Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.244
1.244 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.243 2019/11/14 21:27:30 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;
412: int r, ok = -1;
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) {
435: if ((r = provider_sign(id->sk_provider, id->key, &signature,
436: &slen, data, dlen, agent_decode_alg(key, flags),
437: compat)) != 0) {
1.239 djm 438: error("%s: sign: %s", __func__, ssh_err(r));
1.238 djm 439: goto send;
440: }
441: } else {
442: if ((r = sshkey_sign(id->key, &signature, &slen,
1.239 djm 443: data, dlen, agent_decode_alg(key, flags),
444: NULL, compat)) != 0) {
1.238 djm 445: error("%s: sshkey_sign: %s", __func__, ssh_err(r));
446: goto send;
447: }
1.33 markus 448: }
1.195 djm 449: /* Success */
450: ok = 0;
451: send:
452: sshkey_free(key);
1.33 markus 453: if (ok == 0) {
1.194 markus 454: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
455: (r = sshbuf_put_string(msg, signature, slen)) != 0)
456: fatal("%s: buffer error: %s", __func__, ssh_err(r));
457: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
458: fatal("%s: buffer error: %s", __func__, ssh_err(r));
459:
460: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
461: fatal("%s: buffer error: %s", __func__, ssh_err(r));
462:
463: sshbuf_free(msg);
1.173 djm 464: free(signature);
1.1 deraadt 465: }
466:
1.33 markus 467: /* shared */
1.55 itojun 468: static void
1.221 djm 469: process_remove_identity(SocketEntry *e)
1.1 deraadt 470: {
1.194 markus 471: int r, success = 0;
472: struct sshkey *key = NULL;
1.221 djm 473: Identity *id;
1.21 markus 474:
1.221 djm 475: if ((r = sshkey_froms(e->request, &key)) != 0) {
476: error("%s: get key: %s", __func__, ssh_err(r));
477: goto done;
478: }
479: if ((id = lookup_identity(key)) == NULL) {
480: debug("%s: key not found", __func__);
481: goto done;
482: }
483: /* We have this key, free it. */
484: if (idtab->nentries < 1)
485: fatal("%s: internal error: nentries %d",
486: __func__, idtab->nentries);
487: TAILQ_REMOVE(&idtab->idlist, id, next);
488: free_identity(id);
489: idtab->nentries--;
490: sshkey_free(key);
491: success = 1;
492: done:
1.194 markus 493: send_status(e, success);
1.1 deraadt 494: }
495:
1.55 itojun 496: static void
1.221 djm 497: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 498: {
1.78 provos 499: Identity *id;
1.21 markus 500:
501: /* Loop over all identities and clear the keys. */
1.221 djm 502: for (id = TAILQ_FIRST(&idtab->idlist); id;
503: id = TAILQ_FIRST(&idtab->idlist)) {
504: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 505: free_identity(id);
1.21 markus 506: }
507:
508: /* Mark that there are no identities. */
1.221 djm 509: idtab->nentries = 0;
1.21 markus 510:
511: /* Send success. */
1.194 markus 512: send_status(e, 1);
1.1 deraadt 513: }
514:
1.155 dtucker 515: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 516: static time_t
1.89 markus 517: reaper(void)
518: {
1.175 dtucker 519: time_t deadline = 0, now = monotime();
1.89 markus 520: Identity *id, *nxt;
521:
1.221 djm 522: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
523: nxt = TAILQ_NEXT(id, next);
524: if (id->death == 0)
525: continue;
526: if (now >= id->death) {
527: debug("expiring key '%s'", id->comment);
528: TAILQ_REMOVE(&idtab->idlist, id, next);
529: free_identity(id);
530: idtab->nentries--;
531: } else
532: deadline = (deadline == 0) ? id->death :
533: MINIMUM(deadline, id->death);
1.89 markus 534: }
1.155 dtucker 535: if (deadline == 0 || deadline <= now)
536: return 0;
537: else
538: return (deadline - now);
1.89 markus 539: }
540:
541: static void
1.221 djm 542: process_add_identity(SocketEntry *e)
1.1 deraadt 543: {
1.157 canacar 544: Identity *id;
1.194 markus 545: int success = 0, confirm = 0;
1.228 markus 546: u_int seconds, maxsign;
1.238 djm 547: char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
1.174 dtucker 548: time_t death = 0;
1.194 markus 549: struct sshkey *k = NULL;
550: u_char ctype;
551: int r = SSH_ERR_INTERNAL_ERROR;
1.33 markus 552:
1.221 djm 553: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
554: k == NULL ||
1.194 markus 555: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
556: error("%s: decode private key: %s", __func__, ssh_err(r));
557: goto err;
558: }
559: while (sshbuf_len(e->request)) {
560: if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
561: error("%s: buffer error: %s", __func__, ssh_err(r));
562: goto err;
563: }
564: switch (ctype) {
1.94 markus 565: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.194 markus 566: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
567: error("%s: bad lifetime constraint: %s",
568: __func__, ssh_err(r));
569: goto err;
570: }
571: death = monotime() + seconds;
1.94 markus 572: break;
1.107 markus 573: case SSH_AGENT_CONSTRAIN_CONFIRM:
574: confirm = 1;
575: break;
1.228 markus 576: case SSH_AGENT_CONSTRAIN_MAXSIGN:
577: if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
578: error("%s: bad maxsign constraint: %s",
579: __func__, ssh_err(r));
580: goto err;
581: }
582: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
583: error("%s: cannot enable maxsign: %s",
584: __func__, ssh_err(r));
585: goto err;
586: }
587: break;
1.238 djm 588: case SSH_AGENT_CONSTRAIN_EXTENSION:
589: if ((r = sshbuf_get_cstring(e->request,
590: &ext_name, NULL)) != 0) {
591: error("%s: cannot parse extension: %s",
592: __func__, ssh_err(r));
593: goto err;
594: }
595: debug("%s: constraint ext %s", __func__, ext_name);
596: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
597: if (sk_provider != NULL) {
598: error("%s already set", ext_name);
599: goto err;
600: }
601: if ((r = sshbuf_get_cstring(e->request,
602: &sk_provider, NULL)) != 0) {
603: error("%s: cannot parse %s: %s",
604: __func__, ext_name, ssh_err(r));
605: goto err;
606: }
607: } else {
608: error("%s: unsupported constraint \"%s\"",
609: __func__, ext_name);
610: goto err;
611: }
612: free(ext_name);
613: break;
1.94 markus 614: default:
1.194 markus 615: error("%s: Unknown constraint %d", __func__, ctype);
616: err:
1.238 djm 617: free(sk_provider);
618: free(ext_name);
1.194 markus 619: sshbuf_reset(e->request);
1.173 djm 620: free(comment);
1.194 markus 621: sshkey_free(k);
1.158 djm 622: goto send;
1.94 markus 623: }
624: }
1.238 djm 625: if (sk_provider != NULL) {
1.240 markus 626: if (!sshkey_is_sk(k)) {
1.238 djm 627: error("Cannot add provider: %s is not a security key",
628: sshkey_type(k));
629: free(sk_provider);
630: goto send;
631: }
632: if (match_pattern_list(sk_provider,
633: provider_whitelist, 0) != 1) {
634: error("Refusing add key: provider %s not whitelisted",
635: sk_provider);
636: free(sk_provider);
637: goto send;
638: }
1.242 markus 639: }
640: if ((r = sshkey_shield_private(k)) != 0) {
641: error("%s: shield private key: %s", __func__, ssh_err(r));
642: goto err;
1.238 djm 643: }
1.194 markus 644:
1.158 djm 645: success = 1;
1.106 marc 646: if (lifetime && !death)
1.175 dtucker 647: death = monotime() + lifetime;
1.221 djm 648: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 649: id = xcalloc(1, sizeof(Identity));
1.221 djm 650: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 651: /* Increment the number of identities. */
1.221 djm 652: idtab->nentries++;
1.33 markus 653: } else {
1.228 markus 654: /* key state might have been updated */
655: sshkey_free(id->key);
1.173 djm 656: free(id->comment);
1.238 djm 657: free(id->sk_provider);
1.33 markus 658: }
1.228 markus 659: id->key = k;
1.157 canacar 660: id->comment = comment;
661: id->death = death;
662: id->confirm = confirm;
1.238 djm 663: id->sk_provider = sk_provider;
664:
665: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
666: SSH_FP_DEFAULT)) == NULL)
667: fatal("%s: sshkey_fingerprint failed", __func__);
668: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
669: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
670: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
671: free(fp);
1.33 markus 672: send:
1.194 markus 673: send_status(e, success);
1.1 deraadt 674: }
675:
1.88 markus 676: /* XXX todo: encrypt sensitive data with passphrase */
677: static void
678: process_lock_agent(SocketEntry *e, int lock)
679: {
1.203 dtucker 680: int r, success = 0, delay;
1.213 djm 681: char *passwd;
682: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 683: static u_int fail_count = 0;
684: size_t pwlen;
685:
1.226 djm 686: /*
687: * This is deliberately fatal: the user has requested that we lock,
688: * but we can't parse their request properly. The only safe thing to
689: * do is abort.
690: */
1.203 dtucker 691: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
692: fatal("%s: buffer error: %s", __func__, ssh_err(r));
693: if (pwlen == 0) {
694: debug("empty password not supported");
695: } else if (locked && !lock) {
696: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
697: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
698: fatal("bcrypt_pbkdf");
1.213 djm 699: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 700: debug("agent unlocked");
701: locked = 0;
702: fail_count = 0;
1.213 djm 703: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 704: success = 1;
705: } else {
706: /* delay in 0.1s increments up to 10s */
707: if (fail_count < 100)
708: fail_count++;
709: delay = 100000 * fail_count;
710: debug("unlock failed, delaying %0.1lf seconds",
711: (double)delay/1000000);
712: usleep(delay);
713: }
714: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 715: } else if (!locked && lock) {
1.203 dtucker 716: debug("agent locked");
1.88 markus 717: locked = 1;
1.203 dtucker 718: arc4random_buf(lock_salt, sizeof(lock_salt));
719: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 720: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 721: fatal("bcrypt_pbkdf");
1.88 markus 722: success = 1;
723: }
1.203 dtucker 724: explicit_bzero(passwd, pwlen);
1.173 djm 725: free(passwd);
1.194 markus 726: send_status(e, success);
1.88 markus 727: }
728:
729: static void
1.221 djm 730: no_identities(SocketEntry *e)
1.88 markus 731: {
1.194 markus 732: struct sshbuf *msg;
733: int r;
1.88 markus 734:
1.194 markus 735: if ((msg = sshbuf_new()) == NULL)
736: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 737: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 738: (r = sshbuf_put_u32(msg, 0)) != 0 ||
739: (r = sshbuf_put_stringb(e->output, msg)) != 0)
740: fatal("%s: buffer error: %s", __func__, ssh_err(r));
741: sshbuf_free(msg);
1.88 markus 742: }
1.59 markus 743:
1.163 markus 744: #ifdef ENABLE_PKCS11
1.59 markus 745: static void
1.158 djm 746: process_add_smartcard_key(SocketEntry *e)
1.59 markus 747: {
1.226 djm 748: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 749: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 750: u_int seconds;
1.174 dtucker 751: time_t death = 0;
1.194 markus 752: u_char type;
753: struct sshkey **keys = NULL, *k;
1.84 markus 754: Identity *id;
1.75 deraadt 755:
1.194 markus 756: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 757: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
758: error("%s: buffer error: %s", __func__, ssh_err(r));
759: goto send;
760: }
1.194 markus 761:
762: while (sshbuf_len(e->request)) {
1.226 djm 763: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
764: error("%s: buffer error: %s", __func__, ssh_err(r));
765: goto send;
766: }
1.194 markus 767: switch (type) {
1.110 djm 768: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 769: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
770: error("%s: buffer error: %s",
1.194 markus 771: __func__, ssh_err(r));
1.226 djm 772: goto send;
773: }
1.194 markus 774: death = monotime() + seconds;
1.110 djm 775: break;
776: case SSH_AGENT_CONSTRAIN_CONFIRM:
777: confirm = 1;
778: break;
779: default:
1.221 djm 780: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 781: goto send;
1.110 djm 782: }
783: }
1.215 djm 784: if (realpath(provider, canonical_provider) == NULL) {
785: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
786: provider, strerror(errno));
787: goto send;
788: }
1.238 djm 789: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 790: verbose("refusing PKCS#11 add of \"%.100s\": "
791: "provider not whitelisted", canonical_provider);
792: goto send;
793: }
794: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 795: if (lifetime && !death)
1.175 dtucker 796: death = monotime() + lifetime;
1.110 djm 797:
1.215 djm 798: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 799: for (i = 0; i < count; i++) {
1.84 markus 800: k = keys[i];
1.221 djm 801: if (lookup_identity(k) == NULL) {
1.163 markus 802: id = xcalloc(1, sizeof(Identity));
1.84 markus 803: id->key = k;
1.215 djm 804: id->provider = xstrdup(canonical_provider);
805: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 806: id->death = death;
807: id->confirm = confirm;
1.221 djm 808: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
809: idtab->nentries++;
1.84 markus 810: success = 1;
811: } else {
1.194 markus 812: sshkey_free(k);
1.84 markus 813: }
814: keys[i] = NULL;
1.59 markus 815: }
816: send:
1.173 djm 817: free(pin);
818: free(provider);
819: free(keys);
1.194 markus 820: send_status(e, success);
1.59 markus 821: }
822:
823: static void
824: process_remove_smartcard_key(SocketEntry *e)
825: {
1.217 djm 826: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 827: int r, success = 0;
1.163 markus 828: Identity *id, *nxt;
1.59 markus 829:
1.194 markus 830: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 831: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
832: error("%s: buffer error: %s", __func__, ssh_err(r));
833: goto send;
834: }
1.173 djm 835: free(pin);
1.59 markus 836:
1.217 djm 837: if (realpath(provider, canonical_provider) == NULL) {
838: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
839: provider, strerror(errno));
840: goto send;
841: }
842:
843: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 844: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
845: nxt = TAILQ_NEXT(id, next);
846: /* Skip file--based keys */
847: if (id->provider == NULL)
848: continue;
849: if (!strcmp(canonical_provider, id->provider)) {
850: TAILQ_REMOVE(&idtab->idlist, id, next);
851: free_identity(id);
852: idtab->nentries--;
1.59 markus 853: }
854: }
1.217 djm 855: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 856: success = 1;
857: else
1.221 djm 858: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 859: send:
1.173 djm 860: free(provider);
1.194 markus 861: send_status(e, success);
1.59 markus 862: }
1.163 markus 863: #endif /* ENABLE_PKCS11 */
1.59 markus 864:
1.33 markus 865: /* dispatch incoming messages */
866:
1.223 djm 867: static int
868: process_message(u_int socknum)
1.1 deraadt 869: {
1.194 markus 870: u_int msg_len;
871: u_char type;
872: const u_char *cp;
873: int r;
1.223 djm 874: SocketEntry *e;
875:
876: if (socknum >= sockets_alloc) {
877: fatal("%s: socket number %u >= allocated %u",
878: __func__, socknum, sockets_alloc);
879: }
880: e = &sockets[socknum];
1.89 markus 881:
1.194 markus 882: if (sshbuf_len(e->input) < 5)
1.223 djm 883: return 0; /* Incomplete message header. */
1.194 markus 884: cp = sshbuf_ptr(e->input);
885: msg_len = PEEK_U32(cp);
1.223 djm 886: if (msg_len > AGENT_MAX_LEN) {
887: debug("%s: socket %u (fd=%d) message too long %u > %u",
888: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
889: return -1;
1.21 markus 890: }
1.194 markus 891: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 892: return 0; /* Incomplete message body. */
1.87 markus 893:
894: /* move the current input to e->request */
1.194 markus 895: sshbuf_reset(e->request);
896: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 897: (r = sshbuf_get_u8(e->request, &type)) != 0) {
898: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
899: r == SSH_ERR_STRING_TOO_LARGE) {
900: debug("%s: buffer error: %s", __func__, ssh_err(r));
901: return -1;
902: }
1.194 markus 903: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 904: }
905:
906: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 907:
1.230 djm 908: /* check whether agent is locked */
1.88 markus 909: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 910: sshbuf_reset(e->request);
1.88 markus 911: switch (type) {
912: case SSH2_AGENTC_REQUEST_IDENTITIES:
913: /* send empty lists */
1.221 djm 914: no_identities(e);
1.88 markus 915: break;
916: default:
917: /* send a fail message for all other request types */
1.194 markus 918: send_status(e, 0);
1.88 markus 919: }
1.223 djm 920: return 0;
1.88 markus 921: }
922:
1.21 markus 923: switch (type) {
1.88 markus 924: case SSH_AGENTC_LOCK:
925: case SSH_AGENTC_UNLOCK:
926: process_lock_agent(e, type == SSH_AGENTC_LOCK);
927: break;
1.21 markus 928: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 929: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 930: break;
931: /* ssh2 */
932: case SSH2_AGENTC_SIGN_REQUEST:
933: process_sign_request2(e);
934: break;
935: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 936: process_request_identities(e);
1.33 markus 937: break;
938: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 939: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 940: process_add_identity(e);
1.33 markus 941: break;
942: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 943: process_remove_identity(e);
1.33 markus 944: break;
945: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 946: process_remove_all_identities(e);
1.21 markus 947: break;
1.163 markus 948: #ifdef ENABLE_PKCS11
1.59 markus 949: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 950: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 951: process_add_smartcard_key(e);
1.75 deraadt 952: break;
1.59 markus 953: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
954: process_remove_smartcard_key(e);
1.75 deraadt 955: break;
1.163 markus 956: #endif /* ENABLE_PKCS11 */
1.21 markus 957: default:
958: /* Unknown message. Respond with failure. */
959: error("Unknown message %d", type);
1.194 markus 960: sshbuf_reset(e->request);
961: send_status(e, 0);
1.21 markus 962: break;
963: }
1.223 djm 964: return 0;
1.1 deraadt 965: }
966:
1.55 itojun 967: static void
1.73 stevesk 968: new_socket(sock_type type, int fd)
1.1 deraadt 969: {
1.112 markus 970: u_int i, old_alloc, new_alloc;
1.96 deraadt 971:
1.119 djm 972: set_nonblock(fd);
1.21 markus 973:
974: if (fd > max_fd)
975: max_fd = fd;
976:
977: for (i = 0; i < sockets_alloc; i++)
978: if (sockets[i].type == AUTH_UNUSED) {
979: sockets[i].fd = fd;
1.194 markus 980: if ((sockets[i].input = sshbuf_new()) == NULL)
981: fatal("%s: sshbuf_new failed", __func__);
982: if ((sockets[i].output = sshbuf_new()) == NULL)
983: fatal("%s: sshbuf_new failed", __func__);
984: if ((sockets[i].request = sshbuf_new()) == NULL)
985: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 986: sockets[i].type = type;
1.21 markus 987: return;
988: }
989: old_alloc = sockets_alloc;
1.112 markus 990: new_alloc = sockets_alloc + 10;
1.200 deraadt 991: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 992: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 993: sockets[i].type = AUTH_UNUSED;
1.112 markus 994: sockets_alloc = new_alloc;
1.21 markus 995: sockets[old_alloc].fd = fd;
1.194 markus 996: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
997: fatal("%s: sshbuf_new failed", __func__);
998: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
999: fatal("%s: sshbuf_new failed", __func__);
1000: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
1001: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 1002: sockets[old_alloc].type = type;
1.1 deraadt 1003: }
1004:
1.55 itojun 1005: static int
1.223 djm 1006: handle_socket_read(u_int socknum)
1.1 deraadt 1007: {
1.223 djm 1008: struct sockaddr_un sunaddr;
1009: socklen_t slen;
1010: uid_t euid;
1011: gid_t egid;
1012: int fd;
1013:
1014: slen = sizeof(sunaddr);
1015: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1016: if (fd == -1) {
1.223 djm 1017: error("accept from AUTH_SOCKET: %s", strerror(errno));
1018: return -1;
1019: }
1.237 deraadt 1020: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1021: error("getpeereid %d failed: %s", fd, strerror(errno));
1022: close(fd);
1023: return -1;
1024: }
1025: if ((euid != 0) && (getuid() != euid)) {
1026: error("uid mismatch: peer euid %u != uid %u",
1027: (u_int) euid, (u_int) getuid());
1028: close(fd);
1029: return -1;
1030: }
1031: new_socket(AUTH_CONNECTION, fd);
1032: return 0;
1033: }
1034:
1035: static int
1036: handle_conn_read(u_int socknum)
1037: {
1.233 djm 1038: char buf[AGENT_RBUF_LEN];
1.223 djm 1039: ssize_t len;
1040: int r;
1041:
1042: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1043: if (len == -1) {
1044: if (errno == EAGAIN || errno == EINTR)
1045: return 0;
1046: error("%s: read error on socket %u (fd %d): %s",
1047: __func__, socknum, sockets[socknum].fd,
1048: strerror(errno));
1049: }
1050: return -1;
1051: }
1052: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1053: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1054: explicit_bzero(buf, sizeof(buf));
1055: process_message(socknum);
1056: return 0;
1057: }
1058:
1059: static int
1060: handle_conn_write(u_int socknum)
1061: {
1062: ssize_t len;
1063: int r;
1064:
1065: if (sshbuf_len(sockets[socknum].output) == 0)
1066: return 0; /* shouldn't happen */
1067: if ((len = write(sockets[socknum].fd,
1068: sshbuf_ptr(sockets[socknum].output),
1069: sshbuf_len(sockets[socknum].output))) <= 0) {
1070: if (len == -1) {
1071: if (errno == EAGAIN || errno == EINTR)
1072: return 0;
1073: error("%s: read error on socket %u (fd %d): %s",
1074: __func__, socknum, sockets[socknum].fd,
1075: strerror(errno));
1076: }
1077: return -1;
1078: }
1079: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1080: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1081: return 0;
1082: }
1083:
1084: static void
1.231 djm 1085: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1086: {
1087: size_t i;
1.231 djm 1088: u_int socknum, activefds = npfd;
1.223 djm 1089:
1090: for (i = 0; i < npfd; i++) {
1091: if (pfd[i].revents == 0)
1092: continue;
1093: /* Find sockets entry */
1094: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1095: if (sockets[socknum].type != AUTH_SOCKET &&
1096: sockets[socknum].type != AUTH_CONNECTION)
1097: continue;
1098: if (pfd[i].fd == sockets[socknum].fd)
1099: break;
1100: }
1101: if (socknum >= sockets_alloc) {
1102: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1103: continue;
1104: }
1105: /* Process events */
1106: switch (sockets[socknum].type) {
1107: case AUTH_SOCKET:
1.231 djm 1108: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1109: break;
1110: if (npfd > maxfds) {
1111: debug3("out of fds (active %u >= limit %u); "
1112: "skipping accept", activefds, maxfds);
1113: break;
1114: }
1115: if (handle_socket_read(socknum) == 0)
1116: activefds++;
1.223 djm 1117: break;
1118: case AUTH_CONNECTION:
1119: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1120: handle_conn_read(socknum) != 0) {
1.231 djm 1121: goto close_sock;
1122: }
1123: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1124: handle_conn_write(socknum) != 0) {
1125: close_sock:
1126: if (activefds == 0)
1127: fatal("activefds == 0 at close_sock");
1.223 djm 1128: close_socket(&sockets[socknum]);
1.231 djm 1129: activefds--;
1.223 djm 1130: break;
1131: }
1132: break;
1133: default:
1134: break;
1135: }
1136: }
1137: }
1138:
1139: static int
1.231 djm 1140: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1141: {
1142: struct pollfd *pfd = *pfdp;
1143: size_t i, j, npfd = 0;
1.174 dtucker 1144: time_t deadline;
1.233 djm 1145: int r;
1.46 markus 1146:
1.223 djm 1147: /* Count active sockets */
1.46 markus 1148: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1149: switch (sockets[i].type) {
1150: case AUTH_SOCKET:
1151: case AUTH_CONNECTION:
1.223 djm 1152: npfd++;
1.21 markus 1153: break;
1154: case AUTH_UNUSED:
1155: break;
1156: default:
1157: fatal("Unknown socket type %d", sockets[i].type);
1158: break;
1159: }
1.46 markus 1160: }
1.223 djm 1161: if (npfd != *npfdp &&
1162: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1163: fatal("%s: recallocarray failed", __func__);
1164: *pfdp = pfd;
1165: *npfdp = npfd;
1.46 markus 1166:
1.223 djm 1167: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1168: switch (sockets[i].type) {
1169: case AUTH_SOCKET:
1.231 djm 1170: if (npfd > maxfds) {
1171: debug3("out of fds (active %zu >= limit %u); "
1172: "skipping arming listener", npfd, maxfds);
1173: break;
1174: }
1175: pfd[j].fd = sockets[i].fd;
1176: pfd[j].revents = 0;
1177: pfd[j].events = POLLIN;
1178: j++;
1179: break;
1.46 markus 1180: case AUTH_CONNECTION:
1.223 djm 1181: pfd[j].fd = sockets[i].fd;
1182: pfd[j].revents = 0;
1.233 djm 1183: /*
1184: * Only prepare to read if we can handle a full-size
1185: * input read buffer and enqueue a max size reply..
1186: */
1187: if ((r = sshbuf_check_reserve(sockets[i].input,
1188: AGENT_RBUF_LEN)) == 0 &&
1189: (r = sshbuf_check_reserve(sockets[i].output,
1190: AGENT_MAX_LEN)) == 0)
1191: pfd[j].events = POLLIN;
1192: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1193: fatal("%s: buffer error: %s",
1194: __func__, ssh_err(r));
1195: }
1.194 markus 1196: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1197: pfd[j].events |= POLLOUT;
1198: j++;
1.46 markus 1199: break;
1200: default:
1201: break;
1202: }
1203: }
1.155 dtucker 1204: deadline = reaper();
1205: if (parent_alive_interval != 0)
1206: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1207: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1208: if (deadline == 0) {
1.224 djm 1209: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1210: } else {
1.223 djm 1211: if (deadline > INT_MAX / 1000)
1212: *timeoutp = INT_MAX / 1000;
1213: else
1214: *timeoutp = deadline * 1000;
1.155 dtucker 1215: }
1.46 markus 1216: return (1);
1.21 markus 1217: }
1218:
1.55 itojun 1219: static void
1.113 markus 1220: cleanup_socket(void)
1.15 markus 1221: {
1.187 djm 1222: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1223: return;
1224: debug("%s: cleanup", __func__);
1.48 deraadt 1225: if (socket_name[0])
1226: unlink(socket_name);
1227: if (socket_dir[0])
1228: rmdir(socket_dir);
1.10 markus 1229: }
1230:
1.114 markus 1231: void
1.15 markus 1232: cleanup_exit(int i)
1233: {
1.113 markus 1234: cleanup_socket();
1235: _exit(i);
1.15 markus 1236: }
1237:
1.135 deraadt 1238: /*ARGSUSED*/
1.55 itojun 1239: static void
1.48 deraadt 1240: cleanup_handler(int sig)
1241: {
1.113 markus 1242: cleanup_socket();
1.163 markus 1243: #ifdef ENABLE_PKCS11
1244: pkcs11_terminate();
1245: #endif
1.48 deraadt 1246: _exit(2);
1.113 markus 1247: }
1248:
1.68 markus 1249: static void
1.155 dtucker 1250: check_parent_exists(void)
1.68 markus 1251: {
1.172 dtucker 1252: /*
1253: * If our parent has exited then getppid() will return (pid_t)1,
1254: * so testing for that should be safe.
1255: */
1256: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1257: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1258: cleanup_socket();
1259: _exit(2);
1.68 markus 1260: }
1.48 deraadt 1261: }
1262:
1.55 itojun 1263: static void
1.50 itojun 1264: usage(void)
1.15 markus 1265: {
1.184 deraadt 1266: fprintf(stderr,
1.202 jmc 1267: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1268: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1269: " ssh-agent [-c | -s] -k\n");
1.21 markus 1270: exit(1);
1.15 markus 1271: }
1272:
1.2 provos 1273: int
1274: main(int ac, char **av)
1.1 deraadt 1275: {
1.201 djm 1276: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1277: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1278: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1279: struct rlimit rlim;
1.96 deraadt 1280: extern int optind;
1.98 stevesk 1281: extern char *optarg;
1.21 markus 1282: pid_t pid;
1.96 deraadt 1283: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1284: size_t len;
1.189 djm 1285: mode_t prev_mask;
1.224 djm 1286: int timeout = -1; /* INFTIM */
1.223 djm 1287: struct pollfd *pfd = NULL;
1288: size_t npfd = 0;
1.231 djm 1289: u_int maxfds;
1.123 djm 1290:
1291: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1292: sanitise_stdfd();
1.99 markus 1293:
1294: /* drop */
1295: setegid(getgid());
1296: setgid(getgid());
1.53 markus 1297:
1.231 djm 1298: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1299: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1300:
1.185 markus 1301: #ifdef WITH_OPENSSL
1.170 djm 1302: OpenSSL_add_all_algorithms();
1.185 markus 1303: #endif
1.21 markus 1304:
1.215 djm 1305: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1306: switch (ch) {
1.192 djm 1307: case 'E':
1308: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1309: if (fingerprint_hash == -1)
1310: fatal("Invalid hash algorithm \"%s\"", optarg);
1311: break;
1.21 markus 1312: case 'c':
1313: if (s_flag)
1314: usage();
1315: c_flag++;
1316: break;
1317: case 'k':
1318: k_flag++;
1319: break;
1.215 djm 1320: case 'P':
1.238 djm 1321: if (provider_whitelist != NULL)
1.215 djm 1322: fatal("-P option already specified");
1.238 djm 1323: provider_whitelist = xstrdup(optarg);
1.215 djm 1324: break;
1.21 markus 1325: case 's':
1326: if (c_flag)
1327: usage();
1328: s_flag++;
1329: break;
1.57 markus 1330: case 'd':
1.201 djm 1331: if (d_flag || D_flag)
1.57 markus 1332: usage();
1333: d_flag++;
1334: break;
1.201 djm 1335: case 'D':
1336: if (d_flag || D_flag)
1337: usage();
1338: D_flag++;
1339: break;
1.86 markus 1340: case 'a':
1341: agentsocket = optarg;
1.106 marc 1342: break;
1343: case 't':
1344: if ((lifetime = convtime(optarg)) == -1) {
1345: fprintf(stderr, "Invalid lifetime\n");
1346: usage();
1347: }
1.86 markus 1348: break;
1.21 markus 1349: default:
1350: usage();
1351: }
1352: }
1353: ac -= optind;
1354: av += optind;
1355:
1.201 djm 1356: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1357: usage();
1358:
1.238 djm 1359: if (provider_whitelist == NULL)
1360: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1361:
1.85 markus 1362: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1363: shell = getenv("SHELL");
1.161 tobias 1364: if (shell != NULL && (len = strlen(shell)) > 2 &&
1365: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1366: c_flag = 1;
1367: }
1368: if (k_flag) {
1.136 deraadt 1369: const char *errstr = NULL;
1370:
1.21 markus 1371: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1372: if (pidstr == NULL) {
1373: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1374: SSH_AGENTPID_ENV_NAME);
1.21 markus 1375: exit(1);
1376: }
1.136 deraadt 1377: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1378: if (errstr) {
1379: fprintf(stderr,
1380: "%s=\"%s\", which is not a good PID: %s\n",
1381: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1382: exit(1);
1383: }
1384: if (kill(pid, SIGTERM) == -1) {
1385: perror("kill");
1386: exit(1);
1387: }
1388: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1389: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1390: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1391: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1392: exit(0);
1393: }
1.231 djm 1394:
1395: /*
1396: * Minimum file descriptors:
1397: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1398: * a few spare for libc / stack protectors / sanitisers, etc.
1399: */
1400: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1401: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1402: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1403: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1404: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1405:
1.21 markus 1406: parent_pid = getpid();
1407:
1.86 markus 1408: if (agentsocket == NULL) {
1409: /* Create private directory for agent socket */
1.171 djm 1410: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1411: if (mkdtemp(socket_dir) == NULL) {
1412: perror("mkdtemp: private socket dir");
1413: exit(1);
1414: }
1.91 mpech 1415: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1416: (long)parent_pid);
1.86 markus 1417: } else {
1418: /* Try to use specified agent socket */
1419: socket_dir[0] = '\0';
1420: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1421: }
1422:
1.23 markus 1423: /*
1424: * Create socket early so it will exist before command gets run from
1425: * the parent.
1426: */
1.189 djm 1427: prev_mask = umask(0177);
1.188 millert 1428: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1429: if (sock < 0) {
1.188 millert 1430: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1431: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1432: cleanup_exit(1);
1433: }
1.189 djm 1434: umask(prev_mask);
1.46 markus 1435:
1.23 markus 1436: /*
1437: * Fork, and have the parent execute the command, if any, or present
1438: * the socket data. The child continues as the authentication agent.
1439: */
1.201 djm 1440: if (D_flag || d_flag) {
1441: log_init(__progname,
1442: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1443: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1444: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1445: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1446: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1447: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1448: fflush(stdout);
1.57 markus 1449: goto skip;
1450: }
1.21 markus 1451: pid = fork();
1452: if (pid == -1) {
1453: perror("fork");
1.81 stevesk 1454: cleanup_exit(1);
1.21 markus 1455: }
1456: if (pid != 0) { /* Parent - execute the given command. */
1457: close(sock);
1.91 mpech 1458: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1459: if (ac == 0) {
1460: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1461: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1462: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1463: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1464: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1465: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1466: exit(0);
1467: }
1.36 deraadt 1468: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1469: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1470: perror("setenv");
1471: exit(1);
1472: }
1.21 markus 1473: execvp(av[0], av);
1474: perror(av[0]);
1475: exit(1);
1476: }
1.81 stevesk 1477: /* child */
1478: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1479:
1480: if (setsid() == -1) {
1.81 stevesk 1481: error("setsid: %s", strerror(errno));
1.67 stevesk 1482: cleanup_exit(1);
1483: }
1484:
1485: (void)chdir("/");
1.107 markus 1486: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1487: /* XXX might close listen socket */
1488: (void)dup2(fd, STDIN_FILENO);
1489: (void)dup2(fd, STDOUT_FILENO);
1490: (void)dup2(fd, STDERR_FILENO);
1491: if (fd > 2)
1492: close(fd);
1493: }
1.21 markus 1494:
1.41 markus 1495: /* deny core dumps, since memory contains unencrypted private keys */
1496: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1497: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1498: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1499: cleanup_exit(1);
1500: }
1.57 markus 1501:
1502: skip:
1.187 djm 1503:
1504: cleanup_pid = getpid();
1.163 markus 1505:
1506: #ifdef ENABLE_PKCS11
1507: pkcs11_init(0);
1508: #endif
1.21 markus 1509: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1510: if (ac > 0)
1511: parent_alive_interval = 10;
1.33 markus 1512: idtab_init();
1.61 markus 1513: signal(SIGPIPE, SIG_IGN);
1.201 djm 1514: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1515: signal(SIGHUP, cleanup_handler);
1516: signal(SIGTERM, cleanup_handler);
1.205 djm 1517:
1.215 djm 1518: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1519: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1520:
1.21 markus 1521: while (1) {
1.231 djm 1522: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1523: result = poll(pfd, npfd, timeout);
1.154 dtucker 1524: saved_errno = errno;
1.155 dtucker 1525: if (parent_alive_interval != 0)
1526: check_parent_exists();
1527: (void) reaper(); /* remove expired keys */
1.237 deraadt 1528: if (result == -1) {
1.154 dtucker 1529: if (saved_errno == EINTR)
1.21 markus 1530: continue;
1.223 djm 1531: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1532: } else if (result > 0)
1.231 djm 1533: after_poll(pfd, npfd, maxfds);
1.15 markus 1534: }
1.21 markus 1535: /* NOTREACHED */
1.1 deraadt 1536: }
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