Annotation of src/crypto/external/bsd/openssh/dist/ssh-agent.c, Revision 1.29
1.27 christos 1: /* $NetBSD: ssh-agent.c,v 1.26 2019/04/20 17:16:40 christos Exp $ */
1.29 ! christos 2: /* $OpenBSD: ssh-agent.c,v 1.257 2020/03/06 18:28:27 markus Exp $ */
1.1 christos 3: /*
4: * Author: Tatu Ylonen <ylo@cs.hut.fi>
5: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6: * All rights reserved
7: * The authentication agent program.
8: *
9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
15: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
16: *
17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36: */
37:
1.2 christos 38: #include "includes.h"
1.27 christos 39: __RCSID("$NetBSD: ssh-agent.c,v 1.26 2019/04/20 17:16:40 christos Exp $");
1.19 christos 40:
1.14 christos 41: #include <sys/param.h> /* MIN MAX */
1.1 christos 42: #include <sys/types.h>
43: #include <sys/time.h>
44: #include <sys/queue.h>
45: #include <sys/resource.h>
46: #include <sys/socket.h>
1.13 christos 47: #include <sys/stat.h>
1.1 christos 48: #include <sys/un.h>
1.28 christos 49: #include <sys/wait.h>
1.1 christos 50:
1.13 christos 51: #ifdef WITH_OPENSSL
1.1 christos 52: #include <openssl/evp.h>
1.13 christos 53: #endif
1.1 christos 54:
55: #include <errno.h>
56: #include <fcntl.h>
57: #include <paths.h>
1.21 christos 58: #include <poll.h>
1.1 christos 59: #include <signal.h>
60: #include <stdlib.h>
61: #include <stdio.h>
62: #include <string.h>
1.28 christos 63: #include <stdarg.h>
1.14 christos 64: #include <limits.h>
1.1 christos 65: #include <time.h>
66: #include <unistd.h>
1.15 christos 67: #include <util.h>
1.1 christos 68:
69: #include "xmalloc.h"
70: #include "ssh.h"
1.14 christos 71: #include "sshbuf.h"
72: #include "sshkey.h"
1.1 christos 73: #include "authfd.h"
74: #include "compat.h"
75: #include "log.h"
76: #include "misc.h"
1.2 christos 77: #include "getpeereid.h"
1.13 christos 78: #include "digest.h"
1.14 christos 79: #include "ssherr.h"
1.19 christos 80: #include "match.h"
1.28 christos 81: #include "msg.h"
82: #include "ssherr.h"
83: #include "pathnames.h"
1.5 adam 84: #include "ssh-pkcs11.h"
1.28 christos 85: #include "sk-api.h"
1.1 christos 86:
1.28 christos 87: #ifndef DEFAULT_PROVIDER_WHITELIST
88: # define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/pkg/lib*/*"
1.19 christos 89: #endif
90:
1.21 christos 91: /* Maximum accepted message length */
92: #define AGENT_MAX_LEN (256*1024)
1.26 christos 93: /* Maximum bytes to read from client socket */
94: #define AGENT_RBUF_LEN (4096)
1.21 christos 95:
1.1 christos 96: typedef enum {
97: AUTH_UNUSED,
98: AUTH_SOCKET,
99: AUTH_CONNECTION
100: } sock_type;
101:
102: typedef struct {
103: int fd;
104: sock_type type;
1.14 christos 105: struct sshbuf *input;
106: struct sshbuf *output;
107: struct sshbuf *request;
1.1 christos 108: } SocketEntry;
109:
110: u_int sockets_alloc = 0;
111: SocketEntry *sockets = NULL;
112:
113: typedef struct identity {
114: TAILQ_ENTRY(identity) next;
1.14 christos 115: struct sshkey *key;
1.1 christos 116: char *comment;
1.5 adam 117: char *provider;
1.12 christos 118: time_t death;
1.1 christos 119: u_int confirm;
1.28 christos 120: char *sk_provider;
1.1 christos 121: } Identity;
122:
1.21 christos 123: struct idtable {
1.1 christos 124: int nentries;
125: TAILQ_HEAD(idqueue, identity) idlist;
1.21 christos 126: };
1.1 christos 127:
1.21 christos 128: /* private key table */
129: struct idtable *idtab;
1.1 christos 130:
131: int max_fd = 0;
132:
133: /* pid of shell == parent of agent */
134: pid_t parent_pid = -1;
1.12 christos 135: time_t parent_alive_interval = 0;
1.1 christos 136:
1.13 christos 137: /* pid of process for which cleanup_socket is applicable */
138: pid_t cleanup_pid = 0;
139:
1.1 christos 140: /* pathname and directory for AUTH_SOCKET */
1.14 christos 141: char socket_name[PATH_MAX];
142: char socket_dir[PATH_MAX];
1.1 christos 143:
1.28 christos 144: /* PKCS#11/Security key path whitelist */
145: static char *provider_whitelist;
1.19 christos 146:
1.1 christos 147: /* locking */
1.15 christos 148: #define LOCK_SIZE 32
149: #define LOCK_SALT_SIZE 16
150: #define LOCK_ROUNDS 1
1.1 christos 151: int locked = 0;
1.18 christos 152: u_char lock_pwhash[LOCK_SIZE];
153: u_char lock_salt[LOCK_SALT_SIZE];
1.1 christos 154:
155: extern char *__progname;
156:
1.12 christos 157: /* Default lifetime in seconds (0 == forever) */
158: static long lifetime = 0;
1.1 christos 159:
1.14 christos 160: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
161:
1.1 christos 162: static void
163: close_socket(SocketEntry *e)
164: {
165: close(e->fd);
166: e->fd = -1;
167: e->type = AUTH_UNUSED;
1.14 christos 168: sshbuf_free(e->input);
169: sshbuf_free(e->output);
170: sshbuf_free(e->request);
1.1 christos 171: }
172:
173: static void
174: idtab_init(void)
175: {
1.21 christos 176: idtab = xcalloc(1, sizeof(*idtab));
177: TAILQ_INIT(&idtab->idlist);
178: idtab->nentries = 0;
1.1 christos 179: }
180:
181: static void
182: free_identity(Identity *id)
183: {
1.14 christos 184: sshkey_free(id->key);
1.12 christos 185: free(id->provider);
186: free(id->comment);
1.28 christos 187: free(id->sk_provider);
1.12 christos 188: free(id);
1.1 christos 189: }
190:
191: /* return matching private key for given public key */
192: static Identity *
1.21 christos 193: lookup_identity(struct sshkey *key)
1.1 christos 194: {
195: Identity *id;
196:
1.21 christos 197: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.14 christos 198: if (sshkey_equal(key, id->key))
1.1 christos 199: return (id);
200: }
201: return (NULL);
202: }
203:
204: /* Check confirmation of keysign request */
205: static int
206: confirm_key(Identity *id)
207: {
208: char *p;
209: int ret = -1;
210:
1.14 christos 211: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
212: if (p != NULL &&
213: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.1 christos 214: id->comment, p))
215: ret = 0;
1.12 christos 216: free(p);
1.1 christos 217:
218: return (ret);
219: }
220:
1.14 christos 221: static void
222: send_status(SocketEntry *e, int success)
223: {
224: int r;
225:
226: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
227: (r = sshbuf_put_u8(e->output, success ?
228: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
229: fatal("%s: buffer error: %s", __func__, ssh_err(r));
230: }
231:
1.1 christos 232: /* send list of supported public keys to 'client' */
233: static void
1.21 christos 234: process_request_identities(SocketEntry *e)
1.1 christos 235: {
236: Identity *id;
1.14 christos 237: struct sshbuf *msg;
238: int r;
1.1 christos 239:
1.14 christos 240: if ((msg = sshbuf_new()) == NULL)
241: fatal("%s: sshbuf_new failed", __func__);
1.21 christos 242: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
243: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
1.14 christos 244: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.21 christos 245: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.22 christos 246: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
247: != 0 ||
1.21 christos 248: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
249: error("%s: put key/comment: %s", __func__,
250: ssh_err(r));
251: continue;
1.1 christos 252: }
253: }
1.14 christos 254: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
255: fatal("%s: buffer error: %s", __func__, ssh_err(r));
256: sshbuf_free(msg);
1.1 christos 257: }
258:
259:
1.17 christos 260: static const char *
261: agent_decode_alg(struct sshkey *key, u_int flags)
262: {
263: if (key->type == KEY_RSA) {
264: if (flags & SSH_AGENT_RSA_SHA2_256)
265: return "rsa-sha2-256";
266: else if (flags & SSH_AGENT_RSA_SHA2_512)
267: return "rsa-sha2-512";
1.27 christos 268: } else if (key->type == KEY_RSA_CERT) {
269: if (flags & SSH_AGENT_RSA_SHA2_256)
270: return "rsa-sha2-256-cert-v01@openssh.com";
271: else if (flags & SSH_AGENT_RSA_SHA2_512)
272: return "rsa-sha2-512-cert-v01@openssh.com";
1.17 christos 273: }
274: return NULL;
275: }
276:
1.1 christos 277: /* ssh2 only */
278: static void
279: process_sign_request2(SocketEntry *e)
280: {
1.21 christos 281: const u_char *data;
282: u_char *signature = NULL;
283: size_t dlen, slen = 0;
1.14 christos 284: u_int compat = 0, flags;
285: int r, ok = -1;
1.28 christos 286: char *fp = NULL;
1.14 christos 287: struct sshbuf *msg;
1.21 christos 288: struct sshkey *key = NULL;
1.14 christos 289: struct identity *id;
1.28 christos 290: struct notifier_ctx *notifier = NULL;
1.14 christos 291:
292: if ((msg = sshbuf_new()) == NULL)
293: fatal("%s: sshbuf_new failed", __func__);
1.21 christos 294: if ((r = sshkey_froms(e->request, &key)) != 0 ||
295: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.22 christos 296: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
297: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
298: goto send;
299: }
300:
1.21 christos 301: if ((id = lookup_identity(key)) == NULL) {
1.14 christos 302: verbose("%s: %s key not found", __func__, sshkey_type(key));
303: goto send;
304: }
305: if (id->confirm && confirm_key(id) != 0) {
306: verbose("%s: user refused key", __func__);
307: goto send;
308: }
1.28 christos 309: if (sshkey_is_sk(id->key) &&
310: (id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
311: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
312: SSH_FP_DEFAULT)) == NULL)
313: fatal("%s: fingerprint failed", __func__);
314: notifier = notify_start(0,
315: "Confirm user presence for key %s %s",
316: sshkey_type(id->key), fp);
317: }
1.14 christos 318: if ((r = sshkey_sign(id->key, &signature, &slen,
1.28 christos 319: data, dlen, agent_decode_alg(key, flags),
320: id->sk_provider, compat)) != 0) {
1.17 christos 321: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
1.14 christos 322: goto send;
1.1 christos 323: }
1.14 christos 324: /* Success */
325: ok = 0;
326: send:
1.28 christos 327: notify_complete(notifier);
1.14 christos 328: sshkey_free(key);
1.28 christos 329: free(fp);
1.1 christos 330: if (ok == 0) {
1.14 christos 331: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
332: (r = sshbuf_put_string(msg, signature, slen)) != 0)
333: fatal("%s: buffer error: %s", __func__, ssh_err(r));
334: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
335: fatal("%s: buffer error: %s", __func__, ssh_err(r));
336:
337: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
338: fatal("%s: buffer error: %s", __func__, ssh_err(r));
339:
340: sshbuf_free(msg);
1.12 christos 341: free(signature);
1.1 christos 342: }
343:
344: /* shared */
345: static void
1.21 christos 346: process_remove_identity(SocketEntry *e)
1.1 christos 347: {
1.14 christos 348: int r, success = 0;
349: struct sshkey *key = NULL;
1.21 christos 350: Identity *id;
1.14 christos 351:
1.21 christos 352: if ((r = sshkey_froms(e->request, &key)) != 0) {
353: error("%s: get key: %s", __func__, ssh_err(r));
354: goto done;
355: }
356: if ((id = lookup_identity(key)) == NULL) {
357: debug("%s: key not found", __func__);
358: goto done;
359: }
360: /* We have this key, free it. */
361: if (idtab->nentries < 1)
362: fatal("%s: internal error: nentries %d",
363: __func__, idtab->nentries);
364: TAILQ_REMOVE(&idtab->idlist, id, next);
365: free_identity(id);
366: idtab->nentries--;
367: sshkey_free(key);
368: success = 1;
369: done:
1.14 christos 370: send_status(e, success);
1.1 christos 371: }
372:
373: static void
1.21 christos 374: process_remove_all_identities(SocketEntry *e)
1.1 christos 375: {
376: Identity *id;
377:
378: /* Loop over all identities and clear the keys. */
1.21 christos 379: for (id = TAILQ_FIRST(&idtab->idlist); id;
380: id = TAILQ_FIRST(&idtab->idlist)) {
381: TAILQ_REMOVE(&idtab->idlist, id, next);
1.1 christos 382: free_identity(id);
383: }
384:
385: /* Mark that there are no identities. */
1.21 christos 386: idtab->nentries = 0;
1.1 christos 387:
388: /* Send success. */
1.14 christos 389: send_status(e, 1);
1.1 christos 390: }
391:
392: /* removes expired keys and returns number of seconds until the next expiry */
1.12 christos 393: static time_t
1.1 christos 394: reaper(void)
395: {
1.12 christos 396: time_t deadline = 0, now = monotime();
1.1 christos 397: Identity *id, *nxt;
398:
1.21 christos 399: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
400: nxt = TAILQ_NEXT(id, next);
401: if (id->death == 0)
402: continue;
403: if (now >= id->death) {
404: debug("expiring key '%s'", id->comment);
405: TAILQ_REMOVE(&idtab->idlist, id, next);
406: free_identity(id);
407: idtab->nentries--;
408: } else
409: deadline = (deadline == 0) ? id->death :
410: MINIMUM(deadline, id->death);
1.1 christos 411: }
412: if (deadline == 0 || deadline <= now)
413: return 0;
414: else
415: return (deadline - now);
416: }
417:
418: static void
1.21 christos 419: process_add_identity(SocketEntry *e)
1.1 christos 420: {
421: Identity *id;
1.14 christos 422: int success = 0, confirm = 0;
1.29 ! christos 423: u_int seconds = 0, maxsign;
1.28 christos 424: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
425: char canonical_provider[PATH_MAX];
1.12 christos 426: time_t death = 0;
1.14 christos 427: struct sshkey *k = NULL;
428: u_char ctype;
429: int r = SSH_ERR_INTERNAL_ERROR;
1.1 christos 430:
1.21 christos 431: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
432: k == NULL ||
1.14 christos 433: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
434: error("%s: decode private key: %s", __func__, ssh_err(r));
435: goto err;
436: }
437: while (sshbuf_len(e->request)) {
438: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
439: error("%s: buffer error: %s", __func__, ssh_err(r));
440: goto err;
441: }
442: switch (ctype) {
1.1 christos 443: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.14 christos 444: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
445: error("%s: bad lifetime constraint: %s",
446: __func__, ssh_err(r));
447: goto err;
448: }
449: death = monotime() + seconds;
1.1 christos 450: break;
451: case SSH_AGENT_CONSTRAIN_CONFIRM:
452: confirm = 1;
453: break;
1.22 christos 454: case SSH_AGENT_CONSTRAIN_MAXSIGN:
455: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
456: error("%s: bad maxsign constraint: %s",
457: __func__, ssh_err(r));
458: goto err;
459: }
460: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
461: error("%s: cannot enable maxsign: %s",
462: __func__, ssh_err(r));
463: goto err;
464: }
465: break;
1.28 christos 466: case SSH_AGENT_CONSTRAIN_EXTENSION:
467: if ((r = sshbuf_get_cstring(e->request,
468: &ext_name, NULL)) != 0) {
469: error("%s: cannot parse extension: %s",
470: __func__, ssh_err(r));
471: goto err;
472: }
473: debug("%s: constraint ext %s", __func__, ext_name);
474: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
475: if (sk_provider != NULL) {
476: error("%s already set", ext_name);
477: goto err;
478: }
479: if ((r = sshbuf_get_cstring(e->request,
480: &sk_provider, NULL)) != 0) {
481: error("%s: cannot parse %s: %s",
482: __func__, ext_name, ssh_err(r));
483: goto err;
484: }
485: } else {
486: error("%s: unsupported constraint \"%s\"",
487: __func__, ext_name);
488: goto err;
489: }
490: free(ext_name);
491: break;
1.1 christos 492: default:
1.14 christos 493: error("%s: Unknown constraint %d", __func__, ctype);
494: err:
1.28 christos 495: free(sk_provider);
496: free(ext_name);
1.14 christos 497: sshbuf_reset(e->request);
1.12 christos 498: free(comment);
1.14 christos 499: sshkey_free(k);
1.1 christos 500: goto send;
501: }
502: }
1.28 christos 503: if (sk_provider != NULL) {
504: if (!sshkey_is_sk(k)) {
505: error("Cannot add provider: %s is not an "
506: "authenticator-hosted key", sshkey_type(k));
507: free(sk_provider);
508: goto send;
509: }
510: if (strcasecmp(sk_provider, "internal") == 0) {
511: debug("%s: internal provider", __func__);
512: } else {
513: if (realpath(sk_provider, canonical_provider) == NULL) {
514: verbose("failed provider \"%.100s\": "
515: "realpath: %s", sk_provider,
516: strerror(errno));
517: free(sk_provider);
518: goto send;
519: }
520: free(sk_provider);
521: sk_provider = xstrdup(canonical_provider);
522: if (match_pattern_list(sk_provider,
523: provider_whitelist, 0) != 1) {
524: error("Refusing add key: "
525: "provider %s not whitelisted", sk_provider);
526: free(sk_provider);
527: goto send;
528: }
529: }
530: }
531: if ((r = sshkey_shield_private(k)) != 0) {
532: error("%s: shield private key: %s", __func__, ssh_err(r));
533: goto err;
534: }
1.14 christos 535:
1.1 christos 536: success = 1;
537: if (lifetime && !death)
1.12 christos 538: death = monotime() + lifetime;
1.21 christos 539: if ((id = lookup_identity(k)) == NULL) {
1.5 adam 540: id = xcalloc(1, sizeof(Identity));
1.21 christos 541: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.1 christos 542: /* Increment the number of identities. */
1.21 christos 543: idtab->nentries++;
1.1 christos 544: } else {
1.22 christos 545: /* key state might have been updated */
546: sshkey_free(id->key);
1.12 christos 547: free(id->comment);
1.28 christos 548: free(id->sk_provider);
1.1 christos 549: }
1.22 christos 550: id->key = k;
1.1 christos 551: id->comment = comment;
552: id->death = death;
553: id->confirm = confirm;
1.28 christos 554: id->sk_provider = sk_provider;
555:
556: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
557: SSH_FP_DEFAULT)) == NULL)
558: fatal("%s: sshkey_fingerprint failed", __func__);
559: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
560: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
561: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
562: free(fp);
1.1 christos 563: send:
1.14 christos 564: send_status(e, success);
1.1 christos 565: }
566:
567: /* XXX todo: encrypt sensitive data with passphrase */
568: static void
569: process_lock_agent(SocketEntry *e, int lock)
570: {
1.15 christos 571: int r, success = 0, delay;
1.18 christos 572: char *passwd;
573: u_char passwdhash[LOCK_SIZE];
1.15 christos 574: static u_int fail_count = 0;
575: size_t pwlen;
1.1 christos 576:
1.22 christos 577: /*
578: * This is deliberately fatal: the user has requested that we lock,
579: * but we can't parse their request properly. The only safe thing to
580: * do is abort.
581: */
1.15 christos 582: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
1.14 christos 583: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.15 christos 584: if (pwlen == 0) {
585: debug("empty password not supported");
586: } else if (locked && !lock) {
587: if (bcrypt_pbkdf(passwd, pwlen, (uint8_t *)lock_salt, sizeof(lock_salt),
588: (uint8_t *)passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
589: fatal("bcrypt_pbkdf");
1.18 christos 590: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.15 christos 591: debug("agent unlocked");
592: locked = 0;
593: fail_count = 0;
1.18 christos 594: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.15 christos 595: success = 1;
596: } else {
597: /* delay in 0.1s increments up to 10s */
598: if (fail_count < 100)
599: fail_count++;
600: delay = 100000 * fail_count;
601: debug("unlock failed, delaying %0.1lf seconds",
602: (double)delay/1000000);
603: usleep(delay);
604: }
605: explicit_bzero(passwdhash, sizeof(passwdhash));
1.1 christos 606: } else if (!locked && lock) {
1.15 christos 607: debug("agent locked");
1.1 christos 608: locked = 1;
1.15 christos 609: arc4random_buf(lock_salt, sizeof(lock_salt));
1.18 christos 610: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
611: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.15 christos 612: fatal("bcrypt_pbkdf");
1.1 christos 613: success = 1;
614: }
1.29 ! christos 615: freezero(passwd, pwlen);
1.14 christos 616: send_status(e, success);
1.1 christos 617: }
618:
619: static void
1.21 christos 620: no_identities(SocketEntry *e)
1.1 christos 621: {
1.14 christos 622: struct sshbuf *msg;
623: int r;
1.1 christos 624:
1.14 christos 625: if ((msg = sshbuf_new()) == NULL)
626: fatal("%s: sshbuf_new failed", __func__);
1.21 christos 627: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.14 christos 628: (r = sshbuf_put_u32(msg, 0)) != 0 ||
629: (r = sshbuf_put_stringb(e->output, msg)) != 0)
630: fatal("%s: buffer error: %s", __func__, ssh_err(r));
631: sshbuf_free(msg);
1.1 christos 632: }
633:
1.5 adam 634: #ifdef ENABLE_PKCS11
1.1 christos 635: static void
636: process_add_smartcard_key(SocketEntry *e)
637: {
1.22 christos 638: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.28 christos 639: char **comments = NULL;
1.21 christos 640: int r, i, count = 0, success = 0, confirm = 0;
1.14 christos 641: u_int seconds;
1.12 christos 642: time_t death = 0;
1.14 christos 643: u_char type;
644: struct sshkey **keys = NULL, *k;
1.1 christos 645: Identity *id;
646:
1.14 christos 647: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.22 christos 648: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
649: error("%s: buffer error: %s", __func__, ssh_err(r));
650: goto send;
651: }
1.14 christos 652:
653: while (sshbuf_len(e->request)) {
1.22 christos 654: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
655: error("%s: buffer error: %s", __func__, ssh_err(r));
656: goto send;
657: }
1.14 christos 658: switch (type) {
1.1 christos 659: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.22 christos 660: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
661: error("%s: buffer error: %s",
1.14 christos 662: __func__, ssh_err(r));
1.22 christos 663: goto send;
664: }
1.14 christos 665: death = monotime() + seconds;
1.1 christos 666: break;
667: case SSH_AGENT_CONSTRAIN_CONFIRM:
668: confirm = 1;
669: break;
670: default:
1.21 christos 671: error("%s: Unknown constraint type %d", __func__, type);
1.1 christos 672: goto send;
673: }
674: }
1.19 christos 675: if (realpath(provider, canonical_provider) == NULL) {
676: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
677: provider, strerror(errno));
678: goto send;
679: }
1.28 christos 680: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.19 christos 681: verbose("refusing PKCS#11 add of \"%.100s\": "
682: "provider not whitelisted", canonical_provider);
683: goto send;
684: }
685: debug("%s: add %.100s", __func__, canonical_provider);
1.1 christos 686: if (lifetime && !death)
1.12 christos 687: death = monotime() + lifetime;
1.1 christos 688:
1.28 christos 689: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.5 adam 690: for (i = 0; i < count; i++) {
1.1 christos 691: k = keys[i];
1.21 christos 692: if (lookup_identity(k) == NULL) {
1.5 adam 693: id = xcalloc(1, sizeof(Identity));
1.1 christos 694: id->key = k;
1.28 christos 695: keys[i] = NULL; /* transferred */
1.19 christos 696: id->provider = xstrdup(canonical_provider);
1.28 christos 697: if (*comments[i] != '\0') {
698: id->comment = comments[i];
699: comments[i] = NULL; /* transferred */
700: } else {
701: id->comment = xstrdup(canonical_provider);
702: }
1.1 christos 703: id->death = death;
704: id->confirm = confirm;
1.21 christos 705: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
706: idtab->nentries++;
1.1 christos 707: success = 1;
708: }
1.28 christos 709: sshkey_free(keys[i]);
710: free(comments[i]);
1.1 christos 711: }
712: send:
1.12 christos 713: free(pin);
714: free(provider);
715: free(keys);
1.28 christos 716: free(comments);
1.14 christos 717: send_status(e, success);
1.1 christos 718: }
719:
720: static void
721: process_remove_smartcard_key(SocketEntry *e)
722: {
1.20 christos 723: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.21 christos 724: int r, success = 0;
1.5 adam 725: Identity *id, *nxt;
1.1 christos 726:
1.14 christos 727: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.22 christos 728: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
729: error("%s: buffer error: %s", __func__, ssh_err(r));
730: goto send;
731: }
1.12 christos 732: free(pin);
1.1 christos 733:
1.20 christos 734: if (realpath(provider, canonical_provider) == NULL) {
735: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
736: provider, strerror(errno));
737: goto send;
738: }
739:
740: debug("%s: remove %.100s", __func__, canonical_provider);
1.21 christos 741: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
742: nxt = TAILQ_NEXT(id, next);
743: /* Skip file--based keys */
744: if (id->provider == NULL)
745: continue;
746: if (!strcmp(canonical_provider, id->provider)) {
747: TAILQ_REMOVE(&idtab->idlist, id, next);
748: free_identity(id);
749: idtab->nentries--;
1.1 christos 750: }
751: }
1.20 christos 752: if (pkcs11_del_provider(canonical_provider) == 0)
1.5 adam 753: success = 1;
754: else
1.21 christos 755: error("%s: pkcs11_del_provider failed", __func__);
1.20 christos 756: send:
1.12 christos 757: free(provider);
1.14 christos 758: send_status(e, success);
1.1 christos 759: }
1.5 adam 760: #endif /* ENABLE_PKCS11 */
1.1 christos 761:
762: /* dispatch incoming messages */
763:
1.21 christos 764: static int
765: process_message(u_int socknum)
1.1 christos 766: {
1.14 christos 767: u_int msg_len;
768: u_char type;
769: const u_char *cp;
770: int r;
1.21 christos 771: SocketEntry *e;
772:
773: if (socknum >= sockets_alloc) {
774: fatal("%s: socket number %u >= allocated %u",
775: __func__, socknum, sockets_alloc);
776: }
777: e = &sockets[socknum];
1.1 christos 778:
1.14 christos 779: if (sshbuf_len(e->input) < 5)
1.21 christos 780: return 0; /* Incomplete message header. */
1.14 christos 781: cp = sshbuf_ptr(e->input);
782: msg_len = PEEK_U32(cp);
1.21 christos 783: if (msg_len > AGENT_MAX_LEN) {
784: debug("%s: socket %u (fd=%d) message too long %u > %u",
785: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
786: return -1;
1.1 christos 787: }
1.14 christos 788: if (sshbuf_len(e->input) < msg_len + 4)
1.21 christos 789: return 0; /* Incomplete message body. */
1.1 christos 790:
791: /* move the current input to e->request */
1.14 christos 792: sshbuf_reset(e->request);
793: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.21 christos 794: (r = sshbuf_get_u8(e->request, &type)) != 0) {
795: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
796: r == SSH_ERR_STRING_TOO_LARGE) {
797: debug("%s: buffer error: %s", __func__, ssh_err(r));
798: return -1;
799: }
1.14 christos 800: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.21 christos 801: }
802:
803: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.1 christos 804:
1.24 christos 805: /* check whether agent is locked */
1.1 christos 806: if (locked && type != SSH_AGENTC_UNLOCK) {
1.14 christos 807: sshbuf_reset(e->request);
1.1 christos 808: switch (type) {
809: case SSH2_AGENTC_REQUEST_IDENTITIES:
810: /* send empty lists */
1.21 christos 811: no_identities(e);
1.1 christos 812: break;
813: default:
814: /* send a fail message for all other request types */
1.14 christos 815: send_status(e, 0);
1.1 christos 816: }
1.21 christos 817: return 0;
1.1 christos 818: }
819:
820: switch (type) {
821: case SSH_AGENTC_LOCK:
822: case SSH_AGENTC_UNLOCK:
823: process_lock_agent(e, type == SSH_AGENTC_LOCK);
824: break;
825: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.21 christos 826: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.1 christos 827: break;
828: /* ssh2 */
829: case SSH2_AGENTC_SIGN_REQUEST:
830: process_sign_request2(e);
831: break;
832: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.21 christos 833: process_request_identities(e);
1.1 christos 834: break;
835: case SSH2_AGENTC_ADD_IDENTITY:
836: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.21 christos 837: process_add_identity(e);
1.1 christos 838: break;
839: case SSH2_AGENTC_REMOVE_IDENTITY:
1.21 christos 840: process_remove_identity(e);
1.1 christos 841: break;
842: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.21 christos 843: process_remove_all_identities(e);
1.1 christos 844: break;
1.5 adam 845: #ifdef ENABLE_PKCS11
1.1 christos 846: case SSH_AGENTC_ADD_SMARTCARD_KEY:
847: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
848: process_add_smartcard_key(e);
849: break;
850: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
851: process_remove_smartcard_key(e);
852: break;
1.5 adam 853: #endif /* ENABLE_PKCS11 */
1.1 christos 854: default:
855: /* Unknown message. Respond with failure. */
856: error("Unknown message %d", type);
1.14 christos 857: sshbuf_reset(e->request);
858: send_status(e, 0);
1.1 christos 859: break;
860: }
1.21 christos 861: return 0;
1.1 christos 862: }
863:
864: static void
865: new_socket(sock_type type, int fd)
866: {
867: u_int i, old_alloc, new_alloc;
868:
869: set_nonblock(fd);
870:
871: if (fd > max_fd)
872: max_fd = fd;
873:
874: for (i = 0; i < sockets_alloc; i++)
875: if (sockets[i].type == AUTH_UNUSED) {
876: sockets[i].fd = fd;
1.14 christos 877: if ((sockets[i].input = sshbuf_new()) == NULL)
878: fatal("%s: sshbuf_new failed", __func__);
879: if ((sockets[i].output = sshbuf_new()) == NULL)
880: fatal("%s: sshbuf_new failed", __func__);
881: if ((sockets[i].request = sshbuf_new()) == NULL)
882: fatal("%s: sshbuf_new failed", __func__);
1.1 christos 883: sockets[i].type = type;
884: return;
885: }
886: old_alloc = sockets_alloc;
887: new_alloc = sockets_alloc + 10;
1.15 christos 888: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.1 christos 889: for (i = old_alloc; i < new_alloc; i++)
890: sockets[i].type = AUTH_UNUSED;
891: sockets_alloc = new_alloc;
892: sockets[old_alloc].fd = fd;
1.14 christos 893: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
894: fatal("%s: sshbuf_new failed", __func__);
895: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
896: fatal("%s: sshbuf_new failed", __func__);
897: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
898: fatal("%s: sshbuf_new failed", __func__);
1.1 christos 899: sockets[old_alloc].type = type;
900: }
901:
902: static int
1.21 christos 903: handle_socket_read(u_int socknum)
904: {
905: struct sockaddr_un sunaddr;
906: socklen_t slen;
907: uid_t euid;
908: gid_t egid;
909: int fd;
910:
911: slen = sizeof(sunaddr);
912: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.27 christos 913: if (fd == -1) {
1.21 christos 914: error("accept from AUTH_SOCKET: %s", strerror(errno));
915: return -1;
916: }
1.27 christos 917: if (getpeereid(fd, &euid, &egid) == -1) {
1.21 christos 918: error("getpeereid %d failed: %s", fd, strerror(errno));
919: close(fd);
920: return -1;
921: }
922: if ((euid != 0) && (getuid() != euid)) {
923: error("uid mismatch: peer euid %u != uid %u",
924: (u_int) euid, (u_int) getuid());
925: close(fd);
926: return -1;
927: }
928: new_socket(AUTH_CONNECTION, fd);
929: return 0;
930: }
931:
932: static int
933: handle_conn_read(u_int socknum)
934: {
1.26 christos 935: char buf[AGENT_RBUF_LEN];
1.21 christos 936: ssize_t len;
937: int r;
938:
939: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
940: if (len == -1) {
941: if (errno == EAGAIN || errno == EINTR)
942: return 0;
943: error("%s: read error on socket %u (fd %d): %s",
944: __func__, socknum, sockets[socknum].fd,
945: strerror(errno));
946: }
947: return -1;
948: }
949: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
950: fatal("%s: buffer error: %s", __func__, ssh_err(r));
951: explicit_bzero(buf, sizeof(buf));
952: process_message(socknum);
953: return 0;
954: }
955:
956: static int
957: handle_conn_write(u_int socknum)
958: {
959: ssize_t len;
960: int r;
961:
962: if (sshbuf_len(sockets[socknum].output) == 0)
963: return 0; /* shouldn't happen */
964: if ((len = write(sockets[socknum].fd,
965: sshbuf_ptr(sockets[socknum].output),
966: sshbuf_len(sockets[socknum].output))) <= 0) {
967: if (len == -1) {
968: if (errno == EAGAIN || errno == EINTR)
969: return 0;
970: error("%s: read error on socket %u (fd %d): %s",
971: __func__, socknum, sockets[socknum].fd,
972: strerror(errno));
973: }
974: return -1;
975: }
976: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
977: fatal("%s: buffer error: %s", __func__, ssh_err(r));
978: return 0;
979: }
980:
981: static void
1.24 christos 982: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.21 christos 983: {
984: size_t i;
1.24 christos 985: u_int socknum, activefds = npfd;
1.21 christos 986:
987: for (i = 0; i < npfd; i++) {
988: if (pfd[i].revents == 0)
989: continue;
990: /* Find sockets entry */
991: for (socknum = 0; socknum < sockets_alloc; socknum++) {
992: if (sockets[socknum].type != AUTH_SOCKET &&
993: sockets[socknum].type != AUTH_CONNECTION)
994: continue;
995: if (pfd[i].fd == sockets[socknum].fd)
996: break;
997: }
998: if (socknum >= sockets_alloc) {
999: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1000: continue;
1001: }
1002: /* Process events */
1003: switch (sockets[socknum].type) {
1004: case AUTH_SOCKET:
1.24 christos 1005: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1006: break;
1007: if (npfd > maxfds) {
1008: debug3("out of fds (active %u >= limit %u); "
1009: "skipping accept", activefds, maxfds);
1010: break;
1011: }
1012: if (handle_socket_read(socknum) == 0)
1013: activefds++;
1.21 christos 1014: break;
1015: case AUTH_CONNECTION:
1016: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1017: handle_conn_read(socknum) != 0) {
1.24 christos 1018: goto close_sock;
1019: }
1020: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1021: handle_conn_write(socknum) != 0) {
1022: close_sock:
1023: if (activefds == 0)
1024: fatal("activefds == 0 at close_sock");
1.21 christos 1025: close_socket(&sockets[socknum]);
1.24 christos 1026: activefds--;
1.21 christos 1027: break;
1028: }
1029: break;
1030: default:
1031: break;
1032: }
1033: }
1034: }
1035:
1036: static int
1.24 christos 1037: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.1 christos 1038: {
1.21 christos 1039: struct pollfd *pfd = *pfdp;
1040: size_t i, j, npfd = 0;
1.12 christos 1041: time_t deadline;
1.26 christos 1042: int r;
1.1 christos 1043:
1.21 christos 1044: /* Count active sockets */
1.1 christos 1045: for (i = 0; i < sockets_alloc; i++) {
1046: switch (sockets[i].type) {
1047: case AUTH_SOCKET:
1048: case AUTH_CONNECTION:
1.21 christos 1049: npfd++;
1.1 christos 1050: break;
1051: case AUTH_UNUSED:
1052: break;
1053: default:
1054: fatal("Unknown socket type %d", sockets[i].type);
1055: break;
1056: }
1057: }
1.21 christos 1058: if (npfd != *npfdp &&
1059: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1060: fatal("%s: recallocarray failed", __func__);
1061: *pfdp = pfd;
1062: *npfdp = npfd;
1.1 christos 1063:
1.21 christos 1064: for (i = j = 0; i < sockets_alloc; i++) {
1.1 christos 1065: switch (sockets[i].type) {
1066: case AUTH_SOCKET:
1.24 christos 1067: if (npfd > maxfds) {
1068: debug3("out of fds (active %zu >= limit %u); "
1069: "skipping arming listener", npfd, maxfds);
1070: break;
1071: }
1072: pfd[j].fd = sockets[i].fd;
1073: pfd[j].revents = 0;
1074: pfd[j].events = POLLIN;
1075: j++;
1076: break;
1.1 christos 1077: case AUTH_CONNECTION:
1.21 christos 1078: pfd[j].fd = sockets[i].fd;
1079: pfd[j].revents = 0;
1.26 christos 1080: /*
1081: * Only prepare to read if we can handle a full-size
1082: * input read buffer and enqueue a max size reply..
1083: */
1084: if ((r = sshbuf_check_reserve(sockets[i].input,
1085: AGENT_RBUF_LEN)) == 0 &&
1086: (r = sshbuf_check_reserve(sockets[i].output,
1087: AGENT_MAX_LEN)) == 0)
1088: pfd[j].events = POLLIN;
1089: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1090: fatal("%s: buffer error: %s",
1091: __func__, ssh_err(r));
1092: }
1.14 christos 1093: if (sshbuf_len(sockets[i].output) > 0)
1.21 christos 1094: pfd[j].events |= POLLOUT;
1095: j++;
1.1 christos 1096: break;
1097: default:
1098: break;
1099: }
1100: }
1101: deadline = reaper();
1102: if (parent_alive_interval != 0)
1103: deadline = (deadline == 0) ? parent_alive_interval :
1.19 christos 1104: MINIMUM(deadline, parent_alive_interval);
1.1 christos 1105: if (deadline == 0) {
1.21 christos 1106: *timeoutp = -1; /* INFTIM */
1.1 christos 1107: } else {
1.21 christos 1108: if (deadline > INT_MAX / 1000)
1109: *timeoutp = INT_MAX / 1000;
1110: else
1111: *timeoutp = deadline * 1000;
1.1 christos 1112: }
1113: return (1);
1114: }
1115:
1116: static void
1117: cleanup_socket(void)
1118: {
1.13 christos 1119: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1120: return;
1121: debug("%s: cleanup", __func__);
1.1 christos 1122: if (socket_name[0])
1123: unlink(socket_name);
1124: if (socket_dir[0])
1125: rmdir(socket_dir);
1126: }
1127:
1128: void
1129: cleanup_exit(int i)
1130: {
1131: cleanup_socket();
1132: _exit(i);
1133: }
1134:
1135: /*ARGSUSED*/
1.9 joerg 1136: __dead static void
1.1 christos 1137: cleanup_handler(int sig)
1138: {
1139: cleanup_socket();
1.5 adam 1140: #ifdef ENABLE_PKCS11
1141: pkcs11_terminate();
1142: #endif
1.1 christos 1143: _exit(2);
1144: }
1145:
1146: static void
1147: check_parent_exists(void)
1148: {
1.8 christos 1149: /*
1150: * If our parent has exited then getppid() will return (pid_t)1,
1151: * so testing for that should be safe.
1152: */
1153: if (parent_pid != -1 && getppid() != parent_pid) {
1.1 christos 1154: /* printf("Parent has died - Authentication agent exiting.\n"); */
1155: cleanup_socket();
1156: _exit(2);
1157: }
1158: }
1159:
1.9 joerg 1160: __dead static void
1.1 christos 1161: usage(void)
1162: {
1.13 christos 1163: fprintf(stderr,
1.15 christos 1164: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.28 christos 1165: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.13 christos 1166: " ssh-agent [-c | -s] -k\n");
1.1 christos 1167: exit(1);
1168: }
1169:
1.7 christos 1170: static void
1171: csh_setenv(const char *name, const char *value)
1172: {
1173: printf("setenv %s %s;\n", name, value);
1174: }
1175:
1176: static void
1177: csh_unsetenv(const char *name)
1178: {
1179: printf("unsetenv %s;\n", name);
1180: }
1181:
1182: static void
1183: sh_setenv(const char *name, const char *value)
1184: {
1185: printf("%s=%s; export %s;\n", name, value, name);
1186: }
1187:
1188: static void
1189: sh_unsetenv(const char *name)
1190: {
1191: printf("unset %s;\n", name);
1192: }
1.1 christos 1193: int
1194: main(int ac, char **av)
1195: {
1.15 christos 1196: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.1 christos 1197: int sock, fd, ch, result, saved_errno;
1.6 christos 1198: char *shell, *pidstr, *agentsocket = NULL;
1.1 christos 1199: struct rlimit rlim;
1.21 christos 1200: void (*f_setenv)(const char *, const char *);
1201: void (*f_unsetenv)(const char *);
1.1 christos 1202: extern int optind;
1203: extern char *optarg;
1204: pid_t pid;
1205: char pidstrbuf[1 + 3 * sizeof pid];
1.4 christos 1206: size_t len;
1.13 christos 1207: mode_t prev_mask;
1.21 christos 1208: int timeout = -1; /* INFTIM */
1209: struct pollfd *pfd = NULL;
1210: size_t npfd = 0;
1.24 christos 1211: u_int maxfds;
1.1 christos 1212:
1213: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1214: sanitise_stdfd();
1215:
1216: /* drop */
1217: setegid(getgid());
1218: setgid(getgid());
1219:
1.24 christos 1220: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1221: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1222:
1.13 christos 1223: #ifdef WITH_OPENSSL
1.6 christos 1224: OpenSSL_add_all_algorithms();
1.13 christos 1225: #endif
1.1 christos 1226:
1.19 christos 1227: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.1 christos 1228: switch (ch) {
1.14 christos 1229: case 'E':
1230: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1231: if (fingerprint_hash == -1)
1232: fatal("Invalid hash algorithm \"%s\"", optarg);
1233: break;
1.1 christos 1234: case 'c':
1235: if (s_flag)
1236: usage();
1237: c_flag++;
1238: break;
1239: case 'k':
1240: k_flag++;
1241: break;
1.19 christos 1242: case 'P':
1.28 christos 1243: if (provider_whitelist != NULL)
1.19 christos 1244: fatal("-P option already specified");
1.28 christos 1245: provider_whitelist = xstrdup(optarg);
1.19 christos 1246: break;
1.1 christos 1247: case 's':
1248: if (c_flag)
1249: usage();
1250: s_flag++;
1251: break;
1252: case 'd':
1.15 christos 1253: if (d_flag || D_flag)
1.1 christos 1254: usage();
1255: d_flag++;
1256: break;
1.15 christos 1257: case 'D':
1258: if (d_flag || D_flag)
1259: usage();
1260: D_flag++;
1261: break;
1.1 christos 1262: case 'a':
1263: agentsocket = optarg;
1264: break;
1265: case 't':
1266: if ((lifetime = convtime(optarg)) == -1) {
1267: fprintf(stderr, "Invalid lifetime\n");
1268: usage();
1269: }
1270: break;
1271: default:
1272: usage();
1273: }
1274: }
1275: ac -= optind;
1276: av += optind;
1277:
1.15 christos 1278: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.1 christos 1279: usage();
1280:
1.28 christos 1281: if (provider_whitelist == NULL)
1282: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.19 christos 1283:
1.1 christos 1284: if (ac == 0 && !c_flag && !s_flag) {
1285: shell = getenv("SHELL");
1.4 christos 1286: if (shell != NULL && (len = strlen(shell)) > 2 &&
1287: strncmp(shell + len - 3, "csh", 3) == 0)
1.1 christos 1288: c_flag = 1;
1289: }
1.7 christos 1290: if (c_flag) {
1291: f_setenv = csh_setenv;
1292: f_unsetenv = csh_unsetenv;
1293: } else {
1294: f_setenv = sh_setenv;
1295: f_unsetenv = sh_unsetenv;
1296: }
1.1 christos 1297: if (k_flag) {
1298: const char *errstr = NULL;
1299:
1300: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1301: if (pidstr == NULL) {
1302: fprintf(stderr, "%s not set, cannot kill agent\n",
1303: SSH_AGENTPID_ENV_NAME);
1304: exit(1);
1305: }
1306: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1307: if (errstr) {
1308: fprintf(stderr,
1309: "%s=\"%s\", which is not a good PID: %s\n",
1310: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1311: exit(1);
1312: }
1313: if (kill(pid, SIGTERM) == -1) {
1314: perror("kill");
1315: exit(1);
1316: }
1.7 christos 1317: (*f_unsetenv)(SSH_AUTHSOCKET_ENV_NAME);
1318: (*f_unsetenv)(SSH_AGENTPID_ENV_NAME);
1.1 christos 1319: printf("echo Agent pid %ld killed;\n", (long)pid);
1320: exit(0);
1321: }
1.24 christos 1322:
1323: /*
1324: * Minimum file descriptors:
1325: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1326: * a few spare for libc / stack protectors / sanitisers, etc.
1327: */
1328: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1329: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.26 christos 1330: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.24 christos 1331: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1332: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1333:
1.1 christos 1334: parent_pid = getpid();
1335:
1336: if (agentsocket == NULL) {
1337: /* Create private directory for agent socket */
1.6 christos 1338: mktemp_proto(socket_dir, sizeof(socket_dir));
1.1 christos 1339: if (mkdtemp(socket_dir) == NULL) {
1340: perror("mkdtemp: private socket dir");
1341: exit(1);
1342: }
1343: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1344: (long)parent_pid);
1345: } else {
1346: /* Try to use specified agent socket */
1347: socket_dir[0] = '\0';
1348: strlcpy(socket_name, agentsocket, sizeof socket_name);
1349: }
1350:
1351: /*
1352: * Create socket early so it will exist before command gets run from
1353: * the parent.
1354: */
1.13 christos 1355: prev_mask = umask(0177);
1356: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.1 christos 1357: if (sock < 0) {
1.13 christos 1358: /* XXX - unix_listener() calls error() not perror() */
1.1 christos 1359: *socket_name = '\0'; /* Don't unlink any existing file */
1360: cleanup_exit(1);
1361: }
1.13 christos 1362: umask(prev_mask);
1.1 christos 1363:
1364: /*
1365: * Fork, and have the parent execute the command, if any, or present
1366: * the socket data. The child continues as the authentication agent.
1367: */
1.15 christos 1368: if (D_flag || d_flag) {
1369: log_init(__progname,
1370: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1371: SYSLOG_FACILITY_AUTH, 1);
1372: if (c_flag)
1373: printf("setenv %s %s;\n",
1374: SSH_AUTHSOCKET_ENV_NAME, socket_name);
1375: else
1376: printf("%s=%s; export %s;\n",
1377: SSH_AUTHSOCKET_ENV_NAME, socket_name,
1378: SSH_AUTHSOCKET_ENV_NAME);
1.1 christos 1379: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.17 christos 1380: fflush(stdout);
1.1 christos 1381: goto skip;
1382: }
1383: pid = fork();
1384: if (pid == -1) {
1385: perror("fork");
1386: cleanup_exit(1);
1387: }
1388: if (pid != 0) { /* Parent - execute the given command. */
1389: close(sock);
1390: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1391: if (ac == 0) {
1.7 christos 1392: (*f_setenv)(SSH_AUTHSOCKET_ENV_NAME, socket_name);
1393: (*f_setenv)(SSH_AGENTPID_ENV_NAME, pidstrbuf);
1.1 christos 1394: printf("echo Agent pid %ld;\n", (long)pid);
1395: exit(0);
1396: }
1397: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1398: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1399: perror("setenv");
1400: exit(1);
1401: }
1402: execvp(av[0], av);
1403: perror(av[0]);
1404: exit(1);
1405: }
1406: /* child */
1407: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1408:
1409: if (setsid() == -1) {
1410: error("setsid: %s", strerror(errno));
1411: cleanup_exit(1);
1412: }
1413:
1414: (void)chdir("/");
1.10 christos 1415:
1416: if (sock != STDERR_FILENO + 1) {
1417: if (dup2(sock, STDERR_FILENO + 1) == -1) {
1418: error("dup2: %s", strerror(errno));
1419: cleanup_exit(1);
1420: }
1421: close(sock);
1.11 christos 1422: sock = STDERR_FILENO + 1;
1.10 christos 1423: }
1424: #if defined(F_CLOSEM)
1425: if (fcntl(sock + 1, F_CLOSEM, 0) == -1) {
1426: error("fcntl F_CLOSEM: %s", strerror(errno));
1427: cleanup_exit(1);
1428: }
1429: #else
1430: {
1431: int nfiles;
1432: #if defined(_SC_OPEN_MAX)
1433: nfiles = sysconf(_SC_OPEN_MAX);
1434: #elif defined(RLIMIT_NOFILE)
1435: if (getrlimit(RLIMIT_CORE, &rlim) < 0) {
1436: error("getrlimit RLIMIT_NOFILE: %s", strerror(errno));
1437: cleanup_exit(1);
1438: }
1439: nfiles = rlim.rlim_cur;
1440: #elif defined(OPEN_MAX)
1441: nfiles = OPEN_MAX;
1442: #elif defined(NOFILE)
1443: nfiles = NOFILE;
1444: #else
1445: nfiles = 1024;
1446: #endif
1447: for (fd = sock + 1; fd < nfiles; fd++)
1448: close(fd);
1449: }
1450: #endif
1.1 christos 1451: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1.10 christos 1452: if (dup2(fd, STDIN_FILENO) == -1 ||
1453: dup2(fd, STDOUT_FILENO) == -1 ||
1454: dup2(fd, STDERR_FILENO) == -1) {
1455: error("dup2: %s", strerror(errno));
1456: cleanup_exit(1);
1457: }
1458: if (fd > STDERR_FILENO)
1.1 christos 1459: close(fd);
1460: }
1461:
1462: /* deny core dumps, since memory contains unencrypted private keys */
1463: rlim.rlim_cur = rlim.rlim_max = 0;
1.27 christos 1464: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.1 christos 1465: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1466: cleanup_exit(1);
1467: }
1468:
1469: skip:
1.5 adam 1470:
1.13 christos 1471: cleanup_pid = getpid();
1472:
1.5 adam 1473: #ifdef ENABLE_PKCS11
1474: pkcs11_init(0);
1475: #endif
1.1 christos 1476: new_socket(AUTH_SOCKET, sock);
1477: if (ac > 0)
1478: parent_alive_interval = 10;
1479: idtab_init();
1.28 christos 1480: ssh_signal(SIGPIPE, SIG_IGN);
1481: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1482: ssh_signal(SIGHUP, cleanup_handler);
1483: ssh_signal(SIGTERM, cleanup_handler);
1.1 christos 1484:
1.17 christos 1485: #ifdef __OpenBSD__
1.19 christos 1486: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.17 christos 1487: fatal("%s: pledge: %s", __progname, strerror(errno));
1488: #endif
1489:
1.1 christos 1490: while (1) {
1.24 christos 1491: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.21 christos 1492: result = poll(pfd, npfd, timeout);
1.1 christos 1493: saved_errno = errno;
1494: if (parent_alive_interval != 0)
1495: check_parent_exists();
1496: (void) reaper(); /* remove expired keys */
1.27 christos 1497: if (result == -1) {
1.1 christos 1498: if (saved_errno == EINTR)
1499: continue;
1.21 christos 1500: fatal("poll: %s", strerror(saved_errno));
1.1 christos 1501: } else if (result > 0)
1.24 christos 1502: after_poll(pfd, npfd, maxfds);
1.1 christos 1503: }
1504: /* NOTREACHED */
1505: }
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