having first obtained it via a TIS |
| 1203 | * exchange if we're doing TIS authentication. |
| 1204 | */ |
| 1205 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 1206 | if (*cfg.keyfile && !tried_publickey) |
| 1207 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
| 1208 | |
| 1209 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) { |
| 1210 | char prompt[200]; |
| 1211 | sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost); |
| 1212 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
| 1213 | /* |
| 1214 | * get_password failed to get a password (for |
| 1215 | * example because one was supplied on the command |
| 1216 | * line which has already failed to work). |
| 1217 | * Terminate. |
| 1218 | */ |
| 1219 | logevent("No more passwords to try"); |
| 1220 | ssh_state = SSH_STATE_CLOSED; |
| 1221 | crReturn(1); |
| 1222 | } |
| 1223 | } else { |
| 1224 | |
| 1225 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 1226 | cfg.try_tis_auth && |
| 1227 | (supported_auths_mask & (1<<SSH1_AUTH_TIS))) { |
| 1228 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 1229 | logevent("Requested TIS authentication"); |
| 1230 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
| 1231 | crWaitUntil(ispkt); |
| 1232 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 1233 | logevent("TIS authentication declined"); |
| 1234 | c_write("TIS authentication refused.\r\n", 29); |
| 1235 | } else { |
| 1236 | int challengelen = ((pktin.body[0] << 24) | |
| 1237 | (pktin.body[1] << 16) | |
| 1238 | (pktin.body[2] << 8) | |
| 1239 | (pktin.body[3])); |
| 1240 | logevent("Received TIS challenge"); |
| 1241 | c_write(pktin.body+4, challengelen); |
| 1242 | } |
| 1243 | } |
| 1244 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) |
| 1245 | c_write("password: ", 10); |
| 1246 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 1247 | if (flags & FLAG_VERBOSE) |
| 1248 | c_write("Trying public key authentication.\r\n", 35); |
| 1249 | if (!rsakey_encrypted(cfg.keyfile)) { |
| 1250 | if (flags & FLAG_VERBOSE) |
| 1251 | c_write("No passphrase required.\r\n", 25); |
| 1252 | goto tryauth; |
| 1253 | } |
| 1254 | c_write("passphrase: ", 12); |
| 1255 | } |
| 1256 | |
| 1257 | pos = 0; |
| 1258 | while (pos >= 0) { |
| 1259 | crWaitUntil(!ispkt); |
| 1260 | while (inlen--) switch (c = *in++) { |
| 1261 | case 10: case 13: |
| 1262 | password[pos] = 0; |
| 1263 | pos = -1; |
| 1264 | break; |
| 1265 | case 8: case 127: |
| 1266 | if (pos > 0) |
| 1267 | pos--; |
| 1268 | break; |
| 1269 | case 21: case 27: |
| 1270 | pos = 0; |
| 1271 | break; |
| 1272 | case 3: case 4: |
| 1273 | random_save_seed(); |
| 1274 | exit(0); |
| 1275 | break; |
| 1276 | default: |
| 1277 | if (((c >= ' ' && c <= '~') || |
| 1278 | ((unsigned char)c >= 160)) && pos < sizeof(password)) |
| 1279 | password[pos++] = c; |
| 1280 | break; |
| 1281 | } |
| 1282 | } |
| 1283 | c_write("\r\n", 2); |
| 1284 | |
| 1285 | } |
| 1286 | |
| 1287 | tryauth: |
| 1288 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 1289 | /* |
| 1290 | * Try public key authentication with the specified |
| 1291 | * key file. |
| 1292 | */ |
| 1293 | static struct RSAKey pubkey; |
| 1294 | static Bignum challenge, response; |
| 1295 | static int i; |
| 1296 | static unsigned char buffer[32]; |
| 1297 | |
| 1298 | tried_publickey = 1; |
| 1299 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
| 1300 | if (i == 0) { |
| 1301 | c_write("Couldn't load public key from ", 30); |
| 1302 | c_write(cfg.keyfile, strlen(cfg.keyfile)); |
| 1303 | c_write(".\r\n", 3); |
| 1304 | continue; /* go and try password */ |
| 1305 | } |
| 1306 | if (i == -1) { |
| 1307 | c_write("Wrong passphrase.\r\n", 19); |
| 1308 | tried_publickey = 0; |
| 1309 | continue; /* try again */ |
| 1310 | } |
| 1311 | |
| 1312 | /* |
| 1313 | * Send a public key attempt. |
| 1314 | */ |
| 1315 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 1316 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
| 1317 | |
| 1318 | crWaitUntil(ispkt); |
| 1319 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1320 | if (flags & FLAG_VERBOSE) |
| 1321 | c_write("Server refused our public key.\r\n", 32); |
| 1322 | continue; /* go and try password */ |
| 1323 | } |
| 1324 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) |
| 1325 | fatalbox("Bizarre response to offer of public key"); |
| 1326 | ssh1_read_bignum(pktin.body, &challenge); |
| 1327 | response = rsadecrypt(challenge, &pubkey); |
| 1328 | freebn(pubkey.private_exponent); /* burn the evidence */ |
| 1329 | |
| 1330 | for (i = 0; i < 32; i += 2) { |
| 1331 | buffer[i] = response[16-i/2] >> 8; |
| 1332 | buffer[i+1] = response[16-i/2] & 0xFF; |
| 1333 | } |
| 1334 | |
| 1335 | MD5Init(&md5c); |
| 1336 | MD5Update(&md5c, buffer, 32); |
| 1337 | MD5Update(&md5c, session_id, 16); |
| 1338 | MD5Final(buffer, &md5c); |
| 1339 | |
| 1340 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 1341 | PKT_DATA, buffer, 16, PKT_END); |
| 1342 | |
| 1343 | crWaitUntil(ispkt); |
| 1344 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1345 | if (flags & FLAG_VERBOSE) |
| 1346 | c_write("Failed to authenticate with our public key.\r\n", |
| 1347 | 45); |
| 1348 | continue; /* go and try password */ |
| 1349 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1350 | fatalbox("Bizarre response to RSA authentication response"); |
| 1351 | } |
| 1352 | |
| 1353 | break; /* we're through! */ |
| 1354 | } else { |
| 1355 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
| 1356 | } |
| 1357 | logevent("Sent password"); |
| 1358 | memset(password, 0, strlen(password)); |
| 1359 | crWaitUntil(ispkt); |
| 1360 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1361 | if (flags & FLAG_VERBOSE) |
| 1362 | c_write("Access denied\r\n", 15); |
| 1363 | logevent("Authentication refused"); |
| 1364 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 1365 | logevent("Received disconnect request"); |
| 1366 | ssh_state = SSH_STATE_CLOSED; |
| 1367 | crReturn(1); |
| 1368 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1369 | fatalbox("Strange packet received, type %d", pktin.type); |
| 1370 | } |
| 1371 | } |
| 1372 | |
| 1373 | logevent("Authentication successful"); |
| 1374 | |
| 1375 | crFinish(1); |
| 1376 | } |
| 1377 | |
| 1378 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { |
| 1379 | crBegin; |
| 1380 | |
| 1381 | random_init(); |
| 1382 | |
| 1383 | while (!do_ssh1_login(in, inlen, ispkt)) { |
| 1384 | crReturnV; |
| 1385 | } |
| 1386 | if (ssh_state == SSH_STATE_CLOSED) |
| 1387 | crReturnV; |
| 1388 | |
| 1389 | if (!cfg.nopty) { |
| 1390 | send_packet(SSH1_CMSG_REQUEST_PTY, |
| 1391 | PKT_STR, cfg.termtype, |
| 1392 | PKT_INT, rows, PKT_INT, cols, |
| 1393 | PKT_INT, 0, PKT_INT, 0, |
| 1394 | PKT_CHAR, 0, |
| 1395 | PKT_END); |
| 1396 | ssh_state = SSH_STATE_INTERMED; |
| 1397 | do { crReturnV; } while (!ispkt); |
| 1398 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1399 | fatalbox("Protocol confusion"); |
| 1400 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1401 | c_write("Server refused to allocate pty\r\n", 32); |
| 1402 | } |
| 1403 | logevent("Allocated pty"); |
| 1404 | } |
| 1405 | |
| 1406 | if (*cfg.remote_cmd) |
| 1407 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END); |
| 1408 | else |
| 1409 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 1410 | logevent("Started session"); |
| 1411 | |
| 1412 | ssh_state = SSH_STATE_SESSION; |
| 1413 | if (size_needed) |
| 1414 | ssh_size(); |
| 1415 | |
| 1416 | ssh_send_ok = 1; |
| 1417 | while (1) { |
| 1418 | crReturnV; |
| 1419 | if (ispkt) { |
| 1420 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 1421 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 1422 | long len = GET_32BIT(pktin.body); |
| 1423 | c_write(pktin.body+4, len); |
| 1424 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 1425 | ssh_state = SSH_STATE_CLOSED; |
| 1426 | logevent("Received disconnect request"); |
| 1427 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 1428 | /* may be from EXEC_SHELL on some servers */ |
| 1429 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1430 | /* may be from EXEC_SHELL on some servers |
| 1431 | * if no pty is available or in other odd cases. Ignore */ |
| 1432 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 1433 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 1434 | } else { |
| 1435 | fatalbox("Strange packet received: type %d", pktin.type); |
| 1436 | } |
| 1437 | } else { |
| 1438 | send_packet(SSH1_CMSG_STDIN_DATA, |
| 1439 | PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END); |
| 1440 | } |
| 1441 | } |
| 1442 | |
| 1443 | crFinishV; |
| 1444 | } |
| 1445 | |
| 1446 | /* |
| 1447 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 1448 | */ |
| 1449 | int in_commasep_string(char *needle, char *haystack, int haylen) { |
| 1450 | int needlen = strlen(needle); |
| 1451 | while (1) { |
| 1452 | /* |
| 1453 | * Is it at the start of the string? |
| 1454 | */ |
| 1455 | if (haylen >= needlen && /* haystack is long enough */ |
| 1456 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 1457 | (haylen == needlen || haystack[needlen] == ',') |
| 1458 | /* either , or EOS follows */ |
| 1459 | ) |
| 1460 | return 1; |
| 1461 | /* |
| 1462 | * If not, search for the next comma and resume after that. |
| 1463 | * If no comma found, terminate. |
| 1464 | */ |
| 1465 | while (haylen > 0 && *haystack != ',') |
| 1466 | haylen--, haystack++; |
| 1467 | if (haylen == 0) |
| 1468 | return 0; |
| 1469 | haylen--, haystack++; /* skip over comma itself */ |
| 1470 | } |
| 1471 | } |
| 1472 | |
| 1473 | /* |
| 1474 | * SSH2 key creation method. |
| 1475 | */ |
| 1476 | void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) { |
| 1477 | SHA_State s; |
| 1478 | /* First 20 bytes. */ |
| 1479 | SHA_Init(&s); |
| 1480 | sha_mpint(&s, K); |
| 1481 | SHA_Bytes(&s, H, 20); |
| 1482 | SHA_Bytes(&s, &chr, 1); |
| 1483 | SHA_Bytes(&s, H, 20); |
| 1484 | SHA_Final(&s, keyspace); |
| 1485 | /* Next 20 bytes. */ |
| 1486 | SHA_Init(&s); |
| 1487 | sha_mpint(&s, K); |
| 1488 | SHA_Bytes(&s, H, 20); |
| 1489 | SHA_Bytes(&s, keyspace, 20); |
| 1490 | SHA_Final(&s, keyspace+20); |
| 1491 | } |
| 1492 | |
| 1493 | /* |
| 1494 | * Handle the SSH2 transport layer. |
| 1495 | */ |
| 1496 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
| 1497 | { |
| 1498 | static int i, len; |
| 1499 | static char *str; |
| 1500 | static Bignum e, f, K; |
| 1501 | static struct ssh_cipher *cscipher_tobe = NULL; |
| 1502 | static struct ssh_cipher *sccipher_tobe = NULL; |
| 1503 | static struct ssh_mac *csmac_tobe = NULL; |
| 1504 | static struct ssh_mac *scmac_tobe = NULL; |
| 1505 | static struct ssh_compress *cscomp_tobe = NULL; |
| 1506 | static struct ssh_compress *sccomp_tobe = NULL; |
| 1507 | static char *hostkeydata, *sigdata, *keystr; |
| 1508 | static int hostkeylen, siglen; |
| 1509 | static unsigned char exchange_hash[20]; |
| 1510 | static unsigned char keyspace[40]; |
| 1511 | |
| 1512 | crBegin; |
| 1513 | random_init(); |
| 1514 | |
| 1515 | begin_key_exchange: |
| 1516 | /* |
| 1517 | * Construct and send our key exchange packet. |
| 1518 | */ |
| 1519 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
| 1520 | for (i = 0; i < 16; i++) |
| 1521 | ssh2_pkt_addbyte((unsigned char)random_byte()); |
| 1522 | /* List key exchange algorithms. */ |
| 1523 | ssh2_pkt_addstring_start(); |
| 1524 | for (i = 0; i < lenof(kex_algs); i++) { |
| 1525 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
| 1526 | if (i < lenof(kex_algs)-1) |
| 1527 | ssh2_pkt_addstring_str(","); |
| 1528 | } |
| 1529 | /* List server host key algorithms. */ |
| 1530 | ssh2_pkt_addstring_start(); |
| 1531 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 1532 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
| 1533 | if (i < lenof(hostkey_algs)-1) |
| 1534 | ssh2_pkt_addstring_str(","); |
| 1535 | } |
| 1536 | /* List client->server encryption algorithms. */ |
| 1537 | ssh2_pkt_addstring_start(); |
| 1538 | for (i = 0; i < lenof(ciphers); i++) { |
| 1539 | ssh2_pkt_addstring_str(ciphers[i]->name); |
| 1540 | if (i < lenof(ciphers)-1) |
| 1541 | ssh2_pkt_addstring_str(","); |
| 1542 | } |
| 1543 | /* List server->client encryption algorithms. */ |
| 1544 | ssh2_pkt_addstring_start(); |
| 1545 | for (i = 0; i < lenof(ciphers); i++) { |
| 1546 | ssh2_pkt_addstring_str(ciphers[i]->name); |
| 1547 | if (i < lenof(ciphers)-1) |
| 1548 | ssh2_pkt_addstring_str(","); |
| 1549 | } |
| 1550 | /* List client->server MAC algorithms. */ |
| 1551 | ssh2_pkt_addstring_start(); |
| 1552 | for (i = 0; i < lenof(macs); i++) { |
| 1553 | ssh2_pkt_addstring_str(macs[i]->name); |
| 1554 | if (i < lenof(macs)-1) |
| 1555 | ssh2_pkt_addstring_str(","); |
| 1556 | } |
| 1557 | /* List server->client MAC algorithms. */ |
| 1558 | ssh2_pkt_addstring_start(); |
| 1559 | for (i = 0; i < lenof(macs); i++) { |
| 1560 | ssh2_pkt_addstring_str(macs[i]->name); |
| 1561 | if (i < lenof(macs)-1) |
| 1562 | ssh2_pkt_addstring_str(","); |
| 1563 | } |
| 1564 | /* List client->server compression algorithms. */ |
| 1565 | ssh2_pkt_addstring_start(); |
| 1566 | for (i = 0; i < lenof(compressions); i++) { |
| 1567 | ssh2_pkt_addstring_str(compressions[i]->name); |
| 1568 | if (i < lenof(compressions)-1) |
| 1569 | ssh2_pkt_addstring_str(","); |
| 1570 | } |
| 1571 | /* List server->client compression algorithms. */ |
| 1572 | ssh2_pkt_addstring_start(); |
| 1573 | for (i = 0; i < lenof(compressions); i++) { |
| 1574 | ssh2_pkt_addstring_str(compressions[i]->name); |
| 1575 | if (i < lenof(compressions)-1) |
| 1576 | ssh2_pkt_addstring_str(","); |
| 1577 | } |
| 1578 | /* List client->server languages. Empty list. */ |
| 1579 | ssh2_pkt_addstring_start(); |
| 1580 | /* List server->client languages. Empty list. */ |
| 1581 | ssh2_pkt_addstring_start(); |
| 1582 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 1583 | ssh2_pkt_addbool(FALSE); |
| 1584 | /* Reserved. */ |
| 1585 | ssh2_pkt_adduint32(0); |
| 1586 | sha_string(&exhash, pktout.data+5, pktout.length-5); |
| 1587 | ssh2_pkt_send(); |
| 1588 | |
| 1589 | if (!ispkt) crWaitUntil(ispkt); |
| 1590 | sha_string(&exhash, pktin.data+5, pktin.length-5); |
| 1591 | |
| 1592 | /* |
| 1593 | * Now examine the other side's KEXINIT to see what we're up |
| 1594 | * to. |
| 1595 | */ |
| 1596 | if (pktin.type != SSH2_MSG_KEXINIT) { |
| 1597 | fatalbox("expected key exchange packet from server"); |
| 1598 | } |
| 1599 | kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; |
| 1600 | csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; |
| 1601 | pktin.savedpos += 16; /* skip garbage cookie */ |
| 1602 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
| 1603 | for (i = 0; i < lenof(kex_algs); i++) { |
| 1604 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
| 1605 | kex = kex_algs[i]; |
| 1606 | break; |
| 1607 | } |
| 1608 | } |
| 1609 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
| 1610 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 1611 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 1612 | hostkey = hostkey_algs[i]; |
| 1613 | break; |
| 1614 | } |
| 1615 | } |
| 1616 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
| 1617 | for (i = 0; i < lenof(ciphers); i++) { |
| 1618 | if (in_commasep_string(ciphers[i]->name, str, len)) { |
| 1619 | cscipher_tobe = ciphers[i]; |
| 1620 | break; |
| 1621 | } |
| 1622 | } |
| 1623 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
| 1624 | for (i = 0; i < lenof(ciphers); i++) { |
| 1625 | if (in_commasep_string(ciphers[i]->name, str, len)) { |
| 1626 | sccipher_tobe = ciphers[i]; |
| 1627 | break; |
| 1628 | } |
| 1629 | } |
| 1630 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
| 1631 | for (i = 0; i < lenof(macs); i++) { |
| 1632 | if (in_commasep_string(macs[i]->name, str, len)) { |
| 1633 | csmac_tobe = macs[i]; |
| 1634 | break; |
| 1635 | } |
| 1636 | } |
| 1637 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
| 1638 | for (i = 0; i < lenof(macs); i++) { |
| 1639 | if (in_commasep_string(macs[i]->name, str, len)) { |
| 1640 | scmac_tobe = macs[i]; |
| 1641 | break; |
| 1642 | } |
| 1643 | } |
| 1644 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
| 1645 | for (i = 0; i < lenof(compressions); i++) { |
| 1646 | if (in_commasep_string(compressions[i]->name, str, len)) { |
| 1647 | cscomp_tobe = compressions[i]; |
| 1648 | break; |
| 1649 | } |
| 1650 | } |
| 1651 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
| 1652 | for (i = 0; i < lenof(compressions); i++) { |
| 1653 | if (in_commasep_string(compressions[i]->name, str, len)) { |
| 1654 | sccomp_tobe = compressions[i]; |
| 1655 | break; |
| 1656 | } |
| 1657 | } |
| 1658 | |
| 1659 | /* |
| 1660 | * Currently we only support Diffie-Hellman and DSS, so let's |
| 1661 | * bomb out if those aren't selected. |
| 1662 | */ |
| 1663 | if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) |
| 1664 | fatalbox("internal fault: chaos in SSH 2 transport layer"); |
| 1665 | |
| 1666 | /* |
| 1667 | * Now we begin the fun. Generate and send e for Diffie-Hellman. |
| 1668 | */ |
| 1669 | e = dh_create_e(); |
| 1670 | ssh2_pkt_init(SSH2_MSG_KEXDH_INIT); |
| 1671 | ssh2_pkt_addmp(e); |
| 1672 | ssh2_pkt_send(); |
| 1673 | |
| 1674 | crWaitUntil(ispkt); |
| 1675 | if (pktin.type != SSH2_MSG_KEXDH_REPLY) { |
| 1676 | fatalbox("expected key exchange packet from server"); |
| 1677 | } |
| 1678 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
| 1679 | f = ssh2_pkt_getmp(); |
| 1680 | ssh2_pkt_getstring(&sigdata, &siglen); |
| 1681 | |
| 1682 | K = dh_find_K(f); |
| 1683 | |
| 1684 | sha_string(&exhash, hostkeydata, hostkeylen); |
| 1685 | sha_mpint(&exhash, e); |
| 1686 | sha_mpint(&exhash, f); |
| 1687 | sha_mpint(&exhash, K); |
| 1688 | SHA_Final(&exhash, exchange_hash); |
| 1689 | |
| 1690 | #if 0 |
| 1691 | debug(("Exchange hash is:\r\n")); |
| 1692 | for (i = 0; i < 20; i++) |
| 1693 | debug((" %02x", exchange_hash[i])); |
| 1694 | debug(("\r\n")); |
| 1695 | #endif |
| 1696 | |
| 1697 | hostkey->setkey(hostkeydata, hostkeylen); |
| 1698 | if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) |
| 1699 | fatalbox("Server failed host key check"); |
| 1700 | |
| 1701 | /* |
| 1702 | * Expect SSH2_MSG_NEWKEYS from server. |
| 1703 | */ |
| 1704 | crWaitUntil(ispkt); |
| 1705 | if (pktin.type != SSH2_MSG_NEWKEYS) |
| 1706 | fatalbox("expected new-keys packet from server"); |
| 1707 | |
| 1708 | /* |
| 1709 | * Authenticate remote host: verify host key. (We've already |
| 1710 | * checked the signature of the exchange hash.) |
| 1711 | */ |
| 1712 | keystr = hostkey->fmtkey(); |
| 1713 | verify_ssh_host_key(savedhost, keystr); |
| 1714 | free(keystr); |
| 1715 | |
| 1716 | /* |
| 1717 | * Send SSH2_MSG_NEWKEYS. |
| 1718 | */ |
| 1719 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
| 1720 | ssh2_pkt_send(); |
| 1721 | |
| 1722 | /* |
| 1723 | * Create and initialise session keys. |
| 1724 | */ |
| 1725 | cscipher = cscipher_tobe; |
| 1726 | sccipher = sccipher_tobe; |
| 1727 | csmac = csmac_tobe; |
| 1728 | scmac = scmac_tobe; |
| 1729 | cscomp = cscomp_tobe; |
| 1730 | sccomp = sccomp_tobe; |
| 1731 | /* |
| 1732 | * Set IVs after keys. |
| 1733 | */ |
| 1734 | ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace); |
| 1735 | ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace); |
| 1736 | ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace); |
| 1737 | ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace); |
| 1738 | ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace); |
| 1739 | ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace); |
| 1740 | |
| 1741 | /* |
| 1742 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 1743 | * function so that other things can run on top of the |
| 1744 | * transport. If we ever see a KEXINIT, we must go back to the |
| 1745 | * start. |
| 1746 | */ |
| 1747 | do { |
| 1748 | crReturn(1); |
| 1749 | } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)); |
| 1750 | goto begin_key_exchange; |
| 1751 | |
| 1752 | crFinish(1); |
| 1753 | } |
| 1754 | |
| 1755 | /* |
| 1756 | * SSH2: remote identifier for the main session channel. |
| 1757 | */ |
| 1758 | static unsigned long ssh_remote_channel; |
| 1759 | |
| 1760 | /* |
| 1761 | * Handle the SSH2 userauth and connection layers. |
| 1762 | */ |
| 1763 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
| 1764 | { |
| 1765 | static unsigned long remote_winsize; |
| 1766 | static unsigned long remote_maxpkt; |
| 1767 | |
| 1768 | crBegin; |
| 1769 | |
| 1770 | /* |
| 1771 | * Request userauth protocol, and await a response to it. |
| 1772 | */ |
| 1773 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 1774 | ssh2_pkt_addstring("ssh-userauth"); |
| 1775 | ssh2_pkt_send(); |
| 1776 | crWaitUntilV(ispkt); |
| 1777 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) |
| 1778 | fatalbox("Server refused user authentication protocol"); |
| 1779 | |
| 1780 | /* |
| 1781 | * FIXME: currently we support only password authentication. |
| 1782 | * (This places us technically in violation of the SSH2 spec. |
| 1783 | * We must fix this.) |
| 1784 | */ |
| 1785 | while (1) { |
| 1786 | /* |
| 1787 | * Get a username and a password. |
| 1788 | */ |
| 1789 | static char username[100]; |
| 1790 | static char password[100]; |
| 1791 | static int pos = 0; |
| 1792 | static char c; |
| 1793 | |
| 1794 | if ((flags & FLAG_CONNECTION) && !*cfg.username) { |
| 1795 | c_write("login as: ", 10); |
| 1796 | while (pos >= 0) { |
| 1797 | crWaitUntilV(!ispkt); |
| 1798 | while (inlen--) switch (c = *in++) { |
| 1799 | case 10: case 13: |
| 1800 | username[pos] = 0; |
| 1801 | pos = -1; |
| 1802 | break; |
| 1803 | case 8: case 127: |
| 1804 | if (pos > 0) { |
| 1805 | c_write("\b \b", 3); |
| 1806 | pos--; |
| 1807 | } |
| 1808 | break; |
| 1809 | case 21: case 27: |
| 1810 | while (pos > 0) { |
| 1811 | c_write("\b \b", 3); |
| 1812 | pos--; |
| 1813 | } |
| 1814 | break; |
| 1815 | case 3: case 4: |
| 1816 | random_save_seed(); |
| 1817 | exit(0); |
| 1818 | break; |
| 1819 | default: |
| 1820 | if (((c >= ' ' && c <= '~') || |
| 1821 | ((unsigned char)c >= 160)) && pos < 40) { |
| 1822 | username[pos++] = c; |
| 1823 | c_write(&c, 1); |
| 1824 | } |
| 1825 | break; |
| 1826 | } |
| 1827 | } |
| 1828 | c_write("\r\n", 2); |
| 1829 | username[strcspn(username, "\n\r")] = '\0'; |
| 1830 | } else { |
| 1831 | char stuff[200]; |
| 1832 | strncpy(username, cfg.username, 99); |
| 1833 | username[99] = '\0'; |
| 1834 | if (flags & FLAG_VERBOSE) { |
| 1835 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
| 1836 | c_write(stuff, strlen(stuff)); |
| 1837 | } |
| 1838 | } |
| 1839 | |
| 1840 | if (!(flags & FLAG_WINDOWED)) { |
| 1841 | char prompt[200]; |
| 1842 | sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost); |
| 1843 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
| 1844 | /* |
| 1845 | * get_password failed to get a password (for |
| 1846 | * example because one was supplied on the command |
| 1847 | * line which has already failed to work). |
| 1848 | * Terminate. |
| 1849 | */ |
| 1850 | logevent("No more passwords to try"); |
| 1851 | ssh_state = SSH_STATE_CLOSED; |
| 1852 | crReturnV; |
| 1853 | } |
| 1854 | } else { |
| 1855 | c_write("password: ", 10); |
| 1856 | |
| 1857 | pos = 0; |
| 1858 | while (pos >= 0) { |
| 1859 | crWaitUntilV(!ispkt); |
| 1860 | while (inlen--) switch (c = *in++) { |
| 1861 | case 10: case 13: |
| 1862 | password[pos] = 0; |
| 1863 | pos = -1; |
| 1864 | break; |
| 1865 | case 8: case 127: |
| 1866 | if (pos > 0) |
| 1867 | pos--; |
| 1868 | break; |
| 1869 | case 21: case 27: |
| 1870 | pos = 0; |
| 1871 | break; |
| 1872 | case 3: case 4: |
| 1873 | random_save_seed(); |
| 1874 | exit(0); |
| 1875 | break; |
| 1876 | default: |
| 1877 | if (((c >= ' ' && c <= '~') || |
| 1878 | ((unsigned char)c >= 160)) && pos < 40) |
| 1879 | password[pos++] = c; |
| 1880 | break; |
| 1881 | } |
| 1882 | } |
| 1883 | c_write("\r\n", 2); |
| 1884 | } |
| 1885 | |
| 1886 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 1887 | ssh2_pkt_addstring(username); |
| 1888 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 1889 | ssh2_pkt_addstring("password"); |
| 1890 | ssh2_pkt_addbool(FALSE); |
| 1891 | ssh2_pkt_addstring(password); |
| 1892 | ssh2_pkt_send(); |
| 1893 | |
| 1894 | crWaitUntilV(ispkt); |
| 1895 | if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) { |
| 1896 | c_write("Access denied\r\n", 15); |
| 1897 | logevent("Authentication refused"); |
| 1898 | } else |
| 1899 | break; |
| 1900 | } |
| 1901 | |
| 1902 | /* |
| 1903 | * Now we're authenticated for the connection protocol. The |
| 1904 | * connection protocol will automatically have started at this |
| 1905 | * point; there's no need to send SERVICE_REQUEST. |
| 1906 | */ |
| 1907 | |
| 1908 | /* |
| 1909 | * So now create a channel with a session in it. |
| 1910 | */ |
| 1911 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 1912 | ssh2_pkt_addstring("session"); |
| 1913 | ssh2_pkt_adduint32(100); /* as good as any */ |
| 1914 | ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */ |
| 1915 | ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */ |
| 1916 | ssh2_pkt_send(); |
| 1917 | crWaitUntilV(ispkt); |
| 1918 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 1919 | fatalbox("Server refused to open a session"); |
| 1920 | /* FIXME: error data comes back in FAILURE packet */ |
| 1921 | } |
| 1922 | if (ssh2_pkt_getuint32() != 100) { |
| 1923 | fatalbox("Server's channel confirmation cited wrong channel"); |
| 1924 | } |
| 1925 | ssh_remote_channel = ssh2_pkt_getuint32(); |
| 1926 | remote_winsize = ssh2_pkt_getuint32(); |
| 1927 | remote_maxpkt = ssh2_pkt_getuint32(); |
| 1928 | logevent("Opened channel for session"); |
| 1929 | |
| 1930 | /* |
| 1931 | * Now allocate a pty for the session. |
| 1932 | */ |
| 1933 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 1934 | ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */ |
| 1935 | ssh2_pkt_addstring("pty-req"); |
| 1936 | ssh2_pkt_addbool(1); /* want reply */ |
| 1937 | ssh2_pkt_addstring(cfg.termtype); |
| 1938 | ssh2_pkt_adduint32(cols); |
| 1939 | ssh2_pkt_adduint32(rows); |
| 1940 | ssh2_pkt_adduint32(0); /* pixel width */ |
| 1941 | ssh2_pkt_adduint32(0); /* pixel height */ |
| 1942 | ssh2_pkt_addstring_start(); |
| 1943 | ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */ |
| 1944 | ssh2_pkt_send(); |
| 1945 | |
| 1946 | do { /* FIXME: pay attention to these */ |
| 1947 | crWaitUntilV(ispkt); |
| 1948 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 1949 | |
| 1950 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 1951 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 1952 | fatalbox("Server got confused by pty request"); |
| 1953 | } |
| 1954 | c_write("Server refused to allocate pty\r\n", 32); |
| 1955 | } else { |
| 1956 | logevent("Allocated pty"); |
| 1957 | } |
| 1958 | |
| 1959 | /* |
| 1960 | * Start a shell. |
| 1961 | */ |
| 1962 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 1963 | ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */ |
| 1964 | ssh2_pkt_addstring("shell"); |
| 1965 | ssh2_pkt_addbool(1); /* want reply */ |
| 1966 | ssh2_pkt_send(); |
| 1967 | do { /* FIXME: pay attention to these */ |
| 1968 | crWaitUntilV(ispkt); |
| 1969 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 1970 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 1971 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 1972 | fatalbox("Server got confused by shell request"); |
| 1973 | } |
| 1974 | fatalbox("Server refused to start a shell"); |
| 1975 | } else { |
| 1976 | logevent("Started a shell"); |
| 1977 | } |
| 1978 | |
| 1979 | /* |
| 1980 | * Transfer data! |
| 1981 | */ |
| 1982 | ssh_send_ok = 1; |
| 1983 | while (1) { |
| 1984 | crReturnV; |
| 1985 | if (ispkt) { |
| 1986 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
| 1987 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 1988 | char *data; |
| 1989 | int length; |
| 1990 | if (ssh2_pkt_getuint32() != 100) |
| 1991 | continue; /* wrong channel */ |
| 1992 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 1993 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
| 1994 | continue; /* extended but not stderr */ |
| 1995 | ssh2_pkt_getstring(&data, &length); |
| 1996 | if (data) |
| 1997 | c_write(data, length); |
| 1998 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
| 1999 | ssh_state = SSH_STATE_CLOSED; |
| 2000 | logevent("Received disconnect request"); |
| 2001 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
| 2002 | continue; /* exit status et al; ignore (FIXME?) */ |
| 2003 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 2004 | continue; /* ignore for now (FIXME!) */ |
| 2005 | } else { |
| 2006 | fatalbox("Strange packet received: type %d", pktin.type); |
| 2007 | } |
| 2008 | } else { |
| 2009 | /* FIXME: for now, ignore window size */ |
| 2010 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
| 2011 | ssh2_pkt_adduint32(ssh_remote_channel); |
| 2012 | ssh2_pkt_addstring_start(); |
| 2013 | ssh2_pkt_addstring_data(in, inlen); |
| 2014 | ssh2_pkt_send(); |
| 2015 | } |
| 2016 | } |
| 2017 | |
| 2018 | crFinishV; |
| 2019 | } |
| 2020 | |
| 2021 | /* |
| 2022 | * Handle the top-level SSH2 protocol. |
| 2023 | */ |
| 2024 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
| 2025 | { |
| 2026 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
| 2027 | return; |
| 2028 | do_ssh2_authconn(in, inlen, ispkt); |
| 2029 | } |
| 2030 | |
| 2031 | /* |
| 2032 | * Called to set up the connection. Will arrange for WM_NETEVENT |
| 2033 | * messages to be passed to the specified window, whose window |
| 2034 | * procedure should then call telnet_msg(). |
| 2035 | * |
| 2036 | * Returns an error message, or NULL on success. |
| 2037 | */ |
| 2038 | static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) { |
| 2039 | char *p; |
| 2040 | |
| 2041 | #ifdef MSCRYPTOAPI |
| 2042 | if(crypto_startup() == 0) |
| 2043 | return "Microsoft high encryption pack not installed!"; |
| 2044 | #endif |
| 2045 | |
| 2046 | p = connect_to_host(host, port, realhost); |
| 2047 | if (p != NULL) |
| 2048 | return p; |
| 2049 | |
| 2050 | if (!do_ssh_init()) |
| 2051 | return "Protocol initialisation error"; |
| 2052 | |
| 2053 | if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR) |
| 2054 | switch (WSAGetLastError()) { |
| 2055 | case WSAENETDOWN: return "Network is down"; |
| 2056 | default: return "WSAAsyncSelect(): unknown error"; |
| 2057 | } |
| 2058 | |
| 2059 | return NULL; |
| 2060 | } |
| 2061 | |
| 2062 | /* |
| 2063 | * Process a WM_NETEVENT message. Will return 0 if the connection |
| 2064 | * has closed, or <0 for a socket error. |
| 2065 | */ |
| 2066 | static int ssh_msg (WPARAM wParam, LPARAM lParam) { |
| 2067 | int ret; |
| 2068 | char buf[256]; |
| 2069 | |
| 2070 | /* |
| 2071 | * Because reading less than the whole of the available pending |
| 2072 | * data can generate an FD_READ event, we need to allow for the |
| 2073 | * possibility that FD_READ may arrive with FD_CLOSE already in |
| 2074 | * the queue; so it's possible that we can get here even with s |
| 2075 | * invalid. If so, we return 1 and don't worry about it. |
| 2076 | */ |
| 2077 | if (s == INVALID_SOCKET) |
| 2078 | return 1; |
| 2079 | |
| 2080 | if (WSAGETSELECTERROR(lParam) != 0) |
| 2081 | return -WSAGETSELECTERROR(lParam); |
| 2082 | |
| 2083 | switch (WSAGETSELECTEVENT(lParam)) { |
| 2084 | case FD_READ: |
| 2085 | case FD_CLOSE: |
| 2086 | ret = recv(s, buf, sizeof(buf), 0); |
| 2087 | if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK) |
| 2088 | return 1; |
| 2089 | if (ret < 0) /* any _other_ error */ |
| 2090 | return -10000-WSAGetLastError(); |
| 2091 | if (ret == 0) { |
| 2092 | s = INVALID_SOCKET; |
| 2093 | return 0; |
| 2094 | } |
| 2095 | ssh_gotdata (buf, ret); |
| 2096 | if (ssh_state == SSH_STATE_CLOSED) { |
| 2097 | closesocket(s); |
| 2098 | s = INVALID_SOCKET; |
| 2099 | return 0; |
| 2100 | } |
| 2101 | return 1; |
| 2102 | } |
| 2103 | return 1; /* shouldn't happen, but WTF */ |
| 2104 | } |
| 2105 | |
| 2106 | /* |
| 2107 | * Called to send data down the Telnet connection. |
| 2108 | */ |
| 2109 | static void ssh_send (char *buf, int len) { |
| 2110 | if (s == INVALID_SOCKET) |
| 2111 | return; |
| 2112 | |
| 2113 | ssh_protocol(buf, len, 0); |
| 2114 | } |
| 2115 | |
| 2116 | /* |
| 2117 | * Called to set the size of the window from Telnet's POV. |
| 2118 | */ |
| 2119 | static void ssh_size(void) { |
| 2120 | switch (ssh_state) { |
| 2121 | case SSH_STATE_BEFORE_SIZE: |
| 2122 | case SSH_STATE_CLOSED: |
| 2123 | break; /* do nothing */ |
| 2124 | case SSH_STATE_INTERMED: |
| 2125 | size_needed = TRUE; /* buffer for later */ |
| 2126 | break; |
| 2127 | case SSH_STATE_SESSION: |
| 2128 | if (!cfg.nopty) { |
| 2129 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
| 2130 | PKT_INT, rows, PKT_INT, cols, |
| 2131 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 2132 | } |
| 2133 | } |
| 2134 | } |
| 2135 | |
| 2136 | /* |
| 2137 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
| 2138 | * can send an EOF and collect resulting output (e.g. `plink |
| 2139 | * hostname sort'). |
| 2140 | */ |
| 2141 | static void ssh_special (Telnet_Special code) { |
| 2142 | if (code == TS_EOF) { |
| 2143 | if (ssh_version = 1) { |
| 2144 | send_packet(SSH1_CMSG_EOF, PKT_END); |
| 2145 | } else { |
| 2146 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
| 2147 | ssh2_pkt_adduint32(ssh_remote_channel); |
| 2148 | ssh2_pkt_send(); |
| 2149 | } |
| 2150 | } else { |
| 2151 | /* do nothing */ |
| 2152 | } |
| 2153 | } |
| 2154 | |
| 2155 | |
| 2156 | /* |
| 2157 | * Read and decrypt one incoming SSH packet. |
| 2158 | * (only used by pSCP) |
| 2159 | */ |
| 2160 | static void get_packet(void) |
| 2161 | { |
| 2162 | unsigned char buf[4096], *p; |
| 2163 | long to_read; |
| 2164 | int len; |
| 2165 | |
| 2166 | p = NULL; |
| 2167 | len = 0; |
| 2168 | |
| 2169 | while ((to_read = s_rdpkt(&p, &len)) > 0) { |
| 2170 | if (to_read > sizeof(buf)) to_read = sizeof(buf); |
| 2171 | len = s_read(buf, to_read); |
| 2172 | if (len != to_read) { |
| 2173 | closesocket(s); |
| 2174 | s = INVALID_SOCKET; |
| 2175 | return; |
| 2176 | } |
| 2177 | p = buf; |
| 2178 | } |
| 2179 | |
| 2180 | assert(len == 0); |
| 2181 | } |
| 2182 | |
| 2183 | /* |
| 2184 | * Receive a block of data over the SSH link. Block until |
| 2185 | * all data is available. Return nr of bytes read (0 if lost connection). |
| 2186 | * (only used by pSCP) |
| 2187 | */ |
| 2188 | int ssh_scp_recv(unsigned char *buf, int len) |
| 2189 | { |
| 2190 | static int pending_input_len = 0; |
| 2191 | static unsigned char *pending_input_ptr; |
| 2192 | int to_read = len; |
| 2193 | |
| 2194 | if (pending_input_len >= to_read) { |
| 2195 | memcpy(buf, pending_input_ptr, to_read); |
| 2196 | pending_input_ptr += to_read; |
| 2197 | pending_input_len -= to_read; |
| 2198 | return len; |
| 2199 | } |
| 2200 | |
| 2201 | if (pending_input_len > 0) { |
| 2202 | memcpy(buf, pending_input_ptr, pending_input_len); |
| 2203 | buf += pending_input_len; |
| 2204 | to_read -= pending_input_len; |
| 2205 | pending_input_len = 0; |
| 2206 | } |
| 2207 | |
| 2208 | if (s == INVALID_SOCKET) |
| 2209 | return 0; |
| 2210 | while (to_read > 0) { |
| 2211 | get_packet(); |
| 2212 | if (s == INVALID_SOCKET) |
| 2213 | return 0; |
| 2214 | if (pktin.type == SSH1_SMSG_STDOUT_DATA) { |
| 2215 | int plen = GET_32BIT(pktin.body); |
| 2216 | if (plen <= to_read) { |
| 2217 | memcpy(buf, pktin.body + 4, plen); |
| 2218 | buf += plen; |
| 2219 | to_read -= plen; |
| 2220 | } else { |
| 2221 | memcpy(buf, pktin.body + 4, to_read); |
| 2222 | pending_input_len = plen - to_read; |
| 2223 | pending_input_ptr = pktin.body + 4 + to_read; |
| 2224 | to_read = 0; |
| 2225 | } |
| 2226 | } else if (pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 2227 | int plen = GET_32BIT(pktin.body); |
| 2228 | fwrite(pktin.body + 4, plen, 1, stderr); |
| 2229 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 2230 | logevent("Received disconnect request"); |
| 2231 | } else if (pktin.type == SSH1_SMSG_SUCCESS || |
| 2232 | pktin.type == SSH1_SMSG_FAILURE) { |
| 2233 | /* ignore */ |
| 2234 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 2235 | char logbuf[100]; |
| 2236 | sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body)); |
| 2237 | logevent(logbuf); |
| 2238 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 2239 | logevent("Closing connection"); |
| 2240 | closesocket(s); |
| 2241 | s = INVALID_SOCKET; |
| 2242 | } else { |
| 2243 | fatalbox("Strange packet received: type %d", pktin.type); |
| 2244 | } |
| 2245 | } |
| 2246 | |
| 2247 | return len; |
| 2248 | } |
| 2249 | |
| 2250 | /* |
| 2251 | * Send a block of data over the SSH link. |
| 2252 | * Block until all data is sent. |
| 2253 | * (only used by pSCP) |
| 2254 | */ |
| 2255 | void ssh_scp_send(unsigned char *buf, int len) |
| 2256 | { |
| 2257 | if (s == INVALID_SOCKET) |
| 2258 | return; |
| 2259 | send_packet(SSH1_CMSG_STDIN_DATA, |
| 2260 | PKT_INT, len, PKT_DATA, buf, len, PKT_END); |
| 2261 | } |
| 2262 | |
| 2263 | /* |
| 2264 | * Send an EOF notification to the server. |
| 2265 | * (only used by pSCP) |
| 2266 | */ |
| 2267 | void ssh_scp_send_eof(void) |
| 2268 | { |
| 2269 | if (s == INVALID_SOCKET) |
| 2270 | return; |
| 2271 | send_packet(SSH1_CMSG_EOF, PKT_END); |
| 2272 | } |
| 2273 | |
| 2274 | /* |
| 2275 | * Set up the connection, login on the remote host and |
| 2276 | * start execution of a command. |
| 2277 | * Returns an error message, or NULL on success. |
| 2278 | * (only used by pSCP) |
| 2279 | */ |
| 2280 | char *ssh_scp_init(char *host, int port, char *cmd, char **realhost) |
| 2281 | { |
| 2282 | char buf[160], *p; |
| 2283 | |
| 2284 | #ifdef MSCRYPTOAPI |
| 2285 | if (crypto_startup() == 0) |
| 2286 | return "Microsoft high encryption pack not installed!"; |
| 2287 | #endif |
| 2288 | |
| 2289 | p = connect_to_host(host, port, realhost); |
| 2290 | if (p != NULL) |
| 2291 | return p; |
| 2292 | |
| 2293 | random_init(); |
| 2294 | |
| 2295 | if (!do_ssh_init()) |
| 2296 | return "Protocol initialisation error"; |
| 2297 | |
| 2298 | /* Exchange keys and login */ |
| 2299 | do { |
| 2300 | get_packet(); |
| 2301 | if (s == INVALID_SOCKET) |
| 2302 | return "Connection closed by remote host"; |
| 2303 | } while (!do_ssh1_login(NULL, 0, 1)); |
| 2304 | |
| 2305 | if (ssh_state == SSH_STATE_CLOSED) { |
| 2306 | closesocket(s); |
| 2307 | s = INVALID_SOCKET; |
| 2308 | return "Session initialisation error"; |
| 2309 | } |
| 2310 | |
| 2311 | /* Execute command */ |
| 2312 | sprintf(buf, "Sending command: %.100s", cmd); |
| 2313 | logevent(buf); |
| 2314 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
| 2315 | |
| 2316 | return NULL; |
| 2317 | } |
| 2318 | |
| 2319 | static SOCKET ssh_socket(void) { return s; } |
| 2320 | |
| 2321 | static int ssh_sendok(void) { return ssh_send_ok; } |
| 2322 | |
| 2323 | Backend ssh_backend = { |
| 2324 | ssh_init, |
| 2325 | ssh_msg, |
| 2326 | ssh_send, |
| 2327 | ssh_size, |
| 2328 | ssh_special, |
| 2329 | ssh_socket, |
| 2330 | ssh_sendok |
| 2331 | }; |