Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.231
1.231 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.230 2018/04/10 00:10:49 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) {
1.228 markus 233: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
234: != 0 ||
1.221 djm 235: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
236: error("%s: put key/comment: %s", __func__,
1.220 djm 237: ssh_err(r));
238: continue;
1.33 markus 239: }
1.21 markus 240: }
1.194 markus 241: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
242: fatal("%s: buffer error: %s", __func__, ssh_err(r));
243: sshbuf_free(msg);
1.1 deraadt 244: }
245:
1.33 markus 246:
1.208 markus 247: static char *
248: agent_decode_alg(struct sshkey *key, u_int flags)
249: {
250: if (key->type == KEY_RSA) {
251: if (flags & SSH_AGENT_RSA_SHA2_256)
252: return "rsa-sha2-256";
253: else if (flags & SSH_AGENT_RSA_SHA2_512)
254: return "rsa-sha2-512";
255: }
256: return NULL;
257: }
258:
1.33 markus 259: /* ssh2 only */
1.55 itojun 260: static void
1.33 markus 261: process_sign_request2(SocketEntry *e)
262: {
1.221 djm 263: const u_char *data;
264: u_char *signature = NULL;
265: size_t dlen, slen = 0;
1.194 markus 266: u_int compat = 0, flags;
267: int r, ok = -1;
268: struct sshbuf *msg;
1.221 djm 269: struct sshkey *key = NULL;
1.195 djm 270: struct identity *id;
1.194 markus 271:
1.195 djm 272: if ((msg = sshbuf_new()) == NULL)
273: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 274: if ((r = sshkey_froms(e->request, &key)) != 0 ||
275: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 276: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
277: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
278: goto send;
279: }
280:
1.221 djm 281: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 282: verbose("%s: %s key not found", __func__, sshkey_type(key));
283: goto send;
284: }
285: if (id->confirm && confirm_key(id) != 0) {
286: verbose("%s: user refused key", __func__);
287: goto send;
288: }
289: if ((r = sshkey_sign(id->key, &signature, &slen,
1.208 markus 290: data, dlen, agent_decode_alg(key, flags), compat)) != 0) {
1.209 djm 291: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
1.195 djm 292: goto send;
1.33 markus 293: }
1.195 djm 294: /* Success */
295: ok = 0;
296: send:
297: sshkey_free(key);
1.33 markus 298: if (ok == 0) {
1.194 markus 299: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
300: (r = sshbuf_put_string(msg, signature, slen)) != 0)
301: fatal("%s: buffer error: %s", __func__, ssh_err(r));
302: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
303: fatal("%s: buffer error: %s", __func__, ssh_err(r));
304:
305: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
306: fatal("%s: buffer error: %s", __func__, ssh_err(r));
307:
308: sshbuf_free(msg);
1.173 djm 309: free(signature);
1.1 deraadt 310: }
311:
1.33 markus 312: /* shared */
1.55 itojun 313: static void
1.221 djm 314: process_remove_identity(SocketEntry *e)
1.1 deraadt 315: {
1.194 markus 316: int r, success = 0;
317: struct sshkey *key = NULL;
1.221 djm 318: Identity *id;
1.21 markus 319:
1.221 djm 320: if ((r = sshkey_froms(e->request, &key)) != 0) {
321: error("%s: get key: %s", __func__, ssh_err(r));
322: goto done;
323: }
324: if ((id = lookup_identity(key)) == NULL) {
325: debug("%s: key not found", __func__);
326: goto done;
327: }
328: /* We have this key, free it. */
329: if (idtab->nentries < 1)
330: fatal("%s: internal error: nentries %d",
331: __func__, idtab->nentries);
332: TAILQ_REMOVE(&idtab->idlist, id, next);
333: free_identity(id);
334: idtab->nentries--;
335: sshkey_free(key);
336: success = 1;
337: done:
1.194 markus 338: send_status(e, success);
1.1 deraadt 339: }
340:
1.55 itojun 341: static void
1.221 djm 342: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 343: {
1.78 provos 344: Identity *id;
1.21 markus 345:
346: /* Loop over all identities and clear the keys. */
1.221 djm 347: for (id = TAILQ_FIRST(&idtab->idlist); id;
348: id = TAILQ_FIRST(&idtab->idlist)) {
349: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 350: free_identity(id);
1.21 markus 351: }
