Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.39
1.39 ! markus 1: /* $OpenBSD: ssh-agent.c,v 1.38 2000/11/12 19:03:28 markus Exp $ */
1.15 markus 2:
1.1 deraadt 3: /*
1.22 deraadt 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: * The authentication agent program.
1.33 markus 8: *
1.35 deraadt 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: *
1.33 markus 15: * SSH2 implementation,
16: * Copyright (c) 2000 Markus Friedl. All rights reserved.
1.35 deraadt 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.
1.22 deraadt 37: */
1.1 deraadt 38:
39: #include "includes.h"
1.39 ! markus 40: RCSID("$OpenBSD: ssh-agent.c,v 1.38 2000/11/12 19:03:28 markus Exp $");
1.1 deraadt 41:
42: #include "ssh.h"
43: #include "rsa.h"
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:
1.33 markus 51: #include <openssl/evp.h>
1.27 markus 52: #include <openssl/md5.h>
1.32 markus 53: #include <openssl/dsa.h>
54: #include <openssl/rsa.h>
55: #include "key.h"
56: #include "authfd.h"
1.33 markus 57: #include "kex.h"
1.37 markus 58: #include "compat.h"
1.7 deraadt 59:
1.21 markus 60: typedef struct {
61: int fd;
62: enum {
63: AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION
64: } type;
65: Buffer input;
66: Buffer output;
1.1 deraadt 67: } SocketEntry;
68:
69: unsigned int sockets_alloc = 0;
70: SocketEntry *sockets = NULL;
71:
1.21 markus 72: typedef struct {
1.33 markus 73: Key *key;
1.21 markus 74: char *comment;
1.1 deraadt 75: } Identity;
76:
1.33 markus 77: typedef struct {
78: int nentries;
79: Identity *identities;
80: } Idtab;
81:
82: /* private key table, one per protocol version */
83: Idtab idtable[3];
1.1 deraadt 84:
85: int max_fd = 0;
86:
1.11 markus 87: /* pid of shell == parent of agent */
1.29 deraadt 88: pid_t parent_pid = -1;
1.10 markus 89:
90: /* pathname and directory for AUTH_SOCKET */
91: char socket_name[1024];
92: char socket_dir[1024];
93:
1.20 markus 94: extern char *__progname;
95:
1.2 provos 96: void
1.33 markus 97: idtab_init(void)
1.1 deraadt 98: {
1.33 markus 99: int i;
100: for (i = 0; i <=2; i++){
101: idtable[i].identities = NULL;
102: idtable[i].nentries = 0;
103: }
104: }
105:
106: /* return private key table for requested protocol version */
107: Idtab *
108: idtab_lookup(int version)
109: {
110: if (version < 1 || version > 2)
111: fatal("internal error, bad protocol version %d", version);
112: return &idtable[version];
113: }
114:
115: /* return matching private key for given public key */
116: Key *
117: lookup_private_key(Key *key, int *idx, int version)
118: {
119: int i;
120: Idtab *tab = idtab_lookup(version);
121: for (i = 0; i < tab->nentries; i++) {
122: if (key_equal(key, tab->identities[i].key)) {
123: if (idx != NULL)
124: *idx = i;
125: return tab->identities[i].key;
126: }
127: }
128: return NULL;
129: }
130:
131: /* send list of supported public keys to 'client' */
132: void
133: process_request_identities(SocketEntry *e, int version)
134: {
135: Idtab *tab = idtab_lookup(version);
1.21 markus 136: Buffer msg;
137: int i;
1.1 deraadt 138:
1.21 markus 139: buffer_init(&msg);
1.33 markus 140: buffer_put_char(&msg, (version == 1) ?
141: SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
142: buffer_put_int(&msg, tab->nentries);
143: for (i = 0; i < tab->nentries; i++) {
144: Identity *id = &tab->identities[i];
1.39 ! markus 145: if (id->key->type == KEY_RSA1) {
1.33 markus 146: buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
147: buffer_put_bignum(&msg, id->key->rsa->e);
148: buffer_put_bignum(&msg, id->key->rsa->n);
149: } else {
150: unsigned char *blob;
151: unsigned int blen;
1.39 ! markus 152: key_to_blob(id->key, &blob, &blen);
1.33 markus 153: buffer_put_string(&msg, blob, blen);
154: xfree(blob);
155: }
156: buffer_put_cstring(&msg, id->comment);
1.21 markus 157: }
158: buffer_put_int(&e->output, buffer_len(&msg));
159: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
160: buffer_free(&msg);
1.1 deraadt 161: }
162:
1.33 markus 163: /* ssh1 only */
1.2 provos 164: void
1.33 markus 165: process_authentication_challenge1(SocketEntry *e)
1.1 deraadt 166: {
1.33 markus 167: Key *key, *private;
168: BIGNUM *challenge;
169: int i, len;
1.21 markus 170: Buffer msg;
171: MD5_CTX md;
172: unsigned char buf[32], mdbuf[16], session_id[16];
173: unsigned int response_type;
174:
175: buffer_init(&msg);
1.39 ! markus 176: key = key_new(KEY_RSA1);
1.21 markus 177: challenge = BN_new();
1.33 markus 178:
179: buffer_get_int(&e->input); /* ignored */
180: buffer_get_bignum(&e->input, key->rsa->e);
181: buffer_get_bignum(&e->input, key->rsa->n);
1.21 markus 182: buffer_get_bignum(&e->input, challenge);
183:
1.33 markus 184: /* Only protocol 1.1 is supported */
185: if (buffer_len(&e->input) == 0)
186: goto failure;
187: buffer_get(&e->input, (char *) session_id, 16);
188: response_type = buffer_get_int(&e->input);
189: if (response_type != 1)
190: goto failure;
191:
192: private = lookup_private_key(key, NULL, 1);
193: if (private != NULL) {
194: /* Decrypt the challenge using the private key. */
195: rsa_private_decrypt(challenge, challenge, private->rsa);
196:
197: /* The response is MD5 of decrypted challenge plus session id. */
198: len = BN_num_bytes(challenge);
199: if (len <= 0 || len > 32) {
200: log("process_authentication_challenge: bad challenge length %d", len);
201: goto failure;
202: }
203: memset(buf, 0, 32);
204: BN_bn2bin(challenge, buf + 32 - len);
205: MD5_Init(&md);
206: MD5_Update(&md, buf, 32);
207: MD5_Update(&md, session_id, 16);
208: MD5_Final(mdbuf, &md);
209:
210: /* Send the response. */
211: buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
212: for (i = 0; i < 16; i++)
213: buffer_put_char(&msg, mdbuf[i]);
214: goto send;
215: }
1.21 markus 216:
1.33 markus 217: failure:
218: /* Unknown identity or protocol error. Send failure. */
1.21 markus 219: buffer_put_char(&msg, SSH_AGENT_FAILURE);
220: send:
221: buffer_put_int(&e->output, buffer_len(&msg));
1.33 markus 222: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
223: key_free(key);
224: BN_clear_free(challenge);
225: buffer_free(&msg);
226: }
227:
228: /* ssh2 only */
229: void
230: process_sign_request2(SocketEntry *e)
231: {
232: extern int datafellows;
233: Key *key, *private;
234: unsigned char *blob, *data, *signature = NULL;
235: unsigned int blen, dlen, slen = 0;
1.37 markus 236: int flags;
1.33 markus 237: Buffer msg;
238: int ok = -1;
239:
240: datafellows = 0;
241:
242: blob = buffer_get_string(&e->input, &blen);
243: data = buffer_get_string(&e->input, &dlen);
1.37 markus 244:
245: flags = buffer_get_int(&e->input);
246: if (flags & SSH_AGENT_OLD_SIGNATURE)
247: datafellows = SSH_BUG_SIGBLOB;
1.33 markus 248:
1.39 ! markus 249: key = key_from_blob(blob, blen);
1.33 markus 250: if (key != NULL) {
251: private = lookup_private_key(key, NULL, 2);
252: if (private != NULL)
1.39 ! markus 253: ok = key_sign(private, &signature, &slen, data, dlen);
1.33 markus 254: }
255: key_free(key);
256: buffer_init(&msg);
257: if (ok == 0) {
258: buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
259: buffer_put_string(&msg, signature, slen);
260: } else {
261: buffer_put_char(&msg, SSH_AGENT_FAILURE);
262: }
263: buffer_put_int(&e->output, buffer_len(&msg));
1.21 markus 264: buffer_append(&e->output, buffer_ptr(&msg),
1.33 markus 265: buffer_len(&msg));
1.21 markus 266: buffer_free(&msg);
1.33 markus 267: xfree(data);
268: xfree(blob);
269: if (signature != NULL)
270: xfree(signature);
1.1 deraadt 271: }
272:
1.33 markus 273: /* shared */
1.2 provos 274: void
1.33 markus 275: process_remove_identity(SocketEntry *e, int version)
1.1 deraadt 276: {
1.33 markus 277: Key *key = NULL, *private;
278: unsigned char *blob;
279: unsigned int blen;
1.21 markus 280: unsigned int bits;
1.33 markus 281: int success = 0;
1.21 markus 282:
1.33 markus 283: switch(version){
284: case 1:
1.39 ! markus 285: key = key_new(KEY_RSA1);
1.33 markus 286: bits = buffer_get_int(&e->input);
287: buffer_get_bignum(&e->input, key->rsa->e);
288: buffer_get_bignum(&e->input, key->rsa->n);
289:
290: if (bits != key_size(key))
291: log("Warning: identity keysize mismatch: actual %d, announced %d",
292: key_size(key), bits);
293: break;
294: case 2:
295: blob = buffer_get_string(&e->input, &blen);
1.39 ! markus 296: key = key_from_blob(blob, blen);
1.33 markus 297: xfree(blob);
298: break;
299: }
300: if (key != NULL) {
301: int idx;
302: private = lookup_private_key(key, &idx, version);
303: if (private != NULL) {
1.23 markus 304: /*
305: * We have this key. Free the old key. Since we
306: * don\'t want to leave empty slots in the middle of
307: * the array, we actually free the key there and copy
308: * data from the last entry.
309: */
1.33 markus 310: Idtab *tab = idtab_lookup(version);
311: key_free(tab->identities[idx].key);
312: xfree(tab->identities[idx].comment);
1.38 markus 313: if (tab->nentries < 1)
314: fatal("process_remove_identity: "
315: "internal error: tab->nentries %d",
316: tab->nentries);
317: if (idx != tab->nentries - 1)
318: tab->identities[idx] = tab->identities[tab->nentries - 1];
1.33 markus 319: tab->nentries--;
320: success = 1;
1.21 markus 321: }
1.33 markus 322: key_free(key);
323: }
1.1 deraadt 324: buffer_put_int(&e->output, 1);
1.33 markus 325: buffer_put_char(&e->output,
326: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 327: }
328:
1.2 provos 329: void
1.33 markus 330: process_remove_all_identities(SocketEntry *e, int version)
1.1 deraadt 331: {
1.21 markus 332: unsigned int i;
1.33 markus 333: Idtab *tab = idtab_lookup(version);
1.21 markus 334:
335: /* Loop over all identities and clear the keys. */
1.33 markus 336: for (i = 0; i < tab->nentries; i++) {
337: key_free(tab->identities[i].key);
338: xfree(tab->identities[i].comment);
1.21 markus 339: }
340:
341: /* Mark that there are no identities. */
1.33 markus 342: tab->nentries = 0;
1.21 markus 343:
344: /* Send success. */
345: buffer_put_int(&e->output, 1);
346: buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
347: return;
1.1 deraadt 348: }
349:
1.2 provos 350: void
1.39 ! markus 351: generate_additional_parameters(RSA *rsa)
! 352: {
! 353: BIGNUM *aux;
! 354: BN_CTX *ctx;
! 355: /* Generate additional parameters */
! 356: aux = BN_new();
! 357: ctx = BN_CTX_new();
! 358:
! 359: BN_sub(aux, rsa->q, BN_value_one());
! 360: BN_mod(rsa->dmq1, rsa->d, aux, ctx);
! 361:
! 362: BN_sub(aux, rsa->p, BN_value_one());
! 363: BN_mod(rsa->dmp1, rsa->d, aux, ctx);
! 364:
! 365: BN_clear_free(aux);
! 366: BN_CTX_free(ctx);
! 367: }
! 368:
! 369: void
1.33 markus 370: process_add_identity(SocketEntry *e, int version)
1.1 deraadt 371: {
1.33 markus 372: Key *k = NULL;
1.39 ! markus 373: char *type_name;
1.33 markus 374: char *comment;
1.39 ! markus 375: int type, success = 0;
1.33 markus 376: Idtab *tab = idtab_lookup(version);
377:
378: switch (version) {
379: case 1:
1.39 ! markus 380: k = key_new_private(KEY_RSA1);
! 381: buffer_get_int(&e->input); /* ignored */
! 382: buffer_get_bignum(&e->input, k->rsa->n);
! 383: buffer_get_bignum(&e->input, k->rsa->e);
! 384: buffer_get_bignum(&e->input, k->rsa->d);
! 385: buffer_get_bignum(&e->input, k->rsa->iqmp);
1.33 markus 386:
387: /* SSH and SSL have p and q swapped */
1.39 ! markus 388: buffer_get_bignum(&e->input, k->rsa->q); /* p */
! 389: buffer_get_bignum(&e->input, k->rsa->p); /* q */
1.33 markus 390:
391: /* Generate additional parameters */
1.39 ! markus 392: generate_additional_parameters(k->rsa);
1.33 markus 393: break;
394: case 2:
1.39 ! markus 395: type_name = buffer_get_string(&e->input, NULL);
! 396: type = key_type_from_name(type_name);
! 397: xfree(type_name);
! 398: switch(type) {
! 399: case KEY_DSA:
! 400: k = key_new_private(type);
! 401: buffer_get_bignum2(&e->input, k->dsa->p);
! 402: buffer_get_bignum2(&e->input, k->dsa->q);
! 403: buffer_get_bignum2(&e->input, k->dsa->g);
! 404: buffer_get_bignum2(&e->input, k->dsa->pub_key);
! 405: buffer_get_bignum2(&e->input, k->dsa->priv_key);
! 406: break;
! 407: case KEY_RSA:
! 408: k = key_new_private(type);
! 409: buffer_get_bignum2(&e->input, k->rsa->n);
! 410: buffer_get_bignum2(&e->input, k->rsa->e);
! 411: buffer_get_bignum2(&e->input, k->rsa->d);
! 412: buffer_get_bignum2(&e->input, k->rsa->iqmp);
! 413: buffer_get_bignum2(&e->input, k->rsa->p);
! 414: buffer_get_bignum2(&e->input, k->rsa->q);
! 415:
! 416: /* Generate additional parameters */
! 417: generate_additional_parameters(k->rsa);
! 418: break;
! 419: default:
1.33 markus 420: buffer_clear(&e->input);
421: goto send;
1.21 markus 422: }
1.33 markus 423: break;
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:
1.1 deraadt 446: buffer_put_int(&e->output, 1);
1.33 markus 447: buffer_put_char(&e->output,
448: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 449: }
450:
1.33 markus 451: /* dispatch incoming messages */
452:
1.2 provos 453: void
454: process_message(SocketEntry *e)
1.1 deraadt 455: {
1.21 markus 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) {
1.33 markus 475: /* ssh1 */
476: case SSH_AGENTC_RSA_CHALLENGE:
477: process_authentication_challenge1(e);
478: break;
1.21 markus 479: case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
1.33 markus 480: process_request_identities(e, 1);
1.21 markus 481: break;
482: case SSH_AGENTC_ADD_RSA_IDENTITY:
1.33 markus 483: process_add_identity(e, 1);
1.21 markus 484: break;
485: case SSH_AGENTC_REMOVE_RSA_IDENTITY:
1.33 markus 486: process_remove_identity(e, 1);
1.21 markus 487: break;
488: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.33 markus 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);
1.21 markus 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: }
1.1 deraadt 515: }
516:
1.2 provos 517: void
518: new_socket(int type, int fd)
1.1 deraadt 519: {
1.21 markus 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);
1.1 deraadt 547: }
548:
1.2 provos 549: void
550: prepare_select(fd_set *readset, fd_set *writeset)
1.1 deraadt 551: {
1.21 markus 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: }
567: }
568:
1.28 markus 569: void
1.21 markus 570: after_select(fd_set *readset, fd_set *writeset)
571: {
572: unsigned int i;
573: int len, sock;
1.26 markus 574: socklen_t slen;
1.21 markus 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)) {
1.26 markus 584: slen = sizeof(sunaddr);
585: sock = accept(sockets[i].fd, (struct sockaddr *) & sunaddr, &slen);
1.21 markus 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;
1.30 djm 602: buffer_free(&sockets[i].input);
603: buffer_free(&sockets[i].output);
1.21 markus 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;
1.30 djm 614: buffer_free(&sockets[i].input);
615: buffer_free(&sockets[i].output);
1.21 markus 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: }
1.1 deraadt 625: }
626:
1.6 deraadt 627: void
1.2 provos 628: check_parent_exists(int sig)
1.1 deraadt 629: {
1.29 deraadt 630: if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
1.21 markus 631: /* printf("Parent has died - Authentication agent exiting.\n"); */
632: exit(1);
633: }
634: signal(SIGALRM, check_parent_exists);
635: alarm(10);
1.1 deraadt 636: }
637:
1.15 markus 638: void
639: cleanup_socket(void)
640: {
1.21 markus 641: remove(socket_name);
642: rmdir(socket_dir);
1.10 markus 643: }
644:
1.15 markus 645: void
646: cleanup_exit(int i)
647: {
1.21 markus 648: cleanup_socket();
649: exit(i);
1.15 markus 650: }
651:
652: void
653: usage()
654: {
1.21 markus 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);
1.15 markus 659: }
660:
1.2 provos 661: int
662: main(int ac, char **av)
1.1 deraadt 663: {
1.21 markus 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];
669:
670: while ((ch = getopt(ac, av, "cks")) != -1) {
671: switch (ch) {
672: case 'c':
673: if (s_flag)
674: usage();
675: c_flag++;
676: break;
677: case 'k':
678: k_flag++;
679: break;
680: case 's':
681: if (c_flag)
682: usage();
683: s_flag++;
684: break;
685: default:
686: usage();
687: }
688: }
689: ac -= optind;
690: av += optind;
691:
692: if (ac > 0 && (c_flag || k_flag || s_flag))
693: usage();
694:
695: if (ac == 0 && !c_flag && !k_flag && !s_flag) {
696: shell = getenv("SHELL");
697: if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
698: c_flag = 1;
699: }
700: if (k_flag) {
701: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
702: if (pidstr == NULL) {
703: fprintf(stderr, "%s not set, cannot kill agent\n",
704: SSH_AGENTPID_ENV_NAME);
705: exit(1);
706: }
707: pid = atoi(pidstr);
708: if (pid < 1) { /* XXX PID_MAX check too */
1.29 deraadt 709: /* Yes, PID_MAX check please */
1.21 markus 710: fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
711: SSH_AGENTPID_ENV_NAME, pidstr);
712: exit(1);
713: }
714: if (kill(pid, SIGTERM) == -1) {
715: perror("kill");
716: exit(1);
717: }
718: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
719: printf(format, SSH_AUTHSOCKET_ENV_NAME);
720: printf(format, SSH_AGENTPID_ENV_NAME);
721: printf("echo Agent pid %d killed;\n", pid);
722: exit(0);
723: }
724: parent_pid = getpid();
725:
726: /* Create private directory for agent socket */
727: strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir);
728: if (mkdtemp(socket_dir) == NULL) {
729: perror("mkdtemp: private socket dir");
730: exit(1);
731: }
732: snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir,
733: parent_pid);
734:
1.23 markus 735: /*
736: * Create socket early so it will exist before command gets run from
737: * the parent.
738: */
1.21 markus 739: sock = socket(AF_UNIX, SOCK_STREAM, 0);
740: if (sock < 0) {
741: perror("socket");
742: cleanup_exit(1);
743: }
744: memset(&sunaddr, 0, sizeof(sunaddr));
745: sunaddr.sun_family = AF_UNIX;
746: strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
747: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
748: perror("bind");
749: cleanup_exit(1);
750: }
751: if (listen(sock, 5) < 0) {
752: perror("listen");
753: cleanup_exit(1);
754: }
1.23 markus 755: /*
756: * Fork, and have the parent execute the command, if any, or present
757: * the socket data. The child continues as the authentication agent.
758: */
1.21 markus 759: pid = fork();
760: if (pid == -1) {
761: perror("fork");
762: exit(1);
763: }
764: if (pid != 0) { /* Parent - execute the given command. */
765: close(sock);
766: snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid);
767: if (ac == 0) {
768: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
769: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
770: SSH_AUTHSOCKET_ENV_NAME);
771: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
772: SSH_AGENTPID_ENV_NAME);
773: printf("echo Agent pid %d;\n", pid);
774: exit(0);
775: }
1.36 deraadt 776: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
777: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
778: perror("setenv");
779: exit(1);
780: }
1.21 markus 781: execvp(av[0], av);
782: perror(av[0]);
783: exit(1);
784: }
785: close(0);
786: close(1);
787: close(2);
788:
789: if (setsid() == -1) {
790: perror("setsid");
791: cleanup_exit(1);
792: }
793: if (atexit(cleanup_socket) < 0) {
794: perror("atexit");
795: cleanup_exit(1);
796: }
797: new_socket(AUTH_SOCKET, sock);
798: if (ac > 0) {
799: signal(SIGALRM, check_parent_exists);
800: alarm(10);
801: }
1.33 markus 802: idtab_init();
1.21 markus 803: signal(SIGINT, SIG_IGN);
804: signal(SIGPIPE, SIG_IGN);
1.28 markus 805: signal(SIGHUP, cleanup_exit);
806: signal(SIGTERM, cleanup_exit);
1.21 markus 807: while (1) {
808: FD_ZERO(&readset);
809: FD_ZERO(&writeset);
810: prepare_select(&readset, &writeset);
811: if (select(max_fd + 1, &readset, &writeset, NULL, NULL) < 0) {
812: if (errno == EINTR)
813: continue;
814: exit(1);
815: }
816: after_select(&readset, &writeset);
1.15 markus 817: }
1.21 markus 818: /* NOTREACHED */
1.1 deraadt 819: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-agent.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh