monitor.c

   1 /* $OpenBSD: monitor.c,v 1.88 2006/08/12 20:46:46 miod 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 "xmalloc.h"
  55 #include "ssh.h"
  56 #include "key.h"
  57 #include "buffer.h"
  58 #include "hostfile.h"
  59 #include "auth.h"
  60 #include "cipher.h"
  61 #include "kex.h"
  62 #include "dh.h"
  63 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
  64 #undef TARGET_OS_MAC
  65 #include "zlib.h"
  66 #define TARGET_OS_MAC 1
  67 #else
  68 #include "zlib.h"
  69 #endif
  70 #include "packet.h"
  71 #include "auth-options.h"
  72 #include "sshpty.h"
  73 #include "channels.h"
  74 #include "session.h"
  75 #include "sshlogin.h"
  76 #include "canohost.h"
  77 #include "log.h"
  78 #include "servconf.h"
  79 #include "monitor.h"
  80 #include "monitor_mm.h"
  81 #ifdef GSSAPI
  82 #include "ssh-gss.h"
  83 #endif
  84 #include "monitor_wrap.h"
  85 #include "monitor_fdpass.h"
  86 #include "misc.h"
  87 #include "compat.h"
  88 #include "ssh2.h"
  89
  90 #ifdef GSSAPI
  91 static Gssctxt *gsscontext = NULL;
  92 #endif
  93
  94 /* Imports */
  95 extern ServerOptions options;
  96 extern u_int utmp_len;
  97 extern Newkeys *current_keys[];
  98 extern z_stream incoming_stream;
  99 extern z_stream outgoing_stream;
 100 extern u_char session_id[];
 101 extern Buffer input, output;
 102 extern Buffer auth_debug;
 103 extern int auth_debug_init;
 104 extern Buffer loginmsg;
 105
 106 /* State exported from the child */
 107
 108 struct {
 109         z_stream incoming;
 110         z_stream outgoing;
 111         u_char *keyin;
 112         u_int keyinlen;
 113         u_char *keyout;
 114         u_int keyoutlen;
 115         u_char *ivin;
 116         u_int ivinlen;
 117         u_char *ivout;
 118         u_int ivoutlen;
 119         u_char *ssh1key;
 120         u_int ssh1keylen;
 121         int ssh1cipher;
 122         int ssh1protoflags;
 123         u_char *input;
 124         u_int ilen;
 125         u_char *output;
 126         u_int olen;
 127 } child_state;
 128
 129 /* Functions on the monitor that answer unprivileged requests */
 130
 131 int mm_answer_moduli(int, Buffer *);
 132 int mm_answer_sign(int, Buffer *);
 133 int mm_answer_pwnamallow(int, Buffer *);
 134 int mm_answer_auth2_read_banner(int, Buffer *);
 135 int mm_answer_authserv(int, Buffer *);
 136 int mm_answer_authpassword(int, Buffer *);
 137 int mm_answer_bsdauthquery(int, Buffer *);
 138 int mm_answer_bsdauthrespond(int, Buffer *);
 139 int mm_answer_skeyquery(int, Buffer *);
 140 int mm_answer_skeyrespond(int, Buffer *);
 141 int mm_answer_keyallowed(int, Buffer *);
 142 int mm_answer_keyverify(int, Buffer *);
 143 int mm_answer_pty(int, Buffer *);
 144 int mm_answer_pty_cleanup(int, Buffer *);
 145 int mm_answer_term(int, Buffer *);
 146 int mm_answer_rsa_keyallowed(int, Buffer *);
 147 int mm_answer_rsa_challenge(int, Buffer *);
 148 int mm_answer_rsa_response(int, Buffer *);
 149 int mm_answer_sesskey(int, Buffer *);
 150 int mm_answer_sessid(int, Buffer *);
 151
 152 #ifdef USE_PAM
 153 int mm_answer_pam_start(int, Buffer *);
 154 int mm_answer_pam_account(int, Buffer *);
 155 int mm_answer_pam_init_ctx(int, Buffer *);
 156 int mm_answer_pam_query(int, Buffer *);
 157 int mm_answer_pam_respond(int, Buffer *);
 158 int mm_answer_pam_free_ctx(int, Buffer *);
 159 #endif
 160
 161 #ifdef GSSAPI
 162 int mm_answer_gss_setup_ctx(int, Buffer *);
 163 int mm_answer_gss_accept_ctx(int, Buffer *);
 164 int mm_answer_gss_userok(int, Buffer *);
 165 int mm_answer_gss_checkmic(int, Buffer *);
 166 #endif
 167
 168 #ifdef SSH_AUDIT_EVENTS
 169 int mm_answer_audit_event(int, Buffer *);
 170 int mm_answer_audit_command(int, Buffer *);
 171 #endif
 172
 173 static Authctxt *authctxt;
 174 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 175
 176 /* local state for key verify */
 177 static u_char *key_blob = NULL;
 178 static u_int key_bloblen = 0;
 179 static int key_blobtype = MM_NOKEY;
 180 static char *hostbased_cuser = NULL;
 181 static char *hostbased_chost = NULL;
 182 static char *auth_method = "unknown";
 183 static u_int session_id2_len = 0;
 184 static u_char *session_id2 = NULL;
 185 static pid_t monitor_child_pid;
 186
 187 struct mon_table {
 188         enum monitor_reqtype type;
 189         int flags;
 190         int (*f)(int, Buffer *);
 191 };
 192
 193 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 194 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 195 #define MON_ONCE        0x0010  /* Disable after calling */
 196 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 197
 198 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 199
 200 #define MON_PERMIT      0x1000  /* Request is permitted */
 201
 202 struct mon_table mon_dispatch_proto20[] = {
 203     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 204     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 205     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 206     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 207     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 208     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 209 #ifdef USE_PAM
 210     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 211     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 212     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 213     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 214     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 215     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 216 #endif
 217 #ifdef SSH_AUDIT_EVENTS
 218     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 219 #endif
 220 #ifdef BSD_AUTH
 221     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 222     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 223 #endif
 224 #ifdef SKEY
 225     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 226     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 227 #endif
 228     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 229     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 230 #ifdef GSSAPI
 231     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 232     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 233     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 234     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 235 #endif
 236     {0, 0, NULL}
 237 };
 238
 239 struct mon_table mon_dispatch_postauth20[] = {
 240     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 241     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 242     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 243     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 244     {MONITOR_REQ_TERM, 0, mm_answer_term},
 245 #ifdef SSH_AUDIT_EVENTS
 246     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 247     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 248 #endif
 249     {0, 0, NULL}
 250 };
 251
 252 struct mon_table mon_dispatch_proto15[] = {
 253     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 254     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 255     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 256     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 257     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 258     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 259     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 260     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 261 #ifdef BSD_AUTH
 262     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 263     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 264 #endif
 265 #ifdef SKEY
 266     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 267     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 268 #endif
 269 #ifdef USE_PAM
 270     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 271     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 272     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 273     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 274     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 275     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 276 #endif
