Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.255
1.255 ! naddy 1: /* $OpenBSD: ssh-agent.c,v 1.254 2020/01/25 00:06:48 djm Exp $ */
1.1 deraadt 2: /*
1.22 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * The authentication agent program.
1.33 markus 7: *
1.35 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.56 markus 14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 15: *
16: * Redistribution and use in source and binary forms, with or without
17: * modification, are permitted provided that the following conditions
18: * are met:
19: * 1. Redistributions of source code must retain the above copyright
20: * notice, this list of conditions and the following disclaimer.
21: * 2. Redistributions in binary form must reproduce the above copyright
22: * notice, this list of conditions and the following disclaimer in the
23: * documentation and/or other materials provided with the distribution.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 35: */
1.1 deraadt 36:
1.151 deraadt 37: #include <sys/types.h>
1.153 djm 38: #include <sys/time.h>
1.78 provos 39: #include <sys/queue.h>
1.127 stevesk 40: #include <sys/resource.h>
1.141 stevesk 41: #include <sys/socket.h>
1.189 djm 42: #include <sys/stat.h>
1.128 stevesk 43: #include <sys/un.h>
1.238 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;
1.254 djm 419: char canonical_provider[PATH_MAX];
1.174 dtucker 420: time_t death = 0;
1.194 markus 421: struct sshkey *k = NULL;
422: u_char ctype;
423: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 424:
1.221 djm 425: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
426: k == NULL ||
1.194 markus 427: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
428: error("%s: decode private key: %s", __func__, ssh_err(r));
429: goto err;
430: }
431: while (sshbuf_len(e->request)) {
432: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
433: error("%s: buffer error: %s", __func__, ssh_err(r));
434: goto err;
435: }
436: switch (ctype) {
1.94 markus 437: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 438: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
439: error("%s: bad lifetime constraint: %s",
440: __func__, ssh_err(r));
441: goto err;
442: }
443: death = monotime() + seconds;
1.94 markus 444: break;
1.107 markus 445: case SSH_AGENT_CONSTRAIN_CONFIRM:
446: confirm = 1;
447: break;
1.228 markus 448: case SSH_AGENT_CONSTRAIN_MAXSIGN:
449: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
450: error("%s: bad maxsign constraint: %s",
451: __func__, ssh_err(r));
452: goto err;
453: }
454: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
455: error("%s: cannot enable maxsign: %s",
456: __func__, ssh_err(r));
457: goto err;
458: }
459: break;
1.238 djm 460: case SSH_AGENT_CONSTRAIN_EXTENSION:
461: if ((r = sshbuf_get_cstring(e->request,
462: &ext_name, NULL)) != 0) {
463: error("%s: cannot parse extension: %s",
464: __func__, ssh_err(r));
465: goto err;
466: }
467: debug("%s: constraint ext %s", __func__, ext_name);
468: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
469: if (sk_provider != NULL) {
470: error("%s already set", ext_name);
471: goto err;
472: }
473: if ((r = sshbuf_get_cstring(e->request,
474: &sk_provider, NULL)) != 0) {
475: error("%s: cannot parse %s: %s",
476: __func__, ext_name, ssh_err(r));
477: goto err;
478: }
479: } else {
480: error("%s: unsupported constraint \"%s\"",
481: __func__, ext_name);
482: goto err;
483: }
484: free(ext_name);
485: break;
1.94 markus 486: default:
1.194 markus 487: error("%s: Unknown constraint %d", __func__, ctype);
488: err:
1.238 djm 489: free(sk_provider);
490: free(ext_name);
1.194 markus 491: sshbuf_reset(e->request);
1.173 djm 492: free(comment);
1.194 markus 493: sshkey_free(k);
1.158 djm 494: goto send;
1.94 markus 495: }
496: }
1.238 djm 497: if (sk_provider != NULL) {
1.240 markus 498: if (!sshkey_is_sk(k)) {
1.255 ! naddy 499: error("Cannot add provider: %s is not an "
! 500: "authenticator-hosted key", sshkey_type(k));
1.238 djm 501: free(sk_provider);
502: goto send;
503: }
1.254 djm 504: if (strcasecmp(sk_provider, "internal") == 0) {
1.245 djm 505: debug("%s: internal provider", __func__);
1.254 djm 506: } else {
