crypto/openssh-5/monitor.c

   1 /* $OpenBSD: monitor.c,v 1.94 2007/10/29 04:08:08 dtucker 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 <stdarg.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47
  48 #ifdef SKEY
  49 #ifdef OPIE
  50 #include <opie.h>
  51 #define skey                    opie
  52 #define skeychallenge(k, u, c)  opiechallenge((k), (u), (c))
  53 #define skey_haskey(u)          opie_haskey((u))
  54 #define skey_passcheck(u, r)    opie_passverify((u), (r))
  55 #else
  56 #include <skey.h>
  57 #endif
  58 #endif
  59
  60 #include <openssl/dh.h>
  61
  62 #include "xmalloc.h"
  63 #include "ssh.h"
  64 #include "key.h"
  65 #include "buffer.h"
  66 #include "hostfile.h"
  67 #include "auth.h"
  68 #include "cipher.h"
  69 #include "kex.h"
  70 #include "dh.h"
  71 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
  72 #undef TARGET_OS_MAC
  73 #include "zlib.h"
  74 #define TARGET_OS_MAC 1
  75 #else
  76 #include "zlib.h"
  77 #endif
  78 #include "packet.h"
  79 #include "auth-options.h"
  80 #include "sshpty.h"
  81 #include "channels.h"
  82 #include "session.h"
  83 #include "sshlogin.h"
  84 #include "canohost.h"
  85 #include "log.h"
  86 #include "servconf.h"
  87 #include "monitor.h"
  88 #include "monitor_mm.h"
  89 #ifdef GSSAPI
  90 #include "ssh-gss.h"
  91 #endif
  92 #include "monitor_wrap.h"
  93 #include "monitor_fdpass.h"
  94 #include "misc.h"
  95 #include "compat.h"
  96 #include "ssh2.h"
  97
  98 #ifdef GSSAPI
  99 static Gssctxt *gsscontext = NULL;
 100 #endif
 101
 102 /* Imports */
 103 extern ServerOptions options;
 104 extern u_int utmp_len;
 105 extern Newkeys *current_keys[];
 106 extern z_stream incoming_stream;
 107 extern z_stream outgoing_stream;
 108 extern u_char session_id[];
 109 extern Buffer input, output;
 110 extern Buffer auth_debug;
 111 extern int auth_debug_init;
 112 extern Buffer loginmsg;
 113
 114 /* State exported from the child */
 115
 116 struct {
 117         z_stream incoming;
 118         z_stream outgoing;
 119         u_char *keyin;
 120         u_int keyinlen;
 121         u_char *keyout;
 122         u_int keyoutlen;
 123         u_char *ivin;
 124         u_int ivinlen;
 125         u_char *ivout;
 126         u_int ivoutlen;
 127         u_char *ssh1key;
 128         u_int ssh1keylen;
 129         int ssh1cipher;
 130         int ssh1protoflags;
 131         u_char *input;
 132         u_int ilen;
 133         u_char *output;
 134         u_int olen;
 135 } child_state;
 136
 137 /* Functions on the monitor that answer unprivileged requests */
 138
 139 int mm_answer_moduli(int, Buffer *);
 140 int mm_answer_sign(int, Buffer *);
 141 int mm_answer_pwnamallow(int, Buffer *);
 142 int mm_answer_auth2_read_banner(int, Buffer *);
 143 int mm_answer_authserv(int, Buffer *);
 144 int mm_answer_authpassword(int, Buffer *);
 145 int mm_answer_bsdauthquery(int, Buffer *);
 146 int mm_answer_bsdauthrespond(int, Buffer *);
 147 int mm_answer_skeyquery(int, Buffer *);
 148 int mm_answer_skeyrespond(int, Buffer *);
 149 int mm_answer_keyallowed(int, Buffer *);
 150 int mm_answer_keyverify(int, Buffer *);
 151 int mm_answer_pty(int, Buffer *);
 152 int mm_answer_pty_cleanup(int, Buffer *);
 153 int mm_answer_term(int, Buffer *);
 154 int mm_answer_rsa_keyallowed(int, Buffer *);
 155 int mm_answer_rsa_challenge(int, Buffer *);
 156 int mm_answer_rsa_response(int, Buffer *);
 157 int mm_answer_sesskey(int, Buffer *);
 158 int mm_answer_sessid(int, Buffer *);
 159
 160 #ifdef USE_PAM
 161 int mm_answer_pam_start(int, Buffer *);
 162 int mm_answer_pam_account(int, Buffer *);
 163 int mm_answer_pam_init_ctx(int, Buffer *);
 164 int mm_answer_pam_query(int, Buffer *);
 165 int mm_answer_pam_respond(int, Buffer *);
 166 int mm_answer_pam_free_ctx(int, Buffer *);
 167 #endif
 168
 169 #ifdef GSSAPI
 170 int mm_answer_gss_setup_ctx(int, Buffer *);
 171 int mm_answer_gss_accept_ctx(int, Buffer *);
 172 int mm_answer_gss_userok(int, Buffer *);
 173 int mm_answer_gss_checkmic(int, Buffer *);
 174 #endif
 175
 176 #ifdef SSH_AUDIT_EVENTS
 177 int mm_answer_audit_event(int, Buffer *);
 178 int mm_answer_audit_command(int, Buffer *);
 179 #endif
 180
 181 static Authctxt *authctxt;
 182 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 183
 184 /* local state for key verify */
 185 static u_char *key_blob = NULL;
 186 static u_int key_bloblen = 0;
 187 static int key_blobtype = MM_NOKEY;
 188 static char *hostbased_cuser = NULL;
 189 static char *hostbased_chost = NULL;
 190 static char *auth_method = "unknown";
 191 static u_int session_id2_len = 0;
 192 static u_char *session_id2 = NULL;
 193 static pid_t monitor_child_pid;
 194
 195 struct mon_table {
 196         enum monitor_reqtype type;
 197         int flags;
 198         int (*f)(int, Buffer *);
 199 };
 200
 201 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 202 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 203 #define MON_ONCE        0x0010  /* Disable after calling */
 204 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 205
 206 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 207
 208 #define MON_PERMIT      0x1000  /* Request is permitted */
 209
 210 struct mon_table mon_dispatch_proto20[] = {
 211     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 212     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 213     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 214     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 215     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 216     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 217 #ifdef USE_PAM
 218     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 219     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 220     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 221     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 222     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 223     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 224 #endif
 225 #ifdef SSH_AUDIT_EVENTS
 226     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 227 #endif
 228 #ifdef BSD_AUTH
 229     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 230     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 231 #endif
 232 #ifdef SKEY
 233     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 234     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 235 #endif
 236     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 237     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 238 #ifdef GSSAPI
 239     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 240     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 241     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 242     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 243 #endif
 244     {0, 0, NULL}
 245 };
 246
 247 struct mon_table mon_dispatch_postauth20[] = {
 248     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 249     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 250     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 251     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 252     {MONITOR_REQ_TERM, 0, mm_answer_term},
 253 #ifdef SSH_AUDIT_EVENTS
 254     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 255     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 256 #endif
 257     {0, 0, NULL}
 258 };
 259
 260 struct mon_table mon_dispatch_proto15[] = {
 261     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 262     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 263     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 264     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 265     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 266     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 267     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 268     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 269 #ifdef BSD_AUTH
 270     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 271     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 272 #endif
 273 #ifdef SKEY
 274     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 275     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 276 #endif
 277 #ifdef USE_PAM
 278     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 279     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 280     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 281     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 282     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 283     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 284 #endif
 285 #ifdef SSH_AUDIT_EVENTS
 286     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 287 #endif
 288     {0, 0, NULL}
 289 };
 290
 291 struct mon_table mon_dispatch_postauth15[] = {
 292     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 293     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 294     {MONITOR_REQ_TERM, 0, mm_answer_term},
 295 #ifdef SSH_AUDIT_EVENTS
 296     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 297     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
 298 #endif
 299     {0, 0, NULL}
 300 };
 301
 302 struct mon_table *mon_dispatch;
 303
 304 /* Specifies if a certain message is allowed at the moment */
 305
 306 static void
 307 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 308 {
 309         while (ent->f != NULL) {
 310                 if (ent->type == type) {
 311                         ent->flags &= ~MON_PERMIT;
 312                         ent->flags |= permit ? MON_PERMIT : 0;
 313                         return;
 314                 }
 315                 ent++;
 316         }
 317 }
 318
 319 static void
 320 monitor_permit_authentications(int permit)
 321 {
 322         struct mon_table *ent = mon_dispatch;
 323
 324         while (ent->f != NULL) {
 325                 if (ent->flags & MON_AUTH) {
 326                         ent->flags &= ~MON_PERMIT;
 327                         ent->flags |= permit ? MON_PERMIT : 0;
 328                 }
 329                 ent++;
 330         }
 331 }
 332
 333 void
 334 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 335 {
 336         struct mon_table *ent;
 337         int authenticated = 0;
 338
 339         debug3("preauth child monitor started");
 340
 341         authctxt = _authctxt;
 342         memset(authctxt, 0, sizeof(*authctxt));
 343
 344         authctxt->loginmsg = &loginmsg;
 345
 346         if (compat20) {
 347                 mon_dispatch = mon_dispatch_proto20;
 348
 349                 /* Permit requests for moduli and signatures */
 350                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 351                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 352         } else {
 353                 mon_dispatch = mon_dispatch_proto15;
 354
 355                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 356         }
 357
 358         /* The first few requests do not require asynchronous access */
 359         while (!authenticated) {
 360                 auth_method = "unknown";
 361                 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
 362                 if (authenticated) {
 363                         if (!(ent->flags & MON_AUTHDECIDE))
 364                                 fatal("%s: unexpected authentication from %d",
 365                                     __func__, ent->type);
 366                         if (authctxt->pw->pw_uid == 0 &&
 367                             !auth_root_allowed(auth_method))
 368                                 authenticated = 0;
 369 #ifdef USE_PAM
 370                         /* PAM needs to perform account checks after auth */
 371                         if (options.use_pam && authenticated) {
 372                                 Buffer m;
 373
 374                                 buffer_init(&m);
 375                                 mm_request_receive_expect(pmonitor->m_sendfd,
 376                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 377                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 378                                 buffer_free(&m);
 379                         }
 380 #endif
 381                 }
 382
 383                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 384                         auth_log(authctxt, authenticated, auth_method,
 385                             compat20 ? " ssh2" : "");
 386                         if (!authenticated)
 387                                 authctxt->failures++;
 388                 }
 389         }
 390
 391         if (!authctxt->valid)
 392                 fatal("%s: authenticated invalid user", __func__);
 393         if (strcmp(auth_method, "unknown") == 0)
 394                 fatal("%s: authentication method name unknown", __func__);
 395
 396         debug("%s: %s has been authenticated by privileged process",
 397             __func__, authctxt->user);
 398
 399         mm_get_keystate(pmonitor);
 400 }
 401
 402 static void
 403 monitor_set_child_handler(pid_t pid)
 404 {
 405         monitor_child_pid = pid;
 406 }
 407
 408 static void
 409 monitor_child_handler(int sig)
 410 {
 411         kill(monitor_child_pid, sig);
 412 }
 413
 414 void
 415 monitor_child_postauth(struct monitor *pmonitor)
 416 {
 417         monitor_set_child_handler(pmonitor->m_pid);
 418         signal(SIGHUP, &monitor_child_handler);
 419         signal(SIGTERM, &monitor_child_handler);
 420         signal(SIGINT, &monitor_child_handler);
 421
 422         if (compat20) {
 423                 mon_dispatch = mon_dispatch_postauth20;
 424
 425                 /* Permit requests for moduli and signatures */
 426                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 427                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 428                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 429         } else {
 430                 mon_dispatch = mon_dispatch_postauth15;
 431                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 432         }
 433         if (!no_pty_flag) {
 434                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 435                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 436         }
 437
 438         for (;;)
 439                 monitor_read(pmonitor, mon_dispatch, NULL);
 440 }
 441
 442 void
 443 monitor_sync(struct monitor *pmonitor)
 444 {
 445         if (options.compression) {
 446                 /* The member allocation is not visible, so sync it */
 447                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 448         }
 449 }
 450
 451 int
 452 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 453     struct mon_table **pent)
 454 {
 455         Buffer m;
 456         int ret;
 457         u_char type;
 458
 459         buffer_init(&m);
 460
 461         mm_request_receive(pmonitor->m_sendfd, &m);
 462         type = buffer_get_char(&m);
 463
 464         debug3("%s: checking request %d", __func__, type);
 465
 466         while (ent->f != NULL) {
 467                 if (ent->type == type)
 468                         break;
 469                 ent++;
 470         }
 471
 472         if (ent->f != NULL) {
 473                 if (!(ent->flags & MON_PERMIT))
 474                         fatal("%s: unpermitted request %d", __func__,
 475                             type);
 476                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 477                 buffer_free(&m);
 478
 479                 /* The child may use this request only once, disable it */
 480                 if (ent->flags & MON_ONCE) {
 481                         debug2("%s: %d used once, disabling now", __func__,
 482                             type);
 483                         ent->flags &= ~MON_PERMIT;
 484                 }
 485
 486                 if (pent != NULL)
 487                         *pent = ent;
 488
 489                 return ret;
 490         }
 491
 492         fatal("%s: unsupported request: %d", __func__, type);
 493
 494         /* NOTREACHED */
 495         return (-1);
 496 }
 497
 498 /* allowed key state */
 499 static int
 500 monitor_allowed_key(u_char *blob, u_int bloblen)
 501 {
 502         /* make sure key is allowed */
 503         if (key_blob == NULL || key_bloblen != bloblen ||
 504             memcmp(key_blob, blob, key_bloblen))
 505                 return (0);
 506         return (1);
 507 }
 508
 509 static void
