Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.242
1.242 ! markus 1: /* $OpenBSD: ssh-agent.c,v 1.241 2019/11/12 22:36:44 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;
1.241 djm 277: char *helper, *verbosity = NULL, *fp = NULL;
1.238 djm 278: struct sshbuf *kbuf, *req, *resp;
279: u_char version;
1.241 djm 280: struct notifier_ctx *notifier = NULL;
1.238 djm 281:
282: debug3("%s: start for provider %s", __func__, provider);
283:
284: *sigp = NULL;
285: *lenp = 0;
286:
287: helper = getenv("SSH_SK_HELPER");
288: if (helper == NULL || strlen(helper) == 0)
289: helper = _PATH_SSH_SK_HELPER;
290: if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
291: verbosity = "-vvv";
292:
293: /* Start helper */
294: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
295: error("socketpair: %s", strerror(errno));
296: return SSH_ERR_SYSTEM_ERROR;
297: }
298: if ((pid = fork()) == -1) {
299: error("fork: %s", strerror(errno));
300: close(pair[0]);
301: close(pair[1]);
302: return SSH_ERR_SYSTEM_ERROR;
303: }
304: if (pid == 0) {
305: if ((dup2(pair[1], STDIN_FILENO) == -1) ||
306: (dup2(pair[1], STDOUT_FILENO) == -1))
307: fatal("%s: dup2: %s", __func__, ssh_err(r));
308: close(pair[0]);
309: close(pair[1]);
310: closefrom(STDERR_FILENO + 1);
311: debug("%s: starting %s %s", __func__, helper,
312: verbosity == NULL ? "" : verbosity);
313: execlp(helper, helper, verbosity, (char *)NULL);
314: fatal("%s: execlp: %s", __func__, strerror(errno));
315: }
316: close(pair[1]);
317:
318: if ((kbuf = sshbuf_new()) == NULL ||
319: (req = sshbuf_new()) == NULL ||
320: (resp = sshbuf_new()) == NULL)
321: fatal("%s: sshbuf_new failed", __func__);
322:
323: if ((r = sshkey_private_serialize(key, kbuf)) != 0 ||
324: (r = sshbuf_put_stringb(req, kbuf)) != 0 ||
325: (r = sshbuf_put_cstring(req, provider)) != 0 ||
326: (r = sshbuf_put_string(req, data, datalen)) != 0 ||
327: (r = sshbuf_put_u32(req, compat)) != 0)
328: fatal("%s: compose: %s", __func__, ssh_err(r));
329: if ((r = ssh_msg_send(pair[0], SSH_SK_HELPER_VERSION, req)) != 0) {
330: error("%s: send: %s", __func__, ssh_err(r));
331: goto out;
332: }
1.241 djm 333: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
334: SSH_FP_DEFAULT)) == NULL)
335: fatal("%s: sshkey_fingerprint failed", __func__);
336: notifier = notify_start(0,
337: "Confirm user presence for key %s %s", sshkey_type(key), fp);
1.238 djm 338: if ((r = ssh_msg_recv(pair[0], resp)) != 0) {
339: error("%s: receive: %s", __func__, ssh_err(r));
340: goto out;
341: }
1.241 djm 342: notify_complete(notifier);
343: notifier = NULL;
1.238 djm 344: if ((r = sshbuf_get_u8(resp, &version)) != 0) {
345: error("%s: parse version: %s", __func__, ssh_err(r));
346: goto out;
347: }
348: if (version != SSH_SK_HELPER_VERSION) {
349: error("%s: unsupported version: got %u, expected %u",
350: __func__, version, SSH_SK_HELPER_VERSION);
351: r = SSH_ERR_INVALID_FORMAT;
352: goto out;
353: }
354: if ((r = sshbuf_get_string(resp, sigp, lenp)) != 0) {
355: error("%s: parse signature: %s", __func__, ssh_err(r));
356: r = SSH_ERR_INVALID_FORMAT;
357: goto out;
358: }
359: if (sshbuf_len(resp) != 0) {
360: error("%s: trailing data in response", __func__);
361: r = SSH_ERR_INVALID_FORMAT;
362: goto out;
363: }
364: /* success */
365: r = 0;
366: out:
367: while (waitpid(pid, &status, 0) == -1) {
368: if (errno != EINTR)
369: fatal("%s: waitpid: %s", __func__, ssh_err(r));
370: }
1.241 djm 371: notify_complete(notifier);
1.238 djm 372: if (!WIFEXITED(status)) {
373: error("%s: helper %s exited abnormally", __func__, helper);
374: if (r == 0)
375: r = SSH_ERR_SYSTEM_ERROR;
376: } else if (WEXITSTATUS(status) != 0) {
377: error("%s: helper %s exited with non-zero exit status",
378: __func__, helper);
379: if (r == 0)
380: r = SSH_ERR_SYSTEM_ERROR;
381: }
382: if (r != 0) {
383: freezero(*sigp, *lenp);
384: *sigp = NULL;
385: *lenp = 0;
386: }
387: sshbuf_free(kbuf);
388: sshbuf_free(req);
389: sshbuf_free(resp);
390: return r;
391: }
392:
1.33 markus 393: /* ssh2 only */
1.55 itojun 394: static void
1.33 markus 395: process_sign_request2(SocketEntry *e)
396: {
1.221 djm 397: const u_char *data;
398: u_char *signature = NULL;
399: size_t dlen, slen = 0;
1.194 markus 400: u_int compat = 0, flags;
401: int r, ok = -1;
402: struct sshbuf *msg;
1.221 djm 403: struct sshkey *key = NULL;
1.195 djm 404: struct identity *id;
1.194 markus 405:
1.195 djm 406: if ((msg = sshbuf_new()) == NULL)
