| 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 | /* uncomment this for packet level debugging */ |
| 19 | /* #define DUMP_PACKETS */ |
| 20 | |
| 21 | #define logevent(s) { logevent(s); \ |
| 22 | if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ |
| 23 | { fprintf(stderr, "%s\n", s); fflush(stderr); } } |
| 24 | |
| 25 | #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ |
| 26 | (s ? sk_close(s), s = NULL : 0), \ |
| 27 | connection_fatal msg ) |
| 28 | |
| 29 | #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ |
| 30 | #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ |
| 31 | #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ |
| 32 | #define SSH1_CMSG_USER 4 /* 0x4 */ |
| 33 | #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ |
| 34 | #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ |
| 35 | #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ |
| 36 | #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ |
| 37 | #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ |
| 38 | #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ |
| 39 | #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ |
| 40 | #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ |
| 41 | #define SSH1_SMSG_SUCCESS 14 /* 0xe */ |
| 42 | #define SSH1_SMSG_FAILURE 15 /* 0xf */ |
| 43 | #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ |
| 44 | #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ |
| 45 | #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ |
| 46 | #define SSH1_CMSG_EOF 19 /* 0x13 */ |
| 47 | #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ |
| 48 | #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ |
| 49 | #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ |
| 50 | #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ |
| 51 | #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ |
| 52 | #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ |
| 53 | #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ |
| 54 | #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ |
| 55 | #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ |
| 56 | #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ |
| 57 | #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ |
| 58 | #define SSH1_MSG_IGNORE 32 /* 0x20 */ |
| 59 | #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ |
| 60 | #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ |
| 61 | #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ |
| 62 | #define SSH1_MSG_DEBUG 36 /* 0x24 */ |
| 63 | #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ |
| 64 | #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ |
| 65 | #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ |
| 66 | #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ |
| 67 | #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ |
| 68 | #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ |
| 69 | #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ |
| 70 | |
| 71 | #define SSH1_AUTH_TIS 5 /* 0x5 */ |
| 72 | #define SSH1_AUTH_CCARD 16 /* 0x10 */ |
| 73 | |
| 74 | #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ |
| 75 | /* Mask for protoflags we will echo back to server if seen */ |
| 76 | #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ |
| 77 | |
| 78 | #define SSH2_MSG_DISCONNECT 1 /* 0x1 */ |
| 79 | #define SSH2_MSG_IGNORE 2 /* 0x2 */ |
| 80 | #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ |
| 81 | #define SSH2_MSG_DEBUG 4 /* 0x4 */ |
| 82 | #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ |
| 83 | #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ |
| 84 | #define SSH2_MSG_KEXINIT 20 /* 0x14 */ |
| 85 | #define SSH2_MSG_NEWKEYS 21 /* 0x15 */ |
| 86 | #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ |
| 87 | #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ |
| 88 | #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ |
| 89 | #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ |
| 90 | #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ |
| 91 | #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ |
| 92 | #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ |
| 93 | #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ |
| 94 | #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ |
| 95 | #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ |
| 96 | #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ |
| 97 | #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ |
| 98 | #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ |
| 99 | #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ |
| 100 | #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ |
| 101 | #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ |
| 102 | #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ |
| 103 | #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ |
| 104 | #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ |
| 105 | #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ |
| 106 | #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ |
| 107 | #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ |
| 108 | #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ |
| 109 | #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ |
| 110 | #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ |
| 111 | #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ |
| 112 | #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ |
| 113 | #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ |
| 114 | |
| 115 | #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ |
| 116 | #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ |
| 117 | #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ |
| 118 | #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ |
| 119 | #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ |
| 120 | #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ |
| 121 | #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ |
| 122 | #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ |
| 123 | #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ |
| 124 | #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ |
| 125 | #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ |
| 126 | #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ |
| 127 | #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ |
| 128 | #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ |
| 129 | #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ |
| 130 | |
| 131 | static const char *const ssh2_disconnect_reasons[] = { |
| 132 | NULL, |
| 133 | "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT", |
| 134 | "SSH_DISCONNECT_PROTOCOL_ERROR", |
| 135 | "SSH_DISCONNECT_KEY_EXCHANGE_FAILED", |
| 136 | "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED", |
| 137 | "SSH_DISCONNECT_MAC_ERROR", |
| 138 | "SSH_DISCONNECT_COMPRESSION_ERROR", |
| 139 | "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE", |
| 140 | "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED", |
| 141 | "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE", |
| 142 | "SSH_DISCONNECT_CONNECTION_LOST", |
| 143 | "SSH_DISCONNECT_BY_APPLICATION", |
| 144 | "SSH_DISCONNECT_TOO_MANY_CONNECTIONS", |
| 145 | "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER", |
| 146 | "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE", |
| 147 | "SSH_DISCONNECT_ILLEGAL_USER_NAME", |
| 148 | }; |
| 149 | |
| 150 | #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ |
| 151 | #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ |
| 152 | #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ |
| 153 | #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ |
| 154 | |
| 155 | #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ |
| 156 | |
| 157 | /* |
| 158 | * Various remote-bug flags. |
| 159 | */ |
| 160 | #define BUG_CHOKES_ON_SSH1_IGNORE 1 |
| 161 | #define BUG_SSH2_HMAC 2 |
| 162 | |
| 163 | #define GET_32BIT(cp) \ |
| 164 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
| 165 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
| 166 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
| 167 | ((unsigned long)(unsigned char)(cp)[3])) |
| 168 | |
| 169 | #define PUT_32BIT(cp, value) { \ |
| 170 | (cp)[0] = (unsigned char)((value) >> 24); \ |
| 171 | (cp)[1] = (unsigned char)((value) >> 16); \ |
| 172 | (cp)[2] = (unsigned char)((value) >> 8); \ |
| 173 | (cp)[3] = (unsigned char)(value); } |
| 174 | |
| 175 | enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; |
| 176 | |
| 177 | /* Coroutine mechanics for the sillier bits of the code */ |
| 178 | #define crBegin1 static int crLine = 0; |
| 179 | #define crBegin2 switch(crLine) { case 0:; |
| 180 | #define crBegin crBegin1; crBegin2; |
| 181 | #define crFinish(z) } crLine = 0; return (z) |
| 182 | #define crFinishV } crLine = 0; return |
| 183 | #define crReturn(z) \ |
| 184 | do {\ |
| 185 | crLine=__LINE__; return (z); case __LINE__:;\ |
| 186 | } while (0) |
| 187 | #define crReturnV \ |
| 188 | do {\ |
| 189 | crLine=__LINE__; return; case __LINE__:;\ |
| 190 | } while (0) |
| 191 | #define crStop(z) do{ crLine = 0; return (z); }while(0) |
| 192 | #define crStopV do{ crLine = 0; return; }while(0) |
| 193 | #define crWaitUntil(c) do { crReturn(0); } while (!(c)) |
| 194 | #define crWaitUntilV(c) do { crReturnV; } while (!(c)) |
| 195 | |
| 196 | extern char *x11_init(Socket *, char *, void *); |
| 197 | extern void x11_close(Socket); |
| 198 | extern int x11_send(Socket, char *, int); |
| 199 | extern void x11_invent_auth(char *, int, char *, int); |
| 200 | extern void x11_unthrottle(Socket s); |
| 201 | extern void x11_override_throttle(Socket s, int enable); |
| 202 | |
| 203 | extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c); |
| 204 | extern char *pfd_addforward(char *desthost, int destport, int port); |
| 205 | extern void pfd_close(Socket s); |
| 206 | extern int pfd_send(Socket s, char *data, int len); |
| 207 | extern void pfd_confirm(Socket s); |
| 208 | extern void pfd_unthrottle(Socket s); |
| 209 | extern void pfd_override_throttle(Socket s, int enable); |
| 210 | |
| 211 | /* |
| 212 | * Buffer management constants. There are several of these for |
| 213 | * various different purposes: |
| 214 | * |
| 215 | * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up |
| 216 | * on a local data stream before we throttle the whole SSH |
| 217 | * connection (in SSH1 only). Throttling the whole connection is |
| 218 | * pretty drastic so we set this high in the hope it won't |
| 219 | * happen very often. |
| 220 | * |
| 221 | * - SSH_MAX_BACKLOG is the amount of backlog that must build up |
| 222 | * on the SSH connection itself before we defensively throttle |
| 223 | * _all_ local data streams. This is pretty drastic too (though |
| 224 | * thankfully unlikely in SSH2 since the window mechanism should |
| 225 | * ensure that the server never has any need to throttle its end |
| 226 | * of the connection), so we set this high as well. |
| 227 | * |
| 228 | * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 |
| 229 | * channels. |
| 230 | */ |
| 231 | |
| 232 | #define SSH1_BUFFER_LIMIT 32768 |
| 233 | #define SSH_MAX_BACKLOG 32768 |
| 234 | #define OUR_V2_WINSIZE 16384 |
| 235 | |
| 236 | /* |
| 237 | * Ciphers for SSH2. We miss out single-DES because it isn't |
| 238 | * supported; also 3DES and Blowfish are both done differently from |
| 239 | * SSH1. (3DES uses outer chaining; Blowfish has the opposite |
| 240 | * endianness and different-sized keys.) |
| 241 | */ |
| 242 | const static struct ssh2_ciphers *ciphers[] = { |
| 243 | &ssh2_aes, |
| 244 | &ssh2_blowfish, |
| 245 | &ssh2_3des, |
| 246 | }; |
| 247 | |
| 248 | const static struct ssh_kex *kex_algs[] = { |
| 249 | &ssh_diffiehellman_gex, |
| 250 | &ssh_diffiehellman |
| 251 | }; |
| 252 | |
| 253 | const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; |
| 254 | |
| 255 | static void nullmac_key(unsigned char *key) |
| 256 | { |
| 257 | } |
| 258 | static void nullmac_generate(unsigned char *blk, int len, |
| 259 | unsigned long seq) |
| 260 | { |
| 261 | } |
| 262 | static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) |
| 263 | { |
| 264 | return 1; |
| 265 | } |
| 266 | const static struct ssh_mac ssh_mac_none = { |
| 267 | nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 |
| 268 | }; |
| 269 | const static struct ssh_mac *macs[] = { |
| 270 | &ssh_sha1, &ssh_md5, &ssh_mac_none |
| 271 | }; |
| 272 | const static struct ssh_mac *buggymacs[] = { |
| 273 | &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none |
| 274 | }; |
| 275 | |
| 276 | static void ssh_comp_none_init(void) |
| 277 | { |
| 278 | } |
| 279 | static int ssh_comp_none_block(unsigned char *block, int len, |
| 280 | unsigned char **outblock, int *outlen) |
| 281 | { |
| 282 | return 0; |
| 283 | } |
| 284 | static int ssh_comp_none_disable(void) |
| 285 | { |
| 286 | return 0; |
| 287 | } |
| 288 | const static struct ssh_compress ssh_comp_none = { |
| 289 | "none", |
| 290 | ssh_comp_none_init, ssh_comp_none_block, |
| 291 | ssh_comp_none_init, ssh_comp_none_block, |
| 292 | ssh_comp_none_disable |
| 293 | }; |
| 294 | extern const struct ssh_compress ssh_zlib; |
| 295 | const static struct ssh_compress *compressions[] = { |
| 296 | &ssh_zlib, &ssh_comp_none |
| 297 | }; |
| 298 | |
| 299 | enum { /* channel types */ |
| 300 | CHAN_MAINSESSION, |
| 301 | CHAN_X11, |
| 302 | CHAN_AGENT, |
| 303 | CHAN_SOCKDATA, |
| 304 | CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ |
| 305 | }; |
| 306 | |
| 307 | /* |
| 308 | * 2-3-4 tree storing channels. |
| 309 | */ |
| 310 | struct ssh_channel { |
| 311 | unsigned remoteid, localid; |
| 312 | int type; |
| 313 | int closes; |
| 314 | union { |
| 315 | struct ssh1_data_channel { |
| 316 | int throttling; |
| 317 | } v1; |
| 318 | struct ssh2_data_channel { |
| 319 | bufchain outbuffer; |
| 320 | unsigned remwindow, remmaxpkt; |
| 321 | unsigned locwindow; |
| 322 | } v2; |
| 323 | } v; |
| 324 | union { |
| 325 | struct ssh_agent_channel { |
| 326 | unsigned char *message; |
| 327 | unsigned char msglen[4]; |
| 328 | int lensofar, totallen; |
| 329 | } a; |
| 330 | struct ssh_x11_channel { |
| 331 | Socket s; |
| 332 | } x11; |
| 333 | struct ssh_pfd_channel { |
| 334 | Socket s; |
| 335 | } pfd; |
| 336 | } u; |
| 337 | }; |
| 338 | |
| 339 | /* |
| 340 | * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH |
| 341 | * 2 use this structure in different ways, reflecting SSH 2's |
| 342 | * altogether saner approach to port forwarding. |
| 343 | * |
| 344 | * In SSH 1, you arrange a remote forwarding by sending the server |
| 345 | * the remote port number, and the local destination host:port. |
| 346 | * When a connection comes in, the server sends you back that |
| 347 | * host:port pair, and you connect to it. This is a ready-made |
| 348 | * security hole if you're not on the ball: a malicious server |
| 349 | * could send you back _any_ host:port pair, so if you trustingly |
| 350 | * connect to the address it gives you then you've just opened the |
| 351 | * entire inside of your corporate network just by connecting |
| 352 | * through it to a dodgy SSH server. Hence, we must store a list of |
| 353 | * host:port pairs we _are_ trying to forward to, and reject a |
| 354 | * connection request from the server if it's not in the list. |
| 355 | * |
| 356 | * In SSH 2, each side of the connection minds its own business and |
| 357 | * doesn't send unnecessary information to the other. You arrange a |
| 358 | * remote forwarding by sending the server just the remote port |
| 359 | * number. When a connection comes in, the server tells you which |
| 360 | * of its ports was connected to; and _you_ have to remember what |
| 361 | * local host:port pair went with that port number. |
| 362 | * |
| 363 | * Hence: in SSH 1 this structure stores host:port pairs we intend |
| 364 | * to allow connections to, and is indexed by those host:port |
| 365 | * pairs. In SSH 2 it stores a mapping from source port to |
| 366 | * destination host:port pair, and is indexed by source port. |
| 367 | */ |
| 368 | struct ssh_rportfwd { |
| 369 | unsigned sport, dport; |
| 370 | char dhost[256]; |
| 371 | }; |
| 372 | |
| 373 | struct Packet { |
| 374 | long length; |
| 375 | int type; |
| 376 | unsigned char *data; |
| 377 | unsigned char *body; |
| 378 | long savedpos; |
| 379 | long maxlen; |
| 380 | }; |
| 381 | |
| 382 | static SHA_State exhash, exhashbase; |
| 383 | |
| 384 | static Socket s = NULL; |
| 385 | |
| 386 | static unsigned char session_key[32]; |
| 387 | static int ssh1_compressing; |
| 388 | static int ssh1_remote_protoflags; |
| 389 | static int ssh1_local_protoflags; |
| 390 | static int ssh_agentfwd_enabled; |
| 391 | static int ssh_X11_fwd_enabled; |
| 392 | static int ssh_remote_bugs; |
| 393 | static const struct ssh_cipher *cipher = NULL; |
| 394 | static const struct ssh2_cipher *cscipher = NULL; |
| 395 | static const struct ssh2_cipher *sccipher = NULL; |
| 396 | static const struct ssh_mac *csmac = NULL; |
| 397 | static const struct ssh_mac *scmac = NULL; |
| 398 | static const struct ssh_compress *cscomp = NULL; |
| 399 | static const struct ssh_compress *sccomp = NULL; |
| 400 | static const struct ssh_kex *kex = NULL; |
| 401 | static const struct ssh_signkey *hostkey = NULL; |
| 402 | static unsigned char ssh2_session_id[20]; |
| 403 | int (*ssh_get_line) (const char *prompt, char *str, int maxlen, |
| 404 | int is_pw) = NULL; |
| 405 | |
| 406 | static char *savedhost; |
| 407 | static int savedport; |
| 408 | static int ssh_send_ok; |
| 409 | static int ssh_echoing, ssh_editing; |
| 410 | |
| 411 | static tree234 *ssh_channels; /* indexed by local id */ |
| 412 | static struct ssh_channel *mainchan; /* primary session channel */ |
| 413 | |
| 414 | static tree234 *ssh_rportfwds; |
| 415 | |
| 416 | static enum { |
| 417 | SSH_STATE_PREPACKET, |
| 418 | SSH_STATE_BEFORE_SIZE, |
| 419 | SSH_STATE_INTERMED, |
| 420 | SSH_STATE_SESSION, |
| 421 | SSH_STATE_CLOSED |
| 422 | } ssh_state = SSH_STATE_PREPACKET; |
| 423 | |
| 424 | static int size_needed = FALSE, eof_needed = FALSE; |
| 425 | |
| 426 | static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; |
| 427 | static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; |
| 428 | static unsigned char *deferred_send_data = NULL; |
| 429 | static int deferred_len = 0, deferred_size = 0; |
| 430 | |
| 431 | /* |
| 432 | * Gross hack: pscp will try to start SFTP but fall back to scp1 if |
| 433 | * that fails. This variable is the means by which scp.c can reach |
| 434 | * into the SSH code and find out which one it got. |
| 435 | */ |
| 436 | int ssh_fallback_cmd = 0; |
| 437 | |
| 438 | static int ssh_version; |
| 439 | static int ssh1_throttle_count; |
| 440 | static int ssh_overall_bufsize; |
| 441 | static int ssh_throttled_all; |
| 442 | static int ssh1_stdout_throttling; |
| 443 | static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt); |
| 444 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt); |
| 445 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt); |
| 446 | static void ssh_size(void); |
| 447 | static void ssh_special(Telnet_Special); |
| 448 | static int ssh2_try_send(struct ssh_channel *c); |
| 449 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
| 450 | int len); |
| 451 | static void ssh_throttle_all(int enable, int bufsize); |
| 452 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); |
| 453 | static int (*s_rdpkt) (unsigned char **data, int *datalen); |
| 454 | static int ssh_sendbuffer(void); |
| 455 | |
| 456 | static struct rdpkt1_state_tag { |
| 457 | long len, pad, biglen, to_read; |
| 458 | unsigned long realcrc, gotcrc; |
| 459 | unsigned char *p; |
| 460 | int i; |
| 461 | int chunk; |
| 462 | } rdpkt1_state; |
| 463 | |
| 464 | static struct rdpkt2_state_tag { |
| 465 | long len, pad, payload, packetlen, maclen; |
| 466 | int i; |
| 467 | int cipherblk; |
| 468 | unsigned long incoming_sequence; |
| 469 | } rdpkt2_state; |
| 470 | |
| 471 | static int ssh_channelcmp(void *av, void *bv) |
| 472 | { |
| 473 | struct ssh_channel *a = (struct ssh_channel *) av; |
| 474 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 475 | if (a->localid < b->localid) |
| 476 | return -1; |
| 477 | if (a->localid > b->localid) |
| 478 | return +1; |
| 479 | return 0; |
| 480 | } |
| 481 | static int ssh_channelfind(void *av, void *bv) |
| 482 | { |
| 483 | unsigned *a = (unsigned *) av; |
| 484 | struct ssh_channel *b = (struct ssh_channel *) bv; |
| 485 | if (*a < b->localid) |
| 486 | return -1; |
| 487 | if (*a > b->localid) |
| 488 | return +1; |
| 489 | return 0; |
| 490 | } |
| 491 | |
| 492 | static int ssh_rportcmp_ssh1(void *av, void *bv) |
| 493 | { |
| 494 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 495 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 496 | int i; |
| 497 | if ( (i = strcmp(a->dhost, b->dhost)) != 0) |
| 498 | return i < 0 ? -1 : +1; |
| 499 | if (a->dport > b->dport) |
| 500 | return +1; |
| 501 | if (a->dport < b->dport) |
| 502 | return -1; |
| 503 | return 0; |
| 504 | } |
| 505 | |
| 506 | static int ssh_rportcmp_ssh2(void *av, void *bv) |
| 507 | { |
| 508 | struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; |
| 509 | struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; |
| 510 | |
| 511 | if (a->sport > b->sport) |
| 512 | return +1; |
| 513 | if (a->sport < b->sport) |
| 514 | return -1; |
| 515 | return 0; |
| 516 | } |
| 517 | |
| 518 | static int alloc_channel_id(void) |
| 519 | { |
| 520 | const unsigned CHANNEL_NUMBER_OFFSET = 256; |
| 521 | unsigned low, high, mid; |
| 522 | int tsize; |
| 523 | struct ssh_channel *c; |
| 524 | |
| 525 | /* |
| 526 | * First-fit allocation of channel numbers: always pick the |
| 527 | * lowest unused one. To do this, binary-search using the |
| 528 | * counted B-tree to find the largest channel ID which is in a |
| 529 | * contiguous sequence from the beginning. (Precisely |
| 530 | * everything in that sequence must have ID equal to its tree |
| 531 | * index plus CHANNEL_NUMBER_OFFSET.) |
| 532 | */ |
| 533 | tsize = count234(ssh_channels); |
| 534 | |
| 535 | low = -1; |
| 536 | high = tsize; |
| 537 | while (high - low > 1) { |
| 538 | mid = (high + low) / 2; |
| 539 | c = index234(ssh_channels, mid); |
| 540 | if (c->localid == mid + CHANNEL_NUMBER_OFFSET) |
| 541 | low = mid; /* this one is fine */ |
| 542 | else |
| 543 | high = mid; /* this one is past it */ |
| 544 | } |
| 545 | /* |
| 546 | * Now low points to either -1, or the tree index of the |
| 547 | * largest ID in the initial sequence. |
| 548 | */ |
| 549 | { |
| 550 | unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; |
| 551 | assert(NULL == find234(ssh_channels, &i, ssh_channelfind)); |
| 552 | } |
| 553 | return low + 1 + CHANNEL_NUMBER_OFFSET; |
| 554 | } |
| 555 | |
| 556 | static void c_write(char *buf, int len) |
| 557 | { |
| 558 | if ((flags & FLAG_STDERR)) { |
| 559 | int i; |
| 560 | for (i = 0; i < len; i++) |
| 561 | if (buf[i] != '\r') |
| 562 | fputc(buf[i], stderr); |
| 563 | return; |
| 564 | } |
| 565 | from_backend(1, buf, len); |
| 566 | } |
| 567 | |
| 568 | static void c_write_untrusted(char *buf, int len) |
| 569 | { |
| 570 | int i; |
| 571 | for (i = 0; i < len; i++) { |
| 572 | if (buf[i] == '\n') |
| 573 | c_write("\r\n", 2); |
| 574 | else if ((buf[i] & 0x60) || (buf[i] == '\r')) |
| 575 | c_write(buf + i, 1); |
| 576 | } |
| 577 | } |
| 578 | |
| 579 | static void c_write_str(char *buf) |
| 580 | { |
| 581 | c_write(buf, strlen(buf)); |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * Collect incoming data in the incoming packet buffer. |
| 586 | * Decipher and verify the packet when it is completely read. |
| 587 | * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. |
| 588 | * Update the *data and *datalen variables. |
| 589 | * Return the additional nr of bytes needed, or 0 when |
| 590 | * a complete packet is available. |
| 591 | */ |
| 592 | static int ssh1_rdpkt(unsigned char **data, int *datalen) |
| 593 | { |
| 594 | struct rdpkt1_state_tag *st = &rdpkt1_state; |
| 595 | |
| 596 | crBegin; |
| 597 | |
| 598 | next_packet: |
| 599 | |
| 600 | pktin.type = 0; |
| 601 | pktin.length = 0; |
| 602 | |
| 603 | for (st->i = st->len = 0; st->i < 4; st->i++) { |
| 604 | while ((*datalen) == 0) |
| 605 | crReturn(4 - st->i); |
| 606 | st->len = (st->len << 8) + **data; |
| 607 | (*data)++, (*datalen)--; |
| 608 | } |
| 609 | |
| 610 | #ifdef FWHACK |
| 611 | if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ |
| 612 | st->len = 0x300; /* big enough to carry to end */ |
| 613 | } |
| 614 | #endif |
| 615 | |
| 616 | st->pad = 8 - (st->len % 8); |
| 617 | st->biglen = st->len + st->pad; |
| 618 | pktin.length = st->len - 5; |
| 619 | |
| 620 | if (pktin.maxlen < st->biglen) { |
| 621 | pktin.maxlen = st->biglen; |
| 622 | pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) : |
| 623 | srealloc(pktin.data, st->biglen + APIEXTRA)); |
| 624 | if (!pktin.data) |
| 625 | fatalbox("Out of memory"); |
| 626 | } |
| 627 | |
| 628 | st->to_read = st->biglen; |
| 629 | st->p = pktin.data; |
| 630 | while (st->to_read > 0) { |
| 631 | st->chunk = st->to_read; |
| 632 | while ((*datalen) == 0) |
| 633 | crReturn(st->to_read); |
| 634 | if (st->chunk > (*datalen)) |
| 635 | st->chunk = (*datalen); |
| 636 | memcpy(st->p, *data, st->chunk); |
| 637 | *data += st->chunk; |
| 638 | *datalen -= st->chunk; |
| 639 | st->p += st->chunk; |
| 640 | st->to_read -= st->chunk; |
| 641 | } |
| 642 | |
| 643 | if (cipher) |
| 644 | cipher->decrypt(pktin.data, st->biglen); |
| 645 | #ifdef DUMP_PACKETS |
| 646 | debug(("Got packet len=%d pad=%d\n", st->len, st->pad)); |
| 647 | dmemdump(pktin.data, st->biglen); |
| 648 | #endif |
| 649 | |
| 650 | st->realcrc = crc32(pktin.data, st->biglen - 4); |
| 651 | st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4); |
| 652 | if (st->gotcrc != st->realcrc) { |
| 653 | bombout(("Incorrect CRC received on packet")); |
| 654 | crReturn(0); |
| 655 | } |
| 656 | |
| 657 | pktin.body = pktin.data + st->pad + 1; |
| 658 | |
| 659 | if (ssh1_compressing) { |
| 660 | unsigned char *decompblk; |
| 661 | int decomplen; |
| 662 | #ifdef DUMP_PACKETS |
| 663 | debug(("Packet payload pre-decompression:\n")); |
| 664 | dmemdump(pktin.body - 1, pktin.length + 1); |
| 665 | #endif |
| 666 | zlib_decompress_block(pktin.body - 1, pktin.length + 1, |
| 667 | &decompblk, &decomplen); |
| 668 | |
| 669 | if (pktin.maxlen < st->pad + decomplen) { |
| 670 | pktin.maxlen = st->pad + decomplen; |
| 671 | pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA); |
| 672 | pktin.body = pktin.data + st->pad + 1; |
| 673 | if (!pktin.data) |
| 674 | fatalbox("Out of memory"); |
| 675 | } |
| 676 | |
| 677 | memcpy(pktin.body - 1, decompblk, decomplen); |
| 678 | sfree(decompblk); |
| 679 | pktin.length = decomplen - 1; |
| 680 | #ifdef DUMP_PACKETS |
| 681 | debug(("Packet payload post-decompression:\n")); |
| 682 | dmemdump(pktin.body - 1, pktin.length + 1); |
| 683 | #endif |
| 684 | } |
| 685 | |
| 686 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 687 | pktin.type == SSH1_SMSG_STDERR_DATA || |
| 688 | pktin.type == SSH1_MSG_DEBUG || |
| 689 | pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || |
| 690 | pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 691 | long strlen = GET_32BIT(pktin.body); |
| 692 | if (strlen + 4 != pktin.length) { |
| 693 | bombout(("Received data packet with bogus string length")); |
| 694 | crReturn(0); |
| 695 | } |
| 696 | } |
| 697 | |
| 698 | pktin.type = pktin.body[-1]; |
| 699 | |
| 700 | if (pktin.type == SSH1_MSG_DEBUG) { |
| 701 | /* log debug message */ |
| 702 | char buf[80]; |
| 703 | int strlen = GET_32BIT(pktin.body); |
| 704 | strcpy(buf, "Remote: "); |
| 705 | if (strlen > 70) |
| 706 | strlen = 70; |
| 707 | memcpy(buf + 8, pktin.body + 4, strlen); |
| 708 | buf[8 + strlen] = '\0'; |
| 709 | logevent(buf); |
| 710 | goto next_packet; |
| 711 | } else if (pktin.type == SSH1_MSG_IGNORE) { |
| 712 | /* do nothing */ |
| 713 | goto next_packet; |
| 714 | } |
| 715 | |
| 716 | if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 717 | /* log reason code in disconnect message */ |
| 718 | char buf[256]; |
| 719 | unsigned msglen = GET_32BIT(pktin.body); |
| 720 | unsigned nowlen; |
| 721 | strcpy(buf, "Remote sent disconnect: "); |
| 722 | nowlen = strlen(buf); |
| 723 | if (msglen > sizeof(buf) - nowlen - 1) |
| 724 | msglen = sizeof(buf) - nowlen - 1; |
| 725 | memcpy(buf + nowlen, pktin.body + 4, msglen); |
| 726 | buf[nowlen + msglen] = '\0'; |
| 727 | logevent(buf); |
| 728 | } |
| 729 | |
| 730 | crFinish(0); |
| 731 | } |
| 732 | |
| 733 | static int ssh2_rdpkt(unsigned char **data, int *datalen) |
| 734 | { |
| 735 | struct rdpkt2_state_tag *st = &rdpkt2_state; |
| 736 | |
| 737 | crBegin; |
| 738 | |
| 739 | next_packet: |
| 740 | pktin.type = 0; |
| 741 | pktin.length = 0; |
| 742 | if (sccipher) |
| 743 | st->cipherblk = sccipher->blksize; |
| 744 | else |
| 745 | st->cipherblk = 8; |
| 746 | if (st->cipherblk < 8) |
| 747 | st->cipherblk = 8; |
| 748 | |
| 749 | if (pktin.maxlen < st->cipherblk) { |
| 750 | pktin.maxlen = st->cipherblk; |
| 751 | pktin.data = |
| 752 | (pktin.data == |
| 753 | NULL ? smalloc(st->cipherblk + |
| 754 | APIEXTRA) : srealloc(pktin.data, |
| 755 | st->cipherblk + |
| 756 | APIEXTRA)); |
| 757 | if (!pktin.data) |
| 758 | fatalbox("Out of memory"); |
| 759 | } |
| 760 | |
| 761 | /* |
| 762 | * Acquire and decrypt the first block of the packet. This will |
| 763 | * contain the length and padding details. |
| 764 | */ |
| 765 | for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { |
| 766 | while ((*datalen) == 0) |
| 767 | crReturn(st->cipherblk - st->i); |
| 768 | pktin.data[st->i] = *(*data)++; |
| 769 | (*datalen)--; |
| 770 | } |
| 771 | #ifdef FWHACK |
| 772 | if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */ |
| 773 | /* FIXME */ |
| 774 | } |
| 775 | #endif |
| 776 | if (sccipher) |
| 777 | sccipher->decrypt(pktin.data, st->cipherblk); |
| 778 | |
| 779 | /* |
| 780 | * Now get the length and padding figures. |
| 781 | */ |
| 782 | st->len = GET_32BIT(pktin.data); |
| 783 | st->pad = pktin.data[4]; |
| 784 | |
| 785 | /* |
| 786 | * This enables us to deduce the payload length. |
| 787 | */ |
| 788 | st->payload = st->len - st->pad - 1; |
| 789 | |
| 790 | pktin.length = st->payload + 5; |
| 791 | |
| 792 | /* |
| 793 | * So now we can work out the total packet length. |
| 794 | */ |
| 795 | st->packetlen = st->len + 4; |
| 796 | st->maclen = scmac ? scmac->len : 0; |
| 797 | |
| 798 | /* |
| 799 | * Adjust memory allocation if packet is too big. |
| 800 | */ |
| 801 | if (pktin.maxlen < st->packetlen + st->maclen) { |
| 802 | pktin.maxlen = st->packetlen + st->maclen; |
| 803 | pktin.data = |
| 804 | (pktin.data == |
| 805 | NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data, |
| 806 | pktin.maxlen |
| 807 | + |
| 808 | APIEXTRA)); |
| 809 | if (!pktin.data) |
| 810 | fatalbox("Out of memory"); |
| 811 | } |
| 812 | |
| 813 | /* |
| 814 | * Read and decrypt the remainder of the packet. |
| 815 | */ |
| 816 | for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; |
| 817 | st->i++) { |
| 818 | while ((*datalen) == 0) |
| 819 | crReturn(st->packetlen + st->maclen - st->i); |
| 820 | pktin.data[st->i] = *(*data)++; |
| 821 | (*datalen)--; |
| 822 | } |
| 823 | /* Decrypt everything _except_ the MAC. */ |
| 824 | if (sccipher) |
| 825 | sccipher->decrypt(pktin.data + st->cipherblk, |
| 826 | st->packetlen - st->cipherblk); |
| 827 | |
| 828 | #ifdef DUMP_PACKETS |
| 829 | debug(("Got packet len=%d pad=%d\n", st->len, st->pad)); |
| 830 | dmemdump(pktin.data, st->packetlen); |
| 831 | #endif |
| 832 | |
| 833 | /* |
| 834 | * Check the MAC. |
| 835 | */ |
| 836 | if (scmac |
| 837 | && !scmac->verify(pktin.data, st->len + 4, |
| 838 | st->incoming_sequence)) { |
| 839 | bombout(("Incorrect MAC received on packet")); |
| 840 | crReturn(0); |
| 841 | } |
| 842 | st->incoming_sequence++; /* whether or not we MACed */ |
| 843 | |
| 844 | /* |
| 845 | * Decompress packet payload. |
| 846 | */ |
| 847 | { |
| 848 | unsigned char *newpayload; |
| 849 | int newlen; |
| 850 | if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5, |
| 851 | &newpayload, &newlen)) { |
| 852 | if (pktin.maxlen < newlen + 5) { |
| 853 | pktin.maxlen = newlen + 5; |
| 854 | pktin.data = |
| 855 | (pktin.data == |
| 856 | NULL ? smalloc(pktin.maxlen + |
| 857 | APIEXTRA) : srealloc(pktin.data, |
| 858 | pktin.maxlen + |
| 859 | APIEXTRA)); |
| 860 | if (!pktin.data) |
| 861 | fatalbox("Out of memory"); |
| 862 | } |
| 863 | pktin.length = 5 + newlen; |
| 864 | memcpy(pktin.data + 5, newpayload, newlen); |
| 865 | #ifdef DUMP_PACKETS |
| 866 | debug(("Post-decompression payload:\n")); |
| 867 | dmemdump(pktin.data + 5, newlen); |
| 868 | #endif |
| 869 | |
| 870 | sfree(newpayload); |
| 871 | } |
| 872 | } |
| 873 | |
| 874 | pktin.savedpos = 6; |
| 875 | pktin.type = pktin.data[5]; |
| 876 | |
| 877 | if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) |
| 878 | goto next_packet; /* FIXME: print DEBUG message */ |
| 879 | |
| 880 | if (pktin.type == SSH2_MSG_DISCONNECT) { |
| 881 | /* log reason code in disconnect message */ |
| 882 | char buf[256]; |
| 883 | int reason = GET_32BIT(pktin.data + 6); |
| 884 | unsigned msglen = GET_32BIT(pktin.data + 10); |
| 885 | unsigned nowlen; |
| 886 | if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { |
| 887 | sprintf(buf, "Received disconnect message (%s)", |
| 888 | ssh2_disconnect_reasons[reason]); |
| 889 | } else { |
| 890 | sprintf(buf, "Received disconnect message (unknown type %d)", |
| 891 | reason); |
| 892 | } |
| 893 | logevent(buf); |
| 894 | strcpy(buf, "Disconnection message text: "); |
| 895 | nowlen = strlen(buf); |
| 896 | if (msglen > sizeof(buf) - nowlen - 1) |
| 897 | msglen = sizeof(buf) - nowlen - 1; |
| 898 | memcpy(buf + nowlen, pktin.data + 14, msglen); |
| 899 | buf[nowlen + msglen] = '\0'; |
| 900 | logevent(buf); |
| 901 | } |
| 902 | |
| 903 | crFinish(0); |
| 904 | } |
| 905 | |
| 906 | static void ssh1_pktout_size(int len) |
| 907 | { |
| 908 | int pad, biglen; |
| 909 | |
| 910 | len += 5; /* type and CRC */ |
| 911 | pad = 8 - (len % 8); |
| 912 | biglen = len + pad; |
| 913 | |
| 914 | pktout.length = len - 5; |
| 915 | if (pktout.maxlen < biglen) { |
| 916 | pktout.maxlen = biglen; |
| 917 | #ifdef MSCRYPTOAPI |
| 918 | /* Allocate enough buffer space for extra block |
| 919 | * for MS CryptEncrypt() */ |
| 920 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) : |
| 921 | srealloc(pktout.data, biglen + 12)); |
| 922 | #else |
| 923 | pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) : |
| 924 | srealloc(pktout.data, biglen + 4)); |
| 925 | #endif |
| 926 | if (!pktout.data) |
| 927 | fatalbox("Out of memory"); |
| 928 | } |
| 929 | pktout.body = pktout.data + 4 + pad + 1; |
| 930 | } |
| 931 | |
| 932 | static void s_wrpkt_start(int type, int len) |
| 933 | { |
| 934 | ssh1_pktout_size(len); |
| 935 | pktout.type = type; |
| 936 | } |
| 937 | |
| 938 | static int s_wrpkt_prepare(void) |
| 939 | { |
| 940 | int pad, len, biglen, i; |
| 941 | unsigned long crc; |
| 942 | |
| 943 | pktout.body[-1] = pktout.type; |
| 944 | |
| 945 | #ifdef DUMP_PACKETS |
| 946 | debug(("Packet payload pre-compression:\n")); |
| 947 | dmemdump(pktout.body - 1, pktout.length + 1); |
| 948 | #endif |
| 949 | |
| 950 | if (ssh1_compressing) { |
| 951 | unsigned char *compblk; |
| 952 | int complen; |
| 953 | zlib_compress_block(pktout.body - 1, pktout.length + 1, |
| 954 | &compblk, &complen); |
| 955 | ssh1_pktout_size(complen - 1); |
| 956 | memcpy(pktout.body - 1, compblk, complen); |
| 957 | sfree(compblk); |
| 958 | #ifdef DUMP_PACKETS |
| 959 | debug(("Packet payload post-compression:\n")); |
| 960 | dmemdump(pktout.body - 1, pktout.length + 1); |
| 961 | #endif |
| 962 | } |
| 963 | |
| 964 | len = pktout.length + 5; /* type and CRC */ |
| 965 | pad = 8 - (len % 8); |
| 966 | biglen = len + pad; |
| 967 | |
| 968 | for (i = 0; i < pad; i++) |
| 969 | pktout.data[i + 4] = random_byte(); |
| 970 | crc = crc32(pktout.data + 4, biglen - 4); |
| 971 | PUT_32BIT(pktout.data + biglen, crc); |
| 972 | PUT_32BIT(pktout.data, len); |
| 973 | |
| 974 | #ifdef DUMP_PACKETS |
| 975 | debug(("Sending packet len=%d\n", biglen + 4)); |
| 976 | dmemdump(pktout.data, biglen + 4); |
| 977 | #endif |
| 978 | if (cipher) |
| 979 | cipher->encrypt(pktout.data + 4, biglen); |
| 980 | |
| 981 | return biglen + 4; |
| 982 | } |
| 983 | |
| 984 | static void s_wrpkt(void) |
| 985 | { |
| 986 | int len, backlog; |
| 987 | len = s_wrpkt_prepare(); |
| 988 | backlog = sk_write(s, pktout.data, len); |
| 989 | if (backlog > SSH_MAX_BACKLOG) |
| 990 | ssh_throttle_all(1, backlog); |
| 991 | } |
| 992 | |
| 993 | static void s_wrpkt_defer(void) |
| 994 | { |
| 995 | int len; |
| 996 | len = s_wrpkt_prepare(); |
| 997 | if (deferred_len + len > deferred_size) { |
| 998 | deferred_size = deferred_len + len + 128; |
| 999 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
| 1000 | } |
| 1001 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
| 1002 | deferred_len += len; |
| 1003 | } |
| 1004 | |
| 1005 | /* |
| 1006 | * Construct a packet with the specified contents. |
| 1007 | */ |
| 1008 | static void construct_packet(int pkttype, va_list ap1, va_list ap2) |
| 1009 | { |
| 1010 | unsigned char *p, *argp, argchar; |
| 1011 | unsigned long argint; |
| 1012 | int pktlen, argtype, arglen; |
| 1013 | Bignum bn; |
| 1014 | |
| 1015 | pktlen = 0; |
| 1016 | while ((argtype = va_arg(ap1, int)) != PKT_END) { |
| 1017 | switch (argtype) { |
| 1018 | case PKT_INT: |
| 1019 | (void) va_arg(ap1, int); |
| 1020 | pktlen += 4; |
| 1021 | break; |
| 1022 | case PKT_CHAR: |
| 1023 | (void) va_arg(ap1, char); |
| 1024 | pktlen++; |
| 1025 | break; |
| 1026 | case PKT_DATA: |
| 1027 | (void) va_arg(ap1, unsigned char *); |
| 1028 | arglen = va_arg(ap1, int); |
| 1029 | pktlen += arglen; |
| 1030 | break; |
| 1031 | case PKT_STR: |
| 1032 | argp = va_arg(ap1, unsigned char *); |
| 1033 | arglen = strlen(argp); |
| 1034 | pktlen += 4 + arglen; |
| 1035 | break; |
| 1036 | case PKT_BIGNUM: |
| 1037 | bn = va_arg(ap1, Bignum); |
| 1038 | pktlen += ssh1_bignum_length(bn); |
| 1039 | break; |
| 1040 | default: |
| 1041 | assert(0); |
| 1042 | } |
| 1043 | } |
| 1044 | |
| 1045 | s_wrpkt_start(pkttype, pktlen); |
| 1046 | p = pktout.body; |
| 1047 | |
| 1048 | while ((argtype = va_arg(ap2, int)) != PKT_END) { |
| 1049 | switch (argtype) { |
| 1050 | case PKT_INT: |
| 1051 | argint = va_arg(ap2, int); |
| 1052 | PUT_32BIT(p, argint); |
| 1053 | p += 4; |
| 1054 | break; |
| 1055 | case PKT_CHAR: |
| 1056 | argchar = va_arg(ap2, unsigned char); |
| 1057 | *p = argchar; |
| 1058 | p++; |
| 1059 | break; |
| 1060 | case PKT_DATA: |
| 1061 | argp = va_arg(ap2, unsigned char *); |
| 1062 | arglen = va_arg(ap2, int); |
| 1063 | memcpy(p, argp, arglen); |
| 1064 | p += arglen; |
| 1065 | break; |
| 1066 | case PKT_STR: |
| 1067 | argp = va_arg(ap2, unsigned char *); |
| 1068 | arglen = strlen(argp); |
| 1069 | PUT_32BIT(p, arglen); |
| 1070 | memcpy(p + 4, argp, arglen); |
| 1071 | p += 4 + arglen; |
| 1072 | break; |
| 1073 | case PKT_BIGNUM: |
| 1074 | bn = va_arg(ap2, Bignum); |
| 1075 | p += ssh1_write_bignum(p, bn); |
| 1076 | break; |
| 1077 | } |
| 1078 | } |
| 1079 | } |
| 1080 | |
| 1081 | static void send_packet(int pkttype, ...) |
| 1082 | { |
| 1083 | va_list ap1, ap2; |
| 1084 | va_start(ap1, pkttype); |
| 1085 | va_start(ap2, pkttype); |
| 1086 | construct_packet(pkttype, ap1, ap2); |
| 1087 | s_wrpkt(); |
| 1088 | } |
| 1089 | |
| 1090 | static void defer_packet(int pkttype, ...) |
| 1091 | { |
| 1092 | va_list ap1, ap2; |
| 1093 | va_start(ap1, pkttype); |
| 1094 | va_start(ap2, pkttype); |
| 1095 | construct_packet(pkttype, ap1, ap2); |
| 1096 | s_wrpkt_defer(); |
| 1097 | } |
| 1098 | |
| 1099 | static int ssh_versioncmp(char *a, char *b) |
| 1100 | { |
| 1101 | char *ae, *be; |
| 1102 | unsigned long av, bv; |
| 1103 | |
| 1104 | av = strtoul(a, &ae, 10); |
| 1105 | bv = strtoul(b, &be, 10); |
| 1106 | if (av != bv) |
| 1107 | return (av < bv ? -1 : +1); |
| 1108 | if (*ae == '.') |
| 1109 | ae++; |
| 1110 | if (*be == '.') |
| 1111 | be++; |
| 1112 | av = strtoul(ae, &ae, 10); |
| 1113 | bv = strtoul(be, &be, 10); |
| 1114 | if (av != bv) |
| 1115 | return (av < bv ? -1 : +1); |
| 1116 | return 0; |
| 1117 | } |
| 1118 | |
| 1119 | |
| 1120 | /* |
| 1121 | * Utility routines for putting an SSH-protocol `string' and |
| 1122 | * `uint32' into a SHA state. |
| 1123 | */ |
| 1124 | #include <stdio.h> |
| 1125 | static void sha_string(SHA_State * s, void *str, int len) |
| 1126 | { |
| 1127 | unsigned char lenblk[4]; |
| 1128 | PUT_32BIT(lenblk, len); |
| 1129 | SHA_Bytes(s, lenblk, 4); |
| 1130 | SHA_Bytes(s, str, len); |
| 1131 | } |
| 1132 | |
| 1133 | static void sha_uint32(SHA_State * s, unsigned i) |
| 1134 | { |
| 1135 | unsigned char intblk[4]; |
| 1136 | PUT_32BIT(intblk, i); |
| 1137 | SHA_Bytes(s, intblk, 4); |
| 1138 | } |
| 1139 | |
| 1140 | /* |
| 1141 | * SSH2 packet construction functions. |
| 1142 | */ |
| 1143 | static void ssh2_pkt_ensure(int length) |
| 1144 | { |
| 1145 | if (pktout.maxlen < length) { |
| 1146 | pktout.maxlen = length + 256; |
| 1147 | pktout.data = |
| 1148 | (pktout.data == |
| 1149 | NULL ? smalloc(pktout.maxlen + |
| 1150 | APIEXTRA) : srealloc(pktout.data, |
| 1151 | pktout.maxlen + |
| 1152 | APIEXTRA)); |
| 1153 | if (!pktout.data) |
| 1154 | fatalbox("Out of memory"); |
| 1155 | } |
| 1156 | } |
| 1157 | static void ssh2_pkt_adddata(void *data, int len) |
| 1158 | { |
| 1159 | pktout.length += len; |
| 1160 | ssh2_pkt_ensure(pktout.length); |
| 1161 | memcpy(pktout.data + pktout.length - len, data, len); |
| 1162 | } |
| 1163 | static void ssh2_pkt_addbyte(unsigned char byte) |
| 1164 | { |
| 1165 | ssh2_pkt_adddata(&byte, 1); |
| 1166 | } |
| 1167 | static void ssh2_pkt_init(int pkt_type) |
| 1168 | { |
| 1169 | pktout.length = 5; |
| 1170 | ssh2_pkt_addbyte((unsigned char) pkt_type); |
| 1171 | } |
| 1172 | static void ssh2_pkt_addbool(unsigned char value) |
| 1173 | { |
| 1174 | ssh2_pkt_adddata(&value, 1); |
| 1175 | } |
| 1176 | static void ssh2_pkt_adduint32(unsigned long value) |
| 1177 | { |
| 1178 | unsigned char x[4]; |
| 1179 | PUT_32BIT(x, value); |
| 1180 | ssh2_pkt_adddata(x, 4); |
| 1181 | } |
| 1182 | static void ssh2_pkt_addstring_start(void) |
| 1183 | { |
| 1184 | ssh2_pkt_adduint32(0); |
| 1185 | pktout.savedpos = pktout.length; |
| 1186 | } |
| 1187 | static void ssh2_pkt_addstring_str(char *data) |
| 1188 | { |
| 1189 | ssh2_pkt_adddata(data, strlen(data)); |
| 1190 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 1191 | pktout.length - pktout.savedpos); |
| 1192 | } |
| 1193 | static void ssh2_pkt_addstring_data(char *data, int len) |
| 1194 | { |
| 1195 | ssh2_pkt_adddata(data, len); |
| 1196 | PUT_32BIT(pktout.data + pktout.savedpos - 4, |
| 1197 | pktout.length - pktout.savedpos); |
| 1198 | } |
| 1199 | static void ssh2_pkt_addstring(char *data) |
| 1200 | { |
| 1201 | ssh2_pkt_addstring_start(); |
| 1202 | ssh2_pkt_addstring_str(data); |
| 1203 | } |
| 1204 | static char *ssh2_mpint_fmt(Bignum b, int *len) |
| 1205 | { |
| 1206 | unsigned char *p; |
| 1207 | int i, n = (bignum_bitcount(b) + 7) / 8; |
| 1208 | p = smalloc(n + 1); |
| 1209 | if (!p) |
| 1210 | fatalbox("out of memory"); |
| 1211 | p[0] = 0; |
| 1212 | for (i = 1; i <= n; i++) |
| 1213 | p[i] = bignum_byte(b, n - i); |
| 1214 | i = 0; |
| 1215 | while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) |
| 1216 | i++; |
| 1217 | memmove(p, p + i, n + 1 - i); |
| 1218 | *len = n + 1 - i; |
| 1219 | return p; |
| 1220 | } |
| 1221 | static void ssh2_pkt_addmp(Bignum b) |
| 1222 | { |
| 1223 | unsigned char *p; |
| 1224 | int len; |
| 1225 | p = ssh2_mpint_fmt(b, &len); |
| 1226 | ssh2_pkt_addstring_start(); |
| 1227 | ssh2_pkt_addstring_data(p, len); |
| 1228 | sfree(p); |
| 1229 | } |
| 1230 | |
| 1231 | /* |
| 1232 | * Construct an SSH2 final-form packet: compress it, encrypt it, |
| 1233 | * put the MAC on it. Final packet, ready to be sent, is stored in |
| 1234 | * pktout.data. Total length is returned. |
| 1235 | */ |
| 1236 | static int ssh2_pkt_construct(void) |
| 1237 | { |
| 1238 | int cipherblk, maclen, padding, i; |
| 1239 | static unsigned long outgoing_sequence = 0; |
| 1240 | |
| 1241 | /* |
| 1242 | * Compress packet payload. |
| 1243 | */ |
| 1244 | #ifdef DUMP_PACKETS |
| 1245 | debug(("Pre-compression payload:\n")); |
| 1246 | dmemdump(pktout.data + 5, pktout.length - 5); |
| 1247 | #endif |
| 1248 | { |
| 1249 | unsigned char *newpayload; |
| 1250 | int newlen; |
| 1251 | if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5, |
| 1252 | &newpayload, &newlen)) { |
| 1253 | pktout.length = 5; |
| 1254 | ssh2_pkt_adddata(newpayload, newlen); |
| 1255 | sfree(newpayload); |
| 1256 | } |
| 1257 | } |
| 1258 | |
| 1259 | /* |
| 1260 | * Add padding. At least four bytes, and must also bring total |
| 1261 | * length (minus MAC) up to a multiple of the block size. |
| 1262 | */ |
| 1263 | cipherblk = cscipher ? cscipher->blksize : 8; /* block size */ |
| 1264 | cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ |
| 1265 | padding = 4; |
| 1266 | padding += |
| 1267 | (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk; |
| 1268 | maclen = csmac ? csmac->len : 0; |
| 1269 | ssh2_pkt_ensure(pktout.length + padding + maclen); |
| 1270 | pktout.data[4] = padding; |
| 1271 | for (i = 0; i < padding; i++) |
| 1272 | pktout.data[pktout.length + i] = random_byte(); |
| 1273 | PUT_32BIT(pktout.data, pktout.length + padding - 4); |
| 1274 | if (csmac) |
| 1275 | csmac->generate(pktout.data, pktout.length + padding, |
| 1276 | outgoing_sequence); |
| 1277 | outgoing_sequence++; /* whether or not we MACed */ |
| 1278 | |
| 1279 | #ifdef DUMP_PACKETS |
| 1280 | debug(("Sending packet len=%d\n", pktout.length + padding)); |
| 1281 | dmemdump(pktout.data, pktout.length + padding); |
| 1282 | #endif |
| 1283 | |
| 1284 | if (cscipher) |
| 1285 | cscipher->encrypt(pktout.data, pktout.length + padding); |
| 1286 | |
| 1287 | /* Ready-to-send packet starts at pktout.data. We return length. */ |
| 1288 | return pktout.length + padding + maclen; |
| 1289 | } |
| 1290 | |
| 1291 | /* |
| 1292 | * Construct and send an SSH2 packet immediately. |
| 1293 | */ |
| 1294 | static void ssh2_pkt_send(void) |
| 1295 | { |
| 1296 | int len; |
| 1297 | int backlog; |
| 1298 | len = ssh2_pkt_construct(); |
| 1299 | backlog = sk_write(s, pktout.data, len); |
| 1300 | if (backlog > SSH_MAX_BACKLOG) |
| 1301 | ssh_throttle_all(1, backlog); |
| 1302 | } |
| 1303 | |
| 1304 | /* |
| 1305 | * Construct an SSH2 packet and add it to a deferred data block. |
| 1306 | * Useful for sending multiple packets in a single sk_write() call, |
| 1307 | * to prevent a traffic-analysing listener from being able to work |
| 1308 | * out the length of any particular packet (such as the password |
| 1309 | * packet). |
| 1310 | * |
| 1311 | * Note that because SSH2 sequence-numbers its packets, this can |
| 1312 | * NOT be used as an m4-style `defer' allowing packets to be |
| 1313 | * constructed in one order and sent in another. |
| 1314 | */ |
| 1315 | static void ssh2_pkt_defer(void) |
| 1316 | { |
| 1317 | int len = ssh2_pkt_construct(); |
| 1318 | if (deferred_len + len > deferred_size) { |
| 1319 | deferred_size = deferred_len + len + 128; |
| 1320 | deferred_send_data = srealloc(deferred_send_data, deferred_size); |
| 1321 | } |
| 1322 | memcpy(deferred_send_data + deferred_len, pktout.data, len); |
| 1323 | deferred_len += len; |
| 1324 | } |
| 1325 | |
| 1326 | /* |
| 1327 | * Send the whole deferred data block constructed by |
| 1328 | * ssh2_pkt_defer() or SSH1's defer_packet(). |
| 1329 | */ |
| 1330 | static void ssh_pkt_defersend(void) |
| 1331 | { |
| 1332 | int backlog; |
| 1333 | backlog = sk_write(s, deferred_send_data, deferred_len); |
| 1334 | deferred_len = deferred_size = 0; |
| 1335 | sfree(deferred_send_data); |
| 1336 | deferred_send_data = NULL; |
| 1337 | if (backlog > SSH_MAX_BACKLOG) |
| 1338 | ssh_throttle_all(1, backlog); |
| 1339 | } |
| 1340 | |
| 1341 | #if 0 |
| 1342 | void bndebug(char *string, Bignum b) |
| 1343 | { |
| 1344 | unsigned char *p; |
| 1345 | int i, len; |
| 1346 | p = ssh2_mpint_fmt(b, &len); |
| 1347 | debug(("%s", string)); |
| 1348 | for (i = 0; i < len; i++) |
| 1349 | debug((" %02x", p[i])); |
| 1350 | debug(("\n")); |
| 1351 | sfree(p); |
| 1352 | } |
| 1353 | #endif |
| 1354 | |
| 1355 | static void sha_mpint(SHA_State * s, Bignum b) |
| 1356 | { |
| 1357 | unsigned char *p; |
| 1358 | int len; |
| 1359 | p = ssh2_mpint_fmt(b, &len); |
| 1360 | sha_string(s, p, len); |
| 1361 | sfree(p); |
| 1362 | } |
| 1363 | |
| 1364 | /* |
| 1365 | * SSH2 packet decode functions. |
| 1366 | */ |
| 1367 | static unsigned long ssh2_pkt_getuint32(void) |
| 1368 | { |
| 1369 | unsigned long value; |
| 1370 | if (pktin.length - pktin.savedpos < 4) |
| 1371 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1372 | value = GET_32BIT(pktin.data + pktin.savedpos); |
| 1373 | pktin.savedpos += 4; |
| 1374 | return value; |
| 1375 | } |
| 1376 | static int ssh2_pkt_getbool(void) |
| 1377 | { |
| 1378 | unsigned long value; |
| 1379 | if (pktin.length - pktin.savedpos < 1) |
| 1380 | return 0; /* arrgh, no way to decline (FIXME?) */ |
| 1381 | value = pktin.data[pktin.savedpos] != 0; |
| 1382 | pktin.savedpos++; |
| 1383 | return value; |
| 1384 | } |
| 1385 | static void ssh2_pkt_getstring(char **p, int *length) |
| 1386 | { |
| 1387 | *p = NULL; |
| 1388 | if (pktin.length - pktin.savedpos < 4) |
| 1389 | return; |
| 1390 | *length = GET_32BIT(pktin.data + pktin.savedpos); |
| 1391 | pktin.savedpos += 4; |
| 1392 | if (pktin.length - pktin.savedpos < *length) |
| 1393 | return; |
| 1394 | *p = pktin.data + pktin.savedpos; |
| 1395 | pktin.savedpos += *length; |
| 1396 | } |
| 1397 | static Bignum ssh2_pkt_getmp(void) |
| 1398 | { |
| 1399 | char *p; |
| 1400 | int length; |
| 1401 | Bignum b; |
| 1402 | |
| 1403 | ssh2_pkt_getstring(&p, &length); |
| 1404 | if (!p) |
| 1405 | return NULL; |
| 1406 | if (p[0] & 0x80) { |
| 1407 | bombout(("internal error: Can't handle negative mpints")); |
| 1408 | return NULL; |
| 1409 | } |
| 1410 | b = bignum_from_bytes(p, length); |
| 1411 | return b; |
| 1412 | } |
| 1413 | |
| 1414 | /* |
| 1415 | * Examine the remote side's version string and compare it against |
| 1416 | * a list of known buggy implementations. |
| 1417 | */ |
| 1418 | static void ssh_detect_bugs(char *vstring) |
| 1419 | { |
| 1420 | char *imp; /* pointer to implementation part */ |
| 1421 | imp = vstring; |
| 1422 | imp += strcspn(imp, "-"); |
| 1423 | if (*imp) |
| 1424 | imp++; |
| 1425 | imp += strcspn(imp, "-"); |
| 1426 | if (*imp) |
| 1427 | imp++; |
| 1428 | |
| 1429 | ssh_remote_bugs = 0; |
| 1430 | |
| 1431 | if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || |
| 1432 | !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || |
| 1433 | !strcmp(imp, "1.2.22")) { |
| 1434 | /* |
| 1435 | * These versions don't support SSH1_MSG_IGNORE, so we have |
| 1436 | * to use a different defence against password length |
| 1437 | * sniffing. |
| 1438 | */ |
| 1439 | ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; |
| 1440 | logevent("We believe remote version has SSH1 ignore bug"); |
| 1441 | } |
| 1442 | |
| 1443 | if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || |
| 1444 | !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || |
| 1445 | !strncmp(imp, "2.1 ", 4)) { |
| 1446 | /* |
| 1447 | * These versions have the HMAC bug. |
| 1448 | */ |
| 1449 | ssh_remote_bugs |= BUG_SSH2_HMAC; |
| 1450 | logevent("We believe remote version has SSH2 HMAC bug"); |
| 1451 | } |
| 1452 | } |
| 1453 | |
| 1454 | static int do_ssh_init(unsigned char c) |
| 1455 | { |
| 1456 | static int vslen; |
| 1457 | static char version[10]; |
| 1458 | static char *vstring; |
| 1459 | static int vstrsize; |
| 1460 | static char *vlog; |
| 1461 | static int i; |
| 1462 | |
| 1463 | crBegin; |
| 1464 | |
| 1465 | /* Search for the string "SSH-" in the input. */ |
| 1466 | i = 0; |
| 1467 | while (1) { |
| 1468 | static const int transS[] = { 1, 2, 2, 1 }; |
| 1469 | static const int transH[] = { 0, 0, 3, 0 }; |
| 1470 | static const int transminus[] = { 0, 0, 0, -1 }; |
| 1471 | if (c == 'S') |
| 1472 | i = transS[i]; |
| 1473 | else if (c == 'H') |
| 1474 | i = transH[i]; |
| 1475 | else if (c == '-') |
| 1476 | i = transminus[i]; |
| 1477 | else |
| 1478 | i = 0; |
| 1479 | if (i < 0) |
| 1480 | break; |
| 1481 | crReturn(1); /* get another character */ |
| 1482 | } |
| 1483 | |
| 1484 | vstring = smalloc(16); |
| 1485 | vstrsize = 16; |
| 1486 | strcpy(vstring, "SSH-"); |
| 1487 | vslen = 4; |
| 1488 | i = 0; |
| 1489 | while (1) { |
| 1490 | crReturn(1); /* get another char */ |
| 1491 | if (vslen >= vstrsize - 1) { |
| 1492 | vstrsize += 16; |
| 1493 | vstring = srealloc(vstring, vstrsize); |
| 1494 | } |
| 1495 | vstring[vslen++] = c; |
| 1496 | if (i >= 0) { |
| 1497 | if (c == '-') { |
| 1498 | version[i] = '\0'; |
| 1499 | i = -1; |
| 1500 | } else if (i < sizeof(version) - 1) |
| 1501 | version[i++] = c; |
| 1502 | } else if (c == '\n') |
| 1503 | break; |
| 1504 | } |
| 1505 | |
| 1506 | ssh_agentfwd_enabled = FALSE; |
| 1507 | rdpkt2_state.incoming_sequence = 0; |
| 1508 | |
| 1509 | vstring[vslen] = 0; |
| 1510 | vlog = smalloc(20 + vslen); |
| 1511 | sprintf(vlog, "Server version: %s", vstring); |
| 1512 | ssh_detect_bugs(vstring); |
| 1513 | vlog[strcspn(vlog, "\r\n")] = '\0'; |
| 1514 | logevent(vlog); |
| 1515 | sfree(vlog); |
| 1516 | |
| 1517 | /* |
| 1518 | * Server version "1.99" means we can choose whether we use v1 |
| 1519 | * or v2 protocol. Choice is based on cfg.sshprot. |
| 1520 | */ |
| 1521 | if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) { |
| 1522 | /* |
| 1523 | * This is a v2 server. Begin v2 protocol. |
| 1524 | */ |
| 1525 | char verstring[80], vlog[100]; |
| 1526 | sprintf(verstring, "SSH-2.0-%s", sshver); |
| 1527 | SHA_Init(&exhashbase); |
| 1528 | /* |
| 1529 | * Hash our version string and their version string. |
| 1530 | */ |
| 1531 | sha_string(&exhashbase, verstring, strlen(verstring)); |
| 1532 | sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n")); |
| 1533 | sprintf(vlog, "We claim version: %s", verstring); |
| 1534 | logevent(vlog); |
| 1535 | strcat(verstring, "\n"); |
| 1536 | logevent("Using SSH protocol version 2"); |
| 1537 | sk_write(s, verstring, strlen(verstring)); |
| 1538 | ssh_protocol = ssh2_protocol; |
| 1539 | ssh_version = 2; |
| 1540 | s_rdpkt = ssh2_rdpkt; |
| 1541 | } else { |
| 1542 | /* |
| 1543 | * This is a v1 server. Begin v1 protocol. |
| 1544 | */ |
| 1545 | char verstring[80], vlog[100]; |
| 1546 | sprintf(verstring, "SSH-%s-%s", |
| 1547 | (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"), |
| 1548 | sshver); |
| 1549 | sprintf(vlog, "We claim version: %s", verstring); |
| 1550 | logevent(vlog); |
| 1551 | strcat(verstring, "\n"); |
| 1552 | logevent("Using SSH protocol version 1"); |
| 1553 | sk_write(s, verstring, strlen(verstring)); |
| 1554 | ssh_protocol = ssh1_protocol; |
| 1555 | ssh_version = 1; |
| 1556 | s_rdpkt = ssh1_rdpkt; |
| 1557 | } |
| 1558 | ssh_state = SSH_STATE_BEFORE_SIZE; |
| 1559 | |
| 1560 | sfree(vstring); |
| 1561 | |
| 1562 | crFinish(0); |
| 1563 | } |
| 1564 | |
| 1565 | static void ssh_gotdata(unsigned char *data, int datalen) |
| 1566 | { |
| 1567 | crBegin; |
| 1568 | |
| 1569 | /* |
| 1570 | * To begin with, feed the characters one by one to the |
| 1571 | * protocol initialisation / selection function do_ssh_init(). |
| 1572 | * When that returns 0, we're done with the initial greeting |
| 1573 | * exchange and can move on to packet discipline. |
| 1574 | */ |
| 1575 | while (1) { |
| 1576 | int ret; |
| 1577 | if (datalen == 0) |
| 1578 | crReturnV; /* more data please */ |
| 1579 | ret = do_ssh_init(*data); |
| 1580 | data++; |
| 1581 | datalen--; |
| 1582 | if (ret == 0) |
| 1583 | break; |
| 1584 | } |
| 1585 | |
| 1586 | /* |
| 1587 | * We emerge from that loop when the initial negotiation is |
| 1588 | * over and we have selected an s_rdpkt function. Now pass |
| 1589 | * everything to s_rdpkt, and then pass the resulting packets |
| 1590 | * to the proper protocol handler. |
| 1591 | */ |
| 1592 | if (datalen == 0) |
| 1593 | crReturnV; |
| 1594 | while (1) { |
| 1595 | while (datalen > 0) { |
| 1596 | if (s_rdpkt(&data, &datalen) == 0) { |
| 1597 | ssh_protocol(NULL, 0, 1); |
| 1598 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1599 | return; |
| 1600 | } |
| 1601 | } |
| 1602 | } |
| 1603 | crReturnV; |
| 1604 | } |
| 1605 | crFinishV; |
| 1606 | } |
| 1607 | |
| 1608 | static int ssh_closing(Plug plug, char *error_msg, int error_code, |
| 1609 | int calling_back) |
| 1610 | { |
| 1611 | ssh_state = SSH_STATE_CLOSED; |
| 1612 | if (s) { |
| 1613 | sk_close(s); |
| 1614 | s = NULL; |
| 1615 | } |
| 1616 | if (error_msg) { |
| 1617 | /* A socket error has occurred. */ |
| 1618 | connection_fatal(error_msg); |
| 1619 | } else { |
| 1620 | /* Otherwise, the remote side closed the connection normally. */ |
| 1621 | } |
| 1622 | return 0; |
| 1623 | } |
| 1624 | |
| 1625 | static int ssh_receive(Plug plug, int urgent, char *data, int len) |
| 1626 | { |
| 1627 | ssh_gotdata(data, len); |
| 1628 | if (ssh_state == SSH_STATE_CLOSED) { |
| 1629 | if (s) { |
| 1630 | sk_close(s); |
| 1631 | s = NULL; |
| 1632 | } |
| 1633 | return 0; |
| 1634 | } |
| 1635 | return 1; |
| 1636 | } |
| 1637 | |
| 1638 | static void ssh_sent(Plug plug, int bufsize) |
| 1639 | { |
| 1640 | /* |
| 1641 | * If the send backlog on the SSH socket itself clears, we |
| 1642 | * should unthrottle the whole world if it was throttled. |
| 1643 | */ |
| 1644 | if (bufsize < SSH_MAX_BACKLOG) |
| 1645 | ssh_throttle_all(0, bufsize); |
| 1646 | } |
| 1647 | |
| 1648 | /* |
| 1649 | * Connect to specified host and port. |
| 1650 | * Returns an error message, or NULL on success. |
| 1651 | * Also places the canonical host name into `realhost'. It must be |
| 1652 | * freed by the caller. |
| 1653 | */ |
| 1654 | static char *connect_to_host(char *host, int port, char **realhost) |
| 1655 | { |
| 1656 | static struct plug_function_table fn_table = { |
| 1657 | ssh_closing, |
| 1658 | ssh_receive, |
| 1659 | ssh_sent, |
| 1660 | NULL |
| 1661 | }, *fn_table_ptr = &fn_table; |
| 1662 | |
| 1663 | SockAddr addr; |
| 1664 | char *err; |
| 1665 | #ifdef FWHACK |
| 1666 | char *FWhost; |
| 1667 | int FWport; |
| 1668 | #endif |
| 1669 | |
| 1670 | savedhost = smalloc(1 + strlen(host)); |
| 1671 | if (!savedhost) |
| 1672 | fatalbox("Out of memory"); |
| 1673 | strcpy(savedhost, host); |
| 1674 | |
| 1675 | if (port < 0) |
| 1676 | port = 22; /* default ssh port */ |
| 1677 | savedport = port; |
| 1678 | |
| 1679 | #ifdef FWHACK |
| 1680 | FWhost = host; |
| 1681 | FWport = port; |
| 1682 | host = FWSTR; |
| 1683 | port = 23; |
| 1684 | #endif |
| 1685 | |
| 1686 | /* |
| 1687 | * Try to find host. |
| 1688 | */ |
| 1689 | { |
| 1690 | char buf[200]; |
| 1691 | sprintf(buf, "Looking up host \"%.170s\"", host); |
| 1692 | logevent(buf); |
| 1693 | } |
| 1694 | addr = sk_namelookup(host, realhost); |
| 1695 | if ((err = sk_addr_error(addr))) |
| 1696 | return err; |
| 1697 | |
| 1698 | #ifdef FWHACK |
| 1699 | *realhost = strdup(FWhost); |
| 1700 | #endif |
| 1701 | |
| 1702 | /* |
| 1703 | * Open socket. |
| 1704 | */ |
| 1705 | { |
| 1706 | char buf[200], addrbuf[100]; |
| 1707 | sk_getaddr(addr, addrbuf, 100); |
| 1708 | sprintf(buf, "Connecting to %.100s port %d", addrbuf, port); |
| 1709 | logevent(buf); |
| 1710 | } |
| 1711 | s = sk_new(addr, port, 0, 1, &fn_table_ptr); |
| 1712 | if ((err = sk_socket_error(s))) |
| 1713 | return err; |
| 1714 | |
| 1715 | #ifdef FWHACK |
| 1716 | sk_write(s, "connect ", 8); |
| 1717 | sk_write(s, FWhost, strlen(FWhost)); |
| 1718 | { |
| 1719 | char buf[20]; |
| 1720 | sprintf(buf, " %d\n", FWport); |
| 1721 | sk_write(s, buf, strlen(buf)); |
| 1722 | } |
| 1723 | #endif |
| 1724 | |
| 1725 | return NULL; |
| 1726 | } |
| 1727 | |
| 1728 | /* |
| 1729 | * Throttle or unthrottle the SSH connection. |
| 1730 | */ |
| 1731 | static void ssh1_throttle(int adjust) |
| 1732 | { |
| 1733 | int old_count = ssh1_throttle_count; |
| 1734 | ssh1_throttle_count += adjust; |
| 1735 | assert(ssh1_throttle_count >= 0); |
| 1736 | if (ssh1_throttle_count && !old_count) { |
| 1737 | sk_set_frozen(s, 1); |
| 1738 | } else if (!ssh1_throttle_count && old_count) { |
| 1739 | sk_set_frozen(s, 0); |
| 1740 | } |
| 1741 | } |
| 1742 | |
| 1743 | /* |
| 1744 | * Throttle or unthrottle _all_ local data streams (for when sends |
| 1745 | * on the SSH connection itself back up). |
| 1746 | */ |
| 1747 | static void ssh_throttle_all(int enable, int bufsize) |
| 1748 | { |
| 1749 | int i; |
| 1750 | struct ssh_channel *c; |
| 1751 | |
| 1752 | if (enable == ssh_throttled_all) |
| 1753 | return; |
| 1754 | ssh_throttled_all = enable; |
| 1755 | ssh_overall_bufsize = bufsize; |
| 1756 | if (!ssh_channels) |
| 1757 | return; |
| 1758 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
| 1759 | switch (c->type) { |
| 1760 | case CHAN_MAINSESSION: |
| 1761 | /* |
| 1762 | * This is treated separately, outside the switch. |
| 1763 | */ |
| 1764 | break; |
| 1765 | case CHAN_X11: |
| 1766 | x11_override_throttle(c->u.x11.s, enable); |
| 1767 | break; |
| 1768 | case CHAN_AGENT: |
| 1769 | /* Agent channels require no buffer management. */ |
| 1770 | break; |
| 1771 | case CHAN_SOCKDATA: |
| 1772 | pfd_override_throttle(c->u.x11.s, enable); |
| 1773 | break; |
| 1774 | } |
| 1775 | } |
| 1776 | } |
| 1777 | |
| 1778 | /* |
| 1779 | * Handle the key exchange and user authentication phases. |
| 1780 | */ |
| 1781 | static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) |
| 1782 | { |
| 1783 | int i, j; |
| 1784 | static int len; |
| 1785 | static unsigned char *rsabuf, *keystr1, *keystr2; |
| 1786 | unsigned char cookie[8]; |
| 1787 | struct RSAKey servkey, hostkey; |
| 1788 | struct MD5Context md5c; |
| 1789 | static unsigned long supported_ciphers_mask, supported_auths_mask; |
| 1790 | static int tried_publickey; |
| 1791 | static unsigned char session_id[16]; |
| 1792 | static int cipher_type; |
| 1793 | static char username[100]; |
| 1794 | |
| 1795 | crBegin; |
| 1796 | |
| 1797 | if (!ispkt) |
| 1798 | crWaitUntil(ispkt); |
| 1799 | |
| 1800 | if (pktin.type != SSH1_SMSG_PUBLIC_KEY) { |
| 1801 | bombout(("Public key packet not received")); |
| 1802 | crReturn(0); |
| 1803 | } |
| 1804 | |
| 1805 | logevent("Received public keys"); |
| 1806 | |
| 1807 | memcpy(cookie, pktin.body, 8); |
| 1808 | |
| 1809 | i = makekey(pktin.body + 8, &servkey, &keystr1, 0); |
| 1810 | j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0); |
| 1811 | |
| 1812 | /* |
| 1813 | * Log the host key fingerprint. |
| 1814 | */ |
| 1815 | { |
| 1816 | char logmsg[80]; |
| 1817 | logevent("Host key fingerprint is:"); |
| 1818 | strcpy(logmsg, " "); |
| 1819 | hostkey.comment = NULL; |
| 1820 | rsa_fingerprint(logmsg + strlen(logmsg), |
| 1821 | sizeof(logmsg) - strlen(logmsg), &hostkey); |
| 1822 | logevent(logmsg); |
| 1823 | } |
| 1824 | |
| 1825 | ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j); |
| 1826 | supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j); |
| 1827 | supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j); |
| 1828 | |
| 1829 | ssh1_local_protoflags = |
| 1830 | ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; |
| 1831 | ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; |
| 1832 | |
| 1833 | MD5Init(&md5c); |
| 1834 | MD5Update(&md5c, keystr2, hostkey.bytes); |
| 1835 | MD5Update(&md5c, keystr1, servkey.bytes); |
| 1836 | MD5Update(&md5c, pktin.body, 8); |
| 1837 | MD5Final(session_id, &md5c); |
| 1838 | |
| 1839 | for (i = 0; i < 32; i++) |
| 1840 | session_key[i] = random_byte(); |
| 1841 | |
| 1842 | len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); |
| 1843 | |
| 1844 | rsabuf = smalloc(len); |
| 1845 | if (!rsabuf) |
| 1846 | fatalbox("Out of memory"); |
| 1847 | |
| 1848 | /* |
| 1849 | * Verify the host key. |
| 1850 | */ |
| 1851 | { |
| 1852 | /* |
| 1853 | * First format the key into a string. |
| 1854 | */ |
| 1855 | int len = rsastr_len(&hostkey); |
| 1856 | char fingerprint[100]; |
| 1857 | char *keystr = smalloc(len); |
| 1858 | if (!keystr) |
| 1859 | fatalbox("Out of memory"); |
| 1860 | rsastr_fmt(keystr, &hostkey); |
| 1861 | rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); |
| 1862 | verify_ssh_host_key(savedhost, savedport, "rsa", keystr, |
| 1863 | fingerprint); |
| 1864 | sfree(keystr); |
| 1865 | } |
| 1866 | |
| 1867 | for (i = 0; i < 32; i++) { |
| 1868 | rsabuf[i] = session_key[i]; |
| 1869 | if (i < 16) |
| 1870 | rsabuf[i] ^= session_id[i]; |
| 1871 | } |
| 1872 | |
| 1873 | if (hostkey.bytes > servkey.bytes) { |
| 1874 | rsaencrypt(rsabuf, 32, &servkey); |
| 1875 | rsaencrypt(rsabuf, servkey.bytes, &hostkey); |
| 1876 | } else { |
| 1877 | rsaencrypt(rsabuf, 32, &hostkey); |
| 1878 | rsaencrypt(rsabuf, hostkey.bytes, &servkey); |
| 1879 | } |
| 1880 | |
| 1881 | logevent("Encrypted session key"); |
| 1882 | |
| 1883 | { |
| 1884 | int cipher_chosen = 0, warn = 0; |
| 1885 | char *cipher_string = NULL; |
| 1886 | for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { |
| 1887 | int next_cipher = cfg.ssh_cipherlist[i]; |
| 1888 | if (next_cipher == CIPHER_WARN) { |
| 1889 | /* If/when we choose a cipher, warn about it */ |
| 1890 | warn = 1; |
| 1891 | } else if (next_cipher == CIPHER_AES) { |
| 1892 | /* XXX Probably don't need to mention this. */ |
| 1893 | logevent("AES not supported in SSH1, skipping"); |
| 1894 | } else { |
| 1895 | switch (next_cipher) { |
| 1896 | case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; |
| 1897 | cipher_string = "3DES"; break; |
| 1898 | case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; |
| 1899 | cipher_string = "Blowfish"; break; |
| 1900 | case CIPHER_DES: cipher_type = SSH_CIPHER_DES; |
| 1901 | cipher_string = "single-DES"; break; |
| 1902 | } |
| 1903 | if (supported_ciphers_mask & (1 << cipher_type)) |
| 1904 | cipher_chosen = 1; |
| 1905 | } |
| 1906 | } |
| 1907 | if (!cipher_chosen) { |
| 1908 | if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) |
| 1909 | bombout(("Server violates SSH 1 protocol by not " |
| 1910 | "supporting 3DES encryption")); |
| 1911 | else |
| 1912 | /* shouldn't happen */ |
| 1913 | bombout(("No supported ciphers found")); |
| 1914 | crReturn(0); |
| 1915 | } |
| 1916 | |
| 1917 | /* Warn about chosen cipher if necessary. */ |
| 1918 | if (warn) |
| 1919 | askcipher(cipher_string, 0); |
| 1920 | } |
| 1921 | |
| 1922 | switch (cipher_type) { |
| 1923 | case SSH_CIPHER_3DES: |
| 1924 | logevent("Using 3DES encryption"); |
| 1925 | break; |
| 1926 | case SSH_CIPHER_DES: |
| 1927 | logevent("Using single-DES encryption"); |
| 1928 | break; |
| 1929 | case SSH_CIPHER_BLOWFISH: |
| 1930 | logevent("Using Blowfish encryption"); |
| 1931 | break; |
| 1932 | } |
| 1933 | |
| 1934 | send_packet(SSH1_CMSG_SESSION_KEY, |
| 1935 | PKT_CHAR, cipher_type, |
| 1936 | PKT_DATA, cookie, 8, |
| 1937 | PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF, |
| 1938 | PKT_DATA, rsabuf, len, |
| 1939 | PKT_INT, ssh1_local_protoflags, PKT_END); |
| 1940 | |
| 1941 | logevent("Trying to enable encryption..."); |
| 1942 | |
| 1943 | sfree(rsabuf); |
| 1944 | |
| 1945 | cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : |
| 1946 | cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des; |
| 1947 | cipher->sesskey(session_key); |
| 1948 | |
| 1949 | crWaitUntil(ispkt); |
| 1950 | |
| 1951 | if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 1952 | bombout(("Encryption not successfully enabled")); |
| 1953 | crReturn(0); |
| 1954 | } |
| 1955 | |
| 1956 | logevent("Successfully started encryption"); |
| 1957 | |
| 1958 | fflush(stdout); |
| 1959 | { |
| 1960 | static int pos = 0; |
| 1961 | static char c; |
| 1962 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 1963 | if (ssh_get_line) { |
| 1964 | if (!ssh_get_line("login as: ", |
| 1965 | username, sizeof(username), FALSE)) { |
