Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.271
1.271 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.270 2021/01/26 00:53:31 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) */
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
1.270 djm 205: confirm_key(Identity *id, const char *extra)
1.107 markus 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 &&
1.270 djm 212: ask_permission("Allow use of key %s?\nKey fingerprint %s.%s%s",
213: id->comment, p,
214: extra == NULL ? "" : "\n", extra == NULL ? "" : extra))
1.122 djm 215: ret = 0;
1.173 djm 216: free(p);
1.122 djm 217:
1.107 markus 218: return (ret);
219: }
220:
1.194 markus 221: static void
222: send_status(SocketEntry *e, int success)
223: {
224: int r;
225:
226: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
227: (r = sshbuf_put_u8(e->output, success ?
228: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
1.266 djm 229: fatal_fr(r, "compose");
1.194 markus 230: }
231:
1.33 markus 232: /* send list of supported public keys to 'client' */
1.55 itojun 233: static void
1.221 djm 234: process_request_identities(SocketEntry *e)
1.33 markus 235: {
1.96 deraadt 236: Identity *id;
1.194 markus 237: struct sshbuf *msg;
238: int r;
1.1 deraadt 239:
1.269 djm 240: debug2_f("entering");
241:
1.194 markus 242: if ((msg = sshbuf_new()) == NULL)
1.266 djm 243: fatal_f("sshbuf_new failed");
1.221 djm 244: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
245: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
1.266 djm 246: fatal_fr(r, "compose");
1.221 djm 247: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 248: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
249: != 0 ||
1.221 djm 250: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
1.266 djm 251: error_fr(r, "compose key/comment");
1.220 djm 252: continue;
1.33 markus 253: }
1.21 markus 254: }
1.194 markus 255: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 256: fatal_fr(r, "enqueue");
1.194 markus 257: sshbuf_free(msg);
1.1 deraadt 258: }
259:
1.33 markus 260:
1.208 markus 261: static char *
262: agent_decode_alg(struct sshkey *key, u_int flags)
263: {
264: if (key->type == KEY_RSA) {
265: if (flags & SSH_AGENT_RSA_SHA2_256)
266: return "rsa-sha2-256";
267: else if (flags & SSH_AGENT_RSA_SHA2_512)
268: return "rsa-sha2-512";
1.235 djm 269: } else if (key->type == KEY_RSA_CERT) {
270: if (flags & SSH_AGENT_RSA_SHA2_256)
271: return "rsa-sha2-256-cert-v01@openssh.com";
272: else if (flags & SSH_AGENT_RSA_SHA2_512)
273: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 274: }
275: return NULL;
276: }
277:
1.258 djm 278: /*
1.270 djm 279: * Attempt to parse the contents of a buffer as a SSH publickey userauth
280: * request, checking its contents for consistency and matching the embedded
281: * key against the one that is being used for signing.
282: * Note: does not modify msg buffer.
283: * Optionally extract the username and session ID from the request.
1.258 djm 284: */
285: static int
1.270 djm 286: parse_userauth_request(struct sshbuf *msg, const struct sshkey *expected_key,
287: char **userp, struct sshbuf **sess_idp)
1.258 djm 288: {
1.270 djm 289: struct sshbuf *b = NULL, *sess_id = NULL;
290: char *user = NULL, *service = NULL, *method = NULL, *pkalg = NULL;
1.258 djm 291: int r;
1.270 djm 292: u_char t, sig_follows;
1.258 djm 293: struct sshkey *mkey = NULL;
294:
1.270 djm 295: if (userp != NULL)
296: *userp = NULL;
297: if (sess_idp != NULL)
298: *sess_idp = NULL;
299: if ((b = sshbuf_fromb(msg)) == NULL)
300: fatal_f("sshbuf_fromb");
1.258 djm 301:
302: /* SSH userauth request */
1.270 djm 303: if ((r = sshbuf_froms(b, &sess_id)) != 0)
304: goto out;
305: if (sshbuf_len(sess_id) == 0) {
306: r = SSH_ERR_INVALID_FORMAT;
307: goto out;
308: }
309: if ((r = sshbuf_get_u8(b, &t)) != 0 || /* SSH2_MSG_USERAUTH_REQUEST */
310: (r = sshbuf_get_cstring(b, &user, NULL)) != 0 || /* server user */
311: (r = sshbuf_get_cstring(b, &service, NULL)) != 0 || /* service */
312: (r = sshbuf_get_cstring(b, &method, NULL)) != 0 || /* method */
313: (r = sshbuf_get_u8(b, &sig_follows)) != 0 || /* sig-follows */
314: (r = sshbuf_get_cstring(b, &pkalg, NULL)) != 0 || /* alg */
315: (r = sshkey_froms(b, &mkey)) != 0) /* key */
316: goto out;
317: if (t != SSH2_MSG_USERAUTH_REQUEST ||
318: sig_follows != 1 ||
319: strcmp(service, "ssh-connection") != 0 ||
320: !sshkey_equal(expected_key, mkey) ||
321: sshkey_type_from_name(pkalg) != expected_key->type) {
322: r = SSH_ERR_INVALID_FORMAT;
323: goto out;
324: }
325: if (strcmp(method, "publickey") != 0) {
326: r = SSH_ERR_INVALID_FORMAT;
327: goto out;
328: }
329: if (sshbuf_len(b) != 0) {
330: r = SSH_ERR_INVALID_FORMAT;
331: goto out;
332: }
333: /* success */
334: r = 0;
335: debug3_f("well formed userauth");
336: if (userp != NULL) {
337: *userp = user;
338: user = NULL;
339: }
340: if (sess_idp != NULL) {
341: *sess_idp = sess_id;
342: sess_id = NULL;
1.258 djm 343: }
1.270 djm 344: out:
345: sshbuf_free(b);
346: sshbuf_free(sess_id);
347: free(user);
348: free(service);
349: free(method);
350: free(pkalg);
1.258 djm 351: sshkey_free(mkey);
1.270 djm 352: return r;
353: }
354:
355: /*
356: * Attempt to parse the contents of a buffer as a SSHSIG signature request.
357: * Note: does not modify buffer.
358: */
359: static int
360: parse_sshsig_request(struct sshbuf *msg)
361: {
362: int r;
363: struct sshbuf *b;
364:
365: if ((b = sshbuf_fromb(msg)) == NULL)
366: fatal_f("sshbuf_fromb");
367:
368: if ((r = sshbuf_cmp(b, 0, "SSHSIG", 6)) != 0 ||
369: (r = sshbuf_consume(b, 6)) != 0 ||
370: (r = sshbuf_get_cstring(b, NULL, NULL)) != 0 || /* namespace */
371: (r = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || /* reserved */
372: (r = sshbuf_get_cstring(b, NULL, NULL)) != 0 || /* hashalg */
373: (r = sshbuf_get_string_direct(b, NULL, NULL)) != 0) /* H(msg) */
374: goto out;
375: if (sshbuf_len(b) != 0) {
376: r = SSH_ERR_INVALID_FORMAT;
377: goto out;
378: }
379: /* success */
380: r = 0;
381: out:
1.258 djm 382: sshbuf_free(b);
1.270 djm 383: return r;
384: }
385:
386: /*
387: * This function inspects a message to be signed by a FIDO key that has a
388: * web-like application string (i.e. one that does not begin with "ssh:".
389: * It checks that the message is one of those expected for SSH operations
390: * (pubkey userauth, sshsig, CA key signing) to exclude signing challenges
391: * for the web.
392: */
393: static int
394: check_websafe_message_contents(struct sshkey *key, struct sshbuf *data)
395: {
396: if (parse_userauth_request(data, key, NULL, NULL) == 0) {
397: debug_f("signed data matches public key userauth request");
1.258 djm 398: return 1;
399: }
1.270 djm 400: if (parse_sshsig_request(data) == 0) {
401: debug_f("signed data matches SSHSIG signature request");
1.258 djm 402: return 1;
1.270 djm 403: }
1.258 djm 404:
1.270 djm 405: /* XXX check CA signature operation */
1.258 djm 406:
407: error("web-origin key attempting to sign non-SSH message");
408: return 0;
409: }
410:
1.33 markus 411: /* ssh2 only */
1.55 itojun 412: static void
1.33 markus 413: process_sign_request2(SocketEntry *e)
414: {
1.221 djm 415: u_char *signature = NULL;
1.270 djm 416: size_t i, slen = 0;
1.194 markus 417: u_int compat = 0, flags;
1.247 djm 418: int r, ok = -1;
1.251 djm 419: char *fp = NULL;
1.270 djm 420: struct sshbuf *msg = NULL, *data = NULL;
1.221 djm 421: struct sshkey *key = NULL;
1.195 djm 422: struct identity *id;
1.251 djm 423: struct notifier_ctx *notifier = NULL;
1.194 markus 424:
1.270 djm 425: debug_f("entering");
426:
427: if ((msg = sshbuf_new()) == NULL | (data = sshbuf_new()) == NULL)
1.266 djm 428: fatal_f("sshbuf_new failed");
1.221 djm 429: if ((r = sshkey_froms(e->request, &key)) != 0 ||
1.270 djm 430: (r = sshbuf_get_stringb(e->request, data)) != 0 ||
1.225 djm 431: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
1.266 djm 432: error_fr(r, "parse");
1.225 djm 433: goto send;
434: }
435:
1.221 djm 436: if ((id = lookup_identity(key)) == NULL) {
1.266 djm 437: verbose_f("%s key not found", sshkey_type(key));
1.195 djm 438: goto send;
439: }
1.270 djm 440: if (id->confirm && confirm_key(id, NULL) != 0) {
1.266 djm 441: verbose_f("user refused key");
1.195 djm 442: goto send;
443: }
1.258 djm 444: if (sshkey_is_sk(id->key)) {
445: if (strncmp(id->key->sk_application, "ssh:", 4) != 0 &&
1.270 djm 446: !check_websafe_message_contents(key, data)) {
1.258 djm 447: /* error already logged */
448: goto send;
449: }
450: if ((id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
451: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
452: SSH_FP_DEFAULT)) == NULL)
1.266 djm 453: fatal_f("fingerprint failed");
1.258 djm 454: notifier = notify_start(0,
455: "Confirm user presence for key %s %s",
456: sshkey_type(id->key), fp);
457: }
1.251 djm 458: }
1.263 djm 459: /* XXX support PIN required FIDO keys */
1.251 djm 460: if ((r = sshkey_sign(id->key, &signature, &slen,
1.270 djm 461: sshbuf_ptr(data), sshbuf_len(data), agent_decode_alg(key, flags),
1.263 djm 462: id->sk_provider, NULL, compat)) != 0) {
1.266 djm 463: error_fr(r, "sshkey_sign");
1.251 djm 464: goto send;
1.33 markus 465: }
1.195 djm 466: /* Success */
467: ok = 0;
468: send:
1.267 djm 469: notify_complete(notifier, "User presence confirmed");
1.270 djm 470:
1.33 markus 471: if (ok == 0) {
1.194 markus 472: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
473: (r = sshbuf_put_string(msg, signature, slen)) != 0)
1.266 djm 474: fatal_fr(r, "compose");
1.194 markus 475: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
1.266 djm 476: fatal_fr(r, "compose failure");
1.194 markus 477:
478: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 479: fatal_fr(r, "enqueue");
1.194 markus 480:
1.270 djm 481: sshbuf_free(data);
1.194 markus 482: sshbuf_free(msg);
1.270 djm 483: sshkey_free(key);
484: free(fp);
1.173 djm 485: free(signature);
1.1 deraadt 486: }
487:
1.33 markus 488: /* shared */
1.55 itojun 489: static void
1.221 djm 490: process_remove_identity(SocketEntry *e)
1.1 deraadt 491: {
1.194 markus 492: int r, success = 0;
493: struct sshkey *key = NULL;
1.221 djm 494: Identity *id;
1.21 markus 495:
1.269 djm 496: debug2_f("entering");
1.221 djm 497: if ((r = sshkey_froms(e->request, &key)) != 0) {
1.266 djm 498: error_fr(r, "parse key");
1.221 djm 499: goto done;
500: }
501: if ((id = lookup_identity(key)) == NULL) {
1.266 djm 502: debug_f("key not found");
1.221 djm 503: goto done;
504: }
505: /* We have this key, free it. */
506: if (idtab->nentries < 1)
1.266 djm 507: fatal_f("internal error: nentries %d", idtab->nentries);
1.221 djm 508: TAILQ_REMOVE(&idtab->idlist, id, next);
509: free_identity(id);
510: idtab->nentries--;
511: sshkey_free(key);
512: success = 1;
513: done:
1.194 markus 514: send_status(e, success);
1.1 deraadt 515: }
516:
1.55 itojun 517: static void
1.221 djm 518: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 519: {
1.78 provos 520: Identity *id;
1.21 markus 521:
1.269 djm 522: debug2_f("entering");
1.21 markus 523: /* Loop over all identities and clear the keys. */
1.221 djm 524: for (id = TAILQ_FIRST(&idtab->idlist); id;
525: id = TAILQ_FIRST(&idtab->idlist)) {
526: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 527: free_identity(id);
1.21 markus 528: }
529:
530: /* Mark that there are no identities. */
1.221 djm 531: idtab->nentries = 0;
1.21 markus 532:
533: /* Send success. */
1.194 markus 534: send_status(e, 1);
1.1 deraadt 535: }
536:
1.155 dtucker 537: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 538: static time_t
1.89 markus 539: reaper(void)
540: {
1.175 dtucker 541: time_t deadline = 0, now = monotime();
1.89 markus 542: Identity *id, *nxt;
543:
1.221 djm 544: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
545: nxt = TAILQ_NEXT(id, next);
546: if (id->death == 0)
547: continue;
548: if (now >= id->death) {
549: debug("expiring key '%s'", id->comment);
550: TAILQ_REMOVE(&idtab->idlist, id, next);
551: free_identity(id);
552: idtab->nentries--;
553: } else
554: deadline = (deadline == 0) ? id->death :
555: MINIMUM(deadline, id->death);
1.89 markus 556: }
1.155 dtucker 557: if (deadline == 0 || deadline <= now)
558: return 0;
559: else
560: return (deadline - now);
1.89 markus 561: }
562:
1.271 ! djm 563: static int
! 564: parse_key_constraints(struct sshbuf *m, struct sshkey *k, time_t *deathp,
! 565: u_int *secondsp, int *confirmp, char **sk_providerp)
1.1 deraadt 566: {
1.194 markus 567: u_char ctype;
1.271 ! djm 568: int r;
! 569: u_int seconds, maxsign = 0;
! 570: char *ext_name = NULL, *sk_provider = NULL;
! 571: size_t pos;
! 572: struct sshbuf *b = NULL;
1.33 markus 573:
1.271 ! djm 574: while (sshbuf_len(m)) {
! 575: if ((r = sshbuf_get_u8(m, &ctype)) != 0) {
1.266 djm 576: error_fr(r, "parse constraint type");
1.194 markus 577: goto err;
578: }
579: switch (ctype) {
1.94 markus 580: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.271 ! djm 581: if (*deathp != 0) {
! 582: error_f("lifetime already set");
! 583: goto err;
! 584: }
! 585: if ((r = sshbuf_get_u32(m, &seconds)) != 0) {
1.266 djm 586: error_fr(r, "parse lifetime constraint");
1.194 markus 587: goto err;
588: }
1.271 ! djm 589: *deathp = monotime() + seconds;
! 590: *secondsp = seconds;
1.94 markus 591: break;
1.107 markus 592: case SSH_AGENT_CONSTRAIN_CONFIRM:
1.271 ! djm 593: if (*confirmp != 0) {
! 594: error_f("confirm already set");
! 595: goto err;
! 596: }
! 597: *confirmp = 1;
1.107 markus 598: break;
1.228 markus 599: case SSH_AGENT_CONSTRAIN_MAXSIGN:
1.271 ! djm 600: if (k == NULL) {
! 601: error_f("maxsign not valid here");
! 602: goto err;
! 603: }
! 604: if (maxsign != 0) {
! 605: error_f("maxsign already set");
! 606: goto err;
! 607: }
! 608: if ((r = sshbuf_get_u32(m, &maxsign)) != 0) {
1.266 djm 609: error_fr(r, "parse maxsign constraint");
1.228 markus 610: goto err;
611: }
612: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
1.266 djm 613: error_fr(r, "enable maxsign");
1.228 markus 614: goto err;
615: }
616: break;
1.238 djm 617: case SSH_AGENT_CONSTRAIN_EXTENSION:
1.271 ! djm 618: if ((r = sshbuf_get_cstring(m, &ext_name, NULL)) != 0) {
1.266 djm 619: error_fr(r, "parse constraint extension");
1.238 djm 620: goto err;
621: }
1.266 djm 622: debug_f("constraint ext %s", ext_name);
1.238 djm 623: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
1.271 ! djm 624: if (sk_providerp == NULL) {
! 625: error_f("%s not valid here", ext_name);
! 626: goto err;
! 627: }
! 628: if (*sk_providerp != NULL) {
! 629: error_f("%s already set", ext_name);
1.238 djm 630: goto err;
631: }
1.271 ! djm 632: if ((r = sshbuf_get_cstring(m,
! 633: sk_providerp, NULL)) != 0) {
1.266 djm 634: error_fr(r, "parse %s", ext_name);
1.238 djm 635: goto err;
636: }
637: } else {
1.266 djm 638: error_f("unsupported constraint \"%s\"",
639: ext_name);
1.238 djm 640: goto err;
641: }
642: free(ext_name);
643: break;
1.94 markus 644: default:
1.266 djm 645: error_f("Unknown constraint %d", ctype);
1.194 markus 646: err:
1.238 djm 647: free(ext_name);
1.271 ! djm 648: sshbuf_free(b);
! 649: return -1;
1.94 markus 650: }
651: }
1.271 ! djm 652: /* success */
! 653: return 0;
! 654: }
! 655:
! 656: static void
! 657: process_add_identity(SocketEntry *e)
! 658: {
! 659: Identity *id;
! 660: int success = 0, confirm = 0;
! 661: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
! 662: char canonical_provider[PATH_MAX];
! 663: time_t death = 0;
! 664: u_int seconds = 0;
! 665: struct sshkey *k = NULL;
! 666: int r = SSH_ERR_INTERNAL_ERROR;
! 667:
! 668: debug2_f("entering");
! 669: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
! 670: k == NULL ||
! 671: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
! 672: error_fr(r, "parse");
! 673: goto out;
! 674: }
! 675: if (parse_key_constraints(e->request, k, &death, &seconds, &confirm,
! 676: &sk_provider) != 0) {
! 677: error_f("failed to parse constraints");
! 678: sshbuf_reset(e->request);
! 679: goto out;
! 680: }
! 681:
1.238 djm 682: if (sk_provider != NULL) {
1.240 markus 683: if (!sshkey_is_sk(k)) {
1.255 naddy 684: error("Cannot add provider: %s is not an "
685: "authenticator-hosted key", sshkey_type(k));
1.271 ! djm 686: goto out;
1.238 djm 687: }
1.254 djm 688: if (strcasecmp(sk_provider, "internal") == 0) {
1.266 djm 689: debug_f("internal provider");
1.254 djm 690: } else {
691: if (realpath(sk_provider, canonical_provider) == NULL) {
692: verbose("failed provider \"%.100s\": "
693: "realpath: %s", sk_provider,
694: strerror(errno));
1.271 ! djm 695: goto out;
1.254 djm 696: }
1.238 djm 697: free(sk_provider);
1.254 djm 698: sk_provider = xstrdup(canonical_provider);
699: if (match_pattern_list(sk_provider,
1.260 djm 700: allowed_providers, 0) != 1) {
1.254 djm 701: error("Refusing add key: "
1.260 djm 702: "provider %s not allowed", sk_provider);
1.271 ! djm 703: goto out;
1.254 djm 704: }
1.238 djm 705: }
1.242 markus 706: }
707: if ((r = sshkey_shield_private(k)) != 0) {
1.266 djm 708: error_fr(r, "shield private");
1.271 ! djm 709: goto out;
1.238 djm 710: }
1.106 marc 711: if (lifetime && !death)
1.175 dtucker 712: death = monotime() + lifetime;
1.221 djm 713: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 714: id = xcalloc(1, sizeof(Identity));
1.221 djm 715: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 716: /* Increment the number of identities. */
1.221 djm 717: idtab->nentries++;
1.33 markus 718: } else {
1.228 markus 719: /* key state might have been updated */
720: sshkey_free(id->key);
1.173 djm 721: free(id->comment);
1.238 djm 722: free(id->sk_provider);
1.33 markus 723: }
1.271 ! djm 724: /* success */
1.228 markus 725: id->key = k;
1.157 canacar 726: id->comment = comment;
727: id->death = death;
728: id->confirm = confirm;
1.238 djm 729: id->sk_provider = sk_provider;
730:
731: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
732: SSH_FP_DEFAULT)) == NULL)
1.266 djm 733: fatal_f("sshkey_fingerprint failed");
734: debug_f("add %s %s \"%.100s\" (life: %u) (confirm: %u) "
1.271 ! djm 735: "(provider: %s)", sshkey_ssh_name(k), fp, comment, seconds,
! 736: confirm, sk_provider == NULL ? "none" : sk_provider);
1.238 djm 737: free(fp);
1.271 ! djm 738: /* transferred */
! 739: k = NULL;
! 740: comment = NULL;
! 741: sk_provider = NULL;
! 742: success = 1;
! 743: out:
! 744: free(sk_provider);
! 745: free(comment);
! 746: sshkey_free(k);
1.194 markus 747: send_status(e, success);
1.1 deraadt 748: }
749:
1.88 markus 750: /* XXX todo: encrypt sensitive data with passphrase */
751: static void
752: process_lock_agent(SocketEntry *e, int lock)
753: {
1.203 dtucker 754: int r, success = 0, delay;
1.213 djm 755: char *passwd;
756: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 757: static u_int fail_count = 0;
758: size_t pwlen;
759:
1.269 djm 760: debug2_f("entering");
1.226 djm 761: /*
762: * This is deliberately fatal: the user has requested that we lock,
763: * but we can't parse their request properly. The only safe thing to
764: * do is abort.
765: */
1.203 dtucker 766: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
1.266 djm 767: fatal_fr(r, "parse");
1.203 dtucker 768: if (pwlen == 0) {
769: debug("empty password not supported");
770: } else if (locked && !lock) {
771: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
772: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
773: fatal("bcrypt_pbkdf");
1.213 djm 774: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 775: debug("agent unlocked");
776: locked = 0;
777: fail_count = 0;
1.213 djm 778: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 779: success = 1;
780: } else {
781: /* delay in 0.1s increments up to 10s */
782: if (fail_count < 100)
783: fail_count++;
784: delay = 100000 * fail_count;
785: debug("unlock failed, delaying %0.1lf seconds",
786: (double)delay/1000000);
787: usleep(delay);
788: }
789: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 790: } else if (!locked && lock) {
1.203 dtucker 791: debug("agent locked");
1.88 markus 792: locked = 1;
1.203 dtucker 793: arc4random_buf(lock_salt, sizeof(lock_salt));
794: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 795: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 796: fatal("bcrypt_pbkdf");
1.88 markus 797: success = 1;
798: }
1.256 jsg 799: freezero(passwd, pwlen);
1.194 markus 800: send_status(e, success);
1.88 markus 801: }
802:
803: static void
1.221 djm 804: no_identities(SocketEntry *e)
1.88 markus 805: {
1.194 markus 806: struct sshbuf *msg;
807: int r;
1.88 markus 808:
1.194 markus 809: if ((msg = sshbuf_new()) == NULL)
1.266 djm 810: fatal_f("sshbuf_new failed");
1.221 djm 811: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 812: (r = sshbuf_put_u32(msg, 0)) != 0 ||
813: (r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 814: fatal_fr(r, "compose");
1.194 markus 815: sshbuf_free(msg);
1.88 markus 816: }
1.59 markus 817:
1.163 markus 818: #ifdef ENABLE_PKCS11
1.59 markus 819: static void
1.158 djm 820: process_add_smartcard_key(SocketEntry *e)
1.59 markus 821: {
1.226 djm 822: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.253 djm 823: char **comments = NULL;
1.221 djm 824: int r, i, count = 0, success = 0, confirm = 0;
1.271 ! djm 825: u_int seconds = 0;
1.174 dtucker 826: time_t death = 0;
1.194 markus 827: u_char type;
828: struct sshkey **keys = NULL, *k;
1.84 markus 829: Identity *id;
1.75 deraadt 830:
1.269 djm 831: debug2_f("entering");
1.194 markus 832: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 833: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 djm 834: error_fr(r, "parse");
1.226 djm 835: goto send;
836: }
1.271 ! djm 837: if (parse_key_constraints(e->request, NULL, &death, &seconds, &confirm,
! 838: NULL) != 0) {
! 839: error_f("failed to parse constraints");
! 840: goto send;
1.110 djm 841: }
1.215 djm 842: if (realpath(provider, canonical_provider) == NULL) {
843: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
844: provider, strerror(errno));
845: goto send;
846: }
1.260 djm 847: if (match_pattern_list(canonical_provider, allowed_providers, 0) != 1) {
1.215 djm 848: verbose("refusing PKCS#11 add of \"%.100s\": "
1.260 djm 849: "provider not allowed", canonical_provider);
1.215 djm 850: goto send;
851: }
1.266 djm 852: debug_f("add %.100s", canonical_provider);
1.110 djm 853: if (lifetime && !death)
1.175 dtucker 854: death = monotime() + lifetime;
1.110 djm 855:
1.253 djm 856: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.163 markus 857: for (i = 0; i < count; i++) {
1.84 markus 858: k = keys[i];
1.221 djm 859: if (lookup_identity(k) == NULL) {
1.163 markus 860: id = xcalloc(1, sizeof(Identity));
1.84 markus 861: id->key = k;
1.253 djm 862: keys[i] = NULL; /* transferred */
1.215 djm 863: id->provider = xstrdup(canonical_provider);
1.253 djm 864: if (*comments[i] != '\0') {
865: id->comment = comments[i];
866: comments[i] = NULL; /* transferred */
867: } else {
868: id->comment = xstrdup(canonical_provider);
869: }
1.110 djm 870: id->death = death;
871: id->confirm = confirm;
1.221 djm 872: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
873: idtab->nentries++;
1.84 markus 874: success = 1;
875: }
1.271 ! djm 876: /* XXX update constraints for existing keys */
1.253 djm 877: sshkey_free(keys[i]);
878: free(comments[i]);
1.59 markus 879: }
880: send:
1.173 djm 881: free(pin);
882: free(provider);
883: free(keys);
1.253 djm 884: free(comments);
1.194 markus 885: send_status(e, success);
1.59 markus 886: }
887:
888: static void
889: process_remove_smartcard_key(SocketEntry *e)
890: {
1.217 djm 891: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 892: int r, success = 0;
1.163 markus 893: Identity *id, *nxt;
1.59 markus 894:
1.269 djm 895: debug2_f("entering");
1.194 markus 896: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 897: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 djm 898: error_fr(r, "parse");
1.226 djm 899: goto send;
900: }
1.173 djm 901: free(pin);
1.59 markus 902:
1.217 djm 903: if (realpath(provider, canonical_provider) == NULL) {
904: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
905: provider, strerror(errno));
906: goto send;
907: }
908:
1.266 djm 909: debug_f("remove %.100s", canonical_provider);
1.221 djm 910: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
911: nxt = TAILQ_NEXT(id, next);
912: /* Skip file--based keys */
913: if (id->provider == NULL)
914: continue;
915: if (!strcmp(canonical_provider, id->provider)) {
916: TAILQ_REMOVE(&idtab->idlist, id, next);
917: free_identity(id);
918: idtab->nentries--;
1.59 markus 919: }
920: }
1.217 djm 921: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 922: success = 1;
923: else
1.266 djm 924: error_f("pkcs11_del_provider failed");
1.218 deraadt 925: send:
1.173 djm 926: free(provider);
1.194 markus 927: send_status(e, success);
1.59 markus 928: }
1.163 markus 929: #endif /* ENABLE_PKCS11 */
1.59 markus 930:
1.264 djm 931: /*
932: * dispatch incoming message.
933: * returns 1 on success, 0 for incomplete messages or -1 on error.
934: */
1.223 djm 935: static int
936: process_message(u_int socknum)
1.1 deraadt 937: {
1.194 markus 938: u_int msg_len;
939: u_char type;
940: const u_char *cp;
941: int r;
1.223 djm 942: SocketEntry *e;
943:
1.266 djm 944: if (socknum >= sockets_alloc)
945: fatal_f("sock %u >= allocated %u", socknum, sockets_alloc);
1.223 djm 946: e = &sockets[socknum];
1.89 markus 947:
1.194 markus 948: if (sshbuf_len(e->input) < 5)
1.223 djm 949: return 0; /* Incomplete message header. */
1.194 markus 950: cp = sshbuf_ptr(e->input);
951: msg_len = PEEK_U32(cp);
1.223 djm 952: if (msg_len > AGENT_MAX_LEN) {
1.266 djm 953: debug_f("socket %u (fd=%d) message too long %u > %u",
954: socknum, e->fd, msg_len, AGENT_MAX_LEN);
1.223 djm 955: return -1;
1.21 markus 956: }
1.194 markus 957: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 958: return 0; /* Incomplete message body. */
1.87 markus 959:
960: /* move the current input to e->request */
1.194 markus 961: sshbuf_reset(e->request);
962: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 963: (r = sshbuf_get_u8(e->request, &type)) != 0) {
964: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
965: r == SSH_ERR_STRING_TOO_LARGE) {
1.266 djm 966: error_fr(r, "parse");
1.223 djm 967: return -1;
968: }
1.266 djm 969: fatal_fr(r, "parse");
1.223 djm 970: }
971:
1.266 djm 972: debug_f("socket %u (fd=%d) type %d", socknum, e->fd, type);
1.21 markus 973:
1.230 djm 974: /* check whether agent is locked */
1.88 markus 975: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 976: sshbuf_reset(e->request);
1.88 markus 977: switch (type) {
978: case SSH2_AGENTC_REQUEST_IDENTITIES:
979: /* send empty lists */
1.221 djm 980: no_identities(e);
1.88 markus 981: break;
982: default:
983: /* send a fail message for all other request types */
1.194 markus 984: send_status(e, 0);
1.88 markus 985: }
1.264 djm 986: return 1;
1.88 markus 987: }
988:
1.21 markus 989: switch (type) {
1.88 markus 990: case SSH_AGENTC_LOCK:
991: case SSH_AGENTC_UNLOCK:
992: process_lock_agent(e, type == SSH_AGENTC_LOCK);
993: break;
1.21 markus 994: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 995: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 996: break;
997: /* ssh2 */
998: case SSH2_AGENTC_SIGN_REQUEST:
999: process_sign_request2(e);
1000: break;
1001: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 1002: process_request_identities(e);
1.33 markus 1003: break;
1004: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 1005: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 1006: process_add_identity(e);
1.33 markus 1007: break;
1008: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 1009: process_remove_identity(e);
1.33 markus 1010: break;
1011: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 1012: process_remove_all_identities(e);
1.21 markus 1013: break;
1.163 markus 1014: #ifdef ENABLE_PKCS11
1.59 markus 1015: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 1016: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 1017: process_add_smartcard_key(e);
1.75 deraadt 1018: break;
1.59 markus 1019: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
1020: process_remove_smartcard_key(e);
1.75 deraadt 1021: break;
1.163 markus 1022: #endif /* ENABLE_PKCS11 */
1.21 markus 1023: default:
1024: /* Unknown message. Respond with failure. */
1025: error("Unknown message %d", type);
1.194 markus 1026: sshbuf_reset(e->request);
1027: send_status(e, 0);
1.21 markus 1028: break;
1029: }
1.264 djm 1030: return 1;
1.1 deraadt 1031: }
1032:
1.55 itojun 1033: static void
1.73 stevesk 1034: new_socket(sock_type type, int fd)
1.1 deraadt 1035: {
1.112 markus 1036: u_int i, old_alloc, new_alloc;
1.96 deraadt 1037:
1.269 djm 1038: debug_f("type = %s", type == AUTH_CONNECTION ? "CONNECTION" :
1039: (type == AUTH_SOCKET ? "SOCKET" : "UNKNOWN"));
1.119 djm 1040: set_nonblock(fd);
1.21 markus 1041:
1042: if (fd > max_fd)
1043: max_fd = fd;
1044:
1045: for (i = 0; i < sockets_alloc; i++)
1046: if (sockets[i].type == AUTH_UNUSED) {
1047: sockets[i].fd = fd;
1.266 djm 1048: if ((sockets[i].input = sshbuf_new()) == NULL ||
1049: (sockets[i].output = sshbuf_new()) == NULL ||
1050: (sockets[i].request = sshbuf_new()) == NULL)
1051: fatal_f("sshbuf_new failed");
1.112 markus 1052: sockets[i].type = type;
1.21 markus 1053: return;
1054: }
1055: old_alloc = sockets_alloc;
1.112 markus 1056: new_alloc = sockets_alloc + 10;
1.269 djm 1057: sockets = xrecallocarray(sockets, old_alloc, new_alloc,
1058: sizeof(sockets[0]));
1.112 markus 1059: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 1060: sockets[i].type = AUTH_UNUSED;
1.112 markus 1061: sockets_alloc = new_alloc;
1.21 markus 1062: sockets[old_alloc].fd = fd;
1.266 djm 1063: if ((sockets[old_alloc].input = sshbuf_new()) == NULL ||
1064: (sockets[old_alloc].output = sshbuf_new()) == NULL ||
1065: (sockets[old_alloc].request = sshbuf_new()) == NULL)
1066: fatal_f("sshbuf_new failed");
1.112 markus 1067: sockets[old_alloc].type = type;
1.1 deraadt 1068: }
1069:
1.55 itojun 1070: static int
1.223 djm 1071: handle_socket_read(u_int socknum)
1.1 deraadt 1072: {
1.223 djm 1073: struct sockaddr_un sunaddr;
1074: socklen_t slen;
1075: uid_t euid;
1076: gid_t egid;
1077: int fd;
1078:
1079: slen = sizeof(sunaddr);
1080: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1081: if (fd == -1) {
1.223 djm 1082: error("accept from AUTH_SOCKET: %s", strerror(errno));
1083: return -1;
1084: }
1.237 deraadt 1085: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1086: error("getpeereid %d failed: %s", fd, strerror(errno));
1087: close(fd);
1088: return -1;
1089: }
1090: if ((euid != 0) && (getuid() != euid)) {
1091: error("uid mismatch: peer euid %u != uid %u",
1092: (u_int) euid, (u_int) getuid());
1093: close(fd);
1094: return -1;
1095: }
1096: new_socket(AUTH_CONNECTION, fd);
1097: return 0;
1098: }
1099:
1100: static int
1101: handle_conn_read(u_int socknum)
1102: {
1.233 djm 1103: char buf[AGENT_RBUF_LEN];
1.223 djm 1104: ssize_t len;
1105: int r;
1106:
1107: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1108: if (len == -1) {
1109: if (errno == EAGAIN || errno == EINTR)
1110: return 0;
1.266 djm 1111: error_f("read error on socket %u (fd %d): %s",
1112: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1113: }
1114: return -1;
1115: }
1116: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1.266 djm 1117: fatal_fr(r, "compose");
1.223 djm 1118: explicit_bzero(buf, sizeof(buf));
1.264 djm 1119: for (;;) {
1120: if ((r = process_message(socknum)) == -1)
1121: return -1;
1122: else if (r == 0)
1123: break;
1124: }
1.223 djm 1125: return 0;
1126: }
1127:
1128: static int
1129: handle_conn_write(u_int socknum)
1130: {
1131: ssize_t len;
1132: int r;
1133:
1134: if (sshbuf_len(sockets[socknum].output) == 0)
1135: return 0; /* shouldn't happen */
1136: if ((len = write(sockets[socknum].fd,
1137: sshbuf_ptr(sockets[socknum].output),
1138: sshbuf_len(sockets[socknum].output))) <= 0) {
1139: if (len == -1) {
1140: if (errno == EAGAIN || errno == EINTR)
1141: return 0;
1.266 djm 1142: error_f("read error on socket %u (fd %d): %s",
1143: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1144: }
1145: return -1;
1146: }
1147: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1.266 djm 1148: fatal_fr(r, "consume");
1.223 djm 1149: return 0;
1150: }
1151:
1152: static void
1.231 djm 1153: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1154: {
1155: size_t i;
1.231 djm 1156: u_int socknum, activefds = npfd;
1.223 djm 1157:
1158: for (i = 0; i < npfd; i++) {
1159: if (pfd[i].revents == 0)
1160: continue;
1161: /* Find sockets entry */
1162: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1163: if (sockets[socknum].type != AUTH_SOCKET &&
1164: sockets[socknum].type != AUTH_CONNECTION)
1165: continue;
1166: if (pfd[i].fd == sockets[socknum].fd)
1167: break;
1168: }
1169: if (socknum >= sockets_alloc) {
1.266 djm 1170: error_f("no socket for fd %d", pfd[i].fd);
1.223 djm 1171: continue;
1172: }
1173: /* Process events */
1174: switch (sockets[socknum].type) {
1175: case AUTH_SOCKET:
1.231 djm 1176: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1177: break;
1178: if (npfd > maxfds) {
1179: debug3("out of fds (active %u >= limit %u); "
1180: "skipping accept", activefds, maxfds);
1181: break;
1182: }
1183: if (handle_socket_read(socknum) == 0)
1184: activefds++;
1.223 djm 1185: break;
1186: case AUTH_CONNECTION:
1187: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1188: handle_conn_read(socknum) != 0) {
1.231 djm 1189: goto close_sock;
1190: }
1191: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1192: handle_conn_write(socknum) != 0) {
1193: close_sock:
1194: if (activefds == 0)
1195: fatal("activefds == 0 at close_sock");
1.223 djm 1196: close_socket(&sockets[socknum]);
1.231 djm 1197: activefds--;
1.223 djm 1198: break;
1199: }
1200: break;
1201: default:
1202: break;
1203: }
1204: }
1205: }
1206:
1207: static int
1.231 djm 1208: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1209: {
1210: struct pollfd *pfd = *pfdp;
1211: size_t i, j, npfd = 0;
1.174 dtucker 1212: time_t deadline;
1.233 djm 1213: int r;
1.46 markus 1214:
1.223 djm 1215: /* Count active sockets */
1.46 markus 1216: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1217: switch (sockets[i].type) {
1218: case AUTH_SOCKET:
1219: case AUTH_CONNECTION:
1.223 djm 1220: npfd++;
1.21 markus 1221: break;
1222: case AUTH_UNUSED:
1223: break;
1224: default:
1225: fatal("Unknown socket type %d", sockets[i].type);
1226: break;
1227: }
1.46 markus 1228: }
1.223 djm 1229: if (npfd != *npfdp &&
1230: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1.266 djm 1231: fatal_f("recallocarray failed");
1.223 djm 1232: *pfdp = pfd;
1233: *npfdp = npfd;
1.46 markus 1234:
1.223 djm 1235: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1236: switch (sockets[i].type) {
1237: case AUTH_SOCKET:
1.231 djm 1238: if (npfd > maxfds) {
1239: debug3("out of fds (active %zu >= limit %u); "
1240: "skipping arming listener", npfd, maxfds);
1241: break;
1242: }
1243: pfd[j].fd = sockets[i].fd;
1244: pfd[j].revents = 0;
1245: pfd[j].events = POLLIN;
1246: j++;
1247: break;
1.46 markus 1248: case AUTH_CONNECTION:
1.223 djm 1249: pfd[j].fd = sockets[i].fd;
1250: pfd[j].revents = 0;
1.233 djm 1251: /*
1252: * Only prepare to read if we can handle a full-size
1253: * input read buffer and enqueue a max size reply..
1254: */
1255: if ((r = sshbuf_check_reserve(sockets[i].input,
1256: AGENT_RBUF_LEN)) == 0 &&
1257: (r = sshbuf_check_reserve(sockets[i].output,
1258: AGENT_MAX_LEN)) == 0)
1259: pfd[j].events = POLLIN;
1.266 djm 1260: else if (r != SSH_ERR_NO_BUFFER_SPACE)
1261: fatal_fr(r, "reserve");
1.194 markus 1262: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1263: pfd[j].events |= POLLOUT;
1264: j++;
1.46 markus 1265: break;
1266: default:
1267: break;
1268: }
1269: }
1.155 dtucker 1270: deadline = reaper();
1271: if (parent_alive_interval != 0)
1272: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1273: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1274: if (deadline == 0) {
1.224 djm 1275: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1276: } else {
1.223 djm 1277: if (deadline > INT_MAX / 1000)
1278: *timeoutp = INT_MAX / 1000;
1279: else
1280: *timeoutp = deadline * 1000;
1.155 dtucker 1281: }
1.46 markus 1282: return (1);
1.21 markus 1283: }
1284:
1.55 itojun 1285: static void
1.113 markus 1286: cleanup_socket(void)
1.15 markus 1287: {
1.187 djm 1288: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1289: return;
1.266 djm 1290: debug_f("cleanup");
1.48 deraadt 1291: if (socket_name[0])
1292: unlink(socket_name);
1293: if (socket_dir[0])
1294: rmdir(socket_dir);
1.10 markus 1295: }
1296:
1.114 markus 1297: void
1.15 markus 1298: cleanup_exit(int i)
1299: {
1.113 markus 1300: cleanup_socket();
1301: _exit(i);
1.15 markus 1302: }
1303:
1.135 deraadt 1304: /*ARGSUSED*/
1.55 itojun 1305: static void
1.48 deraadt 1306: cleanup_handler(int sig)
1307: {
1.113 markus 1308: cleanup_socket();
1.163 markus 1309: #ifdef ENABLE_PKCS11
1310: pkcs11_terminate();
1311: #endif
1.48 deraadt 1312: _exit(2);
1.113 markus 1313: }
1314:
1.68 markus 1315: static void
1.155 dtucker 1316: check_parent_exists(void)
1.68 markus 1317: {
1.172 dtucker 1318: /*
1319: * If our parent has exited then getppid() will return (pid_t)1,
1320: * so testing for that should be safe.
1321: */
1322: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1323: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1324: cleanup_socket();
1325: _exit(2);
1.68 markus 1326: }
1.48 deraadt 1327: }
1328:
1.55 itojun 1329: static void
1.50 itojun 1330: usage(void)
1.15 markus 1331: {
1.184 deraadt 1332: fprintf(stderr,
1.250 jmc 1333: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.261 jmc 1334: " [-P allowed_providers] [-t life]\n"
1.260 djm 1335: " ssh-agent [-a bind_address] [-E fingerprint_hash] [-P allowed_providers]\n"
1.259 dtucker 1336: " [-t life] command [arg ...]\n"
1.250 jmc 1337: " ssh-agent [-c | -s] -k\n");
1.21 markus 1338: exit(1);
1.15 markus 1339: }
1340:
1.2 provos 1341: int
1342: main(int ac, char **av)
1.1 deraadt 1343: {
1.201 djm 1344: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.265 djm 1345: int sock, ch, result, saved_errno;
1.96 deraadt 1346: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1347: struct rlimit rlim;
1.96 deraadt 1348: extern int optind;
1.98 stevesk 1349: extern char *optarg;
1.21 markus 1350: pid_t pid;
1.96 deraadt 1351: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1352: size_t len;
1.189 djm 1353: mode_t prev_mask;
1.224 djm 1354: int timeout = -1; /* INFTIM */
1.223 djm 1355: struct pollfd *pfd = NULL;
1356: size_t npfd = 0;
1.231 djm 1357: u_int maxfds;
1.123 djm 1358:
1359: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1360: sanitise_stdfd();
1.99 markus 1361:
1362: /* drop */
1363: setegid(getgid());
1364: setgid(getgid());
1.53 markus 1365:
1.231 djm 1366: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1367: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1368:
1.185 markus 1369: #ifdef WITH_OPENSSL
1.170 djm 1370: OpenSSL_add_all_algorithms();
1.185 markus 1371: #endif
1.21 markus 1372:
1.258 djm 1373: while ((ch = getopt(ac, av, "cDdksE:a:O:P:t:")) != -1) {
1.21 markus 1374: switch (ch) {
1.192 djm 1375: case 'E':
1376: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1377: if (fingerprint_hash == -1)
1378: fatal("Invalid hash algorithm \"%s\"", optarg);
1379: break;
1.21 markus 1380: case 'c':
1381: if (s_flag)
1382: usage();
1383: c_flag++;
1384: break;
1385: case 'k':
1386: k_flag++;
1.258 djm 1387: break;
1388: case 'O':
1389: if (strcmp(optarg, "no-restrict-websafe") == 0)
1390: restrict_websafe = 0;
1391: else
1392: fatal("Unknown -O option");
1.21 markus 1393: break;
1.215 djm 1394: case 'P':
1.260 djm 1395: if (allowed_providers != NULL)
1.215 djm 1396: fatal("-P option already specified");
1.260 djm 1397: allowed_providers = xstrdup(optarg);
1.215 djm 1398: break;
1.21 markus 1399: case 's':
1400: if (c_flag)
1401: usage();
1402: s_flag++;
1403: break;
1.57 markus 1404: case 'd':
1.201 djm 1405: if (d_flag || D_flag)
1.57 markus 1406: usage();
1407: d_flag++;
1408: break;
1.201 djm 1409: case 'D':
1410: if (d_flag || D_flag)
1411: usage();
1412: D_flag++;
1413: break;
1.86 markus 1414: case 'a':
1415: agentsocket = optarg;
1.106 marc 1416: break;
1417: case 't':
1418: if ((lifetime = convtime(optarg)) == -1) {
1419: fprintf(stderr, "Invalid lifetime\n");
1420: usage();
1421: }
1.86 markus 1422: break;
1.21 markus 1423: default:
1424: usage();
1425: }
1426: }
1427: ac -= optind;
1428: av += optind;
1429:
1.201 djm 1430: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1431: usage();
1432:
1.260 djm 1433: if (allowed_providers == NULL)
1.262 djm 1434: allowed_providers = xstrdup(DEFAULT_ALLOWED_PROVIDERS);
1.215 djm 1435:
1.85 markus 1436: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1437: shell = getenv("SHELL");
1.161 tobias 1438: if (shell != NULL && (len = strlen(shell)) > 2 &&
1439: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1440: c_flag = 1;
1441: }
1442: if (k_flag) {
1.136 deraadt 1443: const char *errstr = NULL;
1444:
1.21 markus 1445: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1446: if (pidstr == NULL) {
1447: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1448: SSH_AGENTPID_ENV_NAME);
1.21 markus 1449: exit(1);
1450: }
1.136 deraadt 1451: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1452: if (errstr) {
1453: fprintf(stderr,
1454: "%s=\"%s\", which is not a good PID: %s\n",
1455: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1456: exit(1);
1457: }
1458: if (kill(pid, SIGTERM) == -1) {
1459: perror("kill");
1460: exit(1);
1461: }
1462: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1463: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1464: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1465: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1466: exit(0);
1467: }
1.231 djm 1468:
1469: /*
1470: * Minimum file descriptors:
1471: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1472: * a few spare for libc / stack protectors / sanitisers, etc.
1473: */
1474: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1475: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1476: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1477: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1478: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1479:
1.21 markus 1480: parent_pid = getpid();
1481:
1.86 markus 1482: if (agentsocket == NULL) {
1483: /* Create private directory for agent socket */
1.171 djm 1484: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1485: if (mkdtemp(socket_dir) == NULL) {
1486: perror("mkdtemp: private socket dir");
1487: exit(1);
1488: }
1.91 mpech 1489: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1490: (long)parent_pid);
1.86 markus 1491: } else {
1492: /* Try to use specified agent socket */
1493: socket_dir[0] = '\0';
1494: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1495: }
1496:
1.23 markus 1497: /*
1498: * Create socket early so it will exist before command gets run from
1499: * the parent.
1500: */
1.189 djm 1501: prev_mask = umask(0177);
1.188 millert 1502: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1503: if (sock < 0) {
1.188 millert 1504: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1505: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1506: cleanup_exit(1);
1507: }
1.189 djm 1508: umask(prev_mask);
1.46 markus 1509:
1.23 markus 1510: /*
1511: * Fork, and have the parent execute the command, if any, or present
1512: * the socket data. The child continues as the authentication agent.
1513: */
1.201 djm 1514: if (D_flag || d_flag) {
1515: log_init(__progname,
1516: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1517: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1518: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1519: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1520: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1521: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1522: fflush(stdout);
1.57 markus 1523: goto skip;
1524: }
1.21 markus 1525: pid = fork();
1526: if (pid == -1) {
1527: perror("fork");
1.81 stevesk 1528: cleanup_exit(1);
1.21 markus 1529: }
1530: if (pid != 0) { /* Parent - execute the given command. */
1531: close(sock);
1.91 mpech 1532: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1533: if (ac == 0) {
1534: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1535: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1536: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1537: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1538: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1539: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1540: exit(0);
1541: }
1.36 deraadt 1542: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1543: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1544: perror("setenv");
1545: exit(1);
1546: }
1.21 markus 1547: execvp(av[0], av);
1548: perror(av[0]);
1549: exit(1);
1550: }
1.81 stevesk 1551: /* child */
1552: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1553:
1554: if (setsid() == -1) {
1.81 stevesk 1555: error("setsid: %s", strerror(errno));
1.67 stevesk 1556: cleanup_exit(1);
1557: }
1558:
1559: (void)chdir("/");
1.265 djm 1560: if (stdfd_devnull(1, 1, 1) == -1)
1.266 djm 1561: error_f("stdfd_devnull failed");
1.21 markus 1562:
1.41 markus 1563: /* deny core dumps, since memory contains unencrypted private keys */
1564: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1565: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1566: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1567: cleanup_exit(1);
1568: }
1.57 markus 1569:
1570: skip:
1.187 djm 1571:
1572: cleanup_pid = getpid();
1.163 markus 1573:
1574: #ifdef ENABLE_PKCS11
1575: pkcs11_init(0);
1576: #endif
1.21 markus 1577: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1578: if (ac > 0)
1579: parent_alive_interval = 10;
1.33 markus 1580: idtab_init();
1.252 dtucker 1581: ssh_signal(SIGPIPE, SIG_IGN);
1582: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1583: ssh_signal(SIGHUP, cleanup_handler);
1584: ssh_signal(SIGTERM, cleanup_handler);
1.205 djm 1585:
1.215 djm 1586: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1587: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1588:
1.21 markus 1589: while (1) {
1.231 djm 1590: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1591: result = poll(pfd, npfd, timeout);
1.154 dtucker 1592: saved_errno = errno;
1.155 dtucker 1593: if (parent_alive_interval != 0)
1594: check_parent_exists();
1595: (void) reaper(); /* remove expired keys */
1.237 deraadt 1596: if (result == -1) {
1.154 dtucker 1597: if (saved_errno == EINTR)
1.21 markus 1598: continue;
1.223 djm 1599: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1600: } else if (result > 0)
1.231 djm 1601: after_poll(pfd, npfd, maxfds);
1.15 markus 1602: }
1.21 markus 1603: /* NOTREACHED */
1.1 deraadt 1604: }
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