Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.246
1.246 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.245 2019/11/15 04:12:32 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>
1.196 deraadt 58: #include <limits.h>
1.145 stevesk 59: #include <time.h>
1.144 stevesk 60: #include <unistd.h>
1.203 dtucker 61: #include <util.h>
1.194 markus 62:
1.151 deraadt 63: #include "xmalloc.h"
1.1 deraadt 64: #include "ssh.h"
1.194 markus 65: #include "sshbuf.h"
66: #include "sshkey.h"
1.32 markus 67: #include "authfd.h"
1.37 markus 68: #include "compat.h"
1.47 markus 69: #include "log.h"
1.107 markus 70: #include "misc.h"
1.182 markus 71: #include "digest.h"
1.194 markus 72: #include "ssherr.h"
1.215 djm 73: #include "match.h"
1.238 djm 74: #include "msg.h"
1.244 djm 75: #include "ssherr.h"
1.238 djm 76: #include "pathnames.h"
1.163 markus 77: #include "ssh-pkcs11.h"
1.238 djm 78: #include "ssh-sk.h"
1.59 markus 79:
1.238 djm 80: #ifndef DEFAULT_PROVIDER_WHITELIST
81: # define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 82: #endif
83:
1.223 djm 84: /* Maximum accepted message length */
85: #define AGENT_MAX_LEN (256*1024)
1.233 djm 86: /* Maximum bytes to read from client socket */
87: #define AGENT_RBUF_LEN (4096)
1.223 djm 88:
1.73 stevesk 89: typedef enum {
90: AUTH_UNUSED,
91: AUTH_SOCKET,
92: AUTH_CONNECTION
93: } sock_type;
94:
1.21 markus 95: typedef struct {
96: int fd;
1.73 stevesk 97: sock_type type;
1.194 markus 98: struct sshbuf *input;
99: struct sshbuf *output;
100: struct sshbuf *request;
1.1 deraadt 101: } SocketEntry;
102:
1.45 markus 103: u_int sockets_alloc = 0;
1.1 deraadt 104: SocketEntry *sockets = NULL;
105:
1.78 provos 106: typedef struct identity {
107: TAILQ_ENTRY(identity) next;
1.194 markus 108: struct sshkey *key;
1.21 markus 109: char *comment;
1.163 markus 110: char *provider;
1.174 dtucker 111: time_t death;
1.107 markus 112: u_int confirm;
1.238 djm 113: char *sk_provider;
1.1 deraadt 114: } Identity;
115:
1.221 djm 116: struct idtable {
1.33 markus 117: int nentries;
1.78 provos 118: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 119: };
1.33 markus 120:
1.221 djm 121: /* private key table */
122: struct idtable *idtab;
1.1 deraadt 123:
124: int max_fd = 0;
125:
1.11 markus 126: /* pid of shell == parent of agent */
1.29 deraadt 127: pid_t parent_pid = -1;
1.176 dtucker 128: time_t parent_alive_interval = 0;
1.10 markus 129:
1.187 djm 130: /* pid of process for which cleanup_socket is applicable */
131: pid_t cleanup_pid = 0;
132:
1.10 markus 133: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 134: char socket_name[PATH_MAX];
135: char socket_dir[PATH_MAX];
1.10 markus 136:
1.238 djm 137: /* PKCS#11/Security key path whitelist */
138: static char *provider_whitelist;
1.215 djm 139:
1.88 markus 140: /* locking */
1.203 dtucker 141: #define LOCK_SIZE 32
142: #define LOCK_SALT_SIZE 16
143: #define LOCK_ROUNDS 1
1.88 markus 144: int locked = 0;
1.213 djm 145: u_char lock_pwhash[LOCK_SIZE];
146: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 147:
1.20 markus 148: extern char *__progname;
149:
1.174 dtucker 150: /* Default lifetime in seconds (0 == forever) */
151: static long lifetime = 0;
1.106 marc 152:
1.192 djm 153: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
154:
1.55 itojun 155: static void
1.101 stevesk 156: close_socket(SocketEntry *e)
157: {
158: close(e->fd);
159: e->fd = -1;
160: e->type = AUTH_UNUSED;
1.194 markus 161: sshbuf_free(e->input);
162: sshbuf_free(e->output);
163: sshbuf_free(e->request);
1.101 stevesk 164: }
165:
166: static void
1.33 markus 167: idtab_init(void)
1.1 deraadt 168: {
1.221 djm 169: idtab = xcalloc(1, sizeof(*idtab));
170: TAILQ_INIT(&idtab->idlist);
171: idtab->nentries = 0;
1.33 markus 172: }
173:
1.89 markus 174: static void
175: free_identity(Identity *id)
176: {
1.194 markus 177: sshkey_free(id->key);
1.173 djm 178: free(id->provider);
179: free(id->comment);
1.238 djm 180: free(id->sk_provider);
1.173 djm 181: free(id);
1.89 markus 182: }
183:
1.33 markus 184: /* return matching private key for given public key */
1.78 provos 185: static Identity *
1.221 djm 186: lookup_identity(struct sshkey *key)
1.33 markus 187: {
1.78 provos 188: Identity *id;
189:
1.221 djm 190: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 191: if (sshkey_equal(key, id->key))
1.78 provos 192: return (id);
1.33 markus 193: }
1.78 provos 194: return (NULL);
195: }
196:
1.107 markus 197: /* Check confirmation of keysign request */
198: static int
199: confirm_key(Identity *id)
200: {
1.122 djm 201: char *p;
1.107 markus 202: int ret = -1;
203:
1.194 markus 204: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 205: if (p != NULL &&
206: ask_permission("Allow use of key %s?\nKey fingerprint %s.",
1.122 djm 207: id->comment, p))
208: ret = 0;
1.173 djm 209: free(p);
1.122 djm 210:
1.107 markus 211: return (ret);
212: }
213:
1.194 markus 214: static void
215: send_status(SocketEntry *e, int success)
216: {
217: int r;
218:
219: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
220: (r = sshbuf_put_u8(e->output, success ?
221: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
222: fatal("%s: buffer error: %s", __func__, ssh_err(r));
223: }
224:
1.33 markus 225: /* send list of supported public keys to 'client' */
1.55 itojun 226: static void
1.221 djm 227: process_request_identities(SocketEntry *e)
1.33 markus 228: {
1.96 deraadt 229: Identity *id;
1.194 markus 230: struct sshbuf *msg;
231: int r;
1.1 deraadt 232:
1.194 markus 233: if ((msg = sshbuf_new()) == NULL)
234: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 235: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
236: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
237: fatal("%s: buffer error: %s", __func__, ssh_err(r));
238: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.228 markus 239: if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
240: != 0 ||
1.221 djm 241: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
242: error("%s: put key/comment: %s", __func__,
1.220 djm 243: ssh_err(r));
244: continue;
1.33 markus 245: }
1.21 markus 246: }
1.194 markus 247: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
248: fatal("%s: buffer error: %s", __func__, ssh_err(r));
249: sshbuf_free(msg);
1.1 deraadt 250: }
251:
1.33 markus 252:
1.208 markus 253: static char *
254: agent_decode_alg(struct sshkey *key, u_int flags)
255: {
256: if (key->type == KEY_RSA) {
257: if (flags & SSH_AGENT_RSA_SHA2_256)
258: return "rsa-sha2-256";
259: else if (flags & SSH_AGENT_RSA_SHA2_512)
260: return "rsa-sha2-512";
1.235 djm 261: } else if (key->type == KEY_RSA_CERT) {
262: if (flags & SSH_AGENT_RSA_SHA2_256)
263: return "rsa-sha2-256-cert-v01@openssh.com";
264: else if (flags & SSH_AGENT_RSA_SHA2_512)
265: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 266: }
267: return NULL;
268: }
269:
1.238 djm 270: static int
271: provider_sign(const char *provider, struct sshkey *key,
272: u_char **sigp, size_t *lenp,
273: const u_char *data, size_t datalen,
274: const char *alg, u_int compat)
275: {
276: int status, pair[2], r = SSH_ERR_INTERNAL_ERROR;
277: pid_t pid;
1.241 djm 278: char *helper, *verbosity = NULL, *fp = NULL;
1.238 djm 279: struct sshbuf *kbuf, *req, *resp;
280: u_char version;
1.241 djm 281: struct notifier_ctx *notifier = NULL;
1.238 djm 282:
283: debug3("%s: start for provider %s", __func__, provider);
284:
285: *sigp = NULL;
286: *lenp = 0;
1.243 djm 287:
1.244 djm 288: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
289: SSH_FP_DEFAULT)) == NULL)
290: fatal("%s: sshkey_fingerprint failed", __func__);
291: notifier = notify_start(0,
292: "Confirm user presence for key %s %s", sshkey_type(key), fp);
293:
1.243 djm 294: if (strcasecmp(provider, "internal") == 0) {
1.244 djm 295: r = sshsk_sign(provider, key, sigp, lenp,
1.243 djm 296: data, datalen, compat);
1.244 djm 297: if (r != 0) {
298: error("%s: sshsk_sign internal: %s",
299: __func__, ssh_err(r));
300: }
301: notify_complete(notifier);
302: return r;
1.243 djm 303: }
1.238 djm 304:
305: helper = getenv("SSH_SK_HELPER");
306: if (helper == NULL || strlen(helper) == 0)
307: helper = _PATH_SSH_SK_HELPER;
308: if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
309: verbosity = "-vvv";
310:
311: /* Start helper */
312: if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
313: error("socketpair: %s", strerror(errno));
314: return SSH_ERR_SYSTEM_ERROR;
315: }
316: if ((pid = fork()) == -1) {
317: error("fork: %s", strerror(errno));
318: close(pair[0]);
319: close(pair[1]);
320: return SSH_ERR_SYSTEM_ERROR;
321: }
322: if (pid == 0) {
323: if ((dup2(pair[1], STDIN_FILENO) == -1) ||
324: (dup2(pair[1], STDOUT_FILENO) == -1))
325: fatal("%s: dup2: %s", __func__, ssh_err(r));
326: close(pair[0]);
327: close(pair[1]);
328: closefrom(STDERR_FILENO + 1);
329: debug("%s: starting %s %s", __func__, helper,
330: verbosity == NULL ? "" : verbosity);
331: execlp(helper, helper, verbosity, (char *)NULL);
332: fatal("%s: execlp: %s", __func__, strerror(errno));
333: }
334: close(pair[1]);
335:
336: if ((kbuf = sshbuf_new()) == NULL ||
337: (req = sshbuf_new()) == NULL ||
338: (resp = sshbuf_new()) == NULL)
339: fatal("%s: sshbuf_new failed", __func__);
340:
341: if ((r = sshkey_private_serialize(key, kbuf)) != 0 ||
342: (r = sshbuf_put_stringb(req, kbuf)) != 0 ||
343: (r = sshbuf_put_cstring(req, provider)) != 0 ||
344: (r = sshbuf_put_string(req, data, datalen)) != 0 ||
345: (r = sshbuf_put_u32(req, compat)) != 0)
346: fatal("%s: compose: %s", __func__, ssh_err(r));
347: if ((r = ssh_msg_send(pair[0], SSH_SK_HELPER_VERSION, req)) != 0) {
348: error("%s: send: %s", __func__, ssh_err(r));
349: goto out;
350: }
351: if ((r = ssh_msg_recv(pair[0], resp)) != 0) {
352: error("%s: receive: %s", __func__, ssh_err(r));
353: goto out;
354: }
355: if ((r = sshbuf_get_u8(resp, &version)) != 0) {
356: error("%s: parse version: %s", __func__, ssh_err(r));
357: goto out;
358: }
359: if (version != SSH_SK_HELPER_VERSION) {
360: error("%s: unsupported version: got %u, expected %u",
361: __func__, version, SSH_SK_HELPER_VERSION);
362: r = SSH_ERR_INVALID_FORMAT;
363: goto out;
364: }
365: if ((r = sshbuf_get_string(resp, sigp, lenp)) != 0) {
366: error("%s: parse signature: %s", __func__, ssh_err(r));
367: r = SSH_ERR_INVALID_FORMAT;
368: goto out;
369: }
370: if (sshbuf_len(resp) != 0) {
371: error("%s: trailing data in response", __func__);
372: r = SSH_ERR_INVALID_FORMAT;
373: goto out;
374: }
375: /* success */
376: r = 0;
377: out:
378: while (waitpid(pid, &status, 0) == -1) {
379: if (errno != EINTR)
380: fatal("%s: waitpid: %s", __func__, ssh_err(r));
381: }
1.241 djm 382: notify_complete(notifier);
1.238 djm 383: if (!WIFEXITED(status)) {
384: error("%s: helper %s exited abnormally", __func__, helper);
385: if (r == 0)
386: r = SSH_ERR_SYSTEM_ERROR;
387: } else if (WEXITSTATUS(status) != 0) {
388: error("%s: helper %s exited with non-zero exit status",
389: __func__, helper);
390: if (r == 0)
391: r = SSH_ERR_SYSTEM_ERROR;
392: }
393: if (r != 0) {
394: freezero(*sigp, *lenp);
395: *sigp = NULL;
396: *lenp = 0;
397: }
398: sshbuf_free(kbuf);
399: sshbuf_free(req);
400: sshbuf_free(resp);
401: return r;
402: }
403:
1.33 markus 404: /* ssh2 only */
1.55 itojun 405: static void
1.33 markus 406: process_sign_request2(SocketEntry *e)
407: {
1.221 djm 408: const u_char *data;
409: u_char *signature = NULL;
410: size_t dlen, slen = 0;
1.194 markus 411: u_int compat = 0, flags;
1.246 ! djm 412: int was_shielded, r, r2, ok = -1;
1.194 markus 413: struct sshbuf *msg;
1.221 djm 414: struct sshkey *key = NULL;
1.195 djm 415: struct identity *id;
1.194 markus 416:
1.195 djm 417: if ((msg = sshbuf_new()) == NULL)
418: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 419: if ((r = sshkey_froms(e->request, &key)) != 0 ||
420: (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
1.225 djm 421: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
422: error("%s: couldn't parse request: %s", __func__, ssh_err(r));
423: goto send;
424: }
425:
1.221 djm 426: if ((id = lookup_identity(key)) == NULL) {
1.195 djm 427: verbose("%s: %s key not found", __func__, sshkey_type(key));
428: goto send;
429: }
430: if (id->confirm && confirm_key(id) != 0) {
431: verbose("%s: user refused key", __func__);
432: goto send;
433: }
1.238 djm 434: if (id->sk_provider != NULL) {
1.246 ! djm 435: was_shielded = sshkey_is_shielded(id->key);
! 436: if ((r = sshkey_unshield_private(id->key)) != 0) {
! 437: error("%s: unshield: %s", __func__, ssh_err(r));
! 438: goto send;
! 439: }
! 440: r = provider_sign(id->sk_provider, id->key, &signature,
1.238 djm 441: &slen, data, dlen, agent_decode_alg(key, flags),
1.246 ! djm 442: compat);
! 443: if (was_shielded &&
! 444: (r2 = sshkey_shield_private(id->key)) != 0) {
! 445: error("%s: shield: %s", __func__, ssh_err(r));
! 446: r = r2;
! 447: goto send;
! 448: }
! 449: if (r != 0) {
1.239 djm 450: error("%s: sign: %s", __func__, ssh_err(r));
1.238 djm 451: goto send;
452: }
453: } else {
454: if ((r = sshkey_sign(id->key, &signature, &slen,
1.239 djm 455: data, dlen, agent_decode_alg(key, flags),
456: NULL, compat)) != 0) {
1.238 djm 457: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
458: goto send;
459: }
1.33 markus 460: }
1.195 djm 461: /* Success */
462: ok = 0;
463: send:
464: sshkey_free(key);
1.33 markus 465: if (ok == 0) {
1.194 markus 466: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
467: (r = sshbuf_put_string(msg, signature, slen)) != 0)
468: fatal("%s: buffer error: %s", __func__, ssh_err(r));
469: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
470: fatal("%s: buffer error: %s", __func__, ssh_err(r));
471:
472: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
473: fatal("%s: buffer error: %s", __func__, ssh_err(r));
474:
475: sshbuf_free(msg);
1.173 djm 476: free(signature);
1.1 deraadt 477: }
478:
1.33 markus 479: /* shared */
1.55 itojun 480: static void
1.221 djm 481: process_remove_identity(SocketEntry *e)
1.1 deraadt 482: {
1.194 markus 483: int r, success = 0;
484: struct sshkey *key = NULL;
1.221 djm 485: Identity *id;
1.21 markus 486:
1.221 djm 487: if ((r = sshkey_froms(e->request, &key)) != 0) {
488: error("%s: get key: %s", __func__, ssh_err(r));
489: goto done;
490: }
491: if ((id = lookup_identity(key)) == NULL) {
492: debug("%s: key not found", __func__);
493: goto done;
494: }
495: /* We have this key, free it. */
496: if (idtab->nentries < 1)
497: fatal("%s: internal error: nentries %d",
498: __func__, idtab->nentries);
499: TAILQ_REMOVE(&idtab->idlist, id, next);
500: free_identity(id);
501: idtab->nentries--;
502: sshkey_free(key);
503: success = 1;
504: done:
1.194 markus 505: send_status(e, success);
1.1 deraadt 506: }
507:
1.55 itojun 508: static void
1.221 djm 509: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 510: {
1.78 provos 511: Identity *id;
1.21 markus 512:
513: /* Loop over all identities and clear the keys. */
1.221 djm 514: for (id = TAILQ_FIRST(&idtab->idlist); id;
515: id = TAILQ_FIRST(&idtab->idlist)) {
516: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 517: free_identity(id);
1.21 markus 518: }
519:
520: /* Mark that there are no identities. */
1.221 djm 521: idtab->nentries = 0;
1.21 markus 522:
523: /* Send success. */
1.194 markus 524: send_status(e, 1);
1.1 deraadt 525: }
526:
1.155 dtucker 527: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 528: static time_t
1.89 markus 529: reaper(void)
530: {
1.175 dtucker 531: time_t deadline = 0, now = monotime();
1.89 markus 532: Identity *id, *nxt;
533:
1.221 djm 534: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
535: nxt = TAILQ_NEXT(id, next);
536: if (id->death == 0)
537: continue;
538: if (now >= id->death) {
539: debug("expiring key '%s'", id->comment);
540: TAILQ_REMOVE(&idtab->idlist, id, next);
541: free_identity(id);
542: idtab->nentries--;
543: } else
544: deadline = (deadline == 0) ? id->death :
545: MINIMUM(deadline, id->death);
1.89 markus 546: }
1.155 dtucker 547: if (deadline == 0 || deadline <= now)
548: return 0;
549: else
550: return (deadline - now);
1.89 markus 551: }
552:
553: static void
1.221 djm 554: process_add_identity(SocketEntry *e)
1.1 deraadt 555: {
1.157 canacar 556: Identity *id;
1.194 markus 557: int success = 0, confirm = 0;
1.228 markus 558: u_int seconds, maxsign;
1.238 djm 559: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 560: time_t death = 0;
1.194 markus 561: struct sshkey *k = NULL;
562: u_char ctype;
563: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 564:
1.221 djm 565: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
566: k == NULL ||
1.194 markus 567: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
568: error("%s: decode private key: %s", __func__, ssh_err(r));
569: goto err;
570: }
571: while (sshbuf_len(e->request)) {
572: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
573: error("%s: buffer error: %s", __func__, ssh_err(r));
574: goto err;
575: }
576: switch (ctype) {
1.94 markus 577: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 578: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
579: error("%s: bad lifetime constraint: %s",
580: __func__, ssh_err(r));
581: goto err;
582: }
583: death = monotime() + seconds;
1.94 markus 584: break;
1.107 markus 585: case SSH_AGENT_CONSTRAIN_CONFIRM:
586: confirm = 1;
587: break;
1.228 markus 588: case SSH_AGENT_CONSTRAIN_MAXSIGN:
589: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
590: error("%s: bad maxsign constraint: %s",
591: __func__, ssh_err(r));
592: goto err;
593: }
594: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
595: error("%s: cannot enable maxsign: %s",
596: __func__, ssh_err(r));
597: goto err;
598: }
599: break;
1.238 djm 600: case SSH_AGENT_CONSTRAIN_EXTENSION:
601: if ((r = sshbuf_get_cstring(e->request,
602: &ext_name, NULL)) != 0) {
603: error("%s: cannot parse extension: %s",
604: __func__, ssh_err(r));
605: goto err;
606: }
607: debug("%s: constraint ext %s", __func__, ext_name);
608: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
609: if (sk_provider != NULL) {
610: error("%s already set", ext_name);
611: goto err;
612: }
613: if ((r = sshbuf_get_cstring(e->request,
614: &sk_provider, NULL)) != 0) {
615: error("%s: cannot parse %s: %s",
616: __func__, ext_name, ssh_err(r));
617: goto err;
618: }
619: } else {
620: error("%s: unsupported constraint \"%s\"",
621: __func__, ext_name);
622: goto err;
623: }
624: free(ext_name);
625: break;
1.94 markus 626: default:
1.194 markus 627: error("%s: Unknown constraint %d", __func__, ctype);
628: err:
1.238 djm 629: free(sk_provider);
630: free(ext_name);
1.194 markus 631: sshbuf_reset(e->request);
1.173 djm 632: free(comment);
1.194 markus 633: sshkey_free(k);
1.158 djm 634: goto send;
1.94 markus 635: }
636: }
1.238 djm 637: if (sk_provider != NULL) {
1.240 markus 638: if (!sshkey_is_sk(k)) {
1.238 djm 639: error("Cannot add provider: %s is not a security key",
640: sshkey_type(k));
641: free(sk_provider);
642: goto send;
643: }
1.245 djm 644: if (strcasecmp(sk_provider, "internal") == 0)
645: debug("%s: internal provider", __func__);
646: else if (match_pattern_list(sk_provider,
1.238 djm 647: provider_whitelist, 0) != 1) {
648: error("Refusing add key: provider %s not whitelisted",
649: sk_provider);
650: free(sk_provider);
651: goto send;
652: }
1.242 markus 653: }
654: if ((r = sshkey_shield_private(k)) != 0) {
655: error("%s: shield private key: %s", __func__, ssh_err(r));
656: goto err;
1.238 djm 657: }
1.194 markus 658:
1.158 djm 659: success = 1;
1.106 marc 660: if (lifetime && !death)
1.175 dtucker 661: death = monotime() + lifetime;
1.221 djm 662: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 663: id = xcalloc(1, sizeof(Identity));
1.221 djm 664: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 665: /* Increment the number of identities. */
1.221 djm 666: idtab->nentries++;
1.33 markus 667: } else {
1.228 markus 668: /* key state might have been updated */
669: sshkey_free(id->key);
1.173 djm 670: free(id->comment);
1.238 djm 671: free(id->sk_provider);
1.33 markus 672: }
1.228 markus 673: id->key = k;
1.157 canacar 674: id->comment = comment;
675: id->death = death;
676: id->confirm = confirm;
1.238 djm 677: id->sk_provider = sk_provider;
678:
679: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
680: SSH_FP_DEFAULT)) == NULL)
681: fatal("%s: sshkey_fingerprint failed", __func__);
682: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
683: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
684: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
685: free(fp);
1.33 markus 686: send:
1.194 markus 687: send_status(e, success);
1.1 deraadt 688: }
689:
1.88 markus 690: /* XXX todo: encrypt sensitive data with passphrase */
691: static void
692: process_lock_agent(SocketEntry *e, int lock)
693: {
1.203 dtucker 694: int r, success = 0, delay;
1.213 djm 695: char *passwd;
696: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 697: static u_int fail_count = 0;
698: size_t pwlen;
699:
1.226 djm 700: /*
701: * This is deliberately fatal: the user has requested that we lock,
702: * but we can't parse their request properly. The only safe thing to
703: * do is abort.
704: */
1.203 dtucker 705: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
706: fatal("%s: buffer error: %s", __func__, ssh_err(r));
707: if (pwlen == 0) {
708: debug("empty password not supported");
709: } else if (locked && !lock) {
710: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
711: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
712: fatal("bcrypt_pbkdf");
1.213 djm 713: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 714: debug("agent unlocked");
715: locked = 0;
716: fail_count = 0;
1.213 djm 717: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 718: success = 1;
719: } else {
720: /* delay in 0.1s increments up to 10s */
721: if (fail_count < 100)
722: fail_count++;
723: delay = 100000 * fail_count;
724: debug("unlock failed, delaying %0.1lf seconds",
725: (double)delay/1000000);
726: usleep(delay);
727: }
728: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 729: } else if (!locked && lock) {
1.203 dtucker 730: debug("agent locked");
1.88 markus 731: locked = 1;
1.203 dtucker 732: arc4random_buf(lock_salt, sizeof(lock_salt));
733: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 734: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 735: fatal("bcrypt_pbkdf");
1.88 markus 736: success = 1;
737: }
1.203 dtucker 738: explicit_bzero(passwd, pwlen);
1.173 djm 739: free(passwd);
1.194 markus 740: send_status(e, success);
1.88 markus 741: }
742:
743: static void
1.221 djm 744: no_identities(SocketEntry *e)
1.88 markus 745: {
1.194 markus 746: struct sshbuf *msg;
747: int r;
1.88 markus 748:
1.194 markus 749: if ((msg = sshbuf_new()) == NULL)
750: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 751: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 752: (r = sshbuf_put_u32(msg, 0)) != 0 ||
753: (r = sshbuf_put_stringb(e->output, msg)) != 0)
754: fatal("%s: buffer error: %s", __func__, ssh_err(r));
755: sshbuf_free(msg);
1.88 markus 756: }
1.59 markus 757:
1.163 markus 758: #ifdef ENABLE_PKCS11
1.59 markus 759: static void
1.158 djm 760: process_add_smartcard_key(SocketEntry *e)
1.59 markus 761: {
1.226 djm 762: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 763: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 764: u_int seconds;
1.174 dtucker 765: time_t death = 0;
1.194 markus 766: u_char type;
767: struct sshkey **keys = NULL, *k;
1.84 markus 768: Identity *id;
1.75 deraadt 769:
1.194 markus 770: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 771: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
772: error("%s: buffer error: %s", __func__, ssh_err(r));
773: goto send;
774: }
1.194 markus 775:
776: while (sshbuf_len(e->request)) {
1.226 djm 777: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
778: error("%s: buffer error: %s", __func__, ssh_err(r));
779: goto send;
780: }
1.194 markus 781: switch (type) {
1.110 djm 782: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 783: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
784: error("%s: buffer error: %s",
1.194 markus 785: __func__, ssh_err(r));
1.226 djm 786: goto send;
787: }
1.194 markus 788: death = monotime() + seconds;
1.110 djm 789: break;
790: case SSH_AGENT_CONSTRAIN_CONFIRM:
791: confirm = 1;
792: break;
793: default:
1.221 djm 794: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 795: goto send;
1.110 djm 796: }
797: }
1.215 djm 798: if (realpath(provider, canonical_provider) == NULL) {
799: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
800: provider, strerror(errno));
801: goto send;
802: }
1.238 djm 803: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 804: verbose("refusing PKCS#11 add of \"%.100s\": "
805: "provider not whitelisted", canonical_provider);
806: goto send;
807: }
808: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 809: if (lifetime && !death)
1.175 dtucker 810: death = monotime() + lifetime;
1.110 djm 811:
1.215 djm 812: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 813: for (i = 0; i < count; i++) {
1.84 markus 814: k = keys[i];
1.221 djm 815: if (lookup_identity(k) == NULL) {
1.163 markus 816: id = xcalloc(1, sizeof(Identity));
1.84 markus 817: id->key = k;
1.215 djm 818: id->provider = xstrdup(canonical_provider);
819: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 820: id->death = death;
821: id->confirm = confirm;
1.221 djm 822: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
823: idtab->nentries++;
1.84 markus 824: success = 1;
825: } else {
1.194 markus 826: sshkey_free(k);
1.84 markus 827: }
828: keys[i] = NULL;
1.59 markus 829: }
830: send:
1.173 djm 831: free(pin);
832: free(provider);
833: free(keys);
1.194 markus 834: send_status(e, success);
1.59 markus 835: }
836:
837: static void
838: process_remove_smartcard_key(SocketEntry *e)
839: {
1.217 djm 840: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 841: int r, success = 0;
1.163 markus 842: Identity *id, *nxt;
1.59 markus 843:
1.194 markus 844: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 845: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
846: error("%s: buffer error: %s", __func__, ssh_err(r));
847: goto send;
848: }
1.173 djm 849: free(pin);
1.59 markus 850:
1.217 djm 851: if (realpath(provider, canonical_provider) == NULL) {
852: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
853: provider, strerror(errno));
854: goto send;
855: }
856:
857: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 858: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
859: nxt = TAILQ_NEXT(id, next);
860: /* Skip file--based keys */
861: if (id->provider == NULL)
862: continue;
863: if (!strcmp(canonical_provider, id->provider)) {
864: TAILQ_REMOVE(&idtab->idlist, id, next);
865: free_identity(id);
866: idtab->nentries--;
1.59 markus 867: }
868: }
1.217 djm 869: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 870: success = 1;
871: else
1.221 djm 872: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 873: send:
1.173 djm 874: free(provider);
1.194 markus 875: send_status(e, success);
1.59 markus 876: }
1.163 markus 877: #endif /* ENABLE_PKCS11 */
1.59 markus 878:
1.33 markus 879: /* dispatch incoming messages */
880:
1.223 djm 881: static int
882: process_message(u_int socknum)
1.1 deraadt 883: {
1.194 markus 884: u_int msg_len;
885: u_char type;
886: const u_char *cp;
887: int r;
1.223 djm 888: SocketEntry *e;
889:
890: if (socknum >= sockets_alloc) {
891: fatal("%s: socket number %u >= allocated %u",
892: __func__, socknum, sockets_alloc);
893: }
894: e = &sockets[socknum];
1.89 markus 895:
1.194 markus 896: if (sshbuf_len(e->input) < 5)
1.223 djm 897: return 0; /* Incomplete message header. */
1.194 markus 898: cp = sshbuf_ptr(e->input);
899: msg_len = PEEK_U32(cp);
1.223 djm 900: if (msg_len > AGENT_MAX_LEN) {
901: debug("%s: socket %u (fd=%d) message too long %u > %u",
902: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
903: return -1;
1.21 markus 904: }
1.194 markus 905: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 906: return 0; /* Incomplete message body. */
1.87 markus 907:
908: /* move the current input to e->request */
1.194 markus 909: sshbuf_reset(e->request);
910: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 911: (r = sshbuf_get_u8(e->request, &type)) != 0) {
912: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
913: r == SSH_ERR_STRING_TOO_LARGE) {
914: debug("%s: buffer error: %s", __func__, ssh_err(r));
915: return -1;
916: }
1.194 markus 917: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 918: }
919:
920: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 921:
1.230 djm 922: /* check whether agent is locked */
1.88 markus 923: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 924: sshbuf_reset(e->request);
1.88 markus 925: switch (type) {
926: case SSH2_AGENTC_REQUEST_IDENTITIES:
927: /* send empty lists */
1.221 djm 928: no_identities(e);
1.88 markus 929: break;
930: default:
931: /* send a fail message for all other request types */
1.194 markus 932: send_status(e, 0);
1.88 markus 933: }
1.223 djm 934: return 0;
1.88 markus 935: }
936:
1.21 markus 937: switch (type) {
1.88 markus 938: case SSH_AGENTC_LOCK:
939: case SSH_AGENTC_UNLOCK:
940: process_lock_agent(e, type == SSH_AGENTC_LOCK);
941: break;
1.21 markus 942: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 943: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 944: break;
945: /* ssh2 */
946: case SSH2_AGENTC_SIGN_REQUEST:
947: process_sign_request2(e);
948: break;
949: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 950: process_request_identities(e);
1.33 markus 951: break;
952: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 953: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 954: process_add_identity(e);
1.33 markus 955: break;
956: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 957: process_remove_identity(e);
1.33 markus 958: break;
959: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 960: process_remove_all_identities(e);
1.21 markus 961: break;
1.163 markus 962: #ifdef ENABLE_PKCS11
1.59 markus 963: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 964: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 965: process_add_smartcard_key(e);
1.75 deraadt 966: break;
1.59 markus 967: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
968: process_remove_smartcard_key(e);
1.75 deraadt 969: break;
1.163 markus 970: #endif /* ENABLE_PKCS11 */
1.21 markus 971: default:
972: /* Unknown message. Respond with failure. */
973: error("Unknown message %d", type);
1.194 markus 974: sshbuf_reset(e->request);
975: send_status(e, 0);
1.21 markus 976: break;
977: }
1.223 djm 978: return 0;
1.1 deraadt 979: }
980:
1.55 itojun 981: static void
1.73 stevesk 982: new_socket(sock_type type, int fd)
1.1 deraadt 983: {
1.112 markus 984: u_int i, old_alloc, new_alloc;
1.96 deraadt 985:
1.119 djm 986: set_nonblock(fd);
1.21 markus 987:
988: if (fd > max_fd)
989: max_fd = fd;
990:
991: for (i = 0; i < sockets_alloc; i++)
992: if (sockets[i].type == AUTH_UNUSED) {
993: sockets[i].fd = fd;
1.194 markus 994: if ((sockets[i].input = sshbuf_new()) == NULL)
995: fatal("%s: sshbuf_new failed", __func__);
996: if ((sockets[i].output = sshbuf_new()) == NULL)
997: fatal("%s: sshbuf_new failed", __func__);
998: if ((sockets[i].request = sshbuf_new()) == NULL)
999: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 1000: sockets[i].type = type;
1.21 markus 1001: return;
1002: }
1003: old_alloc = sockets_alloc;
1.112 markus 1004: new_alloc = sockets_alloc + 10;
1.200 deraadt 1005: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 1006: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 1007: sockets[i].type = AUTH_UNUSED;
1.112 markus 1008: sockets_alloc = new_alloc;
1.21 markus 1009: sockets[old_alloc].fd = fd;
1.194 markus 1010: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
1011: fatal("%s: sshbuf_new failed", __func__);
1012: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
1013: fatal("%s: sshbuf_new failed", __func__);
1014: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
1015: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 1016: sockets[old_alloc].type = type;
1.1 deraadt 1017: }
1018:
1.55 itojun 1019: static int
1.223 djm 1020: handle_socket_read(u_int socknum)
1.1 deraadt 1021: {
1.223 djm 1022: struct sockaddr_un sunaddr;
1023: socklen_t slen;
1024: uid_t euid;
1025: gid_t egid;
1026: int fd;
1027:
1028: slen = sizeof(sunaddr);
1029: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1030: if (fd == -1) {
1.223 djm 1031: error("accept from AUTH_SOCKET: %s", strerror(errno));
1032: return -1;
1033: }
1.237 deraadt 1034: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1035: error("getpeereid %d failed: %s", fd, strerror(errno));
1036: close(fd);
1037: return -1;
1038: }
1039: if ((euid != 0) && (getuid() != euid)) {
1040: error("uid mismatch: peer euid %u != uid %u",
1041: (u_int) euid, (u_int) getuid());
1042: close(fd);
1043: return -1;
1044: }
1045: new_socket(AUTH_CONNECTION, fd);
1046: return 0;
1047: }
1048:
1049: static int
1050: handle_conn_read(u_int socknum)
1051: {
1.233 djm 1052: char buf[AGENT_RBUF_LEN];
1.223 djm 1053: ssize_t len;
1054: int r;
1055:
1056: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1057: if (len == -1) {
1058: if (errno == EAGAIN || errno == EINTR)
1059: return 0;
1060: error("%s: read error on socket %u (fd %d): %s",
1061: __func__, socknum, sockets[socknum].fd,
1062: strerror(errno));
1063: }
1064: return -1;
1065: }
1066: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1067: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1068: explicit_bzero(buf, sizeof(buf));
1069: process_message(socknum);
1070: return 0;
1071: }
1072:
1073: static int
1074: handle_conn_write(u_int socknum)
1075: {
1076: ssize_t len;
1077: int r;
1078:
1079: if (sshbuf_len(sockets[socknum].output) == 0)
1080: return 0; /* shouldn't happen */
1081: if ((len = write(sockets[socknum].fd,
1082: sshbuf_ptr(sockets[socknum].output),
1083: sshbuf_len(sockets[socknum].output))) <= 0) {
1084: if (len == -1) {
1085: if (errno == EAGAIN || errno == EINTR)
1086: return 0;
1087: error("%s: read error on socket %u (fd %d): %s",
1088: __func__, socknum, sockets[socknum].fd,
1089: strerror(errno));
1090: }
1091: return -1;
1092: }
1093: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1094: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1095: return 0;
1096: }
1097:
1098: static void
1.231 djm 1099: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1100: {
1101: size_t i;
1.231 djm 1102: u_int socknum, activefds = npfd;
1.223 djm 1103:
1104: for (i = 0; i < npfd; i++) {
1105: if (pfd[i].revents == 0)
1106: continue;
1107: /* Find sockets entry */
1108: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1109: if (sockets[socknum].type != AUTH_SOCKET &&
1110: sockets[socknum].type != AUTH_CONNECTION)
1111: continue;
1112: if (pfd[i].fd == sockets[socknum].fd)
1113: break;
1114: }
1115: if (socknum >= sockets_alloc) {
1116: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1117: continue;
1118: }
1119: /* Process events */
1120: switch (sockets[socknum].type) {
1121: case AUTH_SOCKET:
1.231 djm 1122: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1123: break;
1124: if (npfd > maxfds) {
1125: debug3("out of fds (active %u >= limit %u); "
1126: "skipping accept", activefds, maxfds);
1127: break;
1128: }
1129: if (handle_socket_read(socknum) == 0)
1130: activefds++;
1.223 djm 1131: break;
1132: case AUTH_CONNECTION:
1133: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1134: handle_conn_read(socknum) != 0) {
1.231 djm 1135: goto close_sock;
1136: }
1137: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1138: handle_conn_write(socknum) != 0) {
1139: close_sock:
1140: if (activefds == 0)
1141: fatal("activefds == 0 at close_sock");
1.223 djm 1142: close_socket(&sockets[socknum]);
1.231 djm 1143: activefds--;
1.223 djm 1144: break;
1145: }
1146: break;
1147: default:
1148: break;
1149: }
1150: }
1151: }
1152:
1153: static int
1.231 djm 1154: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1155: {
1156: struct pollfd *pfd = *pfdp;
1157: size_t i, j, npfd = 0;
1.174 dtucker 1158: time_t deadline;
1.233 djm 1159: int r;
1.46 markus 1160:
1.223 djm 1161: /* Count active sockets */
1.46 markus 1162: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1163: switch (sockets[i].type) {
1164: case AUTH_SOCKET:
1165: case AUTH_CONNECTION:
1.223 djm 1166: npfd++;
1.21 markus 1167: break;
1168: case AUTH_UNUSED:
1169: break;
1170: default:
1171: fatal("Unknown socket type %d", sockets[i].type);
1172: break;
1173: }
1.46 markus 1174: }
1.223 djm 1175: if (npfd != *npfdp &&
1176: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1177: fatal("%s: recallocarray failed", __func__);
1178: *pfdp = pfd;
1179: *npfdp = npfd;
1.46 markus 1180:
1.223 djm 1181: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1182: switch (sockets[i].type) {
1183: case AUTH_SOCKET:
1.231 djm 1184: if (npfd > maxfds) {
1185: debug3("out of fds (active %zu >= limit %u); "
1186: "skipping arming listener", npfd, maxfds);
1187: break;
1188: }
1189: pfd[j].fd = sockets[i].fd;
1190: pfd[j].revents = 0;
1191: pfd[j].events = POLLIN;
1192: j++;
1193: break;
1.46 markus 1194: case AUTH_CONNECTION:
1.223 djm 1195: pfd[j].fd = sockets[i].fd;
1196: pfd[j].revents = 0;
1.233 djm 1197: /*
1198: * Only prepare to read if we can handle a full-size
1199: * input read buffer and enqueue a max size reply..
1200: */
1201: if ((r = sshbuf_check_reserve(sockets[i].input,
1202: AGENT_RBUF_LEN)) == 0 &&
1203: (r = sshbuf_check_reserve(sockets[i].output,
1204: AGENT_MAX_LEN)) == 0)
1205: pfd[j].events = POLLIN;
1206: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1207: fatal("%s: buffer error: %s",
1208: __func__, ssh_err(r));
1209: }
1.194 markus 1210: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1211: pfd[j].events |= POLLOUT;
1212: j++;
1.46 markus 1213: break;
1214: default:
1215: break;
1216: }
1217: }
1.155 dtucker 1218: deadline = reaper();
1219: if (parent_alive_interval != 0)
1220: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1221: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1222: if (deadline == 0) {
1.224 djm 1223: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1224: } else {
1.223 djm 1225: if (deadline > INT_MAX / 1000)
1226: *timeoutp = INT_MAX / 1000;
1227: else
1228: *timeoutp = deadline * 1000;
1.155 dtucker 1229: }
1.46 markus 1230: return (1);
1.21 markus 1231: }
1232:
1.55 itojun 1233: static void
1.113 markus 1234: cleanup_socket(void)
1.15 markus 1235: {
1.187 djm 1236: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1237: return;
1238: debug("%s: cleanup", __func__);
1.48 deraadt 1239: if (socket_name[0])
1240: unlink(socket_name);
1241: if (socket_dir[0])
1242: rmdir(socket_dir);
1.10 markus 1243: }
1244:
1.114 markus 1245: void
1.15 markus 1246: cleanup_exit(int i)
1247: {
1.113 markus 1248: cleanup_socket();
1249: _exit(i);
1.15 markus 1250: }
1251:
1.135 deraadt 1252: /*ARGSUSED*/
1.55 itojun 1253: static void
1.48 deraadt 1254: cleanup_handler(int sig)
1255: {
1.113 markus 1256: cleanup_socket();
1.163 markus 1257: #ifdef ENABLE_PKCS11
1258: pkcs11_terminate();
1259: #endif
1.48 deraadt 1260: _exit(2);
1.113 markus 1261: }
1262:
1.68 markus 1263: static void
1.155 dtucker 1264: check_parent_exists(void)
1.68 markus 1265: {
1.172 dtucker 1266: /*
1267: * If our parent has exited then getppid() will return (pid_t)1,
1268: * so testing for that should be safe.
1269: */
1270: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1271: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1272: cleanup_socket();
1273: _exit(2);
1.68 markus 1274: }
1.48 deraadt 1275: }
1276:
1.55 itojun 1277: static void
1.50 itojun 1278: usage(void)
1.15 markus 1279: {
1.184 deraadt 1280: fprintf(stderr,
1.202 jmc 1281: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1282: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1283: " ssh-agent [-c | -s] -k\n");
1.21 markus 1284: exit(1);
1.15 markus 1285: }
1286:
1.2 provos 1287: int
1288: main(int ac, char **av)
1.1 deraadt 1289: {
1.201 djm 1290: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1291: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1292: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1293: struct rlimit rlim;
1.96 deraadt 1294: extern int optind;
1.98 stevesk 1295: extern char *optarg;
1.21 markus 1296: pid_t pid;
1.96 deraadt 1297: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1298: size_t len;
1.189 djm 1299: mode_t prev_mask;
1.224 djm 1300: int timeout = -1; /* INFTIM */
1.223 djm 1301: struct pollfd *pfd = NULL;
1302: size_t npfd = 0;
1.231 djm 1303: u_int maxfds;
1.123 djm 1304:
1305: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1306: sanitise_stdfd();
1.99 markus 1307:
1308: /* drop */
1309: setegid(getgid());
1310: setgid(getgid());
1.53 markus 1311:
1.231 djm 1312: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1313: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1314:
1.185 markus 1315: #ifdef WITH_OPENSSL
1.170 djm 1316: OpenSSL_add_all_algorithms();
1.185 markus 1317: #endif
1.21 markus 1318:
1.215 djm 1319: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1320: switch (ch) {
1.192 djm 1321: case 'E':
1322: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1323: if (fingerprint_hash == -1)
1324: fatal("Invalid hash algorithm \"%s\"", optarg);
1325: break;
1.21 markus 1326: case 'c':
1327: if (s_flag)
1328: usage();
1329: c_flag++;
1330: break;
1331: case 'k':
1332: k_flag++;
1333: break;
1.215 djm 1334: case 'P':
1.238 djm 1335: if (provider_whitelist != NULL)
1.215 djm 1336: fatal("-P option already specified");
1.238 djm 1337: provider_whitelist = xstrdup(optarg);
1.215 djm 1338: break;
1.21 markus 1339: case 's':
1340: if (c_flag)
1341: usage();
1342: s_flag++;
1343: break;
1.57 markus 1344: case 'd':
1.201 djm 1345: if (d_flag || D_flag)
1.57 markus 1346: usage();
1347: d_flag++;
1348: break;
1.201 djm 1349: case 'D':
1350: if (d_flag || D_flag)
1351: usage();
1352: D_flag++;
1353: break;
1.86 markus 1354: case 'a':
1355: agentsocket = optarg;
1.106 marc 1356: break;
1357: case 't':
1358: if ((lifetime = convtime(optarg)) == -1) {
1359: fprintf(stderr, "Invalid lifetime\n");
1360: usage();
1361: }
1.86 markus 1362: break;
1.21 markus 1363: default:
1364: usage();
1365: }
1366: }
1367: ac -= optind;
1368: av += optind;
1369:
1.201 djm 1370: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1371: usage();
1372:
1.238 djm 1373: if (provider_whitelist == NULL)
1374: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1375:
1.85 markus 1376: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1377: shell = getenv("SHELL");
1.161 tobias 1378: if (shell != NULL && (len = strlen(shell)) > 2 &&
1379: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1380: c_flag = 1;
1381: }
1382: if (k_flag) {
1.136 deraadt 1383: const char *errstr = NULL;
1384:
1.21 markus 1385: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1386: if (pidstr == NULL) {
1387: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1388: SSH_AGENTPID_ENV_NAME);
1.21 markus 1389: exit(1);
1390: }
1.136 deraadt 1391: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1392: if (errstr) {
1393: fprintf(stderr,
1394: "%s=\"%s\", which is not a good PID: %s\n",
1395: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1396: exit(1);
1397: }
1398: if (kill(pid, SIGTERM) == -1) {
1399: perror("kill");
1400: exit(1);
1401: }
1402: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1403: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1404: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1405: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1406: exit(0);
1407: }
1.231 djm 1408:
1409: /*
1410: * Minimum file descriptors:
1411: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1412: * a few spare for libc / stack protectors / sanitisers, etc.
1413: */
1414: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1415: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1416: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1417: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1418: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1419:
1.21 markus 1420: parent_pid = getpid();
1421:
1.86 markus 1422: if (agentsocket == NULL) {
1423: /* Create private directory for agent socket */
1.171 djm 1424: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1425: if (mkdtemp(socket_dir) == NULL) {
1426: perror("mkdtemp: private socket dir");
1427: exit(1);
1428: }
1.91 mpech 1429: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1430: (long)parent_pid);
1.86 markus 1431: } else {
1432: /* Try to use specified agent socket */
1433: socket_dir[0] = '\0';
1434: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1435: }
1436:
1.23 markus 1437: /*
1438: * Create socket early so it will exist before command gets run from
1439: * the parent.
1440: */
1.189 djm 1441: prev_mask = umask(0177);
1.188 millert 1442: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1443: if (sock < 0) {
1.188 millert 1444: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1445: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1446: cleanup_exit(1);
1447: }
1.189 djm 1448: umask(prev_mask);
1.46 markus 1449:
1.23 markus 1450: /*
1451: * Fork, and have the parent execute the command, if any, or present
1452: * the socket data. The child continues as the authentication agent.
1453: */
1.201 djm 1454: if (D_flag || d_flag) {
1455: log_init(__progname,
1456: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1457: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1458: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1459: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1460: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1461: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1462: fflush(stdout);
1.57 markus 1463: goto skip;
1464: }
1.21 markus 1465: pid = fork();
1466: if (pid == -1) {
1467: perror("fork");
1.81 stevesk 1468: cleanup_exit(1);
1.21 markus 1469: }
1470: if (pid != 0) { /* Parent - execute the given command. */
1471: close(sock);
1.91 mpech 1472: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1473: if (ac == 0) {
1474: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1475: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1476: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1477: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1478: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1479: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1480: exit(0);
1481: }
1.36 deraadt 1482: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1483: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1484: perror("setenv");
1485: exit(1);
1486: }
1.21 markus 1487: execvp(av[0], av);
1488: perror(av[0]);
1489: exit(1);
1490: }
1.81 stevesk 1491: /* child */
1492: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1493:
1494: if (setsid() == -1) {
1.81 stevesk 1495: error("setsid: %s", strerror(errno));
1.67 stevesk 1496: cleanup_exit(1);
1497: }
1498:
1499: (void)chdir("/");
1.107 markus 1500: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1501: /* XXX might close listen socket */
1502: (void)dup2(fd, STDIN_FILENO);
1503: (void)dup2(fd, STDOUT_FILENO);
1504: (void)dup2(fd, STDERR_FILENO);
1505: if (fd > 2)
1506: close(fd);
1507: }
1.21 markus 1508:
1.41 markus 1509: /* deny core dumps, since memory contains unencrypted private keys */
1510: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1511: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1512: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1513: cleanup_exit(1);
1514: }
1.57 markus 1515:
1516: skip:
1.187 djm 1517:
1518: cleanup_pid = getpid();
1.163 markus 1519:
1520: #ifdef ENABLE_PKCS11
1521: pkcs11_init(0);
1522: #endif
1.21 markus 1523: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1524: if (ac > 0)
1525: parent_alive_interval = 10;
1.33 markus 1526: idtab_init();
1.61 markus 1527: signal(SIGPIPE, SIG_IGN);
1.201 djm 1528: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1529: signal(SIGHUP, cleanup_handler);
1530: signal(SIGTERM, cleanup_handler);
1.205 djm 1531:
1.215 djm 1532: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1533: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1534:
1.21 markus 1535: while (1) {
1.231 djm 1536: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1537: result = poll(pfd, npfd, timeout);
1.154 dtucker 1538: saved_errno = errno;
1.155 dtucker 1539: if (parent_alive_interval != 0)
1540: check_parent_exists();
1541: (void) reaper(); /* remove expired keys */
1.237 deraadt 1542: if (result == -1) {
1.154 dtucker 1543: if (saved_errno == EINTR)
1.21 markus 1544: continue;
1.223 djm 1545: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1546: } else if (result > 0)
1.231 djm 1547: after_poll(pfd, npfd, maxfds);
1.15 markus 1548: }
1.21 markus 1549: /* NOTREACHED */
1.1 deraadt 1550: }
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