crypto/external/bsd/openssh/dist/monitor.c

   1 /*      $NetBSD: monitor.c,v 1.1.1.2 2009/12/27 01:06:58 christos Exp $ */
   2 /* $OpenBSD: monitor.c,v 1.104 2009/06/12 20:43:22 andreas Exp $ */
   3 /*
   4  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
   5  * Copyright 2002 Markus Friedl <markus@openbsd.org>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "includes.h"
  30 __RCSID("$NetBSD: monitor.c,v 1.2 2009/06/07 22:38:46 christos Exp $");
  31 #include <sys/types.h>
  32 #include <sys/wait.h>
  33 #include <sys/socket.h>
  34 #include <sys/tree.h>
  35 #include <sys/param.h>
  36 #include <sys/queue.h>
  37
  38 #include <openssl/dh.h>
  39
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <paths.h>
  43 #include <pwd.h>
  44 #include <signal.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47
  48 #ifdef SKEY
  49 #include <skey.h>
  50 #endif
  51
  52 #include "xmalloc.h"
  53 #include "ssh.h"
  54 #include "key.h"
  55 #include "buffer.h"
  56 #include "hostfile.h"
  57 #include "auth.h"
  58 #include "cipher.h"
  59 #include "kex.h"
  60 #include "dh.h"
  61 #include <zlib.h>
  62 #include "packet.h"
  63 #include "auth-options.h"
  64 #include "sshpty.h"
  65 #include "channels.h"
  66 #include "session.h"
  67 #include "sshlogin.h"
  68 #include "canohost.h"
  69 #include "log.h"
  70 #include "servconf.h"
  71 #include "monitor.h"
  72 #include "monitor_mm.h"
  73 #ifdef GSSAPI
  74 #include "ssh-gss.h"
  75 #endif
  76 #include "monitor_wrap.h"
  77 #include "monitor_fdpass.h"
  78 #include "misc.h"
  79 #include "compat.h"
  80 #include "ssh2.h"
  81 #include "jpake.h"
  82 #include "roaming.h"
  83
  84 #ifdef GSSAPI
  85 static Gssctxt *gsscontext = NULL;
  86 #endif
  87
  88 /* Imports */
  89 extern ServerOptions options;
  90 extern u_int utmp_len;
  91 extern Newkeys *current_keys[];
  92 extern z_stream incoming_stream;
  93 extern z_stream outgoing_stream;
  94 extern u_char session_id[];
  95 extern Buffer auth_debug;
  96 extern int auth_debug_init;
  97 extern Buffer loginmsg;
  98
  99 /* State exported from the child */
 100
 101 struct {
 102         z_stream incoming;
 103         z_stream outgoing;
 104         u_char *keyin;
 105         u_int keyinlen;
 106         u_char *keyout;
 107         u_int keyoutlen;
 108         u_char *ivin;
 109         u_int ivinlen;
 110         u_char *ivout;
 111         u_int ivoutlen;
 112         u_char *ssh1key;
 113         u_int ssh1keylen;
 114         int ssh1cipher;
 115         int ssh1protoflags;
 116         u_char *input;
 117         u_int ilen;
 118         u_char *output;
 119         u_int olen;
 120         u_int64_t sent_bytes;
 121         u_int64_t recv_bytes;
 122 } child_state;
 123
 124 /* Functions on the monitor that answer unprivileged requests */
 125
 126 int mm_answer_moduli(int, Buffer *);
 127 int mm_answer_sign(int, Buffer *);
 128 int mm_answer_pwnamallow(int, Buffer *);
 129 int mm_answer_auth2_read_banner(int, Buffer *);
 130 int mm_answer_authserv(int, Buffer *);
 131 int mm_answer_authpassword(int, Buffer *);
 132 int mm_answer_bsdauthquery(int, Buffer *);
 133 int mm_answer_bsdauthrespond(int, Buffer *);
 134 int mm_answer_skeyquery(int, Buffer *);
 135 int mm_answer_skeyrespond(int, Buffer *);
 136 int mm_answer_keyallowed(int, Buffer *);
 137 int mm_answer_keyverify(int, Buffer *);
 138 int mm_answer_pty(int, Buffer *);
 139 int mm_answer_pty_cleanup(int, Buffer *);
 140 int mm_answer_term(int, Buffer *);
 141 int mm_answer_rsa_keyallowed(int, Buffer *);
 142 int mm_answer_rsa_challenge(int, Buffer *);
 143 int mm_answer_rsa_response(int, Buffer *);
 144 int mm_answer_sesskey(int, Buffer *);
 145 int mm_answer_sessid(int, Buffer *);
 146 int mm_answer_jpake_get_pwdata(int, Buffer *);
 147 int mm_answer_jpake_step1(int, Buffer *);
 148 int mm_answer_jpake_step2(int, Buffer *);
 149 int mm_answer_jpake_key_confirm(int, Buffer *);
 150 int mm_answer_jpake_check_confirm(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 KRB4
 162 int mm_answer_krb4(int, Buffer *);
 163 #endif
 164 #ifdef KRB5
 165 int mm_answer_krb5(int, Buffer *);
 166 #endif
 167
 168 #ifdef GSSAPI
 169 int mm_answer_gss_setup_ctx(int, Buffer *);
 170 int mm_answer_gss_accept_ctx(int, Buffer *);
 171 int mm_answer_gss_userok(int, Buffer *);
 172 int mm_answer_gss_checkmic(int, Buffer *);
 173 #endif
 174
 175 static Authctxt *authctxt;
 176 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 177
 178 /* local state for key verify */
 179 static u_char *key_blob = NULL;
 180 static u_int key_bloblen = 0;
 181 static int key_blobtype = MM_NOKEY;
 182 static char *hostbased_cuser = NULL;
 183 static char *hostbased_chost = NULL;
 184 static char *auth_method = "unknown";
 185 static u_int session_id2_len = 0;
 186 static u_char *session_id2 = NULL;
 187 static pid_t monitor_child_pid;
 188
 189 struct mon_table {
 190         enum monitor_reqtype type;
 191         int flags;
 192         int (*f)(int, Buffer *);
 193 };
 194
 195 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 196 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 197 #define MON_ONCE        0x0010  /* Disable after calling */
 198 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 199
 200 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 201
 202 #define MON_PERMIT      0x1000  /* Request is permitted */
 203
 204 struct mon_table mon_dispatch_proto20[] = {
 205     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 206     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 207     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 208     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 209     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 210     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 211 #ifdef USE_PAM
 212     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 213     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 214     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 215     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 216     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 217     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 218 #endif
 219 #ifdef BSD_AUTH
 220     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 221     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 222 #endif
 223 #ifdef SKEY
 224     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 225     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 226 #endif
 227     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 228     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 229 #ifdef KRB4
 230     {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4},
 231 #endif
 232 #ifdef KRB5
 233     {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5},
 234 #endif
 235 #ifdef GSSAPI
 236     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 237     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 238     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 239     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 240 #endif
 241 #ifdef JPAKE
 242     {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata},
 243     {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1},
 244     {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2},
 245     {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm},
 246     {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm},
 247 #endif
 248     {0, 0, NULL}
 249 };
 250
 251 struct mon_table mon_dispatch_postauth20[] = {
 252     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 253     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 254     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 255     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 256     {MONITOR_REQ_TERM, 0, mm_answer_term},
 257     {0, 0, NULL}
 258 };
 259
 260 struct mon_table mon_dispatch_proto15[] = {
 261     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 262     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 263     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 264     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 265     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 266     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 267     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 268     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 269 #ifdef BSD_AUTH
 270     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 271     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 272 #endif
 273 #ifdef SKEY
 274     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 275     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 276 #endif
 277 #ifdef USE_PAM
 278     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 279     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 280     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 281     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 282     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 283     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 284 #endif
 285 #ifdef KRB4
 286     {MONITOR_REQ_KRB4, MON_ONCE|MON_AUTH, mm_answer_krb4},
 287 #endif
 288 #ifdef KRB5
 289     {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5},
 290 #endif
 291     {0, 0, NULL}
 292 };
 293
 294 struct mon_table mon_dispatch_postauth15[] = {
 295     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 296     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 297     {MONITOR_REQ_TERM, 0, mm_answer_term},
 298     {0, 0, NULL}
 299 };
 300
 301 struct mon_table *mon_dispatch;
 302
 303 /* Specifies if a certain message is allowed at the moment */
 304
 305 static void
 306 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 307 {
 308         while (ent->f != NULL) {
 309                 if (ent->type == type) {
 310                         ent->flags &= ~MON_PERMIT;
 311                         ent->flags |= permit ? MON_PERMIT : 0;
 312                         return;
 313                 }
 314                 ent++;
 315         }
 316 }
 317
 318 static void
 319 monitor_permit_authentications(int permit)
 320 {
 321         struct mon_table *ent = mon_dispatch;
 322
 323         while (ent->f != NULL) {
 324                 if (ent->flags & MON_AUTH) {
 325                         ent->flags &= ~MON_PERMIT;
 326                         ent->flags |= permit ? MON_PERMIT : 0;
 327                 }
 328                 ent++;
 329         }
 330 }
 331
 332 void
 333 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 334 {
 335         struct mon_table *ent;
 336         int authenticated = 0;
 337
 338         debug3("preauth child monitor started");
 339
 340         authctxt = _authctxt;
 341         memset(authctxt, 0, sizeof(*authctxt));
 342
 343         if (compat20) {
 344                 mon_dispatch = mon_dispatch_proto20;
 345
 346                 /* Permit requests for moduli and signatures */
 347                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 348                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 349         } else {
 350                 mon_dispatch = mon_dispatch_proto15;
 351
 352                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 353         }
 354
 355         /* The first few requests do not require asynchronous access */
 356         while (!authenticated) {
 357                 auth_method = "unknown";
 358                 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
 359                 if (authenticated) {
 360                         if (!(ent->flags & MON_AUTHDECIDE))
 361                                 fatal("%s: unexpected authentication from %d",
 362                                     __func__, ent->type);
 363                         if (authctxt->pw->pw_uid == 0 &&
 364                             !auth_root_allowed(auth_method))
 365                                 authenticated = 0;
 366 #ifdef USE_PAM
 367                         /* PAM needs to perform account checks after auth */
 368                         if (options.use_pam && authenticated) {
 369                                 Buffer m;
 370
 371                                 buffer_init(&m);
 372                                 mm_request_receive_expect(pmonitor->m_sendfd,
 373                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 374                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 375                                 buffer_free(&m);
 376                         }
 377 #endif
 378                 }
 379
 380                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 381                         auth_log(authctxt, authenticated, auth_method,
 382                             compat20 ? " ssh2" : "");
 383                         if (!authenticated)
 384                                 authctxt->failures++;
 385                 }
 386 #ifdef JPAKE
 387                 /* Cleanup JPAKE context after authentication */
 388                 if (ent->flags & MON_AUTHDECIDE) {
 389                         if (authctxt->jpake_ctx != NULL) {
 390                                 jpake_free(authctxt->jpake_ctx);
 391                                 authctxt->jpake_ctx = NULL;
 392                         }
 393                 }
 394 #endif
 395         }
 396
 397         if (!authctxt->valid)
 398                 fatal("%s: authenticated invalid user", __func__);
 399         if (strcmp(auth_method, "unknown") == 0)
 400                 fatal("%s: authentication method name unknown", __func__);
 401
 402         debug("%s: %s has been authenticated by privileged process",
 403             __func__, authctxt->user);
 404
 405         mm_get_keystate(pmonitor);
 406 }
 407
 408 static void
 409 monitor_set_child_handler(pid_t pid)
 410 {
 411         monitor_child_pid = pid;
 412 }
 413
 414 static void
 415 monitor_child_handler(int sig)
 416 {
 417         kill(monitor_child_pid, sig);
 418 }
 419
 420 void
 421 monitor_child_postauth(struct monitor *pmonitor)
 422 {
 423         monitor_set_child_handler(pmonitor->m_pid);
 424         signal(SIGHUP, &monitor_child_handler);
 425         signal(SIGTERM, &monitor_child_handler);
 426         signal(SIGINT, &monitor_child_handler);
 427
 428         if (compat20) {
 429                 mon_dispatch = mon_dispatch_postauth20;
 430
 431                 /* Permit requests for moduli and signatures */
 432                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 433                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 434                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 435         } else {
 436                 mon_dispatch = mon_dispatch_postauth15;
 437                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 438         }
 439         if (!no_pty_flag) {
 440                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 441                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 442         }
 443
 444         for (;;)
 445                 monitor_read(pmonitor, mon_dispatch, NULL);
 446 }
 447
 448 void
 449 monitor_sync(struct monitor *pmonitor)
 450 {
 451         if (options.compression) {
 452                 /* The member allocation is not visible, so sync it */
 453                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 454         }
 455 }
 456
 457 int
 458 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 459     struct mon_table **pent)
 460 {
 461         Buffer m;
 462         int ret;
 463         u_char type;
 464
 465         buffer_init(&m);
 466
 467         mm_request_receive(pmonitor->m_sendfd, &m);
 468         type = buffer_get_char(&m);
 469
 470         debug3("%s: checking request %d", __func__, type);
 471
 472         while (ent->f != NULL) {
 473                 if (ent->type == type)
 474                         break;
 475                 ent++;
 476         }
 477
 478         if (ent->f != NULL) {
 479                 if (!(ent->flags & MON_PERMIT))
 480                         fatal("%s: unpermitted request %d", __func__,
 481                             type);
 482                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 483                 buffer_free(&m);
 484
 485                 /* The child may use this request only once, disable it */
 486                 if (ent->flags & MON_ONCE) {
 487                         debug2("%s: %d used once, disabling now", __func__,
 488                             type);
 489                         ent->flags &= ~MON_PERMIT;
 490                 }
 491
 492                 if (pent != NULL)
 493                         *pent = ent;
 494
 495                 return ret;
 496         }
 497
 498         fatal("%s: unsupported request: %d", __func__, type);
 499
 500         /* NOTREACHED */
 501         return (-1);
 502 }
 503
 504 /* allowed key state */
 505 static int
 506 monitor_allowed_key(u_char *blob, u_int bloblen)
 507 {
 508         /* make sure key is allowed */
 509         if (key_blob == NULL || key_bloblen != bloblen ||
 510             memcmp(key_blob, blob, key_bloblen))
 511                 return (0);
 512         return (1);
 513 }
 514
 515 static void
 516 monitor_reset_key_state(void)
 517 {
 518         /* reset state */
 519         if (key_blob != NULL)
 520                 xfree(key_blob);
 521         if (hostbased_cuser != NULL)
 522                 xfree(hostbased_cuser);
 523         if (hostbased_chost != NULL)
 524                 xfree(hostbased_chost);
 525         key_blob = NULL;
 526         key_bloblen = 0;
 527         key_blobtype = MM_NOKEY;
 528         hostbased_cuser = NULL;
 529         hostbased_chost = NULL;
 530 }
 531
 532 int
 533 mm_answer_moduli(int sock, Buffer *m)
 534 {
 535         DH *dh;
 536         int min, want, max;
 537
 538         min = buffer_get_int(m);
 539         want = buffer_get_int(m);
 540         max = buffer_get_int(m);
 541
 542         debug3("%s: got parameters: %d %d %d",
 543             __func__, min, want, max);
 544         /* We need to check here, too, in case the child got corrupted */
 545         if (max < min || want < min || max < want)
 546                 fatal("%s: bad parameters: %d %d %d",
 547                     __func__, min, want, max);
 548
 549         buffer_clear(m);
 550
 551         dh = choose_dh(min, want, max);
 552         if (dh == NULL) {
 553                 buffer_put_char(m, 0);
 554                 return (0);
 555         } else {
 556                 /* Send first bignum */
 557                 buffer_put_char(m, 1);
 558                 buffer_put_bignum2(m, dh->p);
 559                 buffer_put_bignum2(m, dh->g);
 560
 561                 DH_free(dh);
 562         }
 563         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 564         return (0);
 565 }
 566
 567 int
 568 mm_answer_sign(int sock, Buffer *m)
