Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.247
1.247 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.246 2019/11/15 05:37:27 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"
1.244 djm 75: #include "ssherr.h"
1.238 djm 76: #include "pathnames.h"
1.163 markus 77: #include "ssh-pkcs11.h"
1.238 djm 78: #include "ssh-sk.h"
1.59 markus 79:
1.238 djm 80: #ifndef DEFAULT_PROVIDER_WHITELIST
81: # define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 82: #endif
83:
1.223 djm 84: /* Maximum accepted message length */
85: #define AGENT_MAX_LEN (256*1024)
1.233 djm 86: /* Maximum bytes to read from client socket */
87: #define AGENT_RBUF_LEN (4096)
1.223 djm 88:
1.73 stevesk 89: typedef enum {
90: AUTH_UNUSED,
91: AUTH_SOCKET,
92: AUTH_CONNECTION
93: } sock_type;
94:
1.21 markus 95: typedef struct {
96: int fd;
1.73 stevesk 97: sock_type type;
1.194 markus 98: struct sshbuf *input;
99: struct sshbuf *output;
100: struct sshbuf *request;
1.1 deraadt 101: } SocketEntry;
102:
1.45 markus 103: u_int sockets_alloc = 0;
1.1 deraadt 104: SocketEntry *sockets = NULL;
105:
1.78 provos 106: typedef struct identity {
107: TAILQ_ENTRY(identity) next;
1.194 markus 108: struct sshkey *key;
1.21 markus 109: char *comment;
1.163 markus 110: char *provider;
1.174 dtucker 111: time_t death;
1.107 markus 112: u_int confirm;
1.238 djm 113: char *sk_provider;
1.1 deraadt 114: } Identity;
115:
1.221 djm 116: struct idtable {
1.33 markus 117: int nentries;
1.78 provos 118: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 119: };
1.33 markus 120:
1.221 djm 121: /* private key table */
122: struct idtable *idtab;
1.1 deraadt 123:
124: int max_fd = 0;
125:
1.11 markus 126: /* pid of shell == parent of agent */
1.29 deraadt 127: pid_t parent_pid = -1;
1.176 dtucker 128: time_t parent_alive_interval = 0;
1.10 markus 129:
1.187 djm 130: /* pid of process for which cleanup_socket is applicable */
131: pid_t cleanup_pid = 0;
132:
1.10 markus 133: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 134: char socket_name[PATH_MAX];
135: char socket_dir[PATH_MAX];
1.10 markus 136:
1.238 djm 137: /* PKCS#11/Security key path whitelist */
138: static char *provider_whitelist;
1.215 djm 139:
1.88 markus 140: /* locking */
1.203 dtucker 141: #define LOCK_SIZE 32
142: #define LOCK_SALT_SIZE 16
143: #define LOCK_ROUNDS 1
1.88 markus 144: int locked = 0;
1.213 djm 145: u_char lock_pwhash[LOCK_SIZE];
146: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 147:
1.20 markus 148: extern char *__progname;
149:
1.174 dtucker 150: /* Default lifetime in seconds (0 == forever) */
151: static long lifetime = 0;
1.106 marc 152:
1.192 djm 153: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
154:
1.55 itojun 155: static void
1.101 stevesk 156: close_socket(SocketEntry *e)
157: {
158: close(e->fd);
159: e->fd = -1;
160: e->type = AUTH_UNUSED;
1.194 markus 161: sshbuf_free(e->input);
162: sshbuf_free(e->output);
163: sshbuf_free(e->request);
1.101 stevesk 164: }
165:
166: static void
1.33 markus 167: idtab_init(void)
1.1 deraadt 168: {
1.221 djm 169: idtab = xcalloc(1, sizeof(*idtab));
170: TAILQ_INIT(&idtab->idlist);
171: idtab->nentries = 0;
1.33 markus 172: }
173:
1.89 markus 174: static void
175: free_identity(Identity *id)
176: {
1.194 markus 177: sshkey_free(id->key);
1.173 djm 178: free(id->provider);
179: free(id->comment);
1.238 djm 180: free(id->sk_provider);
1.173 djm 181: free(id);
1.89 markus 182: }
183:
1.33 markus 184: /* return matching private key for given public key */
1.78 provos 185: static Identity *
1.221 djm 186: lookup_identity(struct sshkey *key)
1.33 markus 187: {
1.78 provos 188: Identity *id;
189:
1.221 djm 190: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 191: if (sshkey_equal(key, id->key))
1.78 provos 192: return (id);
1.33 markus 193: }
1.78 provos 194: return (NULL);
195: }
196:
1.107 markus 197: /* Check confirmation of keysign request */
198: static int
199: confirm_key(Identity *id)
200: {
1.122 djm 201: char *p;
1.107 markus 202: int ret = -1;
203:
1.194 markus 204: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 205: if (p != NULL &&
206: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 207: id->comment, p))
208: ret = 0;
1.173 djm 209: free(p);
1.122 djm 210:
1.107 markus 211: return (ret);
212: }
213:
1.194 markus 214: static void
215: send_status(SocketEntry *e, int success)
216: {
217: int r;
218:
219: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
220: (r = sshbuf_put_u8(e->output, success ?
