Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.31.2.1
1.31.2.1! jason 1: /* $OpenBSD: ssh-agent.c,v 1.33 2000/08/19 21:34:43 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: * Created: Wed Mar 29 03:46:59 1995 ylo
8: * The authentication agent program.
1.31.2.1! jason 9: *
! 10: * SSH2 implementation,
! 11: * Copyright (c) 2000 Markus Friedl. All rights reserved.
1.22 deraadt 12: */
1.1 deraadt 13:
14: #include "includes.h"
1.31.2.1! jason 15: RCSID("$OpenBSD: ssh-agent.c,v 1.33 2000/08/19 21:34:43 markus Exp $");
1.1 deraadt 16:
17: #include "ssh.h"
18: #include "rsa.h"
19: #include "buffer.h"
20: #include "bufaux.h"
21: #include "xmalloc.h"
22: #include "packet.h"
23: #include "getput.h"
24: #include "mpaux.h"
25:
1.31.2.1! jason 26: #include <openssl/evp.h>
1.27 markus 27: #include <openssl/md5.h>
1.31.2.1! jason 28: #include <openssl/dsa.h>
! 29: #include <openssl/rsa.h>
! 30: #include "key.h"
! 31: #include "authfd.h"
! 32: #include "dsa.h"
! 33: #include "kex.h"
1.7 deraadt 34:
1.21 markus 35: typedef struct {
36: int fd;
37: enum {
38: AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION
39: } type;
40: Buffer input;
41: Buffer output;
1.1 deraadt 42: } SocketEntry;
43:
44: unsigned int sockets_alloc = 0;
45: SocketEntry *sockets = NULL;
46:
1.21 markus 47: typedef struct {
1.31.2.1! jason 48: Key *key;
1.21 markus 49: char *comment;
1.1 deraadt 50: } Identity;
51:
1.31.2.1! jason 52: typedef struct {
! 53: int nentries;
! 54: Identity *identities;
! 55: } Idtab;
! 56:
! 57: /* private key table, one per protocol version */
! 58: Idtab idtable[3];
1.1 deraadt 59:
60: int max_fd = 0;
61:
1.11 markus 62: /* pid of shell == parent of agent */
1.29 deraadt 63: pid_t parent_pid = -1;
1.10 markus 64:
65: /* pathname and directory for AUTH_SOCKET */
66: char socket_name[1024];
67: char socket_dir[1024];
68:
1.20 markus 69: extern char *__progname;
70:
1.2 provos 71: void
1.31.2.1! jason 72: idtab_init(void)
1.1 deraadt 73: {
1.31.2.1! jason 74: int i;
! 75: for (i = 0; i <=2; i++){
! 76: idtable[i].identities = NULL;
! 77: idtable[i].nentries = 0;
! 78: }
! 79: }
! 80:
! 81: /* return private key table for requested protocol version */
! 82: Idtab *
! 83: idtab_lookup(int version)
! 84: {
! 85: if (version < 1 || version > 2)
! 86: fatal("internal error, bad protocol version %d", version);
! 87: return &idtable[version];
! 88: }
! 89:
! 90: /* return matching private key for given public key */
! 91: Key *
! 92: lookup_private_key(Key *key, int *idx, int version)
! 93: {
! 94: int i;
! 95: Idtab *tab = idtab_lookup(version);
! 96: for (i = 0; i < tab->nentries; i++) {
! 97: if (key_equal(key, tab->identities[i].key)) {
! 98: if (idx != NULL)
! 99: *idx = i;
! 100: return tab->identities[i].key;
! 101: }
! 102: }
! 103: return NULL;
! 104: }
! 105:
! 106: /* send list of supported public keys to 'client' */
! 107: void
! 108: process_request_identities(SocketEntry *e, int version)
! 109: {
! 110: Idtab *tab = idtab_lookup(version);
1.21 markus 111: Buffer msg;
112: int i;
1.1 deraadt 113:
1.21 markus 114: buffer_init(&msg);
1.31.2.1! jason 115: buffer_put_char(&msg, (version == 1) ?
! 116: SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
! 117: buffer_put_int(&msg, tab->nentries);
! 118: for (i = 0; i < tab->nentries; i++) {
! 119: Identity *id = &tab->identities[i];
! 120: if (id->key->type == KEY_RSA) {
! 121: buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
! 122: buffer_put_bignum(&msg, id->key->rsa->e);
! 123: buffer_put_bignum(&msg, id->key->rsa->n);
! 124: } else {
! 125: unsigned char *blob;
! 126: unsigned int blen;
! 127: dsa_make_key_blob(id->key, &blob, &blen);
! 128: buffer_put_string(&msg, blob, blen);
! 129: xfree(blob);
! 130: }
! 131: buffer_put_cstring(&msg, id->comment);
1.21 markus 132: }
133: buffer_put_int(&e->output, buffer_len(&msg));
134: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
135: buffer_free(&msg);
1.1 deraadt 136: }
137:
1.31.2.1! jason 138: /* ssh1 only */
1.2 provos 139: void
1.31.2.1! jason 140: process_authentication_challenge1(SocketEntry *e)
1.1 deraadt 141: {
1.31.2.1! jason 142: Key *key, *private;
! 143: BIGNUM *challenge;
! 144: int i, len;
1.21 markus 145: Buffer msg;
146: MD5_CTX md;
147: unsigned char buf[32], mdbuf[16], session_id[16];
148: unsigned int response_type;
149:
150: buffer_init(&msg);
1.31.2.1! jason 151: key = key_new(KEY_RSA);
1.21 markus 152: challenge = BN_new();
1.31.2.1! jason 153:
! 154: buffer_get_int(&e->input); /* ignored */
! 155: buffer_get_bignum(&e->input, key->rsa->e);
! 156: buffer_get_bignum(&e->input, key->rsa->n);
1.21 markus 157: buffer_get_bignum(&e->input, challenge);
158:
1.31.2.1! jason 159: /* Only protocol 1.1 is supported */
! 160: if (buffer_len(&e->input) == 0)
! 161: goto failure;
! 162: buffer_get(&e->input, (char *) session_id, 16);
! 163: response_type = buffer_get_int(&e->input);
! 164: if (response_type != 1)
! 165: goto failure;
! 166:
! 167: private = lookup_private_key(key, NULL, 1);
! 168: if (private != NULL) {
! 169: /* Decrypt the challenge using the private key. */
! 170: rsa_private_decrypt(challenge, challenge, private->rsa);
! 171:
! 172: /* The response is MD5 of decrypted challenge plus session id. */
! 173: len = BN_num_bytes(challenge);
! 174: if (len <= 0 || len > 32) {
! 175: log("process_authentication_challenge: bad challenge length %d", len);
! 176: goto failure;
! 177: }
! 178: memset(buf, 0, 32);
! 179: BN_bn2bin(challenge, buf + 32 - len);
! 180: MD5_Init(&md);
! 181: MD5_Update(&md, buf, 32);
! 182: MD5_Update(&md, session_id, 16);
! 183: MD5_Final(mdbuf, &md);
! 184:
! 185: /* Send the response. */
! 186: buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
! 187: for (i = 0; i < 16; i++)
! 188: buffer_put_char(&msg, mdbuf[i]);
! 189: goto send;
! 190: }
1.21 markus 191:
1.31.2.1! jason 192: failure:
! 193: /* Unknown identity or protocol error. Send failure. */
1.21 markus 194: buffer_put_char(&msg, SSH_AGENT_FAILURE);
195: send:
196: buffer_put_int(&e->output, buffer_len(&msg));
1.31.2.1! jason 197: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
! 198: key_free(key);
! 199: BN_clear_free(challenge);
! 200: buffer_free(&msg);
! 201: }
! 202:
! 203: /* ssh2 only */
! 204: void
! 205: process_sign_request2(SocketEntry *e)
! 206: {
! 207: extern int datafellows;
! 208: Key *key, *private;
! 209: unsigned char *blob, *data, *signature = NULL;
! 210: unsigned int blen, dlen, slen = 0;
! 211: Buffer msg;
! 212: int ok = -1;
! 213:
! 214: datafellows = 0;
! 215:
! 216: blob = buffer_get_string(&e->input, &blen);
! 217: data = buffer_get_string(&e->input, &dlen);
! 218:
! 219: key = dsa_key_from_blob(blob, blen);
! 220: if (key != NULL) {
! 221: private = lookup_private_key(key, NULL, 2);
! 222: if (private != NULL)
! 223: ok = dsa_sign(private, &signature, &slen, data, dlen);
! 224: }
! 225: key_free(key);
! 226: buffer_init(&msg);
! 227: if (ok == 0) {
! 228: buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
! 229: buffer_put_string(&msg, signature, slen);
! 230: } else {
! 231: buffer_put_char(&msg, SSH_AGENT_FAILURE);
! 232: }
! 233: buffer_put_int(&e->output, buffer_len(&msg));
1.21 markus 234: buffer_append(&e->output, buffer_ptr(&msg),
1.31.2.1! jason 235: buffer_len(&msg));
1.21 markus 236: buffer_free(&msg);
1.31.2.1! jason 237: xfree(data);
! 238: xfree(blob);
! 239: if (signature != NULL)
! 240: xfree(signature);
1.1 deraadt 241: }
242:
1.31.2.1! jason 243: /* shared */
1.2 provos 244: void
1.31.2.1! jason 245: process_remove_identity(SocketEntry *e, int version)
1.1 deraadt 246: {
1.31.2.1! jason 247: Key *key = NULL, *private;
! 248: unsigned char *blob;
! 249: unsigned int blen;
1.21 markus 250: unsigned int bits;
1.31.2.1! jason 251: int success = 0;
1.21 markus 252:
1.31.2.1! jason 253: switch(version){
! 254: case 1:
! 255: key = key_new(KEY_RSA);
! 256: bits = buffer_get_int(&e->input);
! 257: buffer_get_bignum(&e->input, key->rsa->e);
! 258: buffer_get_bignum(&e->input, key->rsa->n);
! 259:
! 260: if (bits != key_size(key))
! 261: log("Warning: identity keysize mismatch: actual %d, announced %d",
! 262: key_size(key), bits);
! 263: break;
! 264: case 2:
! 265: blob = buffer_get_string(&e->input, &blen);
! 266: key = dsa_key_from_blob(blob, blen);
! 267: xfree(blob);
! 268: break;
! 269: }
! 270: if (key != NULL) {
! 271: int idx;
! 272: private = lookup_private_key(key, &idx, version);
! 273: if (private != NULL) {
1.23 markus 274: /*
275: * We have this key. Free the old key. Since we
276: * don\'t want to leave empty slots in the middle of
277: * the array, we actually free the key there and copy
278: * data from the last entry.
279: */
1.31.2.1! jason 280: Idtab *tab = idtab_lookup(version);
! 281: key_free(tab->identities[idx].key);
! 282: xfree(tab->identities[idx].comment);
! 283: if (idx != tab->nentries)
! 284: tab->identities[idx] = tab->identities[tab->nentries];
! 285: tab->nentries--;
! 286: success = 1;
1.21 markus 287: }
1.31.2.1! jason 288: key_free(key);
! 289: }
1.1 deraadt 290: buffer_put_int(&e->output, 1);
1.31.2.1! jason 291: buffer_put_char(&e->output,
! 292: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 293: }
294:
1.2 provos 295: void
1.31.2.1! jason 296: process_remove_all_identities(SocketEntry *e, int version)
1.1 deraadt 297: {
1.21 markus 298: unsigned int i;
1.31.2.1! jason 299: Idtab *tab = idtab_lookup(version);
1.21 markus 300:
301: /* Loop over all identities and clear the keys. */
1.31.2.1! jason 302: for (i = 0; i < tab->nentries; i++) {
! 303: key_free(tab->identities[i].key);
! 304: xfree(tab->identities[i].comment);
1.21 markus 305: }
306:
307: /* Mark that there are no identities. */
1.31.2.1! jason 308: tab->nentries = 0;
1.21 markus 309:
310: /* Send success. */
311: buffer_put_int(&e->output, 1);
312: buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
313: return;
1.1 deraadt 314: }
315:
1.2 provos 316: void
1.31.2.1! jason 317: process_add_identity(SocketEntry *e, int version)
1.1 deraadt 318: {
1.31.2.1! jason 319: Key *k = NULL;
! 320: RSA *rsa;
1.21 markus 321: BIGNUM *aux;
322: BN_CTX *ctx;
1.31.2.1! jason 323: char *type;
! 324: char *comment;
! 325: int success = 0;
! 326: Idtab *tab = idtab_lookup(version);
1.21 markus 327:
1.31.2.1! jason 328: switch (version) {
! 329: case 1:
! 330: k = key_new(KEY_RSA);
! 331: rsa = k->rsa;
! 332:
! 333: /* allocate mem for private key */
! 334: /* XXX rsa->n and rsa->e are already allocated */
! 335: rsa->d = BN_new();
! 336: rsa->iqmp = BN_new();
! 337: rsa->q = BN_new();
! 338: rsa->p = BN_new();
! 339: rsa->dmq1 = BN_new();
! 340: rsa->dmp1 = BN_new();
! 341:
! 342: buffer_get_int(&e->input); /* ignored */
! 343:
! 344: buffer_get_bignum(&e->input, rsa->n);
! 345: buffer_get_bignum(&e->input, rsa->e);
! 346: buffer_get_bignum(&e->input, rsa->d);
! 347: buffer_get_bignum(&e->input, rsa->iqmp);
! 348:
! 349: /* SSH and SSL have p and q swapped */
! 350: buffer_get_bignum(&e->input, rsa->q); /* p */
! 351: buffer_get_bignum(&e->input, rsa->p); /* q */
! 352:
! 353: /* Generate additional parameters */
! 354: aux = BN_new();
! 355: ctx = BN_CTX_new();
1.21 markus 356:
1.31.2.1! jason 357: BN_sub(aux, rsa->q, BN_value_one());
! 358: BN_mod(rsa->dmq1, rsa->d, aux, ctx);
1.21 markus 359:
1.31.2.1! jason 360: BN_sub(aux, rsa->p, BN_value_one());
! 361: BN_mod(rsa->dmp1, rsa->d, aux, ctx);
! 362:
! 363: BN_clear_free(aux);
! 364: BN_CTX_free(ctx);
! 365:
! 366: break;
! 367: case 2:
! 368: type = buffer_get_string(&e->input, NULL);
! 369: if (strcmp(type, KEX_DSS)) {
! 370: buffer_clear(&e->input);
! 371: xfree(type);
! 372: goto send;
1.21 markus 373: }
1.31.2.1! jason 374: xfree(type);
! 375:
! 376: k = key_new(KEY_DSA);
! 377:
! 378: /* allocate mem for private key */
! 379: k->dsa->priv_key = BN_new();
1.1 deraadt 380:
1.31.2.1! jason 381: buffer_get_bignum2(&e->input, k->dsa->p);
! 382: buffer_get_bignum2(&e->input, k->dsa->q);
! 383: buffer_get_bignum2(&e->input, k->dsa->g);
! 384: buffer_get_bignum2(&e->input, k->dsa->pub_key);
! 385: buffer_get_bignum2(&e->input, k->dsa->priv_key);
! 386:
! 387: break;
! 388: }
! 389:
! 390: comment = buffer_get_string(&e->input, NULL);
! 391: if (k == NULL) {
! 392: xfree(comment);
! 393: goto send;
! 394: }
! 395: success = 1;
! 396: if (lookup_private_key(k, NULL, version) == NULL) {
! 397: if (tab->nentries == 0)
! 398: tab->identities = xmalloc(sizeof(Identity));
! 399: else
! 400: tab->identities = xrealloc(tab->identities,
! 401: (tab->nentries + 1) * sizeof(Identity));
! 402: tab->identities[tab->nentries].key = k;
! 403: tab->identities[tab->nentries].comment = comment;
! 404: /* Increment the number of identities. */
! 405: tab->nentries++;
! 406: } else {
! 407: key_free(k);
! 408: xfree(comment);
! 409: }
! 410: send:
1.1 deraadt 411: buffer_put_int(&e->output, 1);
1.31.2.1! jason 412: buffer_put_char(&e->output,
! 413: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 414: }
415:
1.31.2.1! jason 416: /* dispatch incoming messages */
! 417:
1.2 provos 418: void
419: process_message(SocketEntry *e)
1.1 deraadt 420: {
1.21 markus 421: unsigned int msg_len;
422: unsigned int type;
423: unsigned char *cp;
424: if (buffer_len(&e->input) < 5)
425: return; /* Incomplete message. */
426: cp = (unsigned char *) buffer_ptr(&e->input);
427: msg_len = GET_32BIT(cp);
428: if (msg_len > 256 * 1024) {
429: shutdown(e->fd, SHUT_RDWR);
430: close(e->fd);
431: e->type = AUTH_UNUSED;
432: return;
433: }
434: if (buffer_len(&e->input) < msg_len + 4)
435: return;
436: buffer_consume(&e->input, 4);
437: type = buffer_get_char(&e->input);
438:
439: switch (type) {
1.31.2.1! jason 440: /* ssh1 */
1.21 markus 441: case SSH_AGENTC_RSA_CHALLENGE:
1.31.2.1! jason 442: process_authentication_challenge1(e);
! 443: break;
! 444: case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
! 445: process_request_identities(e, 1);
1.21 markus 446: break;
447: case SSH_AGENTC_ADD_RSA_IDENTITY:
1.31.2.1! jason 448: process_add_identity(e, 1);
1.21 markus 449: break;
450: case SSH_AGENTC_REMOVE_RSA_IDENTITY:
1.31.2.1! jason 451: process_remove_identity(e, 1);
1.21 markus 452: break;
453: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.31.2.1! jason 454: process_remove_all_identities(e, 1);
! 455: break;
! 456: /* ssh2 */
! 457: case SSH2_AGENTC_SIGN_REQUEST:
! 458: process_sign_request2(e);
! 459: break;
! 460: case SSH2_AGENTC_REQUEST_IDENTITIES:
! 461: process_request_identities(e, 2);
! 462: break;
! 463: case SSH2_AGENTC_ADD_IDENTITY:
! 464: process_add_identity(e, 2);
! 465: break;
! 466: case SSH2_AGENTC_REMOVE_IDENTITY:
! 467: process_remove_identity(e, 2);
! 468: break;
! 469: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
! 470: process_remove_all_identities(e, 2);
1.21 markus 471: break;
472: default:
473: /* Unknown message. Respond with failure. */
474: error("Unknown message %d", type);
475: buffer_clear(&e->input);
476: buffer_put_int(&e->output, 1);
477: buffer_put_char(&e->output, SSH_AGENT_FAILURE);
478: break;
479: }
1.1 deraadt 480: }
481:
1.2 provos 482: void
483: new_socket(int type, int fd)
1.1 deraadt 484: {
1.21 markus 485: unsigned int i, old_alloc;
486: if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
487: error("fcntl O_NONBLOCK: %s", strerror(errno));
488:
489: if (fd > max_fd)
490: max_fd = fd;
491:
492: for (i = 0; i < sockets_alloc; i++)
493: if (sockets[i].type == AUTH_UNUSED) {
494: sockets[i].fd = fd;
495: sockets[i].type = type;
496: buffer_init(&sockets[i].input);
497: buffer_init(&sockets[i].output);
498: return;
499: }
500: old_alloc = sockets_alloc;
501: sockets_alloc += 10;
502: if (sockets)
503: sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0]));
504: else
505: sockets = xmalloc(sockets_alloc * sizeof(sockets[0]));
506: for (i = old_alloc; i < sockets_alloc; i++)
507: sockets[i].type = AUTH_UNUSED;
508: sockets[old_alloc].type = type;
509: sockets[old_alloc].fd = fd;
510: buffer_init(&sockets[old_alloc].input);
511: buffer_init(&sockets[old_alloc].output);
1.1 deraadt 512: }
513:
1.2 provos 514: void
515: prepare_select(fd_set *readset, fd_set *writeset)
1.1 deraadt 516: {
1.21 markus 517: unsigned int i;
518: for (i = 0; i < sockets_alloc; i++)
519: switch (sockets[i].type) {
520: case AUTH_SOCKET:
521: case AUTH_CONNECTION:
522: FD_SET(sockets[i].fd, readset);
523: if (buffer_len(&sockets[i].output) > 0)
524: FD_SET(sockets[i].fd, writeset);
525: break;
526: case AUTH_UNUSED:
527: break;
528: default:
529: fatal("Unknown socket type %d", sockets[i].type);
530: break;
531: }
532: }
533:
1.28 markus 534: void
1.21 markus 535: after_select(fd_set *readset, fd_set *writeset)
536: {
537: unsigned int i;
538: int len, sock;
1.26 markus 539: socklen_t slen;
1.21 markus 540: char buf[1024];
541: struct sockaddr_un sunaddr;
542:
543: for (i = 0; i < sockets_alloc; i++)
544: switch (sockets[i].type) {
545: case AUTH_UNUSED:
546: break;
547: case AUTH_SOCKET:
548: if (FD_ISSET(sockets[i].fd, readset)) {
1.26 markus 549: slen = sizeof(sunaddr);
550: sock = accept(sockets[i].fd, (struct sockaddr *) & sunaddr, &slen);
1.21 markus 551: if (sock < 0) {
552: perror("accept from AUTH_SOCKET");
553: break;
554: }
555: new_socket(AUTH_CONNECTION, sock);
556: }
557: break;
558: case AUTH_CONNECTION:
559: if (buffer_len(&sockets[i].output) > 0 &&
560: FD_ISSET(sockets[i].fd, writeset)) {
561: len = write(sockets[i].fd, buffer_ptr(&sockets[i].output),
562: buffer_len(&sockets[i].output));
563: if (len <= 0) {
564: shutdown(sockets[i].fd, SHUT_RDWR);
565: close(sockets[i].fd);
566: sockets[i].type = AUTH_UNUSED;
1.30 djm 567: buffer_free(&sockets[i].input);
568: buffer_free(&sockets[i].output);
1.21 markus 569: break;
570: }
571: buffer_consume(&sockets[i].output, len);
572: }
573: if (FD_ISSET(sockets[i].fd, readset)) {
574: len = read(sockets[i].fd, buf, sizeof(buf));
575: if (len <= 0) {
576: shutdown(sockets[i].fd, SHUT_RDWR);
577: close(sockets[i].fd);
578: sockets[i].type = AUTH_UNUSED;
1.30 djm 579: buffer_free(&sockets[i].input);
580: buffer_free(&sockets[i].output);
1.21 markus 581: break;
582: }
583: buffer_append(&sockets[i].input, buf, len);
584: process_message(&sockets[i]);
585: }
586: break;
587: default:
588: fatal("Unknown type %d", sockets[i].type);
589: }
1.1 deraadt 590: }
591:
1.6 deraadt 592: void
1.2 provos 593: check_parent_exists(int sig)
1.1 deraadt 594: {
1.29 deraadt 595: if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
1.21 markus 596: /* printf("Parent has died - Authentication agent exiting.\n"); */
597: exit(1);
598: }
599: signal(SIGALRM, check_parent_exists);
600: alarm(10);
1.1 deraadt 601: }
602:
1.15 markus 603: void
604: cleanup_socket(void)
605: {
1.21 markus 606: remove(socket_name);
607: rmdir(socket_dir);
1.10 markus 608: }
609:
1.15 markus 610: void
611: cleanup_exit(int i)
612: {
1.21 markus 613: cleanup_socket();
614: exit(i);
1.15 markus 615: }
616:
617: void
618: usage()
619: {
1.21 markus 620: fprintf(stderr, "ssh-agent version %s\n", SSH_VERSION);
621: fprintf(stderr, "Usage: %s [-c | -s] [-k] [command {args...]]\n",
622: __progname);
623: exit(1);
1.15 markus 624: }
625:
1.2 provos 626: int
627: main(int ac, char **av)
1.1 deraadt 628: {
1.21 markus 629: fd_set readset, writeset;
630: int sock, c_flag = 0, k_flag = 0, s_flag = 0, ch;
631: struct sockaddr_un sunaddr;
632: pid_t pid;
633: char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid];
634:
635: /* check if RSA support exists */
636: if (rsa_alive() == 0) {
637: fprintf(stderr,
638: "%s: no RSA support in libssl and libcrypto. See ssl(8).\n",
639: __progname);
640: exit(1);
641: }
642: while ((ch = getopt(ac, av, "cks")) != -1) {
643: switch (ch) {
644: case 'c':
645: if (s_flag)
646: usage();
647: c_flag++;
648: break;
649: case 'k':
650: k_flag++;
651: break;
652: case 's':
653: if (c_flag)
654: usage();
655: s_flag++;
656: break;
657: default:
658: usage();
659: }
660: }
661: ac -= optind;
662: av += optind;
663:
664: if (ac > 0 && (c_flag || k_flag || s_flag))
665: usage();
666:
667: if (ac == 0 && !c_flag && !k_flag && !s_flag) {
668: shell = getenv("SHELL");
669: if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
670: c_flag = 1;
671: }
672: if (k_flag) {
673: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
674: if (pidstr == NULL) {
675: fprintf(stderr, "%s not set, cannot kill agent\n",
676: SSH_AGENTPID_ENV_NAME);
677: exit(1);
678: }
679: pid = atoi(pidstr);
680: if (pid < 1) { /* XXX PID_MAX check too */
1.29 deraadt 681: /* Yes, PID_MAX check please */
1.21 markus 682: fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
683: SSH_AGENTPID_ENV_NAME, pidstr);
684: exit(1);
685: }
686: if (kill(pid, SIGTERM) == -1) {
687: perror("kill");
688: exit(1);
689: }
690: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
691: printf(format, SSH_AUTHSOCKET_ENV_NAME);
692: printf(format, SSH_AGENTPID_ENV_NAME);
693: printf("echo Agent pid %d killed;\n", pid);
694: exit(0);
695: }
696: parent_pid = getpid();
697:
698: /* Create private directory for agent socket */
699: strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir);
700: if (mkdtemp(socket_dir) == NULL) {
701: perror("mkdtemp: private socket dir");
702: exit(1);
703: }
704: snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir,
705: parent_pid);
706:
1.23 markus 707: /*
708: * Create socket early so it will exist before command gets run from
709: * the parent.
710: */
1.21 markus 711: sock = socket(AF_UNIX, SOCK_STREAM, 0);
712: if (sock < 0) {
713: perror("socket");
714: cleanup_exit(1);
715: }
716: memset(&sunaddr, 0, sizeof(sunaddr));
717: sunaddr.sun_family = AF_UNIX;
718: strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
719: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
720: perror("bind");
721: cleanup_exit(1);
722: }
723: if (listen(sock, 5) < 0) {
724: perror("listen");
725: cleanup_exit(1);
726: }
1.23 markus 727: /*
728: * Fork, and have the parent execute the command, if any, or present
729: * the socket data. The child continues as the authentication agent.
730: */
1.21 markus 731: pid = fork();
732: if (pid == -1) {
733: perror("fork");
734: exit(1);
735: }
736: if (pid != 0) { /* Parent - execute the given command. */
737: close(sock);
738: snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid);
739: if (ac == 0) {
740: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
741: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
742: SSH_AUTHSOCKET_ENV_NAME);
743: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
744: SSH_AGENTPID_ENV_NAME);
745: printf("echo Agent pid %d;\n", pid);
746: exit(0);
747: }
748: setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1);
749: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1);
750: execvp(av[0], av);
751: perror(av[0]);
752: exit(1);
753: }
754: close(0);
755: close(1);
756: close(2);
757:
758: if (setsid() == -1) {
759: perror("setsid");
760: cleanup_exit(1);
761: }
762: if (atexit(cleanup_socket) < 0) {
763: perror("atexit");
764: cleanup_exit(1);
765: }
766: new_socket(AUTH_SOCKET, sock);
767: if (ac > 0) {
768: signal(SIGALRM, check_parent_exists);
769: alarm(10);
770: }
1.31.2.1! jason 771: idtab_init();
1.21 markus 772: signal(SIGINT, SIG_IGN);
773: signal(SIGPIPE, SIG_IGN);
1.28 markus 774: signal(SIGHUP, cleanup_exit);
775: signal(SIGTERM, cleanup_exit);
1.21 markus 776: while (1) {
777: FD_ZERO(&readset);
778: FD_ZERO(&writeset);
779: prepare_select(&readset, &writeset);
780: if (select(max_fd + 1, &readset, &writeset, NULL, NULL) < 0) {
781: if (errno == EINTR)
782: continue;
783: exit(1);
784: }
785: after_select(&readset, &writeset);
1.15 markus 786: }
1.21 markus 787: /* NOTREACHED */
1.1 deraadt 788: }
![[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