Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.239
1.239 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.238 2019/10/31 21:22:01 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>
1.196 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) {
1.239 ! djm 418: error("%s: sign: %s", __func__, ssh_err(r));
1.238 djm 419: goto send;
420: }
421: } else {
422: if ((r = sshkey_sign(id->key, &signature, &slen,
1.239 ! djm 423: data, dlen, agent_decode_alg(key, flags),
! 424: NULL, compat)) != 0) {
1.238 djm 425: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
426: goto send;
427: }
1.33 markus 428: }
1.195 djm 429: /* Success */
430: ok = 0;
431: send:
432: sshkey_free(key);
1.33 markus 433: if (ok == 0) {
1.194 markus 434: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
435: (r = sshbuf_put_string(msg, signature, slen)) != 0)
436: fatal("%s: buffer error: %s", __func__, ssh_err(r));
437: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
438: fatal("%s: buffer error: %s", __func__, ssh_err(r));
439:
440: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
441: fatal("%s: buffer error: %s", __func__, ssh_err(r));
442:
443: sshbuf_free(msg);
1.173 djm 444: free(signature);
1.1 deraadt 445: }
446:
1.33 markus 447: /* shared */
1.55 itojun 448: static void
1.221 djm 449: process_remove_identity(SocketEntry *e)
1.1 deraadt 450: {
1.194 markus 451: int r, success = 0;
452: struct sshkey *key = NULL;
1.221 djm 453: Identity *id;
1.21 markus 454:
1.221 djm 455: if ((r = sshkey_froms(e->request, &key)) != 0) {
456: error("%s: get key: %s", __func__, ssh_err(r));
457: goto done;
458: }
459: if ((id = lookup_identity(key)) == NULL) {
460: debug("%s: key not found", __func__);
461: goto done;
462: }
463: /* We have this key, free it. */
464: if (idtab->nentries < 1)
465: fatal("%s: internal error: nentries %d",
466: __func__, idtab->nentries);
467: TAILQ_REMOVE(&idtab->idlist, id, next);
468: free_identity(id);
469: idtab->nentries--;
470: sshkey_free(key);
471: success = 1;
472: done:
1.194 markus 473: send_status(e, success);
1.1 deraadt 474: }
475:
1.55 itojun 476: static void
1.221 djm 477: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 478: {
1.78 provos 479: Identity *id;
1.21 markus 480:
481: /* Loop over all identities and clear the keys. */
1.221 djm 482: for (id = TAILQ_FIRST(&idtab->idlist); id;
483: id = TAILQ_FIRST(&idtab->idlist)) {
484: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 485: free_identity(id);
1.21 markus 486: }
487:
488: /* Mark that there are no identities. */
1.221 djm 489: idtab->nentries = 0;
1.21 markus 490:
491: /* Send success. */
1.194 markus 492: send_status(e, 1);
1.1 deraadt 493: }
494:
1.155 dtucker 495: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 496: static time_t
1.89 markus 497: reaper(void)
498: {
1.175 dtucker 499: time_t deadline = 0, now = monotime();
1.89 markus 500: Identity *id, *nxt;
501:
1.221 djm 502: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
503: nxt = TAILQ_NEXT(id, next);
504: if (id->death == 0)
505: continue;
506: if (now >= id->death) {
507: debug("expiring key '%s'", id->comment);
508: TAILQ_REMOVE(&idtab->idlist, id, next);
509: free_identity(id);
510: idtab->nentries--;
511: } else
512: deadline = (deadline == 0) ? id->death :
513: MINIMUM(deadline, id->death);
1.89 markus 514: }
1.155 dtucker 515: if (deadline == 0 || deadline <= now)
516: return 0;
517: else
518: return (deadline - now);
1.89 markus 519: }
520:
521: static void
1.221 djm 522: process_add_identity(SocketEntry *e)
1.1 deraadt 523: {
1.157 canacar 524: Identity *id;
1.194 markus 525: int success = 0, confirm = 0;
1.228 markus 526: u_int seconds, maxsign;
1.238 djm 527: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 528: time_t death = 0;
1.194 markus 529: struct sshkey *k = NULL;
530: u_char ctype;
531: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 532:
1.221 djm 533: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
534: k == NULL ||
1.194 markus 535: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
536: error("%s: decode private key: %s", __func__, ssh_err(r));
537: goto err;
538: }
1.236 djm 539: if ((r = sshkey_shield_private(k)) != 0) {