 277 #ifdef SSH_AUDIT_EVENTS
 278     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 279 #endif
 280     {0, 0, NULL}
 281 };
 282
 283 struct mon_table mon_dispatch_postauth15[] = {
 284     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 285     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 286     {MONITOR_REQ_TERM, 0, mm_answer_term},
 287 #ifdef SSH_AUDIT_EVENTS
 288     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 289     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
 290 #endif
 291     {0, 0, NULL}
 292 };
 293
 294 struct mon_table *mon_dispatch;
 295
 296 /* Specifies if a certain message is allowed at the moment */
 297
 298 static void
 299 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 300 {
 301         while (ent->f != NULL) {
 302                 if (ent->type == type) {
 303                         ent->flags &= ~MON_PERMIT;
 304                         ent->flags |= permit ? MON_PERMIT : 0;
 305                         return;
 306                 }
 307                 ent++;
 308         }
 309 }
 310
 311 static void
 312 monitor_permit_authentications(int permit)
 313 {
 314         struct mon_table *ent = mon_dispatch;
 315
 316         while (ent->f != NULL) {
 317                 if (ent->flags & MON_AUTH) {
 318                         ent->flags &= ~MON_PERMIT;
 319                         ent->flags |= permit ? MON_PERMIT : 0;
 320                 }
 321                 ent++;
 322         }
 323 }
 324
 325 void
 326 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 327 {
 328         struct mon_table *ent;
 329         int authenticated = 0;
 330
 331         debug3("preauth child monitor started");
 332
 333         authctxt = _authctxt;
 334         memset(authctxt, 0, sizeof(*authctxt));
 335
 336         authctxt->loginmsg = &loginmsg;
 337
 338         if (compat20) {
 339                 mon_dispatch = mon_dispatch_proto20;
 340
 341                 /* Permit requests for moduli and signatures */
 342                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 343                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 344         } else {
 345                 mon_dispatch = mon_dispatch_proto15;
 346
 347                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 348         }
 349
 350         /* The first few requests do not require asynchronous access */
 351         while (!authenticated) {
 352                 auth_method = "unknown";
 353                 authenticated = monitor_read(pmonitor, mon_dispatch, &ent);
 354                 if (authenticated) {
 355                         if (!(ent->flags & MON_AUTHDECIDE))
 356                                 fatal("%s: unexpected authentication from %d",
 357                                     __func__, ent->type);
 358                         if (authctxt->pw->pw_uid == 0 &&
 359                             !auth_root_allowed(auth_method))
 360                                 authenticated = 0;
 361 #ifdef USE_PAM
 362                         /* PAM needs to perform account checks after auth */
 363                         if (options.use_pam && authenticated) {
 364                                 Buffer m;
 365
 366                                 buffer_init(&m);
 367                                 mm_request_receive_expect(pmonitor->m_sendfd,
 368                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 369                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 370                                 buffer_free(&m);
 371                         }
 372 #endif
 373                 }
 374
 375                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 376                         auth_log(authctxt, authenticated, auth_method,
 377                             compat20 ? " ssh2" : "");
 378                         if (!authenticated)
 379                                 authctxt->failures++;
 380                 }
 381         }
 382
 383         if (!authctxt->valid)
 384                 fatal("%s: authenticated invalid user", __func__);
 385         if (strcmp(auth_method, "unknown") == 0)
 386                 fatal("%s: authentication method name unknown", __func__);
 387
 388         debug("%s: %s has been authenticated by privileged process",
 389             __func__, authctxt->user);
 390
 391         mm_get_keystate(pmonitor);
 392 }
 393
 394 static void
 395 monitor_set_child_handler(pid_t pid)
 396 {
 397         monitor_child_pid = pid;
 398 }
 399
 400 static void
 401 monitor_child_handler(int sig)
 402 {
 403         kill(monitor_child_pid, sig);
 404 }
 405
 406 void
 407 monitor_child_postauth(struct monitor *pmonitor)
 408 {
 409         monitor_set_child_handler(pmonitor->m_pid);
 410         signal(SIGHUP, &monitor_child_handler);
 411         signal(SIGTERM, &monitor_child_handler);
 412
 413         if (compat20) {
 414                 mon_dispatch = mon_dispatch_postauth20;
 415
 416                 /* Permit requests for moduli and signatures */
 417                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 418                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 419                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 420         } else {
 421                 mon_dispatch = mon_dispatch_postauth15;
 422                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 423         }
 424         if (!no_pty_flag) {
 425                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 426                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 427         }
 428
 429         for (;;)
 430                 monitor_read(pmonitor, mon_dispatch, NULL);
 431 }
 432
 433 void
 434 monitor_sync(struct monitor *pmonitor)
 435 {
 436         if (options.compression) {
 437                 /* The member allocation is not visible, so sync it */
 438                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 439         }
 440 }
 441
 442 int
 443 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 444     struct mon_table **pent)
 445 {
 446         Buffer m;
 447         int ret;
 448         u_char type;
 449
 450         buffer_init(&m);
 451
 452         mm_request_receive(pmonitor->m_sendfd, &m);
 453         type = buffer_get_char(&m);
 454
 455         debug3("%s: checking request %d", __func__, type);
 456
 457         while (ent->f != NULL) {
 458                 if (ent->type == type)
 459                         break;
 460                 ent++;
 461         }
 462
 463         if (ent->f != NULL) {
 464                 if (!(ent->flags & MON_PERMIT))
 465                         fatal("%s: unpermitted request %d", __func__,
 466                             type);
 467                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 468                 buffer_free(&m);
 469
 470                 /* The child may use this request only once, disable it */
 471                 if (ent->flags & MON_ONCE) {
 472                         debug2("%s: %d used once, disabling now", __func__,
 473                             type);
 474                         ent->flags &= ~MON_PERMIT;
 475                 }
 476
 477                 if (pent != NULL)
 478                         *pent = ent;
 479
 480                 return ret;
 481         }
 482
 483         fatal("%s: unsupported request: %d", __func__, type);
 484
 485         /* NOTREACHED */
 486         return (-1);
 487 }
 488
 489 /* allowed key state */
 490 static int
 491 monitor_allowed_key(u_char *blob, u_int bloblen)
 492 {
 493         /* make sure key is allowed */
 494         if (key_blob == NULL || key_bloblen != bloblen ||
 495             memcmp(key_blob, blob, key_bloblen))
 496                 return (0);
 497         return (1);
 498 }
 499
 500 static void
 501 monitor_reset_key_state(void)
 502 {
 503         /* reset state */
 504         if (key_blob != NULL)
 505                 xfree(key_blob);
 506         if (hostbased_cuser != NULL)
 507                 xfree(hostbased_cuser);
 508         if (hostbased_chost != NULL)
