Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.251
1.251 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.250 2019/11/19 16:02:32 jmc Exp $ */
1.1 deraadt 2: /*
1.22 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * The authentication agent program.
1.33 markus 7: *
1.35 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.56 markus 14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 15: *
16: * Redistribution and use in source and binary forms, with or without
17: * modification, are permitted provided that the following conditions
18: * are met:
19: * 1. Redistributions of source code must retain the above copyright
20: * notice, this list of conditions and the following disclaimer.
21: * 2. Redistributions in binary form must reproduce the above copyright
22: * notice, this list of conditions and the following disclaimer in the
23: * documentation and/or other materials provided with the distribution.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 35: */
1.1 deraadt 36:
1.151 deraadt 37: #include <sys/types.h>
1.153 djm 38: #include <sys/time.h>
1.78 provos 39: #include <sys/queue.h>
1.127 stevesk 40: #include <sys/resource.h>
1.141 stevesk 41: #include <sys/socket.h>
1.189 djm 42: #include <sys/stat.h>
1.128 stevesk 43: #include <sys/un.h>
1.238 djm 44: #include <sys/wait.h>
1.126 stevesk 45:
1.185 markus 46: #ifdef WITH_OPENSSL
1.146 stevesk 47: #include <openssl/evp.h>
1.185 markus 48: #endif
1.146 stevesk 49:
1.143 stevesk 50: #include <errno.h>
1.142 stevesk 51: #include <fcntl.h>
1.126 stevesk 52: #include <paths.h>
1.223 djm 53: #include <poll.h>
1.129 stevesk 54: #include <signal.h>
1.149 stevesk 55: #include <stdlib.h>
1.150 stevesk 56: #include <stdio.h>
1.146 stevesk 57: #include <string.h>
1.248 naddy 58: #include <stdarg.h>
1.196 deraadt 59: #include <limits.h>
1.145 stevesk 60: #include <time.h>
1.144 stevesk 61: #include <unistd.h>
1.203 dtucker 62: #include <util.h>
1.194 markus 63:
1.151 deraadt 64: #include "xmalloc.h"
1.1 deraadt 65: #include "ssh.h"
1.194 markus 66: #include "sshbuf.h"
67: #include "sshkey.h"
1.32 markus 68: #include "authfd.h"
1.37 markus 69: #include "compat.h"
1.47 markus 70: #include "log.h"
1.107 markus 71: #include "misc.h"
1.182 markus 72: #include "digest.h"
1.194 markus 73: #include "ssherr.h"
1.215 djm 74: #include "match.h"
1.238 djm 75: #include "msg.h"
1.244 djm 76: #include "ssherr.h"
1.238 djm 77: #include "pathnames.h"
1.163 markus 78: #include "ssh-pkcs11.h"
1.251 ! djm 79: #include "sk-api.h"
1.59 markus 80:
1.238 djm 81: #ifndef DEFAULT_PROVIDER_WHITELIST
82: # define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 83: #endif
84:
1.223 djm 85: /* Maximum accepted message length */
86: #define AGENT_MAX_LEN (256*1024)
1.233 djm 87: /* Maximum bytes to read from client socket */
88: #define AGENT_RBUF_LEN (4096)
1.223 djm 89:
1.73 stevesk 90: typedef enum {
91: AUTH_UNUSED,
92: AUTH_SOCKET,
93: AUTH_CONNECTION
94: } sock_type;
95:
1.21 markus 96: typedef struct {
97: int fd;
1.73 stevesk 98: sock_type type;
1.194 markus 99: struct sshbuf *input;
100: struct sshbuf *output;
101: struct sshbuf *request;
1.1 deraadt 102: } SocketEntry;
103:
1.45 markus 104: u_int sockets_alloc = 0;
1.1 deraadt 105: SocketEntry *sockets = NULL;
106:
1.78 provos 107: typedef struct identity {
108: TAILQ_ENTRY(identity) next;
1.194 markus 109: struct sshkey *key;
1.21 markus 110: char *comment;
1.163 markus 111: char *provider;
1.174 dtucker 112: time_t death;
1.107 markus 113: u_int confirm;
1.238 djm 114: char *sk_provider;
1.1 deraadt 115: } Identity;
116:
1.221 djm 117: struct idtable {
1.33 markus 118: int nentries;
1.78 provos 119: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 120: };
1.33 markus 121:
1.221 djm 122: /* private key table */
123: struct idtable *idtab;
1.1 deraadt 124:
125: int max_fd = 0;
126:
1.11 markus 127: /* pid of shell == parent of agent */
1.29 deraadt 128: pid_t parent_pid = -1;
1.176 dtucker 129: time_t parent_alive_interval = 0;
1.10 markus 130:
1.187 djm 131: /* pid of process for which cleanup_socket is applicable */
132: pid_t cleanup_pid = 0;
133:
1.10 markus 134: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 135: char socket_name[PATH_MAX];
136: char socket_dir[PATH_MAX];
1.10 markus 137:
1.238 djm 138: /* PKCS#11/Security key path whitelist */
139: static char *provider_whitelist;
1.215 djm 140:
1.88 markus 141: /* locking */
1.203 dtucker 142: #define LOCK_SIZE 32
143: #define LOCK_SALT_SIZE 16
144: #define LOCK_ROUNDS 1
1.88 markus 145: int locked = 0;
1.213 djm 146: u_char lock_pwhash[LOCK_SIZE];
147: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 148:
1.20 markus 149: extern char *__progname;
150:
1.174 dtucker 151: /* Default lifetime in seconds (0 == forever) */
152: static long lifetime = 0;
1.106 marc 153:
1.192 djm 154: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
155:
1.55 itojun 156: static void
1.101 stevesk 157: close_socket(SocketEntry *e)
158: {
159: close(e->fd);
160: e->fd = -1;
161: e->type = AUTH_UNUSED;
1.194 markus 162: sshbuf_free(e->input);
163: sshbuf_free(e->output);
164: sshbuf_free(e->request);
1.101 stevesk 165: }
166:
167: static void
1.33 markus 168: idtab_init(void)
1.1 deraadt 169: {
1.221 djm 170: idtab = xcalloc(1, sizeof(*idtab));
171: TAILQ_INIT(&idtab->idlist);
172: idtab->nentries = 0;
1.33 markus 173: }
174:
1.89 markus 175: static void
176: free_identity(Identity *id)
177: {
1.194 markus 178: sshkey_free(id->key);
1.173 djm 179: free(id->provider);
180: free(id->comment);
1.238 djm 181: free(id->sk_provider);
1.173 djm 182: free(id);
1.89 markus 183: }
184:
1.33 markus 185: /* return matching private key for given public key */
1.78 provos 186: static Identity *
1.221 djm 187: lookup_identity(struct sshkey *key)
1.33 markus 188: {
1.78 provos 189: Identity *id;
190:
1.221 djm 191: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 192: if (sshkey_equal(key, id->key))
1.78 provos 193: return (id);
1.33 markus 194: }
1.78 provos 195: return (NULL);
196: }
197:
1.107 markus 198: /* Check confirmation of keysign request */
199: static int
200: confirm_key(Identity *id)
201: {
1.122 djm 202: char *p;
1.107 markus 203: int ret = -1;
204:
1.194 markus 205: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 206: if (p != NULL &&
207: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 208: id->comment, p))
209: ret = 0;
1.173 djm 210: free(p);
1.122 djm 211:
1.107 markus 212: return (ret);
213: }
214:
1.194 markus 215: static void
216: send_status(SocketEntry *e, int success)
217: {
218: int r;
219:
220: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
221: (r = sshbuf_put_u8(e->output, success ?
