Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.258
1.258 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.257 2020/03/06 18:28:27 markus Exp $ */
1.1 deraadt 2: /*
1.22 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * The authentication agent program.
1.33 markus 7: *
1.35 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.56 markus 14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 15: *
16: * Redistribution and use in source and binary forms, with or without
17: * modification, are permitted provided that the following conditions
18: * are met:
19: * 1. Redistributions of source code must retain the above copyright
20: * notice, this list of conditions and the following disclaimer.
21: * 2. Redistributions in binary form must reproduce the above copyright
22: * notice, this list of conditions and the following disclaimer in the
23: * documentation and/or other materials provided with the distribution.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 35: */
1.1 deraadt 36:
1.151 deraadt 37: #include <sys/types.h>
1.153 djm 38: #include <sys/time.h>
1.78 provos 39: #include <sys/queue.h>
1.127 stevesk 40: #include <sys/resource.h>
1.141 stevesk 41: #include <sys/socket.h>
1.189 djm 42: #include <sys/stat.h>
1.128 stevesk 43: #include <sys/un.h>
1.238 djm 44: #include <sys/wait.h>
1.126 stevesk 45:
1.185 markus 46: #ifdef WITH_OPENSSL
1.146 stevesk 47: #include <openssl/evp.h>
1.185 markus 48: #endif
1.146 stevesk 49:
1.143 stevesk 50: #include <errno.h>
1.142 stevesk 51: #include <fcntl.h>
1.126 stevesk 52: #include <paths.h>
1.223 djm 53: #include <poll.h>
1.129 stevesk 54: #include <signal.h>
1.149 stevesk 55: #include <stdlib.h>
1.150 stevesk 56: #include <stdio.h>
1.146 stevesk 57: #include <string.h>
1.248 naddy 58: #include <stdarg.h>
1.196 deraadt 59: #include <limits.h>
1.145 stevesk 60: #include <time.h>
1.144 stevesk 61: #include <unistd.h>
1.203 dtucker 62: #include <util.h>
1.194 markus 63:
1.151 deraadt 64: #include "xmalloc.h"
1.1 deraadt 65: #include "ssh.h"
1.258 ! djm 66: #include "ssh2.h"
1.194 markus 67: #include "sshbuf.h"
68: #include "sshkey.h"
1.32 markus 69: #include "authfd.h"
1.37 markus 70: #include "compat.h"
1.47 markus 71: #include "log.h"
1.107 markus 72: #include "misc.h"
1.182 markus 73: #include "digest.h"
1.194 markus 74: #include "ssherr.h"
1.215 djm 75: #include "match.h"
1.238 djm 76: #include "msg.h"
1.244 djm 77: #include "ssherr.h"
1.238 djm 78: #include "pathnames.h"
1.163 markus 79: #include "ssh-pkcs11.h"
1.251 djm 80: #include "sk-api.h"
1.59 markus 81:
1.238 djm 82: #ifndef DEFAULT_PROVIDER_WHITELIST
83: # define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 84: #endif
85:
1.223 djm 86: /* Maximum accepted message length */
87: #define AGENT_MAX_LEN (256*1024)
1.233 djm 88: /* Maximum bytes to read from client socket */
89: #define AGENT_RBUF_LEN (4096)
1.223 djm 90:
1.73 stevesk 91: typedef enum {
92: AUTH_UNUSED,
93: AUTH_SOCKET,
94: AUTH_CONNECTION
95: } sock_type;
96:
1.21 markus 97: typedef struct {
98: int fd;
1.73 stevesk 99: sock_type type;
1.194 markus 100: struct sshbuf *input;
101: struct sshbuf *output;
102: struct sshbuf *request;
1.1 deraadt 103: } SocketEntry;
104:
1.45 markus 105: u_int sockets_alloc = 0;
1.1 deraadt 106: SocketEntry *sockets = NULL;
107:
1.78 provos 108: typedef struct identity {
109: TAILQ_ENTRY(identity) next;
1.194 markus 110: struct sshkey *key;
1.21 markus 111: char *comment;
1.163 markus 112: char *provider;
1.174 dtucker 113: time_t death;
1.107 markus 114: u_int confirm;
1.238 djm 115: char *sk_provider;
1.1 deraadt 116: } Identity;
117:
1.221 djm 118: struct idtable {
1.33 markus 119: int nentries;
1.78 provos 120: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 121: };
1.33 markus 122:
1.221 djm 123: /* private key table */
124: struct idtable *idtab;
1.1 deraadt 125:
126: int max_fd = 0;
127:
1.11 markus 128: /* pid of shell == parent of agent */
1.29 deraadt 129: pid_t parent_pid = -1;
1.176 dtucker 130: time_t parent_alive_interval = 0;
1.10 markus 131:
1.187 djm 132: /* pid of process for which cleanup_socket is applicable */
133: pid_t cleanup_pid = 0;
134:
1.10 markus 135: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 136: char socket_name[PATH_MAX];
137: char socket_dir[PATH_MAX];
1.10 markus 138:
1.238 djm 139: /* PKCS#11/Security key path whitelist */
140: static char *provider_whitelist;
1.215 djm 141:
1.88 markus 142: /* locking */
1.203 dtucker 143: #define LOCK_SIZE 32
144: #define LOCK_SALT_SIZE 16
145: #define LOCK_ROUNDS 1
1.88 markus 146: int locked = 0;
1.213 djm 147: u_char lock_pwhash[LOCK_SIZE];
148: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 149:
1.20 markus 150: extern char *__progname;
151:
1.174 dtucker 152: /* Default lifetime in seconds (0 == forever) */
153: static long lifetime = 0;
1.106 marc 154:
1.192 djm 155: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
156:
1.258 ! djm 157: /* Refuse signing of non-SSH messages for web-origin FIDO keys */
! 158: static int restrict_websafe = 1;
! 159:
1.55 itojun 160: static void
1.101 stevesk 161: close_socket(SocketEntry *e)
162: {
163: close(e->fd);
164: e->fd = -1;
165: e->type = AUTH_UNUSED;
1.194 markus 166: sshbuf_free(e->input);
167: sshbuf_free(e->output);
168: sshbuf_free(e->request);
1.101 stevesk 169: }
170:
171: static void
1.33 markus 172: idtab_init(void)
1.1 deraadt 173: {
1.221 djm 174: idtab = xcalloc(1, sizeof(*idtab));
175: TAILQ_INIT(&idtab->idlist);
176: idtab->nentries = 0;
1.33 markus 177: }
178:
1.89 markus 179: static void
180: free_identity(Identity *id)
181: {
1.194 markus 182: sshkey_free(id->key);
1.173 djm 183: free(id->provider);
184: free(id->comment);
1.238 djm 185: free(id->sk_provider);
1.173 djm 186: free(id);
1.89 markus 187: }
188:
1.33 markus 189: /* return matching private key for given public key */
1.78 provos 190: static Identity *
1.221 djm 191: lookup_identity(struct sshkey *key)
1.33 markus 192: {
1.78 provos 193: Identity *id;
194:
1.221 djm 195: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 196: if (sshkey_equal(key, id->key))
1.78 provos 197: return (id);
1.33 markus 198: }
1.78 provos 199: return (NULL);
200: }
201:
1.107 markus 202: /* Check confirmation of keysign request */
203: static int
204: confirm_key(Identity *id)
205: {
1.122 djm 206: char *p;
1.107 markus 207: int ret = -1;
208:
1.194 markus 209: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 210: if (p != NULL &&
211: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 212: id->comment, p))
213: ret = 0;
1.173 djm 214: free(p);
1.122 djm 215:
1.107 markus 216: return (ret);
217: }
218:
1.194 markus 219: static void
220: send_status(SocketEntry *e, int success)
221: {
222: int r;
223:
224: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
225: (r = sshbuf_put_u8(e->output, success ?
226: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
227: fatal("%s: buffer error: %s", __func__, ssh_err(r));
228: }
229:
1.33 markus 230: /* send list of supported public keys to 'client' */
1.55 itojun 231: static void
1.221 djm 232: process_request_identities(SocketEntry *e)
1.33 markus 233: {
1.96 deraadt 234: Identity *id;
1.194 markus 235: struct sshbuf *msg;
236: int r;
1.1 deraadt 237:
1.194 markus 238: if ((msg = sshbuf_new()) == NULL)
239: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 240: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
241: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
242: fatal("%s: buffer error: %s", __func__, ssh_err(r));
243: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 244: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
245: != 0 ||
1.221 djm 246: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
247: error("%s: put key/comment: %s", __func__,
1.220 djm 248: ssh_err(r));
249: continue;
1.33 markus 250: }
1.21 markus 251: }
1.194 markus 252: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
253: fatal("%s: buffer error: %s", __func__, ssh_err(r));
254: sshbuf_free(msg);
1.1 deraadt 255: }
256:
1.33 markus 257:
1.208 markus 258: static char *
259: agent_decode_alg(struct sshkey *key, u_int flags)
260: {
261: if (key->type == KEY_RSA) {
262: if (flags & SSH_AGENT_RSA_SHA2_256)
263: return "rsa-sha2-256";
264: else if (flags & SSH_AGENT_RSA_SHA2_512)
265: return "rsa-sha2-512";
1.235 djm 266: } else if (key->type == KEY_RSA_CERT) {
267: if (flags & SSH_AGENT_RSA_SHA2_256)
268: return "rsa-sha2-256-cert-v01@openssh.com";
269: else if (flags & SSH_AGENT_RSA_SHA2_512)
270: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 271: }
272: return NULL;
273: }
274:
1.258 ! djm 275: /*
! 276: * This function inspects a message to be signed by a FIDO key that has a
! 277: * web-like application string (i.e. one that does not begin with "ssh:".
! 278: * It checks that the message is one of those expected for SSH operations
! 279: * (pubkey userauth, sshsig, CA key signing) to exclude signing challenges
! 280: * for the web.
! 281: */
! 282: static int
! 283: check_websafe_message_contents(struct sshkey *key,
! 284: const u_char *msg, size_t len)
! 285: {
! 286: int matched = 0;
! 287: struct sshbuf *b;
! 288: u_char m, n;
! 289: char *cp1 = NULL, *cp2 = NULL;
! 290: int r;
! 291: struct sshkey *mkey = NULL;
! 292:
! 293: if ((b = sshbuf_from(msg, len)) == NULL)
! 294: fatal("%s: sshbuf_new", __func__);
! 295:
! 296: /* SSH userauth request */
! 297: if ((r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* sess_id */
! 298: (r = sshbuf_get_u8(b, &m)) == 0 && /* SSH2_MSG_USERAUTH_REQUEST */
! 299: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* server user */
! 300: (r = sshbuf_get_cstring(b, &cp1, NULL)) == 0 && /* service */
! 301: (r = sshbuf_get_cstring(b, &cp2, NULL)) == 0 && /* method */
! 302: (r = sshbuf_get_u8(b, &n)) == 0 && /* sig-follows */
! 303: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* alg */
! 304: (r = sshkey_froms(b, &mkey)) == 0 && /* key */
! 305: sshbuf_len(b) == 0) {
! 306: debug("%s: parsed userauth", __func__);
! 307: if (m == SSH2_MSG_USERAUTH_REQUEST && n == 1 &&
! 308: strcmp(cp1, "ssh-connection") == 0 &&
! 309: strcmp(cp2, "publickey") == 0 &&
! 310: sshkey_equal(key, mkey)) {
! 311: debug("%s: well formed userauth", __func__);
! 312: matched = 1;
! 313: }
! 314: }
! 315: free(cp1);
! 316: free(cp2);
! 317: sshkey_free(mkey);
! 318: sshbuf_free(b);
! 319: if (matched)
! 320: return 1;
! 321:
! 322: if ((b = sshbuf_from(msg, len)) == NULL)
! 323: fatal("%s: sshbuf_new", __func__);
! 324: cp1 = cp2 = NULL;
! 325: mkey = NULL;
! 326:
! 327: /* SSHSIG */
! 328: if ((r = sshbuf_cmp(b, 0, "SSHSIG", 6)) == 0 &&
! 329: (r = sshbuf_consume(b, 6)) == 0 &&
! 330: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* namespace */
! 331: (r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* reserved */
! 332: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* hashalg */
! 333: (r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* H(msg) */
! 334: sshbuf_len(b) == 0) {
! 335: debug("%s: parsed sshsig", __func__);
! 336: matched = 1;
! 337: }
! 338:
! 339: sshbuf_free(b);
! 340: if (matched)
! 341: return 1;
! 342:
! 343: /* XXX CA signature operation */
! 344:
! 345: error("web-origin key attempting to sign non-SSH message");
! 346: return 0;
! 347: }
! 348:
1.33 markus 349: /* ssh2 only */
1.55 itojun 350: static void
1.33 markus 351: process_sign_request2(SocketEntry *e)
352: {
1.221 djm 353: const u_char *data;
354: u_char *signature = NULL;
355: size_t dlen, slen = 0;
1.194 markus 356: u_int compat = 0, flags;
1.247 djm 357: int r, ok = -1;
1.251 djm 358: char *fp = NULL;
1.194 markus 359: struct sshbuf *msg;
1.221 djm 360: struct sshkey *key = NULL;
1.195 djm 361: struct identity *id;
1.251 djm 362: struct notifier_ctx *notifier = NULL;
1.194 markus 363:
1.195 djm 364: if ((msg = sshbuf_new()) == NULL)
365: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 366: if ((r = sshkey_froms(e->request, &key)) != 0 ||
367: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 368: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
369: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
370: goto send;
371: }
372:
1.221 djm 373: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 374: verbose("%s: %s key not found", __func__, sshkey_type(key));
375: goto send;
376: }
377: if (id->confirm && confirm_key(id) != 0) {
378: verbose("%s: user refused key", __func__);
379: goto send;
380: }
1.258 ! djm 381: if (sshkey_is_sk(id->key)) {
! 382: if (strncmp(id->key->sk_application, "ssh:", 4) != 0 &&
! 383: !check_websafe_message_contents(key, data, dlen)) {
! 384: /* error already logged */
! 385: goto send;
! 386: }
! 387: if ((id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
! 388: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 389: SSH_FP_DEFAULT)) == NULL)
! 390: fatal("%s: fingerprint failed", __func__);
! 391: notifier = notify_start(0,
! 392: "Confirm user presence for key %s %s",
! 393: sshkey_type(id->key), fp);
! 394: }
1.251 djm 395: }
396: if ((r = sshkey_sign(id->key, &signature, &slen,
397: data, dlen, agent_decode_alg(key, flags),
398: id->sk_provider, compat)) != 0) {
399: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
400: goto send;
1.33 markus 401: }
1.195 djm 402: /* Success */
403: ok = 0;
404: send:
1.251 djm 405: notify_complete(notifier);
1.195 djm 406: sshkey_free(key);
1.251 djm 407: free(fp);
1.33 markus 408: if (ok == 0) {
1.194 markus 409: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
410: (r = sshbuf_put_string(msg, signature, slen)) != 0)
411: fatal("%s: buffer error: %s", __func__, ssh_err(r));
412: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
413: fatal("%s: buffer error: %s", __func__, ssh_err(r));
414:
415: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
416: fatal("%s: buffer error: %s", __func__, ssh_err(r));
417:
418: sshbuf_free(msg);
1.173 djm 419: free(signature);
1.1 deraadt 420: }
421:
1.33 markus 422: /* shared */
1.55 itojun 423: static void
1.221 djm 424: process_remove_identity(SocketEntry *e)
1.1 deraadt 425: {
1.194 markus 426: int r, success = 0;
427: struct sshkey *key = NULL;
1.221 djm 428: Identity *id;
1.21 markus 429:
1.221 djm 430: if ((r = sshkey_froms(e->request, &key)) != 0) {
431: error("%s: get key: %s", __func__, ssh_err(r));
432: goto done;
433: }
434: if ((id = lookup_identity(key)) == NULL) {
435: debug("%s: key not found", __func__);
436: goto done;
437: }
438: /* We have this key, free it. */
439: if (idtab->nentries < 1)
440: fatal("%s: internal error: nentries %d",
441: __func__, idtab->nentries);
442: TAILQ_REMOVE(&idtab->idlist, id, next);
443: free_identity(id);
444: idtab->nentries--;
445: sshkey_free(key);
446: success = 1;
447: done:
1.194 markus 448: send_status(e, success);
1.1 deraadt 449: }
450:
1.55 itojun 451: static void
1.221 djm 452: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 453: {
1.78 provos 454: Identity *id;
1.21 markus 455:
456: /* Loop over all identities and clear the keys. */
1.221 djm 457: for (id = TAILQ_FIRST(&idtab->idlist); id;
458: id = TAILQ_FIRST(&idtab->idlist)) {
459: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 460: free_identity(id);
1.21 markus 461: }
462:
463: /* Mark that there are no identities. */
1.221 djm 464: idtab->nentries = 0;
1.21 markus 465:
466: /* Send success. */
1.194 markus 467: send_status(e, 1);
1.1 deraadt 468: }
469:
1.155 dtucker 470: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 471: static time_t
1.89 markus 472: reaper(void)
473: {
1.175 dtucker 474: time_t deadline = 0, now = monotime();
1.89 markus 475: Identity *id, *nxt;
476:
1.221 djm 477: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
478: nxt = TAILQ_NEXT(id, next);
479: if (id->death == 0)
480: continue;
481: if (now >= id->death) {
482: debug("expiring key '%s'", id->comment);
483: TAILQ_REMOVE(&idtab->idlist, id, next);
484: free_identity(id);
485: idtab->nentries--;
486: } else
487: deadline = (deadline == 0) ? id->death :
488: MINIMUM(deadline, id->death);
1.89 markus 489: }
1.155 dtucker 490: if (deadline == 0 || deadline <= now)
491: return 0;
492: else
493: return (deadline - now);
1.89 markus 494: }
495:
496: static void
1.221 djm 497: process_add_identity(SocketEntry *e)
1.1 deraadt 498: {
1.157 canacar 499: Identity *id;
1.194 markus 500: int success = 0, confirm = 0;
1.257 markus 501: u_int seconds = 0, maxsign;
1.238 djm 502: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.254 djm 503: char canonical_provider[PATH_MAX];
1.174 dtucker 504: time_t death = 0;
1.194 markus 505: struct sshkey *k = NULL;
506: u_char ctype;
507: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 508:
1.221 djm 509: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
510: k == NULL ||
1.194 markus 511: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
512: error("%s: decode private key: %s", __func__, ssh_err(r));
513: goto err;
514: }
515: while (sshbuf_len(e->request)) {
516: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
517: error("%s: buffer error: %s", __func__, ssh_err(r));
518: goto err;
519: }
520: switch (ctype) {
1.94 markus 521: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 522: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
523: error("%s: bad lifetime constraint: %s",
524: __func__, ssh_err(r));
525: goto err;
526: }
527: death = monotime() + seconds;
1.94 markus 528: break;
1.107 markus 529: case SSH_AGENT_CONSTRAIN_CONFIRM:
530: confirm = 1;
531: break;
1.228 markus 532: case SSH_AGENT_CONSTRAIN_MAXSIGN:
533: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
534: error("%s: bad maxsign constraint: %s",
535: __func__, ssh_err(r));
536: goto err;
537: }
538: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
539: error("%s: cannot enable maxsign: %s",
540: __func__, ssh_err(r));
541: goto err;
542: }
543: break;
1.238 djm 544: case SSH_AGENT_CONSTRAIN_EXTENSION:
545: if ((r = sshbuf_get_cstring(e->request,
546: &ext_name, NULL)) != 0) {
547: error("%s: cannot parse extension: %s",
548: __func__, ssh_err(r));
549: goto err;
550: }
551: debug("%s: constraint ext %s", __func__, ext_name);
552: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
553: if (sk_provider != NULL) {
554: error("%s already set", ext_name);
555: goto err;
556: }
557: if ((r = sshbuf_get_cstring(e->request,
558: &sk_provider, NULL)) != 0) {
559: error("%s: cannot parse %s: %s",
560: __func__, ext_name, ssh_err(r));
561: goto err;
562: }
563: } else {
564: error("%s: unsupported constraint \"%s\"",
565: __func__, ext_name);
566: goto err;
567: }
568: free(ext_name);
569: break;
1.94 markus 570: default:
1.194 markus 571: error("%s: Unknown constraint %d", __func__, ctype);
572: err:
1.238 djm 573: free(sk_provider);
574: free(ext_name);
1.194 markus 575: sshbuf_reset(e->request);
1.173 djm 576: free(comment);
1.194 markus 577: sshkey_free(k);
1.158 djm 578: goto send;
1.94 markus 579: }
580: }
1.238 djm 581: if (sk_provider != NULL) {
1.240 markus 582: if (!sshkey_is_sk(k)) {
1.255 naddy 583: error("Cannot add provider: %s is not an "
584: "authenticator-hosted key", sshkey_type(k));
1.238 djm 585: free(sk_provider);
586: goto send;
587: }
1.254 djm 588: if (strcasecmp(sk_provider, "internal") == 0) {
1.245 djm 589: debug("%s: internal provider", __func__);
1.254 djm 590: } else {
591: if (realpath(sk_provider, canonical_provider) == NULL) {
592: verbose("failed provider \"%.100s\": "
593: "realpath: %s", sk_provider,
594: strerror(errno));
595: free(sk_provider);
596: goto send;
597: }
1.238 djm 598: free(sk_provider);
1.254 djm 599: sk_provider = xstrdup(canonical_provider);
600: if (match_pattern_list(sk_provider,
601: provider_whitelist, 0) != 1) {
602: error("Refusing add key: "
603: "provider %s not whitelisted", sk_provider);
604: free(sk_provider);
605: goto send;
606: }
1.238 djm 607: }
1.242 markus 608: }
609: if ((r = sshkey_shield_private(k)) != 0) {
610: error("%s: shield private key: %s", __func__, ssh_err(r));
611: goto err;
1.238 djm 612: }
1.194 markus 613:
1.158 djm 614: success = 1;
1.106 marc 615: if (lifetime && !death)
1.175 dtucker 616: death = monotime() + lifetime;
1.221 djm 617: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 618: id = xcalloc(1, sizeof(Identity));
1.221 djm 619: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 620: /* Increment the number of identities. */
1.221 djm 621: idtab->nentries++;
1.33 markus 622: } else {
1.228 markus 623: /* key state might have been updated */
624: sshkey_free(id->key);
1.173 djm 625: free(id->comment);
1.238 djm 626: free(id->sk_provider);
1.33 markus 627: }
1.228 markus 628: id->key = k;
1.157 canacar 629: id->comment = comment;
630: id->death = death;
631: id->confirm = confirm;
1.238 djm 632: id->sk_provider = sk_provider;
633:
634: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
635: SSH_FP_DEFAULT)) == NULL)
636: fatal("%s: sshkey_fingerprint failed", __func__);
637: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
638: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
639: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
640: free(fp);
1.33 markus 641: send:
1.194 markus 642: send_status(e, success);
1.1 deraadt 643: }
644:
1.88 markus 645: /* XXX todo: encrypt sensitive data with passphrase */
646: static void
647: process_lock_agent(SocketEntry *e, int lock)
648: {
1.203 dtucker 649: int r, success = 0, delay;
1.213 djm 650: char *passwd;
651: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 652: static u_int fail_count = 0;
653: size_t pwlen;
654:
1.226 djm 655: /*
656: * This is deliberately fatal: the user has requested that we lock,
657: * but we can't parse their request properly. The only safe thing to
658: * do is abort.
659: */
1.203 dtucker 660: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
661: fatal("%s: buffer error: %s", __func__, ssh_err(r));
662: if (pwlen == 0) {
663: debug("empty password not supported");
664: } else if (locked && !lock) {
665: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
666: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
667: fatal("bcrypt_pbkdf");
1.213 djm 668: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 669: debug("agent unlocked");
670: locked = 0;
671: fail_count = 0;
1.213 djm 672: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 673: success = 1;
674: } else {
675: /* delay in 0.1s increments up to 10s */
676: if (fail_count < 100)
677: fail_count++;
678: delay = 100000 * fail_count;
679: debug("unlock failed, delaying %0.1lf seconds",
680: (double)delay/1000000);
681: usleep(delay);
682: }
683: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 684: } else if (!locked && lock) {
1.203 dtucker 685: debug("agent locked");
1.88 markus 686: locked = 1;
1.203 dtucker 687: arc4random_buf(lock_salt, sizeof(lock_salt));
688: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 689: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 690: fatal("bcrypt_pbkdf");
1.88 markus 691: success = 1;
692: }
1.256 jsg 693: freezero(passwd, pwlen);
1.194 markus 694: send_status(e, success);
1.88 markus 695: }
696:
697: static void
1.221 djm 698: no_identities(SocketEntry *e)
1.88 markus 699: {
1.194 markus 700: struct sshbuf *msg;
701: int r;
1.88 markus 702:
1.194 markus 703: if ((msg = sshbuf_new()) == NULL)
704: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 705: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 706: (r = sshbuf_put_u32(msg, 0)) != 0 ||
707: (r = sshbuf_put_stringb(e->output, msg)) != 0)
708: fatal("%s: buffer error: %s", __func__, ssh_err(r));
709: sshbuf_free(msg);
1.88 markus 710: }
1.59 markus 711:
1.163 markus 712: #ifdef ENABLE_PKCS11
1.59 markus 713: static void
1.158 djm 714: process_add_smartcard_key(SocketEntry *e)
1.59 markus 715: {
1.226 djm 716: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.253 djm 717: char **comments = NULL;
1.221 djm 718: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 719: u_int seconds;
1.174 dtucker 720: time_t death = 0;
1.194 markus 721: u_char type;
722: struct sshkey **keys = NULL, *k;
1.84 markus 723: Identity *id;
1.75 deraadt 724:
1.194 markus 725: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 726: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
727: error("%s: buffer error: %s", __func__, ssh_err(r));
728: goto send;
729: }
1.194 markus 730:
731: while (sshbuf_len(e->request)) {
1.226 djm 732: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
733: error("%s: buffer error: %s", __func__, ssh_err(r));
734: goto send;
735: }
1.194 markus 736: switch (type) {
1.110 djm 737: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 738: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
739: error("%s: buffer error: %s",
1.194 markus 740: __func__, ssh_err(r));
1.226 djm 741: goto send;
742: }
1.194 markus 743: death = monotime() + seconds;
1.110 djm 744: break;
745: case SSH_AGENT_CONSTRAIN_CONFIRM:
746: confirm = 1;
747: break;
748: default:
1.221 djm 749: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 750: goto send;
1.110 djm 751: }
752: }
1.215 djm 753: if (realpath(provider, canonical_provider) == NULL) {
754: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
755: provider, strerror(errno));
756: goto send;
757: }
1.238 djm 758: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 759: verbose("refusing PKCS#11 add of \"%.100s\": "
760: "provider not whitelisted", canonical_provider);
761: goto send;
762: }
763: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 764: if (lifetime && !death)
1.175 dtucker 765: death = monotime() + lifetime;
1.110 djm 766:
1.253 djm 767: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.163 markus 768: for (i = 0; i < count; i++) {
1.84 markus 769: k = keys[i];
1.221 djm 770: if (lookup_identity(k) == NULL) {
1.163 markus 771: id = xcalloc(1, sizeof(Identity));
1.84 markus 772: id->key = k;
1.253 djm 773: keys[i] = NULL; /* transferred */
1.215 djm 774: id->provider = xstrdup(canonical_provider);
1.253 djm 775: if (*comments[i] != '\0') {
776: id->comment = comments[i];
777: comments[i] = NULL; /* transferred */
778: } else {
779: id->comment = xstrdup(canonical_provider);
780: }
1.110 djm 781: id->death = death;
782: id->confirm = confirm;
1.221 djm 783: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
784: idtab->nentries++;
1.84 markus 785: success = 1;
786: }
1.253 djm 787: sshkey_free(keys[i]);
788: free(comments[i]);
1.59 markus 789: }
790: send:
1.173 djm 791: free(pin);
792: free(provider);
793: free(keys);
1.253 djm 794: free(comments);
1.194 markus 795: send_status(e, success);
1.59 markus 796: }
797:
798: static void
799: process_remove_smartcard_key(SocketEntry *e)
800: {
1.217 djm 801: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 802: int r, success = 0;
1.163 markus 803: Identity *id, *nxt;
1.59 markus 804:
1.194 markus 805: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 806: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
807: error("%s: buffer error: %s", __func__, ssh_err(r));
808: goto send;
809: }
1.173 djm 810: free(pin);
1.59 markus 811:
1.217 djm 812: if (realpath(provider, canonical_provider) == NULL) {
813: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
814: provider, strerror(errno));
815: goto send;
816: }
817:
818: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 819: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
820: nxt = TAILQ_NEXT(id, next);
821: /* Skip file--based keys */
822: if (id->provider == NULL)
823: continue;
824: if (!strcmp(canonical_provider, id->provider)) {
825: TAILQ_REMOVE(&idtab->idlist, id, next);
826: free_identity(id);
827: idtab->nentries--;
1.59 markus 828: }
829: }
1.217 djm 830: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 831: success = 1;
832: else
1.221 djm 833: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 834: send:
1.173 djm 835: free(provider);
1.194 markus 836: send_status(e, success);
1.59 markus 837: }
1.163 markus 838: #endif /* ENABLE_PKCS11 */
1.59 markus 839:
1.33 markus 840: /* dispatch incoming messages */
841:
1.223 djm 842: static int
843: process_message(u_int socknum)
1.1 deraadt 844: {
1.194 markus 845: u_int msg_len;
846: u_char type;
847: const u_char *cp;
848: int r;
1.223 djm 849: SocketEntry *e;
850:
851: if (socknum >= sockets_alloc) {
852: fatal("%s: socket number %u >= allocated %u",
853: __func__, socknum, sockets_alloc);
854: }
855: e = &sockets[socknum];
1.89 markus 856:
1.194 markus 857: if (sshbuf_len(e->input) < 5)
1.223 djm 858: return 0; /* Incomplete message header. */
1.194 markus 859: cp = sshbuf_ptr(e->input);
860: msg_len = PEEK_U32(cp);
1.223 djm 861: if (msg_len > AGENT_MAX_LEN) {
862: debug("%s: socket %u (fd=%d) message too long %u > %u",
863: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
864: return -1;
1.21 markus 865: }
1.194 markus 866: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 867: return 0; /* Incomplete message body. */
1.87 markus 868:
869: /* move the current input to e->request */
1.194 markus 870: sshbuf_reset(e->request);
871: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 872: (r = sshbuf_get_u8(e->request, &type)) != 0) {
873: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
874: r == SSH_ERR_STRING_TOO_LARGE) {
875: debug("%s: buffer error: %s", __func__, ssh_err(r));
876: return -1;
877: }
1.194 markus 878: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 879: }
880:
881: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 882:
1.230 djm 883: /* check whether agent is locked */
1.88 markus 884: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 885: sshbuf_reset(e->request);
1.88 markus 886: switch (type) {
887: case SSH2_AGENTC_REQUEST_IDENTITIES:
888: /* send empty lists */
1.221 djm 889: no_identities(e);
1.88 markus 890: break;
891: default:
892: /* send a fail message for all other request types */
1.194 markus 893: send_status(e, 0);
1.88 markus 894: }
1.223 djm 895: return 0;
1.88 markus 896: }
897:
1.21 markus 898: switch (type) {
1.88 markus 899: case SSH_AGENTC_LOCK:
900: case SSH_AGENTC_UNLOCK:
901: process_lock_agent(e, type == SSH_AGENTC_LOCK);
902: break;
1.21 markus 903: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 904: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 905: break;
906: /* ssh2 */
907: case SSH2_AGENTC_SIGN_REQUEST:
908: process_sign_request2(e);
909: break;
910: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 911: process_request_identities(e);
1.33 markus 912: break;
913: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 914: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 915: process_add_identity(e);
1.33 markus 916: break;
917: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 918: process_remove_identity(e);
1.33 markus 919: break;
920: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 921: process_remove_all_identities(e);
1.21 markus 922: break;
1.163 markus 923: #ifdef ENABLE_PKCS11
1.59 markus 924: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 925: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 926: process_add_smartcard_key(e);
1.75 deraadt 927: break;
1.59 markus 928: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
929: process_remove_smartcard_key(e);
1.75 deraadt 930: break;
1.163 markus 931: #endif /* ENABLE_PKCS11 */
1.21 markus 932: default:
933: /* Unknown message. Respond with failure. */
934: error("Unknown message %d", type);
1.194 markus 935: sshbuf_reset(e->request);
936: send_status(e, 0);
1.21 markus 937: break;
938: }
1.223 djm 939: return 0;
1.1 deraadt 940: }
941:
1.55 itojun 942: static void
1.73 stevesk 943: new_socket(sock_type type, int fd)
1.1 deraadt 944: {
1.112 markus 945: u_int i, old_alloc, new_alloc;
1.96 deraadt 946:
1.119 djm 947: set_nonblock(fd);
1.21 markus 948:
949: if (fd > max_fd)
950: max_fd = fd;
951:
952: for (i = 0; i < sockets_alloc; i++)
953: if (sockets[i].type == AUTH_UNUSED) {
954: sockets[i].fd = fd;
1.194 markus 955: if ((sockets[i].input = sshbuf_new()) == NULL)
956: fatal("%s: sshbuf_new failed", __func__);
957: if ((sockets[i].output = sshbuf_new()) == NULL)
958: fatal("%s: sshbuf_new failed", __func__);
959: if ((sockets[i].request = sshbuf_new()) == NULL)
960: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 961: sockets[i].type = type;
1.21 markus 962: return;
963: }
964: old_alloc = sockets_alloc;
1.112 markus 965: new_alloc = sockets_alloc + 10;
1.200 deraadt 966: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 967: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 968: sockets[i].type = AUTH_UNUSED;
1.112 markus 969: sockets_alloc = new_alloc;
1.21 markus 970: sockets[old_alloc].fd = fd;
1.194 markus 971: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
972: fatal("%s: sshbuf_new failed", __func__);
973: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
974: fatal("%s: sshbuf_new failed", __func__);
975: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
976: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 977: sockets[old_alloc].type = type;
1.1 deraadt 978: }
979:
1.55 itojun 980: static int
1.223 djm 981: handle_socket_read(u_int socknum)
1.1 deraadt 982: {
1.223 djm 983: struct sockaddr_un sunaddr;
984: socklen_t slen;
985: uid_t euid;
986: gid_t egid;
987: int fd;
988:
989: slen = sizeof(sunaddr);
990: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 991: if (fd == -1) {
1.223 djm 992: error("accept from AUTH_SOCKET: %s", strerror(errno));
993: return -1;
994: }
1.237 deraadt 995: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 996: error("getpeereid %d failed: %s", fd, strerror(errno));
997: close(fd);
998: return -1;
999: }
1000: if ((euid != 0) && (getuid() != euid)) {
1001: error("uid mismatch: peer euid %u != uid %u",
1002: (u_int) euid, (u_int) getuid());
1003: close(fd);
1004: return -1;
1005: }
1006: new_socket(AUTH_CONNECTION, fd);
1007: return 0;
1008: }
1009:
1010: static int
1011: handle_conn_read(u_int socknum)
1012: {
1.233 djm 1013: char buf[AGENT_RBUF_LEN];
1.223 djm 1014: ssize_t len;
1015: int r;
1016:
1017: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1018: if (len == -1) {
1019: if (errno == EAGAIN || errno == EINTR)
1020: return 0;
1021: error("%s: read error on socket %u (fd %d): %s",
1022: __func__, socknum, sockets[socknum].fd,
1023: strerror(errno));
1024: }
1025: return -1;
1026: }
1027: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1028: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1029: explicit_bzero(buf, sizeof(buf));
1030: process_message(socknum);
1031: return 0;
1032: }
1033:
1034: static int
1035: handle_conn_write(u_int socknum)
1036: {
1037: ssize_t len;
1038: int r;
1039:
1040: if (sshbuf_len(sockets[socknum].output) == 0)
1041: return 0; /* shouldn't happen */
1042: if ((len = write(sockets[socknum].fd,
1043: sshbuf_ptr(sockets[socknum].output),
1044: sshbuf_len(sockets[socknum].output))) <= 0) {
1045: if (len == -1) {
1046: if (errno == EAGAIN || errno == EINTR)
1047: return 0;
1048: error("%s: read error on socket %u (fd %d): %s",
1049: __func__, socknum, sockets[socknum].fd,
1050: strerror(errno));
1051: }
1052: return -1;
1053: }
1054: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1055: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1056: return 0;
1057: }
1058:
1059: static void
1.231 djm 1060: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1061: {
1062: size_t i;
1.231 djm 1063: u_int socknum, activefds = npfd;
1.223 djm 1064:
1065: for (i = 0; i < npfd; i++) {
1066: if (pfd[i].revents == 0)
1067: continue;
1068: /* Find sockets entry */
1069: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1070: if (sockets[socknum].type != AUTH_SOCKET &&
1071: sockets[socknum].type != AUTH_CONNECTION)
1072: continue;
1073: if (pfd[i].fd == sockets[socknum].fd)
1074: break;
1075: }
1076: if (socknum >= sockets_alloc) {
1077: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1078: continue;
1079: }
1080: /* Process events */
1081: switch (sockets[socknum].type) {
1082: case AUTH_SOCKET:
1.231 djm 1083: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1084: break;
1085: if (npfd > maxfds) {
1086: debug3("out of fds (active %u >= limit %u); "
1087: "skipping accept", activefds, maxfds);
1088: break;
1089: }
1090: if (handle_socket_read(socknum) == 0)
1091: activefds++;
1.223 djm 1092: break;
1093: case AUTH_CONNECTION:
1094: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1095: handle_conn_read(socknum) != 0) {
1.231 djm 1096: goto close_sock;
1097: }
1098: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1099: handle_conn_write(socknum) != 0) {
1100: close_sock:
1101: if (activefds == 0)
1102: fatal("activefds == 0 at close_sock");
1.223 djm 1103: close_socket(&sockets[socknum]);
1.231 djm 1104: activefds--;
1.223 djm 1105: break;
1106: }
1107: break;
1108: default:
1109: break;
1110: }
1111: }
1112: }
1113:
1114: static int
1.231 djm 1115: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1116: {
1117: struct pollfd *pfd = *pfdp;
1118: size_t i, j, npfd = 0;
1.174 dtucker 1119: time_t deadline;
1.233 djm 1120: int r;
1.46 markus 1121:
1.223 djm 1122: /* Count active sockets */
1.46 markus 1123: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1124: switch (sockets[i].type) {
1125: case AUTH_SOCKET:
1126: case AUTH_CONNECTION:
1.223 djm 1127: npfd++;
1.21 markus 1128: break;
1129: case AUTH_UNUSED:
1130: break;
1131: default:
1132: fatal("Unknown socket type %d", sockets[i].type);
1133: break;
1134: }
1.46 markus 1135: }
1.223 djm 1136: if (npfd != *npfdp &&
1137: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1138: fatal("%s: recallocarray failed", __func__);
1139: *pfdp = pfd;
1140: *npfdp = npfd;
1.46 markus 1141:
1.223 djm 1142: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1143: switch (sockets[i].type) {
1144: case AUTH_SOCKET:
1.231 djm 1145: if (npfd > maxfds) {
1146: debug3("out of fds (active %zu >= limit %u); "
1147: "skipping arming listener", npfd, maxfds);
1148: break;
1149: }
1150: pfd[j].fd = sockets[i].fd;
1151: pfd[j].revents = 0;
1152: pfd[j].events = POLLIN;
1153: j++;
1154: break;
1.46 markus 1155: case AUTH_CONNECTION:
1.223 djm 1156: pfd[j].fd = sockets[i].fd;
1157: pfd[j].revents = 0;
1.233 djm 1158: /*
1159: * Only prepare to read if we can handle a full-size
1160: * input read buffer and enqueue a max size reply..
1161: */
1162: if ((r = sshbuf_check_reserve(sockets[i].input,
1163: AGENT_RBUF_LEN)) == 0 &&
1164: (r = sshbuf_check_reserve(sockets[i].output,
1165: AGENT_MAX_LEN)) == 0)
1166: pfd[j].events = POLLIN;
1167: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1168: fatal("%s: buffer error: %s",
1169: __func__, ssh_err(r));
1170: }
1.194 markus 1171: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1172: pfd[j].events |= POLLOUT;
1173: j++;
1.46 markus 1174: break;
1175: default:
1176: break;
1177: }
1178: }
1.155 dtucker 1179: deadline = reaper();
1180: if (parent_alive_interval != 0)
1181: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1182: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1183: if (deadline == 0) {
1.224 djm 1184: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1185: } else {
1.223 djm 1186: if (deadline > INT_MAX / 1000)
1187: *timeoutp = INT_MAX / 1000;
1188: else
1189: *timeoutp = deadline * 1000;
1.155 dtucker 1190: }
1.46 markus 1191: return (1);
1.21 markus 1192: }
1193:
1.55 itojun 1194: static void
1.113 markus 1195: cleanup_socket(void)
1.15 markus 1196: {
1.187 djm 1197: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1198: return;
1199: debug("%s: cleanup", __func__);
1.48 deraadt 1200: if (socket_name[0])
1201: unlink(socket_name);
1202: if (socket_dir[0])
1203: rmdir(socket_dir);
1.10 markus 1204: }
1205:
1.114 markus 1206: void
1.15 markus 1207: cleanup_exit(int i)
1208: {
1.113 markus 1209: cleanup_socket();
1210: _exit(i);
1.15 markus 1211: }
1212:
1.135 deraadt 1213: /*ARGSUSED*/
1.55 itojun 1214: static void
1.48 deraadt 1215: cleanup_handler(int sig)
1216: {
1.113 markus 1217: cleanup_socket();
1.163 markus 1218: #ifdef ENABLE_PKCS11
1219: pkcs11_terminate();
1220: #endif
1.48 deraadt 1221: _exit(2);
1.113 markus 1222: }
1223:
1.68 markus 1224: static void
1.155 dtucker 1225: check_parent_exists(void)
1.68 markus 1226: {
1.172 dtucker 1227: /*
1228: * If our parent has exited then getppid() will return (pid_t)1,
1229: * so testing for that should be safe.
1230: */
1231: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1232: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1233: cleanup_socket();
1234: _exit(2);
1.68 markus 1235: }
1.48 deraadt 1236: }
1237:
1.55 itojun 1238: static void
1.50 itojun 1239: usage(void)
1.15 markus 1240: {
1.184 deraadt 1241: fprintf(stderr,
1.250 jmc 1242: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1243: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1244: " ssh-agent [-c | -s] -k\n");
1.21 markus 1245: exit(1);
1.15 markus 1246: }
1247:
1.2 provos 1248: int
1249: main(int ac, char **av)
1.1 deraadt 1250: {
1.201 djm 1251: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1252: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1253: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1254: struct rlimit rlim;
1.96 deraadt 1255: extern int optind;
1.98 stevesk 1256: extern char *optarg;
1.21 markus 1257: pid_t pid;
1.96 deraadt 1258: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1259: size_t len;
1.189 djm 1260: mode_t prev_mask;
1.224 djm 1261: int timeout = -1; /* INFTIM */
1.223 djm 1262: struct pollfd *pfd = NULL;
1263: size_t npfd = 0;
1.231 djm 1264: u_int maxfds;
1.123 djm 1265:
1266: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1267: sanitise_stdfd();
1.99 markus 1268:
1269: /* drop */
1270: setegid(getgid());
1271: setgid(getgid());
1.53 markus 1272:
1.231 djm 1273: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1274: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1275:
1.185 markus 1276: #ifdef WITH_OPENSSL
1.170 djm 1277: OpenSSL_add_all_algorithms();
1.185 markus 1278: #endif
1.21 markus 1279:
1.258 ! djm 1280: while ((ch = getopt(ac, av, "cDdksE:a:O:P:t:")) != -1) {
1.21 markus 1281: switch (ch) {
1.192 djm 1282: case 'E':
1283: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1284: if (fingerprint_hash == -1)
1285: fatal("Invalid hash algorithm \"%s\"", optarg);
1286: break;
1.21 markus 1287: case 'c':
1288: if (s_flag)
1289: usage();
1290: c_flag++;
1291: break;
1292: case 'k':
1293: k_flag++;
1.258 ! djm 1294: break;
! 1295: case 'O':
! 1296: if (strcmp(optarg, "no-restrict-websafe") == 0)
! 1297: restrict_websafe = 0;
! 1298: else
! 1299: fatal("Unknown -O option");
1.21 markus 1300: break;
1.215 djm 1301: case 'P':
1.238 djm 1302: if (provider_whitelist != NULL)
1.215 djm 1303: fatal("-P option already specified");
1.238 djm 1304: provider_whitelist = xstrdup(optarg);
1.215 djm 1305: break;
1.21 markus 1306: case 's':
1307: if (c_flag)
1308: usage();
1309: s_flag++;
1310: break;
1.57 markus 1311: case 'd':
1.201 djm 1312: if (d_flag || D_flag)
1.57 markus 1313: usage();
1314: d_flag++;
1315: break;
1.201 djm 1316: case 'D':
1317: if (d_flag || D_flag)
1318: usage();
1319: D_flag++;
1320: break;
1.86 markus 1321: case 'a':
1322: agentsocket = optarg;
1.106 marc 1323: break;
1324: case 't':
1325: if ((lifetime = convtime(optarg)) == -1) {
1326: fprintf(stderr, "Invalid lifetime\n");
1327: usage();
1328: }
1.86 markus 1329: break;
1.21 markus 1330: default:
1331: usage();
1332: }
1333: }
1334: ac -= optind;
1335: av += optind;
1336:
1.201 djm 1337: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1338: usage();
1339:
1.238 djm 1340: if (provider_whitelist == NULL)
1341: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1342:
1.85 markus 1343: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1344: shell = getenv("SHELL");
1.161 tobias 1345: if (shell != NULL && (len = strlen(shell)) > 2 &&
1346: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1347: c_flag = 1;
1348: }
1349: if (k_flag) {
1.136 deraadt 1350: const char *errstr = NULL;
1351:
1.21 markus 1352: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1353: if (pidstr == NULL) {
1354: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1355: SSH_AGENTPID_ENV_NAME);
1.21 markus 1356: exit(1);
1357: }
1.136 deraadt 1358: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1359: if (errstr) {
1360: fprintf(stderr,
1361: "%s=\"%s\", which is not a good PID: %s\n",
1362: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1363: exit(1);
1364: }
1365: if (kill(pid, SIGTERM) == -1) {
1366: perror("kill");
1367: exit(1);
1368: }
1369: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1370: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1371: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1372: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1373: exit(0);
1374: }
1.231 djm 1375:
1376: /*
1377: * Minimum file descriptors:
1378: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1379: * a few spare for libc / stack protectors / sanitisers, etc.
1380: */
1381: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1382: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1383: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1384: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1385: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1386:
1.21 markus 1387: parent_pid = getpid();
1388:
1.86 markus 1389: if (agentsocket == NULL) {
1390: /* Create private directory for agent socket */
1.171 djm 1391: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1392: if (mkdtemp(socket_dir) == NULL) {
1393: perror("mkdtemp: private socket dir");
1394: exit(1);
1395: }
1.91 mpech 1396: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1397: (long)parent_pid);
1.86 markus 1398: } else {
1399: /* Try to use specified agent socket */
1400: socket_dir[0] = '\0';
1401: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1402: }
1403:
1.23 markus 1404: /*
1405: * Create socket early so it will exist before command gets run from
1406: * the parent.
1407: */
1.189 djm 1408: prev_mask = umask(0177);
1.188 millert 1409: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1410: if (sock < 0) {
1.188 millert 1411: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1412: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1413: cleanup_exit(1);
1414: }
1.189 djm 1415: umask(prev_mask);
1.46 markus 1416:
1.23 markus 1417: /*
1418: * Fork, and have the parent execute the command, if any, or present
1419: * the socket data. The child continues as the authentication agent.
1420: */
1.201 djm 1421: if (D_flag || d_flag) {
1422: log_init(__progname,
1423: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1424: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1425: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1426: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1427: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1428: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1429: fflush(stdout);
1.57 markus 1430: goto skip;
1431: }
1.21 markus 1432: pid = fork();
1433: if (pid == -1) {
1434: perror("fork");
1.81 stevesk 1435: cleanup_exit(1);
1.21 markus 1436: }
1437: if (pid != 0) { /* Parent - execute the given command. */
1438: close(sock);
1.91 mpech 1439: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1440: if (ac == 0) {
1441: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1442: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1443: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1444: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1445: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1446: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1447: exit(0);
1448: }
1.36 deraadt 1449: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1450: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1451: perror("setenv");
1452: exit(1);
1453: }
1.21 markus 1454: execvp(av[0], av);
1455: perror(av[0]);
1456: exit(1);
1457: }
1.81 stevesk 1458: /* child */
1459: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1460:
1461: if (setsid() == -1) {
1.81 stevesk 1462: error("setsid: %s", strerror(errno));
1.67 stevesk 1463: cleanup_exit(1);
1464: }
1465:
1466: (void)chdir("/");
1.107 markus 1467: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1468: /* XXX might close listen socket */
1469: (void)dup2(fd, STDIN_FILENO);
1470: (void)dup2(fd, STDOUT_FILENO);
1471: (void)dup2(fd, STDERR_FILENO);
1472: if (fd > 2)
1473: close(fd);
1474: }
1.21 markus 1475:
1.41 markus 1476: /* deny core dumps, since memory contains unencrypted private keys */
1477: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1478: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1479: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1480: cleanup_exit(1);
1481: }
1.57 markus 1482:
1483: skip:
1.187 djm 1484:
1485: cleanup_pid = getpid();
1.163 markus 1486:
1487: #ifdef ENABLE_PKCS11
1488: pkcs11_init(0);
1489: #endif
1.21 markus 1490: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1491: if (ac > 0)
1492: parent_alive_interval = 10;
1.33 markus 1493: idtab_init();
1.252 dtucker 1494: ssh_signal(SIGPIPE, SIG_IGN);
1495: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1496: ssh_signal(SIGHUP, cleanup_handler);
1497: ssh_signal(SIGTERM, cleanup_handler);
1.205 djm 1498:
1.215 djm 1499: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1500: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1501:
1.21 markus 1502: while (1) {
1.231 djm 1503: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1504: result = poll(pfd, npfd, timeout);
1.154 dtucker 1505: saved_errno = errno;
1.155 dtucker 1506: if (parent_alive_interval != 0)
1507: check_parent_exists();
1508: (void) reaper(); /* remove expired keys */
1.237 deraadt 1509: if (result == -1) {
1.154 dtucker 1510: if (saved_errno == EINTR)
1.21 markus 1511: continue;
1.223 djm 1512: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1513: } else if (result > 0)
1.231 djm 1514: after_poll(pfd, npfd, maxfds);
1.15 markus 1515: }
1.21 markus 1516: /* NOTREACHED */
1.1 deraadt 1517: }