| 1966 | /* |
| 1967 | * get_line failed to get a username. |
| 1968 | * Terminate. |
| 1969 | */ |
| 1970 | logevent("No username provided. Abandoning session."); |
| 1971 | ssh_state = SSH_STATE_CLOSED; |
| 1972 | crReturn(1); |
| 1973 | } |
| 1974 | } else { |
| 1975 | c_write_str("login as: "); |
| 1976 | ssh_send_ok = 1; |
| 1977 | while (pos >= 0) { |
| 1978 | crWaitUntil(!ispkt); |
| 1979 | while (inlen--) |
| 1980 | switch (c = *in++) { |
| 1981 | case 10: |
| 1982 | case 13: |
| 1983 | username[pos] = 0; |
| 1984 | pos = -1; |
| 1985 | break; |
| 1986 | case 8: |
| 1987 | case 127: |
| 1988 | if (pos > 0) { |
| 1989 | c_write_str("\b \b"); |
| 1990 | pos--; |
| 1991 | } |
| 1992 | break; |
| 1993 | case 21: |
| 1994 | case 27: |
| 1995 | while (pos > 0) { |
| 1996 | c_write_str("\b \b"); |
| 1997 | pos--; |
| 1998 | } |
| 1999 | break; |
| 2000 | case 3: |
| 2001 | case 4: |
| 2002 | random_save_seed(); |
| 2003 | exit(0); |
| 2004 | break; |
| 2005 | default: |
| 2006 | if (((c >= ' ' && c <= '~') || |
| 2007 | ((unsigned char) c >= 160)) |
| 2008 | && pos < sizeof(username)-1) { |
| 2009 | username[pos++] = c; |
| 2010 | c_write(&c, 1); |
| 2011 | } |
| 2012 | break; |
| 2013 | } |
| 2014 | } |
| 2015 | c_write_str("\r\n"); |
| 2016 | username[strcspn(username, "\n\r")] = '\0'; |
| 2017 | } |
| 2018 | } else { |
| 2019 | strncpy(username, cfg.username, 99); |
| 2020 | username[99] = '\0'; |
| 2021 | } |
| 2022 | |
| 2023 | send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); |
| 2024 | { |
| 2025 | char userlog[22 + sizeof(username)]; |
| 2026 | sprintf(userlog, "Sent username \"%s\"", username); |
| 2027 | logevent(userlog); |
| 2028 | if (flags & FLAG_INTERACTIVE && |
| 2029 | (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { |
| 2030 | strcat(userlog, "\r\n"); |
| 2031 | c_write_str(userlog); |
| 2032 | } |
| 2033 | } |
| 2034 | } |
| 2035 | |
| 2036 | crWaitUntil(ispkt); |
| 2037 | |
| 2038 | tried_publickey = 0; |
| 2039 | |
| 2040 | while (pktin.type == SSH1_SMSG_FAILURE) { |
| 2041 | static char password[100]; |
| 2042 | static char prompt[200]; |
| 2043 | static int pos; |
| 2044 | static char c; |
| 2045 | static int pwpkt_type; |
| 2046 | /* |
| 2047 | * Show password prompt, having first obtained it via a TIS |
| 2048 | * or CryptoCard exchange if we're doing TIS or CryptoCard |
| 2049 | * authentication. |
| 2050 | */ |
| 2051 | pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; |
| 2052 | if (agent_exists()) { |
| 2053 | /* |
| 2054 | * Attempt RSA authentication using Pageant. |
| 2055 | */ |
| 2056 | static unsigned char request[5], *response, *p; |
| 2057 | static int responselen; |
| 2058 | static int i, nkeys; |
| 2059 | static int authed = FALSE; |
| 2060 | void *r; |
| 2061 | |
| 2062 | logevent("Pageant is running. Requesting keys."); |
| 2063 | |
| 2064 | /* Request the keys held by the agent. */ |
| 2065 | PUT_32BIT(request, 1); |
| 2066 | request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; |
| 2067 | agent_query(request, 5, &r, &responselen); |
| 2068 | response = (unsigned char *) r; |
| 2069 | if (response && responselen >= 5 && |
| 2070 | response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { |
| 2071 | p = response + 5; |
| 2072 | nkeys = GET_32BIT(p); |
| 2073 | p += 4; |
| 2074 | { |
| 2075 | char buf[64]; |
| 2076 | sprintf(buf, "Pageant has %d SSH1 keys", nkeys); |
| 2077 | logevent(buf); |
| 2078 | } |
| 2079 | for (i = 0; i < nkeys; i++) { |
| 2080 | static struct RSAKey key; |
| 2081 | static Bignum challenge; |
| 2082 | static char *commentp; |
| 2083 | static int commentlen; |
| 2084 | |
| 2085 | { |
| 2086 | char buf[64]; |
| 2087 | sprintf(buf, "Trying Pageant key #%d", i); |
| 2088 | logevent(buf); |
| 2089 | } |
| 2090 | p += 4; |
| 2091 | p += ssh1_read_bignum(p, &key.exponent); |
| 2092 | p += ssh1_read_bignum(p, &key.modulus); |
| 2093 | commentlen = GET_32BIT(p); |
| 2094 | p += 4; |
| 2095 | commentp = p; |
| 2096 | p += commentlen; |
| 2097 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 2098 | PKT_BIGNUM, key.modulus, PKT_END); |
| 2099 | crWaitUntil(ispkt); |
| 2100 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 2101 | logevent("Key refused"); |
| 2102 | continue; |
| 2103 | } |
| 2104 | logevent("Received RSA challenge"); |
| 2105 | ssh1_read_bignum(pktin.body, &challenge); |
| 2106 | { |
| 2107 | char *agentreq, *q, *ret; |
| 2108 | void *vret; |
| 2109 | int len, retlen; |
| 2110 | len = 1 + 4; /* message type, bit count */ |
| 2111 | len += ssh1_bignum_length(key.exponent); |
| 2112 | len += ssh1_bignum_length(key.modulus); |
| 2113 | len += ssh1_bignum_length(challenge); |
| 2114 | len += 16; /* session id */ |
| 2115 | len += 4; /* response format */ |
| 2116 | agentreq = smalloc(4 + len); |
| 2117 | PUT_32BIT(agentreq, len); |
| 2118 | q = agentreq + 4; |
| 2119 | *q++ = SSH1_AGENTC_RSA_CHALLENGE; |
| 2120 | PUT_32BIT(q, bignum_bitcount(key.modulus)); |
| 2121 | q += 4; |
| 2122 | q += ssh1_write_bignum(q, key.exponent); |
| 2123 | q += ssh1_write_bignum(q, key.modulus); |
| 2124 | q += ssh1_write_bignum(q, challenge); |
| 2125 | memcpy(q, session_id, 16); |
| 2126 | q += 16; |
| 2127 | PUT_32BIT(q, 1); /* response format */ |
| 2128 | agent_query(agentreq, len + 4, &vret, &retlen); |
| 2129 | ret = vret; |
| 2130 | sfree(agentreq); |
| 2131 | if (ret) { |
| 2132 | if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { |
| 2133 | logevent("Sending Pageant's response"); |
| 2134 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 2135 | PKT_DATA, ret + 5, 16, |
| 2136 | PKT_END); |
| 2137 | sfree(ret); |
| 2138 | crWaitUntil(ispkt); |
| 2139 | if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 2140 | logevent |
| 2141 | ("Pageant's response accepted"); |
| 2142 | if (flags & FLAG_VERBOSE) { |
| 2143 | c_write_str |
| 2144 | ("Authenticated using RSA key \""); |
| 2145 | c_write(commentp, commentlen); |
| 2146 | c_write_str("\" from agent\r\n"); |
| 2147 | } |
| 2148 | authed = TRUE; |
| 2149 | } else |
| 2150 | logevent |
| 2151 | ("Pageant's response not accepted"); |
| 2152 | } else { |
| 2153 | logevent |
| 2154 | ("Pageant failed to answer challenge"); |
| 2155 | sfree(ret); |
| 2156 | } |
| 2157 | } else { |
| 2158 | logevent("No reply received from Pageant"); |
| 2159 | } |
| 2160 | } |
| 2161 | freebn(key.exponent); |
| 2162 | freebn(key.modulus); |
| 2163 | freebn(challenge); |
| 2164 | if (authed) |
| 2165 | break; |
| 2166 | } |
| 2167 | } |
| 2168 | if (authed) |
| 2169 | break; |
| 2170 | } |
| 2171 | if (*cfg.keyfile && !tried_publickey) |
| 2172 | pwpkt_type = SSH1_CMSG_AUTH_RSA; |
| 2173 | |
| 2174 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 2175 | cfg.try_tis_auth && |
| 2176 | (supported_auths_mask & (1 << SSH1_AUTH_TIS))) { |
| 2177 | pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; |
| 2178 | logevent("Requested TIS authentication"); |
| 2179 | send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); |
| 2180 | crWaitUntil(ispkt); |
| 2181 | if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { |
| 2182 | logevent("TIS authentication declined"); |
| 2183 | if (flags & FLAG_INTERACTIVE) |
| 2184 | c_write_str("TIS authentication refused.\r\n"); |
| 2185 | } else { |
| 2186 | int challengelen = ((pktin.body[0] << 24) | |
| 2187 | (pktin.body[1] << 16) | |
| 2188 | (pktin.body[2] << 8) | |
| 2189 | (pktin.body[3])); |
| 2190 | logevent("Received TIS challenge"); |
| 2191 | if (challengelen > sizeof(prompt) - 1) |
| 2192 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
| 2193 | memcpy(prompt, pktin.body + 4, challengelen); |
| 2194 | prompt[challengelen] = '\0'; |
| 2195 | } |
| 2196 | } |
| 2197 | if (pktin.type == SSH1_SMSG_FAILURE && |
| 2198 | cfg.try_tis_auth && |
| 2199 | (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) { |
| 2200 | pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; |
| 2201 | logevent("Requested CryptoCard authentication"); |
| 2202 | send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); |
| 2203 | crWaitUntil(ispkt); |
| 2204 | if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { |
| 2205 | logevent("CryptoCard authentication declined"); |
| 2206 | c_write_str("CryptoCard authentication refused.\r\n"); |
| 2207 | } else { |
| 2208 | int challengelen = ((pktin.body[0] << 24) | |
| 2209 | (pktin.body[1] << 16) | |
| 2210 | (pktin.body[2] << 8) | |
| 2211 | (pktin.body[3])); |
| 2212 | logevent("Received CryptoCard challenge"); |
| 2213 | if (challengelen > sizeof(prompt) - 1) |
| 2214 | challengelen = sizeof(prompt) - 1; /* prevent overrun */ |
| 2215 | memcpy(prompt, pktin.body + 4, challengelen); |
| 2216 | strncpy(prompt + challengelen, "\r\nResponse : ", |
| 2217 | sizeof(prompt) - challengelen); |
| 2218 | prompt[sizeof(prompt) - 1] = '\0'; |
| 2219 | } |
| 2220 | } |
| 2221 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 2222 | sprintf(prompt, "%.90s@%.90s's password: ", |
| 2223 | username, savedhost); |
| 2224 | } |
| 2225 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 2226 | char *comment = NULL; |
| 2227 | if (flags & FLAG_VERBOSE) |
| 2228 | c_write_str("Trying public key authentication.\r\n"); |
| 2229 | if (!rsakey_encrypted(cfg.keyfile, &comment)) { |
| 2230 | if (flags & FLAG_VERBOSE) |
| 2231 | c_write_str("No passphrase required.\r\n"); |
| 2232 | goto tryauth; |
| 2233 | } |
| 2234 | sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); |
| 2235 | sfree(comment); |
| 2236 | } |
| 2237 | |
| 2238 | if (ssh_get_line) { |
| 2239 | if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { |
| 2240 | /* |
| 2241 | * get_line failed to get a password (for example |
| 2242 | * because one was supplied on the command line |
| 2243 | * which has already failed to work). Terminate. |
| 2244 | */ |
| 2245 | send_packet(SSH1_MSG_DISCONNECT, |
| 2246 | PKT_STR, "No more passwords available to try", |
| 2247 | PKT_END); |
| 2248 | connection_fatal("Unable to authenticate"); |
| 2249 | ssh_state = SSH_STATE_CLOSED; |
| 2250 | crReturn(1); |
| 2251 | } |
| 2252 | } else { |
| 2253 | c_write_str(prompt); |
| 2254 | pos = 0; |
| 2255 | ssh_send_ok = 1; |
| 2256 | while (pos >= 0) { |
| 2257 | crWaitUntil(!ispkt); |
| 2258 | while (inlen--) |
| 2259 | switch (c = *in++) { |
| 2260 | case 10: |
| 2261 | case 13: |
| 2262 | password[pos] = 0; |
| 2263 | pos = -1; |
| 2264 | break; |
| 2265 | case 8: |
| 2266 | case 127: |
| 2267 | if (pos > 0) |
| 2268 | pos--; |
| 2269 | break; |
| 2270 | case 21: |
| 2271 | case 27: |
| 2272 | pos = 0; |
| 2273 | break; |
| 2274 | case 3: |
| 2275 | case 4: |
| 2276 | random_save_seed(); |
| 2277 | exit(0); |
| 2278 | break; |
| 2279 | default: |
| 2280 | if (pos < sizeof(password)-1) |
| 2281 | password[pos++] = c; |
| 2282 | break; |
| 2283 | } |
| 2284 | } |
| 2285 | c_write_str("\r\n"); |
| 2286 | } |
| 2287 | |
| 2288 | tryauth: |
| 2289 | if (pwpkt_type == SSH1_CMSG_AUTH_RSA) { |
| 2290 | /* |
| 2291 | * Try public key authentication with the specified |
| 2292 | * key file. |
| 2293 | */ |
| 2294 | static struct RSAKey pubkey; |
| 2295 | static Bignum challenge, response; |
| 2296 | static int i; |
| 2297 | static unsigned char buffer[32]; |
| 2298 | |
| 2299 | tried_publickey = 1; |
| 2300 | i = loadrsakey(cfg.keyfile, &pubkey, password); |
| 2301 | if (i == 0) { |
| 2302 | c_write_str("Couldn't load public key from "); |
| 2303 | c_write_str(cfg.keyfile); |
| 2304 | c_write_str(".\r\n"); |
| 2305 | continue; /* go and try password */ |
| 2306 | } |
| 2307 | if (i == -1) { |
| 2308 | c_write_str("Wrong passphrase.\r\n"); |
| 2309 | tried_publickey = 0; |
| 2310 | continue; /* try again */ |
| 2311 | } |
| 2312 | |
| 2313 | /* |
| 2314 | * Send a public key attempt. |
| 2315 | */ |
| 2316 | send_packet(SSH1_CMSG_AUTH_RSA, |
| 2317 | PKT_BIGNUM, pubkey.modulus, PKT_END); |
| 2318 | |
| 2319 | crWaitUntil(ispkt); |
| 2320 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2321 | c_write_str("Server refused our public key.\r\n"); |
| 2322 | continue; /* go and try password */ |
| 2323 | } |
| 2324 | if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { |
| 2325 | bombout(("Bizarre response to offer of public key")); |
| 2326 | crReturn(0); |
| 2327 | } |
| 2328 | ssh1_read_bignum(pktin.body, &challenge); |
| 2329 | response = rsadecrypt(challenge, &pubkey); |
| 2330 | freebn(pubkey.private_exponent); /* burn the evidence */ |
| 2331 | |
| 2332 | for (i = 0; i < 32; i++) { |
| 2333 | buffer[i] = bignum_byte(response, 31 - i); |
| 2334 | } |
| 2335 | |
| 2336 | MD5Init(&md5c); |
| 2337 | MD5Update(&md5c, buffer, 32); |
| 2338 | MD5Update(&md5c, session_id, 16); |
| 2339 | MD5Final(buffer, &md5c); |
| 2340 | |
| 2341 | send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, |
| 2342 | PKT_DATA, buffer, 16, PKT_END); |
| 2343 | |
| 2344 | crWaitUntil(ispkt); |
| 2345 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2346 | if (flags & FLAG_VERBOSE) |
| 2347 | c_write_str |
| 2348 | ("Failed to authenticate with our public key.\r\n"); |
| 2349 | continue; /* go and try password */ |
| 2350 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 2351 | bombout( |
| 2352 | ("Bizarre response to RSA authentication response")); |
| 2353 | crReturn(0); |
| 2354 | } |
| 2355 | |
| 2356 | break; /* we're through! */ |
| 2357 | } else { |
| 2358 | if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { |
| 2359 | /* |
| 2360 | * Defence against traffic analysis: we send a |
| 2361 | * whole bunch of packets containing strings of |
| 2362 | * different lengths. One of these strings is the |
| 2363 | * password, in a SSH1_CMSG_AUTH_PASSWORD packet. |
| 2364 | * The others are all random data in |
| 2365 | * SSH1_MSG_IGNORE packets. This way a passive |
| 2366 | * listener can't tell which is the password, and |
| 2367 | * hence can't deduce the password length. |
| 2368 | * |
| 2369 | * Anybody with a password length greater than 16 |
| 2370 | * bytes is going to have enough entropy in their |
| 2371 | * password that a listener won't find it _that_ |
| 2372 | * much help to know how long it is. So what we'll |
| 2373 | * do is: |
| 2374 | * |
| 2375 | * - if password length < 16, we send 15 packets |
| 2376 | * containing string lengths 1 through 15 |
| 2377 | * |
| 2378 | * - otherwise, we let N be the nearest multiple |
| 2379 | * of 8 below the password length, and send 8 |
| 2380 | * packets containing string lengths N through |
| 2381 | * N+7. This won't obscure the order of |
| 2382 | * magnitude of the password length, but it will |
| 2383 | * introduce a bit of extra uncertainty. |
| 2384 | * |
| 2385 | * A few servers (the old 1.2.18 through 1.2.22) |
| 2386 | * can't deal with SSH1_MSG_IGNORE. For these |
| 2387 | * servers, we need an alternative defence. We make |
| 2388 | * use of the fact that the password is interpreted |
| 2389 | * as a C string: so we can append a NUL, then some |
| 2390 | * random data. |
| 2391 | */ |
| 2392 | if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) { |
| 2393 | char string[64]; |
| 2394 | char *s; |
| 2395 | int len; |
| 2396 | |
| 2397 | len = strlen(password); |
| 2398 | if (len < sizeof(string)) { |
| 2399 | s = string; |
| 2400 | strcpy(string, password); |
| 2401 | len++; /* cover the zero byte */ |
| 2402 | while (len < sizeof(string)) { |
| 2403 | string[len++] = (char) random_byte(); |
| 2404 | } |
| 2405 | } else { |
| 2406 | s = password; |
| 2407 | } |
| 2408 | send_packet(pwpkt_type, PKT_INT, len, |
| 2409 | PKT_DATA, s, len, PKT_END); |
| 2410 | } else { |
| 2411 | int bottom, top, pwlen, i; |
| 2412 | char *randomstr; |
| 2413 | |
| 2414 | pwlen = strlen(password); |
| 2415 | if (pwlen < 16) { |
| 2416 | bottom = 0; /* zero length passwords are OK! :-) */ |
| 2417 | top = 15; |
| 2418 | } else { |
| 2419 | bottom = pwlen & ~7; |
| 2420 | top = bottom + 7; |
| 2421 | } |
| 2422 | |
| 2423 | assert(pwlen >= bottom && pwlen <= top); |
| 2424 | |
| 2425 | randomstr = smalloc(top + 1); |
| 2426 | |
| 2427 | for (i = bottom; i <= top; i++) { |
| 2428 | if (i == pwlen) |
| 2429 | defer_packet(pwpkt_type, PKT_STR, password, |
| 2430 | PKT_END); |
| 2431 | else { |
| 2432 | for (j = 0; j < i; j++) { |
| 2433 | do { |
| 2434 | randomstr[j] = random_byte(); |
| 2435 | } while (randomstr[j] == '\0'); |
| 2436 | } |
| 2437 | randomstr[i] = '\0'; |
| 2438 | defer_packet(SSH1_MSG_IGNORE, |
| 2439 | PKT_STR, randomstr, PKT_END); |
| 2440 | } |
| 2441 | } |
| 2442 | ssh_pkt_defersend(); |
| 2443 | } |
| 2444 | } else { |
| 2445 | send_packet(pwpkt_type, PKT_STR, password, PKT_END); |
| 2446 | } |
| 2447 | } |
| 2448 | logevent("Sent password"); |
| 2449 | memset(password, 0, strlen(password)); |
| 2450 | crWaitUntil(ispkt); |
| 2451 | if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2452 | if (flags & FLAG_VERBOSE) |
| 2453 | c_write_str("Access denied\r\n"); |
| 2454 | logevent("Authentication refused"); |
| 2455 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 2456 | logevent("Received disconnect request"); |
| 2457 | ssh_state = SSH_STATE_CLOSED; |
| 2458 | crReturn(1); |
| 2459 | } else if (pktin.type != SSH1_SMSG_SUCCESS) { |
| 2460 | bombout(("Strange packet received, type %d", pktin.type)); |
| 2461 | crReturn(0); |
| 2462 | } |
| 2463 | } |
| 2464 | |
| 2465 | logevent("Authentication successful"); |
| 2466 | |
| 2467 | crFinish(1); |
| 2468 | } |
| 2469 | |
| 2470 | void sshfwd_close(struct ssh_channel *c) |
| 2471 | { |
| 2472 | if (c && !c->closes) { |
| 2473 | if (ssh_version == 1) { |
| 2474 | send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, |
| 2475 | PKT_END); |
| 2476 | } else { |
| 2477 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 2478 | ssh2_pkt_adduint32(c->remoteid); |
| 2479 | ssh2_pkt_send(); |
| 2480 | } |
| 2481 | c->closes = 1; |
| 2482 | if (c->type == CHAN_X11) { |
| 2483 | c->u.x11.s = NULL; |
| 2484 | logevent("Forwarded X11 connection terminated"); |
| 2485 | } else if (c->type == CHAN_SOCKDATA) { |
| 2486 | c->u.pfd.s = NULL; |
| 2487 | logevent("Forwarded port closed"); |
| 2488 | } |
| 2489 | } |
| 2490 | } |
| 2491 | |
| 2492 | int sshfwd_write(struct ssh_channel *c, char *buf, int len) |
| 2493 | { |
| 2494 | if (ssh_version == 1) { |
| 2495 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 2496 | PKT_INT, c->remoteid, |
| 2497 | PKT_INT, len, PKT_DATA, buf, len, PKT_END); |
| 2498 | /* |
| 2499 | * In SSH1 we can return 0 here - implying that forwarded |
| 2500 | * connections are never individually throttled - because |
| 2501 | * the only circumstance that can cause throttling will be |
| 2502 | * the whole SSH connection backing up, in which case |
| 2503 | * _everything_ will be throttled as a whole. |
| 2504 | */ |
| 2505 | return 0; |
| 2506 | } else { |
| 2507 | ssh2_add_channel_data(c, buf, len); |
| 2508 | return ssh2_try_send(c); |
| 2509 | } |
| 2510 | } |
| 2511 | |
| 2512 | void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) |
| 2513 | { |
| 2514 | if (ssh_version == 1) { |
| 2515 | if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 2516 | c->v.v1.throttling = 0; |
| 2517 | ssh1_throttle(-1); |
| 2518 | } |
| 2519 | } else { |
| 2520 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
| 2521 | } |
| 2522 | } |
| 2523 | |
| 2524 | static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) |
| 2525 | { |
| 2526 | crBegin; |
| 2527 | |
| 2528 | random_init(); |
| 2529 | |
| 2530 | while (!do_ssh1_login(in, inlen, ispkt)) { |
| 2531 | crReturnV; |
| 2532 | } |
| 2533 | if (ssh_state == SSH_STATE_CLOSED) |
| 2534 | crReturnV; |
| 2535 | |
| 2536 | if (cfg.agentfwd && agent_exists()) { |
| 2537 | logevent("Requesting agent forwarding"); |
| 2538 | send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); |
| 2539 | do { |
| 2540 | crReturnV; |
| 2541 | } while (!ispkt); |
| 2542 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2543 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2544 | bombout(("Protocol confusion")); |
| 2545 | crReturnV; |
| 2546 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2547 | logevent("Agent forwarding refused"); |
| 2548 | } else { |
| 2549 | logevent("Agent forwarding enabled"); |
| 2550 | ssh_agentfwd_enabled = TRUE; |
| 2551 | } |
| 2552 | } |
| 2553 | |
| 2554 | if (cfg.x11_forward) { |
| 2555 | char proto[20], data[64]; |
| 2556 | logevent("Requesting X11 forwarding"); |
| 2557 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
| 2558 | if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { |
| 2559 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 2560 | PKT_STR, proto, PKT_STR, data, |
| 2561 | PKT_INT, 0, PKT_END); |
| 2562 | } else { |
| 2563 | send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, |
| 2564 | PKT_STR, proto, PKT_STR, data, PKT_END); |
| 2565 | } |
| 2566 | do { |
| 2567 | crReturnV; |
| 2568 | } while (!ispkt); |
| 2569 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2570 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2571 | bombout(("Protocol confusion")); |
| 2572 | crReturnV; |
| 2573 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2574 | logevent("X11 forwarding refused"); |
| 2575 | } else { |
| 2576 | logevent("X11 forwarding enabled"); |
| 2577 | ssh_X11_fwd_enabled = TRUE; |
| 2578 | } |
| 2579 | } |
| 2580 | |
| 2581 | { |
| 2582 | char type, *e; |
| 2583 | int n; |
| 2584 | int sport,dport; |
| 2585 | char sports[256], dports[256], host[256]; |
| 2586 | char buf[1024]; |
| 2587 | |
| 2588 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh1); |
| 2589 | /* Add port forwardings. */ |
| 2590 | e = cfg.portfwd; |
| 2591 | while (*e) { |
| 2592 | type = *e++; |
| 2593 | n = 0; |
| 2594 | while (*e && *e != '\t') |
| 2595 | sports[n++] = *e++; |
| 2596 | sports[n] = 0; |
| 2597 | if (*e == '\t') |
| 2598 | e++; |
| 2599 | n = 0; |
| 2600 | while (*e && *e != ':') |
| 2601 | host[n++] = *e++; |
| 2602 | host[n] = 0; |
| 2603 | if (*e == ':') |
| 2604 | e++; |
| 2605 | n = 0; |
| 2606 | while (*e) |
| 2607 | dports[n++] = *e++; |
| 2608 | dports[n] = 0; |
| 2609 | e++; |
| 2610 | dport = atoi(dports); |
| 2611 | sport = atoi(sports); |
| 2612 | if (sport && dport) { |
| 2613 | if (type == 'L') { |
| 2614 | pfd_addforward(host, dport, sport); |
| 2615 | sprintf(buf, "Local port %d forwarding to %s:%d", |
| 2616 | sport, host, dport); |
| 2617 | logevent(buf); |
| 2618 | } else { |
| 2619 | struct ssh_rportfwd *pf; |
| 2620 | pf = smalloc(sizeof(*pf)); |
| 2621 | strcpy(pf->dhost, host); |
| 2622 | pf->dport = dport; |
| 2623 | if (add234(ssh_rportfwds, pf) != pf) { |
| 2624 | sprintf(buf, |
| 2625 | "Duplicate remote port forwarding to %s:%d", |
| 2626 | host, dport); |
| 2627 | logevent(buf); |
| 2628 | sfree(pf); |
| 2629 | } else { |
| 2630 | sprintf(buf, "Requesting remote port %d forward to %s:%d", |
| 2631 | sport, host, dport); |
| 2632 | logevent(buf); |