222: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
223: fatal("%s: buffer error: %s", __func__, ssh_err(r));
224: }
225:
1.33 markus 226: /* send list of supported public keys to 'client' */
1.55 itojun 227: static void
1.221 djm 228: process_request_identities(SocketEntry *e)
1.33 markus 229: {
1.96 deraadt 230: Identity *id;
1.194 markus 231: struct sshbuf *msg;
232: int r;
1.1 deraadt 233:
1.194 markus 234: if ((msg = sshbuf_new()) == NULL)
235: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 236: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
237: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
238: fatal("%s: buffer error: %s", __func__, ssh_err(r));
239: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 240: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
241: != 0 ||
1.221 djm 242: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
243: error("%s: put key/comment: %s", __func__,
1.220 djm 244: ssh_err(r));
245: continue;
1.33 markus 246: }
1.21 markus 247: }
1.194 markus 248: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
249: fatal("%s: buffer error: %s", __func__, ssh_err(r));
250: sshbuf_free(msg);
1.1 deraadt 251: }
252:
1.33 markus 253:
1.208 markus 254: static char *
255: agent_decode_alg(struct sshkey *key, u_int flags)
256: {
257: if (key->type == KEY_RSA) {
258: if (flags & SSH_AGENT_RSA_SHA2_256)
259: return "rsa-sha2-256";
260: else if (flags & SSH_AGENT_RSA_SHA2_512)
261: return "rsa-sha2-512";
1.235 djm 262: } else if (key->type == KEY_RSA_CERT) {
263: if (flags & SSH_AGENT_RSA_SHA2_256)
264: return "rsa-sha2-256-cert-v01@openssh.com";
265: else if (flags & SSH_AGENT_RSA_SHA2_512)
266: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 267: }
268: return NULL;
269: }
270:
1.33 markus 271: /* ssh2 only */
1.55 itojun 272: static void
1.33 markus 273: process_sign_request2(SocketEntry *e)
274: {
1.221 djm 275: const u_char *data;
276: u_char *signature = NULL;
277: size_t dlen, slen = 0;
1.194 markus 278: u_int compat = 0, flags;
1.247 djm 279: int r, ok = -1;
1.251 ! djm 280: char *fp = NULL;
1.194 markus 281: struct sshbuf *msg;
1.221 djm 282: struct sshkey *key = NULL;
1.195 djm 283: struct identity *id;
1.251 ! djm 284: struct notifier_ctx *notifier = NULL;
1.194 markus 285:
1.195 djm 286: if ((msg = sshbuf_new()) == NULL)
287: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 288: if ((r = sshkey_froms(e->request, &key)) != 0 ||
289: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 290: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
291: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
292: goto send;
293: }
294:
1.221 djm 295: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 296: verbose("%s: %s key not found", __func__, sshkey_type(key));
297: goto send;
298: }
299: if (id->confirm && confirm_key(id) != 0) {
300: verbose("%s: user refused key", __func__);
301: goto send;
302: }
1.251 ! djm 303: if (sshkey_is_sk(id->key) &&
! 304: (id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
! 305: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 306: SSH_FP_DEFAULT)) == NULL)
! 307: fatal("%s: fingerprint failed", __func__);
! 308: notifier = notify_start(0,
! 309: "Confirm user presence for key %s %s",
! 310: sshkey_type(id->key), fp);
! 311: }
! 312: if ((r = sshkey_sign(id->key, &signature, &slen,
! 313: data, dlen, agent_decode_alg(key, flags),
! 314: id->sk_provider, compat)) != 0) {
! 315: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
! 316: goto send;
1.33 markus 317: }
1.195 djm 318: /* Success */
319: ok = 0;
320: send:
1.251 ! djm 321: notify_complete(notifier);
1.195 djm 322: sshkey_free(key);
1.251 ! djm 323: free(fp);
1.33 markus 324: if (ok == 0) {
1.194 markus 325: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
326: (r = sshbuf_put_string(msg, signature, slen)) != 0)
327: fatal("%s: buffer error: %s", __func__, ssh_err(r));
328: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
329: fatal("%s: buffer error: %s", __func__, ssh_err(r));
330:
331: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
332: fatal("%s: buffer error: %s", __func__, ssh_err(r));
333:
334: sshbuf_free(msg);
1.173 djm 335: free(signature);
1.1 deraadt 336: }
337:
1.33 markus 338: /* shared */
1.55 itojun 339: static void
1.221 djm 340: process_remove_identity(SocketEntry *e)
1.1 deraadt 341: {
1.194 markus 342: int r, success = 0;
343: struct sshkey *key = NULL;
1.221 djm 344: Identity *id;
1.21 markus 345:
1.221 djm 346: if ((r = sshkey_froms(e->request, &key)) != 0) {
347: error("%s: get key: %s", __func__, ssh_err(r));
348: goto done;
349: }
350: if ((id = lookup_identity(key)) == NULL) {
351: debug("%s: key not found", __func__);
352: goto done;
353: }
354: /* We have this key, free it. */
355: if (idtab->nentries < 1)
356: fatal("%s: internal error: nentries %d",
357: __func__, idtab->nentries);
358: TAILQ_REMOVE(&idtab->idlist, id, next);
359: free_identity(id);
360: idtab->nentries--;
361: sshkey_free(key);
362: success = 1;
363: done:
1.194 markus 364: send_status(e, success);
1.1 deraadt 365: }
366:
1.55 itojun 367: static void
1.221 djm 368: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 369: {
1.78 provos 370: Identity *id;
1.21 markus 371:
372: /* Loop over all identities and clear the keys. */
1.221 djm 373: for (id = TAILQ_FIRST(&idtab->idlist); id;
374: id = TAILQ_FIRST(&idtab->idlist)) {
375: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 376: free_identity(id);
1.21 markus 377: }
378:
379: /* Mark that there are no identities. */
1.221 djm 380: idtab->nentries = 0;