540: error("%s: shield private key: %s", __func__, ssh_err(r));
541: goto err;
542: }
1.194 markus 543: while (sshbuf_len(e->request)) {
544: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
545: error("%s: buffer error: %s", __func__, ssh_err(r));
546: goto err;
547: }
548: switch (ctype) {
1.94 markus 549: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 550: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
551: error("%s: bad lifetime constraint: %s",
552: __func__, ssh_err(r));
553: goto err;
554: }
555: death = monotime() + seconds;
1.94 markus 556: break;
1.107 markus 557: case SSH_AGENT_CONSTRAIN_CONFIRM:
558: confirm = 1;
559: break;
1.228 markus 560: case SSH_AGENT_CONSTRAIN_MAXSIGN:
561: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
562: error("%s: bad maxsign constraint: %s",
563: __func__, ssh_err(r));
564: goto err;
565: }
566: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
567: error("%s: cannot enable maxsign: %s",
568: __func__, ssh_err(r));
569: goto err;
570: }
571: break;
1.238 djm 572: case SSH_AGENT_CONSTRAIN_EXTENSION:
573: if ((r = sshbuf_get_cstring(e->request,
574: &ext_name, NULL)) != 0) {
575: error("%s: cannot parse extension: %s",
576: __func__, ssh_err(r));
577: goto err;
578: }
579: debug("%s: constraint ext %s", __func__, ext_name);
580: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
581: if (sk_provider != NULL) {
582: error("%s already set", ext_name);
583: goto err;
584: }
585: if ((r = sshbuf_get_cstring(e->request,
586: &sk_provider, NULL)) != 0) {
587: error("%s: cannot parse %s: %s",
588: __func__, ext_name, ssh_err(r));
589: goto err;
590: }
591: } else {
592: error("%s: unsupported constraint \"%s\"",
593: __func__, ext_name);
594: goto err;
595: }
596: free(ext_name);
597: break;
1.94 markus 598: default:
1.194 markus 599: error("%s: Unknown constraint %d", __func__, ctype);
600: err:
1.238 djm 601: free(sk_provider);
602: free(ext_name);
1.194 markus 603: sshbuf_reset(e->request);
1.173 djm 604: free(comment);
1.194 markus 605: sshkey_free(k);
1.158 djm 606: goto send;
1.94 markus 607: }
608: }
1.238 djm 609: if (sk_provider != NULL) {
610: if (sshkey_type_plain(k->type) != KEY_ECDSA_SK) {
611: error("Cannot add provider: %s is not a security key",
612: sshkey_type(k));
613: free(sk_provider);
614: goto send;
615: }
616: if (match_pattern_list(sk_provider,
617: provider_whitelist, 0) != 1) {
618: error("Refusing add key: provider %s not whitelisted",
619: sk_provider);
620: free(sk_provider);
621: goto send;
622: }
623: }
1.194 markus 624:
1.158 djm 625: success = 1;
1.106 marc 626: if (lifetime && !death)
1.175 dtucker 627: death = monotime() + lifetime;
1.221 djm 628: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 629: id = xcalloc(1, sizeof(Identity));
1.221 djm 630: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 631: /* Increment the number of identities. */
1.221 djm 632: idtab->nentries++;
1.33 markus 633: } else {
1.228 markus 634: /* key state might have been updated */
635: sshkey_free(id->key);
1.173 djm 636: free(id->comment);
1.238 djm 637: free(id->sk_provider);
1.33 markus 638: }
1.228 markus 639: id->key = k;
1.157 canacar 640: id->comment = comment;
641: id->death = death;
642: id->confirm = confirm;
1.238 djm 643: id->sk_provider = sk_provider;
644:
645: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
646: SSH_FP_DEFAULT)) == NULL)
647: fatal("%s: sshkey_fingerprint failed", __func__);
648: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
649: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
650: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
651: free(fp);
1.33 markus 652: send:
1.194 markus 653: send_status(e, success);
1.1 deraadt 654: }
655:
1.88 markus 656: /* XXX todo: encrypt sensitive data with passphrase */
657: static void
658: process_lock_agent(SocketEntry *e, int lock)
659: {
1.203 dtucker 660: int r, success = 0, delay;
1.213 djm 661: char *passwd;
662: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 663: static u_int fail_count = 0;
664: size_t pwlen;
665:
1.226 djm 666: /*
667: * This is deliberately fatal: the user has requested that we lock,
668: * but we can't parse their request properly. The only safe thing to
669: * do is abort.