407: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 408: if ((r = sshkey_froms(e->request, &key)) != 0 ||
409: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 410: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
411: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
412: goto send;
413: }
414:
1.221 djm 415: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 416: verbose("%s: %s key not found", __func__, sshkey_type(key));
417: goto send;
418: }
419: if (id->confirm && confirm_key(id) != 0) {
420: verbose("%s: user refused key", __func__);
421: goto send;
422: }
1.238 djm 423: if (id->sk_provider != NULL) {
424: if ((r = provider_sign(id->sk_provider, id->key, &signature,
425: &slen, data, dlen, agent_decode_alg(key, flags),
426: compat)) != 0) {
1.239 djm 427: error("%s: sign: %s", __func__, ssh_err(r));
1.238 djm 428: goto send;
429: }
430: } else {
431: if ((r = sshkey_sign(id->key, &signature, &slen,
1.239 djm 432: data, dlen, agent_decode_alg(key, flags),
433: NULL, compat)) != 0) {
1.238 djm 434: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
435: goto send;
436: }
1.33 markus 437: }
1.195 djm 438: /* Success */
439: ok = 0;
440: send:
441: sshkey_free(key);
1.33 markus 442: if (ok == 0) {
1.194 markus 443: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
444: (r = sshbuf_put_string(msg, signature, slen)) != 0)
445: fatal("%s: buffer error: %s", __func__, ssh_err(r));
446: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
447: fatal("%s: buffer error: %s", __func__, ssh_err(r));
448:
449: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
450: fatal("%s: buffer error: %s", __func__, ssh_err(r));
451:
452: sshbuf_free(msg);
1.173 djm 453: free(signature);
1.1 deraadt 454: }
455:
1.33 markus 456: /* shared */
1.55 itojun 457: static void
1.221 djm 458: process_remove_identity(SocketEntry *e)
1.1 deraadt 459: {
1.194 markus 460: int r, success = 0;
461: struct sshkey *key = NULL;
1.221 djm 462: Identity *id;
1.21 markus 463:
1.221 djm 464: if ((r = sshkey_froms(e->request, &key)) != 0) {
465: error("%s: get key: %s", __func__, ssh_err(r));
466: goto done;
467: }
468: if ((id = lookup_identity(key)) == NULL) {
469: debug("%s: key not found", __func__);
470: goto done;
471: }
472: /* We have this key, free it. */
473: if (idtab->nentries < 1)
474: fatal("%s: internal error: nentries %d",
475: __func__, idtab->nentries);
476: TAILQ_REMOVE(&idtab->idlist, id, next);
477: free_identity(id);
478: idtab->nentries--;
479: sshkey_free(key);
480: success = 1;
481: done:
1.194 markus 482: send_status(e, success);
1.1 deraadt 483: }
484:
1.55 itojun 485: static void
1.221 djm 486: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 487: {
1.78 provos 488: Identity *id;
1.21 markus 489:
490: /* Loop over all identities and clear the keys. */
1.221 djm 491: for (id = TAILQ_FIRST(&idtab->idlist); id;
492: id = TAILQ_FIRST(&idtab->idlist)) {
493: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 494: free_identity(id);
1.21 markus 495: }
496:
497: /* Mark that there are no identities. */
1.221 djm 498: idtab->nentries = 0;
1.21 markus 499:
500: /* Send success. */
1.194 markus 501: send_status(e, 1);
1.1 deraadt 502: }
503:
1.155 dtucker 504: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 505: static time_t
1.89 markus 506: reaper(void)
507: {
1.175 dtucker 508: time_t deadline = 0, now = monotime();
1.89 markus 509: Identity *id, *nxt;
510:
1.221 djm 511: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
512: nxt = TAILQ_NEXT(id, next);
513: if (id->death == 0)
514: continue;
515: if (now >= id->death) {
516: debug("expiring key '%s'", id->comment);
517: TAILQ_REMOVE(&idtab->idlist, id, next);
518: free_identity(id);
519: idtab->nentries--;
520: } else
521: deadline = (deadline == 0) ? id->death :
522: MINIMUM(deadline, id->death);
1.89 markus 523: }
1.155 dtucker 524: if (deadline == 0 || deadline <= now)
525: return 0;
526: else
527: return (deadline - now);
1.89 markus 528: }
529:
530: static void
1.221 djm 531: process_add_identity(SocketEntry *e)
1.1 deraadt 532: {
1.157 canacar 533: Identity *id;
1.194 markus 534: int success = 0, confirm = 0;
1.228 markus 535: u_int seconds, maxsign;
1.238 djm 536: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 537: time_t death = 0;
1.194 markus 538: struct sshkey *k = NULL;
539: u_char ctype;
540: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 541:
1.221 djm 542: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
543: k == NULL ||
1.194 markus 544: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
545: error("%s: decode private key: %s", __func__, ssh_err(r));
546: goto err;
547: }
548: while (sshbuf_len(e->request)) {
549: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
550: error("%s: buffer error: %s", __func__, ssh_err(r));
551: goto err;
552: }
553: switch (ctype) {
1.94 markus 554: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 555: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
556: error("%s: bad lifetime constraint: %s",
557: __func__, ssh_err(r));
558: goto err;
559: }
560: death = monotime() + seconds;
1.94 markus 561: break;
1.107 markus 562: case SSH_AGENT_CONSTRAIN_CONFIRM:
563: confirm = 1;
564: break;
1.228 markus 565: case SSH_AGENT_CONSTRAIN_MAXSIGN:
566: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
567: error("%s: bad maxsign constraint: %s",
568: __func__, ssh_err(r));
569: goto err;
570: }
571: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
572: error("%s: cannot enable maxsign: %s",
573: __func__, ssh_err(r));
574: goto err;
575: }
576: break;
1.238 djm 577: case SSH_AGENT_CONSTRAIN_EXTENSION:
578: if ((r = sshbuf_get_cstring(e->request,
579: &ext_name, NULL)) != 0) {
580: error("%s: cannot parse extension: %s",
581: __func__, ssh_err(r));
582: goto err;
583: }
584: debug("%s: constraint ext %s", __func__, ext_name);
585: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
586: if (sk_provider != NULL) {
587: error("%s already set", ext_name);
588: goto err;
589: }
590: if ((r = sshbuf_get_cstring(e->request,
591: &sk_provider, NULL)) != 0) {
592: error("%s: cannot parse %s: %s",
593: __func__, ext_name, ssh_err(r));
594: goto err;
595: }
596: } else {
597: error("%s: unsupported constraint \"%s\"",
598: __func__, ext_name);
599: goto err;
600: }
601: free(ext_name);
602: break;
1.94 markus 603: default:
1.194 markus 604: error("%s: Unknown constraint %d", __func__, ctype);
605: err:
1.238 djm 606: free(sk_provider);
607: free(ext_name);
1.194 markus 608: sshbuf_reset(e->request);
1.173 djm 609: free(comment);
1.194 markus 610: sshkey_free(k);
1.158 djm 611: goto send;
1.94 markus 612: }
613: }
1.238 djm 614: if (sk_provider != NULL) {
1.240 markus 615: if (!sshkey_is_sk(k)) {
1.238 djm 616: error("Cannot add provider: %s is not a security key",
617: sshkey_type(k));
618: free(sk_provider);
619: goto send;
620: }
621: if (match_pattern_list(sk_provider,
622: provider_whitelist, 0) != 1) {
623: error("Refusing add key: provider %s not whitelisted",
624: sk_provider);
625: free(sk_provider);
626: goto send;
627: }
1.242 ! markus 628: }
! 629: if ((r = sshkey_shield_private(k)) != 0) {
! 630: error("%s: shield private key: %s", __func__, ssh_err(r));
! 631: goto err;
1.238 djm 632: }
1.194 markus 633:
1.158 djm 634: success = 1;
1.106 marc 635: if (lifetime && !death)
1.175 dtucker 636: death = monotime() + lifetime;
1.221 djm 637: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 638: id = xcalloc(1, sizeof(Identity));
1.221 djm 639: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 640: /* Increment the number of identities. */
1.221 djm 641: idtab->nentries++;
1.33 markus 642: } else {
1.228 markus 643: /* key state might have been updated */
644: sshkey_free(id->key);
1.173 djm 645: free(id->comment);
1.238 djm 646: free(id->sk_provider);
1.33 markus 647: }
1.228 markus 648: id->key = k;
1.157 canacar 649: id->comment = comment;
650: id->death = death;
651: id->confirm = confirm;
1.238 djm 652: id->sk_provider = sk_provider;
653:
654: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
655: SSH_FP_DEFAULT)) == NULL)
656: fatal("%s: sshkey_fingerprint failed", __func__);
657: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
658: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
659: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
660: free(fp);
1.33 markus 661: send:
1.194 markus 662: send_status(e, success);
1.1 deraadt 663: }
664:
1.88 markus 665: /* XXX todo: encrypt sensitive data with passphrase */
666: static void
667: process_lock_agent(SocketEntry *e, int lock)
668: {
1.203 dtucker 669: int r, success = 0, delay;
1.213 djm 670: char *passwd;
671: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 672: static u_int fail_count = 0;
673: size_t pwlen;
674:
1.226 djm 675: /*
676: * This is deliberately fatal: the user has requested that we lock,
677: * but we can't parse their request properly. The only safe thing to
678: * do is abort.
679: */
1.203 dtucker 680: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
681: fatal("%s: buffer error: %s", __func__, ssh_err(r));
682: if (pwlen == 0) {
683: debug("empty password not supported");
684: } else if (locked && !lock) {
685: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
686: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
687: fatal("bcrypt_pbkdf");
1.213 djm 688: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 689: debug("agent unlocked");
690: locked = 0;
691: fail_count = 0;
1.213 djm 692: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 693: success = 1;
694: } else {
695: /* delay in 0.1s increments up to 10s */
696: if (fail_count < 100)
697: fail_count++;
698: delay = 100000 * fail_count;
699: debug("unlock failed, delaying %0.1lf seconds",
700: (double)delay/1000000);
701: usleep(delay);
702: }
703: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 704: } else if (!locked && lock) {
1.203 dtucker 705: debug("agent locked");
1.88 markus 706: locked = 1;
1.203 dtucker 707: arc4random_buf(lock_salt, sizeof(lock_salt));
708: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 709: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 710: fatal("bcrypt_pbkdf");
1.88 markus 711: success = 1;
712: }
1.203 dtucker 713: explicit_bzero(passwd, pwlen);
1.173 djm 714: free(passwd);
1.194 markus 715: send_status(e, success);
1.88 markus 716: }
717:
718: static void
1.221 djm 719: no_identities(SocketEntry *e)
1.88 markus 720: {
1.194 markus 721: struct sshbuf *msg;
722: int r;
1.88 markus 723:
1.194 markus 724: if ((msg = sshbuf_new()) == NULL)
725: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 726: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 727: (r = sshbuf_put_u32(msg, 0)) != 0 ||
728: (r = sshbuf_put_stringb(e->output, msg)) != 0)
729: fatal("%s: buffer error: %s", __func__, ssh_err(r));
730: sshbuf_free(msg);
1.88 markus 731: }
1.59 markus 732:
1.163 markus 733: #ifdef ENABLE_PKCS11
1.59 markus 734: static void
1.158 djm 735: process_add_smartcard_key(SocketEntry *e)
1.59 markus 736: {
1.226 djm 737: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 738: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 739: u_int seconds;
1.174 dtucker 740: time_t death = 0;
1.194 markus 741: u_char type;
742: struct sshkey **keys = NULL, *k;
1.84 markus 743: Identity *id;
1.75 deraadt 744:
1.194 markus 745: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 746: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
747: error("%s: buffer error: %s", __func__, ssh_err(r));
748: goto send;
749: }
1.194 markus 750:
751: while (sshbuf_len(e->request)) {
1.226 djm 752: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
753: error("%s: buffer error: %s", __func__, ssh_err(r));
754: goto send;
755: }
1.194 markus 756: switch (type) {
1.110 djm 757: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 758: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
759: error("%s: buffer error: %s",
1.194 markus 760: __func__, ssh_err(r));
1.226 djm 761: goto send;
762: }
1.194 markus 763: death = monotime() + seconds;
1.110 djm 764: break;
765: case SSH_AGENT_CONSTRAIN_CONFIRM:
766: confirm = 1;
767: break;
768: default:
1.221 djm 769: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 770: goto send;
1.110 djm 771: }
772: }
1.215 djm 773: if (realpath(provider, canonical_provider) == NULL) {
774: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
775: provider, strerror(errno));
776: goto send;
777: }
1.238 djm 778: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 779: verbose("refusing PKCS#11 add of \"%.100s\": "
780: "provider not whitelisted", canonical_provider);
781: goto send;
782: }
783: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 784: if (lifetime && !death)
1.175 dtucker 785: death = monotime() + lifetime;
1.110 djm 786:
1.215 djm 787: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 788: for (i = 0; i < count; i++) {
1.84 markus 789: k = keys[i];
1.221 djm 790: if (lookup_identity(k) == NULL) {
1.163 markus 791: id = xcalloc(1, sizeof(Identity));
1.84 markus 792: id->key = k;
1.215 djm 793: id->provider = xstrdup(canonical_provider);
794: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 795: id->death = death;
796: id->confirm = confirm;
1.221 djm 797: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
798: idtab->nentries++;
1.84 markus 799: success = 1;
800: } else {
1.194 markus 801: sshkey_free(k);
1.84 markus 802: }
803: keys[i] = NULL;
1.59 markus 804: }
805: send:
1.173 djm 806: free(pin);
807: free(provider);
808: free(keys);
1.194 markus 809: send_status(e, success);
1.59 markus 810: }
811:
812: static void
813: process_remove_smartcard_key(SocketEntry *e)
814: {
1.217 djm 815: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 816: int r, success = 0;
1.163 markus 817: Identity *id, *nxt;
1.59 markus 818:
1.194 markus 819: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 820: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
821: error("%s: buffer error: %s", __func__, ssh_err(r));
822: goto send;
823: }
1.173 djm 824: free(pin);
1.59 markus 825:
1.217 djm 826: if (realpath(provider, canonical_provider) == NULL) {
827: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
828: provider, strerror(errno));
829: goto send;
830: }
831:
832: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 833: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
834: nxt = TAILQ_NEXT(id, next);
