Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.235
1.235 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.234 2019/06/06 05:13:13 otto 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)
1.233 djm 84: /* Maximum bytes to read from client socket */
85: #define AGENT_RBUF_LEN (4096)
1.223 djm 86:
1.73 stevesk 87: typedef enum {
88: AUTH_UNUSED,
89: AUTH_SOCKET,
90: AUTH_CONNECTION
91: } sock_type;
92:
1.21 markus 93: typedef struct {
94: int fd;
1.73 stevesk 95: sock_type type;
1.194 markus 96: struct sshbuf *input;
97: struct sshbuf *output;
98: struct sshbuf *request;
1.1 deraadt 99: } SocketEntry;
100:
1.45 markus 101: u_int sockets_alloc = 0;
1.1 deraadt 102: SocketEntry *sockets = NULL;
103:
1.78 provos 104: typedef struct identity {
105: TAILQ_ENTRY(identity) next;
1.194 markus 106: struct sshkey *key;
1.21 markus 107: char *comment;
1.163 markus 108: char *provider;
1.174 dtucker 109: time_t death;
1.107 markus 110: u_int confirm;
1.1 deraadt 111: } Identity;
112:
1.221 djm 113: struct idtable {
1.33 markus 114: int nentries;
1.78 provos 115: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 116: };
1.33 markus 117:
1.221 djm 118: /* private key table */
119: struct idtable *idtab;
1.1 deraadt 120:
121: int max_fd = 0;
122:
1.11 markus 123: /* pid of shell == parent of agent */
1.29 deraadt 124: pid_t parent_pid = -1;
1.176 dtucker 125: time_t parent_alive_interval = 0;
1.10 markus 126:
1.187 djm 127: /* pid of process for which cleanup_socket is applicable */
128: pid_t cleanup_pid = 0;
129:
1.10 markus 130: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 131: char socket_name[PATH_MAX];
132: char socket_dir[PATH_MAX];
1.10 markus 133:
1.215 djm 134: /* PKCS#11 path whitelist */
135: static char *pkcs11_whitelist;
136:
1.88 markus 137: /* locking */
1.203 dtucker 138: #define LOCK_SIZE 32
139: #define LOCK_SALT_SIZE 16
140: #define LOCK_ROUNDS 1
1.88 markus 141: int locked = 0;
1.213 djm 142: u_char lock_pwhash[LOCK_SIZE];
143: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 144:
1.20 markus 145: extern char *__progname;
146:
1.174 dtucker 147: /* Default lifetime in seconds (0 == forever) */
148: static long lifetime = 0;
1.106 marc 149:
1.192 djm 150: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
151:
1.55 itojun 152: static void
1.101 stevesk 153: close_socket(SocketEntry *e)
154: {
155: close(e->fd);
156: e->fd = -1;
157: e->type = AUTH_UNUSED;
1.194 markus 158: sshbuf_free(e->input);
159: sshbuf_free(e->output);
160: sshbuf_free(e->request);
1.101 stevesk 161: }
162:
163: static void
1.33 markus 164: idtab_init(void)
1.1 deraadt 165: {
1.221 djm 166: idtab = xcalloc(1, sizeof(*idtab));
167: TAILQ_INIT(&idtab->idlist);
168: idtab->nentries = 0;
1.33 markus 169: }
170:
1.89 markus 171: static void
172: free_identity(Identity *id)
173: {
1.194 markus 174: sshkey_free(id->key);
1.173 djm 175: free(id->provider);
176: free(id->comment);
177: free(id);
1.89 markus 178: }
179:
1.33 markus 180: /* return matching private key for given public key */
1.78 provos 181: static Identity *
1.221 djm 182: lookup_identity(struct sshkey *key)
1.33 markus 183: {
1.78 provos 184: Identity *id;
185:
1.221 djm 186: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 187: if (sshkey_equal(key, id->key))
1.78 provos 188: return (id);
1.33 markus 189: }
1.78 provos 190: return (NULL);
191: }
192:
1.107 markus 193: /* Check confirmation of keysign request */
194: static int
195: confirm_key(Identity *id)
196: {
1.122 djm 197: char *p;
1.107 markus 198: int ret = -1;
199:
1.194 markus 200: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 201: if (p != NULL &&
202: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 203: id->comment, p))
204: ret = 0;
1.173 djm 205: free(p);
1.122 djm 206:
1.107 markus 207: return (ret);
208: }
209:
1.194 markus 210: static void
211: send_status(SocketEntry *e, int success)
212: {
213: int r;
214:
215: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
216: (r = sshbuf_put_u8(e->output, success ?
217: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
218: fatal("%s: buffer error: %s", __func__, ssh_err(r));
219: }
220:
1.33 markus 221: /* send list of supported public keys to 'client' */
1.55 itojun 222: static void
1.221 djm 223: process_request_identities(SocketEntry *e)
1.33 markus 224: {
1.96 deraadt 225: Identity *id;
1.194 markus 226: struct sshbuf *msg;
227: int r;
1.1 deraadt 228:
1.194 markus 229: if ((msg = sshbuf_new()) == NULL)
230: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 231: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
232: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
233: fatal("%s: buffer error: %s", __func__, ssh_err(r));
234: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 235: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
236: != 0 ||
1.221 djm 237: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
238: error("%s: put key/comment: %s", __func__,
1.220 djm 239: ssh_err(r));
240: continue;
1.33 markus 241: }
1.21 markus 242: }
1.194 markus 243: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
244: fatal("%s: buffer error: %s", __func__, ssh_err(r));
245: sshbuf_free(msg);
1.1 deraadt 246: }
247:
1.33 markus 248:
1.208 markus 249: static char *
250: agent_decode_alg(struct sshkey *key, u_int flags)
251: {
252: if (key->type == KEY_RSA) {
253: if (flags & SSH_AGENT_RSA_SHA2_256)
254: return "rsa-sha2-256";
255: else if (flags & SSH_AGENT_RSA_SHA2_512)
256: return "rsa-sha2-512";
1.235 ! djm 257: } else if (key->type == KEY_RSA_CERT) {
! 258: if (flags & SSH_AGENT_RSA_SHA2_256)
! 259: return "rsa-sha2-256-cert-v01@openssh.com";
! 260: else if (flags & SSH_AGENT_RSA_SHA2_512)
! 261: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 262: }
263: return NULL;
264: }
265:
1.33 markus 266: /* ssh2 only */
1.55 itojun 267: static void
1.33 markus 268: process_sign_request2(SocketEntry *e)
269: {
1.221 djm 270: const u_char *data;
271: u_char *signature = NULL;
272: size_t dlen, slen = 0;
1.194 markus 273: u_int compat = 0, flags;
274: int r, ok = -1;
275: struct sshbuf *msg;
1.221 djm 276: struct sshkey *key = NULL;
1.195 djm 277: struct identity *id;
1.194 markus 278:
1.195 djm 279: if ((msg = sshbuf_new()) == NULL)
280: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 281: if ((r = sshkey_froms(e->request, &key)) != 0 ||
282: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 283: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
284: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
285: goto send;
286: }
287:
1.221 djm 288: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 289: verbose("%s: %s key not found", __func__, sshkey_type(key));
290: goto send;
291: }
292: if (id->confirm && confirm_key(id) != 0) {
293: verbose("%s: user refused key", __func__);
294: goto send;
295: }
296: if ((r = sshkey_sign(id->key, &signature, &slen,
1.208 markus 297: data, dlen, agent_decode_alg(key, flags), compat)) != 0) {
1.209 djm 298: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
1.195 djm 299: goto send;
1.33 markus 300: }
1.195 djm 301: /* Success */
302: ok = 0;
303: send:
304: sshkey_free(key);
1.33 markus 305: if (ok == 0) {
1.194 markus 306: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
307: (r = sshbuf_put_string(msg, signature, slen)) != 0)
308: fatal("%s: buffer error: %s", __func__, ssh_err(r));
309: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
310: fatal("%s: buffer error: %s", __func__, ssh_err(r));
311:
312: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
313: fatal("%s: buffer error: %s", __func__, ssh_err(r));
314:
315: sshbuf_free(msg);
1.173 djm 316: free(signature);
1.1 deraadt 317: }
318:
1.33 markus 319: /* shared */
1.55 itojun 320: static void
1.221 djm 321: process_remove_identity(SocketEntry *e)
1.1 deraadt 322: {
1.194 markus 323: int r, success = 0;
324: struct sshkey *key = NULL;
1.221 djm 325: Identity *id;
1.21 markus 326:
1.221 djm 327: if ((r = sshkey_froms(e->request, &key)) != 0) {
328: error("%s: get key: %s", __func__, ssh_err(r));
329: goto done;
330: }
331: if ((id = lookup_identity(key)) == NULL) {
332: debug("%s: key not found", __func__);
333: goto done;
334: }
335: /* We have this key, free it. */
336: if (idtab->nentries < 1)
337: fatal("%s: internal error: nentries %d",
338: __func__, idtab->nentries);
339: TAILQ_REMOVE(&idtab->idlist, id, next);
340: free_identity(id);
341: idtab->nentries--;
342: sshkey_free(key);
343: success = 1;
344: done:
1.194 markus 345: send_status(e, success);
1.1 deraadt 346: }
347:
1.55 itojun 348: static void
1.221 djm 349: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 350: {
1.78 provos 351: Identity *id;
1.21 markus 352:
353: /* Loop over all identities and clear the keys. */
1.221 djm 354: for (id = TAILQ_FIRST(&idtab->idlist); id;
355: id = TAILQ_FIRST(&idtab->idlist)) {
356: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 357: free_identity(id);
1.21 markus 358: }
359:
360: /* Mark that there are no identities. */
1.221 djm 361: idtab->nentries = 0;
1.21 markus 362:
363: /* Send success. */
1.194 markus 364: send_status(e, 1);
1.1 deraadt 365: }
366:
1.155 dtucker 367: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 368: static time_t
1.89 markus 369: reaper(void)
370: {
1.175 dtucker 371: time_t deadline = 0, now = monotime();
1.89 markus 372: Identity *id, *nxt;
373:
1.221 djm 374: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
375: nxt = TAILQ_NEXT(id, next);
376: if (id->death == 0)
377: continue;
378: if (now >= id->death) {
379: debug("expiring key '%s'", id->comment);
380: TAILQ_REMOVE(&idtab->idlist, id, next);
381: free_identity(id);
382: idtab->nentries--;
383: } else
384: deadline = (deadline == 0) ? id->death :
385: MINIMUM(deadline, id->death);
1.89 markus 386: }
1.155 dtucker 387: if (deadline == 0 || deadline <= now)
388: return 0;
389: else
390: return (deadline - now);
1.89 markus 391: }
392:
393: static void
1.221 djm 394: process_add_identity(SocketEntry *e)
1.1 deraadt 395: {
1.157 canacar 396: Identity *id;
1.194 markus 397: int success = 0, confirm = 0;
1.228 markus 398: u_int seconds, maxsign;
1.194 markus 399: char *comment = NULL;
1.174 dtucker 400: time_t death = 0;
1.194 markus 401: struct sshkey *k = NULL;
402: u_char ctype;
403: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 404:
1.221 djm 405: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
406: k == NULL ||
1.194 markus 407: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
408: error("%s: decode private key: %s", __func__, ssh_err(r));
409: goto err;
410: }
1.186 djm 411:
1.194 markus 412: while (sshbuf_len(e->request)) {
413: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
414: error("%s: buffer error: %s", __func__, ssh_err(r));
415: goto err;
416: }
417: switch (ctype) {
1.94 markus 418: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 419: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
420: error("%s: bad lifetime constraint: %s",
421: __func__, ssh_err(r));
422: goto err;
423: }
424: death = monotime() + seconds;
1.94 markus 425: break;
1.107 markus 426: case SSH_AGENT_CONSTRAIN_CONFIRM:
427: confirm = 1;
428: break;
1.228 markus 429: case SSH_AGENT_CONSTRAIN_MAXSIGN:
430: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
431: error("%s: bad maxsign constraint: %s",
432: __func__, ssh_err(r));
433: goto err;
434: }
435: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
436: error("%s: cannot enable maxsign: %s",
437: __func__, ssh_err(r));
438: goto err;
439: }
440: break;
1.94 markus 441: default:
1.194 markus 442: error("%s: Unknown constraint %d", __func__, ctype);
443: err:
444: sshbuf_reset(e->request);
1.173 djm 445: free(comment);
1.194 markus 446: sshkey_free(k);
1.158 djm 447: goto send;
1.94 markus 448: }
449: }
1.194 markus 450:
1.158 djm 451: success = 1;
1.106 marc 452: if (lifetime && !death)
1.175 dtucker 453: death = monotime() + lifetime;
1.221 djm 454: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 455: id = xcalloc(1, sizeof(Identity));
1.221 djm 456: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 457: /* Increment the number of identities. */
1.221 djm 458: idtab->nentries++;
1.33 markus 459: } else {
1.228 markus 460: /* key state might have been updated */
461: sshkey_free(id->key);
1.173 djm 462: free(id->comment);
1.33 markus 463: }
1.228 markus 464: id->key = k;
1.157 canacar 465: id->comment = comment;
466: id->death = death;
467: id->confirm = confirm;
1.33 markus 468: send:
1.194 markus 469: send_status(e, success);
1.1 deraadt 470: }
471:
1.88 markus 472: /* XXX todo: encrypt sensitive data with passphrase */
473: static void
474: process_lock_agent(SocketEntry *e, int lock)
475: {
1.203 dtucker 476: int r, success = 0, delay;
1.213 djm 477: char *passwd;
478: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 479: static u_int fail_count = 0;
480: size_t pwlen;
481:
1.226 djm 482: /*
483: * This is deliberately fatal: the user has requested that we lock,
484: * but we can't parse their request properly. The only safe thing to
485: * do is abort.
486: */
1.203 dtucker 487: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
488: fatal("%s: buffer error: %s", __func__, ssh_err(r));
489: if (pwlen == 0) {
490: debug("empty password not supported");
491: } else if (locked && !lock) {
492: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
493: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
494: fatal("bcrypt_pbkdf");
1.213 djm 495: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 496: debug("agent unlocked");
497: locked = 0;
498: fail_count = 0;
1.213 djm 499: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 500: success = 1;
501: } else {
502: /* delay in 0.1s increments up to 10s */
503: if (fail_count < 100)
504: fail_count++;
505: delay = 100000 * fail_count;
506: debug("unlock failed, delaying %0.1lf seconds",
507: (double)delay/1000000);
508: usleep(delay);
509: }
510: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 511: } else if (!locked && lock) {
1.203 dtucker 512: debug("agent locked");
1.88 markus 513: locked = 1;
1.203 dtucker 514: arc4random_buf(lock_salt, sizeof(lock_salt));
515: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 516: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 517: fatal("bcrypt_pbkdf");
1.88 markus 518: success = 1;
519: }
1.203 dtucker 520: explicit_bzero(passwd, pwlen);
1.173 djm 521: free(passwd);
1.194 markus 522: send_status(e, success);
1.88 markus 523: }
524:
525: static void
1.221 djm 526: no_identities(SocketEntry *e)
1.88 markus 527: {
1.194 markus 528: struct sshbuf *msg;
529: int r;
1.88 markus 530:
1.194 markus 531: if ((msg = sshbuf_new()) == NULL)
532: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 533: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 534: (r = sshbuf_put_u32(msg, 0)) != 0 ||
535: (r = sshbuf_put_stringb(e->output, msg)) != 0)
536: fatal("%s: buffer error: %s", __func__, ssh_err(r));
537: sshbuf_free(msg);
1.88 markus 538: }
1.59 markus 539:
1.163 markus 540: #ifdef ENABLE_PKCS11
1.59 markus 541: static void
1.158 djm 542: process_add_smartcard_key(SocketEntry *e)
1.59 markus 543: {
1.226 djm 544: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 545: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 546: u_int seconds;
1.174 dtucker 547: time_t death = 0;
1.194 markus 548: u_char type;
549: struct sshkey **keys = NULL, *k;
1.84 markus 550: Identity *id;
1.75 deraadt 551:
1.194 markus 552: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 553: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
554: error("%s: buffer error: %s", __func__, ssh_err(r));
555: goto send;
556: }
1.194 markus 557:
558: while (sshbuf_len(e->request)) {
1.226 djm 559: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
560: error("%s: buffer error: %s", __func__, ssh_err(r));
561: goto send;
562: }
1.194 markus 563: switch (type) {
1.110 djm 564: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 565: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
566: error("%s: buffer error: %s",
1.194 markus 567: __func__, ssh_err(r));
1.226 djm 568: goto send;
569: }
1.194 markus 570: death = monotime() + seconds;
1.110 djm 571: break;
572: case SSH_AGENT_CONSTRAIN_CONFIRM:
573: confirm = 1;
574: break;
575: default:
1.221 djm 576: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 577: goto send;
1.110 djm 578: }
579: }
1.215 djm 580: if (realpath(provider, canonical_provider) == NULL) {
581: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
582: provider, strerror(errno));
583: goto send;
584: }
585: if (match_pattern_list(canonical_provider, pkcs11_whitelist, 0) != 1) {
586: verbose("refusing PKCS#11 add of \"%.100s\": "
587: "provider not whitelisted", canonical_provider);
588: goto send;
589: }
590: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 591: if (lifetime && !death)
1.175 dtucker 592: death = monotime() + lifetime;
1.110 djm 593:
1.215 djm 594: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 595: for (i = 0; i < count; i++) {
1.84 markus 596: k = keys[i];
1.221 djm 597: if (lookup_identity(k) == NULL) {
1.163 markus 598: id = xcalloc(1, sizeof(Identity));
1.84 markus 599: id->key = k;
1.215 djm 600: id->provider = xstrdup(canonical_provider);
601: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 602: id->death = death;
603: id->confirm = confirm;
1.221 djm 604: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
605: idtab->nentries++;
1.84 markus 606: success = 1;
607: } else {
1.194 markus 608: sshkey_free(k);
1.84 markus 609: }
610: keys[i] = NULL;
1.59 markus 611: }
612: send:
1.173 djm 613: free(pin);
614: free(provider);
615: free(keys);
1.194 markus 616: send_status(e, success);
1.59 markus 617: }
618:
619: static void
620: process_remove_smartcard_key(SocketEntry *e)
621: {
1.217 djm 622: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 623: int r, success = 0;
1.163 markus 624: Identity *id, *nxt;
1.59 markus 625:
1.194 markus 626: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 627: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
628: error("%s: buffer error: %s", __func__, ssh_err(r));
629: goto send;
630: }
1.173 djm 631: free(pin);
1.59 markus 632:
1.217 djm 633: if (realpath(provider, canonical_provider) == NULL) {
634: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
635: provider, strerror(errno));
636: goto send;
637: }
638:
639: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 640: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
641: nxt = TAILQ_NEXT(id, next);
642: /* Skip file--based keys */
643: if (id->provider == NULL)
644: continue;
645: if (!strcmp(canonical_provider, id->provider)) {
646: TAILQ_REMOVE(&idtab->idlist, id, next);
647: free_identity(id);
648: idtab->nentries--;
1.59 markus 649: }
650: }
1.217 djm 651: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 652: success = 1;
653: else
1.221 djm 654: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 655: send:
1.173 djm 656: free(provider);
1.194 markus 657: send_status(e, success);
1.59 markus 658: }
1.163 markus 659: #endif /* ENABLE_PKCS11 */
1.59 markus 660:
1.33 markus 661: /* dispatch incoming messages */
