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188adeb2 | 1 | /* $OpenBSD: ssh-agent.c,v 1.37 2000/09/21 11:07:51 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 | |
5260325f | 7 | * The authentication agent program. |
2e73a022 | 8 | * |
bcbf86ec | 9 | * As far as I am concerned, the code I have written for this software |
10 | * can be used freely for any purpose. Any derived versions of this | |
11 | * software must be clearly marked as such, and if the derived work is | |
12 | * incompatible with the protocol description in the RFC file, it must be | |
13 | * called by a name other than "ssh" or "Secure Shell". | |
14 | * | |
2e73a022 | 15 | * SSH2 implementation, |
16 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
bcbf86ec | 17 | * |
18 | * Redistribution and use in source and binary forms, with or without | |
19 | * modification, are permitted provided that the following conditions | |
20 | * are met: | |
21 | * 1. Redistributions of source code must retain the above copyright | |
22 | * notice, this list of conditions and the following disclaimer. | |
23 | * 2. Redistributions in binary form must reproduce the above copyright | |
24 | * notice, this list of conditions and the following disclaimer in the | |
25 | * documentation and/or other materials provided with the distribution. | |
26 | * | |
27 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
28 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
29 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
30 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
31 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
32 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
33 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
34 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
35 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
36 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 37 | */ |
8efc0c15 | 38 | |
39 | #include "includes.h" | |
188adeb2 | 40 | RCSID("$OpenBSD: ssh-agent.c,v 1.37 2000/09/21 11:07:51 markus Exp $"); |
8efc0c15 | 41 | |
42 | #include "ssh.h" | |
43 | #include "rsa.h" | |
8efc0c15 | 44 | #include "buffer.h" |
45 | #include "bufaux.h" | |
46 | #include "xmalloc.h" | |
47 | #include "packet.h" | |
48 | #include "getput.h" | |
49 | #include "mpaux.h" | |
50 | ||
2e73a022 | 51 | #include <openssl/evp.h> |
8efc0c15 | 52 | #include <openssl/md5.h> |
4c8722d9 | 53 | #include <openssl/dsa.h> |
54 | #include <openssl/rsa.h> | |
55 | #include "key.h" | |
56 | #include "authfd.h" | |
2e73a022 | 57 | #include "dsa.h" |
58 | #include "kex.h" | |
188adeb2 | 59 | #include "compat.h" |
8efc0c15 | 60 | |
5260325f | 61 | typedef struct { |
62 | int fd; | |
63 | enum { | |
64 | AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION | |
65 | } type; | |
66 | Buffer input; | |
67 | Buffer output; | |
8efc0c15 | 68 | } SocketEntry; |
69 | ||
70 | unsigned int sockets_alloc = 0; | |
71 | SocketEntry *sockets = NULL; | |
72 | ||
5260325f | 73 | typedef struct { |
2e73a022 | 74 | Key *key; |
5260325f | 75 | char *comment; |
8efc0c15 | 76 | } Identity; |
77 | ||
2e73a022 | 78 | typedef struct { |
79 | int nentries; | |
80 | Identity *identities; | |
81 | } Idtab; | |
82 | ||
83 | /* private key table, one per protocol version */ | |
84 | Idtab idtable[3]; | |
8efc0c15 | 85 | |
86 | int max_fd = 0; | |
87 | ||
88 | /* pid of shell == parent of agent */ | |
9da5c3c9 | 89 | pid_t parent_pid = -1; |
8efc0c15 | 90 | |
91 | /* pathname and directory for AUTH_SOCKET */ | |
92 | char socket_name[1024]; | |
93 | char socket_dir[1024]; | |
94 | ||
5260325f | 95 | #ifdef HAVE___PROGNAME |
96 | extern char *__progname; | |
97 | #else /* HAVE___PROGNAME */ | |
3fd95d9a | 98 | static const char *__progname = "ssh-agent"; |
5260325f | 99 | #endif /* HAVE___PROGNAME */ |
100 | ||
8efc0c15 | 101 | void |
2e73a022 | 102 | idtab_init(void) |
103 | { | |
104 | int i; | |
105 | for (i = 0; i <=2; i++){ | |
106 | idtable[i].identities = NULL; | |
107 | idtable[i].nentries = 0; | |
108 | } | |
109 | } | |
110 | ||
111 | /* return private key table for requested protocol version */ | |
112 | Idtab * | |
113 | idtab_lookup(int version) | |
114 | { | |
115 | if (version < 1 || version > 2) | |
116 | fatal("internal error, bad protocol version %d", version); | |
117 | return &idtable[version]; | |
118 | } | |
119 | ||
120 | /* return matching private key for given public key */ | |
121 | Key * | |
122 | lookup_private_key(Key *key, int *idx, int version) | |
123 | { | |
124 | int i; | |
125 | Idtab *tab = idtab_lookup(version); | |
126 | for (i = 0; i < tab->nentries; i++) { | |
127 | if (key_equal(key, tab->identities[i].key)) { | |
128 | if (idx != NULL) | |
129 | *idx = i; | |
130 | return tab->identities[i].key; | |
131 | } | |
132 | } | |
133 | return NULL; | |
134 | } | |
135 | ||
136 | /* send list of supported public keys to 'client' */ | |
137 | void | |
138 | process_request_identities(SocketEntry *e, int version) | |
8efc0c15 | 139 | { |
2e73a022 | 140 | Idtab *tab = idtab_lookup(version); |
5260325f | 141 | Buffer msg; |
142 | int i; | |
143 | ||
144 | buffer_init(&msg); | |
2e73a022 | 145 | buffer_put_char(&msg, (version == 1) ? |
146 | SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER); | |
147 | buffer_put_int(&msg, tab->nentries); | |
148 | for (i = 0; i < tab->nentries; i++) { | |
149 | Identity *id = &tab->identities[i]; | |
150 | if (id->key->type == KEY_RSA) { | |
151 | buffer_put_int(&msg, BN_num_bits(id->key->rsa->n)); | |
152 | buffer_put_bignum(&msg, id->key->rsa->e); | |
153 | buffer_put_bignum(&msg, id->key->rsa->n); | |
154 | } else { | |
155 | unsigned char *blob; | |
156 | unsigned int blen; | |
157 | dsa_make_key_blob(id->key, &blob, &blen); | |
158 | buffer_put_string(&msg, blob, blen); | |
159 | xfree(blob); | |
160 | } | |
161 | buffer_put_cstring(&msg, id->comment); | |
5260325f | 162 | } |
163 | buffer_put_int(&e->output, buffer_len(&msg)); | |
164 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
165 | buffer_free(&msg); | |
8efc0c15 | 166 | } |
167 | ||
2e73a022 | 168 | /* ssh1 only */ |
8efc0c15 | 169 | void |
2e73a022 | 170 | process_authentication_challenge1(SocketEntry *e) |
8efc0c15 | 171 | { |
2e73a022 | 172 | Key *key, *private; |
173 | BIGNUM *challenge; | |
174 | int i, len; | |
5260325f | 175 | Buffer msg; |
176 | MD5_CTX md; | |
177 | unsigned char buf[32], mdbuf[16], session_id[16]; | |
178 | unsigned int response_type; | |
179 | ||
180 | buffer_init(&msg); | |
2e73a022 | 181 | key = key_new(KEY_RSA); |
5260325f | 182 | challenge = BN_new(); |
5260325f | 183 | |
2e73a022 | 184 | buffer_get_int(&e->input); /* ignored */ |
185 | buffer_get_bignum(&e->input, key->rsa->e); | |
186 | buffer_get_bignum(&e->input, key->rsa->n); | |
187 | buffer_get_bignum(&e->input, challenge); | |
5260325f | 188 | |
2e73a022 | 189 | /* Only protocol 1.1 is supported */ |
190 | if (buffer_len(&e->input) == 0) | |
191 | goto failure; | |
192 | buffer_get(&e->input, (char *) session_id, 16); | |
193 | response_type = buffer_get_int(&e->input); | |
194 | if (response_type != 1) | |
195 | goto failure; | |
196 | ||
197 | private = lookup_private_key(key, NULL, 1); | |
198 | if (private != NULL) { | |
199 | /* Decrypt the challenge using the private key. */ | |
200 | rsa_private_decrypt(challenge, challenge, private->rsa); | |
201 | ||
202 | /* The response is MD5 of decrypted challenge plus session id. */ | |
203 | len = BN_num_bytes(challenge); | |
204 | if (len <= 0 || len > 32) { | |
205 | log("process_authentication_challenge: bad challenge length %d", len); | |
206 | goto failure; | |
5260325f | 207 | } |
2e73a022 | 208 | memset(buf, 0, 32); |
209 | BN_bn2bin(challenge, buf + 32 - len); | |
210 | MD5_Init(&md); | |
211 | MD5_Update(&md, buf, 32); | |
212 | MD5_Update(&md, session_id, 16); | |
213 | MD5_Final(mdbuf, &md); | |
214 | ||
215 | /* Send the response. */ | |
216 | buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE); | |
217 | for (i = 0; i < 16; i++) | |
218 | buffer_put_char(&msg, mdbuf[i]); | |
219 | goto send; | |
220 | } | |
221 | ||
222 | failure: | |
223 | /* Unknown identity or protocol error. Send failure. */ | |
5260325f | 224 | buffer_put_char(&msg, SSH_AGENT_FAILURE); |
225 | send: | |
2e73a022 | 226 | buffer_put_int(&e->output, buffer_len(&msg)); |
227 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
228 | key_free(key); | |
229 | BN_clear_free(challenge); | |
230 | buffer_free(&msg); | |
231 | } | |
232 | ||
233 | /* ssh2 only */ | |
234 | void | |
235 | process_sign_request2(SocketEntry *e) | |
236 | { | |
237 | extern int datafellows; | |
238 | Key *key, *private; | |
239 | unsigned char *blob, *data, *signature = NULL; | |
240 | unsigned int blen, dlen, slen = 0; | |
188adeb2 | 241 | int flags; |
2e73a022 | 242 | Buffer msg; |
243 | int ok = -1; | |
244 | ||
245 | datafellows = 0; | |
246 | ||
247 | blob = buffer_get_string(&e->input, &blen); | |
248 | data = buffer_get_string(&e->input, &dlen); | |
188adeb2 | 249 | |
250 | flags = buffer_get_int(&e->input); | |
251 | if (flags & SSH_AGENT_OLD_SIGNATURE) | |
252 | datafellows = SSH_BUG_SIGBLOB; | |
2e73a022 | 253 | |
254 | key = dsa_key_from_blob(blob, blen); | |
255 | if (key != NULL) { | |
256 | private = lookup_private_key(key, NULL, 2); | |
257 | if (private != NULL) | |
258 | ok = dsa_sign(private, &signature, &slen, data, dlen); | |
259 | } | |
260 | key_free(key); | |
261 | buffer_init(&msg); | |
262 | if (ok == 0) { | |
263 | buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE); | |
264 | buffer_put_string(&msg, signature, slen); | |
265 | } else { | |
266 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
267 | } | |
5260325f | 268 | buffer_put_int(&e->output, buffer_len(&msg)); |
269 | buffer_append(&e->output, buffer_ptr(&msg), | |
2e73a022 | 270 | buffer_len(&msg)); |
5260325f | 271 | buffer_free(&msg); |
2e73a022 | 272 | xfree(data); |
273 | xfree(blob); | |
274 | if (signature != NULL) | |
275 | xfree(signature); | |
8efc0c15 | 276 | } |
277 | ||
2e73a022 | 278 | /* shared */ |
8efc0c15 | 279 | void |
2e73a022 | 280 | process_remove_identity(SocketEntry *e, int version) |
8efc0c15 | 281 | { |
2e73a022 | 282 | Key *key = NULL, *private; |
283 | unsigned char *blob; | |
284 | unsigned int blen; | |
5260325f | 285 | unsigned int bits; |
2e73a022 | 286 | int success = 0; |
287 | ||
288 | switch(version){ | |
289 | case 1: | |
290 | key = key_new(KEY_RSA); | |
291 | bits = buffer_get_int(&e->input); | |
292 | buffer_get_bignum(&e->input, key->rsa->e); | |
293 | buffer_get_bignum(&e->input, key->rsa->n); | |
294 | ||
295 | if (bits != key_size(key)) | |
296 | log("Warning: identity keysize mismatch: actual %d, announced %d", | |
297 | key_size(key), bits); | |
298 | break; | |
299 | case 2: | |
300 | blob = buffer_get_string(&e->input, &blen); | |
301 | key = dsa_key_from_blob(blob, blen); | |
302 | xfree(blob); | |
303 | break; | |
304 | } | |
305 | if (key != NULL) { | |
306 | int idx; | |
307 | private = lookup_private_key(key, &idx, version); | |
308 | if (private != NULL) { | |
aa3378df | 309 | /* |
310 | * We have this key. Free the old key. Since we | |
311 | * don\'t want to leave empty slots in the middle of | |
312 | * the array, we actually free the key there and copy | |
313 | * data from the last entry. | |
314 | */ | |
2e73a022 | 315 | Idtab *tab = idtab_lookup(version); |
316 | key_free(tab->identities[idx].key); | |
317 | xfree(tab->identities[idx].comment); | |
318 | if (idx != tab->nentries) | |
319 | tab->identities[idx] = tab->identities[tab->nentries]; | |
320 | tab->nentries--; | |
321 | success = 1; | |
5260325f | 322 | } |
2e73a022 | 323 | key_free(key); |
324 | } | |
8efc0c15 | 325 | buffer_put_int(&e->output, 1); |
2e73a022 | 326 | buffer_put_char(&e->output, |
327 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
8efc0c15 | 328 | } |
329 | ||
8efc0c15 | 330 | void |
2e73a022 | 331 | process_remove_all_identities(SocketEntry *e, int version) |
8efc0c15 | 332 | { |
5260325f | 333 | unsigned int i; |
2e73a022 | 334 | Idtab *tab = idtab_lookup(version); |
8efc0c15 | 335 | |
5260325f | 336 | /* Loop over all identities and clear the keys. */ |
2e73a022 | 337 | for (i = 0; i < tab->nentries; i++) { |
338 | key_free(tab->identities[i].key); | |
339 | xfree(tab->identities[i].comment); | |
5260325f | 340 | } |
8efc0c15 | 341 | |
5260325f | 342 | /* Mark that there are no identities. */ |
2e73a022 | 343 | tab->nentries = 0; |
8efc0c15 | 344 | |
345 | /* Send success. */ | |
346 | buffer_put_int(&e->output, 1); | |
347 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
348 | return; | |
5260325f | 349 | } |
350 | ||
5260325f | 351 | void |
2e73a022 | 352 | process_add_identity(SocketEntry *e, int version) |
5260325f | 353 | { |
2e73a022 | 354 | Key *k = NULL; |
355 | RSA *rsa; | |
5260325f | 356 | BIGNUM *aux; |
357 | BN_CTX *ctx; | |
2e73a022 | 358 | char *type; |
359 | char *comment; | |
360 | int success = 0; | |
361 | Idtab *tab = idtab_lookup(version); | |
5260325f | 362 | |
2e73a022 | 363 | switch (version) { |
364 | case 1: | |
365 | k = key_new(KEY_RSA); | |
366 | rsa = k->rsa; | |
5260325f | 367 | |
2e73a022 | 368 | /* allocate mem for private key */ |
369 | /* XXX rsa->n and rsa->e are already allocated */ | |
370 | rsa->d = BN_new(); | |
371 | rsa->iqmp = BN_new(); | |
372 | rsa->q = BN_new(); | |
373 | rsa->p = BN_new(); | |
374 | rsa->dmq1 = BN_new(); | |
375 | rsa->dmp1 = BN_new(); | |
376 | ||
377 | buffer_get_int(&e->input); /* ignored */ | |
378 | ||
379 | buffer_get_bignum(&e->input, rsa->n); | |
380 | buffer_get_bignum(&e->input, rsa->e); | |
381 | buffer_get_bignum(&e->input, rsa->d); | |
382 | buffer_get_bignum(&e->input, rsa->iqmp); | |
383 | ||
384 | /* SSH and SSL have p and q swapped */ | |
385 | buffer_get_bignum(&e->input, rsa->q); /* p */ | |
386 | buffer_get_bignum(&e->input, rsa->p); /* q */ | |
387 | ||
388 | /* Generate additional parameters */ | |
389 | aux = BN_new(); | |
390 | ctx = BN_CTX_new(); | |
391 | ||
392 | BN_sub(aux, rsa->q, BN_value_one()); | |
393 | BN_mod(rsa->dmq1, rsa->d, aux, ctx); | |
394 | ||
395 | BN_sub(aux, rsa->p, BN_value_one()); | |
396 | BN_mod(rsa->dmp1, rsa->d, aux, ctx); | |
397 | ||
398 | BN_clear_free(aux); | |
399 | BN_CTX_free(ctx); | |
400 | ||
401 | break; | |
402 | case 2: | |
403 | type = buffer_get_string(&e->input, NULL); | |
404 | if (strcmp(type, KEX_DSS)) { | |
405 | buffer_clear(&e->input); | |
406 | xfree(type); | |
407 | goto send; | |
5260325f | 408 | } |
2e73a022 | 409 | xfree(type); |
5260325f | 410 | |
2e73a022 | 411 | k = key_new(KEY_DSA); |
412 | ||
413 | /* allocate mem for private key */ | |
414 | k->dsa->priv_key = BN_new(); | |
415 | ||
416 | buffer_get_bignum2(&e->input, k->dsa->p); | |
417 | buffer_get_bignum2(&e->input, k->dsa->q); | |
418 | buffer_get_bignum2(&e->input, k->dsa->g); | |
419 | buffer_get_bignum2(&e->input, k->dsa->pub_key); | |
420 | buffer_get_bignum2(&e->input, k->dsa->priv_key); | |
421 | ||
422 | break; | |
423 | } | |
424 | ||
425 | comment = buffer_get_string(&e->input, NULL); | |
426 | if (k == NULL) { | |
427 | xfree(comment); | |
428 | goto send; | |
429 | } | |
430 | success = 1; | |
431 | if (lookup_private_key(k, NULL, version) == NULL) { | |
432 | if (tab->nentries == 0) | |
433 | tab->identities = xmalloc(sizeof(Identity)); | |
434 | else | |
435 | tab->identities = xrealloc(tab->identities, | |
436 | (tab->nentries + 1) * sizeof(Identity)); | |
437 | tab->identities[tab->nentries].key = k; | |
438 | tab->identities[tab->nentries].comment = comment; | |
439 | /* Increment the number of identities. */ | |
440 | tab->nentries++; | |
441 | } else { | |
442 | key_free(k); | |
443 | xfree(comment); | |
444 | } | |
445 | send: | |
5260325f | 446 | buffer_put_int(&e->output, 1); |
2e73a022 | 447 | buffer_put_char(&e->output, |
448 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
8efc0c15 | 449 | } |
450 | ||
2e73a022 | 451 | /* dispatch incoming messages */ |
452 | ||
8efc0c15 | 453 | void |
454 | process_message(SocketEntry *e) | |
455 | { | |
5260325f | 456 | unsigned int msg_len; |
457 | unsigned int type; | |
458 | unsigned char *cp; | |
459 | if (buffer_len(&e->input) < 5) | |
460 | return; /* Incomplete message. */ | |
461 | cp = (unsigned char *) buffer_ptr(&e->input); | |
462 | msg_len = GET_32BIT(cp); | |
463 | if (msg_len > 256 * 1024) { | |
464 | shutdown(e->fd, SHUT_RDWR); | |
465 | close(e->fd); | |
466 | e->type = AUTH_UNUSED; | |
467 | return; | |
468 | } | |
469 | if (buffer_len(&e->input) < msg_len + 4) | |
470 | return; | |
471 | buffer_consume(&e->input, 4); | |
472 | type = buffer_get_char(&e->input); | |
473 | ||
474 | switch (type) { | |
2e73a022 | 475 | /* ssh1 */ |
5260325f | 476 | case SSH_AGENTC_RSA_CHALLENGE: |
2e73a022 | 477 | process_authentication_challenge1(e); |
478 | break; | |
479 | case SSH_AGENTC_REQUEST_RSA_IDENTITIES: | |
480 | process_request_identities(e, 1); | |
5260325f | 481 | break; |
482 | case SSH_AGENTC_ADD_RSA_IDENTITY: | |
2e73a022 | 483 | process_add_identity(e, 1); |
5260325f | 484 | break; |
485 | case SSH_AGENTC_REMOVE_RSA_IDENTITY: | |
2e73a022 | 486 | process_remove_identity(e, 1); |
5260325f | 487 | break; |
488 | case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: | |
2e73a022 | 489 | process_remove_all_identities(e, 1); |
490 | break; | |
491 | /* ssh2 */ | |
492 | case SSH2_AGENTC_SIGN_REQUEST: | |
493 | process_sign_request2(e); | |
494 | break; | |
495 | case SSH2_AGENTC_REQUEST_IDENTITIES: | |
496 | process_request_identities(e, 2); | |
497 | break; | |
498 | case SSH2_AGENTC_ADD_IDENTITY: | |
499 | process_add_identity(e, 2); | |
500 | break; | |
501 | case SSH2_AGENTC_REMOVE_IDENTITY: | |
502 | process_remove_identity(e, 2); | |
503 | break; | |
504 | case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: | |
505 | process_remove_all_identities(e, 2); | |
5260325f | 506 | break; |
507 | default: | |
508 | /* Unknown message. Respond with failure. */ | |
509 | error("Unknown message %d", type); | |
510 | buffer_clear(&e->input); | |
511 | buffer_put_int(&e->output, 1); | |
512 | buffer_put_char(&e->output, SSH_AGENT_FAILURE); | |
513 | break; | |
514 | } | |
8efc0c15 | 515 | } |
516 | ||
517 | void | |
518 | new_socket(int type, int fd) | |
519 | { | |
5260325f | 520 | unsigned int i, old_alloc; |
521 | if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) | |
522 | error("fcntl O_NONBLOCK: %s", strerror(errno)); | |
523 | ||
524 | if (fd > max_fd) | |
525 | max_fd = fd; | |
526 | ||
527 | for (i = 0; i < sockets_alloc; i++) | |
528 | if (sockets[i].type == AUTH_UNUSED) { | |
529 | sockets[i].fd = fd; | |
530 | sockets[i].type = type; | |
531 | buffer_init(&sockets[i].input); | |
532 | buffer_init(&sockets[i].output); | |
533 | return; | |
534 | } | |
535 | old_alloc = sockets_alloc; | |
536 | sockets_alloc += 10; | |
537 | if (sockets) | |
538 | sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0])); | |
539 | else | |
540 | sockets = xmalloc(sockets_alloc * sizeof(sockets[0])); | |
541 | for (i = old_alloc; i < sockets_alloc; i++) | |
542 | sockets[i].type = AUTH_UNUSED; | |
543 | sockets[old_alloc].type = type; | |
544 | sockets[old_alloc].fd = fd; | |
545 | buffer_init(&sockets[old_alloc].input); | |
546 | buffer_init(&sockets[old_alloc].output); | |
8efc0c15 | 547 | } |
548 | ||
549 | void | |
550 | prepare_select(fd_set *readset, fd_set *writeset) | |
551 | { | |
5260325f | 552 | unsigned int i; |
553 | for (i = 0; i < sockets_alloc; i++) | |
554 | switch (sockets[i].type) { | |
555 | case AUTH_SOCKET: | |
556 | case AUTH_CONNECTION: | |
557 | FD_SET(sockets[i].fd, readset); | |
558 | if (buffer_len(&sockets[i].output) > 0) | |
559 | FD_SET(sockets[i].fd, writeset); | |
560 | break; | |
561 | case AUTH_UNUSED: | |
562 | break; | |
563 | default: | |
564 | fatal("Unknown socket type %d", sockets[i].type); | |
565 | break; | |
566 | } | |
8efc0c15 | 567 | } |
568 | ||
6ae2364d | 569 | void |
5260325f | 570 | after_select(fd_set *readset, fd_set *writeset) |
8efc0c15 | 571 | { |
5260325f | 572 | unsigned int i; |
573 | int len, sock; | |
610cd5c6 | 574 | socklen_t slen; |
5260325f | 575 | char buf[1024]; |
576 | struct sockaddr_un sunaddr; | |
577 | ||
578 | for (i = 0; i < sockets_alloc; i++) | |
579 | switch (sockets[i].type) { | |
580 | case AUTH_UNUSED: | |
581 | break; | |
582 | case AUTH_SOCKET: | |
583 | if (FD_ISSET(sockets[i].fd, readset)) { | |
610cd5c6 | 584 | slen = sizeof(sunaddr); |
585 | sock = accept(sockets[i].fd, (struct sockaddr *) & sunaddr, &slen); | |
5260325f | 586 | if (sock < 0) { |
587 | perror("accept from AUTH_SOCKET"); | |
588 | break; | |
589 | } | |
590 | new_socket(AUTH_CONNECTION, sock); | |
591 | } | |
592 | break; | |
593 | case AUTH_CONNECTION: | |
594 | if (buffer_len(&sockets[i].output) > 0 && | |
595 | FD_ISSET(sockets[i].fd, writeset)) { | |
596 | len = write(sockets[i].fd, buffer_ptr(&sockets[i].output), | |
597 | buffer_len(&sockets[i].output)); | |
598 | if (len <= 0) { | |
599 | shutdown(sockets[i].fd, SHUT_RDWR); | |
600 | close(sockets[i].fd); | |
601 | sockets[i].type = AUTH_UNUSED; | |
0ac7199f | 602 | buffer_free(&sockets[i].input); |
603 | buffer_free(&sockets[i].output); | |
5260325f | 604 | break; |
605 | } | |
606 | buffer_consume(&sockets[i].output, len); | |
607 | } | |
608 | if (FD_ISSET(sockets[i].fd, readset)) { | |
609 | len = read(sockets[i].fd, buf, sizeof(buf)); | |
610 | if (len <= 0) { | |
611 | shutdown(sockets[i].fd, SHUT_RDWR); | |
612 | close(sockets[i].fd); | |
613 | sockets[i].type = AUTH_UNUSED; | |
0ac7199f | 614 | buffer_free(&sockets[i].input); |
615 | buffer_free(&sockets[i].output); | |
5260325f | 616 | break; |
617 | } | |
618 | buffer_append(&sockets[i].input, buf, len); | |
619 | process_message(&sockets[i]); | |
620 | } | |
621 | break; | |
622 | default: | |
623 | fatal("Unknown type %d", sockets[i].type); | |
624 | } | |
8efc0c15 | 625 | } |
626 | ||
627 | void | |
628 | check_parent_exists(int sig) | |
629 | { | |
9da5c3c9 | 630 | if (parent_pid != -1 && kill(parent_pid, 0) < 0) { |
5260325f | 631 | /* printf("Parent has died - Authentication agent exiting.\n"); */ |
632 | exit(1); | |
633 | } | |
634 | signal(SIGALRM, check_parent_exists); | |
635 | alarm(10); | |
8efc0c15 | 636 | } |
637 | ||
dae3fa13 | 638 | void |
639 | cleanup_socket(void) | |
640 | { | |
77bb0bca | 641 | unlink(socket_name); |
5260325f | 642 | rmdir(socket_dir); |
8efc0c15 | 643 | } |
644 | ||
dae3fa13 | 645 | void |
646 | cleanup_exit(int i) | |
647 | { | |
5260325f | 648 | cleanup_socket(); |
649 | exit(i); | |
dae3fa13 | 650 | } |
651 | ||
652 | void | |
653 | usage() | |
654 | { | |
5260325f | 655 | fprintf(stderr, "ssh-agent version %s\n", SSH_VERSION); |
656 | fprintf(stderr, "Usage: %s [-c | -s] [-k] [command {args...]]\n", | |
657 | __progname); | |
658 | exit(1); | |
dae3fa13 | 659 | } |
660 | ||
8efc0c15 | 661 | int |
662 | main(int ac, char **av) | |
663 | { | |
5260325f | 664 | fd_set readset, writeset; |
665 | int sock, c_flag = 0, k_flag = 0, s_flag = 0, ch; | |
666 | struct sockaddr_un sunaddr; | |
667 | pid_t pid; | |
668 | char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid]; | |
c04f75f1 | 669 | extern int optind; |
2e73a022 | 670 | |
264dce47 | 671 | init_rng(); |
2e73a022 | 672 | |
5260325f | 673 | /* check if RSA support exists */ |
674 | if (rsa_alive() == 0) { | |
675 | fprintf(stderr, | |
676 | "%s: no RSA support in libssl and libcrypto. See ssl(8).\n", | |
677 | __progname); | |
678 | exit(1); | |
679 | } | |
4e577b89 | 680 | #ifdef __GNU_LIBRARY__ |
681 | while ((ch = getopt(ac, av, "+cks")) != -1) { | |
682 | #else /* __GNU_LIBRARY__ */ | |
5260325f | 683 | while ((ch = getopt(ac, av, "cks")) != -1) { |
4e577b89 | 684 | #endif /* __GNU_LIBRARY__ */ |
5260325f | 685 | switch (ch) { |
686 | case 'c': | |
687 | if (s_flag) | |
688 | usage(); | |
689 | c_flag++; | |
690 | break; | |
691 | case 'k': | |
692 | k_flag++; | |
693 | break; | |
694 | case 's': | |
695 | if (c_flag) | |
696 | usage(); | |
697 | s_flag++; | |
698 | break; | |
699 | default: | |
700 | usage(); | |
701 | } | |
dae3fa13 | 702 | } |
5260325f | 703 | ac -= optind; |
704 | av += optind; | |
705 | ||
706 | if (ac > 0 && (c_flag || k_flag || s_flag)) | |
707 | usage(); | |
708 | ||
709 | if (ac == 0 && !c_flag && !k_flag && !s_flag) { | |
710 | shell = getenv("SHELL"); | |
711 | if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0) | |
712 | c_flag = 1; | |
dae3fa13 | 713 | } |
5260325f | 714 | if (k_flag) { |
715 | pidstr = getenv(SSH_AGENTPID_ENV_NAME); | |
716 | if (pidstr == NULL) { | |
717 | fprintf(stderr, "%s not set, cannot kill agent\n", | |
718 | SSH_AGENTPID_ENV_NAME); | |
719 | exit(1); | |
720 | } | |
721 | pid = atoi(pidstr); | |
722 | if (pid < 1) { /* XXX PID_MAX check too */ | |
9da5c3c9 | 723 | /* Yes, PID_MAX check please */ |
5260325f | 724 | fprintf(stderr, "%s=\"%s\", which is not a good PID\n", |
725 | SSH_AGENTPID_ENV_NAME, pidstr); | |
726 | exit(1); | |
727 | } | |
728 | if (kill(pid, SIGTERM) == -1) { | |
729 | perror("kill"); | |
730 | exit(1); | |
731 | } | |
732 | format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; | |
733 | printf(format, SSH_AUTHSOCKET_ENV_NAME); | |
734 | printf(format, SSH_AGENTPID_ENV_NAME); | |
735 | printf("echo Agent pid %d killed;\n", pid); | |
736 | exit(0); | |
dae3fa13 | 737 | } |
5260325f | 738 | parent_pid = getpid(); |
739 | ||
740 | /* Create private directory for agent socket */ | |
741 | strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir); | |
742 | if (mkdtemp(socket_dir) == NULL) { | |
743 | perror("mkdtemp: private socket dir"); | |
744 | exit(1); | |
745 | } | |
746 | snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir, | |
747 | parent_pid); | |
748 | ||
aa3378df | 749 | /* |
750 | * Create socket early so it will exist before command gets run from | |
751 | * the parent. | |
752 | */ | |
5260325f | 753 | sock = socket(AF_UNIX, SOCK_STREAM, 0); |
754 | if (sock < 0) { | |
755 | perror("socket"); | |
756 | cleanup_exit(1); | |
757 | } | |
758 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
759 | sunaddr.sun_family = AF_UNIX; | |
760 | strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path)); | |
761 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { | |
762 | perror("bind"); | |
763 | cleanup_exit(1); | |
764 | } | |
765 | if (listen(sock, 5) < 0) { | |
766 | perror("listen"); | |
767 | cleanup_exit(1); | |
dae3fa13 | 768 | } |
aa3378df | 769 | /* |
770 | * Fork, and have the parent execute the command, if any, or present | |
771 | * the socket data. The child continues as the authentication agent. | |
772 | */ | |
5260325f | 773 | pid = fork(); |
774 | if (pid == -1) { | |
775 | perror("fork"); | |
776 | exit(1); | |
dae3fa13 | 777 | } |
5260325f | 778 | if (pid != 0) { /* Parent - execute the given command. */ |
779 | close(sock); | |
780 | snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid); | |
781 | if (ac == 0) { | |
782 | format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; | |
783 | printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, | |
784 | SSH_AUTHSOCKET_ENV_NAME); | |
785 | printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, | |
786 | SSH_AGENTPID_ENV_NAME); | |
787 | printf("echo Agent pid %d;\n", pid); | |
788 | exit(0); | |
789 | } | |
bcbf86ec | 790 | if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || |
791 | setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { | |
792 | perror("setenv"); | |
793 | exit(1); | |
794 | } | |
5260325f | 795 | execvp(av[0], av); |
796 | perror(av[0]); | |
797 | exit(1); | |
798 | } | |
799 | close(0); | |
800 | close(1); | |
801 | close(2); | |
dae3fa13 | 802 | |
5260325f | 803 | if (setsid() == -1) { |
804 | perror("setsid"); | |
805 | cleanup_exit(1); | |
806 | } | |
807 | if (atexit(cleanup_socket) < 0) { | |
808 | perror("atexit"); | |
809 | cleanup_exit(1); | |
810 | } | |
811 | new_socket(AUTH_SOCKET, sock); | |
812 | if (ac > 0) { | |
813 | signal(SIGALRM, check_parent_exists); | |
814 | alarm(10); | |
815 | } | |
2e73a022 | 816 | idtab_init(); |
5260325f | 817 | signal(SIGINT, SIG_IGN); |
818 | signal(SIGPIPE, SIG_IGN); | |
6ae2364d | 819 | signal(SIGHUP, cleanup_exit); |
820 | signal(SIGTERM, cleanup_exit); | |
5260325f | 821 | while (1) { |
822 | FD_ZERO(&readset); | |
823 | FD_ZERO(&writeset); | |
824 | prepare_select(&readset, &writeset); | |
825 | if (select(max_fd + 1, &readset, &writeset, NULL, NULL) < 0) { | |
826 | if (errno == EINTR) | |
827 | continue; | |
828 | exit(1); | |
829 | } | |
830 | after_select(&readset, &writeset); | |
8efc0c15 | 831 | } |
5260325f | 832 | /* NOTREACHED */ |
8efc0c15 | 833 | } |