Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.245
1.245 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.244 2019/11/15 02:38:07 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: }
1.245 ! djm 632: if (strcasecmp(sk_provider, "internal") == 0)
! 633: debug("%s: internal provider", __func__);
! 634: else if (match_pattern_list(sk_provider,
1.238 djm 635: provider_whitelist, 0) != 1) {
636: error("Refusing add key: provider %s not whitelisted",
637: sk_provider);
638: free(sk_provider);
639: goto send;
640: }
1.242 markus 641: }
642: if ((r = sshkey_shield_private(k)) != 0) {
643: error("%s: shield private key: %s", __func__, ssh_err(r));
644: goto err;
1.238 djm 645: }
1.194 markus 646:
1.158 djm 647: success = 1;
1.106 marc 648: if (lifetime && !death)
1.175 dtucker 649: death = monotime() + lifetime;
1.221 djm 650: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 651: id = xcalloc(1, sizeof(Identity));
1.221 djm 652: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 653: /* Increment the number of identities. */
1.221 djm 654: idtab->nentries++;
1.33 markus 655: } else {
1.228 markus 656: /* key state might have been updated */
657: sshkey_free(id->key);
1.173 djm 658: free(id->comment);
1.238 djm 659: free(id->sk_provider);
1.33 markus 660: }
1.228 markus 661: id->key = k;
1.157 canacar 662: id->comment = comment;
663: id->death = death;
664: id->confirm = confirm;
1.238 djm 665: id->sk_provider = sk_provider;
666:
667: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
668: SSH_FP_DEFAULT)) == NULL)
669: fatal("%s: sshkey_fingerprint failed", __func__);
670: debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
671: "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
672: seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
673: free(fp);
1.33 markus 674: send:
1.194 markus 675: send_status(e, success);
1.1 deraadt 676: }
677:
1.88 markus 678: /* XXX todo: encrypt sensitive data with passphrase */
679: static void
680: process_lock_agent(SocketEntry *e, int lock)
681: {
1.203 dtucker 682: int r, success = 0, delay;
1.213 djm 683: char *passwd;
684: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 685: static u_int fail_count = 0;
686: size_t pwlen;
687:
1.226 djm 688: /*
689: * This is deliberately fatal: the user has requested that we lock,
690: * but we can't parse their request properly. The only safe thing to
691: * do is abort.
692: */
1.203 dtucker 693: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
694: fatal("%s: buffer error: %s", __func__, ssh_err(r));
695: if (pwlen == 0) {
696: debug("empty password not supported");
697: } else if (locked && !lock) {
698: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
699: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
700: fatal("bcrypt_pbkdf");
1.213 djm 701: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 702: debug("agent unlocked");
703: locked = 0;
704: fail_count = 0;
1.213 djm 705: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 706: success = 1;
707: } else {
708: /* delay in 0.1s increments up to 10s */
709: if (fail_count < 100)
710: fail_count++;
711: delay = 100000 * fail_count;
712: debug("unlock failed, delaying %0.1lf seconds",
713: (double)delay/1000000);
714: usleep(delay);
715: }
716: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 717: } else if (!locked && lock) {
1.203 dtucker 718: debug("agent locked");
1.88 markus 719: locked = 1;
1.203 dtucker 720: arc4random_buf(lock_salt, sizeof(lock_salt));
721: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 722: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 723: fatal("bcrypt_pbkdf");
1.88 markus 724: success = 1;
725: }
1.203 dtucker 726: explicit_bzero(passwd, pwlen);
1.173 djm 727: free(passwd);
1.194 markus 728: send_status(e, success);
1.88 markus 729: }
730:
731: static void
1.221 djm 732: no_identities(SocketEntry *e)
1.88 markus 733: {
1.194 markus 734: struct sshbuf *msg;
735: int r;
1.88 markus 736:
1.194 markus 737: if ((msg = sshbuf_new()) == NULL)
738: fatal("%s: sshbuf_new failed", __func__);
1.221 djm 739: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 740: (r = sshbuf_put_u32(msg, 0)) != 0 ||
741: (r = sshbuf_put_stringb(e->output, msg)) != 0)
742: fatal("%s: buffer error: %s", __func__, ssh_err(r));
743: sshbuf_free(msg);
1.88 markus 744: }
1.59 markus 745:
1.163 markus 746: #ifdef ENABLE_PKCS11
1.59 markus 747: static void
1.158 djm 748: process_add_smartcard_key(SocketEntry *e)
1.59 markus 749: {
1.226 djm 750: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 751: int r, i, count = 0, success = 0, confirm = 0;
1.194 markus 752: u_int seconds;
1.174 dtucker 753: time_t death = 0;
1.194 markus 754: u_char type;
755: struct sshkey **keys = NULL, *k;
1.84 markus 756: Identity *id;
1.75 deraadt 757:
1.194 markus 758: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 759: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
760: error("%s: buffer error: %s", __func__, ssh_err(r));
761: goto send;
762: }
1.194 markus 763:
764: while (sshbuf_len(e->request)) {
1.226 djm 765: if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
766: error("%s: buffer error: %s", __func__, ssh_err(r));
767: goto send;
768: }
1.194 markus 769: switch (type) {
1.110 djm 770: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.226 djm 771: if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
772: error("%s: buffer error: %s",
1.194 markus 773: __func__, ssh_err(r));
1.226 djm 774: goto send;
775: }
1.194 markus 776: death = monotime() + seconds;
1.110 djm 777: break;
778: case SSH_AGENT_CONSTRAIN_CONFIRM:
779: confirm = 1;
780: break;
781: default:
1.221 djm 782: error("%s: Unknown constraint type %d", __func__, type);
1.158 djm 783: goto send;
1.110 djm 784: }
785: }
1.215 djm 786: if (realpath(provider, canonical_provider) == NULL) {
787: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
788: provider, strerror(errno));
789: goto send;
790: }
1.238 djm 791: if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
1.215 djm 792: verbose("refusing PKCS#11 add of \"%.100s\": "
793: "provider not whitelisted", canonical_provider);
794: goto send;
795: }
796: debug("%s: add %.100s", __func__, canonical_provider);
1.110 djm 797: if (lifetime && !death)
1.175 dtucker 798: death = monotime() + lifetime;
1.110 djm 799:
1.215 djm 800: count = pkcs11_add_provider(canonical_provider, pin, &keys);
1.163 markus 801: for (i = 0; i < count; i++) {
1.84 markus 802: k = keys[i];
1.221 djm 803: if (lookup_identity(k) == NULL) {
1.163 markus 804: id = xcalloc(1, sizeof(Identity));
1.84 markus 805: id->key = k;
1.215 djm 806: id->provider = xstrdup(canonical_provider);
807: id->comment = xstrdup(canonical_provider); /* XXX */
1.110 djm 808: id->death = death;
809: id->confirm = confirm;
1.221 djm 810: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
811: idtab->nentries++;
1.84 markus 812: success = 1;
813: } else {
1.194 markus 814: sshkey_free(k);
1.84 markus 815: }
816: keys[i] = NULL;
1.59 markus 817: }
818: send:
1.173 djm 819: free(pin);
820: free(provider);
821: free(keys);
1.194 markus 822: send_status(e, success);
1.59 markus 823: }
824:
825: static void
826: process_remove_smartcard_key(SocketEntry *e)
827: {
1.217 djm 828: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 829: int r, success = 0;
1.163 markus 830: Identity *id, *nxt;
1.59 markus 831:
1.194 markus 832: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 833: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
834: error("%s: buffer error: %s", __func__, ssh_err(r));
835: goto send;
836: }
1.173 djm 837: free(pin);
1.59 markus 838:
1.217 djm 839: if (realpath(provider, canonical_provider) == NULL) {
840: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
841: provider, strerror(errno));
842: goto send;
843: }
844:
845: debug("%s: remove %.100s", __func__, canonical_provider);
1.221 djm 846: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
847: nxt = TAILQ_NEXT(id, next);
848: /* Skip file--based keys */
849: if (id->provider == NULL)
850: continue;
851: if (!strcmp(canonical_provider, id->provider)) {
852: TAILQ_REMOVE(&idtab->idlist, id, next);
853: free_identity(id);
854: idtab->nentries--;
1.59 markus 855: }
856: }
1.217 djm 857: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 858: success = 1;
859: else
1.221 djm 860: error("%s: pkcs11_del_provider failed", __func__);
1.218 deraadt 861: send:
1.173 djm 862: free(provider);
1.194 markus 863: send_status(e, success);
1.59 markus 864: }
1.163 markus 865: #endif /* ENABLE_PKCS11 */
1.59 markus 866:
1.33 markus 867: /* dispatch incoming messages */
868:
1.223 djm 869: static int
870: process_message(u_int socknum)
1.1 deraadt 871: {
1.194 markus 872: u_int msg_len;
873: u_char type;
874: const u_char *cp;
875: int r;
1.223 djm 876: SocketEntry *e;
877:
878: if (socknum >= sockets_alloc) {
879: fatal("%s: socket number %u >= allocated %u",
880: __func__, socknum, sockets_alloc);
881: }
882: e = &sockets[socknum];
1.89 markus 883:
1.194 markus 884: if (sshbuf_len(e->input) < 5)
1.223 djm 885: return 0; /* Incomplete message header. */
1.194 markus 886: cp = sshbuf_ptr(e->input);
887: msg_len = PEEK_U32(cp);
1.223 djm 888: if (msg_len > AGENT_MAX_LEN) {
889: debug("%s: socket %u (fd=%d) message too long %u > %u",
890: __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
891: return -1;
1.21 markus 892: }
1.194 markus 893: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 894: return 0; /* Incomplete message body. */
1.87 markus 895:
896: /* move the current input to e->request */
1.194 markus 897: sshbuf_reset(e->request);
898: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 899: (r = sshbuf_get_u8(e->request, &type)) != 0) {
900: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
901: r == SSH_ERR_STRING_TOO_LARGE) {
902: debug("%s: buffer error: %s", __func__, ssh_err(r));
903: return -1;
904: }
1.194 markus 905: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.223 djm 906: }
907:
908: debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
1.21 markus 909:
1.230 djm 910: /* check whether agent is locked */
1.88 markus 911: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 912: sshbuf_reset(e->request);
1.88 markus 913: switch (type) {
914: case SSH2_AGENTC_REQUEST_IDENTITIES:
915: /* send empty lists */
1.221 djm 916: no_identities(e);
1.88 markus 917: break;
918: default:
919: /* send a fail message for all other request types */
1.194 markus 920: send_status(e, 0);
1.88 markus 921: }
1.223 djm 922: return 0;
1.88 markus 923: }
924:
1.21 markus 925: switch (type) {
1.88 markus 926: case SSH_AGENTC_LOCK:
927: case SSH_AGENTC_UNLOCK:
928: process_lock_agent(e, type == SSH_AGENTC_LOCK);
929: break;
1.21 markus 930: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 931: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 932: break;
933: /* ssh2 */
934: case SSH2_AGENTC_SIGN_REQUEST:
935: process_sign_request2(e);
936: break;
937: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 938: process_request_identities(e);
1.33 markus 939: break;
940: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 941: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 942: process_add_identity(e);
1.33 markus 943: break;
944: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 945: process_remove_identity(e);
1.33 markus 946: break;
947: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 948: process_remove_all_identities(e);
1.21 markus 949: break;
1.163 markus 950: #ifdef ENABLE_PKCS11
1.59 markus 951: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 952: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 953: process_add_smartcard_key(e);
1.75 deraadt 954: break;
1.59 markus 955: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
956: process_remove_smartcard_key(e);
1.75 deraadt 957: break;
1.163 markus 958: #endif /* ENABLE_PKCS11 */
1.21 markus 959: default:
960: /* Unknown message. Respond with failure. */
961: error("Unknown message %d", type);
1.194 markus 962: sshbuf_reset(e->request);
963: send_status(e, 0);
1.21 markus 964: break;
965: }
1.223 djm 966: return 0;
1.1 deraadt 967: }
968:
1.55 itojun 969: static void
1.73 stevesk 970: new_socket(sock_type type, int fd)
1.1 deraadt 971: {
1.112 markus 972: u_int i, old_alloc, new_alloc;
1.96 deraadt 973:
1.119 djm 974: set_nonblock(fd);
1.21 markus 975:
976: if (fd > max_fd)
977: max_fd = fd;
978:
979: for (i = 0; i < sockets_alloc; i++)
980: if (sockets[i].type == AUTH_UNUSED) {
981: sockets[i].fd = fd;
1.194 markus 982: if ((sockets[i].input = sshbuf_new()) == NULL)
983: fatal("%s: sshbuf_new failed", __func__);
984: if ((sockets[i].output = sshbuf_new()) == NULL)
985: fatal("%s: sshbuf_new failed", __func__);
986: if ((sockets[i].request = sshbuf_new()) == NULL)
987: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 988: sockets[i].type = type;
1.21 markus 989: return;
990: }
991: old_alloc = sockets_alloc;
1.112 markus 992: new_alloc = sockets_alloc + 10;
1.200 deraadt 993: sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
1.112 markus 994: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 995: sockets[i].type = AUTH_UNUSED;
1.112 markus 996: sockets_alloc = new_alloc;
1.21 markus 997: sockets[old_alloc].fd = fd;
1.194 markus 998: if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
999: fatal("%s: sshbuf_new failed", __func__);
1000: if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
1001: fatal("%s: sshbuf_new failed", __func__);
1002: if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
1003: fatal("%s: sshbuf_new failed", __func__);
1.112 markus 1004: sockets[old_alloc].type = type;
1.1 deraadt 1005: }
1006:
1.55 itojun 1007: static int
1.223 djm 1008: handle_socket_read(u_int socknum)
1.1 deraadt 1009: {
1.223 djm 1010: struct sockaddr_un sunaddr;
1011: socklen_t slen;
1012: uid_t euid;
1013: gid_t egid;
1014: int fd;
1015:
1016: slen = sizeof(sunaddr);
1017: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1018: if (fd == -1) {
1.223 djm 1019: error("accept from AUTH_SOCKET: %s", strerror(errno));
1020: return -1;
1021: }
1.237 deraadt 1022: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1023: error("getpeereid %d failed: %s", fd, strerror(errno));
1024: close(fd);
1025: return -1;
1026: }
1027: if ((euid != 0) && (getuid() != euid)) {
1028: error("uid mismatch: peer euid %u != uid %u",
1029: (u_int) euid, (u_int) getuid());
1030: close(fd);
1031: return -1;
1032: }
1033: new_socket(AUTH_CONNECTION, fd);
1034: return 0;
1035: }
1036:
1037: static int
1038: handle_conn_read(u_int socknum)
1039: {
1.233 djm 1040: char buf[AGENT_RBUF_LEN];
1.223 djm 1041: ssize_t len;
1042: int r;
1043:
1044: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1045: if (len == -1) {
1046: if (errno == EAGAIN || errno == EINTR)
1047: return 0;
1048: error("%s: read error on socket %u (fd %d): %s",
1049: __func__, socknum, sockets[socknum].fd,
1050: strerror(errno));
1051: }
1052: return -1;
1053: }
1054: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1055: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1056: explicit_bzero(buf, sizeof(buf));
1057: process_message(socknum);
1058: return 0;
1059: }
1060:
1061: static int
1062: handle_conn_write(u_int socknum)
1063: {
1064: ssize_t len;
1065: int r;
1066:
1067: if (sshbuf_len(sockets[socknum].output) == 0)
1068: return 0; /* shouldn't happen */
1069: if ((len = write(sockets[socknum].fd,
1070: sshbuf_ptr(sockets[socknum].output),
1071: sshbuf_len(sockets[socknum].output))) <= 0) {
1072: if (len == -1) {
1073: if (errno == EAGAIN || errno == EINTR)
1074: return 0;
1075: error("%s: read error on socket %u (fd %d): %s",
1076: __func__, socknum, sockets[socknum].fd,
1077: strerror(errno));
1078: }
1079: return -1;
1080: }
1081: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1082: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1083: return 0;
1084: }
1085:
1086: static void
1.231 djm 1087: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1088: {
1089: size_t i;
1.231 djm 1090: u_int socknum, activefds = npfd;
1.223 djm 1091:
1092: for (i = 0; i < npfd; i++) {
1093: if (pfd[i].revents == 0)
1094: continue;
1095: /* Find sockets entry */
1096: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1097: if (sockets[socknum].type != AUTH_SOCKET &&
1098: sockets[socknum].type != AUTH_CONNECTION)
1099: continue;
1100: if (pfd[i].fd == sockets[socknum].fd)
1101: break;
1102: }
1103: if (socknum >= sockets_alloc) {
1104: error("%s: no socket for fd %d", __func__, pfd[i].fd);
1105: continue;
1106: }
1107: /* Process events */
1108: switch (sockets[socknum].type) {
1109: case AUTH_SOCKET:
1.231 djm 1110: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1111: break;
1112: if (npfd > maxfds) {
1113: debug3("out of fds (active %u >= limit %u); "
1114: "skipping accept", activefds, maxfds);
1115: break;
1116: }
1117: if (handle_socket_read(socknum) == 0)
1118: activefds++;
1.223 djm 1119: break;
1120: case AUTH_CONNECTION:
1121: if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
1122: handle_conn_read(socknum) != 0) {
1.231 djm 1123: goto close_sock;
1124: }
1125: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1126: handle_conn_write(socknum) != 0) {
1127: close_sock:
1128: if (activefds == 0)
1129: fatal("activefds == 0 at close_sock");
1.223 djm 1130: close_socket(&sockets[socknum]);
1.231 djm 1131: activefds--;
1.223 djm 1132: break;
1133: }
1134: break;
1135: default:
1136: break;
1137: }
1138: }
1139: }
1140:
1141: static int
1.231 djm 1142: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1143: {
1144: struct pollfd *pfd = *pfdp;
1145: size_t i, j, npfd = 0;
1.174 dtucker 1146: time_t deadline;
1.233 djm 1147: int r;
1.46 markus 1148:
1.223 djm 1149: /* Count active sockets */
1.46 markus 1150: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1151: switch (sockets[i].type) {
1152: case AUTH_SOCKET:
1153: case AUTH_CONNECTION:
1.223 djm 1154: npfd++;
1.21 markus 1155: break;
1156: case AUTH_UNUSED:
1157: break;
1158: default:
1159: fatal("Unknown socket type %d", sockets[i].type);
1160: break;
1161: }
1.46 markus 1162: }
1.223 djm 1163: if (npfd != *npfdp &&
1164: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1165: fatal("%s: recallocarray failed", __func__);
1166: *pfdp = pfd;
1167: *npfdp = npfd;
1.46 markus 1168:
1.223 djm 1169: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1170: switch (sockets[i].type) {
1171: case AUTH_SOCKET:
1.231 djm 1172: if (npfd > maxfds) {
1173: debug3("out of fds (active %zu >= limit %u); "
1174: "skipping arming listener", npfd, maxfds);
1175: break;
1176: }
1177: pfd[j].fd = sockets[i].fd;
1178: pfd[j].revents = 0;
1179: pfd[j].events = POLLIN;
1180: j++;
1181: break;
1.46 markus 1182: case AUTH_CONNECTION:
1.223 djm 1183: pfd[j].fd = sockets[i].fd;
1184: pfd[j].revents = 0;
1.233 djm 1185: /*
1186: * Only prepare to read if we can handle a full-size
1187: * input read buffer and enqueue a max size reply..
1188: */
1189: if ((r = sshbuf_check_reserve(sockets[i].input,
1190: AGENT_RBUF_LEN)) == 0 &&
1191: (r = sshbuf_check_reserve(sockets[i].output,
1192: AGENT_MAX_LEN)) == 0)
1193: pfd[j].events = POLLIN;
1194: else if (r != SSH_ERR_NO_BUFFER_SPACE) {
1195: fatal("%s: buffer error: %s",
1196: __func__, ssh_err(r));
1197: }
1.194 markus 1198: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1199: pfd[j].events |= POLLOUT;
1200: j++;
1.46 markus 1201: break;
1202: default:
1203: break;
1204: }
1205: }
1.155 dtucker 1206: deadline = reaper();
1207: if (parent_alive_interval != 0)
1208: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1209: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1210: if (deadline == 0) {
1.224 djm 1211: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1212: } else {
1.223 djm 1213: if (deadline > INT_MAX / 1000)
1214: *timeoutp = INT_MAX / 1000;
1215: else
1216: *timeoutp = deadline * 1000;
1.155 dtucker 1217: }
1.46 markus 1218: return (1);
1.21 markus 1219: }
1220:
1.55 itojun 1221: static void
1.113 markus 1222: cleanup_socket(void)
1.15 markus 1223: {
1.187 djm 1224: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1225: return;
1226: debug("%s: cleanup", __func__);
1.48 deraadt 1227: if (socket_name[0])
1228: unlink(socket_name);
1229: if (socket_dir[0])
1230: rmdir(socket_dir);
1.10 markus 1231: }
1232:
1.114 markus 1233: void
1.15 markus 1234: cleanup_exit(int i)
1235: {
1.113 markus 1236: cleanup_socket();
1237: _exit(i);
1.15 markus 1238: }
1239:
1.135 deraadt 1240: /*ARGSUSED*/
1.55 itojun 1241: static void
1.48 deraadt 1242: cleanup_handler(int sig)
1243: {
1.113 markus 1244: cleanup_socket();
1.163 markus 1245: #ifdef ENABLE_PKCS11
1246: pkcs11_terminate();
1247: #endif
1.48 deraadt 1248: _exit(2);
1.113 markus 1249: }
1250:
1.68 markus 1251: static void
1.155 dtucker 1252: check_parent_exists(void)
1.68 markus 1253: {
1.172 dtucker 1254: /*
1255: * If our parent has exited then getppid() will return (pid_t)1,
1256: * so testing for that should be safe.
1257: */
1258: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1259: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1260: cleanup_socket();
1261: _exit(2);
1.68 markus 1262: }
1.48 deraadt 1263: }
1264:
1.55 itojun 1265: static void
1.50 itojun 1266: usage(void)
1.15 markus 1267: {
1.184 deraadt 1268: fprintf(stderr,
1.202 jmc 1269: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.238 djm 1270: " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
1.184 deraadt 1271: " ssh-agent [-c | -s] -k\n");
1.21 markus 1272: exit(1);
1.15 markus 1273: }
1274:
1.2 provos 1275: int
1276: main(int ac, char **av)
1.1 deraadt 1277: {
1.201 djm 1278: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.154 dtucker 1279: int sock, fd, ch, result, saved_errno;
1.96 deraadt 1280: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1281: struct rlimit rlim;
1.96 deraadt 1282: extern int optind;
1.98 stevesk 1283: extern char *optarg;
1.21 markus 1284: pid_t pid;
1.96 deraadt 1285: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1286: size_t len;
1.189 djm 1287: mode_t prev_mask;
1.224 djm 1288: int timeout = -1; /* INFTIM */
1.223 djm 1289: struct pollfd *pfd = NULL;
1290: size_t npfd = 0;
1.231 djm 1291: u_int maxfds;
1.123 djm 1292:
1293: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1294: sanitise_stdfd();
1.99 markus 1295:
1296: /* drop */
1297: setegid(getgid());
1298: setgid(getgid());
1.53 markus 1299:
1.231 djm 1300: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1301: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1302:
1.185 markus 1303: #ifdef WITH_OPENSSL
1.170 djm 1304: OpenSSL_add_all_algorithms();
1.185 markus 1305: #endif
1.21 markus 1306:
1.215 djm 1307: while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
1.21 markus 1308: switch (ch) {
1.192 djm 1309: case 'E':
1310: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1311: if (fingerprint_hash == -1)
1312: fatal("Invalid hash algorithm \"%s\"", optarg);
1313: break;
1.21 markus 1314: case 'c':
1315: if (s_flag)
1316: usage();
1317: c_flag++;
1318: break;
1319: case 'k':
1320: k_flag++;
1321: break;
1.215 djm 1322: case 'P':
1.238 djm 1323: if (provider_whitelist != NULL)
1.215 djm 1324: fatal("-P option already specified");
1.238 djm 1325: provider_whitelist = xstrdup(optarg);
1.215 djm 1326: break;
1.21 markus 1327: case 's':
1328: if (c_flag)
1329: usage();
1330: s_flag++;
1331: break;
1.57 markus 1332: case 'd':
1.201 djm 1333: if (d_flag || D_flag)
1.57 markus 1334: usage();
1335: d_flag++;
1336: break;
1.201 djm 1337: case 'D':
1338: if (d_flag || D_flag)
1339: usage();
1340: D_flag++;
1341: break;
1.86 markus 1342: case 'a':
1343: agentsocket = optarg;
1.106 marc 1344: break;
1345: case 't':
1346: if ((lifetime = convtime(optarg)) == -1) {
1347: fprintf(stderr, "Invalid lifetime\n");
1348: usage();
1349: }
1.86 markus 1350: break;
1.21 markus 1351: default:
1352: usage();
1353: }
1354: }
1355: ac -= optind;
1356: av += optind;
1357:
1.201 djm 1358: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1359: usage();
1360:
1.238 djm 1361: if (provider_whitelist == NULL)
1362: provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
1.215 djm 1363:
1.85 markus 1364: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1365: shell = getenv("SHELL");
1.161 tobias 1366: if (shell != NULL && (len = strlen(shell)) > 2 &&
1367: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1368: c_flag = 1;
1369: }
1370: if (k_flag) {
1.136 deraadt 1371: const char *errstr = NULL;
1372:
1.21 markus 1373: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1374: if (pidstr == NULL) {
1375: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1376: SSH_AGENTPID_ENV_NAME);
1.21 markus 1377: exit(1);
1378: }
1.136 deraadt 1379: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1380: if (errstr) {
1381: fprintf(stderr,
1382: "%s=\"%s\", which is not a good PID: %s\n",
1383: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1384: exit(1);
1385: }
1386: if (kill(pid, SIGTERM) == -1) {
1387: perror("kill");
1388: exit(1);
1389: }
1390: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1391: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1392: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1393: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1394: exit(0);
1395: }
1.231 djm 1396:
1397: /*
1398: * Minimum file descriptors:
1399: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1400: * a few spare for libc / stack protectors / sanitisers, etc.
1401: */
1402: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1403: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1404: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1405: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1406: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1407:
1.21 markus 1408: parent_pid = getpid();
1409:
1.86 markus 1410: if (agentsocket == NULL) {
1411: /* Create private directory for agent socket */
1.171 djm 1412: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1413: if (mkdtemp(socket_dir) == NULL) {
1414: perror("mkdtemp: private socket dir");
1415: exit(1);
1416: }
1.91 mpech 1417: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1418: (long)parent_pid);
1.86 markus 1419: } else {
1420: /* Try to use specified agent socket */
1421: socket_dir[0] = '\0';
1422: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1423: }
1424:
1.23 markus 1425: /*
1426: * Create socket early so it will exist before command gets run from
1427: * the parent.
1428: */
1.189 djm 1429: prev_mask = umask(0177);
1.188 millert 1430: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1431: if (sock < 0) {
1.188 millert 1432: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1433: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1434: cleanup_exit(1);
1435: }
1.189 djm 1436: umask(prev_mask);
1.46 markus 1437:
1.23 markus 1438: /*
1439: * Fork, and have the parent execute the command, if any, or present
1440: * the socket data. The child continues as the authentication agent.
1441: */
1.201 djm 1442: if (D_flag || d_flag) {
1443: log_init(__progname,
1444: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1445: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1446: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1447: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1448: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1449: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1450: fflush(stdout);
1.57 markus 1451: goto skip;
1452: }
1.21 markus 1453: pid = fork();
1454: if (pid == -1) {
1455: perror("fork");
1.81 stevesk 1456: cleanup_exit(1);
1.21 markus 1457: }
1458: if (pid != 0) { /* Parent - execute the given command. */
1459: close(sock);
1.91 mpech 1460: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1461: if (ac == 0) {
1462: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1463: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1464: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1465: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1466: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1467: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1468: exit(0);
1469: }
1.36 deraadt 1470: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1471: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1472: perror("setenv");
1473: exit(1);
1474: }
1.21 markus 1475: execvp(av[0], av);
1476: perror(av[0]);
1477: exit(1);
1478: }
1.81 stevesk 1479: /* child */
1480: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1481:
1482: if (setsid() == -1) {
1.81 stevesk 1483: error("setsid: %s", strerror(errno));
1.67 stevesk 1484: cleanup_exit(1);
1485: }
1486:
1487: (void)chdir("/");
1.107 markus 1488: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1489: /* XXX might close listen socket */
1490: (void)dup2(fd, STDIN_FILENO);
1491: (void)dup2(fd, STDOUT_FILENO);
1492: (void)dup2(fd, STDERR_FILENO);
1493: if (fd > 2)
1494: close(fd);
1495: }
1.21 markus 1496:
1.41 markus 1497: /* deny core dumps, since memory contains unencrypted private keys */
1498: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1499: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1500: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1501: cleanup_exit(1);
1502: }
1.57 markus 1503:
1504: skip:
1.187 djm 1505:
1506: cleanup_pid = getpid();
1.163 markus 1507:
1508: #ifdef ENABLE_PKCS11
1509: pkcs11_init(0);
1510: #endif
1.21 markus 1511: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1512: if (ac > 0)
1513: parent_alive_interval = 10;
1.33 markus 1514: idtab_init();
1.61 markus 1515: signal(SIGPIPE, SIG_IGN);
1.201 djm 1516: signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1.48 deraadt 1517: signal(SIGHUP, cleanup_handler);
1518: signal(SIGTERM, cleanup_handler);
1.205 djm 1519:
1.215 djm 1520: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1521: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1522:
1.21 markus 1523: while (1) {
1.231 djm 1524: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1525: result = poll(pfd, npfd, timeout);
1.154 dtucker 1526: saved_errno = errno;
1.155 dtucker 1527: if (parent_alive_interval != 0)
1528: check_parent_exists();
1529: (void) reaper(); /* remove expired keys */
1.237 deraadt 1530: if (result == -1) {
1.154 dtucker 1531: if (saved_errno == EINTR)
1.21 markus 1532: continue;
1.223 djm 1533: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1534: } else if (result > 0)
1.231 djm 1535: after_poll(pfd, npfd, maxfds);
1.15 markus 1536: }
1.21 markus 1537: /* NOTREACHED */
1.1 deraadt 1538: }
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