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f54651ce | 1 | /* $OpenBSD: ssh-agent.c,v 1.27 2000/04/12 09:39:10 markus Exp $ */ |
dae3fa13 | 2 | |
8efc0c15 | 3 | /* |
5260325f | 4 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
5 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
6 | * All rights reserved | |
7 | * Created: Wed Mar 29 03:46:59 1995 ylo | |
8 | * The authentication agent program. | |
9 | */ | |
8efc0c15 | 10 | |
11 | #include "includes.h" | |
f54651ce | 12 | RCSID("$OpenBSD: ssh-agent.c,v 1.27 2000/04/12 09:39:10 markus Exp $"); |
8efc0c15 | 13 | |
14 | #include "ssh.h" | |
15 | #include "rsa.h" | |
16 | #include "authfd.h" | |
17 | #include "buffer.h" | |
18 | #include "bufaux.h" | |
19 | #include "xmalloc.h" | |
20 | #include "packet.h" | |
21 | #include "getput.h" | |
22 | #include "mpaux.h" | |
23 | ||
5881cd60 | 24 | #ifdef HAVE_OPENSSL |
8efc0c15 | 25 | #include <openssl/md5.h> |
5881cd60 | 26 | #endif |
27 | #ifdef HAVE_SSL | |
28 | #include <ssl/md5.h> | |
29 | #endif | |
8efc0c15 | 30 | |
5260325f | 31 | typedef struct { |
32 | int fd; | |
33 | enum { | |
34 | AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION | |
35 | } type; | |
36 | Buffer input; | |
37 | Buffer output; | |
8efc0c15 | 38 | } SocketEntry; |
39 | ||
40 | unsigned int sockets_alloc = 0; | |
41 | SocketEntry *sockets = NULL; | |
42 | ||
5260325f | 43 | typedef struct { |
44 | RSA *key; | |
45 | char *comment; | |
8efc0c15 | 46 | } Identity; |
47 | ||
48 | unsigned int num_identities = 0; | |
49 | Identity *identities = NULL; | |
50 | ||
51 | int max_fd = 0; | |
52 | ||
53 | /* pid of shell == parent of agent */ | |
54 | int parent_pid = -1; | |
55 | ||
56 | /* pathname and directory for AUTH_SOCKET */ | |
57 | char socket_name[1024]; | |
58 | char socket_dir[1024]; | |
59 | ||
5260325f | 60 | #ifdef HAVE___PROGNAME |
61 | extern char *__progname; | |
62 | #else /* HAVE___PROGNAME */ | |
63 | const char *__progname = "ssh-agent"; | |
64 | #endif /* HAVE___PROGNAME */ | |
65 | ||
8efc0c15 | 66 | void |
67 | process_request_identity(SocketEntry *e) | |
68 | { | |
5260325f | 69 | Buffer msg; |
70 | int i; | |
71 | ||
72 | buffer_init(&msg); | |
73 | buffer_put_char(&msg, SSH_AGENT_RSA_IDENTITIES_ANSWER); | |
74 | buffer_put_int(&msg, num_identities); | |
75 | for (i = 0; i < num_identities; i++) { | |
76 | buffer_put_int(&msg, BN_num_bits(identities[i].key->n)); | |
77 | buffer_put_bignum(&msg, identities[i].key->e); | |
78 | buffer_put_bignum(&msg, identities[i].key->n); | |
79 | buffer_put_string(&msg, identities[i].comment, | |
80 | strlen(identities[i].comment)); | |
81 | } | |
82 | buffer_put_int(&e->output, buffer_len(&msg)); | |
83 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
84 | buffer_free(&msg); | |
8efc0c15 | 85 | } |
86 | ||
87 | void | |
88 | process_authentication_challenge(SocketEntry *e) | |
89 | { | |
5260325f | 90 | int i, pub_bits, len; |
91 | BIGNUM *pub_e, *pub_n, *challenge; | |
92 | Buffer msg; | |
93 | MD5_CTX md; | |
94 | unsigned char buf[32], mdbuf[16], session_id[16]; | |
95 | unsigned int response_type; | |
96 | ||
97 | buffer_init(&msg); | |
98 | pub_e = BN_new(); | |
99 | pub_n = BN_new(); | |
100 | challenge = BN_new(); | |
101 | pub_bits = buffer_get_int(&e->input); | |
102 | buffer_get_bignum(&e->input, pub_e); | |
103 | buffer_get_bignum(&e->input, pub_n); | |
104 | buffer_get_bignum(&e->input, challenge); | |
105 | if (buffer_len(&e->input) == 0) { | |
106 | /* Compatibility code for old servers. */ | |
107 | memset(session_id, 0, 16); | |
108 | response_type = 0; | |
109 | } else { | |
110 | /* New code. */ | |
111 | buffer_get(&e->input, (char *) session_id, 16); | |
112 | response_type = buffer_get_int(&e->input); | |
113 | } | |
114 | for (i = 0; i < num_identities; i++) | |
115 | if (pub_bits == BN_num_bits(identities[i].key->n) && | |
116 | BN_cmp(pub_e, identities[i].key->e) == 0 && | |
117 | BN_cmp(pub_n, identities[i].key->n) == 0) { | |
118 | /* Decrypt the challenge using the private key. */ | |
119 | rsa_private_decrypt(challenge, challenge, identities[i].key); | |
120 | ||
121 | /* Compute the desired response. */ | |
122 | switch (response_type) { | |
123 | case 0:/* As of protocol 1.0 */ | |
124 | /* This response type is no longer supported. */ | |
125 | log("Compatibility with ssh protocol 1.0 no longer supported."); | |
126 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
127 | goto send; | |
128 | ||
129 | case 1:/* As of protocol 1.1 */ | |
130 | /* The response is MD5 of decrypted challenge plus session id. */ | |
131 | len = BN_num_bytes(challenge); | |
132 | ||
133 | if (len <= 0 || len > 32) { | |
134 | fatal("process_authentication_challenge: " | |
135 | "bad challenge length %d", len); | |
136 | } | |
137 | memset(buf, 0, 32); | |
138 | BN_bn2bin(challenge, buf + 32 - len); | |
139 | MD5_Init(&md); | |
140 | MD5_Update(&md, buf, 32); | |
141 | MD5_Update(&md, session_id, 16); | |
142 | MD5_Final(mdbuf, &md); | |
143 | break; | |
144 | ||
145 | default: | |
146 | fatal("process_authentication_challenge: bad response_type %d", | |
147 | response_type); | |
148 | break; | |
149 | } | |
150 | ||
151 | /* Send the response. */ | |
152 | buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE); | |
153 | for (i = 0; i < 16; i++) | |
154 | buffer_put_char(&msg, mdbuf[i]); | |
155 | ||
156 | goto send; | |
157 | } | |
158 | /* Unknown identity. Send failure. */ | |
159 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
160 | send: | |
161 | buffer_put_int(&e->output, buffer_len(&msg)); | |
162 | buffer_append(&e->output, buffer_ptr(&msg), | |
163 | buffer_len(&msg)); | |
164 | buffer_free(&msg); | |
165 | BN_clear_free(pub_e); | |
166 | BN_clear_free(pub_n); | |
167 | BN_clear_free(challenge); | |
8efc0c15 | 168 | } |
169 | ||
170 | void | |
171 | process_remove_identity(SocketEntry *e) | |
172 | { | |
5260325f | 173 | unsigned int bits; |
174 | unsigned int i; | |
175 | BIGNUM *dummy, *n; | |
176 | ||
177 | dummy = BN_new(); | |
178 | n = BN_new(); | |
179 | ||
180 | /* Get the key from the packet. */ | |
181 | bits = buffer_get_int(&e->input); | |
182 | buffer_get_bignum(&e->input, dummy); | |
183 | buffer_get_bignum(&e->input, n); | |
184 | ||
185 | if (bits != BN_num_bits(n)) | |
89cafde6 | 186 | error("Warning: identity keysize mismatch: actual %d, announced %d", |
5260325f | 187 | BN_num_bits(n), bits); |
188 | ||
189 | /* Check if we have the key. */ | |
190 | for (i = 0; i < num_identities; i++) | |
191 | if (BN_cmp(identities[i].key->n, n) == 0) { | |
aa3378df | 192 | /* |
193 | * We have this key. Free the old key. Since we | |
194 | * don\'t want to leave empty slots in the middle of | |
195 | * the array, we actually free the key there and copy | |
196 | * data from the last entry. | |
197 | */ | |
5260325f | 198 | RSA_free(identities[i].key); |
199 | xfree(identities[i].comment); | |
200 | if (i < num_identities - 1) | |
201 | identities[i] = identities[num_identities - 1]; | |
202 | num_identities--; | |
203 | BN_clear_free(dummy); | |
204 | BN_clear_free(n); | |
205 | ||
206 | /* Send success. */ | |
207 | buffer_put_int(&e->output, 1); | |
208 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
209 | return; | |
210 | } | |
211 | /* We did not have the key. */ | |
212 | BN_clear(dummy); | |
213 | BN_clear(n); | |
214 | ||
215 | /* Send failure. */ | |
8efc0c15 | 216 | buffer_put_int(&e->output, 1); |
5260325f | 217 | buffer_put_char(&e->output, SSH_AGENT_FAILURE); |
8efc0c15 | 218 | } |
219 | ||
5260325f | 220 | /* |
221 | * Removes all identities from the agent. | |
222 | */ | |
8efc0c15 | 223 | void |
224 | process_remove_all_identities(SocketEntry *e) | |
225 | { | |
5260325f | 226 | unsigned int i; |
8efc0c15 | 227 | |
5260325f | 228 | /* Loop over all identities and clear the keys. */ |
229 | for (i = 0; i < num_identities; i++) { | |
230 | RSA_free(identities[i].key); | |
231 | xfree(identities[i].comment); | |
232 | } | |
8efc0c15 | 233 | |
5260325f | 234 | /* Mark that there are no identities. */ |
235 | num_identities = 0; | |
8efc0c15 | 236 | |
237 | /* Send success. */ | |
238 | buffer_put_int(&e->output, 1); | |
239 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
240 | return; | |
5260325f | 241 | } |
242 | ||
243 | /* | |
244 | * Adds an identity to the agent. | |
245 | */ | |
246 | void | |
247 | process_add_identity(SocketEntry *e) | |
248 | { | |
249 | RSA *k; | |
250 | int i; | |
251 | BIGNUM *aux; | |
252 | BN_CTX *ctx; | |
253 | ||
254 | if (num_identities == 0) | |
255 | identities = xmalloc(sizeof(Identity)); | |
256 | else | |
257 | identities = xrealloc(identities, (num_identities + 1) * sizeof(Identity)); | |
258 | ||
259 | identities[num_identities].key = RSA_new(); | |
260 | k = identities[num_identities].key; | |
261 | buffer_get_int(&e->input); /* bits */ | |
262 | k->n = BN_new(); | |
263 | buffer_get_bignum(&e->input, k->n); | |
264 | k->e = BN_new(); | |
265 | buffer_get_bignum(&e->input, k->e); | |
266 | k->d = BN_new(); | |
267 | buffer_get_bignum(&e->input, k->d); | |
268 | k->iqmp = BN_new(); | |
269 | buffer_get_bignum(&e->input, k->iqmp); | |
270 | /* SSH and SSL have p and q swapped */ | |
271 | k->q = BN_new(); | |
272 | buffer_get_bignum(&e->input, k->q); /* p */ | |
273 | k->p = BN_new(); | |
274 | buffer_get_bignum(&e->input, k->p); /* q */ | |
275 | ||
276 | /* Generate additional parameters */ | |
277 | aux = BN_new(); | |
278 | ctx = BN_CTX_new(); | |
279 | ||
280 | BN_sub(aux, k->q, BN_value_one()); | |
281 | k->dmq1 = BN_new(); | |
282 | BN_mod(k->dmq1, k->d, aux, ctx); | |
283 | ||
284 | BN_sub(aux, k->p, BN_value_one()); | |
285 | k->dmp1 = BN_new(); | |
286 | BN_mod(k->dmp1, k->d, aux, ctx); | |
287 | ||
288 | BN_clear_free(aux); | |
289 | BN_CTX_free(ctx); | |
290 | ||
291 | identities[num_identities].comment = buffer_get_string(&e->input, NULL); | |
292 | ||
293 | /* Check if we already have the key. */ | |
294 | for (i = 0; i < num_identities; i++) | |
295 | if (BN_cmp(identities[i].key->n, k->n) == 0) { | |
aa3378df | 296 | /* |
297 | * We already have this key. Clear and free the new | |
298 | * data and return success. | |
299 | */ | |
5260325f | 300 | RSA_free(k); |
301 | xfree(identities[num_identities].comment); | |
302 | ||
303 | /* Send success. */ | |
304 | buffer_put_int(&e->output, 1); | |
305 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
306 | return; | |
307 | } | |
308 | /* Increment the number of identities. */ | |
309 | num_identities++; | |
310 | ||
311 | /* Send a success message. */ | |
312 | buffer_put_int(&e->output, 1); | |
313 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
8efc0c15 | 314 | } |
315 | ||
316 | void | |
317 | process_message(SocketEntry *e) | |
318 | { | |
5260325f | 319 | unsigned int msg_len; |
320 | unsigned int type; | |
321 | unsigned char *cp; | |
322 | if (buffer_len(&e->input) < 5) | |
323 | return; /* Incomplete message. */ | |
324 | cp = (unsigned char *) buffer_ptr(&e->input); | |
325 | msg_len = GET_32BIT(cp); | |
326 | if (msg_len > 256 * 1024) { | |
327 | shutdown(e->fd, SHUT_RDWR); | |
328 | close(e->fd); | |
329 | e->type = AUTH_UNUSED; | |
330 | return; | |
331 | } | |
332 | if (buffer_len(&e->input) < msg_len + 4) | |
333 | return; | |
334 | buffer_consume(&e->input, 4); | |
335 | type = buffer_get_char(&e->input); | |
336 | ||
337 | switch (type) { | |
338 | case SSH_AGENTC_REQUEST_RSA_IDENTITIES: | |
339 | process_request_identity(e); | |
340 | break; | |
341 | case SSH_AGENTC_RSA_CHALLENGE: | |
342 | process_authentication_challenge(e); | |
343 | break; | |
344 | case SSH_AGENTC_ADD_RSA_IDENTITY: | |
345 | process_add_identity(e); | |
346 | break; | |
347 | case SSH_AGENTC_REMOVE_RSA_IDENTITY: | |
348 | process_remove_identity(e); | |
349 | break; | |
350 | case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: | |
351 | process_remove_all_identities(e); | |
352 | break; | |
353 | default: | |
354 | /* Unknown message. Respond with failure. */ | |
355 | error("Unknown message %d", type); | |
356 | buffer_clear(&e->input); | |
357 | buffer_put_int(&e->output, 1); | |
358 | buffer_put_char(&e->output, SSH_AGENT_FAILURE); | |
359 | break; | |
360 | } | |
8efc0c15 | 361 | } |
362 | ||
363 | void | |
364 | new_socket(int type, int fd) | |
365 | { | |
5260325f | 366 | unsigned int i, old_alloc; |
367 | if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) | |
368 | error("fcntl O_NONBLOCK: %s", strerror(errno)); | |
369 | ||
370 | if (fd > max_fd) | |
371 | max_fd = fd; | |
372 | ||
373 | for (i = 0; i < sockets_alloc; i++) | |
374 | if (sockets[i].type == AUTH_UNUSED) { | |
375 | sockets[i].fd = fd; | |
376 | sockets[i].type = type; | |
377 | buffer_init(&sockets[i].input); | |
378 | buffer_init(&sockets[i].output); | |
379 | return; | |
380 | } | |
381 | old_alloc = sockets_alloc; | |
382 | sockets_alloc += 10; | |
383 | if (sockets) | |
384 | sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0])); | |
385 | else | |
386 | sockets = xmalloc(sockets_alloc * sizeof(sockets[0])); | |
387 | for (i = old_alloc; i < sockets_alloc; i++) | |
388 | sockets[i].type = AUTH_UNUSED; | |
389 | sockets[old_alloc].type = type; | |
390 | sockets[old_alloc].fd = fd; | |
391 | buffer_init(&sockets[old_alloc].input); | |
392 | buffer_init(&sockets[old_alloc].output); | |
8efc0c15 | 393 | } |
394 | ||
395 | void | |
396 | prepare_select(fd_set *readset, fd_set *writeset) | |
397 | { | |
5260325f | 398 | unsigned int i; |
399 | for (i = 0; i < sockets_alloc; i++) | |
400 | switch (sockets[i].type) { | |
401 | case AUTH_SOCKET: | |
402 | case AUTH_CONNECTION: | |
403 | FD_SET(sockets[i].fd, readset); | |
404 | if (buffer_len(&sockets[i].output) > 0) | |
405 | FD_SET(sockets[i].fd, writeset); | |
406 | break; | |
407 | case AUTH_UNUSED: | |
408 | break; | |
409 | default: | |
410 | fatal("Unknown socket type %d", sockets[i].type); | |
411 | break; | |
412 | } | |
8efc0c15 | 413 | } |
414 | ||
5260325f | 415 | void |
416 | after_select(fd_set *readset, fd_set *writeset) | |
8efc0c15 | 417 | { |
5260325f | 418 | unsigned int i; |
419 | int len, sock; | |
610cd5c6 | 420 | socklen_t slen; |
5260325f | 421 | char buf[1024]; |
422 | struct sockaddr_un sunaddr; | |
423 | ||
424 | for (i = 0; i < sockets_alloc; i++) | |
425 | switch (sockets[i].type) { | |
426 | case AUTH_UNUSED: | |
427 | break; | |
428 | case AUTH_SOCKET: | |
429 | if (FD_ISSET(sockets[i].fd, readset)) { | |
610cd5c6 | 430 | slen = sizeof(sunaddr); |
431 | sock = accept(sockets[i].fd, (struct sockaddr *) & sunaddr, &slen); | |
5260325f | 432 | if (sock < 0) { |
433 | perror("accept from AUTH_SOCKET"); | |
434 | break; | |
435 | } | |
436 | new_socket(AUTH_CONNECTION, sock); | |
437 | } | |
438 | break; | |
439 | case AUTH_CONNECTION: | |
440 | if (buffer_len(&sockets[i].output) > 0 && | |
441 | FD_ISSET(sockets[i].fd, writeset)) { | |
442 | len = write(sockets[i].fd, buffer_ptr(&sockets[i].output), | |
443 | buffer_len(&sockets[i].output)); | |
444 | if (len <= 0) { | |
445 | shutdown(sockets[i].fd, SHUT_RDWR); | |
446 | close(sockets[i].fd); | |
447 | sockets[i].type = AUTH_UNUSED; | |
448 | break; | |
449 | } | |
450 | buffer_consume(&sockets[i].output, len); | |
451 | } | |
452 | if (FD_ISSET(sockets[i].fd, readset)) { | |
453 | len = read(sockets[i].fd, buf, sizeof(buf)); | |
454 | if (len <= 0) { | |
455 | shutdown(sockets[i].fd, SHUT_RDWR); | |
456 | close(sockets[i].fd); | |
457 | sockets[i].type = AUTH_UNUSED; | |
458 | break; | |
459 | } | |
460 | buffer_append(&sockets[i].input, buf, len); | |
461 | process_message(&sockets[i]); | |
462 | } | |
463 | break; | |
464 | default: | |
465 | fatal("Unknown type %d", sockets[i].type); | |
466 | } | |
8efc0c15 | 467 | } |
468 | ||
469 | void | |
470 | check_parent_exists(int sig) | |
471 | { | |
5260325f | 472 | if (kill(parent_pid, 0) < 0) { |
473 | /* printf("Parent has died - Authentication agent exiting.\n"); */ | |
474 | exit(1); | |
475 | } | |
476 | signal(SIGALRM, check_parent_exists); | |
477 | alarm(10); | |
8efc0c15 | 478 | } |
479 | ||
dae3fa13 | 480 | void |
481 | cleanup_socket(void) | |
482 | { | |
5260325f | 483 | remove(socket_name); |
484 | rmdir(socket_dir); | |
8efc0c15 | 485 | } |
486 | ||
dae3fa13 | 487 | void |
488 | cleanup_exit(int i) | |
489 | { | |
5260325f | 490 | cleanup_socket(); |
491 | exit(i); | |
dae3fa13 | 492 | } |
493 | ||
494 | void | |
495 | usage() | |
496 | { | |
5260325f | 497 | fprintf(stderr, "ssh-agent version %s\n", SSH_VERSION); |
498 | fprintf(stderr, "Usage: %s [-c | -s] [-k] [command {args...]]\n", | |
499 | __progname); | |
500 | exit(1); | |
dae3fa13 | 501 | } |
502 | ||
8efc0c15 | 503 | int |
504 | main(int ac, char **av) | |
505 | { | |
5260325f | 506 | fd_set readset, writeset; |
507 | int sock, c_flag = 0, k_flag = 0, s_flag = 0, ch; | |
508 | struct sockaddr_un sunaddr; | |
509 | pid_t pid; | |
510 | char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid]; | |
511 | ||
512 | /* check if RSA support exists */ | |
513 | if (rsa_alive() == 0) { | |
514 | fprintf(stderr, | |
515 | "%s: no RSA support in libssl and libcrypto. See ssl(8).\n", | |
516 | __progname); | |
517 | exit(1); | |
518 | } | |
5260325f | 519 | while ((ch = getopt(ac, av, "cks")) != -1) { |
5260325f | 520 | switch (ch) { |
521 | case 'c': | |
522 | if (s_flag) | |
523 | usage(); | |
524 | c_flag++; | |
525 | break; | |
526 | case 'k': | |
527 | k_flag++; | |
528 | break; | |
529 | case 's': | |
530 | if (c_flag) | |
531 | usage(); | |
532 | s_flag++; | |
533 | break; | |
534 | default: | |
535 | usage(); | |
536 | } | |
dae3fa13 | 537 | } |
5260325f | 538 | ac -= optind; |
539 | av += optind; | |
540 | ||
541 | if (ac > 0 && (c_flag || k_flag || s_flag)) | |
542 | usage(); | |
543 | ||
544 | if (ac == 0 && !c_flag && !k_flag && !s_flag) { | |
545 | shell = getenv("SHELL"); | |
546 | if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0) | |
547 | c_flag = 1; | |
dae3fa13 | 548 | } |
5260325f | 549 | if (k_flag) { |
550 | pidstr = getenv(SSH_AGENTPID_ENV_NAME); | |
551 | if (pidstr == NULL) { | |
552 | fprintf(stderr, "%s not set, cannot kill agent\n", | |
553 | SSH_AGENTPID_ENV_NAME); | |
554 | exit(1); | |
555 | } | |
556 | pid = atoi(pidstr); | |
557 | if (pid < 1) { /* XXX PID_MAX check too */ | |
558 | fprintf(stderr, "%s=\"%s\", which is not a good PID\n", | |
559 | SSH_AGENTPID_ENV_NAME, pidstr); | |
560 | exit(1); | |
561 | } | |
562 | if (kill(pid, SIGTERM) == -1) { | |
563 | perror("kill"); | |
564 | exit(1); | |
565 | } | |
566 | format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; | |
567 | printf(format, SSH_AUTHSOCKET_ENV_NAME); | |
568 | printf(format, SSH_AGENTPID_ENV_NAME); | |
569 | printf("echo Agent pid %d killed;\n", pid); | |
570 | exit(0); | |
dae3fa13 | 571 | } |
5260325f | 572 | parent_pid = getpid(); |
573 | ||
574 | /* Create private directory for agent socket */ | |
575 | strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir); | |
576 | if (mkdtemp(socket_dir) == NULL) { | |
577 | perror("mkdtemp: private socket dir"); | |
578 | exit(1); | |
579 | } | |
580 | snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir, | |
581 | parent_pid); | |
582 | ||
aa3378df | 583 | /* |
584 | * Create socket early so it will exist before command gets run from | |
585 | * the parent. | |
586 | */ | |
5260325f | 587 | sock = socket(AF_UNIX, SOCK_STREAM, 0); |
588 | if (sock < 0) { | |
589 | perror("socket"); | |
590 | cleanup_exit(1); | |
591 | } | |
592 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
593 | sunaddr.sun_family = AF_UNIX; | |
594 | strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path)); | |
595 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { | |
596 | perror("bind"); | |
597 | cleanup_exit(1); | |
598 | } | |
599 | if (listen(sock, 5) < 0) { | |
600 | perror("listen"); | |
601 | cleanup_exit(1); | |
dae3fa13 | 602 | } |
aa3378df | 603 | /* |
604 | * Fork, and have the parent execute the command, if any, or present | |
605 | * the socket data. The child continues as the authentication agent. | |
606 | */ | |
5260325f | 607 | pid = fork(); |
608 | if (pid == -1) { | |
609 | perror("fork"); | |
610 | exit(1); | |
dae3fa13 | 611 | } |
5260325f | 612 | if (pid != 0) { /* Parent - execute the given command. */ |
613 | close(sock); | |
614 | snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid); | |
615 | if (ac == 0) { | |
616 | format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; | |
617 | printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, | |
618 | SSH_AUTHSOCKET_ENV_NAME); | |
619 | printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, | |
620 | SSH_AGENTPID_ENV_NAME); | |
621 | printf("echo Agent pid %d;\n", pid); | |
622 | exit(0); | |
623 | } | |
624 | setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1); | |
625 | setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1); | |
626 | execvp(av[0], av); | |
627 | perror(av[0]); | |
628 | exit(1); | |
629 | } | |
630 | close(0); | |
631 | close(1); | |
632 | close(2); | |
dae3fa13 | 633 | |
5260325f | 634 | if (setsid() == -1) { |
635 | perror("setsid"); | |
636 | cleanup_exit(1); | |
637 | } | |
638 | if (atexit(cleanup_socket) < 0) { | |
639 | perror("atexit"); | |
640 | cleanup_exit(1); | |
641 | } | |
642 | new_socket(AUTH_SOCKET, sock); | |
643 | if (ac > 0) { | |
644 | signal(SIGALRM, check_parent_exists); | |
645 | alarm(10); | |
646 | } | |
647 | signal(SIGINT, SIG_IGN); | |
648 | signal(SIGPIPE, SIG_IGN); | |
e02735bb | 649 | signal(SIGHUP, cleanup_exit); |
650 | signal(SIGTERM, cleanup_exit); | |
5260325f | 651 | while (1) { |
652 | FD_ZERO(&readset); | |
653 | FD_ZERO(&writeset); | |
654 | prepare_select(&readset, &writeset); | |
655 | if (select(max_fd + 1, &readset, &writeset, NULL, NULL) < 0) { | |
656 | if (errno == EINTR) | |
657 | continue; | |
658 | exit(1); | |
659 | } | |
660 | after_select(&readset, &writeset); | |
8efc0c15 | 661 | } |
5260325f | 662 | /* NOTREACHED */ |
8efc0c15 | 663 | } |