835: /* Skip file--based keys */
836: if (id->provider == NULL)
837: continue;
838: if (!strcmp(canonical_provider, id->provider)) {
839: TAILQ_REMOVE(&idtab->idlist, id, next);
840: free_identity(id);
841: idtab->nentries--;
1.59 markus 842: }
843: }
1.217 djm 844: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 845: success = 1;
846: else
1.221 djm 847: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 848: send:
1.173 djm 849: free(provider);
1.194 markus 850: send_status(e, success);
1.59 markus 851: }
1.163 markus 852: #endif /* ENABLE_PKCS11 */
1.59 markus 853:
1.33 markus 854: /* dispatch incoming messages */
855:
1.223 djm 856: static int
857: process_message(u_int socknum)
1.1 deraadt 858: {
1.194 markus 859: u_int msg_len;
860: u_char type;
861: const u_char *cp;
862: int r;
1.223 djm 863: SocketEntry *e;
864:
865: if (socknum >= sockets_alloc) {
866: fatal("%s: socket number %u >= allocated %u",
867: __func__, socknum, sockets_alloc);
868: }
869: e = &sockets[socknum];
1.89 markus 870:
1.194 markus 871: if (sshbuf_len(e->input) < 5)
1.223 djm 872: return 0; /* Incomplete message header. */
1.194 markus 873: cp = sshbuf_ptr(e->input);
874: msg_len = PEEK_U32(cp);
1.223 djm 875: if (msg_len > AGENT_MAX_LEN) {
876: debug("%s: socket %u (fd=%d) message too long %u > %u",
877: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
878: return -1;
1.21 markus 879: }
1.194 markus 880: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 881: return 0; /* Incomplete message body. */
1.87 markus 882:
883: /* move the current input to e->request */
1.194 markus 884: sshbuf_reset(e->request);
885: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 886: (r = sshbuf_get_u8(e->request, &type)) != 0) {
887: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
888: r == SSH_ERR_STRING_TOO_LARGE) {
889: debug("%s: buffer error: %s", __func__, ssh_err(r));
890: return -1;
891: }
1.194 markus 892: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 893: }
894:
895: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 896:
1.230 djm 897: /* check whether agent is locked */
1.88 markus 898: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 899: sshbuf_reset(e->request);
1.88 markus 900: switch (type) {
901: case SSH2_AGENTC_REQUEST_IDENTITIES:
902: /* send empty lists */
1.221 djm 903: no_identities(e);
1.88 markus 904: break;
905: default:
906: /* send a fail message for all other request types */
1.194 markus 907: send_status(e, 0);
1.88 markus 908: }
1.223 djm 909: return 0;
1.88 markus 910: }
911:
1.21 markus 912: switch (type) {
1.88 markus 913: case SSH_AGENTC_LOCK:
914: case SSH_AGENTC_UNLOCK:
915: process_lock_agent(e, type == SSH_AGENTC_LOCK);
916: break;
1.21 markus 917: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 918: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 919: break;
920: /* ssh2 */
921: case SSH2_AGENTC_SIGN_REQUEST:
922: process_sign_request2(e);
923: break;
924: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 925: process_request_identities(e);
1.33 markus 926: break;
927: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 928: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 929: process_add_identity(e);
1.33 markus 930: break;
931: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 932: process_remove_identity(e);
1.33 markus 933: break;
934: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 935: process_remove_all_identities(e);
1.21 markus 936: break;
1.163 markus 937: #ifdef ENABLE_PKCS11
1.59 markus 938: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 939: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 940: process_add_smartcard_key(e);
1.75 deraadt 941: break;
1.59 markus 942: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
943: process_remove_smartcard_key(e);
1.75 deraadt 944: break;
1.163 markus 945: #endif /* ENABLE_PKCS11 */
1.21 markus 946: default:
947: /* Unknown message. Respond with failure. */
948: error("Unknown message %d", type);
1.194 markus 949: sshbuf_reset(e->request);
950: send_status(e, 0);
1.21 markus 951: break;
952: }
1.223 djm 953: return 0;
1.1 deraadt 954: }
955:
1.55 itojun 956: static void
1.73 stevesk 957: new_socket(sock_type type, int fd)
1.1 deraadt 958: {
1.112 markus 959: u_int i, old_alloc, new_alloc;
1.96 deraadt 960:
1.119 djm 961: set_nonblock(fd);
1.21 markus 962:
963: if (fd > max_fd)
964: max_fd = fd;
965:
966: for (i = 0; i < sockets_alloc; i++)
967: if (sockets[i].type == AUTH_UNUSED) {
968: sockets[i].fd = fd;
1.194 markus 969: if ((sockets[i].input = sshbuf_new()) == NULL)
970: fatal("%s: sshbuf_new failed", __func__);
971: if ((sockets[i].output = sshbuf_new()) == NULL)
972: fatal("%s: sshbuf_new failed", __func__);
973: if ((sockets[i].request = sshbuf_new()) == NULL)
974: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 975: sockets[i].type = type;
1.21 markus 976: return;
977: }
978: old_alloc = sockets_alloc;
1.112 markus 979: new_alloc = sockets_alloc + 10;
1.200 deraadt 980: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 981: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 982: sockets[i].type = AUTH_UNUSED;
1.112 markus 983: sockets_alloc = new_alloc;
1.21 markus 984: sockets[old_alloc].fd = fd;
1.194 markus 985: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
986: fatal("%s: sshbuf_new failed", __func__);
987: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
988: fatal("%s: sshbuf_new failed", __func__);
