Annotation of src/crypto/external/bsd/openssh/dist/ssh-agent.c, Revision 1.22.2.2
1.22.2.2! martin 1: /* $NetBSD$ */
! 2: /* $OpenBSD: ssh-agent.c,v 1.255 2020/02/06 22:30:54 naddy 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"
1.22.2.2! martin 39: __RCSID("$NetBSD$");
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>
1.22.2.2! martin 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>
1.22.2.2! martin 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"
1.22.2.2! martin 81: #include "msg.h"
! 82: #include "ssherr.h"
! 83: #include "pathnames.h"
1.5 adam 84: #include "ssh-pkcs11.h"
1.22.2.2! martin 85: #include "sk-api.h"
1.1 christos 86:
1.22.2.2! martin 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)
1.22.2.1 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;
1.22.2.2! martin 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:
1.22.2.2! martin 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);
1.22.2.2! martin 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";
1.22.2.2! martin 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;
1.22.2.2! martin 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;
1.22.2.2! martin 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: }
1.22.2.2! martin 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,
1.22.2.2! martin 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:
1.22.2.2! martin 327: notify_complete(notifier);
1.14 christos 328: sshkey_free(key);
1.22.2.2! martin 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;
1.22 christos 423: u_int seconds, maxsign;
1.22.2.2! martin 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;
1.22.2.2! martin 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:
1.22.2.2! martin 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: }
1.22.2.2! martin 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);
1.22.2.2! martin 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;
1.22.2.2! martin 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: }
1.15 christos 615: explicit_bzero(passwd, pwlen);
1.12 christos 616: free(passwd);
1.14 christos 617: send_status(e, success);
1.1 christos 618: }
619:
620: static void
1.21 christos 621: no_identities(SocketEntry *e)
1.1 christos 622: {
1.14 christos 623: struct sshbuf *msg;
624: int r;
1.1 christos 625:
1.14 christos 626: if ((msg = sshbuf_new()) == NULL)
627: fatal("%s: sshbuf_new failed", __func__);
1.21 christos 628: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.14 christos 629: (r = sshbuf_put_u32(msg, 0)) != 0 ||
630: (r = sshbuf_put_stringb(e->output, msg)) != 0)
631: fatal("%s: buffer error: %s", __func__, ssh_err(r));
632: sshbuf_free(msg);
1.1 christos 633: }
634:
1.5 adam 635: #ifdef ENABLE_PKCS11
1.1 christos 636: static void
637: process_add_smartcard_key(SocketEntry *e)
638: {
1.22 christos 639: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.22.2.2! martin 640: char **comments = NULL;
1.21 christos 641: int r, i, count = 0, success = 0, confirm = 0;
1.14 christos 642: u_int seconds;
1.12 christos 643: time_t death = 0;
1.14 christos 644: u_char type;
645: struct sshkey **keys = NULL, *k;
1.1 christos 646: Identity *id;
647:
1.14 christos 648: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.22 christos 649: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
650: error("%s: buffer error: %s", __func__, ssh_err(r));
651: goto send;
652: }
1.14 christos 653:
654: while (sshbuf_len(e->request)) {
1.22 christos 655: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
656: error("%s: buffer error: %s", __func__, ssh_err(r));
657: goto send;
658: }
1.14 christos 659: switch (type) {
1.1 christos 660: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.22 christos 661: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
662: error("%s: buffer error: %s",
1.14 christos 663: __func__, ssh_err(r));
1.22 christos 664: goto send;