 569 {
 570         Key *key;
 571         u_char *p;
 572         u_char *signature;
 573         u_int siglen, datlen;
 574         int keyid;
 575
 576         debug3("%s", __func__);
 577
 578         keyid = buffer_get_int(m);
 579         p = buffer_get_string(m, &datlen);
 580
 581         /*
 582          * Supported KEX types will only return SHA1 (20 byte) or
 583          * SHA256 (32 byte) hashes
 584          */
 585         if (datlen != 20 && datlen != 32)
 586                 fatal("%s: data length incorrect: %u", __func__, datlen);
 587
 588         /* save session id, it will be passed on the first call */
 589         if (session_id2_len == 0) {
 590                 session_id2_len = datlen;
 591                 session_id2 = xmalloc(session_id2_len);
 592                 memcpy(session_id2, p, session_id2_len);
 593         }
 594
 595         if ((key = get_hostkey_by_index(keyid)) == NULL)
 596                 fatal("%s: no hostkey from index %d", __func__, keyid);
 597         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 598                 fatal("%s: key_sign failed", __func__);
 599
 600         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 601
 602         buffer_clear(m);
 603         buffer_put_string(m, signature, siglen);
 604
 605         xfree(p);
 606         xfree(signature);
 607
 608         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 609
 610         /* Turn on permissions for getpwnam */
 611         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 612
 613         return (0);
 614 }
 615
 616 /* Retrieves the password entry and also checks if the user is permitted */
 617
 618 int
 619 mm_answer_pwnamallow(int sock, Buffer *m)
 620 {
 621         char *username;
 622         struct passwd *pwent;
 623         int allowed = 0;
 624
 625         debug3("%s", __func__);
 626
 627         if (authctxt->attempt++ != 0)
 628                 fatal("%s: multiple attempts for getpwnam", __func__);
 629
 630         username = buffer_get_string(m, NULL);
 631
 632         pwent = getpwnamallow(username);
 633
 634         authctxt->user = xstrdup(username);
 635         setproctitle("%s [priv]", pwent ? username : "unknown");
 636         xfree(username);
 637
 638         buffer_clear(m);
 639
 640         if (pwent == NULL) {
 641                 buffer_put_char(m, 0);
 642                 authctxt->pw = fakepw();
 643                 goto out;
 644         }
 645
 646         allowed = 1;
 647         authctxt->pw = pwent;
 648         authctxt->valid = 1;
 649
 650         buffer_put_char(m, 1);
 651         buffer_put_string(m, pwent, sizeof(struct passwd));
 652         buffer_put_cstring(m, pwent->pw_name);
 653         buffer_put_cstring(m, "*");
 654         buffer_put_cstring(m, pwent->pw_gecos);
 655         buffer_put_cstring(m, pwent->pw_class);
 656         buffer_put_cstring(m, pwent->pw_dir);
 657         buffer_put_cstring(m, pwent->pw_shell);
 658
 659  out:
 660         buffer_put_string(m, &options, sizeof(options));
 661         if (options.banner != NULL)
 662                 buffer_put_cstring(m, options.banner);
 663         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 664         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 665
 666         /* For SSHv1 allow authentication now */
 667         if (!compat20)
 668                 monitor_permit_authentications(1);
 669         else {
 670                 /* Allow service/style information on the auth context */
 671                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 672                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 673         }
 674
 675 #ifdef USE_PAM
 676         if (options.use_pam)
 677                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 678 #endif
 679
 680         return (0);
 681 }
 682
 683 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 684 {
 685         char *banner;
 686
 687         buffer_clear(m);
 688         banner = auth2_read_banner();
 689         buffer_put_cstring(m, banner != NULL ? banner : "");
 690         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 691
 692         if (banner != NULL)
 693                 xfree(banner);
 694
 695         return (0);
 696 }
 697
 698 int
 699 mm_answer_authserv(int sock, Buffer *m)
 700 {
 701         monitor_permit_authentications(1);
 702
 703         authctxt->service = buffer_get_string(m, NULL);
 704         authctxt->style = buffer_get_string(m, NULL);
 705         debug3("%s: service=%s, style=%s",
 706             __func__, authctxt->service, authctxt->style);
 707
 708         if (strlen(authctxt->style) == 0) {
 709                 xfree(authctxt->style);
 710                 authctxt->style = NULL;
 711         }
 712
 713         return (0);
 714 }
 715
 716 int
 717 mm_answer_authpassword(int sock, Buffer *m)
 718 {
 719         static int call_count;
 720         char *passwd;
 721         int authenticated;
 722         u_int plen;
 723
 724         passwd = buffer_get_string(m, &plen);
 725         /* Only authenticate if the context is valid */
 726         authenticated = options.password_authentication &&
 727             auth_password(authctxt, passwd);
 728         memset(passwd, 0, strlen(passwd));
 729         xfree(passwd);
 730
 731         buffer_clear(m);
 732         buffer_put_int(m, authenticated);
 733
 734         debug3("%s: sending result %d", __func__, authenticated);
 735         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 736
 737         call_count++;
 738         if (plen == 0 && call_count == 1)
 739                 auth_method = "none";
 740         else
 741                 auth_method = "password";
 742
 743         /* Causes monitor loop to terminate if authenticated */
 744         return (authenticated);
 745 }
 746
 747 #ifdef BSD_AUTH
 748 int
 749 mm_answer_bsdauthquery(int sock, Buffer *m)
 750 {
 751         char *name, *infotxt;
 752         u_int numprompts;
 753         u_int *echo_on;
 754         char **prompts;
 755         u_int success;
 756
 757         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 758             &prompts, &echo_on) < 0 ? 0 : 1;
 759
 760         buffer_clear(m);
 761         buffer_put_int(m, success);
 762         if (success)
 763                 buffer_put_cstring(m, prompts[0]);
 764
 765         debug3("%s: sending challenge success: %u", __func__, success);
 766         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 767
 768         if (success) {
 769                 xfree(name);
 770                 xfree(infotxt);
 771                 xfree(prompts);
 772                 xfree(echo_on);
 773         }
 774
 775         return (0);
 776 }
 777
 778 int
 779 mm_answer_bsdauthrespond(int sock, Buffer *m)
 780 {
 781         char *response;
 782         int authok;
 783
 784         if (authctxt->as == 0)
 785                 fatal("%s: no bsd auth session", __func__);
 786
 787         response = buffer_get_string(m, NULL);
 788         authok = options.challenge_response_authentication &&
 789             auth_userresponse(authctxt->as, response, 0);
 790         authctxt->as = NULL;
 791         debug3("%s: <%s> = <%d>", __func__, response, authok);
 792         xfree(response);
 793
 794         buffer_clear(m);
 795         buffer_put_int(m, authok);
 796
 797         debug3("%s: sending authenticated: %d", __func__, authok);
 798         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 799
 800         auth_method = "bsdauth";
 801
 802         return (authok != 0);
 803 }
 804 #endif
 805
 806 #ifdef SKEY
 807 int
 808 mm_answer_skeyquery(int sock, Buffer *m)
 809 {
 810         struct skey skey;
 811         char challenge[1024];
 812         u_int success;
 813
 814         success = skeychallenge(&skey, authctxt->user, challenge,
 815             sizeof(challenge)) < 0 ? 0 : 1;
 816
 817         buffer_clear(m);
 818         buffer_put_int(m, success);
 819         if (success)
 820                 buffer_put_cstring(m, challenge);
 821
 822         debug3("%s: sending challenge success: %u", __func__, success);
 823         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 824
 825         return (0);
 826 }
 827
 828 int
 829 mm_answer_skeyrespond(int sock, Buffer *m)
 830 {
 831         char *response;
 832         int authok;
 833
 834         response = buffer_get_string(m, NULL);
 835
 836         authok = (options.challenge_response_authentication &&
 837             authctxt->valid &&
 838             skey_haskey(authctxt->pw->pw_name) == 0 &&
 839             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 840
 841         xfree(response);
 842
 843         buffer_clear(m);
 844         buffer_put_int(m, authok);
 845
 846         debug3("%s: sending authenticated: %d", __func__, authok);
 847         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 848
 849         auth_method = "skey";
 850
 851         return (authok != 0);
 852 }
 853 #endif
 854
 855 #ifdef USE_PAM
 856 int
 857 mm_answer_pam_start(int sock, Buffer *m)
 858 {
 859         if (!options.use_pam)
 860                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 861
 862         start_pam(authctxt);
 863
 864         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 865
 866         return (0);
 867 }
 868
 869 int
 870 mm_answer_pam_account(int sock, Buffer *m)
 871 {
 872         u_int ret;
 873
 874         if (!options.use_pam)
 875                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 876
 877         ret = do_pam_account();
 878
 879         buffer_put_int(m, ret);
 880         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 881
 882         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 883
 884         return (ret);
 885 }
 886
 887 static void *sshpam_ctxt, *sshpam_authok;
 888 extern KbdintDevice sshpam_device;
 889
 890 int
 891 mm_answer_pam_init_ctx(int sock, Buffer *m)
 892 {
 893
 894         debug3("%s", __func__);
 895         authctxt->user = buffer_get_string(m, NULL);
 896         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 897         sshpam_authok = NULL;
 898         buffer_clear(m);
 899         if (sshpam_ctxt != NULL) {
 900                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 901                 buffer_put_int(m, 1);
 902         } else {
 903                 buffer_put_int(m, 0);
 904         }
 905         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 906         return (0);
 907 }
 908
 909 int
 910 mm_answer_pam_query(int sock, Buffer *m)
 911 {
 912         char *name, *info, **prompts;
 913         u_int num, *echo_on;
 914         int i, ret;
 915
 916         debug3("%s", __func__);
 917         sshpam_authok = NULL;
 918         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 919         if (ret == 0 && num == 0)
 920                 sshpam_authok = sshpam_ctxt;
 921         if (num > 1 || name == NULL || info == NULL)
 922                 ret = -1;
 923         buffer_clear(m);
 924         buffer_put_int(m, ret);
 925         buffer_put_cstring(m, name);
 926         xfree(name);
 927         buffer_put_cstring(m, info);
 928         xfree(info);
 929         buffer_put_int(m, num);
 930         for (i = 0; i < num; ++i) {
 931                 buffer_put_cstring(m, prompts[i]);
 932                 xfree(prompts[i]);
 933                 buffer_put_int(m, echo_on[i]);
 934         }
 935         if (prompts != NULL)
 936                 xfree(prompts);
 937         if (echo_on != NULL)
 938                 xfree(echo_on);
 939         auth_method = "keyboard-interactive/pam";
 940         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 941         return (0);
 942 }
 943
 944 int
 945 mm_answer_pam_respond(int sock, Buffer *m)
 946 {
 947         char **resp;
 948         u_int num;
 949         int i, ret;
 950
 951         debug3("%s", __func__);
 952         sshpam_authok = NULL;
 953         num = buffer_get_int(m);
 954         if (num > 0) {
 955                 resp = xmalloc(num * sizeof(char *));
 956                 for (i = 0; i < num; ++i)
 957                         resp[i] = buffer_get_string(m, NULL);
 958                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 959                 for (i = 0; i < num; ++i)
 960                         xfree(resp[i]);
 961                 xfree(resp);
 962         } else {
 963                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 964         }
 965         buffer_clear(m);
 966         buffer_put_int(m, ret);