670: */
1.203 dtucker 671: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
672: fatal("%s: buffer error: %s", __func__, ssh_err(r));
673: if (pwlen == 0) {
674: debug("empty password not supported");
675: } else if (locked && !lock) {
676: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
677: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
678: fatal("bcrypt_pbkdf");
1.213 djm 679: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 680: debug("agent unlocked");
681: locked = 0;
682: fail_count = 0;
1.213 djm 683: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 684: success = 1;
685: } else {
686: /* delay in 0.1s increments up to 10s */
687: if (fail_count < 100)
688: fail_count++;
689: delay = 100000 * fail_count;
690: debug("unlock failed, delaying %0.1lf seconds",
691: (double)delay/1000000);
692: usleep(delay);
693: }
694: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 695: } else if (!locked && lock) {
1.203 dtucker 696: debug("agent locked");
1.88 markus 697: locked = 1;
1.203 dtucker 698: arc4random_buf(lock_salt, sizeof(lock_salt));
699: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 700: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 701: fatal("bcrypt_pbkdf");
1.88 markus 702: success = 1;
703: }
1.203 dtucker 704: explicit_bzero(passwd, pwlen);
1.173 djm 705: free(passwd);
1.194 markus 706: send_status(e, success);
1.88 markus 707: }
708:
709: static void
1.221 djm 710: no_identities(SocketEntry *e)
1.88 markus 711: {
1.194 markus 712: struct sshbuf *msg;
713: int r;
1.88 markus 714:
1.194 markus 715: if ((msg = sshbuf_new()) == NULL)
716: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 717: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 718: (r = sshbuf_put_u32(msg, 0)) != 0 ||
719: (r = sshbuf_put_stringb(e->output, msg)) != 0)
720: fatal("%s: buffer error: %s", __func__, ssh_err(r));
721: sshbuf_free(msg);
1.88 markus 722: }
1.59 markus 723:
1.163 markus 724: #ifdef ENABLE_PKCS11
1.59 markus 725: static void
1.158 djm 726: process_add_smartcard_key(SocketEntry *e)
1.59 markus 727: {
1.226 djm 728: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 729: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 730: u_int seconds;
1.174 dtucker 731: time_t death = 0;
1.194 markus 732: u_char type;
733: struct sshkey **keys = NULL, *k;
1.84 markus 734: Identity *id;
1.75 deraadt 735:
1.194 markus 736: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 737: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
738: error("%s: buffer error: %s", __func__, ssh_err(r));
739: goto send;
740: }
1.194 markus 741:
742: while (sshbuf_len(e->request)) {
1.226 djm 743: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
744: error("%s: buffer error: %s", __func__, ssh_err(r));
745: goto send;
746: }
1.194 markus 747: switch (type) {
1.110 djm 748: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 749: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
750: error("%s: buffer error: %s",
1.194 markus 751: __func__, ssh_err(r));
1.226 djm 752: goto send;
753: }
1.194 markus 754: death = monotime() + seconds;
1.110 djm 755: break;
756: case SSH_AGENT_CONSTRAIN_CONFIRM:
757: confirm = 1;
758: break;
759: default:
1.221 djm 760: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 761: goto send;
1.110 djm 762: }
763: }
1.215 djm 764: if (realpath(provider, canonical_provider) == NULL) {
765: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
766: provider, strerror(errno));
767: goto send;
768: }
1.238 djm 769: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 770: verbose("refusing PKCS#11 add of \"%.100s\": "
771: "provider not whitelisted", canonical_provider);
772: goto send;
773: }
774: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 775: if (lifetime && !death)
1.175 dtucker 776: death = monotime() + lifetime;
1.110 djm 777:
1.215 djm 778: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 779: for (i = 0; i < count; i++) {
1.84 markus 780: k = keys[i];
1.221 djm 781: if (lookup_identity(k) == NULL) {
1.163 markus 782: id = xcalloc(1, sizeof(Identity));
1.84 markus 783: id->key = k;
1.215 djm 784: id->provider = xstrdup(canonical_provider);
785: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 786: id->death = death;
787: id->confirm = confirm;
1.221 djm 788: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
789: idtab->nentries++;
1.84 markus 790: success = 1;
791: } else {
1.194 markus 792: sshkey_free(k);
1.84 markus 793: }
794: keys[i] = NULL;
1.59 markus 795: }
796: send:
1.173 djm 797: free(pin);
798: free(provider);
799: free(keys);