662:
1.223 djm 663: static int
664: process_message(u_int socknum)
1.1 deraadt 665: {
1.194 markus 666: u_int msg_len;
667: u_char type;
668: const u_char *cp;
669: int r;
1.223 djm 670: SocketEntry *e;
671:
672: if (socknum >= sockets_alloc) {
673: fatal("%s: socket number %u >= allocated %u",
674: __func__, socknum, sockets_alloc);
675: }
676: e = &sockets[socknum];
1.89 markus 677:
1.194 markus 678: if (sshbuf_len(e->input) < 5)
1.223 djm 679: return 0; /* Incomplete message header. */
1.194 markus 680: cp = sshbuf_ptr(e->input);
681: msg_len = PEEK_U32(cp);
1.223 djm 682: if (msg_len > AGENT_MAX_LEN) {
683: debug("%s: socket %u (fd=%d) message too long %u > %u",
684: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
685: return -1;
1.21 markus 686: }
1.194 markus 687: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 688: return 0; /* Incomplete message body. */
1.87 markus 689:
690: /* move the current input to e->request */
1.194 markus 691: sshbuf_reset(e->request);
692: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 693: (r = sshbuf_get_u8(e->request, &type)) != 0) {
694: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
695: r == SSH_ERR_STRING_TOO_LARGE) {
696: debug("%s: buffer error: %s", __func__, ssh_err(r));
697: return -1;
698: }
1.194 markus 699: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 700: }
701:
702: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 703:
1.230 djm 704: /* check whether agent is locked */
1.88 markus 705: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 706: sshbuf_reset(e->request);
1.88 markus 707: switch (type) {
708: case SSH2_AGENTC_REQUEST_IDENTITIES:
709: /* send empty lists */
1.221 djm 710: no_identities(e);
1.88 markus 711: break;
712: default:
713: /* send a fail message for all other request types */
1.194 markus 714: send_status(e, 0);
1.88 markus 715: }
1.223 djm 716: return 0;
1.88 markus 717: }
718:
1.21 markus 719: switch (type) {
1.88 markus 720: case SSH_AGENTC_LOCK:
721: case SSH_AGENTC_UNLOCK:
722: process_lock_agent(e, type == SSH_AGENTC_LOCK);
723: break;
1.21 markus 724: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 725: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 726: break;
727: /* ssh2 */
728: case SSH2_AGENTC_SIGN_REQUEST:
729: process_sign_request2(e);
730: break;
731: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 732: process_request_identities(e);
1.33 markus 733: break;
734: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 735: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 736: process_add_identity(e);
1.33 markus 737: break;
738: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 739: process_remove_identity(e);
1.33 markus 740: break;
741: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 742: process_remove_all_identities(e);
1.21 markus 743: break;
1.163 markus 744: #ifdef ENABLE_PKCS11
1.59 markus 745: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 746: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 747: process_add_smartcard_key(e);
1.75 deraadt 748: break;
1.59 markus 749: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
750: process_remove_smartcard_key(e);
1.75 deraadt 751: break;
1.163 markus 752: #endif /* ENABLE_PKCS11 */
1.21 markus 753: default:
754: /* Unknown message. Respond with failure. */
755: error("Unknown message %d", type);
1.194 markus 756: sshbuf_reset(e->request);
757: send_status(e, 0);
1.21 markus 758: break;
759: }
1.223 djm 760: return 0;
1.1 deraadt 761: }
762:
1.55 itojun 763: static void
1.73 stevesk 764: new_socket(sock_type type, int fd)
1.1 deraadt 765: {
1.112 markus 766: u_int i, old_alloc, new_alloc;
1.96 deraadt 767:
1.119 djm 768: set_nonblock(fd);
1.21 markus 769:
770: if (fd > max_fd)
771: max_fd = fd;
772:
773: for (i = 0; i < sockets_alloc; i++)
774: if (sockets[i].type == AUTH_UNUSED) {
775: sockets[i].fd = fd;
1.194 markus 776: if ((sockets[i].input = sshbuf_new()) == NULL)
777: fatal("%s: sshbuf_new failed", __func__);
778: if ((sockets[i].output = sshbuf_new()) == NULL)
779: fatal("%s: sshbuf_new failed", __func__);
780: if ((sockets[i].request = sshbuf_new()) == NULL)
781: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 782: sockets[i].type = type;
1.21 markus 783: return;
784: }
785: old_alloc = sockets_alloc;
1.112 markus 786: new_alloc = sockets_alloc + 10;
1.200 deraadt 787: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 788: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 789: sockets[i].type = AUTH_UNUSED;
1.112 markus 790: sockets_alloc = new_alloc;
1.21 markus 791: sockets[old_alloc].fd = fd;
1.194 markus 792: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
793: fatal("%s: sshbuf_new failed", __func__);
794: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
795: fatal("%s: sshbuf_new failed", __func__);
796: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
797: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 798: sockets[old_alloc].type = type;
1.1 deraadt 799: }
800:
1.55 itojun 801: static int
1.223 djm 802: handle_socket_read(u_int socknum)
1.1 deraadt 803: {
1.223 djm 804: struct sockaddr_un sunaddr;
805: socklen_t slen;
806: uid_t euid;
807: gid_t egid;
808: int fd;
809:
810: slen = sizeof(sunaddr);
811: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
812: if (fd < 0) {
813: error("accept from AUTH_SOCKET: %s", strerror(errno));
814: return -1;
815: }
816: if (getpeereid(fd, &euid, &egid) < 0) {
817: error("getpeereid %d failed: %s", fd, strerror(errno));
818: close(fd);
819: return -1;
820: }
821: if ((euid != 0) && (getuid() != euid)) {
822: error("uid mismatch: peer euid %u != uid %u",
823: (u_int) euid, (u_int) getuid());
824: close(fd);
825: return -1;
826: }
827: new_socket(AUTH_CONNECTION, fd);
828: return 0;
829: }
830:
831: static int
832: handle_conn_read(u_int socknum)
833: {
1.233 djm 834: char buf[AGENT_RBUF_LEN];
1.223 djm 835: ssize_t len;
836: int r;
837:
838: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
839: if (len == -1) {
840: if (errno == EAGAIN || errno == EINTR)
841: return 0;
842: error("%s: read error on socket %u (fd %d): %s",
843: __func__, socknum, sockets[socknum].fd,
844: strerror(errno));
845: }
846: return -1;
847: }
848: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
849: fatal("%s: buffer error: %s", __func__, ssh_err(r));
850: explicit_bzero(buf, sizeof(buf));
851: process_message(socknum);
852: return 0;
853: }
854:
855: static int
856: handle_conn_write(u_int socknum)
857: {
858: ssize_t len;
859: int r;
860:
861: if (sshbuf_len(sockets[socknum].output) == 0)
862: return 0; /* shouldn't happen */
863: if ((len = write(sockets[socknum].fd,
864: sshbuf_ptr(sockets[socknum].output),
865: sshbuf_len(sockets[socknum].output))) <= 0) {
866: if (len == -1) {
867: if (errno == EAGAIN || errno == EINTR)
868: return 0;
869: error("%s: read error on socket %u (fd %d): %s",
870: __func__, socknum, sockets[socknum].fd,
871: strerror(errno));
872: }
873: return -1;
874: }
875: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
876: fatal("%s: buffer error: %s", __func__, ssh_err(r));
877: return 0;
878: }
879:
880: static void
1.231 djm 881: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 882: {
883: size_t i;
1.231 djm 884: u_int socknum, activefds = npfd;
1.223 djm 885:
886: for (i = 0; i < npfd; i++) {
887: if (pfd[i].revents == 0)
888: continue;
889: /* Find sockets entry */
890: for (socknum = 0; socknum < sockets_alloc; socknum++) {
891: if (sockets[socknum].type != AUTH_SOCKET &&
892: sockets[socknum].type != AUTH_CONNECTION)
893: continue;
894: if (pfd[i].fd == sockets[socknum].fd)
895: break;
896: }
897: if (socknum >= sockets_alloc) {
898: error("%s: no socket for fd %d", __func__, pfd[i].fd);
899: continue;
900: }
901: /* Process events */
902: switch (sockets[socknum].type) {
903: case AUTH_SOCKET:
1.231 djm 904: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
905: break;
906: if (npfd > maxfds) {
907: debug3("out of fds (active %u >= limit %u); "
908: "skipping accept", activefds, maxfds);
909: break;
910: }
911: if (handle_socket_read(socknum) == 0)
912: activefds++;
1.223 djm 913: break;
914: case AUTH_CONNECTION:
915: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
916: handle_conn_read(socknum) != 0) {
1.231 djm 917: goto close_sock;
918: }
919: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
920: handle_conn_write(socknum) != 0) {
921: close_sock:
922: if (activefds == 0)
923: fatal("activefds == 0 at close_sock");
1.223 djm 924: close_socket(&sockets[socknum]);
1.231 djm 925: activefds--;
1.223 djm 926: break;
927: }
928: break;
929: default:
930: break;
931: }
932: }
933: }
934:
935: static int
1.231 djm 936: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 937: {
938: struct pollfd *pfd = *pfdp;
939: size_t i, j, npfd = 0;
1.174 dtucker 940: time_t deadline;
1.233 djm 941: int r;
1.46 markus 942:
1.223 djm 943: /* Count active sockets */
1.46 markus 944: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 945: switch (sockets[i].type) {
946: case AUTH_SOCKET:
947: case AUTH_CONNECTION:
1.223 djm 948: npfd++;
1.21 markus 949: break;
950: case AUTH_UNUSED:
951: break;
952: default:
953: fatal("Unknown socket type %d", sockets[i].type);
954: break;
955: }
1.46 markus 956: }
1.223 djm 957: if (npfd != *npfdp &&
958: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
959: fatal("%s: recallocarray failed", __func__);
960: *pfdp = pfd;
961: *npfdp = npfd;
1.46 markus 962:
1.223 djm 963: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 964: switch (sockets[i].type) {
965: case AUTH_SOCKET:
1.231 djm 966: if (npfd > maxfds) {
967: debug3("out of fds (active %zu >= limit %u); "
968: "skipping arming listener", npfd, maxfds);
969: break;
970: }
971: pfd[j].fd = sockets[i].fd;
972: pfd[j].revents = 0;
973: pfd[j].events = POLLIN;
974: j++;
975: break;
1.46 markus 976: case AUTH_CONNECTION:
1.223 djm 977: pfd[j].fd = sockets[i].fd;
978: pfd[j].revents = 0;
1.233 djm 979: /*
980: * Only prepare to read if we can handle a full-size
981: * input read buffer and enqueue a max size reply..
982: */
983: if ((r = sshbuf_check_reserve(sockets[i].input,
984: AGENT_RBUF_LEN)) == 0 &&
985: (r = sshbuf_check_reserve(sockets[i].output,
986: AGENT_MAX_LEN)) == 0)
987: pfd[j].events = POLLIN;
988: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
989: fatal("%s: buffer error: %s",
990: __func__, ssh_err(r));
991: }
1.194 markus 992: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 993: pfd[j].events |= POLLOUT;
994: j++;
1.46 markus 995: break;
996: default:
997: break;
998: }
999: }
1.155 dtucker 1000: deadline = reaper();
1001: if (parent_alive_interval != 0)
1002: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1003: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1004: if (deadline == 0) {
1.224 djm 1005: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1006: } else {
1.223 djm 1007: if (deadline > INT_MAX / 1000)
1008: *timeoutp = INT_MAX / 1000;
1009: else
1010: *timeoutp = deadline * 1000;
1.155 dtucker 1011: }
1.46 markus 1012: return (1);
1.21 markus 1013: }
1014:
1.55 itojun 1015: static void
1.113 markus 1016: cleanup_socket(void)
1.15 markus 1017: {
1.187 djm 1018: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1019: return;
1020: debug("%s: cleanup", __func__);
1.48 deraadt 1021: if (socket_name[0])
1022: unlink(socket_name);
1023: if (socket_dir[0])
1024: rmdir(socket_dir);
1.10 markus 1025: }
1026:
1.114 markus 1027: void
1.15 markus 1028: cleanup_exit(int i)
1029: {
1.113 markus 1030: cleanup_socket();
1031: _exit(i);
1.15 markus 1032: }
1033:
1.135 deraadt 1034: /*ARGSUSED*/
1.55 itojun 1035: static void
1.48 deraadt 1036: cleanup_handler(int sig)
1037: {
1.113 markus 1038: cleanup_socket();
1.163 markus 1039: #ifdef ENABLE_PKCS11
1040: pkcs11_terminate();
1041: #endif
1.48 deraadt 1042: _exit(2);
1.113 markus 1043: }
1044:
1.68 markus 1045: static void
1.155 dtucker 1046: check_parent_exists(void)
1.68 markus 1047: {
1.172 dtucker 1048: /*
1049: * If our parent has exited then getppid() will return (pid_t)1,
1050: * so testing for that should be safe.
1051: */
1052: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1053: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1054: cleanup_socket();
1055: _exit(2);
1.68 markus 1056: }
1.48 deraadt 1057: }
1058:
1.55 itojun 1059: static void
1.50 itojun 1060: usage(void)
1.15 markus 1061: {
1.184 deraadt 1062: fprintf(stderr,
1.202 jmc 1063: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.215 djm 1064: " [-P pkcs11_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1065: " ssh-agent [-c | -s] -k\n");
1.21 markus 1066: exit(1);
1.15 markus 1067: }
1068:
1.2 provos 1069: int
1070: main(int ac, char **av)
1.1 deraadt 1071: {
1.201 djm 1072: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1073: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1074: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1075: struct rlimit rlim;
1.96 deraadt 1076: extern int optind;
1.98 stevesk 1077: extern char *optarg;
1.21 markus 1078: pid_t pid;
1.96 deraadt 1079: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1080: size_t len;
1.189 djm 1081: mode_t prev_mask;
1.224 djm 1082: int timeout = -1; /* INFTIM */
1.223 djm 1083: struct pollfd *pfd = NULL;
1084: size_t npfd = 0;
1.231 djm 1085: u_int maxfds;
1.123 djm 1086:
1087: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1088: sanitise_stdfd();
1.99 markus 1089:
1090: /* drop */
1091: setegid(getgid());
1092: setgid(getgid());
1.53 markus 1093:
1.231 djm 1094: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1095: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1096:
1.185 markus 1097: #ifdef WITH_OPENSSL
1.170 djm 1098: OpenSSL_add_all_algorithms();
1.185 markus 1099: #endif
1.21 markus 1100:
1.215 djm 1101: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1102: switch (ch) {
1.192 djm 1103: case 'E':
1104: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1105: if (fingerprint_hash == -1)
1106: fatal("Invalid hash algorithm \"%s\"", optarg);
1107: break;
1.21 markus 1108: case 'c':
1109: if (s_flag)
1110: usage();
1111: c_flag++;
1112: break;
1113: case 'k':
1114: k_flag++;
1115: break;
1.215 djm 1116: case 'P':
1117: if (pkcs11_whitelist != NULL)
1118: fatal("-P option already specified");
1119: pkcs11_whitelist = xstrdup(optarg);
1120: break;
1.21 markus 1121: case 's':
1122: if (c_flag)
1123: usage();
1124: s_flag++;
1125: break;
1.57 markus 1126: case 'd':
1.201 djm 1127: if (d_flag || D_flag)
1.57 markus 1128: usage();
1129: d_flag++;
1130: break;
1.201 djm 1131: case 'D':
1132: if (d_flag || D_flag)
1133: usage();
1134: D_flag++;
1135: break;
1.86 markus 1136: case 'a':
1137: agentsocket = optarg;
1.106 marc 1138: break;
1139: case 't':
1140: if ((lifetime = convtime(optarg)) == -1) {
1141: fprintf(stderr, "Invalid lifetime\n");
1142: usage();
1143: }
1.86 markus 1144: break;
1.21 markus 1145: default:
1146: usage();
1147: }
1148: }
1149: ac -= optind;
1150: av += optind;
1151:
1.201 djm 1152: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1153: usage();
1154:
1.215 djm 1155: if (pkcs11_whitelist == NULL)
1156: pkcs11_whitelist = xstrdup(DEFAULT_PKCS11_WHITELIST);
1157:
1.85 markus 1158: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1159: shell = getenv("SHELL");
1.161 tobias 1160: if (shell != NULL && (len = strlen(shell)) > 2 &&
1161: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1162: c_flag = 1;
1163: }
1164: if (k_flag) {
1.136 deraadt 1165: const char *errstr = NULL;
1166:
1.21 markus 1167: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1168: if (pidstr == NULL) {
1169: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1170: SSH_AGENTPID_ENV_NAME);
1.21 markus 1171: exit(1);
1172: }
1.136 deraadt 1173: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1174: if (errstr) {
1175: fprintf(stderr,
1176: "%s=\"%s\", which is not a good PID: %s\n",
1177: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1178: exit(1);
1179: }
1180: if (kill(pid, SIGTERM) == -1) {
1181: perror("kill");
1182: exit(1);
1183: }
1184: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1185: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1186: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1187: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1188: exit(0);
1189: }
1.231 djm 1190:
1191: /*
1192: * Minimum file descriptors:
1193: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1194: * a few spare for libc / stack protectors / sanitisers, etc.
1195: */
1196: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1197: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1198: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1199: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1200: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1201:
1.21 markus 1202: parent_pid = getpid();
1203:
1.86 markus 1204: if (agentsocket == NULL) {
1205: /* Create private directory for agent socket */
1.171 djm 1206: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1207: if (mkdtemp(socket_dir) == NULL) {
1208: perror("mkdtemp: private socket dir");
1209: exit(1);
1210: }
1.91 mpech 1211: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1212: (long)parent_pid);
1.86 markus 1213: } else {
1214: /* Try to use specified agent socket */
1215: socket_dir[0] = '\0';
1216: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1217: }
1218:
1.23 markus 1219: /*
1220: * Create socket early so it will exist before command gets run from
1221: * the parent.
1222: */
1.189 djm 1223: prev_mask = umask(0177);
1.188 millert 1224: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1225: if (sock < 0) {
1.188 millert 1226: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1227: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1228: cleanup_exit(1);
1229: }
1.189 djm 1230: umask(prev_mask);
1.46 markus 1231:
1.23 markus 1232: /*
1233: * Fork, and have the parent execute the command, if any, or present
1234: * the socket data. The child continues as the authentication agent.
1235: */
1.201 djm 1236: if (D_flag || d_flag) {
1237: log_init(__progname,
1238: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1239: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1240: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1241: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1242: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1243: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1244: fflush(stdout);
1.57 markus 1245: goto skip;
1246: }
1.21 markus 1247: pid = fork();
1248: if (pid == -1) {
1249: perror("fork");
1.81 stevesk 1250: cleanup_exit(1);
1.21 markus 1251: }
1252: if (pid != 0) { /* Parent - execute the given command. */
1253: close(sock);
1.91 mpech 1254: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1255: if (ac == 0) {
1256: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1257: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1258: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1259: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1260: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1261: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1262: exit(0);
1263: }
1.36 deraadt 1264: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1265: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1266: perror("setenv");
1267: exit(1);
1268: }
1.21 markus 1269: execvp(av[0], av);
1270: perror(av[0]);
1271: exit(1);
1272: }
1.81 stevesk 1273: /* child */
1274: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1275:
1276: if (setsid() == -1) {
1.81 stevesk 1277: error("setsid: %s", strerror(errno));
1.67 stevesk 1278: cleanup_exit(1);
1279: }
1280:
1281: (void)chdir("/");
1.107 markus 1282: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1283: /* XXX might close listen socket */
1284: (void)dup2(fd, STDIN_FILENO);
1285: (void)dup2(fd, STDOUT_FILENO);
1286: (void)dup2(fd, STDERR_FILENO);
1287: if (fd > 2)
1288: close(fd);
1289: }
1.21 markus 1290:
1.41 markus 1291: /* deny core dumps, since memory contains unencrypted private keys */
1292: rlim.rlim_cur = rlim.rlim_max = 0;
1293: if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1.81 stevesk 1294: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1295: cleanup_exit(1);
1296: }
1.57 markus 1297:
1298: skip:
1.187 djm 1299:
1300: cleanup_pid = getpid();
1.163 markus 1301:
1302: #ifdef ENABLE_PKCS11
1303: pkcs11_init(0);
1304: #endif
1.21 markus 1305: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1306: if (ac > 0)
1307: parent_alive_interval = 10;
1.33 markus 1308: idtab_init();
1.61 markus 1309: signal(SIGPIPE, SIG_IGN);
1.201 djm 1310: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1311: signal(SIGHUP, cleanup_handler);
1312: signal(SIGTERM, cleanup_handler);
1.205 djm 1313:
1.215 djm 1314: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1315: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1316:
1.21 markus 1317: while (1) {
1.231 djm 1318: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1319: result = poll(pfd, npfd, timeout);
1.154 dtucker 1320: saved_errno = errno;
1.155 dtucker 1321: if (parent_alive_interval != 0)
1322: check_parent_exists();
1323: (void) reaper(); /* remove expired keys */
1.154 dtucker 1324: if (result < 0) {
1325: if (saved_errno == EINTR)
1.21 markus 1326: continue;
1.223 djm 1327: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1328: } else if (result > 0)
1.231 djm 1329: after_poll(pfd, npfd, maxfds);
1.15 markus 1330: }
1.21 markus 1331: /* NOTREACHED */
1.1 deraadt 1332: }
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