507: if (realpath(sk_provider, canonical_provider) == NULL) {
508: verbose("failed provider \"%.100s\": "
509: "realpath: %s", sk_provider,
510: strerror(errno));
511: free(sk_provider);
512: goto send;
513: }
1.238 djm 514: free(sk_provider);
1.254 djm 515: sk_provider = xstrdup(canonical_provider);
516: if (match_pattern_list(sk_provider,
517: provider_whitelist, 0) != 1) {
518: error("Refusing add key: "
519: "provider %s not whitelisted", sk_provider);
520: free(sk_provider);
521: goto send;
522: }
1.238 djm 523: }
1.242 markus 524: }
525: if ((r = sshkey_shield_private(k)) != 0) {
526: error("%s: shield private key: %s", __func__, ssh_err(r));
527: goto err;
1.238 djm 528: }
1.194 markus 529:
1.158 djm 530: success = 1;
1.106 marc 531: if (lifetime && !death)
1.175 dtucker 532: death = monotime() + lifetime;
1.221 djm 533: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 534: id = xcalloc(1, sizeof(Identity));
1.221 djm 535: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 536: /* Increment the number of identities. */
1.221 djm 537: idtab->nentries++;
1.33 markus 538: } else {
1.228 markus 539: /* key state might have been updated */
540: sshkey_free(id->key);
1.173 djm 541: free(id->comment);
1.238 djm 542: free(id->sk_provider);
1.33 markus 543: }
1.228 markus 544: id->key = k;
1.157 canacar 545: id->comment = comment;
546: id->death = death;
547: id->confirm = confirm;
1.238 djm 548: id->sk_provider = sk_provider;
549:
550: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
551: SSH_FP_DEFAULT)) == NULL)
552: fatal("%s: sshkey_fingerprint failed", __func__);
553: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
554: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
555: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
556: free(fp);
1.33 markus 557: send:
1.194 markus 558: send_status(e, success);
1.1 deraadt 559: }
560:
1.88 markus 561: /* XXX todo: encrypt sensitive data with passphrase */
562: static void
563: process_lock_agent(SocketEntry *e, int lock)
564: {
1.203 dtucker 565: int r, success = 0, delay;
1.213 djm 566: char *passwd;
567: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 568: static u_int fail_count = 0;
569: size_t pwlen;
570:
1.226 djm 571: /*
572: * This is deliberately fatal: the user has requested that we lock,
573: * but we can't parse their request properly. The only safe thing to
574: * do is abort.
575: */
1.203 dtucker 576: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
577: fatal("%s: buffer error: %s", __func__, ssh_err(r));
578: if (pwlen == 0) {
579: debug("empty password not supported");
580: } else if (locked && !lock) {
581: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
582: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
583: fatal("bcrypt_pbkdf");
1.213 djm 584: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 585: debug("agent unlocked");
586: locked = 0;
587: fail_count = 0;
1.213 djm 588: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 589: success = 1;
590: } else {
591: /* delay in 0.1s increments up to 10s */
592: if (fail_count < 100)
593: fail_count++;
594: delay = 100000 * fail_count;
595: debug("unlock failed, delaying %0.1lf seconds",
596: (double)delay/1000000);
597: usleep(delay);
598: }
599: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 600: } else if (!locked && lock) {
1.203 dtucker 601: debug("agent locked");
1.88 markus 602: locked = 1;
1.203 dtucker 603: arc4random_buf(lock_salt, sizeof(lock_salt));
604: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 605: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 606: fatal("bcrypt_pbkdf");
1.88 markus 607: success = 1;
608: }
1.203 dtucker 609: explicit_bzero(passwd, pwlen);
1.173 djm 610: free(passwd);
1.194 markus 611: send_status(e, success);
1.88 markus 612: }
613:
614: static void
1.221 djm 615: no_identities(SocketEntry *e)
1.88 markus 616: {
1.194 markus 617: struct sshbuf *msg;
618: int r;
1.88 markus 619:
1.194 markus 620: if ((msg = sshbuf_new()) == NULL)
621: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 622: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 623: (r = sshbuf_put_u32(msg, 0)) != 0 ||
624: (r = sshbuf_put_stringb(e->output, msg)) != 0)
625: fatal("%s: buffer error: %s", __func__, ssh_err(r));
626: sshbuf_free(msg);
1.88 markus 627: }
1.59 markus 628:
1.163 markus 629: #ifdef ENABLE_PKCS11
1.59 markus 630: static void
1.158 djm 631: process_add_smartcard_key(SocketEntry *e)
1.59 markus 632: {
1.226 djm 633: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.253 djm 634: char **comments = NULL;
1.221 djm 635: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 636: u_int seconds;
1.174 dtucker 637: time_t death = 0;
1.194 markus 638: u_char type;
639: struct sshkey **keys = NULL, *k;
1.84 markus 640: Identity *id;
1.75 deraadt 641:
1.194 markus 642: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 643: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
644: error("%s: buffer error: %s", __func__, ssh_err(r));
645: goto send;
646: }
1.194 markus 647:
648: while (sshbuf_len(e->request)) {
1.226 djm 649: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
650: error("%s: buffer error: %s", __func__, ssh_err(r));
651: goto send;
652: }
1.194 markus 653: switch (type) {
1.110 djm 654: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 655: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
656: error("%s: buffer error: %s",
1.194 markus 657: __func__, ssh_err(r));
1.226 djm 658: goto send;
659: }
1.194 markus 660: death = monotime() + seconds;
1.110 djm 661: break;
662: case SSH_AGENT_CONSTRAIN_CONFIRM:
663: confirm = 1;
664: break;
665: default:
1.221 djm 666: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 667: goto send;
1.110 djm 668: }
669: }
1.215 djm 670: if (realpath(provider, canonical_provider) == NULL) {
671: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
672: provider, strerror(errno));
673: goto send;
674: }
1.238 djm 675: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 676: verbose("refusing PKCS#11 add of \"%.100s\": "
677: "provider not whitelisted", canonical_provider);
678: goto send;
679: }
680: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 681: if (lifetime && !death)
1.175 dtucker 682: death = monotime() + lifetime;
1.110 djm 683:
1.253 djm 684: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.163 markus 685: for (i = 0; i < count; i++) {
1.84 markus 686: k = keys[i];
1.221 djm 687: if (lookup_identity(k) == NULL) {
1.163 markus 688: id = xcalloc(1, sizeof(Identity));
1.84 markus 689: id->key = k;
1.253 djm 690: keys[i] = NULL; /* transferred */
1.215 djm 691: id->provider = xstrdup(canonical_provider);
1.253 djm 692: if (*comments[i] != '\0') {
693: id->comment = comments[i];
694: comments[i] = NULL; /* transferred */
695: } else {
696: id->comment = xstrdup(canonical_provider);
697: }
1.110 djm 698: id->death = death;
699: id->confirm = confirm;
1.221 djm 700: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
701: idtab->nentries++;
1.84 markus 702: success = 1;
703: }
1.253 djm 704: sshkey_free(keys[i]);
705: free(comments[i]);
1.59 markus 706: }
707: send:
1.173 djm 708: free(pin);
709: free(provider);
710: free(keys);
1.253 djm 711: free(comments);
1.194 markus 712: send_status(e, success);
1.59 markus 713: }
714:
715: static void
716: process_remove_smartcard_key(SocketEntry *e)
717: {
1.217 djm 718: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 719: int r, success = 0;
1.163 markus 720: Identity *id, *nxt;
1.59 markus 721:
1.194 markus 722: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 723: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
724: error("%s: buffer error: %s", __func__, ssh_err(r));
725: goto send;
726: }
1.173 djm 727: free(pin);
1.59 markus 728:
1.217 djm 729: if (realpath(provider, canonical_provider) == NULL) {
730: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
731: provider, strerror(errno));
732: goto send;
733: }
734:
735: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 736: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
737: nxt = TAILQ_NEXT(id, next);
738: /* Skip file--based keys */
739: if (id->provider == NULL)
740: continue;
741: if (!strcmp(canonical_provider, id->provider)) {
742: TAILQ_REMOVE(&idtab->idlist, id, next);
743: free_identity(id);
744: idtab->nentries--;
1.59 markus 745: }
746: }
1.217 djm 747: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 748: success = 1;
749: else
1.221 djm 750: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 751: send:
1.173 djm 752: free(provider);
1.194 markus 753: send_status(e, success);
1.59 markus 754: }
1.163 markus 755: #endif /* ENABLE_PKCS11 */
1.59 markus 756:
1.33 markus 757: /* dispatch incoming messages */
758:
1.223 djm 759: static int
760: process_message(u_int socknum)
1.1 deraadt 761: {
1.194 markus 762: u_int msg_len;
763: u_char type;
764: const u_char *cp;
765: int r;
1.223 djm 766: SocketEntry *e;
767:
768: if (socknum >= sockets_alloc) {
769: fatal("%s: socket number %u >= allocated %u",
770: __func__, socknum, sockets_alloc);
771: }
772: e = &sockets[socknum];
1.89 markus 773:
1.194 markus 774: if (sshbuf_len(e->input) < 5)
1.223 djm 775: return 0; /* Incomplete message header. */
1.194 markus 776: cp = sshbuf_ptr(e->input);
777: msg_len = PEEK_U32(cp);
1.223 djm 778: if (msg_len > AGENT_MAX_LEN) {
779: debug("%s: socket %u (fd=%d) message too long %u > %u",
780: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
781: return -1;
1.21 markus 782: }
1.194 markus 783: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 784: return 0; /* Incomplete message body. */
1.87 markus 785:
786: /* move the current input to e->request */
1.194 markus 787: sshbuf_reset(e->request);
788: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 789: (r = sshbuf_get_u8(e->request, &type)) != 0) {
790: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
791: r == SSH_ERR_STRING_TOO_LARGE) {
792: debug("%s: buffer error: %s", __func__, ssh_err(r));
793: return -1;
794: }
1.194 markus 795: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 796: }
797:
798: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 799:
1.230 djm 800: /* check whether agent is locked */
1.88 markus 801: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 802: sshbuf_reset(e->request);
1.88 markus 803: switch (type) {
804: case SSH2_AGENTC_REQUEST_IDENTITIES:
805: /* send empty lists */
1.221 djm 806: no_identities(e);
1.88 markus 807: break;
808: default:
809: /* send a fail message for all other request types */
1.194 markus 810: send_status(e, 0);
1.88 markus 811: }
1.223 djm 812: return 0;
1.88 markus 813: }
814:
1.21 markus 815: switch (type) {
1.88 markus 816: case SSH_AGENTC_LOCK:
817: case SSH_AGENTC_UNLOCK:
818: process_lock_agent(e, type == SSH_AGENTC_LOCK);
819: break;
1.21 markus 820: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 821: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 822: break;
823: /* ssh2 */
824: case SSH2_AGENTC_SIGN_REQUEST:
825: process_sign_request2(e);
826: break;
827: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 828: process_request_identities(e);
1.33 markus 829: break;
830: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 831: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 832: process_add_identity(e);
1.33 markus 833: break;
834: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 835: process_remove_identity(e);
1.33 markus 836: break;
837: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 838: process_remove_all_identities(e);
1.21 markus 839: break;
1.163 markus 840: #ifdef ENABLE_PKCS11
1.59 markus 841: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 842: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 843: process_add_smartcard_key(e);
1.75 deraadt 844: break;
1.59 markus 845: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
846: process_remove_smartcard_key(e);
1.75 deraadt 847: break;
1.163 markus 848: #endif /* ENABLE_PKCS11 */
1.21 markus 849: default:
850: /* Unknown message. Respond with failure. */
851: error("Unknown message %d", type);
1.194 markus 852: sshbuf_reset(e->request);
853: send_status(e, 0);
1.21 markus 854: break;
855: }
1.223 djm 856: return 0;
1.1 deraadt 857: }
858:
1.55 itojun 859: static void
1.73 stevesk 860: new_socket(sock_type type, int fd)
1.1 deraadt 861: {
1.112 markus 862: u_int i, old_alloc, new_alloc;
1.96 deraadt 863:
1.119 djm 864: set_nonblock(fd);
1.21 markus 865:
866: if (fd > max_fd)
867: max_fd = fd;
868:
869: for (i = 0; i < sockets_alloc; i++)
870: if (sockets[i].type == AUTH_UNUSED) {
871: sockets[i].fd = fd;
1.194 markus 872: if ((sockets[i].input = sshbuf_new()) == NULL)
873: fatal("%s: sshbuf_new failed", __func__);
874: if ((sockets[i].output = sshbuf_new()) == NULL)
875: fatal("%s: sshbuf_new failed", __func__);
876: if ((sockets[i].request = sshbuf_new()) == NULL)
877: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 878: sockets[i].type = type;
1.21 markus 879: return;
880: }
881: old_alloc = sockets_alloc;
1.112 markus 882: new_alloc = sockets_alloc + 10;
1.200 deraadt 883: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 884: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 885: sockets[i].type = AUTH_UNUSED;
1.112 markus 886: sockets_alloc = new_alloc;
1.21 markus 887: sockets[old_alloc].fd = fd;
1.194 markus 888: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
889: fatal("%s: sshbuf_new failed", __func__);
890: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
891: fatal("%s: sshbuf_new failed", __func__);
892: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
893: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 894: sockets[old_alloc].type = type;
1.1 deraadt 895: }
896:
1.55 itojun 897: static int
1.223 djm 898: handle_socket_read(u_int socknum)
1.1 deraadt 899: {
1.223 djm 900: struct sockaddr_un sunaddr;
901: socklen_t slen;
902: uid_t euid;
903: gid_t egid;
904: int fd;
905:
906: slen = sizeof(sunaddr);
907: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 908: if (fd == -1) {
1.223 djm 909: error("accept from AUTH_SOCKET: %s", strerror(errno));
910: return -1;
911: }
1.237 deraadt 912: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 913: error("getpeereid %d failed: %s", fd, strerror(errno));
914: close(fd);
915: return -1;
916: }
917: if ((euid != 0) && (getuid() != euid)) {
918: error("uid mismatch: peer euid %u != uid %u",
919: (u_int) euid, (u_int) getuid());
920: close(fd);
921: return -1;
922: }
923: new_socket(AUTH_CONNECTION, fd);
924: return 0;
925: }
926:
927: static int
928: handle_conn_read(u_int socknum)
929: {
1.233 djm 930: char buf[AGENT_RBUF_LEN];
1.223 djm 931: ssize_t len;
932: int r;
933:
934: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
935: if (len == -1) {
936: if (errno == EAGAIN || errno == EINTR)
937: return 0;
938: error("%s: read error on socket %u (fd %d): %s",
939: __func__, socknum, sockets[socknum].fd,
940: strerror(errno));
941: }
942: return -1;
943: }
944: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
945: fatal("%s: buffer error: %s", __func__, ssh_err(r));
946: explicit_bzero(buf, sizeof(buf));
947: process_message(socknum);
948: return 0;
949: }
950:
951: static int
952: handle_conn_write(u_int socknum)
953: {
954: ssize_t len;
955: int r;
956:
957: if (sshbuf_len(sockets[socknum].output) == 0)
958: return 0; /* shouldn't happen */
959: if ((len = write(sockets[socknum].fd,
960: sshbuf_ptr(sockets[socknum].output),
961: sshbuf_len(sockets[socknum].output))) <= 0) {
962: if (len == -1) {
963: if (errno == EAGAIN || errno == EINTR)
964: return 0;
965: error("%s: read error on socket %u (fd %d): %s",
966: __func__, socknum, sockets[socknum].fd,
967: strerror(errno));
968: }
969: return -1;
970: }
971: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
972: fatal("%s: buffer error: %s", __func__, ssh_err(r));
973: return 0;
974: }
975:
976: static void
1.231 djm 977: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 978: {
979: size_t i;
1.231 djm 980: u_int socknum, activefds = npfd;
1.223 djm 981:
982: for (i = 0; i < npfd; i++) {
983: if (pfd[i].revents == 0)
984: continue;
985: /* Find sockets entry */
986: for (socknum = 0; socknum < sockets_alloc; socknum++) {
987: if (sockets[socknum].type != AUTH_SOCKET &&
988: sockets[socknum].type != AUTH_CONNECTION)
989: continue;
990: if (pfd[i].fd == sockets[socknum].fd)
991: break;
992: }
993: if (socknum >= sockets_alloc) {
994: error("%s: no socket for fd %d", __func__, pfd[i].fd);
995: continue;
996: }
997: /* Process events */
998: switch (sockets[socknum].type) {
999: case AUTH_SOCKET:
1.231 djm 1000: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1001: break;
1002: if (npfd > maxfds) {
1003: debug3("out of fds (active %u >= limit %u); "
1004: "skipping accept", activefds, maxfds);
1005: break;
1006: }
1007: if (handle_socket_read(socknum) == 0)
1008: activefds++;
1.223 djm 1009: break;
1010: case AUTH_CONNECTION:
1011: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1012: handle_conn_read(socknum) != 0) {
1.231 djm 1013: goto close_sock;
1014: }
1015: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1016: handle_conn_write(socknum) != 0) {
1017: close_sock:
1018: if (activefds == 0)
1019: fatal("activefds == 0 at close_sock");
1.223 djm 1020: close_socket(&sockets[socknum]);
1.231 djm 1021: activefds--;
1.223 djm 1022: break;
1023: }
1024: break;
1025: default:
1026: break;
1027: }
1028: }
1029: }
1030:
1031: static int
1.231 djm 1032: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1033: {
1034: struct pollfd *pfd = *pfdp;
1035: size_t i, j, npfd = 0;
1.174 dtucker 1036: time_t deadline;
1.233 djm 1037: int r;
1.46 markus 1038:
1.223 djm 1039: /* Count active sockets */
1.46 markus 1040: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1041: switch (sockets[i].type) {
1042: case AUTH_SOCKET:
1043: case AUTH_CONNECTION:
1.223 djm 1044: npfd++;
1.21 markus 1045: break;
1046: case AUTH_UNUSED:
1047: break;
1048: default:
1049: fatal("Unknown socket type %d", sockets[i].type);
1050: break;
1051: }
1.46 markus 1052: }
1.223 djm 1053: if (npfd != *npfdp &&
1054: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1055: fatal("%s: recallocarray failed", __func__);
1056: *pfdp = pfd;
1057: *npfdp = npfd;
1.46 markus 1058:
1.223 djm 1059: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1060: switch (sockets[i].type) {
1061: case AUTH_SOCKET:
1.231 djm 1062: if (npfd > maxfds) {
1063: debug3("out of fds (active %zu >= limit %u); "
1064: "skipping arming listener", npfd, maxfds);
1065: break;
1066: }
1067: pfd[j].fd = sockets[i].fd;
1068: pfd[j].revents = 0;
1069: pfd[j].events = POLLIN;
1070: j++;
1071: break;
1.46 markus 1072: case AUTH_CONNECTION:
1.223 djm 1073: pfd[j].fd = sockets[i].fd;
1074: pfd[j].revents = 0;
1.233 djm 1075: /*
1076: * Only prepare to read if we can handle a full-size
1077: * input read buffer and enqueue a max size reply..
1078: */
1079: if ((r = sshbuf_check_reserve(sockets[i].input,
1080: AGENT_RBUF_LEN)) == 0 &&
1081: (r = sshbuf_check_reserve(sockets[i].output,
1082: AGENT_MAX_LEN)) == 0)
1083: pfd[j].events = POLLIN;
1084: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1085: fatal("%s: buffer error: %s",
1086: __func__, ssh_err(r));
1087: }
1.194 markus 1088: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1089: pfd[j].events |= POLLOUT;
1090: j++;
1.46 markus 1091: break;
1092: default:
1093: break;
1094: }
1095: }
1.155 dtucker 1096: deadline = reaper();
1097: if (parent_alive_interval != 0)
1098: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1099: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1100: if (deadline == 0) {
1.224 djm 1101: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1102: } else {
1.223 djm 1103: if (deadline > INT_MAX / 1000)
1104: *timeoutp = INT_MAX / 1000;
1105: else
1106: *timeoutp = deadline * 1000;
1.155 dtucker 1107: }
1.46 markus 1108: return (1);
1.21 markus 1109: }
1110:
1.55 itojun 1111: static void
1.113 markus 1112: cleanup_socket(void)
1.15 markus 1113: {
1.187 djm 1114: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1115: return;
1116: debug("%s: cleanup", __func__);
1.48 deraadt 1117: if (socket_name[0])
1118: unlink(socket_name);
1119: if (socket_dir[0])
1120: rmdir(socket_dir);
1.10 markus 1121: }
1122:
1.114 markus 1123: void
1.15 markus 1124: cleanup_exit(int i)
1125: {
1.113 markus 1126: cleanup_socket();
1127: _exit(i);
1.15 markus 1128: }
1129:
1.135 deraadt 1130: /*ARGSUSED*/
1.55 itojun 1131: static void
1.48 deraadt 1132: cleanup_handler(int sig)
1133: {
1.113 markus 1134: cleanup_socket();
1.163 markus 1135: #ifdef ENABLE_PKCS11
1136: pkcs11_terminate();
1137: #endif
1.48 deraadt 1138: _exit(2);
1.113 markus 1139: }
1140:
1.68 markus 1141: static void
1.155 dtucker 1142: check_parent_exists(void)
1.68 markus 1143: {
1.172 dtucker 1144: /*
1145: * If our parent has exited then getppid() will return (pid_t)1,
1146: * so testing for that should be safe.
1147: */
1148: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1149: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1150: cleanup_socket();
1151: _exit(2);
1.68 markus 1152: }
1.48 deraadt 1153: }
1154:
1.55 itojun 1155: static void
1.50 itojun 1156: usage(void)
1.15 markus 1157: {
1.184 deraadt 1158: fprintf(stderr,
1.250 jmc 1159: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1160: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1161: " ssh-agent [-c | -s] -k\n");
1.21 markus 1162: exit(1);
1.15 markus 1163: }
1164:
1.2 provos 1165: int
1166: main(int ac, char **av)
1.1 deraadt 1167: {
1.201 djm 1168: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1169: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1170: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1171: struct rlimit rlim;
1.96 deraadt 1172: extern int optind;
1.98 stevesk 1173: extern char *optarg;
1.21 markus 1174: pid_t pid;
1.96 deraadt 1175: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1176: size_t len;
1.189 djm 1177: mode_t prev_mask;
1.224 djm 1178: int timeout = -1; /* INFTIM */
1.223 djm 1179: struct pollfd *pfd = NULL;
1180: size_t npfd = 0;
1.231 djm 1181: u_int maxfds;
1.123 djm 1182:
1183: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1184: sanitise_stdfd();
1.99 markus 1185:
1186: /* drop */
1187: setegid(getgid());
1188: setgid(getgid());
1.53 markus 1189:
1.231 djm 1190: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1191: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1192:
1.185 markus 1193: #ifdef WITH_OPENSSL
1.170 djm 1194: OpenSSL_add_all_algorithms();
1.185 markus 1195: #endif
1.21 markus 1196:
1.215 djm 1197: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1198: switch (ch) {
1.192 djm 1199: case 'E':
1200: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1201: if (fingerprint_hash == -1)
1202: fatal("Invalid hash algorithm \"%s\"", optarg);
1203: break;
1.21 markus 1204: case 'c':
1205: if (s_flag)
1206: usage();
1207: c_flag++;
1208: break;
1209: case 'k':
1210: k_flag++;
1211: break;
1.215 djm 1212: case 'P':
1.238 djm 1213: if (provider_whitelist != NULL)
1.215 djm 1214: fatal("-P option already specified");
1.238 djm 1215: provider_whitelist = xstrdup(optarg);
1.215 djm 1216: break;
1.21 markus 1217: case 's':
1218: if (c_flag)
1219: usage();
1220: s_flag++;
1221: break;
1.57 markus 1222: case 'd':
1.201 djm 1223: if (d_flag || D_flag)
1.57 markus 1224: usage();
1225: d_flag++;
1226: break;
1.201 djm 1227: case 'D':
1228: if (d_flag || D_flag)
1229: usage();
1230: D_flag++;
1231: break;
1.86 markus 1232: case 'a':
1233: agentsocket = optarg;
1.106 marc 1234: break;
1235: case 't':
1236: if ((lifetime = convtime(optarg)) == -1) {
1237: fprintf(stderr, "Invalid lifetime\n");
1238: usage();
1239: }
1.86 markus 1240: break;
1.21 markus 1241: default:
1242: usage();
1243: }
1244: }
1245: ac -= optind;
1246: av += optind;
1247:
1.201 djm 1248: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1249: usage();
1250:
1.238 djm 1251: if (provider_whitelist == NULL)
1252: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1253:
1.85 markus 1254: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1255: shell = getenv("SHELL");
1.161 tobias 1256: if (shell != NULL && (len = strlen(shell)) > 2 &&
1257: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1258: c_flag = 1;
1259: }
1260: if (k_flag) {
1.136 deraadt 1261: const char *errstr = NULL;
1262:
1.21 markus 1263: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1264: if (pidstr == NULL) {
1265: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1266: SSH_AGENTPID_ENV_NAME);
1.21 markus 1267: exit(1);
1268: }
1.136 deraadt 1269: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1270: if (errstr) {
1271: fprintf(stderr,
1272: "%s=\"%s\", which is not a good PID: %s\n",
1273: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1274: exit(1);
1275: }
1276: if (kill(pid, SIGTERM) == -1) {
1277: perror("kill");
1278: exit(1);
1279: }
1280: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1281: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1282: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1283: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1284: exit(0);
1285: }
1.231 djm 1286:
1287: /*
1288: * Minimum file descriptors:
1289: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1290: * a few spare for libc / stack protectors / sanitisers, etc.
1291: */
1292: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1293: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1294: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1295: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1296: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1297:
1.21 markus 1298: parent_pid = getpid();
1299:
1.86 markus 1300: if (agentsocket == NULL) {
1301: /* Create private directory for agent socket */
1.171 djm 1302: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1303: if (mkdtemp(socket_dir) == NULL) {
1304: perror("mkdtemp: private socket dir");
1305: exit(1);
1306: }
1.91 mpech 1307: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1308: (long)parent_pid);
1.86 markus 1309: } else {
1310: /* Try to use specified agent socket */
1311: socket_dir[0] = '\0';
1312: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1313: }
1314:
1.23 markus 1315: /*
1316: * Create socket early so it will exist before command gets run from
1317: * the parent.
1318: */
1.189 djm 1319: prev_mask = umask(0177);
1.188 millert 1320: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1321: if (sock < 0) {
1.188 millert 1322: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1323: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1324: cleanup_exit(1);
1325: }
1.189 djm 1326: umask(prev_mask);
1.46 markus 1327:
1.23 markus 1328: /*
1329: * Fork, and have the parent execute the command, if any, or present
1330: * the socket data. The child continues as the authentication agent.
1331: */
1.201 djm 1332: if (D_flag || d_flag) {
1333: log_init(__progname,
1334: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1335: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1336: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1337: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1338: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1339: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1340: fflush(stdout);
1.57 markus 1341: goto skip;
1342: }
1.21 markus 1343: pid = fork();
1344: if (pid == -1) {
1345: perror("fork");
1.81 stevesk 1346: cleanup_exit(1);
1.21 markus 1347: }
1348: if (pid != 0) { /* Parent - execute the given command. */
1349: close(sock);
1.91 mpech 1350: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1351: if (ac == 0) {
1352: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1353: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1354: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1355: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1356: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1357: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1358: exit(0);
1359: }
1.36 deraadt 1360: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1361: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1362: perror("setenv");
1363: exit(1);
1364: }
1.21 markus 1365: execvp(av[0], av);
1366: perror(av[0]);
1367: exit(1);
1368: }
1.81 stevesk 1369: /* child */
1370: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1371:
1372: if (setsid() == -1) {
1.81 stevesk 1373: error("setsid: %s", strerror(errno));
1.67 stevesk 1374: cleanup_exit(1);
1375: }
1376:
1377: (void)chdir("/");
1.107 markus 1378: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1379: /* XXX might close listen socket */
1380: (void)dup2(fd, STDIN_FILENO);
1381: (void)dup2(fd, STDOUT_FILENO);
1382: (void)dup2(fd, STDERR_FILENO);
1383: if (fd > 2)
1384: close(fd);
1385: }
1.21 markus 1386:
1.41 markus 1387: /* deny core dumps, since memory contains unencrypted private keys */
1388: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1389: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1390: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1391: cleanup_exit(1);
1392: }
1.57 markus 1393:
1394: skip:
1.187 djm 1395:
1396: cleanup_pid = getpid();
1.163 markus 1397:
1398: #ifdef ENABLE_PKCS11
1399: pkcs11_init(0);
1400: #endif
1.21 markus 1401: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1402: if (ac > 0)
1403: parent_alive_interval = 10;
1.33 markus 1404: idtab_init();
1.252 dtucker 1405: ssh_signal(SIGPIPE, SIG_IGN);
1406: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1407: ssh_signal(SIGHUP, cleanup_handler);
1408: ssh_signal(SIGTERM, cleanup_handler);
1.205 djm 1409:
1.215 djm 1410: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1411: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1412:
1.21 markus 1413: while (1) {
1.231 djm 1414: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1415: result = poll(pfd, npfd, timeout);
1.154 dtucker 1416: saved_errno = errno;
1.155 dtucker 1417: if (parent_alive_interval != 0)
1418: check_parent_exists();
1419: (void) reaper(); /* remove expired keys */
1.237 deraadt 1420: if (result == -1) {
1.154 dtucker 1421: if (saved_errno == EINTR)
1.21 markus 1422: continue;
1.223 djm 1423: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1424: } else if (result > 0)
1.231 djm 1425: after_poll(pfd, npfd, maxfds);
1.15 markus 1426: }
1.21 markus 1427: /* NOTREACHED */
1.1 deraadt 1428: }
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