Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.88
1.1 deraadt 1: /*
1.22 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * The authentication agent program.
1.33 markus 6: *
1.35 deraadt 7: * As far as I am concerned, the code I have written for this software
8: * can be used freely for any purpose. Any derived versions of this
9: * software must be clearly marked as such, and if the derived work is
10: * incompatible with the protocol description in the RFC file, it must be
11: * called by a name other than "ssh" or "Secure Shell".
12: *
1.56 markus 13: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 34: */
1.1 deraadt 35:
36: #include "includes.h"
1.78 provos 37: #include <sys/queue.h>
1.88 ! markus 38: RCSID("$OpenBSD: ssh-agent.c,v 1.87 2002/06/05 16:48:54 markus Exp $");
1.47 markus 39:
40: #include <openssl/evp.h>
41: #include <openssl/md5.h>
1.1 deraadt 42:
43: #include "ssh.h"
44: #include "rsa.h"
45: #include "buffer.h"
46: #include "bufaux.h"
47: #include "xmalloc.h"
48: #include "getput.h"
1.32 markus 49: #include "key.h"
50: #include "authfd.h"
1.37 markus 51: #include "compat.h"
1.47 markus 52: #include "log.h"
1.7 deraadt 53:
1.59 markus 54: #ifdef SMARTCARD
55: #include "scard.h"
1.71 jakob 56: #endif
1.59 markus 57:
1.73 stevesk 58: typedef enum {
59: AUTH_UNUSED,
60: AUTH_SOCKET,
61: AUTH_CONNECTION
62: } sock_type;
63:
1.21 markus 64: typedef struct {
65: int fd;
1.73 stevesk 66: sock_type type;
1.21 markus 67: Buffer input;
68: Buffer output;
1.87 markus 69: Buffer request;
1.1 deraadt 70: } SocketEntry;
71:
1.45 markus 72: u_int sockets_alloc = 0;
1.1 deraadt 73: SocketEntry *sockets = NULL;
74:
1.78 provos 75: typedef struct identity {
76: TAILQ_ENTRY(identity) next;
1.33 markus 77: Key *key;
1.21 markus 78: char *comment;
1.1 deraadt 79: } Identity;
80:
1.33 markus 81: typedef struct {
82: int nentries;
1.78 provos 83: TAILQ_HEAD(idqueue, identity) idlist;
1.33 markus 84: } Idtab;
85:
86: /* private key table, one per protocol version */
87: Idtab idtable[3];
1.1 deraadt 88:
89: int max_fd = 0;
90:
1.11 markus 91: /* pid of shell == parent of agent */
1.29 deraadt 92: pid_t parent_pid = -1;
1.10 markus 93:
94: /* pathname and directory for AUTH_SOCKET */
95: char socket_name[1024];
96: char socket_dir[1024];
97:
1.88 ! markus 98: /* locking */
! 99: int locked = 0;
! 100: char *lock_passwd = NULL;
! 101:
1.20 markus 102: extern char *__progname;
103:
1.55 itojun 104: static void
1.33 markus 105: idtab_init(void)
1.1 deraadt 106: {
1.33 markus 107: int i;
1.74 deraadt 108: for (i = 0; i <=2; i++) {
1.78 provos 109: TAILQ_INIT(&idtable[i].idlist);
1.33 markus 110: idtable[i].nentries = 0;
111: }
112: }
113:
114: /* return private key table for requested protocol version */
1.55 itojun 115: static Idtab *
1.33 markus 116: idtab_lookup(int version)
117: {
118: if (version < 1 || version > 2)
119: fatal("internal error, bad protocol version %d", version);
120: return &idtable[version];
121: }
122:
123: /* return matching private key for given public key */
1.78 provos 124: static Identity *
125: lookup_identity(Key *key, int version)
1.33 markus 126: {
1.78 provos 127: Identity *id;
128:
1.33 markus 129: Idtab *tab = idtab_lookup(version);
1.78 provos 130: TAILQ_FOREACH(id, &tab->idlist, next) {
131: if (key_equal(key, id->key))
132: return (id);
1.33 markus 133: }
1.78 provos 134: return (NULL);
135: }
136:
137: static void
138: free_identity(Identity *id)
139: {
140: key_free(id->key);
141: xfree(id->comment);
142: xfree(id);
1.33 markus 143: }
144:
145: /* send list of supported public keys to 'client' */
1.55 itojun 146: static void
1.33 markus 147: process_request_identities(SocketEntry *e, int version)
148: {
149: Idtab *tab = idtab_lookup(version);
1.21 markus 150: Buffer msg;
1.78 provos 151: Identity *id;
1.1 deraadt 152:
1.21 markus 153: buffer_init(&msg);
1.33 markus 154: buffer_put_char(&msg, (version == 1) ?
155: SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
156: buffer_put_int(&msg, tab->nentries);
1.78 provos 157: TAILQ_FOREACH(id, &tab->idlist, next) {
1.39 markus 158: if (id->key->type == KEY_RSA1) {
1.33 markus 159: buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
160: buffer_put_bignum(&msg, id->key->rsa->e);
161: buffer_put_bignum(&msg, id->key->rsa->n);
162: } else {
1.45 markus 163: u_char *blob;
164: u_int blen;
1.39 markus 165: key_to_blob(id->key, &blob, &blen);
1.33 markus 166: buffer_put_string(&msg, blob, blen);
167: xfree(blob);
168: }
169: buffer_put_cstring(&msg, id->comment);
1.21 markus 170: }
171: buffer_put_int(&e->output, buffer_len(&msg));
172: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
173: buffer_free(&msg);
1.1 deraadt 174: }
175:
1.33 markus 176: /* ssh1 only */
1.55 itojun 177: static void
1.33 markus 178: process_authentication_challenge1(SocketEntry *e)
1.1 deraadt 179: {
1.78 provos 180: Identity *id;
181: Key *key;
1.33 markus 182: BIGNUM *challenge;
183: int i, len;
1.21 markus 184: Buffer msg;
185: MD5_CTX md;
1.45 markus 186: u_char buf[32], mdbuf[16], session_id[16];
187: u_int response_type;
1.21 markus 188:
189: buffer_init(&msg);
1.39 markus 190: key = key_new(KEY_RSA1);
1.76 markus 191: if ((challenge = BN_new()) == NULL)
192: fatal("process_authentication_challenge1: BN_new failed");
1.33 markus 193:
1.87 markus 194: buffer_get_int(&e->request); /* ignored */
195: buffer_get_bignum(&e->request, key->rsa->e);
196: buffer_get_bignum(&e->request, key->rsa->n);
197: buffer_get_bignum(&e->request, challenge);
1.21 markus 198:
1.33 markus 199: /* Only protocol 1.1 is supported */
1.87 markus 200: if (buffer_len(&e->request) == 0)
1.33 markus 201: goto failure;
1.87 markus 202: buffer_get(&e->request, session_id, 16);
203: response_type = buffer_get_int(&e->request);
1.33 markus 204: if (response_type != 1)
205: goto failure;
206:
1.78 provos 207: id = lookup_identity(key, 1);
208: if (id != NULL) {
209: Key *private = id->key;
1.33 markus 210: /* Decrypt the challenge using the private key. */
1.49 markus 211: if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
212: goto failure;
1.33 markus 213:
214: /* The response is MD5 of decrypted challenge plus session id. */
215: len = BN_num_bytes(challenge);
216: if (len <= 0 || len > 32) {
217: log("process_authentication_challenge: bad challenge length %d", len);
218: goto failure;
219: }
220: memset(buf, 0, 32);
221: BN_bn2bin(challenge, buf + 32 - len);
222: MD5_Init(&md);
223: MD5_Update(&md, buf, 32);
224: MD5_Update(&md, session_id, 16);
225: MD5_Final(mdbuf, &md);
226:
227: /* Send the response. */
228: buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
229: for (i = 0; i < 16; i++)
230: buffer_put_char(&msg, mdbuf[i]);
231: goto send;
232: }
1.21 markus 233:
1.33 markus 234: failure:
235: /* Unknown identity or protocol error. Send failure. */
1.21 markus 236: buffer_put_char(&msg, SSH_AGENT_FAILURE);
237: send:
238: buffer_put_int(&e->output, buffer_len(&msg));
1.33 markus 239: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
240: key_free(key);
241: BN_clear_free(challenge);
242: buffer_free(&msg);
243: }
244:
245: /* ssh2 only */
1.55 itojun 246: static void
1.33 markus 247: process_sign_request2(SocketEntry *e)
248: {
249: extern int datafellows;
1.78 provos 250: Key *key;
1.45 markus 251: u_char *blob, *data, *signature = NULL;
252: u_int blen, dlen, slen = 0;
1.37 markus 253: int flags;
1.33 markus 254: Buffer msg;
255: int ok = -1;
256:
257: datafellows = 0;
1.43 markus 258:
1.87 markus 259: blob = buffer_get_string(&e->request, &blen);
260: data = buffer_get_string(&e->request, &dlen);
1.37 markus 261:
1.87 markus 262: flags = buffer_get_int(&e->request);
1.37 markus 263: if (flags & SSH_AGENT_OLD_SIGNATURE)
264: datafellows = SSH_BUG_SIGBLOB;
1.33 markus 265:
1.39 markus 266: key = key_from_blob(blob, blen);
1.33 markus 267: if (key != NULL) {
1.78 provos 268: Identity *id = lookup_identity(key, 2);
269: if (id != NULL)
270: ok = key_sign(id->key, &signature, &slen, data, dlen);
1.33 markus 271: }
272: key_free(key);
273: buffer_init(&msg);
274: if (ok == 0) {
275: buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
276: buffer_put_string(&msg, signature, slen);
277: } else {
278: buffer_put_char(&msg, SSH_AGENT_FAILURE);
279: }
280: buffer_put_int(&e->output, buffer_len(&msg));
1.21 markus 281: buffer_append(&e->output, buffer_ptr(&msg),
1.33 markus 282: buffer_len(&msg));
1.21 markus 283: buffer_free(&msg);
1.33 markus 284: xfree(data);
285: xfree(blob);
286: if (signature != NULL)
287: xfree(signature);
1.1 deraadt 288: }
289:
1.33 markus 290: /* shared */
1.55 itojun 291: static void
1.33 markus 292: process_remove_identity(SocketEntry *e, int version)
1.1 deraadt 293: {
1.78 provos 294: Key *key = NULL;
1.45 markus 295: u_char *blob;
296: u_int blen;
297: u_int bits;
1.33 markus 298: int success = 0;
1.21 markus 299:
1.74 deraadt 300: switch (version) {
1.33 markus 301: case 1:
1.39 markus 302: key = key_new(KEY_RSA1);
1.87 markus 303: bits = buffer_get_int(&e->request);
304: buffer_get_bignum(&e->request, key->rsa->e);
305: buffer_get_bignum(&e->request, key->rsa->n);
1.33 markus 306:
307: if (bits != key_size(key))
308: log("Warning: identity keysize mismatch: actual %d, announced %d",
1.46 markus 309: key_size(key), bits);
1.33 markus 310: break;
311: case 2:
1.87 markus 312: blob = buffer_get_string(&e->request, &blen);
1.39 markus 313: key = key_from_blob(blob, blen);
1.33 markus 314: xfree(blob);
315: break;
316: }
317: if (key != NULL) {
1.78 provos 318: Identity *id = lookup_identity(key, version);
319: if (id != NULL) {
1.23 markus 320: /*
321: * We have this key. Free the old key. Since we
322: * don\'t want to leave empty slots in the middle of
1.40 markus 323: * the array, we actually free the key there and move
324: * all the entries between the empty slot and the end
325: * of the array.
1.23 markus 326: */
1.33 markus 327: Idtab *tab = idtab_lookup(version);
1.38 markus 328: if (tab->nentries < 1)
329: fatal("process_remove_identity: "
330: "internal error: tab->nentries %d",
331: tab->nentries);
1.78 provos 332: TAILQ_REMOVE(&tab->idlist, id, next);
333: free_identity(id);
1.33 markus 334: tab->nentries--;
335: success = 1;
1.21 markus 336: }
1.33 markus 337: key_free(key);
338: }
1.1 deraadt 339: buffer_put_int(&e->output, 1);
1.33 markus 340: buffer_put_char(&e->output,
341: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 342: }
343:
1.55 itojun 344: static void
1.33 markus 345: process_remove_all_identities(SocketEntry *e, int version)
1.1 deraadt 346: {
1.33 markus 347: Idtab *tab = idtab_lookup(version);
1.78 provos 348: Identity *id;
1.21 markus 349:
350: /* Loop over all identities and clear the keys. */
1.78 provos 351: for (id = TAILQ_FIRST(&tab->idlist); id;
352: id = TAILQ_FIRST(&tab->idlist)) {
353: TAILQ_REMOVE(&tab->idlist, id, next);
354: free_identity(id);
1.21 markus 355: }
356:
357: /* Mark that there are no identities. */
1.33 markus 358: tab->nentries = 0;
1.21 markus 359:
360: /* Send success. */
361: buffer_put_int(&e->output, 1);
362: buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
363: return;
1.1 deraadt 364: }
365:
1.55 itojun 366: static void
1.33 markus 367: process_add_identity(SocketEntry *e, int version)
1.1 deraadt 368: {
1.33 markus 369: Key *k = NULL;
1.39 markus 370: char *type_name;
1.33 markus 371: char *comment;
1.39 markus 372: int type, success = 0;
1.33 markus 373: Idtab *tab = idtab_lookup(version);
374:
375: switch (version) {
376: case 1:
1.39 markus 377: k = key_new_private(KEY_RSA1);
1.87 markus 378: buffer_get_int(&e->request); /* ignored */
379: buffer_get_bignum(&e->request, k->rsa->n);
380: buffer_get_bignum(&e->request, k->rsa->e);
381: buffer_get_bignum(&e->request, k->rsa->d);
382: buffer_get_bignum(&e->request, k->rsa->iqmp);
1.33 markus 383:
384: /* SSH and SSL have p and q swapped */
1.87 markus 385: buffer_get_bignum(&e->request, k->rsa->q); /* p */
386: buffer_get_bignum(&e->request, k->rsa->p); /* q */
1.33 markus 387:
388: /* Generate additional parameters */
1.60 markus 389: rsa_generate_additional_parameters(k->rsa);
1.33 markus 390: break;
391: case 2:
1.87 markus 392: type_name = buffer_get_string(&e->request, NULL);
1.46 markus 393: type = key_type_from_name(type_name);
1.39 markus 394: xfree(type_name);
1.74 deraadt 395: switch (type) {
1.39 markus 396: case KEY_DSA:
397: k = key_new_private(type);
1.87 markus 398: buffer_get_bignum2(&e->request, k->dsa->p);
399: buffer_get_bignum2(&e->request, k->dsa->q);
400: buffer_get_bignum2(&e->request, k->dsa->g);
401: buffer_get_bignum2(&e->request, k->dsa->pub_key);
402: buffer_get_bignum2(&e->request, k->dsa->priv_key);
1.39 markus 403: break;
404: case KEY_RSA:
405: k = key_new_private(type);
1.87 markus 406: buffer_get_bignum2(&e->request, k->rsa->n);
407: buffer_get_bignum2(&e->request, k->rsa->e);
408: buffer_get_bignum2(&e->request, k->rsa->d);
409: buffer_get_bignum2(&e->request, k->rsa->iqmp);
410: buffer_get_bignum2(&e->request, k->rsa->p);
411: buffer_get_bignum2(&e->request, k->rsa->q);
1.39 markus 412:
413: /* Generate additional parameters */
1.60 markus 414: rsa_generate_additional_parameters(k->rsa);
1.39 markus 415: break;
416: default:
1.87 markus 417: buffer_clear(&e->request);
1.33 markus 418: goto send;
1.21 markus 419: }
1.33 markus 420: break;
421: }
1.87 markus 422: comment = buffer_get_string(&e->request, NULL);
1.33 markus 423: if (k == NULL) {
424: xfree(comment);
425: goto send;
426: }
427: success = 1;
1.78 provos 428: if (lookup_identity(k, version) == NULL) {
429: Identity *id = xmalloc(sizeof(Identity));
430: id->key = k;
431: id->comment = comment;
432: TAILQ_INSERT_TAIL(&tab->idlist, id, next);
1.33 markus 433: /* Increment the number of identities. */
434: tab->nentries++;
435: } else {
436: key_free(k);
437: xfree(comment);
438: }
439: send:
1.1 deraadt 440: buffer_put_int(&e->output, 1);
1.33 markus 441: buffer_put_char(&e->output,
442: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 443: }
444:
1.88 ! markus 445: /* XXX todo: encrypt sensitive data with passphrase */
! 446: static void
! 447: process_lock_agent(SocketEntry *e, int lock)
! 448: {
! 449: char *passwd;
! 450: int success = 0;
! 451:
! 452: passwd = buffer_get_string(&e->request, NULL);
! 453: if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
! 454: locked = 0;
! 455: memset(lock_passwd, 0, strlen(lock_passwd));
! 456: xfree(lock_passwd);
! 457: lock_passwd = NULL;
! 458: success = 1;
! 459: } else if (!locked && lock) {
! 460: locked = 1;
! 461: lock_passwd = xstrdup(passwd);
! 462: success = 1;
! 463: }
! 464: memset(passwd, 0, strlen(passwd));
! 465: xfree(passwd);
! 466:
! 467: buffer_put_int(&e->output, 1);
! 468: buffer_put_char(&e->output,
! 469: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
! 470: return;
! 471: }
! 472:
! 473: static void
! 474: no_identities(SocketEntry *e, u_int type)
! 475: {
! 476: Buffer msg;
! 477:
! 478: buffer_init(&msg);
! 479: buffer_put_char(&msg,
! 480: (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
! 481: SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
! 482: buffer_put_int(&msg, 0);
! 483: buffer_put_int(&e->output, buffer_len(&msg));
! 484: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
! 485: buffer_free(&msg);
! 486: }
1.59 markus 487:
488: #ifdef SMARTCARD
489: static void
490: process_add_smartcard_key (SocketEntry *e)
491: {
1.84 markus 492: Identity *id;
1.59 markus 493: Idtab *tab;
1.84 markus 494: Key **keys, *k;
1.83 rees 495: char *sc_reader_id = NULL, *pin;
1.84 markus 496: int i, version, success = 0;
1.75 deraadt 497:
1.87 markus 498: sc_reader_id = buffer_get_string(&e->request, NULL);
499: pin = buffer_get_string(&e->request, NULL);
1.84 markus 500: keys = sc_get_keys(sc_reader_id, pin);
1.69 markus 501: xfree(sc_reader_id);
1.83 rees 502: xfree(pin);
1.59 markus 503:
1.84 markus 504: if (keys == NULL || keys[0] == NULL) {
505: error("sc_get_keys failed");
1.59 markus 506: goto send;
507: }
1.84 markus 508: for (i = 0; keys[i] != NULL; i++) {
509: k = keys[i];
510: version = k->type == KEY_RSA1 ? 1 : 2;
511: tab = idtab_lookup(version);
512: if (lookup_identity(k, version) == NULL) {
513: id = xmalloc(sizeof(Identity));
514: id->key = k;
515: id->comment = xstrdup("smartcard key");
516: TAILQ_INSERT_TAIL(&tab->idlist, id, next);
517: tab->nentries++;
518: success = 1;
519: } else {
520: key_free(k);
521: }
522: keys[i] = NULL;
1.59 markus 523: }
1.84 markus 524: xfree(keys);
1.59 markus 525: send:
526: buffer_put_int(&e->output, 1);
527: buffer_put_char(&e->output,
528: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
529: }
530:
531: static void
532: process_remove_smartcard_key(SocketEntry *e)
533: {
1.84 markus 534: Identity *id;
535: Idtab *tab;
536: Key **keys, *k = NULL;
1.83 rees 537: char *sc_reader_id = NULL, *pin;
1.84 markus 538: int i, version, success = 0;
1.59 markus 539:
1.87 markus 540: sc_reader_id = buffer_get_string(&e->request, NULL);
541: pin = buffer_get_string(&e->request, NULL);
1.84 markus 542: keys = sc_get_keys(sc_reader_id, pin);
1.69 markus 543: xfree(sc_reader_id);
1.83 rees 544: xfree(pin);
1.59 markus 545:
1.84 markus 546: if (keys == NULL || keys[0] == NULL) {
547: error("sc_get_keys failed");
548: goto send;
549: }
550: for (i = 0; keys[i] != NULL; i++) {
551: k = keys[i];
552: version = k->type == KEY_RSA1 ? 1 : 2;
553: if ((id = lookup_identity(k, version)) != NULL) {
554: tab = idtab_lookup(version);
555: TAILQ_REMOVE(&tab->idlist, id, next);
1.59 markus 556: tab->nentries--;
1.78 provos 557: free_identity(id);
1.59 markus 558: success = 1;
559: }
560: key_free(k);
1.84 markus 561: keys[i] = NULL;
1.59 markus 562: }
1.84 markus 563: xfree(keys);
564: send:
1.59 markus 565: buffer_put_int(&e->output, 1);
566: buffer_put_char(&e->output,
567: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
568: }
1.70 jakob 569: #endif /* SMARTCARD */
1.59 markus 570:
1.33 markus 571: /* dispatch incoming messages */
572:
1.55 itojun 573: static void
1.2 provos 574: process_message(SocketEntry *e)
1.1 deraadt 575: {
1.45 markus 576: u_int msg_len;
577: u_int type;
578: u_char *cp;
1.21 markus 579: if (buffer_len(&e->input) < 5)
580: return; /* Incomplete message. */
1.77 stevesk 581: cp = buffer_ptr(&e->input);
1.21 markus 582: msg_len = GET_32BIT(cp);
583: if (msg_len > 256 * 1024) {
584: shutdown(e->fd, SHUT_RDWR);
585: close(e->fd);
586: e->type = AUTH_UNUSED;
1.87 markus 587: buffer_free(&e->input);
588: buffer_free(&e->output);
589: buffer_free(&e->request);
1.21 markus 590: return;
591: }
592: if (buffer_len(&e->input) < msg_len + 4)
593: return;
1.87 markus 594:
595: /* move the current input to e->request */
1.21 markus 596: buffer_consume(&e->input, 4);
1.87 markus 597: buffer_clear(&e->request);
598: buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
599: buffer_consume(&e->input, msg_len);
600: type = buffer_get_char(&e->request);
1.21 markus 601:
1.88 ! markus 602: /* check wheter agent is locked */
! 603: if (locked && type != SSH_AGENTC_UNLOCK) {
! 604: buffer_clear(&e->request);
! 605: switch (type) {
! 606: case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
! 607: case SSH2_AGENTC_REQUEST_IDENTITIES:
! 608: /* send empty lists */
! 609: no_identities(e, type);
! 610: break;
! 611: default:
! 612: /* send a fail message for all other request types */
! 613: buffer_put_int(&e->output, 1);
! 614: buffer_put_char(&e->output, SSH_AGENT_FAILURE);
! 615: }
! 616: return;
! 617: }
! 618:
1.59 markus 619: debug("type %d", type);
1.21 markus 620: switch (type) {
1.88 ! markus 621: case SSH_AGENTC_LOCK:
! 622: case SSH_AGENTC_UNLOCK:
! 623: process_lock_agent(e, type == SSH_AGENTC_LOCK);
! 624: break;
1.33 markus 625: /* ssh1 */
626: case SSH_AGENTC_RSA_CHALLENGE:
627: process_authentication_challenge1(e);
628: break;
1.21 markus 629: case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
1.33 markus 630: process_request_identities(e, 1);
1.21 markus 631: break;
632: case SSH_AGENTC_ADD_RSA_IDENTITY:
1.33 markus 633: process_add_identity(e, 1);
1.21 markus 634: break;
635: case SSH_AGENTC_REMOVE_RSA_IDENTITY:
1.33 markus 636: process_remove_identity(e, 1);
1.21 markus 637: break;
638: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.33 markus 639: process_remove_all_identities(e, 1);
640: break;
641: /* ssh2 */
642: case SSH2_AGENTC_SIGN_REQUEST:
643: process_sign_request2(e);
644: break;
645: case SSH2_AGENTC_REQUEST_IDENTITIES:
646: process_request_identities(e, 2);
647: break;
648: case SSH2_AGENTC_ADD_IDENTITY:
649: process_add_identity(e, 2);
650: break;
651: case SSH2_AGENTC_REMOVE_IDENTITY:
652: process_remove_identity(e, 2);
653: break;
654: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
655: process_remove_all_identities(e, 2);
1.21 markus 656: break;
1.59 markus 657: #ifdef SMARTCARD
658: case SSH_AGENTC_ADD_SMARTCARD_KEY:
659: process_add_smartcard_key(e);
1.75 deraadt 660: break;
1.59 markus 661: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
662: process_remove_smartcard_key(e);
1.75 deraadt 663: break;
1.70 jakob 664: #endif /* SMARTCARD */
1.21 markus 665: default:
666: /* Unknown message. Respond with failure. */
667: error("Unknown message %d", type);
1.87 markus 668: buffer_clear(&e->request);
1.21 markus 669: buffer_put_int(&e->output, 1);
670: buffer_put_char(&e->output, SSH_AGENT_FAILURE);
671: break;
672: }
1.1 deraadt 673: }
674:
1.55 itojun 675: static void
1.73 stevesk 676: new_socket(sock_type type, int fd)
1.1 deraadt 677: {
1.45 markus 678: u_int i, old_alloc;
1.21 markus 679: if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
680: error("fcntl O_NONBLOCK: %s", strerror(errno));
681:
682: if (fd > max_fd)
683: max_fd = fd;
684:
685: for (i = 0; i < sockets_alloc; i++)
686: if (sockets[i].type == AUTH_UNUSED) {
687: sockets[i].fd = fd;
688: sockets[i].type = type;
689: buffer_init(&sockets[i].input);
690: buffer_init(&sockets[i].output);
1.87 markus 691: buffer_init(&sockets[i].request);
1.21 markus 692: return;
693: }
694: old_alloc = sockets_alloc;
695: sockets_alloc += 10;
696: if (sockets)
697: sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0]));
698: else
699: sockets = xmalloc(sockets_alloc * sizeof(sockets[0]));
700: for (i = old_alloc; i < sockets_alloc; i++)
701: sockets[i].type = AUTH_UNUSED;
702: sockets[old_alloc].type = type;
703: sockets[old_alloc].fd = fd;
704: buffer_init(&sockets[old_alloc].input);
705: buffer_init(&sockets[old_alloc].output);
1.87 markus 706: buffer_init(&sockets[old_alloc].request);
1.1 deraadt 707: }
708:
1.55 itojun 709: static int
1.66 markus 710: prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp)
1.1 deraadt 711: {
1.46 markus 712: u_int i, sz;
713: int n = 0;
714:
715: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 716: switch (sockets[i].type) {
717: case AUTH_SOCKET:
718: case AUTH_CONNECTION:
1.46 markus 719: n = MAX(n, sockets[i].fd);
1.21 markus 720: break;
721: case AUTH_UNUSED:
722: break;
723: default:
724: fatal("Unknown socket type %d", sockets[i].type);
725: break;
726: }
1.46 markus 727: }
728:
729: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.66 markus 730: if (*fdrp == NULL || sz > *nallocp) {
1.46 markus 731: if (*fdrp)
1.54 stevesk 732: xfree(*fdrp);
1.46 markus 733: if (*fdwp)
1.54 stevesk 734: xfree(*fdwp);
1.46 markus 735: *fdrp = xmalloc(sz);
736: *fdwp = xmalloc(sz);
1.66 markus 737: *nallocp = sz;
1.46 markus 738: }
1.66 markus 739: if (n < *fdl)
740: debug("XXX shrink: %d < %d", n, *fdl);
741: *fdl = n;
1.46 markus 742: memset(*fdrp, 0, sz);
743: memset(*fdwp, 0, sz);
744:
745: for (i = 0; i < sockets_alloc; i++) {
746: switch (sockets[i].type) {
747: case AUTH_SOCKET:
748: case AUTH_CONNECTION:
749: FD_SET(sockets[i].fd, *fdrp);
750: if (buffer_len(&sockets[i].output) > 0)
751: FD_SET(sockets[i].fd, *fdwp);
752: break;
753: default:
754: break;
755: }
756: }
757: return (1);
1.21 markus 758: }
759:
1.55 itojun 760: static void
1.21 markus 761: after_select(fd_set *readset, fd_set *writeset)
762: {
1.45 markus 763: u_int i;
1.21 markus 764: int len, sock;
1.26 markus 765: socklen_t slen;
1.21 markus 766: char buf[1024];
767: struct sockaddr_un sunaddr;
768:
769: for (i = 0; i < sockets_alloc; i++)
770: switch (sockets[i].type) {
771: case AUTH_UNUSED:
772: break;
773: case AUTH_SOCKET:
774: if (FD_ISSET(sockets[i].fd, readset)) {
1.26 markus 775: slen = sizeof(sunaddr);
1.46 markus 776: sock = accept(sockets[i].fd,
777: (struct sockaddr *) &sunaddr, &slen);
1.21 markus 778: if (sock < 0) {
1.81 stevesk 779: error("accept from AUTH_SOCKET: %s",
780: strerror(errno));
1.21 markus 781: break;
782: }
783: new_socket(AUTH_CONNECTION, sock);
784: }
785: break;
786: case AUTH_CONNECTION:
787: if (buffer_len(&sockets[i].output) > 0 &&
788: FD_ISSET(sockets[i].fd, writeset)) {
1.52 deraadt 789: do {
790: len = write(sockets[i].fd,
791: buffer_ptr(&sockets[i].output),
792: buffer_len(&sockets[i].output));
793: if (len == -1 && (errno == EAGAIN ||
794: errno == EINTR))
795: continue;
796: break;
797: } while (1);
1.21 markus 798: if (len <= 0) {
799: shutdown(sockets[i].fd, SHUT_RDWR);
800: close(sockets[i].fd);
801: sockets[i].type = AUTH_UNUSED;
1.30 djm 802: buffer_free(&sockets[i].input);
803: buffer_free(&sockets[i].output);
1.87 markus 804: buffer_free(&sockets[i].request);
1.21 markus 805: break;
806: }
807: buffer_consume(&sockets[i].output, len);
808: }
809: if (FD_ISSET(sockets[i].fd, readset)) {
1.52 deraadt 810: do {
811: len = read(sockets[i].fd, buf, sizeof(buf));
812: if (len == -1 && (errno == EAGAIN ||
813: errno == EINTR))
814: continue;
815: break;
816: } while (1);
1.21 markus 817: if (len <= 0) {
818: shutdown(sockets[i].fd, SHUT_RDWR);
819: close(sockets[i].fd);
820: sockets[i].type = AUTH_UNUSED;
1.30 djm 821: buffer_free(&sockets[i].input);
822: buffer_free(&sockets[i].output);
1.87 markus 823: buffer_free(&sockets[i].request);
1.21 markus 824: break;
825: }
826: buffer_append(&sockets[i].input, buf, len);
827: process_message(&sockets[i]);
828: }
829: break;
830: default:
831: fatal("Unknown type %d", sockets[i].type);
832: }
1.1 deraadt 833: }
834:
1.55 itojun 835: static void
1.81 stevesk 836: cleanup_socket(void *p)
1.15 markus 837: {
1.48 deraadt 838: if (socket_name[0])
839: unlink(socket_name);
840: if (socket_dir[0])
841: rmdir(socket_dir);
1.10 markus 842: }
843:
1.55 itojun 844: static void
1.15 markus 845: cleanup_exit(int i)
846: {
1.81 stevesk 847: cleanup_socket(NULL);
1.21 markus 848: exit(i);
1.15 markus 849: }
850:
1.55 itojun 851: static void
1.48 deraadt 852: cleanup_handler(int sig)
853: {
1.81 stevesk 854: cleanup_socket(NULL);
1.48 deraadt 855: _exit(2);
1.68 markus 856: }
857:
858: static void
859: check_parent_exists(int sig)
860: {
861: int save_errno = errno;
862:
863: if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
864: /* printf("Parent has died - Authentication agent exiting.\n"); */
865: cleanup_handler(sig); /* safe */
866: }
867: signal(SIGALRM, check_parent_exists);
868: alarm(10);
869: errno = save_errno;
1.48 deraadt 870: }
871:
1.55 itojun 872: static void
1.50 itojun 873: usage(void)
1.15 markus 874: {
1.72 jakob 875: fprintf(stderr, "Usage: %s [options] [command [args ...]]\n",
1.46 markus 876: __progname);
1.72 jakob 877: fprintf(stderr, "Options:\n");
878: fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
879: fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
880: fprintf(stderr, " -k Kill the current agent.\n");
881: fprintf(stderr, " -d Debug mode.\n");
1.86 markus 882: fprintf(stderr, " -a socket Bind agent socket to given name.\n");
1.21 markus 883: exit(1);
1.15 markus 884: }
885:
1.2 provos 886: int
887: main(int ac, char **av)
1.1 deraadt 888: {
1.66 markus 889: int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch, nalloc;
1.21 markus 890: struct sockaddr_un sunaddr;
1.41 markus 891: struct rlimit rlim;
1.21 markus 892: pid_t pid;
893: char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid];
1.86 markus 894: char *agentsocket = NULL;
1.43 markus 895: extern int optind;
1.46 markus 896: fd_set *readsetp = NULL, *writesetp = NULL;
1.53 markus 897:
898: SSLeay_add_all_algorithms();
1.21 markus 899:
1.86 markus 900: while ((ch = getopt(ac, av, "cdksa:")) != -1) {
1.21 markus 901: switch (ch) {
902: case 'c':
903: if (s_flag)
904: usage();
905: c_flag++;
906: break;
907: case 'k':
908: k_flag++;
909: break;
910: case 's':
911: if (c_flag)
912: usage();
913: s_flag++;
914: break;
1.57 markus 915: case 'd':
916: if (d_flag)
917: usage();
918: d_flag++;
919: break;
1.86 markus 920: case 'a':
921: agentsocket = optarg;
922: break;
1.21 markus 923: default:
924: usage();
925: }
926: }
927: ac -= optind;
928: av += optind;
929:
1.57 markus 930: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1.21 markus 931: usage();
932:
1.85 markus 933: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 934: shell = getenv("SHELL");
935: if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
936: c_flag = 1;
937: }
938: if (k_flag) {
939: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
940: if (pidstr == NULL) {
941: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 942: SSH_AGENTPID_ENV_NAME);
1.21 markus 943: exit(1);
944: }
945: pid = atoi(pidstr);
1.46 markus 946: if (pid < 1) {
1.21 markus 947: fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
1.46 markus 948: SSH_AGENTPID_ENV_NAME, pidstr);
1.21 markus 949: exit(1);
950: }
951: if (kill(pid, SIGTERM) == -1) {
952: perror("kill");
953: exit(1);
954: }
955: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
956: printf(format, SSH_AUTHSOCKET_ENV_NAME);
957: printf(format, SSH_AGENTPID_ENV_NAME);
958: printf("echo Agent pid %d killed;\n", pid);
959: exit(0);
960: }
961: parent_pid = getpid();
962:
1.86 markus 963: if (agentsocket == NULL) {
964: /* Create private directory for agent socket */
965: strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir);
966: if (mkdtemp(socket_dir) == NULL) {
967: perror("mkdtemp: private socket dir");
968: exit(1);
969: }
970: snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir,
971: parent_pid);
972: } else {
973: /* Try to use specified agent socket */
974: socket_dir[0] = '\0';
975: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 976: }
977:
1.23 markus 978: /*
979: * Create socket early so it will exist before command gets run from
980: * the parent.
981: */
1.21 markus 982: sock = socket(AF_UNIX, SOCK_STREAM, 0);
983: if (sock < 0) {
984: perror("socket");
985: cleanup_exit(1);
986: }
987: memset(&sunaddr, 0, sizeof(sunaddr));
988: sunaddr.sun_family = AF_UNIX;
989: strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
990: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
991: perror("bind");
992: cleanup_exit(1);
993: }
994: if (listen(sock, 5) < 0) {
995: perror("listen");
996: cleanup_exit(1);
997: }
1.46 markus 998:
1.23 markus 999: /*
1000: * Fork, and have the parent execute the command, if any, or present
1001: * the socket data. The child continues as the authentication agent.
1002: */
1.57 markus 1003: if (d_flag) {
1004: log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
1005: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1006: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1007: SSH_AUTHSOCKET_ENV_NAME);
1008: printf("echo Agent pid %d;\n", parent_pid);
1009: goto skip;
1010: }
1.21 markus 1011: pid = fork();
1012: if (pid == -1) {
1013: perror("fork");
1.81 stevesk 1014: cleanup_exit(1);
1.21 markus 1015: }
1016: if (pid != 0) { /* Parent - execute the given command. */
1017: close(sock);
1018: snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid);
1019: if (ac == 0) {
1020: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1021: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1022: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1023: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1024: SSH_AGENTPID_ENV_NAME);
1.21 markus 1025: printf("echo Agent pid %d;\n", pid);
1026: exit(0);
1027: }
1.36 deraadt 1028: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1029: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1030: perror("setenv");
1031: exit(1);
1032: }
1.21 markus 1033: execvp(av[0], av);
1034: perror(av[0]);
1035: exit(1);
1036: }
1.81 stevesk 1037: /* child */
1038: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1039:
1040: if (setsid() == -1) {
1.81 stevesk 1041: error("setsid: %s", strerror(errno));
1.67 stevesk 1042: cleanup_exit(1);
1043: }
1044:
1045: (void)chdir("/");
1.21 markus 1046: close(0);
1047: close(1);
1048: close(2);
1049:
1.41 markus 1050: /* deny core dumps, since memory contains unencrypted private keys */
1051: rlim.rlim_cur = rlim.rlim_max = 0;
1052: if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1.81 stevesk 1053: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1054: cleanup_exit(1);
1055: }
1.57 markus 1056:
1057: skip:
1.81 stevesk 1058: fatal_add_cleanup(cleanup_socket, NULL);
1.21 markus 1059: new_socket(AUTH_SOCKET, sock);
1060: if (ac > 0) {
1061: signal(SIGALRM, check_parent_exists);
1062: alarm(10);
1063: }
1.33 markus 1064: idtab_init();
1.61 markus 1065: if (!d_flag)
1.57 markus 1066: signal(SIGINT, SIG_IGN);
1.61 markus 1067: signal(SIGPIPE, SIG_IGN);
1.48 deraadt 1068: signal(SIGHUP, cleanup_handler);
1069: signal(SIGTERM, cleanup_handler);
1.66 markus 1070: nalloc = 0;
1071:
1.21 markus 1072: while (1) {
1.66 markus 1073: prepare_select(&readsetp, &writesetp, &max_fd, &nalloc);
1.46 markus 1074: if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) {
1.21 markus 1075: if (errno == EINTR)
1076: continue;
1.81 stevesk 1077: fatal("select: %s", strerror(errno));
1.21 markus 1078: }
1.46 markus 1079: after_select(readsetp, writesetp);
1.15 markus 1080: }
1.21 markus 1081: /* NOTREACHED */
1.1 deraadt 1082: }
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