diff options
Diffstat (limited to 'other/openssh-2.1.1p4/authfd.c')
| -rw-r--r-- | other/openssh-2.1.1p4/authfd.c | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/other/openssh-2.1.1p4/authfd.c b/other/openssh-2.1.1p4/authfd.c new file mode 100644 index 0000000..69fe2ae --- /dev/null +++ b/other/openssh-2.1.1p4/authfd.c | |||
| @@ -0,0 +1,498 @@ | |||
| 1 | /* | ||
| 2 | * | ||
| 3 | * authfd.c | ||
| 4 | * | ||
| 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | ||
| 6 | * | ||
| 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | ||
| 8 | * All rights reserved | ||
| 9 | * | ||
| 10 | * Created: Wed Mar 29 01:30:28 1995 ylo | ||
| 11 | * | ||
| 12 | * Functions for connecting the local authentication agent. | ||
| 13 | * | ||
| 14 | */ | ||
| 15 | |||
| 16 | #include "includes.h" | ||
| 17 | RCSID("$OpenBSD: authfd.c,v 1.21 2000/06/26 09:22:29 markus Exp $"); | ||
| 18 | |||
| 19 | #include "ssh.h" | ||
| 20 | #include "rsa.h" | ||
| 21 | #include "authfd.h" | ||
| 22 | #include "buffer.h" | ||
| 23 | #include "bufaux.h" | ||
| 24 | #include "xmalloc.h" | ||
| 25 | #include "getput.h" | ||
| 26 | |||
| 27 | #include <openssl/rsa.h> | ||
| 28 | |||
| 29 | /* helper */ | ||
| 30 | int ssh_agent_get_reply(AuthenticationConnection *auth); | ||
| 31 | |||
| 32 | /* Returns the number of the authentication fd, or -1 if there is none. */ | ||
| 33 | |||
| 34 | int | ||
| 35 | ssh_get_authentication_socket() | ||
| 36 | { | ||
| 37 | const char *authsocket; | ||
| 38 | int sock; | ||
| 39 | struct sockaddr_un sunaddr; | ||
| 40 | |||
| 41 | authsocket = getenv(SSH_AUTHSOCKET_ENV_NAME); | ||
| 42 | if (!authsocket) | ||
| 43 | return -1; | ||
| 44 | |||
| 45 | sunaddr.sun_family = AF_UNIX; | ||
| 46 | strlcpy(sunaddr.sun_path, authsocket, sizeof(sunaddr.sun_path)); | ||
| 47 | |||
| 48 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | ||
| 49 | if (sock < 0) | ||
| 50 | return -1; | ||
| 51 | |||
| 52 | /* close on exec */ | ||
| 53 | if (fcntl(sock, F_SETFD, 1) == -1) { | ||
| 54 | close(sock); | ||
| 55 | return -1; | ||
| 56 | } | ||
| 57 | if (connect(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { | ||
| 58 | close(sock); | ||
| 59 | return -1; | ||
| 60 | } | ||
| 61 | return sock; | ||
| 62 | } | ||
| 63 | |||
| 64 | /* | ||
| 65 | * Closes the agent socket if it should be closed (depends on how it was | ||
| 66 | * obtained). The argument must have been returned by | ||
| 67 | * ssh_get_authentication_socket(). | ||
| 68 | */ | ||
| 69 | |||
| 70 | void | ||
| 71 | ssh_close_authentication_socket(int sock) | ||
| 72 | { | ||
| 73 | if (getenv(SSH_AUTHSOCKET_ENV_NAME)) | ||
| 74 | close(sock); | ||
| 75 | } | ||
| 76 | |||
| 77 | /* | ||
| 78 | * Opens and connects a private socket for communication with the | ||
| 79 | * authentication agent. Returns the file descriptor (which must be | ||
| 80 | * shut down and closed by the caller when no longer needed). | ||
| 81 | * Returns NULL if an error occurred and the connection could not be | ||
| 82 | * opened. | ||
| 83 | */ | ||
| 84 | |||
| 85 | AuthenticationConnection * | ||
| 86 | ssh_get_authentication_connection() | ||
| 87 | { | ||
| 88 | AuthenticationConnection *auth; | ||
| 89 | int sock; | ||
| 90 | |||
| 91 | sock = ssh_get_authentication_socket(); | ||
| 92 | |||
| 93 | /* | ||
| 94 | * Fail if we couldn't obtain a connection. This happens if we | ||
| 95 | * exited due to a timeout. | ||
| 96 | */ | ||
| 97 | if (sock < 0) | ||
| 98 | return NULL; | ||
| 99 | |||
| 100 | auth = xmalloc(sizeof(*auth)); | ||
| 101 | auth->fd = sock; | ||
| 102 | buffer_init(&auth->packet); | ||
| 103 | buffer_init(&auth->identities); | ||
| 104 | auth->howmany = 0; | ||
| 105 | |||
| 106 | return auth; | ||
| 107 | } | ||
| 108 | |||
| 109 | /* | ||
| 110 | * Closes the connection to the authentication agent and frees any associated | ||
| 111 | * memory. | ||
| 112 | */ | ||
| 113 | |||
| 114 | void | ||
| 115 | ssh_close_authentication_connection(AuthenticationConnection *ac) | ||
| 116 | { | ||
| 117 | buffer_free(&ac->packet); | ||
| 118 | buffer_free(&ac->identities); | ||
| 119 | close(ac->fd); | ||
| 120 | xfree(ac); | ||
| 121 | } | ||
| 122 | |||
| 123 | /* | ||
| 124 | * Returns the first authentication identity held by the agent. | ||
| 125 | * Returns true if an identity is available, 0 otherwise. | ||
| 126 | * The caller must initialize the integers before the call, and free the | ||
| 127 | * comment after a successful call (before calling ssh_get_next_identity). | ||
| 128 | */ | ||
| 129 | |||
| 130 | int | ||
| 131 | ssh_get_first_identity(AuthenticationConnection *auth, | ||
| 132 | BIGNUM *e, BIGNUM *n, char **comment) | ||
| 133 | { | ||
| 134 | unsigned char msg[8192]; | ||
| 135 | int len, l; | ||
| 136 | |||
| 137 | /* | ||
| 138 | * Send a message to the agent requesting for a list of the | ||
| 139 | * identities it can represent. | ||
| 140 | */ | ||
| 141 | msg[0] = 0; | ||
| 142 | msg[1] = 0; | ||
| 143 | msg[2] = 0; | ||
| 144 | msg[3] = 1; | ||
| 145 | msg[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES; | ||
| 146 | if (atomicio(write, auth->fd, msg, 5) != 5) { | ||
| 147 | error("write auth->fd: %.100s", strerror(errno)); | ||
| 148 | return 0; | ||
| 149 | } | ||
| 150 | /* Read the length of the response. XXX implement timeouts here. */ | ||
| 151 | len = 4; | ||
| 152 | while (len > 0) { | ||
| 153 | l = read(auth->fd, msg + 4 - len, len); | ||
| 154 | if (l <= 0) { | ||
| 155 | error("read auth->fd: %.100s", strerror(errno)); | ||
| 156 | return 0; | ||
| 157 | } | ||
| 158 | len -= l; | ||
| 159 | } | ||
| 160 | |||
| 161 | /* | ||
| 162 | * Extract the length, and check it for sanity. (We cannot trust | ||
| 163 | * authentication agents). | ||
| 164 | */ | ||
| 165 | len = GET_32BIT(msg); | ||
| 166 | if (len < 1 || len > 256 * 1024) | ||
| 167 | fatal("Authentication reply message too long: %d\n", len); | ||
| 168 | |||
| 169 | /* Read the packet itself. */ | ||
| 170 | buffer_clear(&auth->identities); | ||
| 171 | while (len > 0) { | ||
| 172 | l = len; | ||
| 173 | if (l > sizeof(msg)) | ||
| 174 | l = sizeof(msg); | ||
| 175 | l = read(auth->fd, msg, l); | ||
| 176 | if (l <= 0) | ||
| 177 | fatal("Incomplete authentication reply."); | ||