1.194 markus 800: send_status(e, success);
1.59 markus 801: }
802:
803: static void
804: process_remove_smartcard_key(SocketEntry *e)
805: {
1.217 djm 806: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 807: int r, success = 0;
1.163 markus 808: Identity *id, *nxt;
1.59 markus 809:
1.194 markus 810: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 811: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
812: error("%s: buffer error: %s", __func__, ssh_err(r));
813: goto send;
814: }
1.173 djm 815: free(pin);
1.59 markus 816:
1.217 djm 817: if (realpath(provider, canonical_provider) == NULL) {
818: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
819: provider, strerror(errno));
820: goto send;
821: }
822:
823: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 824: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
825: nxt = TAILQ_NEXT(id, next);
826: /* Skip file--based keys */
827: if (id->provider == NULL)
828: continue;
829: if (!strcmp(canonical_provider, id->provider)) {
830: TAILQ_REMOVE(&idtab->idlist, id, next);
831: free_identity(id);
832: idtab->nentries--;
1.59 markus 833: }
834: }
1.217 djm 835: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 836: success = 1;
837: else
1.221 djm 838: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 839: send:
1.173 djm 840: free(provider);
1.194 markus 841: send_status(e, success);
1.59 markus 842: }
1.163 markus 843: #endif /* ENABLE_PKCS11 */
1.59 markus 844:
1.33 markus 845: /* dispatch incoming messages */
846:
1.223 djm 847: static int
848: process_message(u_int socknum)
1.1 deraadt 849: {
1.194 markus 850: u_int msg_len;
851: u_char type;
852: const u_char *cp;
853: int r;
1.223 djm 854: SocketEntry *e;
855:
856: if (socknum >= sockets_alloc) {
857: fatal("%s: socket number %u >= allocated %u",
858: __func__, socknum, sockets_alloc);
859: }
860: e = &sockets[socknum];
1.89 markus 861:
1.194 markus 862: if (sshbuf_len(e->input) < 5)
1.223 djm 863: return 0; /* Incomplete message header. */
1.194 markus 864: cp = sshbuf_ptr(e->input);
865: msg_len = PEEK_U32(cp);
1.223 djm 866: if (msg_len > AGENT_MAX_LEN) {
867: debug("%s: socket %u (fd=%d) message too long %u > %u",
868: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
869: return -1;
1.21 markus 870: }
1.194 markus 871: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 872: return 0; /* Incomplete message body. */
1.87 markus 873:
874: /* move the current input to e->request */
1.194 markus 875: sshbuf_reset(e->request);
876: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 877: (r = sshbuf_get_u8(e->request, &type)) != 0) {
878: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
879: r == SSH_ERR_STRING_TOO_LARGE) {
880: debug("%s: buffer error: %s", __func__, ssh_err(r));
881: return -1;
882: }
1.194 markus 883: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 884: }
885:
886: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 887:
1.230 djm 888: /* check whether agent is locked */
1.88 markus 889: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 890: sshbuf_reset(e->request);
1.88 markus 891: switch (type) {
892: case SSH2_AGENTC_REQUEST_IDENTITIES:
893: /* send empty lists */
1.221 djm 894: no_identities(e);
1.88 markus 895: break;
896: default:
897: /* send a fail message for all other request types */
1.194 markus 898: send_status(e, 0);
1.88 markus 899: }
1.223 djm 900: return 0;
1.88 markus 901: }
902:
1.21 markus 903: switch (type) {
1.88 markus 904: case SSH_AGENTC_LOCK:
905: case SSH_AGENTC_UNLOCK:
906: process_lock_agent(e, type == SSH_AGENTC_LOCK);
907: break;
1.21 markus 908: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 909: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 910: break;
911: /* ssh2 */
912: case SSH2_AGENTC_SIGN_REQUEST:
913: process_sign_request2(e);
914: break;
915: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 916: process_request_identities(e);
1.33 markus 917: break;
918: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 919: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 920: process_add_identity(e);
1.33 markus 921: break;
922: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 923: process_remove_identity(e);
1.33 markus 924: break;
925: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 926: process_remove_all_identities(e);
1.21 markus 927: break;
1.163 markus 928: #ifdef ENABLE_PKCS11
1.59 markus 929: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 930: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 931: process_add_smartcard_key(e);
1.75 deraadt 932: break;
1.59 markus 933: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
934: process_remove_smartcard_key(e);
1.75 deraadt 935: break;
1.163 markus 936: #endif /* ENABLE_PKCS11 */
1.21 markus 937: default:
938: /* Unknown message. Respond with failure. */
939: error("Unknown message %d", type);
1.194 markus 940: sshbuf_reset(e->request);
941: send_status(e, 0);
1.21 markus 942: break;
943: }
1.223 djm 944: return 0;
1.1 deraadt 945: }
946:
1.55 itojun 947: static void
1.73 stevesk 948: new_socket(sock_type type, int fd)
1.1 deraadt 949: {
1.112 markus 950: u_int i, old_alloc, new_alloc;
1.96 deraadt 951:
1.119 djm 952: set_nonblock(fd);
1.21 markus 953:
954: if (fd > max_fd)
955: max_fd = fd;
956:
957: for (i = 0; i < sockets_alloc; i++)
958: if (sockets[i].type == AUTH_UNUSED) {
959: sockets[i].fd = fd;
1.194 markus 960: if ((sockets[i].input = sshbuf_new()) == NULL)
961: fatal("%s: sshbuf_new failed", __func__);
962: if ((sockets[i].output = sshbuf_new()) == NULL)
963: fatal("%s: sshbuf_new failed", __func__);
964: if ((sockets[i].request = sshbuf_new()) == NULL)
965: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 966: sockets[i].type = type;
1.21 markus 967: return;
968: }
969: old_alloc = sockets_alloc;
1.112 markus 970: new_alloc = sockets_alloc + 10;
1.200 deraadt 971: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 972: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 973: sockets[i].type = AUTH_UNUSED;
1.112 markus 974: sockets_alloc = new_alloc;
1.21 markus 975: sockets[old_alloc].fd = fd;
1.194 markus 976: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
977: fatal("%s: sshbuf_new failed", __func__);
978: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
979: fatal("%s: sshbuf_new failed", __func__);
980: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
981: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 982: sockets[old_alloc].type = type;
1.1 deraadt 983: }
984:
1.55 itojun 985: static int
1.223 djm 986: handle_socket_read(u_int socknum)
1.1 deraadt 987: {
1.223 djm 988: struct sockaddr_un sunaddr;
989: socklen_t slen;
990: uid_t euid;
991: gid_t egid;
992: int fd;
993:
994: slen = sizeof(sunaddr);
995: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 996: if (fd == -1) {
1.223 djm 997: error("accept from AUTH_SOCKET: %s", strerror(errno));
998: return -1;
999: }
1.237 deraadt 1000: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1001: error("getpeereid %d failed: %s", fd, strerror(errno));
1002: close(fd);
1003: return -1;
1004: }
1005: if ((euid != 0) && (getuid() != euid)) {
1006: error("uid mismatch: peer euid %u != uid %u",
1007: (u_int) euid, (u_int) getuid());
1008: close(fd);
1009: return -1;
1010: }
1011: new_socket(AUTH_CONNECTION, fd);
1012: return 0;
1013: }
1014:
1015: static int
1016: handle_conn_read(u_int socknum)
1017: {
1.233 djm 1018: char buf[AGENT_RBUF_LEN];
1.223 djm 1019: ssize_t len;
1020: int r;
1021:
1022: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1023: if (len == -1) {
1024: if (errno == EAGAIN || errno == EINTR)
1025: return 0;
1026: error("%s: read error on socket %u (fd %d): %s",
1027: __func__, socknum, sockets[socknum].fd,
1028: strerror(errno));
1029: }
1030: return -1;
1031: }
1032: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1033: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1034: explicit_bzero(buf, sizeof(buf));
1035: process_message(socknum);
1036: return 0;
1037: }
1038:
1039: static int
1040: handle_conn_write(u_int socknum)
1041: {
1042: ssize_t len;
1043: int r;
1044:
1045: if (sshbuf_len(sockets[socknum].output) == 0)
1046: return 0; /* shouldn't happen */
1047: if ((len = write(sockets[socknum].fd,
1048: sshbuf_ptr(sockets[socknum].output),
1049: sshbuf_len(sockets[socknum].output))) <= 0) {
1050: if (len == -1) {
1051: if (errno == EAGAIN || errno == EINTR)
1052: return 0;
1053: error("%s: read error on socket %u (fd %d): %s",
1054: __func__, socknum, sockets[socknum].fd,
1055: strerror(errno));
1056: }
1057: return -1;
1058: }
1059: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1060: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1061: return 0;
1062: }
1063:
1064: static void
1.231 djm 1065: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1066: {
1067: size_t i;
1.231 djm 1068: u_int socknum, activefds = npfd;
1.223 djm 1069:
1070: for (i = 0; i < npfd; i++) {
1071: if (pfd[i].revents == 0)
1072: continue;
1073: /* Find sockets entry */
1074: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1075: if (sockets[socknum].type != AUTH_SOCKET &&
1076: sockets[socknum].type != AUTH_CONNECTION)
1077: continue;
1078: if (pfd[i].fd == sockets[socknum].fd)
1079: break;
1080: }
1081: if (socknum >= sockets_alloc) {
1082: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1083: continue;
1084: }
1085: /* Process events */
1086: switch (sockets[socknum].type) {
1087: case AUTH_SOCKET:
1.231 djm 1088: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1089: break;
1090: if (npfd > maxfds) {
1091: debug3("out of fds (active %u >= limit %u); "
1092: "skipping accept", activefds, maxfds);
1093: break;
1094: }
1095: if (handle_socket_read(socknum) == 0)
1096: activefds++;
1.223 djm 1097: break;
1098: case AUTH_CONNECTION:
1099: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1100: handle_conn_read(socknum) != 0) {
1.231 djm 1101: goto close_sock;
1102: }
1103: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1104: handle_conn_write(socknum) != 0) {
1105: close_sock:
1106: if (activefds == 0)
1107: fatal("activefds == 0 at close_sock");
1.223 djm 1108: close_socket(&sockets[socknum]);
1.231 djm 1109: activefds--;
1.223 djm 1110: break;
1111: }
1112: break;
1113: default:
1114: break;
1115: }
1116: }
1117: }
1118:
1119: static int
1.231 djm 1120: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1121: {
1122: struct pollfd *pfd = *pfdp;
1123: size_t i, j, npfd = 0;
1.174 dtucker 1124: time_t deadline;
1.233 djm 1125: int r;
1.46 markus 1126:
1.223 djm 1127: /* Count active sockets */
1.46 markus 1128: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1129: switch (sockets[i].type) {
1130: case AUTH_SOCKET:
1131: case AUTH_CONNECTION:
1.223 djm 1132: npfd++;
1.21 markus 1133: break;
1134: case AUTH_UNUSED:
1135: break;
1136: default:
1137: fatal("Unknown socket type %d", sockets[i].type);
1138: break;
1139: }
1.46 markus 1140: }
1.223 djm 1141: if (npfd != *npfdp &&
1142: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1143: fatal("%s: recallocarray failed", __func__);
1144: *pfdp = pfd;
1145: *npfdp = npfd;
1.46 markus 1146:
1.223 djm 1147: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1148: switch (sockets[i].type) {
1149: case AUTH_SOCKET:
1.231 djm 1150: if (npfd > maxfds) {
1151: debug3("out of fds (active %zu >= limit %u); "
1152: "skipping arming listener", npfd, maxfds);
1153: break;
1154: }
1155: pfd[j].fd = sockets[i].fd;
1156: pfd[j].revents = 0;
1157: pfd[j].events = POLLIN;
1158: j++;
1159: break;
1.46 markus 1160: case AUTH_CONNECTION:
1.223 djm 1161: pfd[j].fd = sockets[i].fd;
1162: pfd[j].revents = 0;
1.233 djm 1163: /*
1164: * Only prepare to read if we can handle a full-size
1165: * input read buffer and enqueue a max size reply..
1166: */
1167: if ((r = sshbuf_check_reserve(sockets[i].input,
1168: AGENT_RBUF_LEN)) == 0 &&
1169: (r = sshbuf_check_reserve(sockets[i].output,
1170: AGENT_MAX_LEN)) == 0)
1171: pfd[j].events = POLLIN;
1172: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1173: fatal("%s: buffer error: %s",
1174: __func__, ssh_err(r));
1175: }
1.194 markus 1176: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1177: pfd[j].events |= POLLOUT;
1178: j++;
1.46 markus 1179: break;
1180: default:
1181: break;
1182: }
1183: }
1.155 dtucker 1184: deadline = reaper();
1185: if (parent_alive_interval != 0)
1186: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1187: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1188: if (deadline == 0) {
1.224 djm 1189: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1190: } else {
1.223 djm 1191: if (deadline > INT_MAX / 1000)
1192: *timeoutp = INT_MAX / 1000;
1193: else
1194: *timeoutp = deadline * 1000;
1.155 dtucker 1195: }
1.46 markus 1196: return (1);
1.21 markus 1197: }
1198:
1.55 itojun 1199: static void
1.113 markus 1200: cleanup_socket(void)
1.15 markus 1201: {
1.187 djm 1202: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1203: return;
1204: debug("%s: cleanup", __func__);
1.48 deraadt 1205: if (socket_name[0])
1206: unlink(socket_name);
1207: if (socket_dir[0])
1208: rmdir(socket_dir);
1.10 markus 1209: }
1210:
1.114 markus 1211: void
1.15 markus 1212: cleanup_exit(int i)
1213: {
1.113 markus 1214: cleanup_socket();
1215: _exit(i);
1.15 markus 1216: }
1217:
1.135 deraadt 1218: /*ARGSUSED*/
1.55 itojun 1219: static void
1.48 deraadt 1220: cleanup_handler(int sig)
1221: {
1.113 markus 1222: cleanup_socket();
1.163 markus 1223: #ifdef ENABLE_PKCS11
1224: pkcs11_terminate();
1225: #endif
1.48 deraadt 1226: _exit(2);
1.113 markus 1227: }
1228:
1.68 markus 1229: static void
1.155 dtucker 1230: check_parent_exists(void)
1.68 markus 1231: {
1.172 dtucker 1232: /*
1233: * If our parent has exited then getppid() will return (pid_t)1,
1234: * so testing for that should be safe.
1235: */
1236: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1237: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1238: cleanup_socket();
1239: _exit(2);
1.68 markus 1240: }
1.48 deraadt 1241: }
1242:
1.55 itojun 1243: static void
1.50 itojun 1244: usage(void)
1.15 markus 1245: {
1.184 deraadt 1246: fprintf(stderr,
1.202 jmc 1247: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1248: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1249: " ssh-agent [-c | -s] -k\n");
1.21 markus 1250: exit(1);
1.15 markus 1251: }
1252:
1.2 provos 1253: int
1254: main(int ac, char **av)
1.1 deraadt 1255: {
1.201 djm 1256: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1257: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1258: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1259: struct rlimit rlim;
1.96 deraadt 1260: extern int optind;
1.98 stevesk 1261: extern char *optarg;
1.21 markus 1262: pid_t pid;
1.96 deraadt 1263: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1264: size_t len;
1.189 djm 1265: mode_t prev_mask;
1.224 djm 1266: int timeout = -1; /* INFTIM */
1.223 djm 1267: struct pollfd *pfd = NULL;
1268: size_t npfd = 0;
1.231 djm 1269: u_int maxfds;
1.123 djm 1270:
1271: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1272: sanitise_stdfd();
1.99 markus 1273:
1274: /* drop */
1275: setegid(getgid());
1276: setgid(getgid());
1.53 markus 1277:
1.231 djm 1278: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1279: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1280:
1.185 markus 1281: #ifdef WITH_OPENSSL
1.170 djm 1282: OpenSSL_add_all_algorithms();
1.185 markus 1283: #endif
1.21 markus 1284:
1.215 djm 1285: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1286: switch (ch) {
1.192 djm 1287: case 'E':
1288: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1289: if (fingerprint_hash == -1)
1290: fatal("Invalid hash algorithm \"%s\"", optarg);
1291: break;
1.21 markus 1292: case 'c':
1293: if (s_flag)
1294: usage();
1295: c_flag++;
1296: break;
1297: case 'k':
1298: k_flag++;
1299: break;
1.215 djm 1300: case 'P':
1.238 djm 1301: if (provider_whitelist != NULL)
1.215 djm 1302: fatal("-P option already specified");
1.238 djm 1303: provider_whitelist = xstrdup(optarg);
1.215 djm 1304: break;
1.21 markus 1305: case 's':
1306: if (c_flag)
1307: usage();
1308: s_flag++;
1309: break;
1.57 markus 1310: case 'd':
1.201 djm 1311: if (d_flag || D_flag)
1.57 markus 1312: usage();
1313: d_flag++;
1314: break;
1.201 djm 1315: case 'D':
1316: if (d_flag || D_flag)
1317: usage();
1318: D_flag++;
1319: break;
1.86 markus 1320: case 'a':
1321: agentsocket = optarg;
1.106 marc 1322: break;
1323: case 't':
1324: if ((lifetime = convtime(optarg)) == -1) {
1325: fprintf(stderr, "Invalid lifetime\n");
1326: usage();
1327: }
1.86 markus 1328: break;
1.21 markus 1329: default:
1330: usage();
1331: }
1332: }
1333: ac -= optind;
1334: av += optind;
1335:
1.201 djm 1336: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1337: usage();
1338:
1.238 djm 1339: if (provider_whitelist == NULL)
1340: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1341:
1.85 markus 1342: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1343: shell = getenv("SHELL");
1.161 tobias 1344: if (shell != NULL && (len = strlen(shell)) > 2 &&
1345: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1346: c_flag = 1;
1347: }
1348: if (k_flag) {
1.136 deraadt 1349: const char *errstr = NULL;
1350:
1.21 markus 1351: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1352: if (pidstr == NULL) {
1353: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1354: SSH_AGENTPID_ENV_NAME);
1.21 markus 1355: exit(1);
1356: }
1.136 deraadt 1357: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1358: if (errstr) {
1359: fprintf(stderr,
1360: "%s=\"%s\", which is not a good PID: %s\n",
1361: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1362: exit(1);
1363: }
1364: if (kill(pid, SIGTERM) == -1) {
1365: perror("kill");
1366: exit(1);
1367: }
1368: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1369: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1370: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1371: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1372: exit(0);
1373: }
1.231 djm 1374:
1375: /*
1376: * Minimum file descriptors:
1377: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1378: * a few spare for libc / stack protectors / sanitisers, etc.
1379: */
1380: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1381: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1382: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1383: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1384: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1385:
1.21 markus 1386: parent_pid = getpid();
1387:
1.86 markus 1388: if (agentsocket == NULL) {
1389: /* Create private directory for agent socket */
1.171 djm 1390: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1391: if (mkdtemp(socket_dir) == NULL) {
1392: perror("mkdtemp: private socket dir");
1393: exit(1);
1394: }
1.91 mpech 1395: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1396: (long)parent_pid);
1.86 markus 1397: } else {
1398: /* Try to use specified agent socket */
1399: socket_dir[0] = '\0';
1400: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1401: }
1402:
1.23 markus 1403: /*
1404: * Create socket early so it will exist before command gets run from
1405: * the parent.
1406: */
1.189 djm 1407: prev_mask = umask(0177);
1.188 millert 1408: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1409: if (sock < 0) {
1.188 millert 1410: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1411: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1412: cleanup_exit(1);
1413: }
1.189 djm 1414: umask(prev_mask);
1.46 markus 1415:
1.23 markus 1416: /*
1417: * Fork, and have the parent execute the command, if any, or present
1418: * the socket data. The child continues as the authentication agent.
1419: */
1.201 djm 1420: if (D_flag || d_flag) {
1421: log_init(__progname,
1422: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1423: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1424: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1425: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1426: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1427: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1428: fflush(stdout);
1.57 markus 1429: goto skip;
1430: }
1.21 markus 1431: pid = fork();
1432: if (pid == -1) {
1433: perror("fork");
1.81 stevesk 1434: cleanup_exit(1);
1.21 markus 1435: }
1436: if (pid != 0) { /* Parent - execute the given command. */
1437: close(sock);
1.91 mpech 1438: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1439: if (ac == 0) {
1440: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1441: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1442: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1443: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1444: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1445: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1446: exit(0);
1447: }
1.36 deraadt 1448: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1449: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1450: perror("setenv");
1451: exit(1);
1452: }
1.21 markus 1453: execvp(av[0], av);
1454: perror(av[0]);
1455: exit(1);
1456: }
1.81 stevesk 1457: /* child */
1458: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1459:
1460: if (setsid() == -1) {
1.81 stevesk 1461: error("setsid: %s", strerror(errno));
1.67 stevesk 1462: cleanup_exit(1);
1463: }
1464:
1465: (void)chdir("/");
1.107 markus 1466: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1467: /* XXX might close listen socket */
1468: (void)dup2(fd, STDIN_FILENO);
1469: (void)dup2(fd, STDOUT_FILENO);
1470: (void)dup2(fd, STDERR_FILENO);
1471: if (fd > 2)
1472: close(fd);
1473: }
1.21 markus 1474:
1.41 markus 1475: /* deny core dumps, since memory contains unencrypted private keys */
1476: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1477: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1478: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1479: cleanup_exit(1);
1480: }
1.57 markus 1481:
1482: skip:
1.187 djm 1483:
1484: cleanup_pid = getpid();
1.163 markus 1485:
1486: #ifdef ENABLE_PKCS11
1487: pkcs11_init(0);
1488: #endif
1.21 markus 1489: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1490: if (ac > 0)
1491: parent_alive_interval = 10;
1.33 markus 1492: idtab_init();
1.61 markus 1493: signal(SIGPIPE, SIG_IGN);
1.201 djm 1494: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1495: signal(SIGHUP, cleanup_handler);
1496: signal(SIGTERM, cleanup_handler);
1.205 djm 1497:
1.215 djm 1498: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1499: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1500:
1.21 markus 1501: while (1) {
1.231 djm 1502: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1503: result = poll(pfd, npfd, timeout);
1.154 dtucker 1504: saved_errno = errno;
1.155 dtucker 1505: if (parent_alive_interval != 0)
1506: check_parent_exists();
1507: (void) reaper(); /* remove expired keys */
1.237 deraadt 1508: if (result == -1) {
1.154 dtucker 1509: if (saved_errno == EINTR)
1.21 markus 1510: continue;
1.223 djm 1511: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1512: } else if (result > 0)
1.231 djm 1513: after_poll(pfd, npfd, maxfds);
1.15 markus 1514: }
1.21 markus 1515: /* NOTREACHED */
1.1 deraadt 1516: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-agent.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh