| 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, \ |
| 23 | (s ? sk_close(s), s = NULL : 0), \ |
| 24 | connection_fatal msg ) |
| 25 | |
| 26 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
| 27 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
| 28 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
| 29 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
| 30 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
| 31 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
| 32 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
| 33 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
| 34 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
| 35 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
| 36 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
| 37 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
| 38 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
| 39 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
| 40 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
| 41 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
| 42 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
| 43 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
| 44 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
| 45 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
| 46 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
| 47 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
| 48 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
| 49 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
| 50 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
| 51 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
| 52 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
| 53 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
| 54 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
| 55 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
| 56 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
| 57 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
| 58 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
| 59 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
| 60 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
| 61 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
| 62 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
| 63 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
| 64 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
| 65 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
| 66 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
| 67 | |
| 68 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
| 69 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
| 70 | |
| 71 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
| 72 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
| 73 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
| 74 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
| 75 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
| 76 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
| 77 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
| 78 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
| 79 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
| 80 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
| 81 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
| 82 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
| 83 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
| 84 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
| 85 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
| 86 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
| 87 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
| 88 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
| 89 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
| 90 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
| 91 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
| 92 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
| 93 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
| 94 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
| 95 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
| 96 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
| 97 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
| 98 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
| 99 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
| 100 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
| 101 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
| 102 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
| 103 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
| 104 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
| 105 | |
| 106 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
| 107 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
| 108 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
| 109 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
| 110 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
| 111 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
| 112 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
| 113 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
| 114 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
| 115 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
| 116 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
| 117 | |
| 118 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
| 119 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
| 120 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
| 121 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
| 122 | |
| 123 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
| 124 | |
| 125 | #define GET_32BIT(cp) \ |
| 126 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
| 127 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 128 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 129 | ((unsigned long)(unsigned char)(cp)[3])) |
| 130 | |
| 131 | #define PUT_32BIT(cp, value) { \ |
| 132 | (cp)[0] = (unsigned char)((value) >> 24); \ |
| 133 | (cp)[1] = (unsigned char)((value) >> 16); \ |
| 134 | (cp)[2] = (unsigned char)((value) >> 8); \ |
| 135 | (cp)[3] = (unsigned char)(value); } |
| 136 | |
| 137 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
| 138 | |
| 139 | /* Coroutine mechanics for the sillier bits of the code */ |
| 140 | #define crBegin1 static int crLine = 0; |
| 141 | #define crBegin2 switch(crLine) { case 0:; |
| 142 | #define crBegin crBegin1; crBegin2; |
| 143 | #define crFinish(z) } crLine = 0; return (z) |
| 144 | #define crFinishV } crLine = 0; return |
| 145 | #define crReturn(z) \ |
| 146 | do {\ |
| 147 | crLine=__LINE__; return (z); case __LINE__:;\ |
| 148 | } while (0) |
| 149 | #define crReturnV \ |
| 150 | do {\ |
| 151 | crLine=__LINE__; return; case __LINE__:;\ |
| 152 | } while (0) |
| 153 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
| 154 | #define crStopV do{ crLine = 0; return; }while(0) |
| 155 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 156 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 157 | |
| 158 | extern char *x11_init (Socket *, char *, void *); |
| 159 | extern void x11_close (Socket); |
| 160 | extern void x11_send (Socket , char *, int); |
| 161 | extern void x11_invent_auth(char *, int, char *, int); |
| 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 ssh2_ciphers *ciphers[] = { |
| 170 | &ssh2_aes, |
| 171 | &ssh2_blowfish, |
| 172 | &ssh2_3des, |
| 173 | }; |
| 174 | |
| 175 | const static struct ssh_kex *kex_algs[] = { |
| 176 | #ifdef DO_DIFFIE_HELLMAN_GEX |
| 177 | &ssh_diffiehellman_gex, |
| 178 | #endif |
| 179 | &ssh_diffiehellman }; |
| 180 | |
| 181 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
| 182 | |
| 183 | static void nullmac_key(unsigned char *key) { } |
| 184 | static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } |
| 185 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } |
| 186 | const static struct ssh_mac ssh_mac_none = { |
| 187 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
| 188 | }; |
| 189 | const static struct ssh_mac *macs[] = { |
| 190 | &ssh_sha1, &ssh_md5, &ssh_mac_none }; |
| 191 | const static struct ssh_mac *buggymacs[] = { |
| 192 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none }; |
| 193 | |
| 194 | static void ssh_comp_none_init(void) { } |
| 195 | static int ssh_comp_none_block(unsigned char *block, int len, |
| 196 | unsigned char **outblock, int *outlen) { |
| 197 | return 0; |
| 198 | } |
| 199 | const static struct ssh_compress ssh_comp_none = { |
| 200 | "none", |
| 201 | ssh_comp_none_init, ssh_comp_none_block, |
| 202 | ssh_comp_none_init, ssh_comp_none_block |
| 203 | }; |
| 204 | extern const struct ssh_compress ssh_zlib; |
| 205 | const static struct ssh_compress *compressions[] = { |
| 206 | &ssh_zlib, &ssh_comp_none }; |
| 207 | |
| 208 | enum { /* channel types */ |
| 209 | CHAN_MAINSESSION, |
| 210 | CHAN_X11, |
| 211 | CHAN_AGENT, |
| 212 | }; |
| 213 | |
| 214 | /* |
| 215 | * 2-3-4 tree storing channels. |
| 216 | */ |
| 217 | struct ssh_channel { |
| 218 | unsigned remoteid, localid; |
| 219 | int type; |
| 220 | int closes; |
| 221 | struct ssh2_data_channel { |
| 222 | unsigned char *outbuffer; |
| 223 | unsigned outbuflen, outbufsize; |
| 224 | unsigned remwindow, remmaxpkt; |
| 225 | } v2; |
| 226 | union { |
| 227 | struct ssh_agent_channel { |
| 228 | unsigned char *message; |
| 229 | unsigned char msglen[4]; |
| 230 | int lensofar, totallen; |
| 231 | } a; |
| 232 | struct ssh_x11_channel { |
| 233 | Socket s; |
| 234 | } x11; |
| 235 | } u; |
| 236 | }; |
| 237 | |
| 238 | struct Packet { |
| 239 | long length; |
| 240 | int type; |
| 241 | unsigned char *data; |
| 242 | unsigned char *body; |
| 243 | long savedpos; |
| 244 | long maxlen; |
| 245 | }; |
| 246 | |
| 247 | static SHA_State exhash, exhashbase; |
| 248 | |
| 249 | static Socket s = NULL; |
| 250 | |
| 251 | static unsigned char session_key[32]; |
| 252 | static int ssh1_compressing; |
| 253 | static int ssh_agentfwd_enabled; |
| 254 | static int ssh_X11_fwd_enabled; |
| 255 | static const struct ssh_cipher *cipher = NULL; |
| 256 | static const struct ssh2_cipher *cscipher = NULL; |
| 257 | static const struct ssh2_cipher *sccipher = NULL; |
| 258 | static const struct ssh_mac *csmac = NULL; |
| 259 | static const struct ssh_mac *scmac = NULL; |
| 260 | static const struct ssh_compress *cscomp = NULL; |
| 261 | static const struct ssh_compress *sccomp = NULL; |
| 262 | static const struct ssh_kex *kex = NULL; |
| 263 | static const struct ssh_signkey *hostkey = NULL; |
| 264 | static unsigned char ssh2_session_id[20]; |
| 265 | int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL; |
| 266 | |
| 267 | static char *savedhost; |
| 268 | static int savedport; |
| 269 | static int ssh_send_ok; |
| 270 | static int ssh_echoing, ssh_editing; |
| 271 | |
| 272 | static tree234 *ssh_channels; /* indexed by local id */ |
| 273 | static struct ssh_channel *mainchan; /* primary session channel */ |
| 274 | |
| 275 | static enum { |
| 276 | SSH_STATE_PREPACKET, |
| 277 | SSH_STATE_BEFORE_SIZE, |
| 278 | SSH_STATE_INTERMED, |
| 279 | SSH_STATE_SESSION, |
| 280 | SSH_STATE_CLOSED |
| 281 | } ssh_state = SSH_STATE_PREPACKET; |
| 282 | |
| 283 | static int size_needed = FALSE, eof_needed = FALSE; |
| 284 | |
| 285 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
| 286 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
| 287 | static unsigned char *deferred_send_data = NULL; |
| 288 | static int deferred_len = 0, deferred_size = 0; |
| 289 | |
| 290 | static int ssh_version; |
| 291 | static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt); |
| 292 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
| 293 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
| 294 | static void ssh_size(void); |
| 295 | static void ssh_special (Telnet_Special); |
| 296 | static void ssh2_try_send(struct ssh_channel *c); |
| 297 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); |
| 298 | |
| 299 | static int (*s_rdpkt)(unsigned char **data, int *datalen); |
| 300 | |
| 301 | static struct rdpkt1_state_tag { |
| 302 | long len, pad, biglen, to_read; |
| 303 | unsigned long realcrc, gotcrc; |
| 304 | unsigned char *p; |
| 305 | int i; |
| 306 | int chunk; |
| 307 | } rdpkt1_state; |
| 308 | |
| 309 | static struct rdpkt2_state_tag { |
| 310 | long len, pad, payload, packetlen, maclen; |
| 311 | int i; |
| 312 | int cipherblk; |
| 313 | unsigned long incoming_sequence; |
| 314 | } rdpkt2_state; |
| 315 | |
| 316 | static int ssh_channelcmp(void *av, void *bv) { |
| 317 | struct ssh_channel *a = (struct ssh_channel *)av; |
| 318 | struct ssh_channel *b = (struct ssh_channel *)bv; |
| 319 | if (a->localid < b->localid) return -1; |
| 320 | if (a->localid > b->localid) return +1; |
| 321 | return 0; |
| 322 | } |
| 323 | static int ssh_channelfind(void *av, void *bv) { |
| 324 | unsigned *a = (unsigned *)av; |
| 325 | struct ssh_channel *b = (struct ssh_channel *)bv; |
| 326 | if (*a < b->localid) return -1; |
| 327 | if (*a > b->localid) return +1; |
| 328 | return 0; |
| 329 | } |
| 330 | |
| 331 | static void c_write (char *buf, int len) { |
| 332 | if ((flags & FLAG_STDERR)) { |
| 333 | int i; |
| 334 | for (i = 0; i < len; i++) |
| 335 | if (buf[i] != '\r') |
| 336 | fputc(buf[i], stderr); |
| 337 | return; |
| 338 | } |
| 339 | from_backend(1, buf, len); |
| 340 | } |
| 341 | |
| 342 | static void c_write_str (char *buf) { |
| 343 | c_write(buf, strlen(buf)); |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * Collect incoming data in the incoming packet buffer. |
| 348 | * Decipher and verify the packet when it is completely read. |
| 349 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 350 | * Update the *data and *datalen variables. |
| 351 | * Return the additional nr of bytes needed, or 0 when |
| 352 | * a complete packet is available. |
| 353 | */ |
| 354 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
| 355 | { |
| 356 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
| 357 | |
| 358 | crBegin; |
| 359 | |
| 360 | next_packet: |
| 361 | |
| 362 | pktin.type = 0; |
| 363 | pktin.length = 0; |
| 364 | |
| 365 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
| 366 | while ((*datalen) == 0) |
| 367 | crReturn(4-st->i); |
| 368 | st->len = (st->len << 8) + **data; |
| 369 | (*data)++, (*datalen)--; |
| 370 | } |
| 371 | |
| 372 | #ifdef FWHACK |
| 373 | if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ |
| 374 | st->len = 0x300; /* big enough to carry to end */ |
| 375 | } |
| 376 | #endif |
| 377 | |
| 378 | st->pad = 8 - (st->len % 8); |
| 379 | st->biglen = st->len + st->pad; |
| 380 | pktin.length = st->len - 5; |
| 381 | |
| 382 | if (pktin.maxlen < st->biglen) { |
| 383 | pktin.maxlen = st->biglen; |
| 384 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) : |
| 385 | srealloc(pktin.data, st->biglen+APIEXTRA)); |
| 386 | if (!pktin.data) |
| 387 | fatalbox("Out of memory"); |
| 388 | } |
| 389 | |
| 390 | st->to_read = st->biglen; |
| 391 | st->p = pktin.data; |
| 392 | while (st->to_read > 0) { |
| 393 | st->chunk = st->to_read; |
| 394 | while ((*datalen) == 0) |
| 395 | crReturn(st->to_read); |
| 396 | if (st->chunk > (*datalen)) |
| 397 | st->chunk = (*datalen); |
| 398 | memcpy(st->p, *data, st->chunk); |
| 399 | *data += st->chunk; |
| 400 | *datalen -= st->chunk; |
| 401 | st->p += st->chunk; |
| 402 | st->to_read -= st->chunk; |
| 403 | } |
| 404 | |
| 405 | if (cipher) |
| 406 | cipher->decrypt(pktin.data, st->biglen); |
| 407 | #if 0 |
| 408 | debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); |
| 409 | for (st->i = 0; st->i < st->biglen; st->i++) |
| 410 | debug((" %02x", (unsigned char)pktin.data[st->i])); |
| 411 | debug(("\r\n")); |
| 412 | #endif |
| 413 | |
| 414 | st->realcrc = crc32(pktin.data, st->biglen-4); |
| 415 | st->gotcrc = GET_32BIT(pktin.data+st->biglen-4); |
| 416 | if (st->gotcrc != st->realcrc) { |
| 417 | bombout(("Incorrect CRC received on packet")); |
| 418 | crReturn(0); |
| 419 | } |
| 420 | |
| 421 | pktin.body = pktin.data + st->pad + 1; |
| 422 | |
| 423 | if (ssh1_compressing) { |
| 424 | unsigned char *decompblk; |
| 425 | int decomplen; |
| 426 | #if 0 |
| 427 | int i; |
| 428 | debug(("Packet payload pre-decompression:\n")); |
| 429 | for (i = -1; i < pktin.length; i++) |
| 430 | debug((" %02x", (unsigned char)pktin.body[i])); |
| 431 | debug(("\r\n")); |
| 432 | #endif |
| 433 | zlib_decompress_block(pktin.body-1, pktin.length+1, |
| 434 | &decompblk, &decomplen); |
| 435 | |
| 436 | if (pktin.maxlen < st->pad + decomplen) { |
| 437 | pktin.maxlen = st->pad + decomplen; |
| 438 | pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA); |
| 439 | pktin.body = pktin.data + st->pad + 1; |
| 440 | if (!pktin.data) |
| 441 | fatalbox("Out of memory"); |
| 442 | } |
| 443 | |
| 444 | memcpy(pktin.body-1, decompblk, decomplen); |
| 445 | sfree(decompblk); |
| 446 | pktin.length = decomplen-1; |
| 447 | #if 0 |
| 448 | debug(("Packet payload post-decompression:\n")); |
| 449 | for (i = -1; i < pktin.length; i++) |
| 450 | debug((" %02x", (unsigned char)pktin.body[i])); |
| 451 | debug(("\r\n")); |
| 452 | #endif |
| 453 | } |
| 454 | |
| 455 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 456 | pktin.type == SSH1_SMSG_STDERR_DATA || |
| 457 | pktin.type == SSH1_MSG_DEBUG || |
| 458 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
| 459 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 460 | long strlen = GET_32BIT(pktin.body); |
| 461 | if (strlen + 4 != pktin.length) { |
| 462 | bombout(("Received data packet with bogus string length")); |
| 463 | crReturn(0); |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | pktin.type = pktin.body[-1]; |
| 468 | |
| 469 | if (pktin.type == SSH1_MSG_DEBUG) { |
| 470 | /* log debug message */ |
| 471 | char buf[80]; |
| 472 | int strlen = GET_32BIT(pktin.body); |
| 473 | strcpy(buf, "Remote: "); |
| 474 | if (strlen > 70) strlen = 70; |
| 475 | memcpy(buf+8, pktin.body+4, strlen); |
| 476 | buf[8+strlen] = '\0'; |
| 477 | logevent(buf); |
| 478 | goto next_packet; |
| 479 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
| 480 | /* do nothing */ |
| 481 | goto next_packet; |
| 482 | } |
| 483 | |
| 484 | crFinish(0); |
| 485 | } |
| 486 | |
| 487 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
| 488 | { |
| 489 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
| 490 | |
| 491 | crBegin; |
| 492 | |
| 493 | next_packet: |
| 494 | pktin.type = 0; |
| 495 | pktin.length = 0; |
| 496 | if (sccipher) |
| 497 | st->cipherblk = sccipher->blksize; |
| 498 | else |
| 499 | st->cipherblk = 8; |
| 500 | if (st->cipherblk < 8) |
| 501 | st->cipherblk = 8; |
| 502 | |
| 503 | if (pktin.maxlen < st->cipherblk) { |
| 504 | pktin.maxlen = st->cipherblk; |
| 505 | pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) : |
| 506 | srealloc(pktin.data, st->cipherblk+APIEXTRA)); |
| 507 | if (!pktin.data) |
| 508 | fatalbox("Out of memory"); |
| 509 | } |
| 510 | |
| 511 | /* |
| 512 | * Acquire and decrypt the first block of the packet. This will |
| 513 | * contain the length and padding details. |
| 514 | */ |
| 515 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
| 516 | while ((*datalen) == 0) |
| 517 | crReturn(st->cipherblk-st->i); |
| 518 | pktin.data[st->i] = *(*data)++; |
| 519 | (*datalen)--; |
| 520 | } |
| 521 | #ifdef FWHACK |
| 522 | if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */ |
| 523 | /* FIXME */ |
| 524 | } |
| 525 | #endif |
| 526 | if (sccipher) |
| 527 | sccipher->decrypt(pktin.data, st->cipherblk); |
| 528 | |
| 529 | /* |
| 530 | * Now get the length and padding figures. |
| 531 | */ |
| 532 | st->len = GET_32BIT(pktin.data); |
| 533 | st->pad = pktin.data[4]; |
| 534 | |
| 535 | /* |
| 536 | * This enables us to deduce the payload length. |
| 537 | */ |
| 538 | st->payload = st->len - st->pad - 1; |
| 539 | |
| 540 | pktin.length = st->payload + 5; |
| 541 | |
| 542 | /* |
| 543 | * So now we can work out the total packet length. |
| 544 | */ |
| 545 | st->packetlen = st->len + 4; |
| 546 | st->maclen = scmac ? scmac->len : 0; |
| 547 | |
| 548 | /* |
| 549 | * Adjust memory allocation if packet is too big. |
| 550 | */ |
| 551 | if (pktin.maxlen < st->packetlen+st->maclen) { |
| 552 | pktin.maxlen = st->packetlen+st->maclen; |
| 553 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
| 554 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
| 555 | if (!pktin.data) |
| 556 | fatalbox("Out of memory"); |
| 557 | } |
| 558 | |
| 559 | /* |
| 560 | * Read and decrypt the remainder of the packet. |
| 561 | */ |
| 562 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { |
| 563 | while ((*datalen) == 0) |
| 564 | crReturn(st->packetlen + st->maclen - st->i); |
| 565 | pktin.data[st->i] = *(*data)++; |
| 566 | (*datalen)--; |
| 567 | } |
| 568 | /* Decrypt everything _except_ the MAC. */ |
| 569 | if (sccipher) |
| 570 | sccipher->decrypt(pktin.data + st->cipherblk, |
| 571 | st->packetlen - st->cipherblk); |
| 572 | |
| 573 | #if 0 |
| 574 | debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); |
| 575 | for (st->i = 0; st->i < st->packetlen; st->i++) |
| 576 | debug((" %02x", (unsigned char)pktin.data[st->i])); |
| 577 | debug(("\r\n")); |
| 578 | #endif |
| 579 | |
| 580 | /* |
| 581 | * Check the MAC. |
| 582 | */ |
| 583 | if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) { |
| 584 | bombout(("Incorrect MAC received on packet")); |
| 585 | crReturn(0); |
| 586 | } |
| 587 | st->incoming_sequence++; /* whether or not we MACed */ |
| 588 | |
| 589 | /* |
| 590 | * Decompress packet payload. |
| 591 | */ |
| 592 | { |
| 593 | unsigned char *newpayload; |
| 594 | int newlen; |
| 595 | if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5, |
| 596 | &newpayload, &newlen)) { |
| 597 | if (pktin.maxlen < newlen+5) { |
| 598 | pktin.maxlen = newlen+5; |
| 599 | pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) : |
| 600 | srealloc(pktin.data, pktin.maxlen+APIEXTRA)); |
| 601 | if (!pktin.data) |
| 602 | fatalbox("Out of memory"); |
| 603 | } |
| 604 | pktin.length = 5 + newlen; |
| 605 | memcpy(pktin.data+5, newpayload, newlen); |
| 606 | #if 0 |
| 607 | debug(("Post-decompression payload:\r\n")); |
| 608 | for (st->i = 0; st->i < newlen; st->i++) |
| 609 | debug((" %02x", (unsigned char)pktin.data[5+st->i])); |
| 610 | debug(("\r\n")); |
| 611 | #endif |
| 612 | |
| 613 | sfree(newpayload); |
| 614 | } |
| 615 | } |
| 616 | |
| 617 | pktin.savedpos = 6; |
| 618 | pktin.type = pktin.data[5]; |
| 619 | |
| 620 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
| 621 | goto next_packet; /* FIXME: print DEBUG message */ |
| 622 | |
| 623 | crFinish(0); |
| 624 | } |
| 625 | |
| 626 | static void ssh1_pktout_size(int len) { |
| 627 | int pad, biglen; |
| 628 | |
| 629 | len += 5; /* type and CRC */ |
| 630 | pad = 8 - (len%8); |
| 631 | biglen = len + pad; |
| 632 | |
| 633 | pktout.length = len-5; |
| 634 | if (pktout.maxlen < biglen) { |
| 635 | pktout.maxlen = biglen; |
| 636 | #ifdef MSCRYPTOAPI |
| 637 | /* Allocate enough buffer space for extra block |
| 638 | * for MS CryptEncrypt() */ |
| 639 | pktout.data = (pktout.data == NULL ? smalloc(biglen+12) : |
| 640 | srealloc(pktout.data, biglen+12)); |
| 641 | #else |
| 642 | pktout.data = (pktout.data == NULL ? smalloc(biglen+4) : |
| 643 | srealloc(pktout.data, biglen+4)); |
| 644 | #endif |
| 645 | if (!pktout.data) |
| 646 | fatalbox("Out of memory"); |
| 647 | } |
| 648 | pktout.body = pktout.data+4+pad+1; |
| 649 | } |
| 650 | |
| 651 | static void s_wrpkt_start(int type, int len) { |
| 652 | ssh1_pktout_size(len); |
| 653 | pktout.type = type; |
| 654 | } |
| 655 | |
| 656 | static void s_wrpkt(void) { |
| 657 | int pad, len, biglen, i; |
| 658 | unsigned long crc; |
| 659 | |
| 660 | pktout.body[-1] = pktout.type; |
| 661 | |
| 662 | if (ssh1_compressing) { |
| 663 | unsigned char *compblk; |
| 664 | int complen; |
| 665 | #if 0 |
| 666 | debug(("Packet payload pre-compression:\n")); |
| 667 | for (i = -1; i < pktout.length; i++) |
| 668 | debug((" %02x", (unsigned char)pktout.body[i])); |
| 669 | debug(("\r\n")); |
| 670 | #endif |
| 671 | zlib_compress_block(pktout.body-1, pktout.length+1, |
| 672 | &compblk, &complen); |
| 673 | ssh1_pktout_size(complen-1); |
| 674 | memcpy(pktout.body-1, compblk, complen); |
| 675 | sfree(compblk); |
| 676 | #if 0 |
| 677 | debug(("Packet payload post-compression:\n")); |
| 678 | for (i = -1; i < pktout.length; i++) |
| 679 | debug((" %02x", (unsigned char)pktout.body[i])); |
| 680 | debug(("\r\n")); |
| 681 | #endif |
| 682 | } |
| 683 | |
| 684 | len = pktout.length + 5; /* type and CRC */ |
| 685 | pad = 8 - (len%8); |
| 686 | biglen = len + pad; |
| 687 | |
| 688 | for (i=0; i<pad; i++) |
| 689 | pktout.data[i+4] = random_byte(); |
| 690 | crc = crc32(pktout.data+4, biglen-4); |
| 691 | PUT_32BIT(pktout.data+biglen, crc); |
| 692 | PUT_32BIT(pktout.data, len); |
| 693 | |
| 694 | #if 0 |
| 695 | debug(("Sending packet len=%d\r\n", biglen+4)); |
| 696 | for (i = 0; i < biglen+4; i++) |
| 697 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 698 | debug(("\r\n")); |
| 699 | #endif |
| 700 | if (cipher) |
| 701 | cipher->encrypt(pktout.data+4, biglen); |
| 702 | |
| 703 | sk_write(s, pktout.data, biglen+4); |
| 704 | } |
| 705 | |
| 706 | /* |
| 707 | * Construct a packet with the specified contents and |
| 708 | * send it to the server. |
| 709 | */ |
| 710 | static void send_packet(int pkttype, ...) |
| 711 | { |
| 712 | va_list args; |
| 713 | unsigned char *p, *argp, argchar; |
| 714 | unsigned long argint; |
| 715 | int pktlen, argtype, arglen; |
| 716 | Bignum bn; |
| 717 | |
| 718 | pktlen = 0; |
| 719 | va_start(args, pkttype); |
| 720 | while ((argtype = va_arg(args, int)) != PKT_END) { |
| 721 | switch (argtype) { |
| 722 | case PKT_INT: |
| 723 | (void) va_arg(args, int); |
| 724 | pktlen += 4; |
| 725 | break; |
| 726 | case PKT_CHAR: |
| 727 | (void) va_arg(args, char); |
| 728 | pktlen++; |
| 729 | break; |
| 730 | case PKT_DATA: |
| 731 | (void) va_arg(args, unsigned char *); |
| 732 | arglen = va_arg(args, int); |
| 733 | pktlen += arglen; |
| 734 | break; |
| 735 | case PKT_STR: |
| 736 | argp = va_arg(args, unsigned char *); |
| 737 | arglen = strlen(argp); |
| 738 | pktlen += 4 + arglen; |
| 739 | break; |
| 740 | case PKT_BIGNUM: |
| 741 | bn = va_arg(args, Bignum); |
| 742 | pktlen += ssh1_bignum_length(bn); |
| 743 | break; |
| 744 | default: |
| 745 | assert(0); |
| 746 | } |
| 747 | } |
| 748 | va_end(args); |
| 749 | |
| 750 | s_wrpkt_start(pkttype, pktlen); |
| 751 | p = pktout.body; |
| 752 | |
| 753 | va_start(args, pkttype); |
| 754 | while ((argtype = va_arg(args, int)) != PKT_END) { |
| 755 | switch (argtype) { |
| 756 | case PKT_INT: |
| 757 | argint = va_arg(args, int); |
| 758 | PUT_32BIT(p, argint); |
| 759 | p += 4; |
| 760 | break; |
| 761 | case PKT_CHAR: |
| 762 | argchar = va_arg(args, unsigned char); |
| 763 | *p = argchar; |
| 764 | p++; |
| 765 | break; |
| 766 | case PKT_DATA: |
| 767 | argp = va_arg(args, unsigned char *); |
| 768 | arglen = va_arg(args, int); |
| 769 | memcpy(p, argp, arglen); |
| 770 | p += arglen; |
| 771 | break; |
| 772 | case PKT_STR: |
| 773 | argp = va_arg(args, unsigned char *); |
| 774 | arglen = strlen(argp); |
| 775 | PUT_32BIT(p, arglen); |
| 776 | memcpy(p + 4, argp, arglen); |
| 777 | p += 4 + arglen; |
| 778 | break; |
| 779 | case PKT_BIGNUM: |
| 780 | bn = va_arg(args, Bignum); |
| 781 | p += ssh1_write_bignum(p, bn); |
| 782 | break; |
| 783 | } |
| 784 | } |
| 785 | va_end(args); |
| 786 | |
| 787 | s_wrpkt(); |
| 788 | } |
| 789 | |
| 790 | static int ssh_versioncmp(char *a, char *b) { |
| 791 | char *ae, *be; |
| 792 | unsigned long av, bv; |
| 793 | |
| 794 | av = strtoul(a, &ae, 10); |
| 795 | bv = strtoul(b, &be, 10); |
| 796 | if (av != bv) return (av < bv ? -1 : +1); |
| 797 | if (*ae == '.') ae++; |
| 798 | if (*be == '.') be++; |
| 799 | av = strtoul(ae, &ae, 10); |
| 800 | bv = strtoul(be, &be, 10); |
| 801 | if (av != bv) return (av < bv ? -1 : +1); |
| 802 | return 0; |
| 803 | } |
| 804 | |
| 805 | |
| 806 | /* |
| 807 | * Utility routines for putting an SSH-protocol `string' and |
| 808 | * `uint32' into a SHA state. |
| 809 | */ |
| 810 | #include <stdio.h> |
| 811 | static void sha_string(SHA_State *s, void *str, int len) { |
| 812 | unsigned char lenblk[4]; |
| 813 | PUT_32BIT(lenblk, len); |
| 814 | SHA_Bytes(s, lenblk, 4); |
| 815 | SHA_Bytes(s, str, len); |
| 816 | } |
| 817 | |
| 818 | static void sha_uint32(SHA_State *s, unsigned i) { |
| 819 | unsigned char intblk[4]; |
| 820 | PUT_32BIT(intblk, i); |
| 821 | SHA_Bytes(s, intblk, 4); |
| 822 | } |
| 823 | |
| 824 | /* |
| 825 | * SSH2 packet construction functions. |
| 826 | */ |
| 827 | static void ssh2_pkt_ensure(int length) { |
| 828 | if (pktout.maxlen < length) { |
| 829 | pktout.maxlen = length + 256; |
| 830 | pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) : |
| 831 | srealloc(pktout.data, pktout.maxlen+APIEXTRA)); |
| 832 | if (!pktout.data) |
| 833 | fatalbox("Out of memory"); |
| 834 | } |
| 835 | } |
| 836 | static void ssh2_pkt_adddata(void *data, int len) { |
| 837 | pktout.length += len; |
| 838 | ssh2_pkt_ensure(pktout.length); |
| 839 | memcpy(pktout.data+pktout.length-len, data, len); |
| 840 | } |
| 841 | static void ssh2_pkt_addbyte(unsigned char byte) { |
| 842 | ssh2_pkt_adddata(&byte, 1); |
| 843 | } |
| 844 | static void ssh2_pkt_init(int pkt_type) { |
| 845 | pktout.length = 5; |
| 846 | ssh2_pkt_addbyte((unsigned char)pkt_type); |
| 847 | } |
| 848 | static void ssh2_pkt_addbool(unsigned char value) { |
| 849 | ssh2_pkt_adddata(&value, 1); |
| 850 | } |
| 851 | static void ssh2_pkt_adduint32(unsigned long value) { |
| 852 | unsigned char x[4]; |
| 853 | PUT_32BIT(x, value); |
| 854 | ssh2_pkt_adddata(x, 4); |
| 855 | } |
| 856 | static void ssh2_pkt_addstring_start(void) { |
| 857 | ssh2_pkt_adduint32(0); |
| 858 | pktout.savedpos = pktout.length; |
| 859 | } |
| 860 | static void ssh2_pkt_addstring_str(char *data) { |
| 861 | ssh2_pkt_adddata(data, strlen(data)); |
| 862 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 863 | pktout.length - pktout.savedpos); |
| 864 | } |
| 865 | static void ssh2_pkt_addstring_data(char *data, int len) { |
| 866 | ssh2_pkt_adddata(data, len); |
| 867 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 868 | pktout.length - pktout.savedpos); |
| 869 | } |
| 870 | static void ssh2_pkt_addstring(char *data) { |
| 871 | ssh2_pkt_addstring_start(); |
| 872 | ssh2_pkt_addstring_str(data); |
| 873 | } |
| 874 | static char *ssh2_mpint_fmt(Bignum b, int *len) { |
| 875 | unsigned char *p; |
| 876 | int i, n = (ssh1_bignum_bitcount(b)+7)/8; |
| 877 | p = smalloc(n + 1); |
| 878 | if (!p) |
| 879 | fatalbox("out of memory"); |
| 880 | p[0] = 0; |
| 881 | for (i = 1; i <= n; i++) |
| 882 | p[i] = bignum_byte(b, n-i); |
| 883 | i = 0; |
| 884 | while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0) |
| 885 | i++; |
| 886 | memmove(p, p+i, n+1-i); |
| 887 | *len = n+1-i; |
| 888 | return p; |
| 889 | } |
| 890 | static void ssh2_pkt_addmp(Bignum b) { |
| 891 | unsigned char *p; |
| 892 | int len; |
| 893 | p = ssh2_mpint_fmt(b, &len); |
| 894 | ssh2_pkt_addstring_start(); |
| 895 | ssh2_pkt_addstring_data(p, len); |
| 896 | sfree(p); |
| 897 | } |
| 898 | |
| 899 | /* |
| 900 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
| 901 | * put the MAC on it. Final packet, ready to be sent, is stored in |
| 902 | * pktout.data. Total length is returned. |
| 903 | */ |
| 904 | static int ssh2_pkt_construct(void) { |
| 905 | int cipherblk, maclen, padding, i; |
| 906 | static unsigned long outgoing_sequence = 0; |
| 907 | |
| 908 | /* |
| 909 | * Compress packet payload. |
| 910 | */ |
| 911 | #if 0 |
| 912 | debug(("Pre-compression payload:\r\n")); |
| 913 | for (i = 5; i < pktout.length; i++) |
| 914 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 915 | debug(("\r\n")); |
| 916 | #endif |
| 917 | { |
| 918 | unsigned char *newpayload; |
| 919 | int newlen; |
| 920 | if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5, |
| 921 | &newpayload, &newlen)) { |
| 922 | pktout.length = 5; |
| 923 | ssh2_pkt_adddata(newpayload, newlen); |
| 924 | sfree(newpayload); |
| 925 | } |
| 926 | } |
| 927 | |
| 928 | /* |
| 929 | * Add padding. At least four bytes, and must also bring total |
| 930 | * length (minus MAC) up to a multiple of the block size. |
| 931 | */ |
| 932 | cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ |
| 933 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 934 | padding = 4; |
| 935 | padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
| 936 | maclen = csmac ? csmac->len : 0; |
| 937 | ssh2_pkt_ensure(pktout.length + padding + maclen); |
| 938 | pktout.data[4] = padding; |
| 939 | for (i = 0; i < padding; i++) |
| 940 | pktout.data[pktout.length + i] = random_byte(); |
| 941 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
| 942 | if (csmac) |
| 943 | csmac->generate(pktout.data, pktout.length + padding, |
| 944 | outgoing_sequence); |
| 945 | outgoing_sequence++; /* whether or not we MACed */ |
| 946 | |
| 947 | #if 0 |
| 948 | debug(("Sending packet len=%d\r\n", pktout.length+padding)); |
| 949 | for (i = 0; i < pktout.length+padding; i++) |
| 950 | debug((" %02x", (unsigned char)pktout.data[i])); |
| 951 | debug(("\r\n")); |
| 952 | #endif |
| 953 | |
| 954 | if (cscipher) |
| 955 | cscipher->encrypt(pktout.data, pktout.length + padding); |
| 956 | |
| 957 | /* Ready-to-send packet starts at pktout.data. We return length. */ |
| 958 | return pktout.length + padding + maclen; |
| 959 | } |
| 960 | |
| 961 | /* |
| 962 | * Construct and send an SSH2 packet immediately. |
| 963 | */ |
| 964 | static void ssh2_pkt_send(void) { |
| 965 | int len = ssh2_pkt_construct(); |
| 966 | sk_write(s, pktout.data, len); |
| 967 | } |
| 968 | |
| 969 | /* |
| 970 | * Construct an SSH2 packet and add it to a deferred data block. |
| 971 | * Useful for sending multiple packets in a single sk_write() call, |
| 972 | * to prevent a traffic-analysing listener from being able to work |
| 973 | * out the length of any particular packet (such as the password |
| 974 | * packet). |
| 975 | * |
| 976 | * Note that because SSH2 sequence-numbers its packets, this can |
| 977 | * NOT be used as an m4-style `defer' allowing packets to be |
| 978 | * constructed in one order and sent in another. |
| 979 | */ |
| 980 | static void ssh2_pkt_defer(void) { |
| 981 | int len = ssh2_pkt_construct(); |
| 982 | if (deferred_len + len > deferred_size) { |
| 983 | deferred_size = deferred_len + len + 128; |
| 984 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
| 985 | } |
| 986 | memcpy(deferred_send_data+deferred_len, pktout.data, len); |
| 987 | deferred_len += len; |
| 988 | } |
| 989 | |
| 990 | /* |
| 991 | * Send the whole deferred data block constructed by |
| 992 | * ssh2_pkt_defer(). |
| 993 | */ |
| 994 | static void ssh2_pkt_defersend(void) { |
| 995 | sk_write(s, deferred_send_data, deferred_len); |
| 996 | deferred_len = deferred_size = 0; |
| 997 | sfree(deferred_send_data); |
| 998 | deferred_send_data = NULL; |
| 999 | } |
| 1000 | |
| 1001 | #if 0 |
| 1002 | void bndebug(char *string, Bignum b) { |
| 1003 | unsigned char *p; |
| 1004 | int i, len; |
| 1005 | p = ssh2_mpint_fmt(b, &len); |
| 1006 | debug(("%s", string)); |
| 1007 | for (i = 0; i < len; i++) |
| 1008 | debug((" %02x", p[i])); |
| 1009 | debug(("\r\n")); |
| 1010 | sfree(p); |
| 1011 | } |
| 1012 | #endif |
| 1013 | |
| 1014 | static void sha_mpint(SHA_State *s, Bignum b) { |
| 1015 | unsigned char *p; |
| 1016 | int len; |
| 1017 | p = ssh2_mpint_fmt(b, &len); |
| 1018 | sha_string(s, p, len); |
| 1019 | sfree(p); |
| 1020 | } |
| 1021 | |
| 1022 | /* |
| 1023 | * SSH2 packet decode functions. |
| 1024 | */ |
| 1025 | static unsigned long ssh2_pkt_getuint32(void) { |
| 1026 | unsigned long value; |
| 1027 | if (pktin.length - pktin.savedpos < 4) |
| 1028 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1029 | value = GET_32BIT(pktin.data+pktin.savedpos); |
| 1030 | pktin.savedpos += 4; |
| 1031 | return value; |
| 1032 | } |
| 1033 | static int ssh2_pkt_getbool(void) { |
| 1034 | unsigned long value; |
| 1035 | if (pktin.length - pktin.savedpos < 1) |
| 1036 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1037 | value = pktin.data[pktin.savedpos] != 0; |
| 1038 | pktin.savedpos++; |
| 1039 | return value; |
| 1040 | } |
| 1041 | static void ssh2_pkt_getstring(char **p, int *length) { |
| 1042 | *p = NULL; |
| 1043 | if (pktin.length - pktin.savedpos < 4) |
| 1044 | return; |
| 1045 | *length = GET_32BIT(pktin.data+pktin.savedpos); |
| 1046 | pktin.savedpos += 4; |
| 1047 | if (pktin.length - pktin.savedpos < *length) |
| 1048 | return; |
| 1049 | *p = pktin.data+pktin.savedpos; |
| 1050 | pktin.savedpos += *length; |
| 1051 | } |
| 1052 | static Bignum ssh2_pkt_getmp(void) { |
| 1053 | char *p; |
| 1054 | int length; |
| 1055 | Bignum b; |
| 1056 | |
| 1057 | ssh2_pkt_getstring(&p, &length); |
| 1058 | if (!p) |
| 1059 | return NULL; |
| 1060 | if (p[0] & 0x80) { |
| 1061 | bombout(("internal error: Can't handle negative mpints")); |
| 1062 | return NULL; |
| 1063 | } |
| 1064 | b = bignum_from_bytes(p, length); |
| 1065 | return b; |
| 1066 | } |
| 1067 | |
| 1068 | static int do_ssh_init(unsigned char c) { |
| 1069 | static char *vsp; |
| 1070 | static char version[10]; |
| 1071 | static char vstring[80]; |
| 1072 | static char vlog[sizeof(vstring)+20]; |
| 1073 | static int i; |
| 1074 | |
| 1075 | crBegin; |
| 1076 | |
| 1077 | /* Search for the string "SSH-" in the input. */ |
| 1078 | i = 0; |
| 1079 | while (1) { |
| 1080 | static const int transS[] = { 1, 2, 2, 1 }; |
| 1081 | static const int transH[] = { 0, 0, 3, 0 }; |
| 1082 | static const int transminus[] = { 0, 0, 0, -1 }; |
| 1083 | if (c == 'S') i = transS[i]; |
| 1084 | else if (c == 'H') i = transH[i]; |
| 1085 | else if (c == '-') i = transminus[i]; |
| 1086 | else i = 0; |
| 1087 | if (i < 0) |
| 1088 | break; |
| 1089 | crReturn(1); /* get another character */ |
| 1090 | } |
| 1091 | |
| 1092 | strcpy(vstring, "SSH-"); |
| 1093 | vsp = vstring+4; |
| 1094 | i = 0; |
| 1095 | while (1) { |
| 1096 | crReturn(1); /* get another char */ |
| 1097 | if (vsp < vstring+sizeof(vstring)-1) |
| 1098 | *vsp++ = c; |
| 1099 | if (i >= 0) { |
| 1100 | if (c == '-') { |
| 1101 | version[i] = '\0'; |
| 1102 | i = -1; |
| 1103 | } else if (i < sizeof(version)-1) |
| 1104 | version[i++] = c; |
| 1105 | } |
| 1106 | else if (c == '\n') |
| 1107 | break; |
| 1108 | } |
| 1109 | |
| 1110 | ssh_agentfwd_enabled = FALSE; |
| 1111 | rdpkt2_state.incoming_sequence = 0; |
| 1112 | |
| 1113 | *vsp = 0; |
| 1114 | sprintf(vlog, "Server version: %s", vstring); |
| 1115 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 1116 | logevent(vlog); |
| 1117 | |
| 1118 | /* |
| 1119 | * Server version "1.99" means we can choose whether we use v1 |
| 1120 | * or v2 protocol. Choice is based on cfg.sshprot. |
| 1121 | */ |
| 1122 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
| 1123 | /* |
| 1124 | * This is a v2 server. Begin v2 protocol. |
| 1125 | */ |
| 1126 | char *verstring = "SSH-2.0-PuTTY"; |
| 1127 | SHA_Init(&exhashbase); |
| 1128 | /* |
| 1129 | * Hash our version string and their version string. |
| 1130 | */ |
| 1131 | sha_string(&exhashbase, verstring, strlen(verstring)); |
| 1132 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
| 1133 | sprintf(vstring, "%s\n", verstring); |
| 1134 | sprintf(vlog, "We claim version: %s", verstring); |
| 1135 | logevent(vlog); |
| 1136 | logevent("Using SSH protocol version 2"); |
| 1137 | sk_write(s, vstring, strlen(vstring)); |
| 1138 | ssh_protocol = ssh2_protocol; |
| 1139 | ssh_version = 2; |
| 1140 | s_rdpkt = ssh2_rdpkt; |
| 1141 | } else { |
| 1142 | /* |
| 1143 | * This is a v1 server. Begin v1 protocol. |
| 1144 | */ |
| 1145 | sprintf(vstring, "SSH-%s-PuTTY\n", |
| 1146 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5")); |
| 1147 | sprintf(vlog, "We claim version: %s", vstring); |
| 1148 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 1149 | logevent(vlog); |
| 1150 | logevent("Using SSH protocol version 1"); |
| 1151 | sk_write(s, vstring, strlen(vstring)); |
| 1152 | ssh_protocol = ssh1_protocol; |
| 1153 | ssh_version = 1; |
| 1154 | s_rdpkt = ssh1_rdpkt; |
| 1155 | } |
| 1156 | ssh_state = SSH_STATE_BEFORE_SIZE; |
| 1157 | |
| 1158 | crFinish(0); |
| 1159 | } |
| 1160 | |
| 1161 | static void ssh_gotdata(unsigned char *data, int datalen) |
| 1162 | { |
| 1163 | crBegin; |
| 1164 | |
| 1165 | /* |
| 1166 | * To begin with, feed the characters one by one to the |
| 1167 | * protocol initialisation / selection function do_ssh_init(). |
| 1168 | * When that returns 0, we're done with the initial greeting |
| 1169 | * exchange and can move on to packet discipline. |
| 1170 | */ |
| 1171 | while (1) { |
| 1172 | int ret; |
| 1173 | if (datalen == 0) |
| 1174 | crReturnV; /* more data please */ |
| 1175 | ret = do_ssh_init(*data); |
| 1176 | data++; datalen--; |
| 1177 | if (ret == 0) |
| 1178 | break; |
| 1179 | } |
| 1180 | |
| 1181 | /* |
| 1182 | * We emerge from that loop when the initial negotiation is |
| 1183 | * over and we have selected an s_rdpkt function. Now pass |
| 1184 | * everything to s_rdpkt, and then pass the resulting packets |
| 1185 | * to the proper protocol handler. |
| 1186 | */ |
| 1187 | if (datalen == 0) |
| 1188 | crReturnV; |
| 1189 | while (1) { |
| 1190 | while (datalen > 0) { |
| 1191 | if ( s_rdpkt(&data, &datalen) == 0 ) { |
| 1192 | ssh_protocol(NULL, 0, 1); |
| 1193 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1194 | return; |
| 1195 | } |
| 1196 | } |
| 1197 | } |
| 1198 | crReturnV; |
| 1199 | } |
| 1200 | crFinishV; |
| 1201 | } |
| 1202 | |
| 1203 | static int ssh_receive(Socket skt, int urgent, char *data, int len) { |
| 1204 | if (urgent==3) { |
| 1205 | /* A socket error has occurred. */ |
| 1206 | ssh_state = SSH_STATE_CLOSED; |
| 1207 | sk_close(s); |
| 1208 | s = NULL; |
| 1209 | connection_fatal(data); |
| 1210 | return 0; |
| 1211 | } else if (!len) { |
| 1212 | /* Connection has closed. */ |
| 1213 | ssh_state = SSH_STATE_CLOSED; |
| 1214 | sk_close(s); |
| 1215 | s = NULL; |
| 1216 | return 0; |
| 1217 | } |
| 1218 | ssh_gotdata (data, len); |
| 1219 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1220 | if (s) { |
| 1221 | sk_close(s); |
| 1222 | s = NULL; |
| 1223 | } |
| 1224 | return 0; |
| 1225 | } |
| 1226 | return 1; |
| 1227 | } |
| 1228 | |
| 1229 | /* |
| 1230 | * Connect to specified host and port. |
| 1231 | * Returns an error message, or NULL on success. |
| 1232 | * Also places the canonical host name into `realhost'. |
| 1233 | */ |
| 1234 | static char *connect_to_host(char *host, int port, char **realhost) |
| 1235 | { |
| 1236 | SockAddr addr; |
| 1237 | char *err; |
| 1238 | #ifdef FWHACK |
| 1239 | char *FWhost; |
| 1240 | int FWport; |
| 1241 | #endif |
| 1242 | |
| 1243 | savedhost = smalloc(1+strlen(host)); |
| 1244 | if (!savedhost) |
| 1245 | fatalbox("Out of memory"); |
| 1246 | strcpy(savedhost, host); |
| 1247 | |
| 1248 | if (port < 0) |
| 1249 | port = 22; /* default ssh port */ |
| 1250 | savedport = port; |
| 1251 | |
| 1252 | #ifdef FWHACK |
| 1253 | FWhost = host; |
| 1254 | FWport = port; |
| 1255 | host = FWSTR; |
| 1256 | port = 23; |
| 1257 | #endif |
| 1258 | |
| 1259 | /* |
| 1260 | * Try to find host. |
| 1261 | */ |
| 1262 | addr = sk_namelookup(host, realhost); |
| 1263 | if ( (err = sk_addr_error(addr)) ) |
| 1264 | return err; |
| 1265 | |
| 1266 | #ifdef FWHACK |
| 1267 | *realhost = FWhost; |
| 1268 | #endif |
| 1269 | |
| 1270 | /* |
| 1271 | * Open socket. |
| 1272 | */ |
| 1273 | s = sk_new(addr, port, 0, 1, ssh_receive); |
| 1274 | if ( (err = sk_socket_error(s)) ) |
| 1275 | return err; |
| 1276 | |
| 1277 | #ifdef FWHACK |
| 1278 | sk_write(s, "connect ", 8); |
| 1279 | sk_write(s, FWhost, strlen(FWhost)); |
| 1280 | { |
| 1281 | char buf[20]; |
| 1282 | sprintf(buf, " %d\n", FWport); |
| 1283 | sk_write(s, buf, strlen(buf)); |
| 1284 | } |
| 1285 | #endif |
| 1286 | |
| 1287 | return NULL; |
| 1288 | } |
| 1289 | |
| 1290 | /* |
| 1291 | * Handle the key exchange and user authentication phases. |
| 1292 | */ |
| 1293 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
| 1294 | { |
| 1295 | int i, j, len; |
| 1296 | unsigned char *rsabuf, *keystr1, *keystr2; |
| 1297 | unsigned char cookie[8]; |
| 1298 | struct RSAKey servkey, hostkey; |
| 1299 | struct MD5Context md5c; |
| 1300 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
| 1301 | static int tried_publickey; |
| 1302 | static unsigned char session_id[16]; |
| 1303 | int cipher_type; |
| 1304 | static char username[100]; |
| 1305 | |
| 1306 | crBegin; |
| 1307 | |
| 1308 | if (!ispkt) crWaitUntil(ispkt); |
| 1309 | |
| 1310 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
| 1311 | bombout(("Public key packet not received")); |
| 1312 | crReturn(0); |
| 1313 | } |
| 1314 | |
| 1315 | logevent("Received public keys"); |
| 1316 | |
| 1317 | memcpy(cookie, pktin.body, 8); |
| 1318 | |
| 1319 | i = makekey(pktin.body+8, &servkey, &keystr1, 0); |
| 1320 | j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); |
| 1321 | |
| 1322 | /* |
| 1323 | * Log the host key fingerprint. |
| 1324 | */ |
| 1325 | { |
| 1326 | char logmsg[80]; |
| 1327 | logevent("Host key fingerprint is:"); |
| 1328 | strcpy(logmsg, " "); |
| 1329 | hostkey.comment = NULL; |
| 1330 | rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg), |
| 1331 | &hostkey); |
| 1332 | logevent(logmsg); |
| 1333 | } |
| 1334 | |
| 1335 | supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j); |
| 1336 | supported_auths_mask = GET_32BIT(pktin.body+16+i+j); |
| 1337 | |
| 1338 | MD5Init(&md5c); |
| 1339 | MD5Update(&md5c, keystr2, hostkey.bytes); |
| 1340 | MD5Update(&md5c, keystr1, servkey.bytes); |
| 1341 | MD5Update(&md5c, pktin.body, 8); |
| 1342 | MD5Final(session_id, &md5c); |
| 1343 | |
| 1344 | for (i=0; i<32; i++) |
| 1345 | session_key[i] = random_byte(); |
| 1346 | |
| 1347 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 1348 | |
| 1349 | rsabuf = smalloc(len); |
| 1350 | if (!rsabuf) |
| 1351 | fatalbox("Out of memory"); |
| 1352 | |
| 1353 | /* |
| 1354 | * Verify the host key. |
| 1355 | */ |
| 1356 | { |
| 1357 | /* |
| 1358 | * First format the key into a string. |
| 1359 | */ |
| 1360 | int len = rsastr_len(&hostkey); |
| 1361 | char fingerprint[100]; |
| 1362 | char *keystr = smalloc(len); |
| 1363 | if (!keystr) |
| 1364 | fatalbox("Out of memory"); |
| 1365 | rsastr_fmt(keystr, &hostkey); |
| 1366 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
| 1367 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint); |
| 1368 | sfree(keystr); |
| 1369 | } |
| 1370 | |
| 1371 | for (i=0; i<32; i++) { |
| 1372 | rsabuf[i] = session_key[i]; |
| 1373 | if (i < 16) |
| 1374 | rsabuf[i] ^= session_id[i]; |
| 1375 | } |
| 1376 | |
| 1377 | if (hostkey.bytes > servkey.bytes) { |
| 1378 | rsaencrypt(rsabuf, 32, &servkey); |
| 1379 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
| 1380 | } else { |
| 1381 | rsaencrypt(rsabuf, 32, &hostkey); |
| 1382 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
| 1383 | } |
| 1384 | |
| 1385 | logevent("Encrypted session key"); |
| 1386 | |
| 1387 | switch (cfg.cipher) { |
| 1388 | case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break; |
| 1389 | case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break; |
| 1390 | case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break; |
| 1391 | case CIPHER_AES: |
| 1392 | c_write_str("AES not supported in SSH1, falling back to 3DES\r\n"); |
| 1393 | cipher_type = SSH_CIPHER_3DES; |
| 1394 | break; |
| 1395 | } |
| 1396 | if ((supported_ciphers_mask & (1 << cipher_type)) == 0) { |
| 1397 | c_write_str("Selected cipher not supported, falling back to 3DES\r\n"); |
| 1398 | cipher_type = SSH_CIPHER_3DES; |
| 1399 | } |
| 1400 | switch (cipher_type) { |
| 1401 | case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break; |
| 1402 | case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break; |
| 1403 | case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break; |
| 1404 | } |
| 1405 | |
| 1406 | send_packet(SSH1_CMSG_SESSION_KEY, |
| 1407 | PKT_CHAR, cipher_type, |
| 1408 | PKT_DATA, cookie, 8, |
| 1409 | PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF, |
| 1410 | PKT_DATA, rsabuf, len, |
| 1411 | PKT_INT, 0, |
| 1412 | PKT_END); |
| 1413 | |
| 1414 | logevent("Trying to enable encryption..."); |
| 1415 | |
| 1416 | sfree(rsabuf); |
| 1417 | |
| 1418 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
| 1419 | cipher_type == SSH_CIPHER_DES ? &ssh_des : |
| 1420 | &ssh_3des; |
| 1421 | cipher->sesskey(session_key); |
| 1422 | |
| 1423 | crWaitUntil(ispkt); |
| 1424 | |
| 1425 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1426 | bombout(("Encryption not successfully enabled")); |
| 1427 | crReturn(0); |
| 1428 | } |
| 1429 | |
| 1430 | logevent("Successfully started encryption"); |
| 1431 | |
| 1432 | fflush(stdout); |
| 1433 | { |
| 1434 | static int pos = 0; |
| 1435 | static char c; |
| 1436 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 1437 | c_write_str("login as: "); |
| 1438 | ssh_send_ok = 1; |
| 1439 | while (pos >= 0) { |
| 1440 | crWaitUntil(!ispkt); |
| 1441 | while (inlen--) switch (c = *in++) { |
| 1442 | case 10: case 13: |
| 1443 | username[pos] = 0; |
| 1444 | pos = -1; |
| 1445 | break; |
| 1446 | case 8: case 127: |
| 1447 | if (pos > 0) { |
| 1448 | c_write_str("\b \b"); |
| 1449 | pos--; |
| 1450 | } |
| 1451 | break; |
| 1452 | case 21: case 27: |
| 1453 | while (pos > 0) { |
| 1454 | c_write_str("\b \b"); |
| 1455 | pos--; |
| 1456 | } |
| 1457 | break; |
| 1458 | case 3: case 4: |
| 1459 | random_save_seed(); |
| 1460 | exit(0); |
| 1461 | break; |
| 1462 | default: |
| 1463 | if (((c >= ' ' && c <= '~') || |
| 1464 | ((unsigned char)c >= 160)) && pos < 40) { |
| 1465 | username[pos++] = c; |
| 1466 | c_write(&c, 1); |
| 1467 | } |
| 1468 | break; |
| 1469 | } |
| 1470 | } |
| 1471 | c_write_str("\r\n"); |
| 1472 | username[strcspn(username, "\n\r")] = '\0'; |
| 1473 | } else { |
| 1474 | strncpy(username, cfg.username, 99); |
| 1475 | username[99] = '\0'; |
| 1476 | } |
| 1477 | |
| 1478 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
| 1479 | { |
| 1480 | char userlog[22+sizeof(username)]; |
| 1481 | sprintf(userlog, "Sent username \"%s\"", username); |
| 1482 | logevent(userlog); |
| 1483 | if (flags & FLAG_INTERACTIVE && |
| 1484 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
| 1485 | strcat(userlog, "\r\n"); |
| 1486 | c_write_str(userlog); |
| 1487 | } |
| 1488 | } |
| 1489 | } |
| 1490 | |
| 1491 | crWaitUntil(ispkt); |
| 1492 | |
| 1493 | tried_publickey = 0; |
| 1494 | |
| 1495 | while (pktin.type == SSH1_SMSG_FAILURE) { |
| 1496 | static char password[100]; |
| 1497 | static char prompt[200]; |
| 1498 | static int pos; |
| 1499 | static char c; |
| 1500 | static int pwpkt_type; |
| 1501 | /* |
| 1502 | * Show password prompt, having first obtained it via a TIS |
| 1503 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
| 1504 | * authentication. |
| 1505 | */ |
| 1506 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 1507 | if (agent_exists()) { |
| 1508 | /* |
| 1509 | * Attempt RSA authentication using Pageant. |
| 1510 | */ |
| 1511 | static unsigned char request[5], *response, *p; |
| 1512 | static int responselen; |
| 1513 | static int i, nkeys; |
| 1514 | static int authed = FALSE; |
| 1515 | void *r; |
| 1516 | |
| 1517 | logevent("Pageant is running. Requesting keys."); |
| 1518 | |
| 1519 | /* Request the keys held by the agent. */ |
| 1520 | PUT_32BIT(request, 1); |
| 1521 | request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
| 1522 | agent_query(request, 5, &r, &responselen); |
| 1523 | response = (unsigned char *)r; |
| 1524 | if (response) { |
| 1525 | p = response + 5; |
| 1526 | nkeys = GET_32BIT(p); p += 4; |
| 1527 | { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys); |
| 1528 | logevent(buf); } |
| 1529 | for (i = 0; i < nkeys; i++) { |
| 1530 | static struct RSAKey key; |
| 1531 | static Bignum challenge; |
| 1532 | static char *commentp; |
| 1533 | static int commentlen; |
| 1534 | |
| 1535 | { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); |
| 1536 | logevent(buf); } |
| 1537 | p += 4; |
| 1538 | p += ssh1_read_bignum(p, &key.exponent); |
| 1539 | p += ssh1_read_bignum(p, &key.modulus); |
| 1540 | commentlen = GET_32BIT(p); p += 4; |
| 1541 | commentp = p; p += commentlen; |
| 1542 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 1543 | PKT_BIGNUM, key.modulus, PKT_END); |
| 1544 | crWaitUntil(ispkt); |
| 1545 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 1546 | logevent("Key refused"); |
| 1547 | continue; |
| 1548 | } |
| 1549 | logevent("Received RSA challenge"); |
| 1550 | ssh1_read_bignum(pktin.body, &challenge); |
| 1551 | { |
| 1552 | char *agentreq, *q, *ret; |
| 1553 | int len, retlen; |
| 1554 | len = 1 + 4; /* message type, bit count */ |
| 1555 | len += ssh1_bignum_length(key.exponent); |
| 1556 | len += ssh1_bignum_length(key.modulus); |
| 1557 | len += ssh1_bignum_length(challenge); |
| 1558 | len += 16; /* session id */ |
| 1559 | len += 4; /* response format */ |
| 1560 | agentreq = smalloc(4 + len); |
| 1561 | PUT_32BIT(agentreq, len); |
| 1562 | q = agentreq + 4; |
| 1563 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
| 1564 | PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus)); |
| 1565 | q += 4; |
| 1566 | q += ssh1_write_bignum(q, key.exponent); |
| 1567 | q += ssh1_write_bignum(q, key.modulus); |
| 1568 | q += ssh1_write_bignum(q, challenge); |
| 1569 | memcpy(q, session_id, 16); q += 16; |
| 1570 | PUT_32BIT(q, 1); /* response format */ |
| 1571 | agent_query(agentreq, len+4, &ret, &retlen); |
| 1572 | sfree(agentreq); |
| 1573 | if (ret) { |
| 1574 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
| 1575 | logevent("Sending Pageant's response"); |
| 1576 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 1577 | PKT_DATA, ret+5, 16, PKT_END); |
| 1578 | sfree(ret); |
| 1579 | crWaitUntil(ispkt); |
| 1580 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 1581 | logevent("Pageant's response accepted"); |
| 1582 | if (flags & FLAG_VERBOSE) { |
| 1583 | c_write_str("Authenticated using RSA key \""); |
| 1584 | c_write(commentp, commentlen); |
| 1585 | c_write_str("\" from agent\r\n"); |
| 1586 | } |
| 1587 | authed = TRUE; |
| 1588 | } else |
| 1589 | logevent("Pageant's response not accepted"); |
| 1590 | } else { |
| 1591 | logevent("Pageant failed to answer challenge"); |
| 1592 | sfree(ret); |
| 1593 | } |
| 1594 | } else { |
| 1595 | logevent("No reply received from Pageant"); |
| 1596 | } |
| 1597 | } |
| 1598 | freebn(key.exponent); |
| 1599 | freebn(key.modulus); |
| 1600 | freebn(challenge); |
| 1601 | if (authed) |
| 1602 | break; |
| 1603 | } |
| 1604 | } |
| 1605 | if (authed) |
| 1606 | break; |
| 1607 | } |
| 1608 | if (*cfg.keyfile && !tried_publickey) |
| 1609 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
| 1610 | |
| 1611 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 1612 | cfg.try_tis_auth && |
| 1613 | (supported_auths_mask & (1<<SSH1_AUTH_TIS))) { |
| 1614 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 1615 | logevent("Requested TIS authentication"); |
| 1616 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
| 1617 | crWaitUntil(ispkt); |
| 1618 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 1619 | logevent("TIS authentication declined"); |
| 1620 | if (flags & FLAG_INTERACTIVE) |
| 1621 | c_write_str("TIS authentication refused.\r\n"); |
| 1622 | } else { |
| 1623 | int challengelen = ((pktin.body[0] << 24) | |
| 1624 | (pktin.body[1] << 16) | |
| 1625 | (pktin.body[2] << 8) | |
| 1626 | (pktin.body[3])); |
| 1627 | logevent("Received TIS challenge"); |
| 1628 | if (challengelen > sizeof(prompt)-1) |
| 1629 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
| 1630 | memcpy(prompt, pktin.body+4, challengelen); |
| 1631 | prompt[challengelen] = '\0'; |
| 1632 | } |
| 1633 | } |
| 1634 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 1635 | cfg.try_tis_auth && |
| 1636 | (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) { |
| 1637 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
| 1638 | logevent("Requested CryptoCard authentication"); |
| 1639 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
| 1640 | crWaitUntil(ispkt); |
| 1641 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 1642 | logevent("CryptoCard authentication declined"); |
| 1643 | c_write_str("CryptoCard authentication refused.\r\n"); |
| 1644 | } else { |
| 1645 | int challengelen = ((pktin.body[0] << 24) | |
| 1646 | (pktin.body[1] << 16) | |
| 1647 | (pktin.body[2] << 8) | |
| 1648 | (pktin.body[3])); |
| 1649 | logevent("Received CryptoCard challenge"); |
| 1650 | if (challengelen > sizeof(prompt)-1) |
| 1651 | challengelen = sizeof(prompt)-1; /* prevent overrun */ |
| 1652 | memcpy(prompt, pktin.body+4, challengelen); |
| 1653 | strncpy(prompt + challengelen, "\r\nResponse : ", |
| 1654 | sizeof(prompt)-challengelen); |
| 1655 | prompt[sizeof(prompt)-1] = '\0'; |
| 1656 | } |
| 1657 | } |
| 1658 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 1659 | sprintf(prompt, "%.90s@%.90s's password: ", |
| 1660 | username, savedhost); |
| 1661 | } |
| 1662 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 1663 | char *comment = NULL; |
| 1664 | if (flags & FLAG_VERBOSE) |
| 1665 | c_write_str("Trying public key authentication.\r\n"); |
| 1666 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
| 1667 | if (flags & FLAG_VERBOSE) |
| 1668 | c_write_str("No passphrase required.\r\n"); |
| 1669 | goto tryauth; |
| 1670 | } |
| 1671 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
| 1672 | sfree(comment); |
| 1673 | } |
| 1674 | |
| 1675 | if (ssh_get_password) { |
| 1676 | if (!ssh_get_password(prompt, password, sizeof(password))) { |
| 1677 | /* |
| 1678 | * get_password failed to get a password (for |
| 1679 | * example because one was supplied on the command |
| 1680 | * line which has already failed to work). |
| 1681 | * Terminate. |
| 1682 | */ |
| 1683 | logevent("No more passwords to try"); |
| 1684 | ssh_state = SSH_STATE_CLOSED; |
| 1685 | crReturn(1); |
| 1686 | } |
| 1687 | } else { |
| 1688 | c_write_str(prompt); |
| 1689 | pos = 0; |
| 1690 | ssh_send_ok = 1; |
| 1691 | while (pos >= 0) { |
| 1692 | crWaitUntil(!ispkt); |
| 1693 | while (inlen--) switch (c = *in++) { |
| 1694 | case 10: case 13: |
| 1695 | password[pos] = 0; |
| 1696 | pos = -1; |
| 1697 | break; |
| 1698 | case 8: case 127: |
| 1699 | if (pos > 0) |
| 1700 | pos--; |
| 1701 | break; |
| 1702 | case 21: case 27: |
| 1703 | pos = 0; |
| 1704 | break; |
| 1705 | case 3: case 4: |
| 1706 | random_save_seed(); |
| 1707 | exit(0); |
| 1708 | break; |
| 1709 | default: |
| 1710 | if (((c >= ' ' && c <= '~') || |
| 1711 | ((unsigned char)c >= 160)) && pos < sizeof(password)) |
| 1712 | password[pos++] = c; |
| 1713 | break; |
| 1714 | } |
| 1715 | } |
| 1716 | c_write_str("\r\n"); |
| 1717 | } |
| 1718 | |
| 1719 | tryauth: |
| 1720 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 1721 | /* |
| 1722 | * Try public key authentication with the specified |
| 1723 | * key file. |
| 1724 | */ |
| 1725 | static struct RSAKey pubkey; |
| 1726 | static Bignum challenge, response; |
| 1727 | static int i; |
| 1728 | static unsigned char buffer[32]; |
| 1729 | |
| 1730 | tried_publickey = 1; |
| 1731 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
| 1732 | if (i == 0) { |
| 1733 | c_write_str("Couldn't load public key from "); |
| 1734 | c_write_str(cfg.keyfile); |
| 1735 | c_write_str(".\r\n"); |
| 1736 | continue; /* go and try password */ |
| 1737 | } |
| 1738 | if (i == -1) { |
| 1739 | c_write_str("Wrong passphrase.\r\n"); |
| 1740 | tried_publickey = 0; |
| 1741 | continue; /* try again */ |
| 1742 | } |
| 1743 | |
| 1744 | /* |
| 1745 | * Send a public key attempt. |
| 1746 | */ |
| 1747 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 1748 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
| 1749 | |
| 1750 | crWaitUntil(ispkt); |
| 1751 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1752 | c_write_str("Server refused our public key.\r\n"); |
| 1753 | continue; /* go and try password */ |
| 1754 | } |
| 1755 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 1756 | bombout(("Bizarre response to offer of public key")); |
| 1757 | crReturn(0); |
| 1758 | } |
| 1759 | ssh1_read_bignum(pktin.body, &challenge); |
| 1760 | response = rsadecrypt(challenge, &pubkey); |
| 1761 | freebn(pubkey.private_exponent); /* burn the evidence */ |
| 1762 | |
| 1763 | for (i = 0; i < 32; i++) { |
| 1764 | buffer[i] = bignum_byte(response, 31-i); |
| 1765 | } |
| 1766 | |
| 1767 | MD5Init(&md5c); |
| 1768 | MD5Update(&md5c, buffer, 32); |
| 1769 | MD5Update(&md5c, session_id, 16); |
| 1770 | MD5Final(buffer, &md5c); |
| 1771 | |
| 1772 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 1773 | PKT_DATA, buffer, 16, PKT_END); |
| 1774 | |
| 1775 | crWaitUntil(ispkt); |
| 1776 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1777 | if (flags & FLAG_VERBOSE) |
| 1778 | c_write_str("Failed to authenticate with our public key.\r\n"); |
| 1779 | continue; /* go and try password */ |
| 1780 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1781 | bombout(("Bizarre response to RSA authentication response")); |
| 1782 | crReturn(0); |
| 1783 | } |
| 1784 | |
| 1785 | break; /* we're through! */ |
| 1786 | } else { |
| 1787 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
| 1788 | } |
| 1789 | logevent("Sent password"); |
| 1790 | memset(password, 0, strlen(password)); |
| 1791 | crWaitUntil(ispkt); |
| 1792 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1793 | if (flags & FLAG_VERBOSE) |
| 1794 | c_write_str("Access denied\r\n"); |
| 1795 | logevent("Authentication refused"); |
| 1796 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 1797 | logevent("Received disconnect request"); |
| 1798 | ssh_state = SSH_STATE_CLOSED; |
| 1799 | crReturn(1); |
| 1800 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1801 | bombout(("Strange packet received, type %d", pktin.type)); |
| 1802 | crReturn(0); |
| 1803 | } |
| 1804 | } |
| 1805 | |
| 1806 | logevent("Authentication successful"); |
| 1807 | |
| 1808 | crFinish(1); |
| 1809 | } |
| 1810 | |
| 1811 | void sshfwd_close(struct ssh_channel *c) { |
| 1812 | if (c) { |
| 1813 | if (ssh_version == 1) { |
| 1814 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END); |
| 1815 | } else { |
| 1816 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 1817 | ssh2_pkt_adduint32(c->remoteid); |
| 1818 | ssh2_pkt_send(); |
| 1819 | } |
| 1820 | c->closes = 1; |
| 1821 | if (c->type == CHAN_X11) { |
| 1822 | c->u.x11.s = NULL; |
| 1823 | logevent("X11 connection terminated"); |
| 1824 | } |
| 1825 | } |
| 1826 | } |
| 1827 | |
| 1828 | void sshfwd_write(struct ssh_channel *c, char *buf, int len) { |
| 1829 | if (ssh_version == 1) { |
| 1830 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 1831 | PKT_INT, c->remoteid, |
| 1832 | PKT_INT, len, |
| 1833 | PKT_DATA, buf, len, |
| 1834 | PKT_END); |
| 1835 | } else { |
| 1836 | ssh2_add_channel_data(c, buf, len); |
| 1837 | ssh2_try_send(c); |
| 1838 | } |
| 1839 | } |
| 1840 | |
| 1841 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { |
| 1842 | crBegin; |
| 1843 | |
| 1844 | random_init(); |
| 1845 | |
| 1846 | while (!do_ssh1_login(in, inlen, ispkt)) { |
| 1847 | crReturnV; |
| 1848 | } |
| 1849 | if (ssh_state == SSH_STATE_CLOSED) |
| 1850 | crReturnV; |
| 1851 | |
| 1852 | if (cfg.agentfwd && agent_exists()) { |
| 1853 | logevent("Requesting agent forwarding"); |
| 1854 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
| 1855 | do { crReturnV; } while (!ispkt); |
| 1856 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1857 | bombout(("Protocol confusion")); |
| 1858 | crReturnV; |
| 1859 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1860 | logevent("Agent forwarding refused"); |
| 1861 | } else { |
| 1862 | logevent("Agent forwarding enabled"); |
| 1863 | ssh_agentfwd_enabled = TRUE; |
| 1864 | } |
| 1865 | } |
| 1866 | |
| 1867 | if (cfg.x11_forward) { |
| 1868 | char proto[20], data[64]; |
| 1869 | logevent("Requesting X11 forwarding"); |
| 1870 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
| 1871 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 1872 | PKT_STR, proto, PKT_STR, data, |
| 1873 | PKT_INT, 0, |
| 1874 | PKT_END); |
| 1875 | do { crReturnV; } while (!ispkt); |
| 1876 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1877 | bombout(("Protocol confusion")); |
| 1878 | crReturnV; |
| 1879 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1880 | logevent("X11 forwarding refused"); |
| 1881 | } else { |
| 1882 | logevent("X11 forwarding enabled"); |
| 1883 | ssh_X11_fwd_enabled = TRUE; |
| 1884 | } |
| 1885 | } |
| 1886 | |
| 1887 | if (!cfg.nopty) { |
| 1888 | send_packet(SSH1_CMSG_REQUEST_PTY, |
| 1889 | PKT_STR, cfg.termtype, |
| 1890 | PKT_INT, rows, PKT_INT, cols, |
| 1891 | PKT_INT, 0, PKT_INT, 0, |
| 1892 | PKT_CHAR, 0, |
| 1893 | PKT_END); |
| 1894 | ssh_state = SSH_STATE_INTERMED; |
| 1895 | do { crReturnV; } while (!ispkt); |
| 1896 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1897 | bombout(("Protocol confusion")); |
| 1898 | crReturnV; |
| 1899 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1900 | c_write_str("Server refused to allocate pty\r\n"); |
| 1901 | ssh_editing = ssh_echoing = 1; |
| 1902 | } |
| 1903 | logevent("Allocated pty"); |
| 1904 | } else { |
| 1905 | ssh_editing = ssh_echoing = 1; |
| 1906 | } |
| 1907 | |
| 1908 | if (cfg.compression) { |
| 1909 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
| 1910 | do { crReturnV; } while (!ispkt); |
| 1911 | if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { |
| 1912 | bombout(("Protocol confusion")); |
| 1913 | crReturnV; |
| 1914 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 1915 | c_write_str("Server refused to compress\r\n"); |
| 1916 | } |
| 1917 | logevent("Started compression"); |
| 1918 | ssh1_compressing = TRUE; |
| 1919 | zlib_compress_init(); |
| 1920 | zlib_decompress_init(); |
| 1921 | } |
| 1922 | |
| 1923 | if (*cfg.remote_cmd) |
| 1924 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END); |
| 1925 | else |
| 1926 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 1927 | logevent("Started session"); |
| 1928 | |
| 1929 | ssh_state = SSH_STATE_SESSION; |
| 1930 | if (size_needed) |
| 1931 | ssh_size(); |
| 1932 | if (eof_needed) |
| 1933 | ssh_special(TS_EOF); |
| 1934 | |
| 1935 | ldisc_send(NULL, 0); /* cause ldisc to notice changes */ |
| 1936 | ssh_send_ok = 1; |
| 1937 | ssh_channels = newtree234(ssh_channelcmp); |
| 1938 | while (1) { |
| 1939 | crReturnV; |
| 1940 | if (ispkt) { |
| 1941 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 1942 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 1943 | long len = GET_32BIT(pktin.body); |
| 1944 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
| 1945 | pktin.body+4, len); |
| 1946 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 1947 | ssh_state = SSH_STATE_CLOSED; |
| 1948 | logevent("Received disconnect request"); |
| 1949 | crReturnV; |
| 1950 | } else if (pktin.type == SSH1_SMSG_X11_OPEN) { |
| 1951 | /* Remote side is trying to open a channel to talk to our |
| 1952 | * X-Server. Give them back a local channel number. */ |
| 1953 | unsigned i; |
| 1954 | struct ssh_channel *c, *d; |
| 1955 | enum234 e; |
| 1956 | |
| 1957 | logevent("Received X11 connect request"); |
| 1958 | /* Refuse if X11 forwarding is disabled. */ |
| 1959 | if (!ssh_X11_fwd_enabled) { |
| 1960 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 1961 | PKT_INT, GET_32BIT(pktin.body), |
| 1962 | PKT_END); |
| 1963 | logevent("Rejected X11 connect request"); |
| 1964 | } else { |
| 1965 | c = smalloc(sizeof(struct ssh_channel)); |
| 1966 | |
| 1967 | if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) { |
| 1968 | logevent("opening X11 forward connection failed"); |
| 1969 | sfree(c); |
| 1970 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 1971 | PKT_INT, GET_32BIT(pktin.body), |
| 1972 | PKT_END); |
| 1973 | } else { |
| 1974 | logevent("opening X11 forward connection succeeded"); |
| 1975 | for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) { |
| 1976 | if (d->localid > i) |
| 1977 | break; /* found a free number */ |
| 1978 | i = d->localid + 1; |
| 1979 | } |
| 1980 | c->remoteid = GET_32BIT(pktin.body); |
| 1981 | c->localid = i; |
| 1982 | c->closes = 0; |
| 1983 | c->type = CHAN_X11; /* identify channel type */ |
| 1984 | add234(ssh_channels, c); |
| 1985 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 1986 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 1987 | PKT_END); |
| 1988 | logevent("Opened X11 forward channel"); |
| 1989 | } |
| 1990 | } |
| 1991 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
| 1992 | /* Remote side is trying to open a channel to talk to our |
| 1993 | * agent. Give them back a local channel number. */ |
| 1994 | unsigned i; |
| 1995 | struct ssh_channel *c; |
| 1996 | enum234 e; |
| 1997 | |
| 1998 | /* Refuse if agent forwarding is disabled. */ |
| 1999 | if (!ssh_agentfwd_enabled) { |
| 2000 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 2001 | PKT_INT, GET_32BIT(pktin.body), |
| 2002 | PKT_END); |
| 2003 | } else { |
| 2004 | i = 1; |
| 2005 | for (c = first234(ssh_channels, &e); c; c = next234(&e)) { |
| 2006 | if (c->localid > i) |
| 2007 | break; /* found a free number */ |
| 2008 | i = c->localid + 1; |
| 2009 | } |
| 2010 | c = smalloc(sizeof(struct ssh_channel)); |
| 2011 | c->remoteid = GET_32BIT(pktin.body); |
| 2012 | c->localid = i; |
| 2013 | c->closes = 0; |
| 2014 | c->type = CHAN_AGENT; /* identify channel type */ |
| 2015 | c->u.a.lensofar = 0; |
| 2016 | add234(ssh_channels, c); |
| 2017 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 2018 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 2019 | PKT_END); |
| 2020 | } |
| 2021 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
| 2022 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
| 2023 | /* Remote side closes a channel. */ |
| 2024 | unsigned i = GET_32BIT(pktin.body); |
| 2025 | struct ssh_channel *c; |
| 2026 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 2027 | if (c) { |
| 2028 | int closetype; |
| 2029 | closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
| 2030 | send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END); |
| 2031 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
| 2032 | logevent("X11 connection closed"); |
| 2033 | assert(c->u.x11.s != NULL); |
| 2034 | x11_close(c->u.x11.s); |
| 2035 | c->u.x11.s = NULL; |
| 2036 | } |
| 2037 | c->closes |= closetype; |
| 2038 | if (c->closes == 3) { |
| 2039 | del234(ssh_channels, c); |
| 2040 | sfree(c); |
| 2041 | } |
| 2042 | } |
| 2043 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
| 2044 | /* Data sent down one of our channels. */ |
| 2045 | int i = GET_32BIT(pktin.body); |
| 2046 | int len = GET_32BIT(pktin.body+4); |
| 2047 | unsigned char *p = pktin.body+8; |
| 2048 | struct ssh_channel *c; |
| 2049 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 2050 | if (c) { |
| 2051 | switch(c->type) { |
| 2052 | case CHAN_X11: |
| 2053 | x11_send(c->u.x11.s, p, len); |
| 2054 | break; |
| 2055 | case CHAN_AGENT: |
| 2056 | /* Data for an agent message. Buffer it. */ |
| 2057 | while (len > 0) { |
| 2058 | if (c->u.a.lensofar < 4) { |
| 2059 | int l = min(4 - c->u.a.lensofar, len); |
| 2060 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, l); |
| 2061 | p += l; len -= l; c->u.a.lensofar += l; |
| 2062 | } |
| 2063 | if (c->u.a.lensofar == 4) { |
| 2064 | c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen); |
| 2065 | c->u.a.message = smalloc(c->u.a.totallen); |
| 2066 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 2067 | } |
| 2068 | if (c->u.a.lensofar >= 4 && len > 0) { |
| 2069 | int l = min(c->u.a.totallen - c->u.a.lensofar, len); |
| 2070 | memcpy(c->u.a.message + c->u.a.lensofar, p, l); |
| 2071 | p += l; len -= l; c->u.a.lensofar += l; |
| 2072 | } |
| 2073 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 2074 | void *reply, *sentreply; |
| 2075 | int replylen; |
| 2076 | agent_query(c->u.a.message, c->u.a.totallen, |
| 2077 | &reply, &replylen); |
| 2078 | if (reply) |
| 2079 | sentreply = reply; |
| 2080 | else { |
| 2081 | /* Fake SSH_AGENT_FAILURE. */ |
| 2082 | sentreply = "\0\0\0\1\5"; |
| 2083 | replylen = 5; |
| 2084 | } |
| 2085 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 2086 | PKT_INT, c->remoteid, |
| 2087 | PKT_INT, replylen, |
| 2088 | PKT_DATA, sentreply, replylen, |
| 2089 | PKT_END); |
| 2090 | if (reply) |
| 2091 | sfree(reply); |
| 2092 | sfree(c->u.a.message); |
| 2093 | c->u.a.lensofar = 0; |
| 2094 | } |
| 2095 | } |
| 2096 | break; |
| 2097 | } |
| 2098 | } |
| 2099 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 2100 | /* may be from EXEC_SHELL on some servers */ |
| 2101 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2102 | /* may be from EXEC_SHELL on some servers |
| 2103 | * if no pty is available or in other odd cases. Ignore */ |
| 2104 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 2105 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 2106 | } else { |
| 2107 | bombout(("Strange packet received: type %d", pktin.type)); |
| 2108 | crReturnV; |
| 2109 | } |
| 2110 | } else { |
| 2111 | while (inlen > 0) { |
| 2112 | int len = min(inlen, 512); |
| 2113 | send_packet(SSH1_CMSG_STDIN_DATA, |
| 2114 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
| 2115 | in += len; |
| 2116 | inlen -= len; |
| 2117 | } |
| 2118 | } |
| 2119 | } |
| 2120 | |
| 2121 | crFinishV; |
| 2122 | } |
| 2123 | |
| 2124 | /* |
| 2125 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 2126 | */ |
| 2127 | static int in_commasep_string(char *needle, char *haystack, int haylen) { |
| 2128 | int needlen = strlen(needle); |
| 2129 | while (1) { |
| 2130 | /* |
| 2131 | * Is it at the start of the string? |
| 2132 | */ |
| 2133 | if (haylen >= needlen && /* haystack is long enough */ |
| 2134 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 2135 | (haylen == needlen || haystack[needlen] == ',') |
| 2136 | /* either , or EOS follows */ |
| 2137 | ) |
| 2138 | return 1; |
| 2139 | /* |
| 2140 | * If not, search for the next comma and resume after that. |
| 2141 | * If no comma found, terminate. |
| 2142 | */ |
| 2143 | while (haylen > 0 && *haystack != ',') |
| 2144 | haylen--, haystack++; |
| 2145 | if (haylen == 0) |
| 2146 | return 0; |
| 2147 | haylen--, haystack++; /* skip over comma itself */ |
| 2148 | } |
| 2149 | } |
| 2150 | |
| 2151 | /* |
| 2152 | * SSH2 key creation method. |
| 2153 | */ |
| 2154 | static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) { |
| 2155 | SHA_State s; |
| 2156 | /* First 20 bytes. */ |
| 2157 | SHA_Init(&s); |
| 2158 | sha_mpint(&s, K); |
| 2159 | SHA_Bytes(&s, H, 20); |
| 2160 | SHA_Bytes(&s, &chr, 1); |
| 2161 | SHA_Bytes(&s, sessid, 20); |
| 2162 | SHA_Final(&s, keyspace); |
| 2163 | /* Next 20 bytes. */ |
| 2164 | SHA_Init(&s); |
| 2165 | sha_mpint(&s, K); |
| 2166 | SHA_Bytes(&s, H, 20); |
| 2167 | SHA_Bytes(&s, keyspace, 20); |
| 2168 | SHA_Final(&s, keyspace+20); |
| 2169 | } |
| 2170 | |
| 2171 | /* |
| 2172 | * Handle the SSH2 transport layer. |
| 2173 | */ |
| 2174 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
| 2175 | { |
| 2176 | static int i, j, len, nbits; |
| 2177 | static char *str; |
| 2178 | static Bignum p, g, e, f, K; |
| 2179 | static int kex_init_value, kex_reply_value; |
| 2180 | static const struct ssh_mac **maclist; |
| 2181 | static int nmacs; |
| 2182 | static const struct ssh2_cipher *cscipher_tobe = NULL; |
| 2183 | static const struct ssh2_cipher *sccipher_tobe = NULL; |
| 2184 | static const struct ssh_mac *csmac_tobe = NULL; |
| 2185 | static const struct ssh_mac *scmac_tobe = NULL; |
| 2186 | static const struct ssh_compress *cscomp_tobe = NULL; |
| 2187 | static const struct ssh_compress *sccomp_tobe = NULL; |
| 2188 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
| 2189 | static int hostkeylen, siglen; |
| 2190 | static void *hkey; /* actual host key */ |
| 2191 | static unsigned char exchange_hash[20]; |
| 2192 | static unsigned char keyspace[40]; |
| 2193 | static const struct ssh2_ciphers *preferred_cipher; |
| 2194 | static const struct ssh_compress *preferred_comp; |
| 2195 | static int first_kex; |
| 2196 | |
| 2197 | crBegin; |
| 2198 | random_init(); |
| 2199 | first_kex = 1; |
| 2200 | |
| 2201 | /* |
| 2202 | * Set up the preferred cipher and compression. |
| 2203 | */ |
| 2204 | if (cfg.cipher == CIPHER_BLOWFISH) { |
| 2205 | preferred_cipher = &ssh2_blowfish; |
| 2206 | } else if (cfg.cipher == CIPHER_DES) { |
| 2207 | logevent("Single DES not supported in SSH2; using 3DES"); |
| 2208 | preferred_cipher = &ssh2_3des; |
| 2209 | } else if (cfg.cipher == CIPHER_3DES) { |
| 2210 | preferred_cipher = &ssh2_3des; |
| 2211 | } else if (cfg.cipher == CIPHER_AES) { |
| 2212 | preferred_cipher = &ssh2_aes; |
| 2213 | } else { |
| 2214 | /* Shouldn't happen, but we do want to initialise to _something_. */ |
| 2215 | preferred_cipher = &ssh2_3des; |
| 2216 | } |
| 2217 | if (cfg.compression) |
| 2218 | preferred_comp = &ssh_zlib; |
| 2219 | else |
| 2220 | preferred_comp = &ssh_comp_none; |
| 2221 | |
| 2222 | /* |
| 2223 | * Be prepared to work around the buggy MAC problem. |
| 2224 | */ |
| 2225 | if (cfg.buggymac) |
| 2226 | maclist = buggymacs, nmacs = lenof(buggymacs); |
| 2227 | else |
| 2228 | maclist = macs, nmacs = lenof(macs); |
| 2229 | |
| 2230 | begin_key_exchange: |
| 2231 | /* |
| 2232 | * Construct and send our key exchange packet. |
| 2233 | */ |
| 2234 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
| 2235 | for (i = 0; i < 16; i++) |
| 2236 | ssh2_pkt_addbyte((unsigned char)random_byte()); |
| 2237 | /* List key exchange algorithms. */ |
| 2238 | ssh2_pkt_addstring_start(); |
| 2239 | for (i = 0; i < lenof(kex_algs); i++) { |
| 2240 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
| 2241 | if (i < lenof(kex_algs)-1) |
| 2242 | ssh2_pkt_addstring_str(","); |
| 2243 | } |
| 2244 | /* List server host key algorithms. */ |
| 2245 | ssh2_pkt_addstring_start(); |
| 2246 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 2247 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
| 2248 | if (i < lenof(hostkey_algs)-1) |
| 2249 | ssh2_pkt_addstring_str(","); |
| 2250 | } |
| 2251 | /* List client->server encryption algorithms. */ |
| 2252 | ssh2_pkt_addstring_start(); |
| 2253 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2254 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2255 | for (j = 0; j < c->nciphers; j++) { |
| 2256 | ssh2_pkt_addstring_str(c->list[j]->name); |
| 2257 | if (i < lenof(ciphers) || j < c->nciphers-1) |
| 2258 | ssh2_pkt_addstring_str(","); |
| 2259 | } |
| 2260 | } |
| 2261 | /* List server->client encryption algorithms. */ |
| 2262 | ssh2_pkt_addstring_start(); |
| 2263 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2264 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2265 | for (j = 0; j < c->nciphers; j++) { |
| 2266 | ssh2_pkt_addstring_str(c->list[j]->name); |
| 2267 | if (i < lenof(ciphers) || j < c->nciphers-1) |
| 2268 | ssh2_pkt_addstring_str(","); |
| 2269 | } |
| 2270 | } |
| 2271 | /* List client->server MAC algorithms. */ |
| 2272 | ssh2_pkt_addstring_start(); |
| 2273 | for (i = 0; i < nmacs; i++) { |
| 2274 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 2275 | if (i < nmacs-1) |
| 2276 | ssh2_pkt_addstring_str(","); |
| 2277 | } |
| 2278 | /* List server->client MAC algorithms. */ |
| 2279 | ssh2_pkt_addstring_start(); |
| 2280 | for (i = 0; i < nmacs; i++) { |
| 2281 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 2282 | if (i < nmacs-1) |
| 2283 | ssh2_pkt_addstring_str(","); |
| 2284 | } |
| 2285 | /* List client->server compression algorithms. */ |
| 2286 | ssh2_pkt_addstring_start(); |
| 2287 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2288 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2289 | ssh2_pkt_addstring_str(c->name); |
| 2290 | if (i < lenof(compressions)) |
| 2291 | ssh2_pkt_addstring_str(","); |
| 2292 | } |
| 2293 | /* List server->client compression algorithms. */ |
| 2294 | ssh2_pkt_addstring_start(); |
| 2295 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2296 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2297 | ssh2_pkt_addstring_str(c->name); |
| 2298 | if (i < lenof(compressions)) |
| 2299 | ssh2_pkt_addstring_str(","); |
| 2300 | } |
| 2301 | /* List client->server languages. Empty list. */ |
| 2302 | ssh2_pkt_addstring_start(); |
| 2303 | /* List server->client languages. Empty list. */ |
| 2304 | ssh2_pkt_addstring_start(); |
| 2305 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 2306 | ssh2_pkt_addbool(FALSE); |
| 2307 | /* Reserved. */ |
| 2308 | ssh2_pkt_adduint32(0); |
| 2309 | |
| 2310 | exhash = exhashbase; |
| 2311 | sha_string(&exhash, pktout.data+5, pktout.length-5); |
| 2312 | |
| 2313 | ssh2_pkt_send(); |
| 2314 | |
| 2315 | if (!ispkt) crWaitUntil(ispkt); |
| 2316 | sha_string(&exhash, pktin.data+5, pktin.length-5); |
| 2317 | |
| 2318 | /* |
| 2319 | * Now examine the other side's KEXINIT to see what we're up |
| 2320 | * to. |
| 2321 | */ |
| 2322 | if (pktin.type != SSH2_MSG_KEXINIT) { |
| 2323 | bombout(("expected key exchange packet from server")); |
| 2324 | crReturn(0); |
| 2325 | } |
| 2326 | kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL; |
| 2327 | csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL; |
| 2328 | pktin.savedpos += 16; /* skip garbage cookie */ |
| 2329 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
| 2330 | for (i = 0; i < lenof(kex_algs); i++) { |
| 2331 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
| 2332 | kex = kex_algs[i]; |
| 2333 | break; |
| 2334 | } |
| 2335 | } |
| 2336 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
| 2337 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 2338 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 2339 | hostkey = hostkey_algs[i]; |
| 2340 | break; |
| 2341 | } |
| 2342 | } |
| 2343 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
| 2344 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2345 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2346 | for (j = 0; j < c->nciphers; j++) { |
| 2347 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 2348 | cscipher_tobe = c->list[j]; |
| 2349 | break; |
| 2350 | } |
| 2351 | } |
| 2352 | if (cscipher_tobe) |
| 2353 | break; |
| 2354 | } |
| 2355 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
| 2356 | for (i = 0; i < lenof(ciphers)+1; i++) { |
| 2357 | const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1]; |
| 2358 | for (j = 0; j < c->nciphers; j++) { |
| 2359 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 2360 | sccipher_tobe = c->list[j]; |
| 2361 | break; |
| 2362 | } |
| 2363 | } |
| 2364 | if (sccipher_tobe) |
| 2365 | break; |
| 2366 | } |
| 2367 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
| 2368 | for (i = 0; i < nmacs; i++) { |
| 2369 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 2370 | csmac_tobe = maclist[i]; |
| 2371 | break; |
| 2372 | } |
| 2373 | } |
| 2374 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
| 2375 | for (i = 0; i < nmacs; i++) { |
| 2376 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 2377 | scmac_tobe = maclist[i]; |
| 2378 | break; |
| 2379 | } |
| 2380 | } |
| 2381 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
| 2382 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2383 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2384 | if (in_commasep_string(c->name, str, len)) { |
| 2385 | cscomp_tobe = c; |
| 2386 | break; |
| 2387 | } |
| 2388 | } |
| 2389 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
| 2390 | for (i = 0; i < lenof(compressions)+1; i++) { |
| 2391 | const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1]; |
| 2392 | if (in_commasep_string(c->name, str, len)) { |
| 2393 | sccomp_tobe = c; |
| 2394 | break; |
| 2395 | } |
| 2396 | } |
| 2397 | |
| 2398 | /* |
| 2399 | * If we're doing Diffie-Hellman group exchange, start by |
| 2400 | * requesting a group. |
| 2401 | */ |
| 2402 | if (kex == &ssh_diffiehellman_gex) { |
| 2403 | int csbits, scbits; |
| 2404 | |
| 2405 | logevent("Doing Diffie-Hellman group exchange"); |
| 2406 | /* |
| 2407 | * Work out number of bits. We start with the maximum key |
| 2408 | * length of either cipher... |
| 2409 | */ |
| 2410 | csbits = cscipher_tobe->keylen; |
| 2411 | scbits = sccipher_tobe->keylen; |
| 2412 | nbits = (csbits > scbits ? csbits : scbits); |
| 2413 | /* The keys only have 160-bit entropy, since they're based on |
| 2414 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
| 2415 | if (nbits > 160) nbits = 160; |
| 2416 | /* |
| 2417 | * ... and then work out how big a DH group we will need to |
| 2418 | * allow that much data. |
| 2419 | */ |
| 2420 | nbits = 512 << ((nbits-1) / 64); |
| 2421 | ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
| 2422 | ssh2_pkt_adduint32(nbits); |
| 2423 | ssh2_pkt_send(); |
| 2424 | |
| 2425 | crWaitUntil(ispkt); |
| 2426 | if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
| 2427 | bombout(("expected key exchange group packet from server")); |
| 2428 | crReturn(0); |
| 2429 | } |
| 2430 | p = ssh2_pkt_getmp(); |
| 2431 | g = ssh2_pkt_getmp(); |
| 2432 | dh_setup_group(p, g); |
| 2433 | kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
| 2434 | kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
| 2435 | } else { |
| 2436 | dh_setup_group1(); |
| 2437 | kex_init_value = SSH2_MSG_KEXDH_INIT; |
| 2438 | kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
| 2439 | } |
| 2440 | |
| 2441 | logevent("Doing Diffie-Hellman key exchange"); |
| 2442 | /* |
| 2443 | * Now generate and send e for Diffie-Hellman. |
| 2444 | */ |
| 2445 | e = dh_create_e(); |
| 2446 | ssh2_pkt_init(kex_init_value); |
| 2447 | ssh2_pkt_addmp(e); |
| 2448 | ssh2_pkt_send(); |
| 2449 | |
| 2450 | crWaitUntil(ispkt); |
| 2451 | if (pktin.type != kex_reply_value) { |
| 2452 | bombout(("expected key exchange reply packet from server")); |
| 2453 | crReturn(0); |
| 2454 | } |
| 2455 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
| 2456 | f = ssh2_pkt_getmp(); |
| 2457 | ssh2_pkt_getstring(&sigdata, &siglen); |
| 2458 | |
| 2459 | K = dh_find_K(f); |
| 2460 | |
| 2461 | sha_string(&exhash, hostkeydata, hostkeylen); |
| 2462 | if (kex == &ssh_diffiehellman_gex) { |
| 2463 | sha_uint32(&exhash, nbits); |
| 2464 | sha_mpint(&exhash, p); |
| 2465 | sha_mpint(&exhash, g); |
| 2466 | } |
| 2467 | sha_mpint(&exhash, e); |
| 2468 | sha_mpint(&exhash, f); |
| 2469 | sha_mpint(&exhash, K); |
| 2470 | SHA_Final(&exhash, exchange_hash); |
| 2471 | |
| 2472 | dh_cleanup(); |
| 2473 | |
| 2474 | #if 0 |
| 2475 | debug(("Exchange hash is:\r\n")); |
| 2476 | for (i = 0; i < 20; i++) |
| 2477 | debug((" %02x", exchange_hash[i])); |
| 2478 | debug(("\r\n")); |
| 2479 | #endif |
| 2480 | |
| 2481 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
| 2482 | if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
| 2483 | bombout(("Server failed host key check")); |
| 2484 | crReturn(0); |
| 2485 | } |
| 2486 | |
| 2487 | /* |
| 2488 | * Expect SSH2_MSG_NEWKEYS from server. |
| 2489 | */ |
| 2490 | crWaitUntil(ispkt); |
| 2491 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
| 2492 | bombout(("expected new-keys packet from server")); |
| 2493 | crReturn(0); |
| 2494 | } |
| 2495 | |
| 2496 | /* |
| 2497 | * Authenticate remote host: verify host key. (We've already |
| 2498 | * checked the signature of the exchange hash.) |
| 2499 | */ |
| 2500 | keystr = hostkey->fmtkey(hkey); |
| 2501 | fingerprint = hostkey->fingerprint(hkey); |
| 2502 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
| 2503 | keystr, fingerprint); |
| 2504 | if (first_kex) { /* don't bother logging this in rekeys */ |
| 2505 | logevent("Host key fingerprint is:"); |
| 2506 | logevent(fingerprint); |
| 2507 | } |
| 2508 | sfree(fingerprint); |
| 2509 | sfree(keystr); |
| 2510 | hostkey->freekey(hkey); |
| 2511 | |
| 2512 | /* |
| 2513 | * Send SSH2_MSG_NEWKEYS. |
| 2514 | */ |
| 2515 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
| 2516 | ssh2_pkt_send(); |
| 2517 | |
| 2518 | /* |
| 2519 | * Create and initialise session keys. |
| 2520 | */ |
| 2521 | cscipher = cscipher_tobe; |
| 2522 | sccipher = sccipher_tobe; |
| 2523 | csmac = csmac_tobe; |
| 2524 | scmac = scmac_tobe; |
| 2525 | cscomp = cscomp_tobe; |
| 2526 | sccomp = sccomp_tobe; |
| 2527 | cscomp->compress_init(); |
| 2528 | sccomp->decompress_init(); |
| 2529 | /* |
| 2530 | * Set IVs after keys. Here we use the exchange hash from the |
| 2531 | * _first_ key exchange. |
| 2532 | */ |
| 2533 | if (first_kex) |
| 2534 | memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); |
| 2535 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); |
| 2536 | cscipher->setcskey(keyspace); |
| 2537 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); |
| 2538 | sccipher->setsckey(keyspace); |
| 2539 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); |
| 2540 | cscipher->setcsiv(keyspace); |
| 2541 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); |
| 2542 | sccipher->setsciv(keyspace); |
| 2543 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); |
| 2544 | csmac->setcskey(keyspace); |
| 2545 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); |
| 2546 | scmac->setsckey(keyspace); |
| 2547 | |
| 2548 | /* |
| 2549 | * If this is the first key exchange phase, we must pass the |
| 2550 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
| 2551 | * wants to see it but because it will need time to initialise |
| 2552 | * itself before it sees an actual packet. In subsequent key |
| 2553 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
| 2554 | * it would only confuse the layer above. |
| 2555 | */ |
| 2556 | if (!first_kex) { |
| 2557 | crReturn(0); |
| 2558 | } |
| 2559 | first_kex = 0; |
| 2560 | |
| 2561 | /* |
| 2562 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 2563 | * function so that other things can run on top of the |
| 2564 | * transport. If we ever see a KEXINIT, we must go back to the |
| 2565 | * start. |
| 2566 | */ |
| 2567 | while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { |
| 2568 | crReturn(1); |
| 2569 | } |
| 2570 | logevent("Server initiated key re-exchange"); |
| 2571 | goto begin_key_exchange; |
| 2572 | |
| 2573 | crFinish(1); |
| 2574 | } |
| 2575 | |
| 2576 | /* |
| 2577 | * Add data to an SSH2 channel output buffer. |
| 2578 | */ |
| 2579 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) { |
| 2580 | if (c->v2.outbufsize < |
| 2581 | c->v2.outbuflen + len) { |
| 2582 | c->v2.outbufsize = |
| 2583 | c->v2.outbuflen + len + 1024; |
| 2584 | c->v2.outbuffer = srealloc(c->v2.outbuffer, |
| 2585 | c->v2.outbufsize); |
| 2586 | } |
| 2587 | memcpy(c->v2.outbuffer + c->v2.outbuflen, |
| 2588 | buf, len); |
| 2589 | c->v2.outbuflen += len; |
| 2590 | } |
| 2591 | |
| 2592 | /* |
| 2593 | * Attempt to send data on an SSH2 channel. |
| 2594 | */ |
| 2595 | static void ssh2_try_send(struct ssh_channel *c) { |
| 2596 | while (c->v2.remwindow > 0 && |
| 2597 | c->v2.outbuflen > 0) { |
| 2598 | unsigned len = c->v2.remwindow; |
| 2599 | if (len > c->v2.outbuflen) |
| 2600 | len = c->v2.outbuflen; |
| 2601 | if (len > c->v2.remmaxpkt) |
| 2602 | len = c->v2.remmaxpkt; |
| 2603 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
| 2604 | ssh2_pkt_adduint32(c->remoteid); |
| 2605 | ssh2_pkt_addstring_start(); |
| 2606 | ssh2_pkt_addstring_data(c->v2.outbuffer, len); |
| 2607 | ssh2_pkt_send(); |
| 2608 | c->v2.outbuflen -= len; |
| 2609 | memmove(c->v2.outbuffer, c->v2.outbuffer+len, |
| 2610 | c->v2.outbuflen); |
| 2611 | c->v2.remwindow -= len; |
| 2612 | } |
| 2613 | } |
| 2614 | |
| 2615 | /* |
| 2616 | * Handle the SSH2 userauth and connection layers. |
| 2617 | */ |
| 2618 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
| 2619 | { |
| 2620 | static unsigned long remote_winsize; |
| 2621 | static unsigned long remote_maxpkt; |
| 2622 | static enum { |
| 2623 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD |
| 2624 | } method; |
| 2625 | static enum { |
| 2626 | AUTH_TYPE_NONE, |
| 2627 | AUTH_TYPE_PUBLICKEY, |
| 2628 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
| 2629 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
| 2630 | AUTH_TYPE_PASSWORD |
| 2631 | } type; |
| 2632 | static int gotit, need_pw, can_pubkey, can_passwd; |
| 2633 | static int tried_pubkey_config, tried_agent; |
| 2634 | static int we_are_in; |
| 2635 | static char username[100]; |
| 2636 | static char pwprompt[200]; |
| 2637 | static char password[100]; |
| 2638 | |
| 2639 | crBegin; |
| 2640 | |
| 2641 | /* |
| 2642 | * Request userauth protocol, and await a response to it. |
| 2643 | */ |
| 2644 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 2645 | ssh2_pkt_addstring("ssh-userauth"); |
| 2646 | ssh2_pkt_send(); |
| 2647 | crWaitUntilV(ispkt); |
| 2648 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
| 2649 | bombout(("Server refused user authentication protocol")); |
| 2650 | crReturnV; |
| 2651 | } |
| 2652 | |
| 2653 | /* |
| 2654 | * We repeat this whole loop, including the username prompt, |
| 2655 | * until we manage a successful authentication. If the user |
| 2656 | * types the wrong _password_, they are sent back to the |
| 2657 | * beginning to try another username. (If they specify a |
| 2658 | * username in the config, they are never asked, even if they |
| 2659 | * do give a wrong password.) |
| 2660 | * |
| 2661 | * I think this best serves the needs of |
| 2662 | * |
| 2663 | * - the people who have no configuration, no keys, and just |
| 2664 | * want to try repeated (username,password) pairs until they |
| 2665 | * type both correctly |
| 2666 | * |
| 2667 | * - people who have keys and configuration but occasionally |
| 2668 | * need to fall back to passwords |
| 2669 | * |
| 2670 | * - people with a key held in Pageant, who might not have |
| 2671 | * logged in to a particular machine before; so they want to |
| 2672 | * type a username, and then _either_ their key will be |
| 2673 | * accepted, _or_ they will type a password. If they mistype |
| 2674 | * the username they will want to be able to get back and |
| 2675 | * retype it! |
| 2676 | */ |
| 2677 | do { |
| 2678 | static int pos; |
| 2679 | static char c; |
| 2680 | |
| 2681 | /* |
| 2682 | * Get a username. |
| 2683 | */ |
| 2684 | pos = 0; |
| 2685 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 2686 | c_write_str("login as: "); |
| 2687 | ssh_send_ok = 1; |
| 2688 | while (pos >= 0) { |
| 2689 | crWaitUntilV(!ispkt); |
| 2690 | while (inlen--) switch (c = *in++) { |
| 2691 | case 10: case 13: |
| 2692 | username[pos] = 0; |
| 2693 | pos = -1; |
| 2694 | break; |
| 2695 | case 8: case 127: |
| 2696 | if (pos > 0) { |
| 2697 | c_write_str("\b \b"); |
| 2698 | pos--; |
| 2699 | } |
| 2700 | break; |
| 2701 | case 21: case 27: |
| 2702 | while (pos > 0) { |
| 2703 | c_write_str("\b \b"); |
| 2704 | pos--; |
| 2705 | } |
| 2706 | break; |
| 2707 | case 3: case 4: |
| 2708 | random_save_seed(); |
| 2709 | exit(0); |
| 2710 | break; |
| 2711 | default: |
| 2712 | if (((c >= ' ' && c <= '~') || |
| 2713 | ((unsigned char)c >= 160)) && pos < 40) { |
| 2714 | username[pos++] = c; |
| 2715 | c_write(&c, 1); |
| 2716 | } |
| 2717 | break; |
| 2718 | } |
| 2719 | } |
| 2720 | c_write_str("\r\n"); |
| 2721 | username[strcspn(username, "\n\r")] = '\0'; |
| 2722 | } else { |
| 2723 | char stuff[200]; |
| 2724 | strncpy(username, cfg.username, 99); |
| 2725 | username[99] = '\0'; |
| 2726 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
| 2727 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
| 2728 | c_write_str(stuff); |
| 2729 | } |
| 2730 | } |
| 2731 | |
| 2732 | /* |
| 2733 | * Send an authentication request using method "none": (a) |
| 2734 | * just in case it succeeds, and (b) so that we know what |
| 2735 | * authentication methods we can usefully try next. |
| 2736 | */ |
| 2737 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 2738 | ssh2_pkt_addstring(username); |
| 2739 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 2740 | ssh2_pkt_addstring("none"); /* method */ |
| 2741 | ssh2_pkt_send(); |
| 2742 | type = AUTH_TYPE_NONE; |
| 2743 | gotit = FALSE; |
| 2744 | we_are_in = FALSE; |
| 2745 | |
| 2746 | tried_pubkey_config = FALSE; |
| 2747 | tried_agent = FALSE; |
| 2748 | |
| 2749 | while (1) { |
| 2750 | /* |
| 2751 | * Wait for the result of the last authentication request. |
| 2752 | */ |
| 2753 | if (!gotit) |
| 2754 | crWaitUntilV(ispkt); |
| 2755 | while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
| 2756 | /* FIXME: should support this */ |
| 2757 | crWaitUntilV(ispkt); |
| 2758 | } |
| 2759 | if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
| 2760 | logevent("Access granted"); |
| 2761 | we_are_in = TRUE; |
| 2762 | break; |
| 2763 | } |
| 2764 | |
| 2765 | if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
| 2766 | bombout(("Strange packet received during authentication: type %d", |
| 2767 | pktin.type)); |
| 2768 | } |
| 2769 | |
| 2770 | gotit = FALSE; |
| 2771 | |
| 2772 | /* |
| 2773 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
| 2774 | * we can look at the string in it and know what we can |
| 2775 | * helpfully try next. |
| 2776 | */ |
| 2777 | { |
| 2778 | char *methods; |
| 2779 | int methlen; |
| 2780 | ssh2_pkt_getstring(&methods, &methlen); |
| 2781 | if (!ssh2_pkt_getbool()) { |
| 2782 | /* |
| 2783 | * We have received an unequivocal Access |
| 2784 | * Denied. This can translate to a variety of |
| 2785 | * messages: |
| 2786 | * |
| 2787 | * - if we'd just tried "none" authentication, |
| 2788 | * it's not worth printing anything at all |
| 2789 | * |
| 2790 | * - if we'd just tried a public key _offer_, |
| 2791 | * the message should be "Server refused our |
| 2792 | * key" (or no message at all if the key |
| 2793 | * came from Pageant) |
| 2794 | * |
| 2795 | * - if we'd just tried anything else, the |
| 2796 | * message really should be "Access denied". |
| 2797 | * |
| 2798 | * Additionally, if we'd just tried password |
| 2799 | * authentication, we should break out of this |
| 2800 | * whole loop so as to go back to the username |
| 2801 | * prompt. |
| 2802 | */ |
| 2803 | if (type == AUTH_TYPE_NONE) { |
| 2804 | /* do nothing */ |
| 2805 | } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
| 2806 | type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
| 2807 | if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
| 2808 | c_write_str("Server refused our key\r\n"); |
| 2809 | logevent("Server refused public key"); |
| 2810 | } else { |
| 2811 | c_write_str("Access denied\r\n"); |
| 2812 | logevent("Access denied"); |
| 2813 | if (type == AUTH_TYPE_PASSWORD) { |
| 2814 | we_are_in = FALSE; |
| 2815 | break; |
| 2816 | } |
| 2817 | } |
| 2818 | } else { |
| 2819 | c_write_str("Further authentication required\r\n"); |
| 2820 | logevent("Further authentication required"); |
| 2821 | } |
| 2822 | |
| 2823 | can_pubkey = in_commasep_string("publickey", methods, methlen); |
| 2824 | can_passwd = in_commasep_string("password", methods, methlen); |
| 2825 | } |
| 2826 | |
| 2827 | method = 0; |
| 2828 | |
| 2829 | if (!method && can_pubkey && agent_exists && !tried_agent) { |
| 2830 | /* |
| 2831 | * Attempt public-key authentication using Pageant. |
| 2832 | */ |
| 2833 | static unsigned char request[5], *response, *p; |
| 2834 | static int responselen; |
| 2835 | static int i, nkeys; |
| 2836 | static int authed = FALSE; |
| 2837 | void *r; |
| 2838 | |
| 2839 | tried_agent = TRUE; |
| 2840 | |
| 2841 | logevent("Pageant is running. Requesting keys."); |
| 2842 | |
| 2843 | /* Request the keys held by the agent. */ |
| 2844 | PUT_32BIT(request, 1); |
| 2845 | request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
| 2846 | agent_query(request, 5, &r, &responselen); |
| 2847 | response = (unsigned char *)r; |
| 2848 | if (response) { |
| 2849 | p = response + 5; |
| 2850 | nkeys = GET_32BIT(p); p += 4; |
| 2851 | { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys); |
| 2852 | logevent(buf); } |
| 2853 | for (i = 0; i < nkeys; i++) { |
| 2854 | static char *pkblob, *alg, *commentp; |
| 2855 | static int pklen, alglen, commentlen; |
| 2856 | static int siglen, retlen, len; |
| 2857 | static char *q, *agentreq, *ret; |
| 2858 | |
| 2859 | { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i); |
| 2860 | logevent(buf); } |
| 2861 | pklen = GET_32BIT(p); p += 4; |
| 2862 | pkblob = p; p += pklen; |
| 2863 | alglen = GET_32BIT(pkblob); |
| 2864 | alg = pkblob + 4; |
| 2865 | commentlen = GET_32BIT(p); p += 4; |
| 2866 | commentp = p; p += commentlen; |
| 2867 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 2868 | ssh2_pkt_addstring(username); |
| 2869 | ssh2_pkt_addstring("ssh-connection");/* service requested */ |
| 2870 | ssh2_pkt_addstring("publickey");/* method */ |
| 2871 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
| 2872 | ssh2_pkt_addstring_start(); |
| 2873 | ssh2_pkt_addstring_data(alg, alglen); |
| 2874 | ssh2_pkt_addstring_start(); |
| 2875 | ssh2_pkt_addstring_data(pkblob, pklen); |
| 2876 | ssh2_pkt_send(); |
| 2877 | |
| 2878 | crWaitUntilV(ispkt); |
| 2879 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 2880 | logevent("Key refused"); |
| 2881 | continue; |
| 2882 | } |
| 2883 | |
| 2884 | c_write_str("Authenticating with public key \""); |
| 2885 | c_write(commentp, commentlen); |
| 2886 | c_write_str("\" from agent\r\n"); |
| 2887 | |
| 2888 | /* |
| 2889 | * Server is willing to accept the key. |
| 2890 | * Construct a SIGN_REQUEST. |
| 2891 | */ |
| 2892 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 2893 | ssh2_pkt_addstring(username); |
| 2894 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 2895 | ssh2_pkt_addstring("publickey"); /* method */ |
| 2896 | ssh2_pkt_addbool(TRUE); |
| 2897 | ssh2_pkt_addstring_start(); |
| 2898 | ssh2_pkt_addstring_data(alg, alglen); |
| 2899 | ssh2_pkt_addstring_start(); |
| 2900 | ssh2_pkt_addstring_data(pkblob, pklen); |
| 2901 | |
| 2902 | siglen = pktout.length - 5 + 4 + 20; |
| 2903 | len = 1; /* message type */ |
| 2904 | len += 4 + pklen; /* key blob */ |
| 2905 | len += 4 + siglen; /* data to sign */ |
| 2906 | len += 4; /* flags */ |
| 2907 | agentreq = smalloc(4 + len); |
| 2908 | PUT_32BIT(agentreq, len); |
| 2909 | q = agentreq + 4; |
| 2910 | *q++ = SSH2_AGENTC_SIGN_REQUEST; |
| 2911 | PUT_32BIT(q, pklen); q += 4; |
| 2912 | memcpy(q, pkblob, pklen); q += pklen; |
| 2913 | PUT_32BIT(q, siglen); q += 4; |
| 2914 | /* Now the data to be signed... */ |
| 2915 | PUT_32BIT(q, 20); q += 4; |
| 2916 | memcpy(q, ssh2_session_id, 20); q += 20; |
| 2917 | memcpy(q, pktout.data+5, pktout.length-5); |
| 2918 | q += pktout.length-5; |
| 2919 | /* And finally the (zero) flags word. */ |
| 2920 | PUT_32BIT(q, 0); |
| 2921 | agent_query(agentreq, len+4, &ret, &retlen); |
| 2922 | sfree(agentreq); |
| 2923 | if (ret) { |
| 2924 | if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
| 2925 | logevent("Sending Pageant's response"); |
| 2926 | ssh2_pkt_addstring_start(); |
| 2927 | ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5)); |
| 2928 | ssh2_pkt_send(); |
| 2929 | authed = TRUE; |
| 2930 | break; |
| 2931 | } else { |
| 2932 | logevent("Pageant failed to answer challenge"); |
| 2933 | sfree(ret); |
| 2934 | } |
| 2935 | } |
| 2936 | } |
| 2937 | if (authed) |
| 2938 | continue; |
| 2939 | } |
| 2940 | } |
| 2941 | |
| 2942 | if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) { |
| 2943 | unsigned char *pub_blob; |
| 2944 | char *algorithm, *comment; |
| 2945 | int pub_blob_len; |
| 2946 | |
| 2947 | tried_pubkey_config = TRUE; |
| 2948 | |
| 2949 | /* |
| 2950 | * Try the public key supplied in the configuration. |
| 2951 | * |
| 2952 | * First, offer the public blob to see if the server is |
| 2953 | * willing to accept it. |
| 2954 | */ |
| 2955 | pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, |
| 2956 | &pub_blob_len); |
| 2957 | if (pub_blob) { |
| 2958 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 2959 | ssh2_pkt_addstring(username); |
| 2960 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 2961 | ssh2_pkt_addstring("publickey");/* method */ |
| 2962 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
| 2963 | ssh2_pkt_addstring(algorithm); |
| 2964 | ssh2_pkt_addstring_start(); |
| 2965 | ssh2_pkt_addstring_data(pub_blob, pub_blob_len); |
| 2966 | ssh2_pkt_send(); |
| 2967 | logevent("Offered public key"); /* FIXME */ |
| 2968 | |
| 2969 | crWaitUntilV(ispkt); |
| 2970 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 2971 | gotit = TRUE; |
| 2972 | type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
| 2973 | continue; /* key refused; give up on it */ |
| 2974 | } |
| 2975 | |
| 2976 | logevent("Offer of public key accepted"); |
| 2977 | /* |
| 2978 | * Actually attempt a serious authentication using |
| 2979 | * the key. |
| 2980 | */ |
| 2981 | if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { |
| 2982 | sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment); |
| 2983 | need_pw = TRUE; |
| 2984 | } else { |
| 2985 | need_pw = FALSE; |
| 2986 | } |
| 2987 | c_write_str("Authenticating with public key \""); |
| 2988 | c_write_str(comment); |
| 2989 | c_write_str("\"\r\n"); |
| 2990 | method = AUTH_PUBLICKEY_FILE; |
| 2991 | } |
| 2992 | } |
| 2993 | |
| 2994 | if (!method && can_passwd) { |
| 2995 | method = AUTH_PASSWORD; |
| 2996 | sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); |
| 2997 | need_pw = TRUE; |
| 2998 | } |
| 2999 | |
| 3000 | if (need_pw) { |
| 3001 | if (ssh_get_password) { |
| 3002 | if (!ssh_get_password(pwprompt, password, sizeof(password))) { |
| 3003 | /* |
| 3004 | * get_password failed to get a password (for |
| 3005 | * example because one was supplied on the command |
| 3006 | * line which has already failed to work). |
| 3007 | * Terminate. |
| 3008 | */ |
| 3009 | logevent("No more passwords to try"); |
| 3010 | ssh_state = SSH_STATE_CLOSED; |
| 3011 | crReturnV; |
| 3012 | } |
| 3013 | } else { |
| 3014 | static int pos = 0; |
| 3015 | static char c; |
| 3016 | |
| 3017 | c_write_str(pwprompt); |
| 3018 | ssh_send_ok = 1; |
| 3019 | |
| 3020 | pos = 0; |
| 3021 | while (pos >= 0) { |
| 3022 | crWaitUntilV(!ispkt); |
| 3023 | while (inlen--) switch (c = *in++) { |
| 3024 | case 10: case 13: |
| 3025 | password[pos] = 0; |
| 3026 | pos = -1; |
| 3027 | break; |
| 3028 | case 8: case 127: |
| 3029 | if (pos > 0) |
| 3030 | pos--; |
| 3031 | break; |
| 3032 | case 21: case 27: |
| 3033 | pos = 0; |
| 3034 | break; |
| 3035 | case 3: case 4: |
| 3036 | random_save_seed(); |
| 3037 | exit(0); |
| 3038 | break; |
| 3039 | default: |
| 3040 | if (((c >= ' ' && c <= '~') || |
| 3041 | ((unsigned char)c >= 160)) && pos < 40) |
| 3042 | password[pos++] = c; |
| 3043 | break; |
| 3044 | } |
| 3045 | } |
| 3046 | c_write_str("\r\n"); |
| 3047 | } |
| 3048 | } |
| 3049 | |
| 3050 | if (method == AUTH_PUBLICKEY_FILE) { |
| 3051 | /* |
| 3052 | * We have our passphrase. Now try the actual authentication. |
| 3053 | */ |
| 3054 | struct ssh2_userkey *key; |
| 3055 | |
| 3056 | key = ssh2_load_userkey(cfg.keyfile, password); |
| 3057 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
| 3058 | if (key == SSH2_WRONG_PASSPHRASE) { |
| 3059 | c_write_str("Wrong passphrase\r\n"); |
| 3060 | tried_pubkey_config = FALSE; |
| 3061 | } else { |
| 3062 | c_write_str("Unable to load private key\r\n"); |
| 3063 | tried_pubkey_config = TRUE; |
| 3064 | } |
| 3065 | /* Send a spurious AUTH_NONE to return to the top. */ |
| 3066 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3067 | ssh2_pkt_addstring(username); |
| 3068 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3069 | ssh2_pkt_addstring("none"); /* method */ |
| 3070 | ssh2_pkt_send(); |
| 3071 | type = AUTH_TYPE_NONE; |
| 3072 | } else { |
| 3073 | unsigned char *blob, *sigdata; |
| 3074 | int blob_len, sigdata_len; |
| 3075 | |
| 3076 | /* |
| 3077 | * We have loaded the private key and the server |
| 3078 | * has announced that it's willing to accept it. |
| 3079 | * Hallelujah. Generate a signature and send it. |
| 3080 | */ |
| 3081 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3082 | ssh2_pkt_addstring(username); |
| 3083 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3084 | ssh2_pkt_addstring("publickey"); /* method */ |
| 3085 | ssh2_pkt_addbool(TRUE); |
| 3086 | ssh2_pkt_addstring(key->alg->name); |
| 3087 | blob = key->alg->public_blob(key->data, &blob_len); |
| 3088 | ssh2_pkt_addstring_start(); |
| 3089 | ssh2_pkt_addstring_data(blob, blob_len); |
| 3090 | sfree(blob); |
| 3091 | |
| 3092 | /* |
| 3093 | * The data to be signed is: |
| 3094 | * |
| 3095 | * string session-id |
| 3096 | * |
| 3097 | * followed by everything so far placed in the |
| 3098 | * outgoing packet. |
| 3099 | */ |
| 3100 | sigdata_len = pktout.length - 5 + 4 + 20; |
| 3101 | sigdata = smalloc(sigdata_len); |
| 3102 | PUT_32BIT(sigdata, 20); |
| 3103 | memcpy(sigdata+4, ssh2_session_id, 20); |
| 3104 | memcpy(sigdata+24, pktout.data+5, pktout.length-5); |
| 3105 | blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len); |
| 3106 | ssh2_pkt_addstring_start(); |
| 3107 | ssh2_pkt_addstring_data(blob, blob_len); |
| 3108 | sfree(blob); |
| 3109 | sfree(sigdata); |
| 3110 | |
| 3111 | ssh2_pkt_send(); |
| 3112 | type = AUTH_TYPE_PUBLICKEY; |
| 3113 | } |
| 3114 | } else if (method == AUTH_PASSWORD) { |
| 3115 | /* |
| 3116 | * We send the password packet lumped tightly together with |
| 3117 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
| 3118 | * string long enough to make the total length of the two |
| 3119 | * packets constant. This should ensure that a passive |
| 3120 | * listener doing traffic analyis can't work out the length |
| 3121 | * of the password. |
| 3122 | * |
| 3123 | * For this to work, we need an assumption about the |
| 3124 | * maximum length of the password packet. I think 256 is |
| 3125 | * pretty conservative. Anyone using a password longer than |
| 3126 | * that probably doesn't have much to worry about from |
| 3127 | * people who find out how long their password is! |
| 3128 | */ |
| 3129 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3130 | ssh2_pkt_addstring(username); |
| 3131 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3132 | ssh2_pkt_addstring("password"); |
| 3133 | ssh2_pkt_addbool(FALSE); |
| 3134 | ssh2_pkt_addstring(password); |
| 3135 | ssh2_pkt_defer(); |
| 3136 | /* |
| 3137 | * We'll include a string that's an exact multiple of the |
| 3138 | * cipher block size. If the cipher is NULL for some |
| 3139 | * reason, we don't do this trick at all because we gain |
| 3140 | * nothing by it. |
| 3141 | */ |
| 3142 | if (cscipher) { |
| 3143 | int i, j; |
| 3144 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 3145 | ssh2_pkt_addstring_start(); |
| 3146 | for (i = deferred_len; i <= 256; i += cscipher->blksize) { |
| 3147 | for (j = 0; j < cscipher->blksize; j++) { |
| 3148 | char c = (char)random_byte(); |
| 3149 | ssh2_pkt_addstring_data(&c, 1); |
| 3150 | } |
| 3151 | } |
| 3152 | ssh2_pkt_defer(); |
| 3153 | } |
| 3154 | ssh2_pkt_defersend(); |
| 3155 | logevent("Sent password"); |
| 3156 | type = AUTH_TYPE_PASSWORD; |
| 3157 | } else { |
| 3158 | c_write_str("No supported authentication methods left to try!\r\n"); |
| 3159 | logevent("No supported authentications offered. Disconnecting"); |
| 3160 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 3161 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 3162 | ssh2_pkt_addstring("No supported authentication methods available"); |
| 3163 | ssh2_pkt_addstring("en"); /* language tag */ |
| 3164 | ssh2_pkt_send(); |
| 3165 | ssh_state = SSH_STATE_CLOSED; |
| 3166 | crReturnV; |
| 3167 | } |
| 3168 | } |
| 3169 | } while (!we_are_in); |
| 3170 | |
| 3171 | /* |
| 3172 | * Now we're authenticated for the connection protocol. The |
| 3173 | * connection protocol will automatically have started at this |
| 3174 | * point; there's no need to send SERVICE_REQUEST. |
| 3175 | */ |
| 3176 | |
| 3177 | /* |
| 3178 | * So now create a channel with a session in it. |
| 3179 | */ |
| 3180 | mainchan = smalloc(sizeof(struct ssh_channel)); |
| 3181 | mainchan->localid = 100; /* as good as any */ |
| 3182 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 3183 | ssh2_pkt_addstring("session"); |
| 3184 | ssh2_pkt_adduint32(mainchan->localid); |
| 3185 | ssh2_pkt_adduint32(0x8000UL); /* our window size */ |
| 3186 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 3187 | ssh2_pkt_send(); |
| 3188 | crWaitUntilV(ispkt); |
| 3189 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 3190 | bombout(("Server refused to open a session")); |
| 3191 | crReturnV; |
| 3192 | /* FIXME: error data comes back in FAILURE packet */ |
| 3193 | } |
| 3194 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
| 3195 | bombout(("Server's channel confirmation cited wrong channel")); |
| 3196 | crReturnV; |
| 3197 | } |
| 3198 | mainchan->remoteid = ssh2_pkt_getuint32(); |
| 3199 | mainchan->type = CHAN_MAINSESSION; |
| 3200 | mainchan->closes = 0; |
| 3201 | mainchan->v2.remwindow = ssh2_pkt_getuint32(); |
| 3202 | mainchan->v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 3203 | mainchan->v2.outbuffer = NULL; |
| 3204 | mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0; |
| 3205 | ssh_channels = newtree234(ssh_channelcmp); |
| 3206 | add234(ssh_channels, mainchan); |
| 3207 | logevent("Opened channel for session"); |
| 3208 | |
| 3209 | /* |
| 3210 | * Potentially enable X11 forwarding. |
| 3211 | */ |
| 3212 | if (cfg.x11_forward) { |
| 3213 | char proto[20], data[64]; |
| 3214 | logevent("Requesting X11 forwarding"); |
| 3215 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
| 3216 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 3217 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 3218 | ssh2_pkt_addstring("x11-req"); |
| 3219 | ssh2_pkt_addbool(1); /* want reply */ |
| 3220 | ssh2_pkt_addbool(0); /* many connections */ |
| 3221 | ssh2_pkt_addstring(proto); |
| 3222 | ssh2_pkt_addstring(data); |
| 3223 | ssh2_pkt_adduint32(0); /* screen number */ |
| 3224 | ssh2_pkt_send(); |
| 3225 | |
| 3226 | do { |
| 3227 | crWaitUntilV(ispkt); |
| 3228 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 3229 | unsigned i = ssh2_pkt_getuint32(); |
| 3230 | struct ssh_channel *c; |
| 3231 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3232 | if (!c) |
| 3233 | continue; /* nonexistent channel */ |
| 3234 | c->v2.remwindow += ssh2_pkt_getuint32(); |
| 3235 | } |
| 3236 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 3237 | |
| 3238 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 3239 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 3240 | bombout(("Server got confused by X11 forwarding request")); |
| 3241 | crReturnV; |
| 3242 | } |
| 3243 | logevent("X11 forwarding refused"); |
| 3244 | } else { |
| 3245 | logevent("X11 forwarding enabled"); |
| 3246 | ssh_X11_fwd_enabled = TRUE; |
| 3247 | } |
| 3248 | } |
| 3249 | |
| 3250 | /* |
| 3251 | * Now allocate a pty for the session. |
| 3252 | */ |
| 3253 | if (!cfg.nopty) { |
| 3254 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 3255 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 3256 | ssh2_pkt_addstring("pty-req"); |
| 3257 | ssh2_pkt_addbool(1); /* want reply */ |
| 3258 | ssh2_pkt_addstring(cfg.termtype); |
| 3259 | ssh2_pkt_adduint32(cols); |
| 3260 | ssh2_pkt_adduint32(rows); |
| 3261 | ssh2_pkt_adduint32(0); /* pixel width */ |
| 3262 | ssh2_pkt_adduint32(0); /* pixel height */ |
| 3263 | ssh2_pkt_addstring_start(); |
| 3264 | ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */ |
| 3265 | ssh2_pkt_send(); |
| 3266 | ssh_state = SSH_STATE_INTERMED; |
| 3267 | |
| 3268 | do { |
| 3269 | crWaitUntilV(ispkt); |
| 3270 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 3271 | unsigned i = ssh2_pkt_getuint32(); |
| 3272 | struct ssh_channel *c; |
| 3273 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3274 | if (!c) |
| 3275 | continue; /* nonexistent channel */ |
| 3276 | c->v2.remwindow += ssh2_pkt_getuint32(); |
| 3277 | } |
| 3278 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 3279 | |
| 3280 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 3281 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 3282 | bombout(("Server got confused by pty request")); |
| 3283 | crReturnV; |
| 3284 | } |
| 3285 | c_write_str("Server refused to allocate pty\r\n"); |
| 3286 | ssh_editing = ssh_echoing = 1; |
| 3287 | } else { |
| 3288 | logevent("Allocated pty"); |
| 3289 | } |
| 3290 | } else { |
| 3291 | ssh_editing = ssh_echoing = 1; |
| 3292 | } |
| 3293 | |
| 3294 | /* |
| 3295 | * Start a shell or a remote command. |
| 3296 | */ |
| 3297 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 3298 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 3299 | if (cfg.ssh_subsys) { |
| 3300 | ssh2_pkt_addstring("subsystem"); |
| 3301 | ssh2_pkt_addbool(1); /* want reply */ |
| 3302 | ssh2_pkt_addstring(cfg.remote_cmd); |
| 3303 | } else if (*cfg.remote_cmd) { |
| 3304 | ssh2_pkt_addstring("exec"); |
| 3305 | ssh2_pkt_addbool(1); /* want reply */ |
| 3306 | ssh2_pkt_addstring(cfg.remote_cmd); |
| 3307 | } else { |
| 3308 | ssh2_pkt_addstring("shell"); |
| 3309 | ssh2_pkt_addbool(1); /* want reply */ |
| 3310 | } |
| 3311 | ssh2_pkt_send(); |
| 3312 | do { |
| 3313 | crWaitUntilV(ispkt); |
| 3314 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 3315 | unsigned i = ssh2_pkt_getuint32(); |
| 3316 | struct ssh_channel *c; |
| 3317 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3318 | if (!c) |
| 3319 | continue; /* nonexistent channel */ |
| 3320 | c->v2.remwindow += ssh2_pkt_getuint32(); |
| 3321 | } |
| 3322 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 3323 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 3324 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 3325 | bombout(("Server got confused by shell/command request")); |
| 3326 | crReturnV; |
| 3327 | } |
| 3328 | bombout(("Server refused to start a shell/command")); |
| 3329 | crReturnV; |
| 3330 | } else { |
| 3331 | logevent("Started a shell/command"); |
| 3332 | } |
| 3333 | |
| 3334 | ssh_state = SSH_STATE_SESSION; |
| 3335 | if (size_needed) |
| 3336 | ssh_size(); |
| 3337 | if (eof_needed) |
| 3338 | ssh_special(TS_EOF); |
| 3339 | |
| 3340 | /* |
| 3341 | * Transfer data! |
| 3342 | */ |
| 3343 | ldisc_send(NULL, 0); /* cause ldisc to notice changes */ |
| 3344 | ssh_send_ok = 1; |
| 3345 | while (1) { |
| 3346 | static int try_send; |
| 3347 | crReturnV; |
| 3348 | try_send = FALSE; |
| 3349 | if (ispkt) { |
| 3350 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
| 3351 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 3352 | char *data; |
| 3353 | int length; |
| 3354 | unsigned i = ssh2_pkt_getuint32(); |
| 3355 | struct ssh_channel *c; |
| 3356 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3357 | if (!c) |
| 3358 | continue; /* nonexistent channel */ |
| 3359 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 3360 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
| 3361 | continue; /* extended but not stderr */ |
| 3362 | ssh2_pkt_getstring(&data, &length); |
| 3363 | if (data) { |
| 3364 | switch (c->type) { |
| 3365 | case CHAN_MAINSESSION: |
| 3366 | from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, |
| 3367 | data, length); |
| 3368 | break; |
| 3369 | case CHAN_X11: |
| 3370 | x11_send(c->u.x11.s, data, length); |
| 3371 | break; |
| 3372 | } |
| 3373 | /* |
| 3374 | * Enlarge the window again at the remote |
| 3375 | * side, just in case it ever runs down and |
| 3376 | * they fail to send us any more data. |
| 3377 | */ |
| 3378 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 3379 | ssh2_pkt_adduint32(c->remoteid); |
| 3380 | ssh2_pkt_adduint32(length); |
| 3381 | ssh2_pkt_send(); |
| 3382 | } |
| 3383 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
| 3384 | ssh_state = SSH_STATE_CLOSED; |
| 3385 | logevent("Received disconnect message"); |
| 3386 | crReturnV; |
| 3387 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
| 3388 | continue; /* exit status et al; ignore (FIXME?) */ |
| 3389 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
| 3390 | unsigned i = ssh2_pkt_getuint32(); |
| 3391 | struct ssh_channel *c; |
| 3392 | |
| 3393 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3394 | if (!c) |
| 3395 | continue; /* nonexistent channel */ |
| 3396 | |
| 3397 | if (c->type == CHAN_X11) { |
| 3398 | /* |
| 3399 | * Remote EOF on an X11 channel means we should |
| 3400 | * wrap up and close the channel ourselves. |
| 3401 | */ |
| 3402 | x11_close(c->u.x11.s); |
| 3403 | sshfwd_close(c); |
| 3404 | } |
| 3405 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
| 3406 | unsigned i = ssh2_pkt_getuint32(); |
| 3407 | struct ssh_channel *c; |
| 3408 | enum234 e; |
| 3409 | |
| 3410 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3411 | if (!c) |
| 3412 | continue; /* nonexistent channel */ |
| 3413 | if (c->closes == 0) { |
| 3414 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 3415 | ssh2_pkt_adduint32(c->remoteid); |
| 3416 | ssh2_pkt_send(); |
| 3417 | } |
| 3418 | /* Do pre-close processing on the channel. */ |
| 3419 | switch (c->type) { |
| 3420 | case CHAN_MAINSESSION: |
| 3421 | break; /* nothing to see here, move along */ |
| 3422 | case CHAN_X11: |
| 3423 | break; |
| 3424 | } |
| 3425 | del234(ssh_channels, c); |
| 3426 | sfree(c->v2.outbuffer); |
| 3427 | sfree(c); |
| 3428 | |
| 3429 | /* |
| 3430 | * See if that was the last channel left open. |
| 3431 | */ |
| 3432 | c = first234(ssh_channels, &e); |
| 3433 | if (!c) { |
| 3434 | logevent("All channels closed. Disconnecting"); |
| 3435 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 3436 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 3437 | ssh2_pkt_addstring("All open channels closed"); |
| 3438 | ssh2_pkt_addstring("en"); /* language tag */ |
| 3439 | ssh2_pkt_send(); |
| 3440 | ssh_state = SSH_STATE_CLOSED; |
| 3441 | crReturnV; |
| 3442 | } |
| 3443 | continue; /* remote sends close; ignore (FIXME) */ |
| 3444 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 3445 | unsigned i = ssh2_pkt_getuint32(); |
| 3446 | struct ssh_channel *c; |
| 3447 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 3448 | if (!c) |
| 3449 | continue; /* nonexistent channel */ |
| 3450 | mainchan->v2.remwindow += ssh2_pkt_getuint32(); |
| 3451 | try_send = TRUE; |
| 3452 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
| 3453 | char *type; |
| 3454 | int typelen; |
| 3455 | char *error = NULL; |
| 3456 | struct ssh_channel *c; |
| 3457 | ssh2_pkt_getstring(&type, &typelen); |
| 3458 | c = smalloc(sizeof(struct ssh_channel)); |
| 3459 | |
| 3460 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
| 3461 | if (!ssh_X11_fwd_enabled) |
| 3462 | error = "X11 forwarding is not enabled"; |
| 3463 | else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) { |
| 3464 | error = "Unable to open an X11 connection"; |
| 3465 | } else { |
| 3466 | c->type = CHAN_X11; |
| 3467 | } |
| 3468 | } else { |
| 3469 | error = "Unsupported channel type requested"; |
| 3470 | } |
| 3471 | |
| 3472 | c->remoteid = ssh2_pkt_getuint32(); |
| 3473 | if (error) { |
| 3474 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 3475 | ssh2_pkt_adduint32(c->remoteid); |
| 3476 | ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); |
| 3477 | ssh2_pkt_addstring(error); |
| 3478 | ssh2_pkt_addstring("en"); /* language tag */ |
| 3479 | ssh2_pkt_send(); |
| 3480 | sfree(c); |
| 3481 | } else { |
| 3482 | struct ssh_channel *d; |
| 3483 | unsigned i; |
| 3484 | enum234 e; |
| 3485 | |
| 3486 | for (i=1, d = first234(ssh_channels, &e); d; |
| 3487 | d = next234(&e)) { |
| 3488 | if (d->localid > i) |
| 3489 | break; /* found a free number */ |
| 3490 | i = d->localid + 1; |
| 3491 | } |
| 3492 | c->localid = i; |
| 3493 | c->closes = 0; |
| 3494 | c->v2.remwindow = ssh2_pkt_getuint32(); |
| 3495 | c->v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 3496 | c->v2.outbuffer = NULL; |
| 3497 | c->v2.outbuflen = c->v2.outbufsize = 0; |
| 3498 | add234(ssh_channels, c); |
| 3499 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 3500 | ssh2_pkt_adduint32(c->remoteid); |
| 3501 | ssh2_pkt_adduint32(c->localid); |
| 3502 | ssh2_pkt_adduint32(0x8000UL); /* our window size */ |
| 3503 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 3504 | ssh2_pkt_send(); |
| 3505 | } |
| 3506 | } else { |
| 3507 | bombout(("Strange packet received: type %d", pktin.type)); |
| 3508 | crReturnV; |
| 3509 | } |
| 3510 | } else { |
| 3511 | /* |
| 3512 | * We have spare data. Add it to the channel buffer. |
| 3513 | */ |
| 3514 | ssh2_add_channel_data(mainchan, in, inlen); |
| 3515 | try_send = TRUE; |
| 3516 | } |
| 3517 | if (try_send) { |
| 3518 | enum234 e; |
| 3519 | struct ssh_channel *c; |
| 3520 | /* |
| 3521 | * Try to send data on all channels if we can. |
| 3522 | */ |
| 3523 | for (c = first234(ssh_channels, &e); c; c = next234(&e)) |
| 3524 | ssh2_try_send(c); |
| 3525 | } |
| 3526 | } |
| 3527 | |
| 3528 | crFinishV; |
| 3529 | } |
| 3530 | |
| 3531 | /* |
| 3532 | * Handle the top-level SSH2 protocol. |
| 3533 | */ |
| 3534 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
| 3535 | { |
| 3536 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
| 3537 | return; |
| 3538 | do_ssh2_authconn(in, inlen, ispkt); |
| 3539 | } |
| 3540 | |
| 3541 | /* |
| 3542 | * Called to set up the connection. |
| 3543 | * |
| 3544 | * Returns an error message, or NULL on success. |
| 3545 | */ |
| 3546 | static char *ssh_init (char *host, int port, char **realhost) { |
| 3547 | char *p; |
| 3548 | |
| 3549 | #ifdef MSCRYPTOAPI |
| 3550 | if(crypto_startup() == 0) |
| 3551 | return "Microsoft high encryption pack not installed!"; |
| 3552 | #endif |
| 3553 | |
| 3554 | ssh_send_ok = 0; |
| 3555 | ssh_editing = 0; |
| 3556 | ssh_echoing = 0; |
| 3557 | |
| 3558 | p = connect_to_host(host, port, realhost); |
| 3559 | if (p != NULL) |
| 3560 | return p; |
| 3561 | |
| 3562 | return NULL; |
| 3563 | } |
| 3564 | |
| 3565 | /* |
| 3566 | * Called to send data down the Telnet connection. |
| 3567 | */ |
| 3568 | static void ssh_send (char *buf, int len) { |
| 3569 | if (s == NULL || ssh_protocol == NULL) |
| 3570 | return; |
| 3571 | |
| 3572 | ssh_protocol(buf, len, 0); |
| 3573 | } |
| 3574 | |
| 3575 | /* |
| 3576 | * Called to set the size of the window from SSH's POV. |
| 3577 | */ |
| 3578 | static void ssh_size(void) { |
| 3579 | switch (ssh_state) { |
| 3580 | case SSH_STATE_BEFORE_SIZE: |
| 3581 | case SSH_STATE_PREPACKET: |
| 3582 | case SSH_STATE_CLOSED: |
| 3583 | break; /* do nothing */ |
| 3584 | case SSH_STATE_INTERMED: |
| 3585 | size_needed = TRUE; /* buffer for later */ |
| 3586 | break; |
| 3587 | case SSH_STATE_SESSION: |
| 3588 | if (!cfg.nopty) { |
| 3589 | if (ssh_version == 1) { |
| 3590 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
| 3591 | PKT_INT, rows, PKT_INT, cols, |
| 3592 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 3593 | } else { |
| 3594 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 3595 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 3596 | ssh2_pkt_addstring("window-change"); |
| 3597 | ssh2_pkt_addbool(0); |
| 3598 | ssh2_pkt_adduint32(cols); |
| 3599 | ssh2_pkt_adduint32(rows); |
| 3600 | ssh2_pkt_adduint32(0); |
| 3601 | ssh2_pkt_adduint32(0); |
| 3602 | ssh2_pkt_send(); |
| 3603 | } |
| 3604 | } |
| 3605 | break; |
| 3606 | } |
| 3607 | } |
| 3608 | |
| 3609 | /* |
| 3610 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
| 3611 | * can send an EOF and collect resulting output (e.g. `plink |
| 3612 | * hostname sort'). |
| 3613 | */ |
| 3614 | static void ssh_special (Telnet_Special code) { |
| 3615 | if (code == TS_EOF) { |
| 3616 | if (ssh_state != SSH_STATE_SESSION) { |
| 3617 | /* |
| 3618 | * Buffer the EOF in case we are pre-SESSION, so we can |
| 3619 | * send it as soon as we reach SESSION. |
| 3620 | */ |
| 3621 | if (code == TS_EOF) |
| 3622 | eof_needed = TRUE; |
| 3623 | return; |
| 3624 | } |
| 3625 | if (ssh_version == 1) { |
| 3626 | send_packet(SSH1_CMSG_EOF, PKT_END); |
| 3627 | } else { |
| 3628 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
| 3629 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 3630 | ssh2_pkt_send(); |
| 3631 | } |
| 3632 | logevent("Sent EOF message"); |
| 3633 | } else if (code == TS_PING) { |
| 3634 | if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET) |
| 3635 | return; |
| 3636 | if (ssh_version == 1) { |
| 3637 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
| 3638 | } else { |
| 3639 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 3640 | ssh2_pkt_addstring_start(); |
| 3641 | ssh2_pkt_send(); |
| 3642 | } |
| 3643 | } else { |
| 3644 | /* do nothing */ |
| 3645 | } |
| 3646 | } |
| 3647 | |
| 3648 | static Socket ssh_socket(void) { return s; } |
| 3649 | |
| 3650 | static int ssh_sendok(void) { return ssh_send_ok; } |
| 3651 | |
| 3652 | static int ssh_ldisc(int option) { |
| 3653 | if (option == LD_ECHO) return ssh_echoing; |
| 3654 | if (option == LD_EDIT) return ssh_editing; |
| 3655 | return FALSE; |
| 3656 | } |
| 3657 | |
| 3658 | Backend ssh_backend = { |
| 3659 | ssh_init, |
| 3660 | ssh_send, |
| 3661 | ssh_size, |
| 3662 | ssh_special, |
| 3663 | ssh_socket, |
| 3664 | ssh_sendok, |
| 3665 | ssh_ldisc, |
| 3666 | 22 |
| 3667 | }; |