665: }
1.14 christos 666: death = monotime() + seconds;
1.1 christos 667: break;
668: case SSH_AGENT_CONSTRAIN_CONFIRM:
669: confirm = 1;
670: break;
671: default:
1.21 christos 672: error("%s: Unknown constraint type %d", __func__, type);
1.1 christos 673: goto send;
674: }
675: }
1.19 christos 676: if (realpath(provider, canonical_provider) == NULL) {
677: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
678: provider, strerror(errno));
679: goto send;
680: }
1.22.2.2! martin 681: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.19 christos 682: verbose("refusing PKCS#11 add of \"%.100s\": "
683: "provider not whitelisted", canonical_provider);
684: goto send;
685: }
686: debug("%s: add %.100s", __func__, canonical_provider);
1.1 christos 687: if (lifetime && !death)
1.12 christos 688: death = monotime() + lifetime;
1.1 christos 689:
1.22.2.2! martin 690: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.5 adam 691: for (i = 0; i < count; i++) {
1.1 christos 692: k = keys[i];
1.21 christos 693: if (lookup_identity(k) == NULL) {
1.5 adam 694: id = xcalloc(1, sizeof(Identity));
1.1 christos 695: id->key = k;
1.22.2.2! martin 696: keys[i] = NULL; /* transferred */
1.19 christos 697: id->provider = xstrdup(canonical_provider);
1.22.2.2! martin 698: if (*comments[i] != '\0') {
! 699: id->comment = comments[i];
! 700: comments[i] = NULL; /* transferred */
! 701: } else {
! 702: id->comment = xstrdup(canonical_provider);
! 703: }
1.1 christos 704: id->death = death;
705: id->confirm = confirm;
1.21 christos 706: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
707: idtab->nentries++;
1.1 christos 708: success = 1;
709: }
1.22.2.2! martin 710: sshkey_free(keys[i]);
! 711: free(comments[i]);
1.1 christos 712: }
713: send:
1.12 christos 714: free(pin);
715: free(provider);
716: free(keys);
1.22.2.2! martin 717: free(comments);
1.14 christos 718: send_status(e, success);
1.1 christos 719: }
720:
721: static void
722: process_remove_smartcard_key(SocketEntry *e)
723: {
1.20 christos 724: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.21 christos 725: int r, success = 0;
1.5 adam 726: Identity *id, *nxt;
1.1 christos 727:
1.14 christos 728: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.22 christos 729: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
730: error("%s: buffer error: %s", __func__, ssh_err(r));
731: goto send;
732: }
1.12 christos 733: free(pin);
1.1 christos 734:
1.20 christos 735: if (realpath(provider, canonical_provider) == NULL) {
736: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
737: provider, strerror(errno));
738: goto send;
739: }
740:
741: debug("%s: remove %.100s", __func__, canonical_provider);
1.21 christos 742: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
743: nxt = TAILQ_NEXT(id, next);
744: /* Skip file--based keys */
745: if (id->provider == NULL)
746: continue;
747: if (!strcmp(canonical_provider, id->provider)) {
748: TAILQ_REMOVE(&idtab->idlist, id, next);
749: free_identity(id);
750: idtab->nentries--;
1.1 christos 751: }
752: }
1.20 christos 753: if (pkcs11_del_provider(canonical_provider) == 0)
1.5 adam 754: success = 1;
755: else
1.21 christos 756: error("%s: pkcs11_del_provider failed", __func__);
1.20 christos 757: send:
1.12 christos 758: free(provider);
1.14 christos 759: send_status(e, success);
1.1 christos 760: }
1.5 adam 761: #endif /* ENABLE_PKCS11 */
1.1 christos 762:
763: /* dispatch incoming messages */
764:
1.21 christos 765: static int
766: process_message(u_int socknum)
1.1 christos 767: {
1.14 christos 768: u_int msg_len;
769: u_char type;
770: const u_char *cp;
771: int r;
1.21 christos 772: SocketEntry *e;
773:
774: if (socknum >= sockets_alloc) {
775: fatal("%s: socket number %u >= allocated %u",
776: __func__, socknum, sockets_alloc);
777: }
778: e = &sockets[socknum];
1.1 christos 779:
1.14 christos 780: if (sshbuf_len(e->input) < 5)
1.21 christos 781: return 0; /* Incomplete message header. */
1.14 christos 782: cp = sshbuf_ptr(e->input);
783: msg_len = PEEK_U32(cp);
1.21 christos 784: if (msg_len > AGENT_MAX_LEN) {
785: debug("%s: socket %u (fd=%d) message too long %u > %u",
786: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
787: return -1;
1.1 christos 788: }
1.14 christos 789: if (sshbuf_len(e->input) < msg_len + 4)
1.21 christos 790: return 0; /* Incomplete message body. */
1.1 christos 791:
792: /* move the current input to e->request */
1.14 christos 793: sshbuf_reset(e->request);
794: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.21 christos 795: (r = sshbuf_get_u8(e->request, &type)) != 0) {
796: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
797: r == SSH_ERR_STRING_TOO_LARGE) {
798: debug("%s: buffer error: %s", __func__, ssh_err(r));
799: return -1;
800: }
1.14 christos 801: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.21 christos 802: }
803:
804: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.1 christos 805:
1.22.2.1 christos 806: /* check whether agent is locked */
1.1 christos 807: if (locked && type != SSH_AGENTC_UNLOCK) {
1.14 christos 808: sshbuf_reset(e->request);
1.1 christos 809: switch (type) {
810: case SSH2_AGENTC_REQUEST_IDENTITIES:
811: /* send empty lists */
1.21 christos 812: no_identities(e);
1.1 christos 813: break;
814: default:
815: /* send a fail message for all other request types */
1.14 christos 816: send_status(e, 0);
1.1 christos 817: }
1.21 christos 818: return 0;
1.1 christos 819: }
820:
821: switch (type) {
822: case SSH_AGENTC_LOCK:
823: case SSH_AGENTC_UNLOCK:
824: process_lock_agent(e, type == SSH_AGENTC_LOCK);
825: break;
826: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.21 christos 827: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.1 christos 828: break;
829: /* ssh2 */
830: case SSH2_AGENTC_SIGN_REQUEST:
831: process_sign_request2(e);
832: break;
833: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.21 christos 834: process_request_identities(e);
1.1 christos 835: break;
836: case SSH2_AGENTC_ADD_IDENTITY:
837: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.21 christos 838: process_add_identity(e);
1.1 christos 839: break;
840: case SSH2_AGENTC_REMOVE_IDENTITY:
1.21 christos 841: process_remove_identity(e);
1.1 christos 842: break;
843: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.21 christos 844: process_remove_all_identities(e);
1.1 christos 845: break;
1.5 adam 846: #ifdef ENABLE_PKCS11
1.1 christos 847: case SSH_AGENTC_ADD_SMARTCARD_KEY:
848: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
849: process_add_smartcard_key(e);
850: break;
851: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
852: process_remove_smartcard_key(e);
853: break;
1.5 adam 854: #endif /* ENABLE_PKCS11 */
1.1 christos 855: default:
856: /* Unknown message. Respond with failure. */
857: error("Unknown message %d", type);
1.14 christos 858: sshbuf_reset(e->request);
859: send_status(e, 0);
1.1 christos 860: break;
861: }
1.21 christos 862: return 0;
1.1 christos 863: }
864:
865: static void
866: new_socket(sock_type type, int fd)
867: {
868: u_int i, old_alloc, new_alloc;
869:
870: set_nonblock(fd);
871:
872: if (fd > max_fd)
873: max_fd = fd;
874:
875: for (i = 0; i < sockets_alloc; i++)
876: if (sockets[i].type == AUTH_UNUSED) {
877: sockets[i].fd = fd;
1.14 christos 878: if ((sockets[i].input = sshbuf_new()) == NULL)
879: fatal("%s: sshbuf_new failed", __func__);
880: if ((sockets[i].output = sshbuf_new()) == NULL)
881: fatal("%s: sshbuf_new failed", __func__);
882: if ((sockets[i].request = sshbuf_new()) == NULL)
883: fatal("%s: sshbuf_new failed", __func__);
1.1 christos 884: sockets[i].type = type;
885: return;
886: }
887: old_alloc = sockets_alloc;
888: new_alloc = sockets_alloc + 10;
1.15 christos 889: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.1 christos 890: for (i = old_alloc; i < new_alloc; i++)
891: sockets[i].type = AUTH_UNUSED;
892: sockets_alloc = new_alloc;
893: sockets[old_alloc].fd = fd;
1.14 christos 894: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
895: fatal("%s: sshbuf_new failed", __func__);
896: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
897: fatal("%s: sshbuf_new failed", __func__);
898: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
899: fatal("%s: sshbuf_new failed", __func__);
1.1 christos 900: sockets[old_alloc].type = type;
901: }
902:
903: static int
1.21 christos 904: handle_socket_read(u_int socknum)
905: {
906: struct sockaddr_un sunaddr;
907: socklen_t slen;
908: uid_t euid;
909: gid_t egid;
910: int fd;
911:
912: slen = sizeof(sunaddr);
913: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.22.2.2! martin 914: if (fd == -1) {
1.21 christos 915: error("accept from AUTH_SOCKET: %s", strerror(errno));
916: return -1;
917: }
1.22.2.2! martin 918: if (getpeereid(fd, &euid, &egid) == -1) {
1.21 christos 919: error("getpeereid %d failed: %s", fd, strerror(errno));
920: close(fd);
921: return -1;
922: }
923: if ((euid != 0) && (getuid() != euid)) {
924: error("uid mismatch: peer euid %u != uid %u",
925: (u_int) euid, (u_int) getuid());
926: close(fd);
927: return -1;
928: }
929: new_socket(AUTH_CONNECTION, fd);
930: return 0;
931: }
932:
933: static int
934: handle_conn_read(u_int socknum)
935: {
1.22.2.1 christos 936: char buf[AGENT_RBUF_LEN];
1.21 christos 937: ssize_t len;
938: int r;
939:
940: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
941: if (len == -1) {
942: if (errno == EAGAIN || errno == EINTR)
943: return 0;
944: error("%s: read error on socket %u (fd %d): %s",
945: __func__, socknum, sockets[socknum].fd,
946: strerror(errno));
947: }
948: return -1;
949: }
950: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
951: fatal("%s: buffer error: %s", __func__, ssh_err(r));
952: explicit_bzero(buf, sizeof(buf));
953: process_message(socknum);
954: return 0;
955: }
956:
957: static int
958: handle_conn_write(u_int socknum)
959: {
960: ssize_t len;
961: int r;
962:
963: if (sshbuf_len(sockets[socknum].output) == 0)
964: return 0; /* shouldn't happen */
965: if ((len = write(sockets[socknum].fd,
966: sshbuf_ptr(sockets[socknum].output),
967: sshbuf_len(sockets[socknum].output))) <= 0) {
968: if (len == -1) {
969: if (errno == EAGAIN || errno == EINTR)
970: return 0;
971: error("%s: read error on socket %u (fd %d): %s",
972: __func__, socknum, sockets[socknum].fd,
973: strerror(errno));
974: }
975: return -1;
976: }
977: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
978: fatal("%s: buffer error: %s", __func__, ssh_err(r));
979: return 0;
980: }
981:
982: static void
1.22.2.1 christos 983: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.21 christos 984: {
985: size_t i;
1.22.2.1 christos 986: u_int socknum, activefds = npfd;
1.21 christos 987:
988: for (i = 0; i < npfd; i++) {
989: if (pfd[i].revents == 0)
990: continue;
991: /* Find sockets entry */
992: for (socknum = 0; socknum < sockets_alloc; socknum++) {
993: if (sockets[socknum].type != AUTH_SOCKET &&
994: sockets[socknum].type != AUTH_CONNECTION)
995: continue;
996: if (pfd[i].fd == sockets[socknum].fd)
997: break;
998: }
999: if (socknum >= sockets_alloc) {
1000: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1001: continue;
1002: }
1003: /* Process events */
1004: switch (sockets[socknum].type) {
1005: case AUTH_SOCKET:
1.22.2.1 christos 1006: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1007: break;
1008: if (npfd > maxfds) {
1009: debug3("out of fds (active %u >= limit %u); "
1010: "skipping accept", activefds, maxfds);
1011: break;
1012: }
1013: if (handle_socket_read(socknum) == 0)
1014: activefds++;
1.21 christos 1015: break;
1016: case AUTH_CONNECTION:
1017: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1018: handle_conn_read(socknum) != 0) {
1.22.2.1 christos 1019: goto close_sock;
1.21 christos 1020: }
1021: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1.22.2.1 christos 1022: handle_conn_write(socknum) != 0) {
1023: close_sock:
1024: if (activefds == 0)
1025: fatal("activefds == 0 at close_sock");
1.21 christos 1026: close_socket(&sockets[socknum]);
1.22.2.1 christos 1027: activefds--;
1028: break;
1029: }
1.21 christos 1030: break;
1031: default:
1032: break;
1033: }
1034: }
1035: }
1036:
1037: static int
1.22.2.1 christos 1038: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.1 christos 1039: {
1.21 christos 1040: struct pollfd *pfd = *pfdp;
1041: size_t i, j, npfd = 0;
1.12 christos 1042: time_t deadline;
1.22.2.1 christos 1043: int r;
1.1 christos 1044:
1.21 christos 1045: /* Count active sockets */
1.1 christos 1046: for (i = 0; i < sockets_alloc; i++) {
1047: switch (sockets[i].type) {
1048: case AUTH_SOCKET:
1049: case AUTH_CONNECTION:
1.21 christos 1050: npfd++;
1.1 christos 1051: break;
1052: case AUTH_UNUSED:
1053: break;
1054: default:
1055: fatal("Unknown socket type %d", sockets[i].type);
1056: break;
1057: }
1058: }
1.21 christos 1059: if (npfd != *npfdp &&
1060: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1061: fatal("%s: recallocarray failed", __func__);
1062: *pfdp = pfd;
1063: *npfdp = npfd;
1.1 christos 1064:
1.21 christos 1065: for (i = j = 0; i < sockets_alloc; i++) {
1.1 christos 1066: switch (sockets[i].type) {
1067: case AUTH_SOCKET:
1.22.2.1 christos 1068: if (npfd > maxfds) {
1069: debug3("out of fds (active %zu >= limit %u); "
1070: "skipping arming listener", npfd, maxfds);
1071: break;
1072: }
1.21 christos 1073: pfd[j].fd = sockets[i].fd;
1074: pfd[j].revents = 0;
1075: pfd[j].events = POLLIN;
1.22.2.1 christos 1076: j++;
1077: break;
1078: case AUTH_CONNECTION:
1079: pfd[j].fd = sockets[i].fd;
1080: pfd[j].revents = 0;
1081: /*
1082: * Only prepare to read if we can handle a full-size
1083: * input read buffer and enqueue a max size reply..
1084: */
1085: if ((r = sshbuf_check_reserve(sockets[i].input,
1086: AGENT_RBUF_LEN)) == 0 &&
1087: (r = sshbuf_check_reserve(sockets[i].output,
1088: AGENT_MAX_LEN)) == 0)
1089: pfd[j].events = POLLIN;
1090: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1091: fatal("%s: buffer error: %s",
1092: __func__, ssh_err(r));
1093: }
1.14 christos 1094: if (sshbuf_len(sockets[i].output) > 0)
1.21 christos 1095: pfd[j].events |= POLLOUT;
1096: j++;
1.1 christos 1097: break;
1098: default:
1099: break;
1100: }
1101: }
1102: deadline = reaper();
1103: if (parent_alive_interval != 0)
1104: deadline = (deadline == 0) ? parent_alive_interval :
1.19 christos 1105: MINIMUM(deadline, parent_alive_interval);
1.1 christos 1106: if (deadline == 0) {
1.21 christos 1107: *timeoutp = -1; /* INFTIM */
1.1 christos 1108: } else {
1.21 christos 1109: if (deadline > INT_MAX / 1000)
1110: *timeoutp = INT_MAX / 1000;
1111: else
1112: *timeoutp = deadline * 1000;
1.1 christos 1113: }
1114: return (1);
1115: }
1116:
1117: static void
1118: cleanup_socket(void)
1119: {
1.13 christos 1120: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1121: return;
1122: debug("%s: cleanup", __func__);
1.1 christos 1123: if (socket_name[0])
1124: unlink(socket_name);
1125: if (socket_dir[0])
1126: rmdir(socket_dir);
1127: }
1128:
1129: void
1130: cleanup_exit(int i)
1131: {
1132: cleanup_socket();
1133: _exit(i);
1134: }
1135:
1136: /*ARGSUSED*/
1.9 joerg 1137: __dead static void
1.1 christos 1138: cleanup_handler(int sig)
1139: {
1140: cleanup_socket();
1.5 adam 1141: #ifdef ENABLE_PKCS11
1142: pkcs11_terminate();
1143: #endif
1.1 christos 1144: _exit(2);
1145: }
1146:
1147: static void
1148: check_parent_exists(void)
1149: {
1.8 christos 1150: /*
1151: * If our parent has exited then getppid() will return (pid_t)1,
1152: * so testing for that should be safe.
1153: */
1154: if (parent_pid != -1 && getppid() != parent_pid) {
1.1 christos 1155: /* printf("Parent has died - Authentication agent exiting.\n"); */
1156: cleanup_socket();
1157: _exit(2);
1158: }
1159: }
1160:
1.9 joerg 1161: __dead static void
1.1 christos 1162: usage(void)
1163: {
1.13 christos 1164: fprintf(stderr,
1.15 christos 1165: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.22.2.2! martin 1166: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.13 christos 1167: " ssh-agent [-c | -s] -k\n");
1.1 christos 1168: exit(1);
1169: }
1170:
1.7 christos 1171: static void
1172: csh_setenv(const char *name, const char *value)
1173: {
1174: printf("setenv %s %s;\n", name, value);
1175: }
1176:
1177: static void
1178: csh_unsetenv(const char *name)
1179: {
1180: printf("unsetenv %s;\n", name);
1181: }
1182:
1183: static void
1184: sh_setenv(const char *name, const char *value)
1185: {
1186: printf("%s=%s; export %s;\n", name, value, name);
1187: }
1188:
1189: static void
1190: sh_unsetenv(const char *name)
1191: {
1192: printf("unset %s;\n", name);
1193: }
1.1 christos 1194: int
1195: main(int ac, char **av)
1196: {
1.15 christos 1197: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.1 christos 1198: int sock, fd, ch, result, saved_errno;
1.6 christos 1199: char *shell, *pidstr, *agentsocket = NULL;
1.1 christos 1200: struct rlimit rlim;
1.21 christos 1201: void (*f_setenv)(const char *, const char *);
1202: void (*f_unsetenv)(const char *);
1.1 christos 1203: extern int optind;
1204: extern char *optarg;
1205: pid_t pid;
1206: char pidstrbuf[1 + 3 * sizeof pid];
1.4 christos 1207: size_t len;
1.13 christos 1208: mode_t prev_mask;
1.21 christos 1209: int timeout = -1; /* INFTIM */
1210: struct pollfd *pfd = NULL;
1211: size_t npfd = 0;
1.22.2.1 christos 1212: u_int maxfds;
1.1 christos 1213:
1214: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1215: sanitise_stdfd();
1216:
1217: /* drop */
1218: setegid(getgid());
1219: setgid(getgid());
1220:
1.22.2.1 christos 1221: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1222: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1223:
1.13 christos 1224: #ifdef WITH_OPENSSL
1.6 christos 1225: OpenSSL_add_all_algorithms();
1.13 christos 1226: #endif
1.1 christos 1227:
1.19 christos 1228: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.1 christos 1229: switch (ch) {
1.14 christos 1230: case 'E':
1231: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1232: if (fingerprint_hash == -1)
1233: fatal("Invalid hash algorithm \"%s\"", optarg);
1234: break;
1.1 christos 1235: case 'c':
1236: if (s_flag)
1237: usage();
1238: c_flag++;
1239: break;
1240: case 'k':
1241: k_flag++;
1242: break;
1.19 christos 1243: case 'P':
1.22.2.2! martin 1244: if (provider_whitelist != NULL)
1.19 christos 1245: fatal("-P option already specified");
1.22.2.2! martin 1246: provider_whitelist = xstrdup(optarg);
1.19 christos 1247: break;
1.1 christos 1248: case 's':
1249: if (c_flag)
1250: usage();
1251: s_flag++;
1252: break;
1253: case 'd':
1.15 christos 1254: if (d_flag || D_flag)
1.1 christos 1255: usage();
1256: d_flag++;
1257: break;
1.15 christos 1258: case 'D':
1259: if (d_flag || D_flag)
1260: usage();
1261: D_flag++;
1262: break;
1.1 christos 1263: case 'a':
1264: agentsocket = optarg;
1265: break;
1266: case 't':
1267: if ((lifetime = convtime(optarg)) == -1) {
1268: fprintf(stderr, "Invalid lifetime\n");
1269: usage();
1270: }
1271: break;
1272: default:
1273: usage();
1274: }
1275: }
1276: ac -= optind;
1277: av += optind;
1278:
1.15 christos 1279: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.1 christos 1280: usage();
1281:
1.22.2.2! martin 1282: if (provider_whitelist == NULL)
! 1283: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.19 christos 1284:
1.1 christos 1285: if (ac == 0 && !c_flag && !s_flag) {
1286: shell = getenv("SHELL");
1.4 christos 1287: if (shell != NULL && (len = strlen(shell)) > 2 &&
1288: strncmp(shell + len - 3, "csh", 3) == 0)
1.1 christos 1289: c_flag = 1;
1290: }
1.7 christos 1291: if (c_flag) {
1292: f_setenv = csh_setenv;
1293: f_unsetenv = csh_unsetenv;
1294: } else {
1295: f_setenv = sh_setenv;
1296: f_unsetenv = sh_unsetenv;
1297: }
1.1 christos 1298: if (k_flag) {
1299: const char *errstr = NULL;
1300:
1301: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1302: if (pidstr == NULL) {
1303: fprintf(stderr, "%s not set, cannot kill agent\n",
1304: SSH_AGENTPID_ENV_NAME);
1305: exit(1);
1306: }
1307: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1308: if (errstr) {
1309: fprintf(stderr,
1310: "%s=\"%s\", which is not a good PID: %s\n",
1311: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1312: exit(1);
1313: }
1314: if (kill(pid, SIGTERM) == -1) {
1315: perror("kill");
1316: exit(1);
1317: }
1.7 christos 1318: (*f_unsetenv)(SSH_AUTHSOCKET_ENV_NAME);
1319: (*f_unsetenv)(SSH_AGENTPID_ENV_NAME);
1.1 christos 1320: printf("echo Agent pid %ld killed;\n", (long)pid);
1321: exit(0);
1322: }
1.22.2.1 christos 1323:
1324: /*
1325: * Minimum file descriptors:
1326: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1327: * a few spare for libc / stack protectors / sanitisers, etc.
1328: */
1329: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1330: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1331: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1332: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1333: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1334:
1.1 christos 1335: parent_pid = getpid();
1336:
1337: if (agentsocket == NULL) {
1338: /* Create private directory for agent socket */
1.6 christos 1339: mktemp_proto(socket_dir, sizeof(socket_dir));
1.1 christos 1340: if (mkdtemp(socket_dir) == NULL) {
1341: perror("mkdtemp: private socket dir");
1342: exit(1);
1343: }
1344: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1345: (long)parent_pid);
1346: } else {
1347: /* Try to use specified agent socket */
1348: socket_dir[0] = '\0';
1349: strlcpy(socket_name, agentsocket, sizeof socket_name);
1350: }
1351:
1352: /*
1353: * Create socket early so it will exist before command gets run from
1354: * the parent.
1355: */
1.13 christos 1356: prev_mask = umask(0177);
1357: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.1 christos 1358: if (sock < 0) {
1.13 christos 1359: /* XXX - unix_listener() calls error() not perror() */
1.1 christos 1360: *socket_name = '\0'; /* Don't unlink any existing file */
1361: cleanup_exit(1);
1362: }
1.13 christos 1363: umask(prev_mask);
1.1 christos 1364:
1365: /*
1366: * Fork, and have the parent execute the command, if any, or present
1367: * the socket data. The child continues as the authentication agent.
1368: */
1.15 christos 1369: if (D_flag || d_flag) {
1370: log_init(__progname,
1371: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1372: SYSLOG_FACILITY_AUTH, 1);
1373: if (c_flag)
1374: printf("setenv %s %s;\n",
1375: SSH_AUTHSOCKET_ENV_NAME, socket_name);
1376: else
1377: printf("%s=%s; export %s;\n",
1378: SSH_AUTHSOCKET_ENV_NAME, socket_name,
1379: SSH_AUTHSOCKET_ENV_NAME);
1.1 christos 1380: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.17 christos 1381: fflush(stdout);
1.1 christos 1382: goto skip;
1383: }
1384: pid = fork();
1385: if (pid == -1) {
1386: perror("fork");
1387: cleanup_exit(1);
1388: }
1389: if (pid != 0) { /* Parent - execute the given command. */
1390: close(sock);
1391: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1392: if (ac == 0) {
1.7 christos 1393: (*f_setenv)(SSH_AUTHSOCKET_ENV_NAME, socket_name);
1394: (*f_setenv)(SSH_AGENTPID_ENV_NAME, pidstrbuf);
1.1 christos 1395: printf("echo Agent pid %ld;\n", (long)pid);
1396: exit(0);
1397: }
1398: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1399: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1400: perror("setenv");
1401: exit(1);
1402: }
1403: execvp(av[0], av);
1404: perror(av[0]);
1405: exit(1);
1406: }
1407: /* child */
1408: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1409:
1410: if (setsid() == -1) {
1411: error("setsid: %s", strerror(errno));
1412: cleanup_exit(1);
1413: }
1414:
1415: (void)chdir("/");
1.10 christos 1416:
1417: if (sock != STDERR_FILENO + 1) {
1418: if (dup2(sock, STDERR_FILENO + 1) == -1) {
1419: error("dup2: %s", strerror(errno));
1420: cleanup_exit(1);
1421: }
1422: close(sock);
1.11 christos 1423: sock = STDERR_FILENO + 1;
1.10 christos 1424: }
1425: #if defined(F_CLOSEM)
1426: if (fcntl(sock + 1, F_CLOSEM, 0) == -1) {
1427: error("fcntl F_CLOSEM: %s", strerror(errno));
1428: cleanup_exit(1);
1429: }
1430: #else
1431: {
1432: int nfiles;
1433: #if defined(_SC_OPEN_MAX)
1434: nfiles = sysconf(_SC_OPEN_MAX);
1435: #elif defined(RLIMIT_NOFILE)
1436: if (getrlimit(RLIMIT_CORE, &rlim) < 0) {
1437: error("getrlimit RLIMIT_NOFILE: %s", strerror(errno));
1438: cleanup_exit(1);
1439: }
1440: nfiles = rlim.rlim_cur;
1441: #elif defined(OPEN_MAX)
1442: nfiles = OPEN_MAX;
1443: #elif defined(NOFILE)
1444: nfiles = NOFILE;
1445: #else
1446: nfiles = 1024;
1447: #endif
1448: for (fd = sock + 1; fd < nfiles; fd++)
1449: close(fd);
1450: }
1451: #endif
1.1 christos 1452: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1.10 christos 1453: if (dup2(fd, STDIN_FILENO) == -1 ||
1454: dup2(fd, STDOUT_FILENO) == -1 ||
1455: dup2(fd, STDERR_FILENO) == -1) {
1456: error("dup2: %s", strerror(errno));
1457: cleanup_exit(1);
1458: }
1459: if (fd > STDERR_FILENO)
1.1 christos 1460: close(fd);
1461: }
1462:
1463: /* deny core dumps, since memory contains unencrypted private keys */
1464: rlim.rlim_cur = rlim.rlim_max = 0;
1.22.2.2! martin 1465: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.1 christos 1466: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1467: cleanup_exit(1);
1468: }
1469:
1470: skip:
1.5 adam 1471:
1.13 christos 1472: cleanup_pid = getpid();
1473:
1.5 adam 1474: #ifdef ENABLE_PKCS11
1475: pkcs11_init(0);
1476: #endif
1.1 christos 1477: new_socket(AUTH_SOCKET, sock);
1478: if (ac > 0)
1479: parent_alive_interval = 10;
1480: idtab_init();
1.22.2.2! martin 1481: ssh_signal(SIGPIPE, SIG_IGN);
! 1482: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
! 1483: ssh_signal(SIGHUP, cleanup_handler);
! 1484: ssh_signal(SIGTERM, cleanup_handler);
1.1 christos 1485:
1.17 christos 1486: #ifdef __OpenBSD__
1.19 christos 1487: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.17 christos 1488: fatal("%s: pledge: %s", __progname, strerror(errno));
1489: #endif
1490:
1.1 christos 1491: while (1) {
1.22.2.1 christos 1492: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.21 christos 1493: result = poll(pfd, npfd, timeout);
1.1 christos 1494: saved_errno = errno;
1495: if (parent_alive_interval != 0)
1496: check_parent_exists();
1497: (void) reaper(); /* remove expired keys */
1.22.2.2! martin 1498: if (result == -1) {
1.1 christos 1499: if (saved_errno == EINTR)
1500: continue;
1.21 christos 1501: fatal("poll: %s", strerror(saved_errno));
1.1 christos 1502: } else if (result > 0)
1.22.2.1 christos 1503: after_poll(pfd, npfd, maxfds);
1.1 christos 1504: }
1505: /* NOTREACHED */
1506: }
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