Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.280
1.280 ! djm 1: /* $OpenBSD: ssh-agent.c,v 1.279 2021/11/18 03:31:44 djm Exp $ */
1.1 deraadt 2: /*
1.22 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * The authentication agent program.
1.33 markus 7: *
1.35 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.56 markus 14: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 15: *
16: * Redistribution and use in source and binary forms, with or without
17: * modification, are permitted provided that the following conditions
18: * are met:
19: * 1. Redistributions of source code must retain the above copyright
20: * notice, this list of conditions and the following disclaimer.
21: * 2. Redistributions in binary form must reproduce the above copyright
22: * notice, this list of conditions and the following disclaimer in the
23: * documentation and/or other materials provided with the distribution.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 35: */
1.1 deraadt 36:
1.151 deraadt 37: #include <sys/types.h>
1.153 djm 38: #include <sys/time.h>
1.78 provos 39: #include <sys/queue.h>
1.127 stevesk 40: #include <sys/resource.h>
1.141 stevesk 41: #include <sys/socket.h>
1.189 djm 42: #include <sys/stat.h>
1.128 stevesk 43: #include <sys/un.h>
1.238 djm 44: #include <sys/wait.h>
1.126 stevesk 45:
1.185 markus 46: #ifdef WITH_OPENSSL
1.146 stevesk 47: #include <openssl/evp.h>
1.185 markus 48: #endif
1.146 stevesk 49:
1.143 stevesk 50: #include <errno.h>
1.142 stevesk 51: #include <fcntl.h>
1.126 stevesk 52: #include <paths.h>
1.223 djm 53: #include <poll.h>
1.129 stevesk 54: #include <signal.h>
1.149 stevesk 55: #include <stdlib.h>
1.150 stevesk 56: #include <stdio.h>
1.146 stevesk 57: #include <string.h>
1.248 naddy 58: #include <stdarg.h>
1.196 deraadt 59: #include <limits.h>
1.145 stevesk 60: #include <time.h>
1.144 stevesk 61: #include <unistd.h>
1.203 dtucker 62: #include <util.h>
1.194 markus 63:
1.151 deraadt 64: #include "xmalloc.h"
1.1 deraadt 65: #include "ssh.h"
1.258 djm 66: #include "ssh2.h"
1.194 markus 67: #include "sshbuf.h"
68: #include "sshkey.h"
1.32 markus 69: #include "authfd.h"
1.37 markus 70: #include "compat.h"
1.47 markus 71: #include "log.h"
1.107 markus 72: #include "misc.h"
1.182 markus 73: #include "digest.h"
1.194 markus 74: #include "ssherr.h"
1.215 djm 75: #include "match.h"
1.238 djm 76: #include "msg.h"
1.244 djm 77: #include "ssherr.h"
1.238 djm 78: #include "pathnames.h"
1.163 markus 79: #include "ssh-pkcs11.h"
1.251 djm 80: #include "sk-api.h"
1.59 markus 81:
1.262 djm 82: #ifndef DEFAULT_ALLOWED_PROVIDERS
83: # define DEFAULT_ALLOWED_PROVIDERS "/usr/lib*/*,/usr/local/lib*/*"
1.215 djm 84: #endif
85:
1.223 djm 86: /* Maximum accepted message length */
1.280 ! djm 87: #define AGENT_MAX_LEN (256*1024)
1.233 djm 88: /* Maximum bytes to read from client socket */
1.280 ! djm 89: #define AGENT_RBUF_LEN (4096)
! 90: /* Maximum number of recorded session IDs/hostkeys per connection */
! 91: #define AGENT_MAX_SESSION_IDS 16
! 92: /* Maximum size of session ID */
! 93: #define AGENT_MAX_SID_LEN 128
! 94:
! 95: /* XXX store hostkey_sid in a refcounted tree */
1.223 djm 96:
1.73 stevesk 97: typedef enum {
1.275 djm 98: AUTH_UNUSED = 0,
99: AUTH_SOCKET = 1,
100: AUTH_CONNECTION = 2,
1.73 stevesk 101: } sock_type;
102:
1.280 ! djm 103: struct hostkey_sid {
! 104: struct sshkey *key;
! 105: struct sshbuf *sid;
! 106: int forwarded;
! 107: };
! 108:
1.274 djm 109: typedef struct socket_entry {
1.21 markus 110: int fd;
1.73 stevesk 111: sock_type type;
1.194 markus 112: struct sshbuf *input;
113: struct sshbuf *output;
114: struct sshbuf *request;
1.280 ! djm 115: size_t nsession_ids;
! 116: struct hostkey_sid *session_ids;
1.1 deraadt 117: } SocketEntry;
118:
1.45 markus 119: u_int sockets_alloc = 0;
1.1 deraadt 120: SocketEntry *sockets = NULL;
121:
1.78 provos 122: typedef struct identity {
123: TAILQ_ENTRY(identity) next;
1.194 markus 124: struct sshkey *key;
1.21 markus 125: char *comment;
1.163 markus 126: char *provider;
1.174 dtucker 127: time_t death;
1.107 markus 128: u_int confirm;
1.238 djm 129: char *sk_provider;
1.1 deraadt 130: } Identity;
131:
1.221 djm 132: struct idtable {
1.33 markus 133: int nentries;
1.78 provos 134: TAILQ_HEAD(idqueue, identity) idlist;
1.221 djm 135: };
1.33 markus 136:
1.221 djm 137: /* private key table */
138: struct idtable *idtab;
1.1 deraadt 139:
140: int max_fd = 0;
141:
1.11 markus 142: /* pid of shell == parent of agent */
1.29 deraadt 143: pid_t parent_pid = -1;
1.176 dtucker 144: time_t parent_alive_interval = 0;
1.10 markus 145:
1.187 djm 146: /* pid of process for which cleanup_socket is applicable */
147: pid_t cleanup_pid = 0;
148:
1.10 markus 149: /* pathname and directory for AUTH_SOCKET */
1.196 deraadt 150: char socket_name[PATH_MAX];
151: char socket_dir[PATH_MAX];
1.10 markus 152:
1.260 djm 153: /* Pattern-list of allowed PKCS#11/Security key paths */
154: static char *allowed_providers;
1.215 djm 155:
1.88 markus 156: /* locking */
1.203 dtucker 157: #define LOCK_SIZE 32
158: #define LOCK_SALT_SIZE 16
159: #define LOCK_ROUNDS 1
1.88 markus 160: int locked = 0;
1.213 djm 161: u_char lock_pwhash[LOCK_SIZE];
162: u_char lock_salt[LOCK_SALT_SIZE];
1.88 markus 163:
1.20 markus 164: extern char *__progname;
165:
1.174 dtucker 166: /* Default lifetime in seconds (0 == forever) */
1.268 dtucker 167: static int lifetime = 0;
1.106 marc 168:
1.192 djm 169: static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
170:
1.258 djm 171: /* Refuse signing of non-SSH messages for web-origin FIDO keys */
172: static int restrict_websafe = 1;
173:
1.55 itojun 174: static void
1.101 stevesk 175: close_socket(SocketEntry *e)
176: {
1.280 ! djm 177: size_t i;
! 178:
1.101 stevesk 179: close(e->fd);
1.194 markus 180: sshbuf_free(e->input);
181: sshbuf_free(e->output);
182: sshbuf_free(e->request);
1.280 ! djm 183: for (i = 0; i < e->nsession_ids; i++) {
! 184: sshkey_free(e->session_ids[i].key);
! 185: sshbuf_free(e->session_ids[i].sid);
! 186: }
! 187: free(e->session_ids);
1.269 djm 188: memset(e, '\0', sizeof(*e));
189: e->fd = -1;
190: e->type = AUTH_UNUSED;
1.101 stevesk 191: }
192:
193: static void
1.33 markus 194: idtab_init(void)
1.1 deraadt 195: {
1.221 djm 196: idtab = xcalloc(1, sizeof(*idtab));
197: TAILQ_INIT(&idtab->idlist);
198: idtab->nentries = 0;
1.33 markus 199: }
200:
1.89 markus 201: static void
202: free_identity(Identity *id)
203: {
1.194 markus 204: sshkey_free(id->key);
1.173 djm 205: free(id->provider);
206: free(id->comment);
1.238 djm 207: free(id->sk_provider);
1.173 djm 208: free(id);
1.89 markus 209: }
210:
1.33 markus 211: /* return matching private key for given public key */
1.78 provos 212: static Identity *
1.221 djm 213: lookup_identity(struct sshkey *key)
1.33 markus 214: {
1.78 provos 215: Identity *id;
216:
1.221 djm 217: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.194 markus 218: if (sshkey_equal(key, id->key))
1.78 provos 219: return (id);
1.33 markus 220: }
1.78 provos 221: return (NULL);
222: }
223:
1.107 markus 224: /* Check confirmation of keysign request */
225: static int
1.270 djm 226: confirm_key(Identity *id, const char *extra)
1.107 markus 227: {
1.122 djm 228: char *p;
1.107 markus 229: int ret = -1;
230:
1.194 markus 231: p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
1.197 djm 232: if (p != NULL &&
1.270 djm 233: ask_permission("Allow use of key %s?\nKey fingerprint %s.%s%s",
234: id->comment, p,
235: extra == NULL ? "" : "\n", extra == NULL ? "" : extra))
1.122 djm 236: ret = 0;
1.173 djm 237: free(p);
1.122 djm 238:
1.107 markus 239: return (ret);
240: }
241:
1.194 markus 242: static void
243: send_status(SocketEntry *e, int success)
244: {
245: int r;
246:
247: if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
248: (r = sshbuf_put_u8(e->output, success ?
249: SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
1.266 djm 250: fatal_fr(r, "compose");
1.194 markus 251: }
252:
1.33 markus 253: /* send list of supported public keys to 'client' */
1.55 itojun 254: static void
1.221 djm 255: process_request_identities(SocketEntry *e)
1.33 markus 256: {
1.96 deraadt 257: Identity *id;
1.194 markus 258: struct sshbuf *msg;
259: int r;
1.1 deraadt 260:
1.269 djm 261: debug2_f("entering");
262:
1.194 markus 263: if ((msg = sshbuf_new()) == NULL)
1.266 djm 264: fatal_f("sshbuf_new failed");
1.221 djm 265: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
266: (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
1.266 djm 267: fatal_fr(r, "compose");
1.221 djm 268: TAILQ_FOREACH(id, &idtab->idlist, next) {
1.278 djm 269: if ((r = sshkey_puts_opts(id->key, msg,
270: SSHKEY_SERIALIZE_INFO)) != 0 ||
1.221 djm 271: (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
1.266 djm 272: error_fr(r, "compose key/comment");
1.220 djm 273: continue;
1.33 markus 274: }
1.21 markus 275: }
1.194 markus 276: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 277: fatal_fr(r, "enqueue");
1.194 markus 278: sshbuf_free(msg);
1.1 deraadt 279: }
280:
1.33 markus 281:
1.208 markus 282: static char *
283: agent_decode_alg(struct sshkey *key, u_int flags)
284: {
285: if (key->type == KEY_RSA) {
286: if (flags & SSH_AGENT_RSA_SHA2_256)
287: return "rsa-sha2-256";
288: else if (flags & SSH_AGENT_RSA_SHA2_512)
289: return "rsa-sha2-512";
1.235 djm 290: } else if (key->type == KEY_RSA_CERT) {
291: if (flags & SSH_AGENT_RSA_SHA2_256)
292: return "rsa-sha2-256-cert-v01@openssh.com";
293: else if (flags & SSH_AGENT_RSA_SHA2_512)
294: return "rsa-sha2-512-cert-v01@openssh.com";
1.208 markus 295: }
296: return NULL;
297: }
298:
1.258 djm 299: /*
1.270 djm 300: * Attempt to parse the contents of a buffer as a SSH publickey userauth
301: * request, checking its contents for consistency and matching the embedded
302: * key against the one that is being used for signing.
303: * Note: does not modify msg buffer.
304: * Optionally extract the username and session ID from the request.
1.258 djm 305: */
306: static int
1.270 djm 307: parse_userauth_request(struct sshbuf *msg, const struct sshkey *expected_key,
308: char **userp, struct sshbuf **sess_idp)
1.258 djm 309: {
1.270 djm 310: struct sshbuf *b = NULL, *sess_id = NULL;
311: char *user = NULL, *service = NULL, *method = NULL, *pkalg = NULL;
1.258 djm 312: int r;
1.270 djm 313: u_char t, sig_follows;
1.258 djm 314: struct sshkey *mkey = NULL;
315:
1.270 djm 316: if (userp != NULL)
317: *userp = NULL;
318: if (sess_idp != NULL)
319: *sess_idp = NULL;
320: if ((b = sshbuf_fromb(msg)) == NULL)
321: fatal_f("sshbuf_fromb");
1.258 djm 322:
323: /* SSH userauth request */
1.270 djm 324: if ((r = sshbuf_froms(b, &sess_id)) != 0)
325: goto out;
326: if (sshbuf_len(sess_id) == 0) {
327: r = SSH_ERR_INVALID_FORMAT;
328: goto out;
329: }
330: if ((r = sshbuf_get_u8(b, &t)) != 0 || /* SSH2_MSG_USERAUTH_REQUEST */
331: (r = sshbuf_get_cstring(b, &user, NULL)) != 0 || /* server user */
332: (r = sshbuf_get_cstring(b, &service, NULL)) != 0 || /* service */
333: (r = sshbuf_get_cstring(b, &method, NULL)) != 0 || /* method */
334: (r = sshbuf_get_u8(b, &sig_follows)) != 0 || /* sig-follows */
335: (r = sshbuf_get_cstring(b, &pkalg, NULL)) != 0 || /* alg */
336: (r = sshkey_froms(b, &mkey)) != 0) /* key */
337: goto out;
338: if (t != SSH2_MSG_USERAUTH_REQUEST ||
339: sig_follows != 1 ||
340: strcmp(service, "ssh-connection") != 0 ||
341: !sshkey_equal(expected_key, mkey) ||
342: sshkey_type_from_name(pkalg) != expected_key->type) {
343: r = SSH_ERR_INVALID_FORMAT;
344: goto out;
345: }
346: if (strcmp(method, "publickey") != 0) {
347: r = SSH_ERR_INVALID_FORMAT;
348: goto out;
349: }
350: if (sshbuf_len(b) != 0) {
351: r = SSH_ERR_INVALID_FORMAT;
352: goto out;
353: }
354: /* success */
355: r = 0;
356: debug3_f("well formed userauth");
357: if (userp != NULL) {
358: *userp = user;
359: user = NULL;
360: }
361: if (sess_idp != NULL) {
362: *sess_idp = sess_id;
363: sess_id = NULL;
1.258 djm 364: }
1.270 djm 365: out:
366: sshbuf_free(b);
367: sshbuf_free(sess_id);
368: free(user);
369: free(service);
370: free(method);
371: free(pkalg);
1.258 djm 372: sshkey_free(mkey);
1.270 djm 373: return r;
374: }
375:
376: /*
377: * Attempt to parse the contents of a buffer as a SSHSIG signature request.
378: * Note: does not modify buffer.
379: */
380: static int
381: parse_sshsig_request(struct sshbuf *msg)
382: {
383: int r;
384: struct sshbuf *b;
385:
386: if ((b = sshbuf_fromb(msg)) == NULL)
387: fatal_f("sshbuf_fromb");
388:
389: if ((r = sshbuf_cmp(b, 0, "SSHSIG", 6)) != 0 ||
390: (r = sshbuf_consume(b, 6)) != 0 ||
391: (r = sshbuf_get_cstring(b, NULL, NULL)) != 0 || /* namespace */
392: (r = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || /* reserved */
393: (r = sshbuf_get_cstring(b, NULL, NULL)) != 0 || /* hashalg */
394: (r = sshbuf_get_string_direct(b, NULL, NULL)) != 0) /* H(msg) */
395: goto out;
396: if (sshbuf_len(b) != 0) {
397: r = SSH_ERR_INVALID_FORMAT;
398: goto out;
399: }
400: /* success */
401: r = 0;
402: out:
1.258 djm 403: sshbuf_free(b);
1.270 djm 404: return r;
405: }
406:
407: /*
408: * This function inspects a message to be signed by a FIDO key that has a
409: * web-like application string (i.e. one that does not begin with "ssh:".
410: * It checks that the message is one of those expected for SSH operations
411: * (pubkey userauth, sshsig, CA key signing) to exclude signing challenges
412: * for the web.
413: */
414: static int
415: check_websafe_message_contents(struct sshkey *key, struct sshbuf *data)
416: {
417: if (parse_userauth_request(data, key, NULL, NULL) == 0) {
418: debug_f("signed data matches public key userauth request");
1.258 djm 419: return 1;
420: }
1.270 djm 421: if (parse_sshsig_request(data) == 0) {
422: debug_f("signed data matches SSHSIG signature request");
1.258 djm 423: return 1;
1.270 djm 424: }
1.258 djm 425:
1.270 djm 426: /* XXX check CA signature operation */
1.258 djm 427:
428: error("web-origin key attempting to sign non-SSH message");
429: return 0;
430: }
431:
1.280 ! djm 432: static int
! 433: buf_equal(const struct sshbuf *a, const struct sshbuf *b)
! 434: {
! 435: if (sshbuf_ptr(a) == NULL || sshbuf_ptr(b) == NULL)
! 436: return SSH_ERR_INVALID_ARGUMENT;
! 437: if (sshbuf_len(a) != sshbuf_len(b))
! 438: return SSH_ERR_INVALID_FORMAT;
! 439: if (timingsafe_bcmp(sshbuf_ptr(a), sshbuf_ptr(b), sshbuf_len(a)) != 0)
! 440: return SSH_ERR_INVALID_FORMAT;
! 441: return 0;
! 442: }
! 443:
1.33 markus 444: /* ssh2 only */
1.55 itojun 445: static void
1.33 markus 446: process_sign_request2(SocketEntry *e)
447: {
1.221 djm 448: u_char *signature = NULL;
1.280 ! djm 449: size_t i, slen = 0;
1.194 markus 450: u_int compat = 0, flags;
1.247 djm 451: int r, ok = -1;
1.280 ! djm 452: char *fp = NULL, *user = NULL, *sig_dest = NULL;
! 453: struct sshbuf *msg = NULL, *data = NULL, *sid = NULL;
1.221 djm 454: struct sshkey *key = NULL;
1.195 djm 455: struct identity *id;
1.251 djm 456: struct notifier_ctx *notifier = NULL;
1.194 markus 457:
1.270 djm 458: debug_f("entering");
459:
1.273 dtucker 460: if ((msg = sshbuf_new()) == NULL || (data = sshbuf_new()) == NULL)
1.266 djm 461: fatal_f("sshbuf_new failed");
1.221 djm 462: if ((r = sshkey_froms(e->request, &key)) != 0 ||
1.270 djm 463: (r = sshbuf_get_stringb(e->request, data)) != 0 ||
1.225 djm 464: (r = sshbuf_get_u32(e->request, &flags)) != 0) {
1.266 djm 465: error_fr(r, "parse");
1.225 djm 466: goto send;
467: }
468:
1.221 djm 469: if ((id = lookup_identity(key)) == NULL) {
1.266 djm 470: verbose_f("%s key not found", sshkey_type(key));
1.195 djm 471: goto send;
472: }
1.280 ! djm 473: /*
! 474: * If session IDs were recorded for this socket, then use them to
! 475: * annotate the confirmation messages with the host keys.
! 476: */
! 477: if (e->nsession_ids > 0 &&
! 478: parse_userauth_request(data, key, &user, &sid) == 0) {
! 479: /*
! 480: * session ID from userauth request should match the final
! 481: * ID in the list recorded in the socket, unless the ssh
! 482: * client at that point lacks the binding extension (or if
! 483: * an attacker is trying to steal use of the agent).
! 484: */
! 485: i = e->nsession_ids - 1;
! 486: if (buf_equal(sid, e->session_ids[i].sid) == 0) {
! 487: if ((fp = sshkey_fingerprint(e->session_ids[i].key,
! 488: SSH_FP_HASH_DEFAULT, SSH_FP_DEFAULT)) == NULL)
! 489: fatal_f("fingerprint failed");
! 490: debug3_f("destination %s %s (slot %zu)",
! 491: sshkey_type(e->session_ids[i].key), fp, i);
! 492: xasprintf(&sig_dest, "public key request for "
! 493: "target user \"%s\" to %s %s", user,
! 494: sshkey_type(e->session_ids[i].key), fp);
! 495: free(fp);
! 496: fp = NULL;
! 497: }
! 498: }
! 499: if (id->confirm && confirm_key(id, sig_dest) != 0) {
1.266 djm 500: verbose_f("user refused key");
1.195 djm 501: goto send;
502: }
1.258 djm 503: if (sshkey_is_sk(id->key)) {
504: if (strncmp(id->key->sk_application, "ssh:", 4) != 0 &&
1.270 djm 505: !check_websafe_message_contents(key, data)) {
1.258 djm 506: /* error already logged */
507: goto send;
508: }
509: if ((id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
510: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
511: SSH_FP_DEFAULT)) == NULL)
1.266 djm 512: fatal_f("fingerprint failed");
1.258 djm 513: notifier = notify_start(0,
1.280 ! djm 514: "Confirm user presence for key %s %s%s%s",
! 515: sshkey_type(id->key), fp,
! 516: sig_dest == NULL ? "" : "\n",
! 517: sig_dest == NULL ? "" : sig_dest);
1.258 djm 518: }
1.251 djm 519: }
1.263 djm 520: /* XXX support PIN required FIDO keys */
1.251 djm 521: if ((r = sshkey_sign(id->key, &signature, &slen,
1.270 djm 522: sshbuf_ptr(data), sshbuf_len(data), agent_decode_alg(key, flags),
1.263 djm 523: id->sk_provider, NULL, compat)) != 0) {
1.266 djm 524: error_fr(r, "sshkey_sign");
1.251 djm 525: goto send;
1.33 markus 526: }
1.195 djm 527: /* Success */
528: ok = 0;
529: send:
1.267 djm 530: notify_complete(notifier, "User presence confirmed");
1.270 djm 531:
1.33 markus 532: if (ok == 0) {
1.194 markus 533: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
534: (r = sshbuf_put_string(msg, signature, slen)) != 0)
1.266 djm 535: fatal_fr(r, "compose");
1.194 markus 536: } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
1.266 djm 537: fatal_fr(r, "compose failure");
1.194 markus 538:
539: if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 540: fatal_fr(r, "enqueue");
1.194 markus 541:
1.280 ! djm 542: sshbuf_free(sid);
1.270 djm 543: sshbuf_free(data);
1.194 markus 544: sshbuf_free(msg);
1.270 djm 545: sshkey_free(key);
546: free(fp);
1.173 djm 547: free(signature);
1.280 ! djm 548: free(sig_dest);
! 549: free(user);
1.1 deraadt 550: }
551:
1.33 markus 552: /* shared */
1.55 itojun 553: static void
1.221 djm 554: process_remove_identity(SocketEntry *e)
1.1 deraadt 555: {
1.194 markus 556: int r, success = 0;
557: struct sshkey *key = NULL;
1.221 djm 558: Identity *id;
1.21 markus 559:
1.269 djm 560: debug2_f("entering");
1.221 djm 561: if ((r = sshkey_froms(e->request, &key)) != 0) {
1.266 djm 562: error_fr(r, "parse key");
1.221 djm 563: goto done;
564: }
565: if ((id = lookup_identity(key)) == NULL) {
1.266 djm 566: debug_f("key not found");
1.221 djm 567: goto done;
568: }
569: /* We have this key, free it. */
570: if (idtab->nentries < 1)
1.266 djm 571: fatal_f("internal error: nentries %d", idtab->nentries);
1.221 djm 572: TAILQ_REMOVE(&idtab->idlist, id, next);
573: free_identity(id);
574: idtab->nentries--;
575: success = 1;
576: done:
1.276 djm 577: sshkey_free(key);
1.194 markus 578: send_status(e, success);
1.1 deraadt 579: }
580:
1.55 itojun 581: static void
1.221 djm 582: process_remove_all_identities(SocketEntry *e)
1.1 deraadt 583: {
1.78 provos 584: Identity *id;
1.21 markus 585:
1.269 djm 586: debug2_f("entering");
1.21 markus 587: /* Loop over all identities and clear the keys. */
1.221 djm 588: for (id = TAILQ_FIRST(&idtab->idlist); id;
589: id = TAILQ_FIRST(&idtab->idlist)) {
590: TAILQ_REMOVE(&idtab->idlist, id, next);
1.78 provos 591: free_identity(id);
1.21 markus 592: }
593:
594: /* Mark that there are no identities. */
1.221 djm 595: idtab->nentries = 0;
1.21 markus 596:
597: /* Send success. */
1.194 markus 598: send_status(e, 1);
1.1 deraadt 599: }
600:
1.155 dtucker 601: /* removes expired keys and returns number of seconds until the next expiry */
1.174 dtucker 602: static time_t
1.89 markus 603: reaper(void)
604: {
1.175 dtucker 605: time_t deadline = 0, now = monotime();
1.89 markus 606: Identity *id, *nxt;
607:
1.221 djm 608: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
609: nxt = TAILQ_NEXT(id, next);
610: if (id->death == 0)
611: continue;
612: if (now >= id->death) {
613: debug("expiring key '%s'", id->comment);
614: TAILQ_REMOVE(&idtab->idlist, id, next);
615: free_identity(id);
616: idtab->nentries--;
617: } else
618: deadline = (deadline == 0) ? id->death :
619: MINIMUM(deadline, id->death);
1.89 markus 620: }
1.155 dtucker 621: if (deadline == 0 || deadline <= now)
622: return 0;
623: else
624: return (deadline - now);
1.89 markus 625: }
626:
1.271 djm 627: static int
1.277 djm 628: parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp)
629: {
630: char *ext_name = NULL;
631: int r;
632:
633: if ((r = sshbuf_get_cstring(m, &ext_name, NULL)) != 0) {
634: error_fr(r, "parse constraint extension");
635: goto out;
636: }
637: debug_f("constraint ext %s", ext_name);
638: if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
639: if (sk_providerp == NULL) {
640: error_f("%s not valid here", ext_name);
641: r = SSH_ERR_INVALID_FORMAT;
642: goto out;
643: }
644: if (*sk_providerp != NULL) {
645: error_f("%s already set", ext_name);
646: r = SSH_ERR_INVALID_FORMAT;
647: goto out;
648: }
649: if ((r = sshbuf_get_cstring(m, sk_providerp, NULL)) != 0) {
650: error_fr(r, "parse %s", ext_name);
651: goto out;
652: }
653: } else {
654: error_f("unsupported constraint \"%s\"", ext_name);
655: r = SSH_ERR_FEATURE_UNSUPPORTED;
656: goto out;
657: }
658: /* success */
659: r = 0;
660: out:
661: free(ext_name);
662: return r;
663: }
664:
665: static int
1.271 djm 666: parse_key_constraints(struct sshbuf *m, struct sshkey *k, time_t *deathp,
667: u_int *secondsp, int *confirmp, char **sk_providerp)
1.1 deraadt 668: {
1.194 markus 669: u_char ctype;
1.271 djm 670: int r;
671: u_int seconds, maxsign = 0;
1.33 markus 672:
1.271 djm 673: while (sshbuf_len(m)) {
674: if ((r = sshbuf_get_u8(m, &ctype)) != 0) {
1.266 djm 675: error_fr(r, "parse constraint type");
1.277 djm 676: goto out;
1.194 markus 677: }
678: switch (ctype) {
1.94 markus 679: case SSH_AGENT_CONSTRAIN_LIFETIME:
1.271 djm 680: if (*deathp != 0) {
681: error_f("lifetime already set");
1.277 djm 682: r = SSH_ERR_INVALID_FORMAT;
683: goto out;
1.271 djm 684: }
685: if ((r = sshbuf_get_u32(m, &seconds)) != 0) {
1.266 djm 686: error_fr(r, "parse lifetime constraint");
1.277 djm 687: goto out;
1.194 markus 688: }
1.271 djm 689: *deathp = monotime() + seconds;
690: *secondsp = seconds;
1.94 markus 691: break;
1.107 markus 692: case SSH_AGENT_CONSTRAIN_CONFIRM:
1.271 djm 693: if (*confirmp != 0) {
694: error_f("confirm already set");
1.277 djm 695: r = SSH_ERR_INVALID_FORMAT;
696: goto out;
1.271 djm 697: }
698: *confirmp = 1;
1.107 markus 699: break;
1.228 markus 700: case SSH_AGENT_CONSTRAIN_MAXSIGN:
1.271 djm 701: if (k == NULL) {
702: error_f("maxsign not valid here");
1.277 djm 703: r = SSH_ERR_INVALID_FORMAT;
704: goto out;
1.271 djm 705: }
706: if (maxsign != 0) {
707: error_f("maxsign already set");
1.277 djm 708: r = SSH_ERR_INVALID_FORMAT;
709: goto out;
1.271 djm 710: }
711: if ((r = sshbuf_get_u32(m, &maxsign)) != 0) {
1.266 djm 712: error_fr(r, "parse maxsign constraint");
1.277 djm 713: goto out;
1.228 markus 714: }
715: if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
1.266 djm 716: error_fr(r, "enable maxsign");
1.277 djm 717: goto out;
1.228 markus 718: }
719: break;
1.238 djm 720: case SSH_AGENT_CONSTRAIN_EXTENSION:
1.277 djm 721: if ((r = parse_key_constraint_extension(m,
722: sk_providerp)) != 0)
723: goto out; /* error already logged */
1.238 djm 724: break;
1.94 markus 725: default:
1.266 djm 726: error_f("Unknown constraint %d", ctype);
1.277 djm 727: r = SSH_ERR_FEATURE_UNSUPPORTED;
728: goto out;
1.94 markus 729: }
730: }
1.271 djm 731: /* success */
1.277 djm 732: r = 0;
733: out:
734: return r;
1.271 djm 735: }
736:
737: static void
738: process_add_identity(SocketEntry *e)
739: {
740: Identity *id;
741: int success = 0, confirm = 0;
1.272 dtucker 742: char *fp, *comment = NULL, *sk_provider = NULL;
1.271 djm 743: char canonical_provider[PATH_MAX];
744: time_t death = 0;
745: u_int seconds = 0;
746: struct sshkey *k = NULL;
747: int r = SSH_ERR_INTERNAL_ERROR;
748:
749: debug2_f("entering");
750: if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
751: k == NULL ||
752: (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
753: error_fr(r, "parse");
754: goto out;
755: }
756: if (parse_key_constraints(e->request, k, &death, &seconds, &confirm,
757: &sk_provider) != 0) {
758: error_f("failed to parse constraints");
759: sshbuf_reset(e->request);
760: goto out;
761: }
762:
1.238 djm 763: if (sk_provider != NULL) {
1.240 markus 764: if (!sshkey_is_sk(k)) {
1.255 naddy 765: error("Cannot add provider: %s is not an "
766: "authenticator-hosted key", sshkey_type(k));
1.271 djm 767: goto out;
1.238 djm 768: }
1.254 djm 769: if (strcasecmp(sk_provider, "internal") == 0) {
1.266 djm 770: debug_f("internal provider");
1.254 djm 771: } else {
772: if (realpath(sk_provider, canonical_provider) == NULL) {
773: verbose("failed provider \"%.100s\": "
774: "realpath: %s", sk_provider,
775: strerror(errno));
1.271 djm 776: goto out;
1.254 djm 777: }
1.238 djm 778: free(sk_provider);
1.254 djm 779: sk_provider = xstrdup(canonical_provider);
780: if (match_pattern_list(sk_provider,
1.260 djm 781: allowed_providers, 0) != 1) {
1.254 djm 782: error("Refusing add key: "
1.260 djm 783: "provider %s not allowed", sk_provider);
1.271 djm 784: goto out;
1.254 djm 785: }
1.238 djm 786: }
1.242 markus 787: }
788: if ((r = sshkey_shield_private(k)) != 0) {
1.266 djm 789: error_fr(r, "shield private");
1.271 djm 790: goto out;
1.238 djm 791: }
1.106 marc 792: if (lifetime && !death)
1.175 dtucker 793: death = monotime() + lifetime;
1.221 djm 794: if ((id = lookup_identity(k)) == NULL) {
1.163 markus 795: id = xcalloc(1, sizeof(Identity));
1.221 djm 796: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
1.33 markus 797: /* Increment the number of identities. */
1.221 djm 798: idtab->nentries++;
1.33 markus 799: } else {
1.228 markus 800: /* key state might have been updated */
801: sshkey_free(id->key);
1.173 djm 802: free(id->comment);
1.238 djm 803: free(id->sk_provider);
1.33 markus 804: }
1.271 djm 805: /* success */
1.228 markus 806: id->key = k;
1.157 canacar 807: id->comment = comment;
808: id->death = death;
809: id->confirm = confirm;
1.238 djm 810: id->sk_provider = sk_provider;
811:
812: if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
813: SSH_FP_DEFAULT)) == NULL)
1.266 djm 814: fatal_f("sshkey_fingerprint failed");
815: debug_f("add %s %s \"%.100s\" (life: %u) (confirm: %u) "
1.271 djm 816: "(provider: %s)", sshkey_ssh_name(k), fp, comment, seconds,
817: confirm, sk_provider == NULL ? "none" : sk_provider);
1.238 djm 818: free(fp);
1.271 djm 819: /* transferred */
820: k = NULL;
821: comment = NULL;
822: sk_provider = NULL;
823: success = 1;
824: out:
825: free(sk_provider);
826: free(comment);
827: sshkey_free(k);
1.194 markus 828: send_status(e, success);
1.1 deraadt 829: }
830:
1.88 markus 831: /* XXX todo: encrypt sensitive data with passphrase */
832: static void
833: process_lock_agent(SocketEntry *e, int lock)
834: {
1.203 dtucker 835: int r, success = 0, delay;
1.213 djm 836: char *passwd;
837: u_char passwdhash[LOCK_SIZE];
1.203 dtucker 838: static u_int fail_count = 0;
839: size_t pwlen;
840:
1.269 djm 841: debug2_f("entering");
1.226 djm 842: /*
843: * This is deliberately fatal: the user has requested that we lock,
844: * but we can't parse their request properly. The only safe thing to
845: * do is abort.
846: */
1.203 dtucker 847: if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
1.266 djm 848: fatal_fr(r, "parse");
1.203 dtucker 849: if (pwlen == 0) {
850: debug("empty password not supported");
851: } else if (locked && !lock) {
852: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
853: passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
854: fatal("bcrypt_pbkdf");
1.213 djm 855: if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
1.203 dtucker 856: debug("agent unlocked");
857: locked = 0;
858: fail_count = 0;
1.213 djm 859: explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
1.203 dtucker 860: success = 1;
861: } else {
862: /* delay in 0.1s increments up to 10s */
863: if (fail_count < 100)
864: fail_count++;
865: delay = 100000 * fail_count;
866: debug("unlock failed, delaying %0.1lf seconds",
867: (double)delay/1000000);
868: usleep(delay);
869: }
870: explicit_bzero(passwdhash, sizeof(passwdhash));
1.88 markus 871: } else if (!locked && lock) {
1.203 dtucker 872: debug("agent locked");
1.88 markus 873: locked = 1;
1.203 dtucker 874: arc4random_buf(lock_salt, sizeof(lock_salt));
875: if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
1.213 djm 876: lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
1.203 dtucker 877: fatal("bcrypt_pbkdf");
1.88 markus 878: success = 1;
879: }
1.256 jsg 880: freezero(passwd, pwlen);
1.194 markus 881: send_status(e, success);
1.88 markus 882: }
883:
884: static void
1.221 djm 885: no_identities(SocketEntry *e)
1.88 markus 886: {
1.194 markus 887: struct sshbuf *msg;
888: int r;
1.88 markus 889:
1.194 markus 890: if ((msg = sshbuf_new()) == NULL)
1.266 djm 891: fatal_f("sshbuf_new failed");
1.221 djm 892: if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
1.194 markus 893: (r = sshbuf_put_u32(msg, 0)) != 0 ||
894: (r = sshbuf_put_stringb(e->output, msg)) != 0)
1.266 djm 895: fatal_fr(r, "compose");
1.194 markus 896: sshbuf_free(msg);
1.88 markus 897: }
1.59 markus 898:
1.163 markus 899: #ifdef ENABLE_PKCS11
1.59 markus 900: static void
1.158 djm 901: process_add_smartcard_key(SocketEntry *e)
1.59 markus 902: {
1.226 djm 903: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.253 djm 904: char **comments = NULL;
1.221 djm 905: int r, i, count = 0, success = 0, confirm = 0;
1.271 djm 906: u_int seconds = 0;
1.174 dtucker 907: time_t death = 0;
1.194 markus 908: struct sshkey **keys = NULL, *k;
1.84 markus 909: Identity *id;
1.75 deraadt 910:
1.269 djm 911: debug2_f("entering");
1.194 markus 912: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 913: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 djm 914: error_fr(r, "parse");
1.226 djm 915: goto send;
916: }
1.271 djm 917: if (parse_key_constraints(e->request, NULL, &death, &seconds, &confirm,
918: NULL) != 0) {
919: error_f("failed to parse constraints");
920: goto send;
1.110 djm 921: }
1.215 djm 922: if (realpath(provider, canonical_provider) == NULL) {
923: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
924: provider, strerror(errno));
925: goto send;
926: }
1.260 djm 927: if (match_pattern_list(canonical_provider, allowed_providers, 0) != 1) {
1.215 djm 928: verbose("refusing PKCS#11 add of \"%.100s\": "
1.260 djm 929: "provider not allowed", canonical_provider);
1.215 djm 930: goto send;
931: }
1.266 djm 932: debug_f("add %.100s", canonical_provider);
1.110 djm 933: if (lifetime && !death)
1.175 dtucker 934: death = monotime() + lifetime;
1.110 djm 935:
1.253 djm 936: count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
1.163 markus 937: for (i = 0; i < count; i++) {
1.84 markus 938: k = keys[i];
1.221 djm 939: if (lookup_identity(k) == NULL) {
1.163 markus 940: id = xcalloc(1, sizeof(Identity));
1.84 markus 941: id->key = k;
1.253 djm 942: keys[i] = NULL; /* transferred */
1.215 djm 943: id->provider = xstrdup(canonical_provider);
1.253 djm 944: if (*comments[i] != '\0') {
945: id->comment = comments[i];
946: comments[i] = NULL; /* transferred */
947: } else {
948: id->comment = xstrdup(canonical_provider);
949: }
1.110 djm 950: id->death = death;
951: id->confirm = confirm;
1.221 djm 952: TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
953: idtab->nentries++;
1.84 markus 954: success = 1;
955: }
1.271 djm 956: /* XXX update constraints for existing keys */
1.253 djm 957: sshkey_free(keys[i]);
958: free(comments[i]);
1.59 markus 959: }
960: send:
1.173 djm 961: free(pin);
962: free(provider);
963: free(keys);
1.253 djm 964: free(comments);
1.194 markus 965: send_status(e, success);
1.59 markus 966: }
967:
968: static void
969: process_remove_smartcard_key(SocketEntry *e)
970: {
1.217 djm 971: char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
1.221 djm 972: int r, success = 0;
1.163 markus 973: Identity *id, *nxt;
1.59 markus 974:
1.269 djm 975: debug2_f("entering");
1.194 markus 976: if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
1.226 djm 977: (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
1.266 djm 978: error_fr(r, "parse");
1.226 djm 979: goto send;
980: }
1.173 djm 981: free(pin);
1.59 markus 982:
1.217 djm 983: if (realpath(provider, canonical_provider) == NULL) {
984: verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
985: provider, strerror(errno));
986: goto send;
987: }
988:
1.266 djm 989: debug_f("remove %.100s", canonical_provider);
1.221 djm 990: for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
991: nxt = TAILQ_NEXT(id, next);
992: /* Skip file--based keys */
993: if (id->provider == NULL)
994: continue;
995: if (!strcmp(canonical_provider, id->provider)) {
996: TAILQ_REMOVE(&idtab->idlist, id, next);
997: free_identity(id);
998: idtab->nentries--;
1.59 markus 999: }
1000: }
1.217 djm 1001: if (pkcs11_del_provider(canonical_provider) == 0)
1.163 markus 1002: success = 1;
1003: else
1.266 djm 1004: error_f("pkcs11_del_provider failed");
1.218 deraadt 1005: send:
1.173 djm 1006: free(provider);
1.194 markus 1007: send_status(e, success);
1.59 markus 1008: }
1.163 markus 1009: #endif /* ENABLE_PKCS11 */
1.59 markus 1010:
1.280 ! djm 1011: static int
! 1012: process_ext_session_bind(SocketEntry *e)
! 1013: {
! 1014: int r, sid_match, key_match;
! 1015: struct sshkey *key = NULL;
! 1016: struct sshbuf *sid = NULL, *sig = NULL;
! 1017: char *fp = NULL;
! 1018: u_char fwd;
! 1019: size_t i;
! 1020:
! 1021: debug2_f("entering");
! 1022: if ((r = sshkey_froms(e->request, &key)) != 0 ||
! 1023: (r = sshbuf_froms(e->request, &sid)) != 0 ||
! 1024: (r = sshbuf_froms(e->request, &sig)) != 0 ||
! 1025: (r = sshbuf_get_u8(e->request, &fwd)) != 0) {
! 1026: error_fr(r, "parse");
! 1027: goto out;
! 1028: }
! 1029: if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
! 1030: SSH_FP_DEFAULT)) == NULL)
! 1031: fatal_f("fingerprint failed");
! 1032: /* check signature with hostkey on session ID */
! 1033: if ((r = sshkey_verify(key, sshbuf_ptr(sig), sshbuf_len(sig),
! 1034: sshbuf_ptr(sid), sshbuf_len(sid), NULL, 0, NULL)) != 0) {
! 1035: error_fr(r, "sshkey_verify for %s %s", sshkey_type(key), fp);
! 1036: goto out;
! 1037: }
! 1038: /* check whether sid/key already recorded */
! 1039: for (i = 0; i < e->nsession_ids; i++) {
! 1040: sid_match = buf_equal(sid, e->session_ids[i].sid) == 0;
! 1041: key_match = sshkey_equal(key, e->session_ids[i].key);
! 1042: if (sid_match && key_match) {
! 1043: debug_f("session ID already recorded for %s %s",
! 1044: sshkey_type(key), fp);
! 1045: r = 0;
! 1046: goto out;
! 1047: } else if (sid_match) {
! 1048: error_f("session ID recorded against different key "
! 1049: "for %s %s", sshkey_type(key), fp);
! 1050: r = -1;
! 1051: goto out;
! 1052: }
! 1053: /*
! 1054: * new sid with previously-seen key can happen, e.g. multiple
! 1055: * connections to the same host.
! 1056: */
! 1057: }
! 1058: /* record new key/sid */
! 1059: if (e->nsession_ids >= AGENT_MAX_SESSION_IDS) {
! 1060: error_f("too many session IDs recorded");
! 1061: goto out;
! 1062: }
! 1063: e->session_ids = xrecallocarray(e->session_ids, e->nsession_ids,
! 1064: e->nsession_ids + 1, sizeof(*e->session_ids));
! 1065: i = e->nsession_ids++;
! 1066: debug_f("recorded %s %s (slot %zu of %d)", sshkey_type(key), fp, i,
! 1067: AGENT_MAX_SESSION_IDS);
! 1068: e->session_ids[i].key = key;
! 1069: e->session_ids[i].forwarded = fwd != 0;
! 1070: key = NULL; /* transferred */
! 1071: /* can't transfer sid; it's refcounted and scoped to request's life */
! 1072: if ((e->session_ids[i].sid = sshbuf_new()) == NULL)
! 1073: fatal_f("sshbuf_new");
! 1074: if ((r = sshbuf_putb(e->session_ids[i].sid, sid)) != 0)
! 1075: fatal_fr(r, "sshbuf_putb session ID");
! 1076: /* success */
! 1077: r = 0;
! 1078: out:
! 1079: sshkey_free(key);
! 1080: sshbuf_free(sid);
! 1081: sshbuf_free(sig);
! 1082: return r == 0 ? 1 : 0;
! 1083: }
! 1084:
! 1085: static void
! 1086: process_extension(SocketEntry *e)
! 1087: {
! 1088: int r, success = 0;
! 1089: char *name;
! 1090:
! 1091: debug2_f("entering");
! 1092: if ((r = sshbuf_get_cstring(e->request, &name, NULL)) != 0) {
! 1093: error_fr(r, "parse");
! 1094: goto send;
! 1095: }
! 1096: if (strcmp(name, "session-bind@openssh.com") == 0)
! 1097: success = process_ext_session_bind(e);
! 1098: else
! 1099: debug_f("unsupported extension \"%s\"", name);
! 1100: send:
! 1101: send_status(e, success);
! 1102: }
1.264 djm 1103: /*
1104: * dispatch incoming message.
1105: * returns 1 on success, 0 for incomplete messages or -1 on error.
1106: */
1.223 djm 1107: static int
1108: process_message(u_int socknum)
1.1 deraadt 1109: {
1.194 markus 1110: u_int msg_len;
1111: u_char type;
1112: const u_char *cp;
1113: int r;
1.223 djm 1114: SocketEntry *e;
1115:
1.266 djm 1116: if (socknum >= sockets_alloc)
1117: fatal_f("sock %u >= allocated %u", socknum, sockets_alloc);
1.223 djm 1118: e = &sockets[socknum];
1.89 markus 1119:
1.194 markus 1120: if (sshbuf_len(e->input) < 5)
1.223 djm 1121: return 0; /* Incomplete message header. */
1.194 markus 1122: cp = sshbuf_ptr(e->input);
1123: msg_len = PEEK_U32(cp);
1.223 djm 1124: if (msg_len > AGENT_MAX_LEN) {
1.266 djm 1125: debug_f("socket %u (fd=%d) message too long %u > %u",
1126: socknum, e->fd, msg_len, AGENT_MAX_LEN);
1.223 djm 1127: return -1;
1.21 markus 1128: }
1.194 markus 1129: if (sshbuf_len(e->input) < msg_len + 4)
1.223 djm 1130: return 0; /* Incomplete message body. */
1.87 markus 1131:
1132: /* move the current input to e->request */
1.194 markus 1133: sshbuf_reset(e->request);
1134: if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
1.223 djm 1135: (r = sshbuf_get_u8(e->request, &type)) != 0) {
1136: if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
1137: r == SSH_ERR_STRING_TOO_LARGE) {
1.266 djm 1138: error_fr(r, "parse");
1.223 djm 1139: return -1;
1140: }
1.266 djm 1141: fatal_fr(r, "parse");
1.223 djm 1142: }
1143:
1.266 djm 1144: debug_f("socket %u (fd=%d) type %d", socknum, e->fd, type);
1.21 markus 1145:
1.230 djm 1146: /* check whether agent is locked */
1.88 markus 1147: if (locked && type != SSH_AGENTC_UNLOCK) {
1.194 markus 1148: sshbuf_reset(e->request);
1.88 markus 1149: switch (type) {
1150: case SSH2_AGENTC_REQUEST_IDENTITIES:
1151: /* send empty lists */
1.221 djm 1152: no_identities(e);
1.88 markus 1153: break;
1154: default:
1155: /* send a fail message for all other request types */
1.194 markus 1156: send_status(e, 0);
1.88 markus 1157: }
1.264 djm 1158: return 1;
1.88 markus 1159: }
1160:
1.21 markus 1161: switch (type) {
1.88 markus 1162: case SSH_AGENTC_LOCK:
1163: case SSH_AGENTC_UNLOCK:
1164: process_lock_agent(e, type == SSH_AGENTC_LOCK);
1165: break;
1.21 markus 1166: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.221 djm 1167: process_remove_all_identities(e); /* safe for !WITH_SSH1 */
1.33 markus 1168: break;
1169: /* ssh2 */
1170: case SSH2_AGENTC_SIGN_REQUEST:
1171: process_sign_request2(e);
1172: break;
1173: case SSH2_AGENTC_REQUEST_IDENTITIES:
1.221 djm 1174: process_request_identities(e);
1.33 markus 1175: break;
1176: case SSH2_AGENTC_ADD_IDENTITY:
1.94 markus 1177: case SSH2_AGENTC_ADD_ID_CONSTRAINED:
1.221 djm 1178: process_add_identity(e);
1.33 markus 1179: break;
1180: case SSH2_AGENTC_REMOVE_IDENTITY:
1.221 djm 1181: process_remove_identity(e);
1.33 markus 1182: break;
1183: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
1.221 djm 1184: process_remove_all_identities(e);
1.21 markus 1185: break;
1.163 markus 1186: #ifdef ENABLE_PKCS11
1.59 markus 1187: case SSH_AGENTC_ADD_SMARTCARD_KEY:
1.110 djm 1188: case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
1.59 markus 1189: process_add_smartcard_key(e);
1.75 deraadt 1190: break;
1.59 markus 1191: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
1192: process_remove_smartcard_key(e);
1.75 deraadt 1193: break;
1.163 markus 1194: #endif /* ENABLE_PKCS11 */
1.280 ! djm 1195: case SSH_AGENTC_EXTENSION:
! 1196: process_extension(e);
! 1197: break;
1.21 markus 1198: default:
1199: /* Unknown message. Respond with failure. */
1200: error("Unknown message %d", type);
1.194 markus 1201: sshbuf_reset(e->request);
1202: send_status(e, 0);
1.21 markus 1203: break;
1204: }
1.264 djm 1205: return 1;
1.1 deraadt 1206: }
1207:
1.55 itojun 1208: static void
1.73 stevesk 1209: new_socket(sock_type type, int fd)
1.1 deraadt 1210: {
1.112 markus 1211: u_int i, old_alloc, new_alloc;
1.96 deraadt 1212:
1.269 djm 1213: debug_f("type = %s", type == AUTH_CONNECTION ? "CONNECTION" :
1214: (type == AUTH_SOCKET ? "SOCKET" : "UNKNOWN"));
1.119 djm 1215: set_nonblock(fd);
1.21 markus 1216:
1217: if (fd > max_fd)
1218: max_fd = fd;
1219:
1220: for (i = 0; i < sockets_alloc; i++)
1221: if (sockets[i].type == AUTH_UNUSED) {
1222: sockets[i].fd = fd;
1.266 djm 1223: if ((sockets[i].input = sshbuf_new()) == NULL ||
1224: (sockets[i].output = sshbuf_new()) == NULL ||
1225: (sockets[i].request = sshbuf_new()) == NULL)
1226: fatal_f("sshbuf_new failed");
1.112 markus 1227: sockets[i].type = type;
1.21 markus 1228: return;
1229: }
1230: old_alloc = sockets_alloc;
1.112 markus 1231: new_alloc = sockets_alloc + 10;
1.269 djm 1232: sockets = xrecallocarray(sockets, old_alloc, new_alloc,
1233: sizeof(sockets[0]));
1.112 markus 1234: for (i = old_alloc; i < new_alloc; i++)
1.21 markus 1235: sockets[i].type = AUTH_UNUSED;
1.112 markus 1236: sockets_alloc = new_alloc;
1.21 markus 1237: sockets[old_alloc].fd = fd;
1.266 djm 1238: if ((sockets[old_alloc].input = sshbuf_new()) == NULL ||
1239: (sockets[old_alloc].output = sshbuf_new()) == NULL ||
1240: (sockets[old_alloc].request = sshbuf_new()) == NULL)
1241: fatal_f("sshbuf_new failed");
1.112 markus 1242: sockets[old_alloc].type = type;
1.1 deraadt 1243: }
1244:
1.55 itojun 1245: static int
1.223 djm 1246: handle_socket_read(u_int socknum)
1.1 deraadt 1247: {
1.223 djm 1248: struct sockaddr_un sunaddr;
1249: socklen_t slen;
1250: uid_t euid;
1251: gid_t egid;
1252: int fd;
1253:
1254: slen = sizeof(sunaddr);
1255: fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
1.237 deraadt 1256: if (fd == -1) {
1.223 djm 1257: error("accept from AUTH_SOCKET: %s", strerror(errno));
1258: return -1;
1259: }
1.237 deraadt 1260: if (getpeereid(fd, &euid, &egid) == -1) {
1.223 djm 1261: error("getpeereid %d failed: %s", fd, strerror(errno));
1262: close(fd);
1263: return -1;
1264: }
1265: if ((euid != 0) && (getuid() != euid)) {
1266: error("uid mismatch: peer euid %u != uid %u",
1267: (u_int) euid, (u_int) getuid());
1268: close(fd);
1269: return -1;
1270: }
1271: new_socket(AUTH_CONNECTION, fd);
1272: return 0;
1273: }
1274:
1275: static int
1276: handle_conn_read(u_int socknum)
1277: {
1.233 djm 1278: char buf[AGENT_RBUF_LEN];
1.223 djm 1279: ssize_t len;
1280: int r;
1281:
1282: if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
1283: if (len == -1) {
1284: if (errno == EAGAIN || errno == EINTR)
1285: return 0;
1.266 djm 1286: error_f("read error on socket %u (fd %d): %s",
1287: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1288: }
1289: return -1;
1290: }
1291: if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
1.266 djm 1292: fatal_fr(r, "compose");
1.223 djm 1293: explicit_bzero(buf, sizeof(buf));
1.264 djm 1294: for (;;) {
1295: if ((r = process_message(socknum)) == -1)
1296: return -1;
1297: else if (r == 0)
1298: break;
1299: }
1.223 djm 1300: return 0;
1301: }
1302:
1303: static int
1304: handle_conn_write(u_int socknum)
1305: {
1306: ssize_t len;
1307: int r;
1308:
1309: if (sshbuf_len(sockets[socknum].output) == 0)
1310: return 0; /* shouldn't happen */
1311: if ((len = write(sockets[socknum].fd,
1312: sshbuf_ptr(sockets[socknum].output),
1313: sshbuf_len(sockets[socknum].output))) <= 0) {
1314: if (len == -1) {
1315: if (errno == EAGAIN || errno == EINTR)
1316: return 0;
1.266 djm 1317: error_f("read error on socket %u (fd %d): %s",
1318: socknum, sockets[socknum].fd, strerror(errno));
1.223 djm 1319: }
1320: return -1;
1321: }
1322: if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
1.266 djm 1323: fatal_fr(r, "consume");
1.223 djm 1324: return 0;
1325: }
1326:
1327: static void
1.231 djm 1328: after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
1.223 djm 1329: {
1330: size_t i;
1.231 djm 1331: u_int socknum, activefds = npfd;
1.223 djm 1332:
1333: for (i = 0; i < npfd; i++) {
1334: if (pfd[i].revents == 0)
1335: continue;
1336: /* Find sockets entry */
1337: for (socknum = 0; socknum < sockets_alloc; socknum++) {
1338: if (sockets[socknum].type != AUTH_SOCKET &&
1339: sockets[socknum].type != AUTH_CONNECTION)
1340: continue;
1341: if (pfd[i].fd == sockets[socknum].fd)
1342: break;
1343: }
1344: if (socknum >= sockets_alloc) {
1.266 djm 1345: error_f("no socket for fd %d", pfd[i].fd);
1.223 djm 1346: continue;
1347: }
1348: /* Process events */
1349: switch (sockets[socknum].type) {
1350: case AUTH_SOCKET:
1.231 djm 1351: if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
1352: break;
1353: if (npfd > maxfds) {
1354: debug3("out of fds (active %u >= limit %u); "
1355: "skipping accept", activefds, maxfds);
1356: break;
1357: }
1358: if (handle_socket_read(socknum) == 0)
1359: activefds++;
1.223 djm 1360: break;
1361: case AUTH_CONNECTION:
1.279 djm 1362: if ((pfd[i].revents & (POLLIN|POLLHUP|POLLERR)) != 0 &&
1363: handle_conn_read(socknum) != 0)
1.231 djm 1364: goto close_sock;
1365: if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
1366: handle_conn_write(socknum) != 0) {
1367: close_sock:
1368: if (activefds == 0)
1369: fatal("activefds == 0 at close_sock");
1.223 djm 1370: close_socket(&sockets[socknum]);
1.231 djm 1371: activefds--;
1.223 djm 1372: break;
1373: }
1374: break;
1375: default:
1376: break;
1377: }
1378: }
1379: }
1380:
1381: static int
1.231 djm 1382: prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
1.223 djm 1383: {
1384: struct pollfd *pfd = *pfdp;
1385: size_t i, j, npfd = 0;
1.174 dtucker 1386: time_t deadline;
1.233 djm 1387: int r;
1.46 markus 1388:
1.223 djm 1389: /* Count active sockets */
1.46 markus 1390: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 1391: switch (sockets[i].type) {
1392: case AUTH_SOCKET:
1393: case AUTH_CONNECTION:
1.223 djm 1394: npfd++;
1.21 markus 1395: break;
1396: case AUTH_UNUSED:
1397: break;
1398: default:
1399: fatal("Unknown socket type %d", sockets[i].type);
1400: break;
1401: }
1.46 markus 1402: }
1.223 djm 1403: if (npfd != *npfdp &&
1404: (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
1.266 djm 1405: fatal_f("recallocarray failed");
1.223 djm 1406: *pfdp = pfd;
1407: *npfdp = npfd;
1.46 markus 1408:
1.223 djm 1409: for (i = j = 0; i < sockets_alloc; i++) {
1.46 markus 1410: switch (sockets[i].type) {
1411: case AUTH_SOCKET:
1.231 djm 1412: if (npfd > maxfds) {
1413: debug3("out of fds (active %zu >= limit %u); "
1414: "skipping arming listener", npfd, maxfds);
1415: break;
1416: }
1417: pfd[j].fd = sockets[i].fd;
1418: pfd[j].revents = 0;
1419: pfd[j].events = POLLIN;
1420: j++;
1421: break;
1.46 markus 1422: case AUTH_CONNECTION:
1.223 djm 1423: pfd[j].fd = sockets[i].fd;
1424: pfd[j].revents = 0;
1.233 djm 1425: /*
1426: * Only prepare to read if we can handle a full-size
1427: * input read buffer and enqueue a max size reply..
1428: */
1429: if ((r = sshbuf_check_reserve(sockets[i].input,
1430: AGENT_RBUF_LEN)) == 0 &&
1431: (r = sshbuf_check_reserve(sockets[i].output,
1.278 djm 1432: AGENT_MAX_LEN)) == 0)
1.233 djm 1433: pfd[j].events = POLLIN;
1.266 djm 1434: else if (r != SSH_ERR_NO_BUFFER_SPACE)
1435: fatal_fr(r, "reserve");
1.194 markus 1436: if (sshbuf_len(sockets[i].output) > 0)
1.223 djm 1437: pfd[j].events |= POLLOUT;
1438: j++;
1.46 markus 1439: break;
1440: default:
1441: break;
1442: }
1443: }
1.155 dtucker 1444: deadline = reaper();
1445: if (parent_alive_interval != 0)
1446: deadline = (deadline == 0) ? parent_alive_interval :
1.214 deraadt 1447: MINIMUM(deadline, parent_alive_interval);
1.155 dtucker 1448: if (deadline == 0) {
1.224 djm 1449: *timeoutp = -1; /* INFTIM */
1.155 dtucker 1450: } else {
1.223 djm 1451: if (deadline > INT_MAX / 1000)
1452: *timeoutp = INT_MAX / 1000;
1453: else
1454: *timeoutp = deadline * 1000;
1.155 dtucker 1455: }
1.46 markus 1456: return (1);
1.21 markus 1457: }
1458:
1.55 itojun 1459: static void
1.113 markus 1460: cleanup_socket(void)
1.15 markus 1461: {
1.187 djm 1462: if (cleanup_pid != 0 && getpid() != cleanup_pid)
1463: return;
1.266 djm 1464: debug_f("cleanup");
1.48 deraadt 1465: if (socket_name[0])
1466: unlink(socket_name);
1467: if (socket_dir[0])
1468: rmdir(socket_dir);
1.10 markus 1469: }
1470:
1.114 markus 1471: void
1.15 markus 1472: cleanup_exit(int i)
1473: {
1.113 markus 1474: cleanup_socket();
1475: _exit(i);
1.15 markus 1476: }
1477:
1.135 deraadt 1478: /*ARGSUSED*/
1.55 itojun 1479: static void
1.48 deraadt 1480: cleanup_handler(int sig)
1481: {
1.113 markus 1482: cleanup_socket();
1.163 markus 1483: #ifdef ENABLE_PKCS11
1484: pkcs11_terminate();
1485: #endif
1.48 deraadt 1486: _exit(2);
1.113 markus 1487: }
1488:
1.68 markus 1489: static void
1.155 dtucker 1490: check_parent_exists(void)
1.68 markus 1491: {
1.172 dtucker 1492: /*
1493: * If our parent has exited then getppid() will return (pid_t)1,
1494: * so testing for that should be safe.
1495: */
1496: if (parent_pid != -1 && getppid() != parent_pid) {
1.68 markus 1497: /* printf("Parent has died - Authentication agent exiting.\n"); */
1.155 dtucker 1498: cleanup_socket();
1499: _exit(2);
1.68 markus 1500: }
1.48 deraadt 1501: }
1502:
1.55 itojun 1503: static void
1.50 itojun 1504: usage(void)
1.15 markus 1505: {
1.184 deraadt 1506: fprintf(stderr,
1.250 jmc 1507: "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1.261 jmc 1508: " [-P allowed_providers] [-t life]\n"
1.260 djm 1509: " ssh-agent [-a bind_address] [-E fingerprint_hash] [-P allowed_providers]\n"
1.259 dtucker 1510: " [-t life] command [arg ...]\n"
1.250 jmc 1511: " ssh-agent [-c | -s] -k\n");
1.21 markus 1512: exit(1);
1.15 markus 1513: }
1514:
1.2 provos 1515: int
1516: main(int ac, char **av)
1.1 deraadt 1517: {
1.201 djm 1518: int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1.265 djm 1519: int sock, ch, result, saved_errno;
1.96 deraadt 1520: char *shell, *format, *pidstr, *agentsocket = NULL;
1.41 markus 1521: struct rlimit rlim;
1.96 deraadt 1522: extern int optind;
1.98 stevesk 1523: extern char *optarg;
1.21 markus 1524: pid_t pid;
1.96 deraadt 1525: char pidstrbuf[1 + 3 * sizeof pid];
1.161 tobias 1526: size_t len;
1.189 djm 1527: mode_t prev_mask;
1.224 djm 1528: int timeout = -1; /* INFTIM */
1.223 djm 1529: struct pollfd *pfd = NULL;
1530: size_t npfd = 0;
1.231 djm 1531: u_int maxfds;
1.123 djm 1532:
1533: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1534: sanitise_stdfd();
1.99 markus 1535:
1536: /* drop */
1537: setegid(getgid());
1538: setgid(getgid());
1.53 markus 1539:
1.231 djm 1540: if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
1541: fatal("%s: getrlimit: %s", __progname, strerror(errno));
1542:
1.185 markus 1543: #ifdef WITH_OPENSSL
1.170 djm 1544: OpenSSL_add_all_algorithms();
1.185 markus 1545: #endif
1.21 markus 1546:
1.258 djm 1547: while ((ch = getopt(ac, av, "cDdksE:a:O:P:t:")) != -1) {
1.21 markus 1548: switch (ch) {
1.192 djm 1549: case 'E':
1550: fingerprint_hash = ssh_digest_alg_by_name(optarg);
1551: if (fingerprint_hash == -1)
1552: fatal("Invalid hash algorithm \"%s\"", optarg);
1553: break;
1.21 markus 1554: case 'c':
1555: if (s_flag)
1556: usage();
1557: c_flag++;
1558: break;
1559: case 'k':
1560: k_flag++;
1.258 djm 1561: break;
1562: case 'O':
1563: if (strcmp(optarg, "no-restrict-websafe") == 0)
1564: restrict_websafe = 0;
1565: else
1566: fatal("Unknown -O option");
1.21 markus 1567: break;
1.215 djm 1568: case 'P':
1.260 djm 1569: if (allowed_providers != NULL)
1.215 djm 1570: fatal("-P option already specified");
1.260 djm 1571: allowed_providers = xstrdup(optarg);
1.215 djm 1572: break;
1.21 markus 1573: case 's':
1574: if (c_flag)
1575: usage();
1576: s_flag++;
1577: break;
1.57 markus 1578: case 'd':
1.201 djm 1579: if (d_flag || D_flag)
1.57 markus 1580: usage();
1581: d_flag++;
1582: break;
1.201 djm 1583: case 'D':
1584: if (d_flag || D_flag)
1585: usage();
1586: D_flag++;
1587: break;
1.86 markus 1588: case 'a':
1589: agentsocket = optarg;
1.106 marc 1590: break;
1591: case 't':
1592: if ((lifetime = convtime(optarg)) == -1) {
1593: fprintf(stderr, "Invalid lifetime\n");
1594: usage();
1595: }
1.86 markus 1596: break;
1.21 markus 1597: default:
1598: usage();
1599: }
1600: }
1601: ac -= optind;
1602: av += optind;
1603:
1.201 djm 1604: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1.21 markus 1605: usage();
1606:
1.260 djm 1607: if (allowed_providers == NULL)
1.262 djm 1608: allowed_providers = xstrdup(DEFAULT_ALLOWED_PROVIDERS);
1.215 djm 1609:
1.85 markus 1610: if (ac == 0 && !c_flag && !s_flag) {
1.21 markus 1611: shell = getenv("SHELL");
1.161 tobias 1612: if (shell != NULL && (len = strlen(shell)) > 2 &&
1613: strncmp(shell + len - 3, "csh", 3) == 0)
1.21 markus 1614: c_flag = 1;
1615: }
1616: if (k_flag) {
1.136 deraadt 1617: const char *errstr = NULL;
1618:
1.21 markus 1619: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1620: if (pidstr == NULL) {
1621: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 1622: SSH_AGENTPID_ENV_NAME);
1.21 markus 1623: exit(1);
1624: }
1.136 deraadt 1625: pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1626: if (errstr) {
1627: fprintf(stderr,
1628: "%s=\"%s\", which is not a good PID: %s\n",
1629: SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1.21 markus 1630: exit(1);
1631: }
1632: if (kill(pid, SIGTERM) == -1) {
1633: perror("kill");
1634: exit(1);
1635: }
1636: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1.140 djm 1637: printf(format, SSH_AUTHSOCKET_ENV_NAME);
1638: printf(format, SSH_AGENTPID_ENV_NAME);
1.91 mpech 1639: printf("echo Agent pid %ld killed;\n", (long)pid);
1.21 markus 1640: exit(0);
1641: }
1.231 djm 1642:
1643: /*
1644: * Minimum file descriptors:
1645: * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
1646: * a few spare for libc / stack protectors / sanitisers, etc.
1647: */
1648: #define SSH_AGENT_MIN_FDS (3+1+1+1+4)
1649: if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
1.232 djm 1650: fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
1.231 djm 1651: __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
1652: maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
1653:
1.21 markus 1654: parent_pid = getpid();
1655:
1.86 markus 1656: if (agentsocket == NULL) {
1657: /* Create private directory for agent socket */
1.171 djm 1658: mktemp_proto(socket_dir, sizeof(socket_dir));
1.86 markus 1659: if (mkdtemp(socket_dir) == NULL) {
1660: perror("mkdtemp: private socket dir");
1661: exit(1);
1662: }
1.91 mpech 1663: snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1664: (long)parent_pid);
1.86 markus 1665: } else {
1666: /* Try to use specified agent socket */
1667: socket_dir[0] = '\0';
1668: strlcpy(socket_name, agentsocket, sizeof socket_name);
1.21 markus 1669: }
1670:
1.23 markus 1671: /*
1672: * Create socket early so it will exist before command gets run from
1673: * the parent.
1674: */
1.189 djm 1675: prev_mask = umask(0177);
1.188 millert 1676: sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1.21 markus 1677: if (sock < 0) {
1.188 millert 1678: /* XXX - unix_listener() calls error() not perror() */
1.121 djm 1679: *socket_name = '\0'; /* Don't unlink any existing file */
1.21 markus 1680: cleanup_exit(1);
1681: }
1.189 djm 1682: umask(prev_mask);
1.46 markus 1683:
1.23 markus 1684: /*
1685: * Fork, and have the parent execute the command, if any, or present
1686: * the socket data. The child continues as the authentication agent.
1687: */
1.201 djm 1688: if (D_flag || d_flag) {
1689: log_init(__progname,
1690: d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1691: SYSLOG_FACILITY_AUTH, 1);
1.57 markus 1692: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1693: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1694: SSH_AUTHSOCKET_ENV_NAME);
1.91 mpech 1695: printf("echo Agent pid %ld;\n", (long)parent_pid);
1.210 dtucker 1696: fflush(stdout);
1.57 markus 1697: goto skip;
1698: }
1.21 markus 1699: pid = fork();
1700: if (pid == -1) {
1701: perror("fork");
1.81 stevesk 1702: cleanup_exit(1);
1.21 markus 1703: }
1704: if (pid != 0) { /* Parent - execute the given command. */
1705: close(sock);
1.91 mpech 1706: snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1.21 markus 1707: if (ac == 0) {
1708: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1709: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 1710: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 1711: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 1712: SSH_AGENTPID_ENV_NAME);
1.91 mpech 1713: printf("echo Agent pid %ld;\n", (long)pid);
1.21 markus 1714: exit(0);
1715: }
1.36 deraadt 1716: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1717: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1718: perror("setenv");
1719: exit(1);
1720: }
1.21 markus 1721: execvp(av[0], av);
1722: perror(av[0]);
1723: exit(1);
1724: }
1.81 stevesk 1725: /* child */
1726: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.67 stevesk 1727:
1728: if (setsid() == -1) {
1.81 stevesk 1729: error("setsid: %s", strerror(errno));
1.67 stevesk 1730: cleanup_exit(1);
1731: }
1732:
1733: (void)chdir("/");
1.265 djm 1734: if (stdfd_devnull(1, 1, 1) == -1)
1.266 djm 1735: error_f("stdfd_devnull failed");
1.21 markus 1736:
1.41 markus 1737: /* deny core dumps, since memory contains unencrypted private keys */
1738: rlim.rlim_cur = rlim.rlim_max = 0;
1.237 deraadt 1739: if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
1.81 stevesk 1740: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.21 markus 1741: cleanup_exit(1);
1742: }
1.57 markus 1743:
1744: skip:
1.187 djm 1745:
1746: cleanup_pid = getpid();
1.163 markus 1747:
1748: #ifdef ENABLE_PKCS11
1749: pkcs11_init(0);
1750: #endif
1.21 markus 1751: new_socket(AUTH_SOCKET, sock);
1.155 dtucker 1752: if (ac > 0)
1753: parent_alive_interval = 10;
1.33 markus 1754: idtab_init();
1.252 dtucker 1755: ssh_signal(SIGPIPE, SIG_IGN);
1756: ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1757: ssh_signal(SIGHUP, cleanup_handler);
1758: ssh_signal(SIGTERM, cleanup_handler);
1.205 djm 1759:
1.215 djm 1760: if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
1.205 djm 1761: fatal("%s: pledge: %s", __progname, strerror(errno));
1.66 markus 1762:
1.21 markus 1763: while (1) {
1.231 djm 1764: prepare_poll(&pfd, &npfd, &timeout, maxfds);
1.223 djm 1765: result = poll(pfd, npfd, timeout);
1.154 dtucker 1766: saved_errno = errno;
1.155 dtucker 1767: if (parent_alive_interval != 0)
1768: check_parent_exists();
1769: (void) reaper(); /* remove expired keys */
1.237 deraadt 1770: if (result == -1) {
1.154 dtucker 1771: if (saved_errno == EINTR)
1.21 markus 1772: continue;
1.223 djm 1773: fatal("poll: %s", strerror(saved_errno));
1.154 dtucker 1774: } else if (result > 0)
1.231 djm 1775: after_poll(pfd, npfd, maxfds);
1.15 markus 1776: }
1.21 markus 1777: /* NOTREACHED */
1.1 deraadt 1778: }
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