crypto/openssh-5/monitor.c

   1 /* $OpenBSD: monitor.c,v 1.99 2008/07/10 18:08:11 markus 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 #include <skey.h>
  50 #endif
  51
  52 #include <openssl/dh.h>
  53
  54 #include "openbsd-compat/sys-queue.h"
  55 #include "xmalloc.h"
  56 #include "ssh.h"
  57 #include "key.h"
  58 #include "buffer.h"
  59 #include "hostfile.h"
  60 #include "auth.h"
  61 #include "cipher.h"
  62 #include "kex.h"
  63 #include "dh.h"
  64 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
  65 #undef TARGET_OS_MAC
  66 #include "zlib.h"
  67 #define TARGET_OS_MAC 1
  68 #else
  69 #include "zlib.h"
  70 #endif
  71 #include "packet.h"
  72 #include "auth-options.h"
  73 #include "sshpty.h"
  74 #include "channels.h"
  75 #include "session.h"
  76 #include "sshlogin.h"
  77 #include "canohost.h"
  78 #include "log.h"
  79 #include "servconf.h"
  80 #include "monitor.h"
  81 #include "monitor_mm.h"
  82 #ifdef GSSAPI
  83 #include "ssh-gss.h"
  84 #endif
  85 #include "monitor_wrap.h"
  86 #include "monitor_fdpass.h"
  87 #include "misc.h"
  88 #include "compat.h"
  89 #include "ssh2.h"
  90
  91 #ifdef GSSAPI
  92 static Gssctxt *gsscontext = NULL;
  93 #endif
  94
  95 /* Imports */
  96 extern ServerOptions options;
  97 extern u_int utmp_len;
  98 extern Newkeys *current_keys[];
  99 extern z_stream incoming_stream;
 100 extern z_stream outgoing_stream;
 101 extern u_char session_id[];
 102 extern Buffer input, output;
 103 extern Buffer auth_debug;
 104 extern int auth_debug_init;
 105 extern Buffer loginmsg;
 106
 107 /* State exported from the child */
 108
 109 struct {
 110         z_stream incoming;
 111         z_stream outgoing;
 112         u_char *keyin;
 113         u_int keyinlen;
 114         u_char *keyout;
 115         u_int keyoutlen;
 116         u_char *ivin;
 117         u_int ivinlen;
 118         u_char *ivout;
 119         u_int ivoutlen;
 120         u_char *ssh1key;
 121         u_int ssh1keylen;
 122         int ssh1cipher;
 123         int ssh1protoflags;
 124         u_char *input;
 125         u_int ilen;
 126         u_char *output;
 127         u_int olen;
 128 } child_state;
 129
 130 /* Functions on the monitor that answer unprivileged requests */
 131
 132 int mm_answer_moduli(int, Buffer *);
 133 int mm_answer_sign(int, Buffer *);
 134 int mm_answer_pwnamallow(int, Buffer *);
 135 int mm_answer_auth2_read_banner(int, Buffer *);
 136 int mm_answer_authserv(int, Buffer *);
 137 int mm_answer_authpassword(int, Buffer *);
 138 int mm_answer_bsdauthquery(int, Buffer *);
 139 int mm_answer_bsdauthrespond(int, Buffer *);
 140 int mm_answer_skeyquery(int, Buffer *);
 141 int mm_answer_skeyrespond(int, Buffer *);
 142 int mm_answer_keyallowed(int, Buffer *);
 143 int mm_answer_keyverify(int, Buffer *);
 144 int mm_answer_pty(int, Buffer *);
 145 int mm_answer_pty_cleanup(int, Buffer *);
 146 int mm_answer_term(int, Buffer *);
 147 int mm_answer_rsa_keyallowed(int, Buffer *);
 148 int mm_answer_rsa_challenge(int, Buffer *);
 149 int mm_answer_rsa_response(int, Buffer *);
 150 int mm_answer_sesskey(int, Buffer *);
 151 int mm_answer_sessid(int, Buffer *);
 152
 153 #ifdef USE_PAM
 154 int mm_answer_pam_start(int, Buffer *);
 155 int mm_answer_pam_account(int, Buffer *);
 156 int mm_answer_pam_init_ctx(int, Buffer *);
 157 int mm_answer_pam_query(int, Buffer *);
 158 int mm_answer_pam_respond(int, Buffer *);
 159 int mm_answer_pam_free_ctx(int, Buffer *);
 160 #endif
 161
 162 #ifdef GSSAPI
 163 int mm_answer_gss_setup_ctx(int, Buffer *);
 164 int mm_answer_gss_accept_ctx(int, Buffer *);
 165 int mm_answer_gss_userok(int, Buffer *);
 166 int mm_answer_gss_checkmic(int, Buffer *);
 167 #endif
 168
 169 #ifdef SSH_AUDIT_EVENTS
 170 int mm_answer_audit_event(int, Buffer *);
 171 int mm_answer_audit_command(int, Buffer *);
 172 #endif
 173
 174 static Authctxt *authctxt;
 175 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 176
 177 /* local state for key verify */
 178 static u_char *key_blob = NULL;
 179 static u_int key_bloblen = 0;
 180 static int key_blobtype = MM_NOKEY;
 181 static char *hostbased_cuser = NULL;
 182 static char *hostbased_chost = NULL;
 183 static char *auth_method = "unknown";
 184 static u_int session_id2_len = 0;
 185 static u_char *session_id2 = NULL;
 186 static pid_t monitor_child_pid;
 187
 188 struct mon_table {
 189         enum monitor_reqtype type;
 190         int flags;
 191         int (*f)(int, Buffer *);
 192 };
 193
 194 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 195 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 196 #define MON_ONCE        0x0010  /* Disable after calling */
 197 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 198
 199 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 200
 201 #define MON_PERMIT      0x1000  /* Request is permitted */
 202
 203 struct mon_table mon_dispatch_proto20[] = {
 204     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 205     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 206     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 207     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 208     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 209     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 210 #ifdef USE_PAM
 211     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 212     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 213     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 214     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 215     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 216     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 217 #endif
 218 #ifdef SSH_AUDIT_EVENTS
 219     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 220 #endif
 221 #ifdef BSD_AUTH
 222     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 223     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 224 #endif
 225 #ifdef SKEY
 226     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 227     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 228 #endif
 229     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 230     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 231 #ifdef GSSAPI
 232     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 233     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 234     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 235     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 236 #endif
 237     {0, 0, NULL}
 238 };
 239
 240 struct mon_table mon_dispatch_postauth20[] = {
 241     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 242     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 243     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 244     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 245     {MONITOR_REQ_TERM, 0, mm_answer_term},
 246 #ifdef SSH_AUDIT_EVENTS
 247     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 248     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 249 #endif
 250     {0, 0, NULL}
 251 };
 252
 253 struct mon_table mon_dispatch_proto15[] = {
 254     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 255     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 256     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 257     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 258     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 259     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 260     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 261     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 262 #ifdef BSD_AUTH
 263     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 264     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 265 #endif
 266 #ifdef SKEY
 267     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 268     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 269 #endif
 270 #ifdef USE_PAM
 271     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 272     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 273     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 274     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 275     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 276     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 277 #endif
