monitor.c

   1 /* $OpenBSD: monitor.c,v 1.86 2006/08/04 20:46:05 stevesk Exp $ */
   2 /*
   3  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
   4  * Copyright 2002 Markus Friedl <markus@openbsd.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "includes.h"
  29
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32 #include <sys/socket.h>
  33 #include "openbsd-compat/sys-tree.h"
  34 #include <sys/wait.h>
  35
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #ifdef HAVE_PATHS_H
  39 #include <paths.h>
  40 #endif
  41 #include <pwd.h>
  42 #include <signal.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 #ifdef SKEY
  47 #include <skey.h>
  48 #endif
  49
  50 #include <openssl/dh.h>
  51
  52 #include "xmalloc.h"
  53 #include "ssh.h"
  54 #include "key.h"
  55 #include "buffer.h"
  56 #include "hostfile.h"
  57 #include "auth.h"
  58 #include "cipher.h"
  59 #include "kex.h"
  60 #include "dh.h"
  61 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
  62 #undef TARGET_OS_MAC
  63 #include "zlib.h"
  64 #define TARGET_OS_MAC 1
  65 #else
  66 #include "zlib.h"
  67 #endif
  68 #include "packet.h"
  69 #include "auth-options.h"
  70 #include "sshpty.h"
  71 #include "channels.h"
  72 #include "session.h"
  73 #include "sshlogin.h"
  74 #include "canohost.h"
  75 #include "log.h"
  76 #include "servconf.h"
  77 #include "monitor.h"
  78 #include "monitor_mm.h"
  79 #ifdef GSSAPI
  80 #include "ssh-gss.h"
  81 #endif
  82 #include "monitor_wrap.h"
  83 #include "monitor_fdpass.h"
  84 #include "misc.h"
  85 #include "compat.h"
  86 #include "ssh2.h"
  87
  88 #ifdef GSSAPI
  89 static Gssctxt *gsscontext = NULL;
  90 #endif
  91
  92 /* Imports */
  93 extern ServerOptions options;
  94 extern u_int utmp_len;
  95 extern Newkeys *current_keys[];
  96 extern z_stream incoming_stream;
  97 extern z_stream outgoing_stream;
  98 extern u_char session_id[];
  99 extern Buffer input, output;
 100 extern Buffer auth_debug;
 101 extern int auth_debug_init;
 102 extern Buffer loginmsg;
 103
 104 /* State exported from the child */
 105
 106 struct {
 107         z_stream incoming;
 108         z_stream outgoing;
 109         u_char *keyin;
 110         u_int keyinlen;
 111         u_char *keyout;
 112         u_int keyoutlen;
 113         u_char *ivin;
 114         u_int ivinlen;
 115         u_char *ivout;
 116         u_int ivoutlen;
 117         u_char *ssh1key;
 118         u_int ssh1keylen;
 119         int ssh1cipher;
 120         int ssh1protoflags;
 121         u_char *input;
 122         u_int ilen;
 123         u_char *output;
 124         u_int olen;
 125 } child_state;
 126
 127 /* Functions on the monitor that answer unprivileged requests */
 128
 129 int mm_answer_moduli(int, Buffer *);
 130 int mm_answer_sign(int, Buffer *);
 131 int mm_answer_pwnamallow(int, Buffer *);
 132 int mm_answer_auth2_read_banner(int, Buffer *);
 133 int mm_answer_authserv(int, Buffer *);
 134 int mm_answer_authpassword(int, Buffer *);
 135 int mm_answer_bsdauthquery(int, Buffer *);
 136 int mm_answer_bsdauthrespond(int, Buffer *);
 137 int mm_answer_skeyquery(int, Buffer *);
 138 int mm_answer_skeyrespond(int, Buffer *);
 139 int mm_answer_keyallowed(int, Buffer *);
 140 int mm_answer_keyverify(int, Buffer *);
 141 int mm_answer_pty(int, Buffer *);
 142 int mm_answer_pty_cleanup(int, Buffer *);
 143 int mm_answer_term(int, Buffer *);
 144 int mm_answer_rsa_keyallowed(int, Buffer *);
 145 int mm_answer_rsa_challenge(int, Buffer *);
 146 int mm_answer_rsa_response(int, Buffer *);
 147 int mm_answer_sesskey(int, Buffer *);
 148 int mm_answer_sessid(int, Buffer *);
 149
 150 #ifdef USE_PAM
 151 int mm_answer_pam_start(int, Buffer *);
 152 int mm_answer_pam_account(int, Buffer *);
 153 int mm_answer_pam_init_ctx(int, Buffer *);
 154 int mm_answer_pam_query(int, Buffer *);
 155 int mm_answer_pam_respond(int, Buffer *);
 156 int mm_answer_pam_free_ctx(int, Buffer *);
 157 #endif
 158
 159 #ifdef GSSAPI
 160 int mm_answer_gss_setup_ctx(int, Buffer *);
 161 int mm_answer_gss_accept_ctx(int, Buffer *);
 162 int mm_answer_gss_userok(int, Buffer *);
 163 int mm_answer_gss_checkmic(int, Buffer *);
 164 #endif
 165
 166 #ifdef SSH_AUDIT_EVENTS
 167 int mm_answer_audit_event(int, Buffer *);
 168 int mm_answer_audit_command(int, Buffer *);
 169 #endif
 170
 171 static Authctxt *authctxt;
 172 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 173
 174 /* local state for key verify */
 175 static u_char *key_blob = NULL;
 176 static u_int key_bloblen = 0;
 177 static int key_blobtype = MM_NOKEY;
 178 static char *hostbased_cuser = NULL;
 179 static char *hostbased_chost = NULL;
 180 static char *auth_method = "unknown";
 181 static u_int session_id2_len = 0;
 182 static u_char *session_id2 = NULL;
 183 static pid_t monitor_child_pid;
 184
 185 struct mon_table {
 186         enum monitor_reqtype type;
 187         int flags;
 188         int (*f)(int, Buffer *);
 189 };
 190
 191 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 192 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 193 #define MON_ONCE        0x0010  /* Disable after calling */
 194 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 195
 196 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 197
 198 #define MON_PERMIT      0x1000  /* Request is permitted */
 199
 200 struct mon_table mon_dispatch_proto20[] = {
 201     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 202     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 203     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 204     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 205     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 206     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 207 #ifdef USE_PAM
 208     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 209     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 210     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 211     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 212     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 213     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 214 #endif
 215 #ifdef SSH_AUDIT_EVENTS
 216     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 217 #endif
 218 #ifdef BSD_AUTH
 219     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 220     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 221 #endif
 222 #ifdef SKEY
 223     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 224     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 225 #endif
 226     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 227     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 228 #ifdef GSSAPI
 229     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 230     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 231     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 232     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 233 #endif
 234     {0, 0, NULL}
 235 };
 236
 237 struct mon_table mon_dispatch_postauth20[] = {
 238     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 239     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 240     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 241     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 242     {MONITOR_REQ_TERM, 0, mm_answer_term},
 243 #ifdef SSH_AUDIT_EVENTS
 244     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 245     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 246 #endif
 247     {0, 0, NULL}
 248 };
 249
 250 struct mon_table mon_dispatch_proto15[] = {
 251     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 252     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 253     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 254     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 255     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 256     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 257     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 258     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 259 #ifdef BSD_AUTH
 260     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 261     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 262 #endif
 263 #ifdef SKEY
 264     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 265     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 266 #endif
 267 #ifdef USE_PAM
 268     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 269     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 270     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 271     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 272     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 273     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 274 #endif
 275 #ifdef SSH_AUDIT_EVENTS
 276     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 277 #endif
 278     {0, 0, NULL}
 279 };
 280
 281 struct mon_table mon_dispatch_postauth15[] = {
 282     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 283     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 284     {MONITOR_REQ_TERM, 0, mm_answer_term},
 285 #ifdef SSH_AUDIT_EVENTS
 286     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 287     {MONITOR_REQ_AUDIT_COMMAND, MON_ONCE, mm_answer_audit_command},
 288 #endif
 289     {0, 0, NULL}
 290 };
 291
 292 struct mon_table *mon_dispatch;
 293
 294 /* Specifies if a certain message is allowed at the moment */
 295
 296 static void
 297 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 298 {
 299         while (ent->f != NULL) {
 300                 if (ent->type == type) {
 301                         ent->flags &= ~MON_PERMIT;
 302                         ent->flags |= permit ? MON_PERMIT : 0;
 303                         return;
 304                 }
 305                 ent++;
 306         }
 307 }
 308
 309 static void
 310 monitor_permit_authentications(int permit)
 311 {
 312         struct mon_table *ent = mon_dispatch;
 313
 314         while (ent->f != NULL) {
 315                 if (ent->flags & MON_AUTH) {
 316                         ent->flags &= ~MON_PERMIT;
 317                         ent->flags |= permit ? MON_PERMIT : 0;
 318                 }
 319                 ent++;
 320         }
 321 }
 322
 323 void
 324 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 325 {
 326         struct mon_table *ent;
 327         int authenticated = 0;
 328
 329         debug3("preauth child monitor started");
 330
 331         authctxt = _authctxt;
 332         memset(authctxt, 0, sizeof(*authctxt));
 333
 334         authctxt->loginmsg = &loginmsg;
 335
 336         if (compat20) {
 337                 mon_dispatch = mon_dispatch_proto20;
 338
 339                 /* Permit requests for moduli and signatures */
 340                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 341                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 342         } else {
 343                 mon_dispatch = mon_dispatch_proto15;
 344
 345                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 346         }
 347
 348         /* The first few requests do not require asynchronous access */
 349         while (!authenticated) {
 350                 auth_method = "unknown";
 351                 authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
 352                 if (authenticated) {
 353                         if (!(ent->flags & MON_AUTHDECIDE))
 354                                 fatal("%s: unexpected authentication from %d",
 355                                     __func__, ent->type);
 356                         if (authctxt->pw->pw_uid == 0 &&
 357                             !auth_root_allowed(auth_method))
 358                                 authenticated = 0;
 359 #ifdef USE_PAM
 360                         /* PAM needs to perform account checks after auth */
 361                         if (options.use_pam && authenticated) {
 362                                 Buffer m;
 363
 364                                 buffer_init(&m);
 365                                 mm_request_receive_expect(pmonitor->m_sendfd,
 366                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 367                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 368                                 buffer_free(&m);
 369                         }
 370 #endif
 371                 }
 372
 373                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 374                         auth_log(authctxt, authenticated, auth_method,
 375                             compat20 ? " ssh2" : "");
 376                         if (!authenticated)
 377                                 authctxt->failures++;
 378                 }
 379         }
 380
 381         if (!authctxt->valid)
 382                 fatal("%s: authenticated invalid user", __func__);
 383         if (strcmp(auth_method, "unknown") == 0)
 384                 fatal("%s: authentication method name unknown", __func__);
 385
 386         debug("%s: %s has been authenticated by privileged process",
 387             __func__, authctxt->user);
 388
 389         mm_get_keystate(pmonitor);
 390 }
 391
 392 static void
 393 monitor_set_child_handler(pid_t pid)
 394 {
 395         monitor_child_pid = pid;
 396 }
 397
 398 static void
 399 monitor_child_handler(int sig)
 400 {
 401         kill(monitor_child_pid, sig);
 402 }
 403
 404 void
 405 monitor_child_postauth(struct monitor *pmonitor)
 406 {
 407         monitor_set_child_handler(pmonitor->m_pid);
 408         signal(SIGHUP, &monitor_child_handler);
 409         signal(SIGTERM, &monitor_child_handler);
 410
 411         if (compat20) {
 412                 mon_dispatch = mon_dispatch_postauth20;
 413
 414                 /* Permit requests for moduli and signatures */
 415                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 416                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 417                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 418         } else {
 419                 mon_dispatch = mon_dispatch_postauth15;
 420                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 421         }
 422         if (!no_pty_flag) {
 423                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 424                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 425         }
 426
 427         for (;;)
 428                 monitor_read(pmonitor, mon_dispatch, NULL);
 429 }
 430
 431 void
 432 monitor_sync(struct monitor *pmonitor)
 433 {
 434         if (options.compression) {
 435                 /* The member allocation is not visible, so sync it */
 436                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 437         }
 438 }
 439
 440 int
 441 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 442     struct mon_table **pent)
 443 {
 444         Buffer m;
 445         int ret;
 446         u_char type;
 447
 448         buffer_init(&m);
 449
 450         mm_request_receive(pmonitor->m_sendfd, &m);
 451         type = buffer_get_char(&m);
 452
 453         debug3("%s: checking request %d", __func__, type);
 454
 455         while (ent->f != NULL) {
 456                 if (ent->type == type)
 457                         break;
 458                 ent++;
 459         }
 460
 461         if (ent->f != NULL) {
 462                 if (!(ent->flags & MON_PERMIT))
 463                         fatal("%s: unpermitted request %d", __func__,
 464                             type);
 465                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 466                 buffer_free(&m);
 467
 468                 /* The child may use this request only once, disable it */
 469                 if (ent->flags & MON_ONCE) {
 470                         debug2("%s: %d used once, disabling now", __func__,
 471                             type);
 472                         ent->flags &= ~MON_PERMIT;
 473                 }
 474
 475                 if (pent != NULL)
 476                         *pent = ent;
 477
 478                 return ret;
 479         }
 480
 481         fatal("%s: unsupported request: %d", __func__, type);
 482
 483         /* NOTREACHED */
 484         return (-1);
 485 }
 486
 487 /* allowed key state */
 488 static int
 489 monitor_allowed_key(u_char *blob, u_int bloblen)
 490 {
 491         /* make sure key is allowed */
 492         if (key_blob == NULL || key_bloblen != bloblen ||
 493             memcmp(key_blob, blob, key_bloblen))
 494                 return (0);