352:
353: /* Mark that there are no identities. */
1.221 djm 354: idtab->nentries = 0;
1.21 markus 355:
356: /* Send success. */
1.194 markus 357: send_status(e, 1);
1.1 deraadt 358: }
359:
1.155 dtucker 360: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 361: static time_t
1.89 markus 362: reaper(void)
363: {
1.175 dtucker 364: time_t deadline = 0, now = monotime();
1.89 markus 365: Identity *id, *nxt;
366:
1.221 djm 367: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
368: nxt = TAILQ_NEXT(id, next);
369: if (id->death == 0)
370: continue;
371: if (now >= id->death) {
372: debug("expiring key '%s'", id->comment);
373: TAILQ_REMOVE(&idtab->idlist, id, next);
374: free_identity(id);
375: idtab->nentries--;
376: } else
377: deadline = (deadline == 0) ? id->death :
378: MINIMUM(deadline, id->death);
1.89 markus 379: }
1.155 dtucker 380: if (deadline == 0 || deadline <= now)
381: return 0;
382: else
383: return (deadline - now);
1.89 markus 384: }
385:
386: static void
1.221 djm 387: process_add_identity(SocketEntry *e)
1.1 deraadt 388: {
1.157 canacar 389: Identity *id;
1.194 markus 390: int success = 0, confirm = 0;
1.228 markus 391: u_int seconds, maxsign;
1.194 markus 392: char *comment = NULL;
1.174 dtucker 393: time_t death = 0;
1.194 markus 394: struct sshkey *k = NULL;
395: u_char ctype;
396: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 397:
1.221 djm 398: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
399: k == NULL ||
1.194 markus 400: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
401: error("%s: decode private key: %s", __func__, ssh_err(r));
402: goto err;
403: }
1.186 djm 404:
1.194 markus 405: while (sshbuf_len(e->request)) {
406: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
407: error("%s: buffer error: %s", __func__, ssh_err(r));
408: goto err;
409: }
410: switch (ctype) {
1.94 markus 411: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 412: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
413: error("%s: bad lifetime constraint: %s",
414: __func__, ssh_err(r));
415: goto err;
416: }
417: death = monotime() + seconds;
1.94 markus 418: break;
1.107 markus 419: case SSH_AGENT_CONSTRAIN_CONFIRM:
420: confirm = 1;
421: break;
1.228 markus 422: case SSH_AGENT_CONSTRAIN_MAXSIGN:
423: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
424: error("%s: bad maxsign constraint: %s",
425: __func__, ssh_err(r));
426: goto err;
427: }
428: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
429: error("%s: cannot enable maxsign: %s",
430: __func__, ssh_err(r));
431: goto err;
432: }
433: break;
1.94 markus 434: default:
1.194 markus 435: error("%s: Unknown constraint %d", __func__, ctype);
436: err:
437: sshbuf_reset(e->request);
1.173 djm 438: free(comment);
1.194 markus 439: sshkey_free(k);
1.158 djm 440: goto send;
1.94 markus 441: }
442: }
1.194 markus 443:
1.158 djm 444: success = 1;
1.106 marc 445: if (lifetime && !death)
1.175 dtucker 446: death = monotime() + lifetime;
1.221 djm 447: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 448: id = xcalloc(1, sizeof(Identity));
1.221 djm 449: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 450: /* Increment the number of identities. */
1.221 djm 451: idtab->nentries++;
1.33 markus 452: } else {
1.228 markus 453: /* key state might have been updated */
454: sshkey_free(id->key);
1.173 djm 455: free(id->comment);
1.33 markus 456: }
1.228 markus 457: id->key = k;
1.157 canacar 458: id->comment = comment;
459: id->death = death;
460: id->confirm = confirm;
1.33 markus 461: send:
1.194 markus 462: send_status(e, success);
1.1 deraadt 463: }
464:
1.88 markus 465: /* XXX todo: encrypt sensitive data with passphrase */
466: static void
467: process_lock_agent(SocketEntry *e, int lock)
468: {
1.203 dtucker 469: int r, success = 0, delay;
1.213 djm 470: char *passwd;
471: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 472: static u_int fail_count = 0;
473: size_t pwlen;
474:
1.226 djm 475: /*
476: * This is deliberately fatal: the user has requested that we lock,
477: * but we can't parse their request properly. The only safe thing to
478: * do is abort.
479: */
1.203 dtucker 480: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
481: fatal("%s: buffer error: %s", __func__, ssh_err(r));
482: if (pwlen == 0) {
483: debug("empty password not supported");
484: } else if (locked && !lock) {
485: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
486: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
487: fatal("bcrypt_pbkdf");
1.213 djm 488: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 489: debug("agent unlocked");
490: locked = 0;
491: fail_count = 0;
1.213 djm 492: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 493: success = 1;
494: } else {
495: /* delay in 0.1s increments up to 10s */
496: if (fail_count < 100)
497: fail_count++;
498: delay = 100000 * fail_count;
499: debug("unlock failed, delaying %0.1lf seconds",
500: (double)delay/1000000);
501: usleep(delay);
502: }
503: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 504: } else if (!locked && lock) {
1.203 dtucker 505: debug("agent locked");
1.88 markus 506: locked = 1;
1.203 dtucker 507: arc4random_buf(lock_salt, sizeof(lock_salt));
508: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 509: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 510: fatal("bcrypt_pbkdf");
1.88 markus 511: success = 1;
512: }
1.203 dtucker 513: explicit_bzero(passwd, pwlen);
1.173 djm 514: free(passwd);
1.194 markus 515: send_status(e, success);
1.88 markus 516: }
517:
518: static void
1.221 djm 519: no_identities(SocketEntry *e)
1.88 markus 520: {
1.194 markus 521: struct sshbuf *msg;
522: int r;
1.88 markus 523:
1.194 markus 524: if ((msg = sshbuf_new()) == NULL)
525: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 526: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 527: (r = sshbuf_put_u32(msg, 0)) != 0 ||
528: (r = sshbuf_put_stringb(e->output, msg)) != 0)
529: fatal("%s: buffer error: %s", __func__, ssh_err(r));
530: sshbuf_free(msg);
1.88 markus 531: }
1.59 markus 532:
1.163 markus 533: #ifdef ENABLE_PKCS11
1.59 markus 534: static void
1.158 djm 535: process_add_smartcard_key(SocketEntry *e)
1.59 markus 536: {
1.226 djm 537: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 538: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 539: u_int seconds;
1.174 dtucker 540: time_t death = 0;
1.194 markus 541: u_char type;
542: struct sshkey **keys = NULL, *k;
1.84 markus 543: Identity *id;
1.75 deraadt 544:
1.194 markus 545: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 546: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
547: error("%s: buffer error: %s", __func__, ssh_err(r));
548: goto send;
549: }
1.194 markus 550:
551: while (sshbuf_len(e->request)) {
1.226 djm 552: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
553: error("%s: buffer error: %s", __func__, ssh_err(r));
554: goto send;
555: }
1.194 markus 556: switch (type) {
1.110 djm 557: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 558: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
559: error("%s: buffer error: %s",
1.194 markus 560: __func__, ssh_err(r));
1.226 djm 561: goto send;
562: }
1.194 markus 563: death = monotime() + seconds;
1.110 djm 564: break;
565: case SSH_AGENT_CONSTRAIN_CONFIRM:
566: confirm = 1;
567: break;
568: default:
1.221 djm 569: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 570: goto send;
1.110 djm 571: }
572: }
1.215 djm 573: if (realpath(provider, canonical_provider) == NULL) {
574: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
575: provider, strerror(errno));
576: goto send;
577: }
578: if (match_pattern_list(canonical_provider, pkcs11_whitelist, 0) != 1) {
579: verbose("refusing PKCS#11 add of \"%.100s\": "
580: "provider not whitelisted", canonical_provider);
581: goto send;
582: }
583: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 584: if (lifetime && !death)
1.175 dtucker 585: death = monotime() + lifetime;
1.110 djm 586:
1.215 djm 587: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 588: for (i = 0; i < count; i++) {
1.84 markus 589: k = keys[i];
1.221 djm 590: if (lookup_identity(k) == NULL) {
1.163 markus 591: id = xcalloc(1, sizeof(Identity));
1.84 markus 592: id->key = k;
1.215 djm 593: id->provider = xstrdup(canonical_provider);
594: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 595: id->death = death;
596: id->confirm = confirm;
1.221 djm 597: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
598: idtab->nentries++;
1.84 markus 599: success = 1;
600: } else {
1.194 markus 601: sshkey_free(k);
1.84 markus 602: }
603: keys[i] = NULL;
1.59 markus 604: }
605: send:
1.173 djm 606: free(pin);
607: free(provider);
608: free(keys);
1.194 markus 609: send_status(e, success);
1.59 markus 610: }
611:
612: static void
613: process_remove_smartcard_key(SocketEntry *e)
614: {
1.217 djm 615: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 616: int r, success = 0;
1.163 markus 617: Identity *id, *nxt;
1.59 markus 618:
1.194 markus 619: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 620: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
621: error("%s: buffer error: %s", __func__, ssh_err(r));
622: goto send;
623: }
1.173 djm 624: free(pin);
1.59 markus 625:
1.217 djm 626: if (realpath(provider, canonical_provider) == NULL) {
627: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
628: provider, strerror(errno));
629: goto send;
630: }
631:
632: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 633: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
634: nxt = TAILQ_NEXT(id, next);
635: /* Skip file--based keys */
636: if (id->provider == NULL)
637: continue;
638: if (!strcmp(canonical_provider, id->provider)) {
639: TAILQ_REMOVE(&idtab->idlist, id, next);
640: free_identity(id);
641: idtab->nentries--;
1.59 markus 642: }
643: }
1.217 djm 644: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 645: success = 1;
646: else
1.221 djm 647: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 648: send:
1.173 djm 649: free(provider);
1.194 markus 650: send_status(e, success);
1.59 markus 651: }
1.163 markus 652: #endif /* ENABLE_PKCS11 */
1.59 markus 653:
1.33 markus 654: /* dispatch incoming messages */
655:
1.223 djm 656: static int
657: process_message(u_int socknum)
1.1 deraadt 658: {
1.194 markus 659: u_int msg_len;
660: u_char type;
661: const u_char *cp;
662: int r;
1.223 djm 663: SocketEntry *e;
664:
665: if (socknum >= sockets_alloc) {
666: fatal("%s: socket number %u >= allocated %u",
667: __func__, socknum, sockets_alloc);
668: }
669: e = &sockets[socknum];
1.89 markus 670:
1.194 markus 671: if (sshbuf_len(e->input) < 5)
1.223 djm 672: return 0; /* Incomplete message header. */
1.194 markus 673: cp = sshbuf_ptr(e->input);
674: msg_len = PEEK_U32(cp);
1.223 djm 675: if (msg_len > AGENT_MAX_LEN) {
676: debug("%s: socket %u (fd=%d) message too long %u > %u",
677: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
678: return -1;
1.21 markus 679: }
1.194 markus 680: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 681: return 0; /* Incomplete message body. */
1.87 markus 682:
683: /* move the current input to e->request */
1.194 markus 684: sshbuf_reset(e->request);
685: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 686: (r = sshbuf_get_u8(e->request, &type)) != 0) {
687: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
688: r == SSH_ERR_STRING_TOO_LARGE) {
689: debug("%s: buffer error: %s", __func__, ssh_err(r));
690: return -1;
691: }
1.194 markus 692: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 693: }
694:
695: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 696:
1.230 djm 697: /* check whether agent is locked */
1.88 markus 698: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 699: sshbuf_reset(e->request);
1.88 markus 700: switch (type) {
701: case SSH2_AGENTC_REQUEST_IDENTITIES:
702: /* send empty lists */
1.221 djm 703: no_identities(e);
1.88 markus 704: break;
705: default:
706: /* send a fail message for all other request types */
1.194 markus 707: send_status(e, 0);
1.88 markus 708: }
1.223 djm 709: return 0;
1.88 markus 710: }
711:
1.21 markus 712: switch (type) {
1.88 markus 713: case SSH_AGENTC_LOCK:
714: case SSH_AGENTC_UNLOCK:
715: process_lock_agent(e, type == SSH_AGENTC_LOCK);
716: break;
1.21 markus 717: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 718: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 719: break;
720: /* ssh2 */
721: case SSH2_AGENTC_SIGN_REQUEST:
722: process_sign_request2(e);
723: break;
724: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 725: process_request_identities(e);
1.33 markus 726: break;
727: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 728: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 729: process_add_identity(e);
1.33 markus 730: break;
731: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 732: process_remove_identity(e);
1.33 markus 733: break;
734: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 735: process_remove_all_identities(e);
1.21 markus 736: break;
1.163 markus 737: #ifdef ENABLE_PKCS11
1.59 markus 738: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 739: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 740: process_add_smartcard_key(e);
1.75 deraadt 741: break;
1.59 markus 742: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
743: process_remove_smartcard_key(e);
1.75 deraadt 744: break;
1.163 markus 745: #endif /* ENABLE_PKCS11 */
1.21 markus 746: default:
747: /* Unknown message. Respond with failure. */
748: error("Unknown message %d", type);
1.194 markus 749: sshbuf_reset(e->request);
750: send_status(e, 0);
1.21 markus 751: break;
752: }
1.223 djm 753: return 0;
1.1 deraadt 754: }
755:
1.55 itojun 756: static void
1.73 stevesk 757: new_socket(sock_type type, int fd)
1.1 deraadt 758: {
1.112 markus 759: u_int i, old_alloc, new_alloc;
1.96 deraadt 760:
1.119 djm 761: set_nonblock(fd);
1.21 markus 762:
763: if (fd > max_fd)
764: max_fd = fd;
765:
766: for (i = 0; i < sockets_alloc; i++)
767: if (sockets[i].type == AUTH_UNUSED) {
768: sockets[i].fd = fd;
1.194 markus 769: if ((sockets[i].input = sshbuf_new()) == NULL)
770: fatal("%s: sshbuf_new failed", __func__);
771: if ((sockets[i].output = sshbuf_new()) == NULL)
772: fatal("%s: sshbuf_new failed", __func__);
773: if ((sockets[i].request = sshbuf_new()) == NULL)
774: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 775: sockets[i].type = type;
1.21 markus 776: return;
777: }
778: old_alloc = sockets_alloc;
1.112 markus 779: new_alloc = sockets_alloc + 10;
1.200 deraadt 780: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 781: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 782: sockets[i].type = AUTH_UNUSED;
1.112 markus 783: sockets_alloc = new_alloc;
1.21 markus 784: sockets[old_alloc].fd = fd;
1.194 markus 785: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
786: fatal("%s: sshbuf_new failed", __func__);
787: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
788: fatal("%s: sshbuf_new failed", __func__);
789: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
790: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 791: sockets[old_alloc].type = type;
1.1 deraadt 792: }
793:
1.55 itojun 794: static int
1.223 djm 795: handle_socket_read(u_int socknum)
1.1 deraadt 796: {
1.223 djm 797: struct sockaddr_un sunaddr;
798: socklen_t slen;
799: uid_t euid;
800: gid_t egid;
801: int fd;
802:
803: slen = sizeof(sunaddr);
804: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
805: if (fd < 0) {
806: error("accept from AUTH_SOCKET: %s", strerror(errno));
807: return -1;
808: }
809: if (getpeereid(fd, &euid, &egid) < 0) {
810: error("getpeereid %d failed: %s", fd, strerror(errno));
811: close(fd);
812: return -1;
813: }
814: if ((euid != 0) && (getuid() != euid)) {
815: error("uid mismatch: peer euid %u != uid %u",
816: (u_int) euid, (u_int) getuid());
817: close(fd);
818: return -1;
819: }
820: new_socket(AUTH_CONNECTION, fd);
821: return 0;
822: }
823:
824: static int
825: handle_conn_read(u_int socknum)
826: {
827: char buf[1024];
828: ssize_t len;
829: int r;
830:
831: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
832: if (len == -1) {
833: if (errno == EAGAIN || errno == EINTR)
834: return 0;
835: error("%s: read error on socket %u (fd %d): %s",
836: __func__, socknum, sockets[socknum].fd,
837: strerror(errno));
838: }
839: return -1;
840: }
841: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
842: fatal("%s: buffer error: %s", __func__, ssh_err(r));
843: explicit_bzero(buf, sizeof(buf));
844: process_message(socknum);
845: return 0;
846: }
847:
848: static int
849: handle_conn_write(u_int socknum)
850: {
851: ssize_t len;
852: int r;
853:
854: if (sshbuf_len(sockets[socknum].output) == 0)
855: return 0; /* shouldn't happen */
856: if ((len = write(sockets[socknum].fd,
857: sshbuf_ptr(sockets[socknum].output),
858: sshbuf_len(sockets[socknum].output))) <= 0) {
859: if (len == -1) {
860: if (errno == EAGAIN || errno == EINTR)
861: return 0;
862: error("%s: read error on socket %u (fd %d): %s",
863: __func__, socknum, sockets[socknum].fd,
864: strerror(errno));
865: }
866: return -1;
867: }
868: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
869: fatal("%s: buffer error: %s", __func__, ssh_err(r));
870: return 0;
871: }
872:
873: static void
1.231 ! djm 874: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 875: {
876: size_t i;
1.231 ! djm 877: u_int socknum, activefds = npfd;
1.223 djm 878:
879: for (i = 0; i < npfd; i++) {
880: if (pfd[i].revents == 0)
881: continue;
882: /* Find sockets entry */
883: for (socknum = 0; socknum < sockets_alloc; socknum++) {
884: if (sockets[socknum].type != AUTH_SOCKET &&
885: sockets[socknum].type != AUTH_CONNECTION)
886: continue;
887: if (pfd[i].fd == sockets[socknum].fd)
888: break;
889: }
890: if (socknum >= sockets_alloc) {
891: error("%s: no socket for fd %d", __func__, pfd[i].fd);
892: continue;
893: }
894: /* Process events */
895: switch (sockets[socknum].type) {
896: case AUTH_SOCKET:
1.231 ! djm 897: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
! 898: break;
! 899: if (npfd > maxfds) {
! 900: debug3("out of fds (active %u >= limit %u); "
! 901: "skipping accept", activefds, maxfds);
! 902: break;
! 903: }
! 904: if (handle_socket_read(socknum) == 0)
! 905: activefds++;
1.223 djm 906: break;
907: case AUTH_CONNECTION:
908: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
909: handle_conn_read(socknum) != 0) {
1.231 ! djm 910: goto close_sock;
! 911: }
! 912: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
! 913: handle_conn_write(socknum) != 0) {
! 914: close_sock:
! 915: if (activefds == 0)
! 916: fatal("activefds == 0 at close_sock");
1.223 djm 917: close_socket(&sockets[socknum]);
1.231 ! djm 918: activefds--;
1.223 djm 919: break;
920: }
921: break;
922: default:
923: break;
924: }
925: }
926: }
927:
928: static int
1.231 ! djm 929: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 930: {
931: struct pollfd *pfd = *pfdp;
932: size_t i, j, npfd = 0;
1.174 dtucker 933: time_t deadline;
1.46 markus 934:
1.223 djm 935: /* Count active sockets */
1.46 markus 936: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 937: switch (sockets[i].type) {
938: case AUTH_SOCKET:
939: case AUTH_CONNECTION:
1.223 djm 940: npfd++;
1.21 markus 941: break;
942: case AUTH_UNUSED:
943: break;
944: default:
945: fatal("Unknown socket type %d", sockets[i].type);
946: break;
947: }
1.46 markus 948: }
1.223 djm 949: if (npfd != *npfdp &&
950: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
951: fatal("%s: recallocarray failed", __func__);
952: *pfdp = pfd;
953: *npfdp = npfd;
1.46 markus 954:
1.223 djm 955: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 956: switch (sockets[i].type) {
957: case AUTH_SOCKET:
1.231 ! djm 958: if (npfd > maxfds) {
! 959: debug3("out of fds (active %zu >= limit %u); "
! 960: "skipping arming listener", npfd, maxfds);
! 961: break;
! 962: }
! 963: pfd[j].fd = sockets[i].fd;
! 964: pfd[j].revents = 0;
! 965: pfd[j].events = POLLIN;
! 966: j++;
! 967: break;
1.46 markus 968: case AUTH_CONNECTION:
1.223 djm 969: pfd[j].fd = sockets[i].fd;
970: pfd[j].revents = 0;
971: /* XXX backoff when input buffer full */
972: pfd[j].events = POLLIN;
1.194 markus 973: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 974: pfd[j].events |= POLLOUT;
975: j++;
1.46 markus 976: break;
977: default:
978: break;
979: }
980: }
1.155 dtucker 981: deadline = reaper();
982: if (parent_alive_interval != 0)
983: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 984: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 985: if (deadline == 0) {
1.224 djm 986: *timeoutp = -1; /* INFTIM */
1.155 dtucker 987: } else {
1.223 djm 988: if (deadline > INT_MAX / 1000)
989: *timeoutp = INT_MAX / 1000;
990: else
991: *timeoutp = deadline * 1000;
1.155 dtucker 992: }
1.46 markus 993: return (1);
1.21 markus 994: }
995:
1.55 itojun 996: static void
1.113 markus 997: cleanup_socket(void)
1.15 markus 998: {
1.187 djm 999: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1000: return;
1001: debug("%s: cleanup", __func__);
1.48 deraadt 1002: if (socket_name[0])
1003: unlink(socket_name);
1004: if (socket_dir[0])
1005: rmdir(socket_dir);
1.10 markus 1006: }
1007:
1.114 markus 1008: void
1.15 markus 1009: cleanup_exit(int i)
1010: {
1.113 markus 1011: cleanup_socket();
1012: _exit(i);
1.15 markus 1013: }
1014:
1.135 deraadt 1015: /*ARGSUSED*/
1.55 itojun 1016: static void
1.48 deraadt 1017: cleanup_handler(int sig)
1018: {
1.113 markus 1019: cleanup_socket();
1.163 markus 1020: #ifdef ENABLE_PKCS11
1021: pkcs11_terminate();
1022: #endif
1.48 deraadt 1023: _exit(2);
1.113 markus 1024: }
1025:
1.68 markus 1026: static void
1.155 dtucker 1027: check_parent_exists(void)
1.68 markus 1028: {
1.172 dtucker 1029: /*
1030: * If our parent has exited then getppid() will return (pid_t)1,
1031: * so testing for that should be safe.
1032: */
1033: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1034: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1035: cleanup_socket();
1036: _exit(2);
1.68 markus 1037: }
1.48 deraadt 1038: }
1039:
1.55 itojun 1040: static void
1.50 itojun 1041: usage(void)
1.15 markus 1042: {
1.184 deraadt 1043: fprintf(stderr,
1.202 jmc 1044: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.215 djm 1045: " [-P pkcs11_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1046: " ssh-agent [-c | -s] -k\n");
1.21 markus 1047: exit(1);
1.15 markus 1048: }
1049:
1.2 provos 1050: int
1051: main(int ac, char **av)
1.1 deraadt 1052: {
1.201 djm 1053: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1054: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1055: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1056: struct rlimit rlim;
1.96 deraadt 1057: extern int optind;
1.98 stevesk 1058: extern char *optarg;
1.21 markus 1059: pid_t pid;
1.96 deraadt 1060: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1061: size_t len;
1.189 djm 1062: mode_t prev_mask;
1.224 djm 1063: int timeout = -1; /* INFTIM */
1.223 djm 1064: struct pollfd *pfd = NULL;
1065: size_t npfd = 0;
1.231 ! djm 1066: u_int maxfds;
1.123 djm 1067:
1.212 dtucker 1068: ssh_malloc_init(); /* must be called before any mallocs */
1.123 djm 1069: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1070: sanitise_stdfd();
1.99 markus 1071:
1072: /* drop */
1073: setegid(getgid());
1074: setgid(getgid());
1.53 markus 1075:
1.231 ! djm 1076: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
! 1077: fatal("%s: getrlimit: %s", __progname, strerror(errno));
! 1078:
1.185 markus 1079: #ifdef WITH_OPENSSL
1.170 djm 1080: OpenSSL_add_all_algorithms();
1.185 markus 1081: #endif
1.21 markus 1082:
1.215 djm 1083: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1084: switch (ch) {
1.192 djm 1085: case 'E':
1086: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1087: if (fingerprint_hash == -1)
1088: fatal("Invalid hash algorithm \"%s\"", optarg);
1089: break;
1.21 markus 1090: case 'c':
1091: if (s_flag)
1092: usage();
1093: c_flag++;
1094: break;
1095: case 'k':
1096: k_flag++;
1097: break;
1.215 djm 1098: case 'P':
1099: if (pkcs11_whitelist != NULL)
1100: fatal("-P option already specified");
1101: pkcs11_whitelist = xstrdup(optarg);
1102: break;
1.21 markus 1103: case 's':
1104: if (c_flag)
1105: usage();
1106: s_flag++;
1107: break;
1.57 markus 1108: case 'd':
1.201 djm 1109: if (d_flag || D_flag)
1.57 markus 1110: usage();
1111: d_flag++;
1112: break;
1.201 djm 1113: case 'D':
1114: if (d_flag || D_flag)
1115: usage();
1116: D_flag++;
1117: break;
1.86 markus 1118: case 'a':
1119: agentsocket = optarg;
1.106 marc 1120: break;
1121: case 't':
1122: if ((lifetime = convtime(optarg)) == -1) {
1123: fprintf(stderr, "Invalid lifetime\n");
1124: usage();
1125: }
1.86 markus 1126: break;
1.21 markus 1127: default:
1128: usage();
1129: }
1130: }
1131: ac -= optind;
1132: av += optind;
1133:
1.201 djm 1134: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1135: usage();
1136:
1.215 djm 1137: if (pkcs11_whitelist == NULL)
1138: pkcs11_whitelist = xstrdup(DEFAULT_PKCS11_WHITELIST);
1139:
1.85 markus 1140: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1141: shell = getenv("SHELL");
1.161 tobias 1142: if (shell != NULL && (len = strlen(shell)) > 2 &&
1143: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1144: c_flag = 1;
1145: }
1146: if (k_flag) {
1.136 deraadt 1147: const char *errstr = NULL;
1148:
1.21 markus 1149: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1150: if (pidstr == NULL) {
1151: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1152: SSH_AGENTPID_ENV_NAME);
1.21 markus 1153: exit(1);
1154: }
1.136 deraadt 1155: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1156: if (errstr) {
1157: fprintf(stderr,
1158: "%s=\"%s\", which is not a good PID: %s\n",
1159: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1160: exit(1);
1161: }
1162: if (kill(pid, SIGTERM) == -1) {
1163: perror("kill");
1164: exit(1);
1165: }
1166: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1167: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1168: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1169: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1170: exit(0);
1171: }
1.231 ! djm 1172:
! 1173: /*
! 1174: * Minimum file descriptors:
! 1175: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
! 1176: * a few spare for libc / stack protectors / sanitisers, etc.
! 1177: */
! 1178: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
! 1179: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
! 1180: fatal("%s: file descriptior rlimit %lld too low (minimum %u)",
! 1181: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
! 1182: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
! 1183:
1.21 markus 1184: parent_pid = getpid();
1185:
1.86 markus 1186: if (agentsocket == NULL) {
1187: /* Create private directory for agent socket */
1.171 djm 1188: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1189: if (mkdtemp(socket_dir) == NULL) {
1190: perror("mkdtemp: private socket dir");
1191: exit(1);
1192: }
1.91 mpech 1193: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1194: (long)parent_pid);
1.86 markus 1195: } else {
1196: /* Try to use specified agent socket */
1197: socket_dir[0] = '\0';
1198: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1199: }
1200:
1.23 markus 1201: /*
1202: * Create socket early so it will exist before command gets run from
1203: * the parent.
1204: */
1.189 djm 1205: prev_mask = umask(0177);
1.188 millert 1206: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1207: if (sock < 0) {
1.188 millert 1208: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1209: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1210: cleanup_exit(1);
1211: }
1.189 djm 1212: umask(prev_mask);
1.46 markus 1213:
1.23 markus 1214: /*
1215: * Fork, and have the parent execute the command, if any, or present
1216: * the socket data. The child continues as the authentication agent.
1217: */
1.201 djm 1218: if (D_flag || d_flag) {
1219: log_init(__progname,
1220: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1221: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1222: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1223: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1224: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1225: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1226: fflush(stdout);
1.57 markus 1227: goto skip;
1228: }
1.21 markus 1229: pid = fork();
1230: if (pid == -1) {
1231: perror("fork");
1.81 stevesk 1232: cleanup_exit(1);
1.21 markus 1233: }
1234: if (pid != 0) { /* Parent - execute the given command. */
1235: close(sock);
1.91 mpech 1236: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1237: if (ac == 0) {
1238: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1239: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1240: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1241: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1242: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1243: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1244: exit(0);
1245: }
1.36 deraadt 1246: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1247: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1248: perror("setenv");
1249: exit(1);
1250: }
1.21 markus 1251: execvp(av[0], av);
1252: perror(av[0]);
1253: exit(1);
1254: }
1.81 stevesk 1255: /* child */
1256: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1257:
1258: if (setsid() == -1) {
1.81 stevesk 1259: error("setsid: %s", strerror(errno));
1.67 stevesk 1260: cleanup_exit(1);
1261: }
1262:
1263: (void)chdir("/");
1.107 markus 1264: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1265: /* XXX might close listen socket */
1266: (void)dup2(fd, STDIN_FILENO);
1267: (void)dup2(fd, STDOUT_FILENO);
1268: (void)dup2(fd, STDERR_FILENO);
1269: if (fd > 2)
1270: close(fd);
1271: }
1.21 markus 1272:
1.41 markus 1273: /* deny core dumps, since memory contains unencrypted private keys */
1274: rlim.rlim_cur = rlim.rlim_max = 0;
1275: if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1.81 stevesk 1276: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1277: cleanup_exit(1);
1278: }
1.57 markus 1279:
1280: skip:
1.187 djm 1281:
1282: cleanup_pid = getpid();
1.163 markus 1283:
1284: #ifdef ENABLE_PKCS11
1285: pkcs11_init(0);
1286: #endif
1.21 markus 1287: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1288: if (ac > 0)
1289: parent_alive_interval = 10;
1.33 markus 1290: idtab_init();
1.61 markus 1291: signal(SIGPIPE, SIG_IGN);
1.201 djm 1292: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1293: signal(SIGHUP, cleanup_handler);
1294: signal(SIGTERM, cleanup_handler);
1.205 djm 1295:
1.215 djm 1296: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1297: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1298:
1.21 markus 1299: while (1) {
1.231 ! djm 1300: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1301: result = poll(pfd, npfd, timeout);
1.154 dtucker 1302: saved_errno = errno;
1.155 dtucker 1303: if (parent_alive_interval != 0)
1304: check_parent_exists();
1305: (void) reaper(); /* remove expired keys */
1.154 dtucker 1306: if (result < 0) {
1307: if (saved_errno == EINTR)
1.21 markus 1308: continue;
1.223 djm 1309: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1310: } else if (result > 0)
1.231 ! djm 1311: after_poll(pfd, npfd, maxfds);
1.15 markus 1312: }
1.21 markus 1313: /* NOTREACHED */
1.1 deraadt 1314: }
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