 967         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 968         auth_method = "keyboard-interactive/pam";
 969         if (ret == 0)
 970                 sshpam_authok = sshpam_ctxt;
 971         return (0);
 972 }
 973
 974 int
 975 mm_answer_pam_free_ctx(int sock, Buffer *m)
 976 {
 977
 978         debug3("%s", __func__);
 979         (sshpam_device.free_ctx)(sshpam_ctxt);
 980         buffer_clear(m);
 981         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 982         auth_method = "keyboard-interactive/pam";
 983         return (sshpam_authok == sshpam_ctxt);
 984 }
 985 #endif
 986
 987 static void
 988 mm_append_debug(Buffer *m)
 989 {
 990         if (auth_debug_init && buffer_len(&auth_debug)) {
 991                 debug3("%s: Appending debug messages for child", __func__);
 992                 buffer_append(m, buffer_ptr(&auth_debug),
 993                     buffer_len(&auth_debug));
 994                 buffer_clear(&auth_debug);
 995         }
 996 }
 997
 998 int
 999 mm_answer_keyallowed(int sock, Buffer *m)
1000 {
1001         Key *key;
1002         char *cuser, *chost;
1003         u_char *blob;
1004         u_int bloblen;
1005         enum mm_keytype type = 0;
1006         int allowed = 0;
1007
1008         debug3("%s entering", __func__);
1009
1010         type = buffer_get_int(m);
1011         cuser = buffer_get_string(m, NULL);
1012         chost = buffer_get_string(m, NULL);
1013         blob = buffer_get_string(m, &bloblen);
1014
1015         key = key_from_blob(blob, bloblen);
1016
1017         if ((compat20 && type == MM_RSAHOSTKEY) ||
1018             (!compat20 && type != MM_RSAHOSTKEY))
1019                 fatal("%s: key type and protocol mismatch", __func__);
1020
1021         debug3("%s: key_from_blob: %p", __func__, key);
1022
1023         if (key != NULL && authctxt->valid) {
1024                 switch (type) {
1025                 case MM_USERKEY:
1026                         allowed = options.pubkey_authentication &&
1027                             user_key_allowed(authctxt->pw, key);
1028                         auth_method = "publickey";
1029                         if (options.pubkey_authentication && allowed != 1)
1030                                 auth_clear_options();
1031                         break;
1032                 case MM_HOSTKEY:
1033                         allowed = options.hostbased_authentication &&
1034                             hostbased_key_allowed(authctxt->pw,
1035                             cuser, chost, key);
1036                         auth_method = "hostbased";
1037                         break;
1038                 case MM_RSAHOSTKEY:
1039                         key->type = KEY_RSA1; /* XXX */
1040                         allowed = options.rhosts_rsa_authentication &&
1041                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1042                             cuser, chost, key);
1043                         if (options.rhosts_rsa_authentication && allowed != 1)
1044                                 auth_clear_options();
1045                         auth_method = "rsa";
1046                         break;
1047                 default:
1048                         fatal("%s: unknown key type %d", __func__, type);
1049                         break;
1050                 }
1051         }
1052         if (key != NULL)
1053                 key_free(key);
1054
1055         /* clear temporarily storage (used by verify) */
1056         monitor_reset_key_state();
1057
1058         if (allowed) {
1059                 /* Save temporarily for comparison in verify */
1060                 key_blob = blob;
1061                 key_bloblen = bloblen;
1062                 key_blobtype = type;
1063                 hostbased_cuser = cuser;
1064                 hostbased_chost = chost;
1065         } else {
1066                 /* Log failed attempt */
1067                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1068                 xfree(blob);
1069                 xfree(cuser);
1070                 xfree(chost);
1071         }
1072
1073         debug3("%s: key %p is %s",
1074             __func__, key, allowed ? "allowed" : "not allowed");
1075
1076         buffer_clear(m);
1077         buffer_put_int(m, allowed);
1078         buffer_put_int(m, forced_command != NULL);
1079
1080         mm_append_debug(m);
1081
1082         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1083
1084         if (type == MM_RSAHOSTKEY)
1085                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1086
1087         return (0);
1088 }
1089
1090 static int
1091 monitor_valid_userblob(u_char *data, u_int datalen)
1092 {
1093         Buffer b;
1094         char *p;
1095         u_int len;
1096         int fail = 0;
1097
1098         buffer_init(&b);
1099         buffer_append(&b, data, datalen);
1100
1101         if (datafellows & SSH_OLD_SESSIONID) {
1102                 p = buffer_ptr(&b);
1103                 len = buffer_len(&b);
1104                 if ((session_id2 == NULL) ||
1105                     (len < session_id2_len) ||
1106                     (memcmp(p, session_id2, session_id2_len) != 0))
1107                         fail++;
1108                 buffer_consume(&b, session_id2_len);
1109         } else {
1110                 p = buffer_get_string(&b, &len);
1111                 if ((session_id2 == NULL) ||
1112                     (len != session_id2_len) ||
1113                     (memcmp(p, session_id2, session_id2_len) != 0))
1114                         fail++;
1115                 xfree(p);
1116         }
1117         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1118                 fail++;
1119         p = buffer_get_string(&b, NULL);
1120         if (strcmp(authctxt->user, p) != 0) {
1121                 logit("wrong user name passed to monitor: expected %s != %.100s",
1122                     authctxt->user, p);
1123                 fail++;
1124         }
1125         xfree(p);
1126         buffer_skip_string(&b);
1127         if (datafellows & SSH_BUG_PKAUTH) {
1128                 if (!buffer_get_char(&b))
1129                         fail++;
1130         } else {
1131                 p = buffer_get_string(&b, NULL);
1132                 if (strcmp("publickey", p) != 0)
1133                         fail++;
1134                 xfree(p);
1135                 if (!buffer_get_char(&b))
1136                         fail++;
1137                 buffer_skip_string(&b);
1138         }
1139         buffer_skip_string(&b);
1140         if (buffer_len(&b) != 0)
1141                 fail++;
1142         buffer_free(&b);
1143         return (fail == 0);
1144 }
1145
1146 static int
1147 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1148     char *chost)
1149 {
1150         Buffer b;
1151         char *p;
1152         u_int len;
1153         int fail = 0;
1154
1155         buffer_init(&b);
1156         buffer_append(&b, data, datalen);
1157
1158         p = buffer_get_string(&b, &len);
1159         if ((session_id2 == NULL) ||
1160             (len != session_id2_len) ||
1161             (memcmp(p, session_id2, session_id2_len) != 0))
1162                 fail++;
1163         xfree(p);
1164
1165         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1166                 fail++;
1167         p = buffer_get_string(&b, NULL);
1168         if (strcmp(authctxt->user, p) != 0) {
1169                 logit("wrong user name passed to monitor: expected %s != %.100s",
1170                     authctxt->user, p);
1171                 fail++;
1172         }
1173         xfree(p);
1174         buffer_skip_string(&b); /* service */
1175         p = buffer_get_string(&b, NULL);
1176         if (strcmp(p, "hostbased") != 0)
1177                 fail++;
1178         xfree(p);
1179         buffer_skip_string(&b); /* pkalg */
1180         buffer_skip_string(&b); /* pkblob */
1181
1182         /* verify client host, strip trailing dot if necessary */
1183         p = buffer_get_string(&b, NULL);
1184         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1185                 p[len - 1] = '\0';
1186         if (strcmp(p, chost) != 0)
1187                 fail++;
1188         xfree(p);
1189
1190         /* verify client user */
1191         p = buffer_get_string(&b, NULL);
1192         if (strcmp(p, cuser) != 0)
1193                 fail++;
1194         xfree(p);
1195
1196         if (buffer_len(&b) != 0)
1197                 fail++;
1198         buffer_free(&b);
1199         return (fail == 0);
1200 }
1201
1202 int
1203 mm_answer_keyverify(int sock, Buffer *m)
1204 {
1205         Key *key;
1206         u_char *signature, *data, *blob;
1207         u_int signaturelen, datalen, bloblen;
1208         int verified = 0;
1209         int valid_data = 0;
1210
1211         blob = buffer_get_string(m, &bloblen);
1212         signature = buffer_get_string(m, &signaturelen);
1213         data = buffer_get_string(m, &datalen);
1214
1215         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1216           !monitor_allowed_key(blob, bloblen))
1217                 fatal("%s: bad key, not previously allowed", __func__);
1218
1219         key = key_from_blob(blob, bloblen);
1220         if (key == NULL)
1221                 fatal("%s: bad public key blob", __func__);
1222
1223         switch (key_blobtype) {
1224         case MM_USERKEY:
1225                 valid_data = monitor_valid_userblob(data, datalen);
1226                 break;
1227         case MM_HOSTKEY:
1228                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1229                     hostbased_cuser, hostbased_chost);
1230                 break;
1231         default:
1232                 valid_data = 0;
1233                 break;
1234         }
1235         if (!valid_data)
1236                 fatal("%s: bad signature data blob", __func__);
1237
1238         verified = key_verify(key, signature, signaturelen, data, datalen);
1239         debug3("%s: key %p signature %s",
1240             __func__, key, (verified == 1) ? "verified" : "unverified");
1241
1242         key_free(key);
1243         xfree(blob);
1244         xfree(signature);
1245         xfree(data);
1246
1247         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1248
1249         monitor_reset_key_state();
1250
1251         buffer_clear(m);
1252         buffer_put_int(m, verified);
1253         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1254
1255         return (verified == 1);
1256 }
1257
1258 static void
1259 mm_record_login(Session *s, struct passwd *pw)
1260 {
1261         socklen_t fromlen;
1262         struct sockaddr_storage from;
1263
1264         /*
1265          * Get IP address of client. If the connection is not a socket, let
1266          * the address be 0.0.0.0.
1267          */
1268         memset(&from, 0, sizeof(from));
1269         fromlen = sizeof(from);
1270         if (packet_connection_is_on_socket()) {
1271                 if (getpeername(packet_get_connection_in(),
1272                     (struct sockaddr *)&from, &fromlen) < 0) {
1273                         debug("getpeername: %.100s", strerror(errno));
1274                         cleanup_exit(255);
1275                 }
1276         }
1277         /* Record that there was a login on that tty from the remote host. */
1278         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1279             get_remote_name_or_ip(utmp_len, options.use_dns),
1280             (struct sockaddr *)&from, fromlen);
1281 }
1282
1283 static void
1284 mm_session_close(Session *s)
1285 {
1286         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1287         if (s->ttyfd != -1) {
1288                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1289                 session_pty_cleanup2(s);
1290         }
1291         session_unused(s->self);
1292 }
1293
1294 int
1295 mm_answer_pty(int sock, Buffer *m)
1296 {
1297         extern struct monitor *pmonitor;
1298         Session *s;
1299         int res, fd0;
1300
1301         debug3("%s entering", __func__);
1302
1303         buffer_clear(m);
1304         s = session_new();
1305         if (s == NULL)
1306                 goto error;
1307         s->authctxt = authctxt;
1308         s->pw = authctxt->pw;
1309         s->pid = pmonitor->m_pid;
1310         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1311         if (res == 0)
1312                 goto error;
1313         pty_setowner(authctxt->pw, s->tty);
1314
1315         buffer_put_int(m, 1);
1316         buffer_put_cstring(m, s->tty);
1317
1318         /* We need to trick ttyslot */
1319         if (dup2(s->ttyfd, 0) == -1)