| 2633 | send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST, |
| 2634 | PKT_INT, sport, |
| 2635 | PKT_STR, host, |
| 2636 | PKT_INT, dport, |
| 2637 | PKT_END); |
| 2638 | } |
| 2639 | } |
| 2640 | } |
| 2641 | } |
| 2642 | } |
| 2643 | |
| 2644 | if (!cfg.nopty) { |
| 2645 | send_packet(SSH1_CMSG_REQUEST_PTY, |
| 2646 | PKT_STR, cfg.termtype, |
| 2647 | PKT_INT, rows, PKT_INT, cols, |
| 2648 | PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END); |
| 2649 | ssh_state = SSH_STATE_INTERMED; |
| 2650 | do { |
| 2651 | crReturnV; |
| 2652 | } while (!ispkt); |
| 2653 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2654 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2655 | bombout(("Protocol confusion")); |
| 2656 | crReturnV; |
| 2657 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2658 | c_write_str("Server refused to allocate pty\r\n"); |
| 2659 | ssh_editing = ssh_echoing = 1; |
| 2660 | } |
| 2661 | logevent("Allocated pty"); |
| 2662 | } else { |
| 2663 | ssh_editing = ssh_echoing = 1; |
| 2664 | } |
| 2665 | |
| 2666 | if (cfg.compression) { |
| 2667 | send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); |
| 2668 | do { |
| 2669 | crReturnV; |
| 2670 | } while (!ispkt); |
| 2671 | if (pktin.type != SSH1_SMSG_SUCCESS |
| 2672 | && pktin.type != SSH1_SMSG_FAILURE) { |
| 2673 | bombout(("Protocol confusion")); |
| 2674 | crReturnV; |
| 2675 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2676 | c_write_str("Server refused to compress\r\n"); |
| 2677 | } |
| 2678 | logevent("Started compression"); |
| 2679 | ssh1_compressing = TRUE; |
| 2680 | zlib_compress_init(); |
| 2681 | zlib_decompress_init(); |
| 2682 | } |
| 2683 | |
| 2684 | /* |
| 2685 | * Start the shell or command. |
| 2686 | * |
| 2687 | * Special case: if the first-choice command is an SSH2 |
| 2688 | * subsystem (hence not usable here) and the second choice |
| 2689 | * exists, we fall straight back to that. |
| 2690 | */ |
| 2691 | { |
| 2692 | char *cmd = cfg.remote_cmd_ptr; |
| 2693 | |
| 2694 | if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) { |
| 2695 | cmd = cfg.remote_cmd_ptr2; |
| 2696 | ssh_fallback_cmd = TRUE; |
| 2697 | } |
| 2698 | if (*cmd) |
| 2699 | send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); |
| 2700 | else |
| 2701 | send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); |
| 2702 | logevent("Started session"); |
| 2703 | } |
| 2704 | |
| 2705 | ssh_state = SSH_STATE_SESSION; |
| 2706 | if (size_needed) |
| 2707 | ssh_size(); |
| 2708 | if (eof_needed) |
| 2709 | ssh_special(TS_EOF); |
| 2710 | |
| 2711 | ldisc_send(NULL, 0); /* cause ldisc to notice changes */ |
| 2712 | ssh_send_ok = 1; |
| 2713 | ssh_channels = newtree234(ssh_channelcmp); |
| 2714 | while (1) { |
| 2715 | crReturnV; |
| 2716 | if (ispkt) { |
| 2717 | if (pktin.type == SSH1_SMSG_STDOUT_DATA || |
| 2718 | pktin.type == SSH1_SMSG_STDERR_DATA) { |
| 2719 | long len = GET_32BIT(pktin.body); |
| 2720 | int bufsize = |
| 2721 | from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, |
| 2722 | pktin.body + 4, len); |
| 2723 | if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 2724 | ssh1_stdout_throttling = 1; |
| 2725 | ssh1_throttle(+1); |
| 2726 | } |
| 2727 | } else if (pktin.type == SSH1_MSG_DISCONNECT) { |
| 2728 | ssh_state = SSH_STATE_CLOSED; |
| 2729 | logevent("Received disconnect request"); |
| 2730 | crReturnV; |
| 2731 | } else if (pktin.type == SSH1_SMSG_X11_OPEN) { |
| 2732 | /* Remote side is trying to open a channel to talk to our |
| 2733 | * X-Server. Give them back a local channel number. */ |
| 2734 | struct ssh_channel *c; |
| 2735 | |
| 2736 | logevent("Received X11 connect request"); |
| 2737 | /* Refuse if X11 forwarding is disabled. */ |
| 2738 | if (!ssh_X11_fwd_enabled) { |
| 2739 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 2740 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
| 2741 | logevent("Rejected X11 connect request"); |
| 2742 | } else { |
| 2743 | c = smalloc(sizeof(struct ssh_channel)); |
| 2744 | |
| 2745 | if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) { |
| 2746 | logevent("opening X11 forward connection failed"); |
| 2747 | sfree(c); |
| 2748 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 2749 | PKT_INT, GET_32BIT(pktin.body), |
| 2750 | PKT_END); |
| 2751 | } else { |
| 2752 | logevent |
| 2753 | ("opening X11 forward connection succeeded"); |
| 2754 | c->remoteid = GET_32BIT(pktin.body); |
| 2755 | c->localid = alloc_channel_id(); |
| 2756 | c->closes = 0; |
| 2757 | c->v.v1.throttling = 0; |
| 2758 | c->type = CHAN_X11; /* identify channel type */ |
| 2759 | add234(ssh_channels, c); |
| 2760 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 2761 | PKT_INT, c->remoteid, PKT_INT, |
| 2762 | c->localid, PKT_END); |
| 2763 | logevent("Opened X11 forward channel"); |
| 2764 | } |
| 2765 | } |
| 2766 | } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) { |
| 2767 | /* Remote side is trying to open a channel to talk to our |
| 2768 | * agent. Give them back a local channel number. */ |
| 2769 | struct ssh_channel *c; |
| 2770 | |
| 2771 | /* Refuse if agent forwarding is disabled. */ |
| 2772 | if (!ssh_agentfwd_enabled) { |
| 2773 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 2774 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
| 2775 | } else { |
| 2776 | c = smalloc(sizeof(struct ssh_channel)); |
| 2777 | c->remoteid = GET_32BIT(pktin.body); |
| 2778 | c->localid = alloc_channel_id(); |
| 2779 | c->closes = 0; |
| 2780 | c->v.v1.throttling = 0; |
| 2781 | c->type = CHAN_AGENT; /* identify channel type */ |
| 2782 | c->u.a.lensofar = 0; |
| 2783 | add234(ssh_channels, c); |
| 2784 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 2785 | PKT_INT, c->remoteid, PKT_INT, c->localid, |
| 2786 | PKT_END); |
| 2787 | } |
| 2788 | } else if (pktin.type == SSH1_MSG_PORT_OPEN) { |
| 2789 | /* Remote side is trying to open a channel to talk to a |
| 2790 | * forwarded port. Give them back a local channel number. */ |
| 2791 | struct ssh_channel *c; |
| 2792 | struct ssh_rportfwd pf; |
| 2793 | int hostsize, port; |
| 2794 | char host[256], buf[1024]; |
| 2795 | char *p, *h, *e; |
| 2796 | c = smalloc(sizeof(struct ssh_channel)); |
| 2797 | |
| 2798 | hostsize = GET_32BIT(pktin.body+4); |
| 2799 | for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) { |
| 2800 | if (h+1 < host+sizeof(host)) |
| 2801 | *h++ = *p; |
| 2802 | p++; |
| 2803 | } |
| 2804 | *h = 0; |
| 2805 | port = GET_32BIT(p); |
| 2806 | |
| 2807 | strcpy(pf.dhost, host); |
| 2808 | pf.dport = port; |
| 2809 | |
| 2810 | if (find234(ssh_rportfwds, &pf, NULL) == NULL) { |
| 2811 | sprintf(buf, "Rejected remote port open request for %s:%d", |
| 2812 | host, port); |
| 2813 | logevent(buf); |
| 2814 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 2815 | PKT_INT, GET_32BIT(pktin.body), PKT_END); |
| 2816 | } else { |
| 2817 | sprintf(buf, "Received remote port open request for %s:%d", |
| 2818 | host, port); |
| 2819 | logevent(buf); |
| 2820 | e = pfd_newconnect(&c->u.pfd.s, host, port, c); |
| 2821 | if (e != NULL) { |
| 2822 | char buf[256]; |
| 2823 | sprintf(buf, "Port open failed: %s", e); |
| 2824 | logevent(buf); |
| 2825 | sfree(c); |
| 2826 | send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE, |
| 2827 | PKT_INT, GET_32BIT(pktin.body), |
| 2828 | PKT_END); |
| 2829 | } else { |
| 2830 | c->remoteid = GET_32BIT(pktin.body); |
| 2831 | c->localid = alloc_channel_id(); |
| 2832 | c->closes = 0; |
| 2833 | c->v.v1.throttling = 0; |
| 2834 | c->type = CHAN_SOCKDATA; /* identify channel type */ |
| 2835 | add234(ssh_channels, c); |
| 2836 | send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, |
| 2837 | PKT_INT, c->remoteid, PKT_INT, |
| 2838 | c->localid, PKT_END); |
| 2839 | logevent("Forwarded port opened successfully"); |
| 2840 | } |
| 2841 | } |
| 2842 | |
| 2843 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 2844 | unsigned int remoteid = GET_32BIT(pktin.body); |
| 2845 | unsigned int localid = GET_32BIT(pktin.body+4); |
| 2846 | struct ssh_channel *c; |
| 2847 | |
| 2848 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
| 2849 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 2850 | c->remoteid = localid; |
| 2851 | c->type = CHAN_SOCKDATA; |
| 2852 | pfd_confirm(c->u.pfd.s); |
| 2853 | } |
| 2854 | |
| 2855 | } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { |
| 2856 | unsigned int remoteid = GET_32BIT(pktin.body); |
| 2857 | unsigned int localid = GET_32BIT(pktin.body+4); |
| 2858 | struct ssh_channel *c; |
| 2859 | |
| 2860 | c = find234(ssh_channels, &remoteid, ssh_channelfind); |
| 2861 | if (c && c->type == CHAN_SOCKDATA_DORMANT) { |
| 2862 | logevent("Forwarded connection refused by server"); |
| 2863 | pfd_close(c->u.pfd.s); |
| 2864 | del234(ssh_channels, c); |
| 2865 | sfree(c); |
| 2866 | } |
| 2867 | |
| 2868 | } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE || |
| 2869 | pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) { |
| 2870 | /* Remote side closes a channel. */ |
| 2871 | unsigned i = GET_32BIT(pktin.body); |
| 2872 | struct ssh_channel *c; |
| 2873 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 2874 | if (c) { |
| 2875 | int closetype; |
| 2876 | closetype = |
| 2877 | (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); |
| 2878 | if (!(c->closes & closetype)) |
| 2879 | send_packet(pktin.type, PKT_INT, c->remoteid, |
| 2880 | PKT_END); |
| 2881 | if ((c->closes == 0) && (c->type == CHAN_X11)) { |
| 2882 | logevent("Forwarded X11 connection terminated"); |
| 2883 | assert(c->u.x11.s != NULL); |
| 2884 | x11_close(c->u.x11.s); |
| 2885 | c->u.x11.s = NULL; |
| 2886 | } |
| 2887 | if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) { |
| 2888 | logevent("Forwarded port closed"); |
| 2889 | assert(c->u.pfd.s != NULL); |
| 2890 | pfd_close(c->u.pfd.s); |
| 2891 | c->u.pfd.s = NULL; |
| 2892 | } |
| 2893 | c->closes |= closetype; |
| 2894 | if (c->closes == 3) { |
| 2895 | del234(ssh_channels, c); |
| 2896 | sfree(c); |
| 2897 | } |
| 2898 | } |
| 2899 | } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { |
| 2900 | /* Data sent down one of our channels. */ |
| 2901 | int i = GET_32BIT(pktin.body); |
| 2902 | int len = GET_32BIT(pktin.body + 4); |
| 2903 | unsigned char *p = pktin.body + 8; |
| 2904 | struct ssh_channel *c; |
| 2905 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 2906 | if (c) { |
| 2907 | int bufsize; |
| 2908 | switch (c->type) { |
| 2909 | case CHAN_X11: |
| 2910 | bufsize = x11_send(c->u.x11.s, p, len); |
| 2911 | break; |
| 2912 | case CHAN_SOCKDATA: |
| 2913 | bufsize = pfd_send(c->u.pfd.s, p, len); |
| 2914 | break; |
| 2915 | case CHAN_AGENT: |
| 2916 | /* Data for an agent message. Buffer it. */ |
| 2917 | while (len > 0) { |
| 2918 | if (c->u.a.lensofar < 4) { |
| 2919 | int l = min(4 - c->u.a.lensofar, len); |
| 2920 | memcpy(c->u.a.msglen + c->u.a.lensofar, p, |
| 2921 | l); |
| 2922 | p += l; |
| 2923 | len -= l; |
| 2924 | c->u.a.lensofar += l; |
| 2925 | } |
| 2926 | if (c->u.a.lensofar == 4) { |
| 2927 | c->u.a.totallen = |
| 2928 | 4 + GET_32BIT(c->u.a.msglen); |
| 2929 | c->u.a.message = smalloc(c->u.a.totallen); |
| 2930 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 2931 | } |
| 2932 | if (c->u.a.lensofar >= 4 && len > 0) { |
| 2933 | int l = |
| 2934 | min(c->u.a.totallen - c->u.a.lensofar, |
| 2935 | len); |
| 2936 | memcpy(c->u.a.message + c->u.a.lensofar, p, |
| 2937 | l); |
| 2938 | p += l; |
| 2939 | len -= l; |
| 2940 | c->u.a.lensofar += l; |
| 2941 | } |
| 2942 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 2943 | void *reply, *sentreply; |
| 2944 | int replylen; |
| 2945 | agent_query(c->u.a.message, |
| 2946 | c->u.a.totallen, &reply, |
| 2947 | &replylen); |
| 2948 | if (reply) |
| 2949 | sentreply = reply; |
| 2950 | else { |
| 2951 | /* Fake SSH_AGENT_FAILURE. */ |
| 2952 | sentreply = "\0\0\0\1\5"; |
| 2953 | replylen = 5; |
| 2954 | } |
| 2955 | send_packet(SSH1_MSG_CHANNEL_DATA, |
| 2956 | PKT_INT, c->remoteid, |
| 2957 | PKT_INT, replylen, |
| 2958 | PKT_DATA, sentreply, replylen, |
| 2959 | PKT_END); |
| 2960 | if (reply) |
| 2961 | sfree(reply); |
| 2962 | sfree(c->u.a.message); |
| 2963 | c->u.a.lensofar = 0; |
| 2964 | } |
| 2965 | } |
| 2966 | bufsize = 0; /* agent channels never back up */ |
| 2967 | break; |
| 2968 | } |
| 2969 | if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { |
| 2970 | c->v.v1.throttling = 1; |
| 2971 | ssh1_throttle(+1); |
| 2972 | } |
| 2973 | } |
| 2974 | } else if (pktin.type == SSH1_SMSG_SUCCESS) { |
| 2975 | /* may be from EXEC_SHELL on some servers */ |
| 2976 | } else if (pktin.type == SSH1_SMSG_FAILURE) { |
| 2977 | /* may be from EXEC_SHELL on some servers |
| 2978 | * if no pty is available or in other odd cases. Ignore */ |
| 2979 | } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { |
| 2980 | send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); |
| 2981 | } else { |
| 2982 | bombout(("Strange packet received: type %d", pktin.type)); |
| 2983 | crReturnV; |
| 2984 | } |
| 2985 | } else { |
| 2986 | while (inlen > 0) { |
| 2987 | int len = min(inlen, 512); |
| 2988 | send_packet(SSH1_CMSG_STDIN_DATA, |
| 2989 | PKT_INT, len, PKT_DATA, in, len, PKT_END); |
| 2990 | in += len; |
| 2991 | inlen -= len; |
| 2992 | } |
| 2993 | } |
| 2994 | } |
| 2995 | |
| 2996 | crFinishV; |
| 2997 | } |
| 2998 | |
| 2999 | /* |
| 3000 | * Utility routine for decoding comma-separated strings in KEXINIT. |
| 3001 | */ |
| 3002 | static int in_commasep_string(char *needle, char *haystack, int haylen) |
| 3003 | { |
| 3004 | int needlen = strlen(needle); |
| 3005 | while (1) { |
| 3006 | /* |
| 3007 | * Is it at the start of the string? |
| 3008 | */ |
| 3009 | if (haylen >= needlen && /* haystack is long enough */ |
| 3010 | !memcmp(needle, haystack, needlen) && /* initial match */ |
| 3011 | (haylen == needlen || haystack[needlen] == ',') |
| 3012 | /* either , or EOS follows */ |
| 3013 | ) |
| 3014 | return 1; |
| 3015 | /* |
| 3016 | * If not, search for the next comma and resume after that. |
| 3017 | * If no comma found, terminate. |
| 3018 | */ |
| 3019 | while (haylen > 0 && *haystack != ',') |
| 3020 | haylen--, haystack++; |
| 3021 | if (haylen == 0) |
| 3022 | return 0; |
| 3023 | haylen--, haystack++; /* skip over comma itself */ |
| 3024 | } |
| 3025 | } |
| 3026 | |
| 3027 | /* |
| 3028 | * SSH2 key creation method. |
| 3029 | */ |
| 3030 | static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, |
| 3031 | char *keyspace) |
| 3032 | { |
| 3033 | SHA_State s; |
| 3034 | /* First 20 bytes. */ |
| 3035 | SHA_Init(&s); |
| 3036 | sha_mpint(&s, K); |
| 3037 | SHA_Bytes(&s, H, 20); |
| 3038 | SHA_Bytes(&s, &chr, 1); |
| 3039 | SHA_Bytes(&s, sessid, 20); |
| 3040 | SHA_Final(&s, keyspace); |
| 3041 | /* Next 20 bytes. */ |
| 3042 | SHA_Init(&s); |
| 3043 | sha_mpint(&s, K); |
| 3044 | SHA_Bytes(&s, H, 20); |
| 3045 | SHA_Bytes(&s, keyspace, 20); |
| 3046 | SHA_Final(&s, keyspace + 20); |
| 3047 | } |
| 3048 | |
| 3049 | /* |
| 3050 | * Handle the SSH2 transport layer. |
| 3051 | */ |
| 3052 | static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) |
| 3053 | { |
| 3054 | static int i, j, len, nbits, pbits, warn; |
| 3055 | static char *str; |
| 3056 | static Bignum p, g, e, f, K; |
| 3057 | static int kex_init_value, kex_reply_value; |
| 3058 | static const struct ssh_mac **maclist; |
| 3059 | static int nmacs; |
| 3060 | static const struct ssh2_cipher *cscipher_tobe = NULL; |
| 3061 | static const struct ssh2_cipher *sccipher_tobe = NULL; |
| 3062 | static const struct ssh_mac *csmac_tobe = NULL; |
| 3063 | static const struct ssh_mac *scmac_tobe = NULL; |
| 3064 | static const struct ssh_compress *cscomp_tobe = NULL; |
| 3065 | static const struct ssh_compress *sccomp_tobe = NULL; |
| 3066 | static char *hostkeydata, *sigdata, *keystr, *fingerprint; |
| 3067 | static int hostkeylen, siglen; |
| 3068 | static void *hkey; /* actual host key */ |
| 3069 | static unsigned char exchange_hash[20]; |
| 3070 | static unsigned char keyspace[40]; |
| 3071 | static int n_preferred_ciphers; |
| 3072 | static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; |
| 3073 | static const struct ssh_compress *preferred_comp; |
| 3074 | static int first_kex; |
| 3075 | |
| 3076 | crBegin; |
| 3077 | random_init(); |
| 3078 | first_kex = 1; |
| 3079 | |
| 3080 | /* |
| 3081 | * Set up the preferred ciphers. (NULL => warn below here) |
| 3082 | */ |
| 3083 | n_preferred_ciphers = 0; |
| 3084 | for (i = 0; i < CIPHER_MAX; i++) { |
| 3085 | switch (cfg.ssh_cipherlist[i]) { |
| 3086 | case CIPHER_BLOWFISH: |
| 3087 | preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish; |
| 3088 | n_preferred_ciphers++; |
| 3089 | break; |
| 3090 | case CIPHER_DES: |
| 3091 | /* Not supported in SSH2; silently drop */ |
| 3092 | break; |
| 3093 | case CIPHER_3DES: |
| 3094 | preferred_ciphers[n_preferred_ciphers] = &ssh2_3des; |
| 3095 | n_preferred_ciphers++; |
| 3096 | break; |
| 3097 | case CIPHER_AES: |
| 3098 | preferred_ciphers[n_preferred_ciphers] = &ssh2_aes; |
| 3099 | n_preferred_ciphers++; |
| 3100 | break; |
| 3101 | case CIPHER_WARN: |
| 3102 | /* Flag for later. Don't bother if it's the last in |
| 3103 | * the list. */ |
| 3104 | if (i < CIPHER_MAX - 1) { |
| 3105 | preferred_ciphers[n_preferred_ciphers] = NULL; |
| 3106 | n_preferred_ciphers++; |
| 3107 | } |
| 3108 | break; |
| 3109 | } |
| 3110 | } |
| 3111 | |
| 3112 | /* |
| 3113 | * Set up preferred compression. |
| 3114 | */ |
| 3115 | if (cfg.compression) |
| 3116 | preferred_comp = &ssh_zlib; |
| 3117 | else |
| 3118 | preferred_comp = &ssh_comp_none; |
| 3119 | |
| 3120 | /* |
| 3121 | * Be prepared to work around the buggy MAC problem. |
| 3122 | */ |
| 3123 | if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC)) |
| 3124 | maclist = buggymacs, nmacs = lenof(buggymacs); |
| 3125 | else |
| 3126 | maclist = macs, nmacs = lenof(macs); |
| 3127 | |
| 3128 | begin_key_exchange: |
| 3129 | /* |
| 3130 | * Construct and send our key exchange packet. |
| 3131 | */ |
| 3132 | ssh2_pkt_init(SSH2_MSG_KEXINIT); |
| 3133 | for (i = 0; i < 16; i++) |
| 3134 | ssh2_pkt_addbyte((unsigned char) random_byte()); |
| 3135 | /* List key exchange algorithms. */ |
| 3136 | ssh2_pkt_addstring_start(); |
| 3137 | for (i = 0; i < lenof(kex_algs); i++) { |
| 3138 | ssh2_pkt_addstring_str(kex_algs[i]->name); |
| 3139 | if (i < lenof(kex_algs) - 1) |
| 3140 | ssh2_pkt_addstring_str(","); |
| 3141 | } |
| 3142 | /* List server host key algorithms. */ |
| 3143 | ssh2_pkt_addstring_start(); |
| 3144 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 3145 | ssh2_pkt_addstring_str(hostkey_algs[i]->name); |
| 3146 | if (i < lenof(hostkey_algs) - 1) |
| 3147 | ssh2_pkt_addstring_str(","); |
| 3148 | } |
| 3149 | /* List client->server encryption algorithms. */ |
| 3150 | ssh2_pkt_addstring_start(); |
| 3151 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3152 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3153 | if (!c) continue; /* warning flag */ |
| 3154 | for (j = 0; j < c->nciphers; j++) { |
| 3155 | ssh2_pkt_addstring_str(c->list[j]->name); |
| 3156 | if (i < n_preferred_ciphers || j < c->nciphers - 1) |
| 3157 | ssh2_pkt_addstring_str(","); |
| 3158 | } |
| 3159 | } |
| 3160 | /* List server->client encryption algorithms. */ |
| 3161 | ssh2_pkt_addstring_start(); |
| 3162 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3163 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3164 | if (!c) continue; /* warning flag */ |
| 3165 | for (j = 0; j < c->nciphers; j++) { |
| 3166 | ssh2_pkt_addstring_str(c->list[j]->name); |
| 3167 | if (i < n_preferred_ciphers || j < c->nciphers - 1) |
| 3168 | ssh2_pkt_addstring_str(","); |
| 3169 | } |
| 3170 | } |
| 3171 | /* List client->server MAC algorithms. */ |
| 3172 | ssh2_pkt_addstring_start(); |
| 3173 | for (i = 0; i < nmacs; i++) { |
| 3174 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 3175 | if (i < nmacs - 1) |
| 3176 | ssh2_pkt_addstring_str(","); |
| 3177 | } |
| 3178 | /* List server->client MAC algorithms. */ |
| 3179 | ssh2_pkt_addstring_start(); |
| 3180 | for (i = 0; i < nmacs; i++) { |
| 3181 | ssh2_pkt_addstring_str(maclist[i]->name); |
| 3182 | if (i < nmacs - 1) |
| 3183 | ssh2_pkt_addstring_str(","); |
| 3184 | } |
| 3185 | /* List client->server compression algorithms. */ |
| 3186 | ssh2_pkt_addstring_start(); |
| 3187 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3188 | const struct ssh_compress *c = |
| 3189 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3190 | ssh2_pkt_addstring_str(c->name); |
| 3191 | if (i < lenof(compressions)) |
| 3192 | ssh2_pkt_addstring_str(","); |
| 3193 | } |
| 3194 | /* List server->client compression algorithms. */ |
| 3195 | ssh2_pkt_addstring_start(); |
| 3196 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3197 | const struct ssh_compress *c = |
| 3198 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3199 | ssh2_pkt_addstring_str(c->name); |
| 3200 | if (i < lenof(compressions)) |
| 3201 | ssh2_pkt_addstring_str(","); |
| 3202 | } |
| 3203 | /* List client->server languages. Empty list. */ |
| 3204 | ssh2_pkt_addstring_start(); |
| 3205 | /* List server->client languages. Empty list. */ |
| 3206 | ssh2_pkt_addstring_start(); |
| 3207 | /* First KEX packet does _not_ follow, because we're not that brave. */ |
| 3208 | ssh2_pkt_addbool(FALSE); |
| 3209 | /* Reserved. */ |
| 3210 | ssh2_pkt_adduint32(0); |
| 3211 | |
| 3212 | exhash = exhashbase; |
| 3213 | sha_string(&exhash, pktout.data + 5, pktout.length - 5); |
| 3214 | |
| 3215 | ssh2_pkt_send(); |
| 3216 | |
| 3217 | if (!ispkt) |
| 3218 | crWaitUntil(ispkt); |
| 3219 | sha_string(&exhash, pktin.data + 5, pktin.length - 5); |
| 3220 | |
| 3221 | /* |
| 3222 | * Now examine the other side's KEXINIT to see what we're up |
| 3223 | * to. |
| 3224 | */ |
| 3225 | if (pktin.type != SSH2_MSG_KEXINIT) { |
| 3226 | bombout(("expected key exchange packet from server")); |
| 3227 | crReturn(0); |
| 3228 | } |
| 3229 | kex = NULL; |
| 3230 | hostkey = NULL; |
| 3231 | cscipher_tobe = NULL; |
| 3232 | sccipher_tobe = NULL; |
| 3233 | csmac_tobe = NULL; |
| 3234 | scmac_tobe = NULL; |
| 3235 | cscomp_tobe = NULL; |
| 3236 | sccomp_tobe = NULL; |
| 3237 | pktin.savedpos += 16; /* skip garbage cookie */ |
| 3238 | ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */ |
| 3239 | for (i = 0; i < lenof(kex_algs); i++) { |
| 3240 | if (in_commasep_string(kex_algs[i]->name, str, len)) { |
| 3241 | kex = kex_algs[i]; |
| 3242 | break; |
| 3243 | } |
| 3244 | } |
| 3245 | ssh2_pkt_getstring(&str, &len); /* host key algorithms */ |
| 3246 | for (i = 0; i < lenof(hostkey_algs); i++) { |
| 3247 | if (in_commasep_string(hostkey_algs[i]->name, str, len)) { |
| 3248 | hostkey = hostkey_algs[i]; |
| 3249 | break; |
| 3250 | } |
| 3251 | } |
| 3252 | ssh2_pkt_getstring(&str, &len); /* client->server cipher */ |
| 3253 | warn = 0; |
| 3254 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3255 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3256 | if (!c) { |
| 3257 | warn = 1; |
| 3258 | } else { |
| 3259 | for (j = 0; j < c->nciphers; j++) { |
| 3260 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 3261 | cscipher_tobe = c->list[j]; |
| 3262 | break; |
| 3263 | } |
| 3264 | } |
| 3265 | } |
| 3266 | if (cscipher_tobe) { |
| 3267 | if (warn) |
| 3268 | askcipher(cscipher_tobe->name, 1); |
| 3269 | break; |
| 3270 | } |
| 3271 | } |
| 3272 | ssh2_pkt_getstring(&str, &len); /* server->client cipher */ |
| 3273 | warn = 0; |
| 3274 | for (i = 0; i < n_preferred_ciphers; i++) { |
| 3275 | const struct ssh2_ciphers *c = preferred_ciphers[i]; |
| 3276 | if (!c) { |
| 3277 | warn = 1; |
| 3278 | } else { |
| 3279 | for (j = 0; j < c->nciphers; j++) { |
| 3280 | if (in_commasep_string(c->list[j]->name, str, len)) { |
| 3281 | sccipher_tobe = c->list[j]; |
| 3282 | break; |
| 3283 | } |
| 3284 | } |
| 3285 | } |
| 3286 | if (sccipher_tobe) { |
| 3287 | if (warn) |
| 3288 | askcipher(sccipher_tobe->name, 2); |
| 3289 | break; |
| 3290 | } |
| 3291 | } |
| 3292 | ssh2_pkt_getstring(&str, &len); /* client->server mac */ |
| 3293 | for (i = 0; i < nmacs; i++) { |
| 3294 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 3295 | csmac_tobe = maclist[i]; |
| 3296 | break; |
| 3297 | } |
| 3298 | } |
| 3299 | ssh2_pkt_getstring(&str, &len); /* server->client mac */ |
| 3300 | for (i = 0; i < nmacs; i++) { |
| 3301 | if (in_commasep_string(maclist[i]->name, str, len)) { |
| 3302 | scmac_tobe = maclist[i]; |
| 3303 | break; |
| 3304 | } |
| 3305 | } |
| 3306 | ssh2_pkt_getstring(&str, &len); /* client->server compression */ |
| 3307 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3308 | const struct ssh_compress *c = |
| 3309 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3310 | if (in_commasep_string(c->name, str, len)) { |
| 3311 | cscomp_tobe = c; |
| 3312 | break; |
| 3313 | } |
| 3314 | } |
| 3315 | ssh2_pkt_getstring(&str, &len); /* server->client compression */ |
| 3316 | for (i = 0; i < lenof(compressions) + 1; i++) { |
| 3317 | const struct ssh_compress *c = |
| 3318 | i == 0 ? preferred_comp : compressions[i - 1]; |
| 3319 | if (in_commasep_string(c->name, str, len)) { |
| 3320 | sccomp_tobe = c; |
| 3321 | break; |
| 3322 | } |
| 3323 | } |
| 3324 | |
| 3325 | /* |
| 3326 | * Work out the number of bits of key we will need from the key |
| 3327 | * exchange. We start with the maximum key length of either |
| 3328 | * cipher... |
| 3329 | */ |
| 3330 | { |
| 3331 | int csbits, scbits; |
| 3332 | |
| 3333 | csbits = cscipher_tobe->keylen; |
| 3334 | scbits = sccipher_tobe->keylen; |
| 3335 | nbits = (csbits > scbits ? csbits : scbits); |
| 3336 | } |
| 3337 | /* The keys only have 160-bit entropy, since they're based on |
| 3338 | * a SHA-1 hash. So cap the key size at 160 bits. */ |
| 3339 | if (nbits > 160) |
| 3340 | nbits = 160; |
| 3341 | |
| 3342 | /* |
| 3343 | * If we're doing Diffie-Hellman group exchange, start by |
| 3344 | * requesting a group. |
| 3345 | */ |
| 3346 | if (kex == &ssh_diffiehellman_gex) { |
| 3347 | logevent("Doing Diffie-Hellman group exchange"); |
| 3348 | /* |
| 3349 | * Work out how big a DH group we will need to allow that |
| 3350 | * much data. |
| 3351 | */ |
| 3352 | pbits = 512 << ((nbits - 1) / 64); |
| 3353 | ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); |
| 3354 | ssh2_pkt_adduint32(pbits); |
| 3355 | ssh2_pkt_send(); |
| 3356 | |
| 3357 | crWaitUntil(ispkt); |
| 3358 | if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) { |
| 3359 | bombout(("expected key exchange group packet from server")); |
| 3360 | crReturn(0); |
| 3361 | } |
| 3362 | p = ssh2_pkt_getmp(); |
| 3363 | g = ssh2_pkt_getmp(); |
| 3364 | dh_setup_group(p, g); |
| 3365 | kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; |
| 3366 | kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; |
| 3367 | } else { |
| 3368 | dh_setup_group1(); |
| 3369 | kex_init_value = SSH2_MSG_KEXDH_INIT; |
| 3370 | kex_reply_value = SSH2_MSG_KEXDH_REPLY; |
| 3371 | } |
| 3372 | |
| 3373 | logevent("Doing Diffie-Hellman key exchange"); |
| 3374 | /* |
| 3375 | * Now generate and send e for Diffie-Hellman. |
| 3376 | */ |
| 3377 | e = dh_create_e(nbits * 2); |
| 3378 | ssh2_pkt_init(kex_init_value); |
| 3379 | ssh2_pkt_addmp(e); |
| 3380 | ssh2_pkt_send(); |
| 3381 | |
| 3382 | crWaitUntil(ispkt); |
| 3383 | if (pktin.type != kex_reply_value) { |
| 3384 | bombout(("expected key exchange reply packet from server")); |
| 3385 | crReturn(0); |
| 3386 | } |
| 3387 | ssh2_pkt_getstring(&hostkeydata, &hostkeylen); |
| 3388 | f = ssh2_pkt_getmp(); |
| 3389 | ssh2_pkt_getstring(&sigdata, &siglen); |
| 3390 | |
| 3391 | K = dh_find_K(f); |
| 3392 | |
| 3393 | sha_string(&exhash, hostkeydata, hostkeylen); |
| 3394 | if (kex == &ssh_diffiehellman_gex) { |
| 3395 | sha_uint32(&exhash, pbits); |
| 3396 | sha_mpint(&exhash, p); |
| 3397 | sha_mpint(&exhash, g); |
| 3398 | } |
| 3399 | sha_mpint(&exhash, e); |
| 3400 | sha_mpint(&exhash, f); |
| 3401 | sha_mpint(&exhash, K); |
| 3402 | SHA_Final(&exhash, exchange_hash); |
| 3403 | |
| 3404 | dh_cleanup(); |
| 3405 | |
| 3406 | #if 0 |
| 3407 | debug(("Exchange hash is:\n")); |
| 3408 | dmemdump(exchange_hash, 20); |
| 3409 | #endif |
| 3410 | |
| 3411 | hkey = hostkey->newkey(hostkeydata, hostkeylen); |
| 3412 | if (!hkey || |
| 3413 | !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { |
| 3414 | bombout(("Server's host key did not match the signature supplied")); |
| 3415 | crReturn(0); |
| 3416 | } |
| 3417 | |
| 3418 | /* |
| 3419 | * Expect SSH2_MSG_NEWKEYS from server. |
| 3420 | */ |
| 3421 | crWaitUntil(ispkt); |
| 3422 | if (pktin.type != SSH2_MSG_NEWKEYS) { |
| 3423 | bombout(("expected new-keys packet from server")); |
| 3424 | crReturn(0); |
| 3425 | } |
| 3426 | |
| 3427 | /* |
| 3428 | * Authenticate remote host: verify host key. (We've already |
| 3429 | * checked the signature of the exchange hash.) |
| 3430 | */ |
| 3431 | keystr = hostkey->fmtkey(hkey); |
| 3432 | fingerprint = hostkey->fingerprint(hkey); |
| 3433 | verify_ssh_host_key(savedhost, savedport, hostkey->keytype, |
| 3434 | keystr, fingerprint); |
| 3435 | if (first_kex) { /* don't bother logging this in rekeys */ |
| 3436 | logevent("Host key fingerprint is:"); |
| 3437 | logevent(fingerprint); |
| 3438 | } |
| 3439 | sfree(fingerprint); |
| 3440 | sfree(keystr); |
| 3441 | hostkey->freekey(hkey); |
| 3442 | |
| 3443 | /* |
| 3444 | * Send SSH2_MSG_NEWKEYS. |
| 3445 | */ |
| 3446 | ssh2_pkt_init(SSH2_MSG_NEWKEYS); |
| 3447 | ssh2_pkt_send(); |
| 3448 | |
| 3449 | /* |
| 3450 | * Create and initialise session keys. |
| 3451 | */ |
| 3452 | cscipher = cscipher_tobe; |
| 3453 | sccipher = sccipher_tobe; |
| 3454 | csmac = csmac_tobe; |
| 3455 | scmac = scmac_tobe; |
| 3456 | cscomp = cscomp_tobe; |
| 3457 | sccomp = sccomp_tobe; |
| 3458 | cscomp->compress_init(); |
| 3459 | sccomp->decompress_init(); |
| 3460 | /* |
| 3461 | * Set IVs after keys. Here we use the exchange hash from the |
| 3462 | * _first_ key exchange. |
| 3463 | */ |
| 3464 | if (first_kex) |
| 3465 | memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash)); |
| 3466 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace); |
| 3467 | cscipher->setcskey(keyspace); |
| 3468 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace); |
| 3469 | sccipher->setsckey(keyspace); |
| 3470 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace); |
| 3471 | cscipher->setcsiv(keyspace); |
| 3472 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace); |
| 3473 | sccipher->setsciv(keyspace); |
| 3474 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace); |
| 3475 | csmac->setcskey(keyspace); |
| 3476 | ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace); |
| 3477 | scmac->setsckey(keyspace); |
| 3478 | |
| 3479 | /* |
| 3480 | * If this is the first key exchange phase, we must pass the |
| 3481 | * SSH2_MSG_NEWKEYS packet to the next layer, not because it |
| 3482 | * wants to see it but because it will need time to initialise |
| 3483 | * itself before it sees an actual packet. In subsequent key |
| 3484 | * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because |
| 3485 | * it would only confuse the layer above. |
| 3486 | */ |
| 3487 | if (!first_kex) { |
| 3488 | crReturn(0); |
| 3489 | } |
| 3490 | first_kex = 0; |
| 3491 | |
| 3492 | /* |
| 3493 | * Now we're encrypting. Begin returning 1 to the protocol main |
| 3494 | * function so that other things can run on top of the |
| 3495 | * transport. If we ever see a KEXINIT, we must go back to the |
| 3496 | * start. |
| 3497 | */ |
| 3498 | while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) { |
| 3499 | crReturn(1); |
| 3500 | } |
| 3501 | logevent("Server initiated key re-exchange"); |
| 3502 | goto begin_key_exchange; |
| 3503 | |
| 3504 | crFinish(1); |
| 3505 | } |
| 3506 | |
| 3507 | /* |
| 3508 | * Add data to an SSH2 channel output buffer. |
| 3509 | */ |
| 3510 | static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, |
| 3511 | int len) |
| 3512 | { |
| 3513 | bufchain_add(&c->v.v2.outbuffer, buf, len); |
| 3514 | } |
| 3515 | |
| 3516 | /* |
| 3517 | * Attempt to send data on an SSH2 channel. |
| 3518 | */ |
| 3519 | static int ssh2_try_send(struct ssh_channel *c) |
| 3520 | { |
| 3521 | while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { |
| 3522 | int len; |
| 3523 | void *data; |
| 3524 | bufchain_prefix(&c->v.v2.outbuffer, &data, &len); |
| 3525 | if ((unsigned)len > c->v.v2.remwindow) |
| 3526 | len = c->v.v2.remwindow; |
| 3527 | if ((unsigned)len > c->v.v2.remmaxpkt) |
| 3528 | len = c->v.v2.remmaxpkt; |
| 3529 | ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); |
| 3530 | ssh2_pkt_adduint32(c->remoteid); |
| 3531 | ssh2_pkt_addstring_start(); |
| 3532 | ssh2_pkt_addstring_data(data, len); |
| 3533 | ssh2_pkt_send(); |
| 3534 | bufchain_consume(&c->v.v2.outbuffer, len); |
| 3535 | c->v.v2.remwindow -= len; |
| 3536 | } |
| 3537 | |
| 3538 | /* |
| 3539 | * After having sent as much data as we can, return the amount |
| 3540 | * still buffered. |
| 3541 | */ |
| 3542 | return bufchain_size(&c->v.v2.outbuffer); |
| 3543 | } |
| 3544 | |
| 3545 | /* |
| 3546 | * Potentially enlarge the window on an SSH2 channel. |
| 3547 | */ |
| 3548 | static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) |
| 3549 | { |
| 3550 | if (newwin > c->v.v2.locwindow) { |
| 3551 | ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 3552 | ssh2_pkt_adduint32(c->remoteid); |
| 3553 | ssh2_pkt_adduint32(newwin - c->v.v2.locwindow); |
| 3554 | ssh2_pkt_send(); |
| 3555 | c->v.v2.locwindow = newwin; |
| 3556 | } |
| 3557 | } |
| 3558 | |
| 3559 | /* |
| 3560 | * Handle the SSH2 userauth and connection layers. |
| 3561 | */ |
| 3562 | static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) |
| 3563 | { |
| 3564 | static enum { |
| 3565 | AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, |
| 3566 | AUTH_PASSWORD, |
| 3567 | AUTH_KEYBOARD_INTERACTIVE |
| 3568 | } method; |
| 3569 | static enum { |
| 3570 | AUTH_TYPE_NONE, |
| 3571 | AUTH_TYPE_PUBLICKEY, |
| 3572 | AUTH_TYPE_PUBLICKEY_OFFER_LOUD, |
| 3573 | AUTH_TYPE_PUBLICKEY_OFFER_QUIET, |
| 3574 | AUTH_TYPE_PASSWORD, |
| 3575 | AUTH_TYPE_KEYBOARD_INTERACTIVE, |
| 3576 | AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET |
| 3577 | } type; |
| 3578 | static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; |
| 3579 | static int tried_pubkey_config, tried_agent, tried_keyb_inter; |
| 3580 | static int kbd_inter_running; |
| 3581 | static int we_are_in; |
| 3582 | static int num_prompts, echo; |
| 3583 | static char username[100]; |
| 3584 | static char pwprompt[200]; |
| 3585 | static char password[100]; |
| 3586 | |
| 3587 | crBegin; |
| 3588 | |
| 3589 | /* |
| 3590 | * Request userauth protocol, and await a response to it. |
| 3591 | */ |
| 3592 | ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); |
| 3593 | ssh2_pkt_addstring("ssh-userauth"); |
| 3594 | ssh2_pkt_send(); |
| 3595 | crWaitUntilV(ispkt); |
| 3596 | if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) { |
| 3597 | bombout(("Server refused user authentication protocol")); |
| 3598 | crReturnV; |
| 3599 | } |
| 3600 | |
| 3601 | /* |
| 3602 | * We repeat this whole loop, including the username prompt, |
| 3603 | * until we manage a successful authentication. If the user |
| 3604 | * types the wrong _password_, they are sent back to the |
| 3605 | * beginning to try another username. (If they specify a |
| 3606 | * username in the config, they are never asked, even if they |
| 3607 | * do give a wrong password.) |
| 3608 | * |
| 3609 | * I think this best serves the needs of |
| 3610 | * |
| 3611 | * - the people who have no configuration, no keys, and just |
| 3612 | * want to try repeated (username,password) pairs until they |
| 3613 | * type both correctly |
| 3614 | * |
| 3615 | * - people who have keys and configuration but occasionally |
| 3616 | * need to fall back to passwords |
| 3617 | * |
| 3618 | * - people with a key held in Pageant, who might not have |
| 3619 | * logged in to a particular machine before; so they want to |
| 3620 | * type a username, and then _either_ their key will be |
| 3621 | * accepted, _or_ they will type a password. If they mistype |
| 3622 | * the username they will want to be able to get back and |
| 3623 | * retype it! |
| 3624 | */ |
| 3625 | do { |
| 3626 | static int pos; |
| 3627 | static char c; |
| 3628 | |
| 3629 | /* |
| 3630 | * Get a username. |
| 3631 | */ |
| 3632 | pos = 0; |
| 3633 | if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { |
| 3634 | if (ssh_get_line) { |
| 3635 | if (!ssh_get_line("login as: ", |
| 3636 | username, sizeof(username), FALSE)) { |
| 3637 | /* |
| 3638 | * get_line failed to get a username. |
| 3639 | * Terminate. |
| 3640 | */ |
| 3641 | logevent("No username provided. Abandoning session."); |
| 3642 | ssh_state = SSH_STATE_CLOSED; |
| 3643 | crReturnV; |
| 3644 | } |
| 3645 | } else { |
| 3646 | c_write_str("login as: "); |
| 3647 | ssh_send_ok = 1; |
| 3648 | while (pos >= 0) { |
| 3649 | crWaitUntilV(!ispkt); |
| 3650 | while (inlen--) |
| 3651 | switch (c = *in++) { |
| 3652 | case 10: |
| 3653 | case 13: |
| 3654 | username[pos] = 0; |
| 3655 | pos = -1; |
| 3656 | break; |
| 3657 | case 8: |
| 3658 | case 127: |
| 3659 | if (pos > 0) { |
| 3660 | c_write_str("\b \b"); |
| 3661 | pos--; |
| 3662 | } |
| 3663 | break; |
| 3664 | case 21: |
| 3665 | case 27: |
| 3666 | while (pos > 0) { |
| 3667 | c_write_str("\b \b"); |
| 3668 | pos--; |
| 3669 | } |
| 3670 | break; |
| 3671 | case 3: |
| 3672 | case 4: |
| 3673 | random_save_seed(); |
| 3674 | exit(0); |
| 3675 | break; |
| 3676 | default: |
| 3677 | if (((c >= ' ' && c <= '~') || |
| 3678 | ((unsigned char) c >= 160)) |
| 3679 | && pos < sizeof(username)-1) { |
| 3680 | username[pos++] = c; |
| 3681 | c_write(&c, 1); |
| 3682 | } |
| 3683 | break; |
| 3684 | } |
| 3685 | } |
| 3686 | } |
| 3687 | c_write_str("\r\n"); |
| 3688 | username[strcspn(username, "\n\r")] = '\0'; |
| 3689 | } else { |
| 3690 | char stuff[200]; |
| 3691 | strncpy(username, cfg.username, 99); |
| 3692 | username[99] = '\0'; |
| 3693 | if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { |
| 3694 | sprintf(stuff, "Using username \"%s\".\r\n", username); |
| 3695 | c_write_str(stuff); |
| 3696 | } |
| 3697 | } |
| 3698 | |
| 3699 | /* |
| 3700 | * Send an authentication request using method "none": (a) |
| 3701 | * just in case it succeeds, and (b) so that we know what |
| 3702 | * authentication methods we can usefully try next. |
| 3703 | */ |
| 3704 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3705 | ssh2_pkt_addstring(username); |
| 3706 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3707 | ssh2_pkt_addstring("none"); /* method */ |
| 3708 | ssh2_pkt_send(); |
| 3709 | type = AUTH_TYPE_NONE; |
| 3710 | gotit = FALSE; |
| 3711 | we_are_in = FALSE; |
| 3712 | |
| 3713 | tried_pubkey_config = FALSE; |
| 3714 | tried_agent = FALSE; |
| 3715 | tried_keyb_inter = FALSE; |
| 3716 | kbd_inter_running = FALSE; |
| 3717 | |
| 3718 | while (1) { |
| 3719 | /* |
| 3720 | * Wait for the result of the last authentication request. |
| 3721 | */ |
| 3722 | if (!gotit) |
| 3723 | crWaitUntilV(ispkt); |
| 3724 | while (pktin.type == SSH2_MSG_USERAUTH_BANNER) { |
| 3725 | char *banner; |
| 3726 | int size; |
| 3727 | /* |
| 3728 | * Don't show the banner if we're operating in |
| 3729 | * non-verbose non-interactive mode. (It's probably |
| 3730 | * a script, which means nobody will read the |
| 3731 | * banner _anyway_, and moreover the printing of |
| 3732 | * the banner will screw up processing on the |
| 3733 | * output of (say) plink.) |
| 3734 | */ |
| 3735 | if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) { |
| 3736 | ssh2_pkt_getstring(&banner, &size); |
| 3737 | if (banner) |
| 3738 | c_write_untrusted(banner, size); |
| 3739 | } |
| 3740 | crWaitUntilV(ispkt); |
| 3741 | } |
| 3742 | if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) { |
| 3743 | logevent("Access granted"); |
| 3744 | we_are_in = TRUE; |
| 3745 | break; |
| 3746 | } |
| 3747 | |
| 3748 | if (kbd_inter_running && |
| 3749 | pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 3750 | /* |
| 3751 | * This is a further prompt in keyboard-interactive |
| 3752 | * authentication. Do nothing. |
| 3753 | */ |
| 3754 | } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) { |
| 3755 | bombout(("Strange packet received during authentication: type %d", |
| 3756 | pktin.type)); |
| 3757 | crReturnV; |
| 3758 | } |
| 3759 | |
| 3760 | gotit = FALSE; |
| 3761 | |
| 3762 | /* |
| 3763 | * OK, we're now sitting on a USERAUTH_FAILURE message, so |
| 3764 | * we can look at the string in it and know what we can |
| 3765 | * helpfully try next. |
| 3766 | */ |
| 3767 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) { |
| 3768 | char *methods; |
| 3769 | int methlen; |
| 3770 | ssh2_pkt_getstring(&methods, &methlen); |
| 3771 | kbd_inter_running = FALSE; |
| 3772 | if (!ssh2_pkt_getbool()) { |
| 3773 | /* |
| 3774 | * We have received an unequivocal Access |
| 3775 | * Denied. This can translate to a variety of |
| 3776 | * messages: |
| 3777 | * |
| 3778 | * - if we'd just tried "none" authentication, |
| 3779 | * it's not worth printing anything at all |
| 3780 | * |
| 3781 | * - if we'd just tried a public key _offer_, |
| 3782 | * the message should be "Server refused our |
| 3783 | * key" (or no message at all if the key |
| 3784 | * came from Pageant) |
| 3785 | * |
| 3786 | * - if we'd just tried anything else, the |
| 3787 | * message really should be "Access denied". |
| 3788 | * |
| 3789 | * Additionally, if we'd just tried password |
| 3790 | * authentication, we should break out of this |
| 3791 | * whole loop so as to go back to the username |
| 3792 | * prompt. |
| 3793 | */ |
| 3794 | if (type == AUTH_TYPE_NONE) { |
| 3795 | /* do nothing */ |
| 3796 | } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || |
| 3797 | type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { |
| 3798 | if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) |
| 3799 | c_write_str("Server refused our key\r\n"); |
| 3800 | logevent("Server refused public key"); |
| 3801 | } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { |
| 3802 | /* server declined keyboard-interactive; ignore */ |
| 3803 | } else { |
| 3804 | c_write_str("Access denied\r\n"); |
| 3805 | logevent("Access denied"); |
| 3806 | if (type == AUTH_TYPE_PASSWORD) { |
| 3807 | we_are_in = FALSE; |
| 3808 | break; |
| 3809 | } |
| 3810 | } |
| 3811 | } else { |
| 3812 | c_write_str("Further authentication required\r\n"); |
| 3813 | logevent("Further authentication required"); |
| 3814 | } |
| 3815 | |
| 3816 | can_pubkey = |
| 3817 | in_commasep_string("publickey", methods, methlen); |
| 3818 | can_passwd = |
| 3819 | in_commasep_string("password", methods, methlen); |
| 3820 | can_keyb_inter = |
| 3821 | in_commasep_string("keyboard-interactive", methods, methlen); |
| 3822 | } |
| 3823 | |
| 3824 | method = 0; |
| 3825 | |
| 3826 | if (!method && can_pubkey && agent_exists() && !tried_agent) { |
| 3827 | /* |
| 3828 | * Attempt public-key authentication using Pageant. |
| 3829 | */ |
| 3830 | static unsigned char request[5], *response, *p; |
| 3831 | static int responselen; |
| 3832 | static int i, nkeys; |
| 3833 | static int authed = FALSE; |
| 3834 | void *r; |
| 3835 | |
| 3836 | tried_agent = TRUE; |
| 3837 | |
| 3838 | logevent("Pageant is running. Requesting keys."); |
| 3839 | |
| 3840 | /* Request the keys held by the agent. */ |
| 3841 | PUT_32BIT(request, 1); |
| 3842 | request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; |
| 3843 | agent_query(request, 5, &r, &responselen); |
| 3844 | response = (unsigned char *) r; |
| 3845 | if (response && responselen >= 5 && |
| 3846 | response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { |
| 3847 | p = response + 5; |
| 3848 | nkeys = GET_32BIT(p); |
| 3849 | p += 4; |
| 3850 | { |
| 3851 | char buf[64]; |
| 3852 | sprintf(buf, "Pageant has %d SSH2 keys", nkeys); |
| 3853 | logevent(buf); |
| 3854 | } |
| 3855 | for (i = 0; i < nkeys; i++) { |
| 3856 | static char *pkblob, *alg, *commentp; |
| 3857 | static int pklen, alglen, commentlen; |
| 3858 | static int siglen, retlen, len; |
| 3859 | static char *q, *agentreq, *ret; |
| 3860 | void *vret; |
| 3861 | |
| 3862 | { |
| 3863 | char buf[64]; |
| 3864 | sprintf(buf, "Trying Pageant key #%d", i); |
| 3865 | logevent(buf); |
| 3866 | } |
| 3867 | pklen = GET_32BIT(p); |
| 3868 | p += 4; |
| 3869 | pkblob = p; |
| 3870 | p += pklen; |
| 3871 | alglen = GET_32BIT(pkblob); |
| 3872 | alg = pkblob + 4; |
| 3873 | commentlen = GET_32BIT(p); |
| 3874 | p += 4; |
| 3875 | commentp = p; |
| 3876 | p += commentlen; |
| 3877 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3878 | ssh2_pkt_addstring(username); |
| 3879 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3880 | ssh2_pkt_addstring("publickey"); /* method */ |
| 3881 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
| 3882 | ssh2_pkt_addstring_start(); |
| 3883 | ssh2_pkt_addstring_data(alg, alglen); |
| 3884 | ssh2_pkt_addstring_start(); |
| 3885 | ssh2_pkt_addstring_data(pkblob, pklen); |
| 3886 | ssh2_pkt_send(); |
| 3887 | |
| 3888 | crWaitUntilV(ispkt); |
| 3889 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 3890 | logevent("Key refused"); |
| 3891 | continue; |
| 3892 | } |
| 3893 | |
| 3894 | if (flags & FLAG_VERBOSE) { |
| 3895 | c_write_str |
| 3896 | ("Authenticating with public key \""); |
| 3897 | c_write(commentp, commentlen); |