 495         return (1);
 496 }
 497
 498 static void
 499 monitor_reset_key_state(void)
 500 {
 501         /* reset state */
 502         if (key_blob != NULL)
 503                 xfree(key_blob);
 504         if (hostbased_cuser != NULL)
 505                 xfree(hostbased_cuser);
 506         if (hostbased_chost != NULL)
 507                 xfree(hostbased_chost);
 508         key_blob = NULL;
 509         key_bloblen = 0;
 510         key_blobtype = MM_NOKEY;
 511         hostbased_cuser = NULL;
 512         hostbased_chost = NULL;
 513 }
 514
 515 int
 516 mm_answer_moduli(int sock, Buffer *m)
 517 {
 518         DH *dh;
 519         int min, want, max;
 520
 521         min = buffer_get_int(m);
 522         want = buffer_get_int(m);
 523         max = buffer_get_int(m);
 524
 525         debug3("%s: got parameters: %d %d %d",
 526             __func__, min, want, max);
 527         /* We need to check here, too, in case the child got corrupted */
 528         if (max < min || want < min || max < want)
 529                 fatal("%s: bad parameters: %d %d %d",
 530                     __func__, min, want, max);
 531
 532         buffer_clear(m);
 533
 534         dh = choose_dh(min, want, max);
 535         if (dh == NULL) {
 536                 buffer_put_char(m, 0);
 537                 return (0);
 538         } else {
 539                 /* Send first bignum */
 540                 buffer_put_char(m, 1);
 541                 buffer_put_bignum2(m, dh->p);
 542                 buffer_put_bignum2(m, dh->g);
 543
 544                 DH_free(dh);
 545         }
 546         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 547         return (0);
 548 }
 549
 550 int
 551 mm_answer_sign(int sock, Buffer *m)
 552 {
 553         Key *key;
 554         u_char *p;
 555         u_char *signature;
 556         u_int siglen, datlen;
 557         int keyid;
 558
 559         debug3("%s", __func__);
 560
 561         keyid = buffer_get_int(m);
 562         p = buffer_get_string(m, &datlen);
 563
 564         /*
 565          * Supported KEX types will only return SHA1 (20 byte) or
 566          * SHA256 (32 byte) hashes
 567          */
 568         if (datlen != 20 && datlen != 32)
 569                 fatal("%s: data length incorrect: %u", __func__, datlen);
 570
 571         /* save session id, it will be passed on the first call */
 572         if (session_id2_len == 0) {
 573                 session_id2_len = datlen;
 574                 session_id2 = xmalloc(session_id2_len);
 575                 memcpy(session_id2, p, session_id2_len);
 576         }
 577
 578         if ((key = get_hostkey_by_index(keyid)) == NULL)
 579                 fatal("%s: no hostkey from index %d", __func__, keyid);
 580         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 581                 fatal("%s: key_sign failed", __func__);
 582
 583         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 584
 585         buffer_clear(m);
 586         buffer_put_string(m, signature, siglen);
 587
 588         xfree(p);
 589         xfree(signature);
 590
 591         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 592
 593         /* Turn on permissions for getpwnam */
 594         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 595
 596         return (0);
 597 }
 598
 599 /* Retrieves the password entry and also checks if the user is permitted */
 600
 601 int
 602 mm_answer_pwnamallow(int sock, Buffer *m)
 603 {
 604         char *username;
 605         struct passwd *pwent;
 606         int allowed = 0;
 607
 608         debug3("%s", __func__);
 609
 610         if (authctxt->attempt++ != 0)
 611                 fatal("%s: multiple attempts for getpwnam", __func__);
 612
 613         username = buffer_get_string(m, NULL);
 614
 615         pwent = getpwnamallow(username);
 616
 617         authctxt->user = xstrdup(username);
 618         setproctitle("%s [priv]", pwent ? username : "unknown");
 619         xfree(username);
 620
 621         buffer_clear(m);
 622
 623         if (pwent == NULL) {
 624                 buffer_put_char(m, 0);
 625                 authctxt->pw = fakepw();
 626                 goto out;
 627         }
 628
 629         allowed = 1;
 630         authctxt->pw = pwent;
 631         authctxt->valid = 1;
 632
 633         buffer_put_char(m, 1);
 634         buffer_put_string(m, pwent, sizeof(struct passwd));
 635         buffer_put_cstring(m, pwent->pw_name);
 636         buffer_put_cstring(m, "*");
 637         buffer_put_cstring(m, pwent->pw_gecos);
 638 #ifdef HAVE_PW_CLASS_IN_PASSWD
 639         buffer_put_cstring(m, pwent->pw_class);
 640 #endif
 641         buffer_put_cstring(m, pwent->pw_dir);
 642         buffer_put_cstring(m, pwent->pw_shell);
 643
 644  out:
 645         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 646         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 647
 648         /* For SSHv1 allow authentication now */
 649         if (!compat20)
 650                 monitor_permit_authentications(1);
 651         else {
 652                 /* Allow service/style information on the auth context */
 653                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 654                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 655         }
 656
 657 #ifdef USE_PAM
 658         if (options.use_pam)
 659                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 660 #endif
 661 #ifdef SSH_AUDIT_EVENTS
 662         monitor_permit(mon_dispatch, MONITOR_REQ_AUDIT_COMMAND, 1);
 663 #endif
 664
 665         return (0);
 666 }
 667
 668 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 669 {
 670         char *banner;
 671
 672         buffer_clear(m);
 673         banner = auth2_read_banner();
 674         buffer_put_cstring(m, banner != NULL ? banner : "");
 675         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 676
 677         if (banner != NULL)
 678                 xfree(banner);
 679
 680         return (0);
 681 }
 682
 683 int
 684 mm_answer_authserv(int sock, Buffer *m)
 685 {
 686         monitor_permit_authentications(1);
 687
 688         authctxt->service = buffer_get_string(m, NULL);
 689         authctxt->style = buffer_get_string(m, NULL);
 690         debug3("%s: service=%s, style=%s",
 691             __func__, authctxt->service, authctxt->style);
 692
 693         if (strlen(authctxt->style) == 0) {
 694                 xfree(authctxt->style);
 695                 authctxt->style = NULL;
 696         }
 697
 698         return (0);
 699 }
 700
 701 int
 702 mm_answer_authpassword(int sock, Buffer *m)
 703 {
 704         static int call_count;
 705         char *passwd;
 706         int authenticated;
 707         u_int plen;
 708
 709         passwd = buffer_get_string(m, &plen);
 710         /* Only authenticate if the context is valid */
 711         authenticated = options.password_authentication &&
 712             auth_password(authctxt, passwd);
 713         memset(passwd, 0, strlen(passwd));
 714         xfree(passwd);
 715
 716         buffer_clear(m);
 717         buffer_put_int(m, authenticated);
 718
 719         debug3("%s: sending result %d", __func__, authenticated);
 720         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 721
 722         call_count++;
 723         if (plen == 0 && call_count == 1)
 724                 auth_method = "none";
 725         else
 726                 auth_method = "password";
 727
 728         /* Causes monitor loop to terminate if authenticated */
 729         return (authenticated);
 730 }
 731
 732 #ifdef BSD_AUTH
 733 int
 734 mm_answer_bsdauthquery(int sock, Buffer *m)
 735 {
 736         char *name, *infotxt;
 737         u_int numprompts;
 738         u_int *echo_on;
 739         char **prompts;
 740         u_int success;
 741
 742         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 743             &prompts, &echo_on) < 0 ? 0 : 1;
 744
 745         buffer_clear(m);
 746         buffer_put_int(m, success);
 747         if (success)
 748                 buffer_put_cstring(m, prompts[0]);
 749
 750         debug3("%s: sending challenge success: %u", __func__, success);
 751         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 752
 753         if (success) {
 754                 xfree(name);
 755                 xfree(infotxt);
 756                 xfree(prompts);
 757                 xfree(echo_on);
 758         }
 759
 760         return (0);
 761 }
 762
 763 int
 764 mm_answer_bsdauthrespond(int sock, Buffer *m)
 765 {
 766         char *response;
 767         int authok;
 768
 769         if (authctxt->as == 0)
 770                 fatal("%s: no bsd auth session", __func__);
 771
 772         response = buffer_get_string(m, NULL);
 773         authok = options.challenge_response_authentication &&
 774             auth_userresponse(authctxt->as, response, 0);
 775         authctxt->as = NULL;
 776         debug3("%s: <%s> = <%d>", __func__, response, authok);
 777         xfree(response);
 778
 779         buffer_clear(m);
 780         buffer_put_int(m, authok);
 781
 782         debug3("%s: sending authenticated: %d", __func__, authok);
 783         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 784
 785         auth_method = "bsdauth";
 786
 787         return (authok != 0);
 788 }
 789 #endif
 790
 791 #ifdef SKEY
 792 int
 793 mm_answer_skeyquery(int sock, Buffer *m)
 794 {
 795         struct skey skey;
 796         char challenge[1024];
 797         u_int success;
 798
 799         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 800             sizeof(challenge)) < 0 ? 0 : 1;
 801
 802         buffer_clear(m);
 803         buffer_put_int(m, success);
 804         if (success)
 805                 buffer_put_cstring(m, challenge);
 806
 807         debug3("%s: sending challenge success: %u", __func__, success);
 808         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 809
 810         return (0);
 811 }
 812
 813 int
 814 mm_answer_skeyrespond(int sock, Buffer *m)
 815 {
 816         char *response;
 817         int authok;
 818
 819         response = buffer_get_string(m, NULL);
 820
 821         authok = (options.challenge_response_authentication &&
 822             authctxt->valid &&
 823             skey_haskey(authctxt->pw->pw_name) == 0 &&
 824             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 825
 826         xfree(response);
 827
 828         buffer_clear(m);
 829         buffer_put_int(m, authok);
 830
 831         debug3("%s: sending authenticated: %d", __func__, authok);
 832         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 833
 834         auth_method = "skey";
 835
 836         return (authok != 0);
 837 }
 838 #endif
 839
 840 #ifdef USE_PAM
 841 int
 842 mm_answer_pam_start(int sock, Buffer *m)
 843 {
 844         if (!options.use_pam)
 845                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 846
 847         start_pam(authctxt);
 848
 849         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 850
 851         return (0);
 852 }
 853
 854 int
 855 mm_answer_pam_account(int sock, Buffer *m)
 856 {
 857         u_int ret;
 858
 859         if (!options.use_pam)
 860                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 861
 862         ret = do_pam_account();
 863
 864         buffer_put_int(m, ret);
 865         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 866
 867         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 868
 869         return (ret);
 870 }
 871
 872 static void *sshpam_ctxt, *sshpam_authok;
 873 extern KbdintDevice sshpam_device;
 874
 875 int
 876 mm_answer_pam_init_ctx(int sock, Buffer *m)
 877 {
 878
 879         debug3("%s", __func__);
 880         authctxt->user = buffer_get_string(m, NULL);
 881         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 882         sshpam_authok = NULL;
 883         buffer_clear(m);
 884         if (sshpam_ctxt != NULL) {
 885                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 886                 buffer_put_int(m, 1);
 887         } else {
 888                 buffer_put_int(m, 0);
 889         }
 890         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 891         return (0);
 892 }
 893
 894 int
 895 mm_answer_pam_query(int sock, Buffer *m)
 896 {
 897         char *name, *info, **prompts;
 898         u_int i, num, *echo_on;
 899         int ret;
 900
 901         debug3("%s", __func__);
 902         sshpam_authok = NULL;
 903         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 904         if (ret == 0 && num == 0)
 905                 sshpam_authok = sshpam_ctxt;
 906         if (num > 1 || name == NULL || info == NULL)
 907                 ret = -1;
 908         buffer_clear(m);
 909         buffer_put_int(m, ret);
 910         buffer_put_cstring(m, name);
 911         xfree(name);
 912         buffer_put_cstring(m, info);
 913         xfree(info);
 914         buffer_put_int(m, num);
 915         for (i = 0; i < num; ++i) {
 916                 buffer_put_cstring(m, prompts[i]);
 917                 xfree(prompts[i]);
 918                 buffer_put_int(m, echo_on[i]);
 919         }
 920         if (prompts != NULL)
 921                 xfree(prompts);
 922         if (echo_on != NULL)
 923                 xfree(echo_on);
 924         auth_method = "keyboard-interactive/pam";
 925         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 926         return (0);
 927 }
 928
 929 int
 930 mm_answer_pam_respond(int sock, Buffer *m)
 931 {
 932         char **resp;
 933         u_int i, num;
 934         int ret;
 935
 936         debug3("%s", __func__);
 937         sshpam_authok = NULL;
 938         num = buffer_get_int(m);
 939         if (num > 0) {
 940                 resp = xcalloc(num, sizeof(char *));
 941                 for (i = 0; i < num; ++i)
 942                         resp[i] = buffer_get_string(m, NULL);
 943                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 944                 for (i = 0; i < num; ++i)
 945                         xfree(resp[i]);
 946                 xfree(resp);
 947         } else {
 948                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 949         }
 950         buffer_clear(m);
 951         buffer_put_int(m, ret);
 952         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 953         auth_method = "keyboard-interactive/pam";
 954         if (ret == 0)
 955                 sshpam_authok = sshpam_ctxt;
 956         return (0);
 957 }
 958
 959 int
 960 mm_answer_pam_free_ctx(int sock, Buffer *m)
 961 {
 962
 963         debug3("%s", __func__);
 964         (sshpam_device.free_ctx)(sshpam_ctxt);
 965         buffer_clear(m);
 966         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 967         auth_method = "keyboard-interactive/pam";
 968         return (sshpam_authok == sshpam_ctxt);
 969 }
 970 #endif
 971
 972 static void
 973 mm_append_debug(Buffer *m)
 974 {
 975         if (auth_debug_init && buffer_len(&auth_debug)) {
 976                 debug3("%s: Appending debug messages for child", __func__);
 977                 buffer_append(m, buffer_ptr(&auth_debug),
 978                     buffer_len(&auth_debug));
 979                 buffer_clear(&auth_debug);
 980         }
 981 }
 982
 983 int
 984 mm_answer_keyallowed(int sock, Buffer *m)
 985 {
 986         Key *key;
 987         char *cuser, *chost;
 988         u_char *blob;
 989         u_int bloblen;
 990         enum mm_keytype type = 0;
 991         int allowed = 0;
 992
 993         debug3("%s entering", __func__);
 994
 995         type = buffer_get_int(m);
 996         cuser = buffer_get_string(m, NULL);
 997         chost = buffer_get_string(m, NULL);
 998         blob = buffer_get_string(m, &bloblen);
 999
1000         key = key_from_blob(blob, bloblen);
1001
1002         if ((compat20 && type == MM_RSAHOSTKEY) ||
1003             (!compat20 && type != MM_RSAHOSTKEY))
1004                 fatal("%s: key type and protocol mismatch", __func__);
1005
1006         debug3("%s: key_from_blob: %p", __func__, key);
1007
1008         if (key != NULL && authctxt->valid) {
1009                 switch (type) {
1010                 case MM_USERKEY:
1011                         allowed = options.pubkey_authentication &&
1012                             user_key_allowed(authctxt->pw, key);
1013                         auth_method = "publickey";
1014                         break;
1015                 case MM_HOSTKEY:
1016                         allowed = options.hostbased_authentication &&
1017                             hostbased_key_allowed(authctxt->pw,
1018                             cuser, chost, key);
1019                         auth_method = "hostbased";
1020                         break;
1021                 case MM_RSAHOSTKEY:
1022                         key->type = KEY_RSA1; /* XXX */
1023                         allowed = options.rhosts_rsa_authentication &&
1024                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1025                             cuser, chost, key);
1026                         auth_method = "rsa";
1027                         break;
1028                 default:
1029                         fatal("%s: unknown key type %d", __func__, type);
1030                         break;
1031                 }
1032         }
1033         if (key != NULL)
1034                 key_free(key);
1035
1036         /* clear temporarily storage (used by verify) */
1037         monitor_reset_key_state();
1038
1039         if (allowed) {
1040                 /* Save temporarily for comparison in verify */
1041                 key_blob = blob;
1042                 key_bloblen = bloblen;
1043                 key_blobtype = type;
1044                 hostbased_cuser = cuser;
1045                 hostbased_chost = chost;
1046         } else {
1047                 /* Log failed attempt */
1048                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1049                 xfree(blob);
1050                 xfree(cuser);
1051                 xfree(chost);
1052         }
1053
1054         debug3("%s: key %p is %s",
1055             __func__, key, allowed ? "allowed" : "disallowed");
1056
1057         buffer_clear(m);
1058         buffer_put_int(m, allowed);
1059         buffer_put_int(m, forced_command != NULL);
1060
1061         mm_append_debug(m);
1062
1063         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1064
1065         if (type == MM_RSAHOSTKEY)
1066                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1067
1068         return (0);
1069 }
1070
1071 static int
1072 monitor_valid_userblob(u_char *data, u_int datalen)
1073 {
1074         Buffer b;
1075         char *p;
1076         u_int len;
1077         int fail = 0;
1078
1079         buffer_init(&b);
1080         buffer_append(&b, data, datalen);
1081
1082         if (datafellows & SSH_OLD_SESSIONID) {
1083                 p = buffer_ptr(&b);
1084                 len = buffer_len(&b);
1085                 if ((session_id2 == NULL) ||
1086                     (len < session_id2_len) ||
1087                     (memcmp(p, session_id2, session_id2_len) != 0))
1088                         fail++;
1089                 buffer_consume(&b, session_id2_len);
1090         } else {
1091                 p = buffer_get_string(&b, &len);
1092                 if ((session_id2 == NULL) ||
1093                     (len != session_id2_len) ||
1094                     (memcmp(p, session_id2, session_id2_len) != 0))
1095                         fail++;
1096                 xfree(p);
1097         }
1098         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1099                 fail++;
1100         p = buffer_get_string(&b, NULL);
1101         if (strcmp(authctxt->user, p) != 0) {
1102                 logit("wrong user name passed to monitor: expected %s != %.100s",
1103                     authctxt->user, p);
1104                 fail++;
1105         }
1106         xfree(p);
1107         buffer_skip_string(&b);
1108         if (datafellows & SSH_BUG_PKAUTH) {
1109                 if (!buffer_get_char(&b))
1110                         fail++;
1111         } else {
1112                 p = buffer_get_string(&b, NULL);
1113                 if (strcmp("publickey", p) != 0)
1114                         fail++;
1115                 xfree(p);
1116                 if (!buffer_get_char(&b))
1117                         fail++;
1118                 buffer_skip_string(&b);
1119         }
1120         buffer_skip_string(&b);
1121         if (buffer_len(&b) != 0)
1122                 fail++;
1123         buffer_free(&b);
1124         return (fail == 0);
1125 }
1126
1127 static int
1128 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1129     char *chost)
1130 {
1131         Buffer b;
1132         char *p;
1133         u_int len;
1134         int fail = 0;
1135
1136         buffer_init(&b);
1137         buffer_append(&b, data, datalen);
1138
1139         p = buffer_get_string(&b, &len);
1140         if ((session_id2 == NULL) ||
1141             (len != session_id2_len) ||
1142             (memcmp(p, session_id2, session_id2_len) != 0))
1143                 fail++;
1144         xfree(p);
1145
1146         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1147                 fail++;
1148         p = buffer_get_string(&b, NULL);
1149         if (strcmp(authctxt->user, p) != 0) {
1150                 logit("wrong user name passed to monitor: expected %s != %.100s",
1151                     authctxt->user, p);
1152                 fail++;
1153         }
1154         xfree(p);
1155         buffer_skip_string(&b); /* service */
1156         p = buffer_get_string(&b, NULL);
1157         if (strcmp(p, "hostbased") != 0)
1158                 fail++;
1159         xfree(p);
1160         buffer_skip_string(&b); /* pkalg */
1161         buffer_skip_string(&b); /* pkblob */
1162
1163         /* verify client host, strip trailing dot if necessary */
1164         p = buffer_get_string(&b, NULL);
1165         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1166                 p[len - 1] = '\0';
1167         if (strcmp(p, chost) != 0)
1168                 fail++;
1169         xfree(p);
1170
1171         /* verify client user */
1172         p = buffer_get_string(&b, NULL);
1173         if (strcmp(p, cuser) != 0)
1174                 fail++;
1175         xfree(p);
1176
1177         if (buffer_len(&b) != 0)
1178                 fail++;
1179         buffer_free(&b);
1180         return (fail == 0);
1181 }
1182
1183 int
1184 mm_answer_keyverify(int sock, Buffer *m)
1185 {
1186         Key *key;
1187         u_char *signature, *data, *blob;
1188         u_int signaturelen, datalen, bloblen;
1189         int verified = 0;
1190         int valid_data = 0;
1191
1192         blob = buffer_get_string(m, &bloblen);
1193         signature = buffer_get_string(m, &signaturelen);
1194         data = buffer_get_string(m, &datalen);
1195
1196         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1197           !monitor_allowed_key(blob, bloblen))
1198                 fatal("%s: bad key, not previously allowed", __func__);
1199
1200         key = key_from_blob(blob, bloblen);
1201         if (key == NULL)
1202                 fatal("%s: bad public key blob", __func__);
1203
1204         switch (key_blobtype) {
1205         case MM_USERKEY:
1206                 valid_data = monitor_valid_userblob(data, datalen);
1207                 break;
1208         case MM_HOSTKEY:
1209                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1210                     hostbased_cuser, hostbased_chost);
1211                 break;
1212         default:
1213                 valid_data = 0;
1214                 break;
1215         }
1216         if (!valid_data)
1217                 fatal("%s: bad signature data blob", __func__);
1218
1219         verified = key_verify(key, signature, signaturelen, data, datalen);
1220         debug3("%s: key %p signature %s",
1221             __func__, key, verified ? "verified" : "unverified");
1222
1223         key_free(key);
1224         xfree(blob);
1225         xfree(signature);
1226         xfree(data);
1227
1228         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1229
1230         monitor_reset_key_state();
1231
1232         buffer_clear(m);
1233         buffer_put_int(m, verified);
1234         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1235
1236         return (verified);
1237 }
1238
1239 static void
1240 mm_record_login(Session *s, struct passwd *pw)
1241 {
1242         socklen_t fromlen;
1243         struct sockaddr_storage from;
1244
1245         /*
1246          * Get IP address of client. If the connection is not a socket, let
1247          * the address be 0.0.0.0.
1248          */
1249         memset(&from, 0, sizeof(from));
1250         fromlen = sizeof(from);
1251         if (packet_connection_is_on_socket()) {
1252                 if (getpeername(packet_get_connection_in(),
1253                     (struct sockaddr *)&from, &fromlen) < 0) {
1254                         debug("getpeername: %.100s", strerror(errno));
1255                         cleanup_exit(255);
1256                 }
1257         }
1258         /* Record that there was a login on that tty from the remote host. */
1259         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1260             get_remote_name_or_ip(utmp_len, options.use_dns),
1261             (struct sockaddr *)&from, fromlen);
1262 }
1263
1264 static void
1265 mm_session_close(Session *s)
1266 {
1267         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1268         if (s->ttyfd != -1) {
1269                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1270                 session_pty_cleanup2(s);
1271         }
1272         s->used = 0;
1273 }
1274
1275 int
1276 mm_answer_pty(int sock, Buffer *m)
1277 {
1278         extern struct monitor *pmonitor;
1279         Session *s;
1280         int res, fd0;
1281
1282         debug3("%s entering", __func__);
1283
1284         buffer_clear(m);
1285         s = session_new();
1286         if (s == NULL)
1287                 goto error;
1288         s->authctxt = authctxt;
1289         s->pw = authctxt->pw;
1290         s->pid = pmonitor->m_pid;
1291         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1292         if (res == 0)
1293                 goto error;
1294         pty_setowner(authctxt->pw, s->tty);
1295
1296         buffer_put_int(m, 1);
1297         buffer_put_cstring(m, s->tty);
1298
1299         /* We need to trick ttyslot */
1300         if (dup2(s->ttyfd, 0) == -1)
1301                 fatal("%s: dup2", __func__);
1302
1303         mm_record_login(s, authctxt->pw);
1304
1305         /* Now we can close the file descriptor again */
1306         close(0);
1307
1308         /* send messages generated by record_login */
1309         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1310         buffer_clear(&loginmsg);
1311
1312         mm_request_send(sock, MONITOR_ANS_PTY, m);
1313
1314         mm_send_fd(sock, s->ptyfd);
1315         mm_send_fd(sock, s->ttyfd);
1316
1317         /* make sure nothing uses fd 0 */
1318         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1319                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1320         if (fd0 != 0)
1321                 error("%s: fd0 %d != 0", __func__, fd0);
1322
1323         /* slave is not needed */
1324         close(s->ttyfd);
1325         s->ttyfd = s->ptyfd;
1326         /* no need to dup() because nobody closes ptyfd */
1327         s->ptymaster = s->ptyfd;
1328
1329         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1330
1331         return (0);
1332
1333  error:
1334         if (s != NULL)
1335                 mm_session_close(s);
1336         buffer_put_int(m, 0);
1337         mm_request_send(sock, MONITOR_ANS_PTY, m);
1338         return (0);
1339 }
1340
1341 int
1342 mm_answer_pty_cleanup(int sock, Buffer *m)
1343 {
1344         Session *s;
1345         char *tty;
1346
1347         debug3("%s entering", __func__);
1348
1349         tty = buffer_get_string(m, NULL);
1350         if ((s = session_by_tty(tty)) != NULL)
1351                 mm_session_close(s);
1352         buffer_clear(m);
1353         xfree(tty);
1354         return (0);
1355 }
1356
1357 int
1358 mm_answer_sesskey(int sock, Buffer *m)
1359 {
1360         BIGNUM *p;
1361         int rsafail;
1362
1363         /* Turn off permissions */
1364         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1365
1366         if ((p = BN_new()) == NULL)
1367                 fatal("%s: BN_new", __func__);
1368
1369         buffer_get_bignum2(m, p);
1370
1371         rsafail = ssh1_session_key(p);
1372
1373         buffer_clear(m);
1374         buffer_put_int(m, rsafail);
1375         buffer_put_bignum2(m, p);
1376
1377         BN_clear_free(p);
1378
1379         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1380
1381         /* Turn on permissions for sessid passing */
1382         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1383
1384         return (0);
1385 }
1386
1387 int
1388 mm_answer_sessid(int sock, Buffer *m)
1389 {
1390         int i;
1391
1392         debug3("%s entering", __func__);
1393
1394         if (buffer_len(m) != 16)
1395                 fatal("%s: bad ssh1 session id", __func__);
1396         for (i = 0; i < 16; i++)
1397                 session_id[i] = buffer_get_char(m);
1398
1399         /* Turn on permissions for getpwnam */
1400         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1401
1402         return (0);
1403 }
1404
1405 int
1406 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1407 {
1408         BIGNUM *client_n;
1409         Key *key = NULL;
1410         u_char *blob = NULL;
1411         u_int blen = 0;
1412         int allowed = 0;
1413
1414         debug3("%s entering", __func__);
1415
1416         auth_method = "rsa";
1417         if (options.rsa_authentication && authctxt->valid) {
1418                 if ((client_n = BN_new()) == NULL)
1419                         fatal("%s: BN_new", __func__);
1420                 buffer_get_bignum2(m, client_n);
1421                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1422                 BN_clear_free(client_n);
1423         }
1424         buffer_clear(m);
1425         buffer_put_int(m, allowed);
1426         buffer_put_int(m, forced_command != NULL);
1427
1428         /* clear temporarily storage (used by generate challenge) */
1429         monitor_reset_key_state();
1430
1431         if (allowed && key != NULL) {
1432                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1433                 if (key_to_blob(key, &blob, &blen) == 0)
1434                         fatal("%s: key_to_blob failed", __func__);
1435                 buffer_put_string(m, blob, blen);
1436
1437                 /* Save temporarily for comparison in verify */
1438                 key_blob = blob;
1439                 key_bloblen = blen;
1440                 key_blobtype = MM_RSAUSERKEY;
1441         }
1442         if (key != NULL)
1443                 key_free(key);
1444
1445         mm_append_debug(m);
1446
1447         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1448
1449         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1450         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1451         return (0);
1452 }
1453
1454 int
1455 mm_answer_rsa_challenge(int sock, Buffer *m)
1456 {
1457         Key *key = NULL;
1458         u_char *blob;
1459         u_int blen;
1460
1461         debug3("%s entering", __func__);
1462
1463         if (!authctxt->valid)
1464                 fatal("%s: authctxt not valid", __func__);
1465         blob = buffer_get_string(m, &blen);
1466         if (!monitor_allowed_key(blob, blen))
1467                 fatal("%s: bad key, not previously allowed", __func__);
1468         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1469                 fatal("%s: key type mismatch", __func__);
1470         if ((key = key_from_blob(blob, blen)) == NULL)
1471                 fatal("%s: received bad key", __func__);
1472
1473         if (ssh1_challenge)
1474                 BN_clear_free(ssh1_challenge);
1475         ssh1_challenge = auth_rsa_generate_challenge(key);
1476
1477         buffer_clear(m);
1478         buffer_put_bignum2(m, ssh1_challenge);
1479
1480         debug3("%s sending reply", __func__);
1481         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1482
1483         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1484
1485         xfree(blob);
1486         key_free(key);
1487         return (0);
1488 }
1489
1490 int
1491 mm_answer_rsa_response(int sock, Buffer *m)
1492 {
1493         Key *key = NULL;
1494         u_char *blob, *response;
1495         u_int blen, len;
1496         int success;
1497
1498         debug3("%s entering", __func__);
1499
1500         if (!authctxt->valid)
1501                 fatal("%s: authctxt not valid", __func__);
1502         if (ssh1_challenge == NULL)
1503                 fatal("%s: no ssh1_challenge", __func__);
1504
1505         blob = buffer_get_string(m, &blen);
1506         if (!monitor_allowed_key(blob, blen))
1507                 fatal("%s: bad key, not previously allowed", __func__);
1508         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1509                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1510         if ((key = key_from_blob(blob, blen)) == NULL)
1511                 fatal("%s: received bad key", __func__);
1512         response = buffer_get_string(m, &len);
1513         if (len != 16)
1514                 fatal("%s: received bad response to challenge", __func__);
1515         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1516
1517         xfree(blob);
1518         key_free(key);
1519         xfree(response);
1520
1521         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1522
1523         /* reset state */
1524         BN_clear_free(ssh1_challenge);
1525         ssh1_challenge = NULL;
1526         monitor_reset_key_state();
1527
1528         buffer_clear(m);
1529         buffer_put_int(m, success);
1530         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1531
1532         return (success);
1533 }
1534
1535 int
1536 mm_answer_term(int sock, Buffer *req)
1537 {
1538         extern struct monitor *pmonitor;
1539         int res, status;
1540
1541         debug3("%s: tearing down sessions", __func__);
1542
1543         /* The child is terminating */
1544         session_destroy_all(&mm_session_close);
1545
1546         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1547                 if (errno != EINTR)
1548                         exit(1);
1549
1550         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1551
1552         /* Terminate process */
1553         exit(res);
1554 }
1555
1556 #ifdef SSH_AUDIT_EVENTS
1557 /* Report that an audit event occurred */
1558 int
1559 mm_answer_audit_event(int socket, Buffer *m)
1560 {
1561         ssh_audit_event_t event;
1562
1563         debug3("%s entering", __func__);
1564
1565         event = buffer_get_int(m);
1566         switch(event) {
1567         case SSH_AUTH_FAIL_PUBKEY:
1568         case SSH_AUTH_FAIL_HOSTBASED:
1569         case SSH_AUTH_FAIL_GSSAPI:
1570         case SSH_LOGIN_EXCEED_MAXTRIES:
1571         case SSH_LOGIN_ROOT_DENIED:
1572         case SSH_CONNECTION_CLOSE:
1573         case SSH_INVALID_USER:
1574                 audit_event(event);
1575                 break;
1576         default:
1577                 fatal("Audit event type %d not permitted", event);
1578         }
1579
1580         return (0);
1581 }
1582
1583 int
1584 mm_answer_audit_command(int socket, Buffer *m)
1585 {
1586         u_int len;
1587         char *cmd;
1588
1589         debug3("%s entering", __func__);
1590         cmd = buffer_get_string(m, &len);
1591         /* sanity check command, if so how? */
1592         audit_run_command(cmd);
1593         xfree(cmd);
1594         return (0);
1595 }
1596 #endif /* SSH_AUDIT_EVENTS */
1597
1598 void
1599 monitor_apply_keystate(struct monitor *pmonitor)
1600 {
1601         if (compat20) {
1602                 set_newkeys(MODE_IN);
1603                 set_newkeys(MODE_OUT);
1604         } else {
1605                 packet_set_protocol_flags(child_state.ssh1protoflags);
1606                 packet_set_encryption_key(child_state.ssh1key,
1607                     child_state.ssh1keylen, child_state.ssh1cipher);
1608                 xfree(child_state.ssh1key);
1609         }
1610
1611         /* for rc4 and other stateful ciphers */
1612         packet_set_keycontext(MODE_OUT, child_state.keyout);
1613         xfree(child_state.keyout);
1614         packet_set_keycontext(MODE_IN, child_state.keyin);
1615         xfree(child_state.keyin);
1616
1617         if (!compat20) {
1618                 packet_set_iv(MODE_OUT, child_state.ivout);
1619                 xfree(child_state.ivout);
1620                 packet_set_iv(MODE_IN, child_state.ivin);
1621                 xfree(child_state.ivin);
1622         }
1623
1624         memcpy(&incoming_stream, &child_state.incoming,
1625             sizeof(incoming_stream));
1626         memcpy(&outgoing_stream, &child_state.outgoing,
1627             sizeof(outgoing_stream));
1628
1629         /* Update with new address */
1630         if (options.compression)
1631                 mm_init_compression(pmonitor->m_zlib);
1632
1633         /* Network I/O buffers */
1634         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1635         buffer_clear(&input);
1636         buffer_append(&input, child_state.input, child_state.ilen);
1637         memset(child_state.input, 0, child_state.ilen);
1638         xfree(child_state.input);
1639
1640         buffer_clear(&output);
1641         buffer_append(&output, child_state.output, child_state.olen);
1642         memset(child_state.output, 0, child_state.olen);
1643         xfree(child_state.output);
1644 }
1645
1646 static Kex *
1647 mm_get_kex(Buffer *m)
1648 {
1649         Kex *kex;
1650         void *blob;
1651         u_int bloblen;
1652
1653         kex = xcalloc(1, sizeof(*kex));
1654         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1655         if ((session_id2 == NULL) ||
1656             (kex->session_id_len != session_id2_len) ||
1657             (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1658                 fatal("mm_get_get: internal error: bad session id");
1659         kex->we_need = buffer_get_int(m);
1660         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1661         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1662         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1663         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1664         kex->server = 1;
1665         kex->hostkey_type = buffer_get_int(m);
1666         kex->kex_type = buffer_get_int(m);
1667         blob = buffer_get_string(m, &bloblen);
1668         buffer_init(&kex->my);
1669         buffer_append(&kex->my, blob, bloblen);
1670         xfree(blob);
1671         blob = buffer_get_string(m, &bloblen);
1672         buffer_init(&kex->peer);
1673         buffer_append(&kex->peer, blob, bloblen);
1674         xfree(blob);
1675         kex->done = 1;
1676         kex->flags = buffer_get_int(m);
1677         kex->client_version_string = buffer_get_string(m, NULL);
1678         kex->server_version_string = buffer_get_string(m, NULL);
1679         kex->load_host_key=&get_hostkey_by_type;
1680         kex->host_key_index=&get_hostkey_index;
1681
1682         return (kex);
1683 }
1684
1685 /* This function requries careful sanity checking */
1686
1687 void
1688 mm_get_keystate(struct monitor *pmonitor)
1689 {
1690         Buffer m;
1691         u_char *blob, *p;
1692         u_int bloblen, plen;
1693         u_int32_t seqnr, packets;
1694         u_int64_t blocks;
1695
1696         debug3("%s: Waiting for new keys", __func__);
1697
1698         buffer_init(&m);
1699         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1700         if (!compat20) {
1701                 child_state.ssh1protoflags = buffer_get_int(&m);
1702                 child_state.ssh1cipher = buffer_get_int(&m);
1703                 child_state.ssh1key = buffer_get_string(&m,
1704                     &child_state.ssh1keylen);
1705                 child_state.ivout = buffer_get_string(&m,
1706                     &child_state.ivoutlen);
1707                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1708                 goto skip;
1709         } else {
1710                 /* Get the Kex for rekeying */
1711                 *pmonitor->m_pkex = mm_get_kex(&m);
1712         }
1713
1714         blob = buffer_get_string(&m, &bloblen);
1715         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1716         xfree(blob);
1717
1718         debug3("%s: Waiting for second key", __func__);
1719         blob = buffer_get_string(&m, &bloblen);
1720         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1721         xfree(blob);
1722
1723         /* Now get sequence numbers for the packets */
1724         seqnr = buffer_get_int(&m);
1725         blocks = buffer_get_int64(&m);
1726         packets = buffer_get_int(&m);
1727         packet_set_state(MODE_OUT, seqnr, blocks, packets);
1728         seqnr = buffer_get_int(&m);
1729         blocks = buffer_get_int64(&m);
1730         packets = buffer_get_int(&m);
1731         packet_set_state(MODE_IN, seqnr, blocks, packets);
1732
1733  skip:
1734         /* Get the key context */
1735         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1736         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1737
1738         debug3("%s: Getting compression state", __func__);
1739         /* Get compression state */
1740         p = buffer_get_string(&m, &plen);
1741         if (plen != sizeof(child_state.outgoing))
1742                 fatal("%s: bad request size", __func__);
1743         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1744         xfree(p);
1745
1746         p = buffer_get_string(&m, &plen);
1747         if (plen != sizeof(child_state.incoming))
1748                 fatal("%s: bad request size", __func__);
1749         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1750         xfree(p);
1751
1752         /* Network I/O buffers */
1753         debug3("%s: Getting Network I/O buffers", __func__);
1754         child_state.input = buffer_get_string(&m, &child_state.ilen);
1755         child_state.output = buffer_get_string(&m, &child_state.olen);
1756
1757         buffer_free(&m);
1758 }
1759
1760
1761 /* Allocation functions for zlib */
1762 void *
1763 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1764 {
1765         size_t len = (size_t) size * ncount;
1766         void *address;
1767
1768         if (len == 0 || ncount > SIZE_T_MAX / size)
1769                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1770
1771         address = mm_malloc(mm, len);
1772
1773         return (address);
1774 }
1775
1776 void
1777 mm_zfree(struct mm_master *mm, void *address)
1778 {
1779         mm_free(mm, address);
1780 }
1781
1782 void
1783 mm_init_compression(struct mm_master *mm)
1784 {
1785         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1786         outgoing_stream.zfree = (free_func)mm_zfree;
1787         outgoing_stream.opaque = mm;
1788
1789         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1790         incoming_stream.zfree = (free_func)mm_zfree;
1791         incoming_stream.opaque = mm;
1792 }
1793
1794 /* XXX */
1795
1796 #define FD_CLOSEONEXEC(x) do { \
1797         if (fcntl(x, F_SETFD, 1) == -1) \
1798                 fatal("fcntl(%d, F_SETFD)", x); \
1799 } while (0)
1800
1801 static void
1802 monitor_socketpair(int *pair)
1803 {
1804 #ifdef HAVE_SOCKETPAIR
1805         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1806                 fatal("%s: socketpair", __func__);
1807 #else
1808         fatal("%s: UsePrivilegeSeparation=yes not supported",
1809             __func__);
1810 #endif
1811         FD_CLOSEONEXEC(pair[0]);
1812         FD_CLOSEONEXEC(pair[1]);
1813 }
1814
1815 #define MM_MEMSIZE      65536
1816
1817 struct monitor *
1818 monitor_init(void)
1819 {
1820         struct monitor *mon;
1821         int pair[2];
1822
1823         mon = xcalloc(1, sizeof(*mon));
1824
1825         monitor_socketpair(pair);
1826
1827         mon->m_recvfd = pair[0];
1828         mon->m_sendfd = pair[1];
1829
1830         /* Used to share zlib space across processes */
1831         if (options.compression) {
1832                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1833                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1834
1835                 /* Compression needs to share state across borders */
1836                 mm_init_compression(mon->m_zlib);
1837         }
1838
1839         return mon;
1840 }
1841
1842 void
1843 monitor_reinit(struct monitor *mon)
1844 {
1845         int pair[2];
1846
1847         monitor_socketpair(pair);
1848
1849         mon->m_recvfd = pair[0];
1850         mon->m_sendfd = pair[1];
1851 }
1852
1853 #ifdef GSSAPI
1854 int
1855 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1856 {
1857         gss_OID_desc goid;
1858         OM_uint32 major;
1859         u_int len;
1860
1861         goid.elements = buffer_get_string(m, &len);
1862         goid.length = len;
1863
1864         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1865
1866         xfree(goid.elements);
1867
1868         buffer_clear(m);
1869         buffer_put_int(m, major);
1870
1871         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1872
1873         /* Now we have a context, enable the step */
1874         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1875
1876         return (0);
1877 }
1878
1879 int
1880 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1881 {
1882         gss_buffer_desc in;
1883         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1884         OM_uint32 major, minor;
1885         OM_uint32 flags = 0; /* GSI needs this */
1886         u_int len;
1887
1888         in.value = buffer_get_string(m, &len);
1889         in.length = len;
1890         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1891         xfree(in.value);
1892
1893         buffer_clear(m);
1894         buffer_put_int(m, major);
1895         buffer_put_string(m, out.value, out.length);
1896         buffer_put_int(m, flags);
1897         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1898
1899         gss_release_buffer(&minor, &out);
1900
1901         if (major == GSS_S_COMPLETE) {
1902                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1903                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1904                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1905         }
1906         return (0);
1907 }
1908
1909 int
1910 mm_answer_gss_checkmic(int sock, Buffer *m)
1911 {
1912         gss_buffer_desc gssbuf, mic;
1913         OM_uint32 ret;
1914         u_int len;
1915
1916         gssbuf.value = buffer_get_string(m, &len);
1917         gssbuf.length = len;
1918         mic.value = buffer_get_string(m, &len);
1919         mic.length = len;
1920
1921         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1922
1923         xfree(gssbuf.value);
1924         xfree(mic.value);
1925
1926         buffer_clear(m);
1927         buffer_put_int(m, ret);
1928
1929         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1930
1931         if (!GSS_ERROR(ret))
1932                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1933
1934         return (0);
1935 }
1936
1937 int
1938 mm_answer_gss_userok(int sock, Buffer *m)
1939 {
1940         int authenticated;
1941
1942         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1943
1944         buffer_clear(m);
1945         buffer_put_int(m, authenticated);
1946
1947         debug3("%s: sending result %d", __func__, authenticated);
1948         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1949
1950         auth_method = "gssapi-with-mic";
1951
1952         /* Monitor loop will terminate if authenticated */
1953         return (authenticated);
1954 }
1955 #endif /* GSSAPI */