crypto/openssh/ssh-agent.c

   1 /* $OpenBSD: ssh-agent.c,v 1.166 2010/04/16 01:47:26 djm Exp $ */
   2 /*
   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.
   7  *
   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  *
  14  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  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.
  35  */
  36
  37 #include "includes.h"
  38
  39 #include <sys/types.h>
  40 #include <sys/param.h>
  41 #include <sys/resource.h>
  42 #include <sys/stat.h>
  43 #include <sys/socket.h>
  44 #ifdef HAVE_SYS_TIME_H
  45 # include <sys/time.h>
  46 #endif
  47 #ifdef HAVE_SYS_UN_H
  48 # include <sys/un.h>
  49 #endif
  50 #include "openbsd-compat/sys-queue.h"
  51
  52 #include <openssl/evp.h>
  53 #include <openssl/md5.h>
  54 #include "openbsd-compat/openssl-compat.h"
  55
  56 #include <errno.h>
  57 #include <fcntl.h>
  58 #ifdef HAVE_PATHS_H
  59 # include <paths.h>
  60 #endif
  61 #include <signal.h>
  62 #include <stdarg.h>
  63 #include <stdio.h>
  64 #include <stdlib.h>
  65 #include <time.h>
  66 #include <string.h>
  67 #include <unistd.h>
  68
  69 #include "xmalloc.h"
  70 #include "ssh.h"
  71 #include "rsa.h"
  72 #include "buffer.h"
  73 #include "key.h"
  74 #include "authfd.h"
  75 #include "compat.h"
  76 #include "log.h"
  77 #include "misc.h"
  78
  79 #ifdef ENABLE_PKCS11
  80 #include "ssh-pkcs11.h"
  81 #endif
  82
  83 #if defined(HAVE_SYS_PRCTL_H)
  84 #include <sys/prctl.h>  /* For prctl() and PR_SET_DUMPABLE */
  85 #endif
  86
  87 typedef enum {
  88         AUTH_UNUSED,
  89         AUTH_SOCKET,
  90         AUTH_CONNECTION
  91 } sock_type;
  92
  93 typedef struct {
  94         int fd;
  95         sock_type type;
  96         Buffer input;
  97         Buffer output;
  98         Buffer request;
  99 } SocketEntry;
 100
 101 u_int sockets_alloc = 0;
 102 SocketEntry *sockets = NULL;
 103
 104 typedef struct identity {
 105         TAILQ_ENTRY(identity) next;
 106         Key *key;
 107         char *comment;
 108         char *provider;
 109         u_int death;
 110         u_int confirm;
 111 } Identity;
 112
 113 typedef struct {
 114         int nentries;
 115         TAILQ_HEAD(idqueue, identity) idlist;
 116 } Idtab;
 117
 118 /* private key table, one per protocol version */
 119 Idtab idtable[3];
 120
 121 int max_fd = 0;
 122
 123 /* pid of shell == parent of agent */
 124 pid_t parent_pid = -1;
 125 u_int parent_alive_interval = 0;
 126
 127 /* pathname and directory for AUTH_SOCKET */
 128 char socket_name[MAXPATHLEN];
 129 char socket_dir[MAXPATHLEN];
 130
 131 /* locking */
 132 int locked = 0;
 133 char *lock_passwd = NULL;
 134
 135 extern char *__progname;
 136
 137 /* Default lifetime (0 == forever) */
 138 static int lifetime = 0;
 139
 140 static void
 141 close_socket(SocketEntry *e)
 142 {
 143         close(e->fd);
 144         e->fd = -1;
 145         e->type = AUTH_UNUSED;
 146         buffer_free(&e->input);
 147         buffer_free(&e->output);
 148         buffer_free(&e->request);
 149 }
 150
 151 static void
 152 idtab_init(void)
 153 {
 154         int i;
 155
 156         for (i = 0; i <=2; i++) {
 157                 TAILQ_INIT(&idtable[i].idlist);
 158                 idtable[i].nentries = 0;
 159         }
 160 }
 161
 162 /* return private key table for requested protocol version */
 163 static Idtab *
 164 idtab_lookup(int version)
 165 {
 166         if (version < 1 || version > 2)
 167                 fatal("internal error, bad protocol version %d", version);
 168         return &idtable[version];
 169 }
 170
 171 static void
 172 free_identity(Identity *id)
 173 {
 174         key_free(id->key);
 175         if (id->provider != NULL)
 176                 xfree(id->provider);
 177         xfree(id->comment);
 178         xfree(id);
 179 }
 180
 181 /* return matching private key for given public key */
 182 static Identity *
 183 lookup_identity(Key *key, int version)
 184 {
 185         Identity *id;
 186
 187         Idtab *tab = idtab_lookup(version);
 188         TAILQ_FOREACH(id, &tab->idlist, next) {
 189                 if (key_equal(key, id->key))
 190                         return (id);
 191         }
 192         return (NULL);
 193 }
 194
 195 /* Check confirmation of keysign request */
 196 static int
 197 confirm_key(Identity *id)
 198 {
 199         char *p;
 200         int ret = -1;
 201
 202         p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
 203         if (ask_permission("Allow use of key %s?\nKey fingerprint %s.",
 204             id->comment, p))
 205                 ret = 0;
 206         xfree(p);
 207
 208         return (ret);
 209 }
 210
 211 /* send list of supported public keys to 'client' */
 212 static void
 213 process_request_identities(SocketEntry *e, int version)
 214 {
 215         Idtab *tab = idtab_lookup(version);
 216         Identity *id;
 217         Buffer msg;
 218
 219         buffer_init(&msg);
 220         buffer_put_char(&msg, (version == 1) ?
 221             SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
 222         buffer_put_int(&msg, tab->nentries);
 223         TAILQ_FOREACH(id, &tab->idlist, next) {
 224                 if (id->key->type == KEY_RSA1) {
 225                         buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
 226                         buffer_put_bignum(&msg, id->key->rsa->e);
 227                         buffer_put_bignum(&msg, id->key->rsa->n);
 228                 } else {
 229                         u_char *blob;
 230                         u_int blen;
 231                         key_to_blob(id->key, &blob, &blen);
 232                         buffer_put_string(&msg, blob, blen);
 233                         xfree(blob);
 234                 }
 235                 buffer_put_cstring(&msg, id->comment);
 236         }
 237         buffer_put_int(&e->output, buffer_len(&msg));
 238         buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
 239         buffer_free(&msg);
 240 }
 241
 242 /* ssh1 only */
 243 static void
 244 process_authentication_challenge1(SocketEntry *e)
 245 {
 246         u_char buf[32], mdbuf[16], session_id[16];
 247         u_int response_type;
 248         BIGNUM *challenge;
 249         Identity *id;
 250         int i, len;
 251         Buffer msg;
 252         MD5_CTX md;
 253         Key *key;
 254
 255         buffer_init(&msg);
 256         key = key_new(KEY_RSA1);
 257         if ((challenge = BN_new()) == NULL)
 258                 fatal("process_authentication_challenge1: BN_new failed");
 259
 260         (void) buffer_get_int(&e->request);                     /* ignored */
 261         buffer_get_bignum(&e->request, key->rsa->e);
 262         buffer_get_bignum(&e->request, key->rsa->n);
 263         buffer_get_bignum(&e->request, challenge);
 264
 265         /* Only protocol 1.1 is supported */
 266         if (buffer_len(&e->request) == 0)
 267                 goto failure;
 268         buffer_get(&e->request, session_id, 16);
 269         response_type = buffer_get_int(&e->request);
 270         if (response_type != 1)
 271                 goto failure;
 272
 273         id = lookup_identity(key, 1);
 274         if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
 275                 Key *private = id->key;
 276                 /* Decrypt the challenge using the private key. */
 277                 if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
 278                         goto failure;
 279
 280                 /* The response is MD5 of decrypted challenge plus session id. */
 281                 len = BN_num_bytes(challenge);
 282                 if (len <= 0 || len > 32) {
 283                         logit("process_authentication_challenge: bad challenge length %d", len);
 284                         goto failure;
 285                 }
 286                 memset(buf, 0, 32);
 287                 BN_bn2bin(challenge, buf + 32 - len);
 288                 MD5_Init(&md);
 289                 MD5_Update(&md, buf, 32);
 290                 MD5_Update(&md, session_id, 16);
 291                 MD5_Final(mdbuf, &md);
 292
 293                 /* Send the response. */
 294                 buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
 295                 for (i = 0; i < 16; i++)
 296                         buffer_put_char(&msg, mdbuf[i]);
 297                 goto send;
 298         }
 299
 300 failure:
 301         /* Unknown identity or protocol error.  Send failure. */
 302         buffer_put_char(&msg, SSH_AGENT_FAILURE);
 303 send:
 304         buffer_put_int(&e->output, buffer_len(&msg));
 305         buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
 306         key_free(key);
 307         BN_clear_free(challenge);
 308         buffer_free(&msg);
 309 }
 310
 311 /* ssh2 only */
 312 static void
 313 process_sign_request2(SocketEntry *e)
 314 {
 315         u_char *blob, *data, *signature = NULL;
 316         u_int blen, dlen, slen = 0;
 317         extern int datafellows;
 318         int odatafellows;
 319         int ok = -1, flags;
 320         Buffer msg;
 321         Key *key;
 322
 323         datafellows = 0;
 324
 325         blob = buffer_get_string(&e->request, &blen);
 326         data = buffer_get_string(&e->request, &dlen);
 327
 328         flags = buffer_get_int(&e->request);
 329         odatafellows = datafellows;
 330         if (flags & SSH_AGENT_OLD_SIGNATURE)
 331                 datafellows = SSH_BUG_SIGBLOB;
 332
 333         key = key_from_blob(blob, blen);
 334         if (key != NULL) {
 335                 Identity *id = lookup_identity(key, 2);
 336                 if (id != NULL && (!id->confirm || confirm_key(id) == 0))
 337                         ok = key_sign(id->key, &signature, &slen, data, dlen);
 338                 key_free(key);
 339         }
 340         buffer_init(&msg);
 341         if (ok == 0) {
 342                 buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
 343                 buffer_put_string(&msg, signature, slen);
 344         } else {
 345                 buffer_put_char(&msg, SSH_AGENT_FAILURE);
 346         }
 347         buffer_put_int(&e->output, buffer_len(&msg));
 348         buffer_append(&e->output, buffer_ptr(&msg),
 349             buffer_len(&msg));
 350         buffer_free(&msg);
 351         xfree(data);
 352         xfree(blob);
 353         if (signature != NULL)
 354                 xfree(signature);
 355         datafellows = odatafellows;
 356 }
 357
 358 /* shared */
 359 static void
 360 process_remove_identity(SocketEntry *e, int version)
 361 {
 362         u_int blen, bits;
 363         int success = 0;
 364         Key *key = NULL;
 365         u_char *blob;
 366
 367         switch (version) {
 368         case 1:
 369                 key = key_new(KEY_RSA1);
 370                 bits = buffer_get_int(&e->request);
 371                 buffer_get_bignum(&e->request, key->rsa->e);
 372                 buffer_get_bignum(&e->request, key->rsa->n);
 373
 374                 if (bits != key_size(key))
 375                         logit("Warning: identity keysize mismatch: actual %u, announced %u",
 376                             key_size(key), bits);
 377                 break;
 378         case 2:
 379                 blob = buffer_get_string(&e->request, &blen);
 380                 key = key_from_blob(blob, blen);
 381                 xfree(blob);
 382                 break;
 383         }
 384         if (key != NULL) {
 385                 Identity *id = lookup_identity(key, version);
 386                 if (id != NULL) {
 387                         /*
 388                          * We have this key.  Free the old key.  Since we
 389                          * don't want to leave empty slots in the middle of
 390                          * the array, we actually free the key there and move
 391                          * all the entries between the empty slot and the end
 392                          * of the array.
 393                          */
 394                         Idtab *tab = idtab_lookup(version);
 395                         if (tab->nentries < 1)
 396                                 fatal("process_remove_identity: "
 397                                     "internal error: tab->nentries %d",
 398                                     tab->nentries);
 399                         TAILQ_REMOVE(&tab->idlist, id, next);
 400                         free_identity(id);
 401                         tab->nentries--;
 402                         success = 1;
 403                 }
 404                 key_free(key);
 405         }
 406         buffer_put_int(&e->output, 1);
 407         buffer_put_char(&e->output,
 408             success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
 409 }
 410
 411 static void
 412 process_remove_all_identities(SocketEntry *e, int version)
 413 {
 414         Idtab *tab = idtab_lookup(version);
 415         Identity *id;
 416
 417         /* Loop over all identities and clear the keys. */
 418         for (id = TAILQ_FIRST(&tab->idlist); id;
 419             id = TAILQ_FIRST(&tab->idlist)) {
 420                 TAILQ_REMOVE(&tab->idlist, id, next);
 421                 free_identity(id);
 422         }
 423
 424         /* Mark that there are no identities. */
 425         tab->nentries = 0;
 426
 427         /* Send success. */
 428         buffer_put_int(&e->output, 1);
 429         buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
 430 }
 431
 432 /* removes expired keys and returns number of seconds until the next expiry */
 433 static u_int
 434 reaper(void)
 435 {
 436         u_int deadline = 0, now = time(NULL);
 437         Identity *id, *nxt;
 438         int version;
 439         Idtab *tab;
 440
 441         for (version = 1; version < 3; version++) {
 442                 tab = idtab_lookup(version);
 443                 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
 444                         nxt = TAILQ_NEXT(id, next);
 445                         if (id->death == 0)
 446                                 continue;
 447                         if (now >= id->death) {
 448                                 debug("expiring key '%s'", id->comment);
 449                                 TAILQ_REMOVE(&tab->idlist, id, next);
 450                                 free_identity(id);
 451                                 tab->nentries--;
 452                         } else
 453                                 deadline = (deadline == 0) ? id->death :
 454                                     MIN(deadline, id->death);
 455                 }
 456         }
 457         if (deadline == 0 || deadline <= now)
 458                 return 0;
 459         else
 460                 return (deadline - now);
 461 }
 462
 463 static void
 464 process_add_identity(SocketEntry *e, int version)
 465 {
 466         Idtab *tab = idtab_lookup(version);
 467         Identity *id;
 468         int type, success = 0, death = 0, confirm = 0;
 469         char *type_name, *comment;
 470         Key *k = NULL;
 471         u_char *cert;
 472         u_int len;
 473
 474         switch (version) {
 475         case 1:
 476                 k = key_new_private(KEY_RSA1);
 477                 (void) buffer_get_int(&e->request);             /* ignored */
 478                 buffer_get_bignum(&e->request, k->rsa->n);
 479                 buffer_get_bignum(&e->request, k->rsa->e);
 480                 buffer_get_bignum(&e->request, k->rsa->d);
 481                 buffer_get_bignum(&e->request, k->rsa->iqmp);
 482
 483                 /* SSH and SSL have p and q swapped */
 484                 buffer_get_bignum(&e->request, k->rsa->q);      /* p */
 485                 buffer_get_bignum(&e->request, k->rsa->p);      /* q */
 486
 487                 /* Generate additional parameters */
 488                 rsa_generate_additional_parameters(k->rsa);
 489                 break;
 490         case 2:
 491                 type_name = buffer_get_string(&e->request, NULL);
 492                 type = key_type_from_name(type_name);
 493                 xfree(type_name);
 494                 switch (type) {
 495                 case KEY_DSA:
 496                         k = key_new_private(type);
 497                         buffer_get_bignum2(&e->request, k->dsa->p);
 498                         buffer_get_bignum2(&e->request, k->dsa->q);
 499                         buffer_get_bignum2(&e->request, k->dsa->g);
 500                         buffer_get_bignum2(&e->request, k->dsa->pub_key);
 501                         buffer_get_bignum2(&e->request, k->dsa->priv_key);
 502                         break;
 503                 case KEY_DSA_CERT_V00:
 504                 case KEY_DSA_CERT:
 505                         cert = buffer_get_string(&e->request, &len);
 506                         if ((k = key_from_blob(cert, len)) == NULL)
 507                                 fatal("Certificate parse failed");
 508                         xfree(cert);
 509                         key_add_private(k);
 510                         buffer_get_bignum2(&e->request, k->dsa->priv_key);
 511                         break;
 512                 case KEY_RSA:
 513                         k = key_new_private(type);
 514                         buffer_get_bignum2(&e->request, k->rsa->n);
 515                         buffer_get_bignum2(&e->request, k->rsa->e);
 516                         buffer_get_bignum2(&e->request, k->rsa->d);
 517                         buffer_get_bignum2(&e->request, k->rsa->iqmp);
 518                         buffer_get_bignum2(&e->request, k->rsa->p);
 519                         buffer_get_bignum2(&e->request, k->rsa->q);
 520
 521                         /* Generate additional parameters */
 522                         rsa_generate_additional_parameters(k->rsa);
 523                         break;
 524                 case KEY_RSA_CERT_V00:
 525                 case KEY_RSA_CERT:
 526                         cert = buffer_get_string(&e->request, &len);
 527                         if ((k = key_from_blob(cert, len)) == NULL)
 528                                 fatal("Certificate parse failed");
 529                         xfree(cert);
 530                         key_add_private(k);
 531                         buffer_get_bignum2(&e->request, k->rsa->d);
 532                         buffer_get_bignum2(&e->request, k->rsa->iqmp);
 533                         buffer_get_bignum2(&e->request, k->rsa->p);
 534                         buffer_get_bignum2(&e->request, k->rsa->q);
 535                         break;
 536                 default:
 537                         buffer_clear(&e->request);
 538                         goto send;
 539                 }
 540                 break;
 541         }
 542         /* enable blinding */
 543         switch (k->type) {
 544         case KEY_RSA:
 545         case KEY_RSA_CERT_V00:
 546         case KEY_RSA_CERT:
 547         case KEY_RSA1:
 548                 if (RSA_blinding_on(k->rsa, NULL) != 1) {
 549                         error("process_add_identity: RSA_blinding_on failed");
 550                         key_free(k);
 551                         goto send;
 552                 }
 553                 break;
 554         }
 555         comment = buffer_get_string(&e->request, NULL);
 556         if (k == NULL) {
 557                 xfree(comment);
 558                 goto send;
 559         }
 560         while (buffer_len(&e->request)) {
 561                 switch ((type = buffer_get_char(&e->request))) {
 562                 case SSH_AGENT_CONSTRAIN_LIFETIME:
 563                         death = time(NULL) + buffer_get_int(&e->request);
 564                         break;
 565                 case SSH_AGENT_CONSTRAIN_CONFIRM:
 566                         confirm = 1;
 567                         break;
 568                 default:
 569                         error("process_add_identity: "
 570                             "Unknown constraint type %d", type);
 571                         xfree(comment);
 572                         key_free(k);
 573                         goto send;
 574                 }
 575         }
 576         success = 1;
 577         if (lifetime && !death)
 578                 death = time(NULL) + lifetime;
 579         if ((id = lookup_identity(k, version)) == NULL) {
 580                 id = xcalloc(1, sizeof(Identity));
 581                 id->key = k;
 582                 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
 583                 /* Increment the number of identities. */
 584                 tab->nentries++;
 585         } else {
 586                 key_free(k);
 587                 xfree(id->comment);
 588         }
 589         id->comment = comment;
 590         id->death = death;
 591         id->confirm = confirm;
 592 send:
 593         buffer_put_int(&e->output, 1);
 594         buffer_put_char(&e->output,
 595             success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
 596 }
 597
 598 /* XXX todo: encrypt sensitive data with passphrase */
 599 static void
 600 process_lock_agent(SocketEntry *e, int lock)
 601 {
 602         int success = 0;
 603         char *passwd;
 604
 605         passwd = buffer_get_string(&e->request, NULL);
 606         if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
 607                 locked = 0;
 608                 memset(lock_passwd, 0, strlen(lock_passwd));
 609                 xfree(lock_passwd);
 610                 lock_passwd = NULL;
 611                 success = 1;
 612         } else if (!locked && lock) {
 613                 locked = 1;
 614                 lock_passwd = xstrdup(passwd);
 615                 success = 1;
 616         }
 617         memset(passwd, 0, strlen(passwd));
 618         xfree(passwd);
 619
 620         buffer_put_int(&e->output, 1);
 621         buffer_put_char(&e->output,
 622             success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
 623 }
 624
 625 static void
 626 no_identities(SocketEntry *e, u_int type)
 627 {
 628         Buffer msg;
 629
 630         buffer_init(&msg);
 631         buffer_put_char(&msg,
 632             (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
 633             SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
 634         buffer_put_int(&msg, 0);
 635         buffer_put_int(&e->output, buffer_len(&msg));
 636         buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
 637         buffer_free(&msg);
 638 }
 639
 640 #ifdef ENABLE_PKCS11
 641 static void
 642 process_add_smartcard_key(SocketEntry *e)
 643 {
 644         char *provider = NULL, *pin;
 645         int i, type, version, count = 0, success = 0, death = 0, confirm = 0;
 646         Key **keys = NULL, *k;
 647         Identity *id;
 648         Idtab *tab;
 649
 650         provider = buffer_get_string(&e->request, NULL);
 651         pin = buffer_get_string(&e->request, NULL);
 652
 653         while (buffer_len(&e->request)) {
 654                 switch ((type = buffer_get_char(&e->request))) {
 655                 case SSH_AGENT_CONSTRAIN_LIFETIME:
 656                         death = time(NULL) + buffer_get_int(&e->request);
 657                         break;
 658                 case SSH_AGENT_CONSTRAIN_CONFIRM:
 659                         confirm = 1;
 660                         break;
 661                 default:
 662                         error("process_add_smartcard_key: "
 663                             "Unknown constraint type %d", type);
 664                         goto send;
 665                 }
 666         }
 667         if (lifetime && !death)
 668                 death = time(NULL) + lifetime;
 669
 670         count = pkcs11_add_provider(provider, pin, &keys);
 671         for (i = 0; i < count; i++) {
 672                 k = keys[i];
 673                 version = k->type == KEY_RSA1 ? 1 : 2;
 674                 tab = idtab_lookup(version);
 675                 if (lookup_identity(k, version) == NULL) {
 676                         id = xcalloc(1, sizeof(Identity));
 677                         id->key = k;
 678                         id->provider = xstrdup(provider);
 679                         id->comment = xstrdup(provider); /* XXX */
 680                         id->death = death;
 681                         id->confirm = confirm;
 682                         TAILQ_INSERT_TAIL(&tab->idlist, id, next);
 683                         tab->nentries++;
 684                         success = 1;
 685                 } else {
 686                         key_free(k);
 687                 }
 688                 keys[i] = NULL;
 689         }
 690 send:
 691         if (pin)
 692                 xfree(pin);
 693         if (provider)
 694                 xfree(provider);
 695         if (keys)
 696                 xfree(keys);
 697         buffer_put_int(&e->output, 1);
 698         buffer_put_char(&e->output,
 699             success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
 700 }
 701
 702 static void
 703 process_remove_smartcard_key(SocketEntry *e)
 704 {
 705         char *provider = NULL, *pin = NULL;
 706         int version, success = 0;
 707         Identity *id, *nxt;
 708         Idtab *tab;
 709
 710         provider = buffer_get_string(&e->request, NULL);
 711         pin = buffer_get_string(&e->request, NULL);
 712         xfree(pin);
 713
 714         for (version = 1; version < 3; version++) {
 715                 tab = idtab_lookup(version);
 716                 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
 717                         nxt = TAILQ_NEXT(id, next);
 718                         if (!strcmp(provider, id->provider)) {
 719                                 TAILQ_REMOVE(&tab->idlist, id, next);
 720                                 free_identity(id);
 721                                 tab->nentries--;
 722                         }
 723                 }
 724         }
 725         if (pkcs11_del_provider(provider) == 0)
 726                 success = 1;
 727         else
 728                 error("process_remove_smartcard_key:"
 729                     " pkcs11_del_provider failed");
 730         xfree(provider);
 731         buffer_put_int(&e->output, 1);
 732         buffer_put_char(&e->output,
 733             success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
 734 }
 735 #endif /* ENABLE_PKCS11 */
 736
 737 /* dispatch incoming messages */
 738
 739 static void
 740 process_message(SocketEntry *e)
 741 {
 742         u_int msg_len, type;
 743         u_char *cp;
 744
 745         if (buffer_len(&e->input) < 5)
 746                 return;         /* Incomplete message. */
 747         cp = buffer_ptr(&e->input);
 748         msg_len = get_u32(cp);
 749         if (msg_len > 256 * 1024) {
 750                 close_socket(e);
 751                 return;
 752         }
 753         if (buffer_len(&e->input) < msg_len + 4)
 754                 return;
 755
 756         /* move the current input to e->request */
 757         buffer_consume(&e->input, 4);
 758         buffer_clear(&e->request);
 759         buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
 760         buffer_consume(&e->input, msg_len);
 761         type = buffer_get_char(&e->request);
 762
 763         /* check wheter agent is locked */
 764         if (locked && type != SSH_AGENTC_UNLOCK) {
 765                 buffer_clear(&e->request);
 766                 switch (type) {
 767                 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
 768                 case SSH2_AGENTC_REQUEST_IDENTITIES:
 769                         /* send empty lists */
 770                         no_identities(e, type);
 771                         break;
 772                 default:
 773                         /* send a fail message for all other request types */
 774                         buffer_put_int(&e->output, 1);
 775                         buffer_put_char(&e->output, SSH_AGENT_FAILURE);
 776                 }
 777                 return;
 778         }
 779
 780         debug("type %d", type);
 781         switch (type) {
 782         case SSH_AGENTC_LOCK:
 783         case SSH_AGENTC_UNLOCK:
 784                 process_lock_agent(e, type == SSH_AGENTC_LOCK);
 785                 break;
 786         /* ssh1 */
 787         case SSH_AGENTC_RSA_CHALLENGE:
 788                 process_authentication_challenge1(e);
 789                 break;
 790         case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
 791                 process_request_identities(e, 1);
 792                 break;
 793         case SSH_AGENTC_ADD_RSA_IDENTITY:
 794         case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
 795                 process_add_identity(e, 1);
 796                 break;
 797         case SSH_AGENTC_REMOVE_RSA_IDENTITY:
 798                 process_remove_identity(e, 1);
 799                 break;
 800         case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
 801                 process_remove_all_identities(e, 1);
 802                 break;
 803         /* ssh2 */
 804         case SSH2_AGENTC_SIGN_REQUEST:
 805                 process_sign_request2(e);
 806                 break;
 807         case SSH2_AGENTC_REQUEST_IDENTITIES:
 808                 process_request_identities(e, 2);
 809                 break;
 810         case SSH2_AGENTC_ADD_IDENTITY:
 811         case SSH2_AGENTC_ADD_ID_CONSTRAINED:
 812                 process_add_identity(e, 2);
 813                 break;
 814         case SSH2_AGENTC_REMOVE_IDENTITY:
 815                 process_remove_identity(e, 2);
 816                 break;
 817         case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
 818                 process_remove_all_identities(e, 2);
 819                 break;
 820 #ifdef ENABLE_PKCS11
 821         case SSH_AGENTC_ADD_SMARTCARD_KEY:
 822         case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
 823                 process_add_smartcard_key(e);
 824                 break;
 825         case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
 826                 process_remove_smartcard_key(e);
 827                 break;
 828 #endif /* ENABLE_PKCS11 */
 829         default:
 830                 /* Unknown message.  Respond with failure. */
 831                 error("Unknown message %d", type);
 832                 buffer_clear(&e->request);
 833                 buffer_put_int(&e->output, 1);
 834                 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
 835                 break;
 836         }
 837 }
 838
 839 static void
 840 new_socket(sock_type type, int fd)
 841 {
 842         u_int i, old_alloc, new_alloc;
 843
 844         set_nonblock(fd);
 845
 846         if (fd > max_fd)
 847                 max_fd = fd;
 848
 849         for (i = 0; i < sockets_alloc; i++)
 850                 if (sockets[i].type == AUTH_UNUSED) {
 851                         sockets[i].fd = fd;
 852                         buffer_init(&sockets[i].input);
 853                         buffer_init(&sockets[i].output);
 854                         buffer_init(&sockets[i].request);
 855                         sockets[i].type = type;
 856                         return;
 857                 }
 858         old_alloc = sockets_alloc;
 859         new_alloc = sockets_alloc + 10;
 860         sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0]));
 861         for (i = old_alloc; i < new_alloc; i++)
 862                 sockets[i].type = AUTH_UNUSED;
 863         sockets_alloc = new_alloc;
 864         sockets[old_alloc].fd = fd;
 865         buffer_init(&sockets[old_alloc].input);
 866         buffer_init(&sockets[old_alloc].output);
 867         buffer_init(&sockets[old_alloc].request);
 868         sockets[old_alloc].type = type;
 869 }
 870
 871 static int
 872 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
 873     struct timeval **tvpp)
 874 {
 875         u_int i, sz, deadline;
 876         int n = 0;
 877         static struct timeval tv;
 878
 879         for (i = 0; i < sockets_alloc; i++) {
 880                 switch (sockets[i].type) {
 881                 case AUTH_SOCKET:
 882                 case AUTH_CONNECTION:
 883                         n = MAX(n, sockets[i].fd);
 884                         break;
 885                 case AUTH_UNUSED:
 886                         break;
 887                 default:
 888                         fatal("Unknown socket type %d", sockets[i].type);
 889                         break;
 890                 }
 891         }
 892
 893         sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
 894         if (*fdrp == NULL || sz > *nallocp) {
 895                 if (*fdrp)
 896                         xfree(*fdrp);
 897                 if (*fdwp)
 898                         xfree(*fdwp);
 899                 *fdrp = xmalloc(sz);
 900                 *fdwp = xmalloc(sz);
 901                 *nallocp = sz;
 902         }
 903         if (n < *fdl)
 904                 debug("XXX shrink: %d < %d", n, *fdl);
 905         *fdl = n;
 906         memset(*fdrp, 0, sz);
 907         memset(*fdwp, 0, sz);
 908
 909         for (i = 0; i < sockets_alloc; i++) {
 910                 switch (sockets[i].type) {
 911                 case AUTH_SOCKET:
 912                 case AUTH_CONNECTION:
 913                         FD_SET(sockets[i].fd, *fdrp);
 914                         if (buffer_len(&sockets[i].output) > 0)
 915                                 FD_SET(sockets[i].fd, *fdwp);
 916                         break;
 917                 default:
 918                         break;
 919                 }
 920         }
 921         deadline = reaper();
 922         if (parent_alive_interval != 0)
 923                 deadline = (deadline == 0) ? parent_alive_interval :
 924                     MIN(deadline, parent_alive_interval);
 925         if (deadline == 0) {
 926                 *tvpp = NULL;
 927         } else {
 928                 tv.tv_sec = deadline;
 929                 tv.tv_usec = 0;
 930                 *tvpp = &tv;
 931         }
 932         return (1);
 933 }
 934
 935 static void
 936 after_select(fd_set *readset, fd_set *writeset)
 937 {
 938         struct sockaddr_un sunaddr;
 939         socklen_t slen;
 940         char buf[1024];
 941         int len, sock;
 942         u_int i, orig_alloc;
 943         uid_t euid;
 944         gid_t egid;
 945
 946         for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++)
 947                 switch (sockets[i].type) {
 948                 case AUTH_UNUSED:
 949                         break;
 950                 case AUTH_SOCKET:
 951                         if (FD_ISSET(sockets[i].fd, readset)) {
 952                                 slen = sizeof(sunaddr);
 953                                 sock = accept(sockets[i].fd,
 954                                     (struct sockaddr *)&sunaddr, &slen);
 955                                 if (sock < 0) {
 956                                         error("accept from AUTH_SOCKET: %s",
 957                                             strerror(errno));
 958                                         break;
 959                                 }
 960                                 if (getpeereid(sock, &euid, &egid) < 0) {
 961                                         error("getpeereid %d failed: %s",
 962                                             sock, strerror(errno));
 963                                         close(sock);
 964                                         break;
 965                                 }
 966                                 if ((euid != 0) && (getuid() != euid)) {
 967                                         error("uid mismatch: "
 968                                             "peer euid %u != uid %u",
 969                                             (u_int) euid, (u_int) getuid());
 970                                         close(sock);
 971                                         break;
 972                                 }
 973                                 new_socket(AUTH_CONNECTION, sock);
 974                         }
 975                         break;
 976                 case AUTH_CONNECTION:
 977                         if (buffer_len(&sockets[i].output) > 0 &&
 978                             FD_ISSET(sockets[i].fd, writeset)) {
 979                                 len = write(sockets[i].fd,
 980                                     buffer_ptr(&sockets[i].output),
 981                                     buffer_len(&sockets[i].output));
 982                                 if (len == -1 && (errno == EAGAIN ||
 983                                     errno == EWOULDBLOCK ||
 984                                     errno == EINTR))
 985                                         continue;
 986                                 if (len <= 0) {
 987                                         close_socket(&sockets[i]);
 988                                         break;
 989                                 }
 990                                 buffer_consume(&sockets[i].output, len);
 991                         }
 992                         if (FD_ISSET(sockets[i].fd, readset)) {
 993                                 len = read(sockets[i].fd, buf, sizeof(buf));
 994                                 if (len == -1 && (errno == EAGAIN ||
 995                                     errno == EWOULDBLOCK ||
 996                                     errno == EINTR))
 997                                         continue;
 998                                 if (len <= 0) {
 999                                         close_socket(&sockets[i]);
1000                                         break;
1001                                 }
1002                                 buffer_append(&sockets[i].input, buf, len);
1003                                 process_message(&sockets[i]);
1004                         }
1005                         break;
1006                 default:
1007                         fatal("Unknown type %d", sockets[i].type);
1008                 }
1009 }
1010
1011 static void
1012 cleanup_socket(void)
1013 {
1014         if (socket_name[0])
1015                 unlink(socket_name);
1016         if (socket_dir[0])
1017                 rmdir(socket_dir);
1018 }
1019
1020 void
1021 cleanup_exit(int i)
1022 {
1023         cleanup_socket();
1024         _exit(i);
1025 }
1026
1027 /*ARGSUSED*/
1028 static void
1029 cleanup_handler(int sig)
1030 {
1031         cleanup_socket();
1032 #ifdef ENABLE_PKCS11
1033         pkcs11_terminate();
1034 #endif
1035         _exit(2);
1036 }
1037
1038 static void
1039 check_parent_exists(void)
1040 {
1041         if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
1042                 /* printf("Parent has died - Authentication agent exiting.\n"); */
1043                 cleanup_socket();
1044                 _exit(2);
1045         }
1046 }
1047
1048 static void
1049 usage(void)
1050 {
1051         fprintf(stderr, "usage: %s [options] [command [arg ...]]\n",
1052             __progname);
1053         fprintf(stderr, "Options:\n");
1054         fprintf(stderr, "  -c          Generate C-shell commands on stdout.\n");
1055         fprintf(stderr, "  -s          Generate Bourne shell commands on stdout.\n");
1056         fprintf(stderr, "  -k          Kill the current agent.\n");
1057         fprintf(stderr, "  -d          Debug mode.\n");
1058         fprintf(stderr, "  -a socket   Bind agent socket to given name.\n");
1059         fprintf(stderr, "  -t life     Default identity lifetime (seconds).\n");
1060         exit(1);
1061 }
1062
1063 int
1064 main(int ac, char **av)
1065 {
1066         int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
1067         int sock, fd, ch, result, saved_errno;
1068         u_int nalloc;
1069         char *shell, *format, *pidstr, *agentsocket = NULL;
1070         fd_set *readsetp = NULL, *writesetp = NULL;
1071         struct sockaddr_un sunaddr;
1072 #ifdef HAVE_SETRLIMIT
1073         struct rlimit rlim;
1074 #endif
1075         int prev_mask;
1076         extern int optind;
1077         extern char *optarg;
1078         pid_t pid;
1079         char pidstrbuf[1 + 3 * sizeof pid];
1080         struct timeval *tvp = NULL;
1081         size_t len;
1082
1083         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1084         sanitise_stdfd();
1085
1086         /* drop */
1087         setegid(getgid());
1088         setgid(getgid());
1089         setuid(geteuid());
1090
1091 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1092         /* Disable ptrace on Linux without sgid bit */
1093         prctl(PR_SET_DUMPABLE, 0);
1094 #endif
1095
1096         SSLeay_add_all_algorithms();
1097
1098         __progname = ssh_get_progname(av[0]);
1099         init_rng();
1100         seed_rng();
1101
1102         while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
1103                 switch (ch) {
1104                 case 'c':
1105                         if (s_flag)
1106                                 usage();
1107                         c_flag++;
1108                         break;
1109                 case 'k':
1110                         k_flag++;
1111                         break;
1112                 case 's':
1113                         if (c_flag)
1114                                 usage();
1115                         s_flag++;
1116                         break;
1117                 case 'd':
1118                         if (d_flag)
1119                                 usage();
1120                         d_flag++;
1121                         break;
1122                 case 'a':
1123                         agentsocket = optarg;
1124                         break;
1125                 case 't':
1126                         if ((lifetime = convtime(optarg)) == -1) {
1127                                 fprintf(stderr, "Invalid lifetime\n");
1128                                 usage();
1129                         }
1130                         break;
1131                 default:
1132                         usage();
1133                 }
1134         }
1135         ac -= optind;
1136         av += optind;
1137
1138         if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1139                 usage();
1140
1141         if (ac == 0 && !c_flag && !s_flag) {
1142                 shell = getenv("SHELL");
1143                 if (shell != NULL && (len = strlen(shell)) > 2 &&
1144                     strncmp(shell + len - 3, "csh", 3) == 0)
1145                         c_flag = 1;
1146         }
1147         if (k_flag) {
1148                 const char *errstr = NULL;
1149
1150                 pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1151                 if (pidstr == NULL) {
1152                         fprintf(stderr, "%s not set, cannot kill agent\n",
1153                             SSH_AGENTPID_ENV_NAME);
1154                         exit(1);
1155                 }
1156                 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1157                 if (errstr) {
1158                         fprintf(stderr,
1159                             "%s=\"%s\", which is not a good PID: %s\n",
1160                             SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1161                         exit(1);
1162                 }
1163                 if (kill(pid, SIGTERM) == -1) {
1164                         perror("kill");
1165                         exit(1);
1166                 }
1167                 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1168                 printf(format, SSH_AUTHSOCKET_ENV_NAME);
1169                 printf(format, SSH_AGENTPID_ENV_NAME);
1170                 printf("echo Agent pid %ld killed;\n", (long)pid);
1171                 exit(0);
1172         }
1173         parent_pid = getpid();
1174
1175         if (agentsocket == NULL) {
1176                 /* Create private directory for agent socket */
1177                 strlcpy(socket_dir, "/tmp/ssh-XXXXXXXXXX", sizeof socket_dir);
1178                 if (mkdtemp(socket_dir) == NULL) {
1179                         perror("mkdtemp: private socket dir");
1180                         exit(1);
1181                 }
1182                 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1183                     (long)parent_pid);
1184         } else {
1185                 /* Try to use specified agent socket */
1186                 socket_dir[0] = '\0';
1187                 strlcpy(socket_name, agentsocket, sizeof socket_name);
1188         }
1189
1190         /*
1191          * Create socket early so it will exist before command gets run from
1192          * the parent.
1193          */
1194         sock = socket(AF_UNIX, SOCK_STREAM, 0);
1195         if (sock < 0) {
1196                 perror("socket");
1197                 *socket_name = '\0'; /* Don't unlink any existing file */
1198                 cleanup_exit(1);
1199         }
1200         memset(&sunaddr, 0, sizeof(sunaddr));
1201         sunaddr.sun_family = AF_UNIX;
1202         strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
1203         prev_mask = umask(0177);
1204         if (bind(sock, (struct sockaddr *) &sunaddr, sizeof(sunaddr)) < 0) {
1205                 perror("bind");
1206                 *socket_name = '\0'; /* Don't unlink any existing file */
1207                 umask(prev_mask);
1208                 cleanup_exit(1);
1209         }
1210         umask(prev_mask);
1211         if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1212                 perror("listen");
1213                 cleanup_exit(1);
1214         }
1215
1216         /*
1217          * Fork, and have the parent execute the command, if any, or present
1218          * the socket data.  The child continues as the authentication agent.
1219          */
1220         if (d_flag) {
1221                 log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
1222                 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1223                 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1224                     SSH_AUTHSOCKET_ENV_NAME);
1225                 printf("echo Agent pid %ld;\n", (long)parent_pid);
1226                 goto skip;
1227         }
1228         pid = fork();
1229         if (pid == -1) {
1230                 perror("fork");
1231                 cleanup_exit(1);
1232         }
1233         if (pid != 0) {         /* Parent - execute the given command. */
1234                 close(sock);
1235                 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1236                 if (ac == 0) {
1237                         format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1238                         printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1239                             SSH_AUTHSOCKET_ENV_NAME);
1240                         printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1241                             SSH_AGENTPID_ENV_NAME);
1242                         printf("echo Agent pid %ld;\n", (long)pid);
1243                         exit(0);
1244                 }
1245                 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1246                     setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1247                         perror("setenv");
1248                         exit(1);
1249                 }
1250                 execvp(av[0], av);
1251                 perror(av[0]);
1252                 exit(1);
1253         }
1254         /* child */
1255         log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1256
1257         if (setsid() == -1) {
1258                 error("setsid: %s", strerror(errno));
1259                 cleanup_exit(1);
1260         }
1261
1262         (void)chdir("/");
1263         if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1264                 /* XXX might close listen socket */
1265                 (void)dup2(fd, STDIN_FILENO);
1266                 (void)dup2(fd, STDOUT_FILENO);
1267                 (void)dup2(fd, STDERR_FILENO);
1268                 if (fd > 2)
1269                         close(fd);
1270         }
1271
1272 #ifdef HAVE_SETRLIMIT
1273         /* deny core dumps, since memory contains unencrypted private keys */
1274         rlim.rlim_cur = rlim.rlim_max = 0;
1275         if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1276                 error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1277                 cleanup_exit(1);
1278         }
1279 #endif
1280
1281 skip:
1282
1283 #ifdef ENABLE_PKCS11
1284         pkcs11_init(0);
1285 #endif
1286         new_socket(AUTH_SOCKET, sock);
1287         if (ac > 0)
1288                 parent_alive_interval = 10;
1289         idtab_init();
1290         if (!d_flag)
1291                 signal(SIGINT, SIG_IGN);
1292         signal(SIGPIPE, SIG_IGN);
1293         signal(SIGHUP, cleanup_handler);
1294         signal(SIGTERM, cleanup_handler);
1295         nalloc = 0;
1296
1297         while (1) {
1298                 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp);
1299                 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp);
1300                 saved_errno = errno;
1301                 if (parent_alive_interval != 0)
1302                         check_parent_exists();
1303                 (void) reaper();        /* remove expired keys */
1304                 if (result < 0) {
1305                         if (saved_errno == EINTR)
1306                                 continue;
1307                         fatal("select: %s", strerror(saved_errno));
1308                 } else if (result > 0)
1309                         after_select(readsetp, writesetp);
1310         }
1311         /* NOTREACHED */
1312 }