 510 monitor_reset_key_state(void)
 511 {
 512         /* reset state */
 513         if (key_blob != NULL)
 514                 xfree(key_blob);
 515         if (hostbased_cuser != NULL)
 516                 xfree(hostbased_cuser);
 517         if (hostbased_chost != NULL)
 518                 xfree(hostbased_chost);
 519         key_blob = NULL;
 520         key_bloblen = 0;
 521         key_blobtype = MM_NOKEY;
 522         hostbased_cuser = NULL;
 523         hostbased_chost = NULL;
 524 }
 525
 526 int
 527 mm_answer_moduli(int sock, Buffer *m)
 528 {
 529         DH *dh;
 530         int min, want, max;
 531
 532         min = buffer_get_int(m);
 533         want = buffer_get_int(m);
 534         max = buffer_get_int(m);
 535
 536         debug3("%s: got parameters: %d %d %d",
 537             __func__, min, want, max);
 538         /* We need to check here, too, in case the child got corrupted */
 539         if (max < min || want < min || max < want)
 540                 fatal("%s: bad parameters: %d %d %d",
 541                     __func__, min, want, max);
 542
 543         buffer_clear(m);
 544
 545         dh = choose_dh(min, want, max);
 546         if (dh == NULL) {
 547                 buffer_put_char(m, 0);
 548                 return (0);
 549         } else {
 550                 /* Send first bignum */
 551                 buffer_put_char(m, 1);
 552                 buffer_put_bignum2(m, dh->p);
 553                 buffer_put_bignum2(m, dh->g);
 554
 555                 DH_free(dh);
 556         }
 557         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 558         return (0);
 559 }
 560
 561 int
 562 mm_answer_sign(int sock, Buffer *m)
 563 {
 564         Key *key;
 565         u_char *p;
 566         u_char *signature;
 567         u_int siglen, datlen;
 568         int keyid;
 569
 570         debug3("%s", __func__);
 571
 572         keyid = buffer_get_int(m);
 573         p = buffer_get_string(m, &datlen);
 574
 575         /*
 576          * Supported KEX types will only return SHA1 (20 byte) or
 577          * SHA256 (32 byte) hashes
 578          */
 579         if (datlen != 20 && datlen != 32)
 580                 fatal("%s: data length incorrect: %u", __func__, datlen);
 581
 582         /* save session id, it will be passed on the first call */
 583         if (session_id2_len == 0) {
 584                 session_id2_len = datlen;
 585                 session_id2 = xmalloc(session_id2_len);
 586                 memcpy(session_id2, p, session_id2_len);
 587         }
 588
 589         if ((key = get_hostkey_by_index(keyid)) == NULL)
 590                 fatal("%s: no hostkey from index %d", __func__, keyid);
 591         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 592                 fatal("%s: key_sign failed", __func__);
 593
 594         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 595
 596         buffer_clear(m);
 597         buffer_put_string(m, signature, siglen);
 598
 599         xfree(p);
 600         xfree(signature);
 601
 602         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 603
 604         /* Turn on permissions for getpwnam */
 605         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 606
 607         return (0);
 608 }
 609
 610 /* Retrieves the password entry and also checks if the user is permitted */
 611
 612 int
 613 mm_answer_pwnamallow(int sock, Buffer *m)
 614 {
 615         char *username;
 616         struct passwd *pwent;
 617         int allowed = 0;
 618
 619         debug3("%s", __func__);
 620
 621         if (authctxt->attempt++ != 0)
 622                 fatal("%s: multiple attempts for getpwnam", __func__);
 623
 624         username = buffer_get_string(m, NULL);
 625
 626         pwent = getpwnamallow(username);
 627
 628         authctxt->user = xstrdup(username);
 629         setproctitle("%s [priv]", pwent ? username : "unknown");
 630         xfree(username);
 631
 632         buffer_clear(m);
 633
 634         if (pwent == NULL) {
 635                 buffer_put_char(m, 0);
 636                 authctxt->pw = fakepw();
 637                 goto out;
 638         }
 639
 640         allowed = 1;
 641         authctxt->pw = pwent;
 642         authctxt->valid = 1;
 643
 644         buffer_put_char(m, 1);
 645         buffer_put_string(m, pwent, sizeof(struct passwd));
 646         buffer_put_cstring(m, pwent->pw_name);
 647         buffer_put_cstring(m, "*");
 648         buffer_put_cstring(m, pwent->pw_gecos);
 649 #ifdef HAVE_PW_CLASS_IN_PASSWD
 650         buffer_put_cstring(m, pwent->pw_class);
 651 #endif
 652         buffer_put_cstring(m, pwent->pw_dir);
 653         buffer_put_cstring(m, pwent->pw_shell);
 654
 655  out:
 656         buffer_put_string(m, &options, sizeof(options));
 657         if (options.banner != NULL)
 658                 buffer_put_cstring(m, options.banner);
 659         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 660         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 661
 662         /* For SSHv1 allow authentication now */
 663         if (!compat20)
 664                 monitor_permit_authentications(1);
 665         else {
 666                 /* Allow service/style information on the auth context */
 667                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 668                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 669         }
 670
 671 #ifdef USE_PAM
 672         if (options.use_pam)
 673                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 674 #endif
 675
 676         return (0);
 677 }
 678
 679 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 680 {
 681         char *banner;
 682
 683         buffer_clear(m);
 684         banner = auth2_read_banner();
 685         buffer_put_cstring(m, banner != NULL ? banner : "");
 686         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 687
 688         if (banner != NULL)
 689                 xfree(banner);
 690
 691         return (0);
 692 }
 693
 694 int
 695 mm_answer_authserv(int sock, Buffer *m)
 696 {
 697         monitor_permit_authentications(1);
 698
 699         authctxt->service = buffer_get_string(m, NULL);
 700         authctxt->style = buffer_get_string(m, NULL);
 701         debug3("%s: service=%s, style=%s",
 702             __func__, authctxt->service, authctxt->style);
 703
 704         if (strlen(authctxt->style) == 0) {
 705                 xfree(authctxt->style);
 706                 authctxt->style = NULL;
 707         }
 708
 709         return (0);
 710 }
 711
 712 int
 713 mm_answer_authpassword(int sock, Buffer *m)
 714 {
 715         static int call_count;
 716         char *passwd;
 717         int authenticated;
 718         u_int plen;
 719
 720         passwd = buffer_get_string(m, &plen);
 721         /* Only authenticate if the context is valid */
 722         authenticated = options.password_authentication &&
 723             auth_password(authctxt, passwd);
 724         memset(passwd, 0, strlen(passwd));
 725         xfree(passwd);
 726
 727         buffer_clear(m);
 728         buffer_put_int(m, authenticated);
 729
 730         debug3("%s: sending result %d", __func__, authenticated);
 731         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 732
 733         call_count++;
 734         if (plen == 0 && call_count == 1)
 735                 auth_method = "none";
 736         else
 737                 auth_method = "password";
 738
 739         /* Causes monitor loop to terminate if authenticated */
 740         return (authenticated);
 741 }
 742
 743 #ifdef BSD_AUTH
 744 int
 745 mm_answer_bsdauthquery(int sock, Buffer *m)
 746 {
 747         char *name, *infotxt;
 748         u_int numprompts;
 749         u_int *echo_on;
 750         char **prompts;
 751         u_int success;
 752
 753         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 754             &prompts, &echo_on) < 0 ? 0 : 1;
 755
 756         buffer_clear(m);
 757         buffer_put_int(m, success);
 758         if (success)
 759                 buffer_put_cstring(m, prompts[0]);
 760
 761         debug3("%s: sending challenge success: %u", __func__, success);
 762         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 763
 764         if (success) {
 765                 xfree(name);
 766                 xfree(infotxt);
 767                 xfree(prompts);
 768                 xfree(echo_on);
 769         }
 770
 771         return (0);
 772 }
 773
 774 int
 775 mm_answer_bsdauthrespond(int sock, Buffer *m)
 776 {
 777         char *response;
 778         int authok;
 779
 780         if (authctxt->as == 0)
 781                 fatal("%s: no bsd auth session", __func__);
 782
 783         response = buffer_get_string(m, NULL);
 784         authok = options.challenge_response_authentication &&
 785             auth_userresponse(authctxt->as, response, 0);
 786         authctxt->as = NULL;
 787         debug3("%s: <%s> = <%d>", __func__, response, authok);
 788         xfree(response);
 789
 790         buffer_clear(m);
 791         buffer_put_int(m, authok);
 792
 793         debug3("%s: sending authenticated: %d", __func__, authok);
 794         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 795
 796         auth_method = "bsdauth";
 797
 798         return (authok != 0);
 799 }
 800 #endif
 801
 802 #ifdef SKEY
 803 int
 804 mm_answer_skeyquery(int sock, Buffer *m)
 805 {
 806         struct skey skey;
 807         char challenge[1024];
 808         u_int success;
 809
 810         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 811             sizeof(challenge)) < 0 ? 0 : 1;
 812
 813         buffer_clear(m);
 814         buffer_put_int(m, success);
 815         if (success)
 816                 buffer_put_cstring(m, challenge);
 817
 818         debug3("%s: sending challenge success: %u", __func__, success);
 819         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 820
 821         return (0);
 822 }
 823
 824 int
 825 mm_answer_skeyrespond(int sock, Buffer *m)
 826 {
 827         char *response;
 828         int authok;
 829
 830         response = buffer_get_string(m, NULL);
 831
 832         authok = (options.challenge_response_authentication &&
 833             authctxt->valid &&
 834             skey_haskey(authctxt->pw->pw_name) == 0 &&
 835             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 836
 837         xfree(response);
 838
 839         buffer_clear(m);
 840         buffer_put_int(m, authok);
 841
 842         debug3("%s: sending authenticated: %d", __func__, authok);
 843         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 844
 845         auth_method = "skey";
 846
 847         return (authok != 0);
 848 }
 849 #endif
 850
 851 #ifdef USE_PAM
 852 int
 853 mm_answer_pam_start(int sock, Buffer *m)
 854 {
 855         if (!options.use_pam)
 856                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 857
 858         start_pam(authctxt);
 859
 860         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 861
 862         return (0);
 863 }
 864
 865 int
 866 mm_answer_pam_account(int sock, Buffer *m)
 867 {
 868         u_int ret;
 869
 870         if (!options.use_pam)
 871                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 872
 873         ret = do_pam_account();
 874
 875         buffer_put_int(m, ret);
 876         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 877
 878         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 879
 880         return (ret);
 881 }
 882
 883 static void *sshpam_ctxt, *sshpam_authok;
 884 extern KbdintDevice sshpam_device;
 885
 886 int
 887 mm_answer_pam_init_ctx(int sock, Buffer *m)
 888 {
 889
 890         debug3("%s", __func__);
 891         authctxt->user = buffer_get_string(m, NULL);
 892         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 893         sshpam_authok = NULL;
 894         buffer_clear(m);
 895         if (sshpam_ctxt != NULL) {
 896                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 897                 buffer_put_int(m, 1);
 898         } else {
 899                 buffer_put_int(m, 0);
 900         }
 901         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 902         return (0);
 903 }
 904
 905 int
 906 mm_answer_pam_query(int sock, Buffer *m)
 907 {
 908         char *name, *info, **prompts;
 909         u_int i, num, *echo_on;
 910         int ret;
 911
 912         debug3("%s", __func__);
 913         sshpam_authok = NULL;
 914         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 915         if (ret == 0 && num == 0)
 916                 sshpam_authok = sshpam_ctxt;
 917         if (num > 1 || name == NULL || info == NULL)
 918                 ret = -1;
 919         buffer_clear(m);
 920         buffer_put_int(m, ret);
 921         buffer_put_cstring(m, name);
 922         xfree(name);
 923         buffer_put_cstring(m, info);
 924         xfree(info);
 925         buffer_put_int(m, num);
 926         for (i = 0; i < num; ++i) {
 927                 buffer_put_cstring(m, prompts[i]);
 928                 xfree(prompts[i]);
 929                 buffer_put_int(m, echo_on[i]);
 930         }
 931         if (prompts != NULL)
 932                 xfree(prompts);
 933         if (echo_on != NULL)
 934                 xfree(echo_on);
 935         auth_method = "keyboard-interactive/pam";
 936         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 937         return (0);
 938 }
 939
 940 int
 941 mm_answer_pam_respond(int sock, Buffer *m)
 942 {
 943         char **resp;
 944         u_int i, num;
 945         int ret;
 946
 947         debug3("%s", __func__);
 948         sshpam_authok = NULL;
 949         num = buffer_get_int(m);
 950         if (num > 0) {
 951                 resp = xcalloc(num, sizeof(char *));
 952                 for (i = 0; i < num; ++i)
 953                         resp[i] = buffer_get_string(m, NULL);
 954                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 955                 for (i = 0; i < num; ++i)
 956                         xfree(resp[i]);
 957                 xfree(resp);
 958         } else {
 959                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 960         }
 961         buffer_clear(m);
 962         buffer_put_int(m, ret);
 963         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 964         auth_method = "keyboard-interactive/pam";
 965         if (ret == 0)
 966                 sshpam_authok = sshpam_ctxt;
 967         return (0);
 968 }
 969
 970 int
 971 mm_answer_pam_free_ctx(int sock, Buffer *m)
 972 {
 973
 974         debug3("%s", __func__);
 975         (sshpam_device.free_ctx)(sshpam_ctxt);
 976         buffer_clear(m);
 977         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 978         auth_method = "keyboard-interactive/pam";
 979         return (sshpam_authok == sshpam_ctxt);
 980 }
 981 #endif
 982
 983 static void
 984 mm_append_debug(Buffer *m)
 985 {
 986         if (auth_debug_init && buffer_len(&auth_debug)) {
 987                 debug3("%s: Appending debug messages for child", __func__);
 988                 buffer_append(m, buffer_ptr(&auth_debug),
 989                     buffer_len(&auth_debug));
 990                 buffer_clear(&auth_debug);
 991         }
 992 }
 993
 994 int
 995 mm_answer_keyallowed(int sock, Buffer *m)
 996 {
 997         Key *key;
 998         char *cuser, *chost;
 999         u_char *blob;
1000         u_int bloblen;
1001         enum mm_keytype type = 0;
1002         int allowed = 0;
1003
1004         debug3("%s entering", __func__);
1005
1006         type = buffer_get_int(m);
1007         cuser = buffer_get_string(m, NULL);
1008         chost = buffer_get_string(m, NULL);
1009         blob = buffer_get_string(m, &bloblen);
1010
1011         key = key_from_blob(blob, bloblen);
1012
1013         if ((compat20 && type == MM_RSAHOSTKEY) ||
1014             (!compat20 && type != MM_RSAHOSTKEY))
1015                 fatal("%s: key type and protocol mismatch", __func__);
1016
1017         debug3("%s: key_from_blob: %p", __func__, key);
1018
1019         if (key != NULL && authctxt->valid) {
1020                 switch (type) {
1021                 case MM_USERKEY:
1022                         allowed = options.pubkey_authentication &&
1023                             user_key_allowed(authctxt->pw, key);
1024                         auth_method = "publickey";
1025                         break;
1026                 case MM_HOSTKEY:
1027                         allowed = options.hostbased_authentication &&
1028                             hostbased_key_allowed(authctxt->pw,
1029                             cuser, chost, key);
1030                         auth_method = "hostbased";
1031                         break;
1032                 case MM_RSAHOSTKEY:
1033                         key->type = KEY_RSA1; /* XXX */
1034                         allowed = options.rhosts_rsa_authentication &&
1035                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1036                             cuser, chost, key);
1037                         auth_method = "rsa";
1038                         break;
1039                 default:
1040                         fatal("%s: unknown key type %d", __func__, type);
1041                         break;
1042                 }
1043         }
1044         if (key != NULL)
1045                 key_free(key);
1046
1047         /* clear temporarily storage (used by verify) */
1048         monitor_reset_key_state();
1049
1050         if (allowed) {
1051                 /* Save temporarily for comparison in verify */
1052                 key_blob = blob;
1053                 key_bloblen = bloblen;
1054                 key_blobtype = type;
1055                 hostbased_cuser = cuser;
1056                 hostbased_chost = chost;
1057         } else {
1058                 /* Log failed attempt */
1059                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1060                 xfree(blob);
1061                 xfree(cuser);
1062                 xfree(chost);
1063         }
1064
1065         debug3("%s: key %p is %s",
1066             __func__, key, allowed ? "allowed" : "disallowed");
1067
1068         buffer_clear(m);
1069         buffer_put_int(m, allowed);
1070         buffer_put_int(m, forced_command != NULL);
1071
1072         mm_append_debug(m);
1073
1074         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1075
1076         if (type == MM_RSAHOSTKEY)
1077                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1078
1079         return (0);
1080 }
1081
1082 static int
1083 monitor_valid_userblob(u_char *data, u_int datalen)
1084 {
1085         Buffer b;
1086         char *p;
1087         u_int len;
1088         int fail = 0;
1089
1090         buffer_init(&b);
1091         buffer_append(&b, data, datalen);
1092
1093         if (datafellows & SSH_OLD_SESSIONID) {
1094                 p = buffer_ptr(&b);
1095                 len = buffer_len(&b);
1096                 if ((session_id2 == NULL) ||
1097                     (len < session_id2_len) ||
1098                     (memcmp(p, session_id2, session_id2_len) != 0))
1099                         fail++;
1100                 buffer_consume(&b, session_id2_len);
1101         } else {
1102                 p = buffer_get_string(&b, &len);
1103                 if ((session_id2 == NULL) ||
1104                     (len != session_id2_len) ||
1105                     (memcmp(p, session_id2, session_id2_len) != 0))
1106                         fail++;
1107                 xfree(p);
1108         }
1109         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1110                 fail++;
1111         p = buffer_get_string(&b, NULL);
1112         if (strcmp(authctxt->user, p) != 0) {
1113                 logit("wrong user name passed to monitor: expected %s != %.100s",
1114                     authctxt->user, p);
1115                 fail++;
1116         }
1117         xfree(p);
1118         buffer_skip_string(&b);
1119         if (datafellows & SSH_BUG_PKAUTH) {
1120                 if (!buffer_get_char(&b))
1121                         fail++;
1122         } else {
1123                 p = buffer_get_string(&b, NULL);
1124                 if (strcmp("publickey", p) != 0)
1125                         fail++;
1126                 xfree(p);
1127                 if (!buffer_get_char(&b))
1128                         fail++;
1129                 buffer_skip_string(&b);
1130         }
1131         buffer_skip_string(&b);
1132         if (buffer_len(&b) != 0)
1133                 fail++;
1134         buffer_free(&b);
1135         return (fail == 0);
1136 }
1137
1138 static int
1139 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1140     char *chost)
1141 {
1142         Buffer b;
1143         char *p;
1144         u_int len;
1145         int fail = 0;
1146
1147         buffer_init(&b);
1148         buffer_append(&b, data, datalen);
1149
1150         p = buffer_get_string(&b, &len);
1151         if ((session_id2 == NULL) ||
1152             (len != session_id2_len) ||
1153             (memcmp(p, session_id2, session_id2_len) != 0))
1154                 fail++;
1155         xfree(p);
1156
1157         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1158                 fail++;
1159         p = buffer_get_string(&b, NULL);
1160         if (strcmp(authctxt->user, p) != 0) {
1161                 logit("wrong user name passed to monitor: expected %s != %.100s",
1162                     authctxt->user, p);
1163                 fail++;
1164         }
1165         xfree(p);
1166         buffer_skip_string(&b); /* service */
1167         p = buffer_get_string(&b, NULL);
1168         if (strcmp(p, "hostbased") != 0)
1169                 fail++;
1170         xfree(p);
1171         buffer_skip_string(&b); /* pkalg */
1172         buffer_skip_string(&b); /* pkblob */
1173
1174         /* verify client host, strip trailing dot if necessary */
1175         p = buffer_get_string(&b, NULL);
1176         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1177                 p[len - 1] = '\0';
1178         if (strcmp(p, chost) != 0)
1179                 fail++;
1180         xfree(p);
1181
1182         /* verify client user */
1183         p = buffer_get_string(&b, NULL);
1184         if (strcmp(p, cuser) != 0)
1185                 fail++;
1186         xfree(p);
1187
1188         if (buffer_len(&b) != 0)
1189                 fail++;
1190         buffer_free(&b);
1191         return (fail == 0);
1192 }
1193
1194 int
1195 mm_answer_keyverify(int sock, Buffer *m)
1196 {
1197         Key *key;
1198         u_char *signature, *data, *blob;
1199         u_int signaturelen, datalen, bloblen;
1200         int verified = 0;
1201         int valid_data = 0;
1202
1203         blob = buffer_get_string(m, &bloblen);
1204         signature = buffer_get_string(m, &signaturelen);
1205         data = buffer_get_string(m, &datalen);
1206
1207         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1208           !monitor_allowed_key(blob, bloblen))
1209                 fatal("%s: bad key, not previously allowed", __func__);
1210
1211         key = key_from_blob(blob, bloblen);
1212         if (key == NULL)
1213                 fatal("%s: bad public key blob", __func__);
1214
1215         switch (key_blobtype) {
1216         case MM_USERKEY:
1217                 valid_data = monitor_valid_userblob(data, datalen);
1218                 break;
1219         case MM_HOSTKEY:
1220                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1221                     hostbased_cuser, hostbased_chost);
1222                 break;
1223         default:
1224                 valid_data = 0;
1225                 break;
1226         }
1227         if (!valid_data)
1228                 fatal("%s: bad signature data blob", __func__);
1229
1230         verified = key_verify(key, signature, signaturelen, data, datalen);
1231         debug3("%s: key %p signature %s",
1232             __func__, key, (verified == 1) ? "verified" : "unverified");
1233
1234         key_free(key);
1235         xfree(blob);
1236         xfree(signature);
1237         xfree(data);
1238
1239         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1240
1241         monitor_reset_key_state();
1242
1243         buffer_clear(m);
1244         buffer_put_int(m, verified);
1245         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1246
1247         return (verified == 1);
1248 }
1249
1250 static void
1251 mm_record_login(Session *s, struct passwd *pw)
1252 {
1253         socklen_t fromlen;
1254         struct sockaddr_storage from;
1255
1256         /*
1257          * Get IP address of client. If the connection is not a socket, let
1258          * the address be 0.0.0.0.
1259          */
1260         memset(&from, 0, sizeof(from));
1261         fromlen = sizeof(from);
1262         if (packet_connection_is_on_socket()) {
1263                 if (getpeername(packet_get_connection_in(),
1264                     (struct sockaddr *)&from, &fromlen) < 0) {
1265                         debug("getpeername: %.100s", strerror(errno));
1266                         cleanup_exit(255);
1267                 }
1268         }
1269         /* Record that there was a login on that tty from the remote host. */
1270         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1271             get_remote_name_or_ip(utmp_len, options.use_dns),
1272             (struct sockaddr *)&from, fromlen);
1273 }
1274
1275 static void
1276 mm_session_close(Session *s)
1277 {
1278         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1279         if (s->ttyfd != -1) {
1280                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1281                 session_pty_cleanup2(s);
1282         }
1283         s->used = 0;
1284 }
1285
1286 int
1287 mm_answer_pty(int sock, Buffer *m)
1288 {
1289         extern struct monitor *pmonitor;
1290         Session *s;
1291         int res, fd0;
1292
1293         debug3("%s entering", __func__);
1294
1295         buffer_clear(m);
1296         s = session_new();
1297         if (s == NULL)
1298                 goto error;
1299         s->authctxt = authctxt;
1300         s->pw = authctxt->pw;
1301         s->pid = pmonitor->m_pid;
1302         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1303         if (res == 0)
1304                 goto error;
1305         pty_setowner(authctxt->pw, s->tty);
1306
1307         buffer_put_int(m, 1);
1308         buffer_put_cstring(m, s->tty);
1309
1310         /* We need to trick ttyslot */
1311         if (dup2(s->ttyfd, 0) == -1)
1312                 fatal("%s: dup2", __func__);
1313
1314         mm_record_login(s, authctxt->pw);
1315
1316         /* Now we can close the file descriptor again */
1317         close(0);
1318
1319         /* send messages generated by record_login */
1320         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1321         buffer_clear(&loginmsg);
1322
1323         mm_request_send(sock, MONITOR_ANS_PTY, m);
1324
1325         if (mm_send_fd(sock, s->ptyfd) == -1 ||
1326             mm_send_fd(sock, s->ttyfd) == -1)
1327                 fatal("%s: send fds failed", __func__);
1328
1329         /* make sure nothing uses fd 0 */
1330         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1331                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1332         if (fd0 != 0)
1333                 error("%s: fd0 %d != 0", __func__, fd0);
1334
1335         /* slave is not needed */
1336         close(s->ttyfd);
1337         s->ttyfd = s->ptyfd;
1338         /* no need to dup() because nobody closes ptyfd */
1339         s->ptymaster = s->ptyfd;
1340
1341         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1342
1343         return (0);
1344
1345  error:
1346         if (s != NULL)
1347                 mm_session_close(s);
1348         buffer_put_int(m, 0);
1349         mm_request_send(sock, MONITOR_ANS_PTY, m);
1350         return (0);
1351 }
1352
1353 int
1354 mm_answer_pty_cleanup(int sock, Buffer *m)
1355 {
1356         Session *s;
1357         char *tty;
1358
1359         debug3("%s entering", __func__);
1360
1361         tty = buffer_get_string(m, NULL);
1362         if ((s = session_by_tty(tty)) != NULL)
1363                 mm_session_close(s);
1364         buffer_clear(m);
1365         xfree(tty);
1366         return (0);
1367 }
1368
1369 int
1370 mm_answer_sesskey(int sock, Buffer *m)
1371 {
1372         BIGNUM *p;
1373         int rsafail;
1374
1375         /* Turn off permissions */
1376         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1377
1378         if ((p = BN_new()) == NULL)
1379                 fatal("%s: BN_new", __func__);
1380
1381         buffer_get_bignum2(m, p);
1382
1383         rsafail = ssh1_session_key(p);
1384
1385         buffer_clear(m);
1386         buffer_put_int(m, rsafail);
1387         buffer_put_bignum2(m, p);
1388
1389         BN_clear_free(p);
1390
1391         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1392
1393         /* Turn on permissions for sessid passing */
1394         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1395
1396         return (0);
1397 }
1398
1399 int
1400 mm_answer_sessid(int sock, Buffer *m)
1401 {
1402         int i;
1403
1404         debug3("%s entering", __func__);
1405
1406         if (buffer_len(m) != 16)
1407                 fatal("%s: bad ssh1 session id", __func__);
1408         for (i = 0; i < 16; i++)
1409                 session_id[i] = buffer_get_char(m);
1410
1411         /* Turn on permissions for getpwnam */
1412         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1413
1414         return (0);
1415 }
1416
1417 int
1418 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1419 {
1420         BIGNUM *client_n;
1421         Key *key = NULL;
1422         u_char *blob = NULL;
1423         u_int blen = 0;
1424         int allowed = 0;
1425
1426         debug3("%s entering", __func__);
1427
1428         auth_method = "rsa";
1429         if (options.rsa_authentication && authctxt->valid) {
1430                 if ((client_n = BN_new()) == NULL)
1431                         fatal("%s: BN_new", __func__);
1432                 buffer_get_bignum2(m, client_n);
1433                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1434                 BN_clear_free(client_n);
1435         }
1436         buffer_clear(m);
1437         buffer_put_int(m, allowed);
1438         buffer_put_int(m, forced_command != NULL);
1439
1440         /* clear temporarily storage (used by generate challenge) */
1441         monitor_reset_key_state();
1442
1443         if (allowed && key != NULL) {
1444                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1445                 if (key_to_blob(key, &blob, &blen) == 0)
1446                         fatal("%s: key_to_blob failed", __func__);
1447                 buffer_put_string(m, blob, blen);
1448
1449                 /* Save temporarily for comparison in verify */
1450                 key_blob = blob;
1451                 key_bloblen = blen;
1452                 key_blobtype = MM_RSAUSERKEY;
1453         }
1454         if (key != NULL)
1455                 key_free(key);
1456
1457         mm_append_debug(m);
1458
1459         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1460
1461         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1462         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1463         return (0);
1464 }
1465
1466 int
1467 mm_answer_rsa_challenge(int sock, Buffer *m)
1468 {
1469         Key *key = NULL;
1470         u_char *blob;
1471         u_int blen;
1472
1473         debug3("%s entering", __func__);
1474
1475         if (!authctxt->valid)
1476                 fatal("%s: authctxt not valid", __func__);
1477         blob = buffer_get_string(m, &blen);
1478         if (!monitor_allowed_key(blob, blen))
1479                 fatal("%s: bad key, not previously allowed", __func__);
1480         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1481                 fatal("%s: key type mismatch", __func__);
1482         if ((key = key_from_blob(blob, blen)) == NULL)
1483                 fatal("%s: received bad key", __func__);
1484
1485         if (ssh1_challenge)
1486                 BN_clear_free(ssh1_challenge);
1487         ssh1_challenge = auth_rsa_generate_challenge(key);
1488
1489         buffer_clear(m);
1490         buffer_put_bignum2(m, ssh1_challenge);
1491
1492         debug3("%s sending reply", __func__);
1493         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1494
1495         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1496
1497         xfree(blob);
1498         key_free(key);
1499         return (0);
1500 }
1501
1502 int
1503 mm_answer_rsa_response(int sock, Buffer *m)
1504 {
1505         Key *key = NULL;
1506         u_char *blob, *response;
1507         u_int blen, len;
1508         int success;
1509
1510         debug3("%s entering", __func__);
1511
1512         if (!authctxt->valid)
1513                 fatal("%s: authctxt not valid", __func__);
1514         if (ssh1_challenge == NULL)
1515                 fatal("%s: no ssh1_challenge", __func__);
1516
1517         blob = buffer_get_string(m, &blen);
1518         if (!monitor_allowed_key(blob, blen))
1519                 fatal("%s: bad key, not previously allowed", __func__);
1520         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1521                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1522         if ((key = key_from_blob(blob, blen)) == NULL)
1523                 fatal("%s: received bad key", __func__);
1524         response = buffer_get_string(m, &len);
1525         if (len != 16)
1526                 fatal("%s: received bad response to challenge", __func__);
1527         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1528
1529         xfree(blob);
1530         key_free(key);
1531         xfree(response);
1532
1533         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1534
1535         /* reset state */
1536         BN_clear_free(ssh1_challenge);
1537         ssh1_challenge = NULL;
1538         monitor_reset_key_state();
1539
1540         buffer_clear(m);
1541         buffer_put_int(m, success);
1542         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1543
1544         return (success);
1545 }
1546
1547 int
1548 mm_answer_term(int sock, Buffer *req)
1549 {
1550         extern struct monitor *pmonitor;
1551         int res, status;
1552
1553         debug3("%s: tearing down sessions", __func__);
1554
1555         /* The child is terminating */
1556         session_destroy_all(&mm_session_close);
1557
1558 #ifdef USE_PAM
1559         if (options.use_pam)
1560                 sshpam_cleanup();
1561 #endif
1562
1563         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1564                 if (errno != EINTR)
1565                         exit(1);
1566
1567         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1568
1569         /* Terminate process */
1570         exit(res);
1571 }
1572
1573 #ifdef SSH_AUDIT_EVENTS
1574 /* Report that an audit event occurred */
1575 int
1576 mm_answer_audit_event(int socket, Buffer *m)
1577 {
1578         ssh_audit_event_t event;
1579
1580         debug3("%s entering", __func__);
1581
1582         event = buffer_get_int(m);
1583         switch(event) {
1584         case SSH_AUTH_FAIL_PUBKEY:
1585         case SSH_AUTH_FAIL_HOSTBASED:
1586         case SSH_AUTH_FAIL_GSSAPI:
1587         case SSH_LOGIN_EXCEED_MAXTRIES:
1588         case SSH_LOGIN_ROOT_DENIED:
1589         case SSH_CONNECTION_CLOSE:
1590         case SSH_INVALID_USER:
1591                 audit_event(event);
1592                 break;
1593         default:
1594                 fatal("Audit event type %d not permitted", event);
1595         }
1596
1597         return (0);
1598 }
1599
1600 int
1601 mm_answer_audit_command(int socket, Buffer *m)
1602 {
1603         u_int len;
1604         char *cmd;
1605
1606         debug3("%s entering", __func__);
1607         cmd = buffer_get_string(m, &len);
1608         /* sanity check command, if so how? */
1609         audit_run_command(cmd);
1610         xfree(cmd);
1611         return (0);
1612 }
1613 #endif /* SSH_AUDIT_EVENTS */
1614
1615 void
1616 monitor_apply_keystate(struct monitor *pmonitor)
1617 {
1618         if (compat20) {
1619                 set_newkeys(MODE_IN);
1620                 set_newkeys(MODE_OUT);
1621         } else {
1622                 packet_set_protocol_flags(child_state.ssh1protoflags);
1623                 packet_set_encryption_key(child_state.ssh1key,
1624                     child_state.ssh1keylen, child_state.ssh1cipher);
1625                 xfree(child_state.ssh1key);
1626         }
1627
1628         /* for rc4 and other stateful ciphers */
1629         packet_set_keycontext(MODE_OUT, child_state.keyout);
1630         xfree(child_state.keyout);
1631         packet_set_keycontext(MODE_IN, child_state.keyin);
1632         xfree(child_state.keyin);
1633
1634         if (!compat20) {
1635                 packet_set_iv(MODE_OUT, child_state.ivout);
1636                 xfree(child_state.ivout);
1637                 packet_set_iv(MODE_IN, child_state.ivin);
1638                 xfree(child_state.ivin);
1639         }
1640
1641         memcpy(&incoming_stream, &child_state.incoming,
1642             sizeof(incoming_stream));
1643         memcpy(&outgoing_stream, &child_state.outgoing,
1644             sizeof(outgoing_stream));
1645
1646         /* Update with new address */
1647         if (options.compression)
1648                 mm_init_compression(pmonitor->m_zlib);
1649
1650         /* Network I/O buffers */
1651         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1652         buffer_clear(&input);
1653         buffer_append(&input, child_state.input, child_state.ilen);
1654         memset(child_state.input, 0, child_state.ilen);
1655         xfree(child_state.input);
1656
1657         buffer_clear(&output);
1658         buffer_append(&output, child_state.output, child_state.olen);
1659         memset(child_state.output, 0, child_state.olen);
1660         xfree(child_state.output);
1661 }
1662
1663 static Kex *
1664 mm_get_kex(Buffer *m)
1665 {
1666         Kex *kex;
1667         void *blob;
1668         u_int bloblen;
1669
1670         kex = xcalloc(1, sizeof(*kex));
1671         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1672         if ((session_id2 == NULL) ||
1673             (kex->session_id_len != session_id2_len) ||
1674             (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1675                 fatal("mm_get_get: internal error: bad session id");
1676         kex->we_need = buffer_get_int(m);
1677         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1678         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1679         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1680         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1681         kex->server = 1;
1682         kex->hostkey_type = buffer_get_int(m);
1683         kex->kex_type = buffer_get_int(m);
1684         blob = buffer_get_string(m, &bloblen);
1685         buffer_init(&kex->my);
1686         buffer_append(&kex->my, blob, bloblen);
1687         xfree(blob);
1688         blob = buffer_get_string(m, &bloblen);
1689         buffer_init(&kex->peer);
1690         buffer_append(&kex->peer, blob, bloblen);
1691         xfree(blob);
1692         kex->done = 1;
1693         kex->flags = buffer_get_int(m);
1694         kex->client_version_string = buffer_get_string(m, NULL);
1695         kex->server_version_string = buffer_get_string(m, NULL);
1696         kex->load_host_key=&get_hostkey_by_type;
1697         kex->host_key_index=&get_hostkey_index;
1698
1699         return (kex);
1700 }
1701
1702 /* This function requries careful sanity checking */
1703
1704 void
1705 mm_get_keystate(struct monitor *pmonitor)
1706 {
1707         Buffer m;
1708         u_char *blob, *p;
1709         u_int bloblen, plen;
1710         u_int32_t seqnr, packets;
1711         u_int64_t blocks;
1712
1713         debug3("%s: Waiting for new keys", __func__);
1714
1715         buffer_init(&m);
1716         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1717         if (!compat20) {
1718                 child_state.ssh1protoflags = buffer_get_int(&m);
1719                 child_state.ssh1cipher = buffer_get_int(&m);
1720                 child_state.ssh1key = buffer_get_string(&m,
1721                     &child_state.ssh1keylen);
1722                 child_state.ivout = buffer_get_string(&m,
1723                     &child_state.ivoutlen);
1724                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1725                 goto skip;
1726         } else {
1727                 /* Get the Kex for rekeying */
1728                 *pmonitor->m_pkex = mm_get_kex(&m);
1729         }
1730
1731         blob = buffer_get_string(&m, &bloblen);
1732         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1733         xfree(blob);
1734
1735         debug3("%s: Waiting for second key", __func__);
1736         blob = buffer_get_string(&m, &bloblen);
1737         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1738         xfree(blob);
1739
1740         /* Now get sequence numbers for the packets */
1741         seqnr = buffer_get_int(&m);
1742         blocks = buffer_get_int64(&m);
1743         packets = buffer_get_int(&m);
1744         packet_set_state(MODE_OUT, seqnr, blocks, packets);
1745         seqnr = buffer_get_int(&m);
1746         blocks = buffer_get_int64(&m);
1747         packets = buffer_get_int(&m);
1748         packet_set_state(MODE_IN, seqnr, blocks, packets);
1749
1750  skip:
1751         /* Get the key context */
1752         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1753         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1754
1755         debug3("%s: Getting compression state", __func__);
1756         /* Get compression state */
1757         p = buffer_get_string(&m, &plen);
1758         if (plen != sizeof(child_state.outgoing))
1759                 fatal("%s: bad request size", __func__);
1760         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1761         xfree(p);
1762
1763         p = buffer_get_string(&m, &plen);
1764         if (plen != sizeof(child_state.incoming))
1765                 fatal("%s: bad request size", __func__);
1766         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1767         xfree(p);
1768
1769         /* Network I/O buffers */
1770         debug3("%s: Getting Network I/O buffers", __func__);
1771         child_state.input = buffer_get_string(&m, &child_state.ilen);
1772         child_state.output = buffer_get_string(&m, &child_state.olen);
1773
1774         buffer_free(&m);
1775 }
1776
1777
1778 /* Allocation functions for zlib */
1779 void *
1780 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1781 {
1782         size_t len = (size_t) size * ncount;
1783         void *address;
1784
1785         if (len == 0 || ncount > SIZE_T_MAX / size)
1786                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1787
1788         address = mm_malloc(mm, len);
1789
1790         return (address);
1791 }
1792
1793 void
1794 mm_zfree(struct mm_master *mm, void *address)
1795 {
1796         mm_free(mm, address);
1797 }
1798
1799 void
1800 mm_init_compression(struct mm_master *mm)
1801 {
1802         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1803         outgoing_stream.zfree = (free_func)mm_zfree;
1804         outgoing_stream.opaque = mm;
1805
1806         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1807         incoming_stream.zfree = (free_func)mm_zfree;
1808         incoming_stream.opaque = mm;
1809 }
1810
1811 /* XXX */
1812
1813 #define FD_CLOSEONEXEC(x) do { \
1814         if (fcntl(x, F_SETFD, 1) == -1) \
1815                 fatal("fcntl(%d, F_SETFD)", x); \
1816 } while (0)
1817
1818 static void
1819 monitor_socketpair(int *pair)
1820 {
1821 #ifdef HAVE_SOCKETPAIR
1822         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1823                 fatal("%s: socketpair", __func__);
1824 #else
1825         fatal("%s: UsePrivilegeSeparation=yes not supported",
1826             __func__);
1827 #endif
1828         FD_CLOSEONEXEC(pair[0]);
1829         FD_CLOSEONEXEC(pair[1]);
1830 }
1831
1832 #define MM_MEMSIZE      65536
1833
1834 struct monitor *
1835 monitor_init(void)
1836 {
1837         struct monitor *mon;
1838         int pair[2];
1839
1840         mon = xcalloc(1, sizeof(*mon));
1841
1842         monitor_socketpair(pair);
1843
1844         mon->m_recvfd = pair[0];
1845         mon->m_sendfd = pair[1];
1846
1847         /* Used to share zlib space across processes */
1848         if (options.compression) {
1849                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1850                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1851
1852                 /* Compression needs to share state across borders */
1853                 mm_init_compression(mon->m_zlib);
1854         }
1855
1856         return mon;
1857 }
1858
1859 void
1860 monitor_reinit(struct monitor *mon)
1861 {
1862         int pair[2];
1863
1864         monitor_socketpair(pair);
1865
1866         mon->m_recvfd = pair[0];
1867         mon->m_sendfd = pair[1];
1868 }
1869
1870 #ifdef GSSAPI
1871 int
1872 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1873 {
1874         gss_OID_desc goid;
1875         OM_uint32 major;
1876         u_int len;
1877
1878         goid.elements = buffer_get_string(m, &len);
1879         goid.length = len;
1880
1881         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1882
1883         xfree(goid.elements);
1884
1885         buffer_clear(m);
1886         buffer_put_int(m, major);
1887
1888         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1889
1890         /* Now we have a context, enable the step */
1891         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1892
1893         return (0);
1894 }
1895
1896 int
1897 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1898 {
1899         gss_buffer_desc in;
1900         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1901         OM_uint32 major, minor;
1902         OM_uint32 flags = 0; /* GSI needs this */
1903         u_int len;
1904
1905         in.value = buffer_get_string(m, &len);
1906         in.length = len;
1907         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1908         xfree(in.value);
1909
1910         buffer_clear(m);
1911         buffer_put_int(m, major);
1912         buffer_put_string(m, out.value, out.length);
1913         buffer_put_int(m, flags);
1914         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1915
1916         gss_release_buffer(&minor, &out);
1917
1918         if (major == GSS_S_COMPLETE) {
1919                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1920                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1921                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1922         }
1923         return (0);
1924 }
1925
1926 int
1927 mm_answer_gss_checkmic(int sock, Buffer *m)
1928 {
1929         gss_buffer_desc gssbuf, mic;
1930         OM_uint32 ret;
1931         u_int len;
1932
1933         gssbuf.value = buffer_get_string(m, &len);
1934         gssbuf.length = len;
1935         mic.value = buffer_get_string(m, &len);
1936         mic.length = len;
1937
1938         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1939
1940         xfree(gssbuf.value);
1941         xfree(mic.value);
1942
1943         buffer_clear(m);
1944         buffer_put_int(m, ret);
1945
1946         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1947
1948         if (!GSS_ERROR(ret))
1949                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1950
1951         return (0);
1952 }
1953
1954 int
1955 mm_answer_gss_userok(int sock, Buffer *m)
1956 {
1957         int authenticated;
1958
1959         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1960
1961         buffer_clear(m);
1962         buffer_put_int(m, authenticated);
1963
1964         debug3("%s: sending result %d", __func__, authenticated);
1965         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1966
1967         auth_method = "gssapi-with-mic";
1968
1969         /* Monitor loop will terminate if authenticated */
1970         return (authenticated);
1971 }
1972 #endif /* GSSAPI */