Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.248
1.248 ! naddy 1: /* $OpenBSD: ssh-agent.c,v 1.247 2019/11/16 22:36:48 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"
1.238 djm 79: #include "ssh-sk.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:
1.238 djm 271: static int
272: provider_sign(const char *provider, struct sshkey *key,
273: u_char **sigp, size_t *lenp,
274: const u_char *data, size_t datalen,
275: const char *alg, u_int compat)
276: {
277: int status, pair[2], r = SSH_ERR_INTERNAL_ERROR;
278: pid_t pid;
1.241 djm 279: char *helper, *verbosity = NULL, *fp = NULL;
1.238 djm 280: struct sshbuf *kbuf, *req, *resp;
281: u_char version;
1.241 djm 282: struct notifier_ctx *notifier = NULL;
1.238 djm 283:
284: debug3("%s: start for provider %s", __func__, provider);
285:
286: *sigp = NULL;
287: *lenp = 0;
1.243 djm 288:
1.238 djm 289: helper = getenv("SSH_SK_HELPER");
290: if (helper == NULL || strlen(helper) == 0)
291: helper = _PATH_SSH_SK_HELPER;
292: if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
293: verbosity = "-vvv";
294:
295: /* Start helper */
296: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
297: error("socketpair: %s", strerror(errno));
298: return SSH_ERR_SYSTEM_ERROR;
299: }
300: if ((pid = fork()) == -1) {
301: error("fork: %s", strerror(errno));
302: close(pair[0]);
303: close(pair[1]);
304: return SSH_ERR_SYSTEM_ERROR;
305: }
306: if (pid == 0) {
307: if ((dup2(pair[1], STDIN_FILENO) == -1) ||
308: (dup2(pair[1], STDOUT_FILENO) == -1))
309: fatal("%s: dup2: %s", __func__, ssh_err(r));
310: close(pair[0]);
311: close(pair[1]);
312: closefrom(STDERR_FILENO + 1);
313: debug("%s: starting %s %s", __func__, helper,
314: verbosity == NULL ? "" : verbosity);
315: execlp(helper, helper, verbosity, (char *)NULL);
316: fatal("%s: execlp: %s", __func__, strerror(errno));
317: }
318: close(pair[1]);
319:
320: if ((kbuf = sshbuf_new()) == NULL ||
321: (req = sshbuf_new()) == NULL ||
322: (resp = sshbuf_new()) == NULL)
323: fatal("%s: sshbuf_new failed", __func__);
324:
325: if ((r = sshkey_private_serialize(key, kbuf)) != 0 ||
326: (r = sshbuf_put_stringb(req, kbuf)) != 0 ||
327: (r = sshbuf_put_cstring(req, provider)) != 0 ||
328: (r = sshbuf_put_string(req, data, datalen)) != 0 ||
329: (r = sshbuf_put_u32(req, compat)) != 0)
330: fatal("%s: compose: %s", __func__, ssh_err(r));
1.247 djm 331:
332: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
333: SSH_FP_DEFAULT)) == NULL)
334: fatal("%s: sshkey_fingerprint failed", __func__);
335: notifier = notify_start(0,
336: "Confirm user presence for key %s %s", sshkey_type(key), fp);
337:
1.238 djm 338: if ((r = ssh_msg_send(pair[0], SSH_SK_HELPER_VERSION, req)) != 0) {
339: error("%s: send: %s", __func__, ssh_err(r));
340: goto out;
341: }
342: if ((r = ssh_msg_recv(pair[0], resp)) != 0) {
343: error("%s: receive: %s", __func__, ssh_err(r));
344: goto out;
345: }
346: if ((r = sshbuf_get_u8(resp, &version)) != 0) {
347: error("%s: parse version: %s", __func__, ssh_err(r));
348: goto out;
349: }
350: if (version != SSH_SK_HELPER_VERSION) {
351: error("%s: unsupported version: got %u, expected %u",
352: __func__, version, SSH_SK_HELPER_VERSION);
353: r = SSH_ERR_INVALID_FORMAT;
354: goto out;
355: }
356: if ((r = sshbuf_get_string(resp, sigp, lenp)) != 0) {
357: error("%s: parse signature: %s", __func__, ssh_err(r));
358: r = SSH_ERR_INVALID_FORMAT;
359: goto out;
360: }
361: if (sshbuf_len(resp) != 0) {
362: error("%s: trailing data in response", __func__);
363: r = SSH_ERR_INVALID_FORMAT;
364: goto out;
365: }
366: /* success */
367: r = 0;
368: out:
369: while (waitpid(pid, &status, 0) == -1) {
370: if (errno != EINTR)
371: fatal("%s: waitpid: %s", __func__, ssh_err(r));
372: }
1.241 djm 373: notify_complete(notifier);
1.238 djm 374: if (!WIFEXITED(status)) {
375: error("%s: helper %s exited abnormally", __func__, helper);
376: if (r == 0)
377: r = SSH_ERR_SYSTEM_ERROR;
378: } else if (WEXITSTATUS(status) != 0) {
379: error("%s: helper %s exited with non-zero exit status",
380: __func__, helper);
381: if (r == 0)
382: r = SSH_ERR_SYSTEM_ERROR;
383: }
384: if (r != 0) {
385: freezero(*sigp, *lenp);
386: *sigp = NULL;
387: *lenp = 0;
388: }
389: sshbuf_free(kbuf);
390: sshbuf_free(req);
391: sshbuf_free(resp);
392: return r;
393: }
394:
1.33 markus 395: /* ssh2 only */
1.55 itojun 396: static void
1.33 markus 397: process_sign_request2(SocketEntry *e)
398: {
1.221 djm 399: const u_char *data;
400: u_char *signature = NULL;
401: size_t dlen, slen = 0;
1.194 markus 402: u_int compat = 0, flags;
1.247 djm 403: int r, ok = -1;
1.194 markus 404: struct sshbuf *msg;
1.221 djm 405: struct sshkey *key = NULL;
1.195 djm 406: struct identity *id;
1.194 markus 407:
1.195 djm 408: if ((msg = sshbuf_new()) == NULL)
409: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 410: if ((r = sshkey_froms(e->request, &key)) != 0 ||
411: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 412: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
413: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
414: goto send;
415: }
416:
1.221 djm 417: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 418: verbose("%s: %s key not found", __func__, sshkey_type(key));
419: goto send;
420: }
421: if (id->confirm && confirm_key(id) != 0) {
422: verbose("%s: user refused key", __func__);
423: goto send;
424: }
1.238 djm 425: if (id->sk_provider != NULL) {
1.247 djm 426: if ((r = provider_sign(id->sk_provider, id->key, &signature,
1.238 djm 427: &slen, data, dlen, agent_decode_alg(key, flags),
1.247 djm 428: compat)) != 0) {
1.239 djm 429: error("%s: sign: %s", __func__, ssh_err(r));
1.238 djm 430: goto send;
431: }
432: } else {
433: if ((r = sshkey_sign(id->key, &signature, &slen,
1.239 djm 434: data, dlen, agent_decode_alg(key, flags),
435: NULL, compat)) != 0) {
1.238 djm 436: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
437: goto send;
438: }
1.33 markus 439: }
1.195 djm 440: /* Success */
441: ok = 0;
442: send:
443: sshkey_free(key);
1.33 markus 444: if (ok == 0) {
1.194 markus 445: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
446: (r = sshbuf_put_string(msg, signature, slen)) != 0)
447: fatal("%s: buffer error: %s", __func__, ssh_err(r));
448: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
449: fatal("%s: buffer error: %s", __func__, ssh_err(r));
450:
451: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
452: fatal("%s: buffer error: %s", __func__, ssh_err(r));
453:
454: sshbuf_free(msg);
1.173 djm 455: free(signature);
1.1 deraadt 456: }
457:
1.33 markus 458: /* shared */
1.55 itojun 459: static void
1.221 djm 460: process_remove_identity(SocketEntry *e)
1.1 deraadt 461: {
1.194 markus 462: int r, success = 0;
463: struct sshkey *key = NULL;
1.221 djm 464: Identity *id;
1.21 markus 465:
1.221 djm 466: if ((r = sshkey_froms(e->request, &key)) != 0) {
467: error("%s: get key: %s", __func__, ssh_err(r));
468: goto done;
469: }
470: if ((id = lookup_identity(key)) == NULL) {
471: debug("%s: key not found", __func__);
472: goto done;
473: }
474: /* We have this key, free it. */
475: if (idtab->nentries < 1)
476: fatal("%s: internal error: nentries %d",
477: __func__, idtab->nentries);
478: TAILQ_REMOVE(&idtab->idlist, id, next);
479: free_identity(id);
480: idtab->nentries--;
481: sshkey_free(key);
482: success = 1;
483: done:
1.194 markus 484: send_status(e, success);
1.1 deraadt 485: }
486:
1.55 itojun 487: static void
1.221 djm 488: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 489: {
1.78 provos 490: Identity *id;
1.21 markus 491:
492: /* Loop over all identities and clear the keys. */
1.221 djm 493: for (id = TAILQ_FIRST(&idtab->idlist); id;
494: id = TAILQ_FIRST(&idtab->idlist)) {
495: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 496: free_identity(id);
1.21 markus 497: }
498:
499: /* Mark that there are no identities. */
1.221 djm 500: idtab->nentries = 0;
1.21 markus 501:
502: /* Send success. */
1.194 markus 503: send_status(e, 1);
1.1 deraadt 504: }
505:
1.155 dtucker 506: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 507: static time_t
1.89 markus 508: reaper(void)
509: {
1.175 dtucker 510: time_t deadline = 0, now = monotime();
1.89 markus 511: Identity *id, *nxt;
512:
1.221 djm 513: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
514: nxt = TAILQ_NEXT(id, next);
515: if (id->death == 0)
516: continue;
517: if (now >= id->death) {
518: debug("expiring key '%s'", id->comment);
519: TAILQ_REMOVE(&idtab->idlist, id, next);
520: free_identity(id);
521: idtab->nentries--;
522: } else
523: deadline = (deadline == 0) ? id->death :
524: MINIMUM(deadline, id->death);
1.89 markus 525: }
1.155 dtucker 526: if (deadline == 0 || deadline <= now)
527: return 0;
528: else
529: return (deadline - now);
1.89 markus 530: }
531:
532: static void
1.221 djm 533: process_add_identity(SocketEntry *e)
1.1 deraadt 534: {
1.157 canacar 535: Identity *id;
1.194 markus 536: int success = 0, confirm = 0;
1.228 markus 537: u_int seconds, maxsign;
1.238 djm 538: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 539: time_t death = 0;
1.194 markus 540: struct sshkey *k = NULL;
541: u_char ctype;
542: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 543:
1.221 djm 544: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
545: k == NULL ||
1.194 markus 546: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
547: error("%s: decode private key: %s", __func__, ssh_err(r));
548: goto err;
549: }
550: while (sshbuf_len(e->request)) {
551: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
552: error("%s: buffer error: %s", __func__, ssh_err(r));
553: goto err;
554: }
555: switch (ctype) {
1.94 markus 556: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 557: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
558: error("%s: bad lifetime constraint: %s",
559: __func__, ssh_err(r));
560: goto err;
561: }
562: death = monotime() + seconds;
1.94 markus 563: break;
1.107 markus 564: case SSH_AGENT_CONSTRAIN_CONFIRM:
565: confirm = 1;
566: break;
1.228 markus 567: case SSH_AGENT_CONSTRAIN_MAXSIGN:
568: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
569: error("%s: bad maxsign constraint: %s",
570: __func__, ssh_err(r));
571: goto err;
572: }
573: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
574: error("%s: cannot enable maxsign: %s",
575: __func__, ssh_err(r));
576: goto err;
577: }
578: break;
1.238 djm 579: case SSH_AGENT_CONSTRAIN_EXTENSION:
580: if ((r = sshbuf_get_cstring(e->request,
581: &ext_name, NULL)) != 0) {
582: error("%s: cannot parse extension: %s",
583: __func__, ssh_err(r));
584: goto err;
585: }
586: debug("%s: constraint ext %s", __func__, ext_name);
587: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
588: if (sk_provider != NULL) {
589: error("%s already set", ext_name);
590: goto err;
591: }
592: if ((r = sshbuf_get_cstring(e->request,
593: &sk_provider, NULL)) != 0) {
594: error("%s: cannot parse %s: %s",
595: __func__, ext_name, ssh_err(r));
596: goto err;
597: }
598: } else {
599: error("%s: unsupported constraint \"%s\"",
600: __func__, ext_name);
601: goto err;
602: }
603: free(ext_name);
604: break;
1.94 markus 605: default:
1.194 markus 606: error("%s: Unknown constraint %d", __func__, ctype);
607: err:
1.238 djm 608: free(sk_provider);
609: free(ext_name);
1.194 markus 610: sshbuf_reset(e->request);
1.173 djm 611: free(comment);
1.194 markus 612: sshkey_free(k);
1.158 djm 613: goto send;
1.94 markus 614: }
615: }
1.238 djm 616: if (sk_provider != NULL) {
1.240 markus 617: if (!sshkey_is_sk(k)) {
1.238 djm 618: error("Cannot add provider: %s is not a security key",
619: sshkey_type(k));
620: free(sk_provider);
621: goto send;
622: }
1.245 djm 623: if (strcasecmp(sk_provider, "internal") == 0)
624: debug("%s: internal provider", __func__);
625: else if (match_pattern_list(sk_provider,
1.238 djm 626: provider_whitelist, 0) != 1) {
627: error("Refusing add key: provider %s not whitelisted",
628: sk_provider);
629: free(sk_provider);
630: goto send;
631: }
1.242 markus 632: }
633: if ((r = sshkey_shield_private(k)) != 0) {
634: error("%s: shield private key: %s", __func__, ssh_err(r));
635: goto err;
1.238 djm 636: }
1.194 markus 637:
1.158 djm 638: success = 1;
1.106 marc 639: if (lifetime && !death)
1.175 dtucker 640: death = monotime() + lifetime;
1.221 djm 641: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 642: id = xcalloc(1, sizeof(Identity));
1.221 djm 643: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 644: /* Increment the number of identities. */
1.221 djm 645: idtab->nentries++;
1.33 markus 646: } else {
1.228 markus 647: /* key state might have been updated */
648: sshkey_free(id->key);
1.173 djm 649: free(id->comment);
1.238 djm 650: free(id->sk_provider);
1.33 markus 651: }
1.228 markus 652: id->key = k;
1.157 canacar 653: id->comment = comment;
654: id->death = death;
655: id->confirm = confirm;
1.238 djm 656: id->sk_provider = sk_provider;
657:
658: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
659: SSH_FP_DEFAULT)) == NULL)
660: fatal("%s: sshkey_fingerprint failed", __func__);
661: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
662: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
663: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
664: free(fp);
1.33 markus 665: send:
1.194 markus 666: send_status(e, success);
1.1 deraadt 667: }
668:
1.88 markus 669: /* XXX todo: encrypt sensitive data with passphrase */
670: static void
671: process_lock_agent(SocketEntry *e, int lock)
672: {
1.203 dtucker 673: int r, success = 0, delay;
1.213 djm 674: char *passwd;
675: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 676: static u_int fail_count = 0;
677: size_t pwlen;
678:
1.226 djm 679: /*
680: * This is deliberately fatal: the user has requested that we lock,
681: * but we can't parse their request properly. The only safe thing to
682: * do is abort.
683: */
1.203 dtucker 684: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
685: fatal("%s: buffer error: %s", __func__, ssh_err(r));
686: if (pwlen == 0) {
687: debug("empty password not supported");
688: } else if (locked && !lock) {
689: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
690: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
691: fatal("bcrypt_pbkdf");
1.213 djm 692: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 693: debug("agent unlocked");
694: locked = 0;
695: fail_count = 0;
1.213 djm 696: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 697: success = 1;
698: } else {
699: /* delay in 0.1s increments up to 10s */
700: if (fail_count < 100)
701: fail_count++;
702: delay = 100000 * fail_count;
703: debug("unlock failed, delaying %0.1lf seconds",
704: (double)delay/1000000);
705: usleep(delay);
706: }
707: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 708: } else if (!locked && lock) {
1.203 dtucker 709: debug("agent locked");
1.88 markus 710: locked = 1;
1.203 dtucker 711: arc4random_buf(lock_salt, sizeof(lock_salt));
712: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 713: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 714: fatal("bcrypt_pbkdf");
1.88 markus 715: success = 1;
716: }
1.203 dtucker 717: explicit_bzero(passwd, pwlen);
1.173 djm 718: free(passwd);
1.194 markus 719: send_status(e, success);
1.88 markus 720: }
721:
722: static void
1.221 djm 723: no_identities(SocketEntry *e)
1.88 markus 724: {
1.194 markus 725: struct sshbuf *msg;
726: int r;
1.88 markus 727:
1.194 markus 728: if ((msg = sshbuf_new()) == NULL)
729: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 730: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 731: (r = sshbuf_put_u32(msg, 0)) != 0 ||
732: (r = sshbuf_put_stringb(e->output, msg)) != 0)
733: fatal("%s: buffer error: %s", __func__, ssh_err(r));
734: sshbuf_free(msg);
1.88 markus 735: }
1.59 markus 736:
1.163 markus 737: #ifdef ENABLE_PKCS11
1.59 markus 738: static void
1.158 djm 739: process_add_smartcard_key(SocketEntry *e)
1.59 markus 740: {
1.226 djm 741: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 742: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 743: u_int seconds;
1.174 dtucker 744: time_t death = 0;
1.194 markus 745: u_char type;
746: struct sshkey **keys = NULL, *k;
1.84 markus 747: Identity *id;
1.75 deraadt 748:
1.194 markus 749: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 750: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
751: error("%s: buffer error: %s", __func__, ssh_err(r));
752: goto send;
753: }
1.194 markus 754:
755: while (sshbuf_len(e->request)) {
1.226 djm 756: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
757: error("%s: buffer error: %s", __func__, ssh_err(r));
758: goto send;
759: }
1.194 markus 760: switch (type) {
1.110 djm 761: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 762: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
763: error("%s: buffer error: %s",
1.194 markus 764: __func__, ssh_err(r));
1.226 djm 765: goto send;
766: }
1.194 markus 767: death = monotime() + seconds;
1.110 djm 768: break;
769: case SSH_AGENT_CONSTRAIN_CONFIRM:
770: confirm = 1;
771: break;
772: default:
1.221 djm 773: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 774: goto send;
1.110 djm 775: }
776: }
1.215 djm 777: if (realpath(provider, canonical_provider) == NULL) {
778: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
779: provider, strerror(errno));
780: goto send;
781: }
1.238 djm 782: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 783: verbose("refusing PKCS#11 add of \"%.100s\": "
784: "provider not whitelisted", canonical_provider);
785: goto send;
786: }
787: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 788: if (lifetime && !death)
1.175 dtucker 789: death = monotime() + lifetime;
1.110 djm 790:
1.215 djm 791: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 792: for (i = 0; i < count; i++) {
1.84 markus 793: k = keys[i];
1.221 djm 794: if (lookup_identity(k) == NULL) {
1.163 markus 795: id = xcalloc(1, sizeof(Identity));
1.84 markus 796: id->key = k;
1.215 djm 797: id->provider = xstrdup(canonical_provider);
798: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 799: id->death = death;
800: id->confirm = confirm;
1.221 djm 801: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
802: idtab->nentries++;
1.84 markus 803: success = 1;
804: } else {
1.194 markus 805: sshkey_free(k);
1.84 markus 806: }
807: keys[i] = NULL;
1.59 markus 808: }
809: send:
1.173 djm 810: free(pin);
811: free(provider);
812: free(keys);
1.194 markus 813: send_status(e, success);
1.59 markus 814: }
815:
816: static void
817: process_remove_smartcard_key(SocketEntry *e)
818: {
1.217 djm 819: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 820: int r, success = 0;
1.163 markus 821: Identity *id, *nxt;
1.59 markus 822:
1.194 markus 823: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 824: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
825: error("%s: buffer error: %s", __func__, ssh_err(r));
826: goto send;
827: }
1.173 djm 828: free(pin);
1.59 markus 829:
1.217 djm 830: if (realpath(provider, canonical_provider) == NULL) {
831: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
832: provider, strerror(errno));
833: goto send;
834: }
835:
836: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 837: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
838: nxt = TAILQ_NEXT(id, next);
839: /* Skip file--based keys */
840: if (id->provider == NULL)
841: continue;
842: if (!strcmp(canonical_provider, id->provider)) {
843: TAILQ_REMOVE(&idtab->idlist, id, next);
844: free_identity(id);
845: idtab->nentries--;
1.59 markus 846: }
847: }
1.217 djm 848: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 849: success = 1;
850: else
1.221 djm 851: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 852: send:
1.173 djm 853: free(provider);
1.194 markus 854: send_status(e, success);
1.59 markus 855: }
1.163 markus 856: #endif /* ENABLE_PKCS11 */
1.59 markus 857:
1.33 markus 858: /* dispatch incoming messages */
859:
1.223 djm 860: static int
861: process_message(u_int socknum)
1.1 deraadt 862: {
1.194 markus 863: u_int msg_len;
864: u_char type;
865: const u_char *cp;
866: int r;
1.223 djm 867: SocketEntry *e;
868:
869: if (socknum >= sockets_alloc) {
870: fatal("%s: socket number %u >= allocated %u",
871: __func__, socknum, sockets_alloc);
872: }
873: e = &sockets[socknum];
1.89 markus 874:
1.194 markus 875: if (sshbuf_len(e->input) < 5)
1.223 djm 876: return 0; /* Incomplete message header. */
1.194 markus 877: cp = sshbuf_ptr(e->input);
878: msg_len = PEEK_U32(cp);
1.223 djm 879: if (msg_len > AGENT_MAX_LEN) {
880: debug("%s: socket %u (fd=%d) message too long %u > %u",
881: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
882: return -1;
1.21 markus 883: }
1.194 markus 884: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 885: return 0; /* Incomplete message body. */
1.87 markus 886:
887: /* move the current input to e->request */
1.194 markus 888: sshbuf_reset(e->request);
889: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 890: (r = sshbuf_get_u8(e->request, &type)) != 0) {
891: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
892: r == SSH_ERR_STRING_TOO_LARGE) {
893: debug("%s: buffer error: %s", __func__, ssh_err(r));
894: return -1;
895: }
1.194 markus 896: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 897: }
898:
899: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 900:
1.230 djm 901: /* check whether agent is locked */
1.88 markus 902: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 903: sshbuf_reset(e->request);
1.88 markus 904: switch (type) {
905: case SSH2_AGENTC_REQUEST_IDENTITIES:
906: /* send empty lists */
1.221 djm 907: no_identities(e);
1.88 markus 908: break;
909: default:
910: /* send a fail message for all other request types */
1.194 markus 911: send_status(e, 0);
1.88 markus 912: }
1.223 djm 913: return 0;
1.88 markus 914: }
915:
1.21 markus 916: switch (type) {
1.88 markus 917: case SSH_AGENTC_LOCK:
918: case SSH_AGENTC_UNLOCK:
919: process_lock_agent(e, type == SSH_AGENTC_LOCK);
920: break;
1.21 markus 921: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 922: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 923: break;
924: /* ssh2 */
925: case SSH2_AGENTC_SIGN_REQUEST:
926: process_sign_request2(e);
927: break;
928: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 929: process_request_identities(e);
1.33 markus 930: break;
931: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 932: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 933: process_add_identity(e);
1.33 markus 934: break;
935: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 936: process_remove_identity(e);
1.33 markus 937: break;
938: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 939: process_remove_all_identities(e);
1.21 markus 940: break;
1.163 markus 941: #ifdef ENABLE_PKCS11
1.59 markus 942: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 943: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 944: process_add_smartcard_key(e);
1.75 deraadt 945: break;
1.59 markus 946: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
947: process_remove_smartcard_key(e);
1.75 deraadt 948: break;
1.163 markus 949: #endif /* ENABLE_PKCS11 */
1.21 markus 950: default:
951: /* Unknown message. Respond with failure. */
952: error("Unknown message %d", type);
1.194 markus 953: sshbuf_reset(e->request);
954: send_status(e, 0);
1.21 markus 955: break;
956: }
1.223 djm 957: return 0;
1.1 deraadt 958: }
959:
1.55 itojun 960: static void
1.73 stevesk 961: new_socket(sock_type type, int fd)
1.1 deraadt 962: {
1.112 markus 963: u_int i, old_alloc, new_alloc;
1.96 deraadt 964:
1.119 djm 965: set_nonblock(fd);
1.21 markus 966:
967: if (fd > max_fd)
968: max_fd = fd;
969:
970: for (i = 0; i < sockets_alloc; i++)
971: if (sockets[i].type == AUTH_UNUSED) {
972: sockets[i].fd = fd;
1.194 markus 973: if ((sockets[i].input = sshbuf_new()) == NULL)
974: fatal("%s: sshbuf_new failed", __func__);
975: if ((sockets[i].output = sshbuf_new()) == NULL)
976: fatal("%s: sshbuf_new failed", __func__);
977: if ((sockets[i].request = sshbuf_new()) == NULL)
978: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 979: sockets[i].type = type;
1.21 markus 980: return;
981: }
982: old_alloc = sockets_alloc;
1.112 markus 983: new_alloc = sockets_alloc + 10;
1.200 deraadt 984: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 985: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 986: sockets[i].type = AUTH_UNUSED;
1.112 markus 987: sockets_alloc = new_alloc;
1.21 markus 988: sockets[old_alloc].fd = fd;
1.194 markus 989: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
990: fatal("%s: sshbuf_new failed", __func__);
991: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
992: fatal("%s: sshbuf_new failed", __func__);
993: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
994: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 995: sockets[old_alloc].type = type;
1.1 deraadt 996: }
997:
1.55 itojun 998: static int
1.223 djm 999: handle_socket_read(u_int socknum)
1.1 deraadt 1000: {
1.223 djm 1001: struct sockaddr_un sunaddr;
1002: socklen_t slen;
1003: uid_t euid;
1004: gid_t egid;
1005: int fd;
1006:
1007: slen = sizeof(sunaddr);
1008: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1009: if (fd == -1) {
1.223 djm 1010: error("accept from AUTH_SOCKET: %s", strerror(errno));
1011: return -1;
1012: }
1.237 deraadt 1013: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1014: error("getpeereid %d failed: %s", fd, strerror(errno));
1015: close(fd);
1016: return -1;
1017: }
1018: if ((euid != 0) && (getuid() != euid)) {
1019: error("uid mismatch: peer euid %u != uid %u",
1020: (u_int) euid, (u_int) getuid());
1021: close(fd);
1022: return -1;
1023: }
1024: new_socket(AUTH_CONNECTION, fd);
1025: return 0;
1026: }
1027:
1028: static int
1029: handle_conn_read(u_int socknum)
1030: {
1.233 djm 1031: char buf[AGENT_RBUF_LEN];
1.223 djm 1032: ssize_t len;
1033: int r;
1034:
1035: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1036: if (len == -1) {
1037: if (errno == EAGAIN || errno == EINTR)
1038: return 0;
1039: error("%s: read error on socket %u (fd %d): %s",
1040: __func__, socknum, sockets[socknum].fd,
1041: strerror(errno));
1042: }
1043: return -1;
1044: }
1045: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1046: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1047: explicit_bzero(buf, sizeof(buf));
1048: process_message(socknum);
1049: return 0;
1050: }
1051:
1052: static int
1053: handle_conn_write(u_int socknum)
1054: {
1055: ssize_t len;
1056: int r;
1057:
1058: if (sshbuf_len(sockets[socknum].output) == 0)
1059: return 0; /* shouldn't happen */
1060: if ((len = write(sockets[socknum].fd,
1061: sshbuf_ptr(sockets[socknum].output),
1062: sshbuf_len(sockets[socknum].output))) <= 0) {
1063: if (len == -1) {
1064: if (errno == EAGAIN || errno == EINTR)
1065: return 0;
1066: error("%s: read error on socket %u (fd %d): %s",
1067: __func__, socknum, sockets[socknum].fd,
1068: strerror(errno));
1069: }
1070: return -1;
1071: }
1072: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1073: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1074: return 0;
1075: }
1076:
1077: static void
1.231 djm 1078: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1079: {
1080: size_t i;
1.231 djm 1081: u_int socknum, activefds = npfd;
1.223 djm 1082:
1083: for (i = 0; i < npfd; i++) {
1084: if (pfd[i].revents == 0)
1085: continue;
1086: /* Find sockets entry */
1087: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1088: if (sockets[socknum].type != AUTH_SOCKET &&
1089: sockets[socknum].type != AUTH_CONNECTION)
1090: continue;
1091: if (pfd[i].fd == sockets[socknum].fd)
1092: break;
1093: }
1094: if (socknum >= sockets_alloc) {
1095: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1096: continue;
1097: }
1098: /* Process events */
1099: switch (sockets[socknum].type) {
1100: case AUTH_SOCKET:
1.231 djm 1101: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1102: break;
1103: if (npfd > maxfds) {
1104: debug3("out of fds (active %u >= limit %u); "
1105: "skipping accept", activefds, maxfds);
1106: break;
1107: }
1108: if (handle_socket_read(socknum) == 0)
1109: activefds++;
1.223 djm 1110: break;
1111: case AUTH_CONNECTION:
1112: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1113: handle_conn_read(socknum) != 0) {
1.231 djm 1114: goto close_sock;
1115: }
1116: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1117: handle_conn_write(socknum) != 0) {
1118: close_sock:
1119: if (activefds == 0)
1120: fatal("activefds == 0 at close_sock");
1.223 djm 1121: close_socket(&sockets[socknum]);
1.231 djm 1122: activefds--;
1.223 djm 1123: break;
1124: }
1125: break;
1126: default:
1127: break;
1128: }
1129: }
1130: }
1131:
1132: static int
1.231 djm 1133: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1134: {
1135: struct pollfd *pfd = *pfdp;
1136: size_t i, j, npfd = 0;
1.174 dtucker 1137: time_t deadline;
1.233 djm 1138: int r;
1.46 markus 1139:
1.223 djm 1140: /* Count active sockets */
1.46 markus 1141: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1142: switch (sockets[i].type) {
1143: case AUTH_SOCKET:
1144: case AUTH_CONNECTION:
1.223 djm 1145: npfd++;
1.21 markus 1146: break;
1147: case AUTH_UNUSED:
1148: break;
1149: default:
1150: fatal("Unknown socket type %d", sockets[i].type);
1151: break;
1152: }
1.46 markus 1153: }
1.223 djm 1154: if (npfd != *npfdp &&
1155: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1156: fatal("%s: recallocarray failed", __func__);
1157: *pfdp = pfd;
1158: *npfdp = npfd;
1.46 markus 1159:
1.223 djm 1160: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1161: switch (sockets[i].type) {
1162: case AUTH_SOCKET:
1.231 djm 1163: if (npfd > maxfds) {
1164: debug3("out of fds (active %zu >= limit %u); "
1165: "skipping arming listener", npfd, maxfds);
1166: break;
1167: }
1168: pfd[j].fd = sockets[i].fd;
1169: pfd[j].revents = 0;
1170: pfd[j].events = POLLIN;
1171: j++;
1172: break;
1.46 markus 1173: case AUTH_CONNECTION:
1.223 djm 1174: pfd[j].fd = sockets[i].fd;
1175: pfd[j].revents = 0;
1.233 djm 1176: /*
1177: * Only prepare to read if we can handle a full-size
1178: * input read buffer and enqueue a max size reply..
1179: */
1180: if ((r = sshbuf_check_reserve(sockets[i].input,
1181: AGENT_RBUF_LEN)) == 0 &&
1182: (r = sshbuf_check_reserve(sockets[i].output,
1183: AGENT_MAX_LEN)) == 0)
1184: pfd[j].events = POLLIN;
1185: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1186: fatal("%s: buffer error: %s",
1187: __func__, ssh_err(r));
1188: }
1.194 markus 1189: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1190: pfd[j].events |= POLLOUT;
1191: j++;
1.46 markus 1192: break;
1193: default:
1194: break;
1195: }
1196: }
1.155 dtucker 1197: deadline = reaper();
1198: if (parent_alive_interval != 0)
1199: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1200: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1201: if (deadline == 0) {
1.224 djm 1202: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1203: } else {
1.223 djm 1204: if (deadline > INT_MAX / 1000)
1205: *timeoutp = INT_MAX / 1000;
1206: else
1207: *timeoutp = deadline * 1000;
1.155 dtucker 1208: }
1.46 markus 1209: return (1);
1.21 markus 1210: }
1211:
1.55 itojun 1212: static void
1.113 markus 1213: cleanup_socket(void)
1.15 markus 1214: {
1.187 djm 1215: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1216: return;
1217: debug("%s: cleanup", __func__);
1.48 deraadt 1218: if (socket_name[0])
1219: unlink(socket_name);
1220: if (socket_dir[0])
1221: rmdir(socket_dir);
1.10 markus 1222: }
1223:
1.114 markus 1224: void
1.15 markus 1225: cleanup_exit(int i)
1226: {
1.113 markus 1227: cleanup_socket();
1228: _exit(i);
1.15 markus 1229: }
1230:
1.135 deraadt 1231: /*ARGSUSED*/
1.55 itojun 1232: static void
1.48 deraadt 1233: cleanup_handler(int sig)
1234: {
1.113 markus 1235: cleanup_socket();
1.163 markus 1236: #ifdef ENABLE_PKCS11
1237: pkcs11_terminate();
1238: #endif
1.48 deraadt 1239: _exit(2);
1.113 markus 1240: }
1241:
1.68 markus 1242: static void
1.155 dtucker 1243: check_parent_exists(void)
1.68 markus 1244: {
1.172 dtucker 1245: /*
1246: * If our parent has exited then getppid() will return (pid_t)1,
1247: * so testing for that should be safe.
1248: */
1249: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1250: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1251: cleanup_socket();
1252: _exit(2);
1.68 markus 1253: }
1.48 deraadt 1254: }
1255:
1.55 itojun 1256: static void
1.50 itojun 1257: usage(void)
1.15 markus 1258: {
1.184 deraadt 1259: fprintf(stderr,
1.202 jmc 1260: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1261: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1262: " ssh-agent [-c | -s] -k\n");
1.21 markus 1263: exit(1);
1.15 markus 1264: }
1265:
1.2 provos 1266: int
1267: main(int ac, char **av)
1.1 deraadt 1268: {
1.201 djm 1269: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1270: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1271: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1272: struct rlimit rlim;
1.96 deraadt 1273: extern int optind;
1.98 stevesk 1274: extern char *optarg;
1.21 markus 1275: pid_t pid;
1.96 deraadt 1276: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1277: size_t len;
1.189 djm 1278: mode_t prev_mask;
1.224 djm 1279: int timeout = -1; /* INFTIM */
1.223 djm 1280: struct pollfd *pfd = NULL;
1281: size_t npfd = 0;
1.231 djm 1282: u_int maxfds;
1.123 djm 1283:
1284: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1285: sanitise_stdfd();
1.99 markus 1286:
1287: /* drop */
1288: setegid(getgid());
1289: setgid(getgid());
1.53 markus 1290:
1.231 djm 1291: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1292: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1293:
1.185 markus 1294: #ifdef WITH_OPENSSL
1.170 djm 1295: OpenSSL_add_all_algorithms();
1.185 markus 1296: #endif
1.21 markus 1297:
1.215 djm 1298: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1299: switch (ch) {
1.192 djm 1300: case 'E':
1301: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1302: if (fingerprint_hash == -1)
1303: fatal("Invalid hash algorithm \"%s\"", optarg);
1304: break;
1.21 markus 1305: case 'c':
1306: if (s_flag)
1307: usage();
1308: c_flag++;
1309: break;
1310: case 'k':
1311: k_flag++;
1312: break;
1.215 djm 1313: case 'P':
1.238 djm 1314: if (provider_whitelist != NULL)
1.215 djm 1315: fatal("-P option already specified");
1.238 djm 1316: provider_whitelist = xstrdup(optarg);
1.215 djm 1317: break;
1.21 markus 1318: case 's':
1319: if (c_flag)
1320: usage();
1321: s_flag++;
1322: break;
1.57 markus 1323: case 'd':
1.201 djm 1324: if (d_flag || D_flag)
1.57 markus 1325: usage();
1326: d_flag++;
1327: break;
1.201 djm 1328: case 'D':
1329: if (d_flag || D_flag)
1330: usage();
1331: D_flag++;
1332: break;
1.86 markus 1333: case 'a':
1334: agentsocket = optarg;
1.106 marc 1335: break;
1336: case 't':
1337: if ((lifetime = convtime(optarg)) == -1) {
1338: fprintf(stderr, "Invalid lifetime\n");
1339: usage();
1340: }
1.86 markus 1341: break;
1.21 markus 1342: default:
1343: usage();
1344: }
1345: }
1346: ac -= optind;
1347: av += optind;
1348:
1.201 djm 1349: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1350: usage();
1351:
1.238 djm 1352: if (provider_whitelist == NULL)
1353: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1354:
1.85 markus 1355: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1356: shell = getenv("SHELL");
1.161 tobias 1357: if (shell != NULL && (len = strlen(shell)) > 2 &&
1358: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1359: c_flag = 1;
1360: }
1361: if (k_flag) {
1.136 deraadt 1362: const char *errstr = NULL;
1363:
1.21 markus 1364: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1365: if (pidstr == NULL) {
1366: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1367: SSH_AGENTPID_ENV_NAME);
1.21 markus 1368: exit(1);
1369: }
1.136 deraadt 1370: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1371: if (errstr) {
1372: fprintf(stderr,
1373: "%s=\"%s\", which is not a good PID: %s\n",
1374: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1375: exit(1);
1376: }
1377: if (kill(pid, SIGTERM) == -1) {
1378: perror("kill");
1379: exit(1);
1380: }
1381: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1382: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1383: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1384: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1385: exit(0);
1386: }
1.231 djm 1387:
1388: /*
1389: * Minimum file descriptors:
1390: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1391: * a few spare for libc / stack protectors / sanitisers, etc.
1392: */
1393: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1394: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1395: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1396: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1397: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1398:
1.21 markus 1399: parent_pid = getpid();
1400:
1.86 markus 1401: if (agentsocket == NULL) {
1402: /* Create private directory for agent socket */
1.171 djm 1403: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1404: if (mkdtemp(socket_dir) == NULL) {
1405: perror("mkdtemp: private socket dir");
1406: exit(1);
1407: }
1.91 mpech 1408: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1409: (long)parent_pid);
1.86 markus 1410: } else {
1411: /* Try to use specified agent socket */
1412: socket_dir[0] = '\0';
1413: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1414: }
1415:
1.23 markus 1416: /*
1417: * Create socket early so it will exist before command gets run from
1418: * the parent.
1419: */
1.189 djm 1420: prev_mask = umask(0177);
1.188 millert 1421: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1422: if (sock < 0) {
1.188 millert 1423: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1424: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1425: cleanup_exit(1);
1426: }
1.189 djm 1427: umask(prev_mask);
1.46 markus 1428:
1.23 markus 1429: /*
1430: * Fork, and have the parent execute the command, if any, or present
1431: * the socket data. The child continues as the authentication agent.
1432: */
1.201 djm 1433: if (D_flag || d_flag) {
1434: log_init(__progname,
1435: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1436: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1437: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1438: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1439: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1440: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1441: fflush(stdout);
1.57 markus 1442: goto skip;
1443: }
1.21 markus 1444: pid = fork();
1445: if (pid == -1) {
1446: perror("fork");
1.81 stevesk 1447: cleanup_exit(1);
1.21 markus 1448: }
1449: if (pid != 0) { /* Parent - execute the given command. */
1450: close(sock);
1.91 mpech 1451: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1452: if (ac == 0) {
1453: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1454: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1455: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1456: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1457: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1458: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1459: exit(0);
1460: }
1.36 deraadt 1461: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1462: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1463: perror("setenv");
1464: exit(1);
1465: }
1.21 markus 1466: execvp(av[0], av);
1467: perror(av[0]);
1468: exit(1);
1469: }
1.81 stevesk 1470: /* child */
1471: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1472:
1473: if (setsid() == -1) {
1.81 stevesk 1474: error("setsid: %s", strerror(errno));
1.67 stevesk 1475: cleanup_exit(1);
1476: }
1477:
1478: (void)chdir("/");
1.107 markus 1479: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1480: /* XXX might close listen socket */
1481: (void)dup2(fd, STDIN_FILENO);
1482: (void)dup2(fd, STDOUT_FILENO);
1483: (void)dup2(fd, STDERR_FILENO);
1484: if (fd > 2)
1485: close(fd);
1486: }
1.21 markus 1487:
1.41 markus 1488: /* deny core dumps, since memory contains unencrypted private keys */
1489: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1490: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1491: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1492: cleanup_exit(1);
1493: }
1.57 markus 1494:
1495: skip:
1.187 djm 1496:
1497: cleanup_pid = getpid();
1.163 markus 1498:
1499: #ifdef ENABLE_PKCS11
1500: pkcs11_init(0);
1501: #endif
1.21 markus 1502: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1503: if (ac > 0)
1504: parent_alive_interval = 10;
1.33 markus 1505: idtab_init();
1.61 markus 1506: signal(SIGPIPE, SIG_IGN);
1.201 djm 1507: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1508: signal(SIGHUP, cleanup_handler);
1509: signal(SIGTERM, cleanup_handler);
1.205 djm 1510:
1.215 djm 1511: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1512: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1513:
1.21 markus 1514: while (1) {
1.231 djm 1515: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1516: result = poll(pfd, npfd, timeout);
1.154 dtucker 1517: saved_errno = errno;
1.155 dtucker 1518: if (parent_alive_interval != 0)
1519: check_parent_exists();
1520: (void) reaper(); /* remove expired keys */
1.237 deraadt 1521: if (result == -1) {
1.154 dtucker 1522: if (saved_errno == EINTR)
1.21 markus 1523: continue;
1.223 djm 1524: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1525: } else if (result > 0)
1.231 djm 1526: after_poll(pfd, npfd, maxfds);
1.15 markus 1527: }
1.21 markus 1528: /* NOTREACHED */
1.1 deraadt 1529: }
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