989: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
990: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 991: sockets[old_alloc].type = type;
1.1 deraadt 992: }
993:
1.55 itojun 994: static int
1.223 djm 995: handle_socket_read(u_int socknum)
1.1 deraadt 996: {
1.223 djm 997: struct sockaddr_un sunaddr;
998: socklen_t slen;
999: uid_t euid;
1000: gid_t egid;
1001: int fd;
1002:
1003: slen = sizeof(sunaddr);
1004: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1005: if (fd == -1) {
1.223 djm 1006: error("accept from AUTH_SOCKET: %s", strerror(errno));
1007: return -1;
1008: }
1.237 deraadt 1009: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1010: error("getpeereid %d failed: %s", fd, strerror(errno));
1011: close(fd);
1012: return -1;
1013: }
1014: if ((euid != 0) && (getuid() != euid)) {
1015: error("uid mismatch: peer euid %u != uid %u",
1016: (u_int) euid, (u_int) getuid());
1017: close(fd);
1018: return -1;
1019: }
1020: new_socket(AUTH_CONNECTION, fd);
1021: return 0;
1022: }
1023:
1024: static int
1025: handle_conn_read(u_int socknum)
1026: {
1.233 djm 1027: char buf[AGENT_RBUF_LEN];
1.223 djm 1028: ssize_t len;
1029: int r;
1030:
1031: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1032: if (len == -1) {
1033: if (errno == EAGAIN || errno == EINTR)
1034: return 0;
1035: error("%s: read error on socket %u (fd %d): %s",
1036: __func__, socknum, sockets[socknum].fd,
1037: strerror(errno));
1038: }
1039: return -1;
1040: }
1041: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1042: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1043: explicit_bzero(buf, sizeof(buf));
1044: process_message(socknum);
1045: return 0;
1046: }
1047:
1048: static int
1049: handle_conn_write(u_int socknum)
1050: {
1051: ssize_t len;
1052: int r;
1053:
1054: if (sshbuf_len(sockets[socknum].output) == 0)
1055: return 0; /* shouldn't happen */
1056: if ((len = write(sockets[socknum].fd,
1057: sshbuf_ptr(sockets[socknum].output),
1058: sshbuf_len(sockets[socknum].output))) <= 0) {
1059: if (len == -1) {
1060: if (errno == EAGAIN || errno == EINTR)
1061: return 0;
1062: error("%s: read error on socket %u (fd %d): %s",
1063: __func__, socknum, sockets[socknum].fd,
1064: strerror(errno));
1065: }
1066: return -1;
1067: }
1068: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1069: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1070: return 0;
1071: }
1072:
1073: static void
1.231 djm 1074: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1075: {
1076: size_t i;
1.231 djm 1077: u_int socknum, activefds = npfd;
1.223 djm 1078:
1079: for (i = 0; i < npfd; i++) {
1080: if (pfd[i].revents == 0)
1081: continue;
1082: /* Find sockets entry */
1083: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1084: if (sockets[socknum].type != AUTH_SOCKET &&
1085: sockets[socknum].type != AUTH_CONNECTION)
1086: continue;
1087: if (pfd[i].fd == sockets[socknum].fd)
1088: break;
1089: }
1090: if (socknum >= sockets_alloc) {
1091: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1092: continue;
1093: }
1094: /* Process events */
1095: switch (sockets[socknum].type) {
1096: case AUTH_SOCKET:
1.231 djm 1097: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1098: break;
1099: if (npfd > maxfds) {
1100: debug3("out of fds (active %u >= limit %u); "
1101: "skipping accept", activefds, maxfds);
1102: break;
1103: }
1104: if (handle_socket_read(socknum) == 0)
1105: activefds++;
1.223 djm 1106: break;
1107: case AUTH_CONNECTION:
1108: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1109: handle_conn_read(socknum) != 0) {
1.231 djm 1110: goto close_sock;
1111: }
1112: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1113: handle_conn_write(socknum) != 0) {
1114: close_sock:
1115: if (activefds == 0)
1116: fatal("activefds == 0 at close_sock");
1.223 djm 1117: close_socket(&sockets[socknum]);
1.231 djm 1118: activefds--;
1.223 djm 1119: break;
1120: }
1121: break;
1122: default:
1123: break;
1124: }
1125: }
1126: }
1127:
1128: static int
1.231 djm 1129: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1130: {
1131: struct pollfd *pfd = *pfdp;
1132: size_t i, j, npfd = 0;
1.174 dtucker 1133: time_t deadline;
1.233 djm 1134: int r;
1.46 markus 1135:
1.223 djm 1136: /* Count active sockets */
1.46 markus 1137: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1138: switch (sockets[i].type) {
1139: case AUTH_SOCKET:
1140: case AUTH_CONNECTION:
1.223 djm 1141: npfd++;
1.21 markus 1142: break;
1143: case AUTH_UNUSED:
1144: break;
1145: default:
1146: fatal("Unknown socket type %d", sockets[i].type);
1147: break;
1148: }
1.46 markus 1149: }
1.223 djm 1150: if (npfd != *npfdp &&
1151: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1152: fatal("%s: recallocarray failed", __func__);
1153: *pfdp = pfd;
1154: *npfdp = npfd;
1.46 markus 1155:
1.223 djm 1156: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1157: switch (sockets[i].type) {
1158: case AUTH_SOCKET:
1.231 djm 1159: if (npfd > maxfds) {
1160: debug3("out of fds (active %zu >= limit %u); "
1161: "skipping arming listener", npfd, maxfds);
1162: break;
1163: }
1164: pfd[j].fd = sockets[i].fd;
1165: pfd[j].revents = 0;
1166: pfd[j].events = POLLIN;
1167: j++;
1168: break;
1.46 markus 1169: case AUTH_CONNECTION:
1.223 djm 1170: pfd[j].fd = sockets[i].fd;
1171: pfd[j].revents = 0;
1.233 djm 1172: /*
1173: * Only prepare to read if we can handle a full-size
1174: * input read buffer and enqueue a max size reply..
1175: */
1176: if ((r = sshbuf_check_reserve(sockets[i].input,
1177: AGENT_RBUF_LEN)) == 0 &&
1178: (r = sshbuf_check_reserve(sockets[i].output,
1179: AGENT_MAX_LEN)) == 0)
1180: pfd[j].events = POLLIN;
1181: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1182: fatal("%s: buffer error: %s",
1183: __func__, ssh_err(r));
1184: }
1.194 markus 1185: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1186: pfd[j].events |= POLLOUT;
1187: j++;
1.46 markus 1188: break;
1189: default:
1190: break;
1191: }
1192: }
1.155 dtucker 1193: deadline = reaper();
1194: if (parent_alive_interval != 0)
1195: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1196: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1197: if (deadline == 0) {
1.224 djm 1198: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1199: } else {
1.223 djm 1200: if (deadline > INT_MAX / 1000)
1201: *timeoutp = INT_MAX / 1000;
1202: else
1203: *timeoutp = deadline * 1000;
1.155 dtucker 1204: }
1.46 markus 1205: return (1);
1.21 markus 1206: }
1207:
1.55 itojun 1208: static void
1.113 markus 1209: cleanup_socket(void)
1.15 markus 1210: {
1.187 djm 1211: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1212: return;
1213: debug("%s: cleanup", __func__);
1.48 deraadt 1214: if (socket_name[0])
1215: unlink(socket_name);
1216: if (socket_dir[0])
1217: rmdir(socket_dir);
1.10 markus 1218: }
1219:
1.114 markus 1220: void
1.15 markus 1221: cleanup_exit(int i)
1222: {
1.113 markus 1223: cleanup_socket();
1224: _exit(i);
1.15 markus 1225: }
1226:
1.135 deraadt 1227: /*ARGSUSED*/
1.55 itojun 1228: static void
1.48 deraadt 1229: cleanup_handler(int sig)
1230: {
1.113 markus 1231: cleanup_socket();
1.163 markus 1232: #ifdef ENABLE_PKCS11
1233: pkcs11_terminate();
1234: #endif
1.48 deraadt 1235: _exit(2);
1.113 markus 1236: }
1237:
1.68 markus 1238: static void
1.155 dtucker 1239: check_parent_exists(void)
1.68 markus 1240: {
1.172 dtucker 1241: /*
1242: * If our parent has exited then getppid() will return (pid_t)1,
1243: * so testing for that should be safe.
1244: */
1245: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1246: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1247: cleanup_socket();
1248: _exit(2);
1.68 markus 1249: }
1.48 deraadt 1250: }
1251:
1.55 itojun 1252: static void
1.50 itojun 1253: usage(void)
1.15 markus 1254: {
1.184 deraadt 1255: fprintf(stderr,
1.202 jmc 1256: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1257: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1258: " ssh-agent [-c | -s] -k\n");
1.21 markus 1259: exit(1);
1.15 markus 1260: }
1261:
1.2 provos 1262: int
1263: main(int ac, char **av)
1.1 deraadt 1264: {
1.201 djm 1265: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1266: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1267: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1268: struct rlimit rlim;
1.96 deraadt 1269: extern int optind;
1.98 stevesk 1270: extern char *optarg;
1.21 markus 1271: pid_t pid;
1.96 deraadt 1272: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1273: size_t len;
1.189 djm 1274: mode_t prev_mask;
1.224 djm 1275: int timeout = -1; /* INFTIM */
1.223 djm 1276: struct pollfd *pfd = NULL;
1277: size_t npfd = 0;
1.231 djm 1278: u_int maxfds;
1.123 djm 1279:
1280: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1281: sanitise_stdfd();
1.99 markus 1282:
1283: /* drop */
1284: setegid(getgid());
1285: setgid(getgid());
1.53 markus 1286:
1.231 djm 1287: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1288: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1289:
1.185 markus 1290: #ifdef WITH_OPENSSL
1.170 djm 1291: OpenSSL_add_all_algorithms();
1.185 markus 1292: #endif
1.21 markus 1293:
1.215 djm 1294: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1295: switch (ch) {
1.192 djm 1296: case 'E':
1297: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1298: if (fingerprint_hash == -1)
1299: fatal("Invalid hash algorithm \"%s\"", optarg);
1300: break;
1.21 markus 1301: case 'c':
1302: if (s_flag)
1303: usage();
1304: c_flag++;
1305: break;
1306: case 'k':
1307: k_flag++;
1308: break;
1.215 djm 1309: case 'P':
1.238 djm 1310: if (provider_whitelist != NULL)
1.215 djm 1311: fatal("-P option already specified");
1.238 djm 1312: provider_whitelist = xstrdup(optarg);
1.215 djm 1313: break;
1.21 markus 1314: case 's':
1315: if (c_flag)
1316: usage();
1317: s_flag++;
1318: break;
1.57 markus 1319: case 'd':
1.201 djm 1320: if (d_flag || D_flag)
1.57 markus 1321: usage();
1322: d_flag++;
1323: break;
1.201 djm 1324: case 'D':
1325: if (d_flag || D_flag)
1326: usage();
1327: D_flag++;
1328: break;
1.86 markus 1329: case 'a':
1330: agentsocket = optarg;
1.106 marc 1331: break;
1332: case 't':
1333: if ((lifetime = convtime(optarg)) == -1) {
1334: fprintf(stderr, "Invalid lifetime\n");
1335: usage();
1336: }
1.86 markus 1337: break;
1.21 markus 1338: default:
1339: usage();
1340: }
1341: }
1342: ac -= optind;
1343: av += optind;
1344:
1.201 djm 1345: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1346: usage();
1347:
1.238 djm 1348: if (provider_whitelist == NULL)
1349: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1350:
1.85 markus 1351: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1352: shell = getenv("SHELL");
1.161 tobias 1353: if (shell != NULL && (len = strlen(shell)) > 2 &&
1354: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1355: c_flag = 1;
1356: }
1357: if (k_flag) {
1.136 deraadt 1358: const char *errstr = NULL;
1359:
1.21 markus 1360: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1361: if (pidstr == NULL) {
1362: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1363: SSH_AGENTPID_ENV_NAME);
1.21 markus 1364: exit(1);
1365: }
1.136 deraadt 1366: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1367: if (errstr) {
1368: fprintf(stderr,
1369: "%s=\"%s\", which is not a good PID: %s\n",
1370: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1371: exit(1);
1372: }
1373: if (kill(pid, SIGTERM) == -1) {
1374: perror("kill");
1375: exit(1);
1376: }
1377: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1378: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1379: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1380: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1381: exit(0);
1382: }
1.231 djm 1383:
1384: /*
1385: * Minimum file descriptors:
1386: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1387: * a few spare for libc / stack protectors / sanitisers, etc.
1388: */
1389: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1390: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1391: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1392: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1393: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1394:
1.21 markus 1395: parent_pid = getpid();
1396:
1.86 markus 1397: if (agentsocket == NULL) {
1398: /* Create private directory for agent socket */
1.171 djm 1399: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1400: if (mkdtemp(socket_dir) == NULL) {
1401: perror("mkdtemp: private socket dir");
1402: exit(1);
1403: }
1.91 mpech 1404: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1405: (long)parent_pid);
1.86 markus 1406: } else {
1407: /* Try to use specified agent socket */
1408: socket_dir[0] = '\0';
1409: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1410: }
1411:
1.23 markus 1412: /*
1413: * Create socket early so it will exist before command gets run from
1414: * the parent.
1415: */
1.189 djm 1416: prev_mask = umask(0177);
1.188 millert 1417: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1418: if (sock < 0) {
1.188 millert 1419: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1420: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1421: cleanup_exit(1);
1422: }
1.189 djm 1423: umask(prev_mask);
1.46 markus 1424:
1.23 markus 1425: /*
1426: * Fork, and have the parent execute the command, if any, or present
1427: * the socket data. The child continues as the authentication agent.
1428: */
1.201 djm 1429: if (D_flag || d_flag) {
1430: log_init(__progname,
1431: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1432: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1433: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1434: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1435: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1436: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1437: fflush(stdout);
1.57 markus 1438: goto skip;
1439: }
1.21 markus 1440: pid = fork();
1441: if (pid == -1) {
1442: perror("fork");
1.81 stevesk 1443: cleanup_exit(1);
1.21 markus 1444: }
1445: if (pid != 0) { /* Parent - execute the given command. */
1446: close(sock);
1.91 mpech 1447: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1448: if (ac == 0) {
1449: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1450: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1451: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1452: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1453: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1454: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1455: exit(0);
1456: }
1.36 deraadt 1457: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1458: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1459: perror("setenv");
1460: exit(1);
1461: }
1.21 markus 1462: execvp(av[0], av);
1463: perror(av[0]);
1464: exit(1);
1465: }
1.81 stevesk 1466: /* child */
1467: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1468:
1469: if (setsid() == -1) {
1.81 stevesk 1470: error("setsid: %s", strerror(errno));
1.67 stevesk 1471: cleanup_exit(1);
1472: }
1473:
1474: (void)chdir("/");
1.107 markus 1475: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1476: /* XXX might close listen socket */
1477: (void)dup2(fd, STDIN_FILENO);
1478: (void)dup2(fd, STDOUT_FILENO);
1479: (void)dup2(fd, STDERR_FILENO);
1480: if (fd > 2)
1481: close(fd);
1482: }
1.21 markus 1483:
1.41 markus 1484: /* deny core dumps, since memory contains unencrypted private keys */
1485: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1486: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1487: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1488: cleanup_exit(1);
1489: }
1.57 markus 1490:
1491: skip:
1.187 djm 1492:
1493: cleanup_pid = getpid();
1.163 markus 1494:
1495: #ifdef ENABLE_PKCS11
1496: pkcs11_init(0);
1497: #endif
1.21 markus 1498: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1499: if (ac > 0)
1500: parent_alive_interval = 10;
1.33 markus 1501: idtab_init();
1.61 markus 1502: signal(SIGPIPE, SIG_IGN);
1.201 djm 1503: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1504: signal(SIGHUP, cleanup_handler);
1505: signal(SIGTERM, cleanup_handler);
1.205 djm 1506:
1.215 djm 1507: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1508: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1509:
1.21 markus 1510: while (1) {
1.231 djm 1511: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1512: result = poll(pfd, npfd, timeout);
1.154 dtucker 1513: saved_errno = errno;
1.155 dtucker 1514: if (parent_alive_interval != 0)
1515: check_parent_exists();
1516: (void) reaper(); /* remove expired keys */
1.237 deraadt 1517: if (result == -1) {
1.154 dtucker 1518: if (saved_errno == EINTR)
1.21 markus 1519: continue;
1.223 djm 1520: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1521: } else if (result > 0)
1.231 djm 1522: after_poll(pfd, npfd, maxfds);
1.15 markus 1523: }
1.21 markus 1524: /* NOTREACHED */
1.1 deraadt 1525: }
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