Annotation of src/crypto/external/bsd/openssh/dist/ssh-agent.c, Revision 1.1.1.25
1.1.1.25! christos 1: /* $OpenBSD: ssh-agent.c,v 1.287 2022/01/14 03:43:48 djm Exp $ */
1.1 christos 2: /*
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.
7: *
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: *
14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
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.
35: */
36:
37: #include <sys/types.h>
38: #include <sys/time.h>
39: #include <sys/queue.h>
40: #include <sys/resource.h>
41: #include <sys/socket.h>
1.1.1.7 christos 42: #include <sys/stat.h>
1.1 christos 43: #include <sys/un.h>
1.1.1.20 christos 44: #include <sys/wait.h>
1.1 christos 45:
1.1.1.7 christos 46: #ifdef WITH_OPENSSL
1.1 christos 47: #include <openssl/evp.h>
1.1.1.7 christos 48: #endif
1.1 christos 49:
50: #include <errno.h>
51: #include <fcntl.h>
52: #include <paths.h>
1.1.1.15 christos 53: #include <poll.h>
1.1 christos 54: #include <signal.h>
55: #include <stdlib.h>
56: #include <stdio.h>
57: #include <string.h>
1.1.1.20 christos 58: #include <stdarg.h>
1.1.1.8 christos 59: #include <limits.h>
1.1 christos 60: #include <time.h>
61: #include <unistd.h>
1.1.1.9 christos 62: #include <util.h>
1.1 christos 63:
64: #include "xmalloc.h"
65: #include "ssh.h"
1.1.1.22 christos 66: #include "ssh2.h"
1.1.1.8 christos 67: #include "sshbuf.h"
68: #include "sshkey.h"
1.1 christos 69: #include "authfd.h"
70: #include "compat.h"
71: #include "log.h"
72: #include "misc.h"
1.1.1.7 christos 73: #include "digest.h"
1.1.1.8 christos 74: #include "ssherr.h"
1.1.1.13 christos 75: #include "match.h"
1.1.1.20 christos 76: #include "msg.h"
77: #include "ssherr.h"
78: #include "pathnames.h"
1.1.1.3 adam 79: #include "ssh-pkcs11.h"
1.1.1.20 christos 80: #include "sk-api.h"
1.1.1.25! christos 81: #include "myproposal.h"
1.1 christos 82:
1.1.1.22 christos 83: #ifndef DEFAULT_ALLOWED_PROVIDERS
84: # define DEFAULT_ALLOWED_PROVIDERS "/usr/lib*/*,/usr/local/lib*/*"
1.1.1.13 christos 85: #endif
86:
1.1.1.15 christos 87: /* Maximum accepted message length */
1.1.1.25! christos 88: #define AGENT_MAX_LEN (256*1024)
1.1.1.18 christos 89: /* Maximum bytes to read from client socket */
1.1.1.25! christos 90: #define AGENT_RBUF_LEN (4096)
! 91: /* Maximum number of recorded session IDs/hostkeys per connection */
! 92: #define AGENT_MAX_SESSION_IDS 16
! 93: /* Maximum size of session ID */
! 94: #define AGENT_MAX_SID_LEN 128
! 95: /* Maximum number of destination constraints to accept on a key */
! 96: #define AGENT_MAX_DEST_CONSTRAINTS 1024
! 97:
! 98: /* XXX store hostkey_sid in a refcounted tree */
1.1.1.15 christos 99:
1.1 christos 100: typedef enum {
1.1.1.23 christos 101: AUTH_UNUSED = 0,
102: AUTH_SOCKET = 1,
103: AUTH_CONNECTION = 2,
1.1 christos 104: } sock_type;
105:
1.1.1.25! christos 106: struct hostkey_sid {
! 107: struct sshkey *key;
! 108: struct sshbuf *sid;
! 109: int forwarded;
! 110: };
! 111:
1.1.1.23 christos 112: typedef struct socket_entry {
1.1 christos 113: int fd;
114: sock_type type;
1.1.1.8 christos 115: struct sshbuf *input;
116: struct sshbuf *output;
117: struct sshbuf *request;
1.1.1.25! christos 118: size_t nsession_ids;
! 119: struct hostkey_sid *session_ids;
1.1 christos 120: } SocketEntry;
121:
122: u_int sockets_alloc = 0;
123: SocketEntry *sockets = NULL;
124:
125: typedef struct identity {
126: TAILQ_ENTRY(identity) next;
1.1.1.8 christos 127: struct sshkey *key;
1.1 christos 128: char *comment;
1.1.1.3 adam 129: char *provider;
1.1.1.6 christos 130: time_t death;
1.1 christos 131: u_int confirm;
1.1.1.20 christos 132: char *sk_provider;
1.1.1.25! christos 133: struct dest_constraint *dest_constraints;
! 134: size_t ndest_constraints;
1.1 christos 135: } Identity;
136:
1.1.1.15 christos 137: struct idtable {
1.1 christos 138: int nentries;
139: TAILQ_HEAD(idqueue, identity) idlist;
1.1.1.15 christos 140: };
1.1 christos 141:
1.1.1.15 christos 142: /* private key table */
143: struct idtable *idtab;
1.1 christos 144:
145: int max_fd = 0;
146:
147: /* pid of shell == parent of agent */
148: pid_t parent_pid = -1;
1.1.1.6 christos 149: time_t parent_alive_interval = 0;
1.1 christos 150:
1.1.1.7 christos 151: /* pid of process for which cleanup_socket is applicable */
152: pid_t cleanup_pid = 0;
153:
1.1 christos 154: /* pathname and directory for AUTH_SOCKET */
1.1.1.8 christos 155: char socket_name[PATH_MAX];
156: char socket_dir[PATH_MAX];
1.1 christos 157:
1.1.1.22 christos 158: /* Pattern-list of allowed PKCS#11/Security key paths */
159: static char *allowed_providers;
1.1.1.13 christos 160:
1.1 christos 161: /* locking */
1.1.1.9 christos 162: #define LOCK_SIZE 32
163: #define LOCK_SALT_SIZE 16
164: #define LOCK_ROUNDS 1
1.1 christos 165: int locked = 0;
1.1.1.12 christos 166: u_char lock_pwhash[LOCK_SIZE];
167: u_char lock_salt[LOCK_SALT_SIZE];
1.1 christos 168:
169: extern char *__progname;
170:
1.1.1.6 christos 171: /* Default lifetime in seconds (0 == forever) */
1.1.1.23 christos 172: static int lifetime = 0;
1.1 christos 173:
1.1.1.8 christos 174: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
175:
1.1.1.22 christos 176: /* Refuse signing of non-SSH messages for web-origin FIDO keys */
177: static int restrict_websafe = 1;
178:
1.1 christos 179: static void
180: close_socket(SocketEntry *e)
181: {
1.1.1.25! christos 182: size_t i;
! 183:
1.1 christos 184: close(e->fd);
1.1.1.8 christos 185: sshbuf_free(e->input);
186: sshbuf_free(e->output);
187: sshbuf_free(e->request);
1.1.1.25! christos 188: for (i = 0; i < e->nsession_ids; i++) {
! 189: sshkey_free(e->session_ids[i].key);
! 190: sshbuf_free(e->session_ids[i].sid);
! 191: }
! 192: free(e->session_ids);
1.1.1.23 christos 193: memset(e, '\0', sizeof(*e));
194: e->fd = -1;
195: e->type = AUTH_UNUSED;
1.1 christos 196: }
197:
198: static void
199: idtab_init(void)
200: {
1.1.1.15 christos 201: idtab = xcalloc(1, sizeof(*idtab));
202: TAILQ_INIT(&idtab->idlist);
203: idtab->nentries = 0;
1.1 christos 204: }
205:
206: static void
1.1.1.25! christos 207: free_dest_constraint_hop(struct dest_constraint_hop *dch)
! 208: {
! 209: u_int i;
! 210:
! 211: if (dch == NULL)
! 212: return;
! 213: free(dch->user);
! 214: free(dch->hostname);
! 215: for (i = 0; i < dch->nkeys; i++)
! 216: sshkey_free(dch->keys[i]);
! 217: free(dch->keys);
! 218: free(dch->key_is_ca);
! 219: }
! 220:
! 221: static void
! 222: free_dest_constraints(struct dest_constraint *dcs, size_t ndcs)
! 223: {
! 224: size_t i;
! 225:
! 226: for (i = 0; i < ndcs; i++) {
! 227: free_dest_constraint_hop(&dcs[i].from);
! 228: free_dest_constraint_hop(&dcs[i].to);
! 229: }
! 230: free(dcs);
! 231: }
! 232:
! 233: static void
1.1 christos 234: free_identity(Identity *id)
235: {
1.1.1.8 christos 236: sshkey_free(id->key);
1.1.1.6 christos 237: free(id->provider);
238: free(id->comment);
1.1.1.20 christos 239: free(id->sk_provider);
1.1.1.25! christos 240: free_dest_constraints(id->dest_constraints, id->ndest_constraints);
1.1.1.6 christos 241: free(id);
1.1 christos 242: }
243:
1.1.1.25! christos 244: /*
! 245: * Match 'key' against the key/CA list in a destination constraint hop
! 246: * Returns 0 on success or -1 otherwise.
! 247: */
! 248: static int
! 249: match_key_hop(const char *tag, const struct sshkey *key,
! 250: const struct dest_constraint_hop *dch)
! 251: {
! 252: const char *reason = NULL;
! 253: const char *hostname = dch->hostname ? dch->hostname : "(ORIGIN)";
! 254: u_int i;
! 255: char *fp;
! 256:
! 257: if (key == NULL)
! 258: return -1;
! 259: /* XXX logspam */
! 260: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 261: SSH_FP_DEFAULT)) == NULL)
! 262: fatal_f("fingerprint failed");
! 263: debug3_f("%s: entering hostname %s, requested key %s %s, %u keys avail",
! 264: tag, hostname, sshkey_type(key), fp, dch->nkeys);
! 265: free(fp);
! 266: for (i = 0; i < dch->nkeys; i++) {
! 267: if (dch->keys[i] == NULL)
! 268: return -1;
! 269: /* XXX logspam */
! 270: if ((fp = sshkey_fingerprint(dch->keys[i], SSH_FP_HASH_DEFAULT,
! 271: SSH_FP_DEFAULT)) == NULL)
! 272: fatal_f("fingerprint failed");
! 273: debug3_f("%s: key %u: %s%s %s", tag, i,
! 274: dch->key_is_ca[i] ? "CA " : "",
! 275: sshkey_type(dch->keys[i]), fp);
! 276: free(fp);
! 277: if (!sshkey_is_cert(key)) {
! 278: /* plain key */
! 279: if (dch->key_is_ca[i] ||
! 280: !sshkey_equal(key, dch->keys[i]))
! 281: continue;
! 282: return 0;
! 283: }
! 284: /* certificate */
! 285: if (!dch->key_is_ca[i])
! 286: continue;
! 287: if (key->cert == NULL || key->cert->signature_key == NULL)
! 288: return -1; /* shouldn't happen */
! 289: if (!sshkey_equal(key->cert->signature_key, dch->keys[i]))
! 290: continue;
! 291: if (sshkey_cert_check_host(key, hostname, 1,
! 292: SSH_ALLOWED_CA_SIGALGS, &reason) != 0) {
! 293: debug_f("cert %s / hostname %s rejected: %s",
! 294: key->cert->key_id, hostname, reason);
! 295: continue;
! 296: }
! 297: return 0;
! 298: }
! 299: return -1;
! 300: }
! 301:
! 302: /* Check destination constraints on an identity against the hostkey/user */
! 303: static int
! 304: permitted_by_dest_constraints(const struct sshkey *fromkey,
! 305: const struct sshkey *tokey, Identity *id, const char *user,
! 306: const char **hostnamep)
! 307: {
! 308: size_t i;
! 309: struct dest_constraint *d;
! 310:
! 311: if (hostnamep != NULL)
! 312: *hostnamep = NULL;
! 313: for (i = 0; i < id->ndest_constraints; i++) {
! 314: d = id->dest_constraints + i;
! 315: /* XXX remove logspam */
! 316: debug2_f("constraint %zu %s%s%s (%u keys) > %s%s%s (%u keys)",
! 317: i, d->from.user ? d->from.user : "",
! 318: d->from.user ? "@" : "",
! 319: d->from.hostname ? d->from.hostname : "(ORIGIN)",
! 320: d->from.nkeys,
! 321: d->to.user ? d->to.user : "", d->to.user ? "@" : "",
! 322: d->to.hostname ? d->to.hostname : "(ANY)", d->to.nkeys);
! 323:
! 324: /* Match 'from' key */
! 325: if (fromkey == NULL) {
! 326: /* We are matching the first hop */
! 327: if (d->from.hostname != NULL || d->from.nkeys != 0)
! 328: continue;
! 329: } else if (match_key_hop("from", fromkey, &d->from) != 0)
! 330: continue;
! 331:
! 332: /* Match 'to' key */
! 333: if (tokey != NULL && match_key_hop("to", tokey, &d->to) != 0)
! 334: continue;
! 335:
! 336: /* Match user if specified */
! 337: if (d->to.user != NULL && user != NULL &&
! 338: !match_pattern(user, d->to.user))
! 339: continue;
! 340:
! 341: /* successfully matched this constraint */
! 342: if (hostnamep != NULL)
! 343: *hostnamep = d->to.hostname;
! 344: debug2_f("allowed for hostname %s",
! 345: d->to.hostname == NULL ? "*" : d->to.hostname);
! 346: return 0;
! 347: }
! 348: /* no match */
! 349: debug2_f("%s identity \"%s\" not permitted for this destination",
! 350: sshkey_type(id->key), id->comment);
! 351: return -1;
! 352: }
! 353:
! 354: /*
! 355: * Check whether hostkeys on a SocketEntry and the optionally specified user
! 356: * are permitted by the destination constraints on the Identity.
! 357: * Returns 0 on success or -1 otherwise.
! 358: */
! 359: static int
! 360: identity_permitted(Identity *id, SocketEntry *e, char *user,
! 361: const char **forward_hostnamep, const char **last_hostnamep)
! 362: {
! 363: size_t i;
! 364: const char **hp;
! 365: struct hostkey_sid *hks;
! 366: const struct sshkey *fromkey = NULL;
! 367: const char *test_user;
! 368: char *fp1, *fp2;
! 369:
! 370: /* XXX remove logspam */
! 371: debug3_f("entering: key %s comment \"%s\", %zu socket bindings, "
! 372: "%zu constraints", sshkey_type(id->key), id->comment,
! 373: e->nsession_ids, id->ndest_constraints);
! 374: if (id->ndest_constraints == 0)
! 375: return 0; /* unconstrained */
! 376: if (e->nsession_ids == 0)
! 377: return 0; /* local use */
! 378: /*
! 379: * Walk through the hops recorded by session_id and try to find a
! 380: * constraint that satisfies each.
! 381: */
! 382: for (i = 0; i < e->nsession_ids; i++) {
! 383: hks = e->session_ids + i;
! 384: if (hks->key == NULL)
! 385: fatal_f("internal error: no bound key");
! 386: /* XXX remove logspam */
! 387: fp1 = fp2 = NULL;
! 388: if (fromkey != NULL &&
! 389: (fp1 = sshkey_fingerprint(fromkey, SSH_FP_HASH_DEFAULT,
! 390: SSH_FP_DEFAULT)) == NULL)
! 391: fatal_f("fingerprint failed");
! 392: if ((fp2 = sshkey_fingerprint(hks->key, SSH_FP_HASH_DEFAULT,
! 393: SSH_FP_DEFAULT)) == NULL)
! 394: fatal_f("fingerprint failed");
! 395: debug3_f("socketentry fd=%d, entry %zu %s, "
! 396: "from hostkey %s %s to user %s hostkey %s %s",
! 397: e->fd, i, hks->forwarded ? "FORWARD" : "AUTH",
! 398: fromkey ? sshkey_type(fromkey) : "(ORIGIN)",
! 399: fromkey ? fp1 : "", user ? user : "(ANY)",
! 400: sshkey_type(hks->key), fp2);
! 401: free(fp1);
! 402: free(fp2);
! 403: /*
! 404: * Record the hostnames for the initial forwarding and
! 405: * the final destination.
! 406: */
! 407: hp = NULL;
! 408: if (i == e->nsession_ids - 1)
! 409: hp = last_hostnamep;
! 410: else if (i == 0)
! 411: hp = forward_hostnamep;
! 412: /* Special handling for final recorded binding */
! 413: test_user = NULL;
! 414: if (i == e->nsession_ids - 1) {
! 415: /* Can only check user at final hop */
! 416: test_user = user;
! 417: /*
! 418: * user is only presented for signature requests.
! 419: * If this is the case, make sure last binding is not
! 420: * for a forwarding.
! 421: */
! 422: if (hks->forwarded && user != NULL) {
! 423: error_f("tried to sign on forwarding hop");
! 424: return -1;
! 425: }
! 426: } else if (!hks->forwarded) {
! 427: error_f("tried to forward though signing bind");
! 428: return -1;
! 429: }
! 430: if (permitted_by_dest_constraints(fromkey, hks->key, id,
! 431: test_user, hp) != 0)
! 432: return -1;
! 433: fromkey = hks->key;
! 434: }
! 435: /*
! 436: * Another special case: if the last bound session ID was for a
! 437: * forwarding, and this function is not being called to check a sign
! 438: * request (i.e. no 'user' supplied), then only permit the key if
! 439: * there is a permission that would allow it to be used at another
! 440: * destination. This hides keys that are allowed to be used to
! 441: * authenticate *to* a host but not permitted for *use* beyond it.
! 442: */
! 443: hks = &e->session_ids[e->nsession_ids - 1];
! 444: if (hks->forwarded && user == NULL &&
! 445: permitted_by_dest_constraints(hks->key, NULL, id,
! 446: NULL, NULL) != 0) {
! 447: debug3_f("key permitted at host but not after");
! 448: return -1;
! 449: }
! 450:
! 451: /* success */
! 452: return 0;
! 453: }
! 454:
1.1 christos 455: /* return matching private key for given public key */
456: static Identity *
1.1.1.15 christos 457: lookup_identity(struct sshkey *key)
1.1 christos 458: {
459: Identity *id;
460:
1.1.1.15 christos 461: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.1.1.8 christos 462: if (sshkey_equal(key, id->key))
1.1 christos 463: return (id);
464: }
465: return (NULL);
466: }
467:
468: /* Check confirmation of keysign request */
469: static int
1.1.1.23 christos 470: confirm_key(Identity *id, const char *extra)
1.1 christos 471: {
472: char *p;
473: int ret = -1;
474:
1.1.1.8 christos 475: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
476: if (p != NULL &&
1.1.1.23 christos 477: ask_permission("Allow use of key %s?\nKey fingerprint %s.%s%s",
478: id->comment, p,
479: extra == NULL ? "" : "\n", extra == NULL ? "" : extra))
1.1 christos 480: ret = 0;
1.1.1.6 christos 481: free(p);
1.1 christos 482:
483: return (ret);
484: }
485:
1.1.1.8 christos 486: static void
487: send_status(SocketEntry *e, int success)
488: {
489: int r;
490:
491: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
492: (r = sshbuf_put_u8(e->output, success ?
493: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
1.1.1.23 christos 494: fatal_fr(r, "compose");
1.1.1.8 christos 495: }
496:
1.1 christos 497: /* send list of supported public keys to 'client' */
498: static void
1.1.1.15 christos 499: process_request_identities(SocketEntry *e)
1.1 christos 500: {
501: Identity *id;
1.1.1.25! christos 502: struct sshbuf *msg, *keys;
1.1.1.8 christos 503: int r;
1.1.1.25! christos 504: u_int nentries = 0;
1.1 christos 505:
1.1.1.23 christos 506: debug2_f("entering");
507:
1.1.1.25! christos 508: if ((msg = sshbuf_new()) == NULL || (keys = sshbuf_new()) == NULL)
1.1.1.23 christos 509: fatal_f("sshbuf_new failed");
1.1.1.15 christos 510: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.1.1.25! christos 511: /* identity not visible, don't include in response */
! 512: if (identity_permitted(id, e, NULL, NULL, NULL) != 0)
! 513: continue;
! 514: if ((r = sshkey_puts_opts(id->key, keys,
1.1.1.24 christos 515: SSHKEY_SERIALIZE_INFO)) != 0 ||
1.1.1.25! christos 516: (r = sshbuf_put_cstring(keys, id->comment)) != 0) {
1.1.1.23 christos 517: error_fr(r, "compose key/comment");
1.1.1.15 christos 518: continue;
1.1.1.8 christos 519: }
1.1.1.25! christos 520: nentries++;
1.1 christos 521: }
1.1.1.25! christos 522: debug2_f("replying with %u allowed of %u available keys",
! 523: nentries, idtab->nentries);
! 524: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
! 525: (r = sshbuf_put_u32(msg, nentries)) != 0 ||
! 526: (r = sshbuf_putb(msg, keys)) != 0)
! 527: fatal_fr(r, "compose");
1.1.1.8 christos 528: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.1.1.23 christos 529: fatal_fr(r, "enqueue");
1.1.1.8 christos 530: sshbuf_free(msg);
1.1.1.25! christos 531: sshbuf_free(keys);
1.1 christos 532: }
1.1.1.15 christos 533:
1.1 christos 534:
1.1.1.11 christos 535: static char *
536: agent_decode_alg(struct sshkey *key, u_int flags)
537: {
538: if (key->type == KEY_RSA) {
539: if (flags & SSH_AGENT_RSA_SHA2_256)
540: return "rsa-sha2-256";
541: else if (flags & SSH_AGENT_RSA_SHA2_512)
542: return "rsa-sha2-512";
1.1.1.19 christos 543: } else if (key->type == KEY_RSA_CERT) {
544: if (flags & SSH_AGENT_RSA_SHA2_256)
545: return "rsa-sha2-256-cert-v01@openssh.com";
546: else if (flags & SSH_AGENT_RSA_SHA2_512)
547: return "rsa-sha2-512-cert-v01@openssh.com";
1.1.1.11 christos 548: }
549: return NULL;
550: }
551:
1.1.1.22 christos 552: /*
1.1.1.23 christos 553: * Attempt to parse the contents of a buffer as a SSH publickey userauth
554: * request, checking its contents for consistency and matching the embedded
555: * key against the one that is being used for signing.
556: * Note: does not modify msg buffer.
1.1.1.25! christos 557: * Optionally extract the username, session ID and/or hostkey from the request.
1.1.1.22 christos 558: */
559: static int
1.1.1.23 christos 560: parse_userauth_request(struct sshbuf *msg, const struct sshkey *expected_key,
1.1.1.25! christos 561: char **userp, struct sshbuf **sess_idp, struct sshkey **hostkeyp)
1.1.1.22 christos 562: {
1.1.1.23 christos 563: struct sshbuf *b = NULL, *sess_id = NULL;
564: char *user = NULL, *service = NULL, *method = NULL, *pkalg = NULL;
1.1.1.22 christos 565: int r;
1.1.1.23 christos 566: u_char t, sig_follows;
1.1.1.25! christos 567: struct sshkey *mkey = NULL, *hostkey = NULL;
1.1.1.22 christos 568:
1.1.1.23 christos 569: if (userp != NULL)
570: *userp = NULL;
571: if (sess_idp != NULL)
572: *sess_idp = NULL;
1.1.1.25! christos 573: if (hostkeyp != NULL)
! 574: *hostkeyp = NULL;
1.1.1.23 christos 575: if ((b = sshbuf_fromb(msg)) == NULL)
576: fatal_f("sshbuf_fromb");
1.1.1.22 christos 577:
578: /* SSH userauth request */
1.1.1.23 christos 579: if ((r = sshbuf_froms(b, &sess_id)) != 0)
580: goto out;
581: if (sshbuf_len(sess_id) == 0) {
582: r = SSH_ERR_INVALID_FORMAT;
583: goto out;
584: }
585: if ((r = sshbuf_get_u8(b, &t)) != 0 || /* SSH2_MSG_USERAUTH_REQUEST */
586: (r = sshbuf_get_cstring(b, &user, NULL)) != 0 || /* server user */
587: (r = sshbuf_get_cstring(b, &service, NULL)) != 0 || /* service */
588: (r = sshbuf_get_cstring(b, &method, NULL)) != 0 || /* method */
589: (r = sshbuf_get_u8(b, &sig_follows)) != 0 || /* sig-follows */
590: (r = sshbuf_get_cstring(b, &pkalg, NULL)) != 0 || /* alg */
591: (r = sshkey_froms(b, &mkey)) != 0) /* key */
592: goto out;
593: if (t != SSH2_MSG_USERAUTH_REQUEST ||
594: sig_follows != 1 ||
595: strcmp(service, "ssh-connection") != 0 ||
596: !sshkey_equal(expected_key, mkey) ||
597: sshkey_type_from_name(pkalg) != expected_key->type) {
598: r = SSH_ERR_INVALID_FORMAT;
599: goto out;
600: }
1.1.1.25! christos 601: if (strcmp(method, "publickey-hostbound-v00@openssh.com") == 0) {
! 602: if ((r = sshkey_froms(b, &hostkey)) != 0)
! 603: goto out;
! 604: } else if (strcmp(method, "publickey") != 0) {
1.1.1.23 christos 605: r = SSH_ERR_INVALID_FORMAT;
606: goto out;
607: }
608: if (sshbuf_len(b) != 0) {
609: r = SSH_ERR_INVALID_FORMAT;
610: goto out;
611: }
612: /* success */
613: r = 0;
614: debug3_f("well formed userauth");
615: if (userp != NULL) {
616: *userp = user;
617: user = NULL;
618: }
619: if (sess_idp != NULL) {
620: *sess_idp = sess_id;
621: sess_id = NULL;
1.1.1.22 christos 622: }
1.1.1.25! christos 623: if (hostkeyp != NULL) {
! 624: *hostkeyp = hostkey;
! 625: hostkey = NULL;
! 626: }
1.1.1.23 christos 627: out:
1.1.1.22 christos 628: sshbuf_free(b);
1.1.1.23 christos 629: sshbuf_free(sess_id);
630: free(user);
631: free(service);
632: free(method);
633: free(pkalg);
634: sshkey_free(mkey);
1.1.1.25! christos 635: sshkey_free(hostkey);
1.1.1.23 christos 636: return r;
637: }
1.1.1.22 christos 638:
1.1.1.23 christos 639: /*
640: * Attempt to parse the contents of a buffer as a SSHSIG signature request.
641: * Note: does not modify buffer.
642: */
643: static int
644: parse_sshsig_request(struct sshbuf *msg)
645: {
646: int r;
647: struct sshbuf *b;
648:
649: if ((b = sshbuf_fromb(msg)) == NULL)
650: fatal_f("sshbuf_fromb");
1.1.1.22 christos 651:
1.1.1.23 christos 652: if ((r = sshbuf_cmp(b, 0, "SSHSIG", 6)) != 0 ||
653: (r = sshbuf_consume(b, 6)) != 0 ||
654: (r = sshbuf_get_cstring(b, NULL, NULL)) != 0 || /* namespace */
655: (r = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || /* reserved */
656: (r = sshbuf_get_cstring(b, NULL, NULL)) != 0 || /* hashalg */
657: (r = sshbuf_get_string_direct(b, NULL, NULL)) != 0) /* H(msg) */
658: goto out;
659: if (sshbuf_len(b) != 0) {
660: r = SSH_ERR_INVALID_FORMAT;
661: goto out;
662: }
663: /* success */
664: r = 0;
665: out:
1.1.1.22 christos 666: sshbuf_free(b);
1.1.1.23 christos 667: return r;
668: }
669:
670: /*
671: * This function inspects a message to be signed by a FIDO key that has a
672: * web-like application string (i.e. one that does not begin with "ssh:".
673: * It checks that the message is one of those expected for SSH operations
674: * (pubkey userauth, sshsig, CA key signing) to exclude signing challenges
675: * for the web.
676: */
677: static int
678: check_websafe_message_contents(struct sshkey *key, struct sshbuf *data)
679: {
1.1.1.25! christos 680: if (parse_userauth_request(data, key, NULL, NULL, NULL) == 0) {
1.1.1.23 christos 681: debug_f("signed data matches public key userauth request");
1.1.1.22 christos 682: return 1;
1.1.1.23 christos 683: }
684: if (parse_sshsig_request(data) == 0) {
685: debug_f("signed data matches SSHSIG signature request");
686: return 1;
687: }
1.1.1.22 christos 688:
1.1.1.23 christos 689: /* XXX check CA signature operation */
1.1.1.22 christos 690:
691: error("web-origin key attempting to sign non-SSH message");
692: return 0;
693: }
694:
1.1.1.25! christos 695: static int
! 696: buf_equal(const struct sshbuf *a, const struct sshbuf *b)
! 697: {
! 698: if (sshbuf_ptr(a) == NULL || sshbuf_ptr(b) == NULL)
! 699: return SSH_ERR_INVALID_ARGUMENT;
! 700: if (sshbuf_len(a) != sshbuf_len(b))
! 701: return SSH_ERR_INVALID_FORMAT;
! 702: if (timingsafe_bcmp(sshbuf_ptr(a), sshbuf_ptr(b), sshbuf_len(a)) != 0)
! 703: return SSH_ERR_INVALID_FORMAT;
! 704: return 0;
! 705: }
! 706:
1.1 christos 707: /* ssh2 only */
708: static void
709: process_sign_request2(SocketEntry *e)
710: {
1.1.1.15 christos 711: u_char *signature = NULL;
1.1.1.23 christos 712: size_t slen = 0;
1.1.1.8 christos 713: u_int compat = 0, flags;
1.1.1.25! christos 714: int r, ok = -1, retried = 0;
! 715: char *fp = NULL, *pin = NULL, *prompt = NULL;
! 716: char *user = NULL, *sig_dest = NULL;
! 717: const char *fwd_host = NULL, *dest_host = NULL;
! 718: struct sshbuf *msg = NULL, *data = NULL, *sid = NULL;
! 719: struct sshkey *key = NULL, *hostkey = NULL;
1.1.1.8 christos 720: struct identity *id;
1.1.1.20 christos 721: struct notifier_ctx *notifier = NULL;
1.1.1.8 christos 722:
1.1.1.23 christos 723: debug_f("entering");
724:
725: if ((msg = sshbuf_new()) == NULL || (data = sshbuf_new()) == NULL)
726: fatal_f("sshbuf_new failed");
1.1.1.15 christos 727: if ((r = sshkey_froms(e->request, &key)) != 0 ||
1.1.1.23 christos 728: (r = sshbuf_get_stringb(e->request, data)) != 0 ||
1.1.1.16 christos 729: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
1.1.1.23 christos 730: error_fr(r, "parse");
1.1.1.16 christos 731: goto send;
732: }
733:
1.1.1.15 christos 734: if ((id = lookup_identity(key)) == NULL) {
1.1.1.23 christos 735: verbose_f("%s key not found", sshkey_type(key));
1.1.1.8 christos 736: goto send;
1.1 christos 737: }
1.1.1.25! christos 738: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 739: SSH_FP_DEFAULT)) == NULL)
! 740: fatal_f("fingerprint failed");
! 741:
! 742: if (id->ndest_constraints != 0) {
! 743: if (e->nsession_ids == 0) {
! 744: logit_f("refusing use of destination-constrained key "
! 745: "to sign on unbound connection");
! 746: goto send;
! 747: }
! 748: if (parse_userauth_request(data, key, &user, &sid,
! 749: &hostkey) != 0) {
! 750: logit_f("refusing use of destination-constrained key "
! 751: "to sign an unidentified signature");
! 752: goto send;
! 753: }
! 754: /* XXX logspam */
! 755: debug_f("user=%s", user);
! 756: if (identity_permitted(id, e, user, &fwd_host, &dest_host) != 0)
! 757: goto send;
! 758: /* XXX display fwd_host/dest_host in askpass UI */
! 759: /*
! 760: * Ensure that the session ID is the most recent one
! 761: * registered on the socket - it should have been bound by
! 762: * ssh immediately before userauth.
! 763: */
! 764: if (buf_equal(sid,
! 765: e->session_ids[e->nsession_ids - 1].sid) != 0) {
! 766: error_f("unexpected session ID (%zu listed) on "
! 767: "signature request for target user %s with "
! 768: "key %s %s", e->nsession_ids, user,
! 769: sshkey_type(id->key), fp);
! 770: goto send;
! 771: }
! 772: /*
! 773: * Ensure that the hostkey embedded in the signature matches
! 774: * the one most recently bound to the socket. An exception is
! 775: * made for the initial forwarding hop.
! 776: */
! 777: if (e->nsession_ids > 1 && hostkey == NULL) {
! 778: error_f("refusing use of destination-constrained key: "
! 779: "no hostkey recorded in signature for forwarded "
! 780: "connection");
! 781: goto send;
! 782: }
! 783: if (hostkey != NULL && !sshkey_equal(hostkey,
! 784: e->session_ids[e->nsession_ids - 1].key)) {
! 785: error_f("refusing use of destination-constrained key: "
! 786: "mismatch between hostkey in request and most "
! 787: "recently bound session");
! 788: goto send;
! 789: }
! 790: xasprintf(&sig_dest, "public key authentication request for "
! 791: "user \"%s\" to listed host", user);
! 792: }
! 793: if (id->confirm && confirm_key(id, sig_dest) != 0) {
1.1.1.23 christos 794: verbose_f("user refused key");
1.1.1.8 christos 795: goto send;
796: }
1.1.1.22 christos 797: if (sshkey_is_sk(id->key)) {
798: if (strncmp(id->key->sk_application, "ssh:", 4) != 0 &&
1.1.1.23 christos 799: !check_websafe_message_contents(key, data)) {
1.1.1.22 christos 800: /* error already logged */
801: goto send;
802: }
1.1.1.25! christos 803: if ((id->key->sk_flags & SSH_SK_USER_VERIFICATION_REQD)) {
! 804: /* XXX include sig_dest */
! 805: xasprintf(&prompt, "Enter PIN%sfor %s key %s: ",
! 806: (id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD) ?
! 807: " and confirm user presence " : " ",
1.1.1.22 christos 808: sshkey_type(id->key), fp);
1.1.1.25! christos 809: pin = read_passphrase(prompt, RP_USE_ASKPASS);
! 810: free(prompt);
! 811: prompt = NULL;
! 812: } else if ((id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
! 813: notifier = notify_start(0,
! 814: "Confirm user presence for key %s %s%s%s",
! 815: sshkey_type(id->key), fp,
! 816: sig_dest == NULL ? "" : "\n",
! 817: sig_dest == NULL ? "" : sig_dest);
1.1.1.22 christos 818: }
1.1.1.20 christos 819: }
1.1.1.25! christos 820: retry_pin:
1.1.1.8 christos 821: if ((r = sshkey_sign(id->key, &signature, &slen,
1.1.1.23 christos 822: sshbuf_ptr(data), sshbuf_len(data), agent_decode_alg(key, flags),
1.1.1.25! christos 823: id->sk_provider, pin, compat)) != 0) {
! 824: debug_fr(r, "sshkey_sign");
! 825: if (pin == NULL && !retried && sshkey_is_sk(id->key) &&
! 826: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
! 827: if (notifier) {
! 828: notify_complete(notifier, NULL);
! 829: notifier = NULL;
! 830: }
! 831: /* XXX include sig_dest */
! 832: xasprintf(&prompt, "Enter PIN%sfor %s key %s: ",
! 833: (id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD) ?
! 834: " and confirm user presence " : " ",
! 835: sshkey_type(id->key), fp);
! 836: pin = read_passphrase(prompt, RP_USE_ASKPASS);
! 837: retried = 1;
! 838: goto retry_pin;
! 839: }
1.1.1.23 christos 840: error_fr(r, "sshkey_sign");
1.1.1.8 christos 841: goto send;
842: }
843: /* Success */
844: ok = 0;
845: send:
1.1.1.23 christos 846: notify_complete(notifier, "User presence confirmed");
847:
1.1.1.8 christos 848: if (ok == 0) {
849: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
850: (r = sshbuf_put_string(msg, signature, slen)) != 0)
1.1.1.23 christos 851: fatal_fr(r, "compose");
1.1.1.8 christos 852: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
1.1.1.23 christos 853: fatal_fr(r, "compose failure");
1.1.1.8 christos 854:
855: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.1.1.23 christos 856: fatal_fr(r, "enqueue");
1.1.1.8 christos 857:
1.1.1.25! christos 858: sshbuf_free(sid);
1.1.1.23 christos 859: sshbuf_free(data);
1.1.1.8 christos 860: sshbuf_free(msg);
1.1.1.23 christos 861: sshkey_free(key);
1.1.1.25! christos 862: sshkey_free(hostkey);
1.1.1.23 christos 863: free(fp);
1.1.1.6 christos 864: free(signature);
1.1.1.25! christos 865: free(sig_dest);
! 866: free(user);
! 867: free(prompt);
! 868: if (pin != NULL)
! 869: freezero(pin, strlen(pin));
1.1 christos 870: }
871:
872: /* shared */
873: static void
1.1.1.15 christos 874: process_remove_identity(SocketEntry *e)
1.1 christos 875: {
1.1.1.8 christos 876: int r, success = 0;
877: struct sshkey *key = NULL;
1.1.1.15 christos 878: Identity *id;
1.1.1.8 christos 879:
1.1.1.23 christos 880: debug2_f("entering");
1.1.1.15 christos 881: if ((r = sshkey_froms(e->request, &key)) != 0) {
1.1.1.23 christos 882: error_fr(r, "parse key");
1.1.1.15 christos 883: goto done;
884: }
885: if ((id = lookup_identity(key)) == NULL) {
1.1.1.23 christos 886: debug_f("key not found");
1.1.1.15 christos 887: goto done;
888: }
1.1.1.25! christos 889: /* identity not visible, cannot be removed */
! 890: if (identity_permitted(id, e, NULL, NULL, NULL) != 0)
! 891: goto done; /* error already logged */
1.1.1.15 christos 892: /* We have this key, free it. */
893: if (idtab->nentries < 1)
1.1.1.23 christos 894: fatal_f("internal error: nentries %d", idtab->nentries);
1.1.1.15 christos 895: TAILQ_REMOVE(&idtab->idlist, id, next);
896: free_identity(id);
897: idtab->nentries--;
898: success = 1;
899: done:
1.1.1.23 christos 900: sshkey_free(key);
1.1.1.8 christos 901: send_status(e, success);
1.1 christos 902: }
903:
904: static void
1.1.1.15 christos 905: process_remove_all_identities(SocketEntry *e)
1.1 christos 906: {
907: Identity *id;
908:
1.1.1.23 christos 909: debug2_f("entering");
1.1 christos 910: /* Loop over all identities and clear the keys. */
1.1.1.15 christos 911: for (id = TAILQ_FIRST(&idtab->idlist); id;
912: id = TAILQ_FIRST(&idtab->idlist)) {
913: TAILQ_REMOVE(&idtab->idlist, id, next);
1.1 christos 914: free_identity(id);
915: }
916:
917: /* Mark that there are no identities. */
1.1.1.15 christos 918: idtab->nentries = 0;
1.1 christos 919:
920: /* Send success. */
1.1.1.8 christos 921: send_status(e, 1);
1.1 christos 922: }
923:
924: /* removes expired keys and returns number of seconds until the next expiry */
1.1.1.6 christos 925: static time_t
1.1 christos 926: reaper(void)
927: {
1.1.1.6 christos 928: time_t deadline = 0, now = monotime();
1.1 christos 929: Identity *id, *nxt;
930:
1.1.1.15 christos 931: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
932: nxt = TAILQ_NEXT(id, next);
933: if (id->death == 0)
934: continue;
935: if (now >= id->death) {
936: debug("expiring key '%s'", id->comment);
937: TAILQ_REMOVE(&idtab->idlist, id, next);
938: free_identity(id);
939: idtab->nentries--;
940: } else
941: deadline = (deadline == 0) ? id->death :
942: MINIMUM(deadline, id->death);
1.1 christos 943: }
944: if (deadline == 0 || deadline <= now)
945: return 0;
946: else
947: return (deadline - now);
948: }
949:
1.1.1.23 christos 950: static int
1.1.1.25! christos 951: parse_dest_constraint_hop(struct sshbuf *b, struct dest_constraint_hop *dch)
! 952: {
! 953: u_char key_is_ca;
! 954: size_t elen = 0;
! 955: int r;
! 956: struct sshkey *k = NULL;
! 957: char *fp;
! 958:
! 959: memset(dch, '\0', sizeof(*dch));
! 960: if ((r = sshbuf_get_cstring(b, &dch->user, NULL)) != 0 ||
! 961: (r = sshbuf_get_cstring(b, &dch->hostname, NULL)) != 0 ||
! 962: (r = sshbuf_get_string_direct(b, NULL, &elen)) != 0) {
! 963: error_fr(r, "parse");
! 964: goto out;
! 965: }
! 966: if (elen != 0) {
! 967: error_f("unsupported extensions (len %zu)", elen);
! 968: r = SSH_ERR_FEATURE_UNSUPPORTED;
! 969: goto out;
! 970: }
! 971: if (*dch->hostname == '\0') {
! 972: free(dch->hostname);
! 973: dch->hostname = NULL;
! 974: }
! 975: if (*dch->user == '\0') {
! 976: free(dch->user);
! 977: dch->user = NULL;
! 978: }
! 979: while (sshbuf_len(b) != 0) {
! 980: dch->keys = xrecallocarray(dch->keys, dch->nkeys,
! 981: dch->nkeys + 1, sizeof(*dch->keys));
! 982: dch->key_is_ca = xrecallocarray(dch->key_is_ca, dch->nkeys,
! 983: dch->nkeys + 1, sizeof(*dch->key_is_ca));
! 984: if ((r = sshkey_froms(b, &k)) != 0 ||
! 985: (r = sshbuf_get_u8(b, &key_is_ca)) != 0)
! 986: goto out;
! 987: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
! 988: SSH_FP_DEFAULT)) == NULL)
! 989: fatal_f("fingerprint failed");
! 990: debug3_f("%s%s%s: adding %skey %s %s",
! 991: dch->user == NULL ? "" : dch->user,
! 992: dch->user == NULL ? "" : "@",
! 993: dch->hostname, key_is_ca ? "CA " : "", sshkey_type(k), fp);
! 994: free(fp);
! 995: dch->keys[dch->nkeys] = k;
! 996: dch->key_is_ca[dch->nkeys] = key_is_ca != 0;
! 997: dch->nkeys++;
! 998: k = NULL; /* transferred */
! 999: }
! 1000: /* success */
! 1001: r = 0;
! 1002: out:
! 1003: sshkey_free(k);
! 1004: return r;
! 1005: }
! 1006:
! 1007: static int
! 1008: parse_dest_constraint(struct sshbuf *m, struct dest_constraint *dc)
! 1009: {
! 1010: struct sshbuf *b = NULL, *frombuf = NULL, *tobuf = NULL;
! 1011: int r;
! 1012: size_t elen = 0;
! 1013:
! 1014: debug3_f("entering");
! 1015:
! 1016: memset(dc, '\0', sizeof(*dc));
! 1017: if ((r = sshbuf_froms(m, &b)) != 0 ||
! 1018: (r = sshbuf_froms(b, &frombuf)) != 0 ||
! 1019: (r = sshbuf_froms(b, &tobuf)) != 0 ||
! 1020: (r = sshbuf_get_string_direct(b, NULL, &elen)) != 0) {
! 1021: error_fr(r, "parse");
! 1022: goto out;
! 1023: }
! 1024: if ((r = parse_dest_constraint_hop(frombuf, &dc->from) != 0) ||
! 1025: (r = parse_dest_constraint_hop(tobuf, &dc->to) != 0))
! 1026: goto out; /* already logged */
! 1027: if (elen != 0) {
! 1028: error_f("unsupported extensions (len %zu)", elen);
! 1029: r = SSH_ERR_FEATURE_UNSUPPORTED;
! 1030: goto out;
! 1031: }
! 1032: debug2_f("parsed %s (%u keys) > %s%s%s (%u keys)",
! 1033: dc->from.hostname ? dc->from.hostname : "(ORIGIN)", dc->from.nkeys,
! 1034: dc->to.user ? dc->to.user : "", dc->to.user ? "@" : "",
! 1035: dc->to.hostname ? dc->to.hostname : "(ANY)", dc->to.nkeys);
! 1036: /* check consistency */
! 1037: if ((dc->from.hostname == NULL) != (dc->from.nkeys == 0) ||
! 1038: dc->from.user != NULL) {
! 1039: error_f("inconsistent \"from\" specification");
! 1040: r = SSH_ERR_INVALID_FORMAT;
! 1041: goto out;
! 1042: }
! 1043: if (dc->to.hostname == NULL || dc->to.nkeys == 0) {
! 1044: error_f("incomplete \"to\" specification");
! 1045: r = SSH_ERR_INVALID_FORMAT;
! 1046: goto out;
! 1047: }
! 1048: /* success */
! 1049: r = 0;
! 1050: out:
! 1051: sshbuf_free(b);
! 1052: sshbuf_free(frombuf);
! 1053: sshbuf_free(tobuf);
! 1054: return r;
! 1055: }
! 1056:
! 1057: static int
! 1058: parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp,
! 1059: struct dest_constraint **dcsp, size_t *ndcsp)
1.1.1.23 christos 1060: {
1061: char *ext_name = NULL;
1062: int r;
1.1.1.25! christos 1063: struct sshbuf *b = NULL;
1.1.1.23 christos 1064:
1065: if ((r = sshbuf_get_cstring(m, &ext_name, NULL)) != 0) {
1066: error_fr(r, "parse constraint extension");
1067: goto out;
1068: }
1069: debug_f("constraint ext %s", ext_name);
1070: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
1071: if (sk_providerp == NULL) {
1072: error_f("%s not valid here", ext_name);
1073: r = SSH_ERR_INVALID_FORMAT;
1074: goto out;
1075: }
1076: if (*sk_providerp != NULL) {
1077: error_f("%s already set", ext_name);
1078: r = SSH_ERR_INVALID_FORMAT;
1079: goto out;
1080: }
1081: if ((r = sshbuf_get_cstring(m, sk_providerp, NULL)) != 0) {
1082: error_fr(r, "parse %s", ext_name);
1083: goto out;
1084: }
1.1.1.25! christos 1085: } else if (strcmp(ext_name,
! 1086: "restrict-destination-v00@openssh.com") == 0) {
! 1087: if (*dcsp != NULL) {
! 1088: error_f("%s already set", ext_name);
! 1089: goto out;
! 1090: }
! 1091: if ((r = sshbuf_froms(m, &b)) != 0) {
! 1092: error_fr(r, "parse %s outer", ext_name);
! 1093: goto out;
! 1094: }
! 1095: while (sshbuf_len(b) != 0) {
! 1096: if (*ndcsp >= AGENT_MAX_DEST_CONSTRAINTS) {
! 1097: error_f("too many %s constraints", ext_name);
! 1098: goto out;
! 1099: }
! 1100: *dcsp = xrecallocarray(*dcsp, *ndcsp, *ndcsp + 1,
! 1101: sizeof(**dcsp));
! 1102: if ((r = parse_dest_constraint(b,
! 1103: *dcsp + (*ndcsp)++)) != 0)
! 1104: goto out; /* error already logged */
! 1105: }
1.1.1.23 christos 1106: } else {
1107: error_f("unsupported constraint \"%s\"", ext_name);
1108: r = SSH_ERR_FEATURE_UNSUPPORTED;
1109: goto out;
1110: }
1111: /* success */
1112: r = 0;
1113: out:
1114: free(ext_name);
1.1.1.25! christos 1115: sshbuf_free(b);
1.1.1.23 christos 1116: return r;
1117: }
1118:
1119: static int
1120: parse_key_constraints(struct sshbuf *m, struct sshkey *k, time_t *deathp,
1.1.1.25! christos 1121: u_int *secondsp, int *confirmp, char **sk_providerp,
! 1122: struct dest_constraint **dcsp, size_t *ndcsp)
1.1 christos 1123: {
1.1.1.8 christos 1124: u_char ctype;
1.1.1.23 christos 1125: int r;
1126: u_int seconds, maxsign = 0;
1.1 christos 1127:
1.1.1.23 christos 1128: while (sshbuf_len(m)) {
1129: if ((r = sshbuf_get_u8(m, &ctype)) != 0) {
1130: error_fr(r, "parse constraint type");
1131: goto out;
1.1.1.8 christos 1132: }
1133: switch (ctype) {
1.1 christos 1134: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.1.1.23 christos 1135: if (*deathp != 0) {
1136: error_f("lifetime already set");
1137: r = SSH_ERR_INVALID_FORMAT;
1138: goto out;
1139: }
1140: if ((r = sshbuf_get_u32(m, &seconds)) != 0) {
1141: error_fr(r, "parse lifetime constraint");
1142: goto out;
1.1.1.8 christos 1143: }
1.1.1.23 christos 1144: *deathp = monotime() + seconds;
1145: *secondsp = seconds;
1.1 christos 1146: break;
1147: case SSH_AGENT_CONSTRAIN_CONFIRM:
1.1.1.23 christos 1148: if (*confirmp != 0) {
1149: error_f("confirm already set");
1150: r = SSH_ERR_INVALID_FORMAT;
1151: goto out;
1152: }
1153: *confirmp = 1;
1.1 christos 1154: break;
1.1.1.16 christos 1155: case SSH_AGENT_CONSTRAIN_MAXSIGN:
1.1.1.23 christos 1156: if (k == NULL) {
1157: error_f("maxsign not valid here");
1158: r = SSH_ERR_INVALID_FORMAT;
1159: goto out;
1160: }
1161: if (maxsign != 0) {
1162: error_f("maxsign already set");
1163: r = SSH_ERR_INVALID_FORMAT;
1164: goto out;
1165: }
1166: if ((r = sshbuf_get_u32(m, &maxsign)) != 0) {
1167: error_fr(r, "parse maxsign constraint");
1168: goto out;
1.1.1.16 christos 1169: }
1170: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
1.1.1.23 christos 1171: error_fr(r, "enable maxsign");
1172: goto out;
1.1.1.16 christos 1173: }
1174: break;
1.1.1.20 christos 1175: case SSH_AGENT_CONSTRAIN_EXTENSION:
1.1.1.23 christos 1176: if ((r = parse_key_constraint_extension(m,
1.1.1.25! christos 1177: sk_providerp, dcsp, ndcsp)) != 0)
1.1.1.23 christos 1178: goto out; /* error already logged */
1.1.1.20 christos 1179: break;
1.1 christos 1180: default:
1.1.1.23 christos 1181: error_f("Unknown constraint %d", ctype);
1182: r = SSH_ERR_FEATURE_UNSUPPORTED;
1183: goto out;
1.1 christos 1184: }
1185: }
1.1.1.23 christos 1186: /* success */
1187: r = 0;
1188: out:
1189: return r;
1190: }
1191:
1192: static void
1193: process_add_identity(SocketEntry *e)
1194: {
1195: Identity *id;
1196: int success = 0, confirm = 0;
1197: char *fp, *comment = NULL, *sk_provider = NULL;
1198: char canonical_provider[PATH_MAX];
1199: time_t death = 0;
1200: u_int seconds = 0;
1.1.1.25! christos 1201: struct dest_constraint *dest_constraints = NULL;
! 1202: size_t ndest_constraints = 0;
1.1.1.23 christos 1203: struct sshkey *k = NULL;
1204: int r = SSH_ERR_INTERNAL_ERROR;
1205:
1206: debug2_f("entering");
1207: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
1208: k == NULL ||
1209: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
1210: error_fr(r, "parse");
1211: goto out;
1212: }
1213: if (parse_key_constraints(e->request, k, &death, &seconds, &confirm,
1.1.1.25! christos 1214: &sk_provider, &dest_constraints, &ndest_constraints) != 0) {
1.1.1.23 christos 1215: error_f("failed to parse constraints");
1216: sshbuf_reset(e->request);
1217: goto out;
1218: }
1219:
1.1.1.20 christos 1220: if (sk_provider != NULL) {
1221: if (!sshkey_is_sk(k)) {
1222: error("Cannot add provider: %s is not an "
1223: "authenticator-hosted key", sshkey_type(k));
1.1.1.23 christos 1224: goto out;
1.1.1.20 christos 1225: }
1226: if (strcasecmp(sk_provider, "internal") == 0) {
1.1.1.23 christos 1227: debug_f("internal provider");
1.1.1.20 christos 1228: } else {
1229: if (realpath(sk_provider, canonical_provider) == NULL) {
1230: verbose("failed provider \"%.100s\": "
1231: "realpath: %s", sk_provider,
1232: strerror(errno));
1.1.1.23 christos 1233: goto out;
1.1.1.20 christos 1234: }
1235: free(sk_provider);
1236: sk_provider = xstrdup(canonical_provider);
1237: if (match_pattern_list(sk_provider,
1.1.1.22 christos 1238: allowed_providers, 0) != 1) {
1.1.1.20 christos 1239: error("Refusing add key: "
1.1.1.22 christos 1240: "provider %s not allowed", sk_provider);
1.1.1.23 christos 1241: goto out;
1.1.1.20 christos 1242: }
1243: }
1244: }
1245: if ((r = sshkey_shield_private(k)) != 0) {
1.1.1.23 christos 1246: error_fr(r, "shield private");
1247: goto out;
1.1.1.20 christos 1248: }
1.1 christos 1249: if (lifetime && !death)
1.1.1.6 christos 1250: death = monotime() + lifetime;
1.1.1.15 christos 1251: if ((id = lookup_identity(k)) == NULL) {
1.1.1.3 adam 1252: id = xcalloc(1, sizeof(Identity));
1.1.1.15 christos 1253: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.1 christos 1254: /* Increment the number of identities. */
1.1.1.15 christos 1255: idtab->nentries++;
1.1 christos 1256: } else {
1.1.1.25! christos 1257: /* identity not visible, do not update */
! 1258: if (identity_permitted(id, e, NULL, NULL, NULL) != 0)
! 1259: goto out; /* error already logged */
1.1.1.16 christos 1260: /* key state might have been updated */
1261: sshkey_free(id->key);
1.1.1.6 christos 1262: free(id->comment);
1.1.1.20 christos 1263: free(id->sk_provider);
1.1.1.25! christos 1264: free_dest_constraints(id->dest_constraints,
! 1265: id->ndest_constraints);
1.1 christos 1266: }
1.1.1.23 christos 1267: /* success */
1.1.1.16 christos 1268: id->key = k;
1.1 christos 1269: id->comment = comment;
1270: id->death = death;
1271: id->confirm = confirm;
1.1.1.20 christos 1272: id->sk_provider = sk_provider;
1.1.1.25! christos 1273: id->dest_constraints = dest_constraints;
! 1274: id->ndest_constraints = ndest_constraints;
1.1.1.20 christos 1275:
1276: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
1277: SSH_FP_DEFAULT)) == NULL)
1.1.1.23 christos 1278: fatal_f("sshkey_fingerprint failed");
1279: debug_f("add %s %s \"%.100s\" (life: %u) (confirm: %u) "
1.1.1.25! christos 1280: "(provider: %s) (destination constraints: %zu)",
! 1281: sshkey_ssh_name(k), fp, comment, seconds, confirm,
! 1282: sk_provider == NULL ? "none" : sk_provider, ndest_constraints);
1.1.1.20 christos 1283: free(fp);
1.1.1.23 christos 1284: /* transferred */
1285: k = NULL;
1286: comment = NULL;
1287: sk_provider = NULL;
1.1.1.25! christos 1288: dest_constraints = NULL;
! 1289: ndest_constraints = 0;
1.1.1.23 christos 1290: success = 1;
1291: out:
1292: free(sk_provider);
1293: free(comment);
1294: sshkey_free(k);
1.1.1.25! christos 1295: free_dest_constraints(dest_constraints, ndest_constraints);
1.1.1.8 christos 1296: send_status(e, success);
1.1 christos 1297: }
1298:
1299: /* XXX todo: encrypt sensitive data with passphrase */
1300: static void
1301: process_lock_agent(SocketEntry *e, int lock)
1302: {
1.1.1.9 christos 1303: int r, success = 0, delay;
1.1.1.12 christos 1304: char *passwd;
1305: u_char passwdhash[LOCK_SIZE];
1.1.1.9 christos 1306: static u_int fail_count = 0;
1307: size_t pwlen;
1.1 christos 1308:
1.1.1.23 christos 1309: debug2_f("entering");
1.1.1.16 christos 1310: /*
1311: * This is deliberately fatal: the user has requested that we lock,
1312: * but we can't parse their request properly. The only safe thing to
1313: * do is abort.
1314: */
1.1.1.9 christos 1315: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
1.1.1.23 christos 1316: fatal_fr(r, "parse");
1.1.1.9 christos 1317: if (pwlen == 0) {
1318: debug("empty password not supported");
1319: } else if (locked && !lock) {
1320: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1321: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
1322: fatal("bcrypt_pbkdf");
1.1.1.12 christos 1323: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.1.1.9 christos 1324: debug("agent unlocked");
1325: locked = 0;
1326: fail_count = 0;
1.1.1.12 christos 1327: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.1.1.9 christos 1328: success = 1;
1329: } else {
1330: /* delay in 0.1s increments up to 10s */
1331: if (fail_count < 100)
1332: fail_count++;
1333: delay = 100000 * fail_count;
1334: debug("unlock failed, delaying %0.1lf seconds",
1335: (double)delay/1000000);
1336: usleep(delay);
1337: }
1338: explicit_bzero(passwdhash, sizeof(passwdhash));
1.1 christos 1339: } else if (!locked && lock) {
1.1.1.9 christos 1340: debug("agent locked");
1.1 christos 1341: locked = 1;
1.1.1.9 christos 1342: arc4random_buf(lock_salt, sizeof(lock_salt));
1343: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.1.1.12 christos 1344: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.1.1.9 christos 1345: fatal("bcrypt_pbkdf");
1.1 christos 1346: success = 1;
1347: }
1.1.1.21 christos 1348: freezero(passwd, pwlen);
1.1.1.8 christos 1349: send_status(e, success);
1.1 christos 1350: }
1351:
1352: static void
1.1.1.15 christos 1353: no_identities(SocketEntry *e)
1.1 christos 1354: {
1.1.1.8 christos 1355: struct sshbuf *msg;
1356: int r;
1.1 christos 1357:
1.1.1.8 christos 1358: if ((msg = sshbuf_new()) == NULL)
1.1.1.23 christos 1359: fatal_f("sshbuf_new failed");
1.1.1.15 christos 1360: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.1.1.8 christos 1361: (r = sshbuf_put_u32(msg, 0)) != 0 ||
1362: (r = sshbuf_put_stringb(e->output, msg)) != 0)
1.1.1.23 christos 1363: fatal_fr(r, "compose");
1.1.1.8 christos 1364: sshbuf_free(msg);
1.1 christos 1365: }
1366:
1.1.1.3 adam 1367: #ifdef ENABLE_PKCS11
1.1 christos 1368: static void
1369: process_add_smartcard_key(SocketEntry *e)
1370: {
1.1.1.16 christos 1371: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.1.1.20 christos 1372: char **comments = NULL;
1.1.1.15 christos 1373: int r, i, count = 0, success = 0, confirm = 0;
1.1.1.23 christos 1374: u_int seconds = 0;
1.1.1.6 christos 1375: time_t death = 0;
1.1.1.8 christos 1376: struct sshkey **keys = NULL, *k;
1.1 christos 1377: Identity *id;
1.1.1.25! christos 1378: struct dest_constraint *dest_constraints = NULL;
! 1379: size_t ndest_constraints = 0;
1.1 christos 1380:
1.1.1.23 christos 1381: debug2_f("entering");
1.1.1.8 christos 1382: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.1.1.16 christos 1383: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.1.1.23 christos 1384: error_fr(r, "parse");
1.1.1.16 christos 1385: goto send;
1386: }
1.1.1.23 christos 1387: if (parse_key_constraints(e->request, NULL, &death, &seconds, &confirm,
1.1.1.25! christos 1388: NULL, &dest_constraints, &ndest_constraints) != 0) {
1.1.1.23 christos 1389: error_f("failed to parse constraints");
1390: goto send;
1.1 christos 1391: }
1.1.1.13 christos 1392: if (realpath(provider, canonical_provider) == NULL) {
1393: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
1394: provider, strerror(errno));
1395: goto send;
1396: }
1.1.1.22 christos 1397: if (match_pattern_list(canonical_provider, allowed_providers, 0) != 1) {
1.1.1.13 christos 1398: verbose("refusing PKCS#11 add of \"%.100s\": "
1.1.1.22 christos 1399: "provider not allowed", canonical_provider);
1.1.1.13 christos 1400: goto send;
1401: }
1.1.1.23 christos 1402: debug_f("add %.100s", canonical_provider);
1.1 christos 1403: if (lifetime && !death)
1.1.1.6 christos 1404: death = monotime() + lifetime;
1.1 christos 1405:
1.1.1.20 christos 1406: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.1.1.3 adam 1407: for (i = 0; i < count; i++) {
1.1 christos 1408: k = keys[i];
1.1.1.15 christos 1409: if (lookup_identity(k) == NULL) {
1.1.1.3 adam 1410: id = xcalloc(1, sizeof(Identity));
1.1 christos 1411: id->key = k;
1.1.1.20 christos 1412: keys[i] = NULL; /* transferred */
1.1.1.13 christos 1413: id->provider = xstrdup(canonical_provider);
1.1.1.20 christos 1414: if (*comments[i] != '\0') {
1415: id->comment = comments[i];
1416: comments[i] = NULL; /* transferred */
1417: } else {
1418: id->comment = xstrdup(canonical_provider);
1419: }
1.1 christos 1420: id->death = death;
1421: id->confirm = confirm;
1.1.1.25! christos 1422: id->dest_constraints = dest_constraints;
! 1423: id->ndest_constraints = ndest_constraints;
! 1424: dest_constraints = NULL; /* transferred */
! 1425: ndest_constraints = 0;
1.1.1.15 christos 1426: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1427: idtab->nentries++;
1.1 christos 1428: success = 1;
1429: }
1.1.1.23 christos 1430: /* XXX update constraints for existing keys */
1.1.1.20 christos 1431: sshkey_free(keys[i]);
1432: free(comments[i]);
1.1 christos 1433: }
1434: send:
1.1.1.6 christos 1435: free(pin);
1436: free(provider);
1437: free(keys);
1.1.1.20 christos 1438: free(comments);
1.1.1.25! christos 1439: free_dest_constraints(dest_constraints, ndest_constraints);
1.1.1.8 christos 1440: send_status(e, success);
1.1 christos 1441: }
1442:
1443: static void
1444: process_remove_smartcard_key(SocketEntry *e)
1445: {
1.1.1.14 christos 1446: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.1.1.15 christos 1447: int r, success = 0;
1.1.1.3 adam 1448: Identity *id, *nxt;
1.1 christos 1449:
1.1.1.23 christos 1450: debug2_f("entering");
1.1.1.8 christos 1451: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.1.1.16 christos 1452: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.1.1.23 christos 1453: error_fr(r, "parse");
1.1.1.16 christos 1454: goto send;
1455: }
1.1.1.6 christos 1456: free(pin);
1.1 christos 1457:
1.1.1.14 christos 1458: if (realpath(provider, canonical_provider) == NULL) {
1459: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
1460: provider, strerror(errno));
1461: goto send;
1462: }
1463:
1.1.1.23 christos 1464: debug_f("remove %.100s", canonical_provider);
1.1.1.15 christos 1465: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
1466: nxt = TAILQ_NEXT(id, next);
1467: /* Skip file--based keys */
1468: if (id->provider == NULL)
1469: continue;
1470: if (!strcmp(canonical_provider, id->provider)) {
1471: TAILQ_REMOVE(&idtab->idlist, id, next);
1472: free_identity(id);
1473: idtab->nentries--;
1.1 christos 1474: }
1475: }
1.1.1.14 christos 1476: if (pkcs11_del_provider(canonical_provider) == 0)
1.1.1.3 adam 1477: success = 1;
1478: else
1.1.1.23 christos 1479: error_f("pkcs11_del_provider failed");
1.1.1.14 christos 1480: send:
1.1.1.6 christos 1481: free(provider);
1.1.1.8 christos 1482: send_status(e, success);
1.1 christos 1483: }
1.1.1.3 adam 1484: #endif /* ENABLE_PKCS11 */
1.1 christos 1485:
1.1.1.25! christos 1486: static int
! 1487: process_ext_session_bind(SocketEntry *e)
! 1488: {
! 1489: int r, sid_match, key_match;
! 1490: struct sshkey *key = NULL;
! 1491: struct sshbuf *sid = NULL, *sig = NULL;
! 1492: char *fp = NULL;
! 1493: size_t i;
! 1494: u_char fwd = 0;
! 1495:
! 1496: debug2_f("entering");
! 1497: if ((r = sshkey_froms(e->request, &key)) != 0 ||
! 1498: (r = sshbuf_froms(e->request, &sid)) != 0 ||
! 1499: (r = sshbuf_froms(e->request, &sig)) != 0 ||
! 1500: (r = sshbuf_get_u8(e->request, &fwd)) != 0) {
! 1501: error_fr(r, "parse");
! 1502: goto out;
! 1503: }
! 1504: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 1505: SSH_FP_DEFAULT)) == NULL)
! 1506: fatal_f("fingerprint failed");
! 1507: /* check signature with hostkey on session ID */
! 1508: if ((r = sshkey_verify(key, sshbuf_ptr(sig), sshbuf_len(sig),
! 1509: sshbuf_ptr(sid), sshbuf_len(sid), NULL, 0, NULL)) != 0) {
! 1510: error_fr(r, "sshkey_verify for %s %s", sshkey_type(key), fp);
! 1511: goto out;
! 1512: }
! 1513: /* check whether sid/key already recorded */
! 1514: for (i = 0; i < e->nsession_ids; i++) {
! 1515: if (!e->session_ids[i].forwarded) {
! 1516: error_f("attempt to bind session ID to socket "
! 1517: "previously bound for authentication attempt");
! 1518: r = -1;
! 1519: goto out;
! 1520: }
! 1521: sid_match = buf_equal(sid, e->session_ids[i].sid) == 0;
! 1522: key_match = sshkey_equal(key, e->session_ids[i].key);
! 1523: if (sid_match && key_match) {
! 1524: debug_f("session ID already recorded for %s %s",
! 1525: sshkey_type(key), fp);
! 1526: r = 0;
! 1527: goto out;
! 1528: } else if (sid_match) {
! 1529: error_f("session ID recorded against different key "
! 1530: "for %s %s", sshkey_type(key), fp);
! 1531: r = -1;
! 1532: goto out;
! 1533: }
! 1534: /*
! 1535: * new sid with previously-seen key can happen, e.g. multiple
! 1536: * connections to the same host.
! 1537: */
! 1538: }
! 1539: /* record new key/sid */
! 1540: if (e->nsession_ids >= AGENT_MAX_SESSION_IDS) {
! 1541: error_f("too many session IDs recorded");
! 1542: goto out;
! 1543: }
! 1544: e->session_ids = xrecallocarray(e->session_ids, e->nsession_ids,
! 1545: e->nsession_ids + 1, sizeof(*e->session_ids));
! 1546: i = e->nsession_ids++;
! 1547: debug_f("recorded %s %s (slot %zu of %d)", sshkey_type(key), fp, i,
! 1548: AGENT_MAX_SESSION_IDS);
! 1549: e->session_ids[i].key = key;
! 1550: e->session_ids[i].forwarded = fwd != 0;
! 1551: key = NULL; /* transferred */
! 1552: /* can't transfer sid; it's refcounted and scoped to request's life */
! 1553: if ((e->session_ids[i].sid = sshbuf_new()) == NULL)
! 1554: fatal_f("sshbuf_new");
! 1555: if ((r = sshbuf_putb(e->session_ids[i].sid, sid)) != 0)
! 1556: fatal_fr(r, "sshbuf_putb session ID");
! 1557: /* success */
! 1558: r = 0;
! 1559: out:
! 1560: sshkey_free(key);
! 1561: sshbuf_free(sid);
! 1562: sshbuf_free(sig);
! 1563: return r == 0 ? 1 : 0;
! 1564: }
! 1565:
! 1566: static void
! 1567: process_extension(SocketEntry *e)
! 1568: {
! 1569: int r, success = 0;
! 1570: char *name;
! 1571:
! 1572: debug2_f("entering");
! 1573: if ((r = sshbuf_get_cstring(e->request, &name, NULL)) != 0) {
! 1574: error_fr(r, "parse");
! 1575: goto send;
! 1576: }
! 1577: if (strcmp(name, "session-bind@openssh.com") == 0)
! 1578: success = process_ext_session_bind(e);
! 1579: else
! 1580: debug_f("unsupported extension \"%s\"", name);
! 1581: free(name);
! 1582: send:
! 1583: send_status(e, success);
! 1584: }
1.1.1.22 christos 1585: /*
1586: * dispatch incoming message.
1587: * returns 1 on success, 0 for incomplete messages or -1 on error.
1588: */
1.1.1.15 christos 1589: static int
1590: process_message(u_int socknum)
1.1 christos 1591: {
1.1.1.8 christos 1592: u_int msg_len;
1593: u_char type;
1594: const u_char *cp;
1595: int r;
1.1.1.15 christos 1596: SocketEntry *e;
1597:
1.1.1.23 christos 1598: if (socknum >= sockets_alloc)
1599: fatal_f("sock %u >= allocated %u", socknum, sockets_alloc);
1.1.1.15 christos 1600: e = &sockets[socknum];
1.1 christos 1601:
1.1.1.8 christos 1602: if (sshbuf_len(e->input) < 5)
1.1.1.15 christos 1603: return 0; /* Incomplete message header. */
1.1.1.8 christos 1604: cp = sshbuf_ptr(e->input);
1605: msg_len = PEEK_U32(cp);
1.1.1.15 christos 1606: if (msg_len > AGENT_MAX_LEN) {
1.1.1.23 christos 1607: debug_f("socket %u (fd=%d) message too long %u > %u",
1608: socknum, e->fd, msg_len, AGENT_MAX_LEN);
1.1.1.15 christos 1609: return -1;
1.1 christos 1610: }
1.1.1.8 christos 1611: if (sshbuf_len(e->input) < msg_len + 4)
1.1.1.15 christos 1612: return 0; /* Incomplete message body. */
1.1 christos 1613:
1614: /* move the current input to e->request */
1.1.1.8 christos 1615: sshbuf_reset(e->request);
1616: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.1.1.15 christos 1617: (r = sshbuf_get_u8(e->request, &type)) != 0) {
1618: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
1619: r == SSH_ERR_STRING_TOO_LARGE) {
1.1.1.23 christos 1620: error_fr(r, "parse");
1.1.1.15 christos 1621: return -1;
1622: }
1.1.1.23 christos 1623: fatal_fr(r, "parse");
1.1.1.15 christos 1624: }
1625:
1.1.1.23 christos 1626: debug_f("socket %u (fd=%d) type %d", socknum, e->fd, type);
1.1 christos 1627:
1.1.1.17 christos 1628: /* check whether agent is locked */
1.1 christos 1629: if (locked && type != SSH_AGENTC_UNLOCK) {
1.1.1.8 christos 1630: sshbuf_reset(e->request);
1.1 christos 1631: switch (type) {
1632: case SSH2_AGENTC_REQUEST_IDENTITIES:
1633: /* send empty lists */
1.1.1.15 christos 1634: no_identities(e);
1.1 christos 1635: break;
1636: default:
1637: /* send a fail message for all other request types */
1.1.1.8 christos 1638: send_status(e, 0);
1.1 christos 1639: }
1.1.1.22 christos 1640: return 1;
1.1 christos 1641: }
1642:
1643: switch (type) {
1644: case SSH_AGENTC_LOCK:
1645: case SSH_AGENTC_UNLOCK:
1646: process_lock_agent(e, type == SSH_AGENTC_LOCK);
1647: break;
1648: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.1.1.15 christos 1649: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.1 christos 1650: break;
1651: /* ssh2 */
1652: case SSH2_AGENTC_SIGN_REQUEST:
1653: process_sign_request2(e);
1654: break;
1655: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.1.1.15 christos 1656: process_request_identities(e);
1.1 christos 1657: break;
1658: case SSH2_AGENTC_ADD_IDENTITY:
1659: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.1.1.15 christos 1660: process_add_identity(e);
1.1 christos 1661: break;
1662: case SSH2_AGENTC_REMOVE_IDENTITY:
1.1.1.15 christos 1663: process_remove_identity(e);
1.1 christos 1664: break;
1665: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.1.1.15 christos 1666: process_remove_all_identities(e);
1.1 christos 1667: break;
1.1.1.3 adam 1668: #ifdef ENABLE_PKCS11
1.1 christos 1669: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1670: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1671: process_add_smartcard_key(e);
1672: break;
1673: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
1674: process_remove_smartcard_key(e);
1675: break;
1.1.1.3 adam 1676: #endif /* ENABLE_PKCS11 */
1.1.1.25! christos 1677: case SSH_AGENTC_EXTENSION:
! 1678: process_extension(e);
! 1679: break;
1.1 christos 1680: default:
1681: /* Unknown message. Respond with failure. */
1682: error("Unknown message %d", type);
1.1.1.8 christos 1683: sshbuf_reset(e->request);
1684: send_status(e, 0);
1.1 christos 1685: break;
1686: }
1.1.1.22 christos 1687: return 1;
1.1 christos 1688: }
1689:
1690: static void
1691: new_socket(sock_type type, int fd)
1692: {
1693: u_int i, old_alloc, new_alloc;
1694:
1.1.1.23 christos 1695: debug_f("type = %s", type == AUTH_CONNECTION ? "CONNECTION" :
1696: (type == AUTH_SOCKET ? "SOCKET" : "UNKNOWN"));
1.1 christos 1697: set_nonblock(fd);
1698:
1699: if (fd > max_fd)
1700: max_fd = fd;
1701:
1702: for (i = 0; i < sockets_alloc; i++)
1703: if (sockets[i].type == AUTH_UNUSED) {
1704: sockets[i].fd = fd;
1.1.1.23 christos 1705: if ((sockets[i].input = sshbuf_new()) == NULL ||
1706: (sockets[i].output = sshbuf_new()) == NULL ||
1707: (sockets[i].request = sshbuf_new()) == NULL)
1708: fatal_f("sshbuf_new failed");
1.1 christos 1709: sockets[i].type = type;
1710: return;
1711: }
1712: old_alloc = sockets_alloc;
1713: new_alloc = sockets_alloc + 10;
1.1.1.23 christos 1714: sockets = xrecallocarray(sockets, old_alloc, new_alloc,
1715: sizeof(sockets[0]));
1.1 christos 1716: for (i = old_alloc; i < new_alloc; i++)
1717: sockets[i].type = AUTH_UNUSED;
1718: sockets_alloc = new_alloc;
1719: sockets[old_alloc].fd = fd;
1.1.1.23 christos 1720: if ((sockets[old_alloc].input = sshbuf_new()) == NULL ||
1721: (sockets[old_alloc].output = sshbuf_new()) == NULL ||
1722: (sockets[old_alloc].request = sshbuf_new()) == NULL)
1723: fatal_f("sshbuf_new failed");
1.1 christos 1724: sockets[old_alloc].type = type;
1725: }
1726:
1727: static int
1.1.1.15 christos 1728: handle_socket_read(u_int socknum)
1.1 christos 1729: {
1.1.1.15 christos 1730: struct sockaddr_un sunaddr;
1731: socklen_t slen;
1732: uid_t euid;
1733: gid_t egid;
1734: int fd;
1735:
1736: slen = sizeof(sunaddr);
1737: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.1.1.19 christos 1738: if (fd == -1) {
1.1.1.15 christos 1739: error("accept from AUTH_SOCKET: %s", strerror(errno));
1740: return -1;
1741: }
1.1.1.19 christos 1742: if (getpeereid(fd, &euid, &egid) == -1) {
1.1.1.15 christos 1743: error("getpeereid %d failed: %s", fd, strerror(errno));
1744: close(fd);
1745: return -1;
1746: }
1747: if ((euid != 0) && (getuid() != euid)) {
1748: error("uid mismatch: peer euid %u != uid %u",
1749: (u_int) euid, (u_int) getuid());
1750: close(fd);
1751: return -1;
1752: }
1753: new_socket(AUTH_CONNECTION, fd);
1754: return 0;
1755: }
1756:
1757: static int
1758: handle_conn_read(u_int socknum)
1759: {
1.1.1.18 christos 1760: char buf[AGENT_RBUF_LEN];
1.1.1.15 christos 1761: ssize_t len;
1762: int r;
1763:
1764: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1765: if (len == -1) {
1766: if (errno == EAGAIN || errno == EINTR)
1767: return 0;
1.1.1.23 christos 1768: error_f("read error on socket %u (fd %d): %s",
1769: socknum, sockets[socknum].fd, strerror(errno));
1.1.1.15 christos 1770: }
1771: return -1;
1772: }
1773: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1.1.1.23 christos 1774: fatal_fr(r, "compose");
1.1.1.15 christos 1775: explicit_bzero(buf, sizeof(buf));
1.1.1.22 christos 1776: for (;;) {
1777: if ((r = process_message(socknum)) == -1)
1778: return -1;
1779: else if (r == 0)
1780: break;
1781: }
1.1.1.15 christos 1782: return 0;
1783: }
1784:
1785: static int
1786: handle_conn_write(u_int socknum)
1787: {
1788: ssize_t len;
1789: int r;
1790:
1791: if (sshbuf_len(sockets[socknum].output) == 0)
1792: return 0; /* shouldn't happen */
1793: if ((len = write(sockets[socknum].fd,
1794: sshbuf_ptr(sockets[socknum].output),
1795: sshbuf_len(sockets[socknum].output))) <= 0) {
1796: if (len == -1) {
1797: if (errno == EAGAIN || errno == EINTR)
1798: return 0;
1.1.1.23 christos 1799: error_f("read error on socket %u (fd %d): %s",
1800: socknum, sockets[socknum].fd, strerror(errno));
1.1.1.15 christos 1801: }
1802: return -1;
1803: }
1804: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1.1.1.23 christos 1805: fatal_fr(r, "consume");
1.1.1.15 christos 1806: return 0;
1807: }
1808:
1809: static void
1.1.1.17 christos 1810: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.1.1.15 christos 1811: {
1812: size_t i;
1.1.1.17 christos 1813: u_int socknum, activefds = npfd;
1.1.1.15 christos 1814:
1815: for (i = 0; i < npfd; i++) {
1816: if (pfd[i].revents == 0)
1817: continue;
1818: /* Find sockets entry */
1819: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1820: if (sockets[socknum].type != AUTH_SOCKET &&
1821: sockets[socknum].type != AUTH_CONNECTION)
1822: continue;
1823: if (pfd[i].fd == sockets[socknum].fd)
1824: break;
1825: }
1826: if (socknum >= sockets_alloc) {
1.1.1.23 christos 1827: error_f("no socket for fd %d", pfd[i].fd);
1.1.1.15 christos 1828: continue;
1829: }
1830: /* Process events */
1831: switch (sockets[socknum].type) {
1832: case AUTH_SOCKET:
1.1.1.17 christos 1833: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1834: break;
1835: if (npfd > maxfds) {
1836: debug3("out of fds (active %u >= limit %u); "
1837: "skipping accept", activefds, maxfds);
1838: break;
1839: }
1840: if (handle_socket_read(socknum) == 0)
1841: activefds++;
1.1.1.15 christos 1842: break;
1843: case AUTH_CONNECTION:
1.1.1.25! christos 1844: if ((pfd[i].revents & (POLLIN|POLLHUP|POLLERR)) != 0 &&
! 1845: handle_conn_read(socknum) != 0)
1.1.1.17 christos 1846: goto close_sock;
1.1.1.15 christos 1847: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1.1.1.17 christos 1848: handle_conn_write(socknum) != 0) {
1849: close_sock:
1850: if (activefds == 0)
1851: fatal("activefds == 0 at close_sock");
1.1.1.15 christos 1852: close_socket(&sockets[socknum]);
1.1.1.17 christos 1853: activefds--;
1854: break;
1855: }
1.1.1.15 christos 1856: break;
1857: default:
1858: break;
1859: }
1860: }
1861: }
1862:
1863: static int
1.1.1.17 christos 1864: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.1.1.15 christos 1865: {
1866: struct pollfd *pfd = *pfdp;
1867: size_t i, j, npfd = 0;
1.1.1.6 christos 1868: time_t deadline;
1.1.1.18 christos 1869: int r;
1.1 christos 1870:
1.1.1.15 christos 1871: /* Count active sockets */
1.1 christos 1872: for (i = 0; i < sockets_alloc; i++) {
1873: switch (sockets[i].type) {
1874: case AUTH_SOCKET:
1875: case AUTH_CONNECTION:
1.1.1.15 christos 1876: npfd++;
1.1 christos 1877: break;
1878: case AUTH_UNUSED:
1879: break;
1880: default:
1881: fatal("Unknown socket type %d", sockets[i].type);
1882: break;
1883: }
1884: }
1.1.1.15 christos 1885: if (npfd != *npfdp &&
1886: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1.1.1.23 christos 1887: fatal_f("recallocarray failed");
1.1.1.15 christos 1888: *pfdp = pfd;
1889: *npfdp = npfd;
1.1 christos 1890:
1.1.1.15 christos 1891: for (i = j = 0; i < sockets_alloc; i++) {
1.1 christos 1892: switch (sockets[i].type) {
1893: case AUTH_SOCKET:
1.1.1.17 christos 1894: if (npfd > maxfds) {
1895: debug3("out of fds (active %zu >= limit %u); "
1896: "skipping arming listener", npfd, maxfds);
1897: break;
1898: }
1899: pfd[j].fd = sockets[i].fd;
1900: pfd[j].revents = 0;
1901: pfd[j].events = POLLIN;
1902: j++;
1903: break;
1.1 christos 1904: case AUTH_CONNECTION:
1.1.1.15 christos 1905: pfd[j].fd = sockets[i].fd;
1906: pfd[j].revents = 0;
1.1.1.18 christos 1907: /*
1908: * Only prepare to read if we can handle a full-size
1909: * input read buffer and enqueue a max size reply..
1910: */
1911: if ((r = sshbuf_check_reserve(sockets[i].input,
1912: AGENT_RBUF_LEN)) == 0 &&
1913: (r = sshbuf_check_reserve(sockets[i].output,
1.1.1.24 christos 1914: AGENT_MAX_LEN)) == 0)
1.1.1.18 christos 1915: pfd[j].events = POLLIN;
1.1.1.23 christos 1916: else if (r != SSH_ERR_NO_BUFFER_SPACE)
1917: fatal_fr(r, "reserve");
1.1.1.8 christos 1918: if (sshbuf_len(sockets[i].output) > 0)
1.1.1.15 christos 1919: pfd[j].events |= POLLOUT;
1920: j++;
1.1 christos 1921: break;
1922: default:
1923: break;
1924: }
1925: }
1926: deadline = reaper();
1927: if (parent_alive_interval != 0)
1928: deadline = (deadline == 0) ? parent_alive_interval :
1.1.1.13 christos 1929: MINIMUM(deadline, parent_alive_interval);
1.1 christos 1930: if (deadline == 0) {
1.1.1.15 christos 1931: *timeoutp = -1; /* INFTIM */
1.1 christos 1932: } else {
1.1.1.15 christos 1933: if (deadline > INT_MAX / 1000)
1934: *timeoutp = INT_MAX / 1000;
1935: else
1936: *timeoutp = deadline * 1000;
1.1 christos 1937: }
1938: return (1);
1939: }
1940:
1941: static void
1942: cleanup_socket(void)
1943: {
1.1.1.7 christos 1944: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1945: return;
1.1.1.23 christos 1946: debug_f("cleanup");
1.1 christos 1947: if (socket_name[0])
1948: unlink(socket_name);
1949: if (socket_dir[0])
1950: rmdir(socket_dir);
1951: }
1952:
1953: void
1954: cleanup_exit(int i)
1955: {
1956: cleanup_socket();
1957: _exit(i);
1958: }
1959:
1960: /*ARGSUSED*/
1961: static void
1962: cleanup_handler(int sig)
1963: {
1964: cleanup_socket();
1.1.1.3 adam 1965: #ifdef ENABLE_PKCS11
1966: pkcs11_terminate();
1967: #endif
1.1 christos 1968: _exit(2);
1969: }
1970:
1971: static void
1972: check_parent_exists(void)
1973: {
1.1.1.5 christos 1974: /*
1975: * If our parent has exited then getppid() will return (pid_t)1,
1976: * so testing for that should be safe.
1977: */
1978: if (parent_pid != -1 && getppid() != parent_pid) {
1.1 christos 1979: /* printf("Parent has died - Authentication agent exiting.\n"); */
1980: cleanup_socket();
1981: _exit(2);
1982: }
1983: }
1984:
1985: static void
1986: usage(void)
1987: {
1.1.1.7 christos 1988: fprintf(stderr,
1.1.1.9 christos 1989: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.1.1.22 christos 1990: " [-P allowed_providers] [-t life]\n"
1991: " ssh-agent [-a bind_address] [-E fingerprint_hash] [-P allowed_providers]\n"
1992: " [-t life] command [arg ...]\n"
1.1.1.7 christos 1993: " ssh-agent [-c | -s] -k\n");
1.1 christos 1994: exit(1);
1995: }
1996:
1997: int
1998: main(int ac, char **av)
1999: {
1.1.1.9 christos 2000: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.1.1.23 christos 2001: int sock, ch, result, saved_errno;
1.1 christos 2002: char *shell, *format, *pidstr, *agentsocket = NULL;
2003: struct rlimit rlim;
2004: extern int optind;
2005: extern char *optarg;
2006: pid_t pid;
2007: char pidstrbuf[1 + 3 * sizeof pid];
1.1.1.2 christos 2008: size_t len;
1.1.1.7 christos 2009: mode_t prev_mask;
1.1.1.15 christos 2010: int timeout = -1; /* INFTIM */
2011: struct pollfd *pfd = NULL;
2012: size_t npfd = 0;
1.1.1.17 christos 2013: u_int maxfds;
1.1 christos 2014:
2015: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
2016: sanitise_stdfd();
2017:
2018: /* drop */
2019: setegid(getgid());
2020: setgid(getgid());
2021:
1.1.1.17 christos 2022: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
2023: fatal("%s: getrlimit: %s", __progname, strerror(errno));
2024:
1.1.1.7 christos 2025: #ifdef WITH_OPENSSL
1.1.1.4 christos 2026: OpenSSL_add_all_algorithms();
1.1.1.7 christos 2027: #endif
1.1 christos 2028:
1.1.1.22 christos 2029: while ((ch = getopt(ac, av, "cDdksE:a:O:P:t:")) != -1) {
1.1 christos 2030: switch (ch) {
1.1.1.8 christos 2031: case 'E':
2032: fingerprint_hash = ssh_digest_alg_by_name(optarg);
2033: if (fingerprint_hash == -1)
2034: fatal("Invalid hash algorithm \"%s\"", optarg);
2035: break;
1.1 christos 2036: case 'c':
2037: if (s_flag)
2038: usage();
2039: c_flag++;
2040: break;
2041: case 'k':
2042: k_flag++;
2043: break;
1.1.1.22 christos 2044: case 'O':
2045: if (strcmp(optarg, "no-restrict-websafe") == 0)
2046: restrict_websafe = 0;
2047: else
2048: fatal("Unknown -O option");
2049: break;
1.1.1.13 christos 2050: case 'P':
1.1.1.22 christos 2051: if (allowed_providers != NULL)
1.1.1.13 christos 2052: fatal("-P option already specified");
1.1.1.22 christos 2053: allowed_providers = xstrdup(optarg);
1.1.1.13 christos 2054: break;
1.1 christos 2055: case 's':
2056: if (c_flag)
2057: usage();
2058: s_flag++;
2059: break;
2060: case 'd':
1.1.1.9 christos 2061: if (d_flag || D_flag)
1.1 christos 2062: usage();
2063: d_flag++;
2064: break;
1.1.1.9 christos 2065: case 'D':
2066: if (d_flag || D_flag)
2067: usage();
2068: D_flag++;
2069: break;
1.1 christos 2070: case 'a':
2071: agentsocket = optarg;
2072: break;
2073: case 't':
2074: if ((lifetime = convtime(optarg)) == -1) {
2075: fprintf(stderr, "Invalid lifetime\n");
2076: usage();
2077: }
2078: break;
2079: default:
2080: usage();
2081: }
2082: }
2083: ac -= optind;
2084: av += optind;
2085:
1.1.1.9 christos 2086: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.1 christos 2087: usage();
2088:
1.1.1.22 christos 2089: if (allowed_providers == NULL)
2090: allowed_providers = xstrdup(DEFAULT_ALLOWED_PROVIDERS);
1.1.1.13 christos 2091:
1.1 christos 2092: if (ac == 0 && !c_flag && !s_flag) {
2093: shell = getenv("SHELL");
1.1.1.2 christos 2094: if (shell != NULL && (len = strlen(shell)) > 2 &&
2095: strncmp(shell + len - 3, "csh", 3) == 0)
1.1 christos 2096: c_flag = 1;
2097: }
2098: if (k_flag) {
2099: const char *errstr = NULL;
2100:
2101: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
2102: if (pidstr == NULL) {
2103: fprintf(stderr, "%s not set, cannot kill agent\n",
2104: SSH_AGENTPID_ENV_NAME);
2105: exit(1);
2106: }
2107: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
2108: if (errstr) {
2109: fprintf(stderr,
2110: "%s=\"%s\", which is not a good PID: %s\n",
2111: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
2112: exit(1);
2113: }
2114: if (kill(pid, SIGTERM) == -1) {
2115: perror("kill");
2116: exit(1);
2117: }
2118: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
2119: printf(format, SSH_AUTHSOCKET_ENV_NAME);
2120: printf(format, SSH_AGENTPID_ENV_NAME);
2121: printf("echo Agent pid %ld killed;\n", (long)pid);
2122: exit(0);
2123: }
1.1.1.17 christos 2124:
2125: /*
2126: * Minimum file descriptors:
2127: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
2128: * a few spare for libc / stack protectors / sanitisers, etc.
2129: */
2130: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
2131: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.1.1.18 christos 2132: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.1.1.17 christos 2133: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
2134: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
2135:
1.1 christos 2136: parent_pid = getpid();
2137:
2138: if (agentsocket == NULL) {
2139: /* Create private directory for agent socket */
1.1.1.4 christos 2140: mktemp_proto(socket_dir, sizeof(socket_dir));
1.1 christos 2141: if (mkdtemp(socket_dir) == NULL) {
2142: perror("mkdtemp: private socket dir");
2143: exit(1);
2144: }
2145: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
2146: (long)parent_pid);
2147: } else {
2148: /* Try to use specified agent socket */
2149: socket_dir[0] = '\0';
2150: strlcpy(socket_name, agentsocket, sizeof socket_name);
2151: }
2152:
2153: /*
2154: * Create socket early so it will exist before command gets run from
2155: * the parent.
2156: */
1.1.1.7 christos 2157: prev_mask = umask(0177);
2158: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.1 christos 2159: if (sock < 0) {
1.1.1.7 christos 2160: /* XXX - unix_listener() calls error() not perror() */
1.1 christos 2161: *socket_name = '\0'; /* Don't unlink any existing file */
2162: cleanup_exit(1);
2163: }
1.1.1.7 christos 2164: umask(prev_mask);
1.1 christos 2165:
2166: /*
2167: * Fork, and have the parent execute the command, if any, or present
2168: * the socket data. The child continues as the authentication agent.
2169: */
1.1.1.9 christos 2170: if (D_flag || d_flag) {
2171: log_init(__progname,
2172: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
2173: SYSLOG_FACILITY_AUTH, 1);
1.1 christos 2174: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
2175: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
2176: SSH_AUTHSOCKET_ENV_NAME);
2177: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.1.1.11 christos 2178: fflush(stdout);
1.1 christos 2179: goto skip;
2180: }
2181: pid = fork();
2182: if (pid == -1) {
2183: perror("fork");
2184: cleanup_exit(1);
2185: }
2186: if (pid != 0) { /* Parent - execute the given command. */
2187: close(sock);
2188: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
2189: if (ac == 0) {
2190: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
2191: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
2192: SSH_AUTHSOCKET_ENV_NAME);
2193: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
2194: SSH_AGENTPID_ENV_NAME);
2195: printf("echo Agent pid %ld;\n", (long)pid);
2196: exit(0);
2197: }
2198: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
2199: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
2200: perror("setenv");
2201: exit(1);
2202: }
2203: execvp(av[0], av);
2204: perror(av[0]);
2205: exit(1);
2206: }
2207: /* child */
2208: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
2209:
2210: if (setsid() == -1) {
2211: error("setsid: %s", strerror(errno));
2212: cleanup_exit(1);
2213: }
2214:
2215: (void)chdir("/");
1.1.1.23 christos 2216: if (stdfd_devnull(1, 1, 1) == -1)
2217: error_f("stdfd_devnull failed");
1.1 christos 2218:
2219: /* deny core dumps, since memory contains unencrypted private keys */
2220: rlim.rlim_cur = rlim.rlim_max = 0;
1.1.1.19 christos 2221: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.1 christos 2222: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
2223: cleanup_exit(1);
2224: }
2225:
2226: skip:
1.1.1.3 adam 2227:
1.1.1.7 christos 2228: cleanup_pid = getpid();
2229:
1.1.1.3 adam 2230: #ifdef ENABLE_PKCS11
2231: pkcs11_init(0);
2232: #endif
1.1 christos 2233: new_socket(AUTH_SOCKET, sock);
2234: if (ac > 0)
2235: parent_alive_interval = 10;
2236: idtab_init();
1.1.1.20 christos 2237: ssh_signal(SIGPIPE, SIG_IGN);
2238: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
2239: ssh_signal(SIGHUP, cleanup_handler);
2240: ssh_signal(SIGTERM, cleanup_handler);
1.1 christos 2241:
1.1.1.13 christos 2242: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.1.1.11 christos 2243: fatal("%s: pledge: %s", __progname, strerror(errno));
2244:
1.1 christos 2245: while (1) {
1.1.1.17 christos 2246: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.1.1.15 christos 2247: result = poll(pfd, npfd, timeout);
1.1 christos 2248: saved_errno = errno;
2249: if (parent_alive_interval != 0)
2250: check_parent_exists();
2251: (void) reaper(); /* remove expired keys */
1.1.1.19 christos 2252: if (result == -1) {
1.1 christos 2253: if (saved_errno == EINTR)
2254: continue;
1.1.1.15 christos 2255: fatal("poll: %s", strerror(saved_errno));
1.1 christos 2256: } else if (result > 0)
1.1.1.17 christos 2257: after_poll(pfd, npfd, maxfds);
1.1 christos 2258: }
2259: /* NOTREACHED */
2260: }
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