221: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
222: fatal("%s: buffer error: %s", __func__, ssh_err(r));
223: }
224:
1.33 markus 225: /* send list of supported public keys to 'client' */
1.55 itojun 226: static void
1.221 djm 227: process_request_identities(SocketEntry *e)
1.33 markus 228: {
1.96 deraadt 229: Identity *id;
1.194 markus 230: struct sshbuf *msg;
231: int r;
1.1 deraadt 232:
1.194 markus 233: if ((msg = sshbuf_new()) == NULL)
234: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 235: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
236: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
237: fatal("%s: buffer error: %s", __func__, ssh_err(r));
238: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 239: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
240: != 0 ||
1.221 djm 241: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
242: error("%s: put key/comment: %s", __func__,
1.220 djm 243: ssh_err(r));
244: continue;
1.33 markus 245: }
1.21 markus 246: }
1.194 markus 247: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
248: fatal("%s: buffer error: %s", __func__, ssh_err(r));
249: sshbuf_free(msg);
1.1 deraadt 250: }
251:
1.33 markus 252:
1.208 markus 253: static char *
254: agent_decode_alg(struct sshkey *key, u_int flags)
255: {
256: if (key->type == KEY_RSA) {
257: if (flags & SSH_AGENT_RSA_SHA2_256)
258: return "rsa-sha2-256";
259: else if (flags & SSH_AGENT_RSA_SHA2_512)
260: return "rsa-sha2-512";
1.235 djm 261: } else if (key->type == KEY_RSA_CERT) {
262: if (flags & SSH_AGENT_RSA_SHA2_256)
263: return "rsa-sha2-256-cert-v01@openssh.com";
264: else if (flags & SSH_AGENT_RSA_SHA2_512)
265: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 266: }
267: return NULL;
268: }
269:
1.238 djm 270: static int
271: provider_sign(const char *provider, struct sshkey *key,
272: u_char **sigp, size_t *lenp,
273: const u_char *data, size_t datalen,
274: const char *alg, u_int compat)
275: {
276: int status, pair[2], r = SSH_ERR_INTERNAL_ERROR;
277: pid_t pid;
1.241 djm 278: char *helper, *verbosity = NULL, *fp = NULL;
1.238 djm 279: struct sshbuf *kbuf, *req, *resp;
280: u_char version;
1.241 djm 281: struct notifier_ctx *notifier = NULL;
1.238 djm 282:
283: debug3("%s: start for provider %s", __func__, provider);
284:
285: *sigp = NULL;
286: *lenp = 0;
1.243 djm 287:
1.238 djm 288: helper = getenv("SSH_SK_HELPER");
289: if (helper == NULL || strlen(helper) == 0)
290: helper = _PATH_SSH_SK_HELPER;
291: if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
292: verbosity = "-vvv";
293:
294: /* Start helper */
295: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
296: error("socketpair: %s", strerror(errno));
297: return SSH_ERR_SYSTEM_ERROR;
298: }
299: if ((pid = fork()) == -1) {
300: error("fork: %s", strerror(errno));
301: close(pair[0]);
302: close(pair[1]);
303: return SSH_ERR_SYSTEM_ERROR;
304: }
305: if (pid == 0) {
306: if ((dup2(pair[1], STDIN_FILENO) == -1) ||
307: (dup2(pair[1], STDOUT_FILENO) == -1))
308: fatal("%s: dup2: %s", __func__, ssh_err(r));
309: close(pair[0]);
310: close(pair[1]);
311: closefrom(STDERR_FILENO + 1);
312: debug("%s: starting %s %s", __func__, helper,
313: verbosity == NULL ? "" : verbosity);
314: execlp(helper, helper, verbosity, (char *)NULL);
315: fatal("%s: execlp: %s", __func__, strerror(errno));
316: }
317: close(pair[1]);
318:
319: if ((kbuf = sshbuf_new()) == NULL ||
320: (req = sshbuf_new()) == NULL ||
321: (resp = sshbuf_new()) == NULL)
322: fatal("%s: sshbuf_new failed", __func__);
323:
324: if ((r = sshkey_private_serialize(key, kbuf)) != 0 ||
325: (r = sshbuf_put_stringb(req, kbuf)) != 0 ||
326: (r = sshbuf_put_cstring(req, provider)) != 0 ||
327: (r = sshbuf_put_string(req, data, datalen)) != 0 ||
328: (r = sshbuf_put_u32(req, compat)) != 0)
329: fatal("%s: compose: %s", __func__, ssh_err(r));
1.247 ! djm 330:
! 331: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 332: SSH_FP_DEFAULT)) == NULL)
! 333: fatal("%s: sshkey_fingerprint failed", __func__);
! 334: notifier = notify_start(0,
! 335: "Confirm user presence for key %s %s", sshkey_type(key), fp);
! 336:
1.238 djm 337: if ((r = ssh_msg_send(pair[0], SSH_SK_HELPER_VERSION, req)) != 0) {
338: error("%s: send: %s", __func__, ssh_err(r));
339: goto out;
340: }
341: if ((r = ssh_msg_recv(pair[0], resp)) != 0) {
342: error("%s: receive: %s", __func__, ssh_err(r));
343: goto out;
344: }
345: if ((r = sshbuf_get_u8(resp, &version)) != 0) {
346: error("%s: parse version: %s", __func__, ssh_err(r));
347: goto out;
348: }
349: if (version != SSH_SK_HELPER_VERSION) {
350: error("%s: unsupported version: got %u, expected %u",
351: __func__, version, SSH_SK_HELPER_VERSION);
352: r = SSH_ERR_INVALID_FORMAT;
353: goto out;
354: }
355: if ((r = sshbuf_get_string(resp, sigp, lenp)) != 0) {
356: error("%s: parse signature: %s", __func__, ssh_err(r));
357: r = SSH_ERR_INVALID_FORMAT;
358: goto out;
359: }
360: if (sshbuf_len(resp) != 0) {
361: error("%s: trailing data in response", __func__);
362: r = SSH_ERR_INVALID_FORMAT;
363: goto out;
364: }
365: /* success */
366: r = 0;
367: out:
368: while (waitpid(pid, &status, 0) == -1) {
369: if (errno != EINTR)
370: fatal("%s: waitpid: %s", __func__, ssh_err(r));
371: }
1.241 djm 372: notify_complete(notifier);
1.238 djm 373: if (!WIFEXITED(status)) {
374: error("%s: helper %s exited abnormally", __func__, helper);
375: if (r == 0)
376: r = SSH_ERR_SYSTEM_ERROR;
377: } else if (WEXITSTATUS(status) != 0) {
378: error("%s: helper %s exited with non-zero exit status",
379: __func__, helper);
380: if (r == 0)
381: r = SSH_ERR_SYSTEM_ERROR;
382: }
383: if (r != 0) {
384: freezero(*sigp, *lenp);
385: *sigp = NULL;
386: *lenp = 0;
387: }
388: sshbuf_free(kbuf);
389: sshbuf_free(req);
390: sshbuf_free(resp);
391: return r;
392: }
393:
1.33 markus 394: /* ssh2 only */
1.55 itojun 395: static void
1.33 markus 396: process_sign_request2(SocketEntry *e)
397: {
1.221 djm 398: const u_char *data;
399: u_char *signature = NULL;
400: size_t dlen, slen = 0;
1.194 markus 401: u_int compat = 0, flags;
1.247 ! djm 402: int r, ok = -1;
1.194 markus 403: struct sshbuf *msg;
1.221 djm 404: struct sshkey *key = NULL;
1.195 djm 405: struct identity *id;
1.194 markus 406:
1.195 djm 407: if ((msg = sshbuf_new()) == NULL)
408: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 409: if ((r = sshkey_froms(e->request, &key)) != 0 ||
410: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 411: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
412: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
413: goto send;
414: }
415:
1.221 djm 416: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 417: verbose("%s: %s key not found", __func__, sshkey_type(key));
418: goto send;
419: }
420: if (id->confirm && confirm_key(id) != 0) {
421: verbose("%s: user refused key", __func__);
422: goto send;
423: }
1.238 djm 424: if (id->sk_provider != NULL) {
1.247 ! djm 425: if ((r = provider_sign(id->sk_provider, id->key, &signature,
1.238 djm 426: &slen, data, dlen, agent_decode_alg(key, flags),
1.247 ! djm 427: compat)) != 0) {
1.239 djm 428: error("%s: sign: %s", __func__, ssh_err(r));
1.238 djm 429: goto send;
430: }
431: } else {
432: if ((r = sshkey_sign(id->key, &signature, &slen,
1.239 djm 433: data, dlen, agent_decode_alg(key, flags),
434: NULL, compat)) != 0) {
1.238 djm 435: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
436: goto send;
437: }
1.33 markus 438: }
1.195 djm 439: /* Success */
440: ok = 0;
441: send:
442: sshkey_free(key);
1.33 markus 443: if (ok == 0) {
1.194 markus 444: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
445: (r = sshbuf_put_string(msg, signature, slen)) != 0)
446: fatal("%s: buffer error: %s", __func__, ssh_err(r));
447: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
448: fatal("%s: buffer error: %s", __func__, ssh_err(r));
449:
450: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
451: fatal("%s: buffer error: %s", __func__, ssh_err(r));
452:
453: sshbuf_free(msg);
1.173 djm 454: free(signature);
1.1 deraadt 455: }
456:
1.33 markus 457: /* shared */
1.55 itojun 458: static void
1.221 djm 459: process_remove_identity(SocketEntry *e)
1.1 deraadt 460: {
1.194 markus 461: int r, success = 0;
462: struct sshkey *key = NULL;
1.221 djm 463: Identity *id;
1.21 markus 464:
1.221 djm 465: if ((r = sshkey_froms(e->request, &key)) != 0) {
466: error("%s: get key: %s", __func__, ssh_err(r));
467: goto done;
468: }
469: if ((id = lookup_identity(key)) == NULL) {
470: debug("%s: key not found", __func__);
471: goto done;
472: }
473: /* We have this key, free it. */
474: if (idtab->nentries < 1)
475: fatal("%s: internal error: nentries %d",
476: __func__, idtab->nentries);
477: TAILQ_REMOVE(&idtab->idlist, id, next);
478: free_identity(id);
479: idtab->nentries--;
480: sshkey_free(key);
481: success = 1;
482: done:
1.194 markus 483: send_status(e, success);
1.1 deraadt 484: }
485:
1.55 itojun 486: static void
1.221 djm 487: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 488: {
1.78 provos 489: Identity *id;
1.21 markus 490:
491: /* Loop over all identities and clear the keys. */
1.221 djm 492: for (id = TAILQ_FIRST(&idtab->idlist); id;
493: id = TAILQ_FIRST(&idtab->idlist)) {
494: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 495: free_identity(id);
1.21 markus 496: }
497:
498: /* Mark that there are no identities. */
1.221 djm 499: idtab->nentries = 0;
1.21 markus 500:
501: /* Send success. */
1.194 markus 502: send_status(e, 1);
1.1 deraadt 503: }
504:
1.155 dtucker 505: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 506: static time_t
1.89 markus 507: reaper(void)
508: {
1.175 dtucker 509: time_t deadline = 0, now = monotime();
1.89 markus 510: Identity *id, *nxt;
511:
1.221 djm 512: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
513: nxt = TAILQ_NEXT(id, next);
514: if (id->death == 0)
515: continue;
516: if (now >= id->death) {
517: debug("expiring key '%s'", id->comment);
518: TAILQ_REMOVE(&idtab->idlist, id, next);
519: free_identity(id);
520: idtab->nentries--;
521: } else
522: deadline = (deadline == 0) ? id->death :
523: MINIMUM(deadline, id->death);
1.89 markus 524: }
1.155 dtucker 525: if (deadline == 0 || deadline <= now)
526: return 0;
527: else
528: return (deadline - now);
1.89 markus 529: }
530:
531: static void
1.221 djm 532: process_add_identity(SocketEntry *e)
1.1 deraadt 533: {
1.157 canacar 534: Identity *id;
1.194 markus 535: int success = 0, confirm = 0;
1.228 markus 536: u_int seconds, maxsign;
1.238 djm 537: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 538: time_t death = 0;
1.194 markus 539: struct sshkey *k = NULL;
540: u_char ctype;
541: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 542:
1.221 djm 543: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
544: k == NULL ||
1.194 markus 545: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
546: error("%s: decode private key: %s", __func__, ssh_err(r));
547: goto err;
548: }
549: while (sshbuf_len(e->request)) {
550: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
551: error("%s: buffer error: %s", __func__, ssh_err(r));
552: goto err;
553: }
554: switch (ctype) {
1.94 markus 555: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 556: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
557: error("%s: bad lifetime constraint: %s",
558: __func__, ssh_err(r));
559: goto err;
560: }
561: death = monotime() + seconds;
1.94 markus 562: break;
1.107 markus 563: case SSH_AGENT_CONSTRAIN_CONFIRM:
564: confirm = 1;
565: break;
1.228 markus 566: case SSH_AGENT_CONSTRAIN_MAXSIGN:
567: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
568: error("%s: bad maxsign constraint: %s",
569: __func__, ssh_err(r));
570: goto err;
571: }
572: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
573: error("%s: cannot enable maxsign: %s",
574: __func__, ssh_err(r));
575: goto err;
576: }
577: break;
1.238 djm 578: case SSH_AGENT_CONSTRAIN_EXTENSION:
579: if ((r = sshbuf_get_cstring(e->request,
580: &ext_name, NULL)) != 0) {
581: error("%s: cannot parse extension: %s",
582: __func__, ssh_err(r));
583: goto err;
584: }
585: debug("%s: constraint ext %s", __func__, ext_name);
586: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
587: if (sk_provider != NULL) {
588: error("%s already set", ext_name);
589: goto err;
590: }
591: if ((r = sshbuf_get_cstring(e->request,
592: &sk_provider, NULL)) != 0) {
593: error("%s: cannot parse %s: %s",
594: __func__, ext_name, ssh_err(r));
595: goto err;
596: }
597: } else {
598: error("%s: unsupported constraint \"%s\"",
599: __func__, ext_name);
600: goto err;
601: }
602: free(ext_name);
603: break;
1.94 markus 604: default:
1.194 markus 605: error("%s: Unknown constraint %d", __func__, ctype);
606: err:
1.238 djm 607: free(sk_provider);
608: free(ext_name);
1.194 markus 609: sshbuf_reset(e->request);
1.173 djm 610: free(comment);
1.194 markus 611: sshkey_free(k);
1.158 djm 612: goto send;
1.94 markus 613: }
614: }
1.238 djm 615: if (sk_provider != NULL) {
1.240 markus 616: if (!sshkey_is_sk(k)) {
1.238 djm 617: error("Cannot add provider: %s is not a security key",
618: sshkey_type(k));
619: free(sk_provider);
620: goto send;
621: }
1.245 djm 622: if (strcasecmp(sk_provider, "internal") == 0)
623: debug("%s: internal provider", __func__);
624: else if (match_pattern_list(sk_provider,
1.238 djm 625: provider_whitelist, 0) != 1) {
626: error("Refusing add key: provider %s not whitelisted",
627: sk_provider);
628: free(sk_provider);
629: goto send;
630: }
1.242 markus 631: }
632: if ((r = sshkey_shield_private(k)) != 0) {
633: error("%s: shield private key: %s", __func__, ssh_err(r));
634: goto err;
1.238 djm 635: }
1.194 markus 636:
1.158 djm 637: success = 1;
1.106 marc 638: if (lifetime && !death)
1.175 dtucker 639: death = monotime() + lifetime;
1.221 djm 640: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 641: id = xcalloc(1, sizeof(Identity));
1.221 djm 642: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 643: /* Increment the number of identities. */
1.221 djm 644: idtab->nentries++;
1.33 markus 645: } else {
1.228 markus 646: /* key state might have been updated */
647: sshkey_free(id->key);
1.173 djm 648: free(id->comment);
1.238 djm 649: free(id->sk_provider);
1.33 markus 650: }
1.228 markus 651: id->key = k;
1.157 canacar 652: id->comment = comment;
653: id->death = death;
654: id->confirm = confirm;
1.238 djm 655: id->sk_provider = sk_provider;
656:
657: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
658: SSH_FP_DEFAULT)) == NULL)
659: fatal("%s: sshkey_fingerprint failed", __func__);
660: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
661: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
662: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
663: free(fp);
1.33 markus 664: send:
1.194 markus 665: send_status(e, success);
1.1 deraadt 666: }
667:
1.88 markus 668: /* XXX todo: encrypt sensitive data with passphrase */
669: static void
670: process_lock_agent(SocketEntry *e, int lock)
671: {
1.203 dtucker 672: int r, success = 0, delay;
1.213 djm 673: char *passwd;
674: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 675: static u_int fail_count = 0;
676: size_t pwlen;
677:
1.226 djm 678: /*
679: * This is deliberately fatal: the user has requested that we lock,
680: * but we can't parse their request properly. The only safe thing to
681: * do is abort.
682: */
1.203 dtucker 683: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
684: fatal("%s: buffer error: %s", __func__, ssh_err(r));
685: if (pwlen == 0) {
686: debug("empty password not supported");
687: } else if (locked && !lock) {
688: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
689: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
690: fatal("bcrypt_pbkdf");
1.213 djm 691: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 692: debug("agent unlocked");
693: locked = 0;
694: fail_count = 0;
1.213 djm 695: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 696: success = 1;
697: } else {
698: /* delay in 0.1s increments up to 10s */
699: if (fail_count < 100)
700: fail_count++;
701: delay = 100000 * fail_count;
702: debug("unlock failed, delaying %0.1lf seconds",
703: (double)delay/1000000);
704: usleep(delay);
705: }
706: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 707: } else if (!locked && lock) {
1.203 dtucker 708: debug("agent locked");
1.88 markus 709: locked = 1;
1.203 dtucker 710: arc4random_buf(lock_salt, sizeof(lock_salt));
711: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 712: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 713: fatal("bcrypt_pbkdf");
1.88 markus 714: success = 1;
715: }
1.203 dtucker 716: explicit_bzero(passwd, pwlen);
1.173 djm 717: free(passwd);
1.194 markus 718: send_status(e, success);
1.88 markus 719: }
720:
721: static void
1.221 djm 722: no_identities(SocketEntry *e)
1.88 markus 723: {
1.194 markus 724: struct sshbuf *msg;
725: int r;
1.88 markus 726:
1.194 markus 727: if ((msg = sshbuf_new()) == NULL)
728: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 729: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 730: (r = sshbuf_put_u32(msg, 0)) != 0 ||
731: (r = sshbuf_put_stringb(e->output, msg)) != 0)
732: fatal("%s: buffer error: %s", __func__, ssh_err(r));
733: sshbuf_free(msg);
1.88 markus 734: }
1.59 markus 735:
1.163 markus 736: #ifdef ENABLE_PKCS11
1.59 markus 737: static void
1.158 djm 738: process_add_smartcard_key(SocketEntry *e)
1.59 markus 739: {
1.226 djm 740: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 741: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 742: u_int seconds;
1.174 dtucker 743: time_t death = 0;
1.194 markus 744: u_char type;
745: struct sshkey **keys = NULL, *k;
1.84 markus 746: Identity *id;
1.75 deraadt 747:
1.194 markus 748: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 749: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
750: error("%s: buffer error: %s", __func__, ssh_err(r));
751: goto send;
752: }
1.194 markus 753:
754: while (sshbuf_len(e->request)) {
1.226 djm 755: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
756: error("%s: buffer error: %s", __func__, ssh_err(r));
757: goto send;
758: }
1.194 markus 759: switch (type) {
1.110 djm 760: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 761: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
762: error("%s: buffer error: %s",
1.194 markus 763: __func__, ssh_err(r));
1.226 djm 764: goto send;
765: }
1.194 markus 766: death = monotime() + seconds;
1.110 djm 767: break;
768: case SSH_AGENT_CONSTRAIN_CONFIRM:
769: confirm = 1;
770: break;
771: default:
1.221 djm 772: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 773: goto send;
1.110 djm 774: }
775: }
1.215 djm 776: if (realpath(provider, canonical_provider) == NULL) {
777: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
778: provider, strerror(errno));
779: goto send;
780: }
1.238 djm 781: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 782: verbose("refusing PKCS#11 add of \"%.100s\": "
783: "provider not whitelisted", canonical_provider);
784: goto send;
785: }
786: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 787: if (lifetime && !death)
1.175 dtucker 788: death = monotime() + lifetime;
1.110 djm 789:
1.215 djm 790: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 791: for (i = 0; i < count; i++) {
1.84 markus 792: k = keys[i];
1.221 djm 793: if (lookup_identity(k) == NULL) {
1.163 markus 794: id = xcalloc(1, sizeof(Identity));
1.84 markus 795: id->key = k;
1.215 djm 796: id->provider = xstrdup(canonical_provider);
797: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 798: id->death = death;
799: id->confirm = confirm;
1.221 djm 800: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
801: idtab->nentries++;
1.84 markus 802: success = 1;
803: } else {
1.194 markus 804: sshkey_free(k);
1.84 markus 805: }
806: keys[i] = NULL;
1.59 markus 807: }
808: send:
1.173 djm 809: free(pin);
810: free(provider);
811: free(keys);
1.194 markus 812: send_status(e, success);
1.59 markus 813: }
814:
815: static void
816: process_remove_smartcard_key(SocketEntry *e)
817: {
1.217 djm 818: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 819: int r, success = 0;
1.163 markus 820: Identity *id, *nxt;
1.59 markus 821:
1.194 markus 822: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 823: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
824: error("%s: buffer error: %s", __func__, ssh_err(r));
825: goto send;
826: }
1.173 djm 827: free(pin);
1.59 markus 828:
1.217 djm 829: if (realpath(provider, canonical_provider) == NULL) {
830: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
831: provider, strerror(errno));
832: goto send;
833: }
834:
835: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 836: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
837: nxt = TAILQ_NEXT(id, next);
838: /* Skip file--based keys */
839: if (id->provider == NULL)
840: continue;
841: if (!strcmp(canonical_provider, id->provider)) {
842: TAILQ_REMOVE(&idtab->idlist, id, next);
843: free_identity(id);
844: idtab->nentries--;
1.59 markus 845: }
846: }
1.217 djm 847: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 848: success = 1;
849: else
1.221 djm 850: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 851: send:
1.173 djm 852: free(provider);
1.194 markus 853: send_status(e, success);
1.59 markus 854: }
1.163 markus 855: #endif /* ENABLE_PKCS11 */
1.59 markus 856:
1.33 markus 857: /* dispatch incoming messages */
858:
1.223 djm 859: static int
860: process_message(u_int socknum)
1.1 deraadt 861: {
1.194 markus 862: u_int msg_len;
863: u_char type;
864: const u_char *cp;
865: int r;
1.223 djm 866: SocketEntry *e;
867:
868: if (socknum >= sockets_alloc) {
869: fatal("%s: socket number %u >= allocated %u",
870: __func__, socknum, sockets_alloc);
871: }
872: e = &sockets[socknum];
1.89 markus 873:
1.194 markus 874: if (sshbuf_len(e->input) < 5)
1.223 djm 875: return 0; /* Incomplete message header. */
1.194 markus 876: cp = sshbuf_ptr(e->input);
877: msg_len = PEEK_U32(cp);
1.223 djm 878: if (msg_len > AGENT_MAX_LEN) {
879: debug("%s: socket %u (fd=%d) message too long %u > %u",
880: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
881: return -1;
1.21 markus 882: }
1.194 markus 883: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 884: return 0; /* Incomplete message body. */
1.87 markus 885:
886: /* move the current input to e->request */
1.194 markus 887: sshbuf_reset(e->request);
888: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 889: (r = sshbuf_get_u8(e->request, &type)) != 0) {
890: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
891: r == SSH_ERR_STRING_TOO_LARGE) {
892: debug("%s: buffer error: %s", __func__, ssh_err(r));
893: return -1;
894: }
1.194 markus 895: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 896: }
897:
898: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 899:
1.230 djm 900: /* check whether agent is locked */
1.88 markus 901: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 902: sshbuf_reset(e->request);
1.88 markus 903: switch (type) {
904: case SSH2_AGENTC_REQUEST_IDENTITIES:
905: /* send empty lists */
1.221 djm 906: no_identities(e);
1.88 markus 907: break;
908: default:
909: /* send a fail message for all other request types */
1.194 markus 910: send_status(e, 0);
1.88 markus 911: }
1.223 djm 912: return 0;
1.88 markus 913: }
914:
1.21 markus 915: switch (type) {
1.88 markus 916: case SSH_AGENTC_LOCK:
917: case SSH_AGENTC_UNLOCK:
918: process_lock_agent(e, type == SSH_AGENTC_LOCK);
919: break;
1.21 markus 920: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 921: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 922: break;
923: /* ssh2 */
924: case SSH2_AGENTC_SIGN_REQUEST:
925: process_sign_request2(e);
926: break;
927: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 928: process_request_identities(e);
1.33 markus 929: break;
930: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 931: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 932: process_add_identity(e);
1.33 markus 933: break;
934: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 935: process_remove_identity(e);
1.33 markus 936: break;
937: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 938: process_remove_all_identities(e);
1.21 markus 939: break;
1.163 markus 940: #ifdef ENABLE_PKCS11
1.59 markus 941: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 942: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 943: process_add_smartcard_key(e);
1.75 deraadt 944: break;
1.59 markus 945: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
946: process_remove_smartcard_key(e);
1.75 deraadt 947: break;
1.163 markus 948: #endif /* ENABLE_PKCS11 */
1.21 markus 949: default:
950: /* Unknown message. Respond with failure. */
951: error("Unknown message %d", type);
1.194 markus 952: sshbuf_reset(e->request);
953: send_status(e, 0);
1.21 markus 954: break;
955: }
1.223 djm 956: return 0;
1.1 deraadt 957: }
958:
1.55 itojun 959: static void
1.73 stevesk 960: new_socket(sock_type type, int fd)
1.1 deraadt 961: {
1.112 markus 962: u_int i, old_alloc, new_alloc;
1.96 deraadt 963:
1.119 djm 964: set_nonblock(fd);
1.21 markus 965:
966: if (fd > max_fd)
967: max_fd = fd;
968:
969: for (i = 0; i < sockets_alloc; i++)
970: if (sockets[i].type == AUTH_UNUSED) {
971: sockets[i].fd = fd;
1.194 markus 972: if ((sockets[i].input = sshbuf_new()) == NULL)
973: fatal("%s: sshbuf_new failed", __func__);
974: if ((sockets[i].output = sshbuf_new()) == NULL)
975: fatal("%s: sshbuf_new failed", __func__);
976: if ((sockets[i].request = sshbuf_new()) == NULL)
977: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 978: sockets[i].type = type;
1.21 markus 979: return;
980: }
981: old_alloc = sockets_alloc;
1.112 markus 982: new_alloc = sockets_alloc + 10;
1.200 deraadt 983: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 984: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 985: sockets[i].type = AUTH_UNUSED;
1.112 markus 986: sockets_alloc = new_alloc;
1.21 markus 987: sockets[old_alloc].fd = fd;
1.194 markus 988: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
989: fatal("%s: sshbuf_new failed", __func__);
990: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
991: fatal("%s: sshbuf_new failed", __func__);
992: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
993: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 994: sockets[old_alloc].type = type;
1.1 deraadt 995: }
996:
1.55 itojun 997: static int
1.223 djm 998: handle_socket_read(u_int socknum)
1.1 deraadt 999: {
1.223 djm 1000: struct sockaddr_un sunaddr;
1001: socklen_t slen;
1002: uid_t euid;
1003: gid_t egid;
1004: int fd;
1005:
1006: slen = sizeof(sunaddr);
1007: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1008: if (fd == -1) {
1.223 djm 1009: error("accept from AUTH_SOCKET: %s", strerror(errno));
1010: return -1;
1011: }
1.237 deraadt 1012: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1013: error("getpeereid %d failed: %s", fd, strerror(errno));
1014: close(fd);
1015: return -1;
1016: }
1017: if ((euid != 0) && (getuid() != euid)) {
1018: error("uid mismatch: peer euid %u != uid %u",
1019: (u_int) euid, (u_int) getuid());
1020: close(fd);
1021: return -1;
1022: }
1023: new_socket(AUTH_CONNECTION, fd);
1024: return 0;
1025: }
1026:
1027: static int
1028: handle_conn_read(u_int socknum)
1029: {
1.233 djm 1030: char buf[AGENT_RBUF_LEN];
1.223 djm 1031: ssize_t len;
1032: int r;
1033:
1034: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1035: if (len == -1) {
1036: if (errno == EAGAIN || errno == EINTR)
1037: return 0;
1038: error("%s: read error on socket %u (fd %d): %s",
1039: __func__, socknum, sockets[socknum].fd,
1040: strerror(errno));
1041: }
1042: return -1;
1043: }
1044: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1045: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1046: explicit_bzero(buf, sizeof(buf));
1047: process_message(socknum);
1048: return 0;
1049: }
1050:
1051: static int
1052: handle_conn_write(u_int socknum)
1053: {
1054: ssize_t len;
1055: int r;
1056:
1057: if (sshbuf_len(sockets[socknum].output) == 0)
1058: return 0; /* shouldn't happen */
1059: if ((len = write(sockets[socknum].fd,
1060: sshbuf_ptr(sockets[socknum].output),
1061: sshbuf_len(sockets[socknum].output))) <= 0) {
1062: if (len == -1) {
1063: if (errno == EAGAIN || errno == EINTR)
1064: return 0;
1065: error("%s: read error on socket %u (fd %d): %s",
1066: __func__, socknum, sockets[socknum].fd,
1067: strerror(errno));
1068: }
1069: return -1;
1070: }
1071: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1072: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1073: return 0;
1074: }
1075:
1076: static void
1.231 djm 1077: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1078: {
1079: size_t i;
1.231 djm 1080: u_int socknum, activefds = npfd;
1.223 djm 1081:
1082: for (i = 0; i < npfd; i++) {
1083: if (pfd[i].revents == 0)
1084: continue;
1085: /* Find sockets entry */
1086: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1087: if (sockets[socknum].type != AUTH_SOCKET &&
1088: sockets[socknum].type != AUTH_CONNECTION)
1089: continue;
1090: if (pfd[i].fd == sockets[socknum].fd)
1091: break;
1092: }
1093: if (socknum >= sockets_alloc) {
1094: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1095: continue;
1096: }
1097: /* Process events */
1098: switch (sockets[socknum].type) {
1099: case AUTH_SOCKET:
1.231 djm 1100: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1101: break;
1102: if (npfd > maxfds) {
1103: debug3("out of fds (active %u >= limit %u); "
1104: "skipping accept", activefds, maxfds);
1105: break;
1106: }
1107: if (handle_socket_read(socknum) == 0)
1108: activefds++;
1.223 djm 1109: break;
1110: case AUTH_CONNECTION:
1111: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1112: handle_conn_read(socknum) != 0) {
1.231 djm 1113: goto close_sock;
1114: }
1115: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1116: handle_conn_write(socknum) != 0) {
1117: close_sock:
1118: if (activefds == 0)
1119: fatal("activefds == 0 at close_sock");
1.223 djm 1120: close_socket(&sockets[socknum]);
1.231 djm 1121: activefds--;
1.223 djm 1122: break;
1123: }
1124: break;
1125: default:
1126: break;
1127: }
1128: }
1129: }
1130:
1131: static int
1.231 djm 1132: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1133: {
1134: struct pollfd *pfd = *pfdp;
1135: size_t i, j, npfd = 0;
1.174 dtucker 1136: time_t deadline;
1.233 djm 1137: int r;
1.46 markus 1138:
1.223 djm 1139: /* Count active sockets */
1.46 markus 1140: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1141: switch (sockets[i].type) {
1142: case AUTH_SOCKET:
1143: case AUTH_CONNECTION:
1.223 djm 1144: npfd++;
1.21 markus 1145: break;
1146: case AUTH_UNUSED:
1147: break;
1148: default:
1149: fatal("Unknown socket type %d", sockets[i].type);
1150: break;
1151: }
1.46 markus 1152: }
1.223 djm 1153: if (npfd != *npfdp &&
1154: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1155: fatal("%s: recallocarray failed", __func__);
1156: *pfdp = pfd;
1157: *npfdp = npfd;
1.46 markus 1158:
1.223 djm 1159: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1160: switch (sockets[i].type) {
1161: case AUTH_SOCKET:
1.231 djm 1162: if (npfd > maxfds) {
1163: debug3("out of fds (active %zu >= limit %u); "
1164: "skipping arming listener", npfd, maxfds);
1165: break;
1166: }
1167: pfd[j].fd = sockets[i].fd;
1168: pfd[j].revents = 0;
1169: pfd[j].events = POLLIN;
1170: j++;
1171: break;
1.46 markus 1172: case AUTH_CONNECTION:
1.223 djm 1173: pfd[j].fd = sockets[i].fd;
1174: pfd[j].revents = 0;
1.233 djm 1175: /*
1176: * Only prepare to read if we can handle a full-size
1177: * input read buffer and enqueue a max size reply..
1178: */
1179: if ((r = sshbuf_check_reserve(sockets[i].input,
1180: AGENT_RBUF_LEN)) == 0 &&
1181: (r = sshbuf_check_reserve(sockets[i].output,
1182: AGENT_MAX_LEN)) == 0)
1183: pfd[j].events = POLLIN;
1184: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1185: fatal("%s: buffer error: %s",
1186: __func__, ssh_err(r));
1187: }
1.194 markus 1188: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1189: pfd[j].events |= POLLOUT;
1190: j++;
1.46 markus 1191: break;
1192: default:
1193: break;
1194: }
1195: }
1.155 dtucker 1196: deadline = reaper();
1197: if (parent_alive_interval != 0)
1198: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1199: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1200: if (deadline == 0) {
1.224 djm 1201: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1202: } else {
1.223 djm 1203: if (deadline > INT_MAX / 1000)
1204: *timeoutp = INT_MAX / 1000;
1205: else
1206: *timeoutp = deadline * 1000;
1.155 dtucker 1207: }
1.46 markus 1208: return (1);
1.21 markus 1209: }
1210:
1.55 itojun 1211: static void
1.113 markus 1212: cleanup_socket(void)
1.15 markus 1213: {
1.187 djm 1214: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1215: return;
1216: debug("%s: cleanup", __func__);
1.48 deraadt 1217: if (socket_name[0])
1218: unlink(socket_name);
1219: if (socket_dir[0])
1220: rmdir(socket_dir);
1.10 markus 1221: }
1222:
1.114 markus 1223: void
1.15 markus 1224: cleanup_exit(int i)
1225: {
1.113 markus 1226: cleanup_socket();
1227: _exit(i);
1.15 markus 1228: }
1229:
1.135 deraadt 1230: /*ARGSUSED*/
1.55 itojun 1231: static void
1.48 deraadt 1232: cleanup_handler(int sig)
1233: {
1.113 markus 1234: cleanup_socket();
1.163 markus 1235: #ifdef ENABLE_PKCS11
1236: pkcs11_terminate();
1237: #endif
1.48 deraadt 1238: _exit(2);
1.113 markus 1239: }
1240:
1.68 markus 1241: static void
1.155 dtucker 1242: check_parent_exists(void)
1.68 markus 1243: {
1.172 dtucker 1244: /*
1245: * If our parent has exited then getppid() will return (pid_t)1,
1246: * so testing for that should be safe.
1247: */
1248: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1249: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1250: cleanup_socket();
1251: _exit(2);
1.68 markus 1252: }
1.48 deraadt 1253: }
1254:
1.55 itojun 1255: static void
1.50 itojun 1256: usage(void)
1.15 markus 1257: {
1.184 deraadt 1258: fprintf(stderr,
1.202 jmc 1259: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1260: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1261: " ssh-agent [-c | -s] -k\n");
1.21 markus 1262: exit(1);
1.15 markus 1263: }
1264:
1.2 provos 1265: int
1266: main(int ac, char **av)
1.1 deraadt 1267: {
1.201 djm 1268: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1269: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1270: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1271: struct rlimit rlim;
1.96 deraadt 1272: extern int optind;
1.98 stevesk 1273: extern char *optarg;
1.21 markus 1274: pid_t pid;
1.96 deraadt 1275: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1276: size_t len;
1.189 djm 1277: mode_t prev_mask;
1.224 djm 1278: int timeout = -1; /* INFTIM */
1.223 djm 1279: struct pollfd *pfd = NULL;
1280: size_t npfd = 0;
1.231 djm 1281: u_int maxfds;
1.123 djm 1282:
1283: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1284: sanitise_stdfd();
1.99 markus 1285:
1286: /* drop */
1287: setegid(getgid());
1288: setgid(getgid());
1.53 markus 1289:
1.231 djm 1290: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1291: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1292:
1.185 markus 1293: #ifdef WITH_OPENSSL
1.170 djm 1294: OpenSSL_add_all_algorithms();
1.185 markus 1295: #endif
1.21 markus 1296:
1.215 djm 1297: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1298: switch (ch) {
1.192 djm 1299: case 'E':
1300: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1301: if (fingerprint_hash == -1)
1302: fatal("Invalid hash algorithm \"%s\"", optarg);
1303: break;
1.21 markus 1304: case 'c':
1305: if (s_flag)
1306: usage();
1307: c_flag++;
1308: break;
1309: case 'k':
1310: k_flag++;
1311: break;
1.215 djm 1312: case 'P':
1.238 djm 1313: if (provider_whitelist != NULL)
1.215 djm 1314: fatal("-P option already specified");
1.238 djm 1315: provider_whitelist = xstrdup(optarg);
1.215 djm 1316: break;
1.21 markus 1317: case 's':
1318: if (c_flag)
1319: usage();
1320: s_flag++;
1321: break;
1.57 markus 1322: case 'd':
1.201 djm 1323: if (d_flag || D_flag)
1.57 markus 1324: usage();
1325: d_flag++;
1326: break;
1.201 djm 1327: case 'D':
1328: if (d_flag || D_flag)
1329: usage();
1330: D_flag++;
1331: break;
1.86 markus 1332: case 'a':
1333: agentsocket = optarg;
1.106 marc 1334: break;
1335: case 't':
1336: if ((lifetime = convtime(optarg)) == -1) {
1337: fprintf(stderr, "Invalid lifetime\n");
1338: usage();
1339: }
1.86 markus 1340: break;
1.21 markus 1341: default:
1342: usage();
1343: }
1344: }
1345: ac -= optind;
1346: av += optind;
1347:
1.201 djm 1348: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1349: usage();
1350:
1.238 djm 1351: if (provider_whitelist == NULL)
1352: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1353:
1.85 markus 1354: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1355: shell = getenv("SHELL");
1.161 tobias 1356: if (shell != NULL && (len = strlen(shell)) > 2 &&
1357: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1358: c_flag = 1;
1359: }
1360: if (k_flag) {
1.136 deraadt 1361: const char *errstr = NULL;
1362:
1.21 markus 1363: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1364: if (pidstr == NULL) {
1365: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1366: SSH_AGENTPID_ENV_NAME);
1.21 markus 1367: exit(1);
1368: }
1.136 deraadt 1369: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1370: if (errstr) {
1371: fprintf(stderr,
1372: "%s=\"%s\", which is not a good PID: %s\n",
1373: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1374: exit(1);
1375: }
1376: if (kill(pid, SIGTERM) == -1) {
1377: perror("kill");
1378: exit(1);
1379: }
1380: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1381: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1382: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1383: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1384: exit(0);
1385: }
1.231 djm 1386:
1387: /*
1388: * Minimum file descriptors:
1389: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1390: * a few spare for libc / stack protectors / sanitisers, etc.
1391: */
1392: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1393: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1394: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1395: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1396: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1397:
1.21 markus 1398: parent_pid = getpid();
1399:
1.86 markus 1400: if (agentsocket == NULL) {
1401: /* Create private directory for agent socket */
1.171 djm 1402: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1403: if (mkdtemp(socket_dir) == NULL) {
1404: perror("mkdtemp: private socket dir");
1405: exit(1);
1406: }
1.91 mpech 1407: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1408: (long)parent_pid);
1.86 markus 1409: } else {
1410: /* Try to use specified agent socket */
1411: socket_dir[0] = '\0';
1412: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1413: }
1414:
1.23 markus 1415: /*
1416: * Create socket early so it will exist before command gets run from
1417: * the parent.
1418: */
1.189 djm 1419: prev_mask = umask(0177);
1.188 millert 1420: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1421: if (sock < 0) {
1.188 millert 1422: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1423: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1424: cleanup_exit(1);
1425: }
1.189 djm 1426: umask(prev_mask);
1.46 markus 1427:
1.23 markus 1428: /*
1429: * Fork, and have the parent execute the command, if any, or present
1430: * the socket data. The child continues as the authentication agent.
1431: */
1.201 djm 1432: if (D_flag || d_flag) {
1433: log_init(__progname,
1434: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1435: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1436: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1437: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1438: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1439: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1440: fflush(stdout);
1.57 markus 1441: goto skip;
1442: }
1.21 markus 1443: pid = fork();
1444: if (pid == -1) {
1445: perror("fork");
1.81 stevesk 1446: cleanup_exit(1);
1.21 markus 1447: }
1448: if (pid != 0) { /* Parent - execute the given command. */
1449: close(sock);
1.91 mpech 1450: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1451: if (ac == 0) {
1452: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1453: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1454: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1455: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1456: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1457: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1458: exit(0);
1459: }
1.36 deraadt 1460: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1461: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1462: perror("setenv");
1463: exit(1);
1464: }
1.21 markus 1465: execvp(av[0], av);
1466: perror(av[0]);
1467: exit(1);
1468: }
1.81 stevesk 1469: /* child */
1470: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1471:
1472: if (setsid() == -1) {
1.81 stevesk 1473: error("setsid: %s", strerror(errno));
1.67 stevesk 1474: cleanup_exit(1);
1475: }
1476:
1477: (void)chdir("/");
1.107 markus 1478: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1479: /* XXX might close listen socket */
1480: (void)dup2(fd, STDIN_FILENO);
1481: (void)dup2(fd, STDOUT_FILENO);
1482: (void)dup2(fd, STDERR_FILENO);
1483: if (fd > 2)
1484: close(fd);
1485: }
1.21 markus 1486:
1.41 markus 1487: /* deny core dumps, since memory contains unencrypted private keys */
1488: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1489: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1490: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1491: cleanup_exit(1);
1492: }
1.57 markus 1493:
1494: skip:
1.187 djm 1495:
1496: cleanup_pid = getpid();
1.163 markus 1497:
1498: #ifdef ENABLE_PKCS11
1499: pkcs11_init(0);
1500: #endif
1.21 markus 1501: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1502: if (ac > 0)
1503: parent_alive_interval = 10;
1.33 markus 1504: idtab_init();
1.61 markus 1505: signal(SIGPIPE, SIG_IGN);
1.201 djm 1506: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1507: signal(SIGHUP, cleanup_handler);
1508: signal(SIGTERM, cleanup_handler);
1.205 djm 1509:
1.215 djm 1510: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1511: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1512:
1.21 markus 1513: while (1) {
1.231 djm 1514: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1515: result = poll(pfd, npfd, timeout);
1.154 dtucker 1516: saved_errno = errno;
1.155 dtucker 1517: if (parent_alive_interval != 0)
1518: check_parent_exists();
1519: (void) reaper(); /* remove expired keys */
1.237 deraadt 1520: if (result == -1) {
1.154 dtucker 1521: if (saved_errno == EINTR)
1.21 markus 1522: continue;
1.223 djm 1523: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1524: } else if (result > 0)
1.231 djm 1525: after_poll(pfd, npfd, maxfds);
1.15 markus 1526: }
1.21 markus 1527: /* NOTREACHED */
1.1 deraadt 1528: }
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