Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.266
1.266 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.265 2020/10/03 09:22:26 djm Exp $ */
1.1 deraadt 2: /*
1.22 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * The authentication agent program.
1.33 markus 7: *
1.35 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.56 markus 14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 15: *
16: * Redistribution and use in source and binary forms, with or without
17: * modification, are permitted provided that the following conditions
18: * are met:
19: * 1. Redistributions of source code must retain the above copyright
20: * notice, this list of conditions and the following disclaimer.
21: * 2. Redistributions in binary form must reproduce the above copyright
22: * notice, this list of conditions and the following disclaimer in the
23: * documentation and/or other materials provided with the distribution.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 35: */
1.1 deraadt 36:
1.151 deraadt 37: #include <sys/types.h>
1.153 djm 38: #include <sys/time.h>
1.78 provos 39: #include <sys/queue.h>
1.127 stevesk 40: #include <sys/resource.h>
1.141 stevesk 41: #include <sys/socket.h>
1.189 djm 42: #include <sys/stat.h>
1.128 stevesk 43: #include <sys/un.h>
1.238 djm 44: #include <sys/wait.h>
1.126 stevesk 45:
1.185 markus 46: #ifdef WITH_OPENSSL
1.146 stevesk 47: #include <openssl/evp.h>
1.185 markus 48: #endif
1.146 stevesk 49:
1.143 stevesk 50: #include <errno.h>
1.142 stevesk 51: #include <fcntl.h>
1.126 stevesk 52: #include <paths.h>
1.223 djm 53: #include <poll.h>
1.129 stevesk 54: #include <signal.h>
1.149 stevesk 55: #include <stdlib.h>
1.150 stevesk 56: #include <stdio.h>
1.146 stevesk 57: #include <string.h>
1.248 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:
1.262 djm 82: #ifndef DEFAULT_ALLOWED_PROVIDERS
83: # define DEFAULT_ALLOWED_PROVIDERS "/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:
1.260 djm 139: /* Pattern-list of allowed PKCS#11/Security key paths */
140: static char *allowed_providers;
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)
1.266 ! djm 227: fatal_fr(r, "compose");
1.194 markus 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)
1.266 ! djm 239: fatal_f("sshbuf_new failed");
1.221 djm 240: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
241: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
1.266 ! djm 242: fatal_fr(r, "compose");
1.221 djm 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) {
1.266 ! djm 247: error_fr(r, "compose key/comment");
1.220 djm 248: continue;
1.33 markus 249: }
1.21 markus 250: }
1.194 markus 251: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 ! djm 252: fatal_fr(r, "enqueue");
1.194 markus 253: sshbuf_free(msg);
1.1 deraadt 254: }
255:
1.33 markus 256:
1.208 markus 257: static char *
258: agent_decode_alg(struct sshkey *key, u_int flags)
259: {
260: if (key->type == KEY_RSA) {
261: if (flags & SSH_AGENT_RSA_SHA2_256)
262: return "rsa-sha2-256";
263: else if (flags & SSH_AGENT_RSA_SHA2_512)
264: return "rsa-sha2-512";
1.235 djm 265: } else if (key->type == KEY_RSA_CERT) {
266: if (flags & SSH_AGENT_RSA_SHA2_256)
267: return "rsa-sha2-256-cert-v01@openssh.com";
268: else if (flags & SSH_AGENT_RSA_SHA2_512)
269: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 270: }
271: return NULL;
272: }
273:
1.258 djm 274: /*
275: * This function inspects a message to be signed by a FIDO key that has a
276: * web-like application string (i.e. one that does not begin with "ssh:".
277: * It checks that the message is one of those expected for SSH operations
278: * (pubkey userauth, sshsig, CA key signing) to exclude signing challenges
279: * for the web.
280: */
281: static int
282: check_websafe_message_contents(struct sshkey *key,
283: const u_char *msg, size_t len)
284: {
285: int matched = 0;
286: struct sshbuf *b;
287: u_char m, n;
288: char *cp1 = NULL, *cp2 = NULL;
289: int r;
290: struct sshkey *mkey = NULL;
291:
292: if ((b = sshbuf_from(msg, len)) == NULL)
1.266 ! djm 293: fatal_f("sshbuf_new");
1.258 djm 294:
295: /* SSH userauth request */
296: if ((r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* sess_id */
297: (r = sshbuf_get_u8(b, &m)) == 0 && /* SSH2_MSG_USERAUTH_REQUEST */
298: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* server user */
299: (r = sshbuf_get_cstring(b, &cp1, NULL)) == 0 && /* service */
300: (r = sshbuf_get_cstring(b, &cp2, NULL)) == 0 && /* method */
301: (r = sshbuf_get_u8(b, &n)) == 0 && /* sig-follows */
302: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* alg */
303: (r = sshkey_froms(b, &mkey)) == 0 && /* key */
304: sshbuf_len(b) == 0) {
1.266 ! djm 305: debug_f("parsed userauth");
1.258 djm 306: if (m == SSH2_MSG_USERAUTH_REQUEST && n == 1 &&
307: strcmp(cp1, "ssh-connection") == 0 &&
308: strcmp(cp2, "publickey") == 0 &&
309: sshkey_equal(key, mkey)) {
1.266 ! djm 310: debug_f("well formed userauth");
1.258 djm 311: matched = 1;
312: }
313: }
314: free(cp1);
315: free(cp2);
316: sshkey_free(mkey);
317: sshbuf_free(b);
318: if (matched)
319: return 1;
320:
321: if ((b = sshbuf_from(msg, len)) == NULL)
1.266 ! djm 322: fatal_f("sshbuf_new");
1.258 djm 323: cp1 = cp2 = NULL;
324: mkey = NULL;
325:
326: /* SSHSIG */
327: if ((r = sshbuf_cmp(b, 0, "SSHSIG", 6)) == 0 &&
328: (r = sshbuf_consume(b, 6)) == 0 &&
329: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* namespace */
330: (r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* reserved */
331: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* hashalg */
332: (r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* H(msg) */
333: sshbuf_len(b) == 0) {
1.266 ! djm 334: debug_f("parsed sshsig");
1.258 djm 335: matched = 1;
336: }
337:
338: sshbuf_free(b);
339: if (matched)
340: return 1;
341:
342: /* XXX CA signature operation */
343:
344: error("web-origin key attempting to sign non-SSH message");
345: return 0;
346: }
347:
1.33 markus 348: /* ssh2 only */
1.55 itojun 349: static void
1.33 markus 350: process_sign_request2(SocketEntry *e)
351: {
1.221 djm 352: const u_char *data;
353: u_char *signature = NULL;
354: size_t dlen, slen = 0;
1.194 markus 355: u_int compat = 0, flags;
1.247 djm 356: int r, ok = -1;
1.251 djm 357: char *fp = NULL;
1.194 markus 358: struct sshbuf *msg;
1.221 djm 359: struct sshkey *key = NULL;
1.195 djm 360: struct identity *id;
1.251 djm 361: struct notifier_ctx *notifier = NULL;
1.194 markus 362:
1.195 djm 363: if ((msg = sshbuf_new()) == NULL)
1.266 ! djm 364: fatal_f("sshbuf_new failed");
1.221 djm 365: if ((r = sshkey_froms(e->request, &key)) != 0 ||
366: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 367: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
1.266 ! djm 368: error_fr(r, "parse");
1.225 djm 369: goto send;
370: }
371:
1.221 djm 372: if ((id = lookup_identity(key)) == NULL) {
1.266 ! djm 373: verbose_f("%s key not found", sshkey_type(key));
1.195 djm 374: goto send;
375: }
376: if (id->confirm && confirm_key(id) != 0) {
1.266 ! djm 377: verbose_f("user refused key");
1.195 djm 378: goto send;
379: }
1.258 djm 380: if (sshkey_is_sk(id->key)) {
381: if (strncmp(id->key->sk_application, "ssh:", 4) != 0 &&
382: !check_websafe_message_contents(key, data, dlen)) {
383: /* error already logged */
384: goto send;
385: }
386: if ((id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
387: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
388: SSH_FP_DEFAULT)) == NULL)
1.266 ! djm 389: fatal_f("fingerprint failed");
1.258 djm 390: notifier = notify_start(0,
391: "Confirm user presence for key %s %s",
392: sshkey_type(id->key), fp);
393: }
1.251 djm 394: }
1.263 djm 395: /* XXX support PIN required FIDO keys */
1.251 djm 396: if ((r = sshkey_sign(id->key, &signature, &slen,
397: data, dlen, agent_decode_alg(key, flags),
1.263 djm 398: id->sk_provider, NULL, compat)) != 0) {
1.266 ! djm 399: error_fr(r, "sshkey_sign");
1.251 djm 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)
1.266 ! djm 411: fatal_fr(r, "compose");
1.194 markus 412: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
1.266 ! djm 413: fatal_fr(r, "compose failure");
1.194 markus 414:
415: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 ! djm 416: fatal_fr(r, "enqueue");
1.194 markus 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) {
1.266 ! djm 431: error_fr(r, "parse key");
1.221 djm 432: goto done;
433: }
434: if ((id = lookup_identity(key)) == NULL) {
1.266 ! djm 435: debug_f("key not found");
1.221 djm 436: goto done;
437: }
438: /* We have this key, free it. */
439: if (idtab->nentries < 1)
1.266 ! djm 440: fatal_f("internal error: nentries %d", idtab->nentries);
1.221 djm 441: TAILQ_REMOVE(&idtab->idlist, id, next);
442: free_identity(id);
443: idtab->nentries--;
444: sshkey_free(key);
445: success = 1;
446: done:
1.194 markus 447: send_status(e, success);
1.1 deraadt 448: }
449:
1.55 itojun 450: static void
1.221 djm 451: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 452: {
1.78 provos 453: Identity *id;
1.21 markus 454:
455: /* Loop over all identities and clear the keys. */
1.221 djm 456: for (id = TAILQ_FIRST(&idtab->idlist); id;
457: id = TAILQ_FIRST(&idtab->idlist)) {
458: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 459: free_identity(id);
1.21 markus 460: }
461:
462: /* Mark that there are no identities. */
1.221 djm 463: idtab->nentries = 0;
1.21 markus 464:
465: /* Send success. */
1.194 markus 466: send_status(e, 1);
1.1 deraadt 467: }
468:
1.155 dtucker 469: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 470: static time_t
1.89 markus 471: reaper(void)
472: {
1.175 dtucker 473: time_t deadline = 0, now = monotime();
1.89 markus 474: Identity *id, *nxt;
475:
1.221 djm 476: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
477: nxt = TAILQ_NEXT(id, next);
478: if (id->death == 0)
479: continue;
480: if (now >= id->death) {
481: debug("expiring key '%s'", id->comment);
482: TAILQ_REMOVE(&idtab->idlist, id, next);
483: free_identity(id);
484: idtab->nentries--;
485: } else
486: deadline = (deadline == 0) ? id->death :
487: MINIMUM(deadline, id->death);
1.89 markus 488: }
1.155 dtucker 489: if (deadline == 0 || deadline <= now)
490: return 0;
491: else
492: return (deadline - now);
1.89 markus 493: }
494:
495: static void
1.221 djm 496: process_add_identity(SocketEntry *e)
1.1 deraadt 497: {
1.157 canacar 498: Identity *id;
1.194 markus 499: int success = 0, confirm = 0;
1.257 markus 500: u_int seconds = 0, maxsign;
1.238 djm 501: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.254 djm 502: char canonical_provider[PATH_MAX];
1.174 dtucker 503: time_t death = 0;
1.194 markus 504: struct sshkey *k = NULL;
505: u_char ctype;
506: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 507:
1.221 djm 508: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
509: k == NULL ||
1.194 markus 510: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
1.266 ! djm 511: error_fr(r, "parse");
1.194 markus 512: goto err;
513: }
514: while (sshbuf_len(e->request)) {
515: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
1.266 ! djm 516: error_fr(r, "parse constraint type");
1.194 markus 517: goto err;
518: }
519: switch (ctype) {
1.94 markus 520: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 521: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
1.266 ! djm 522: error_fr(r, "parse lifetime constraint");
1.194 markus 523: goto err;
524: }
525: death = monotime() + seconds;
1.94 markus 526: break;
1.107 markus 527: case SSH_AGENT_CONSTRAIN_CONFIRM:
528: confirm = 1;
529: break;
1.228 markus 530: case SSH_AGENT_CONSTRAIN_MAXSIGN:
531: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
1.266 ! djm 532: error_fr(r, "parse maxsign constraint");
1.228 markus 533: goto err;
534: }
535: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
1.266 ! djm 536: error_fr(r, "enable maxsign");
1.228 markus 537: goto err;
538: }
539: break;
1.238 djm 540: case SSH_AGENT_CONSTRAIN_EXTENSION:
541: if ((r = sshbuf_get_cstring(e->request,
542: &ext_name, NULL)) != 0) {
1.266 ! djm 543: error_fr(r, "parse constraint extension");
1.238 djm 544: goto err;
545: }
1.266 ! djm 546: debug_f("constraint ext %s", ext_name);
1.238 djm 547: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
548: if (sk_provider != NULL) {
549: error("%s already set", ext_name);
550: goto err;
551: }
552: if ((r = sshbuf_get_cstring(e->request,
553: &sk_provider, NULL)) != 0) {
1.266 ! djm 554: error_fr(r, "parse %s", ext_name);
1.238 djm 555: goto err;
556: }
557: } else {
1.266 ! djm 558: error_f("unsupported constraint \"%s\"",
! 559: ext_name);
1.238 djm 560: goto err;
561: }
562: free(ext_name);
563: break;
1.94 markus 564: default:
1.266 ! djm 565: error_f("Unknown constraint %d", ctype);
1.194 markus 566: err:
1.238 djm 567: free(sk_provider);
568: free(ext_name);
1.194 markus 569: sshbuf_reset(e->request);
1.173 djm 570: free(comment);
1.194 markus 571: sshkey_free(k);
1.158 djm 572: goto send;
1.94 markus 573: }
574: }
1.238 djm 575: if (sk_provider != NULL) {
1.240 markus 576: if (!sshkey_is_sk(k)) {
1.255 naddy 577: error("Cannot add provider: %s is not an "
578: "authenticator-hosted key", sshkey_type(k));
1.238 djm 579: free(sk_provider);
580: goto send;
581: }
1.254 djm 582: if (strcasecmp(sk_provider, "internal") == 0) {
1.266 ! djm 583: debug_f("internal provider");
1.254 djm 584: } else {
585: if (realpath(sk_provider, canonical_provider) == NULL) {
586: verbose("failed provider \"%.100s\": "
587: "realpath: %s", sk_provider,
588: strerror(errno));
589: free(sk_provider);
590: goto send;
591: }
1.238 djm 592: free(sk_provider);
1.254 djm 593: sk_provider = xstrdup(canonical_provider);
594: if (match_pattern_list(sk_provider,
1.260 djm 595: allowed_providers, 0) != 1) {
1.254 djm 596: error("Refusing add key: "
1.260 djm 597: "provider %s not allowed", sk_provider);
1.254 djm 598: free(sk_provider);
599: goto send;
600: }
1.238 djm 601: }
1.242 markus 602: }
603: if ((r = sshkey_shield_private(k)) != 0) {
1.266 ! djm 604: error_fr(r, "shield private");
1.242 markus 605: goto err;
1.238 djm 606: }
1.194 markus 607:
1.158 djm 608: success = 1;
1.106 marc 609: if (lifetime && !death)
1.175 dtucker 610: death = monotime() + lifetime;
1.221 djm 611: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 612: id = xcalloc(1, sizeof(Identity));
1.221 djm 613: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 614: /* Increment the number of identities. */
1.221 djm 615: idtab->nentries++;
1.33 markus 616: } else {
1.228 markus 617: /* key state might have been updated */
618: sshkey_free(id->key);
1.173 djm 619: free(id->comment);
1.238 djm 620: free(id->sk_provider);
1.33 markus 621: }
1.228 markus 622: id->key = k;
1.157 canacar 623: id->comment = comment;
624: id->death = death;
625: id->confirm = confirm;
1.238 djm 626: id->sk_provider = sk_provider;
627:
628: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
629: SSH_FP_DEFAULT)) == NULL)
1.266 ! djm 630: fatal_f("sshkey_fingerprint failed");
! 631: debug_f("add %s %s \"%.100s\" (life: %u) (confirm: %u) "
! 632: "(provider: %s)", sshkey_ssh_name(k), fp, comment,
1.238 djm 633: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
634: free(fp);
1.33 markus 635: send:
1.194 markus 636: send_status(e, success);
1.1 deraadt 637: }
638:
1.88 markus 639: /* XXX todo: encrypt sensitive data with passphrase */
640: static void
641: process_lock_agent(SocketEntry *e, int lock)
642: {
1.203 dtucker 643: int r, success = 0, delay;
1.213 djm 644: char *passwd;
645: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 646: static u_int fail_count = 0;
647: size_t pwlen;
648:
1.226 djm 649: /*
650: * This is deliberately fatal: the user has requested that we lock,
651: * but we can't parse their request properly. The only safe thing to
652: * do is abort.
653: */
1.203 dtucker 654: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
1.266 ! djm 655: fatal_fr(r, "parse");
1.203 dtucker 656: if (pwlen == 0) {
657: debug("empty password not supported");
658: } else if (locked && !lock) {
659: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
660: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
661: fatal("bcrypt_pbkdf");
1.213 djm 662: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 663: debug("agent unlocked");
664: locked = 0;
665: fail_count = 0;
1.213 djm 666: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 667: success = 1;
668: } else {
669: /* delay in 0.1s increments up to 10s */
670: if (fail_count < 100)
671: fail_count++;
672: delay = 100000 * fail_count;
673: debug("unlock failed, delaying %0.1lf seconds",
674: (double)delay/1000000);
675: usleep(delay);
676: }
677: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 678: } else if (!locked && lock) {
1.203 dtucker 679: debug("agent locked");
1.88 markus 680: locked = 1;
1.203 dtucker 681: arc4random_buf(lock_salt, sizeof(lock_salt));
682: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 683: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 684: fatal("bcrypt_pbkdf");
1.88 markus 685: success = 1;
686: }
1.256 jsg 687: freezero(passwd, pwlen);
1.194 markus 688: send_status(e, success);
1.88 markus 689: }
690:
691: static void
1.221 djm 692: no_identities(SocketEntry *e)
1.88 markus 693: {
1.194 markus 694: struct sshbuf *msg;
695: int r;
1.88 markus 696:
1.194 markus 697: if ((msg = sshbuf_new()) == NULL)
1.266 ! djm 698: fatal_f("sshbuf_new failed");
1.221 djm 699: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 700: (r = sshbuf_put_u32(msg, 0)) != 0 ||
701: (r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 ! djm 702: fatal_fr(r, "compose");
1.194 markus 703: sshbuf_free(msg);
1.88 markus 704: }
1.59 markus 705:
1.163 markus 706: #ifdef ENABLE_PKCS11
1.59 markus 707: static void
1.158 djm 708: process_add_smartcard_key(SocketEntry *e)
1.59 markus 709: {
1.226 djm 710: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.253 djm 711: char **comments = NULL;
1.221 djm 712: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 713: u_int seconds;
1.174 dtucker 714: time_t death = 0;
1.194 markus 715: u_char type;
716: struct sshkey **keys = NULL, *k;
1.84 markus 717: Identity *id;
1.75 deraadt 718:
1.194 markus 719: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 720: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 ! djm 721: error_fr(r, "parse");
1.226 djm 722: goto send;
723: }
1.194 markus 724:
725: while (sshbuf_len(e->request)) {
1.226 djm 726: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
1.266 ! djm 727: error_fr(r, "parse type");
1.226 djm 728: goto send;
729: }
1.194 markus 730: switch (type) {
1.110 djm 731: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 732: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
1.266 ! djm 733: error_fr(r, "parse lifetime");
1.226 djm 734: goto send;
735: }
1.194 markus 736: death = monotime() + seconds;
1.110 djm 737: break;
738: case SSH_AGENT_CONSTRAIN_CONFIRM:
739: confirm = 1;
740: break;
741: default:
1.266 ! djm 742: error_f("Unknown constraint type %d", type);
1.158 djm 743: goto send;
1.110 djm 744: }
745: }
1.215 djm 746: if (realpath(provider, canonical_provider) == NULL) {
747: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
748: provider, strerror(errno));
749: goto send;
750: }
1.260 djm 751: if (match_pattern_list(canonical_provider, allowed_providers, 0) != 1) {
1.215 djm 752: verbose("refusing PKCS#11 add of \"%.100s\": "
1.260 djm 753: "provider not allowed", canonical_provider);
1.215 djm 754: goto send;
755: }
1.266 ! djm 756: debug_f("add %.100s", canonical_provider);
1.110 djm 757: if (lifetime && !death)
1.175 dtucker 758: death = monotime() + lifetime;
1.110 djm 759:
1.253 djm 760: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.163 markus 761: for (i = 0; i < count; i++) {
1.84 markus 762: k = keys[i];
1.221 djm 763: if (lookup_identity(k) == NULL) {
1.163 markus 764: id = xcalloc(1, sizeof(Identity));
1.84 markus 765: id->key = k;
1.253 djm 766: keys[i] = NULL; /* transferred */
1.215 djm 767: id->provider = xstrdup(canonical_provider);
1.253 djm 768: if (*comments[i] != '\0') {
769: id->comment = comments[i];
770: comments[i] = NULL; /* transferred */
771: } else {
772: id->comment = xstrdup(canonical_provider);
773: }
1.110 djm 774: id->death = death;
775: id->confirm = confirm;
1.221 djm 776: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
777: idtab->nentries++;
1.84 markus 778: success = 1;
779: }
1.253 djm 780: sshkey_free(keys[i]);
781: free(comments[i]);
1.59 markus 782: }
783: send:
1.173 djm 784: free(pin);
785: free(provider);
786: free(keys);
1.253 djm 787: free(comments);
1.194 markus 788: send_status(e, success);
1.59 markus 789: }
790:
791: static void
792: process_remove_smartcard_key(SocketEntry *e)
793: {
1.217 djm 794: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 795: int r, success = 0;
1.163 markus 796: Identity *id, *nxt;
1.59 markus 797:
1.194 markus 798: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 799: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 ! djm 800: error_fr(r, "parse");
1.226 djm 801: goto send;
802: }
1.173 djm 803: free(pin);
1.59 markus 804:
1.217 djm 805: if (realpath(provider, canonical_provider) == NULL) {
806: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
807: provider, strerror(errno));
808: goto send;
809: }
810:
1.266 ! djm 811: debug_f("remove %.100s", canonical_provider);
1.221 djm 812: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
813: nxt = TAILQ_NEXT(id, next);
814: /* Skip file--based keys */
815: if (id->provider == NULL)
816: continue;
817: if (!strcmp(canonical_provider, id->provider)) {
818: TAILQ_REMOVE(&idtab->idlist, id, next);
819: free_identity(id);
820: idtab->nentries--;
1.59 markus 821: }
822: }
1.217 djm 823: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 824: success = 1;
825: else
1.266 ! djm 826: error_f("pkcs11_del_provider failed");
1.218 deraadt 827: send:
1.173 djm 828: free(provider);
1.194 markus 829: send_status(e, success);
1.59 markus 830: }
1.163 markus 831: #endif /* ENABLE_PKCS11 */
1.59 markus 832:
1.264 djm 833: /*
834: * dispatch incoming message.
835: * returns 1 on success, 0 for incomplete messages or -1 on error.
836: */
1.223 djm 837: static int
838: process_message(u_int socknum)
1.1 deraadt 839: {
1.194 markus 840: u_int msg_len;
841: u_char type;
842: const u_char *cp;
843: int r;
1.223 djm 844: SocketEntry *e;
845:
1.266 ! djm 846: if (socknum >= sockets_alloc)
! 847: fatal_f("sock %u >= allocated %u", socknum, sockets_alloc);
1.223 djm 848: e = &sockets[socknum];
1.89 markus 849:
1.194 markus 850: if (sshbuf_len(e->input) < 5)
1.223 djm 851: return 0; /* Incomplete message header. */
1.194 markus 852: cp = sshbuf_ptr(e->input);
853: msg_len = PEEK_U32(cp);
1.223 djm 854: if (msg_len > AGENT_MAX_LEN) {
1.266 ! djm 855: debug_f("socket %u (fd=%d) message too long %u > %u",
! 856: socknum, e->fd, msg_len, AGENT_MAX_LEN);
1.223 djm 857: return -1;
1.21 markus 858: }
1.194 markus 859: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 860: return 0; /* Incomplete message body. */
1.87 markus 861:
862: /* move the current input to e->request */
1.194 markus 863: sshbuf_reset(e->request);
864: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 865: (r = sshbuf_get_u8(e->request, &type)) != 0) {
866: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
867: r == SSH_ERR_STRING_TOO_LARGE) {
1.266 ! djm 868: error_fr(r, "parse");
1.223 djm 869: return -1;
870: }
1.266 ! djm 871: fatal_fr(r, "parse");
1.223 djm 872: }
873:
1.266 ! djm 874: debug_f("socket %u (fd=%d) type %d", socknum, e->fd, type);
1.21 markus 875:
1.230 djm 876: /* check whether agent is locked */
1.88 markus 877: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 878: sshbuf_reset(e->request);
1.88 markus 879: switch (type) {
880: case SSH2_AGENTC_REQUEST_IDENTITIES:
881: /* send empty lists */
1.221 djm 882: no_identities(e);
1.88 markus 883: break;
884: default:
885: /* send a fail message for all other request types */
1.194 markus 886: send_status(e, 0);
1.88 markus 887: }
1.264 djm 888: return 1;
1.88 markus 889: }
890:
1.21 markus 891: switch (type) {
1.88 markus 892: case SSH_AGENTC_LOCK:
893: case SSH_AGENTC_UNLOCK:
894: process_lock_agent(e, type == SSH_AGENTC_LOCK);
895: break;
1.21 markus 896: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 897: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 898: break;
899: /* ssh2 */
900: case SSH2_AGENTC_SIGN_REQUEST:
901: process_sign_request2(e);
902: break;
903: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 904: process_request_identities(e);
1.33 markus 905: break;
906: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 907: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 908: process_add_identity(e);
1.33 markus 909: break;
910: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 911: process_remove_identity(e);
1.33 markus 912: break;
913: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 914: process_remove_all_identities(e);
1.21 markus 915: break;
1.163 markus 916: #ifdef ENABLE_PKCS11
1.59 markus 917: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 918: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 919: process_add_smartcard_key(e);
1.75 deraadt 920: break;
1.59 markus 921: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
922: process_remove_smartcard_key(e);
1.75 deraadt 923: break;
1.163 markus 924: #endif /* ENABLE_PKCS11 */
1.21 markus 925: default:
926: /* Unknown message. Respond with failure. */
927: error("Unknown message %d", type);
1.194 markus 928: sshbuf_reset(e->request);
929: send_status(e, 0);
1.21 markus 930: break;
931: }
1.264 djm 932: return 1;
1.1 deraadt 933: }
934:
1.55 itojun 935: static void
1.73 stevesk 936: new_socket(sock_type type, int fd)
1.1 deraadt 937: {
1.112 markus 938: u_int i, old_alloc, new_alloc;
1.96 deraadt 939:
1.119 djm 940: set_nonblock(fd);
1.21 markus 941:
942: if (fd > max_fd)
943: max_fd = fd;
944:
945: for (i = 0; i < sockets_alloc; i++)
946: if (sockets[i].type == AUTH_UNUSED) {
947: sockets[i].fd = fd;
1.266 ! djm 948: if ((sockets[i].input = sshbuf_new()) == NULL ||
! 949: (sockets[i].output = sshbuf_new()) == NULL ||
! 950: (sockets[i].request = sshbuf_new()) == NULL)
! 951: fatal_f("sshbuf_new failed");
1.112 markus 952: sockets[i].type = type;
1.21 markus 953: return;
954: }
955: old_alloc = sockets_alloc;
1.112 markus 956: new_alloc = sockets_alloc + 10;
1.200 deraadt 957: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 958: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 959: sockets[i].type = AUTH_UNUSED;
1.112 markus 960: sockets_alloc = new_alloc;
1.21 markus 961: sockets[old_alloc].fd = fd;
1.266 ! djm 962: if ((sockets[old_alloc].input = sshbuf_new()) == NULL ||
! 963: (sockets[old_alloc].output = sshbuf_new()) == NULL ||
! 964: (sockets[old_alloc].request = sshbuf_new()) == NULL)
! 965: fatal_f("sshbuf_new failed");
1.112 markus 966: sockets[old_alloc].type = type;
1.1 deraadt 967: }
968:
1.55 itojun 969: static int
1.223 djm 970: handle_socket_read(u_int socknum)
1.1 deraadt 971: {
1.223 djm 972: struct sockaddr_un sunaddr;
973: socklen_t slen;
974: uid_t euid;
975: gid_t egid;
976: int fd;
977:
978: slen = sizeof(sunaddr);
979: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 980: if (fd == -1) {
1.223 djm 981: error("accept from AUTH_SOCKET: %s", strerror(errno));
982: return -1;
983: }
1.237 deraadt 984: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 985: error("getpeereid %d failed: %s", fd, strerror(errno));
986: close(fd);
987: return -1;
988: }
989: if ((euid != 0) && (getuid() != euid)) {
990: error("uid mismatch: peer euid %u != uid %u",
991: (u_int) euid, (u_int) getuid());
992: close(fd);
993: return -1;
994: }
995: new_socket(AUTH_CONNECTION, fd);
996: return 0;
997: }
998:
999: static int
1000: handle_conn_read(u_int socknum)
1001: {
1.233 djm 1002: char buf[AGENT_RBUF_LEN];
1.223 djm 1003: ssize_t len;
1004: int r;
1005:
1006: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1007: if (len == -1) {
1008: if (errno == EAGAIN || errno == EINTR)
1009: return 0;
1.266 ! djm 1010: error_f("read error on socket %u (fd %d): %s",
! 1011: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1012: }
1013: return -1;
1014: }
1015: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1.266 ! djm 1016: fatal_fr(r, "compose");
1.223 djm 1017: explicit_bzero(buf, sizeof(buf));
1.264 djm 1018: for (;;) {
1019: if ((r = process_message(socknum)) == -1)
1020: return -1;
1021: else if (r == 0)
1022: break;
1023: }
1.223 djm 1024: return 0;
1025: }
1026:
1027: static int
1028: handle_conn_write(u_int socknum)
1029: {
1030: ssize_t len;
1031: int r;
1032:
1033: if (sshbuf_len(sockets[socknum].output) == 0)
1034: return 0; /* shouldn't happen */
1035: if ((len = write(sockets[socknum].fd,
1036: sshbuf_ptr(sockets[socknum].output),
1037: sshbuf_len(sockets[socknum].output))) <= 0) {
1038: if (len == -1) {
1039: if (errno == EAGAIN || errno == EINTR)
1040: return 0;
1.266 ! djm 1041: error_f("read error on socket %u (fd %d): %s",
! 1042: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1043: }
1044: return -1;
1045: }
1046: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1.266 ! djm 1047: fatal_fr(r, "consume");
1.223 djm 1048: return 0;
1049: }
1050:
1051: static void
1.231 djm 1052: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1053: {
1054: size_t i;
1.231 djm 1055: u_int socknum, activefds = npfd;
1.223 djm 1056:
1057: for (i = 0; i < npfd; i++) {
1058: if (pfd[i].revents == 0)
1059: continue;
1060: /* Find sockets entry */
1061: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1062: if (sockets[socknum].type != AUTH_SOCKET &&
1063: sockets[socknum].type != AUTH_CONNECTION)
1064: continue;
1065: if (pfd[i].fd == sockets[socknum].fd)
1066: break;
1067: }
1068: if (socknum >= sockets_alloc) {
1.266 ! djm 1069: error_f("no socket for fd %d", pfd[i].fd);
1.223 djm 1070: continue;
1071: }
1072: /* Process events */
1073: switch (sockets[socknum].type) {
1074: case AUTH_SOCKET:
1.231 djm 1075: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1076: break;
1077: if (npfd > maxfds) {
1078: debug3("out of fds (active %u >= limit %u); "
1079: "skipping accept", activefds, maxfds);
1080: break;
1081: }
1082: if (handle_socket_read(socknum) == 0)
1083: activefds++;
1.223 djm 1084: break;
1085: case AUTH_CONNECTION:
1086: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1087: handle_conn_read(socknum) != 0) {
1.231 djm 1088: goto close_sock;
1089: }
1090: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1091: handle_conn_write(socknum) != 0) {
1092: close_sock:
1093: if (activefds == 0)
1094: fatal("activefds == 0 at close_sock");
1.223 djm 1095: close_socket(&sockets[socknum]);
1.231 djm 1096: activefds--;
1.223 djm 1097: break;
1098: }
1099: break;
1100: default:
1101: break;
1102: }
1103: }
1104: }
1105:
1106: static int
1.231 djm 1107: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1108: {
1109: struct pollfd *pfd = *pfdp;
1110: size_t i, j, npfd = 0;
1.174 dtucker 1111: time_t deadline;
1.233 djm 1112: int r;
1.46 markus 1113:
1.223 djm 1114: /* Count active sockets */
1.46 markus 1115: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1116: switch (sockets[i].type) {
1117: case AUTH_SOCKET:
1118: case AUTH_CONNECTION:
1.223 djm 1119: npfd++;
1.21 markus 1120: break;
1121: case AUTH_UNUSED:
1122: break;
1123: default:
1124: fatal("Unknown socket type %d", sockets[i].type);
1125: break;
1126: }
1.46 markus 1127: }
1.223 djm 1128: if (npfd != *npfdp &&
1129: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1.266 ! djm 1130: fatal_f("recallocarray failed");
1.223 djm 1131: *pfdp = pfd;
1132: *npfdp = npfd;
1.46 markus 1133:
1.223 djm 1134: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1135: switch (sockets[i].type) {
1136: case AUTH_SOCKET:
1.231 djm 1137: if (npfd > maxfds) {
1138: debug3("out of fds (active %zu >= limit %u); "
1139: "skipping arming listener", npfd, maxfds);
1140: break;
1141: }
1142: pfd[j].fd = sockets[i].fd;
1143: pfd[j].revents = 0;
1144: pfd[j].events = POLLIN;
1145: j++;
1146: break;
1.46 markus 1147: case AUTH_CONNECTION:
1.223 djm 1148: pfd[j].fd = sockets[i].fd;
1149: pfd[j].revents = 0;
1.233 djm 1150: /*
1151: * Only prepare to read if we can handle a full-size
1152: * input read buffer and enqueue a max size reply..
1153: */
1154: if ((r = sshbuf_check_reserve(sockets[i].input,
1155: AGENT_RBUF_LEN)) == 0 &&
1156: (r = sshbuf_check_reserve(sockets[i].output,
1157: AGENT_MAX_LEN)) == 0)
1158: pfd[j].events = POLLIN;
1.266 ! djm 1159: else if (r != SSH_ERR_NO_BUFFER_SPACE)
! 1160: fatal_fr(r, "reserve");
1.194 markus 1161: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1162: pfd[j].events |= POLLOUT;
1163: j++;
1.46 markus 1164: break;
1165: default:
1166: break;
1167: }
1168: }
1.155 dtucker 1169: deadline = reaper();
1170: if (parent_alive_interval != 0)
1171: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1172: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1173: if (deadline == 0) {
1.224 djm 1174: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1175: } else {
1.223 djm 1176: if (deadline > INT_MAX / 1000)
1177: *timeoutp = INT_MAX / 1000;
1178: else
1179: *timeoutp = deadline * 1000;
1.155 dtucker 1180: }
1.46 markus 1181: return (1);
1.21 markus 1182: }
1183:
1.55 itojun 1184: static void
1.113 markus 1185: cleanup_socket(void)
1.15 markus 1186: {
1.187 djm 1187: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1188: return;
1.266 ! djm 1189: debug_f("cleanup");
1.48 deraadt 1190: if (socket_name[0])
1191: unlink(socket_name);
1192: if (socket_dir[0])
1193: rmdir(socket_dir);
1.10 markus 1194: }
1195:
1.114 markus 1196: void
1.15 markus 1197: cleanup_exit(int i)
1198: {
1.113 markus 1199: cleanup_socket();
1200: _exit(i);
1.15 markus 1201: }
1202:
1.135 deraadt 1203: /*ARGSUSED*/
1.55 itojun 1204: static void
1.48 deraadt 1205: cleanup_handler(int sig)
1206: {
1.113 markus 1207: cleanup_socket();
1.163 markus 1208: #ifdef ENABLE_PKCS11
1209: pkcs11_terminate();
1210: #endif
1.48 deraadt 1211: _exit(2);
1.113 markus 1212: }
1213:
1.68 markus 1214: static void
1.155 dtucker 1215: check_parent_exists(void)
1.68 markus 1216: {
1.172 dtucker 1217: /*
1218: * If our parent has exited then getppid() will return (pid_t)1,
1219: * so testing for that should be safe.
1220: */
1221: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1222: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1223: cleanup_socket();
1224: _exit(2);
1.68 markus 1225: }
1.48 deraadt 1226: }
1227:
1.55 itojun 1228: static void
1.50 itojun 1229: usage(void)
1.15 markus 1230: {
1.184 deraadt 1231: fprintf(stderr,
1.250 jmc 1232: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.261 jmc 1233: " [-P allowed_providers] [-t life]\n"
1.260 djm 1234: " ssh-agent [-a bind_address] [-E fingerprint_hash] [-P allowed_providers]\n"
1.259 dtucker 1235: " [-t life] command [arg ...]\n"
1.250 jmc 1236: " ssh-agent [-c | -s] -k\n");
1.21 markus 1237: exit(1);
1.15 markus 1238: }
1239:
1.2 provos 1240: int
1241: main(int ac, char **av)
1.1 deraadt 1242: {
1.201 djm 1243: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.265 djm 1244: int sock, ch, result, saved_errno;
1.96 deraadt 1245: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1246: struct rlimit rlim;
1.96 deraadt 1247: extern int optind;
1.98 stevesk 1248: extern char *optarg;
1.21 markus 1249: pid_t pid;
1.96 deraadt 1250: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1251: size_t len;
1.189 djm 1252: mode_t prev_mask;
1.224 djm 1253: int timeout = -1; /* INFTIM */
1.223 djm 1254: struct pollfd *pfd = NULL;
1255: size_t npfd = 0;
1.231 djm 1256: u_int maxfds;
1.123 djm 1257:
1258: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1259: sanitise_stdfd();
1.99 markus 1260:
1261: /* drop */
1262: setegid(getgid());
1263: setgid(getgid());
1.53 markus 1264:
1.231 djm 1265: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1266: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1267:
1.185 markus 1268: #ifdef WITH_OPENSSL
1.170 djm 1269: OpenSSL_add_all_algorithms();
1.185 markus 1270: #endif
1.21 markus 1271:
1.258 djm 1272: while ((ch = getopt(ac, av, "cDdksE:a:O:P:t:")) != -1) {
1.21 markus 1273: switch (ch) {
1.192 djm 1274: case 'E':
1275: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1276: if (fingerprint_hash == -1)
1277: fatal("Invalid hash algorithm \"%s\"", optarg);
1278: break;
1.21 markus 1279: case 'c':
1280: if (s_flag)
1281: usage();
1282: c_flag++;
1283: break;
1284: case 'k':
1285: k_flag++;
1.258 djm 1286: break;
1287: case 'O':
1288: if (strcmp(optarg, "no-restrict-websafe") == 0)
1289: restrict_websafe = 0;
1290: else
1291: fatal("Unknown -O option");
1.21 markus 1292: break;
1.215 djm 1293: case 'P':
1.260 djm 1294: if (allowed_providers != NULL)
1.215 djm 1295: fatal("-P option already specified");
1.260 djm 1296: allowed_providers = xstrdup(optarg);
1.215 djm 1297: break;
1.21 markus 1298: case 's':
1299: if (c_flag)
1300: usage();
1301: s_flag++;
1302: break;
1.57 markus 1303: case 'd':
1.201 djm 1304: if (d_flag || D_flag)
1.57 markus 1305: usage();
1306: d_flag++;
1307: break;
1.201 djm 1308: case 'D':
1309: if (d_flag || D_flag)
1310: usage();
1311: D_flag++;
1312: break;
1.86 markus 1313: case 'a':
1314: agentsocket = optarg;
1.106 marc 1315: break;
1316: case 't':
1317: if ((lifetime = convtime(optarg)) == -1) {
1318: fprintf(stderr, "Invalid lifetime\n");
1319: usage();
1320: }
1.86 markus 1321: break;
1.21 markus 1322: default:
1323: usage();
1324: }
1325: }
1326: ac -= optind;
1327: av += optind;
1328:
1.201 djm 1329: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1330: usage();
1331:
1.260 djm 1332: if (allowed_providers == NULL)
1.262 djm 1333: allowed_providers = xstrdup(DEFAULT_ALLOWED_PROVIDERS);
1.215 djm 1334:
1.85 markus 1335: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1336: shell = getenv("SHELL");
1.161 tobias 1337: if (shell != NULL && (len = strlen(shell)) > 2 &&
1338: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1339: c_flag = 1;
1340: }
1341: if (k_flag) {
1.136 deraadt 1342: const char *errstr = NULL;
1343:
1.21 markus 1344: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1345: if (pidstr == NULL) {
1346: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1347: SSH_AGENTPID_ENV_NAME);
1.21 markus 1348: exit(1);
1349: }
1.136 deraadt 1350: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1351: if (errstr) {
1352: fprintf(stderr,
1353: "%s=\"%s\", which is not a good PID: %s\n",
1354: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1355: exit(1);
1356: }
1357: if (kill(pid, SIGTERM) == -1) {
1358: perror("kill");
1359: exit(1);
1360: }
1361: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1362: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1363: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1364: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1365: exit(0);
1366: }
1.231 djm 1367:
1368: /*
1369: * Minimum file descriptors:
1370: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1371: * a few spare for libc / stack protectors / sanitisers, etc.
1372: */
1373: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1374: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1375: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1376: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1377: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1378:
1.21 markus 1379: parent_pid = getpid();
1380:
1.86 markus 1381: if (agentsocket == NULL) {
1382: /* Create private directory for agent socket */
1.171 djm 1383: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1384: if (mkdtemp(socket_dir) == NULL) {
1385: perror("mkdtemp: private socket dir");
1386: exit(1);
1387: }
1.91 mpech 1388: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1389: (long)parent_pid);
1.86 markus 1390: } else {
1391: /* Try to use specified agent socket */
1392: socket_dir[0] = '\0';
1393: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1394: }
1395:
1.23 markus 1396: /*
1397: * Create socket early so it will exist before command gets run from
1398: * the parent.
1399: */
1.189 djm 1400: prev_mask = umask(0177);
1.188 millert 1401: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1402: if (sock < 0) {
1.188 millert 1403: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1404: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1405: cleanup_exit(1);
1406: }
1.189 djm 1407: umask(prev_mask);
1.46 markus 1408:
1.23 markus 1409: /*
1410: * Fork, and have the parent execute the command, if any, or present
1411: * the socket data. The child continues as the authentication agent.
1412: */
1.201 djm 1413: if (D_flag || d_flag) {
1414: log_init(__progname,
1415: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1416: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1417: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1418: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1419: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1420: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1421: fflush(stdout);
1.57 markus 1422: goto skip;
1423: }
1.21 markus 1424: pid = fork();
1425: if (pid == -1) {
1426: perror("fork");
1.81 stevesk 1427: cleanup_exit(1);
1.21 markus 1428: }
1429: if (pid != 0) { /* Parent - execute the given command. */
1430: close(sock);
1.91 mpech 1431: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1432: if (ac == 0) {
1433: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1434: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1435: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1436: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1437: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1438: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1439: exit(0);
1440: }
1.36 deraadt 1441: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1442: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1443: perror("setenv");
1444: exit(1);
1445: }
1.21 markus 1446: execvp(av[0], av);
1447: perror(av[0]);
1448: exit(1);
1449: }
1.81 stevesk 1450: /* child */
1451: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1452:
1453: if (setsid() == -1) {
1.81 stevesk 1454: error("setsid: %s", strerror(errno));
1.67 stevesk 1455: cleanup_exit(1);
1456: }
1457:
1458: (void)chdir("/");
1.265 djm 1459: if (stdfd_devnull(1, 1, 1) == -1)
1.266 ! djm 1460: error_f("stdfd_devnull failed");
1.21 markus 1461:
1.41 markus 1462: /* deny core dumps, since memory contains unencrypted private keys */
1463: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1464: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1465: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1466: cleanup_exit(1);
1467: }
1.57 markus 1468:
1469: skip:
1.187 djm 1470:
1471: cleanup_pid = getpid();
1.163 markus 1472:
1473: #ifdef ENABLE_PKCS11
1474: pkcs11_init(0);
1475: #endif
1.21 markus 1476: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1477: if (ac > 0)
1478: parent_alive_interval = 10;
1.33 markus 1479: idtab_init();
1.252 dtucker 1480: ssh_signal(SIGPIPE, SIG_IGN);
1481: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1482: ssh_signal(SIGHUP, cleanup_handler);
1483: ssh_signal(SIGTERM, cleanup_handler);
1.205 djm 1484:
1.215 djm 1485: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1486: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1487:
1.21 markus 1488: while (1) {
1.231 djm 1489: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1490: result = poll(pfd, npfd, timeout);
1.154 dtucker 1491: saved_errno = errno;
1.155 dtucker 1492: if (parent_alive_interval != 0)
1493: check_parent_exists();
1494: (void) reaper(); /* remove expired keys */
1.237 deraadt 1495: if (result == -1) {
1.154 dtucker 1496: if (saved_errno == EINTR)
1.21 markus 1497: continue;
1.223 djm 1498: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1499: } else if (result > 0)
1.231 djm 1500: after_poll(pfd, npfd, maxfds);
1.15 markus 1501: }
1.21 markus 1502: /* NOTREACHED */
1.1 deraadt 1503: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-agent.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh