Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.238
1.238 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.237 2019/06/28 13:35:04 deraadt 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>
1.196 deraadt 58: #include <limits.h>
1.145 stevesk 59: #include <time.h>
1.144 stevesk 60: #include <unistd.h>
1.203 dtucker 61: #include <util.h>
1.194 markus 62:
1.151 deraadt 63: #include "xmalloc.h"
1.1 deraadt 64: #include "ssh.h"
1.194 markus 65: #include "sshbuf.h"
66: #include "sshkey.h"
1.32 markus 67: #include "authfd.h"
1.37 markus 68: #include "compat.h"
1.47 markus 69: #include "log.h"
1.107 markus 70: #include "misc.h"
1.182 markus 71: #include "digest.h"
1.194 markus 72: #include "ssherr.h"
1.215 djm 73: #include "match.h"
1.238 ! djm 74: #include "msg.h"
! 75: #include "pathnames.h"
1.163 markus 76: #include "ssh-pkcs11.h"
1.238 ! djm 77: #include "ssh-sk.h"
1.59 markus 78:
1.238 ! djm 79: #ifndef DEFAULT_PROVIDER_WHITELIST
! 80: # define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 81: #endif
82:
1.223 djm 83: /* Maximum accepted message length */
84: #define AGENT_MAX_LEN (256*1024)
1.233 djm 85: /* Maximum bytes to read from client socket */
86: #define AGENT_RBUF_LEN (4096)
1.223 djm 87:
1.73 stevesk 88: typedef enum {
89: AUTH_UNUSED,
90: AUTH_SOCKET,
91: AUTH_CONNECTION
92: } sock_type;
93:
1.21 markus 94: typedef struct {
95: int fd;
1.73 stevesk 96: sock_type type;
1.194 markus 97: struct sshbuf *input;
98: struct sshbuf *output;
99: struct sshbuf *request;
1.1 deraadt 100: } SocketEntry;
101:
1.45 markus 102: u_int sockets_alloc = 0;
1.1 deraadt 103: SocketEntry *sockets = NULL;
104:
1.78 provos 105: typedef struct identity {
106: TAILQ_ENTRY(identity) next;
1.194 markus 107: struct sshkey *key;
1.21 markus 108: char *comment;
1.163 markus 109: char *provider;
1.174 dtucker 110: time_t death;
1.107 markus 111: u_int confirm;
1.238 ! djm 112: char *sk_provider;
1.1 deraadt 113: } Identity;
114:
1.221 djm 115: struct idtable {
1.33 markus 116: int nentries;
1.78 provos 117: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 118: };
1.33 markus 119:
1.221 djm 120: /* private key table */
121: struct idtable *idtab;
1.1 deraadt 122:
123: int max_fd = 0;
124:
1.11 markus 125: /* pid of shell == parent of agent */
1.29 deraadt 126: pid_t parent_pid = -1;
1.176 dtucker 127: time_t parent_alive_interval = 0;
1.10 markus 128:
1.187 djm 129: /* pid of process for which cleanup_socket is applicable */
130: pid_t cleanup_pid = 0;
131:
1.10 markus 132: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 133: char socket_name[PATH_MAX];
134: char socket_dir[PATH_MAX];
1.10 markus 135:
1.238 ! djm 136: /* PKCS#11/Security key path whitelist */
! 137: static char *provider_whitelist;
1.215 djm 138:
1.88 markus 139: /* locking */
1.203 dtucker 140: #define LOCK_SIZE 32
141: #define LOCK_SALT_SIZE 16
142: #define LOCK_ROUNDS 1
1.88 markus 143: int locked = 0;
1.213 djm 144: u_char lock_pwhash[LOCK_SIZE];
145: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 146:
1.20 markus 147: extern char *__progname;
148:
1.174 dtucker 149: /* Default lifetime in seconds (0 == forever) */
150: static long lifetime = 0;
1.106 marc 151:
1.192 djm 152: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
153:
1.55 itojun 154: static void
1.101 stevesk 155: close_socket(SocketEntry *e)
156: {
157: close(e->fd);
158: e->fd = -1;
159: e->type = AUTH_UNUSED;
1.194 markus 160: sshbuf_free(e->input);
161: sshbuf_free(e->output);
162: sshbuf_free(e->request);
1.101 stevesk 163: }
164:
165: static void
1.33 markus 166: idtab_init(void)
1.1 deraadt 167: {
1.221 djm 168: idtab = xcalloc(1, sizeof(*idtab));
169: TAILQ_INIT(&idtab->idlist);
170: idtab->nentries = 0;
1.33 markus 171: }
172:
1.89 markus 173: static void
174: free_identity(Identity *id)
175: {
1.194 markus 176: sshkey_free(id->key);
1.173 djm 177: free(id->provider);
178: free(id->comment);
1.238 ! djm 179: free(id->sk_provider);
1.173 djm 180: free(id);
1.89 markus 181: }
182:
1.33 markus 183: /* return matching private key for given public key */
1.78 provos 184: static Identity *
1.221 djm 185: lookup_identity(struct sshkey *key)
1.33 markus 186: {
1.78 provos 187: Identity *id;
188:
1.221 djm 189: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 190: if (sshkey_equal(key, id->key))
1.78 provos 191: return (id);
1.33 markus 192: }
1.78 provos 193: return (NULL);
194: }
195:
1.107 markus 196: /* Check confirmation of keysign request */
197: static int
198: confirm_key(Identity *id)
199: {
1.122 djm 200: char *p;
1.107 markus 201: int ret = -1;
202:
1.194 markus 203: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 204: if (p != NULL &&
205: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 206: id->comment, p))
207: ret = 0;
1.173 djm 208: free(p);
1.122 djm 209:
1.107 markus 210: return (ret);
211: }
212:
1.194 markus 213: static void
214: send_status(SocketEntry *e, int success)
215: {
216: int r;
217:
218: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
219: (r = sshbuf_put_u8(e->output, success ?
