Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.227
1.227 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.226 2017/11/15 02:10:16 djm Exp $ */
1.1 deraadt 2: /*
1.22 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * The authentication agent program.
1.33 markus 7: *
1.35 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.56 markus 14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 15: *
16: * Redistribution and use in source and binary forms, with or without
17: * modification, are permitted provided that the following conditions
18: * are met:
19: * 1. Redistributions of source code must retain the above copyright
20: * notice, this list of conditions and the following disclaimer.
21: * 2. Redistributions in binary form must reproduce the above copyright
22: * notice, this list of conditions and the following disclaimer in the
23: * documentation and/or other materials provided with the distribution.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 35: */
1.1 deraadt 36:
1.151 deraadt 37: #include <sys/types.h>
1.153 djm 38: #include <sys/time.h>
1.78 provos 39: #include <sys/queue.h>
1.127 stevesk 40: #include <sys/resource.h>
1.141 stevesk 41: #include <sys/socket.h>
1.189 djm 42: #include <sys/stat.h>
1.128 stevesk 43: #include <sys/un.h>
1.126 stevesk 44:
1.185 markus 45: #ifdef WITH_OPENSSL
1.146 stevesk 46: #include <openssl/evp.h>
1.185 markus 47: #endif
1.146 stevesk 48:
1.143 stevesk 49: #include <errno.h>
1.142 stevesk 50: #include <fcntl.h>
1.126 stevesk 51: #include <paths.h>
1.223 djm 52: #include <poll.h>
1.129 stevesk 53: #include <signal.h>
1.149 stevesk 54: #include <stdlib.h>
1.150 stevesk 55: #include <stdio.h>
1.146 stevesk 56: #include <string.h>
1.196 deraadt 57: #include <limits.h>
1.145 stevesk 58: #include <time.h>
1.144 stevesk 59: #include <unistd.h>
1.203 dtucker 60: #include <util.h>
1.194 markus 61:
1.151 deraadt 62: #include "xmalloc.h"
1.1 deraadt 63: #include "ssh.h"
1.194 markus 64: #include "sshbuf.h"
65: #include "sshkey.h"
1.32 markus 66: #include "authfd.h"
1.37 markus 67: #include "compat.h"
1.47 markus 68: #include "log.h"
1.107 markus 69: #include "misc.h"
1.182 markus 70: #include "digest.h"
1.194 markus 71: #include "ssherr.h"
1.215 djm 72: #include "match.h"
1.7 deraadt 73:
1.163 markus 74: #ifdef ENABLE_PKCS11
75: #include "ssh-pkcs11.h"
1.71 jakob 76: #endif
1.59 markus 77:
1.215 djm 78: #ifndef DEFAULT_PKCS11_WHITELIST
1.216 djm 79: # define DEFAULT_PKCS11_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 80: #endif
81:
1.223 djm 82: /* Maximum accepted message length */
83: #define AGENT_MAX_LEN (256*1024)
84:
1.73 stevesk 85: typedef enum {
86: AUTH_UNUSED,
87: AUTH_SOCKET,
88: AUTH_CONNECTION
89: } sock_type;
90:
1.21 markus 91: typedef struct {
92: int fd;
1.73 stevesk 93: sock_type type;
1.194 markus 94: struct sshbuf *input;
95: struct sshbuf *output;
96: struct sshbuf *request;
1.1 deraadt 97: } SocketEntry;
98:
1.45 markus 99: u_int sockets_alloc = 0;
1.1 deraadt 100: SocketEntry *sockets = NULL;
101:
1.78 provos 102: typedef struct identity {
103: TAILQ_ENTRY(identity) next;
1.194 markus 104: struct sshkey *key;
1.21 markus 105: char *comment;
1.163 markus 106: char *provider;
1.174 dtucker 107: time_t death;
1.107 markus 108: u_int confirm;
1.1 deraadt 109: } Identity;
110:
1.221 djm 111: struct idtable {
1.33 markus 112: int nentries;
1.78 provos 113: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 114: };
1.33 markus 115:
1.221 djm 116: /* private key table */
117: struct idtable *idtab;
1.1 deraadt 118:
119: int max_fd = 0;
120:
1.11 markus 121: /* pid of shell == parent of agent */
1.29 deraadt 122: pid_t parent_pid = -1;
1.176 dtucker 123: time_t parent_alive_interval = 0;
1.10 markus 124:
1.187 djm 125: /* pid of process for which cleanup_socket is applicable */
126: pid_t cleanup_pid = 0;
127:
1.10 markus 128: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 129: char socket_name[PATH_MAX];
130: char socket_dir[PATH_MAX];
1.10 markus 131:
1.215 djm 132: /* PKCS#11 path whitelist */
133: static char *pkcs11_whitelist;
134:
1.88 markus 135: /* locking */
1.203 dtucker 136: #define LOCK_SIZE 32
137: #define LOCK_SALT_SIZE 16
138: #define LOCK_ROUNDS 1
1.88 markus 139: int locked = 0;
1.213 djm 140: u_char lock_pwhash[LOCK_SIZE];
141: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 142:
1.20 markus 143: extern char *__progname;
144:
1.174 dtucker 145: /* Default lifetime in seconds (0 == forever) */
146: static long lifetime = 0;
1.106 marc 147:
1.192 djm 148: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
149:
1.55 itojun 150: static void
1.101 stevesk 151: close_socket(SocketEntry *e)
152: {
153: close(e->fd);
154: e->fd = -1;
155: e->type = AUTH_UNUSED;
1.194 markus 156: sshbuf_free(e->input);
157: sshbuf_free(e->output);
158: sshbuf_free(e->request);
1.101 stevesk 159: }
160:
161: static void
1.33 markus 162: idtab_init(void)
1.1 deraadt 163: {
1.221 djm 164: idtab = xcalloc(1, sizeof(*idtab));
165: TAILQ_INIT(&idtab->idlist);
166: idtab->nentries = 0;
1.33 markus 167: }
168:
1.89 markus 169: static void
170: free_identity(Identity *id)
171: {
1.194 markus 172: sshkey_free(id->key);
1.173 djm 173: free(id->provider);
174: free(id->comment);
175: free(id);
1.89 markus 176: }
177:
1.33 markus 178: /* return matching private key for given public key */
1.78 provos 179: static Identity *
1.221 djm 180: lookup_identity(struct sshkey *key)
1.33 markus 181: {
1.78 provos 182: Identity *id;
183:
1.221 djm 184: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 185: if (sshkey_equal(key, id->key))
1.78 provos 186: return (id);
1.33 markus 187: }
1.78 provos 188: return (NULL);
189: }
190:
1.107 markus 191: /* Check confirmation of keysign request */
192: static int
193: confirm_key(Identity *id)
194: {
1.122 djm 195: char *p;
1.107 markus 196: int ret = -1;
197:
1.194 markus 198: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 199: if (p != NULL &&
200: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 201: id->comment, p))
202: ret = 0;
1.173 djm 203: free(p);
1.122 djm 204:
1.107 markus 205: return (ret);
206: }
207:
1.194 markus 208: static void
209: send_status(SocketEntry *e, int success)
210: {
211: int r;
212:
213: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
214: (r = sshbuf_put_u8(e->output, success ?
215: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
216: fatal("%s: buffer error: %s", __func__, ssh_err(r));
217: }
218:
1.33 markus 219: /* send list of supported public keys to 'client' */
1.55 itojun 220: static void
1.221 djm 221: process_request_identities(SocketEntry *e)
1.33 markus 222: {
1.96 deraadt 223: Identity *id;
1.194 markus 224: struct sshbuf *msg;
225: int r;
1.1 deraadt 226:
1.194 markus 227: if ((msg = sshbuf_new()) == NULL)
228: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 229: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
230: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
231: fatal("%s: buffer error: %s", __func__, ssh_err(r));
232: TAILQ_FOREACH(id, &idtab->idlist, next) {
233: if ((r = sshkey_puts(id->key, msg)) != 0 ||
234: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
235: error("%s: put key/comment: %s", __func__,
1.220 djm 236: ssh_err(r));
237: continue;
1.33 markus 238: }
1.21 markus 239: }
1.194 markus 240: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
241: fatal("%s: buffer error: %s", __func__, ssh_err(r));
242: sshbuf_free(msg);
1.1 deraadt 243: }
244:
1.33 markus 245:
1.208 markus 246: static char *
247: agent_decode_alg(struct sshkey *key, u_int flags)
248: {
249: if (key->type == KEY_RSA) {
250: if (flags & SSH_AGENT_RSA_SHA2_256)
251: return "rsa-sha2-256";
252: else if (flags & SSH_AGENT_RSA_SHA2_512)
253: return "rsa-sha2-512";
254: }
255: return NULL;
256: }
257:
1.33 markus 258: /* ssh2 only */
1.55 itojun 259: static void
1.33 markus 260: process_sign_request2(SocketEntry *e)
261: {
1.221 djm 262: const u_char *data;
263: u_char *signature = NULL;
264: size_t dlen, slen = 0;
1.194 markus 265: u_int compat = 0, flags;
266: int r, ok = -1;
267: struct sshbuf *msg;
1.221 djm 268: struct sshkey *key = NULL;
1.195 djm 269: struct identity *id;
1.194 markus 270:
1.195 djm 271: if ((msg = sshbuf_new()) == NULL)
272: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 273: if ((r = sshkey_froms(e->request, &key)) != 0 ||
274: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 275: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
276: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
277: goto send;
278: }
279:
1.221 djm 280: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 281: verbose("%s: %s key not found", __func__, sshkey_type(key));
282: goto send;
283: }
284: if (id->confirm && confirm_key(id) != 0) {
285: verbose("%s: user refused key", __func__);
286: goto send;
287: }
288: if ((r = sshkey_sign(id->key, &signature, &slen,
1.208 markus 289: data, dlen, agent_decode_alg(key, flags), compat)) != 0) {
1.209 djm 290: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
1.195 djm 291: goto send;
1.33 markus 292: }
1.195 djm 293: /* Success */
294: ok = 0;
295: send:
296: sshkey_free(key);
1.33 markus 297: if (ok == 0) {
1.194 markus 298: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
299: (r = sshbuf_put_string(msg, signature, slen)) != 0)
300: fatal("%s: buffer error: %s", __func__, ssh_err(r));
301: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
302: fatal("%s: buffer error: %s", __func__, ssh_err(r));
303:
304: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
305: fatal("%s: buffer error: %s", __func__, ssh_err(r));
306:
307: sshbuf_free(msg);
1.173 djm 308: free(signature);
1.1 deraadt 309: }
310:
1.33 markus 311: /* shared */
1.55 itojun 312: static void
1.221 djm 313: process_remove_identity(SocketEntry *e)
1.1 deraadt 314: {
1.194 markus 315: int r, success = 0;
316: struct sshkey *key = NULL;
1.221 djm 317: Identity *id;
1.21 markus 318:
1.221 djm 319: if ((r = sshkey_froms(e->request, &key)) != 0) {
320: error("%s: get key: %s", __func__, ssh_err(r));
321: goto done;
322: }
323: if ((id = lookup_identity(key)) == NULL) {
324: debug("%s: key not found", __func__);
325: goto done;
326: }
327: /* We have this key, free it. */
328: if (idtab->nentries < 1)
329: fatal("%s: internal error: nentries %d",
330: __func__, idtab->nentries);
331: TAILQ_REMOVE(&idtab->idlist, id, next);
332: free_identity(id);
333: idtab->nentries--;
334: sshkey_free(key);
335: success = 1;
336: done:
1.194 markus 337: send_status(e, success);
1.1 deraadt 338: }
339:
1.55 itojun 340: static void
1.221 djm 341: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 342: {
1.78 provos 343: Identity *id;
1.21 markus 344:
345: /* Loop over all identities and clear the keys. */
1.221 djm 346: for (id = TAILQ_FIRST(&idtab->idlist); id;
347: id = TAILQ_FIRST(&idtab->idlist)) {
348: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 349: free_identity(id);
1.21 markus 350: }
351:
352: /* Mark that there are no identities. */
1.221 djm 353: idtab->nentries = 0;
1.21 markus 354:
355: /* Send success. */
1.194 markus 356: send_status(e, 1);
1.1 deraadt 357: }
358:
1.155 dtucker 359: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 360: static time_t
1.89 markus 361: reaper(void)
362: {
1.175 dtucker 363: time_t deadline = 0, now = monotime();
1.89 markus 364: Identity *id, *nxt;
365:
1.221 djm 366: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
367: nxt = TAILQ_NEXT(id, next);
368: if (id->death == 0)
369: continue;
370: if (now >= id->death) {
371: debug("expiring key '%s'", id->comment);
372: TAILQ_REMOVE(&idtab->idlist, id, next);
373: free_identity(id);
374: idtab->nentries--;
375: } else
376: deadline = (deadline == 0) ? id->death :
377: MINIMUM(deadline, id->death);
1.89 markus 378: }
1.155 dtucker 379: if (deadline == 0 || deadline <= now)
380: return 0;
381: else
382: return (deadline - now);
1.89 markus 383: }
384:
385: static void
1.221 djm 386: process_add_identity(SocketEntry *e)
1.1 deraadt 387: {
1.157 canacar 388: Identity *id;
1.194 markus 389: int success = 0, confirm = 0;
390: u_int seconds;
391: char *comment = NULL;
1.174 dtucker 392: time_t death = 0;
1.194 markus 393: struct sshkey *k = NULL;
394: u_char ctype;
395: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 396:
1.221 djm 397: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
398: k == NULL ||
1.194 markus 399: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
400: error("%s: decode private key: %s", __func__, ssh_err(r));
401: goto err;
402: }
1.186 djm 403:
1.194 markus 404: while (sshbuf_len(e->request)) {
405: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
406: error("%s: buffer error: %s", __func__, ssh_err(r));
407: goto err;
408: }
409: switch (ctype) {
1.94 markus 410: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 411: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
412: error("%s: bad lifetime constraint: %s",
413: __func__, ssh_err(r));
414: goto err;
415: }
416: death = monotime() + seconds;
1.94 markus 417: break;
1.107 markus 418: case SSH_AGENT_CONSTRAIN_CONFIRM:
419: confirm = 1;
420: break;
1.94 markus 421: default:
1.194 markus 422: error("%s: Unknown constraint %d", __func__, ctype);
423: err:
424: sshbuf_reset(e->request);
1.173 djm 425: free(comment);
1.194 markus 426: sshkey_free(k);
1.158 djm 427: goto send;
1.94 markus 428: }
429: }
1.194 markus 430:
1.158 djm 431: success = 1;
1.106 marc 432: if (lifetime && !death)
1.175 dtucker 433: death = monotime() + lifetime;
1.221 djm 434: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 435: id = xcalloc(1, sizeof(Identity));
1.78 provos 436: id->key = k;
1.221 djm 437: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 438: /* Increment the number of identities. */
1.221 djm 439: idtab->nentries++;
1.33 markus 440: } else {
1.194 markus 441: sshkey_free(k);
1.173 djm 442: free(id->comment);
1.33 markus 443: }
1.157 canacar 444: id->comment = comment;
445: id->death = death;
446: id->confirm = confirm;
1.33 markus 447: send:
1.194 markus 448: send_status(e, success);
1.1 deraadt 449: }
450:
1.88 markus 451: /* XXX todo: encrypt sensitive data with passphrase */
452: static void
453: process_lock_agent(SocketEntry *e, int lock)
454: {
1.203 dtucker 455: int r, success = 0, delay;
1.213 djm 456: char *passwd;
457: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 458: static u_int fail_count = 0;
459: size_t pwlen;
460:
1.226 djm 461: /*
462: * This is deliberately fatal: the user has requested that we lock,
463: * but we can't parse their request properly. The only safe thing to
464: * do is abort.
465: */
1.203 dtucker 466: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
467: fatal("%s: buffer error: %s", __func__, ssh_err(r));
468: if (pwlen == 0) {
469: debug("empty password not supported");
470: } else if (locked && !lock) {
471: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
472: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
473: fatal("bcrypt_pbkdf");
1.213 djm 474: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 475: debug("agent unlocked");
476: locked = 0;
477: fail_count = 0;
1.213 djm 478: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 479: success = 1;
480: } else {
481: /* delay in 0.1s increments up to 10s */
482: if (fail_count < 100)
483: fail_count++;
484: delay = 100000 * fail_count;
485: debug("unlock failed, delaying %0.1lf seconds",
486: (double)delay/1000000);
487: usleep(delay);
488: }
489: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 490: } else if (!locked && lock) {
1.203 dtucker 491: debug("agent locked");
1.88 markus 492: locked = 1;
1.203 dtucker 493: arc4random_buf(lock_salt, sizeof(lock_salt));
494: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 495: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 496: fatal("bcrypt_pbkdf");
1.88 markus 497: success = 1;
498: }
1.203 dtucker 499: explicit_bzero(passwd, pwlen);
1.173 djm 500: free(passwd);
1.194 markus 501: send_status(e, success);
1.88 markus 502: }
503:
504: static void
1.221 djm 505: no_identities(SocketEntry *e)
1.88 markus 506: {
1.194 markus 507: struct sshbuf *msg;
508: int r;
1.88 markus 509:
1.194 markus 510: if ((msg = sshbuf_new()) == NULL)
511: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 512: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 513: (r = sshbuf_put_u32(msg, 0)) != 0 ||
514: (r = sshbuf_put_stringb(e->output, msg)) != 0)
515: fatal("%s: buffer error: %s", __func__, ssh_err(r));
516: sshbuf_free(msg);
1.88 markus 517: }
1.59 markus 518:
1.163 markus 519: #ifdef ENABLE_PKCS11
1.59 markus 520: static void
1.158 djm 521: process_add_smartcard_key(SocketEntry *e)
1.59 markus 522: {
1.226 djm 523: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 524: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 525: u_int seconds;
1.174 dtucker 526: time_t death = 0;
1.194 markus 527: u_char type;
528: struct sshkey **keys = NULL, *k;
1.84 markus 529: Identity *id;
1.75 deraadt 530:
1.194 markus 531: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 532: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
533: error("%s: buffer error: %s", __func__, ssh_err(r));
534: goto send;
535: }
1.194 markus 536:
537: while (sshbuf_len(e->request)) {
1.226 djm 538: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
539: error("%s: buffer error: %s", __func__, ssh_err(r));
540: goto send;
541: }
1.194 markus 542: switch (type) {
1.110 djm 543: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 544: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
545: error("%s: buffer error: %s",
1.194 markus 546: __func__, ssh_err(r));
1.226 djm 547: goto send;
548: }
1.194 markus 549: death = monotime() + seconds;
1.110 djm 550: break;
551: case SSH_AGENT_CONSTRAIN_CONFIRM:
552: confirm = 1;
553: break;
554: default:
1.221 djm 555: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 556: goto send;
1.110 djm 557: }
558: }
1.215 djm 559: if (realpath(provider, canonical_provider) == NULL) {
560: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
561: provider, strerror(errno));
562: goto send;
563: }
564: if (match_pattern_list(canonical_provider, pkcs11_whitelist, 0) != 1) {
565: verbose("refusing PKCS#11 add of \"%.100s\": "
566: "provider not whitelisted", canonical_provider);
567: goto send;
568: }
569: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 570: if (lifetime && !death)
1.175 dtucker 571: death = monotime() + lifetime;
1.110 djm 572:
1.215 djm 573: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 574: for (i = 0; i < count; i++) {
1.84 markus 575: k = keys[i];
1.221 djm 576: if (lookup_identity(k) == NULL) {
1.163 markus 577: id = xcalloc(1, sizeof(Identity));
1.84 markus 578: id->key = k;
1.215 djm 579: id->provider = xstrdup(canonical_provider);
580: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 581: id->death = death;
582: id->confirm = confirm;
1.221 djm 583: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
584: idtab->nentries++;
1.84 markus 585: success = 1;
586: } else {
1.194 markus 587: sshkey_free(k);
1.84 markus 588: }
589: keys[i] = NULL;
1.59 markus 590: }
591: send:
1.173 djm 592: free(pin);
593: free(provider);
594: free(keys);
1.194 markus 595: send_status(e, success);
1.59 markus 596: }
597:
598: static void
599: process_remove_smartcard_key(SocketEntry *e)
600: {
1.217 djm 601: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 602: int r, success = 0;
1.163 markus 603: Identity *id, *nxt;
1.59 markus 604:
1.194 markus 605: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 606: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
607: error("%s: buffer error: %s", __func__, ssh_err(r));
608: goto send;
609: }
1.173 djm 610: free(pin);
1.59 markus 611:
1.217 djm 612: if (realpath(provider, canonical_provider) == NULL) {
613: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
614: provider, strerror(errno));
615: goto send;
616: }
617:
618: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 619: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
620: nxt = TAILQ_NEXT(id, next);
621: /* Skip file--based keys */
622: if (id->provider == NULL)
623: continue;
624: if (!strcmp(canonical_provider, id->provider)) {
625: TAILQ_REMOVE(&idtab->idlist, id, next);
626: free_identity(id);
627: idtab->nentries--;
1.59 markus 628: }
629: }
1.217 djm 630: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 631: success = 1;
632: else
1.221 djm 633: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 634: send:
1.173 djm 635: free(provider);
1.194 markus 636: send_status(e, success);
1.59 markus 637: }
1.163 markus 638: #endif /* ENABLE_PKCS11 */
1.59 markus 639:
1.33 markus 640: /* dispatch incoming messages */
641:
1.223 djm 642: static int
643: process_message(u_int socknum)
1.1 deraadt 644: {
1.194 markus 645: u_int msg_len;
646: u_char type;
647: const u_char *cp;
648: int r;
1.223 djm 649: SocketEntry *e;
650:
651: if (socknum >= sockets_alloc) {
652: fatal("%s: socket number %u >= allocated %u",
653: __func__, socknum, sockets_alloc);
654: }
655: e = &sockets[socknum];
1.89 markus 656:
1.194 markus 657: if (sshbuf_len(e->input) < 5)
1.223 djm 658: return 0; /* Incomplete message header. */
1.194 markus 659: cp = sshbuf_ptr(e->input);
660: msg_len = PEEK_U32(cp);
1.223 djm 661: if (msg_len > AGENT_MAX_LEN) {
662: debug("%s: socket %u (fd=%d) message too long %u > %u",
663: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
664: return -1;
1.21 markus 665: }
1.194 markus 666: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 667: return 0; /* Incomplete message body. */
1.87 markus 668:
669: /* move the current input to e->request */
1.194 markus 670: sshbuf_reset(e->request);
671: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 672: (r = sshbuf_get_u8(e->request, &type)) != 0) {
673: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
674: r == SSH_ERR_STRING_TOO_LARGE) {
675: debug("%s: buffer error: %s", __func__, ssh_err(r));
676: return -1;
677: }
1.194 markus 678: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 679: }
680:
681: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 682:
1.88 markus 683: /* check wheter agent is locked */
684: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 685: sshbuf_reset(e->request);
1.88 markus 686: switch (type) {
687: case SSH2_AGENTC_REQUEST_IDENTITIES:
688: /* send empty lists */
1.221 djm 689: no_identities(e);
1.88 markus 690: break;
691: default:
692: /* send a fail message for all other request types */
1.194 markus 693: send_status(e, 0);
1.88 markus 694: }
1.223 djm 695: return 0;
1.88 markus 696: }
697:
1.21 markus 698: switch (type) {
1.88 markus 699: case SSH_AGENTC_LOCK:
700: case SSH_AGENTC_UNLOCK:
701: process_lock_agent(e, type == SSH_AGENTC_LOCK);
702: break;
1.21 markus 703: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 704: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 705: break;
706: /* ssh2 */
707: case SSH2_AGENTC_SIGN_REQUEST:
708: process_sign_request2(e);
709: break;
710: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 711: process_request_identities(e);
1.33 markus 712: break;
713: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 714: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 715: process_add_identity(e);
1.33 markus 716: break;
717: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 718: process_remove_identity(e);
1.33 markus 719: break;
720: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 721: process_remove_all_identities(e);
1.21 markus 722: break;
1.163 markus 723: #ifdef ENABLE_PKCS11
1.59 markus 724: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 725: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 726: process_add_smartcard_key(e);
1.75 deraadt 727: break;
1.59 markus 728: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
729: process_remove_smartcard_key(e);
1.75 deraadt 730: break;
1.163 markus 731: #endif /* ENABLE_PKCS11 */
1.21 markus 732: default:
733: /* Unknown message. Respond with failure. */
734: error("Unknown message %d", type);
1.194 markus 735: sshbuf_reset(e->request);
736: send_status(e, 0);
1.21 markus 737: break;
738: }
1.223 djm 739: return 0;
1.1 deraadt 740: }
741:
1.55 itojun 742: static void
1.73 stevesk 743: new_socket(sock_type type, int fd)
1.1 deraadt 744: {
1.112 markus 745: u_int i, old_alloc, new_alloc;
1.96 deraadt 746:
1.119 djm 747: set_nonblock(fd);
1.21 markus 748:
749: if (fd > max_fd)
750: max_fd = fd;
751:
752: for (i = 0; i < sockets_alloc; i++)
753: if (sockets[i].type == AUTH_UNUSED) {
754: sockets[i].fd = fd;
1.194 markus 755: if ((sockets[i].input = sshbuf_new()) == NULL)
756: fatal("%s: sshbuf_new failed", __func__);
757: if ((sockets[i].output = sshbuf_new()) == NULL)
758: fatal("%s: sshbuf_new failed", __func__);
759: if ((sockets[i].request = sshbuf_new()) == NULL)
760: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 761: sockets[i].type = type;
1.21 markus 762: return;
763: }
764: old_alloc = sockets_alloc;
1.112 markus 765: new_alloc = sockets_alloc + 10;
1.200 deraadt 766: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 767: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 768: sockets[i].type = AUTH_UNUSED;
1.112 markus 769: sockets_alloc = new_alloc;
1.21 markus 770: sockets[old_alloc].fd = fd;
1.194 markus 771: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
772: fatal("%s: sshbuf_new failed", __func__);
773: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
774: fatal("%s: sshbuf_new failed", __func__);
775: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
776: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 777: sockets[old_alloc].type = type;
1.1 deraadt 778: }
779:
1.55 itojun 780: static int
1.223 djm 781: handle_socket_read(u_int socknum)
1.1 deraadt 782: {
1.223 djm 783: struct sockaddr_un sunaddr;
784: socklen_t slen;
785: uid_t euid;
786: gid_t egid;
787: int fd;
788:
789: slen = sizeof(sunaddr);
790: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
791: if (fd < 0) {
792: error("accept from AUTH_SOCKET: %s", strerror(errno));
793: return -1;
794: }
795: if (getpeereid(fd, &euid, &egid) < 0) {
796: error("getpeereid %d failed: %s", fd, strerror(errno));
797: close(fd);
798: return -1;
799: }
800: if ((euid != 0) && (getuid() != euid)) {
801: error("uid mismatch: peer euid %u != uid %u",
802: (u_int) euid, (u_int) getuid());
803: close(fd);
804: return -1;
805: }
806: new_socket(AUTH_CONNECTION, fd);
807: return 0;
808: }
809:
810: static int
811: handle_conn_read(u_int socknum)
812: {
813: char buf[1024];
814: ssize_t len;
815: int r;
816:
817: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
818: if (len == -1) {
819: if (errno == EAGAIN || errno == EINTR)
820: return 0;
821: error("%s: read error on socket %u (fd %d): %s",
822: __func__, socknum, sockets[socknum].fd,
823: strerror(errno));
824: }
825: return -1;
826: }
827: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
828: fatal("%s: buffer error: %s", __func__, ssh_err(r));
829: explicit_bzero(buf, sizeof(buf));
830: process_message(socknum);
831: return 0;
832: }
833:
834: static int
835: handle_conn_write(u_int socknum)
836: {
837: ssize_t len;
838: int r;
839:
840: if (sshbuf_len(sockets[socknum].output) == 0)
841: return 0; /* shouldn't happen */
842: if ((len = write(sockets[socknum].fd,
843: sshbuf_ptr(sockets[socknum].output),
844: sshbuf_len(sockets[socknum].output))) <= 0) {
845: if (len == -1) {
846: if (errno == EAGAIN || errno == EINTR)
847: return 0;
848: error("%s: read error on socket %u (fd %d): %s",
849: __func__, socknum, sockets[socknum].fd,
850: strerror(errno));
851: }
852: return -1;
853: }
854: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
855: fatal("%s: buffer error: %s", __func__, ssh_err(r));
856: return 0;
857: }
858:
859: static void
860: after_poll(struct pollfd *pfd, size_t npfd)
861: {
862: size_t i;
863: u_int socknum;
864:
865: for (i = 0; i < npfd; i++) {
866: if (pfd[i].revents == 0)
867: continue;
868: /* Find sockets entry */
869: for (socknum = 0; socknum < sockets_alloc; socknum++) {
870: if (sockets[socknum].type != AUTH_SOCKET &&
871: sockets[socknum].type != AUTH_CONNECTION)
872: continue;
873: if (pfd[i].fd == sockets[socknum].fd)
874: break;
875: }
876: if (socknum >= sockets_alloc) {
877: error("%s: no socket for fd %d", __func__, pfd[i].fd);
878: continue;
879: }
880: /* Process events */
881: switch (sockets[socknum].type) {
882: case AUTH_SOCKET:
883: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
884: handle_socket_read(socknum) != 0)
885: close_socket(&sockets[socknum]);
886: break;
887: case AUTH_CONNECTION:
888: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
889: handle_conn_read(socknum) != 0) {
890: close_socket(&sockets[socknum]);
891: break;
892: }
893: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
894: handle_conn_write(socknum) != 0)
895: close_socket(&sockets[socknum]);
896: break;
897: default:
898: break;
899: }
900: }
901: }
902:
903: static int
904: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp)
905: {
906: struct pollfd *pfd = *pfdp;
907: size_t i, j, npfd = 0;
1.174 dtucker 908: time_t deadline;
1.46 markus 909:
1.223 djm 910: /* Count active sockets */
1.46 markus 911: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 912: switch (sockets[i].type) {
913: case AUTH_SOCKET:
914: case AUTH_CONNECTION:
1.223 djm 915: npfd++;
1.21 markus 916: break;
917: case AUTH_UNUSED:
918: break;
919: default:
920: fatal("Unknown socket type %d", sockets[i].type);
921: break;
922: }
1.46 markus 923: }
1.223 djm 924: if (npfd != *npfdp &&
925: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
926: fatal("%s: recallocarray failed", __func__);
927: *pfdp = pfd;
928: *npfdp = npfd;
1.46 markus 929:
1.223 djm 930: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 931: switch (sockets[i].type) {
932: case AUTH_SOCKET:
933: case AUTH_CONNECTION:
1.223 djm 934: pfd[j].fd = sockets[i].fd;
935: pfd[j].revents = 0;
936: /* XXX backoff when input buffer full */
937: pfd[j].events = POLLIN;
1.194 markus 938: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 939: pfd[j].events |= POLLOUT;
940: j++;
1.46 markus 941: break;
942: default:
943: break;
944: }
945: }
1.155 dtucker 946: deadline = reaper();
947: if (parent_alive_interval != 0)
948: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 949: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 950: if (deadline == 0) {
1.224 djm 951: *timeoutp = -1; /* INFTIM */
1.155 dtucker 952: } else {
1.223 djm 953: if (deadline > INT_MAX / 1000)
954: *timeoutp = INT_MAX / 1000;
955: else
956: *timeoutp = deadline * 1000;
1.155 dtucker 957: }
1.46 markus 958: return (1);
1.21 markus 959: }
960:
1.55 itojun 961: static void
1.113 markus 962: cleanup_socket(void)
1.15 markus 963: {
1.187 djm 964: if (cleanup_pid != 0 && getpid() != cleanup_pid)
965: return;
966: debug("%s: cleanup", __func__);
1.48 deraadt 967: if (socket_name[0])
968: unlink(socket_name);
969: if (socket_dir[0])
970: rmdir(socket_dir);
1.10 markus 971: }
972:
1.114 markus 973: void
1.15 markus 974: cleanup_exit(int i)
975: {
1.113 markus 976: cleanup_socket();
977: _exit(i);
1.15 markus 978: }
979:
1.135 deraadt 980: /*ARGSUSED*/
1.55 itojun 981: static void
1.48 deraadt 982: cleanup_handler(int sig)
983: {
1.113 markus 984: cleanup_socket();
1.163 markus 985: #ifdef ENABLE_PKCS11
986: pkcs11_terminate();
987: #endif
1.48 deraadt 988: _exit(2);
1.113 markus 989: }
990:
1.68 markus 991: static void
1.155 dtucker 992: check_parent_exists(void)
1.68 markus 993: {
1.172 dtucker 994: /*
995: * If our parent has exited then getppid() will return (pid_t)1,
996: * so testing for that should be safe.
997: */
998: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 999: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1000: cleanup_socket();
1001: _exit(2);
1.68 markus 1002: }
1.48 deraadt 1003: }
1004:
1.55 itojun 1005: static void
1.50 itojun 1006: usage(void)
1.15 markus 1007: {
1.184 deraadt 1008: fprintf(stderr,
1.202 jmc 1009: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.215 djm 1010: " [-P pkcs11_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1011: " ssh-agent [-c | -s] -k\n");
1.21 markus 1012: exit(1);
1.15 markus 1013: }
1014:
1.2 provos 1015: int
1016: main(int ac, char **av)
1.1 deraadt 1017: {
1.201 djm 1018: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1019: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1020: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1021: struct rlimit rlim;
1.96 deraadt 1022: extern int optind;
1.98 stevesk 1023: extern char *optarg;
1.21 markus 1024: pid_t pid;
1.96 deraadt 1025: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1026: size_t len;
1.189 djm 1027: mode_t prev_mask;
1.224 djm 1028: int timeout = -1; /* INFTIM */
1.223 djm 1029: struct pollfd *pfd = NULL;
1030: size_t npfd = 0;
1.123 djm 1031:
1.212 dtucker 1032: ssh_malloc_init(); /* must be called before any mallocs */
1.123 djm 1033: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1034: sanitise_stdfd();
1.99 markus 1035:
1036: /* drop */
1037: setegid(getgid());
1038: setgid(getgid());
1.53 markus 1039:
1.185 markus 1040: #ifdef WITH_OPENSSL
1.170 djm 1041: OpenSSL_add_all_algorithms();
1.185 markus 1042: #endif
1.21 markus 1043:
1.215 djm 1044: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1045: switch (ch) {
1.192 djm 1046: case 'E':
1047: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1048: if (fingerprint_hash == -1)
1049: fatal("Invalid hash algorithm \"%s\"", optarg);
1050: break;
1.21 markus 1051: case 'c':
1052: if (s_flag)
1053: usage();
1054: c_flag++;
1055: break;
1056: case 'k':
1057: k_flag++;
1058: break;
1.215 djm 1059: case 'P':
1060: if (pkcs11_whitelist != NULL)
1061: fatal("-P option already specified");
1062: pkcs11_whitelist = xstrdup(optarg);
1063: break;
1.21 markus 1064: case 's':
1065: if (c_flag)
1066: usage();
1067: s_flag++;
1068: break;
1.57 markus 1069: case 'd':
1.201 djm 1070: if (d_flag || D_flag)
1.57 markus 1071: usage();
1072: d_flag++;
1073: break;
1.201 djm 1074: case 'D':
1075: if (d_flag || D_flag)
1076: usage();
1077: D_flag++;
1078: break;
1.86 markus 1079: case 'a':
1080: agentsocket = optarg;
1.106 marc 1081: break;
1082: case 't':
1083: if ((lifetime = convtime(optarg)) == -1) {
1084: fprintf(stderr, "Invalid lifetime\n");
1085: usage();
1086: }
1.86 markus 1087: break;
1.21 markus 1088: default:
1089: usage();
1090: }
1091: }
1092: ac -= optind;
1093: av += optind;
1094:
1.201 djm 1095: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1096: usage();
1097:
1.215 djm 1098: if (pkcs11_whitelist == NULL)
1099: pkcs11_whitelist = xstrdup(DEFAULT_PKCS11_WHITELIST);
1100:
1.85 markus 1101: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1102: shell = getenv("SHELL");
1.161 tobias 1103: if (shell != NULL && (len = strlen(shell)) > 2 &&
1104: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1105: c_flag = 1;
1106: }
1107: if (k_flag) {
1.136 deraadt 1108: const char *errstr = NULL;
1109:
1.21 markus 1110: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1111: if (pidstr == NULL) {
1112: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1113: SSH_AGENTPID_ENV_NAME);
1.21 markus 1114: exit(1);
1115: }
1.136 deraadt 1116: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1117: if (errstr) {
1118: fprintf(stderr,
1119: "%s=\"%s\", which is not a good PID: %s\n",
1120: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1121: exit(1);
1122: }
1123: if (kill(pid, SIGTERM) == -1) {
1124: perror("kill");
1125: exit(1);
1126: }
1127: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1128: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1129: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1130: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1131: exit(0);
1132: }
1133: parent_pid = getpid();
1134:
1.86 markus 1135: if (agentsocket == NULL) {
1136: /* Create private directory for agent socket */
1.171 djm 1137: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1138: if (mkdtemp(socket_dir) == NULL) {
1139: perror("mkdtemp: private socket dir");
1140: exit(1);
1141: }
1.91 mpech 1142: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1143: (long)parent_pid);
1.86 markus 1144: } else {
1145: /* Try to use specified agent socket */
1146: socket_dir[0] = '\0';
1147: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1148: }
1149:
1.23 markus 1150: /*
1151: * Create socket early so it will exist before command gets run from
1152: * the parent.
1153: */
1.189 djm 1154: prev_mask = umask(0177);
1.188 millert 1155: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1156: if (sock < 0) {
1.188 millert 1157: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1158: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1159: cleanup_exit(1);
1160: }
1.189 djm 1161: umask(prev_mask);
1.46 markus 1162:
1.23 markus 1163: /*
1164: * Fork, and have the parent execute the command, if any, or present
1165: * the socket data. The child continues as the authentication agent.
1166: */
1.201 djm 1167: if (D_flag || d_flag) {
1168: log_init(__progname,
1169: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1170: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1171: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1172: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1173: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1174: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1175: fflush(stdout);
1.57 markus 1176: goto skip;
1177: }
1.21 markus 1178: pid = fork();
1179: if (pid == -1) {
1180: perror("fork");
1.81 stevesk 1181: cleanup_exit(1);
1.21 markus 1182: }
1183: if (pid != 0) { /* Parent - execute the given command. */
1184: close(sock);
1.91 mpech 1185: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1186: if (ac == 0) {
1187: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1188: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1189: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1190: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1191: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1192: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1193: exit(0);
1194: }
1.36 deraadt 1195: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1196: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1197: perror("setenv");
1198: exit(1);
1199: }
1.21 markus 1200: execvp(av[0], av);
1201: perror(av[0]);
1202: exit(1);
1203: }
1.81 stevesk 1204: /* child */
1205: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1206:
1207: if (setsid() == -1) {
1.81 stevesk 1208: error("setsid: %s", strerror(errno));
1.67 stevesk 1209: cleanup_exit(1);
1210: }
1211:
1212: (void)chdir("/");
1.107 markus 1213: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1214: /* XXX might close listen socket */
1215: (void)dup2(fd, STDIN_FILENO);
1216: (void)dup2(fd, STDOUT_FILENO);
1217: (void)dup2(fd, STDERR_FILENO);
1218: if (fd > 2)
1219: close(fd);
1220: }
1.21 markus 1221:
1.41 markus 1222: /* deny core dumps, since memory contains unencrypted private keys */
1223: rlim.rlim_cur = rlim.rlim_max = 0;
1224: if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1.81 stevesk 1225: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1226: cleanup_exit(1);
1227: }
1.57 markus 1228:
1229: skip:
1.187 djm 1230:
1231: cleanup_pid = getpid();
1.163 markus 1232:
1233: #ifdef ENABLE_PKCS11
1234: pkcs11_init(0);
1235: #endif
1.21 markus 1236: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1237: if (ac > 0)
1238: parent_alive_interval = 10;
1.33 markus 1239: idtab_init();
1.61 markus 1240: signal(SIGPIPE, SIG_IGN);
1.201 djm 1241: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1242: signal(SIGHUP, cleanup_handler);
1243: signal(SIGTERM, cleanup_handler);
1.205 djm 1244:
1.215 djm 1245: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1246: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1247:
1.21 markus 1248: while (1) {
1.223 djm 1249: prepare_poll(&pfd, &npfd, &timeout);
1250: result = poll(pfd, npfd, timeout);
1.154 dtucker 1251: saved_errno = errno;
1.155 dtucker 1252: if (parent_alive_interval != 0)
1253: check_parent_exists();
1254: (void) reaper(); /* remove expired keys */
1.154 dtucker 1255: if (result < 0) {
1256: if (saved_errno == EINTR)
1.21 markus 1257: continue;
1.223 djm 1258: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1259: } else if (result > 0)
1.223 djm 1260: after_poll(pfd, npfd);
1.15 markus 1261: }
1.21 markus 1262: /* NOTREACHED */
1.1 deraadt 1263: }
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