Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.269
1.269 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.268 2021/01/11 02:12:58 dtucker 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) */
1.268 dtucker 153: static int 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);
1.194 markus 164: sshbuf_free(e->input);
165: sshbuf_free(e->output);
166: sshbuf_free(e->request);
1.269 ! djm 167: memset(e, '\0', sizeof(*e));
! 168: e->fd = -1;
! 169: e->type = AUTH_UNUSED;
1.101 stevesk 170: }
171:
172: static void
1.33 markus 173: idtab_init(void)
1.1 deraadt 174: {
1.221 djm 175: idtab = xcalloc(1, sizeof(*idtab));
176: TAILQ_INIT(&idtab->idlist);
177: idtab->nentries = 0;
1.33 markus 178: }
179:
1.89 markus 180: static void
181: free_identity(Identity *id)
182: {
1.194 markus 183: sshkey_free(id->key);
1.173 djm 184: free(id->provider);
185: free(id->comment);
1.238 djm 186: free(id->sk_provider);
1.173 djm 187: free(id);
1.89 markus 188: }
189:
1.33 markus 190: /* return matching private key for given public key */
1.78 provos 191: static Identity *
1.221 djm 192: lookup_identity(struct sshkey *key)
1.33 markus 193: {
1.78 provos 194: Identity *id;
195:
1.221 djm 196: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 197: if (sshkey_equal(key, id->key))
1.78 provos 198: return (id);
1.33 markus 199: }
1.78 provos 200: return (NULL);
201: }
202:
1.107 markus 203: /* Check confirmation of keysign request */
204: static int
205: confirm_key(Identity *id)
206: {
1.122 djm 207: char *p;
1.107 markus 208: int ret = -1;
209:
1.194 markus 210: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 211: if (p != NULL &&
212: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 213: id->comment, p))
214: ret = 0;
1.173 djm 215: free(p);
1.122 djm 216:
1.107 markus 217: return (ret);
218: }
219:
1.194 markus 220: static void
221: send_status(SocketEntry *e, int success)
222: {
223: int r;
224:
225: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
226: (r = sshbuf_put_u8(e->output, success ?
227: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
1.266 djm 228: fatal_fr(r, "compose");
1.194 markus 229: }
230:
1.33 markus 231: /* send list of supported public keys to 'client' */
1.55 itojun 232: static void
1.221 djm 233: process_request_identities(SocketEntry *e)
1.33 markus 234: {
1.96 deraadt 235: Identity *id;
1.194 markus 236: struct sshbuf *msg;
237: int r;
1.1 deraadt 238:
1.269 ! djm 239: debug2_f("entering");
! 240:
1.194 markus 241: if ((msg = sshbuf_new()) == NULL)
1.266 djm 242: fatal_f("sshbuf_new failed");
1.221 djm 243: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
244: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
1.266 djm 245: fatal_fr(r, "compose");
1.221 djm 246: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 247: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
248: != 0 ||
1.221 djm 249: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
1.266 djm 250: error_fr(r, "compose key/comment");
1.220 djm 251: continue;
1.33 markus 252: }
1.21 markus 253: }
1.194 markus 254: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 255: fatal_fr(r, "enqueue");
1.194 markus 256: sshbuf_free(msg);
1.1 deraadt 257: }
258:
1.33 markus 259:
1.208 markus 260: static char *
261: agent_decode_alg(struct sshkey *key, u_int flags)
262: {
263: if (key->type == KEY_RSA) {
264: if (flags & SSH_AGENT_RSA_SHA2_256)
265: return "rsa-sha2-256";
266: else if (flags & SSH_AGENT_RSA_SHA2_512)
267: return "rsa-sha2-512";
1.235 djm 268: } else if (key->type == KEY_RSA_CERT) {
269: if (flags & SSH_AGENT_RSA_SHA2_256)
270: return "rsa-sha2-256-cert-v01@openssh.com";
271: else if (flags & SSH_AGENT_RSA_SHA2_512)
272: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 273: }
274: return NULL;
275: }
276:
1.258 djm 277: /*
278: * This function inspects a message to be signed by a FIDO key that has a
279: * web-like application string (i.e. one that does not begin with "ssh:".
280: * It checks that the message is one of those expected for SSH operations
281: * (pubkey userauth, sshsig, CA key signing) to exclude signing challenges
282: * for the web.
283: */
284: static int
285: check_websafe_message_contents(struct sshkey *key,
286: const u_char *msg, size_t len)
287: {
288: int matched = 0;
289: struct sshbuf *b;
290: u_char m, n;
291: char *cp1 = NULL, *cp2 = NULL;
292: int r;
293: struct sshkey *mkey = NULL;
294:
295: if ((b = sshbuf_from(msg, len)) == NULL)
1.266 djm 296: fatal_f("sshbuf_new");
1.258 djm 297:
298: /* SSH userauth request */
299: if ((r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* sess_id */
300: (r = sshbuf_get_u8(b, &m)) == 0 && /* SSH2_MSG_USERAUTH_REQUEST */
301: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* server user */
302: (r = sshbuf_get_cstring(b, &cp1, NULL)) == 0 && /* service */
303: (r = sshbuf_get_cstring(b, &cp2, NULL)) == 0 && /* method */
304: (r = sshbuf_get_u8(b, &n)) == 0 && /* sig-follows */
305: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* alg */
306: (r = sshkey_froms(b, &mkey)) == 0 && /* key */
307: sshbuf_len(b) == 0) {
1.266 djm 308: debug_f("parsed userauth");
1.258 djm 309: if (m == SSH2_MSG_USERAUTH_REQUEST && n == 1 &&
310: strcmp(cp1, "ssh-connection") == 0 &&
311: strcmp(cp2, "publickey") == 0 &&
312: sshkey_equal(key, mkey)) {
1.266 djm 313: debug_f("well formed userauth");
1.258 djm 314: matched = 1;
315: }
316: }
317: free(cp1);
318: free(cp2);
319: sshkey_free(mkey);
320: sshbuf_free(b);
321: if (matched)
322: return 1;
323:
324: if ((b = sshbuf_from(msg, len)) == NULL)
1.266 djm 325: fatal_f("sshbuf_new");
1.258 djm 326: cp1 = cp2 = NULL;
327: mkey = NULL;
328:
329: /* SSHSIG */
330: if ((r = sshbuf_cmp(b, 0, "SSHSIG", 6)) == 0 &&
331: (r = sshbuf_consume(b, 6)) == 0 &&
332: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* namespace */
333: (r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* reserved */
334: (r = sshbuf_get_cstring(b, NULL, NULL)) == 0 && /* hashalg */
335: (r = sshbuf_get_string_direct(b, NULL, NULL)) == 0 && /* H(msg) */
336: sshbuf_len(b) == 0) {
1.266 djm 337: debug_f("parsed sshsig");
1.258 djm 338: matched = 1;
339: }
340:
341: sshbuf_free(b);
342: if (matched)
343: return 1;
344:
345: /* XXX CA signature operation */
346:
347: error("web-origin key attempting to sign non-SSH message");
348: return 0;
349: }
350:
1.33 markus 351: /* ssh2 only */
1.55 itojun 352: static void
1.33 markus 353: process_sign_request2(SocketEntry *e)
354: {
1.221 djm 355: const u_char *data;
356: u_char *signature = NULL;
357: size_t dlen, slen = 0;
1.194 markus 358: u_int compat = 0, flags;
1.247 djm 359: int r, ok = -1;
1.251 djm 360: char *fp = NULL;
1.194 markus 361: struct sshbuf *msg;
1.221 djm 362: struct sshkey *key = NULL;
1.195 djm 363: struct identity *id;
1.251 djm 364: struct notifier_ctx *notifier = NULL;
1.194 markus 365:
1.195 djm 366: if ((msg = sshbuf_new()) == NULL)
1.266 djm 367: fatal_f("sshbuf_new failed");
1.221 djm 368: if ((r = sshkey_froms(e->request, &key)) != 0 ||
369: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 370: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
1.266 djm 371: error_fr(r, "parse");
1.225 djm 372: goto send;
373: }
374:
1.221 djm 375: if ((id = lookup_identity(key)) == NULL) {
1.266 djm 376: verbose_f("%s key not found", sshkey_type(key));
1.195 djm 377: goto send;
378: }
379: if (id->confirm && confirm_key(id) != 0) {
1.266 djm 380: verbose_f("user refused key");
1.195 djm 381: goto send;
382: }
1.258 djm 383: if (sshkey_is_sk(id->key)) {
384: if (strncmp(id->key->sk_application, "ssh:", 4) != 0 &&
385: !check_websafe_message_contents(key, data, dlen)) {
386: /* error already logged */
387: goto send;
388: }
389: if ((id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
390: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
391: SSH_FP_DEFAULT)) == NULL)
1.266 djm 392: fatal_f("fingerprint failed");
1.258 djm 393: notifier = notify_start(0,
394: "Confirm user presence for key %s %s",
395: sshkey_type(id->key), fp);
396: }
1.251 djm 397: }
1.263 djm 398: /* XXX support PIN required FIDO keys */
1.251 djm 399: if ((r = sshkey_sign(id->key, &signature, &slen,
400: data, dlen, agent_decode_alg(key, flags),
1.263 djm 401: id->sk_provider, NULL, compat)) != 0) {
1.266 djm 402: error_fr(r, "sshkey_sign");
1.251 djm 403: goto send;
1.33 markus 404: }
1.195 djm 405: /* Success */
406: ok = 0;
407: send:
1.267 djm 408: notify_complete(notifier, "User presence confirmed");
1.195 djm 409: sshkey_free(key);
1.251 djm 410: free(fp);
1.33 markus 411: if (ok == 0) {
1.194 markus 412: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
413: (r = sshbuf_put_string(msg, signature, slen)) != 0)
1.266 djm 414: fatal_fr(r, "compose");
1.194 markus 415: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
1.266 djm 416: fatal_fr(r, "compose failure");
1.194 markus 417:
418: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 419: fatal_fr(r, "enqueue");
1.194 markus 420:
421: sshbuf_free(msg);
1.173 djm 422: free(signature);
1.1 deraadt 423: }
424:
1.33 markus 425: /* shared */
1.55 itojun 426: static void
1.221 djm 427: process_remove_identity(SocketEntry *e)
1.1 deraadt 428: {
1.194 markus 429: int r, success = 0;
430: struct sshkey *key = NULL;
1.221 djm 431: Identity *id;
1.21 markus 432:
1.269 ! djm 433: debug2_f("entering");
1.221 djm 434: if ((r = sshkey_froms(e->request, &key)) != 0) {
1.266 djm 435: error_fr(r, "parse key");
1.221 djm 436: goto done;
437: }
438: if ((id = lookup_identity(key)) == NULL) {
1.266 djm 439: debug_f("key not found");
1.221 djm 440: goto done;
441: }
442: /* We have this key, free it. */
443: if (idtab->nentries < 1)
1.266 djm 444: fatal_f("internal error: nentries %d", idtab->nentries);
1.221 djm 445: TAILQ_REMOVE(&idtab->idlist, id, next);
446: free_identity(id);
447: idtab->nentries--;
448: sshkey_free(key);
449: success = 1;
450: done:
1.194 markus 451: send_status(e, success);
1.1 deraadt 452: }
453:
1.55 itojun 454: static void
1.221 djm 455: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 456: {
1.78 provos 457: Identity *id;
1.21 markus 458:
1.269 ! djm 459: debug2_f("entering");
1.21 markus 460: /* Loop over all identities and clear the keys. */
1.221 djm 461: for (id = TAILQ_FIRST(&idtab->idlist); id;
462: id = TAILQ_FIRST(&idtab->idlist)) {
463: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 464: free_identity(id);
1.21 markus 465: }
466:
467: /* Mark that there are no identities. */
1.221 djm 468: idtab->nentries = 0;
1.21 markus 469:
470: /* Send success. */
1.194 markus 471: send_status(e, 1);
1.1 deraadt 472: }
473:
1.155 dtucker 474: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 475: static time_t
1.89 markus 476: reaper(void)
477: {
1.175 dtucker 478: time_t deadline = 0, now = monotime();
1.89 markus 479: Identity *id, *nxt;
480:
1.221 djm 481: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
482: nxt = TAILQ_NEXT(id, next);
483: if (id->death == 0)
484: continue;
485: if (now >= id->death) {
486: debug("expiring key '%s'", id->comment);
487: TAILQ_REMOVE(&idtab->idlist, id, next);
488: free_identity(id);
489: idtab->nentries--;
490: } else
491: deadline = (deadline == 0) ? id->death :
492: MINIMUM(deadline, id->death);
1.89 markus 493: }
1.155 dtucker 494: if (deadline == 0 || deadline <= now)
495: return 0;
496: else
497: return (deadline - now);
1.89 markus 498: }
499:
500: static void
1.221 djm 501: process_add_identity(SocketEntry *e)
1.1 deraadt 502: {
1.157 canacar 503: Identity *id;
1.194 markus 504: int success = 0, confirm = 0;
1.257 markus 505: u_int seconds = 0, maxsign;
1.238 djm 506: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.254 djm 507: char canonical_provider[PATH_MAX];
1.174 dtucker 508: time_t death = 0;
1.194 markus 509: struct sshkey *k = NULL;
510: u_char ctype;
511: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 512:
1.269 ! djm 513: debug2_f("entering");
1.221 djm 514: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
515: k == NULL ||
1.194 markus 516: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
1.266 djm 517: error_fr(r, "parse");
1.194 markus 518: goto err;
519: }
520: while (sshbuf_len(e->request)) {
521: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
1.266 djm 522: error_fr(r, "parse constraint type");
1.194 markus 523: goto err;
524: }
525: switch (ctype) {
1.94 markus 526: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 527: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
1.266 djm 528: error_fr(r, "parse lifetime constraint");
1.194 markus 529: goto err;
530: }
531: death = monotime() + seconds;
1.94 markus 532: break;
1.107 markus 533: case SSH_AGENT_CONSTRAIN_CONFIRM:
534: confirm = 1;
535: break;
1.228 markus 536: case SSH_AGENT_CONSTRAIN_MAXSIGN:
537: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
1.266 djm 538: error_fr(r, "parse maxsign constraint");
1.228 markus 539: goto err;
540: }
541: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
1.266 djm 542: error_fr(r, "enable maxsign");
1.228 markus 543: goto err;
544: }
545: break;
1.238 djm 546: case SSH_AGENT_CONSTRAIN_EXTENSION:
547: if ((r = sshbuf_get_cstring(e->request,
548: &ext_name, NULL)) != 0) {
1.266 djm 549: error_fr(r, "parse constraint extension");
1.238 djm 550: goto err;
551: }
1.266 djm 552: debug_f("constraint ext %s", ext_name);
1.238 djm 553: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
554: if (sk_provider != NULL) {
555: error("%s already set", ext_name);
556: goto err;
557: }
558: if ((r = sshbuf_get_cstring(e->request,
559: &sk_provider, NULL)) != 0) {
1.266 djm 560: error_fr(r, "parse %s", ext_name);
1.238 djm 561: goto err;
562: }
563: } else {
1.266 djm 564: error_f("unsupported constraint \"%s\"",
565: ext_name);
1.238 djm 566: goto err;
567: }
568: free(ext_name);
569: break;
1.94 markus 570: default:
1.266 djm 571: error_f("Unknown constraint %d", ctype);
1.194 markus 572: err:
1.238 djm 573: free(sk_provider);
574: free(ext_name);
1.194 markus 575: sshbuf_reset(e->request);
1.173 djm 576: free(comment);
1.194 markus 577: sshkey_free(k);
1.158 djm 578: goto send;
1.94 markus 579: }
580: }
1.238 djm 581: if (sk_provider != NULL) {
1.240 markus 582: if (!sshkey_is_sk(k)) {
1.255 naddy 583: error("Cannot add provider: %s is not an "
584: "authenticator-hosted key", sshkey_type(k));
1.238 djm 585: free(sk_provider);
586: goto send;
587: }
1.254 djm 588: if (strcasecmp(sk_provider, "internal") == 0) {
1.266 djm 589: debug_f("internal provider");
1.254 djm 590: } else {
591: if (realpath(sk_provider, canonical_provider) == NULL) {
592: verbose("failed provider \"%.100s\": "
593: "realpath: %s", sk_provider,
594: strerror(errno));
595: free(sk_provider);
596: goto send;
597: }
1.238 djm 598: free(sk_provider);
1.254 djm 599: sk_provider = xstrdup(canonical_provider);
600: if (match_pattern_list(sk_provider,
1.260 djm 601: allowed_providers, 0) != 1) {
1.254 djm 602: error("Refusing add key: "
1.260 djm 603: "provider %s not allowed", sk_provider);
1.254 djm 604: free(sk_provider);
605: goto send;
606: }
1.238 djm 607: }
1.242 markus 608: }
609: if ((r = sshkey_shield_private(k)) != 0) {
1.266 djm 610: error_fr(r, "shield private");
1.242 markus 611: goto err;
1.238 djm 612: }
1.194 markus 613:
1.158 djm 614: success = 1;
1.106 marc 615: if (lifetime && !death)
1.175 dtucker 616: death = monotime() + lifetime;
1.221 djm 617: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 618: id = xcalloc(1, sizeof(Identity));
1.221 djm 619: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 620: /* Increment the number of identities. */
1.221 djm 621: idtab->nentries++;
1.33 markus 622: } else {
1.228 markus 623: /* key state might have been updated */
624: sshkey_free(id->key);
1.173 djm 625: free(id->comment);
1.238 djm 626: free(id->sk_provider);
1.33 markus 627: }
1.228 markus 628: id->key = k;
1.157 canacar 629: id->comment = comment;
630: id->death = death;
631: id->confirm = confirm;
1.238 djm 632: id->sk_provider = sk_provider;
633:
634: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
635: SSH_FP_DEFAULT)) == NULL)
1.266 djm 636: fatal_f("sshkey_fingerprint failed");
637: debug_f("add %s %s \"%.100s\" (life: %u) (confirm: %u) "
638: "(provider: %s)", sshkey_ssh_name(k), fp, comment,
1.238 djm 639: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
640: free(fp);
1.33 markus 641: send:
1.194 markus 642: send_status(e, success);
1.1 deraadt 643: }
644:
1.88 markus 645: /* XXX todo: encrypt sensitive data with passphrase */
646: static void
647: process_lock_agent(SocketEntry *e, int lock)
648: {
1.203 dtucker 649: int r, success = 0, delay;
1.213 djm 650: char *passwd;
651: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 652: static u_int fail_count = 0;
653: size_t pwlen;
654:
1.269 ! djm 655: debug2_f("entering");
1.226 djm 656: /*
657: * This is deliberately fatal: the user has requested that we lock,
658: * but we can't parse their request properly. The only safe thing to
659: * do is abort.
660: */
1.203 dtucker 661: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
1.266 djm 662: fatal_fr(r, "parse");
1.203 dtucker 663: if (pwlen == 0) {
664: debug("empty password not supported");
665: } else if (locked && !lock) {
666: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
667: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
668: fatal("bcrypt_pbkdf");
1.213 djm 669: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 670: debug("agent unlocked");
671: locked = 0;
672: fail_count = 0;
1.213 djm 673: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 674: success = 1;
675: } else {
676: /* delay in 0.1s increments up to 10s */
677: if (fail_count < 100)
678: fail_count++;
679: delay = 100000 * fail_count;
680: debug("unlock failed, delaying %0.1lf seconds",
681: (double)delay/1000000);
682: usleep(delay);
683: }
684: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 685: } else if (!locked && lock) {
1.203 dtucker 686: debug("agent locked");
1.88 markus 687: locked = 1;
1.203 dtucker 688: arc4random_buf(lock_salt, sizeof(lock_salt));
689: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 690: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 691: fatal("bcrypt_pbkdf");
1.88 markus 692: success = 1;
693: }
1.256 jsg 694: freezero(passwd, pwlen);
1.194 markus 695: send_status(e, success);
1.88 markus 696: }
697:
698: static void
1.221 djm 699: no_identities(SocketEntry *e)
1.88 markus 700: {
1.194 markus 701: struct sshbuf *msg;
702: int r;
1.88 markus 703:
1.194 markus 704: if ((msg = sshbuf_new()) == NULL)
1.266 djm 705: fatal_f("sshbuf_new failed");
1.221 djm 706: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 707: (r = sshbuf_put_u32(msg, 0)) != 0 ||
708: (r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 709: fatal_fr(r, "compose");
1.194 markus 710: sshbuf_free(msg);
1.88 markus 711: }
1.59 markus 712:
1.163 markus 713: #ifdef ENABLE_PKCS11
1.59 markus 714: static void
1.158 djm 715: process_add_smartcard_key(SocketEntry *e)
1.59 markus 716: {
1.226 djm 717: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.253 djm 718: char **comments = NULL;
1.221 djm 719: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 720: u_int seconds;
1.174 dtucker 721: time_t death = 0;
1.194 markus 722: u_char type;
723: struct sshkey **keys = NULL, *k;
1.84 markus 724: Identity *id;
1.75 deraadt 725:
1.269 ! djm 726: debug2_f("entering");
1.194 markus 727: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 728: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 djm 729: error_fr(r, "parse");
1.226 djm 730: goto send;
731: }
1.194 markus 732:
733: while (sshbuf_len(e->request)) {
1.226 djm 734: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
1.266 djm 735: error_fr(r, "parse type");
1.226 djm 736: goto send;
737: }
1.194 markus 738: switch (type) {
1.110 djm 739: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 740: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
1.266 djm 741: error_fr(r, "parse lifetime");
1.226 djm 742: goto send;
743: }
1.194 markus 744: death = monotime() + seconds;
1.110 djm 745: break;
746: case SSH_AGENT_CONSTRAIN_CONFIRM:
747: confirm = 1;
748: break;
749: default:
1.266 djm 750: error_f("Unknown constraint type %d", type);
1.158 djm 751: goto send;
1.110 djm 752: }
753: }
1.215 djm 754: if (realpath(provider, canonical_provider) == NULL) {
755: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
756: provider, strerror(errno));
757: goto send;
758: }
1.260 djm 759: if (match_pattern_list(canonical_provider, allowed_providers, 0) != 1) {
1.215 djm 760: verbose("refusing PKCS#11 add of \"%.100s\": "
1.260 djm 761: "provider not allowed", canonical_provider);
1.215 djm 762: goto send;
763: }
1.266 djm 764: debug_f("add %.100s", canonical_provider);
1.110 djm 765: if (lifetime && !death)
1.175 dtucker 766: death = monotime() + lifetime;
1.110 djm 767:
1.253 djm 768: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.163 markus 769: for (i = 0; i < count; i++) {
1.84 markus 770: k = keys[i];
1.221 djm 771: if (lookup_identity(k) == NULL) {
1.163 markus 772: id = xcalloc(1, sizeof(Identity));
1.84 markus 773: id->key = k;
1.253 djm 774: keys[i] = NULL; /* transferred */
1.215 djm 775: id->provider = xstrdup(canonical_provider);
1.253 djm 776: if (*comments[i] != '\0') {
777: id->comment = comments[i];
778: comments[i] = NULL; /* transferred */
779: } else {
780: id->comment = xstrdup(canonical_provider);
781: }
1.110 djm 782: id->death = death;
783: id->confirm = confirm;
1.221 djm 784: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
785: idtab->nentries++;
1.84 markus 786: success = 1;
787: }
1.253 djm 788: sshkey_free(keys[i]);
789: free(comments[i]);
1.59 markus 790: }
791: send:
1.173 djm 792: free(pin);
793: free(provider);
794: free(keys);
1.253 djm 795: free(comments);
1.194 markus 796: send_status(e, success);
1.59 markus 797: }
798:
799: static void
800: process_remove_smartcard_key(SocketEntry *e)
801: {
1.217 djm 802: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 803: int r, success = 0;
1.163 markus 804: Identity *id, *nxt;
1.59 markus 805:
1.269 ! djm 806: debug2_f("entering");
1.194 markus 807: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 808: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 djm 809: error_fr(r, "parse");
1.226 djm 810: goto send;
811: }
1.173 djm 812: free(pin);
1.59 markus 813:
1.217 djm 814: if (realpath(provider, canonical_provider) == NULL) {
815: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
816: provider, strerror(errno));
817: goto send;
818: }
819:
1.266 djm 820: debug_f("remove %.100s", canonical_provider);
1.221 djm 821: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
822: nxt = TAILQ_NEXT(id, next);
823: /* Skip file--based keys */
824: if (id->provider == NULL)
825: continue;
826: if (!strcmp(canonical_provider, id->provider)) {
827: TAILQ_REMOVE(&idtab->idlist, id, next);
828: free_identity(id);
829: idtab->nentries--;
1.59 markus 830: }
831: }
1.217 djm 832: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 833: success = 1;
834: else
1.266 djm 835: error_f("pkcs11_del_provider failed");
1.218 deraadt 836: send:
1.173 djm 837: free(provider);
1.194 markus 838: send_status(e, success);
1.59 markus 839: }
1.163 markus 840: #endif /* ENABLE_PKCS11 */
1.59 markus 841:
1.264 djm 842: /*
843: * dispatch incoming message.
844: * returns 1 on success, 0 for incomplete messages or -1 on error.
845: */
1.223 djm 846: static int
847: process_message(u_int socknum)
1.1 deraadt 848: {
1.194 markus 849: u_int msg_len;
850: u_char type;
851: const u_char *cp;
852: int r;
1.223 djm 853: SocketEntry *e;
854:
1.266 djm 855: if (socknum >= sockets_alloc)
856: fatal_f("sock %u >= allocated %u", socknum, sockets_alloc);
1.223 djm 857: e = &sockets[socknum];
1.89 markus 858:
1.194 markus 859: if (sshbuf_len(e->input) < 5)
1.223 djm 860: return 0; /* Incomplete message header. */
1.194 markus 861: cp = sshbuf_ptr(e->input);
862: msg_len = PEEK_U32(cp);
1.223 djm 863: if (msg_len > AGENT_MAX_LEN) {
1.266 djm 864: debug_f("socket %u (fd=%d) message too long %u > %u",
865: socknum, e->fd, msg_len, AGENT_MAX_LEN);
1.223 djm 866: return -1;
1.21 markus 867: }
1.194 markus 868: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 869: return 0; /* Incomplete message body. */
1.87 markus 870:
871: /* move the current input to e->request */
1.194 markus 872: sshbuf_reset(e->request);
873: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 874: (r = sshbuf_get_u8(e->request, &type)) != 0) {
875: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
876: r == SSH_ERR_STRING_TOO_LARGE) {
1.266 djm 877: error_fr(r, "parse");
1.223 djm 878: return -1;
879: }
1.266 djm 880: fatal_fr(r, "parse");
1.223 djm 881: }
882:
1.266 djm 883: debug_f("socket %u (fd=%d) type %d", socknum, e->fd, type);
1.21 markus 884:
1.230 djm 885: /* check whether agent is locked */
1.88 markus 886: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 887: sshbuf_reset(e->request);
1.88 markus 888: switch (type) {
889: case SSH2_AGENTC_REQUEST_IDENTITIES:
890: /* send empty lists */
1.221 djm 891: no_identities(e);
1.88 markus 892: break;
893: default:
894: /* send a fail message for all other request types */
1.194 markus 895: send_status(e, 0);
1.88 markus 896: }
1.264 djm 897: return 1;
1.88 markus 898: }
899:
1.21 markus 900: switch (type) {
1.88 markus 901: case SSH_AGENTC_LOCK:
902: case SSH_AGENTC_UNLOCK:
903: process_lock_agent(e, type == SSH_AGENTC_LOCK);
904: break;
1.21 markus 905: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 906: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 907: break;
908: /* ssh2 */
909: case SSH2_AGENTC_SIGN_REQUEST:
910: process_sign_request2(e);
911: break;
912: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 913: process_request_identities(e);
1.33 markus 914: break;
915: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 916: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 917: process_add_identity(e);
1.33 markus 918: break;
919: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 920: process_remove_identity(e);
1.33 markus 921: break;
922: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 923: process_remove_all_identities(e);
1.21 markus 924: break;
1.163 markus 925: #ifdef ENABLE_PKCS11
1.59 markus 926: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 927: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 928: process_add_smartcard_key(e);
1.75 deraadt 929: break;
1.59 markus 930: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
931: process_remove_smartcard_key(e);
1.75 deraadt 932: break;
1.163 markus 933: #endif /* ENABLE_PKCS11 */
1.21 markus 934: default:
935: /* Unknown message. Respond with failure. */
936: error("Unknown message %d", type);
1.194 markus 937: sshbuf_reset(e->request);
938: send_status(e, 0);
1.21 markus 939: break;
940: }
1.264 djm 941: return 1;
1.1 deraadt 942: }
943:
1.55 itojun 944: static void
1.73 stevesk 945: new_socket(sock_type type, int fd)
1.1 deraadt 946: {
1.112 markus 947: u_int i, old_alloc, new_alloc;
1.96 deraadt 948:
1.269 ! djm 949: debug_f("type = %s", type == AUTH_CONNECTION ? "CONNECTION" :
! 950: (type == AUTH_SOCKET ? "SOCKET" : "UNKNOWN"));
1.119 djm 951: set_nonblock(fd);
1.21 markus 952:
953: if (fd > max_fd)
954: max_fd = fd;
955:
956: for (i = 0; i < sockets_alloc; i++)
957: if (sockets[i].type == AUTH_UNUSED) {
958: sockets[i].fd = fd;
1.266 djm 959: if ((sockets[i].input = sshbuf_new()) == NULL ||
960: (sockets[i].output = sshbuf_new()) == NULL ||
961: (sockets[i].request = sshbuf_new()) == NULL)
962: fatal_f("sshbuf_new failed");
1.112 markus 963: sockets[i].type = type;
1.21 markus 964: return;
965: }
966: old_alloc = sockets_alloc;
1.112 markus 967: new_alloc = sockets_alloc + 10;
1.269 ! djm 968: sockets = xrecallocarray(sockets, old_alloc, new_alloc,
! 969: sizeof(sockets[0]));
1.112 markus 970: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 971: sockets[i].type = AUTH_UNUSED;
1.112 markus 972: sockets_alloc = new_alloc;
1.21 markus 973: sockets[old_alloc].fd = fd;
1.266 djm 974: if ((sockets[old_alloc].input = sshbuf_new()) == NULL ||
975: (sockets[old_alloc].output = sshbuf_new()) == NULL ||
976: (sockets[old_alloc].request = sshbuf_new()) == NULL)
977: fatal_f("sshbuf_new failed");
1.112 markus 978: sockets[old_alloc].type = type;
1.1 deraadt 979: }
980:
1.55 itojun 981: static int
1.223 djm 982: handle_socket_read(u_int socknum)
1.1 deraadt 983: {
1.223 djm 984: struct sockaddr_un sunaddr;
985: socklen_t slen;
986: uid_t euid;
987: gid_t egid;
988: int fd;
989:
990: slen = sizeof(sunaddr);
991: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 992: if (fd == -1) {
1.223 djm 993: error("accept from AUTH_SOCKET: %s", strerror(errno));
994: return -1;
995: }
1.237 deraadt 996: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 997: error("getpeereid %d failed: %s", fd, strerror(errno));
998: close(fd);
999: return -1;
1000: }
1001: if ((euid != 0) && (getuid() != euid)) {
1002: error("uid mismatch: peer euid %u != uid %u",
1003: (u_int) euid, (u_int) getuid());
1004: close(fd);
1005: return -1;
1006: }
1007: new_socket(AUTH_CONNECTION, fd);
1008: return 0;
1009: }
1010:
1011: static int
1012: handle_conn_read(u_int socknum)
1013: {
1.233 djm 1014: char buf[AGENT_RBUF_LEN];
1.223 djm 1015: ssize_t len;
1016: int r;
1017:
1018: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1019: if (len == -1) {
1020: if (errno == EAGAIN || errno == EINTR)
1021: return 0;
1.266 djm 1022: error_f("read error on socket %u (fd %d): %s",
1023: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1024: }
1025: return -1;
1026: }
1027: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1.266 djm 1028: fatal_fr(r, "compose");
1.223 djm 1029: explicit_bzero(buf, sizeof(buf));
1.264 djm 1030: for (;;) {
1031: if ((r = process_message(socknum)) == -1)
1032: return -1;
1033: else if (r == 0)
1034: break;
1035: }
1.223 djm 1036: return 0;
1037: }
1038:
1039: static int
1040: handle_conn_write(u_int socknum)
1041: {
1042: ssize_t len;
1043: int r;
1044:
1045: if (sshbuf_len(sockets[socknum].output) == 0)
1046: return 0; /* shouldn't happen */
1047: if ((len = write(sockets[socknum].fd,
1048: sshbuf_ptr(sockets[socknum].output),
1049: sshbuf_len(sockets[socknum].output))) <= 0) {
1050: if (len == -1) {
1051: if (errno == EAGAIN || errno == EINTR)
1052: return 0;
1.266 djm 1053: error_f("read error on socket %u (fd %d): %s",
1054: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1055: }
1056: return -1;
1057: }
1058: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1.266 djm 1059: fatal_fr(r, "consume");
1.223 djm 1060: return 0;
1061: }
1062:
1063: static void
1.231 djm 1064: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1065: {
1066: size_t i;
1.231 djm 1067: u_int socknum, activefds = npfd;
1.223 djm 1068:
1069: for (i = 0; i < npfd; i++) {
1070: if (pfd[i].revents == 0)
1071: continue;
1072: /* Find sockets entry */
1073: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1074: if (sockets[socknum].type != AUTH_SOCKET &&
1075: sockets[socknum].type != AUTH_CONNECTION)
1076: continue;
1077: if (pfd[i].fd == sockets[socknum].fd)
1078: break;
1079: }
1080: if (socknum >= sockets_alloc) {
1.266 djm 1081: error_f("no socket for fd %d", pfd[i].fd);
1.223 djm 1082: continue;
1083: }
1084: /* Process events */
1085: switch (sockets[socknum].type) {
1086: case AUTH_SOCKET:
1.231 djm 1087: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1088: break;
1089: if (npfd > maxfds) {
1090: debug3("out of fds (active %u >= limit %u); "
1091: "skipping accept", activefds, maxfds);
1092: break;
1093: }
1094: if (handle_socket_read(socknum) == 0)
1095: activefds++;
1.223 djm 1096: break;
1097: case AUTH_CONNECTION:
1098: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1099: handle_conn_read(socknum) != 0) {
1.231 djm 1100: goto close_sock;
1101: }
1102: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1103: handle_conn_write(socknum) != 0) {
1104: close_sock:
1105: if (activefds == 0)
1106: fatal("activefds == 0 at close_sock");
1.223 djm 1107: close_socket(&sockets[socknum]);
1.231 djm 1108: activefds--;
1.223 djm 1109: break;
1110: }
1111: break;
1112: default:
1113: break;
1114: }
1115: }
1116: }
1117:
1118: static int
1.231 djm 1119: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1120: {
1121: struct pollfd *pfd = *pfdp;
1122: size_t i, j, npfd = 0;
1.174 dtucker 1123: time_t deadline;
1.233 djm 1124: int r;
1.46 markus 1125:
1.223 djm 1126: /* Count active sockets */
1.46 markus 1127: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1128: switch (sockets[i].type) {
1129: case AUTH_SOCKET:
1130: case AUTH_CONNECTION:
1.223 djm 1131: npfd++;
1.21 markus 1132: break;
1133: case AUTH_UNUSED:
1134: break;
1135: default:
1136: fatal("Unknown socket type %d", sockets[i].type);
1137: break;
1138: }
1.46 markus 1139: }
1.223 djm 1140: if (npfd != *npfdp &&
1141: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1.266 djm 1142: fatal_f("recallocarray failed");
1.223 djm 1143: *pfdp = pfd;
1144: *npfdp = npfd;
1.46 markus 1145:
1.223 djm 1146: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1147: switch (sockets[i].type) {
1148: case AUTH_SOCKET:
1.231 djm 1149: if (npfd > maxfds) {
1150: debug3("out of fds (active %zu >= limit %u); "
1151: "skipping arming listener", npfd, maxfds);
1152: break;
1153: }
1154: pfd[j].fd = sockets[i].fd;
1155: pfd[j].revents = 0;
1156: pfd[j].events = POLLIN;
1157: j++;
1158: break;
1.46 markus 1159: case AUTH_CONNECTION:
1.223 djm 1160: pfd[j].fd = sockets[i].fd;
1161: pfd[j].revents = 0;
1.233 djm 1162: /*
1163: * Only prepare to read if we can handle a full-size
1164: * input read buffer and enqueue a max size reply..
1165: */
1166: if ((r = sshbuf_check_reserve(sockets[i].input,
1167: AGENT_RBUF_LEN)) == 0 &&
1168: (r = sshbuf_check_reserve(sockets[i].output,
1169: AGENT_MAX_LEN)) == 0)
1170: pfd[j].events = POLLIN;
1.266 djm 1171: else if (r != SSH_ERR_NO_BUFFER_SPACE)
1172: fatal_fr(r, "reserve");
1.194 markus 1173: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1174: pfd[j].events |= POLLOUT;
1175: j++;
1.46 markus 1176: break;
1177: default:
1178: break;
1179: }
1180: }
1.155 dtucker 1181: deadline = reaper();
1182: if (parent_alive_interval != 0)
1183: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1184: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1185: if (deadline == 0) {
1.224 djm 1186: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1187: } else {
1.223 djm 1188: if (deadline > INT_MAX / 1000)
1189: *timeoutp = INT_MAX / 1000;
1190: else
1191: *timeoutp = deadline * 1000;
1.155 dtucker 1192: }
1.46 markus 1193: return (1);
1.21 markus 1194: }
1195:
1.55 itojun 1196: static void
1.113 markus 1197: cleanup_socket(void)
1.15 markus 1198: {
1.187 djm 1199: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1200: return;
1.266 djm 1201: debug_f("cleanup");
1.48 deraadt 1202: if (socket_name[0])
1203: unlink(socket_name);
1204: if (socket_dir[0])
1205: rmdir(socket_dir);
1.10 markus 1206: }
1207:
1.114 markus 1208: void
1.15 markus 1209: cleanup_exit(int i)
1210: {
1.113 markus 1211: cleanup_socket();
1212: _exit(i);
1.15 markus 1213: }
1214:
1.135 deraadt 1215: /*ARGSUSED*/
1.55 itojun 1216: static void
1.48 deraadt 1217: cleanup_handler(int sig)
1218: {
1.113 markus 1219: cleanup_socket();
1.163 markus 1220: #ifdef ENABLE_PKCS11
1221: pkcs11_terminate();
1222: #endif
1.48 deraadt 1223: _exit(2);
1.113 markus 1224: }
1225:
1.68 markus 1226: static void
1.155 dtucker 1227: check_parent_exists(void)
1.68 markus 1228: {
1.172 dtucker 1229: /*
1230: * If our parent has exited then getppid() will return (pid_t)1,
1231: * so testing for that should be safe.
1232: */
1233: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1234: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1235: cleanup_socket();
1236: _exit(2);
1.68 markus 1237: }
1.48 deraadt 1238: }
1239:
1.55 itojun 1240: static void
1.50 itojun 1241: usage(void)
1.15 markus 1242: {
1.184 deraadt 1243: fprintf(stderr,
1.250 jmc 1244: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.261 jmc 1245: " [-P allowed_providers] [-t life]\n"
1.260 djm 1246: " ssh-agent [-a bind_address] [-E fingerprint_hash] [-P allowed_providers]\n"
1.259 dtucker 1247: " [-t life] command [arg ...]\n"
1.250 jmc 1248: " ssh-agent [-c | -s] -k\n");
1.21 markus 1249: exit(1);
1.15 markus 1250: }
1251:
1.2 provos 1252: int
1253: main(int ac, char **av)
1.1 deraadt 1254: {
1.201 djm 1255: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.265 djm 1256: int sock, ch, result, saved_errno;
1.96 deraadt 1257: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1258: struct rlimit rlim;
1.96 deraadt 1259: extern int optind;
1.98 stevesk 1260: extern char *optarg;
1.21 markus 1261: pid_t pid;
1.96 deraadt 1262: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1263: size_t len;
1.189 djm 1264: mode_t prev_mask;
1.224 djm 1265: int timeout = -1; /* INFTIM */
1.223 djm 1266: struct pollfd *pfd = NULL;
1267: size_t npfd = 0;
1.231 djm 1268: u_int maxfds;
1.123 djm 1269:
1270: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1271: sanitise_stdfd();
1.99 markus 1272:
1273: /* drop */
1274: setegid(getgid());
1275: setgid(getgid());
1.53 markus 1276:
1.231 djm 1277: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1278: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1279:
1.185 markus 1280: #ifdef WITH_OPENSSL
1.170 djm 1281: OpenSSL_add_all_algorithms();
1.185 markus 1282: #endif
1.21 markus 1283:
1.258 djm 1284: while ((ch = getopt(ac, av, "cDdksE:a:O:P:t:")) != -1) {
1.21 markus 1285: switch (ch) {
1.192 djm 1286: case 'E':
1287: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1288: if (fingerprint_hash == -1)
1289: fatal("Invalid hash algorithm \"%s\"", optarg);
1290: break;
1.21 markus 1291: case 'c':
1292: if (s_flag)
1293: usage();
1294: c_flag++;
1295: break;
1296: case 'k':
1297: k_flag++;
1.258 djm 1298: break;
1299: case 'O':
1300: if (strcmp(optarg, "no-restrict-websafe") == 0)
1301: restrict_websafe = 0;
1302: else
1303: fatal("Unknown -O option");
1.21 markus 1304: break;
1.215 djm 1305: case 'P':
1.260 djm 1306: if (allowed_providers != NULL)
1.215 djm 1307: fatal("-P option already specified");
1.260 djm 1308: allowed_providers = xstrdup(optarg);
1.215 djm 1309: break;
1.21 markus 1310: case 's':
1311: if (c_flag)
1312: usage();
1313: s_flag++;
1314: break;
1.57 markus 1315: case 'd':
1.201 djm 1316: if (d_flag || D_flag)
1.57 markus 1317: usage();
1318: d_flag++;
1319: break;
1.201 djm 1320: case 'D':
1321: if (d_flag || D_flag)
1322: usage();
1323: D_flag++;
1324: break;
1.86 markus 1325: case 'a':
1326: agentsocket = optarg;
1.106 marc 1327: break;
1328: case 't':
1329: if ((lifetime = convtime(optarg)) == -1) {
1330: fprintf(stderr, "Invalid lifetime\n");
1331: usage();
1332: }
1.86 markus 1333: break;
1.21 markus 1334: default:
1335: usage();
1336: }
1337: }
1338: ac -= optind;
1339: av += optind;
1340:
1.201 djm 1341: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1342: usage();
1343:
1.260 djm 1344: if (allowed_providers == NULL)
1.262 djm 1345: allowed_providers = xstrdup(DEFAULT_ALLOWED_PROVIDERS);
1.215 djm 1346:
1.85 markus 1347: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1348: shell = getenv("SHELL");
1.161 tobias 1349: if (shell != NULL && (len = strlen(shell)) > 2 &&
1350: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1351: c_flag = 1;
1352: }
1353: if (k_flag) {
1.136 deraadt 1354: const char *errstr = NULL;
1355:
1.21 markus 1356: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1357: if (pidstr == NULL) {
1358: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1359: SSH_AGENTPID_ENV_NAME);
1.21 markus 1360: exit(1);
1361: }
1.136 deraadt 1362: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1363: if (errstr) {
1364: fprintf(stderr,
1365: "%s=\"%s\", which is not a good PID: %s\n",
1366: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1367: exit(1);
1368: }
1369: if (kill(pid, SIGTERM) == -1) {
1370: perror("kill");
1371: exit(1);
1372: }
1373: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1374: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1375: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1376: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1377: exit(0);
1378: }
1.231 djm 1379:
1380: /*
1381: * Minimum file descriptors:
1382: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1383: * a few spare for libc / stack protectors / sanitisers, etc.
1384: */
1385: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1386: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1387: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1388: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1389: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1390:
1.21 markus 1391: parent_pid = getpid();
1392:
1.86 markus 1393: if (agentsocket == NULL) {
1394: /* Create private directory for agent socket */
1.171 djm 1395: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1396: if (mkdtemp(socket_dir) == NULL) {
1397: perror("mkdtemp: private socket dir");
1398: exit(1);
1399: }
1.91 mpech 1400: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1401: (long)parent_pid);
1.86 markus 1402: } else {
1403: /* Try to use specified agent socket */
1404: socket_dir[0] = '\0';
1405: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1406: }
1407:
1.23 markus 1408: /*
1409: * Create socket early so it will exist before command gets run from
1410: * the parent.
1411: */
1.189 djm 1412: prev_mask = umask(0177);
1.188 millert 1413: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1414: if (sock < 0) {
1.188 millert 1415: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1416: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1417: cleanup_exit(1);
1418: }
1.189 djm 1419: umask(prev_mask);
1.46 markus 1420:
1.23 markus 1421: /*
1422: * Fork, and have the parent execute the command, if any, or present
1423: * the socket data. The child continues as the authentication agent.
1424: */
1.201 djm 1425: if (D_flag || d_flag) {
1426: log_init(__progname,
1427: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1428: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1429: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1430: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1431: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1432: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1433: fflush(stdout);
1.57 markus 1434: goto skip;
1435: }
1.21 markus 1436: pid = fork();
1437: if (pid == -1) {
1438: perror("fork");
1.81 stevesk 1439: cleanup_exit(1);
1.21 markus 1440: }
1441: if (pid != 0) { /* Parent - execute the given command. */
1442: close(sock);
1.91 mpech 1443: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1444: if (ac == 0) {
1445: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1446: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1447: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1448: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1449: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1450: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1451: exit(0);
1452: }
1.36 deraadt 1453: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1454: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1455: perror("setenv");
1456: exit(1);
1457: }
1.21 markus 1458: execvp(av[0], av);
1459: perror(av[0]);
1460: exit(1);
1461: }
1.81 stevesk 1462: /* child */
1463: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1464:
1465: if (setsid() == -1) {
1.81 stevesk 1466: error("setsid: %s", strerror(errno));
1.67 stevesk 1467: cleanup_exit(1);
1468: }
1469:
1470: (void)chdir("/");
1.265 djm 1471: if (stdfd_devnull(1, 1, 1) == -1)
1.266 djm 1472: error_f("stdfd_devnull failed");
1.21 markus 1473:
1.41 markus 1474: /* deny core dumps, since memory contains unencrypted private keys */
1475: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1476: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1477: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1478: cleanup_exit(1);
1479: }
1.57 markus 1480:
1481: skip:
1.187 djm 1482:
1483: cleanup_pid = getpid();
1.163 markus 1484:
1485: #ifdef ENABLE_PKCS11
1486: pkcs11_init(0);
1487: #endif
1.21 markus 1488: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1489: if (ac > 0)
1490: parent_alive_interval = 10;
1.33 markus 1491: idtab_init();
1.252 dtucker 1492: ssh_signal(SIGPIPE, SIG_IGN);
1493: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1494: ssh_signal(SIGHUP, cleanup_handler);
1495: ssh_signal(SIGTERM, cleanup_handler);
1.205 djm 1496:
1.215 djm 1497: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1498: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1499:
1.21 markus 1500: while (1) {
1.231 djm 1501: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1502: result = poll(pfd, npfd, timeout);
1.154 dtucker 1503: saved_errno = errno;
1.155 dtucker 1504: if (parent_alive_interval != 0)
1505: check_parent_exists();
1506: (void) reaper(); /* remove expired keys */
1.237 deraadt 1507: if (result == -1) {
1.154 dtucker 1508: if (saved_errno == EINTR)
1.21 markus 1509: continue;
1.223 djm 1510: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1511: } else if (result > 0)
1.231 djm 1512: after_poll(pfd, npfd, maxfds);
1.15 markus 1513: }
1.21 markus 1514: /* NOTREACHED */
1.1 deraadt 1515: }
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