220: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
221: fatal("%s: buffer error: %s", __func__, ssh_err(r));
222: }
223:
1.33 markus 224: /* send list of supported public keys to 'client' */
1.55 itojun 225: static void
1.221 djm 226: process_request_identities(SocketEntry *e)
1.33 markus 227: {
1.96 deraadt 228: Identity *id;
1.194 markus 229: struct sshbuf *msg;
230: int r;
1.1 deraadt 231:
1.194 markus 232: if ((msg = sshbuf_new()) == NULL)
233: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 234: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
235: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
236: fatal("%s: buffer error: %s", __func__, ssh_err(r));
237: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 238: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
239: != 0 ||
1.221 djm 240: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
241: error("%s: put key/comment: %s", __func__,
1.220 djm 242: ssh_err(r));
243: continue;
1.33 markus 244: }
1.21 markus 245: }
1.194 markus 246: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
247: fatal("%s: buffer error: %s", __func__, ssh_err(r));
248: sshbuf_free(msg);
1.1 deraadt 249: }
250:
1.33 markus 251:
1.208 markus 252: static char *
253: agent_decode_alg(struct sshkey *key, u_int flags)
254: {
255: if (key->type == KEY_RSA) {
256: if (flags & SSH_AGENT_RSA_SHA2_256)
257: return "rsa-sha2-256";
258: else if (flags & SSH_AGENT_RSA_SHA2_512)
259: return "rsa-sha2-512";
1.235 djm 260: } else if (key->type == KEY_RSA_CERT) {
261: if (flags & SSH_AGENT_RSA_SHA2_256)
262: return "rsa-sha2-256-cert-v01@openssh.com";
263: else if (flags & SSH_AGENT_RSA_SHA2_512)
264: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 265: }
266: return NULL;
267: }
268:
1.238 ! djm 269: static int
! 270: provider_sign(const char *provider, struct sshkey *key,
! 271: u_char **sigp, size_t *lenp,
! 272: const u_char *data, size_t datalen,
! 273: const char *alg, u_int compat)
! 274: {
! 275: int status, pair[2], r = SSH_ERR_INTERNAL_ERROR;
! 276: pid_t pid;
! 277: char *helper, *verbosity = NULL;
! 278: struct sshbuf *kbuf, *req, *resp;
! 279: u_char version;
! 280:
! 281: debug3("%s: start for provider %s", __func__, provider);
! 282:
! 283: *sigp = NULL;
! 284: *lenp = 0;
! 285:
! 286: helper = getenv("SSH_SK_HELPER");
! 287: if (helper == NULL || strlen(helper) == 0)
! 288: helper = _PATH_SSH_SK_HELPER;
! 289: if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
! 290: verbosity = "-vvv";
! 291:
! 292: /* Start helper */
! 293: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
! 294: error("socketpair: %s", strerror(errno));
! 295: return SSH_ERR_SYSTEM_ERROR;
! 296: }
! 297: if ((pid = fork()) == -1) {
! 298: error("fork: %s", strerror(errno));
! 299: close(pair[0]);
! 300: close(pair[1]);
! 301: return SSH_ERR_SYSTEM_ERROR;
! 302: }
! 303: if (pid == 0) {
! 304: if ((dup2(pair[1], STDIN_FILENO) == -1) ||
! 305: (dup2(pair[1], STDOUT_FILENO) == -1))
! 306: fatal("%s: dup2: %s", __func__, ssh_err(r));
! 307: close(pair[0]);
! 308: close(pair[1]);
! 309: closefrom(STDERR_FILENO + 1);
! 310: debug("%s: starting %s %s", __func__, helper,
! 311: verbosity == NULL ? "" : verbosity);
! 312: execlp(helper, helper, verbosity, (char *)NULL);
! 313: fatal("%s: execlp: %s", __func__, strerror(errno));
! 314: }
! 315: close(pair[1]);
! 316:
! 317: if ((kbuf = sshbuf_new()) == NULL ||
! 318: (req = sshbuf_new()) == NULL ||
! 319: (resp = sshbuf_new()) == NULL)
! 320: fatal("%s: sshbuf_new failed", __func__);
! 321:
! 322: if ((r = sshkey_private_serialize(key, kbuf)) != 0 ||
! 323: (r = sshbuf_put_stringb(req, kbuf)) != 0 ||
! 324: (r = sshbuf_put_cstring(req, provider)) != 0 ||
! 325: (r = sshbuf_put_string(req, data, datalen)) != 0 ||
! 326: (r = sshbuf_put_u32(req, compat)) != 0)
! 327: fatal("%s: compose: %s", __func__, ssh_err(r));
! 328: if ((r = ssh_msg_send(pair[0], SSH_SK_HELPER_VERSION, req)) != 0) {
! 329: error("%s: send: %s", __func__, ssh_err(r));
! 330: goto out;
! 331: }
! 332: if ((r = ssh_msg_recv(pair[0], resp)) != 0) {
! 333: error("%s: receive: %s", __func__, ssh_err(r));
! 334: goto out;
! 335: }
! 336: if ((r = sshbuf_get_u8(resp, &version)) != 0) {
! 337: error("%s: parse version: %s", __func__, ssh_err(r));
! 338: goto out;
! 339: }
! 340: if (version != SSH_SK_HELPER_VERSION) {
! 341: error("%s: unsupported version: got %u, expected %u",
! 342: __func__, version, SSH_SK_HELPER_VERSION);
! 343: r = SSH_ERR_INVALID_FORMAT;
! 344: goto out;
! 345: }
! 346: if ((r = sshbuf_get_string(resp, sigp, lenp)) != 0) {
! 347: error("%s: parse signature: %s", __func__, ssh_err(r));
! 348: r = SSH_ERR_INVALID_FORMAT;
! 349: goto out;
! 350: }
! 351: if (sshbuf_len(resp) != 0) {
! 352: error("%s: trailing data in response", __func__);
! 353: r = SSH_ERR_INVALID_FORMAT;
! 354: goto out;
! 355: }
! 356: /* success */
! 357: r = 0;
! 358: out:
! 359: while (waitpid(pid, &status, 0) == -1) {
! 360: if (errno != EINTR)
! 361: fatal("%s: waitpid: %s", __func__, ssh_err(r));
! 362: }
! 363: if (!WIFEXITED(status)) {
! 364: error("%s: helper %s exited abnormally", __func__, helper);
! 365: if (r == 0)
! 366: r = SSH_ERR_SYSTEM_ERROR;
! 367: } else if (WEXITSTATUS(status) != 0) {
! 368: error("%s: helper %s exited with non-zero exit status",
! 369: __func__, helper);
! 370: if (r == 0)
! 371: r = SSH_ERR_SYSTEM_ERROR;
! 372: }
! 373: if (r != 0) {
! 374: freezero(*sigp, *lenp);
! 375: *sigp = NULL;
! 376: *lenp = 0;
! 377: }
! 378: sshbuf_free(kbuf);
! 379: sshbuf_free(req);
! 380: sshbuf_free(resp);
! 381: return r;
! 382: }
! 383:
1.33 markus 384: /* ssh2 only */
1.55 itojun 385: static void
1.33 markus 386: process_sign_request2(SocketEntry *e)
387: {
1.221 djm 388: const u_char *data;
389: u_char *signature = NULL;
390: size_t dlen, slen = 0;
1.194 markus 391: u_int compat = 0, flags;
392: int r, ok = -1;
393: struct sshbuf *msg;
1.221 djm 394: struct sshkey *key = NULL;
1.195 djm 395: struct identity *id;
1.194 markus 396:
1.195 djm 397: if ((msg = sshbuf_new()) == NULL)
398: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 399: if ((r = sshkey_froms(e->request, &key)) != 0 ||
400: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 401: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
402: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
403: goto send;
404: }
405:
1.221 djm 406: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 407: verbose("%s: %s key not found", __func__, sshkey_type(key));
408: goto send;
409: }
410: if (id->confirm && confirm_key(id) != 0) {
411: verbose("%s: user refused key", __func__);
412: goto send;
413: }
1.238 ! djm 414: if (id->sk_provider != NULL) {
! 415: if ((r = provider_sign(id->sk_provider, id->key, &signature,
! 416: &slen, data, dlen, agent_decode_alg(key, flags),
! 417: compat)) != 0) {
! 418: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
! 419: goto send;
! 420: }
! 421: } else {
! 422: if ((r = sshkey_sign(id->key, &signature, &slen,
! 423: data, dlen, agent_decode_alg(key, flags), compat)) != 0) {
! 424: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
! 425: goto send;
! 426: }
1.33 markus 427: }
1.195 djm 428: /* Success */
429: ok = 0;
430: send:
431: sshkey_free(key);
1.33 markus 432: if (ok == 0) {
1.194 markus 433: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
434: (r = sshbuf_put_string(msg, signature, slen)) != 0)
435: fatal("%s: buffer error: %s", __func__, ssh_err(r));
436: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
437: fatal("%s: buffer error: %s", __func__, ssh_err(r));
438:
439: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
440: fatal("%s: buffer error: %s", __func__, ssh_err(r));
441:
442: sshbuf_free(msg);
1.173 djm 443: free(signature);
1.1 deraadt 444: }
445:
1.33 markus 446: /* shared */
1.55 itojun 447: static void
1.221 djm 448: process_remove_identity(SocketEntry *e)
1.1 deraadt 449: {
1.194 markus 450: int r, success = 0;
451: struct sshkey *key = NULL;
1.221 djm 452: Identity *id;
1.21 markus 453:
1.221 djm 454: if ((r = sshkey_froms(e->request, &key)) != 0) {
455: error("%s: get key: %s", __func__, ssh_err(r));
456: goto done;
457: }
458: if ((id = lookup_identity(key)) == NULL) {
459: debug("%s: key not found", __func__);
460: goto done;
461: }
462: /* We have this key, free it. */
463: if (idtab->nentries < 1)
464: fatal("%s: internal error: nentries %d",
465: __func__, idtab->nentries);
466: TAILQ_REMOVE(&idtab->idlist, id, next);
467: free_identity(id);
468: idtab->nentries--;
469: sshkey_free(key);
470: success = 1;
471: done:
1.194 markus 472: send_status(e, success);
1.1 deraadt 473: }
474:
1.55 itojun 475: static void
1.221 djm 476: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 477: {
1.78 provos 478: Identity *id;
1.21 markus 479:
480: /* Loop over all identities and clear the keys. */
1.221 djm 481: for (id = TAILQ_FIRST(&idtab->idlist); id;
482: id = TAILQ_FIRST(&idtab->idlist)) {
483: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 484: free_identity(id);
1.21 markus 485: }
486:
487: /* Mark that there are no identities. */
1.221 djm 488: idtab->nentries = 0;
1.21 markus 489:
490: /* Send success. */
1.194 markus 491: send_status(e, 1);
1.1 deraadt 492: }
493:
1.155 dtucker 494: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 495: static time_t
1.89 markus 496: reaper(void)
497: {
1.175 dtucker 498: time_t deadline = 0, now = monotime();
1.89 markus 499: Identity *id, *nxt;
500:
1.221 djm 501: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
502: nxt = TAILQ_NEXT(id, next);
503: if (id->death == 0)
504: continue;
505: if (now >= id->death) {
506: debug("expiring key '%s'", id->comment);
507: TAILQ_REMOVE(&idtab->idlist, id, next);
508: free_identity(id);
509: idtab->nentries--;
510: } else
511: deadline = (deadline == 0) ? id->death :
512: MINIMUM(deadline, id->death);
1.89 markus 513: }
1.155 dtucker 514: if (deadline == 0 || deadline <= now)
515: return 0;
516: else
517: return (deadline - now);
1.89 markus 518: }
519:
520: static void
1.221 djm 521: process_add_identity(SocketEntry *e)
1.1 deraadt 522: {
1.157 canacar 523: Identity *id;
1.194 markus 524: int success = 0, confirm = 0;
1.228 markus 525: u_int seconds, maxsign;
1.238 ! djm 526: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 527: time_t death = 0;
1.194 markus 528: struct sshkey *k = NULL;
529: u_char ctype;
530: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 531:
1.221 djm 532: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
533: k == NULL ||
1.194 markus 534: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
535: error("%s: decode private key: %s", __func__, ssh_err(r));
536: goto err;
537: }
1.236 djm 538: if ((r = sshkey_shield_private(k)) != 0) {
539: error("%s: shield private key: %s", __func__, ssh_err(r));
540: goto err;
541: }
1.194 markus 542: while (sshbuf_len(e->request)) {
543: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
544: error("%s: buffer error: %s", __func__, ssh_err(r));
545: goto err;
546: }
547: switch (ctype) {
1.94 markus 548: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 549: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
550: error("%s: bad lifetime constraint: %s",
551: __func__, ssh_err(r));
552: goto err;
553: }
554: death = monotime() + seconds;
1.94 markus 555: break;
1.107 markus 556: case SSH_AGENT_CONSTRAIN_CONFIRM:
557: confirm = 1;
558: break;
1.228 markus 559: case SSH_AGENT_CONSTRAIN_MAXSIGN:
560: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
561: error("%s: bad maxsign constraint: %s",
562: __func__, ssh_err(r));
563: goto err;
564: }
565: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
566: error("%s: cannot enable maxsign: %s",
567: __func__, ssh_err(r));
568: goto err;
569: }
570: break;
1.238 ! djm 571: case SSH_AGENT_CONSTRAIN_EXTENSION:
! 572: if ((r = sshbuf_get_cstring(e->request,
! 573: &ext_name, NULL)) != 0) {
! 574: error("%s: cannot parse extension: %s",
! 575: __func__, ssh_err(r));
! 576: goto err;
! 577: }
! 578: debug("%s: constraint ext %s", __func__, ext_name);
! 579: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
! 580: if (sk_provider != NULL) {
! 581: error("%s already set", ext_name);
! 582: goto err;
! 583: }
! 584: if ((r = sshbuf_get_cstring(e->request,
! 585: &sk_provider, NULL)) != 0) {
! 586: error("%s: cannot parse %s: %s",
! 587: __func__, ext_name, ssh_err(r));
! 588: goto err;
! 589: }
! 590: } else {
! 591: error("%s: unsupported constraint \"%s\"",
! 592: __func__, ext_name);
! 593: goto err;
! 594: }
! 595: free(ext_name);
! 596: break;
1.94 markus 597: default:
1.194 markus 598: error("%s: Unknown constraint %d", __func__, ctype);
599: err:
1.238 ! djm 600: free(sk_provider);
! 601: free(ext_name);
1.194 markus 602: sshbuf_reset(e->request);
1.173 djm 603: free(comment);
1.194 markus 604: sshkey_free(k);
1.158 djm 605: goto send;
1.94 markus 606: }
607: }
1.238 ! djm 608: if (sk_provider != NULL) {
! 609: if (sshkey_type_plain(k->type) != KEY_ECDSA_SK) {
! 610: error("Cannot add provider: %s is not a security key",
! 611: sshkey_type(k));
! 612: free(sk_provider);
! 613: goto send;
! 614: }
! 615: if (match_pattern_list(sk_provider,
! 616: provider_whitelist, 0) != 1) {
! 617: error("Refusing add key: provider %s not whitelisted",
! 618: sk_provider);
! 619: free(sk_provider);
! 620: goto send;
! 621: }
! 622: }
1.194 markus 623:
1.158 djm 624: success = 1;
1.106 marc 625: if (lifetime && !death)
1.175 dtucker 626: death = monotime() + lifetime;
1.221 djm 627: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 628: id = xcalloc(1, sizeof(Identity));
1.221 djm 629: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 630: /* Increment the number of identities. */
1.221 djm 631: idtab->nentries++;
1.33 markus 632: } else {
1.228 markus 633: /* key state might have been updated */
634: sshkey_free(id->key);
1.173 djm 635: free(id->comment);
1.238 ! djm 636: free(id->sk_provider);
1.33 markus 637: }
1.228 markus 638: id->key = k;
1.157 canacar 639: id->comment = comment;
640: id->death = death;
641: id->confirm = confirm;
1.238 ! djm 642: id->sk_provider = sk_provider;
! 643:
! 644: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
! 645: SSH_FP_DEFAULT)) == NULL)
! 646: fatal("%s: sshkey_fingerprint failed", __func__);
! 647: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
! 648: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
! 649: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
! 650: free(fp);
1.33 markus 651: send:
1.194 markus 652: send_status(e, success);
1.1 deraadt 653: }
654:
1.88 markus 655: /* XXX todo: encrypt sensitive data with passphrase */
656: static void
657: process_lock_agent(SocketEntry *e, int lock)
658: {
1.203 dtucker 659: int r, success = 0, delay;
1.213 djm 660: char *passwd;
661: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 662: static u_int fail_count = 0;
663: size_t pwlen;
664:
1.226 djm 665: /*
666: * This is deliberately fatal: the user has requested that we lock,
667: * but we can't parse their request properly. The only safe thing to
668: * do is abort.
669: */
1.203 dtucker 670: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
671: fatal("%s: buffer error: %s", __func__, ssh_err(r));
672: if (pwlen == 0) {
673: debug("empty password not supported");
674: } else if (locked && !lock) {
675: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
676: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
677: fatal("bcrypt_pbkdf");
1.213 djm 678: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 679: debug("agent unlocked");
680: locked = 0;
681: fail_count = 0;
1.213 djm 682: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 683: success = 1;
684: } else {
685: /* delay in 0.1s increments up to 10s */
686: if (fail_count < 100)
687: fail_count++;
688: delay = 100000 * fail_count;
689: debug("unlock failed, delaying %0.1lf seconds",
690: (double)delay/1000000);
691: usleep(delay);
692: }
693: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 694: } else if (!locked && lock) {
1.203 dtucker 695: debug("agent locked");
1.88 markus 696: locked = 1;
1.203 dtucker 697: arc4random_buf(lock_salt, sizeof(lock_salt));
698: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 699: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 700: fatal("bcrypt_pbkdf");
1.88 markus 701: success = 1;
702: }
1.203 dtucker 703: explicit_bzero(passwd, pwlen);
1.173 djm 704: free(passwd);
1.194 markus 705: send_status(e, success);
1.88 markus 706: }
707:
708: static void
1.221 djm 709: no_identities(SocketEntry *e)
1.88 markus 710: {
1.194 markus 711: struct sshbuf *msg;
712: int r;
1.88 markus 713:
1.194 markus 714: if ((msg = sshbuf_new()) == NULL)
715: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 716: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 717: (r = sshbuf_put_u32(msg, 0)) != 0 ||
718: (r = sshbuf_put_stringb(e->output, msg)) != 0)
719: fatal("%s: buffer error: %s", __func__, ssh_err(r));
720: sshbuf_free(msg);
1.88 markus 721: }
1.59 markus 722:
1.163 markus 723: #ifdef ENABLE_PKCS11
1.59 markus 724: static void
1.158 djm 725: process_add_smartcard_key(SocketEntry *e)
1.59 markus 726: {
1.226 djm 727: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 728: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 729: u_int seconds;
1.174 dtucker 730: time_t death = 0;
1.194 markus 731: u_char type;
732: struct sshkey **keys = NULL, *k;
1.84 markus 733: Identity *id;
1.75 deraadt 734:
1.194 markus 735: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 736: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
737: error("%s: buffer error: %s", __func__, ssh_err(r));
738: goto send;
739: }
1.194 markus 740:
741: while (sshbuf_len(e->request)) {
1.226 djm 742: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
743: error("%s: buffer error: %s", __func__, ssh_err(r));
744: goto send;
745: }
1.194 markus 746: switch (type) {
1.110 djm 747: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 748: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
749: error("%s: buffer error: %s",
1.194 markus 750: __func__, ssh_err(r));
1.226 djm 751: goto send;
752: }
1.194 markus 753: death = monotime() + seconds;
1.110 djm 754: break;
755: case SSH_AGENT_CONSTRAIN_CONFIRM:
756: confirm = 1;
757: break;
758: default:
1.221 djm 759: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 760: goto send;
1.110 djm 761: }
762: }
1.215 djm 763: if (realpath(provider, canonical_provider) == NULL) {
764: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
765: provider, strerror(errno));
766: goto send;
767: }
1.238 ! djm 768: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 769: verbose("refusing PKCS#11 add of \"%.100s\": "
770: "provider not whitelisted", canonical_provider);
771: goto send;
772: }
773: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 774: if (lifetime && !death)