| 178 | buffer_append(&auth->identities, (char *) msg, l); | ||
| 179 | len -= l; | ||
| 180 | } | ||
| 181 | |||
| 182 | /* Get message type, and verify that we got a proper answer. */ | ||
| 183 | buffer_get(&auth->identities, (char *) msg, 1); | ||
| 184 | if (msg[0] != SSH_AGENT_RSA_IDENTITIES_ANSWER) | ||
| 185 | fatal("Bad authentication reply message type: %d", msg[0]); | ||
| 186 | |||
| 187 | /* Get the number of entries in the response and check it for sanity. */ | ||
| 188 | auth->howmany = buffer_get_int(&auth->identities); | ||
| 189 | if (auth->howmany > 1024) | ||
| 190 | fatal("Too many identities in authentication reply: %d\n", auth->howmany); | ||
| 191 | |||
| 192 | /* Return the first entry (if any). */ | ||
| 193 | return ssh_get_next_identity(auth, e, n, comment); | ||
| 194 | } | ||
| 195 | |||
| 196 | /* | ||
| 197 | * Returns the next authentication identity for the agent. Other functions | ||
| 198 | * can be called between this and ssh_get_first_identity or two calls of this | ||
| 199 | * function. This returns 0 if there are no more identities. The caller | ||
| 200 | * must free comment after a successful return. | ||
| 201 | */ | ||
| 202 | |||
| 203 | int | ||
| 204 | ssh_get_next_identity(AuthenticationConnection *auth, | ||
| 205 | BIGNUM *e, BIGNUM *n, char **comment) | ||
| 206 | { | ||
| 207 | unsigned int bits; | ||
| 208 | |||
| 209 | /* Return failure if no more entries. */ | ||
| 210 | if (auth->howmany <= 0) | ||
| 211 | return 0; | ||
| 212 | |||
| 213 | /* | ||
| 214 | * Get the next entry from the packet. These will abort with a fatal | ||
| 215 | * error if the packet is too short or contains corrupt data. | ||
| 216 | */ | ||
| 217 | bits = buffer_get_int(&auth->identities); | ||
| 218 | buffer_get_bignum(&auth->identities, e); | ||
| 219 | buffer_get_bignum(&auth->identities, n); | ||
| 220 | *comment = buffer_get_string(&auth->identities, NULL); | ||
| 221 | |||
| 222 | if (bits != BN_num_bits(n)) | ||
| 223 | log("Warning: identity keysize mismatch: actual %d, announced %u", | ||
| 224 | BN_num_bits(n), bits); | ||
| 225 | |||
| 226 | /* Decrement the number of remaining entries. */ | ||
| 227 | auth->howmany--; | ||
| 228 | |||
| 229 | return 1; | ||
| 230 | } | ||
| 231 | |||
| 232 | /* | ||
| 233 | * Generates a random challenge, sends it to the agent, and waits for | ||
| 234 | * response from the agent. Returns true (non-zero) if the agent gave the | ||
| 235 | * correct answer, zero otherwise. Response type selects the style of | ||
| 236 | * response desired, with 0 corresponding to protocol version 1.0 (no longer | ||
| 237 | * supported) and 1 corresponding to protocol version 1.1. | ||
| 238 | */ | ||
| 239 | |||
| 240 | int | ||
| 241 | ssh_decrypt_challenge(AuthenticationConnection *auth, | ||
| 242 | BIGNUM* e, BIGNUM *n, BIGNUM *challenge, | ||
| 243 | unsigned char session_id[16], | ||
| 244 | unsigned int response_type, | ||
| 245 | unsigned char response[16]) | ||
| 246 | { | ||
| 247 | Buffer buffer; | ||
| 248 | unsigned char buf[8192]; | ||
| 249 | int len, l, i; | ||
| 250 | |||
| 251 | /* Response type 0 is no longer supported. */ | ||
| 252 | if (response_type == 0) | ||
| 253 | fatal("Compatibility with ssh protocol version 1.0 no longer supported."); | ||
| 254 | |||
| 255 | /* Format a message to the agent. */ | ||
| 256 | buf[0] = SSH_AGENTC_RSA_CHALLENGE; | ||
| 257 | buffer_init(&buffer); | ||
| 258 | buffer_append(&buffer, (char *) buf, 1); | ||
| 259 | buffer_put_int(&buffer, BN_num_bits(n)); | ||
| 260 | buffer_put_bignum(&buffer, e); | ||
| 261 | buffer_put_bignum(&buffer, n); | ||
| 262 | buffer_put_bignum(&buffer, challenge); | ||
| 263 | buffer_append(&buffer, (char *) session_id, 16); | ||
| 264 | buffer_put_int(&buffer, response_type); | ||
| 265 | |||
| 266 | /* Get the length of the message, and format it in the buffer. */ | ||
| 267 | len = buffer_len(&buffer); | ||
| 268 | PUT_32BIT(buf, len); | ||
| 269 | |||
| 270 | /* Send the length and then the packet to the agent. */ | ||
| 271 | if (atomicio(write, auth->fd, buf, 4) != 4 || | ||
| 272 | atomicio(write, auth->fd, buffer_ptr(&buffer), | ||
| 273 | buffer_len(&buffer)) != buffer_len(&buffer)) { | ||
| 274 | error("Error writing to authentication socket."); | ||
| 275 | error_cleanup: | ||
| 276 | buffer_free(&buffer); | ||
| 277 | return 0; | ||
| 278 | } | ||
| 279 | /* | ||
| 280 | * Wait for response from the agent. First read the length of the | ||
| 281 | * response packet. | ||
| 282 | */ | ||
| 283 | len = 4; | ||
| 284 | while (len > 0) { | ||
| 285 | l = read(auth->fd, buf + 4 - len, len); | ||
| 286 | if (l <= 0) { | ||
| 287 | error("Error reading response length from authentication socket."); | ||
| 288 | goto error_cleanup; | ||
| 289 | } | ||
| 290 | len -= l; | ||
| 291 | } | ||
| 292 | |||
| 293 | /* Extract the length, and check it for sanity. */ | ||
| 294 | len = GET_32BIT(buf); | ||
| 295 | if (len > 256 * 1024) | ||
| 296 | fatal("Authentication response too long: %d", len); | ||
| 297 | |||
| 298 | /* Read the rest of the response in tothe buffer. */ | ||
| 299 | buffer_clear(&buffer); | ||
| 300 | while (len > 0) { | ||
| 301 | l = len; | ||
| 302 | if (l > sizeof(buf)) | ||
| 303 | l = sizeof(buf); | ||
| 304 | l = read(auth->fd, buf, l); | ||
| 305 | if (l <= 0) { | ||
| 306 | error("Error reading response from authentication socket."); | ||
| 307 | goto error_cleanup; | ||
| 308 | } | ||
| 309 | buffer_append(&buffer, (char *) buf, l); | ||
| 310 | len -= l; | ||
| 311 | } | ||
| 312 | |||
| 313 | /* Get the type of the packet. */ | ||
| 314 | buffer_get(&buffer, (char *) buf, 1); | ||
| 315 | |||
| 316 | /* Check for agent failure message. */ | ||
| 317 | if (buf[0] == SSH_AGENT_FAILURE) { | ||
| 318 | log("Agent admitted failure to authenticate using the key."); | ||
| 319 | goto error_cleanup; | ||
| 320 | } | ||
| 321 | /* Now it must be an authentication response packet. */ | ||
| 322 | if (buf[0] != SSH_AGENT_RSA_RESPONSE) | ||
| 323 | fatal("Bad authentication response: %d", buf[0]); | ||
| 324 | |||
| 325 | /* | ||
| 326 | * Get the response from the packet. This will abort with a fatal | ||
| 327 | * error if the packet is corrupt. | ||
| 328 | */ | ||
| 329 | for (i = 0; i < 16; i++) | ||
| 330 | response[i] = buffer_get_char(&buffer); | ||
| 331 | |||
| 332 | /* The buffer containing the packet is no longer needed. */ | ||
| 333 | buffer_free(&buffer); | ||
| 334 | |||
| 335 | /* Correct answer. */ | ||
| 336 | return 1; | ||
| 337 | } | ||
| 338 | |||
| 339 | /* | ||
| 340 | * Adds an identity to the authentication server. This call is not meant to | ||
| 341 | * be used by normal applications. | ||
| 342 | */ | ||
| 343 | |||
| 344 | int | ||
| 345 | ssh_add_identity(AuthenticationConnection *auth, | ||
| 346 | RSA * key, const char *comment) | ||
| 347 | { | ||
| 348 | Buffer buffer; | ||
| 349 | unsigned char buf[8192]; | ||
| 350 | int len; | ||
| 351 | |||
| 352 | /* Format a message to the agent. */ | ||
| 353 | buffer_init(&buffer); | ||
| 354 | buffer_put_char(&buffer, SSH_AGENTC_ADD_RSA_IDENTITY); | ||
| 355 | buffer_put_int(&buffer, BN_num_bits(key->n)); | ||
| 356 | buffer_put_bignum(&buffer, key->n); | ||
| 357 | buffer_put_bignum(&buffer, key->e); | ||
| 358 | buffer_put_bignum(&buffer, key->d); | ||
| 359 | /* To keep within the protocol: p < q for ssh. in SSL p > q */ | ||
| 360 | buffer_put_bignum(&buffer, key->iqmp); /* ssh key->u */ | ||
| 361 | buffer_put_bignum(&buffer, key->q); /* ssh key->p, SSL key->q */ | ||
| 362 | buffer_put_bignum(&buffer, key->p); /* ssh key->q, SSL key->p */ | ||
| 363 | buffer_put_string(&buffer, comment, strlen(comment)); | ||
| 364 | |||
| 365 | /* Get the length of the message, and format it in the buffer. */ | ||
| 366 | len = buffer_len(&buffer); | ||
| 367 | PUT_32BIT(buf, len); | ||
| 368 | |||
| 369 | /* Send the length and then the packet to the agent. */ | ||
| 370 | if (atomicio(write, auth->fd, buf, 4) != 4 || | ||
| 371 | atomicio(write, auth->fd, buffer_ptr(&buffer), | ||
| 372 | buffer_len(&buffer)) != buffer_len(&buffer)) { | ||
| 373 | error("Error writing to authentication socket."); | ||
| 374 | buffer_free(&buffer); | ||
| 375 | return 0; | ||
| 376 | } | ||
| 377 | buffer_free(&buffer); | ||
| 378 | return ssh_agent_get_reply(auth); | ||
| 379 | } | ||
| 380 | |||
| 381 | /* | ||
| 382 | * Removes an identity from the authentication server. This call is not | ||
| 383 | * meant to be used by normal applications. | ||
| 384 | */ | ||
| 385 | |||
| 386 | int | ||
| 387 | ssh_remove_identity(AuthenticationConnection *auth, RSA *key) | ||
| 388 | { | ||
| 389 | Buffer buffer; | ||
| 390 | unsigned char buf[5]; | ||
| 391 | int len; | ||
| 392 | |||
| 393 | /* Format a message to the agent. */ | ||
| 394 | buffer_init(&buffer); | ||
| 395 | buffer_put_char(&buffer, SSH_AGENTC_REMOVE_RSA_IDENTITY); | ||
| 396 | buffer_put_int(&buffer, BN_num_bits(key->n)); | ||
| 397 | buffer_put_bignum(&buffer, key->e); | ||
| 398 | buffer_put_bignum(&buffer, key->n); | ||
| 399 | |||
| 400 | /* Get the length of the message, and format it in the buffer. */ | ||
| 401 | len = buffer_len(&buffer); | ||
| 402 | PUT_32BIT(buf, len); | ||
| 403 | |||
| 404 | /* Send the length and then the packet to the agent. */ | ||
| 405 | if (atomicio(write, auth->fd, buf, 4) != 4 || | ||
| 406 | atomicio(write, auth->fd, buffer_ptr(&buffer), | ||
| 407 | buffer_len(&buffer)) != buffer_len(&buffer)) { | ||
| 408 | error("Error writing to authentication socket."); | ||
| 409 | buffer_free(&buffer); | ||
| 410 | return 0; | ||
| 411 | } | ||
| 412 | buffer_free(&buffer); | ||
| 413 | return ssh_agent_get_reply(auth); | ||
| 414 | } | ||
| 415 | |||
| 416 | /* | ||
| 417 | * Removes all identities from the agent. This call is not meant to be used | ||
| 418 | * by normal applications. | ||
| 419 | */ | ||
| 420 | |||
| 421 | int | ||
| 422 | ssh_remove_all_identities(AuthenticationConnection *auth) | ||
| 423 | { | ||
| 424 | unsigned char buf[5]; | ||
| 425 | |||
| 426 | /* Get the length of the message, and format it in the buffer. */ | ||
| 427 | PUT_32BIT(buf, 1); | ||
| 428 | buf[4] = SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES; | ||
| 429 | |||
| 430 | /* Send the length and then the packet to the agent. */ | ||
| 431 | if (atomicio(write, auth->fd, buf, 5) != 5) { | ||
| 432 | error("Error writing to authentication socket."); | ||
| 433 | return 0; | ||
| 434 | } | ||
| 435 | return ssh_agent_get_reply(auth); | ||
| 436 | } | ||
| 437 | |||
| 438 | /* | ||
| 439 | * Read for reply from agent. returns 1 for success, 0 on error | ||
| 440 | */ | ||
| 441 | |||
| 442 | int | ||
| 443 | ssh_agent_get_reply(AuthenticationConnection *auth) | ||
| 444 | { | ||
| 445 | Buffer buffer; | ||
| 446 | unsigned char buf[8192]; | ||
| 447 | int len, l, type; | ||
| 448 | |||
| 449 | /* | ||
| 450 | * Wait for response from the agent. First read the length of the | ||
| 451 | * response packet. | ||
| 452 | */ | ||
| 453 | len = 4; | ||
| 454 | while (len > 0) { | ||
| 455 | l = read(auth->fd, buf + 4 - len, len); | ||
| 456 | if (l <= 0) { | ||
| 457 | error("Error reading response length from authentication socket."); | ||
| 458 | buffer_free(&buffer); | ||
| 459 | return 0; | ||
| 460 | } | ||
| 461 | len -= l; | ||
| 462 | } | ||
| 463 | |||
| 464 | /* Extract the length, and check it for sanity. */ | ||
| 465 | len = GET_32BIT(buf); | ||
| 466 | if (len > 256 * 1024) | ||
| 467 | fatal("Response from agent too long: %d", len); | ||
| 468 | |||
| 469 | /* Read the rest of the response in to the buffer. */ | ||
| 470 | buffer_init(&buffer); | ||
| 471 | while (len > 0) { | ||
| 472 | l = len; | ||
| 473 | if (l > sizeof(buf)) | ||
| 474 | l = sizeof(buf); | ||
| 475 | l = read(auth->fd, buf, l); | ||
| 476 | if (l <= 0) { | ||
| 477 | error("Error reading response from authentication socket."); | ||
| 478 | buffer_free(&buffer); | ||
| 479 | return 0; | ||
| 480 | } | ||
| 481 | buffer_append(&buffer, (char *) buf, l); | ||
| 482 | len -= l; | ||
| 483 | } | ||
| 484 | |||
| 485 | /* Get the type of the packet. */ | ||
| 486 | type = buffer_get_char(&buffer); | ||
| 487 | buffer_free(&buffer); | ||
| 488 | switch (type) { | ||
| 489 | case SSH_AGENT_FAILURE: | ||
| 490 | return 0; | ||
| 491 | case SSH_AGENT_SUCCESS: | ||
| 492 | return 1; | ||
| 493 | default: | ||
| 494 | fatal("Bad response from authentication agent: %d", type); | ||
| 495 | } | ||
| 496 | /* NOTREACHED */ | ||
| 497 | return 0; | ||
| 498 | } | ||