 278 #ifdef SSH_AUDIT_EVENTS
 279     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 280 #endif
 281     {0, 0, NULL}
 282 };
 283
 284 struct mon_table mon_dispatch_postauth15[] = {
 285     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 286     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 287     {MONITOR_REQ_TERM, 0, mm_answer_term},
 288 #ifdef SSH_AUDIT_EVENTS
 289     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 290     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
 291 #endif
 292     {0, 0, NULL}
 293 };
 294
 295 struct mon_table *mon_dispatch;
 296
 297 /* Specifies if a certain message is allowed at the moment */
 298
 299 static void
 300 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 301 {
 302         while (ent->f != NULL) {
 303                 if (ent->type == type) {
 304                         ent->flags &= ~MON_PERMIT;
 305                         ent->flags |= permit ? MON_PERMIT : 0;
 306                         return;
 307                 }
 308                 ent++;
 309         }
 310 }
 311
 312 static void
 313 monitor_permit_authentications(int permit)
 314 {
 315         struct mon_table *ent = mon_dispatch;
 316
 317         while (ent->f != NULL) {
 318                 if (ent->flags & MON_AUTH) {
 319                         ent->flags &= ~MON_PERMIT;
 320                         ent->flags |= permit ? MON_PERMIT : 0;
 321                 }
 322                 ent++;
 323         }
 324 }
 325
 326 void
 327 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 328 {
 329         struct mon_table *ent;
 330         int authenticated = 0;
 331
 332         debug3("preauth child monitor started");
 333
 334         authctxt = _authctxt;
 335         memset(authctxt, 0, sizeof(*authctxt));
 336
 337         authctxt->loginmsg = &loginmsg;
 338
 339         if (compat20) {
 340                 mon_dispatch = mon_dispatch_proto20;
 341
 342                 /* Permit requests for moduli and signatures */
 343                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 344                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 345         } else {
 346                 mon_dispatch = mon_dispatch_proto15;
 347
 348                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 349         }
 350
 351         /* The first few requests do not require asynchronous access */
 352         while (!authenticated) {
 353                 auth_method = "unknown";
 354                 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
 355                 if (authenticated) {
 356                         if (!(ent->flags & MON_AUTHDECIDE))
 357                                 fatal("%s: unexpected authentication from %d",
 358                                     __func__, ent->type);
 359                         if (authctxt->pw->pw_uid == 0 &&
 360                             !auth_root_allowed(auth_method))
 361                                 authenticated = 0;
 362 #ifdef USE_PAM
 363                         /* PAM needs to perform account checks after auth */
 364                         if (options.use_pam && authenticated) {
 365                                 Buffer m;
 366
 367                                 buffer_init(&m);
 368                                 mm_request_receive_expect(pmonitor->m_sendfd,
 369                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 370                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 371                                 buffer_free(&m);
 372                         }
 373 #endif
 374                 }
 375
 376                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 377                         auth_log(authctxt, authenticated, auth_method,
 378                             compat20 ? " ssh2" : "");
 379                         if (!authenticated)
 380                                 authctxt->failures++;
 381                 }
 382         }
 383
 384         if (!authctxt->valid)
 385                 fatal("%s: authenticated invalid user", __func__);
 386         if (strcmp(auth_method, "unknown") == 0)
 387                 fatal("%s: authentication method name unknown", __func__);
 388
 389         debug("%s: %s has been authenticated by privileged process",
 390             __func__, authctxt->user);
 391
 392         mm_get_keystate(pmonitor);
 393 }
 394
 395 static void
 396 monitor_set_child_handler(pid_t pid)
 397 {
 398         monitor_child_pid = pid;
 399 }
 400
 401 static void
 402 monitor_child_handler(int sig)
 403 {
 404         kill(monitor_child_pid, sig);
 405 }
 406
 407 void
 408 monitor_child_postauth(struct monitor *pmonitor)
 409 {
 410         monitor_set_child_handler(pmonitor->m_pid);
 411         signal(SIGHUP, &monitor_child_handler);
 412         signal(SIGTERM, &monitor_child_handler);
 413         signal(SIGINT, &monitor_child_handler);
 414
 415         if (compat20) {
 416                 mon_dispatch = mon_dispatch_postauth20;
 417
 418                 /* Permit requests for moduli and signatures */
 419                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 420                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 421                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 422         } else {
 423                 mon_dispatch = mon_dispatch_postauth15;
 424                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 425         }
 426         if (!no_pty_flag) {
 427                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 428                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 429         }
 430
 431         for (;;)
 432                 monitor_read(pmonitor, mon_dispatch, NULL);
 433 }
 434
 435 void
 436 monitor_sync(struct monitor *pmonitor)
 437 {
 438         if (options.compression) {
 439                 /* The member allocation is not visible, so sync it */
 440                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 441         }
 442 }
 443
 444 int
 445 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 446     struct mon_table **pent)
 447 {
 448         Buffer m;
 449         int ret;
 450         u_char type;
 451
 452         buffer_init(&m);
 453
 454         mm_request_receive(pmonitor->m_sendfd, &m);
 455         type = buffer_get_char(&m);
 456
 457         debug3("%s: checking request %d", __func__, type);
 458
 459         while (ent->f != NULL) {
 460                 if (ent->type == type)
 461                         break;
 462                 ent++;
 463         }
 464
 465         if (ent->f != NULL) {
 466                 if (!(ent->flags & MON_PERMIT))
 467                         fatal("%s: unpermitted request %d", __func__,
 468                             type);
 469                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 470                 buffer_free(&m);
 471
 472                 /* The child may use this request only once, disable it */
 473                 if (ent->flags & MON_ONCE) {
 474                         debug2("%s: %d used once, disabling now", __func__,
 475                             type);
 476                         ent->flags &= ~MON_PERMIT;
 477                 }
 478
 479                 if (pent != NULL)
 480                         *pent = ent;
 481
 482                 return ret;
 483         }
 484
 485         fatal("%s: unsupported request: %d", __func__, type);
 486
 487         /* NOTREACHED */
 488         return (-1);
 489 }
 490
 491 /* allowed key state */
 492 static int
 493 monitor_allowed_key(u_char *blob, u_int bloblen)
 494 {
 495         /* make sure key is allowed */
 496         if (key_blob == NULL || key_bloblen != bloblen ||
 497             memcmp(key_blob, blob, key_bloblen))
 498                 return (0);
 499         return (1);
 500 }
 501
 502 static void
 503 monitor_reset_key_state(void)
 504 {
 505         /* reset state */
 506         if (key_blob != NULL)
 507                 xfree(key_blob);
 508         if (hostbased_cuser != NULL)
 509                 xfree(hostbased_cuser);
 510         if (hostbased_chost != NULL)
 511                 xfree(hostbased_chost);
 512         key_blob = NULL;
 513         key_bloblen = 0;
 514         key_blobtype = MM_NOKEY;
 515         hostbased_cuser = NULL;
 516         hostbased_chost = NULL;
 517 }
 518
 519 int
 520 mm_answer_moduli(int sock, Buffer *m)
 521 {
 522         DH *dh;
 523         int min, want, max;
 524
 525         min = buffer_get_int(m);
 526         want = buffer_get_int(m);
 527         max = buffer_get_int(m);
 528
 529         debug3("%s: got parameters: %d %d %d",
 530             __func__, min, want, max);
 531         /* We need to check here, too, in case the child got corrupted */
 532         if (max < min || want < min || max < want)
 533                 fatal("%s: bad parameters: %d %d %d",
 534                     __func__, min, want, max);
 535
 536         buffer_clear(m);
 537
 538         dh = choose_dh(min, want, max);
 539         if (dh == NULL) {
 540                 buffer_put_char(m, 0);
 541                 return (0);
 542         } else {
 543                 /* Send first bignum */
 544                 buffer_put_char(m, 1);
 545                 buffer_put_bignum2(m, dh->p);
 546                 buffer_put_bignum2(m, dh->g);
 547
 548                 DH_free(dh);
 549         }
 550         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 551         return (0);
 552 }
 553
 554 int
 555 mm_answer_sign(int sock, Buffer *m)
 556 {
 557         Key *key;
 558         u_char *p;
 559         u_char *signature;
 560         u_int siglen, datlen;
 561         int keyid;
 562
 563         debug3("%s", __func__);
 564
 565         keyid = buffer_get_int(m);
 566         p = buffer_get_string(m, &datlen);
 567
 568         /*
 569          * Supported KEX types will only return SHA1 (20 byte) or
 570          * SHA256 (32 byte) hashes
 571          */
 572         if (datlen != 20 && datlen != 32)
 573                 fatal("%s: data length incorrect: %u", __func__, datlen);
 574
 575         /* save session id, it will be passed on the first call */
 576         if (session_id2_len == 0) {
 577                 session_id2_len = datlen;
 578                 session_id2 = xmalloc(session_id2_len);
 579                 memcpy(session_id2, p, session_id2_len);
 580         }
 581
 582         if ((key = get_hostkey_by_index(keyid)) == NULL)
 583                 fatal("%s: no hostkey from index %d", __func__, keyid);
 584         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 585                 fatal("%s: key_sign failed", __func__);
 586
 587         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 588
 589         buffer_clear(m);
 590         buffer_put_string(m, signature, siglen);
 591
 592         xfree(p);
 593         xfree(signature);
 594
 595         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 596
 597         /* Turn on permissions for getpwnam */
 598         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 599
 600         return (0);
 601 }
 602
 603 /* Retrieves the password entry and also checks if the user is permitted */
 604
 605 int
 606 mm_answer_pwnamallow(int sock, Buffer *m)
 607 {
 608         char *username;
 609         struct passwd *pwent;
 610         int allowed = 0;
 611
 612         debug3("%s", __func__);
 613
 614         if (authctxt->attempt++ != 0)
 615                 fatal("%s: multiple attempts for getpwnam", __func__);
 616
 617         username = buffer_get_string(m, NULL);
 618
 619         pwent = getpwnamallow(username);
 620
 621         authctxt->user = xstrdup(username);
 622         setproctitle("%s [priv]", pwent ? username : "unknown");
 623         xfree(username);
 624
 625         buffer_clear(m);
 626
 627         if (pwent == NULL) {
 628                 buffer_put_char(m, 0);
 629                 authctxt->pw = fakepw();
 630                 goto out;
 631         }
 632
 633         allowed = 1;
 634         authctxt->pw = pwent;
 635         authctxt->valid = 1;
 636
 637         buffer_put_char(m, 1);
 638         buffer_put_string(m, pwent, sizeof(struct passwd));
 639         buffer_put_cstring(m, pwent->pw_name);
 640         buffer_put_cstring(m, "*");
 641         buffer_put_cstring(m, pwent->pw_gecos);
 642 #ifdef HAVE_PW_CLASS_IN_PASSWD
 643         buffer_put_cstring(m, pwent->pw_class);
 644 #endif
 645         buffer_put_cstring(m, pwent->pw_dir);
 646         buffer_put_cstring(m, pwent->pw_shell);
 647
 648  out:
 649         buffer_put_string(m, &options, sizeof(options));
 650         if (options.banner != NULL)
 651                 buffer_put_cstring(m, options.banner);
 652         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 653         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 654
 655         /* For SSHv1 allow authentication now */
 656         if (!compat20)
 657                 monitor_permit_authentications(1);
 658         else {
 659                 /* Allow service/style information on the auth context */
 660                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 661                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 662         }
 663
 664 #ifdef USE_PAM
 665         if (options.use_pam)
 666                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 667 #endif
 668
 669         return (0);
 670 }
 671
 672 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 673 {
 674         char *banner;
 675
 676         buffer_clear(m);
 677         banner = auth2_read_banner();
 678         buffer_put_cstring(m, banner != NULL ? banner : "");
 679         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 680
 681         if (banner != NULL)
 682                 xfree(banner);
 683
 684         return (0);
 685 }
 686
 687 int
 688 mm_answer_authserv(int sock, Buffer *m)
 689 {
 690         monitor_permit_authentications(1);
 691
 692         authctxt->service = buffer_get_string(m, NULL);
 693         authctxt->style = buffer_get_string(m, NULL);
 694         debug3("%s: service=%s, style=%s",
 695             __func__, authctxt->service, authctxt->style);
 696
 697         if (strlen(authctxt->style) == 0) {
 698                 xfree(authctxt->style);
 699                 authctxt->style = NULL;
 700         }
 701
 702         return (0);
 703 }
 704
 705 int
 706 mm_answer_authpassword(int sock, Buffer *m)
 707 {
 708         static int call_count;
 709         char *passwd;
 710         int authenticated;
 711         u_int plen;
 712
 713         passwd = buffer_get_string(m, &plen);
 714         /* Only authenticate if the context is valid */
 715         authenticated = options.password_authentication &&
 716             auth_password(authctxt, passwd);
 717         memset(passwd, 0, strlen(passwd));
 718         xfree(passwd);
 719
 720         buffer_clear(m);
 721         buffer_put_int(m, authenticated);
 722
 723         debug3("%s: sending result %d", __func__, authenticated);
 724         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 725
 726         call_count++;
 727         if (plen == 0 && call_count == 1)
 728                 auth_method = "none";
 729         else
 730                 auth_method = "password";
 731
 732         /* Causes monitor loop to terminate if authenticated */
 733         return (authenticated);
 734 }
 735
 736 #ifdef BSD_AUTH
 737 int
 738 mm_answer_bsdauthquery(int sock, Buffer *m)
 739 {
 740         char *name, *infotxt;
 741         u_int numprompts;
 742         u_int *echo_on;
 743         char **prompts;
 744         u_int success;
 745
 746         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 747             &prompts, &echo_on) < 0 ? 0 : 1;
 748
 749         buffer_clear(m);
 750         buffer_put_int(m, success);
 751         if (success)
 752                 buffer_put_cstring(m, prompts[0]);
 753
 754         debug3("%s: sending challenge success: %u", __func__, success);
 755         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 756
 757         if (success) {
 758                 xfree(name);
 759                 xfree(infotxt);
 760                 xfree(prompts);
 761                 xfree(echo_on);
 762         }
 763
 764         return (0);
 765 }
 766
 767 int
 768 mm_answer_bsdauthrespond(int sock, Buffer *m)
 769 {
 770         char *response;
 771         int authok;
 772
 773         if (authctxt->as == 0)
 774                 fatal("%s: no bsd auth session", __func__);
 775
 776         response = buffer_get_string(m, NULL);
 777         authok = options.challenge_response_authentication &&
 778             auth_userresponse(authctxt->as, response, 0);
 779         authctxt->as = NULL;
 780         debug3("%s: <%s> = <%d>", __func__, response, authok);
 781         xfree(response);
 782
 783         buffer_clear(m);
 784         buffer_put_int(m, authok);
 785
 786         debug3("%s: sending authenticated: %d", __func__, authok);
 787         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 788
 789         auth_method = "bsdauth";
 790
 791         return (authok != 0);
 792 }
 793 #endif
 794
 795 #ifdef SKEY
 796 int
 797 mm_answer_skeyquery(int sock, Buffer *m)
 798 {
 799         struct skey skey;
 800         char challenge[1024];
 801         u_int success;
 802
 803         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 804             sizeof(challenge)) < 0 ? 0 : 1;
 805
 806         buffer_clear(m);
 807         buffer_put_int(m, success);
 808         if (success)
 809                 buffer_put_cstring(m, challenge);
 810
 811         debug3("%s: sending challenge success: %u", __func__, success);
 812         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 813
 814         return (0);
 815 }
 816
 817 int
 818 mm_answer_skeyrespond(int sock, Buffer *m)
 819 {
 820         char *response;
 821         int authok;
 822
 823         response = buffer_get_string(m, NULL);
 824
 825         authok = (options.challenge_response_authentication &&
 826             authctxt->valid &&
 827             skey_haskey(authctxt->pw->pw_name) == 0 &&
 828             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 829
 830         xfree(response);
 831
 832         buffer_clear(m);
 833         buffer_put_int(m, authok);
 834
 835         debug3("%s: sending authenticated: %d", __func__, authok);
 836         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 837
 838         auth_method = "skey";
 839
 840         return (authok != 0);
 841 }
 842 #endif
 843
 844 #ifdef USE_PAM
 845 int
 846 mm_answer_pam_start(int sock, Buffer *m)
 847 {
 848         if (!options.use_pam)
 849                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 850
 851         start_pam(authctxt);
 852
 853         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 854
 855         return (0);
 856 }
 857
 858 int
 859 mm_answer_pam_account(int sock, Buffer *m)
 860 {
 861         u_int ret;
 862
 863         if (!options.use_pam)
 864                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 865
 866         ret = do_pam_account();
 867
 868         buffer_put_int(m, ret);
 869         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 870
 871         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 872
 873         return (ret);
 874 }
 875
 876 static void *sshpam_ctxt, *sshpam_authok;
 877 extern KbdintDevice sshpam_device;
 878
 879 int
 880 mm_answer_pam_init_ctx(int sock, Buffer *m)
 881 {
 882
 883         debug3("%s", __func__);
 884         authctxt->user = buffer_get_string(m, NULL);
 885         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 886         sshpam_authok = NULL;
 887         buffer_clear(m);
 888         if (sshpam_ctxt != NULL) {
 889                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 890                 buffer_put_int(m, 1);
 891         } else {
 892                 buffer_put_int(m, 0);
 893         }
 894         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 895         return (0);
 896 }
 897
 898 int
 899 mm_answer_pam_query(int sock, Buffer *m)
 900 {
 901         char *name, *info, **prompts;
 902         u_int i, num, *echo_on;
 903         int ret;
 904
 905         debug3("%s", __func__);
 906         sshpam_authok = NULL;
 907         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 908         if (ret == 0 && num == 0)
 909                 sshpam_authok = sshpam_ctxt;
 910         if (num > 1 || name == NULL || info == NULL)
 911                 ret = -1;
 912         buffer_clear(m);
 913         buffer_put_int(m, ret);
 914         buffer_put_cstring(m, name);
 915         xfree(name);
 916         buffer_put_cstring(m, info);
 917         xfree(info);
 918         buffer_put_int(m, num);
 919         for (i = 0; i < num; ++i) {
 920                 buffer_put_cstring(m, prompts[i]);
 921                 xfree(prompts[i]);
 922                 buffer_put_int(m, echo_on[i]);
 923         }
 924         if (prompts != NULL)
 925                 xfree(prompts);
 926         if (echo_on != NULL)
 927                 xfree(echo_on);
 928         auth_method = "keyboard-interactive/pam";
 929         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 930         return (0);
 931 }
 932
 933 int
 934 mm_answer_pam_respond(int sock, Buffer *m)
 935 {
 936         char **resp;
 937         u_int i, num;
 938         int ret;
 939
 940         debug3("%s", __func__);
 941         sshpam_authok = NULL;
 942         num = buffer_get_int(m);
 943         if (num > 0) {
 944                 resp = xcalloc(num, sizeof(char *));
 945                 for (i = 0; i < num; ++i)
 946                         resp[i] = buffer_get_string(m, NULL);
 947                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 948                 for (i = 0; i < num; ++i)
 949                         xfree(resp[i]);
 950                 xfree(resp);
 951         } else {
 952                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 953         }
 954         buffer_clear(m);
 955         buffer_put_int(m, ret);
 956         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 957         auth_method = "keyboard-interactive/pam";
 958         if (ret == 0)
 959                 sshpam_authok = sshpam_ctxt;
 960         return (0);
 961 }
 962
 963 int
 964 mm_answer_pam_free_ctx(int sock, Buffer *m)
 965 {
 966
 967         debug3("%s", __func__);
 968         (sshpam_device.free_ctx)(sshpam_ctxt);
 969         buffer_clear(m);
 970         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 971         auth_method = "keyboard-interactive/pam";
 972         return (sshpam_authok == sshpam_ctxt);
 973 }
 974 #endif
 975
 976 static void
 977 mm_append_debug(Buffer *m)
 978 {
 979         if (auth_debug_init && buffer_len(&auth_debug)) {
 980                 debug3("%s: Appending debug messages for child", __func__);
 981                 buffer_append(m, buffer_ptr(&auth_debug),
 982                     buffer_len(&auth_debug));
 983                 buffer_clear(&auth_debug);
 984         }
 985 }
 986
 987 int
 988 mm_answer_keyallowed(int sock, Buffer *m)
 989 {
 990         Key *key;
 991         char *cuser, *chost;
 992         u_char *blob;
 993         u_int bloblen;
 994         enum mm_keytype type = 0;
 995         int allowed = 0;
 996
 997         debug3("%s entering", __func__);
 998
 999         type = buffer_get_int(m);
1000         cuser = buffer_get_string(m, NULL);
1001         chost = buffer_get_string(m, NULL);
1002         blob = buffer_get_string(m, &bloblen);
1003
1004         key = key_from_blob(blob, bloblen);
1005
1006         if ((compat20 && type == MM_RSAHOSTKEY) ||
1007             (!compat20 && type != MM_RSAHOSTKEY))
1008                 fatal("%s: key type and protocol mismatch", __func__);
1009
1010         debug3("%s: key_from_blob: %p", __func__, key);
1011
1012         if (key != NULL && authctxt->valid) {
1013                 switch (type) {
1014                 case MM_USERKEY:
1015                         allowed = options.pubkey_authentication &&
1016                             user_key_allowed(authctxt->pw, key);
1017                         auth_method = "publickey";
1018                         if (options.pubkey_authentication && allowed != 1)
1019                                 auth_clear_options();
1020                         break;
1021                 case MM_HOSTKEY:
1022                         allowed = options.hostbased_authentication &&
1023                             hostbased_key_allowed(authctxt->pw,
1024                             cuser, chost, key);
1025                         auth_method = "hostbased";
1026                         break;
1027                 case MM_RSAHOSTKEY:
1028                         key->type = KEY_RSA1; /* XXX */
1029                         allowed = options.rhosts_rsa_authentication &&
1030                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1031                             cuser, chost, key);
1032                         if (options.rhosts_rsa_authentication && allowed != 1)
1033                                 auth_clear_options();
1034                         auth_method = "rsa";
1035                         break;
1036                 default:
1037                         fatal("%s: unknown key type %d", __func__, type);
1038                         break;
1039                 }
1040         }
1041         if (key != NULL)
1042                 key_free(key);
1043
1044         /* clear temporarily storage (used by verify) */
1045         monitor_reset_key_state();
1046
1047         if (allowed) {
1048                 /* Save temporarily for comparison in verify */
1049                 key_blob = blob;
1050                 key_bloblen = bloblen;
1051                 key_blobtype = type;
1052                 hostbased_cuser = cuser;
1053                 hostbased_chost = chost;
1054         } else {
1055                 /* Log failed attempt */
1056                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1057                 xfree(blob);
1058                 xfree(cuser);
1059                 xfree(chost);
1060         }
1061
1062         debug3("%s: key %p is %s",
1063             __func__, key, allowed ? "allowed" : "not allowed");
1064
1065         buffer_clear(m);
1066         buffer_put_int(m, allowed);
1067         buffer_put_int(m, forced_command != NULL);
1068
1069         mm_append_debug(m);
1070
1071         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1072
1073         if (type == MM_RSAHOSTKEY)
1074                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1075
1076         return (0);
1077 }
1078
1079 static int
1080 monitor_valid_userblob(u_char *data, u_int datalen)
1081 {
1082         Buffer b;
1083         char *p;
1084         u_int len;
1085         int fail = 0;
1086
1087         buffer_init(&b);
1088         buffer_append(&b, data, datalen);
1089
1090         if (datafellows & SSH_OLD_SESSIONID) {
1091                 p = buffer_ptr(&b);
1092                 len = buffer_len(&b);
1093                 if ((session_id2 == NULL) ||
1094                     (len < session_id2_len) ||
1095                     (memcmp(p, session_id2, session_id2_len) != 0))
1096                         fail++;
1097                 buffer_consume(&b, session_id2_len);
1098         } else {
1099                 p = buffer_get_string(&b, &len);
1100                 if ((session_id2 == NULL) ||
1101                     (len != session_id2_len) ||
1102                     (memcmp(p, session_id2, session_id2_len) != 0))
1103                         fail++;
1104                 xfree(p);
1105         }
1106         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1107                 fail++;
1108         p = buffer_get_string(&b, NULL);
1109         if (strcmp(authctxt->user, p) != 0) {
1110                 logit("wrong user name passed to monitor: expected %s != %.100s",
1111                     authctxt->user, p);
1112                 fail++;
1113         }
1114         xfree(p);
1115         buffer_skip_string(&b);
1116         if (datafellows & SSH_BUG_PKAUTH) {
1117                 if (!buffer_get_char(&b))
1118                         fail++;
1119         } else {
1120                 p = buffer_get_string(&b, NULL);
1121                 if (strcmp("publickey", p) != 0)
1122                         fail++;
1123                 xfree(p);
1124                 if (!buffer_get_char(&b))
1125                         fail++;
1126                 buffer_skip_string(&b);
1127         }
1128         buffer_skip_string(&b);
1129         if (buffer_len(&b) != 0)
1130                 fail++;
1131         buffer_free(&b);
1132         return (fail == 0);
1133 }
1134
1135 static int
1136 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1137     char *chost)
1138 {
1139         Buffer b;
1140         char *p;
1141         u_int len;
1142         int fail = 0;
1143
1144         buffer_init(&b);
1145         buffer_append(&b, data, datalen);
1146
1147         p = buffer_get_string(&b, &len);
1148         if ((session_id2 == NULL) ||
1149             (len != session_id2_len) ||
1150             (memcmp(p, session_id2, session_id2_len) != 0))
1151                 fail++;
1152         xfree(p);
1153
1154         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1155                 fail++;
1156         p = buffer_get_string(&b, NULL);
1157         if (strcmp(authctxt->user, p) != 0) {
1158                 logit("wrong user name passed to monitor: expected %s != %.100s",
1159                     authctxt->user, p);
1160                 fail++;
1161         }
1162         xfree(p);
1163         buffer_skip_string(&b); /* service */
1164         p = buffer_get_string(&b, NULL);
1165         if (strcmp(p, "hostbased") != 0)
1166                 fail++;
1167         xfree(p);
1168         buffer_skip_string(&b); /* pkalg */
1169         buffer_skip_string(&b); /* pkblob */
1170
1171         /* verify client host, strip trailing dot if necessary */
1172         p = buffer_get_string(&b, NULL);
1173         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1174                 p[len - 1] = '\0';
1175         if (strcmp(p, chost) != 0)
1176                 fail++;
1177         xfree(p);
1178
1179         /* verify client user */
1180         p = buffer_get_string(&b, NULL);
1181         if (strcmp(p, cuser) != 0)
1182                 fail++;
1183         xfree(p);
1184
1185         if (buffer_len(&b) != 0)
1186                 fail++;
1187         buffer_free(&b);
1188         return (fail == 0);
1189 }
1190
1191 int
1192 mm_answer_keyverify(int sock, Buffer *m)
1193 {
1194         Key *key;
1195         u_char *signature, *data, *blob;
1196         u_int signaturelen, datalen, bloblen;
1197         int verified = 0;
1198         int valid_data = 0;
1199
1200         blob = buffer_get_string(m, &bloblen);
1201         signature = buffer_get_string(m, &signaturelen);
1202         data = buffer_get_string(m, &datalen);
1203
1204         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1205           !monitor_allowed_key(blob, bloblen))
1206                 fatal("%s: bad key, not previously allowed", __func__);
1207
1208         key = key_from_blob(blob, bloblen);
1209         if (key == NULL)
1210                 fatal("%s: bad public key blob", __func__);
1211
1212         switch (key_blobtype) {
1213         case MM_USERKEY:
1214                 valid_data = monitor_valid_userblob(data, datalen);
1215                 break;
1216         case MM_HOSTKEY:
1217                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1218                     hostbased_cuser, hostbased_chost);
1219                 break;
1220         default:
1221                 valid_data = 0;
1222                 break;
1223         }
1224         if (!valid_data)
1225                 fatal("%s: bad signature data blob", __func__);
1226
1227         verified = key_verify(key, signature, signaturelen, data, datalen);
1228         debug3("%s: key %p signature %s",
1229             __func__, key, (verified == 1) ? "verified" : "unverified");
1230
1231         key_free(key);
1232         xfree(blob);
1233         xfree(signature);
1234         xfree(data);
1235
1236         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1237
1238         monitor_reset_key_state();
1239
1240         buffer_clear(m);
1241         buffer_put_int(m, verified);
1242         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1243
1244         return (verified == 1);
1245 }
1246
1247 static void
1248 mm_record_login(Session *s, struct passwd *pw)
1249 {
1250         socklen_t fromlen;
1251         struct sockaddr_storage from;
1252
1253         /*
1254          * Get IP address of client. If the connection is not a socket, let
1255          * the address be 0.0.0.0.
1256          */
1257         memset(&from, 0, sizeof(from));
1258         fromlen = sizeof(from);
1259         if (packet_connection_is_on_socket()) {
1260                 if (getpeername(packet_get_connection_in(),
1261                     (struct sockaddr *)&from, &fromlen) < 0) {
1262                         debug("getpeername: %.100s", strerror(errno));
1263                         cleanup_exit(255);
1264                 }
1265         }
1266         /* Record that there was a login on that tty from the remote host. */
1267         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1268             get_remote_name_or_ip(utmp_len, options.use_dns),
1269             (struct sockaddr *)&from, fromlen);
1270 }
1271
1272 static void
1273 mm_session_close(Session *s)
1274 {
1275         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1276         if (s->ttyfd != -1) {
1277                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1278                 session_pty_cleanup2(s);
1279         }
1280         session_unused(s->self);
1281 }
1282
1283 int
1284 mm_answer_pty(int sock, Buffer *m)
1285 {
1286         extern struct monitor *pmonitor;
1287         Session *s;
1288         int res, fd0;
1289
1290         debug3("%s entering", __func__);
1291
1292         buffer_clear(m);
1293         s = session_new();
1294         if (s == NULL)
1295                 goto error;
1296         s->authctxt = authctxt;
1297         s->pw = authctxt->pw;
1298         s->pid = pmonitor->m_pid;
1299         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1300         if (res == 0)
1301                 goto error;
1302         pty_setowner(authctxt->pw, s->tty);
1303
1304         buffer_put_int(m, 1);
1305         buffer_put_cstring(m, s->tty);
1306
1307         /* We need to trick ttyslot */
1308         if (dup2(s->ttyfd, 0) == -1)
1309                 fatal("%s: dup2", __func__);
1310
1311         mm_record_login(s, authctxt->pw);
1312
1313         /* Now we can close the file descriptor again */
1314         close(0);
1315
1316         /* send messages generated by record_login */
1317         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1318         buffer_clear(&loginmsg);
1319
1320         mm_request_send(sock, MONITOR_ANS_PTY, m);
1321
1322         if (mm_send_fd(sock, s->ptyfd) == -1 ||
1323             mm_send_fd(sock, s->ttyfd) == -1)
1324                 fatal("%s: send fds failed", __func__);
1325
1326         /* make sure nothing uses fd 0 */
1327         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1328                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1329         if (fd0 != 0)
1330                 error("%s: fd0 %d != 0", __func__, fd0);
1331
1332         /* slave is not needed */
1333         close(s->ttyfd);
1334         s->ttyfd = s->ptyfd;
1335         /* no need to dup() because nobody closes ptyfd */
1336         s->ptymaster = s->ptyfd;
1337
1338         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1339
1340         return (0);
1341
1342  error:
1343         if (s != NULL)
1344                 mm_session_close(s);
1345         buffer_put_int(m, 0);
1346         mm_request_send(sock, MONITOR_ANS_PTY, m);
1347         return (0);
1348 }
1349
1350 int
1351 mm_answer_pty_cleanup(int sock, Buffer *m)
1352 {
1353         Session *s;
1354         char *tty;
1355
1356         debug3("%s entering", __func__);
1357
1358         tty = buffer_get_string(m, NULL);
1359         if ((s = session_by_tty(tty)) != NULL)
1360                 mm_session_close(s);
1361         buffer_clear(m);
1362         xfree(tty);
1363         return (0);
1364 }
1365
1366 int
1367 mm_answer_sesskey(int sock, Buffer *m)
1368 {
1369         BIGNUM *p;
1370         int rsafail;
1371
1372         /* Turn off permissions */
1373         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1374
1375         if ((p = BN_new()) == NULL)
1376                 fatal("%s: BN_new", __func__);
1377
1378         buffer_get_bignum2(m, p);
1379
1380         rsafail = ssh1_session_key(p);
1381
1382         buffer_clear(m);
1383         buffer_put_int(m, rsafail);
1384         buffer_put_bignum2(m, p);
1385
1386         BN_clear_free(p);
1387
1388         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1389
1390         /* Turn on permissions for sessid passing */
1391         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1392
1393         return (0);
1394 }
1395
1396 int
1397 mm_answer_sessid(int sock, Buffer *m)
1398 {
1399         int i;
1400
1401         debug3("%s entering", __func__);
1402
1403         if (buffer_len(m) != 16)
1404                 fatal("%s: bad ssh1 session id", __func__);
1405         for (i = 0; i < 16; i++)
1406                 session_id[i] = buffer_get_char(m);
1407
1408         /* Turn on permissions for getpwnam */
1409         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1410
1411         return (0);
1412 }
1413
1414 int
1415 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1416 {
1417         BIGNUM *client_n;
1418         Key *key = NULL;
1419         u_char *blob = NULL;
1420         u_int blen = 0;
1421         int allowed = 0;
1422
1423         debug3("%s entering", __func__);
1424
1425         auth_method = "rsa";
1426         if (options.rsa_authentication && authctxt->valid) {
1427                 if ((client_n = BN_new()) == NULL)
1428                         fatal("%s: BN_new", __func__);
1429                 buffer_get_bignum2(m, client_n);
1430                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1431                 BN_clear_free(client_n);
1432         }
1433         buffer_clear(m);
1434         buffer_put_int(m, allowed);
1435         buffer_put_int(m, forced_command != NULL);
1436
1437         /* clear temporarily storage (used by generate challenge) */
1438         monitor_reset_key_state();
1439
1440         if (allowed && key != NULL) {
1441                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1442                 if (key_to_blob(key, &blob, &blen) == 0)
1443                         fatal("%s: key_to_blob failed", __func__);
1444                 buffer_put_string(m, blob, blen);
1445
1446                 /* Save temporarily for comparison in verify */
1447                 key_blob = blob;
1448                 key_bloblen = blen;
1449                 key_blobtype = MM_RSAUSERKEY;
1450         }
1451         if (key != NULL)
1452                 key_free(key);
1453
1454         mm_append_debug(m);
1455
1456         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1457
1458         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1459         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1460         return (0);
1461 }
1462
1463 int
1464 mm_answer_rsa_challenge(int sock, Buffer *m)
1465 {
1466         Key *key = NULL;
1467         u_char *blob;
1468         u_int blen;
1469
1470         debug3("%s entering", __func__);
1471
1472         if (!authctxt->valid)
1473                 fatal("%s: authctxt not valid", __func__);
1474         blob = buffer_get_string(m, &blen);
1475         if (!monitor_allowed_key(blob, blen))
1476                 fatal("%s: bad key, not previously allowed", __func__);
1477         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1478                 fatal("%s: key type mismatch", __func__);
1479         if ((key = key_from_blob(blob, blen)) == NULL)
1480                 fatal("%s: received bad key", __func__);
1481
1482         if (ssh1_challenge)
1483                 BN_clear_free(ssh1_challenge);
1484         ssh1_challenge = auth_rsa_generate_challenge(key);
1485
1486         buffer_clear(m);
1487         buffer_put_bignum2(m, ssh1_challenge);
1488
1489         debug3("%s sending reply", __func__);
1490         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1491
1492         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1493
1494         xfree(blob);
1495         key_free(key);
1496         return (0);
1497 }
1498
1499 int
1500 mm_answer_rsa_response(int sock, Buffer *m)
1501 {
1502         Key *key = NULL;
1503         u_char *blob, *response;
1504         u_int blen, len;
1505         int success;
1506
1507         debug3("%s entering", __func__);
1508
1509         if (!authctxt->valid)
1510                 fatal("%s: authctxt not valid", __func__);
1511         if (ssh1_challenge == NULL)
1512                 fatal("%s: no ssh1_challenge", __func__);
1513
1514         blob = buffer_get_string(m, &blen);
1515         if (!monitor_allowed_key(blob, blen))
1516                 fatal("%s: bad key, not previously allowed", __func__);
1517         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1518                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1519         if ((key = key_from_blob(blob, blen)) == NULL)
1520                 fatal("%s: received bad key", __func__);
1521         response = buffer_get_string(m, &len);
1522         if (len != 16)
1523                 fatal("%s: received bad response to challenge", __func__);
1524         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1525
1526         xfree(blob);
1527         key_free(key);
1528         xfree(response);
1529
1530         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1531
1532         /* reset state */
1533         BN_clear_free(ssh1_challenge);
1534         ssh1_challenge = NULL;
1535         monitor_reset_key_state();
1536
1537         buffer_clear(m);
1538         buffer_put_int(m, success);
1539         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1540
1541         return (success);
1542 }
1543
1544 int
1545 mm_answer_term(int sock, Buffer *req)
1546 {
1547         extern struct monitor *pmonitor;
1548         int res, status;
1549
1550         debug3("%s: tearing down sessions", __func__);
1551
1552         /* The child is terminating */
1553         session_destroy_all(&mm_session_close);
1554
1555 #ifdef USE_PAM
1556         if (options.use_pam)
1557                 sshpam_cleanup();
1558 #endif
1559
1560         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1561                 if (errno != EINTR)
1562                         exit(1);
1563
1564         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1565
1566         /* Terminate process */
1567         exit(res);
1568 }
1569
1570 #ifdef SSH_AUDIT_EVENTS
1571 /* Report that an audit event occurred */
1572 int
1573 mm_answer_audit_event(int socket, Buffer *m)
1574 {
1575         ssh_audit_event_t event;
1576
1577         debug3("%s entering", __func__);
1578
1579         event = buffer_get_int(m);
1580         switch(event) {
1581         case SSH_AUTH_FAIL_PUBKEY:
1582         case SSH_AUTH_FAIL_HOSTBASED:
1583         case SSH_AUTH_FAIL_GSSAPI:
1584         case SSH_LOGIN_EXCEED_MAXTRIES:
1585         case SSH_LOGIN_ROOT_DENIED:
1586         case SSH_CONNECTION_CLOSE:
1587         case SSH_INVALID_USER:
1588                 audit_event(event);
1589                 break;
1590         default:
1591                 fatal("Audit event type %d not permitted", event);
1592         }
1593
1594         return (0);
1595 }
1596
1597 int
1598 mm_answer_audit_command(int socket, Buffer *m)
1599 {
1600         u_int len;
1601         char *cmd;
1602
1603         debug3("%s entering", __func__);
1604         cmd = buffer_get_string(m, &len);
1605         /* sanity check command, if so how? */
1606         audit_run_command(cmd);
1607         xfree(cmd);
1608         return (0);
1609 }
1610 #endif /* SSH_AUDIT_EVENTS */
1611
1612 void
1613 monitor_apply_keystate(struct monitor *pmonitor)
1614 {
1615         if (compat20) {
1616                 set_newkeys(MODE_IN);
1617                 set_newkeys(MODE_OUT);
1618         } else {
1619                 packet_set_protocol_flags(child_state.ssh1protoflags);
1620                 packet_set_encryption_key(child_state.ssh1key,
1621                     child_state.ssh1keylen, child_state.ssh1cipher);
1622                 xfree(child_state.ssh1key);
1623         }
1624
1625         /* for rc4 and other stateful ciphers */
1626         packet_set_keycontext(MODE_OUT, child_state.keyout);
1627         xfree(child_state.keyout);
1628         packet_set_keycontext(MODE_IN, child_state.keyin);
1629         xfree(child_state.keyin);
1630
1631         if (!compat20) {
1632                 packet_set_iv(MODE_OUT, child_state.ivout);
1633                 xfree(child_state.ivout);
1634                 packet_set_iv(MODE_IN, child_state.ivin);
1635                 xfree(child_state.ivin);
1636         }
1637
1638         memcpy(&incoming_stream, &child_state.incoming,
1639             sizeof(incoming_stream));
1640         memcpy(&outgoing_stream, &child_state.outgoing,
1641             sizeof(outgoing_stream));
1642
1643         /* Update with new address */
1644         if (options.compression)
1645                 mm_init_compression(pmonitor->m_zlib);
1646
1647         /* Network I/O buffers */
1648         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1649         buffer_clear(&input);
1650         buffer_append(&input, child_state.input, child_state.ilen);
1651         memset(child_state.input, 0, child_state.ilen);
1652         xfree(child_state.input);
1653
1654         buffer_clear(&output);
1655         buffer_append(&output, child_state.output, child_state.olen);
1656         memset(child_state.output, 0, child_state.olen);
1657         xfree(child_state.output);
1658 }
1659
1660 static Kex *
1661 mm_get_kex(Buffer *m)
1662 {
1663         Kex *kex;
1664         void *blob;
1665         u_int bloblen;
1666
1667         kex = xcalloc(1, sizeof(*kex));
1668         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1669         if ((session_id2 == NULL) ||
1670             (kex->session_id_len != session_id2_len) ||
1671             (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1672                 fatal("mm_get_get: internal error: bad session id");
1673         kex->we_need = buffer_get_int(m);
1674         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1675         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1676         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1677         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1678         kex->server = 1;
1679         kex->hostkey_type = buffer_get_int(m);
1680         kex->kex_type = buffer_get_int(m);
1681         blob = buffer_get_string(m, &bloblen);
1682         buffer_init(&kex->my);
1683         buffer_append(&kex->my, blob, bloblen);
1684         xfree(blob);
1685         blob = buffer_get_string(m, &bloblen);
1686         buffer_init(&kex->peer);
1687         buffer_append(&kex->peer, blob, bloblen);
1688         xfree(blob);
1689         kex->done = 1;
1690         kex->flags = buffer_get_int(m);
1691         kex->client_version_string = buffer_get_string(m, NULL);
1692         kex->server_version_string = buffer_get_string(m, NULL);
1693         kex->load_host_key=&get_hostkey_by_type;
1694         kex->host_key_index=&get_hostkey_index;
1695
1696         return (kex);
1697 }
1698
1699 /* This function requries careful sanity checking */
1700
1701 void
1702 mm_get_keystate(struct monitor *pmonitor)
1703 {
1704         Buffer m;
1705         u_char *blob, *p;
1706         u_int bloblen, plen;
1707         u_int32_t seqnr, packets;
1708         u_int64_t blocks, bytes;
1709
1710         debug3("%s: Waiting for new keys", __func__);
1711
1712         buffer_init(&m);
1713         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1714         if (!compat20) {
1715                 child_state.ssh1protoflags = buffer_get_int(&m);
1716                 child_state.ssh1cipher = buffer_get_int(&m);
1717                 child_state.ssh1key = buffer_get_string(&m,
1718                     &child_state.ssh1keylen);
1719                 child_state.ivout = buffer_get_string(&m,
1720                     &child_state.ivoutlen);
1721                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1722                 goto skip;
1723         } else {
1724                 /* Get the Kex for rekeying */
1725                 *pmonitor->m_pkex = mm_get_kex(&m);
1726         }
1727
1728         blob = buffer_get_string(&m, &bloblen);
1729         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1730         xfree(blob);
1731
1732         debug3("%s: Waiting for second key", __func__);
1733         blob = buffer_get_string(&m, &bloblen);
1734         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1735         xfree(blob);
1736
1737         /* Now get sequence numbers for the packets */
1738         seqnr = buffer_get_int(&m);
1739         blocks = buffer_get_int64(&m);
1740         packets = buffer_get_int(&m);
1741         bytes = buffer_get_int64(&m);
1742         packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1743         seqnr = buffer_get_int(&m);
1744         blocks = buffer_get_int64(&m);
1745         packets = buffer_get_int(&m);
1746         bytes = buffer_get_int64(&m);
1747         packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1748
1749  skip:
1750         /* Get the key context */
1751         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1752         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1753
1754         debug3("%s: Getting compression state", __func__);
1755         /* Get compression state */
1756         p = buffer_get_string(&m, &plen);
1757         if (plen != sizeof(child_state.outgoing))
1758                 fatal("%s: bad request size", __func__);
1759         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1760         xfree(p);
1761
1762         p = buffer_get_string(&m, &plen);
1763         if (plen != sizeof(child_state.incoming))
1764                 fatal("%s: bad request size", __func__);
1765         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1766         xfree(p);
1767
1768         /* Network I/O buffers */
1769         debug3("%s: Getting Network I/O buffers", __func__);
1770         child_state.input = buffer_get_string(&m, &child_state.ilen);
1771         child_state.output = buffer_get_string(&m, &child_state.olen);
1772
1773         buffer_free(&m);
1774 }
1775
1776
1777 /* Allocation functions for zlib */
1778 void *
1779 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1780 {
1781         size_t len = (size_t) size * ncount;
1782         void *address;
1783
1784         if (len == 0 || ncount > SIZE_T_MAX / size)
1785                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1786
1787         address = mm_malloc(mm, len);
1788
1789         return (address);
1790 }
1791
1792 void
1793 mm_zfree(struct mm_master *mm, void *address)
1794 {
1795         mm_free(mm, address);
1796 }
1797
1798 void
1799 mm_init_compression(struct mm_master *mm)
1800 {
1801         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1802         outgoing_stream.zfree = (free_func)mm_zfree;
1803         outgoing_stream.opaque = mm;
1804
1805         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1806         incoming_stream.zfree = (free_func)mm_zfree;
1807         incoming_stream.opaque = mm;
1808 }
1809
1810 /* XXX */
1811
1812 #define FD_CLOSEONEXEC(x) do { \
1813         if (fcntl(x, F_SETFD, 1) == -1) \
1814                 fatal("fcntl(%d, F_SETFD)", x); \
1815 } while (0)
1816
1817 static void
1818 monitor_socketpair(int *pair)
1819 {
1820 #ifdef HAVE_SOCKETPAIR
1821         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1822                 fatal("%s: socketpair", __func__);
1823 #else
1824         fatal("%s: UsePrivilegeSeparation=yes not supported",
1825             __func__);
1826 #endif
1827         FD_CLOSEONEXEC(pair[0]);
1828         FD_CLOSEONEXEC(pair[1]);
1829 }
1830
1831 #define MM_MEMSIZE      65536
1832
1833 struct monitor *
1834 monitor_init(void)
1835 {
1836         struct monitor *mon;
1837         int pair[2];
1838
1839         mon = xcalloc(1, sizeof(*mon));
1840
1841         monitor_socketpair(pair);
1842
1843         mon->m_recvfd = pair[0];
1844         mon->m_sendfd = pair[1];
1845
1846         /* Used to share zlib space across processes */
1847         if (options.compression) {
1848                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1849                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1850
1851                 /* Compression needs to share state across borders */
1852                 mm_init_compression(mon->m_zlib);
1853         }
1854
1855         return mon;
1856 }
1857
1858 void
1859 monitor_reinit(struct monitor *mon)
1860 {
1861         int pair[2];
1862
1863         monitor_socketpair(pair);
1864
1865         mon->m_recvfd = pair[0];
1866         mon->m_sendfd = pair[1];
1867 }
1868
1869 #ifdef GSSAPI
1870 int
1871 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1872 {
1873         gss_OID_desc goid;
1874         OM_uint32 major;
1875         u_int len;
1876
1877         goid.elements = buffer_get_string(m, &len);
1878         goid.length = len;
1879
1880         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1881
1882         xfree(goid.elements);
1883
1884         buffer_clear(m);
1885         buffer_put_int(m, major);
1886
1887         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1888
1889         /* Now we have a context, enable the step */
1890         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1891
1892         return (0);
1893 }
1894
1895 int
1896 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1897 {
1898         gss_buffer_desc in;
1899         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1900         OM_uint32 major, minor;
1901         OM_uint32 flags = 0; /* GSI needs this */
1902         u_int len;
1903
1904         in.value = buffer_get_string(m, &len);
1905         in.length = len;
1906         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1907         xfree(in.value);
1908
1909         buffer_clear(m);
1910         buffer_put_int(m, major);
1911         buffer_put_string(m, out.value, out.length);
1912         buffer_put_int(m, flags);
1913         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1914
1915         gss_release_buffer(&minor, &out);
1916
1917         if (major == GSS_S_COMPLETE) {
1918                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1919                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1920                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1921         }
1922         return (0);
1923 }
1924
1925 int
1926 mm_answer_gss_checkmic(int sock, Buffer *m)
1927 {
1928         gss_buffer_desc gssbuf, mic;
1929         OM_uint32 ret;
1930         u_int len;
1931
1932         gssbuf.value = buffer_get_string(m, &len);
1933         gssbuf.length = len;
1934         mic.value = buffer_get_string(m, &len);
1935         mic.length = len;
1936
1937         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1938
1939         xfree(gssbuf.value);
1940         xfree(mic.value);
1941
1942         buffer_clear(m);
1943         buffer_put_int(m, ret);
1944
1945         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1946
1947         if (!GSS_ERROR(ret))
1948                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1949
1950         return (0);
1951 }
1952
1953 int
1954 mm_answer_gss_userok(int sock, Buffer *m)
1955 {
1956         int authenticated;
1957
1958         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1959
1960         buffer_clear(m);
1961         buffer_put_int(m, authenticated);
1962
1963         debug3("%s: sending result %d", __func__, authenticated);
1964         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1965
1966         auth_method = "gssapi-with-mic";
1967
1968         /* Monitor loop will terminate if authenticated */
1969         return (authenticated);
1970 }
1971 #endif /* GSSAPI */