 509                 xfree(hostbased_chost);
 510         key_blob = NULL;
 511         key_bloblen = 0;
 512         key_blobtype = MM_NOKEY;
 513         hostbased_cuser = NULL;
 514         hostbased_chost = NULL;
 515 }
 516
 517 int
 518 mm_answer_moduli(int sock, Buffer *m)
 519 {
 520         DH *dh;
 521         int min, want, max;
 522
 523         min = buffer_get_int(m);
 524         want = buffer_get_int(m);
 525         max = buffer_get_int(m);
 526
 527         debug3("%s: got parameters: %d %d %d",
 528             __func__, min, want, max);
 529         /* We need to check here, too, in case the child got corrupted */
 530         if (max < min || want < min || max < want)
 531                 fatal("%s: bad parameters: %d %d %d",
 532                     __func__, min, want, max);
 533
 534         buffer_clear(m);
 535
 536         dh = choose_dh(min, want, max);
 537         if (dh == NULL) {
 538                 buffer_put_char(m, 0);
 539                 return (0);
 540         } else {
 541                 /* Send first bignum */
 542                 buffer_put_char(m, 1);
 543                 buffer_put_bignum2(m, dh->p);
 544                 buffer_put_bignum2(m, dh->g);
 545
 546                 DH_free(dh);
 547         }
 548         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 549         return (0);
 550 }
 551
 552 int
 553 mm_answer_sign(int sock, Buffer *m)
 554 {
 555         Key *key;
 556         u_char *p;
 557         u_char *signature;
 558         u_int siglen, datlen;
 559         int keyid;
 560
 561         debug3("%s", __func__);
 562
 563         keyid = buffer_get_int(m);
 564         p = buffer_get_string(m, &datlen);
 565
 566         /*
 567          * Supported KEX types will only return SHA1 (20 byte) or
 568          * SHA256 (32 byte) hashes
 569          */
 570         if (datlen != 20 && datlen != 32)
 571                 fatal("%s: data length incorrect: %u", __func__, datlen);
 572
 573         /* save session id, it will be passed on the first call */
 574         if (session_id2_len == 0) {
 575                 session_id2_len = datlen;
 576                 session_id2 = xmalloc(session_id2_len);
 577                 memcpy(session_id2, p, session_id2_len);
 578         }
 579
 580         if ((key = get_hostkey_by_index(keyid)) == NULL)
 581                 fatal("%s: no hostkey from index %d", __func__, keyid);
 582         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 583                 fatal("%s: key_sign failed", __func__);
 584
 585         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 586
 587         buffer_clear(m);
 588         buffer_put_string(m, signature, siglen);
 589
 590         xfree(p);
 591         xfree(signature);
 592
 593         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 594
 595         /* Turn on permissions for getpwnam */
 596         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 597
 598         return (0);
 599 }
 600
 601 /* Retrieves the password entry and also checks if the user is permitted */
 602
 603 int
 604 mm_answer_pwnamallow(int sock, Buffer *m)
 605 {
 606         char *username;
 607         struct passwd *pwent;
 608         int allowed = 0;
 609
 610         debug3("%s", __func__);
 611
 612         if (authctxt->attempt++ != 0)
 613                 fatal("%s: multiple attempts for getpwnam", __func__);
 614
 615         username = buffer_get_string(m, NULL);
 616
 617         pwent = getpwnamallow(username);
 618
 619         authctxt->user = xstrdup(username);
 620         setproctitle("%s [priv]", pwent ? username : "unknown");
 621         xfree(username);
 622
 623         buffer_clear(m);
 624
 625         if (pwent == NULL) {
 626                 buffer_put_char(m, 0);
 627                 authctxt->pw = fakepw();
 628                 goto out;
 629         }
 630
 631         allowed = 1;
 632         authctxt->pw = pwent;
 633         authctxt->valid = 1;
 634
 635         buffer_put_char(m, 1);
 636         buffer_put_string(m, pwent, sizeof(struct passwd));
 637         buffer_put_cstring(m, pwent->pw_name);
 638         buffer_put_cstring(m, "*");
 639         buffer_put_cstring(m, pwent->pw_gecos);
 640 #ifdef HAVE_PW_CLASS_IN_PASSWD
 641         buffer_put_cstring(m, pwent->pw_class);
 642 #endif
 643         buffer_put_cstring(m, pwent->pw_dir);
 644         buffer_put_cstring(m, pwent->pw_shell);
 645
 646  out:
 647         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 648         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 649
 650         /* For SSHv1 allow authentication now */
 651         if (!compat20)
 652                 monitor_permit_authentications(1);
 653         else {
 654                 /* Allow service/style information on the auth context */
 655                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 656                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 657         }
 658
 659 #ifdef USE_PAM
 660         if (options.use_pam)
 661                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 662 #endif
 663
 664         return (0);
 665 }
 666
 667 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 668 {
 669         char *banner;
 670
 671         buffer_clear(m);
 672         banner = auth2_read_banner();
 673         buffer_put_cstring(m, banner != NULL ? banner : "");
 674         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 675
 676         if (banner != NULL)
 677                 xfree(banner);
 678
 679         return (0);
 680 }
 681
 682 int
 683 mm_answer_authserv(int sock, Buffer *m)
 684 {
 685         monitor_permit_authentications(1);
 686
 687         authctxt->service = buffer_get_string(m, NULL);
 688         authctxt->style = buffer_get_string(m, NULL);
 689         debug3("%s: service=%s, style=%s",
 690             __func__, authctxt->service, authctxt->style);
 691
 692         if (strlen(authctxt->style) == 0) {
 693                 xfree(authctxt->style);
 694                 authctxt->style = NULL;
 695         }
 696
 697         return (0);
 698 }
 699
 700 int
 701 mm_answer_authpassword(int sock, Buffer *m)
 702 {
 703         static int call_count;
 704         char *passwd;
 705         int authenticated;
 706         u_int plen;
 707
 708         passwd = buffer_get_string(m, &plen);
 709         /* Only authenticate if the context is valid */
 710         authenticated = options.password_authentication &&
 711             auth_password(authctxt, passwd);
 712         memset(passwd, 0, strlen(passwd));
 713         xfree(passwd);
 714
 715         buffer_clear(m);
 716         buffer_put_int(m, authenticated);
 717
 718         debug3("%s: sending result %d", __func__, authenticated);
 719         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 720
 721         call_count++;
 722         if (plen == 0 && call_count == 1)
 723                 auth_method = "none";
 724         else
 725                 auth_method = "password";
 726
 727         /* Causes monitor loop to terminate if authenticated */
 728         return (authenticated);
 729 }
 730
 731 #ifdef BSD_AUTH
 732 int
 733 mm_answer_bsdauthquery(int sock, Buffer *m)
 734 {
 735         char *name, *infotxt;
 736         u_int numprompts;
 737         u_int *echo_on;
 738         char **prompts;
 739         u_int success;
 740
 741         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 742             &prompts, &echo_on) < 0 ? 0 : 1;
 743
 744         buffer_clear(m);
 745         buffer_put_int(m, success);
 746         if (success)
 747                 buffer_put_cstring(m, prompts[0]);
 748
 749         debug3("%s: sending challenge success: %u", __func__, success);
 750         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 751
 752         if (success) {
 753                 xfree(name);
 754                 xfree(infotxt);
 755                 xfree(prompts);
 756                 xfree(echo_on);
 757         }
 758
 759         return (0);
 760 }
 761
 762 int
 763 mm_answer_bsdauthrespond(int sock, Buffer *m)
 764 {
 765         char *response;
 766         int authok;
 767
 768         if (authctxt->as == 0)
 769                 fatal("%s: no bsd auth session", __func__);
 770
 771         response = buffer_get_string(m, NULL);
 772         authok = options.challenge_response_authentication &&
 773             auth_userresponse(authctxt->as, response, 0);
 774         authctxt->as = NULL;
 775         debug3("%s: <%s> = <%d>", __func__, response, authok);
 776         xfree(response);
 777
 778         buffer_clear(m);
 779         buffer_put_int(m, authok);
 780
 781         debug3("%s: sending authenticated: %d", __func__, authok);
 782         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 783
 784         auth_method = "bsdauth";
 785
 786         return (authok != 0);
 787 }
 788 #endif
 789
 790 #ifdef SKEY
 791 int
 792 mm_answer_skeyquery(int sock, Buffer *m)
 793 {
 794         struct skey skey;
 795         char challenge[1024];
 796         u_int success;
 797
 798         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 799             sizeof(challenge)) < 0 ? 0 : 1;
 800
 801         buffer_clear(m);
 802         buffer_put_int(m, success);
 803         if (success)
 804                 buffer_put_cstring(m, challenge);
 805
 806         debug3("%s: sending challenge success: %u", __func__, success);
 807         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 808
 809         return (0);
 810 }
 811
 812 int
 813 mm_answer_skeyrespond(int sock, Buffer *m)
 814 {
 815         char *response;
 816         int authok;
 817
 818         response = buffer_get_string(m, NULL);
 819
 820         authok = (options.challenge_response_authentication &&
 821             authctxt->valid &&
 822             skey_haskey(authctxt->pw->pw_name) == 0 &&
 823             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 824
 825         xfree(response);
 826
 827         buffer_clear(m);
 828         buffer_put_int(m, authok);
 829
 830         debug3("%s: sending authenticated: %d", __func__, authok);
 831         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 832
 833         auth_method = "skey";
 834
 835         return (authok != 0);
 836 }
 837 #endif
 838
 839 #ifdef USE_PAM
 840 int
 841 mm_answer_pam_start(int sock, Buffer *m)
 842 {
 843         if (!options.use_pam)
 844                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 845
 846         start_pam(authctxt);
 847
 848         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 849
 850         return (0);
 851 }
 852
 853 int
 854 mm_answer_pam_account(int sock, Buffer *m)
 855 {
 856         u_int ret;
 857
 858         if (!options.use_pam)
 859                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 860
 861         ret = do_pam_account();
 862
 863         buffer_put_int(m, ret);
 864         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 865
 866         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 867
 868         return (ret);
 869 }
 870
 871 static void *sshpam_ctxt, *sshpam_authok;
 872 extern KbdintDevice sshpam_device;
 873
 874 int
 875 mm_answer_pam_init_ctx(int sock, Buffer *m)
 876 {
 877
 878         debug3("%s", __func__);
 879         authctxt->user = buffer_get_string(m, NULL);
 880         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 881         sshpam_authok = NULL;
 882         buffer_clear(m);
 883         if (sshpam_ctxt != NULL) {
 884                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 885                 buffer_put_int(m, 1);
 886         } else {
 887                 buffer_put_int(m, 0);
 888         }
 889         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 890         return (0);
 891 }
 892
 893 int
 894 mm_answer_pam_query(int sock, Buffer *m)
 895 {
 896         char *name, *info, **prompts;
 897         u_int i, num, *echo_on;
 898         int ret;
 899
 900         debug3("%s", __func__);
 901         sshpam_authok = NULL;
 902         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 903         if (ret == 0 && num == 0)
 904                 sshpam_authok = sshpam_ctxt;
 905         if (num > 1 || name == NULL || info == NULL)
 906                 ret = -1;
 907         buffer_clear(m);
 908         buffer_put_int(m, ret);
 909         buffer_put_cstring(m, name);
 910         xfree(name);
 911         buffer_put_cstring(m, info);
 912         xfree(info);
 913         buffer_put_int(m, num);
 914         for (i = 0; i < num; ++i) {
 915                 buffer_put_cstring(m, prompts[i]);
 916                 xfree(prompts[i]);
 917                 buffer_put_int(m, echo_on[i]);
 918         }
 919         if (prompts != NULL)
 920                 xfree(prompts);
 921         if (echo_on != NULL)
 922                 xfree(echo_on);
 923         auth_method = "keyboard-interactive/pam";
 924         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 925         return (0);
 926 }
 927
 928 int
 929 mm_answer_pam_respond(int sock, Buffer *m)
 930 {
 931         char **resp;
 932         u_int i, num;
 933         int ret;
 934
 935         debug3("%s", __func__);
 936         sshpam_authok = NULL;
 937         num = buffer_get_int(m);
 938         if (num > 0) {
 939                 resp = xcalloc(num, sizeof(char *));
 940                 for (i = 0; i < num; ++i)
 941                         resp[i] = buffer_get_string(m, NULL);
 942                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 943                 for (i = 0; i < num; ++i)
 944                         xfree(resp[i]);
 945                 xfree(resp);
 946         } else {
 947                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 948         }
 949         buffer_clear(m);
 950         buffer_put_int(m, ret);
 951         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 952         auth_method = "keyboard-interactive/pam";
 953         if (ret == 0)
 954                 sshpam_authok = sshpam_ctxt;
 955         return (0);
 956 }
 957
 958 int
 959 mm_answer_pam_free_ctx(int sock, Buffer *m)
 960 {
 961
 962         debug3("%s", __func__);
 963         (sshpam_device.free_ctx)(sshpam_ctxt);
 964         buffer_clear(m);
 965         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 966         auth_method = "keyboard-interactive/pam";
 967         return (sshpam_authok == sshpam_ctxt);
 968 }
 969 #endif
 970
 971 static void
 972 mm_append_debug(Buffer *m)
 973 {
 974         if (auth_debug_init && buffer_len(&auth_debug)) {
 975                 debug3("%s: Appending debug messages for child", __func__);
 976                 buffer_append(m, buffer_ptr(&auth_debug),
 977                     buffer_len(&auth_debug));
 978                 buffer_clear(&auth_debug);
 979         }
 980 }
 981
 982 int
 983 mm_answer_keyallowed(int sock, Buffer *m)
 984 {
 985         Key *key;
 986         char *cuser, *chost;
 987         u_char *blob;
 988         u_int bloblen;
 989         enum mm_keytype type = 0;
 990         int allowed = 0;
 991
 992         debug3("%s entering", __func__);
 993
 994         type = buffer_get_int(m);
 995         cuser = buffer_get_string(m, NULL);
 996         chost = buffer_get_string(m, NULL);
 997         blob = buffer_get_string(m, &bloblen);
 998
 999         key = key_from_blob(blob, bloblen);
1000
1001         if ((compat20 && type == MM_RSAHOSTKEY) ||
1002             (!compat20 && type != MM_RSAHOSTKEY))
1003                 fatal("%s: key type and protocol mismatch", __func__);
1004
1005         debug3("%s: key_from_blob: %p", __func__, key);
1006
1007         if (key != NULL && authctxt->valid) {
1008                 switch (type) {
1009                 case MM_USERKEY:
1010                         allowed = options.pubkey_authentication &&
1011                             user_key_allowed(authctxt->pw, key);
1012                         auth_method = "publickey";
1013                         break;
1014                 case MM_HOSTKEY:
1015                         allowed = options.hostbased_authentication &&
1016                             hostbased_key_allowed(authctxt->pw,
1017                             cuser, chost, key);
1018                         auth_method = "hostbased";
1019                         break;
1020                 case MM_RSAHOSTKEY:
1021                         key->type = KEY_RSA1; /* XXX */
1022                         allowed = options.rhosts_rsa_authentication &&
1023                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1024                             cuser, chost, key);
1025                         auth_method = "rsa";
1026                         break;
1027                 default:
1028                         fatal("%s: unknown key type %d", __func__, type);
1029                         break;
1030                 }
1031         }
1032         if (key != NULL)
1033                 key_free(key);
1034
1035         /* clear temporarily storage (used by verify) */
1036         monitor_reset_key_state();
1037
1038         if (allowed) {
1039                 /* Save temporarily for comparison in verify */
1040                 key_blob = blob;
1041                 key_bloblen = bloblen;
1042                 key_blobtype = type;
1043                 hostbased_cuser = cuser;
1044                 hostbased_chost = chost;
1045         } else {
1046                 /* Log failed attempt */
1047                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1048                 xfree(blob);
1049                 xfree(cuser);
1050                 xfree(chost);
1051         }
1052
1053         debug3("%s: key %p is %s",
1054             __func__, key, allowed ? "allowed" : "disallowed");
1055
1056         buffer_clear(m);
1057         buffer_put_int(m, allowed);
1058         buffer_put_int(m, forced_command != NULL);
1059
1060         mm_append_debug(m);
1061
1062         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1063
1064         if (type == MM_RSAHOSTKEY)
1065                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1066
1067         return (0);
1068 }
1069
1070 static int
1071 monitor_valid_userblob(u_char *data, u_int datalen)
1072 {
1073         Buffer b;
1074         char *p;
1075         u_int len;
1076         int fail = 0;
1077
1078         buffer_init(&b);
1079         buffer_append(&b, data, datalen);
1080
1081         if (datafellows & SSH_OLD_SESSIONID) {
1082                 p = buffer_ptr(&b);
1083                 len = buffer_len(&b);
1084                 if ((session_id2 == NULL) ||
1085                     (len < session_id2_len) ||
1086                     (memcmp(p, session_id2, session_id2_len) != 0))
1087                         fail++;
1088                 buffer_consume(&b, session_id2_len);
1089         } else {
1090                 p = buffer_get_string(&b, &len);
1091                 if ((session_id2 == NULL) ||
1092                     (len != session_id2_len) ||
1093                     (memcmp(p, session_id2, session_id2_len) != 0))
1094                         fail++;
1095                 xfree(p);
1096         }
1097         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1098                 fail++;
1099         p = buffer_get_string(&b, NULL);
1100         if (strcmp(authctxt->user, p) != 0) {
1101                 logit("wrong user name passed to monitor: expected %s != %.100s",
1102                     authctxt->user, p);
1103                 fail++;
1104         }
1105         xfree(p);
1106         buffer_skip_string(&b);
1107         if (datafellows & SSH_BUG_PKAUTH) {
1108                 if (!buffer_get_char(&b))
1109                         fail++;
1110         } else {
1111                 p = buffer_get_string(&b, NULL);
1112                 if (strcmp("publickey", p) != 0)
1113                         fail++;
1114                 xfree(p);
1115                 if (!buffer_get_char(&b))
1116                         fail++;
1117                 buffer_skip_string(&b);
1118         }
1119         buffer_skip_string(&b);
1120         if (buffer_len(&b) != 0)
1121                 fail++;
1122         buffer_free(&b);
1123         return (fail == 0);
1124 }
1125
1126 static int
1127 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1128     char *chost)
1129 {
1130         Buffer b;
1131         char *p;
1132         u_int len;
1133         int fail = 0;
1134
1135         buffer_init(&b);
1136         buffer_append(&b, data, datalen);
1137
1138         p = buffer_get_string(&b, &len);
1139         if ((session_id2 == NULL) ||
1140             (len != session_id2_len) ||
1141             (memcmp(p, session_id2, session_id2_len) != 0))
1142                 fail++;
1143         xfree(p);
1144
1145         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1146                 fail++;
1147         p = buffer_get_string(&b, NULL);
1148         if (strcmp(authctxt->user, p) != 0) {
1149                 logit("wrong user name passed to monitor: expected %s != %.100s",
1150                     authctxt->user, p);
1151                 fail++;
1152         }
1153         xfree(p);
1154         buffer_skip_string(&b); /* service */
1155         p = buffer_get_string(&b, NULL);
1156         if (strcmp(p, "hostbased") != 0)
1157                 fail++;
1158         xfree(p);
1159         buffer_skip_string(&b); /* pkalg */
1160         buffer_skip_string(&b); /* pkblob */
1161
1162         /* verify client host, strip trailing dot if necessary */
1163         p = buffer_get_string(&b, NULL);
1164         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1165                 p[len - 1] = '\0';
1166         if (strcmp(p, chost) != 0)
1167                 fail++;
1168         xfree(p);
1169
1170         /* verify client user */
1171         p = buffer_get_string(&b, NULL);
1172         if (strcmp(p, cuser) != 0)
1173                 fail++;
1174         xfree(p);
1175
1176         if (buffer_len(&b) != 0)
1177                 fail++;
1178         buffer_free(&b);
1179         return (fail == 0);
1180 }
1181
1182 int
1183 mm_answer_keyverify(int sock, Buffer *m)
1184 {
1185         Key *key;
1186         u_char *signature, *data, *blob;
1187         u_int signaturelen, datalen, bloblen;
1188         int verified = 0;
1189         int valid_data = 0;
1190
1191         blob = buffer_get_string(m, &bloblen);
1192         signature = buffer_get_string(m, &signaturelen);
1193         data = buffer_get_string(m, &datalen);
1194
1195         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1196           !monitor_allowed_key(blob, bloblen))
1197                 fatal("%s: bad key, not previously allowed", __func__);
1198
1199         key = key_from_blob(blob, bloblen);
1200         if (key == NULL)
1201                 fatal("%s: bad public key blob", __func__);
1202
1203         switch (key_blobtype) {
1204         case MM_USERKEY:
1205                 valid_data = monitor_valid_userblob(data, datalen);
1206                 break;
1207         case MM_HOSTKEY:
1208                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1209                     hostbased_cuser, hostbased_chost);
1210                 break;
1211         default:
1212                 valid_data = 0;
1213                 break;
1214         }
1215         if (!valid_data)
1216                 fatal("%s: bad signature data blob", __func__);
1217
1218         verified = key_verify(key, signature, signaturelen, data, datalen);
1219         debug3("%s: key %p signature %s",
1220             __func__, key, verified ? "verified" : "unverified");
1221
1222         key_free(key);
1223         xfree(blob);
1224         xfree(signature);
1225         xfree(data);
1226
1227         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1228
1229         monitor_reset_key_state();
1230
1231         buffer_clear(m);
1232         buffer_put_int(m, verified);
1233         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1234
1235         return (verified);
1236 }
1237
1238 static void
1239 mm_record_login(Session *s, struct passwd *pw)
1240 {
1241         socklen_t fromlen;
1242         struct sockaddr_storage from;
1243
1244         /*
1245          * Get IP address of client. If the connection is not a socket, let
1246          * the address be 0.0.0.0.
