| 1 | #include <windows.h> |
| 2 | #include <stdio.h> |
| 3 | #include <stdlib.h> |
| 4 | #include <stdarg.h> |
| 5 | #include <assert.h> |
| 6 | |
| 7 | #include "putty.h" |
| 8 | #include "tree234.h" |
| 9 | #include "ssh.h" |
| 10 | |
| 11 | #ifndef FALSE |
| 12 | #define FALSE 0 |
| 13 | #endif |
| 14 | #ifndef TRUE |
| 15 | #define TRUE 1 |
| 16 | #endif |
| 17 | |
| 18 | #define logevent(s) { logevent(s); \ |
| 19 | if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ |
| 20 | fprintf(stderr, "%s\n", s); } |
| 21 | |
| 22 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \ |
| 23 | s = NULL, connection_fatal msg ) |
| 24 | |
| 25 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
| 26 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
| 27 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
| 28 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
| 29 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
| 30 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
| 31 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
| 32 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
| 33 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
| 34 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
| 35 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
| 36 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
| 37 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
| 38 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
| 39 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
| 40 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
| 41 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
| 42 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
| 43 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
| 44 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
| 45 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
| 46 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
| 47 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
| 48 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
| 49 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
| 50 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
| 51 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
| 52 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
| 53 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
| 54 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
| 55 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
| 56 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
| 57 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
| 58 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
| 59 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
| 60 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
| 61 | |
| 62 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
| 63 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
| 64 | |
| 65 | #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */ |
| 66 | #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */ |
| 67 | #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */ |
| 68 | #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */ |
| 69 | #define SSH_AGENT_FAILURE 5 /* 0x5 */ |
| 70 | #define SSH_AGENT_SUCCESS 6 /* 0x6 */ |
| 71 | #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */ |
| 72 | #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */ |
| 73 | |
| 74 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
| 75 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
| 76 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
| 77 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
| 78 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
| 79 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
| 80 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
| 81 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
| 82 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
| 83 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
| 84 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
| 85 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
| 86 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
| 87 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
| 88 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
| 89 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
| 90 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
| 91 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
| 92 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
| 93 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
| 94 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
| 95 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
| 96 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
| 97 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
| 98 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
| 99 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
| 100 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
| 101 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
| 102 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
| 103 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
| 104 | |
| 105 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
| 106 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
| 107 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
| 108 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
| 109 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
| 110 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
| 111 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
| 112 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
| 113 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
| 114 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
| 115 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
| 116 | |
| 117 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
| 118 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
| 119 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
| 120 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
| 121 | |
| 122 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
| 123 | |
| 124 | #define GET_32BIT(cp) \ |
| 125 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
| 126 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 127 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 128 | ((unsigned long)(unsigned char)(cp)[3])) |
| 129 | |
| 130 | #define PUT_32BIT(cp, value) { \ |
| 131 | (cp)[0] = (unsigned char)((value) >> 24); \ |
| 132 | (cp)[1] = (unsigned char)((value) >> 16); \ |
| 133 | (cp)[2] = (unsigned char)((value) >> 8); \ |
| 134 | (cp)[3] = (unsigned char)(value); } |
| 135 | |
| 136 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
| 137 | |
| 138 | /* Coroutine mechanics for the sillier bits of the code */ |
| 139 | #define crBegin1 static int crLine = 0; |
| 140 | #define crBegin2 switch(crLine) { case 0:; |
| 141 | #define crBegin crBegin1; crBegin2; |
| 142 | #define crFinish(z) } crLine = 0; return (z) |
| 143 | #define crFinishV } crLine = 0; return |
| 144 | #define crReturn(z) \ |
| 145 | do {\ |
| 146 | crLine=__LINE__; return (z); case __LINE__:;\ |
| 147 | } while (0) |
| 148 | #define crReturnV \ |
| 149 | do {\ |
| 150 | crLine=__LINE__; return; case __LINE__:;\ |
| 151 | } while (0) |
| 152 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
| 153 | #define crStopV do{ crLine = 0; return; }while(0) |
| 154 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 155 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 156 | |
| 157 | extern const struct ssh_cipher ssh_3des; |
| 158 | extern const struct ssh_cipher ssh_3des_ssh2; |
| 159 | extern const struct ssh_cipher ssh_des; |
| 160 | extern const struct ssh_cipher ssh_blowfish_ssh1; |
| 161 | extern const struct ssh_cipher ssh_blowfish_ssh2; |
| 162 | |
| 163 | /* |
| 164 | * Ciphers for SSH2. We miss out single-DES because it isn't |
| 165 | * supported; also 3DES and Blowfish are both done differently from |
| 166 | * SSH1. (3DES uses outer chaining; Blowfish has the opposite |
| 167 | * endianness and different-sized keys.) |
| 168 | */ |
| 169 | const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 }; |
| 170 | |
| 171 | extern const struct ssh_kex ssh_diffiehellman; |
| 172 | const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; |
| 173 | |
| 174 | extern const struct ssh_signkey ssh_dss; |
| 175 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss }; |
| 176 | |
| 177 | extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy; |
| 178 | |
| 179 | static void nullmac_key(unsigned char *key) { } |
| 180 | static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } |
| 181 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } |
| 182 | const static struct ssh_mac ssh_mac_none = { |
| 183 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
| 184 | }; |
| 185 | const static struct ssh_mac *macs[] = { |
| 186 | &ssh_sha1, &ssh_md5, &ssh_mac_none }; |
| 187 | const static struct ssh_mac *buggymacs[] = { |
| 188 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none }; |
| 189 | |
| 190 | static void ssh_comp_none_init(void) { } |
| 191 | static int ssh_comp_none_block(unsigned char *block, int len, |
| 192 | unsigned char **outblock, int *outlen) { |
| 193 | return 0; |
| 194 | } |
| 195 | const static struct ssh_compress ssh_comp_none = { |
| 196 | "none", |
| 197 | ssh_comp_none_init, ssh_comp_none_block, |
| 198 | ssh_comp_none_init, ssh_comp_none_block |
| 199 | }; |
| 200 | extern const struct ssh_compress ssh_zlib; |
| 201 | const static struct ssh_compress *compressions[] = { |
| 202 | &ssh_zlib, &ssh_comp_none }; |
| 203 | |
| 204 | /* |
| 205 | * 2-3-4 tree storing channels. |
| 206 | */ |
| 207 | struct ssh_channel { |
| 208 | unsigned remoteid, localid; |
| 209 | int type; |
| 210 | int closes; |
| 211 | union { |
| 212 | struct ssh_agent_channel { |
| 213 | unsigned char *message; |
| 214 | unsigned char msglen[4]; |
| 215 | int lensofar, totallen; |
| 216 | } a; |
| 217 | struct ssh2_data_channel { |
| 218 | unsigned char *outbuffer; |
| 219 | unsigned outbuflen, outbufsize; |
| 220 | unsigned remwindow, remmaxpkt; |
| 221 | } v2; |
| 222 | } u; |
| 223 | }; |
| 224 | |
| 225 | struct Packet { |
| 226 | long length; |
| 227 | int type; |
| 228 | unsigned char *data; |
| 229 | unsigned char *body; |
| 230 | long savedpos; |
| 231 | long maxlen; |
| 232 | }; |
| 233 | |
| 234 | static SHA_State exhash, exhashbase; |
| 235 | |
| 236 | static Socket s = NULL; |
| 237 | |
| 238 | static unsigned char session_key[32]; |
| 239 | static int ssh1_compressing; |
| 240 | static int ssh_agentfwd_enabled; |
| 241 | static const struct ssh_cipher *cipher = NULL; |
| 242 | static const struct ssh_cipher *cscipher = NULL; |
| 243 | static const struct ssh_cipher *sccipher = NULL; |
| 244 | static const struct ssh_mac *csmac = NULL; |
| 245 | static const struct ssh_mac *scmac = NULL; |
| 246 | static const struct ssh_compress *cscomp = NULL; |
| 247 | static const struct ssh_compress *sccomp = NULL; |
| 248 | static const struct ssh_kex *kex = NULL; |
| 249 | static const struct ssh_signkey *hostkey = NULL; |
| 250 | int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL; |
| 251 | |
| 252 | static char *savedhost; |
| 253 | static int savedport; |
| 254 | static int ssh_send_ok; |
| 255 | |
| 256 | static tree234 *ssh_channels; /* indexed by local id */ |
| 257 | static struct ssh_channel *mainchan; /* primary session channel */ |
| 258 | |
| 259 | static enum { |
| 260 | SSH_STATE_PREPACKET, |
| 261 | SSH_STATE_BEFORE_SIZE, |
| 262 | SSH_STATE_INTERMED, |
| 263 | SSH_STATE_SESSION, |
| 264 | SSH_STATE_CLOSED |
| 265 | } ssh_state = SSH_STATE_PREPACKET; |
| 266 | |
| 267 | static int size_needed = FALSE, eof_needed = FALSE; |
| 268 | |
| 269 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
| 270 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
| 271 | |
| 272 | static int ssh_version; |
| 273 | static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt); |
| 274 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
| 275 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
| 276 | static void ssh_size(void); |
| 277 | static void ssh_special (Telnet_Special); |
| 278 | |
| 279 | static int (*s_rdpkt)(unsigned char **data, int *datalen); |
| 280 | |
| 281 | static struct rdpkt1_state_tag { |
| 282 | long len, pad, biglen, to_read; |
| 283 | unsigned long realcrc, gotcrc; |
| 284 | unsigned char *p; |
| 285 | int i; |
| 286 | int chunk; |
| 287 | } rdpkt1_state; |
| 288 | |
| 289 | static struct rdpkt2_state_tag { |
| 290 | long len, pad, payload, packetlen, maclen; |
| 291 | int i; |
| 292 | int cipherblk; |
| 293 | unsigned long incoming_sequence; |
| 294 | } rdpkt2_state; |
| 295 | |
| 296 | static int ssh_channelcmp(void *av, void *bv) { |
| 297 | struct ssh_channel *a = (struct ssh_channel *)av; |
| 298 | struct ssh_channel *b = (struct ssh_channel *)bv; |
| 299 | if (a->localid < b->localid) return -1; |
| 300 | if (a->localid > b->localid) return +1; |
| 301 | return 0; |
| 302 | } |
| 303 | static int ssh_channelfind(void *av, void *bv) { |
| 304 | unsigned *a = (unsigned *)av; |
| 305 | struct ssh_channel *b = (struct ssh_channel *)bv; |
| 306 | if (*a < b->localid) return -1; |
| 307 | if (*a > b->localid) return +1; |
| 308 | return 0; |
| 309 | } |
| 310 | |
| 311 | static void c_write (char *buf, int len) { |
| 312 | if ((flags & FLAG_STDERR)) { |
| 313 | int i; |
| 314 | for (i = 0; i < len; i++) |
| 315 | if (buf[i] != '\r') |
| 316 | fputc(buf[i], stderr); |
| 317 | return; |
| 318 | } |
| 319 | from_backend(1, buf, len); |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * Collect incoming data in the incoming packet buffer. |
| 324 | * Decipher and verify the packet when it is completely read. |
| 325 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 326 | * Update the *data and *datalen variables. |
| 327 | * Return the additional nr of bytes needed, or 0 when |
| 328 | * a complete packet is available. |
| 329 | */ |
| 330 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
| 331 | { |
| 332 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
| 333 | |
| 334 | crBegin; |
| 335 | |
| 336 | next_packet: |
| 337 | |
| 338 | pktin.type = 0; |
| 339 | pktin.length = 0; |
| 340 | |
| 341 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
| 342 | while ((*datalen) == 0) |
| 343 | crReturn(4-st->i); |
| 344 | st->len = (st->len << 8) + **data; |
| 345 | (*data)++, (*datalen)--; |
| 346 | } |
| 347 | |
| 348 | #ifdef FWHACK |
| 349 | if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ |
| 350 | st->len = 0x300; /* big enough to carry to end */ |
| 351 | } |
| 352 | #endif |
| 353 | |
| 354 | st->pad = 8 - (st->len % 8); |
| 355 | st->biglen = st->len + st->pad; |
| 356 | pktin.length = st->len - 5; |
| 357 | |
| 358 | if (pktin.maxlen < st->biglen) { |
| 359 | pktin.maxlen = st->biglen; |
| 360 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) : |
| 361 | srealloc(pktin.data, st->biglen+APIEXTRA)); |
| 362 | if (!pktin.data) |
| 363 | fatalbox("Out of memory"); |
| 364 | } |
| 365 | |
| 366 | st->to_read = st->biglen; |
| 367 | st->p = pktin.data; |
| 368 | while (st->to_read > 0) { |
| 369 | st->chunk = st->to_read; |
| 370 | while ((*datalen) == 0) |
| 371 | crReturn(st->to_read); |
| 372 | if (st->chunk > (*datalen)) |
| 373 | st->chunk = (*datalen); |
| 374 | memcpy(st->p, *data, st->chunk); |
| 375 | *data += st->chunk; |
| 376 | *datalen -= st->chunk; |
| 377 | st->p += st->chunk; |
| 378 | st->to_read -= st->chunk; |
| 379 | } |
| 380 | |
| 381 | if (cipher) |
| 382 | cipher->decrypt(pktin.data, st->biglen); |
| 383 | #if 0 |
| 384 | debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); |
| 385 | for (st->i = 0; st->i < st->biglen; st->i++) |
| 386 | debug((" %02x", (unsigned char)pktin.data[st->i])); |
| 387 | debug(("\r\n")); |
| 388 | #endif |
| 389 | |
| 390 | st->realcrc = crc32(pktin.data, st->biglen-4); |
| 391 | st->gotcrc = GET_32BIT(pktin.data+st->biglen-4); |
| 392 | if (st->gotcrc != st->realcrc) { |
| 393 | bombout(("Incorrect CRC received on packet")); |
| 394 | crReturn(0); |
| 395 | } |
| 396 | |
| 397 | pktin.body = pktin.data + st->pad + 1; |
| 398 | |
| 399 | if (ssh1_compressing) { |
| 400 | unsigned char *decompblk; |
| 401 | int decomplen; |
| 402 | #if 0 |
| 403 | int i; |
| 404 | debug(("Packet payload pre-decompression:\n")); |
| 405 | for (i = -1; i < pktin.length; i++) |
| 406 | debug((" %02x", (unsigned char)pktin.body[i])); |
| 407 | debug(("\r\n")); |
| 408 | #endif |
| 409 | zlib_decompress_block(pktin.body-1, pktin.length+1, |
| 410 | &decompblk, &decomplen); |
| 411 | |
| 412 | if (pktin.maxlen < st->pad + decomplen) { |
| 413 | pktin.maxlen = st->pad + decomplen; |
| 414 | pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA); |
| 415 | pktin.body = pktin.data + st->pad + 1; |
| 416 | if (!pktin.data) |
| 417 | fatalbox("Out of memory"); |
| 418 | } |
| 419 | |
| 420 | memcpy(pktin.body-1, decompblk, decomplen); |
| 421 | sfree(decompblk); |
| 422 | pktin.length = decomplen-1; |
| 423 | #if 0 |
| 424 | debug(("Packet payload post-decompression:\n")); |
| 425 | for (i = -1; i < pktin.length; i++) |
| 426 | debug((" %02x", (unsigned char)pktin.body[i])); |
| 427 | debug(("\r\n")); |
| 428 | #endif |
| 429 | } |
| 430 | |
| 431 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 432 | pktin.type == SSH1_SMSG_STDERR_DATA || |
| 433 | pktin.type == SSH1_MSG_DEBUG || |
| 434 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
| 435 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 436 | long strlen = GET_32BIT(pktin.body); |
| 437 | if (strlen + 4 != pktin.length) { |
| 438 | bombout(("Received data packet with bogus string length")); |
| 439 | crReturn(0); |
| 440 | } |
| 441 | } |
| 442 | |
| 443 | pktin.type = pktin.body[-1]; |
| 444 | |
| 445 | if (pktin.type == SSH1_MSG_DEBUG) { |
| 446 | /* log debug message */ |
| 447 | char buf[80]; |
| 448 | int strlen = GET_32BIT(pktin.body); |
| 449 | strcpy(buf, "Remote: "); |
| 450 | if (strlen > 70) strlen = 70; |
| 451 | memcpy(buf+8, pktin.body+4, strlen); |
| 452 | buf[8+strlen] = '\0'; |
| 453 | logevent(buf); |
| 454 | goto next_packet; |
| 455 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
| 456 | /* do nothing */ |
| 457 | goto next_packet; |
| 458 | } |
| 459 | |
| 460 | crFinish(0); |
| 461 | } |
| 462 | |
| 463 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
| 464 | { |
| 465 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
| 466 | |
| 467 | crBegin; |
| 468 | |
| 469 | next_packet: |
| 470 | pktin.type = 0; |
| 471 | pktin.length = 0; |
| 472 | if (sccipher) |
| 473 | st->cipherblk = sccipher->blksize; |
| 474 | else |
| 475 | st->cipherblk = 8; |
| 476 | if (st->cipherblk < 8) |
| 477 | st->cipherblk = 8; |
| 478 | |
| 479 | if (pktin.maxlen < st->cipherblk) { |
| 480 | pktin.maxlen = st->cipherblk; |
| 481 | pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) : |
| 482 | srealloc(pktin.data, st->cipherblk+APIEXTRA)); |
| 483 | if (!pktin.data) |
| 484 | fatalbox("Out of memory"); |
| 485 | } |
| 486 | |
| 487 | /* |
| 488 | * Acquire and decrypt the first block of the packet. This will |
| 489 | * contain the length and padding details. |
| 490 | */ |
| 491 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
| 492 | while ((*datalen) == 0) |
| 493 | crReturn(st->cipherblk-st->i); |
| 494 | pktin.data[st->i] = *(*data)++; |
| 495 | (*datalen)--; |
| 496 | } |
| 497 | #ifdef FWHACK |
| 498 | if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */ |
| 499 | /* FIXME */ |
| 500 | } |
| 501 | #endif |
| 502 | if (sccipher) |
| 503 | sccipher->decrypt(pktin.data, st->cipherblk); |
| 504 | |
| 505 | /* |
| 506 | * Now get the length and padding figures. |
| 507 | */ |
| 508 | st->len = GET_32BIT(pktin.data); |
| 509 | st->pad = pktin.data[4]; |
| 510 | |
| 511 | /* |
| 512 | * This enables us to deduce the payload length. |
| 513 | */ |
| 514 | st->payload = st->len - st->pad - 1; |
| 515 | |
| 516 | pktin.length = st->payload + 5; |
| 517 | |
| 518 | /* |
| 519 | * So now we can work out the total packet length. |
| 520 | */ |
| 521 | st->packetlen = st->len + 4; |
| 522 | st->maclen = scmac ? scmac->len : 0; |
| 523 | |
| 524 | /* |
| 525 | * Adjust memory allocation if packet is too big. |
| 526 | */ |
| 527 | if (pktin.maxlen < st->packetlen+st->maclen) { |
| 528 | pktin.maxlen = st->packetlen+st->maclen; |
| 529 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
| 530 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
| 531 | if (!pktin.data) |
| 532 | fatalbox("Out of memory"); |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * Read and decrypt the remainder of the packet. |
| 537 | */ |
| 538 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { |
| 539 | while ((*datalen) == 0) |
| 540 | crReturn(st->packetlen + st->maclen - st->i); |
| 541 | pktin.data[st->i] = *(*data)++; |
| 542 | (*datalen)--; |
| 543 | } |
| 544 | /* Decrypt everything _except_ the MAC. */ |
| 545 | if (sccipher) |
| 546 | sccipher->decrypt(pktin.data + st->cipherblk, |
| 547 | st->packetlen - st->cipherblk); |
| 548 | |
| 549 | #if 0 |
| 550 | debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); |
| 551 | for (st->i = 0; st->i < st->packetlen; st->i++) |
| 552 | debug((" %02x", (unsigned char)pktin.data[st->i])); |
| 553 | debug(("\r\n")); |
| 554 | #endif |
| 555 | |
| 556 | /* |
| 557 | * Check the MAC. |
| 558 | */ |
| 559 | if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) { |
| 560 | bombout(("Incorrect MAC received on packet")); |
| 561 | crReturn(0); |
| 562 | } |
| 563 | st->incoming_sequence++; /* whether or not we MACed */ |
| 564 | |
| 565 | /* |
| 566 | * Decompress packet payload. |
| 567 | */ |
| 568 | { |
| 569 | unsigned char *newpayload; |
| 570 | int newlen; |
| 571 | if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5, |
| 572 | &newpayload, &newlen)) { |
| 573 | if (pktin.maxlen < newlen+5) { |
| 574 | pktin.maxlen = newlen+5; |
| 575 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
| 576 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
| 577 | if (!pktin.data) |
| 578 | fatalbox("Out of memory"); |
| 579 | } |
| 580 | pktin.length = 5 + newlen; |
| 581 | memcpy(pktin.data+5, newpayload, newlen); |
| 582 | #if 0 |
| 583 | debug(("Post-decompression payload:\r\n")); |
| 584 | for (st->i = 0; st->i < newlen; st->i++) |
| 585 | debug((" %02x", (unsigned char)pktin.data[5+st->i])); |
| 586 | debug(("\r\n")); |
| 587 | #endif |
| 588 | |
| 589 | sfree(newpayload); |
| 590 | } |
| 591 | } |
| 592 | |
| 593 | pktin.savedpos = 6; |
| 594 | pktin.type = pktin.data[5]; |
| 595 | |
| 596 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
| 597 | goto next_packet; /* FIXME: print DEBUG message */ |
| 598 | |
| 599 | crFinish(0); |
| 600 | } |
| 601 | |
| 602 | static void ssh1_pktout_size(int len) { |
| 603 | int pad, biglen; |
| 604 | |
| 605 | len += 5; /* type and CRC */ |
| 606 | pad = 8 - (len%8); |
| 607 | biglen = len + pad; |
| 608 | |
| 609 | pktout.length = len-5; |
| 610 | if (pktout.maxlen < biglen) { |
| 611 | pktout.maxlen = biglen; |
| 612 | #ifdef MSCRYPTOAPI |
| 613 | /* Allocate enough buffer space for extra block |
| 614 | * for MS CryptEncrypt() */ |
| 615 | pktout.data = (pktout.data == NULL ? smalloc(biglen+12) : |
| 616 | srealloc(pktout.data, biglen+12)); |
| 617 | #else |
| 618 | pktout.data = (pktout.data == NULL ? smalloc(biglen+4) : |
| 619 | srealloc(pktout.data, biglen+4)); |
| 620 | #endif |
| 621 | if (!pktout.data) |
| 622 | fatalbox("Out of memory"); |
| 623 | } |
| 624 | pktout.body = pktout.data+4+pad+1; |
| 625 | } |
| 626 | |
| 627 | static void s_wrpkt_start(int type, int len) { |
| 628 | ssh1_pktout_size(len); |
| 629 | pktout.type = type; |
| 630 | } |
| 631 | |
| 632 | static void s_wrpkt(void) { |
| 633 | int pad, len, biglen, i; |
| 634 | unsigned long crc; |
| 635 | |
| 636 | pktout.body[-1] = pktout.type; |
| 637 | |
| 638 | if (ssh1_compressing) { |
| 639 | unsigned char *compblk; |
| 640 | int complen; |
| 641 | #if 0 |
| 642 | debug(("Packet payload pre-compression:\n")); |
| 643 | for (i = -1; i < pktout.length; i++) |
| 644 | debug((" %02x", (unsigned char)pktout.body[i])); |
| 645 | debug(("\r\n")); |
| 646 | #endif |
| 647 | zlib_compress_block(pktout.body-1, pktout.length+1, |
| 648 | &compblk, &complen); |
| 649 | ssh1_pktout_size(complen-1); |
| 650 | memcpy(pktout.body-1, compblk, complen); |
| 651 | sfree(compblk); |
| 652 | #if 0 |
| 653 | debug(("Packet payload post-compression:\n")); |
| 654 | for (i = -1; i < pktout.length; i++) |
| 655 | debug((" %02x", (unsigned char)pktout.body[i])); |
| 656 | debug(("\r\n")); |
| 657 | #endif |
| 658 | } |
| 659 | |
| 660 | len = pktout.length + 5; /* type and CRC */ |
| 661 | pad = 8 - (len%8); |
| 662 | biglen = len + pad; |
| 663 | |
| 664 | for (i=0; i<pad; i++) |
| 665 | pktout.data[i+4] = random_byte(); |
| 666 | crc = crc32(pktout.data+4, biglen-4); |
| 667 | PUT_32BIT(pktout.data+biglen, crc); |
| 668 | PUT_32BIT(pktout.data, len); |
| 669 | |
| 670 | #if 0 |
| 671 | debug(("Sending packet len=%d\r\n", biglen+4)); |
| 672 | for (i = 0; i < biglen+4; i++) |
| 673 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 674 | debug(("\r\n")); |
| 675 | #endif |
| 676 | if (cipher) |
| 677 | cipher->encrypt(pktout.data+4, biglen); |
| 678 | |
| 679 | sk_write(s, pktout.data, biglen+4); |
| 680 | } |
| 681 | |
| 682 | /* |
| 683 | * Construct a packet with the specified contents and |
| 684 | * send it to the server. |
| 685 | */ |
| 686 | static void send_packet(int pkttype, ...) |
| 687 | { |
| 688 | va_list args; |
| 689 | unsigned char *p, *argp, argchar; |
| 690 | unsigned long argint; |
| 691 | int pktlen, argtype, arglen; |
| 692 | Bignum bn; |
| 693 | |
| 694 | pktlen = 0; |
| 695 | va_start(args, pkttype); |
| 696 | while ((argtype = va_arg(args, int)) != PKT_END) { |
| 697 | switch (argtype) { |
| 698 | case PKT_INT: |
| 699 | (void) va_arg(args, int); |
| 700 | pktlen += 4; |
| 701 | break; |
| 702 | case PKT_CHAR: |
| 703 | (void) va_arg(args, char); |
| 704 | pktlen++; |
| 705 | break; |
| 706 | case PKT_DATA: |
| 707 | (void) va_arg(args, unsigned char *); |
| 708 | arglen = va_arg(args, int); |
| 709 | pktlen += arglen; |
| 710 | break; |
| 711 | case PKT_STR: |
| 712 | argp = va_arg(args, unsigned char *); |
| 713 | arglen = strlen(argp); |
| 714 | pktlen += 4 + arglen; |
| 715 | break; |
| 716 | case PKT_BIGNUM: |
| 717 | bn = va_arg(args, Bignum); |
| 718 | pktlen += ssh1_bignum_length(bn); |
| 719 | break; |
| 720 | default: |
| 721 | assert(0); |
| 722 | } |
| 723 | } |
| 724 | va_end(args); |
| 725 | |
| 726 | s_wrpkt_start(pkttype, pktlen); |
| 727 | p = pktout.body; |
| 728 | |
| 729 | va_start(args, pkttype); |
| 730 | while ((argtype = va_arg(args, int)) != PKT_END) { |
| 731 | switch (argtype) { |
| 732 | case PKT_INT: |
| 733 | argint = va_arg(args, int); |
| 734 | PUT_32BIT(p, argint); |
| 735 | p += 4; |
| 736 | break; |
| 737 | case PKT_CHAR: |
| 738 | argchar = va_arg(args, unsigned char); |
| 739 | *p = argchar; |
| 740 | p++; |
| 741 | break; |
| 742 | case PKT_DATA: |
| 743 | argp = va_arg(args, unsigned char *); |
| 744 | arglen = va_arg(args, int); |
| 745 | memcpy(p, argp, arglen); |
| 746 | p += arglen; |
| 747 | break; |
| 748 | case PKT_STR: |
| 749 | argp = va_arg(args, unsigned char *); |
| 750 | arglen = strlen(argp); |
| 751 | PUT_32BIT(p, arglen); |
| 752 | memcpy(p + 4, argp, arglen); |
| 753 | p += 4 + arglen; |
| 754 | break; |
| 755 | case PKT_BIGNUM: |
| 756 | bn = va_arg(args, Bignum); |
| 757 | p += ssh1_write_bignum(p, bn); |
| 758 | break; |
| 759 | } |
| 760 | } |
| 761 | va_end(args); |
| 762 | |
| 763 | s_wrpkt(); |
| 764 | } |
| 765 | |
| 766 | static int ssh_versioncmp(char *a, char *b) { |
| 767 | char *ae, *be; |
| 768 | unsigned long av, bv; |
| 769 | |
| 770 | av = strtoul(a, &ae, 10); |
| 771 | bv = strtoul(b, &be, 10); |
| 772 | if (av != bv) return (av < bv ? -1 : +1); |
| 773 | if (*ae == '.') ae++; |
| 774 | if (*be == '.') be++; |
| 775 | av = strtoul(ae, &ae, 10); |
| 776 | bv = strtoul(be, &be, 10); |
| 777 | if (av != bv) return (av < bv ? -1 : +1); |
| 778 | return 0; |
| 779 | } |
| 780 | |
| 781 | |
| 782 | /* |
| 783 | * Utility routine for putting an SSH-protocol `string' into a SHA |
| 784 | * state. |
| 785 | */ |
| 786 | #include <stdio.h> |
| 787 | static void sha_string(SHA_State *s, void *str, int len) { |
| 788 | unsigned char lenblk[4]; |
| 789 | PUT_32BIT(lenblk, len); |
| 790 | SHA_Bytes(s, lenblk, 4); |
| 791 | SHA_Bytes(s, str, len); |
| 792 | } |
| 793 | |
| 794 | /* |
| 795 | * SSH2 packet construction functions. |
| 796 | */ |
| 797 | static void ssh2_pkt_adddata(void *data, int len) { |
| 798 | pktout.length += len; |
| 799 | if (pktout.maxlen < pktout.length) { |
| 800 | pktout.maxlen = pktout.length + 256; |
| 801 | pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) : |
| 802 | srealloc(pktout.data, pktout.maxlen+APIEXTRA)); |
| 803 | if (!pktout.data) |
| 804 | fatalbox("Out of memory"); |
| 805 | } |
| 806 | memcpy(pktout.data+pktout.length-len, data, len); |
| 807 | } |
| 808 | static void ssh2_pkt_addbyte(unsigned char byte) { |
| 809 | ssh2_pkt_adddata(&byte, 1); |
| 810 | } |
| 811 | static void ssh2_pkt_init(int pkt_type) { |
| 812 | pktout.length = 5; |
| 813 | ssh2_pkt_addbyte((unsigned char)pkt_type); |
| 814 | } |
| 815 | static void ssh2_pkt_addbool(unsigned char value) { |
| 816 | ssh2_pkt_adddata(&value, 1); |
| 817 | } |
| 818 | static void ssh2_pkt_adduint32(unsigned long value) { |
| 819 | unsigned char x[4]; |
| 820 | PUT_32BIT(x, value); |
| 821 | ssh2_pkt_adddata(x, 4); |
| 822 | } |
| 823 | static void ssh2_pkt_addstring_start(void) { |
| 824 | ssh2_pkt_adduint32(0); |
| 825 | pktout.savedpos = pktout.length; |
| 826 | } |
| 827 | static void ssh2_pkt_addstring_str(char *data) { |
| 828 | ssh2_pkt_adddata(data, strlen(data)); |
| 829 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 830 | pktout.length - pktout.savedpos); |
| 831 | } |
| 832 | static void ssh2_pkt_addstring_data(char *data, int len) { |
| 833 | ssh2_pkt_adddata(data, len); |
| 834 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 835 | pktout.length - pktout.savedpos); |
| 836 | } |
| 837 | static void ssh2_pkt_addstring(char *data) { |
| 838 | ssh2_pkt_addstring_start(); |
| 839 | ssh2_pkt_addstring_str(data); |
| 840 | } |
| 841 | static char *ssh2_mpint_fmt(Bignum b, int *len) { |
| 842 | unsigned char *p; |
| 843 | int i, n = b[0]; |
| 844 | p = smalloc(n * 2 + 1); |
| 845 | if (!p) |
| 846 | fatalbox("out of memory"); |
| 847 | p[0] = 0; |
| 848 | for (i = 0; i < n; i++) { |
| 849 | p[i*2+1] = (b[n-i] >> 8) & 0xFF; |
| 850 | p[i*2+2] = (b[n-i] ) & 0xFF; |
| 851 | } |
| 852 | i = 0; |
| 853 | while (p[i] == 0 && (p[i+1] & 0x80) == 0) |
| 854 | i++; |
| 855 | memmove(p, p+i, n*2+1-i); |
| 856 | *len = n*2+1-i; |
| 857 | return p; |
| 858 | } |
| 859 | static void ssh2_pkt_addmp(Bignum b) { |
| 860 | unsigned char *p; |
| 861 | int len; |
| 862 | p = ssh2_mpint_fmt(b, &len); |
| 863 | ssh2_pkt_addstring_start(); |
| 864 | ssh2_pkt_addstring_data(p, len); |
| 865 | sfree(p); |
| 866 | } |
| 867 | static void ssh2_pkt_send(void) { |
| 868 | int cipherblk, maclen, padding, i; |
| 869 | static unsigned long outgoing_sequence = 0; |
| 870 | |
| 871 | /* |
| 872 | * Compress packet payload. |
| 873 | */ |
| 874 | #if 0 |
| 875 | debug(("Pre-compression payload:\r\n")); |
| 876 | for (i = 5; i < pktout.length; i++) |
| 877 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 878 | debug(("\r\n")); |
| 879 | #endif |
| 880 | { |
| 881 | unsigned char *newpayload; |
| 882 | int newlen; |
| 883 | if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5, |
| 884 | &newpayload, &newlen)) { |
| 885 | pktout.length = 5; |
| 886 | ssh2_pkt_adddata(newpayload, newlen); |
| 887 | sfree(newpayload); |
| 888 | } |
| 889 | } |
| 890 | |
| 891 | /* |
| 892 | * Add padding. At least four bytes, and must also bring total |
| 893 | * length (minus MAC) up to a multiple of the block size. |
| 894 | */ |
| 895 | cipherblk = cipher ? cipher->blksize : 8; /* block size */ |
| 896 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 897 | padding = 4; |
| 898 | padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
| 899 | pktout.data[4] = padding; |
| 900 | for (i = 0; i < padding; i++) |
| 901 | pktout.data[pktout.length + i] = random_byte(); |
| 902 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
| 903 | if (csmac) |
| 904 | csmac->generate(pktout.data, pktout.length + padding, |
| 905 | outgoing_sequence); |
| 906 | outgoing_sequence++; /* whether or not we MACed */ |
| 907 | |
| 908 | #if 0 |
| 909 | debug(("Sending packet len=%d\r\n", pktout.length+padding)); |
| 910 | for (i = 0; i < pktout.length+padding; i++) |
| 911 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 912 | debug(("\r\n")); |
| 913 | #endif |
| 914 | |
| 915 | if (cscipher) |
| 916 | cscipher->encrypt(pktout.data, pktout.length + padding); |
| 917 | maclen = csmac ? csmac->len : 0; |
| 918 | |
| 919 | sk_write(s, pktout.data, pktout.length + padding + maclen); |
| 920 | } |
| 921 | |
| 922 | #if 0 |
| 923 | void bndebug(char *string, Bignum b) { |
| 924 | unsigned char *p; |
| 925 | int i, len; |
| 926 | p = ssh2_mpint_fmt(b, &len); |
| 927 | debug(("%s", string)); |
| 928 | for (i = 0; i < len; i++) |
| 929 | debug((" %02x", p[i])); |
| 930 | debug(("\r\n")); |
| 931 | sfree(p); |
| 932 | } |
| 933 | #endif |
| 934 | |
| 935 | static void sha_mpint(SHA_State *s, Bignum b) { |
| 936 | unsigned char *p; |
| 937 | int len; |
| 938 | p = ssh2_mpint_fmt(b, &len); |
| 939 | sha_string(s, p, len); |
| 940 | sfree(p); |
| 941 | } |
| 942 | |
| 943 | /* |
| 944 | * SSH2 packet decode functions. |
| 945 | */ |
| 946 | static unsigned long ssh2_pkt_getuint32(void) { |
| 947 | unsigned long value; |
| 948 | if (pktin.length - pktin.savedpos < 4) |
| 949 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 950 | value = GET_32BIT(pktin.data+pktin.savedpos); |
| 951 | pktin.savedpos += 4; |
| 952 | return value; |
| 953 | } |
| 954 | static void ssh2_pkt_getstring(char **p, int *length) { |
| 955 | *p = NULL; |
| 956 | if (pktin.length - pktin.savedpos < 4) |
| 957 | return; |
| 958 | *length = GET_32BIT(pktin.data+pktin.savedpos); |
| 959 | pktin.savedpos += 4; |
| 960 | if (pktin.length - pktin.savedpos < *length) |
| 961 | return; |
| 962 | *p = pktin.data+pktin.savedpos; |
| 963 | pktin.savedpos += *length; |
| 964 | } |
| 965 | static Bignum ssh2_pkt_getmp(void) { |
| 966 | char *p; |
| 967 | int i, j, length; |
| 968 | Bignum b; |
| 969 | |
| 970 | ssh2_pkt_getstring(&p, &length); |
| 971 | if (!p) |
| 972 | return NULL; |
| 973 | if (p[0] & 0x80) { |
| 974 | bombout(("internal error: Can't handle negative mpints")); |
| 975 | return NULL; |
| 976 | } |
| 977 | b = newbn((length+1)/2); |
| 978 | for (i = 0; i < length; i++) { |
| 979 | j = length - 1 - i; |
| 980 | if (j & 1) |
| 981 | b[j/2+1] |= ((unsigned char)p[i]) << 8; |
| 982 | else |
| 983 | b[j/2+1] |= ((unsigned char)p[i]); |
| 984 | } |
| 985 | while (b[0] > 1 && b[b[0]] == 0) b[0]--; |
| 986 | return b; |
| 987 | } |
| 988 | |
| 989 | static int do_ssh_init(unsigned char c) { |
| 990 | static char *vsp; |
| 991 | static char version[10]; |
| 992 | static char vstring[80]; |
| 993 | static char vlog[sizeof(vstring)+20]; |
| 994 | static int i; |
| 995 | |
| 996 | crBegin; |
| 997 | |
| 998 | /* Search for the string "SSH-" in the input. */ |
| 999 | i = 0; |
| 1000 | while (1) { |
| 1001 | static const int transS[] = { 1, 2, 2, 1 }; |
| 1002 | static const int transH[] = { 0, 0, 3, 0 }; |
| 1003 | static const int transminus[] = { 0, 0, 0, -1 }; |
| 1004 | if (c == 'S') i = transS[i]; |
| 1005 | else if (c == 'H') i = transH[i]; |
| 1006 | else if (c == '-') i = transminus[i]; |
| 1007 | else i = 0; |
| 1008 | if (i < 0) |
| 1009 | break; |
| 1010 | crReturn(1); /* get another character */ |
| 1011 | } |
| 1012 | |
| 1013 | strcpy(vstring, "SSH-"); |
| 1014 | vsp = vstring+4; |
| 1015 | i = 0; |
| 1016 | while (1) { |
| 1017 | crReturn(1); /* get another char */ |
| 1018 | if (vsp < vstring+sizeof(vstring)-1) |
| 1019 | *vsp++ = c; |
| 1020 | if (i >= 0) { |
| 1021 | if (c == '-') { |
| 1022 | version[i] = '\0'; |
| 1023 | i = -1; |
| 1024 | } else if (i < sizeof(version)-1) |
| 1025 | version[i++] = c; |
| 1026 | } |
| 1027 | else if (c == '\n') |
| 1028 | break; |
| 1029 | } |
| 1030 | |
| 1031 | ssh_agentfwd_enabled = FALSE; |
| 1032 | rdpkt2_state.incoming_sequence = 0; |
| 1033 | |
| 1034 | *vsp = 0; |
| 1035 | sprintf(vlog, "Server version: %s", vstring); |
| 1036 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 1037 | logevent(vlog); |
| 1038 | |
| 1039 | /* |
| 1040 | * Server version "1.99" means we can choose whether we use v1 |
| 1041 | * or v2 protocol. Choice is based on cfg.sshprot. |
| 1042 | */ |
| 1043 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
| 1044 | /* |
| 1045 | * This is a v2 server. Begin v2 protocol. |
| 1046 | */ |
| 1047 | char *verstring = "SSH-2.0-PuTTY"; |
| 1048 | SHA_Init(&exhashbase); |
| 1049 | /* |
| 1050 | * Hash our version string and their version string. |
| 1051 | */ |
| 1052 | sha_string(&exhashbase, verstring, strlen(verstring)); |
| 1053 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
| 1054 | sprintf(vstring, "%s\n", verstring); |
| 1055 | sprintf(vlog, "We claim version: %s", verstring); |
| 1056 | logevent(vlog); |
| 1057 | logevent("Using SSH protocol version 2"); |
| 1058 | sk_write(s, vstring, strlen(vstring)); |
| 1059 | ssh_protocol = ssh2_protocol; |
| 1060 | ssh_version = 2; |
| 1061 | s_rdpkt = ssh2_rdpkt; |
| 1062 | } else { |
| 1063 | /* |
| 1064 | * This is a v1 server. Begin v1 protocol. |
| 1065 | */ |
| 1066 | sprintf(vstring, "SSH-%s-PuTTY\n", |
| 1067 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5")); |
| 1068 | sprintf(vlog, "We claim version: %s", vstring); |
| 1069 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 1070 | logevent(vlog); |
| 1071 | logevent("Using SSH protocol version 1"); |
| 1072 | sk_write(s, vstring, strlen(vstring)); |
| 1073 | ssh_protocol = ssh1_protocol; |
| 1074 | ssh_version = 1; |
| 1075 | s_rdpkt = ssh1_rdpkt; |
| 1076 | } |
| 1077 | ssh_state = SSH_STATE_BEFORE_SIZE; |
| 1078 | |
| 1079 | crFinish(0); |
| 1080 | } |
| 1081 | |
| 1082 | static void ssh_gotdata(unsigned char *data, int datalen) |
| 1083 | { |
| 1084 | crBegin; |
| 1085 | |
| 1086 | /* |
| 1087 | * To begin with, feed the characters one by one to the |
| 1088 | * protocol initialisation / selection function do_ssh_init(). |
| 1089 | * When that returns 0, we're done with the initial greeting |
| 1090 | * exchange and can move on to packet discipline. |
| 1091 | */ |
| 1092 | while (1) { |
| 1093 | int ret; |
| 1094 | if (datalen == 0) |
| 1095 | crReturnV; /* more data please */ |
| 1096 | ret = do_ssh_init(*data); |
| 1097 | data++; datalen--; |
| 1098 | if (ret == 0) |
| 1099 | break; |
| 1100 | } |
| 1101 | |
| 1102 | /* |
| 1103 | * We emerge from that loop when the initial negotiation is |
| 1104 | * over and we have selected an s_rdpkt function. Now pass |
| 1105 | * everything to s_rdpkt, and then pass the resulting packets |
| 1106 | * to the proper protocol handler. |
| 1107 | */ |
| 1108 | if (datalen == 0) |
| 1109 | crReturnV; |
| 1110 | while (1) { |
| 1111 | while (datalen > 0) { |
| 1112 | if ( s_rdpkt(&data, &datalen) == 0 ) { |
| 1113 | ssh_protocol(NULL, 0, 1); |
| 1114 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1115 | return; |
| 1116 | } |
| 1117 | } |
| 1118 | } |
| 1119 | crReturnV; |
| 1120 | } |
| 1121 | crFinishV; |
| 1122 | } |
| 1123 | |
| 1124 | static int ssh_receive(Socket skt, int urgent, char *data, int len) { |
| 1125 | if (!len) { |
| 1126 | /* Connection has closed. */ |
| 1127 | sk_close(s); |
| 1128 | s = NULL; |
| 1129 | return 0; |
| 1130 | } |
| 1131 | ssh_gotdata (data, len); |
| 1132 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1133 | if (s) { |
| 1134 | sk_close(s); |
| 1135 | s = NULL; |
| 1136 | } |
| 1137 | return 0; |
| 1138 | } |
| 1139 | return 1; |
| 1140 | } |
| 1141 | |
| 1142 | /* |
| 1143 | * Connect to specified host and port. |
| 1144 | * Returns an error message, or NULL on success. |
| 1145 | * Also places the canonical host name into `realhost'. |
| 1146 | */ |
| 1147 | static char *connect_to_host(char *host, int port, char **realhost) |
| 1148 | { |
| 1149 | SockAddr addr; |
| 1150 | char *err; |
| 1151 | #ifdef FWHACK |
| 1152 | char *FWhost; |
| 1153 | int FWport; |
| 1154 | #endif |
| 1155 | |
| 1156 | savedhost = smalloc(1+strlen(host)); |
| 1157 | if (!savedhost) |
| 1158 | fatalbox("Out of memory"); |
| 1159 | strcpy(savedhost, host); |
| 1160 | |
| 1161 | if (port < 0) |
| 1162 | port = 22; /* default ssh port */ |
| 1163 | savedport = port; |
| 1164 | |
| 1165 | #ifdef FWHACK |
| 1166 | FWhost = host; |
| 1167 | FWport = port; |
| 1168 | host = FWSTR; |
| 1169 | port = 23; |
| 1170 | #endif |
| 1171 | |
| 1172 | /* |
| 1173 | * Try to find host. |
| 1174 | */ |
| 1175 | addr = sk_namelookup(host, realhost); |
| 1176 | if ( (err = sk_addr_error(addr)) ) |
| 1177 | return err; |
| 1178 | |
| 1179 | #ifdef FWHACK |
| 1180 | *realhost = FWhost; |
| 1181 | #endif |
| 1182 | |
| 1183 | /* |
| 1184 | * Open socket. |
| 1185 | */ |
| 1186 | s = sk_new(addr, port, ssh_receive); |
| 1187 | if ( (err = sk_socket_error(s)) ) |
| 1188 | return err; |
| 1189 | |
| 1190 | #ifdef FWHACK |
| 1191 | sk_write(s, "connect ", 8); |
| 1192 | sk_write(s, FWhost, strlen(FWhost)); |
| 1193 | { |
| 1194 | char buf[20]; |
| 1195 | sprintf(buf, " %d\n", FWport); |
| 1196 | sk_write(s, buf, strlen(buf)); |
| 1197 | } |
| 1198 | #endif |
| 1199 | |
| 1200 | return NULL; |
| 1201 | } |
| 1202 | |
| 1203 | /* |
| 1204 | * Handle the key exchange and user authentication phases. |
| 1205 | */ |
| 1206 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
| 1207 | { |
| 1208 | int i, j, len; |
| 1209 | unsigned char *rsabuf, *keystr1, *keystr2; |
| 1210 | unsigned char cookie[8]; |
| 1211 | struct RSAKey servkey, hostkey; |
| 1212 | struct MD5Context md5c; |
| 1213 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
| 1214 | static int tried_publickey; |
| 1215 | static unsigned char session_id[16]; |
| 1216 | int cipher_type; |
| 1217 | static char username[100]; |
| 1218 | |
| 1219 | crBegin; |
| 1220 | |
| 1221 | if (!ispkt) crWaitUntil(ispkt); |
| 1222 | |
| 1223 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
| 1224 | bombout(("Public key packet not received")); |
| 1225 | crReturn(0); |
| 1226 | } |
| 1227 | |
| 1228 | logevent("Received public keys"); |
| 1229 | |
| 1230 | memcpy(cookie, pktin.body, 8); |
| 1231 | |
| 1232 | i = makekey(pktin.body+8, &servkey, &keystr1, 0); |
| 1233 | j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); |
| 1234 | |
| 1235 | /* |
| 1236 | * Log the host key fingerprint. |
| 1237 | */ |
| 1238 | { |
| 1239 | char logmsg[80]; |
| 1240 | logevent("Host key fingerprint is:"); |
| 1241 | strcpy(logmsg, " "); |
| 1242 | hostkey.comment = NULL; |
| 1243 | rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg), |
| 1244 | &hostkey); |
| 1245 | logevent(logmsg); |
| 1246 | } |
| 1247 | |
| 1248 | supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); |
| 1249 | supported_auths_mask = GET_32BIT(pktin.body+16+i+j); |
| 1250 | |
| 1251 | MD5Init(&md5c); |
| 1252 | MD5Update(&md5c, keystr2, hostkey.bytes); |
| 1253 | MD5Update(&md5c, keystr1, servkey.bytes); |
| 1254 | MD5Update(&md5c, pktin.body, 8); |
| 1255 | MD5Final(session_id, &md5c); |
| 1256 | |
| 1257 | for (i=0; i<32; i++) |
| 1258 | session_key[i] = random_byte(); |
| 1259 | |
| 1260 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 1261 | |
| 1262 | rsabuf = smalloc(len); |
| 1263 | if (!rsabuf) |
| 1264 | fatalbox("Out of memory"); |
| 1265 | |
| 1266 | /* |
| 1267 | * Verify the host key. |
| 1268 | */ |
| 1269 | { |
| 1270 | /* |
| 1271 | * First format the key into a string. |
| 1272 | */ |
| 1273 | int len = rsastr_len(&hostkey); |
| 1274 | char fingerprint[100]; |
| 1275 | char *keystr = smalloc(len); |
| 1276 | if (!keystr) |
| 1277 | fatalbox("Out of memory"); |
| 1278 | rsastr_fmt(keystr, &hostkey); |
| 1279 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
| 1280 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint); |
| 1281 | sfree(keystr); |
| 1282 | } |
| 1283 | |
| 1284 | for (i=0; i<32; i++) { |
| 1285 | rsabuf[i] = session_key[i]; |
| 1286 | if (i < 16) |
| 1287 | rsabuf[i] ^= session_id[i]; |
| 1288 | } |
| 1289 | |
| 1290 | if (hostkey.bytes > servkey.bytes) { |
| 1291 | rsaencrypt(rsabuf, 32, &servkey); |
| 1292 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
| 1293 | } else { |
| 1294 | rsaencrypt(rsabuf, 32, &hostkey); |
| 1295 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
| 1296 | } |
| 1297 | |
| 1298 | logevent("Encrypted session key"); |
| 1299 | |
| 1300 | cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH : |
| 1301 | cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES : |
| 1302 | SSH_CIPHER_3DES; |
| 1303 | if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { |
| 1304 | c_write("Selected cipher not supported, falling back to 3DES\r\n", 53); |
| 1305 | cipher_type = SSH_CIPHER_3DES; |
| 1306 | } |
| 1307 | switch (cipher_type) { |
| 1308 | case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; |
| 1309 | case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; |
| 1310 | case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; |
| 1311 | } |
| 1312 | |
| 1313 | send_packet(SSH1_CMSG_SESSION_KEY, |
| 1314 | PKT_CHAR, cipher_type, |
| 1315 | PKT_DATA, cookie, 8, |
| 1316 | PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, |
| 1317 | PKT_DATA, rsabuf, len, |
| 1318 | PKT_INT, 0, |
| 1319 | PKT_END); |
| 1320 | |
| 1321 | logevent("Trying to enable encryption..."); |
| 1322 | |
| 1323 | sfree(rsabuf); |
| 1324 | |
| 1325 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
| 1326 | cipher_type == SSH_CIPHER_DES ? &ssh_des : |
| 1327 | &ssh_3des; |
| 1328 | cipher->sesskey(session_key); |
| 1329 | |
| 1330 | crWaitUntil(ispkt); |
| 1331 | |
| 1332 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1333 | bombout(("Encryption not successfully enabled")); |
| 1334 | crReturn(0); |
| 1335 | } |
| 1336 | |
| 1337 | logevent("Successfully started encryption"); |
| 1338 | |
| 1339 | fflush(stdout); |
| 1340 | { |
| 1341 | static int pos = 0; |
| 1342 | static char c; |
| 1343 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 1344 | c_write("login as: ", 10); |
| 1345 | ssh_send_ok = 1; |
| 1346 | while (pos >= 0) { |
| 1347 | crWaitUntil(!ispkt); |
| 1348 | while (inlen--) switch (c = *in++) { |
| 1349 | case 10: case 13: |
| 1350 | username[pos] = 0; |
| 1351 | pos = -1; |
| 1352 | break; |
| 1353 | case 8: case 127: |
| 1354 | if (pos > 0) { |
| 1355 | c_write("\b \b", 3); |
| 1356 | pos--; |
| 1357 | } |
| 1358 | break; |
| 1359 | case 21: case 27: |
| 1360 | while (pos > 0) { |
| 1361 | c_write("\b \b", 3); |
| 1362 | pos--; |
| 1363 | } |
| 1364 | break; |
| 1365 | case 3: case 4: |
| 1366 | random_save_seed(); |
| 1367 | exit(0); |
| 1368 | break; |
| 1369 | default: |
| 1370 | if (((c >= ' ' && c <= '~') || |
| 1371 | ((unsigned char)c >= 160)) && pos < 40) { |
| 1372 | username[pos++] = c; |
| 1373 | c_write(&c, 1); |
| 1374 | } |
| 1375 | break; |
| 1376 | } |
| 1377 | } |
| 1378 | c_write("\r\n", 2); |
| 1379 | username[strcspn(username, "\n\r")] = '\0'; |
| 1380 | } else { |
| 1381 | strncpy(username, cfg.username, 99); |
| 1382 | username[99] = '\0'; |
| 1383 | } |
| 1384 | |
| 1385 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
| 1386 | { |
| 1387 | char userlog[22+sizeof(username)]; |
| 1388 | sprintf(userlog, "Sent username \"%s\"", username); |
| 1389 | logevent(userlog); |
| 1390 | if (flags & FLAG_INTERACTIVE && |
| 1391 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
| 1392 | strcat(userlog, "\r\n"); |
| 1393 | c_write(userlog, strlen(userlog)); |
| 1394 | } |
| 1395 | } |
| 1396 | } |
| 1397 | |
| 1398 | crWaitUntil(ispkt); |
| 1399 | |
| 1400 | tried_publickey = 0; |
| 1401 | |
| 1402 | while (pktin.type == SSH1_SMSG_FAILURE) { |
| 1403 | static char password[100]; |
| 1404 | static char prompt[200]; |
| 1405 | static int pos; |
| 1406 | static char c; |
| 1407 | static int pwpkt_type; |
| 1408 | /* |
| 1409 | * Show password prompt, having first obtained it via a TIS |
| 1410 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
| 1411 | * authentication. |
| 1412 | */ |
| 1413 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 1414 | if (agent_exists()) { |
| 1415 | /* |
| 1416 | * Attempt RSA authentication using Pageant. |
| 1417 | */ |
| 1418 | static unsigned char request[5], *response, *p; |
| 1419 | static int responselen; |
| 1420 | static int i, nkeys; |
| 1421 | static int authed = FALSE; |
| 1422 | void *r; |
| 1423 | |
| 1424 | logevent("Pageant is running. Requesting keys."); |
| 1425 | |
| 1426 | /* Request the keys held by the agent. */ |
| 1427 | PUT_32BIT(request, 1); |
| 1428 | request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES; |
| 1429 | agent_query(request, 5, &r, &responselen); |
| 1430 | response = (unsigned char *)r; |
| 1431 | if (response) { |
| 1432 | p = response + 5; |
| 1433 | nkeys = GET_32BIT(p); p += 4; |
| 1434 | { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys); |
| 1435 | logevent(buf); } |
| 1436 | for (i = 0; i < nkeys; i++) { |
| 1437 | static struct RSAKey key; |
| 1438 | static Bignum challenge; |
| 1439 | static char *commentp; |
| 1440 | static int commentlen; |
| 1441 | |
| 1442 | { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); |
| 1443 | logevent(buf); } |
| 1444 | p += 4; |
| 1445 | p += ssh1_read_bignum(p, &key.exponent); |
| 1446 | p += ssh1_read_bignum(p, &key.modulus); |
| 1447 | commentlen = GET_32BIT(p); p += 4; |
| 1448 | commentp = p; p += commentlen; |
| 1449 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 1450 | PKT_BIGNUM, key.modulus, PKT_END); |
| 1451 | crWaitUntil(ispkt); |
| 1452 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 1453 | logevent("Key refused"); |
| 1454 | continue; |
| 1455 | } |
| 1456 | logevent("Received RSA challenge"); |
| 1457 | ssh1_read_bignum(pktin.body, &challenge); |
| 1458 | { |
| 1459 | char *agentreq, *q, *ret; |
| 1460 | int len, retlen; |
| 1461 | len = 1 + 4; /* message type, bit count */ |
| 1462 | len += ssh1_bignum_length(key.exponent); |
| 1463 | len += ssh1_bignum_length(key.modulus); |
| 1464 | len += ssh1_bignum_length(challenge); |
| 1465 | len += 16; /* session id */ |
| 1466 | len += 4; /* response format */ |
| 1467 | agentreq = smalloc(4 + len); |
| 1468 | PUT_32BIT(agentreq, len); |
| 1469 | q = agentreq + 4; |
| 1470 | *q++ = SSH_AGENTC_RSA_CHALLENGE; |
| 1471 | PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus)); |
| 1472 | q += 4; |
| 1473 | q += ssh1_write_bignum(q, key.exponent); |
| 1474 | q += ssh1_write_bignum(q, key.modulus); |
| 1475 | q += ssh1_write_bignum(q, challenge); |
| 1476 | memcpy(q, session_id, 16); q += 16; |
| 1477 | PUT_32BIT(q, 1); /* response format */ |
| 1478 | agent_query(agentreq, len+4, &ret, &retlen); |
| 1479 | sfree(agentreq); |
| 1480 | if (ret) { |
| 1481 | if (ret[4] == SSH_AGENT_RSA_RESPONSE) { |
| 1482 | logevent("Sending Pageant's response"); |
| 1483 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 1484 | PKT_DATA, ret+5, 16, PKT_END); |
| 1485 | sfree(ret); |
| 1486 | crWaitUntil(ispkt); |
| 1487 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 1488 | logevent("Pageant's response accepted"); |
| 1489 | if (flags & FLAG_VERBOSE) { |
| 1490 | c_write("Authenticated using RSA key \"", |
| 1491 | 29); |
| 1492 | c_write(commentp, commentlen); |
| 1493 | c_write("\" from agent\r\n", 14); |
| 1494 | } |
| 1495 | authed = TRUE; |
| 1496 | } else |
| 1497 | logevent("Pageant's response not accepted"); |
| 1498 | } else { |
| 1499 | logevent("Pageant failed to answer challenge"); |
| 1500 | sfree(ret); |
| 1501 | } |
| 1502 | } else { |
| 1503 | logevent("No reply received from Pageant"); |
| 1504 | } |
| 1505 | } |
| 1506 | freebn(key.exponent); |
| 1507 | freebn(key.modulus); |
| 1508 | freebn(challenge); |
| 1509 | if (authed) |
| 1510 | break; |
| 1511 | } |
| 1512 | } |
| 1513 | if (authed) |
| 1514 | break; |
| 1515 | } |
| 1516 | if (*cfg.keyfile && !tried_publickey) |
| 1517 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
| 1518 | |
| 1519 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 1520 | cfg.try_tis_auth && |
| 1521 | (supported_auths_mask & (1<<SSH1_AUTH_TIS))) { |
| 1522 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 1523 | logevent("Requested TIS authentication"); |
| 1524 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
| 1525 | crWaitUntil(ispkt); |
| 1526 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 1527 | logevent("TIS authentication declined"); |
| 1528 | if (flags & FLAG_INTERACTIVE) |
| 1529 | c_write("TIS authentication refused.\r\n", 29); |
| 1530 | } else { |
| 1531 | int challengelen = ((pktin.body[0] << 24) | |
| 1532 | (pktin.body[1] << 16) | |
| 1533 | (pktin.body[2] << 8) | |
| 1534 | (pktin.body[3])); |
| 1535 | logevent("Received TIS challenge"); |
| 1536 | if (challengelen > sizeof(prompt)-1) |
| 1537 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
| 1538 | memcpy(prompt, pktin.body+4, challengelen); |
| 1539 | prompt[challengelen] = '\0'; |
| 1540 | } |
| 1541 | } |
| 1542 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 1543 | cfg.try_tis_auth && |
| 1544 | (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) { |
| 1545 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
| 1546 | logevent("Requested CryptoCard authentication"); |
| 1547 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
| 1548 | crWaitUntil(ispkt); |
| 1549 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 1550 | logevent("CryptoCard authentication declined"); |
| 1551 | c_write("CryptoCard authentication refused.\r\n", 29); |
| 1552 | } else { |
| 1553 | int challengelen = ((pktin.body[0] << 24) | |
| 1554 | (pktin.body[1] << 16) | |
| 1555 | (pktin.body[2] << 8) | |
| 1556 | (pktin.body[3])); |
| 1557 | logevent("Received CryptoCard challenge"); |
| 1558 | if (challengelen > sizeof(prompt)-1) |
| 1559 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
| 1560 | memcpy(prompt, pktin.body+4, challengelen); |
| 1561 | strncpy(prompt + challengelen, "\r\nResponse : ", |
| 1562 | sizeof(prompt)-challengelen); |
| 1563 | prompt[sizeof(prompt)-1] = '\0'; |
| 1564 | } |
| 1565 | } |
| 1566 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 1567 | sprintf(prompt, "%.90s@%.90s's password: ", |
| 1568 | username, savedhost); |
| 1569 | } |
| 1570 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 1571 | char *comment = NULL; |
| 1572 | if (flags & FLAG_VERBOSE) |
| 1573 | c_write("Trying public key authentication.\r\n", 35); |
| 1574 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
| 1575 | if (flags & FLAG_VERBOSE) |
| 1576 | c_write("No passphrase required.\r\n", 25); |
| 1577 | goto tryauth; |
| 1578 | } |
| 1579 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
| 1580 | sfree(comment); |
| 1581 | } |
| 1582 | |
| 1583 | if (ssh_get_password) { |
| 1584 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
| 1585 | /* |
| 1586 | * get_password failed to get a password (for |
| 1587 | * example because one was supplied on the command |
| 1588 | * line which has already failed to work). |
| 1589 | * Terminate. |
| 1590 | */ |
| 1591 | logevent("No more passwords to try"); |
| 1592 | ssh_state = SSH_STATE_CLOSED; |
| 1593 | crReturn(1); |
| 1594 | } |
| 1595 | } else { |
| 1596 | c_write(prompt, strlen(prompt)); |
| 1597 | pos = 0; |
| 1598 | ssh_send_ok = 1; |
| 1599 | while (pos >= 0) { |
| 1600 | crWaitUntil(!ispkt); |
| 1601 | while (inlen--) switch (c = *in++) { |
| 1602 | case 10: case 13: |
| 1603 | password[pos] = 0; |
| 1604 | pos = -1; |
| 1605 | break; |
| 1606 | case 8: case 127: |
| 1607 | if (pos > 0) |
| 1608 | pos--; |
| 1609 | break; |
| 1610 | case 21: case 27: |
| 1611 | pos = 0; |
| 1612 | break; |
| 1613 | case 3: case 4: |
| 1614 | random_save_seed(); |
| 1615 | exit(0); |
| 1616 | break; |
| 1617 | default: |
| 1618 | if (((c >= ' ' && c <= '~') || |
| 1619 | ((unsigned char)c >= 160)) && pos < sizeof(password)) |
| 1620 | password[pos++] = c; |
| 1621 | break; |
| 1622 | } |
| 1623 | } |
| 1624 | c_write("\r\n", 2); |
| 1625 | } |
| 1626 | |
| 1627 | tryauth: |
| 1628 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 1629 | /* |
| 1630 | * Try public key authentication with the specified |
| 1631 | * key file. |
| 1632 | */ |
| 1633 | static struct RSAKey pubkey; |
| 1634 | static Bignum challenge, response; |
| 1635 | static int i; |
| 1636 | static unsigned char buffer[32]; |
| 1637 | |
| 1638 | tried_publickey = 1; |
| 1639 | i = loadrsakey(cfg.keyfile, &pubkey, NULL, password); |
| 1640 | if (i == 0) { |
| 1641 | c_write("Couldn't load public key from ", 30); |
| 1642 | c_write(cfg.keyfile, strlen(cfg.keyfile)); |
| 1643 | c_write(".\r\n", 3); |
| 1644 | continue; /* go and try password */ |
| 1645 | } |
| 1646 | if (i == -1) { |
| 1647 | c_write("Wrong passphrase.\r\n", 19); |
| 1648 | tried_publickey = 0; |
| 1649 | continue; /* try again */ |
| 1650 | } |
| 1651 | |
| 1652 | /* |
| 1653 | * Send a public key attempt. |
| 1654 | */ |
| 1655 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 1656 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
| 1657 | |
| 1658 | crWaitUntil(ispkt); |
| 1659 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1660 | c_write("Server refused our public key.\r\n", 32); |
| 1661 | continue; /* go and try password */ |
| 1662 | } |
| 1663 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 1664 | bombout(("Bizarre response to offer of public key")); |
| 1665 | crReturn(0); |
| 1666 | } |
| 1667 | ssh1_read_bignum(pktin.body, &challenge); |
| 1668 | response = rsadecrypt(challenge, &pubkey); |
| 1669 | freebn(pubkey.private_exponent); /* burn the evidence */ |
| 1670 | |
| 1671 | for (i = 0; i < 32; i += 2) { |
| 1672 | buffer[i] = response[16-i/2] >> 8; |
| 1673 | buffer[i+1] = response[16-i/2] & 0xFF; |
| 1674 | } |
| 1675 | |
| 1676 | MD5Init(&md5c); |
| 1677 | MD5Update(&md5c, buffer, 32); |
| 1678 | MD5Update(&md5c, session_id, 16); |
| 1679 | MD5Final(buffer, &md5c); |
| 1680 | |
| 1681 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 1682 | PKT_DATA, buffer, 16, PKT_END); |
| 1683 | |
| 1684 | crWaitUntil(ispkt); |
| 1685 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1686 | if (flags & FLAG_VERBOSE) |
| 1687 | c_write("Failed to authenticate with our public key.\r\n", |
| 1688 | 45); |
| 1689 | continue; /* go and try password */ |
| 1690 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1691 | bombout(("Bizarre response to RSA authentication response")); |
| 1692 | crReturn(0); |
| 1693 | } |
| 1694 | |
| 1695 | break; /* we're through! */ |
| 1696 | } else { |
| 1697 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
| 1698 | } |
| 1699 | logevent("Sent password"); |
| 1700 | memset(password, 0, strlen(password)); |
| 1701 | crWaitUntil(ispkt); |
| 1702 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1703 | if (flags & FLAG_VERBOSE) |
| 1704 | c_write("Access denied\r\n", 15); |
| 1705 | logevent("Authentication refused"); |
| 1706 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 1707 | logevent("Received disconnect request"); |
| 1708 | ssh_state = SSH_STATE_CLOSED; |
| 1709 | crReturn(1); |
| 1710 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1711 | bombout(("Strange packet received, type %d", pktin.type)); |
| 1712 | crReturn(0); |
| 1713 | } |
| 1714 | } |
| 1715 | |
| 1716 | logevent("Authentication successful"); |
| 1717 | |
| 1718 | crFinish(1); |
| 1719 | } |
| 1720 | |
| 1721 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { |
| 1722 | crBegin; |
| 1723 | |
| 1724 | random_init(); |
| 1725 | |
| 1726 | while (!do_ssh1_login(in, inlen, ispkt)) { |
| 1727 | crReturnV; |
| 1728 | } |
| 1729 | if (ssh_state == SSH_STATE_CLOSED) |
| 1730 | crReturnV; |
| 1731 | |
| 1732 | if (cfg.agentfwd && agent_exists()) { |
| 1733 | logevent("Requesting agent forwarding"); |
| 1734 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
| 1735 | do { crReturnV; } while (!ispkt); |
| 1736 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1737 | bombout(("Protocol confusion")); |
| 1738 | crReturnV; |
| 1739 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1740 | logevent("Agent forwarding refused"); |
| 1741 | } else { |
| 1742 | logevent("Agent forwarding enabled"); |
| 1743 | ssh_agentfwd_enabled = TRUE; |
| 1744 | } |
| 1745 | } |
| 1746 | |
| 1747 | if (!cfg.nopty) { |
| 1748 | send_packet(SSH1_CMSG_REQUEST_PTY, |
| 1749 | PKT_STR, cfg.termtype, |
| 1750 | PKT_INT, rows, PKT_INT, cols, |
| 1751 | PKT_INT, 0, PKT_INT, 0, |
| 1752 | PKT_CHAR, 0, |
| 1753 | PKT_END); |
| 1754 | ssh_state = SSH_STATE_INTERMED; |
| 1755 | do { crReturnV; } while (!ispkt); |
| 1756 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1757 | bombout(("Protocol confusion")); |
| 1758 | crReturnV; |
| 1759 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1760 | c_write("Server refused to allocate pty\r\n", 32); |
| 1761 | } |
| 1762 | logevent("Allocated pty"); |
| 1763 | } |
| 1764 | |
| 1765 | if (cfg.compression) { |
| 1766 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
| 1767 | do { crReturnV; } while (!ispkt); |
| 1768 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1769 | bombout(("Protocol confusion")); |
| 1770 | crReturnV; |
| 1771 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1772 | c_write("Server refused to compress\r\n", 32); |
| 1773 | } |
| 1774 | logevent("Started compression"); |
| 1775 | ssh1_compressing = TRUE; |
| 1776 | zlib_compress_init(); |
| 1777 | zlib_decompress_init(); |
| 1778 | } |
| 1779 | |
| 1780 | if (*cfg.remote_cmd) |
| 1781 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END); |
| 1782 | else |
| 1783 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 1784 | logevent("Started session"); |
| 1785 | |
| 1786 | ssh_state = SSH_STATE_SESSION; |
| 1787 | if (size_needed) |
| 1788 | ssh_size(); |
| 1789 | if (eof_needed) |
| 1790 | ssh_special(TS_EOF); |
| 1791 | |
| 1792 | ssh_send_ok = 1; |
| 1793 | ssh_channels = newtree234(ssh_channelcmp); |
| 1794 | begin_session(); |
| 1795 | while (1) { |
| 1796 | crReturnV; |
| 1797 | if (ispkt) { |
| 1798 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 1799 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 1800 | long len = GET_32BIT(pktin.body); |
| 1801 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
| 1802 | pktin.body+4, len); |
| 1803 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 1804 | ssh_state = SSH_STATE_CLOSED; |
| 1805 | logevent("Received disconnect request"); |
| 1806 | crReturnV; |
| 1807 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
| 1808 | /* Remote side is trying to open a channel to talk to our |
| 1809 | * agent. Give them back a local channel number. */ |
| 1810 | unsigned i; |
| 1811 | struct ssh_channel *c; |
| 1812 | enum234 e; |
| 1813 | |
| 1814 | /* Refuse if agent forwarding is disabled. */ |
| 1815 | if (!ssh_agentfwd_enabled) { |
| 1816 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 1817 | PKT_INT, GET_32BIT(pktin.body), |
| 1818 | PKT_END); |
| 1819 | } else { |
| 1820 | i = 1; |
| 1821 | for (c = first234(ssh_channels, &e); c; c = next234(&e)) { |
| 1822 | if (c->localid > i) |
| 1823 | break; /* found a free number */ |
| 1824 | i = c->localid + 1; |
| 1825 | } |
| 1826 | c = smalloc(sizeof(struct ssh_channel)); |
| 1827 | c->remoteid = GET_32BIT(pktin.body); |
| 1828 | c->localid = i; |
| 1829 | c->closes = 0; |
| 1830 | c->type = SSH1_SMSG_AGENT_OPEN;/* identify channel type */ |
| 1831 | c->u.a.lensofar = 0; |
| 1832 | add234(ssh_channels, c); |
| 1833 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 1834 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 1835 | PKT_END); |
| 1836 | } |
| 1837 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
| 1838 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
| 1839 | /* Remote side closes a channel. */ |
| 1840 | unsigned i = GET_32BIT(pktin.body); |
| 1841 | struct ssh_channel *c; |
| 1842 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 1843 | if (c) { |
| 1844 | int closetype; |
| 1845 | closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
| 1846 | send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END); |
| 1847 | c->closes |= closetype; |
| 1848 | if (c->closes == 3) { |
| 1849 | del234(ssh_channels, c); |
| 1850 | sfree(c); |
| 1851 | } |
| 1852 | } |
| 1853 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
| 1854 | /* Data sent down one of our channels. */ |
| 1855 | int i = GET_32BIT(pktin.body); |
| 1856 | int len = GET_32BIT(pktin.body+4); |
| 1857 | unsigned char *p = pktin.body+8; |
| 1858 | struct ssh_channel *c; |
| 1859 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 1860 | if (c) { |
| 1861 | switch(c->type) { |
| 1862 | case SSH1_SMSG_AGENT_OPEN: |
| 1863 | /* Data for an agent message. Buffer it. */ |
| 1864 | while (len > 0) { |
| 1865 | if (c->u.a.lensofar < 4) { |
| 1866 | int l = min(4 - c->u.a.lensofar, len); |
| 1867 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, l); |
| 1868 | p += l; len -= l; c->u.a.lensofar += l; |
| 1869 | } |
| 1870 | if (c->u.a.lensofar == 4) { |
| 1871 | c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen); |
| 1872 | c->u.a.message = smalloc(c->u.a.totallen); |
| 1873 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 1874 | } |
| 1875 | if (c->u.a.lensofar >= 4 && len > 0) { |
| 1876 | int l = min(c->u.a.totallen - c->u.a.lensofar, len); |
| 1877 | memcpy(c->u.a.message + c->u.a.lensofar, p, l); |
| 1878 | p += l; len -= l; c->u.a.lensofar += l; |
| 1879 | } |
| 1880 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 1881 | void *reply, *sentreply; |
| 1882 | int replylen; |
| 1883 | agent_query(c->u.a.message, c->u.a.totallen, |
| 1884 | &reply, &replylen); |
| 1885 | if (reply) |
| 1886 | sentreply = reply; |
| 1887 | else { |
| 1888 | /* Fake SSH_AGENT_FAILURE. */ |
| 1889 | sentreply = "\0\0\0\1\5"; |
| 1890 | replylen = 5; |
| 1891 | } |
| 1892 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 1893 | PKT_INT, c->remoteid, |
| 1894 | PKT_INT, replylen, |
| 1895 | PKT_DATA, sentreply, replylen, |
| 1896 | PKT_END); |
| 1897 | if (reply) |
| 1898 | sfree(reply); |
| 1899 | sfree(c->u.a.message); |
| 1900 | c->u.a.lensofar = 0; |
| 1901 | } |
| 1902 | } |
| 1903 | break; |
| 1904 | } |
| 1905 | } |
| 1906 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 1907 | /* may be from EXEC_SHELL on some servers */ |
| 1908 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1909 | /* may be from EXEC_SHELL on some servers |
| 1910 | * if no pty is available or in other odd cases. Ignore */ |
| 1911 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 1912 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 1913 | } else { |
| 1914 | bombout(("Strange packet received: type %d", pktin.type)); |
| 1915 | crReturnV; |
| 1916 | } |
| 1917 | } else { |
| 1918 | while (inlen > 0) { |
| 1919 | int len = min(inlen, 512); |
| 1920 | send_packet(SSH1_CMSG_STDIN_DATA, |
| 1921 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
| 1922 | in += len; |
| 1923 | inlen -= len; |
| 1924 | } |
| 1925 | } |
| 1926 | } |
| 1927 | |
| 1928 | crFinishV; |
| 1929 | } |
| 1930 | |
| 1931 | /* |
| 1932 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 1933 | */ |
| 1934 | static int in_commasep_string(char *needle, char *haystack, int haylen) { |
| 1935 | int needlen = strlen(needle); |
| 1936 | while (1) { |
| 1937 | /* |
| 1938 | * Is it at the start of the string? |
| 1939 | */ |
| 1940 | if (haylen >= needlen && /* haystack is long enough */ |
| 1941 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 1942 | (haylen == needlen || haystack[needlen] == ',') |
| 1943 | /* either , or EOS follows */ |
| 1944 | ) |
| 1945 | return 1; |
| 1946 | /* |
| 1947 | * If not, search for the next comma and resume after that. |
| 1948 | * If no comma found, terminate. |
| 1949 | */ |
| 1950 | while (haylen > 0 && *haystack != ',') |
| 1951 | haylen--, haystack++; |
| 1952 | if (haylen == 0) |
| 1953 | return 0; |
| 1954 | haylen--, haystack++; /* skip over comma itself */ |
| 1955 | } |
| 1956 | } |
| 1957 | |
| 1958 | /* |
| 1959 | * SSH2 key creation method. |
| 1960 | */ |
| 1961 | static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) { |
| 1962 | SHA_State s; |
| 1963 | /* First 20 bytes. */ |
| 1964 | SHA_Init(&s); |
| 1965 | sha_mpint(&s, K); |
| 1966 | SHA_Bytes(&s, H, 20); |
| 1967 | SHA_Bytes(&s, &chr, 1); |
| 1968 | SHA_Bytes(&s, H, 20); |
| 1969 | SHA_Final(&s, keyspace); |
| 1970 | /* Next 20 bytes. */ |
| 1971 | SHA_Init(&s); |
| 1972 | sha_mpint(&s, K); |
| 1973 | SHA_Bytes(&s, H, 20); |
| 1974 | SHA_Bytes(&s, keyspace, 20); |
| 1975 | SHA_Final(&s, keyspace+20); |
| 1976 | } |
| 1977 | |
| 1978 | /* |
| 1979 | * Handle the SSH2 transport layer. |
| 1980 | */ |
| 1981 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
| 1982 | { |
| 1983 | static int i, len; |
| 1984 | static char *str; |
| 1985 | static Bignum e, f, K; |
| 1986 | static const struct ssh_mac **maclist; |
| 1987 | static int nmacs; |
| 1988 | static const struct ssh_cipher *cscipher_tobe = NULL; |
| 1989 | static const struct ssh_cipher *sccipher_tobe = NULL; |
| 1990 | static const struct ssh_mac *csmac_tobe = NULL; |
| 1991 | static const struct ssh_mac *scmac_tobe = NULL; |
| 1992 | static const struct ssh_compress *cscomp_tobe = NULL; |
| 1993 | static const struct ssh_compress *sccomp_tobe = NULL; |
| 1994 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
| 1995 | static int hostkeylen, siglen; |
| 1996 | static void *hkey; /* actual host key */ |
| 1997 | static unsigned char exchange_hash[20]; |
| 1998 | static unsigned char keyspace[40]; |
| 1999 | static const struct ssh_cipher *preferred_cipher; |
| 2000 | static const struct ssh_compress *preferred_comp; |
| 2001 | static int first_kex; |
| 2002 | |
| 2003 | crBegin; |
| 2004 | random_init(); |
| 2005 | first_kex = 1; |
| 2006 | |
| 2007 | /* |
| 2008 | * Set up the preferred cipher and compression. |
| 2009 | */ |
| 2010 | if (cfg.cipher == CIPHER_BLOWFISH) { |
| 2011 | preferred_cipher = &ssh_blowfish_ssh2; |
| 2012 | } else if (cfg.cipher == CIPHER_DES) { |
| 2013 | logevent("Single DES not supported in SSH2; using 3DES"); |
| 2014 | preferred_cipher = &ssh_3des_ssh2; |
| 2015 | } else if (cfg.cipher == CIPHER_3DES) { |
| 2016 | preferred_cipher = &ssh_3des_ssh2; |
| 2017 | } else { |
| 2018 | /* Shouldn't happen, but we do want to initialise to _something_. */ |
| 2019 | preferred_cipher = &ssh_3des_ssh2; |
| 2020 | } |
| 2021 | if (cfg.compression) |
| 2022 | preferred_comp = &ssh_zlib; |
| 2023 | else |
| 2024 | preferred_comp = &ssh_comp_none; |
| 2025 | |
| 2026 | /* |
| 2027 | * Be prepared to work around the buggy MAC problem. |
| 2028 | */ |
| 2029 | if (cfg.buggymac) |
| 2030 | maclist = buggymacs, nmacs = lenof(buggymacs); |
| 2031 | else |
| 2032 | maclist = macs, nmacs = lenof(macs); |
| 2033 | |
| 2034 | begin_key_exchange: |
| 2035 | /* |
| 2036 | * Construct and send our key exchange packet. |
| 2037 | */ |
| 2038 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
| 2039 | for (i = 0; i < 16; i++) |
| 2040 | ssh2_pkt_addbyte((unsigned char)random_byte()); |
| 2041 | /* List key exchange algorithms. */ |
| 2042 | ssh2_pkt_addstring_start(); |
| 2043 | for (i = 0; i < lenof(kex_algs); i++) { |
| 2044 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
| 2045 | if (i < lenof(kex_algs)-1) |
| 2046 | ssh2_pkt_addstring_str(","); |
| 2047 | } |
| 2048 | /* List server host key algorithms. */ |
| 2049 | ssh2_pkt_addstring_start(); |
| 2050 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 2051 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
| 2052 | if (i < lenof(hostkey_algs)-1) |
| 2053 | ssh2_pkt_addstring_str(","); |
| 2054 | } |
| 2055 | /* List client->server encryption algorithms. */ |
| 2056 | ssh2_pkt_addstring_start(); |
| 2057 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2058 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2059 | ssh2_pkt_addstring_str(c->name); |
| 2060 | if (i < lenof(ciphers)) |
| 2061 | ssh2_pkt_addstring_str(","); |
| 2062 | } |
| 2063 | /* List server->client encryption algorithms. */ |
| 2064 | ssh2_pkt_addstring_start(); |
| 2065 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2066 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2067 | ssh2_pkt_addstring_str(c->name); |
| 2068 | if (i < lenof(ciphers)) |
| 2069 | ssh2_pkt_addstring_str(","); |
| 2070 | } |
| 2071 | /* List client->server MAC algorithms. */ |
| 2072 | ssh2_pkt_addstring_start(); |
| 2073 | for (i = 0; i < nmacs; i++) { |
| 2074 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 2075 | if (i < nmacs-1) |
| 2076 | ssh2_pkt_addstring_str(","); |
| 2077 | } |
| 2078 | /* List server->client MAC algorithms. */ |
| 2079 | ssh2_pkt_addstring_start(); |
| 2080 | for (i = 0; i < nmacs; i++) { |
| 2081 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 2082 | if (i < nmacs-1) |
| 2083 | ssh2_pkt_addstring_str(","); |
| 2084 | } |
| 2085 | /* List client->server compression algorithms. */ |
| 2086 | ssh2_pkt_addstring_start(); |
| 2087 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2088 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2089 | ssh2_pkt_addstring_str(c->name); |
| 2090 | if (i < lenof(compressions)) |
| 2091 | ssh2_pkt_addstring_str(","); |
| 2092 | } |
| 2093 | /* List server->client compression algorithms. */ |
| 2094 | ssh2_pkt_addstring_start(); |
| 2095 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2096 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2097 | ssh2_pkt_addstring_str(c->name); |
| 2098 | if (i < lenof(compressions)) |
| 2099 | ssh2_pkt_addstring_str(","); |
| 2100 | } |
| 2101 | /* List client->server languages. Empty list. */ |
| 2102 | ssh2_pkt_addstring_start(); |
| 2103 | /* List server->client languages. Empty list. */ |
| 2104 | ssh2_pkt_addstring_start(); |
| 2105 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 2106 | ssh2_pkt_addbool(FALSE); |
| 2107 | /* Reserved. */ |
| 2108 | ssh2_pkt_adduint32(0); |
| 2109 | |
| 2110 | exhash = exhashbase; |
| 2111 | sha_string(&exhash, pktout.data+5, pktout.length-5); |
| 2112 | |
| 2113 | ssh2_pkt_send(); |
| 2114 | |
| 2115 | if (!ispkt) crWaitUntil(ispkt); |
| 2116 | sha_string(&exhash, pktin.data+5, pktin.length-5); |
| 2117 | |
| 2118 | /* |
| 2119 | * Now examine the other side's KEXINIT to see what we're up |
| 2120 | * to. |
| 2121 | */ |
| 2122 | if (pktin.type != SSH2_MSG_KEXINIT) { |
| 2123 | bombout(("expected key exchange packet from server")); |
| 2124 | crReturn(0); |
| 2125 | } |
| 2126 | kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; |
| 2127 | csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; |
| 2128 | pktin.savedpos += 16; /* skip garbage cookie */ |
| 2129 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
| 2130 | for (i = 0; i < lenof(kex_algs); i++) { |
| 2131 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
| 2132 | kex = kex_algs[i]; |
| 2133 | break; |
| 2134 | } |
| 2135 | } |
| 2136 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
| 2137 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 2138 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 2139 | hostkey = hostkey_algs[i]; |
| 2140 | break; |
| 2141 | } |
| 2142 | } |
| 2143 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
| 2144 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2145 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2146 | if (in_commasep_string(c->name, str, len)) { |
| 2147 | cscipher_tobe = c; |
| 2148 | break; |
| 2149 | } |
| 2150 | } |
| 2151 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
| 2152 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2153 | const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2154 | if (in_commasep_string(c->name, str, len)) { |
| 2155 | sccipher_tobe = c; |
| 2156 | break; |
| 2157 | } |
| 2158 | } |
| 2159 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
| 2160 | for (i = 0; i < nmacs; i++) { |
| 2161 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 2162 | csmac_tobe = maclist[i]; |
| 2163 | break; |
| 2164 | } |
| 2165 | } |
| 2166 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
| 2167 | for (i = 0; i < nmacs; i++) { |
| 2168 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 2169 | scmac_tobe = maclist[i]; |
| 2170 | break; |
| 2171 | } |
| 2172 | } |
| 2173 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
| 2174 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2175 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2176 | if (in_commasep_string(c->name, str, len)) { |
| 2177 | cscomp_tobe = c; |
| 2178 | break; |
| 2179 | } |
| 2180 | } |
| 2181 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
| 2182 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2183 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2184 | if (in_commasep_string(c->name, str, len)) { |
| 2185 | sccomp_tobe = c; |
| 2186 | break; |
| 2187 | } |
| 2188 | } |
| 2189 | |
| 2190 | /* |
| 2191 | * Currently we only support Diffie-Hellman and DSS, so let's |
| 2192 | * bomb out if those aren't selected. |
| 2193 | */ |
| 2194 | if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) { |
| 2195 | bombout(("internal fault: chaos in SSH 2 transport layer")); |
| 2196 | crReturn(0); |
| 2197 | } |
| 2198 | |
| 2199 | /* |
| 2200 | * Now we begin the fun. Generate and send e for Diffie-Hellman. |
| 2201 | */ |
| 2202 | e = dh_create_e(); |
| 2203 | ssh2_pkt_init(SSH2_MSG_KEXDH_INIT); |
| 2204 | ssh2_pkt_addmp(e); |
| 2205 | ssh2_pkt_send(); |
| 2206 | |
| 2207 | crWaitUntil(ispkt); |
| 2208 | if (pktin.type != SSH2_MSG_KEXDH_REPLY) { |
| 2209 | bombout(("expected key exchange packet from server")); |
| 2210 | crReturn(0); |
| 2211 | } |
| 2212 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
| 2213 | f = ssh2_pkt_getmp(); |
| 2214 | ssh2_pkt_getstring(&sigdata, &siglen); |
| 2215 | |
| 2216 | K = dh_find_K(f); |
| 2217 | |
| 2218 | sha_string(&exhash, hostkeydata, hostkeylen); |
| 2219 | sha_mpint(&exhash, e); |
| 2220 | sha_mpint(&exhash, f); |
| 2221 | sha_mpint(&exhash, K); |
| 2222 | SHA_Final(&exhash, exchange_hash); |
| 2223 | |
| 2224 | #if 0 |
| 2225 | debug(("Exchange hash is:\r\n")); |
| 2226 | for (i = 0; i < 20; i++) |
| 2227 | debug((" %02x", exchange_hash[i])); |
| 2228 | debug(("\r\n")); |
| 2229 | #endif |
| 2230 | |
| 2231 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
| 2232 | if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
| 2233 | bombout(("Server failed host key check")); |
| 2234 | crReturn(0); |
| 2235 | } |
| 2236 | |
| 2237 | /* |
| 2238 | * Expect SSH2_MSG_NEWKEYS from server. |
| 2239 | */ |
| 2240 | crWaitUntil(ispkt); |
| 2241 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
| 2242 | bombout(("expected new-keys packet from server")); |
| 2243 | crReturn(0); |
| 2244 | } |
| 2245 | |
| 2246 | /* |
| 2247 | * Authenticate remote host: verify host key. (We've already |
| 2248 | * checked the signature of the exchange hash.) |
| 2249 | */ |
| 2250 | keystr = hostkey->fmtkey(hkey); |
| 2251 | fingerprint = hostkey->fingerprint(hkey); |
| 2252 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
| 2253 | keystr, fingerprint); |
| 2254 | logevent("Host key fingerprint is:"); |
| 2255 | logevent(fingerprint); |
| 2256 | sfree(fingerprint); |
| 2257 | sfree(keystr); |
| 2258 | hostkey->freekey(hkey); |
| 2259 | |
| 2260 | /* |
| 2261 | * Send SSH2_MSG_NEWKEYS. |
| 2262 | */ |
| 2263 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
| 2264 | ssh2_pkt_send(); |
| 2265 | |
| 2266 | /* |
| 2267 | * Create and initialise session keys. |
| 2268 | */ |
| 2269 | cscipher = cscipher_tobe; |
| 2270 | sccipher = sccipher_tobe; |
| 2271 | csmac = csmac_tobe; |
| 2272 | scmac = scmac_tobe; |
| 2273 | cscomp = cscomp_tobe; |
| 2274 | sccomp = sccomp_tobe; |
| 2275 | cscomp->compress_init(); |
| 2276 | sccomp->decompress_init(); |
| 2277 | /* |
| 2278 | * Set IVs after keys. |
| 2279 | */ |
| 2280 | ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace); |
| 2281 | ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace); |
| 2282 | ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace); |
| 2283 | ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace); |
| 2284 | ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace); |
| 2285 | ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace); |
| 2286 | |
| 2287 | /* |
| 2288 | * If this is the first key exchange phase, we must pass the |
| 2289 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
| 2290 | * wants to see it but because it will need time to initialise |
| 2291 | * itself before it sees an actual packet. In subsequent key |
| 2292 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
| 2293 | * it would only confuse the layer above. |
| 2294 | */ |
| 2295 | if (!first_kex) { |
| 2296 | crReturn(0); |
| 2297 | } |
| 2298 | first_kex = 0; |
| 2299 | |
| 2300 | /* |
| 2301 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 2302 | * function so that other things can run on top of the |
| 2303 | * transport. If we ever see a KEXINIT, we must go back to the |
| 2304 | * start. |
| 2305 | */ |
| 2306 | do { |
| 2307 | crReturn(1); |
| 2308 | } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)); |
| 2309 | goto begin_key_exchange; |
| 2310 | |
| 2311 | crFinish(1); |
| 2312 | } |
| 2313 | |
| 2314 | /* |
| 2315 | * Handle the SSH2 userauth and connection layers. |
| 2316 | */ |
| 2317 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
| 2318 | { |
| 2319 | static unsigned long remote_winsize; |
| 2320 | static unsigned long remote_maxpkt; |
| 2321 | |
| 2322 | crBegin; |
| 2323 | |
| 2324 | /* |
| 2325 | * Request userauth protocol, and await a response to it. |
| 2326 | */ |
| 2327 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 2328 | ssh2_pkt_addstring("ssh-userauth"); |
| 2329 | ssh2_pkt_send(); |
| 2330 | crWaitUntilV(ispkt); |
| 2331 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
| 2332 | bombout(("Server refused user authentication protocol")); |
| 2333 | crReturnV; |
| 2334 | } |
| 2335 | |
| 2336 | /* |
| 2337 | * FIXME: currently we support only password authentication. |
| 2338 | * (This places us technically in violation of the SSH2 spec. |
| 2339 | * We must fix this.) |
| 2340 | */ |
| 2341 | while (1) { |
| 2342 | /* |
| 2343 | * Get a username and a password. |
| 2344 | */ |
| 2345 | static char username[100]; |
| 2346 | static char password[100]; |
| 2347 | static int pos = 0; |
| 2348 | static char c; |
| 2349 | |
| 2350 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 2351 | c_write("login as: ", 10); |
| 2352 | ssh_send_ok = 1; |
| 2353 | while (pos >= 0) { |
| 2354 | crWaitUntilV(!ispkt); |
| 2355 | while (inlen--) switch (c = *in++) { |
| 2356 | case 10: case 13: |
| 2357 | username[pos] = 0; |
| 2358 | pos = -1; |
| 2359 | break; |
| 2360 | case 8: case 127: |
| 2361 | if (pos > 0) { |
| 2362 | c_write("\b \b", 3); |
| 2363 | pos--; |
| 2364 | } |
| 2365 | break; |
| 2366 | case 21: case 27: |
| 2367 | while (pos > 0) { |
| 2368 | c_write("\b \b", 3); |
| 2369 | pos--; |
| 2370 | } |
| 2371 | break; |
| 2372 | case 3: case 4: |
| 2373 | random_save_seed(); |
| 2374 | exit(0); |
| 2375 | break; |
| 2376 | default: |
| 2377 | if (((c >= ' ' && c <= '~') || |
| 2378 | ((unsigned char)c >= 160)) && pos < 40) { |
| 2379 | username[pos++] = c; |
| 2380 | c_write(&c, 1); |
| 2381 | } |
| 2382 | break; |
| 2383 | } |
| 2384 | } |
| 2385 | c_write("\r\n", 2); |
| 2386 | username[strcspn(username, "\n\r")] = '\0'; |
| 2387 | } else { |
| 2388 | char stuff[200]; |
| 2389 | strncpy(username, cfg.username, 99); |
| 2390 | username[99] = '\0'; |
| 2391 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
| 2392 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
| 2393 | c_write(stuff, strlen(stuff)); |
| 2394 | } |
| 2395 | } |
| 2396 | |
| 2397 | if (ssh_get_password) { |
| 2398 | char prompt[200]; |
| 2399 | sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost); |
| 2400 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
| 2401 | /* |
| 2402 | * get_password failed to get a password (for |
| 2403 | * example because one was supplied on the command |
| 2404 | * line which has already failed to work). |
| 2405 | * Terminate. |
| 2406 | */ |
| 2407 | logevent("No more passwords to try"); |
| 2408 | ssh_state = SSH_STATE_CLOSED; |
| 2409 | crReturnV; |
| 2410 | } |
| 2411 | } else { |
| 2412 | c_write("password: ", 10); |
| 2413 | ssh_send_ok = 1; |
| 2414 | |
| 2415 | pos = 0; |
| 2416 | while (pos >= 0) { |
| 2417 | crWaitUntilV(!ispkt); |
| 2418 | while (inlen--) switch (c = *in++) { |
| 2419 | case 10: case 13: |
| 2420 | password[pos] = 0; |
| 2421 | pos = -1; |
| 2422 | break; |
| 2423 | case 8: case 127: |
| 2424 | if (pos > 0) |
| 2425 | pos--; |
| 2426 | break; |
| 2427 | case 21: case 27: |
| 2428 | pos = 0; |
| 2429 | break; |
| 2430 | case 3: case 4: |
| 2431 | random_save_seed(); |
| 2432 | exit(0); |
| 2433 | break; |
| 2434 | default: |
| 2435 | if (((c >= ' ' && c <= '~') || |
| 2436 | ((unsigned char)c >= 160)) && pos < 40) |
| 2437 | password[pos++] = c; |
| 2438 | break; |
| 2439 | } |
| 2440 | } |
| 2441 | c_write("\r\n", 2); |
| 2442 | } |
| 2443 | |
| 2444 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 2445 | ssh2_pkt_addstring(username); |
| 2446 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 2447 | ssh2_pkt_addstring("password"); |
| 2448 | ssh2_pkt_addbool(FALSE); |
| 2449 | ssh2_pkt_addstring(password); |
| 2450 | ssh2_pkt_send(); |
| 2451 | |
| 2452 | crWaitUntilV(ispkt); |
| 2453 | if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) { |
| 2454 | c_write("Access denied\r\n", 15); |
| 2455 | logevent("Authentication refused"); |
| 2456 | } else |
| 2457 | break; |
| 2458 | } |
| 2459 | |
| 2460 | /* |
| 2461 | * Now we're authenticated for the connection protocol. The |
| 2462 | * connection protocol will automatically have started at this |
| 2463 | * point; there's no need to send SERVICE_REQUEST. |
| 2464 | */ |
| 2465 | |
| 2466 | /* |
| 2467 | * So now create a channel with a session in it. |
| 2468 | */ |
| 2469 | mainchan = smalloc(sizeof(struct ssh_channel)); |
| 2470 | mainchan->localid = 100; /* as good as any */ |
| 2471 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 2472 | ssh2_pkt_addstring("session"); |
| 2473 | ssh2_pkt_adduint32(mainchan->localid); |
| 2474 | ssh2_pkt_adduint32(0x8000UL); /* our window size */ |
| 2475 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 2476 | ssh2_pkt_send(); |
| 2477 | crWaitUntilV(ispkt); |
| 2478 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 2479 | bombout(("Server refused to open a session")); |
| 2480 | crReturnV; |
| 2481 | /* FIXME: error data comes back in FAILURE packet */ |
| 2482 | } |
| 2483 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
| 2484 | bombout(("Server's channel confirmation cited wrong channel")); |
| 2485 | crReturnV; |
| 2486 | } |
| 2487 | mainchan->remoteid = ssh2_pkt_getuint32(); |
| 2488 | mainchan->u.v2.remwindow = ssh2_pkt_getuint32(); |
| 2489 | mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 2490 | mainchan->u.v2.outbuffer = NULL; |
| 2491 | mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0; |
| 2492 | logevent("Opened channel for session"); |
| 2493 | |
| 2494 | /* |
| 2495 | * Now allocate a pty for the session. |
| 2496 | */ |
| 2497 | if (!cfg.nopty) { |
| 2498 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 2499 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 2500 | ssh2_pkt_addstring("pty-req"); |
| 2501 | ssh2_pkt_addbool(1); /* want reply */ |
| 2502 | ssh2_pkt_addstring(cfg.termtype); |
| 2503 | ssh2_pkt_adduint32(cols); |
| 2504 | ssh2_pkt_adduint32(rows); |
| 2505 | ssh2_pkt_adduint32(0); /* pixel width */ |
| 2506 | ssh2_pkt_adduint32(0); /* pixel height */ |
| 2507 | ssh2_pkt_addstring_start(); |
| 2508 | ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */ |
| 2509 | ssh2_pkt_send(); |
| 2510 | ssh_state = SSH_STATE_INTERMED; |
| 2511 | |
| 2512 | do { |
| 2513 | crWaitUntilV(ispkt); |
| 2514 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 2515 | /* FIXME: be able to handle other channels here */ |
| 2516 | if (ssh2_pkt_getuint32() != mainchan->localid) |
| 2517 | continue; /* wrong channel */ |
| 2518 | mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); |
| 2519 | } |
| 2520 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 2521 | |
| 2522 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 2523 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 2524 | bombout(("Server got confused by pty request")); |
| 2525 | crReturnV; |
| 2526 | } |
| 2527 | c_write("Server refused to allocate pty\r\n", 32); |
| 2528 | } else { |
| 2529 | logevent("Allocated pty"); |
| 2530 | } |
| 2531 | } |
| 2532 | |
| 2533 | /* |
| 2534 | * Start a shell or a remote command. |
| 2535 | */ |
| 2536 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 2537 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 2538 | if (*cfg.remote_cmd) { |
| 2539 | ssh2_pkt_addstring("exec"); |
| 2540 | ssh2_pkt_addbool(1); /* want reply */ |
| 2541 | ssh2_pkt_addstring(cfg.remote_cmd); |
| 2542 | } else { |
| 2543 | ssh2_pkt_addstring("shell"); |
| 2544 | ssh2_pkt_addbool(1); /* want reply */ |
| 2545 | } |
| 2546 | ssh2_pkt_send(); |
| 2547 | do { |
| 2548 | crWaitUntilV(ispkt); |
| 2549 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 2550 | /* FIXME: be able to handle other channels here */ |
| 2551 | if (ssh2_pkt_getuint32() != mainchan->localid) |
| 2552 | continue; /* wrong channel */ |
| 2553 | mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); |
| 2554 | } |
| 2555 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 2556 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 2557 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 2558 | bombout(("Server got confused by shell/command request")); |
| 2559 | crReturnV; |
| 2560 | } |
| 2561 | bombout(("Server refused to start a shell/command")); |
| 2562 | crReturnV; |
| 2563 | } else { |
| 2564 | logevent("Started a shell/command"); |
| 2565 | } |
| 2566 | |
| 2567 | ssh_state = SSH_STATE_SESSION; |
| 2568 | if (size_needed) |
| 2569 | ssh_size(); |
| 2570 | if (eof_needed) |
| 2571 | ssh_special(TS_EOF); |
| 2572 | |
| 2573 | /* |
| 2574 | * Transfer data! |
| 2575 | */ |
| 2576 | ssh_send_ok = 1; |
| 2577 | begin_session(); |
| 2578 | while (1) { |
| 2579 | static int try_send; |
| 2580 | crReturnV; |
| 2581 | try_send = FALSE; |
| 2582 | if (ispkt) { |
| 2583 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
| 2584 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 2585 | char *data; |
| 2586 | int length; |
| 2587 | /* FIXME: be able to handle other channels here */ |
| 2588 | if (ssh2_pkt_getuint32() != mainchan->localid) |
| 2589 | continue; /* wrong channel */ |
| 2590 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 2591 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
| 2592 | continue; /* extended but not stderr */ |
| 2593 | ssh2_pkt_getstring(&data, &length); |
| 2594 | if (data) { |
| 2595 | from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, |
| 2596 | data, length); |
| 2597 | /* |
| 2598 | * Enlarge the window again at the remote side, |
| 2599 | * just in case it ever runs down and they fail |
| 2600 | * to send us any more data. |
| 2601 | */ |
| 2602 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 2603 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 2604 | ssh2_pkt_adduint32(length); |
| 2605 | ssh2_pkt_send(); |
| 2606 | } |
| 2607 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
| 2608 | ssh_state = SSH_STATE_CLOSED; |
| 2609 | logevent("Received disconnect message"); |
| 2610 | crReturnV; |
| 2611 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
| 2612 | continue; /* exit status et al; ignore (FIXME?) */ |
| 2613 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
| 2614 | continue; /* remote sends EOF; ignore */ |
| 2615 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
| 2616 | /* FIXME: be able to handle other channels here */ |
| 2617 | if (ssh2_pkt_getuint32() != mainchan->localid) |
| 2618 | continue; /* wrong channel */ |
| 2619 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 2620 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 2621 | ssh2_pkt_send(); |
| 2622 | /* FIXME: mark the channel as closed */ |
| 2623 | if (1 /* FIXME: "all channels are closed" */) { |
| 2624 | logevent("All channels closed. Disconnecting"); |
| 2625 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 2626 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 2627 | ssh2_pkt_addstring("All open channels closed"); |
| 2628 | ssh2_pkt_addstring("en"); /* language tag */ |
| 2629 | ssh2_pkt_send(); |
| 2630 | ssh_state = SSH_STATE_CLOSED; |
| 2631 | crReturnV; |
| 2632 | } |
| 2633 | continue; /* remote sends close; ignore (FIXME) */ |
| 2634 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 2635 | /* FIXME: be able to handle other channels here */ |
| 2636 | if (ssh2_pkt_getuint32() != mainchan->localid) |
| 2637 | continue; /* wrong channel */ |
| 2638 | mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); |
| 2639 | try_send = TRUE; |
| 2640 | } else { |
| 2641 | bombout(("Strange packet received: type %d", pktin.type)); |
| 2642 | crReturnV; |
| 2643 | } |
| 2644 | } else { |
| 2645 | /* |
| 2646 | * We have spare data. Add it to the channel buffer. |
| 2647 | */ |
| 2648 | if (mainchan->u.v2.outbufsize < |
| 2649 | mainchan->u.v2.outbuflen + inlen) { |
| 2650 | mainchan->u.v2.outbufsize = |
| 2651 | mainchan->u.v2.outbuflen + inlen + 1024; |
| 2652 | mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer, |
| 2653 | mainchan->u.v2.outbufsize); |
| 2654 | } |
| 2655 | memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen, |
| 2656 | in, inlen); |
| 2657 | mainchan->u.v2.outbuflen += inlen; |
| 2658 | try_send = TRUE; |
| 2659 | } |
| 2660 | if (try_send) { |
| 2661 | /* |
| 2662 | * Try to send data on the channel if we can. (FIXME: |
| 2663 | * on _all_ channels.) |
| 2664 | */ |
| 2665 | while (mainchan->u.v2.remwindow > 0 && |
| 2666 | mainchan->u.v2.outbuflen > 0) { |
| 2667 | unsigned len = mainchan->u.v2.remwindow; |
| 2668 | if (len > mainchan->u.v2.outbuflen) |
| 2669 | len = mainchan->u.v2.outbuflen; |
| 2670 | if (len > mainchan->u.v2.remmaxpkt) |
| 2671 | len = mainchan->u.v2.remmaxpkt; |
| 2672 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
| 2673 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 2674 | ssh2_pkt_addstring_start(); |
| 2675 | ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len); |
| 2676 | ssh2_pkt_send(); |
| 2677 | mainchan->u.v2.outbuflen -= len; |
| 2678 | memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len, |
| 2679 | mainchan->u.v2.outbuflen); |
| 2680 | mainchan->u.v2.remwindow -= len; |
| 2681 | } |
| 2682 | } |
| 2683 | } |
| 2684 | |
| 2685 | crFinishV; |
| 2686 | } |
| 2687 | |
| 2688 | /* |
| 2689 | * Handle the top-level SSH2 protocol. |
| 2690 | */ |
| 2691 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
| 2692 | { |
| 2693 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
| 2694 | return; |
| 2695 | do_ssh2_authconn(in, inlen, ispkt); |
| 2696 | } |
| 2697 | |
| 2698 | /* |
| 2699 | * Called to set up the connection. |
| 2700 | * |
| 2701 | * Returns an error message, or NULL on success. |
| 2702 | */ |
| 2703 | static char *ssh_init (char *host, int port, char **realhost) { |
| 2704 | char *p; |
| 2705 | |
| 2706 | #ifdef MSCRYPTOAPI |
| 2707 | if(crypto_startup() == 0) |
| 2708 | return "Microsoft high encryption pack not installed!"; |
| 2709 | #endif |
| 2710 | |
| 2711 | ssh_send_ok = 0; |
| 2712 | |
| 2713 | p = connect_to_host(host, port, realhost); |
| 2714 | if (p != NULL) |
| 2715 | return p; |
| 2716 | |
| 2717 | return NULL; |
| 2718 | } |
| 2719 | |
| 2720 | /* |
| 2721 | * Called to send data down the Telnet connection. |
| 2722 | */ |
| 2723 | static void ssh_send (char *buf, int len) { |
| 2724 | if (s == NULL || ssh_protocol == NULL) |
| 2725 | return; |
| 2726 | |
| 2727 | ssh_protocol(buf, len, 0); |
| 2728 | } |
| 2729 | |
| 2730 | /* |
| 2731 | * Called to set the size of the window from SSH's POV. |
| 2732 | */ |
| 2733 | static void ssh_size(void) { |
| 2734 | switch (ssh_state) { |
| 2735 | case SSH_STATE_BEFORE_SIZE: |
| 2736 | case SSH_STATE_PREPACKET: |
| 2737 | case SSH_STATE_CLOSED: |
| 2738 | break; /* do nothing */ |
| 2739 | case SSH_STATE_INTERMED: |
| 2740 | size_needed = TRUE; /* buffer for later */ |
| 2741 | break; |
| 2742 | case SSH_STATE_SESSION: |
| 2743 | if (!cfg.nopty) { |
| 2744 | if (ssh_version == 1) { |
| 2745 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
| 2746 | PKT_INT, rows, PKT_INT, cols, |
| 2747 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 2748 | } else { |
| 2749 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 2750 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 2751 | ssh2_pkt_addstring("window-change"); |
| 2752 | ssh2_pkt_addbool(0); |
| 2753 | ssh2_pkt_adduint32(cols); |
| 2754 | ssh2_pkt_adduint32(rows); |
| 2755 | ssh2_pkt_adduint32(0); |
| 2756 | ssh2_pkt_adduint32(0); |
| 2757 | ssh2_pkt_send(); |
| 2758 | } |
| 2759 | } |
| 2760 | break; |
| 2761 | } |
| 2762 | } |
| 2763 | |
| 2764 | /* |
| 2765 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
| 2766 | * can send an EOF and collect resulting output (e.g. `plink |
| 2767 | * hostname sort'). |
| 2768 | */ |
| 2769 | static void ssh_special (Telnet_Special code) { |
| 2770 | if (code == TS_EOF) { |
| 2771 | if (ssh_state != SSH_STATE_SESSION) { |
| 2772 | /* |
| 2773 | * Buffer the EOF in case we are pre-SESSION, so we can |
| 2774 | * send it as soon as we reach SESSION. |
| 2775 | */ |
| 2776 | if (code == TS_EOF) |
| 2777 | eof_needed = TRUE; |
| 2778 | return; |
| 2779 | } |
| 2780 | if (ssh_version == 1) { |
| 2781 | send_packet(SSH1_CMSG_EOF, PKT_END); |
| 2782 | } else { |
| 2783 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
| 2784 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 2785 | ssh2_pkt_send(); |
| 2786 | } |
| 2787 | logevent("Sent EOF message"); |
| 2788 | } else if (code == TS_PING) { |
| 2789 | if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET) |
| 2790 | return; |
| 2791 | if (ssh_version == 1) { |
| 2792 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
| 2793 | } else { |
| 2794 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 2795 | ssh2_pkt_addstring_start(); |
| 2796 | ssh2_pkt_send(); |
| 2797 | } |
| 2798 | } else { |
| 2799 | /* do nothing */ |
| 2800 | } |
| 2801 | } |
| 2802 | |
| 2803 | static Socket ssh_socket(void) { return s; } |
| 2804 | |
| 2805 | static int ssh_sendok(void) { return ssh_send_ok; } |
| 2806 | |
| 2807 | Backend ssh_backend = { |
| 2808 | ssh_init, |
| 2809 | ssh_send, |
| 2810 | ssh_size, |
| 2811 | ssh_special, |
| 2812 | ssh_socket, |
| 2813 | ssh_sendok, |
| 2814 | 22 |
| 2815 | }; |