1.175 dtucker 775: death = monotime() + lifetime;
1.110 djm 776:
1.215 djm 777: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 778: for (i = 0; i < count; i++) {
1.84 markus 779: k = keys[i];
1.221 djm 780: if (lookup_identity(k) == NULL) {
1.163 markus 781: id = xcalloc(1, sizeof(Identity));
1.84 markus 782: id->key = k;
1.215 djm 783: id->provider = xstrdup(canonical_provider);
784: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 785: id->death = death;
786: id->confirm = confirm;
1.221 djm 787: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
788: idtab->nentries++;
1.84 markus 789: success = 1;
790: } else {
1.194 markus 791: sshkey_free(k);
1.84 markus 792: }
793: keys[i] = NULL;
1.59 markus 794: }
795: send:
1.173 djm 796: free(pin);
797: free(provider);
798: free(keys);
1.194 markus 799: send_status(e, success);
1.59 markus 800: }
801:
802: static void
803: process_remove_smartcard_key(SocketEntry *e)
804: {
1.217 djm 805: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 806: int r, success = 0;
1.163 markus 807: Identity *id, *nxt;
1.59 markus 808:
1.194 markus 809: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 810: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
811: error("%s: buffer error: %s", __func__, ssh_err(r));
812: goto send;
813: }
1.173 djm 814: free(pin);
1.59 markus 815:
1.217 djm 816: if (realpath(provider, canonical_provider) == NULL) {
817: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
818: provider, strerror(errno));
819: goto send;
820: }
821:
822: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 823: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
824: nxt = TAILQ_NEXT(id, next);
825: /* Skip file--based keys */
826: if (id->provider == NULL)
827: continue;
828: if (!strcmp(canonical_provider, id->provider)) {
829: TAILQ_REMOVE(&idtab->idlist, id, next);
830: free_identity(id);
831: idtab->nentries--;
1.59 markus 832: }
833: }
1.217 djm 834: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 835: success = 1;
836: else
1.221 djm 837: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 838: send:
1.173 djm 839: free(provider);
1.194 markus 840: send_status(e, success);
1.59 markus 841: }
1.163 markus 842: #endif /* ENABLE_PKCS11 */
1.59 markus 843:
1.33 markus 844: /* dispatch incoming messages */
845:
1.223 djm 846: static int
847: process_message(u_int socknum)
1.1 deraadt 848: {
1.194 markus 849: u_int msg_len;
850: u_char type;
851: const u_char *cp;
852: int r;
1.223 djm 853: SocketEntry *e;
854:
855: if (socknum >= sockets_alloc) {
856: fatal("%s: socket number %u >= allocated %u",
857: __func__, socknum, sockets_alloc);
858: }
859: e = &sockets[socknum];
1.89 markus 860:
1.194 markus 861: if (sshbuf_len(e->input) < 5)
1.223 djm 862: return 0; /* Incomplete message header. */
1.194 markus 863: cp = sshbuf_ptr(e->input);
864: msg_len = PEEK_U32(cp);
1.223 djm 865: if (msg_len > AGENT_MAX_LEN) {
866: debug("%s: socket %u (fd=%d) message too long %u > %u",
867: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
868: return -1;
1.21 markus 869: }
1.194 markus 870: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 871: return 0; /* Incomplete message body. */
1.87 markus 872:
873: /* move the current input to e->request */
1.194 markus 874: sshbuf_reset(e->request);
875: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 876: (r = sshbuf_get_u8(e->request, &type)) != 0) {
877: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
878: r == SSH_ERR_STRING_TOO_LARGE) {
879: debug("%s: buffer error: %s", __func__, ssh_err(r));
880: return -1;
881: }
1.194 markus 882: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 883: }
884:
885: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 886:
1.230 djm 887: /* check whether agent is locked */
1.88 markus 888: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 889: sshbuf_reset(e->request);
1.88 markus 890: switch (type) {
891: case SSH2_AGENTC_REQUEST_IDENTITIES:
892: /* send empty lists */
1.221 djm 893: no_identities(e);
1.88 markus 894: break;
895: default:
896: /* send a fail message for all other request types */
1.194 markus 897: send_status(e, 0);
1.88 markus 898: }
1.223 djm 899: return 0;
1.88 markus 900: }
901:
1.21 markus 902: switch (type) {
1.88 markus 903: case SSH_AGENTC_LOCK:
904: case SSH_AGENTC_UNLOCK:
905: process_lock_agent(e, type == SSH_AGENTC_LOCK);
906: break;
1.21 markus 907: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 908: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 909: break;
910: /* ssh2 */
911: case SSH2_AGENTC_SIGN_REQUEST:
912: process_sign_request2(e);
913: break;
914: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 915: process_request_identities(e);
1.33 markus 916: break;
917: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 918: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 919: process_add_identity(e);
1.33 markus 920: break;
921: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 922: process_remove_identity(e);
1.33 markus 923: break;
924: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 925: process_remove_all_identities(e);
1.21 markus 926: break;
1.163 markus 927: #ifdef ENABLE_PKCS11
1.59 markus 928: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 929: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 930: process_add_smartcard_key(e);
1.75 deraadt 931: break;
1.59 markus 932: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
933: process_remove_smartcard_key(e);
1.75 deraadt 934: break;
1.163 markus 935: #endif /* ENABLE_PKCS11 */
1.21 markus 936: default:
937: /* Unknown message. Respond with failure. */
938: error("Unknown message %d", type);
1.194 markus 939: sshbuf_reset(e->request);
940: send_status(e, 0);
1.21 markus 941: break;
942: }
1.223 djm 943: return 0;
1.1 deraadt 944: }
945:
1.55 itojun 946: static void
1.73 stevesk 947: new_socket(sock_type type, int fd)
1.1 deraadt 948: {
1.112 markus 949: u_int i, old_alloc, new_alloc;
1.96 deraadt 950:
1.119 djm 951: set_nonblock(fd);
1.21 markus 952:
953: if (fd > max_fd)
954: max_fd = fd;
955:
956: for (i = 0; i < sockets_alloc; i++)
957: if (sockets[i].type == AUTH_UNUSED) {
958: sockets[i].fd = fd;
1.194 markus 959: if ((sockets[i].input = sshbuf_new()) == NULL)
960: fatal("%s: sshbuf_new failed", __func__);
961: if ((sockets[i].output = sshbuf_new()) == NULL)
962: fatal("%s: sshbuf_new failed", __func__);
963: if ((sockets[i].request = sshbuf_new()) == NULL)
964: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 965: sockets[i].type = type;
1.21 markus 966: return;
967: }
968: old_alloc = sockets_alloc;
1.112 markus 969: new_alloc = sockets_alloc + 10;
1.200 deraadt 970: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 971: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 972: sockets[i].type = AUTH_UNUSED;
1.112 markus 973: sockets_alloc = new_alloc;
1.21 markus 974: sockets[old_alloc].fd = fd;
1.194 markus 975: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
976: fatal("%s: sshbuf_new failed", __func__);
977: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
978: fatal("%s: sshbuf_new failed", __func__);
979: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
980: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 981: sockets[old_alloc].type = type;
1.1 deraadt 982: }
983:
1.55 itojun 984: static int
1.223 djm 985: handle_socket_read(u_int socknum)
1.1 deraadt 986: {
1.223 djm 987: struct sockaddr_un sunaddr;
988: socklen_t slen;
989: uid_t euid;
990: gid_t egid;
991: int fd;
992:
993: slen = sizeof(sunaddr);
994: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 995: if (fd == -1) {
1.223 djm 996: error("accept from AUTH_SOCKET: %s", strerror(errno));
997: return -1;
998: }
1.237 deraadt 999: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1000: error("getpeereid %d failed: %s", fd, strerror(errno));
1001: close(fd);
1002: return -1;
1003: }
1004: if ((euid != 0) && (getuid() != euid)) {
1005: error("uid mismatch: peer euid %u != uid %u",
1006: (u_int) euid, (u_int) getuid());
1007: close(fd);
1008: return -1;
1009: }
1010: new_socket(AUTH_CONNECTION, fd);
1011: return 0;
1012: }
1013:
1014: static int
1015: handle_conn_read(u_int socknum)
1016: {
1.233 djm 1017: char buf[AGENT_RBUF_LEN];
1.223 djm 1018: ssize_t len;
1019: int r;
1020:
1021: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1022: if (len == -1) {
1023: if (errno == EAGAIN || errno == EINTR)
1024: return 0;
1025: error("%s: read error on socket %u (fd %d): %s",
1026: __func__, socknum, sockets[socknum].fd,
1027: strerror(errno));
1028: }
1029: return -1;
1030: }
1031: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1032: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1033: explicit_bzero(buf, sizeof(buf));
1034: process_message(socknum);
1035: return 0;
1036: }
1037:
1038: static int
1039: handle_conn_write(u_int socknum)
1040: {
1041: ssize_t len;
1042: int r;
1043:
1044: if (sshbuf_len(sockets[socknum].output) == 0)
1045: return 0; /* shouldn't happen */
1046: if ((len = write(sockets[socknum].fd,
1047: sshbuf_ptr(sockets[socknum].output),
1048: sshbuf_len(sockets[socknum].output))) <= 0) {
1049: if (len == -1) {
1050: if (errno == EAGAIN || errno == EINTR)
1051: return 0;
1052: error("%s: read error on socket %u (fd %d): %s",
1053: __func__, socknum, sockets[socknum].fd,
1054: strerror(errno));
1055: }
1056: return -1;
1057: }
1058: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1059: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1060: return 0;
1061: }
1062:
1063: static void
1.231 djm 1064: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1065: {
1066: size_t i;
1.231 djm 1067: u_int socknum, activefds = npfd;
1.223 djm 1068:
1069: for (i = 0; i < npfd; i++) {
1070: if (pfd[i].revents == 0)
1071: continue;
1072: /* Find sockets entry */
1073: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1074: if (sockets[socknum].type != AUTH_SOCKET &&
1075: sockets[socknum].type != AUTH_CONNECTION)
1076: continue;
1077: if (pfd[i].fd == sockets[socknum].fd)
1078: break;
1079: }
1080: if (socknum >= sockets_alloc) {
1081: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1082: continue;
1083: }
1084: /* Process events */
1085: switch (sockets[socknum].type) {
1086: case AUTH_SOCKET:
1.231 djm 1087: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1088: break;
1089: if (npfd > maxfds) {
1090: debug3("out of fds (active %u >= limit %u); "
1091: "skipping accept", activefds, maxfds);
1092: break;
1093: }
1094: if (handle_socket_read(socknum) == 0)
1095: activefds++;
1.223 djm 1096: break;
1097: case AUTH_CONNECTION:
1098: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1099: handle_conn_read(socknum) != 0) {
1.231 djm 1100: goto close_sock;
1101: }
1102: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1103: handle_conn_write(socknum) != 0) {
1104: close_sock:
1105: if (activefds == 0)
1106: fatal("activefds == 0 at close_sock");
1.223 djm 1107: close_socket(&sockets[socknum]);
1.231 djm 1108: activefds--;
1.223 djm 1109: break;
1110: }
1111: break;
1112: default:
1113: break;
1114: }
1115: }
1116: }
1117:
1118: static int
1.231 djm 1119: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1120: {
1121: struct pollfd *pfd = *pfdp;
1122: size_t i, j, npfd = 0;
1.174 dtucker 1123: time_t deadline;
1.233 djm 1124: int r;
1.46 markus 1125:
1.223 djm 1126: /* Count active sockets */
1.46 markus 1127: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1128: switch (sockets[i].type) {
1129: case AUTH_SOCKET:
1130: case AUTH_CONNECTION:
1.223 djm 1131: npfd++;
1.21 markus 1132: break;
1133: case AUTH_UNUSED:
1134: break;
1135: default:
1136: fatal("Unknown socket type %d", sockets[i].type);
1137: break;
1138: }
1.46 markus 1139: }
1.223 djm 1140: if (npfd != *npfdp &&
1141: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1142: fatal("%s: recallocarray failed", __func__);
1143: *pfdp = pfd;
1144: *npfdp = npfd;
1.46 markus 1145:
1.223 djm 1146: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1147: switch (sockets[i].type) {
1148: case AUTH_SOCKET:
1.231 djm 1149: if (npfd > maxfds) {
1150: debug3("out of fds (active %zu >= limit %u); "
1151: "skipping arming listener", npfd, maxfds);
1152: break;
1153: }
1154: pfd[j].fd = sockets[i].fd;
1155: pfd[j].revents = 0;
1156: pfd[j].events = POLLIN;
1157: j++;
1158: break;
1.46 markus 1159: case AUTH_CONNECTION:
1.223 djm 1160: pfd[j].fd = sockets[i].fd;
1161: pfd[j].revents = 0;
1.233 djm 1162: /*
1163: * Only prepare to read if we can handle a full-size
1164: * input read buffer and enqueue a max size reply..
1165: */
1166: if ((r = sshbuf_check_reserve(sockets[i].input,
1167: AGENT_RBUF_LEN)) == 0 &&
1168: (r = sshbuf_check_reserve(sockets[i].output,
1169: AGENT_MAX_LEN)) == 0)
1170: pfd[j].events = POLLIN;
1171: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1172: fatal("%s: buffer error: %s",
1173: __func__, ssh_err(r));
1174: }
1.194 markus 1175: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1176: pfd[j].events |= POLLOUT;
1177: j++;
1.46 markus 1178: break;
1179: default:
1180: break;
1181: }
1182: }
1.155 dtucker 1183: deadline = reaper();
1184: if (parent_alive_interval != 0)
1185: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1186: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1187: if (deadline == 0) {
1.224 djm 1188: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1189: } else {
1.223 djm 1190: if (deadline > INT_MAX / 1000)
1191: *timeoutp = INT_MAX / 1000;
1192: else
1193: *timeoutp = deadline * 1000;
1.155 dtucker 1194: }
1.46 markus 1195: return (1);
1.21 markus 1196: }
1197:
1.55 itojun 1198: static void
1.113 markus 1199: cleanup_socket(void)
1.15 markus 1200: {
1.187 djm 1201: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1202: return;
1203: debug("%s: cleanup", __func__);
1.48 deraadt 1204: if (socket_name[0])
1205: unlink(socket_name);
1206: if (socket_dir[0])
1207: rmdir(socket_dir);
1.10 markus 1208: }
1209:
1.114 markus 1210: void
1.15 markus 1211: cleanup_exit(int i)
1212: {
1.113 markus 1213: cleanup_socket();
1214: _exit(i);
1.15 markus 1215: }
1216:
1.135 deraadt 1217: /*ARGSUSED*/
1.55 itojun 1218: static void
1.48 deraadt 1219: cleanup_handler(int sig)
1220: {
1.113 markus 1221: cleanup_socket();
1.163 markus 1222: #ifdef ENABLE_PKCS11
1223: pkcs11_terminate();
1224: #endif
1.48 deraadt 1225: _exit(2);
1.113 markus 1226: }
1227:
1.68 markus 1228: static void
1.155 dtucker 1229: check_parent_exists(void)
1.68 markus 1230: {
1.172 dtucker 1231: /*
1232: * If our parent has exited then getppid() will return (pid_t)1,
1233: * so testing for that should be safe.
1234: */
1235: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1236: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1237: cleanup_socket();
1238: _exit(2);
1.68 markus 1239: }
1.48 deraadt 1240: }
1241:
1.55 itojun 1242: static void
1.50 itojun 1243: usage(void)
1.15 markus 1244: {
1.184 deraadt 1245: fprintf(stderr,
1.202 jmc 1246: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 ! djm 1247: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1248: " ssh-agent [-c | -s] -k\n");
1.21 markus 1249: exit(1);
1.15 markus 1250: }
1251:
1.2 provos 1252: int
1253: main(int ac, char **av)
1.1 deraadt 1254: {
1.201 djm 1255: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1256: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1257: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1258: struct rlimit rlim;
1.96 deraadt 1259: extern int optind;
1.98 stevesk 1260: extern char *optarg;
1.21 markus 1261: pid_t pid;
1.96 deraadt 1262: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1263: size_t len;
1.189 djm 1264: mode_t prev_mask;
1.224 djm 1265: int timeout = -1; /* INFTIM */
1.223 djm 1266: struct pollfd *pfd = NULL;
1267: size_t npfd = 0;
1.231 djm 1268: u_int maxfds;
1.123 djm 1269:
1270: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1271: sanitise_stdfd();
1.99 markus 1272:
1273: /* drop */
1274: setegid(getgid());
1275: setgid(getgid());
1.53 markus 1276:
1.231 djm 1277: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1278: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1279:
1.185 markus 1280: #ifdef WITH_OPENSSL
1.170 djm 1281: OpenSSL_add_all_algorithms();
1.185 markus 1282: #endif
1.21 markus 1283:
1.215 djm 1284: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1285: switch (ch) {
1.192 djm 1286: case 'E':
1287: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1288: if (fingerprint_hash == -1)
1289: fatal("Invalid hash algorithm \"%s\"", optarg);
1290: break;
1.21 markus 1291: case 'c':
1292: if (s_flag)
1293: usage();
1294: c_flag++;
1295: break;
1296: case 'k':
1297: k_flag++;
1298: break;
1.215 djm 1299: case 'P':
1.238 ! djm 1300: if (provider_whitelist != NULL)
1.215 djm 1301: fatal("-P option already specified");
1.238 ! djm 1302: provider_whitelist = xstrdup(optarg);
1.215 djm 1303: break;
1.21 markus 1304: case 's':
1305: if (c_flag)
1306: usage();
1307: s_flag++;
1308: break;
1.57 markus 1309: case 'd':
1.201 djm 1310: if (d_flag || D_flag)
1.57 markus 1311: usage();
1312: d_flag++;
1313: break;
1.201 djm 1314: case 'D':
1315: if (d_flag || D_flag)
1316: usage();
1317: D_flag++;
1318: break;
1.86 markus 1319: case 'a':
1320: agentsocket = optarg;
1.106 marc 1321: break;
1322: case 't':
1323: if ((lifetime = convtime(optarg)) == -1) {
1324: fprintf(stderr, "Invalid lifetime\n");
1325: usage();
1326: }
1.86 markus 1327: break;
1.21 markus 1328: default:
1329: usage();
1330: }
1331: }
1332: ac -= optind;
1333: av += optind;
1334:
1.201 djm 1335: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1336: usage();
1337:
1.238 ! djm 1338: if (provider_whitelist == NULL)
! 1339: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1340:
1.85 markus 1341: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1342: shell = getenv("SHELL");
1.161 tobias 1343: if (shell != NULL && (len = strlen(shell)) > 2 &&
1344: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1345: c_flag = 1;
1346: }
1347: if (k_flag) {
1.136 deraadt 1348: const char *errstr = NULL;
1349:
1.21 markus 1350: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1351: if (pidstr == NULL) {
1352: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1353: SSH_AGENTPID_ENV_NAME);
1.21 markus 1354: exit(1);
1355: }
1.136 deraadt 1356: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1357: if (errstr) {
1358: fprintf(stderr,
1359: "%s=\"%s\", which is not a good PID: %s\n",
1360: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1361: exit(1);
1362: }
1363: if (kill(pid, SIGTERM) == -1) {
1364: perror("kill");
1365: exit(1);
1366: }
1367: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1368: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1369: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1370: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1371: exit(0);
1372: }
1.231 djm 1373:
1374: /*
1375: * Minimum file descriptors:
1376: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1377: * a few spare for libc / stack protectors / sanitisers, etc.
1378: */
1379: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1380: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1381: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1382: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1383: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1384:
1.21 markus 1385: parent_pid = getpid();
1386:
1.86 markus 1387: if (agentsocket == NULL) {
1388: /* Create private directory for agent socket */
1.171 djm 1389: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1390: if (mkdtemp(socket_dir) == NULL) {
1391: perror("mkdtemp: private socket dir");
1392: exit(1);
1393: }
1.91 mpech 1394: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1395: (long)parent_pid);
1.86 markus 1396: } else {
1397: /* Try to use specified agent socket */
1398: socket_dir[0] = '\0';
1399: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1400: }
1401:
1.23 markus 1402: /*
1403: * Create socket early so it will exist before command gets run from
1404: * the parent.
1405: */
1.189 djm 1406: prev_mask = umask(0177);
1.188 millert 1407: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1408: if (sock < 0) {
1.188 millert 1409: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1410: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1411: cleanup_exit(1);
1412: }
1.189 djm 1413: umask(prev_mask);
1.46 markus 1414:
1.23 markus 1415: /*
1416: * Fork, and have the parent execute the command, if any, or present
1417: * the socket data. The child continues as the authentication agent.
1418: */
1.201 djm 1419: if (D_flag || d_flag) {
1420: log_init(__progname,
1421: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1422: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1423: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1424: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1425: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1426: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1427: fflush(stdout);
1.57 markus 1428: goto skip;
1429: }
1.21 markus 1430: pid = fork();
1431: if (pid == -1) {
1432: perror("fork");
1.81 stevesk 1433: cleanup_exit(1);
1.21 markus 1434: }
1435: if (pid != 0) { /* Parent - execute the given command. */
1436: close(sock);
1.91 mpech 1437: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1438: if (ac == 0) {
1439: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1440: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1441: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1442: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1443: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1444: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1445: exit(0);
1446: }
1.36 deraadt 1447: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1448: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1449: perror("setenv");
1450: exit(1);
1451: }
1.21 markus 1452: execvp(av[0], av);
1453: perror(av[0]);
1454: exit(1);
1455: }
1.81 stevesk 1456: /* child */
1457: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1458:
1459: if (setsid() == -1) {
1.81 stevesk 1460: error("setsid: %s", strerror(errno));
1.67 stevesk 1461: cleanup_exit(1);
1462: }
1463:
1464: (void)chdir("/");
1.107 markus 1465: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1466: /* XXX might close listen socket */
1467: (void)dup2(fd, STDIN_FILENO);
1468: (void)dup2(fd, STDOUT_FILENO);
1469: (void)dup2(fd, STDERR_FILENO);
1470: if (fd > 2)
1471: close(fd);
1472: }
1.21 markus 1473:
1.41 markus 1474: /* deny core dumps, since memory contains unencrypted private keys */
1475: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1476: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1477: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1478: cleanup_exit(1);
1479: }
1.57 markus 1480:
1481: skip:
1.187 djm 1482:
1483: cleanup_pid = getpid();
1.163 markus 1484:
1485: #ifdef ENABLE_PKCS11
1486: pkcs11_init(0);
1487: #endif
1.21 markus 1488: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1489: if (ac > 0)
1490: parent_alive_interval = 10;
1.33 markus 1491: idtab_init();
1.61 markus 1492: signal(SIGPIPE, SIG_IGN);
1.201 djm 1493: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1494: signal(SIGHUP, cleanup_handler);
1495: signal(SIGTERM, cleanup_handler);
1.205 djm 1496:
1.215 djm 1497: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1498: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1499:
1.21 markus 1500: while (1) {
1.231 djm 1501: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1502: result = poll(pfd, npfd, timeout);
1.154 dtucker 1503: saved_errno = errno;
1.155 dtucker 1504: if (parent_alive_interval != 0)
1505: check_parent_exists();
1506: (void) reaper(); /* remove expired keys */
1.237 deraadt 1507: if (result == -1) {
1.154 dtucker 1508: if (saved_errno == EINTR)
1.21 markus 1509: continue;
1.223 djm 1510: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1511: } else if (result > 0)
1.231 djm 1512: after_poll(pfd, npfd, maxfds);
1.15 markus 1513: }
1.21 markus 1514: /* NOTREACHED */
1.1 deraadt 1515: }