1.21 markus 381:
382: /* Send success. */
1.194 markus 383: send_status(e, 1);
1.1 deraadt 384: }
385:
1.155 dtucker 386: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 387: static time_t
1.89 markus 388: reaper(void)
389: {
1.175 dtucker 390: time_t deadline = 0, now = monotime();
1.89 markus 391: Identity *id, *nxt;
392:
1.221 djm 393: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
394: nxt = TAILQ_NEXT(id, next);
395: if (id->death == 0)
396: continue;
397: if (now >= id->death) {
398: debug("expiring key '%s'", id->comment);
399: TAILQ_REMOVE(&idtab->idlist, id, next);
400: free_identity(id);
401: idtab->nentries--;
402: } else
403: deadline = (deadline == 0) ? id->death :
404: MINIMUM(deadline, id->death);
1.89 markus 405: }
1.155 dtucker 406: if (deadline == 0 || deadline <= now)
407: return 0;
408: else
409: return (deadline - now);
1.89 markus 410: }
411:
412: static void
1.221 djm 413: process_add_identity(SocketEntry *e)
1.1 deraadt 414: {
1.157 canacar 415: Identity *id;
1.194 markus 416: int success = 0, confirm = 0;
1.228 markus 417: u_int seconds, maxsign;
1.238 djm 418: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 419: time_t death = 0;
1.194 markus 420: struct sshkey *k = NULL;
421: u_char ctype;
422: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 423:
1.221 djm 424: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
425: k == NULL ||
1.194 markus 426: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
427: error("%s: decode private key: %s", __func__, ssh_err(r));
428: goto err;
429: }
430: while (sshbuf_len(e->request)) {
431: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
432: error("%s: buffer error: %s", __func__, ssh_err(r));
433: goto err;
434: }
435: switch (ctype) {
1.94 markus 436: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 437: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
438: error("%s: bad lifetime constraint: %s",
439: __func__, ssh_err(r));
440: goto err;
441: }
442: death = monotime() + seconds;
1.94 markus 443: break;
1.107 markus 444: case SSH_AGENT_CONSTRAIN_CONFIRM:
445: confirm = 1;
446: break;
1.228 markus 447: case SSH_AGENT_CONSTRAIN_MAXSIGN:
448: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
449: error("%s: bad maxsign constraint: %s",
450: __func__, ssh_err(r));
451: goto err;
452: }
453: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
454: error("%s: cannot enable maxsign: %s",
455: __func__, ssh_err(r));
456: goto err;
457: }
458: break;
1.238 djm 459: case SSH_AGENT_CONSTRAIN_EXTENSION:
460: if ((r = sshbuf_get_cstring(e->request,
461: &ext_name, NULL)) != 0) {
462: error("%s: cannot parse extension: %s",
463: __func__, ssh_err(r));
464: goto err;
465: }
466: debug("%s: constraint ext %s", __func__, ext_name);
467: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
468: if (sk_provider != NULL) {
469: error("%s already set", ext_name);
470: goto err;
471: }
472: if ((r = sshbuf_get_cstring(e->request,
473: &sk_provider, NULL)) != 0) {
474: error("%s: cannot parse %s: %s",
475: __func__, ext_name, ssh_err(r));
476: goto err;
477: }
478: } else {
479: error("%s: unsupported constraint \"%s\"",
480: __func__, ext_name);
481: goto err;
482: }
483: free(ext_name);
484: break;
1.94 markus 485: default:
1.194 markus 486: error("%s: Unknown constraint %d", __func__, ctype);
487: err:
1.238 djm 488: free(sk_provider);
489: free(ext_name);
1.194 markus 490: sshbuf_reset(e->request);
1.173 djm 491: free(comment);
1.194 markus 492: sshkey_free(k);
1.158 djm 493: goto send;
1.94 markus 494: }
495: }
1.238 djm 496: if (sk_provider != NULL) {
1.240 markus 497: if (!sshkey_is_sk(k)) {
1.238 djm 498: error("Cannot add provider: %s is not a security key",
499: sshkey_type(k));
500: free(sk_provider);
501: goto send;
502: }
1.245 djm 503: if (strcasecmp(sk_provider, "internal") == 0)
504: debug("%s: internal provider", __func__);
505: else if (match_pattern_list(sk_provider,
1.238 djm 506: provider_whitelist, 0) != 1) {
507: error("Refusing add key: provider %s not whitelisted",
508: sk_provider);
509: free(sk_provider);
510: goto send;
511: }
1.242 markus 512: }
513: if ((r = sshkey_shield_private(k)) != 0) {
514: error("%s: shield private key: %s", __func__, ssh_err(r));
515: goto err;
1.238 djm 516: }
1.194 markus 517:
1.158 djm 518: success = 1;
1.106 marc 519: if (lifetime && !death)
1.175 dtucker 520: death = monotime() + lifetime;
1.221 djm 521: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 522: id = xcalloc(1, sizeof(Identity));
1.221 djm 523: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 524: /* Increment the number of identities. */
1.221 djm 525: idtab->nentries++;
1.33 markus 526: } else {
1.228 markus 527: /* key state might have been updated */
528: sshkey_free(id->key);
1.173 djm 529: free(id->comment);
1.238 djm 530: free(id->sk_provider);
1.33 markus 531: }
1.228 markus 532: id->key = k;
1.157 canacar 533: id->comment = comment;
534: id->death = death;
535: id->confirm = confirm;
1.238 djm 536: id->sk_provider = sk_provider;
537:
538: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
539: SSH_FP_DEFAULT)) == NULL)
540: fatal("%s: sshkey_fingerprint failed", __func__);
541: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
542: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
543: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
544: free(fp);
1.33 markus 545: send:
1.194 markus 546: send_status(e, success);
1.1 deraadt 547: }
548:
1.88 markus 549: /* XXX todo: encrypt sensitive data with passphrase */
550: static void
551: process_lock_agent(SocketEntry *e, int lock)
552: {
1.203 dtucker 553: int r, success = 0, delay;
1.213 djm 554: char *passwd;
555: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 556: static u_int fail_count = 0;
557: size_t pwlen;
558:
1.226 djm 559: /*
560: * This is deliberately fatal: the user has requested that we lock,
561: * but we can't parse their request properly. The only safe thing to
562: * do is abort.
563: */
1.203 dtucker 564: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
565: fatal("%s: buffer error: %s", __func__, ssh_err(r));
566: if (pwlen == 0) {
567: debug("empty password not supported");
568: } else if (locked && !lock) {
569: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
570: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
571: fatal("bcrypt_pbkdf");
1.213 djm 572: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 573: debug("agent unlocked");
574: locked = 0;
575: fail_count = 0;
1.213 djm 576: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 577: success = 1;
578: } else {
579: /* delay in 0.1s increments up to 10s */
580: if (fail_count < 100)
581: fail_count++;
582: delay = 100000 * fail_count;
583: debug("unlock failed, delaying %0.1lf seconds",
584: (double)delay/1000000);
585: usleep(delay);
586: }
587: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 588: } else if (!locked && lock) {
1.203 dtucker 589: debug("agent locked");
1.88 markus 590: locked = 1;
1.203 dtucker 591: arc4random_buf(lock_salt, sizeof(lock_salt));
592: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 593: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 594: fatal("bcrypt_pbkdf");
1.88 markus 595: success = 1;
596: }
1.203 dtucker 597: explicit_bzero(passwd, pwlen);
1.173 djm 598: free(passwd);
1.194 markus 599: send_status(e, success);
1.88 markus 600: }
601:
602: static void
1.221 djm 603: no_identities(SocketEntry *e)
1.88 markus 604: {
1.194 markus 605: struct sshbuf *msg;
606: int r;
1.88 markus 607:
1.194 markus 608: if ((msg = sshbuf_new()) == NULL)
609: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 610: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 611: (r = sshbuf_put_u32(msg, 0)) != 0 ||
612: (r = sshbuf_put_stringb(e->output, msg)) != 0)
613: fatal("%s: buffer error: %s", __func__, ssh_err(r));
614: sshbuf_free(msg);
1.88 markus 615: }
1.59 markus 616:
1.163 markus 617: #ifdef ENABLE_PKCS11
1.59 markus 618: static void
1.158 djm 619: process_add_smartcard_key(SocketEntry *e)
1.59 markus 620: {
1.226 djm 621: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 622: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 623: u_int seconds;
1.174 dtucker 624: time_t death = 0;
1.194 markus 625: u_char type;
626: struct sshkey **keys = NULL, *k;
1.84 markus 627: Identity *id;
1.75 deraadt 628:
1.194 markus 629: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 630: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
631: error("%s: buffer error: %s", __func__, ssh_err(r));
632: goto send;
633: }
1.194 markus 634:
635: while (sshbuf_len(e->request)) {
1.226 djm 636: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
637: error("%s: buffer error: %s", __func__, ssh_err(r));
638: goto send;
639: }
1.194 markus 640: switch (type) {
1.110 djm 641: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 642: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
643: error("%s: buffer error: %s",
1.194 markus 644: __func__, ssh_err(r));
1.226 djm 645: goto send;
646: }
1.194 markus 647: death = monotime() + seconds;
1.110 djm 648: break;
649: case SSH_AGENT_CONSTRAIN_CONFIRM:
650: confirm = 1;
651: break;
652: default:
1.221 djm 653: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 654: goto send;
1.110 djm 655: }
656: }
1.215 djm 657: if (realpath(provider, canonical_provider) == NULL) {
658: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
659: provider, strerror(errno));
660: goto send;
661: }
1.238 djm 662: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 663: verbose("refusing PKCS#11 add of \"%.100s\": "
664: "provider not whitelisted", canonical_provider);
665: goto send;
666: }
667: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 668: if (lifetime && !death)
1.175 dtucker 669: death = monotime() + lifetime;
1.110 djm 670:
1.215 djm 671: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 672: for (i = 0; i < count; i++) {
1.84 markus 673: k = keys[i];
1.221 djm 674: if (lookup_identity(k) == NULL) {
1.163 markus 675: id = xcalloc(1, sizeof(Identity));
1.84 markus 676: id->key = k;
1.215 djm 677: id->provider = xstrdup(canonical_provider);
678: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 679: id->death = death;
680: id->confirm = confirm;
1.221 djm 681: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
682: idtab->nentries++;
1.84 markus 683: success = 1;
684: } else {
1.194 markus 685: sshkey_free(k);
1.84 markus 686: }
687: keys[i] = NULL;
1.59 markus 688: }
689: send:
1.173 djm 690: free(pin);
691: free(provider);
692: free(keys);
1.194 markus 693: send_status(e, success);
1.59 markus 694: }
695:
696: static void
697: process_remove_smartcard_key(SocketEntry *e)
698: {
1.217 djm 699: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 700: int r, success = 0;
1.163 markus 701: Identity *id, *nxt;
1.59 markus 702:
1.194 markus 703: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 704: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
705: error("%s: buffer error: %s", __func__, ssh_err(r));
706: goto send;
707: }
1.173 djm 708: free(pin);
1.59 markus 709:
1.217 djm 710: if (realpath(provider, canonical_provider) == NULL) {
711: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
712: provider, strerror(errno));
713: goto send;
714: }
715:
716: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 717: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
718: nxt = TAILQ_NEXT(id, next);
719: /* Skip file--based keys */
720: if (id->provider == NULL)
721: continue;
722: if (!strcmp(canonical_provider, id->provider)) {
723: TAILQ_REMOVE(&idtab->idlist, id, next);
724: free_identity(id);
725: idtab->nentries--;
1.59 markus 726: }
727: }
1.217 djm 728: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 729: success = 1;
730: else
1.221 djm 731: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 732: send:
1.173 djm 733: free(provider);
1.194 markus 734: send_status(e, success);
1.59 markus 735: }
1.163 markus 736: #endif /* ENABLE_PKCS11 */
1.59 markus 737:
1.33 markus 738: /* dispatch incoming messages */
739:
1.223 djm 740: static int
741: process_message(u_int socknum)
1.1 deraadt 742: {
1.194 markus 743: u_int msg_len;
744: u_char type;
745: const u_char *cp;
746: int r;
1.223 djm 747: SocketEntry *e;
748:
749: if (socknum >= sockets_alloc) {
750: fatal("%s: socket number %u >= allocated %u",
751: __func__, socknum, sockets_alloc);
752: }
753: e = &sockets[socknum];
1.89 markus 754:
1.194 markus 755: if (sshbuf_len(e->input) < 5)
1.223 djm 756: return 0; /* Incomplete message header. */
1.194 markus 757: cp = sshbuf_ptr(e->input);
758: msg_len = PEEK_U32(cp);
1.223 djm 759: if (msg_len > AGENT_MAX_LEN) {
760: debug("%s: socket %u (fd=%d) message too long %u > %u",
761: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
762: return -1;
1.21 markus 763: }
1.194 markus 764: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 765: return 0; /* Incomplete message body. */
1.87 markus 766:
767: /* move the current input to e->request */
1.194 markus 768: sshbuf_reset(e->request);
769: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 770: (r = sshbuf_get_u8(e->request, &type)) != 0) {
771: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
772: r == SSH_ERR_STRING_TOO_LARGE) {
773: debug("%s: buffer error: %s", __func__, ssh_err(r));
774: return -1;
775: }
1.194 markus 776: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 777: }
778:
779: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 780:
1.230 djm 781: /* check whether agent is locked */
1.88 markus 782: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 783: sshbuf_reset(e->request);
1.88 markus 784: switch (type) {
785: case SSH2_AGENTC_REQUEST_IDENTITIES:
786: /* send empty lists */
1.221 djm 787: no_identities(e);
1.88 markus 788: break;
789: default:
790: /* send a fail message for all other request types */
1.194 markus 791: send_status(e, 0);
1.88 markus 792: }
1.223 djm 793: return 0;
1.88 markus 794: }
795:
1.21 markus 796: switch (type) {
1.88 markus 797: case SSH_AGENTC_LOCK:
798: case SSH_AGENTC_UNLOCK:
799: process_lock_agent(e, type == SSH_AGENTC_LOCK);
800: break;
1.21 markus 801: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 802: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 803: break;
804: /* ssh2 */
805: case SSH2_AGENTC_SIGN_REQUEST:
806: process_sign_request2(e);
807: break;
808: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 809: process_request_identities(e);
1.33 markus 810: break;
811: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 812: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 813: process_add_identity(e);
1.33 markus 814: break;
815: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 816: process_remove_identity(e);
1.33 markus 817: break;
818: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 819: process_remove_all_identities(e);
1.21 markus 820: break;
1.163 markus 821: #ifdef ENABLE_PKCS11
1.59 markus 822: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 823: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 824: process_add_smartcard_key(e);
1.75 deraadt 825: break;
1.59 markus 826: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
827: process_remove_smartcard_key(e);
1.75 deraadt 828: break;
1.163 markus 829: #endif /* ENABLE_PKCS11 */
1.21 markus 830: default:
831: /* Unknown message. Respond with failure. */
832: error("Unknown message %d", type);
1.194 markus 833: sshbuf_reset(e->request);
834: send_status(e, 0);
1.21 markus 835: break;
836: }
1.223 djm 837: return 0;
1.1 deraadt 838: }
839:
1.55 itojun 840: static void
1.73 stevesk 841: new_socket(sock_type type, int fd)
1.1 deraadt 842: {
1.112 markus 843: u_int i, old_alloc, new_alloc;
1.96 deraadt 844:
1.119 djm 845: set_nonblock(fd);
1.21 markus 846:
847: if (fd > max_fd)
848: max_fd = fd;
849:
850: for (i = 0; i < sockets_alloc; i++)
851: if (sockets[i].type == AUTH_UNUSED) {
852: sockets[i].fd = fd;
1.194 markus 853: if ((sockets[i].input = sshbuf_new()) == NULL)
854: fatal("%s: sshbuf_new failed", __func__);
855: if ((sockets[i].output = sshbuf_new()) == NULL)
856: fatal("%s: sshbuf_new failed", __func__);
857: if ((sockets[i].request = sshbuf_new()) == NULL)
858: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 859: sockets[i].type = type;
1.21 markus 860: return;
861: }
862: old_alloc = sockets_alloc;
1.112 markus 863: new_alloc = sockets_alloc + 10;
1.200 deraadt 864: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 865: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 866: sockets[i].type = AUTH_UNUSED;
1.112 markus 867: sockets_alloc = new_alloc;
1.21 markus 868: sockets[old_alloc].fd = fd;
1.194 markus 869: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
870: fatal("%s: sshbuf_new failed", __func__);
871: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
872: fatal("%s: sshbuf_new failed", __func__);
873: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
874: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 875: sockets[old_alloc].type = type;
1.1 deraadt 876: }
877:
1.55 itojun 878: static int
1.223 djm 879: handle_socket_read(u_int socknum)
1.1 deraadt 880: {
1.223 djm 881: struct sockaddr_un sunaddr;
882: socklen_t slen;
883: uid_t euid;
884: gid_t egid;
885: int fd;
886:
887: slen = sizeof(sunaddr);
888: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 889: if (fd == -1) {
1.223 djm 890: error("accept from AUTH_SOCKET: %s", strerror(errno));
891: return -1;
892: }
1.237 deraadt 893: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 894: error("getpeereid %d failed: %s", fd, strerror(errno));
895: close(fd);
896: return -1;
897: }
898: if ((euid != 0) && (getuid() != euid)) {
899: error("uid mismatch: peer euid %u != uid %u",
900: (u_int) euid, (u_int) getuid());
901: close(fd);
902: return -1;
903: }
904: new_socket(AUTH_CONNECTION, fd);
905: return 0;
906: }
907:
908: static int
909: handle_conn_read(u_int socknum)
910: {
1.233 djm 911: char buf[AGENT_RBUF_LEN];
1.223 djm 912: ssize_t len;
913: int r;
914:
915: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
916: if (len == -1) {
917: if (errno == EAGAIN || errno == EINTR)
918: return 0;
919: error("%s: read error on socket %u (fd %d): %s",
920: __func__, socknum, sockets[socknum].fd,
921: strerror(errno));
922: }
923: return -1;
924: }
925: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
926: fatal("%s: buffer error: %s", __func__, ssh_err(r));
927: explicit_bzero(buf, sizeof(buf));
928: process_message(socknum);
929: return 0;
930: }
931:
932: static int
933: handle_conn_write(u_int socknum)
934: {
935: ssize_t len;
936: int r;
937:
938: if (sshbuf_len(sockets[socknum].output) == 0)
939: return 0; /* shouldn't happen */
940: if ((len = write(sockets[socknum].fd,
941: sshbuf_ptr(sockets[socknum].output),
942: sshbuf_len(sockets[socknum].output))) <= 0) {
943: if (len == -1) {
944: if (errno == EAGAIN || errno == EINTR)
945: return 0;
946: error("%s: read error on socket %u (fd %d): %s",
947: __func__, socknum, sockets[socknum].fd,
948: strerror(errno));
949: }
950: return -1;
951: }
952: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
953: fatal("%s: buffer error: %s", __func__, ssh_err(r));
954: return 0;
955: }
956:
957: static void
1.231 djm 958: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 959: {
960: size_t i;
1.231 djm 961: u_int socknum, activefds = npfd;
1.223 djm 962:
963: for (i = 0; i < npfd; i++) {
964: if (pfd[i].revents == 0)
965: continue;
966: /* Find sockets entry */
967: for (socknum = 0; socknum < sockets_alloc; socknum++) {
968: if (sockets[socknum].type != AUTH_SOCKET &&
969: sockets[socknum].type != AUTH_CONNECTION)
970: continue;
971: if (pfd[i].fd == sockets[socknum].fd)
972: break;
973: }
974: if (socknum >= sockets_alloc) {
975: error("%s: no socket for fd %d", __func__, pfd[i].fd);
976: continue;
977: }
978: /* Process events */
979: switch (sockets[socknum].type) {
980: case AUTH_SOCKET:
1.231 djm 981: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
982: break;
983: if (npfd > maxfds) {
984: debug3("out of fds (active %u >= limit %u); "
985: "skipping accept", activefds, maxfds);
986: break;
987: }
988: if (handle_socket_read(socknum) == 0)
989: activefds++;
1.223 djm 990: break;
991: case AUTH_CONNECTION:
992: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
993: handle_conn_read(socknum) != 0) {
1.231 djm 994: goto close_sock;
995: }
996: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
997: handle_conn_write(socknum) != 0) {
998: close_sock:
999: if (activefds == 0)
1000: fatal("activefds == 0 at close_sock");
1.223 djm 1001: close_socket(&sockets[socknum]);
1.231 djm 1002: activefds--;
1.223 djm 1003: break;
1004: }
1005: break;
1006: default:
1007: break;
1008: }
1009: }
1010: }
1011:
1012: static int
1.231 djm 1013: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1014: {
1015: struct pollfd *pfd = *pfdp;
1016: size_t i, j, npfd = 0;
1.174 dtucker 1017: time_t deadline;
1.233 djm 1018: int r;
1.46 markus 1019:
1.223 djm 1020: /* Count active sockets */
1.46 markus 1021: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1022: switch (sockets[i].type) {
1023: case AUTH_SOCKET:
1024: case AUTH_CONNECTION:
1.223 djm 1025: npfd++;
1.21 markus 1026: break;
1027: case AUTH_UNUSED:
1028: break;
1029: default:
1030: fatal("Unknown socket type %d", sockets[i].type);
1031: break;
1032: }
1.46 markus 1033: }
1.223 djm 1034: if (npfd != *npfdp &&
1035: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1036: fatal("%s: recallocarray failed", __func__);
1037: *pfdp = pfd;
1038: *npfdp = npfd;
1.46 markus 1039:
1.223 djm 1040: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1041: switch (sockets[i].type) {
1042: case AUTH_SOCKET:
1.231 djm 1043: if (npfd > maxfds) {
1044: debug3("out of fds (active %zu >= limit %u); "
1045: "skipping arming listener", npfd, maxfds);
1046: break;
1047: }
1048: pfd[j].fd = sockets[i].fd;
1049: pfd[j].revents = 0;
1050: pfd[j].events = POLLIN;
1051: j++;
1052: break;
1.46 markus 1053: case AUTH_CONNECTION:
1.223 djm 1054: pfd[j].fd = sockets[i].fd;
1055: pfd[j].revents = 0;
1.233 djm 1056: /*
1057: * Only prepare to read if we can handle a full-size
1058: * input read buffer and enqueue a max size reply..
1059: */
1060: if ((r = sshbuf_check_reserve(sockets[i].input,
1061: AGENT_RBUF_LEN)) == 0 &&
1062: (r = sshbuf_check_reserve(sockets[i].output,
1063: AGENT_MAX_LEN)) == 0)
1064: pfd[j].events = POLLIN;
1065: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1066: fatal("%s: buffer error: %s",
1067: __func__, ssh_err(r));
1068: }
1.194 markus 1069: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1070: pfd[j].events |= POLLOUT;
1071: j++;
1.46 markus 1072: break;
1073: default:
1074: break;
1075: }
1076: }
1.155 dtucker 1077: deadline = reaper();
1078: if (parent_alive_interval != 0)
1079: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1080: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1081: if (deadline == 0) {
1.224 djm 1082: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1083: } else {
1.223 djm 1084: if (deadline > INT_MAX / 1000)
1085: *timeoutp = INT_MAX / 1000;
1086: else
1087: *timeoutp = deadline * 1000;
1.155 dtucker 1088: }
1.46 markus 1089: return (1);
1.21 markus 1090: }
1091:
1.55 itojun 1092: static void
1.113 markus 1093: cleanup_socket(void)
1.15 markus 1094: {
1.187 djm 1095: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1096: return;
1097: debug("%s: cleanup", __func__);
1.48 deraadt 1098: if (socket_name[0])
1099: unlink(socket_name);
1100: if (socket_dir[0])
1101: rmdir(socket_dir);
1.10 markus 1102: }
1103:
1.114 markus 1104: void
1.15 markus 1105: cleanup_exit(int i)
1106: {
1.113 markus 1107: cleanup_socket();
1108: _exit(i);
1.15 markus 1109: }
1110:
1.135 deraadt 1111: /*ARGSUSED*/
1.55 itojun 1112: static void
1.48 deraadt 1113: cleanup_handler(int sig)
1114: {
1.113 markus 1115: cleanup_socket();
1.163 markus 1116: #ifdef ENABLE_PKCS11
1117: pkcs11_terminate();
1118: #endif
1.48 deraadt 1119: _exit(2);
1.113 markus 1120: }
1121:
1.68 markus 1122: static void
1.155 dtucker 1123: check_parent_exists(void)
1.68 markus 1124: {
1.172 dtucker 1125: /*
1126: * If our parent has exited then getppid() will return (pid_t)1,
1127: * so testing for that should be safe.
1128: */
1129: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1130: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1131: cleanup_socket();
1132: _exit(2);
1.68 markus 1133: }
1.48 deraadt 1134: }
1135:
1.55 itojun 1136: static void
1.50 itojun 1137: usage(void)
1.15 markus 1138: {
1.184 deraadt 1139: fprintf(stderr,
1.250 jmc 1140: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1141: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1142: " ssh-agent [-c | -s] -k\n");
1.21 markus 1143: exit(1);
1.15 markus 1144: }
1145:
1.2 provos 1146: int
1147: main(int ac, char **av)
1.1 deraadt 1148: {
1.201 djm 1149: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1150: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1151: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1152: struct rlimit rlim;
1.96 deraadt 1153: extern int optind;
1.98 stevesk 1154: extern char *optarg;
1.21 markus 1155: pid_t pid;
1.96 deraadt 1156: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1157: size_t len;
1.189 djm 1158: mode_t prev_mask;
1.224 djm 1159: int timeout = -1; /* INFTIM */
1.223 djm 1160: struct pollfd *pfd = NULL;
1161: size_t npfd = 0;
1.231 djm 1162: u_int maxfds;
1.123 djm 1163:
1164: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1165: sanitise_stdfd();
1.99 markus 1166:
1167: /* drop */
1168: setegid(getgid());
1169: setgid(getgid());
1.53 markus 1170:
1.231 djm 1171: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1172: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1173:
1.185 markus 1174: #ifdef WITH_OPENSSL
1.170 djm 1175: OpenSSL_add_all_algorithms();
1.185 markus 1176: #endif
1.21 markus 1177:
1.215 djm 1178: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1179: switch (ch) {
1.192 djm 1180: case 'E':
1181: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1182: if (fingerprint_hash == -1)
1183: fatal("Invalid hash algorithm \"%s\"", optarg);
1184: break;
1.21 markus 1185: case 'c':
1186: if (s_flag)
1187: usage();
1188: c_flag++;
1189: break;
1190: case 'k':
1191: k_flag++;
1192: break;
1.215 djm 1193: case 'P':
1.238 djm 1194: if (provider_whitelist != NULL)
1.215 djm 1195: fatal("-P option already specified");
1.238 djm 1196: provider_whitelist = xstrdup(optarg);
1.215 djm 1197: break;
1.21 markus 1198: case 's':
1199: if (c_flag)
1200: usage();
1201: s_flag++;
1202: break;
1.57 markus 1203: case 'd':
1.201 djm 1204: if (d_flag || D_flag)
1.57 markus 1205: usage();
1206: d_flag++;
1207: break;
1.201 djm 1208: case 'D':
1209: if (d_flag || D_flag)
1210: usage();
1211: D_flag++;
1212: break;
1.86 markus 1213: case 'a':
1214: agentsocket = optarg;
1.106 marc 1215: break;
1216: case 't':
1217: if ((lifetime = convtime(optarg)) == -1) {
1218: fprintf(stderr, "Invalid lifetime\n");
1219: usage();
1220: }
1.86 markus 1221: break;
1.21 markus 1222: default:
1223: usage();
1224: }
1225: }
1226: ac -= optind;
1227: av += optind;
1228:
1.201 djm 1229: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1230: usage();
1231:
1.238 djm 1232: if (provider_whitelist == NULL)
1233: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1234:
1.85 markus 1235: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1236: shell = getenv("SHELL");
1.161 tobias 1237: if (shell != NULL && (len = strlen(shell)) > 2 &&
1238: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1239: c_flag = 1;
1240: }
1241: if (k_flag) {
1.136 deraadt 1242: const char *errstr = NULL;
1243:
1.21 markus 1244: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1245: if (pidstr == NULL) {
1246: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1247: SSH_AGENTPID_ENV_NAME);
1.21 markus 1248: exit(1);
1249: }
1.136 deraadt 1250: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1251: if (errstr) {
1252: fprintf(stderr,
1253: "%s=\"%s\", which is not a good PID: %s\n",
1254: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1255: exit(1);
1256: }
1257: if (kill(pid, SIGTERM) == -1) {
1258: perror("kill");
1259: exit(1);
1260: }
1261: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1262: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1263: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1264: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1265: exit(0);
1266: }
1.231 djm 1267:
1268: /*
1269: * Minimum file descriptors:
1270: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1271: * a few spare for libc / stack protectors / sanitisers, etc.
1272: */
1273: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1274: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1275: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1276: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1277: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1278:
1.21 markus 1279: parent_pid = getpid();
1280:
1.86 markus 1281: if (agentsocket == NULL) {
1282: /* Create private directory for agent socket */
1.171 djm 1283: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1284: if (mkdtemp(socket_dir) == NULL) {
1285: perror("mkdtemp: private socket dir");
1286: exit(1);
1287: }
1.91 mpech 1288: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1289: (long)parent_pid);
1.86 markus 1290: } else {
1291: /* Try to use specified agent socket */
1292: socket_dir[0] = '\0';
1293: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1294: }
1295:
1.23 markus 1296: /*
1297: * Create socket early so it will exist before command gets run from
1298: * the parent.
1299: */
1.189 djm 1300: prev_mask = umask(0177);
1.188 millert 1301: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1302: if (sock < 0) {
1.188 millert 1303: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1304: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1305: cleanup_exit(1);
1306: }
1.189 djm 1307: umask(prev_mask);
1.46 markus 1308:
1.23 markus 1309: /*
1310: * Fork, and have the parent execute the command, if any, or present
1311: * the socket data. The child continues as the authentication agent.
1312: */
1.201 djm 1313: if (D_flag || d_flag) {
1314: log_init(__progname,
1315: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1316: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1317: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1318: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1319: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1320: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1321: fflush(stdout);
1.57 markus 1322: goto skip;
1323: }
1.21 markus 1324: pid = fork();
1325: if (pid == -1) {
1326: perror("fork");
1.81 stevesk 1327: cleanup_exit(1);
1.21 markus 1328: }
1329: if (pid != 0) { /* Parent - execute the given command. */
1330: close(sock);
1.91 mpech 1331: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1332: if (ac == 0) {
1333: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1334: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1335: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1336: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1337: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1338: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1339: exit(0);
1340: }
1.36 deraadt 1341: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1342: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1343: perror("setenv");
1344: exit(1);
1345: }
1.21 markus 1346: execvp(av[0], av);
1347: perror(av[0]);
1348: exit(1);
1349: }
1.81 stevesk 1350: /* child */
1351: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1352:
1353: if (setsid() == -1) {
1.81 stevesk 1354: error("setsid: %s", strerror(errno));
1.67 stevesk 1355: cleanup_exit(1);
1356: }
1357:
1358: (void)chdir("/");
1.107 markus 1359: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1360: /* XXX might close listen socket */
1361: (void)dup2(fd, STDIN_FILENO);
1362: (void)dup2(fd, STDOUT_FILENO);
1363: (void)dup2(fd, STDERR_FILENO);
1364: if (fd > 2)
1365: close(fd);
1366: }
1.21 markus 1367:
1.41 markus 1368: /* deny core dumps, since memory contains unencrypted private keys */
1369: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1370: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1371: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1372: cleanup_exit(1);
1373: }
1.57 markus 1374:
1375: skip:
1.187 djm 1376:
1377: cleanup_pid = getpid();
1.163 markus 1378:
1379: #ifdef ENABLE_PKCS11
1380: pkcs11_init(0);
1381: #endif
1.21 markus 1382: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1383: if (ac > 0)
1384: parent_alive_interval = 10;
1.33 markus 1385: idtab_init();
1.61 markus 1386: signal(SIGPIPE, SIG_IGN);
1.201 djm 1387: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1388: signal(SIGHUP, cleanup_handler);
1389: signal(SIGTERM, cleanup_handler);
1.205 djm 1390:
1.215 djm 1391: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1392: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1393:
1.21 markus 1394: while (1) {
1.231 djm 1395: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1396: result = poll(pfd, npfd, timeout);
1.154 dtucker 1397: saved_errno = errno;
1.155 dtucker 1398: if (parent_alive_interval != 0)
1399: check_parent_exists();
1400: (void) reaper(); /* remove expired keys */
1.237 deraadt 1401: if (result == -1) {
1.154 dtucker 1402: if (saved_errno == EINTR)
1.21 markus 1403: continue;
1.223 djm 1404: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1405: } else if (result > 0)
1.231 djm 1406: after_poll(pfd, npfd, maxfds);
1.15 markus 1407: }
1.21 markus 1408: /* NOTREACHED */
1.1 deraadt 1409: }
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