1247          */
1248         memset(&from, 0, sizeof(from));
1249         fromlen = sizeof(from);
1250         if (packet_connection_is_on_socket()) {
1251                 if (getpeername(packet_get_connection_in(),
1252                     (struct sockaddr *)&from, &fromlen) < 0) {
1253                         debug("getpeername: %.100s", strerror(errno));
1254                         cleanup_exit(255);
1255                 }
1256         }
1257         /* Record that there was a login on that tty from the remote host. */
1258         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1259             get_remote_name_or_ip(utmp_len, options.use_dns),
1260             (struct sockaddr *)&from, fromlen);
1261 }
1262
1263 static void
1264 mm_session_close(Session *s)
1265 {
1266         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1267         if (s->ttyfd != -1) {
1268                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1269                 session_pty_cleanup2(s);
1270         }
1271         s->used = 0;
1272 }
1273
1274 int
1275 mm_answer_pty(int sock, Buffer *m)
1276 {
1277         extern struct monitor *pmonitor;
1278         Session *s;
1279         int res, fd0;
1280
1281         debug3("%s entering", __func__);
1282
1283         buffer_clear(m);
1284         s = session_new();
1285         if (s == NULL)
1286                 goto error;
1287         s->authctxt = authctxt;
1288         s->pw = authctxt->pw;
1289         s->pid = pmonitor->m_pid;
1290         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1291         if (res == 0)
1292                 goto error;
1293         pty_setowner(authctxt->pw, s->tty);
1294
1295         buffer_put_int(m, 1);
1296         buffer_put_cstring(m, s->tty);
1297
1298         /* We need to trick ttyslot */
1299         if (dup2(s->ttyfd, 0) == -1)
1300                 fatal("%s: dup2", __func__);
1301
1302         mm_record_login(s, authctxt->pw);
1303
1304         /* Now we can close the file descriptor again */
1305         close(0);
1306
1307         /* send messages generated by record_login */
1308         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1309         buffer_clear(&loginmsg);
1310
1311         mm_request_send(sock, MONITOR_ANS_PTY, m);
1312
1313         mm_send_fd(sock, s->ptyfd);
1314         mm_send_fd(sock, s->ttyfd);
1315
1316         /* make sure nothing uses fd 0 */
1317         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1318                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1319         if (fd0 != 0)
1320                 error("%s: fd0 %d != 0", __func__, fd0);
1321
1322         /* slave is not needed */
1323         close(s->ttyfd);
1324         s->ttyfd = s->ptyfd;
1325         /* no need to dup() because nobody closes ptyfd */
1326         s->ptymaster = s->ptyfd;
1327
1328         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1329
1330         return (0);
1331
1332  error:
1333         if (s != NULL)
1334                 mm_session_close(s);
1335         buffer_put_int(m, 0);
1336         mm_request_send(sock, MONITOR_ANS_PTY, m);
1337         return (0);
1338 }
1339
1340 int
1341 mm_answer_pty_cleanup(int sock, Buffer *m)
1342 {
1343         Session *s;
1344         char *tty;
1345
1346         debug3("%s entering", __func__);
1347
1348         tty = buffer_get_string(m, NULL);
1349         if ((s = session_by_tty(tty)) != NULL)
1350                 mm_session_close(s);
1351         buffer_clear(m);
1352         xfree(tty);
1353         return (0);
1354 }
1355
1356 int
1357 mm_answer_sesskey(int sock, Buffer *m)
1358 {
1359         BIGNUM *p;
1360         int rsafail;
1361
1362         /* Turn off permissions */
1363         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1364
1365         if ((p = BN_new()) == NULL)
1366                 fatal("%s: BN_new", __func__);
1367
1368         buffer_get_bignum2(m, p);
1369
1370         rsafail = ssh1_session_key(p);
1371
1372         buffer_clear(m);
1373         buffer_put_int(m, rsafail);
1374         buffer_put_bignum2(m, p);
1375
1376         BN_clear_free(p);
1377
1378         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1379
1380         /* Turn on permissions for sessid passing */
1381         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1382
1383         return (0);
1384 }
1385
1386 int
1387 mm_answer_sessid(int sock, Buffer *m)
1388 {
1389         int i;
1390
1391         debug3("%s entering", __func__);
1392
1393         if (buffer_len(m) != 16)
1394                 fatal("%s: bad ssh1 session id", __func__);
1395         for (i = 0; i < 16; i++)
1396                 session_id[i] = buffer_get_char(m);
1397
1398         /* Turn on permissions for getpwnam */
1399         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1400
1401         return (0);
1402 }
1403
1404 int
1405 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1406 {
1407         BIGNUM *client_n;
1408         Key *key = NULL;
1409         u_char *blob = NULL;
1410         u_int blen = 0;
1411         int allowed = 0;
1412
1413         debug3("%s entering", __func__);
1414
1415         auth_method = "rsa";
1416         if (options.rsa_authentication && authctxt->valid) {
1417                 if ((client_n = BN_new()) == NULL)
1418                         fatal("%s: BN_new", __func__);
1419                 buffer_get_bignum2(m, client_n);
1420                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1421                 BN_clear_free(client_n);
1422         }
1423         buffer_clear(m);
1424         buffer_put_int(m, allowed);
1425         buffer_put_int(m, forced_command != NULL);
1426
1427         /* clear temporarily storage (used by generate challenge) */
1428         monitor_reset_key_state();
1429
1430         if (allowed && key != NULL) {
1431                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1432                 if (key_to_blob(key, &blob, &blen) == 0)
1433                         fatal("%s: key_to_blob failed", __func__);
1434                 buffer_put_string(m, blob, blen);
1435
1436                 /* Save temporarily for comparison in verify */
1437                 key_blob = blob;
1438                 key_bloblen = blen;
1439                 key_blobtype = MM_RSAUSERKEY;
1440         }
1441         if (key != NULL)
1442                 key_free(key);
1443
1444         mm_append_debug(m);
1445
1446         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1447
1448         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1449         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1450         return (0);
1451 }
1452
1453 int
1454 mm_answer_rsa_challenge(int sock, Buffer *m)
1455 {
1456         Key *key = NULL;
1457         u_char *blob;
1458         u_int blen;
1459
1460         debug3("%s entering", __func__);
1461
1462         if (!authctxt->valid)
1463                 fatal("%s: authctxt not valid", __func__);
1464         blob = buffer_get_string(m, &blen);
1465         if (!monitor_allowed_key(blob, blen))
1466                 fatal("%s: bad key, not previously allowed", __func__);
1467         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1468                 fatal("%s: key type mismatch", __func__);
1469         if ((key = key_from_blob(blob, blen)) == NULL)
1470                 fatal("%s: received bad key", __func__);
1471
1472         if (ssh1_challenge)
1473                 BN_clear_free(ssh1_challenge);
1474         ssh1_challenge = auth_rsa_generate_challenge(key);
1475
1476         buffer_clear(m);
1477         buffer_put_bignum2(m, ssh1_challenge);
1478
1479         debug3("%s sending reply", __func__);
1480         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1481
1482         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1483
1484         xfree(blob);
1485         key_free(key);
1486         return (0);
1487 }
1488
1489 int
1490 mm_answer_rsa_response(int sock, Buffer *m)
1491 {
1492         Key *key = NULL;
1493         u_char *blob, *response;
1494         u_int blen, len;
1495         int success;
1496
1497         debug3("%s entering", __func__);
1498
1499         if (!authctxt->valid)
1500                 fatal("%s: authctxt not valid", __func__);
1501         if (ssh1_challenge == NULL)
1502                 fatal("%s: no ssh1_challenge", __func__);
1503
1504         blob = buffer_get_string(m, &blen);
1505         if (!monitor_allowed_key(blob, blen))
1506                 fatal("%s: bad key, not previously allowed", __func__);
1507         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1508                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1509         if ((key = key_from_blob(blob, blen)) == NULL)
1510                 fatal("%s: received bad key", __func__);
1511         response = buffer_get_string(m, &len);
1512         if (len != 16)
1513                 fatal("%s: received bad response to challenge", __func__);
1514         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1515
1516         xfree(blob);
1517         key_free(key);
1518         xfree(response);
1519
1520         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1521
1522         /* reset state */
1523         BN_clear_free(ssh1_challenge);
1524         ssh1_challenge = NULL;
1525         monitor_reset_key_state();
1526
1527         buffer_clear(m);
1528         buffer_put_int(m, success);
1529         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1530
1531         return (success);
1532 }
1533
1534 int
1535 mm_answer_term(int sock, Buffer *req)
1536 {
1537         extern struct monitor *pmonitor;
1538         int res, status;
1539
1540         debug3("%s: tearing down sessions", __func__);
1541
1542         /* The child is terminating */
1543         session_destroy_all(&mm_session_close);
1544
1545         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1546                 if (errno != EINTR)
1547                         exit(1);
1548
1549         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1550
1551         /* Terminate process */
1552         exit(res);
1553 }
1554
1555 #ifdef SSH_AUDIT_EVENTS
1556 /* Report that an audit event occurred */
1557 int
1558 mm_answer_audit_event(int socket, Buffer *m)
1559 {
1560         ssh_audit_event_t event;
1561
1562         debug3("%s entering", __func__);
1563
1564         event = buffer_get_int(m);
1565         switch(event) {
1566         case SSH_AUTH_FAIL_PUBKEY:
1567         case SSH_AUTH_FAIL_HOSTBASED:
1568         case SSH_AUTH_FAIL_GSSAPI:
1569         case SSH_LOGIN_EXCEED_MAXTRIES:
1570         case SSH_LOGIN_ROOT_DENIED:
1571         case SSH_CONNECTION_CLOSE:
1572         case SSH_INVALID_USER:
1573                 audit_event(event);
1574                 break;
1575         default:
1576                 fatal("Audit event type %d not permitted", event);
1577         }
1578
1579         return (0);
1580 }
1581
1582 int
1583 mm_answer_audit_command(int socket, Buffer *m)
1584 {
1585         u_int len;
1586         char *cmd;
1587
1588         debug3("%s entering", __func__);
1589         cmd = buffer_get_string(m, &len);
1590         /* sanity check command, if so how? */
1591         audit_run_command(cmd);
1592         xfree(cmd);
1593         return (0);
1594 }
1595 #endif /* SSH_AUDIT_EVENTS */
1596
1597 void
1598 monitor_apply_keystate(struct monitor *pmonitor)
1599 {
1600         if (compat20) {
1601                 set_newkeys(MODE_IN);
1602                 set_newkeys(MODE_OUT);
1603         } else {
1604                 packet_set_protocol_flags(child_state.ssh1protoflags);
1605                 packet_set_encryption_key(child_state.ssh1key,
1606                     child_state.ssh1keylen, child_state.ssh1cipher);
1607                 xfree(child_state.ssh1key);
1608         }
1609
1610         /* for rc4 and other stateful ciphers */
1611         packet_set_keycontext(MODE_OUT, child_state.keyout);
1612         xfree(child_state.keyout);
1613         packet_set_keycontext(MODE_IN, child_state.keyin);
1614         xfree(child_state.keyin);
1615
1616         if (!compat20) {
1617                 packet_set_iv(MODE_OUT, child_state.ivout);
1618                 xfree(child_state.ivout);
1619                 packet_set_iv(MODE_IN, child_state.ivin);
1620                 xfree(child_state.ivin);
1621         }
1622
1623         memcpy(&incoming_stream, &child_state.incoming,
1624             sizeof(incoming_stream));
1625         memcpy(&outgoing_stream, &child_state.outgoing,
1626             sizeof(outgoing_stream));
1627
1628         /* Update with new address */
1629         if (options.compression)
1630                 mm_init_compression(pmonitor->m_zlib);
1631
1632         /* Network I/O buffers */
1633         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1634         buffer_clear(&input);
1635         buffer_append(&input, child_state.input, child_state.ilen);
1636         memset(child_state.input, 0, child_state.ilen);
1637         xfree(child_state.input);
1638
1639         buffer_clear(&output);
1640         buffer_append(&output, child_state.output, child_state.olen);
1641         memset(child_state.output, 0, child_state.olen);
1642         xfree(child_state.output);
1643 }
1644
1645 static Kex *
1646 mm_get_kex(Buffer *m)
1647 {
1648         Kex *kex;
1649         void *blob;
1650         u_int bloblen;
1651
1652         kex = xcalloc(1, sizeof(*kex));
1653         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1654         if ((session_id2 == NULL) ||
1655             (kex->session_id_len != session_id2_len) ||
1656             (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1657                 fatal("mm_get_get: internal error: bad session id");
1658         kex->we_need = buffer_get_int(m);
1659         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1660         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1661         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1662         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1663         kex->server = 1;
1664         kex->hostkey_type = buffer_get_int(m);
1665         kex->kex_type = buffer_get_int(m);
1666         blob = buffer_get_string(m, &bloblen);
1667         buffer_init(&kex->my);
1668         buffer_append(&kex->my, blob, bloblen);
1669         xfree(blob);
1670         blob = buffer_get_string(m, &bloblen);
1671         buffer_init(&kex->peer);
1672         buffer_append(&kex->peer, blob, bloblen);
1673         xfree(blob);
1674         kex->done = 1;
1675         kex->flags = buffer_get_int(m);
1676         kex->client_version_string = buffer_get_string(m, NULL);
1677         kex->server_version_string = buffer_get_string(m, NULL);
1678         kex->load_host_key=&get_hostkey_by_type;
1679         kex->host_key_index=&get_hostkey_index;
1680
1681         return (kex);
1682 }
1683
1684 /* This function requries careful sanity checking */
1685
1686 void
1687 mm_get_keystate(struct monitor *pmonitor)
1688 {
1689         Buffer m;
1690         u_char *blob, *p;
1691         u_int bloblen, plen;
1692         u_int32_t seqnr, packets;
1693         u_int64_t blocks;
1694
1695         debug3("%s: Waiting for new keys", __func__);
1696
1697         buffer_init(&m);
1698         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1699         if (!compat20) {
1700                 child_state.ssh1protoflags = buffer_get_int(&m);
1701                 child_state.ssh1cipher = buffer_get_int(&m);
1702                 child_state.ssh1key = buffer_get_string(&m,
1703                     &child_state.ssh1keylen);
1704                 child_state.ivout = buffer_get_string(&m,
1705                     &child_state.ivoutlen);
1706                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1707                 goto skip;
1708         } else {
1709                 /* Get the Kex for rekeying */
1710                 *pmonitor->m_pkex = mm_get_kex(&m);
1711         }
1712
1713         blob = buffer_get_string(&m, &bloblen);
1714         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1715         xfree(blob);
1716
1717         debug3("%s: Waiting for second key", __func__);
1718         blob = buffer_get_string(&m, &bloblen);
1719         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1720         xfree(blob);
1721
1722         /* Now get sequence numbers for the packets */
1723         seqnr = buffer_get_int(&m);
1724         blocks = buffer_get_int64(&m);
1725         packets = buffer_get_int(&m);
1726         packet_set_state(MODE_OUT, seqnr, blocks, packets);
1727         seqnr = buffer_get_int(&m);
1728         blocks = buffer_get_int64(&m);
1729         packets = buffer_get_int(&m);
1730         packet_set_state(MODE_IN, seqnr, blocks, packets);
1731
1732  skip:
1733         /* Get the key context */
1734         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1735         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1736
1737         debug3("%s: Getting compression state", __func__);
1738         /* Get compression state */
1739         p = buffer_get_string(&m, &plen);
1740         if (plen != sizeof(child_state.outgoing))
1741                 fatal("%s: bad request size", __func__);
1742         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1743         xfree(p);
1744
1745         p = buffer_get_string(&m, &plen);
1746         if (plen != sizeof(child_state.incoming))
1747                 fatal("%s: bad request size", __func__);
1748         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1749         xfree(p);
1750
1751         /* Network I/O buffers */
1752         debug3("%s: Getting Network I/O buffers", __func__);
1753         child_state.input = buffer_get_string(&m, &child_state.ilen);
1754         child_state.output = buffer_get_string(&m, &child_state.olen);
1755
1756         buffer_free(&m);
1757 }
1758
1759
1760 /* Allocation functions for zlib */
1761 void *
1762 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1763 {
1764         size_t len = (size_t) size * ncount;
1765         void *address;
1766
1767         if (len == 0 || ncount > SIZE_T_MAX / size)
1768                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1769
1770         address = mm_malloc(mm, len);
1771
1772         return (address);
1773 }
1774
1775 void
1776 mm_zfree(struct mm_master *mm, void *address)
1777 {
1778         mm_free(mm, address);
1779 }
1780
1781 void
1782 mm_init_compression(struct mm_master *mm)
1783 {
1784         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1785         outgoing_stream.zfree = (free_func)mm_zfree;
1786         outgoing_stream.opaque = mm;
1787
1788         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1789         incoming_stream.zfree = (free_func)mm_zfree;
1790         incoming_stream.opaque = mm;
1791 }
1792
1793 /* XXX */
1794
1795 #define FD_CLOSEONEXEC(x) do { \
1796         if (fcntl(x, F_SETFD, 1) == -1) \
1797                 fatal("fcntl(%d, F_SETFD)", x); \
1798 } while (0)
1799
1800 static void
1801 monitor_socketpair(int *pair)
1802 {
1803 #ifdef HAVE_SOCKETPAIR
1804         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1805                 fatal("%s: socketpair", __func__);
1806 #else
1807         fatal("%s: UsePrivilegeSeparation=yes not supported",
1808             __func__);
1809 #endif
1810         FD_CLOSEONEXEC(pair[0]);
1811         FD_CLOSEONEXEC(pair[1]);
1812 }
1813
1814 #define MM_MEMSIZE      65536
1815
1816 struct monitor *
1817 monitor_init(void)
1818 {
1819         struct monitor *mon;
1820         int pair[2];
1821
1822         mon = xcalloc(1, sizeof(*mon));
1823
1824         monitor_socketpair(pair);
1825
1826         mon->m_recvfd = pair[0];
1827         mon->m_sendfd = pair[1];
1828
1829         /* Used to share zlib space across processes */
1830         if (options.compression) {
1831                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1832                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1833
1834                 /* Compression needs to share state across borders */
1835                 mm_init_compression(mon->m_zlib);
1836         }
1837
1838         return mon;
1839 }
1840
1841 void
1842 monitor_reinit(struct monitor *mon)
1843 {
1844         int pair[2];
1845
1846         monitor_socketpair(pair);
1847
1848         mon->m_recvfd = pair[0];
1849         mon->m_sendfd = pair[1];
1850 }
1851
1852 #ifdef GSSAPI
1853 int
1854 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1855 {
1856         gss_OID_desc goid;
1857         OM_uint32 major;
1858         u_int len;
1859
1860         goid.elements = buffer_get_string(m, &len);
1861         goid.length = len;
1862
1863         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1864
1865         xfree(goid.elements);
1866
1867         buffer_clear(m);
1868         buffer_put_int(m, major);
1869
1870         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1871
1872         /* Now we have a context, enable the step */
1873         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1874
1875         return (0);
1876 }
1877
1878 int
1879 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1880 {
1881         gss_buffer_desc in;
1882         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1883         OM_uint32 major, minor;
1884         OM_uint32 flags = 0; /* GSI needs this */
1885         u_int len;
1886
1887         in.value = buffer_get_string(m, &len);
1888         in.length = len;
1889         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1890         xfree(in.value);
1891
1892         buffer_clear(m);
1893         buffer_put_int(m, major);
1894         buffer_put_string(m, out.value, out.length);
1895         buffer_put_int(m, flags);
1896         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1897
1898         gss_release_buffer(&minor, &out);
1899
1900         if (major == GSS_S_COMPLETE) {
1901                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1902                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1903                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1904         }
1905         return (0);
1906 }
1907
1908 int
1909 mm_answer_gss_checkmic(int sock, Buffer *m)
1910 {
1911         gss_buffer_desc gssbuf, mic;
1912         OM_uint32 ret;
1913         u_int len;
1914
1915         gssbuf.value = buffer_get_string(m, &len);
1916         gssbuf.length = len;
1917         mic.value = buffer_get_string(m, &len);
1918         mic.length = len;
1919
1920         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1921
1922         xfree(gssbuf.value);
1923         xfree(mic.value);
1924
1925         buffer_clear(m);
1926         buffer_put_int(m, ret);
1927
1928         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1929
1930         if (!GSS_ERROR(ret))
1931                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1932
1933         return (0);
1934 }
1935
1936 int
1937 mm_answer_gss_userok(int sock, Buffer *m)
1938 {
1939         int authenticated;
1940
1941         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1942
1943         buffer_clear(m);
1944         buffer_put_int(m, authenticated);
1945
1946         debug3("%s: sending result %d", __func__, authenticated);
1947         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1948
1949         auth_method = "gssapi-with-mic";
1950
1951         /* Monitor loop will terminate if authenticated */
1952         return (authenticated);
1953 }
1954 #endif /* GSSAPI */