| 3898 | c_write_str("\" from agent\r\n"); |
| 3899 | } |
| 3900 | |
| 3901 | /* |
| 3902 | * Server is willing to accept the key. |
| 3903 | * Construct a SIGN_REQUEST. |
| 3904 | */ |
| 3905 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3906 | ssh2_pkt_addstring(username); |
| 3907 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3908 | ssh2_pkt_addstring("publickey"); /* method */ |
| 3909 | ssh2_pkt_addbool(TRUE); |
| 3910 | ssh2_pkt_addstring_start(); |
| 3911 | ssh2_pkt_addstring_data(alg, alglen); |
| 3912 | ssh2_pkt_addstring_start(); |
| 3913 | ssh2_pkt_addstring_data(pkblob, pklen); |
| 3914 | |
| 3915 | siglen = pktout.length - 5 + 4 + 20; |
| 3916 | len = 1; /* message type */ |
| 3917 | len += 4 + pklen; /* key blob */ |
| 3918 | len += 4 + siglen; /* data to sign */ |
| 3919 | len += 4; /* flags */ |
| 3920 | agentreq = smalloc(4 + len); |
| 3921 | PUT_32BIT(agentreq, len); |
| 3922 | q = agentreq + 4; |
| 3923 | *q++ = SSH2_AGENTC_SIGN_REQUEST; |
| 3924 | PUT_32BIT(q, pklen); |
| 3925 | q += 4; |
| 3926 | memcpy(q, pkblob, pklen); |
| 3927 | q += pklen; |
| 3928 | PUT_32BIT(q, siglen); |
| 3929 | q += 4; |
| 3930 | /* Now the data to be signed... */ |
| 3931 | PUT_32BIT(q, 20); |
| 3932 | q += 4; |
| 3933 | memcpy(q, ssh2_session_id, 20); |
| 3934 | q += 20; |
| 3935 | memcpy(q, pktout.data + 5, pktout.length - 5); |
| 3936 | q += pktout.length - 5; |
| 3937 | /* And finally the (zero) flags word. */ |
| 3938 | PUT_32BIT(q, 0); |
| 3939 | agent_query(agentreq, len + 4, &vret, &retlen); |
| 3940 | ret = vret; |
| 3941 | sfree(agentreq); |
| 3942 | if (ret) { |
| 3943 | if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) { |
| 3944 | logevent("Sending Pageant's response"); |
| 3945 | ssh2_pkt_addstring_start(); |
| 3946 | ssh2_pkt_addstring_data(ret + 9, |
| 3947 | GET_32BIT(ret + |
| 3948 | 5)); |
| 3949 | ssh2_pkt_send(); |
| 3950 | authed = TRUE; |
| 3951 | break; |
| 3952 | } else { |
| 3953 | logevent |
| 3954 | ("Pageant failed to answer challenge"); |
| 3955 | sfree(ret); |
| 3956 | } |
| 3957 | } |
| 3958 | } |
| 3959 | if (authed) |
| 3960 | continue; |
| 3961 | } |
| 3962 | } |
| 3963 | |
| 3964 | if (!method && can_pubkey && *cfg.keyfile |
| 3965 | && !tried_pubkey_config) { |
| 3966 | unsigned char *pub_blob; |
| 3967 | char *algorithm, *comment; |
| 3968 | int pub_blob_len; |
| 3969 | |
| 3970 | tried_pubkey_config = TRUE; |
| 3971 | |
| 3972 | /* |
| 3973 | * Try the public key supplied in the configuration. |
| 3974 | * |
| 3975 | * First, offer the public blob to see if the server is |
| 3976 | * willing to accept it. |
| 3977 | */ |
| 3978 | pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm, |
| 3979 | &pub_blob_len); |
| 3980 | if (pub_blob) { |
| 3981 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 3982 | ssh2_pkt_addstring(username); |
| 3983 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 3984 | ssh2_pkt_addstring("publickey"); /* method */ |
| 3985 | ssh2_pkt_addbool(FALSE); /* no signature included */ |
| 3986 | ssh2_pkt_addstring(algorithm); |
| 3987 | ssh2_pkt_addstring_start(); |
| 3988 | ssh2_pkt_addstring_data(pub_blob, pub_blob_len); |
| 3989 | ssh2_pkt_send(); |
| 3990 | logevent("Offered public key"); /* FIXME */ |
| 3991 | |
| 3992 | crWaitUntilV(ispkt); |
| 3993 | if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) { |
| 3994 | gotit = TRUE; |
| 3995 | type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; |
| 3996 | continue; /* key refused; give up on it */ |
| 3997 | } |
| 3998 | |
| 3999 | logevent("Offer of public key accepted"); |
| 4000 | /* |
| 4001 | * Actually attempt a serious authentication using |
| 4002 | * the key. |
| 4003 | */ |
| 4004 | if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) { |
| 4005 | sprintf(pwprompt, |
| 4006 | "Passphrase for key \"%.100s\": ", |
| 4007 | comment); |
| 4008 | need_pw = TRUE; |
| 4009 | } else { |
| 4010 | need_pw = FALSE; |
| 4011 | } |
| 4012 | c_write_str("Authenticating with public key \""); |
| 4013 | c_write_str(comment); |
| 4014 | c_write_str("\"\r\n"); |
| 4015 | method = AUTH_PUBLICKEY_FILE; |
| 4016 | } |
| 4017 | } |
| 4018 | |
| 4019 | if (!method && can_keyb_inter && !tried_keyb_inter) { |
| 4020 | method = AUTH_KEYBOARD_INTERACTIVE; |
| 4021 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4022 | tried_keyb_inter = TRUE; |
| 4023 | |
| 4024 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4025 | ssh2_pkt_addstring(username); |
| 4026 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4027 | ssh2_pkt_addstring("keyboard-interactive"); /* method */ |
| 4028 | ssh2_pkt_addstring(""); /* lang */ |
| 4029 | ssh2_pkt_addstring(""); |
| 4030 | ssh2_pkt_send(); |
| 4031 | |
| 4032 | crWaitUntilV(ispkt); |
| 4033 | if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { |
| 4034 | if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) |
| 4035 | gotit = TRUE; |
| 4036 | logevent("Keyboard-interactive authentication refused"); |
| 4037 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; |
| 4038 | continue; |
| 4039 | } |
| 4040 | |
| 4041 | kbd_inter_running = TRUE; |
| 4042 | } |
| 4043 | |
| 4044 | if (kbd_inter_running) { |
| 4045 | method = AUTH_KEYBOARD_INTERACTIVE; |
| 4046 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4047 | tried_keyb_inter = TRUE; |
| 4048 | |
| 4049 | /* We've got packet with that "interactive" info |
| 4050 | dump banners, and set its prompt as ours */ |
| 4051 | { |
| 4052 | char *name, *inst, *lang, *prompt; |
| 4053 | int name_len, inst_len, lang_len, prompt_len; |
| 4054 | ssh2_pkt_getstring(&name, &name_len); |
| 4055 | ssh2_pkt_getstring(&inst, &inst_len); |
| 4056 | ssh2_pkt_getstring(&lang, &lang_len); |
| 4057 | if (name_len > 0) |
| 4058 | c_write_untrusted(name, name_len); |
| 4059 | if (inst_len > 0) |
| 4060 | c_write_untrusted(inst, inst_len); |
| 4061 | num_prompts = ssh2_pkt_getuint32(); |
| 4062 | |
| 4063 | ssh2_pkt_getstring(&prompt, &prompt_len); |
| 4064 | strncpy(pwprompt, prompt, sizeof(pwprompt)); |
| 4065 | need_pw = TRUE; |
| 4066 | |
| 4067 | echo = ssh2_pkt_getbool(); |
| 4068 | } |
| 4069 | } |
| 4070 | |
| 4071 | if (!method && can_passwd) { |
| 4072 | method = AUTH_PASSWORD; |
| 4073 | sprintf(pwprompt, "%.90s@%.90s's password: ", username, |
| 4074 | savedhost); |
| 4075 | need_pw = TRUE; |
| 4076 | } |
| 4077 | |
| 4078 | if (need_pw) { |
| 4079 | if (ssh_get_line) { |
| 4080 | if (!ssh_get_line(pwprompt, password, |
| 4081 | sizeof(password), TRUE)) { |
| 4082 | /* |
| 4083 | * get_line failed to get a password (for |
| 4084 | * example because one was supplied on the |
| 4085 | * command line which has already failed to |
| 4086 | * work). Terminate. |
| 4087 | */ |
| 4088 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 4089 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 4090 | ssh2_pkt_addstring |
| 4091 | ("No more passwords available to try"); |
| 4092 | ssh2_pkt_addstring("en"); /* language tag */ |
| 4093 | ssh2_pkt_send(); |
| 4094 | connection_fatal("Unable to authenticate"); |
| 4095 | ssh_state = SSH_STATE_CLOSED; |
| 4096 | crReturnV; |
| 4097 | } |
| 4098 | } else { |
| 4099 | static int pos = 0; |
| 4100 | static char c; |
| 4101 | |
| 4102 | c_write_untrusted(pwprompt, strlen(pwprompt)); |
| 4103 | ssh_send_ok = 1; |
| 4104 | |
| 4105 | pos = 0; |
| 4106 | while (pos >= 0) { |
| 4107 | crWaitUntilV(!ispkt); |
| 4108 | while (inlen--) |
| 4109 | switch (c = *in++) { |
| 4110 | case 10: |
| 4111 | case 13: |
| 4112 | password[pos] = 0; |
| 4113 | pos = -1; |
| 4114 | break; |
| 4115 | case 8: |
| 4116 | case 127: |
| 4117 | if (pos > 0) |
| 4118 | pos--; |
| 4119 | break; |
| 4120 | case 21: |
| 4121 | case 27: |
| 4122 | pos = 0; |
| 4123 | break; |
| 4124 | case 3: |
| 4125 | case 4: |
| 4126 | random_save_seed(); |
| 4127 | exit(0); |
| 4128 | break; |
| 4129 | default: |
| 4130 | if (pos < sizeof(password)-1) |
| 4131 | password[pos++] = c; |
| 4132 | break; |
| 4133 | } |
| 4134 | } |
| 4135 | c_write_str("\r\n"); |
| 4136 | } |
| 4137 | } |
| 4138 | |
| 4139 | if (method == AUTH_PUBLICKEY_FILE) { |
| 4140 | /* |
| 4141 | * We have our passphrase. Now try the actual authentication. |
| 4142 | */ |
| 4143 | struct ssh2_userkey *key; |
| 4144 | |
| 4145 | key = ssh2_load_userkey(cfg.keyfile, password); |
| 4146 | if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { |
| 4147 | if (key == SSH2_WRONG_PASSPHRASE) { |
| 4148 | c_write_str("Wrong passphrase\r\n"); |
| 4149 | tried_pubkey_config = FALSE; |
| 4150 | } else { |
| 4151 | c_write_str("Unable to load private key\r\n"); |
| 4152 | tried_pubkey_config = TRUE; |
| 4153 | } |
| 4154 | /* Send a spurious AUTH_NONE to return to the top. */ |
| 4155 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4156 | ssh2_pkt_addstring(username); |
| 4157 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4158 | ssh2_pkt_addstring("none"); /* method */ |
| 4159 | ssh2_pkt_send(); |
| 4160 | type = AUTH_TYPE_NONE; |
| 4161 | } else { |
| 4162 | unsigned char *blob, *sigdata; |
| 4163 | int blob_len, sigdata_len; |
| 4164 | |
| 4165 | /* |
| 4166 | * We have loaded the private key and the server |
| 4167 | * has announced that it's willing to accept it. |
| 4168 | * Hallelujah. Generate a signature and send it. |
| 4169 | */ |
| 4170 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4171 | ssh2_pkt_addstring(username); |
| 4172 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4173 | ssh2_pkt_addstring("publickey"); /* method */ |
| 4174 | ssh2_pkt_addbool(TRUE); |
| 4175 | ssh2_pkt_addstring(key->alg->name); |
| 4176 | blob = key->alg->public_blob(key->data, &blob_len); |
| 4177 | ssh2_pkt_addstring_start(); |
| 4178 | ssh2_pkt_addstring_data(blob, blob_len); |
| 4179 | sfree(blob); |
| 4180 | |
| 4181 | /* |
| 4182 | * The data to be signed is: |
| 4183 | * |
| 4184 | * string session-id |
| 4185 | * |
| 4186 | * followed by everything so far placed in the |
| 4187 | * outgoing packet. |
| 4188 | */ |
| 4189 | sigdata_len = pktout.length - 5 + 4 + 20; |
| 4190 | sigdata = smalloc(sigdata_len); |
| 4191 | PUT_32BIT(sigdata, 20); |
| 4192 | memcpy(sigdata + 4, ssh2_session_id, 20); |
| 4193 | memcpy(sigdata + 24, pktout.data + 5, |
| 4194 | pktout.length - 5); |
| 4195 | blob = |
| 4196 | key->alg->sign(key->data, sigdata, sigdata_len, |
| 4197 | &blob_len); |
| 4198 | ssh2_pkt_addstring_start(); |
| 4199 | ssh2_pkt_addstring_data(blob, blob_len); |
| 4200 | sfree(blob); |
| 4201 | sfree(sigdata); |
| 4202 | |
| 4203 | ssh2_pkt_send(); |
| 4204 | type = AUTH_TYPE_PUBLICKEY; |
| 4205 | } |
| 4206 | } else if (method == AUTH_PASSWORD) { |
| 4207 | /* |
| 4208 | * We send the password packet lumped tightly together with |
| 4209 | * an SSH_MSG_IGNORE packet. The IGNORE packet contains a |
| 4210 | * string long enough to make the total length of the two |
| 4211 | * packets constant. This should ensure that a passive |
| 4212 | * listener doing traffic analyis can't work out the length |
| 4213 | * of the password. |
| 4214 | * |
| 4215 | * For this to work, we need an assumption about the |
| 4216 | * maximum length of the password packet. I think 256 is |
| 4217 | * pretty conservative. Anyone using a password longer than |
| 4218 | * that probably doesn't have much to worry about from |
| 4219 | * people who find out how long their password is! |
| 4220 | */ |
| 4221 | ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); |
| 4222 | ssh2_pkt_addstring(username); |
| 4223 | ssh2_pkt_addstring("ssh-connection"); /* service requested */ |
| 4224 | ssh2_pkt_addstring("password"); |
| 4225 | ssh2_pkt_addbool(FALSE); |
| 4226 | ssh2_pkt_addstring(password); |
| 4227 | ssh2_pkt_defer(); |
| 4228 | /* |
| 4229 | * We'll include a string that's an exact multiple of the |
| 4230 | * cipher block size. If the cipher is NULL for some |
| 4231 | * reason, we don't do this trick at all because we gain |
| 4232 | * nothing by it. |
| 4233 | */ |
| 4234 | if (cscipher) { |
| 4235 | int stringlen, i; |
| 4236 | |
| 4237 | stringlen = (256 - deferred_len); |
| 4238 | stringlen += cscipher->blksize - 1; |
| 4239 | stringlen -= (stringlen % cscipher->blksize); |
| 4240 | if (cscomp) { |
| 4241 | /* |
| 4242 | * Temporarily disable actual compression, |
| 4243 | * so we can guarantee to get this string |
| 4244 | * exactly the length we want it. The |
| 4245 | * compression-disabling routine should |
| 4246 | * return an integer indicating how many |
| 4247 | * bytes we should adjust our string length |
| 4248 | * by. |
| 4249 | */ |
| 4250 | stringlen -= cscomp->disable_compression(); |
| 4251 | } |
| 4252 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 4253 | ssh2_pkt_addstring_start(); |
| 4254 | for (i = 0; i < stringlen; i++) { |
| 4255 | char c = (char) random_byte(); |
| 4256 | ssh2_pkt_addstring_data(&c, 1); |
| 4257 | } |
| 4258 | ssh2_pkt_defer(); |
| 4259 | } |
| 4260 | ssh_pkt_defersend(); |
| 4261 | logevent("Sent password"); |
| 4262 | type = AUTH_TYPE_PASSWORD; |
| 4263 | } else if (method == AUTH_KEYBOARD_INTERACTIVE) { |
| 4264 | ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); |
| 4265 | ssh2_pkt_adduint32(num_prompts); |
| 4266 | ssh2_pkt_addstring(password); |
| 4267 | memset(password, 0, sizeof(password)); |
| 4268 | ssh2_pkt_send(); |
| 4269 | type = AUTH_TYPE_KEYBOARD_INTERACTIVE; |
| 4270 | } else { |
| 4271 | c_write_str |
| 4272 | ("No supported authentication methods left to try!\r\n"); |
| 4273 | logevent |
| 4274 | ("No supported authentications offered. Disconnecting"); |
| 4275 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 4276 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 4277 | ssh2_pkt_addstring |
| 4278 | ("No supported authentication methods available"); |
| 4279 | ssh2_pkt_addstring("en"); /* language tag */ |
| 4280 | ssh2_pkt_send(); |
| 4281 | ssh_state = SSH_STATE_CLOSED; |
| 4282 | crReturnV; |
| 4283 | } |
| 4284 | } |
| 4285 | } while (!we_are_in); |
| 4286 | |
| 4287 | /* |
| 4288 | * Now we're authenticated for the connection protocol. The |
| 4289 | * connection protocol will automatically have started at this |
| 4290 | * point; there's no need to send SERVICE_REQUEST. |
| 4291 | */ |
| 4292 | |
| 4293 | /* |
| 4294 | * So now create a channel with a session in it. |
| 4295 | */ |
| 4296 | ssh_channels = newtree234(ssh_channelcmp); |
| 4297 | mainchan = smalloc(sizeof(struct ssh_channel)); |
| 4298 | mainchan->localid = alloc_channel_id(); |
| 4299 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 4300 | ssh2_pkt_addstring("session"); |
| 4301 | ssh2_pkt_adduint32(mainchan->localid); |
| 4302 | mainchan->v.v2.locwindow = OUR_V2_WINSIZE; |
| 4303 | ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */ |
| 4304 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 4305 | ssh2_pkt_send(); |
| 4306 | crWaitUntilV(ispkt); |
| 4307 | if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 4308 | bombout(("Server refused to open a session")); |
| 4309 | crReturnV; |
| 4310 | /* FIXME: error data comes back in FAILURE packet */ |
| 4311 | } |
| 4312 | if (ssh2_pkt_getuint32() != mainchan->localid) { |
| 4313 | bombout(("Server's channel confirmation cited wrong channel")); |
| 4314 | crReturnV; |
| 4315 | } |
| 4316 | mainchan->remoteid = ssh2_pkt_getuint32(); |
| 4317 | mainchan->type = CHAN_MAINSESSION; |
| 4318 | mainchan->closes = 0; |
| 4319 | mainchan->v.v2.remwindow = ssh2_pkt_getuint32(); |
| 4320 | mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 4321 | bufchain_init(&mainchan->v.v2.outbuffer); |
| 4322 | add234(ssh_channels, mainchan); |
| 4323 | logevent("Opened channel for session"); |
| 4324 | |
| 4325 | /* |
| 4326 | * Potentially enable X11 forwarding. |
| 4327 | */ |
| 4328 | if (cfg.x11_forward) { |
| 4329 | char proto[20], data[64]; |
| 4330 | logevent("Requesting X11 forwarding"); |
| 4331 | x11_invent_auth(proto, sizeof(proto), data, sizeof(data)); |
| 4332 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4333 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 4334 | ssh2_pkt_addstring("x11-req"); |
| 4335 | ssh2_pkt_addbool(1); /* want reply */ |
| 4336 | ssh2_pkt_addbool(0); /* many connections */ |
| 4337 | ssh2_pkt_addstring(proto); |
| 4338 | ssh2_pkt_addstring(data); |
| 4339 | ssh2_pkt_adduint32(0); /* screen number */ |
| 4340 | ssh2_pkt_send(); |
| 4341 | |
| 4342 | do { |
| 4343 | crWaitUntilV(ispkt); |
| 4344 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4345 | unsigned i = ssh2_pkt_getuint32(); |
| 4346 | struct ssh_channel *c; |
| 4347 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4348 | if (!c) |
| 4349 | continue; /* nonexistent channel */ |
| 4350 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4351 | } |
| 4352 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4353 | |
| 4354 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4355 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4356 | bombout(("Server got confused by X11 forwarding request")); |
| 4357 | crReturnV; |
| 4358 | } |
| 4359 | logevent("X11 forwarding refused"); |
| 4360 | } else { |
| 4361 | logevent("X11 forwarding enabled"); |
| 4362 | ssh_X11_fwd_enabled = TRUE; |
| 4363 | } |
| 4364 | } |
| 4365 | |
| 4366 | /* |
| 4367 | * Enable port forwardings. |
| 4368 | */ |
| 4369 | { |
| 4370 | static char *e; /* preserve across crReturn */ |
| 4371 | char type; |
| 4372 | int n; |
| 4373 | int sport,dport; |
| 4374 | char sports[256], dports[256], host[256]; |
| 4375 | char buf[1024]; |
| 4376 | |
| 4377 | ssh_rportfwds = newtree234(ssh_rportcmp_ssh2); |
| 4378 | /* Add port forwardings. */ |
| 4379 | e = cfg.portfwd; |
| 4380 | while (*e) { |
| 4381 | type = *e++; |
| 4382 | n = 0; |
| 4383 | while (*e && *e != '\t') |
| 4384 | sports[n++] = *e++; |
| 4385 | sports[n] = 0; |
| 4386 | if (*e == '\t') |
| 4387 | e++; |
| 4388 | n = 0; |
| 4389 | while (*e && *e != ':') |
| 4390 | host[n++] = *e++; |
| 4391 | host[n] = 0; |
| 4392 | if (*e == ':') |
| 4393 | e++; |
| 4394 | n = 0; |
| 4395 | while (*e) |
| 4396 | dports[n++] = *e++; |
| 4397 | dports[n] = 0; |
| 4398 | e++; |
| 4399 | dport = atoi(dports); |
| 4400 | sport = atoi(sports); |
| 4401 | if (sport && dport) { |
| 4402 | if (type == 'L') { |
| 4403 | pfd_addforward(host, dport, sport); |
| 4404 | sprintf(buf, "Local port %d forwarding to %s:%d", |
| 4405 | sport, host, dport); |
| 4406 | logevent(buf); |
| 4407 | } else { |
| 4408 | struct ssh_rportfwd *pf; |
| 4409 | pf = smalloc(sizeof(*pf)); |
| 4410 | strcpy(pf->dhost, host); |
| 4411 | pf->dport = dport; |
| 4412 | pf->sport = sport; |
| 4413 | if (add234(ssh_rportfwds, pf) != pf) { |
| 4414 | sprintf(buf, |
| 4415 | "Duplicate remote port forwarding to %s:%d", |
| 4416 | host, dport); |
| 4417 | logevent(buf); |
| 4418 | sfree(pf); |
| 4419 | } else { |
| 4420 | sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)", |
| 4421 | sport, host, dport); |
| 4422 | logevent(buf); |
| 4423 | ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); |
| 4424 | ssh2_pkt_addstring("tcpip-forward"); |
| 4425 | ssh2_pkt_addbool(1);/* want reply */ |
| 4426 | ssh2_pkt_addstring("127.0.0.1"); |
| 4427 | ssh2_pkt_adduint32(sport); |
| 4428 | ssh2_pkt_send(); |
| 4429 | |
| 4430 | do { |
| 4431 | crWaitUntilV(ispkt); |
| 4432 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4433 | unsigned i = ssh2_pkt_getuint32(); |
| 4434 | struct ssh_channel *c; |
| 4435 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4436 | if (!c) |
| 4437 | continue;/* nonexistent channel */ |
| 4438 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4439 | } |
| 4440 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4441 | |
| 4442 | if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) { |
| 4443 | if (pktin.type != SSH2_MSG_REQUEST_FAILURE) { |
| 4444 | bombout(("Server got confused by port forwarding request")); |
| 4445 | crReturnV; |
| 4446 | } |
| 4447 | logevent("Server refused this port forwarding"); |
| 4448 | } else { |
| 4449 | logevent("Remote port forwarding enabled"); |
| 4450 | } |
| 4451 | } |
| 4452 | } |
| 4453 | } |
| 4454 | } |
| 4455 | } |
| 4456 | |
| 4457 | /* |
| 4458 | * Potentially enable agent forwarding. |
| 4459 | */ |
| 4460 | if (cfg.agentfwd && agent_exists()) { |
| 4461 | logevent("Requesting OpenSSH-style agent forwarding"); |
| 4462 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4463 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 4464 | ssh2_pkt_addstring("auth-agent-req@openssh.com"); |
| 4465 | ssh2_pkt_addbool(1); /* want reply */ |
| 4466 | ssh2_pkt_send(); |
| 4467 | |
| 4468 | do { |
| 4469 | crWaitUntilV(ispkt); |
| 4470 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4471 | unsigned i = ssh2_pkt_getuint32(); |
| 4472 | struct ssh_channel *c; |
| 4473 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4474 | if (!c) |
| 4475 | continue; /* nonexistent channel */ |
| 4476 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4477 | } |
| 4478 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4479 | |
| 4480 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4481 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4482 | bombout( |
| 4483 | ("Server got confused by agent forwarding request")); |
| 4484 | crReturnV; |
| 4485 | } |
| 4486 | logevent("Agent forwarding refused"); |
| 4487 | } else { |
| 4488 | logevent("Agent forwarding enabled"); |
| 4489 | ssh_agentfwd_enabled = TRUE; |
| 4490 | } |
| 4491 | } |
| 4492 | |
| 4493 | /* |
| 4494 | * Now allocate a pty for the session. |
| 4495 | */ |
| 4496 | if (!cfg.nopty) { |
| 4497 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4498 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 4499 | ssh2_pkt_addstring("pty-req"); |
| 4500 | ssh2_pkt_addbool(1); /* want reply */ |
| 4501 | ssh2_pkt_addstring(cfg.termtype); |
| 4502 | ssh2_pkt_adduint32(cols); |
| 4503 | ssh2_pkt_adduint32(rows); |
| 4504 | ssh2_pkt_adduint32(0); /* pixel width */ |
| 4505 | ssh2_pkt_adduint32(0); /* pixel height */ |
| 4506 | ssh2_pkt_addstring_start(); |
| 4507 | ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */ |
| 4508 | ssh2_pkt_send(); |
| 4509 | ssh_state = SSH_STATE_INTERMED; |
| 4510 | |
| 4511 | do { |
| 4512 | crWaitUntilV(ispkt); |
| 4513 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4514 | unsigned i = ssh2_pkt_getuint32(); |
| 4515 | struct ssh_channel *c; |
| 4516 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4517 | if (!c) |
| 4518 | continue; /* nonexistent channel */ |
| 4519 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4520 | } |
| 4521 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4522 | |
| 4523 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4524 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4525 | bombout(("Server got confused by pty request")); |
| 4526 | crReturnV; |
| 4527 | } |
| 4528 | c_write_str("Server refused to allocate pty\r\n"); |
| 4529 | ssh_editing = ssh_echoing = 1; |
| 4530 | } else { |
| 4531 | logevent("Allocated pty"); |
| 4532 | } |
| 4533 | } else { |
| 4534 | ssh_editing = ssh_echoing = 1; |
| 4535 | } |
| 4536 | |
| 4537 | /* |
| 4538 | * Start a shell or a remote command. We may have to attempt |
| 4539 | * this twice if the config data has provided a second choice |
| 4540 | * of command. |
| 4541 | */ |
| 4542 | while (1) { |
| 4543 | int subsys; |
| 4544 | char *cmd; |
| 4545 | |
| 4546 | if (ssh_fallback_cmd) { |
| 4547 | subsys = cfg.ssh_subsys2; |
| 4548 | cmd = cfg.remote_cmd_ptr2; |
| 4549 | } else { |
| 4550 | subsys = cfg.ssh_subsys; |
| 4551 | cmd = cfg.remote_cmd_ptr; |
| 4552 | } |
| 4553 | |
| 4554 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 4555 | ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ |
| 4556 | if (subsys) { |
| 4557 | ssh2_pkt_addstring("subsystem"); |
| 4558 | ssh2_pkt_addbool(1); /* want reply */ |
| 4559 | ssh2_pkt_addstring(cmd); |
| 4560 | } else if (*cmd) { |
| 4561 | ssh2_pkt_addstring("exec"); |
| 4562 | ssh2_pkt_addbool(1); /* want reply */ |
| 4563 | ssh2_pkt_addstring(cmd); |
| 4564 | } else { |
| 4565 | ssh2_pkt_addstring("shell"); |
| 4566 | ssh2_pkt_addbool(1); /* want reply */ |
| 4567 | } |
| 4568 | ssh2_pkt_send(); |
| 4569 | do { |
| 4570 | crWaitUntilV(ispkt); |
| 4571 | if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4572 | unsigned i = ssh2_pkt_getuint32(); |
| 4573 | struct ssh_channel *c; |
| 4574 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4575 | if (!c) |
| 4576 | continue; /* nonexistent channel */ |
| 4577 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4578 | } |
| 4579 | } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
| 4580 | if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { |
| 4581 | if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { |
| 4582 | bombout(("Server got confused by shell/command request")); |
| 4583 | crReturnV; |
| 4584 | } |
| 4585 | /* |
| 4586 | * We failed to start the command. If this is the |
| 4587 | * fallback command, we really are finished; if it's |
| 4588 | * not, and if the fallback command exists, try falling |
| 4589 | * back to it before complaining. |
| 4590 | */ |
| 4591 | if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) { |
| 4592 | logevent("Primary command failed; attempting fallback"); |
| 4593 | ssh_fallback_cmd = TRUE; |
| 4594 | continue; |
| 4595 | } |
| 4596 | bombout(("Server refused to start a shell/command")); |
| 4597 | crReturnV; |
| 4598 | } else { |
| 4599 | logevent("Started a shell/command"); |
| 4600 | } |
| 4601 | break; |
| 4602 | } |
| 4603 | |
| 4604 | ssh_state = SSH_STATE_SESSION; |
| 4605 | if (size_needed) |
| 4606 | ssh_size(); |
| 4607 | if (eof_needed) |
| 4608 | ssh_special(TS_EOF); |
| 4609 | |
| 4610 | /* |
| 4611 | * Transfer data! |
| 4612 | */ |
| 4613 | ldisc_send(NULL, 0); /* cause ldisc to notice changes */ |
| 4614 | ssh_send_ok = 1; |
| 4615 | while (1) { |
| 4616 | static int try_send; |
| 4617 | crReturnV; |
| 4618 | try_send = FALSE; |
| 4619 | if (ispkt) { |
| 4620 | if (pktin.type == SSH2_MSG_CHANNEL_DATA || |
| 4621 | pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { |
| 4622 | char *data; |
| 4623 | int length; |
| 4624 | unsigned i = ssh2_pkt_getuint32(); |
| 4625 | struct ssh_channel *c; |
| 4626 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4627 | if (!c) |
| 4628 | continue; /* nonexistent channel */ |
| 4629 | if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && |
| 4630 | ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) |
| 4631 | continue; /* extended but not stderr */ |
| 4632 | ssh2_pkt_getstring(&data, &length); |
| 4633 | if (data) { |
| 4634 | int bufsize; |
| 4635 | c->v.v2.locwindow -= length; |
| 4636 | switch (c->type) { |
| 4637 | case CHAN_MAINSESSION: |
| 4638 | bufsize = |
| 4639 | from_backend(pktin.type == |
| 4640 | SSH2_MSG_CHANNEL_EXTENDED_DATA, |
| 4641 | data, length); |
| 4642 | break; |
| 4643 | case CHAN_X11: |
| 4644 | bufsize = x11_send(c->u.x11.s, data, length); |
| 4645 | break; |
| 4646 | case CHAN_SOCKDATA: |
| 4647 | bufsize = pfd_send(c->u.pfd.s, data, length); |
| 4648 | break; |
| 4649 | case CHAN_AGENT: |
| 4650 | while (length > 0) { |
| 4651 | if (c->u.a.lensofar < 4) { |
| 4652 | int l = min(4 - c->u.a.lensofar, length); |
| 4653 | memcpy(c->u.a.msglen + c->u.a.lensofar, |
| 4654 | data, l); |
| 4655 | data += l; |
| 4656 | length -= l; |
| 4657 | c->u.a.lensofar += l; |
| 4658 | } |
| 4659 | if (c->u.a.lensofar == 4) { |
| 4660 | c->u.a.totallen = |
| 4661 | 4 + GET_32BIT(c->u.a.msglen); |
| 4662 | c->u.a.message = smalloc(c->u.a.totallen); |
| 4663 | memcpy(c->u.a.message, c->u.a.msglen, 4); |
| 4664 | } |
| 4665 | if (c->u.a.lensofar >= 4 && length > 0) { |
| 4666 | int l = |
| 4667 | min(c->u.a.totallen - c->u.a.lensofar, |
| 4668 | length); |
| 4669 | memcpy(c->u.a.message + c->u.a.lensofar, |
| 4670 | data, l); |
| 4671 | data += l; |
| 4672 | length -= l; |
| 4673 | c->u.a.lensofar += l; |
| 4674 | } |
| 4675 | if (c->u.a.lensofar == c->u.a.totallen) { |
| 4676 | void *reply, *sentreply; |
| 4677 | int replylen; |
| 4678 | agent_query(c->u.a.message, |
| 4679 | c->u.a.totallen, &reply, |
| 4680 | &replylen); |
| 4681 | if (reply) |
| 4682 | sentreply = reply; |
| 4683 | else { |
| 4684 | /* Fake SSH_AGENT_FAILURE. */ |
| 4685 | sentreply = "\0\0\0\1\5"; |
| 4686 | replylen = 5; |
| 4687 | } |
| 4688 | ssh2_add_channel_data(c, sentreply, |
| 4689 | replylen); |
| 4690 | try_send = TRUE; |
| 4691 | if (reply) |
| 4692 | sfree(reply); |
| 4693 | sfree(c->u.a.message); |
| 4694 | c->u.a.lensofar = 0; |
| 4695 | } |
| 4696 | } |
| 4697 | bufsize = 0; |
| 4698 | break; |
| 4699 | } |
| 4700 | /* |
| 4701 | * If we are not buffering too much data, |
| 4702 | * enlarge the window again at the remote side. |
| 4703 | */ |
| 4704 | if (bufsize < OUR_V2_WINSIZE) |
| 4705 | ssh2_set_window(c, OUR_V2_WINSIZE - bufsize); |
| 4706 | } |
| 4707 | } else if (pktin.type == SSH2_MSG_DISCONNECT) { |
| 4708 | ssh_state = SSH_STATE_CLOSED; |
| 4709 | logevent("Received disconnect message"); |
| 4710 | crReturnV; |
| 4711 | } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { |
| 4712 | continue; /* exit status et al; ignore (FIXME?) */ |
| 4713 | } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { |
| 4714 | unsigned i = ssh2_pkt_getuint32(); |
| 4715 | struct ssh_channel *c; |
| 4716 | |
| 4717 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4718 | if (!c) |
| 4719 | continue; /* nonexistent channel */ |
| 4720 | |
| 4721 | if (c->type == CHAN_X11) { |
| 4722 | /* |
| 4723 | * Remote EOF on an X11 channel means we should |
| 4724 | * wrap up and close the channel ourselves. |
| 4725 | */ |
| 4726 | x11_close(c->u.x11.s); |
| 4727 | sshfwd_close(c); |
| 4728 | } else if (c->type == CHAN_AGENT) { |
| 4729 | sshfwd_close(c); |
| 4730 | } else if (c->type == CHAN_SOCKDATA) { |
| 4731 | pfd_close(c->u.pfd.s); |
| 4732 | sshfwd_close(c); |
| 4733 | } |
| 4734 | } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { |
| 4735 | unsigned i = ssh2_pkt_getuint32(); |
| 4736 | struct ssh_channel *c; |
| 4737 | |
| 4738 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4739 | if (!c) |
| 4740 | continue; /* nonexistent channel */ |
| 4741 | /* Do pre-close processing on the channel. */ |
| 4742 | switch (c->type) { |
| 4743 | case CHAN_MAINSESSION: |
| 4744 | break; /* nothing to see here, move along */ |
| 4745 | case CHAN_X11: |
| 4746 | if (c->u.x11.s != NULL) |
| 4747 | x11_close(c->u.x11.s); |
| 4748 | sshfwd_close(c); |
| 4749 | break; |
| 4750 | case CHAN_AGENT: |
| 4751 | sshfwd_close(c); |
| 4752 | break; |
| 4753 | case CHAN_SOCKDATA: |
| 4754 | if (c->u.pfd.s != NULL) |
| 4755 | pfd_close(c->u.pfd.s); |
| 4756 | sshfwd_close(c); |
| 4757 | break; |
| 4758 | } |
| 4759 | if (c->closes == 0) { |
| 4760 | ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); |
| 4761 | ssh2_pkt_adduint32(c->remoteid); |
| 4762 | ssh2_pkt_send(); |
| 4763 | } |
| 4764 | del234(ssh_channels, c); |
| 4765 | bufchain_clear(&c->v.v2.outbuffer); |
| 4766 | sfree(c); |
| 4767 | |
| 4768 | /* |
| 4769 | * See if that was the last channel left open. |
| 4770 | */ |
| 4771 | if (count234(ssh_channels) == 0) { |
| 4772 | logevent("All channels closed. Disconnecting"); |
| 4773 | ssh2_pkt_init(SSH2_MSG_DISCONNECT); |
| 4774 | ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); |
| 4775 | ssh2_pkt_addstring("All open channels closed"); |
| 4776 | ssh2_pkt_addstring("en"); /* language tag */ |
| 4777 | ssh2_pkt_send(); |
| 4778 | ssh_state = SSH_STATE_CLOSED; |
| 4779 | crReturnV; |
| 4780 | } |
| 4781 | continue; /* remote sends close; ignore (FIXME) */ |
| 4782 | } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { |
| 4783 | unsigned i = ssh2_pkt_getuint32(); |
| 4784 | struct ssh_channel *c; |
| 4785 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4786 | if (!c) |
| 4787 | continue; /* nonexistent channel */ |
| 4788 | c->v.v2.remwindow += ssh2_pkt_getuint32(); |
| 4789 | try_send = TRUE; |
| 4790 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { |
| 4791 | unsigned i = ssh2_pkt_getuint32(); |
| 4792 | struct ssh_channel *c; |
| 4793 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4794 | if (!c) |
| 4795 | continue; /* nonexistent channel */ |
| 4796 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 4797 | continue; /* dunno why they're confirming this */ |
| 4798 | c->remoteid = ssh2_pkt_getuint32(); |
| 4799 | c->type = CHAN_SOCKDATA; |
| 4800 | c->closes = 0; |
| 4801 | c->v.v2.remwindow = ssh2_pkt_getuint32(); |
| 4802 | c->v.v2.remmaxpkt = ssh2_pkt_getuint32(); |
| 4803 | bufchain_init(&c->v.v2.outbuffer); |
| 4804 | pfd_confirm(c->u.pfd.s); |
| 4805 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { |
| 4806 | unsigned i = ssh2_pkt_getuint32(); |
| 4807 | struct ssh_channel *c; |
| 4808 | c = find234(ssh_channels, &i, ssh_channelfind); |
| 4809 | if (!c) |
| 4810 | continue; /* nonexistent channel */ |
| 4811 | if (c->type != CHAN_SOCKDATA_DORMANT) |
| 4812 | continue; /* dunno why they're failing this */ |
| 4813 | |
| 4814 | logevent("Forwarded connection refused by server"); |
| 4815 | |
| 4816 | pfd_close(c->u.pfd.s); |
| 4817 | |
| 4818 | del234(ssh_channels, c); |
| 4819 | sfree(c); |
| 4820 | } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { |
| 4821 | char *type; |
| 4822 | int typelen; |
| 4823 | char *error = NULL; |
| 4824 | struct ssh_channel *c; |
| 4825 | unsigned remid, winsize, pktsize; |
| 4826 | ssh2_pkt_getstring(&type, &typelen); |
| 4827 | c = smalloc(sizeof(struct ssh_channel)); |
| 4828 | |
| 4829 | remid = ssh2_pkt_getuint32(); |
| 4830 | winsize = ssh2_pkt_getuint32(); |
| 4831 | pktsize = ssh2_pkt_getuint32(); |
| 4832 | |
| 4833 | if (typelen == 3 && !memcmp(type, "x11", 3)) { |
| 4834 | if (!ssh_X11_fwd_enabled) |
| 4835 | error = "X11 forwarding is not enabled"; |
| 4836 | else if (x11_init(&c->u.x11.s, cfg.x11_display, c) != |
| 4837 | NULL) { |
| 4838 | error = "Unable to open an X11 connection"; |
| 4839 | } else { |
| 4840 | c->type = CHAN_X11; |
| 4841 | } |
| 4842 | } else if (typelen == 15 && |
| 4843 | !memcmp(type, "forwarded-tcpip", 15)) { |
| 4844 | struct ssh_rportfwd pf, *realpf; |
| 4845 | char *dummy; |
| 4846 | int dummylen; |
| 4847 | ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */ |
| 4848 | pf.sport = ssh2_pkt_getuint32(); |
| 4849 | realpf = find234(ssh_rportfwds, &pf, NULL); |
| 4850 | if (realpf == NULL) { |
| 4851 | error = "Remote port is not recognised"; |
| 4852 | } else { |
| 4853 | char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost, |
| 4854 | realpf->dport, c); |
| 4855 | char buf[1024]; |
| 4856 | sprintf(buf, "Received remote port open request for %s:%d", |
| 4857 | realpf->dhost, realpf->dport); |
| 4858 | logevent(buf); |
| 4859 | if (e != NULL) { |
| 4860 | sprintf(buf, "Port open failed: %s", e); |
| 4861 | logevent(buf); |
| 4862 | error = "Port open failed"; |
| 4863 | } else { |
| 4864 | logevent("Forwarded port opened successfully"); |
| 4865 | c->type = CHAN_SOCKDATA; |
| 4866 | } |
| 4867 | } |
| 4868 | } else if (typelen == 22 && |
| 4869 | !memcmp(type, "auth-agent@openssh.com", 3)) { |
| 4870 | if (!ssh_agentfwd_enabled) |
| 4871 | error = "Agent forwarding is not enabled"; |
| 4872 | else { |
| 4873 | c->type = CHAN_AGENT; /* identify channel type */ |
| 4874 | c->u.a.lensofar = 0; |
| 4875 | } |
| 4876 | } else { |
| 4877 | error = "Unsupported channel type requested"; |
| 4878 | } |
| 4879 | |
| 4880 | c->remoteid = remid; |
| 4881 | if (error) { |
| 4882 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
| 4883 | ssh2_pkt_adduint32(c->remoteid); |
| 4884 | ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED); |
| 4885 | ssh2_pkt_addstring(error); |
| 4886 | ssh2_pkt_addstring("en"); /* language tag */ |
| 4887 | ssh2_pkt_send(); |
| 4888 | sfree(c); |
| 4889 | } else { |
| 4890 | c->localid = alloc_channel_id(); |
| 4891 | c->closes = 0; |
| 4892 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
| 4893 | c->v.v2.remwindow = winsize; |
| 4894 | c->v.v2.remmaxpkt = pktsize; |
| 4895 | bufchain_init(&c->v.v2.outbuffer); |
| 4896 | add234(ssh_channels, c); |
| 4897 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); |
| 4898 | ssh2_pkt_adduint32(c->remoteid); |
| 4899 | ssh2_pkt_adduint32(c->localid); |
| 4900 | ssh2_pkt_adduint32(c->v.v2.locwindow); |
| 4901 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 4902 | ssh2_pkt_send(); |
| 4903 | } |
| 4904 | } else { |
| 4905 | bombout(("Strange packet received: type %d", pktin.type)); |
| 4906 | crReturnV; |
| 4907 | } |
| 4908 | } else { |
| 4909 | /* |
| 4910 | * We have spare data. Add it to the channel buffer. |
| 4911 | */ |
| 4912 | ssh2_add_channel_data(mainchan, in, inlen); |
| 4913 | try_send = TRUE; |
| 4914 | } |
| 4915 | if (try_send) { |
| 4916 | int i; |
| 4917 | struct ssh_channel *c; |
| 4918 | /* |
| 4919 | * Try to send data on all channels if we can. |
| 4920 | */ |
| 4921 | for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) { |
| 4922 | int bufsize = ssh2_try_send(c); |
| 4923 | if (bufsize == 0) { |
| 4924 | switch (c->type) { |
| 4925 | case CHAN_MAINSESSION: |
| 4926 | /* stdin need not receive an unthrottle |
| 4927 | * notification since it will be polled */ |
| 4928 | break; |
| 4929 | case CHAN_X11: |
| 4930 | x11_unthrottle(c->u.x11.s); |
| 4931 | break; |
| 4932 | case CHAN_AGENT: |
| 4933 | /* agent sockets are request/response and need no |
| 4934 | * buffer management */ |
| 4935 | break; |
| 4936 | case CHAN_SOCKDATA: |
| 4937 | pfd_unthrottle(c->u.pfd.s); |
| 4938 | break; |
| 4939 | } |
| 4940 | } |
| 4941 | } |
| 4942 | } |
| 4943 | } |
| 4944 | |
| 4945 | crFinishV; |
| 4946 | } |
| 4947 | |
| 4948 | /* |
| 4949 | * Handle the top-level SSH2 protocol. |
| 4950 | */ |
| 4951 | static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) |
| 4952 | { |
| 4953 | if (do_ssh2_transport(in, inlen, ispkt) == 0) |
| 4954 | return; |
| 4955 | do_ssh2_authconn(in, inlen, ispkt); |
| 4956 | } |
| 4957 | |
| 4958 | /* |
| 4959 | * Called to set up the connection. |
| 4960 | * |
| 4961 | * Returns an error message, or NULL on success. |
| 4962 | */ |
| 4963 | static char *ssh_init(char *host, int port, char **realhost) |
| 4964 | { |
| 4965 | char *p; |
| 4966 | |
| 4967 | #ifdef MSCRYPTOAPI |
| 4968 | if (crypto_startup() == 0) |
| 4969 | return "Microsoft high encryption pack not installed!"; |
| 4970 | #endif |
| 4971 | |
| 4972 | ssh_send_ok = 0; |
| 4973 | ssh_editing = 0; |
| 4974 | ssh_echoing = 0; |
| 4975 | ssh1_throttle_count = 0; |
| 4976 | ssh_overall_bufsize = 0; |
| 4977 | ssh_fallback_cmd = 0; |
| 4978 | |
| 4979 | p = connect_to_host(host, port, realhost); |
| 4980 | if (p != NULL) |
| 4981 | return p; |
| 4982 | |
| 4983 | return NULL; |
| 4984 | } |
| 4985 | |
| 4986 | /* |
| 4987 | * Called to send data down the Telnet connection. |
| 4988 | */ |
| 4989 | static int ssh_send(char *buf, int len) |
| 4990 | { |
| 4991 | if (s == NULL || ssh_protocol == NULL) |
| 4992 | return 0; |
| 4993 | |
| 4994 | ssh_protocol(buf, len, 0); |
| 4995 | |
| 4996 | return ssh_sendbuffer(); |
| 4997 | } |
| 4998 | |
| 4999 | /* |
| 5000 | * Called to query the current amount of buffered stdin data. |
| 5001 | */ |
| 5002 | static int ssh_sendbuffer(void) |
| 5003 | { |
| 5004 | int override_value; |
| 5005 | |
| 5006 | if (s == NULL || ssh_protocol == NULL) |
| 5007 | return 0; |
| 5008 | |
| 5009 | /* |
| 5010 | * If the SSH socket itself has backed up, add the total backup |
| 5011 | * size on that to any individual buffer on the stdin channel. |
| 5012 | */ |
| 5013 | override_value = 0; |
| 5014 | if (ssh_throttled_all) |
| 5015 | override_value = ssh_overall_bufsize; |
| 5016 | |
| 5017 | if (ssh_version == 1) { |
| 5018 | return override_value; |
| 5019 | } else if (ssh_version == 2) { |
| 5020 | if (!mainchan || mainchan->closes > 0) |
| 5021 | return override_value; |
| 5022 | else |
| 5023 | return override_value + bufchain_size(&mainchan->v.v2.outbuffer); |
| 5024 | } |
| 5025 | |
| 5026 | return 0; |
| 5027 | } |
| 5028 | |
| 5029 | /* |
| 5030 | * Called to set the size of the window from SSH's POV. |
| 5031 | */ |
| 5032 | static void ssh_size(void) |
| 5033 | { |
| 5034 | switch (ssh_state) { |
| 5035 | case SSH_STATE_BEFORE_SIZE: |
| 5036 | case SSH_STATE_PREPACKET: |
| 5037 | case SSH_STATE_CLOSED: |
| 5038 | break; /* do nothing */ |
| 5039 | case SSH_STATE_INTERMED: |
| 5040 | size_needed = TRUE; /* buffer for later */ |
| 5041 | break; |
| 5042 | case SSH_STATE_SESSION: |
| 5043 | if (!cfg.nopty) { |
| 5044 | if (ssh_version == 1) { |
| 5045 | send_packet(SSH1_CMSG_WINDOW_SIZE, |
| 5046 | PKT_INT, rows, PKT_INT, cols, |
| 5047 | PKT_INT, 0, PKT_INT, 0, PKT_END); |
| 5048 | } else { |
| 5049 | ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); |
| 5050 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 5051 | ssh2_pkt_addstring("window-change"); |
| 5052 | ssh2_pkt_addbool(0); |
| 5053 | ssh2_pkt_adduint32(cols); |
| 5054 | ssh2_pkt_adduint32(rows); |
| 5055 | ssh2_pkt_adduint32(0); |
| 5056 | ssh2_pkt_adduint32(0); |
| 5057 | ssh2_pkt_send(); |
| 5058 | } |
| 5059 | } |
| 5060 | break; |
| 5061 | } |
| 5062 | } |
| 5063 | |
| 5064 | /* |
| 5065 | * Send Telnet special codes. TS_EOF is useful for `plink', so you |
| 5066 | * can send an EOF and collect resulting output (e.g. `plink |
| 5067 | * hostname sort'). |
| 5068 | */ |
| 5069 | static void ssh_special(Telnet_Special code) |
| 5070 | { |
| 5071 | if (code == TS_EOF) { |
| 5072 | if (ssh_state != SSH_STATE_SESSION) { |
| 5073 | /* |
| 5074 | * Buffer the EOF in case we are pre-SESSION, so we can |
| 5075 | * send it as soon as we reach SESSION. |
| 5076 | */ |
| 5077 | if (code == TS_EOF) |
| 5078 | eof_needed = TRUE; |
| 5079 | return; |
| 5080 | } |
| 5081 | if (ssh_version == 1) { |
| 5082 | send_packet(SSH1_CMSG_EOF, PKT_END); |
| 5083 | } else { |
| 5084 | ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); |
| 5085 | ssh2_pkt_adduint32(mainchan->remoteid); |
| 5086 | ssh2_pkt_send(); |
| 5087 | } |
| 5088 | logevent("Sent EOF message"); |
| 5089 | } else if (code == TS_PING) { |
| 5090 | if (ssh_state == SSH_STATE_CLOSED |
| 5091 | || ssh_state == SSH_STATE_PREPACKET) return; |
| 5092 | if (ssh_version == 1) { |
| 5093 | send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); |
| 5094 | } else { |
| 5095 | ssh2_pkt_init(SSH2_MSG_IGNORE); |
| 5096 | ssh2_pkt_addstring_start(); |
| 5097 | ssh2_pkt_send(); |
| 5098 | } |
| 5099 | } else { |
| 5100 | /* do nothing */ |
| 5101 | } |
| 5102 | } |
| 5103 | |
| 5104 | void *new_sock_channel(Socket s) |
| 5105 | { |
| 5106 | struct ssh_channel *c; |
| 5107 | c = smalloc(sizeof(struct ssh_channel)); |
| 5108 | |
| 5109 | if (c) { |
| 5110 | c->remoteid = -1; /* to be set when open confirmed */ |
| 5111 | c->localid = alloc_channel_id(); |
| 5112 | c->closes = 0; |
| 5113 | c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ |
| 5114 | c->u.pfd.s = s; |
| 5115 | add234(ssh_channels, c); |
| 5116 | } |
| 5117 | return c; |
| 5118 | } |
| 5119 | |
| 5120 | /* |
| 5121 | * This is called when stdout/stderr (the entity to which |
| 5122 | * from_backend sends data) manages to clear some backlog. |
| 5123 | */ |
| 5124 | void ssh_unthrottle(int bufsize) |
| 5125 | { |
| 5126 | if (ssh_version == 1) { |
| 5127 | if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { |
| 5128 | ssh1_stdout_throttling = 0; |
| 5129 | ssh1_throttle(-1); |
| 5130 | } |
| 5131 | } else { |
| 5132 | if (mainchan && mainchan->closes == 0) |
| 5133 | ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize); |
| 5134 | } |
| 5135 | } |
| 5136 | |
| 5137 | void ssh_send_port_open(void *channel, char *hostname, int port, char *org) |
| 5138 | { |
| 5139 | struct ssh_channel *c = (struct ssh_channel *)channel; |
| 5140 | char buf[1024]; |
| 5141 | |
| 5142 | sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port); |
| 5143 | logevent(buf); |
| 5144 | |
| 5145 | if (ssh_version == 1) { |
| 5146 | send_packet(SSH1_MSG_PORT_OPEN, |
| 5147 | PKT_INT, c->localid, |
| 5148 | PKT_STR, hostname, |
| 5149 | PKT_INT, port, |
| 5150 | //PKT_STR, <org:orgport>, |
| 5151 | PKT_END); |
| 5152 | } else { |
| 5153 | ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); |
| 5154 | ssh2_pkt_addstring("direct-tcpip"); |
| 5155 | ssh2_pkt_adduint32(c->localid); |
| 5156 | c->v.v2.locwindow = OUR_V2_WINSIZE; |
| 5157 | ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */ |
| 5158 | ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ |
| 5159 | ssh2_pkt_addstring(hostname); |
| 5160 | ssh2_pkt_adduint32(port); |
| 5161 | /* |
| 5162 | * We make up values for the originator data; partly it's |
| 5163 | * too much hassle to keep track, and partly I'm not |
| 5164 | * convinced the server should be told details like that |
| 5165 | * about my local network configuration. |
| 5166 | */ |
| 5167 | ssh2_pkt_addstring("client-side-connection"); |
| 5168 | ssh2_pkt_adduint32(0); |
| 5169 | ssh2_pkt_send(); |
| 5170 | } |
| 5171 | } |
| 5172 | |
| 5173 | |
| 5174 | static Socket ssh_socket(void) |
| 5175 | { |
| 5176 | return s; |
| 5177 | } |
| 5178 | |
| 5179 | static int ssh_sendok(void) |
| 5180 | { |
| 5181 | return ssh_send_ok; |
| 5182 | } |
| 5183 | |
| 5184 | static int ssh_ldisc(int option) |
| 5185 | { |
| 5186 | if (option == LD_ECHO) |
| 5187 | return ssh_echoing; |
| 5188 | if (option == LD_EDIT) |
| 5189 | return ssh_editing; |
| 5190 | return FALSE; |
| 5191 | } |
| 5192 | |
| 5193 | Backend ssh_backend = { |
| 5194 | ssh_init, |
| 5195 | ssh_send, |
| 5196 | ssh_sendbuffer, |
| 5197 | ssh_size, |
| 5198 | ssh_special, |
| 5199 | ssh_socket, |
| 5200 | ssh_sendok, |
| 5201 | ssh_ldisc, |
| 5202 | ssh_unthrottle, |
| 5203 | 22 |
| 5204 | }; |