1320                 fatal("%s: dup2", __func__);
1321
1322         mm_record_login(s, authctxt->pw);
1323
1324         /* Now we can close the file descriptor again */
1325         close(0);
1326
1327         /* send messages generated by record_login */
1328         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1329         buffer_clear(&loginmsg);
1330
1331         mm_request_send(sock, MONITOR_ANS_PTY, m);
1332
1333         if (mm_send_fd(sock, s->ptyfd) == -1 ||
1334             mm_send_fd(sock, s->ttyfd) == -1)
1335                 fatal("%s: send fds failed", __func__);
1336
1337         /* make sure nothing uses fd 0 */
1338         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1339                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1340         if (fd0 != 0)
1341                 error("%s: fd0 %d != 0", __func__, fd0);
1342
1343         /* slave is not needed */
1344         close(s->ttyfd);
1345         s->ttyfd = s->ptyfd;
1346         /* no need to dup() because nobody closes ptyfd */
1347         s->ptymaster = s->ptyfd;
1348
1349         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1350
1351         return (0);
1352
1353  error:
1354         if (s != NULL)
1355                 mm_session_close(s);
1356         buffer_put_int(m, 0);
1357         mm_request_send(sock, MONITOR_ANS_PTY, m);
1358         return (0);
1359 }
1360
1361 int
1362 mm_answer_pty_cleanup(int sock, Buffer *m)
1363 {
1364         Session *s;
1365         char *tty;
1366
1367         debug3("%s entering", __func__);
1368
1369         tty = buffer_get_string(m, NULL);
1370         if ((s = session_by_tty(tty)) != NULL)
1371                 mm_session_close(s);
1372         buffer_clear(m);
1373         xfree(tty);
1374         return (0);
1375 }
1376
1377 int
1378 mm_answer_sesskey(int sock, Buffer *m)
1379 {
1380         BIGNUM *p;
1381         int rsafail;
1382
1383         /* Turn off permissions */
1384         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1385
1386         if ((p = BN_new()) == NULL)
1387                 fatal("%s: BN_new", __func__);
1388
1389         buffer_get_bignum2(m, p);
1390
1391         rsafail = ssh1_session_key(p);
1392
1393         buffer_clear(m);
1394         buffer_put_int(m, rsafail);
1395         buffer_put_bignum2(m, p);
1396
1397         BN_clear_free(p);
1398
1399         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1400
1401         /* Turn on permissions for sessid passing */
1402         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1403
1404         return (0);
1405 }
1406
1407 int
1408 mm_answer_sessid(int sock, Buffer *m)
1409 {
1410         int i;
1411
1412         debug3("%s entering", __func__);
1413
1414         if (buffer_len(m) != 16)
1415                 fatal("%s: bad ssh1 session id", __func__);
1416         for (i = 0; i < 16; i++)
1417                 session_id[i] = buffer_get_char(m);
1418
1419         /* Turn on permissions for getpwnam */
1420         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1421
1422         return (0);
1423 }
1424
1425 int
1426 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1427 {
1428         BIGNUM *client_n;
1429         Key *key = NULL;
1430         u_char *blob = NULL;
1431         u_int blen = 0;
1432         int allowed = 0;
1433
1434         debug3("%s entering", __func__);
1435
1436         auth_method = "rsa";
1437         if (options.rsa_authentication && authctxt->valid) {
1438                 if ((client_n = BN_new()) == NULL)
1439                         fatal("%s: BN_new", __func__);
1440                 buffer_get_bignum2(m, client_n);
1441                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1442                 BN_clear_free(client_n);
1443         }
1444         buffer_clear(m);
1445         buffer_put_int(m, allowed);
1446         buffer_put_int(m, forced_command != NULL);
1447
1448         /* clear temporarily storage (used by generate challenge) */
1449         monitor_reset_key_state();
1450
1451         if (allowed && key != NULL) {
1452                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1453                 if (key_to_blob(key, &blob, &blen) == 0)
1454                         fatal("%s: key_to_blob failed", __func__);
1455                 buffer_put_string(m, blob, blen);
1456
1457                 /* Save temporarily for comparison in verify */
1458                 key_blob = blob;
1459                 key_bloblen = blen;
1460                 key_blobtype = MM_RSAUSERKEY;
1461         }
1462         if (key != NULL)
1463                 key_free(key);
1464
1465         mm_append_debug(m);
1466
1467         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1468
1469         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1470         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1471         return (0);
1472 }
1473
1474 int
1475 mm_answer_rsa_challenge(int sock, Buffer *m)
1476 {
1477         Key *key = NULL;
1478         u_char *blob;
1479         u_int blen;
1480
1481         debug3("%s entering", __func__);
1482
1483         if (!authctxt->valid)
1484                 fatal("%s: authctxt not valid", __func__);
1485         blob = buffer_get_string(m, &blen);
1486         if (!monitor_allowed_key(blob, blen))
1487                 fatal("%s: bad key, not previously allowed", __func__);
1488         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1489                 fatal("%s: key type mismatch", __func__);
1490         if ((key = key_from_blob(blob, blen)) == NULL)
1491                 fatal("%s: received bad key", __func__);
1492         if (key->type != KEY_RSA)
1493                 fatal("%s: received bad key type %d", __func__, key->type);
1494         key->type = KEY_RSA1;
1495         if (ssh1_challenge)
1496                 BN_clear_free(ssh1_challenge);
1497         ssh1_challenge = auth_rsa_generate_challenge(key);
1498
1499         buffer_clear(m);
1500         buffer_put_bignum2(m, ssh1_challenge);
1501
1502         debug3("%s sending reply", __func__);
1503         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1504
1505         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1506
1507         xfree(blob);
1508         key_free(key);
1509         return (0);
1510 }
1511
1512 int
1513 mm_answer_rsa_response(int sock, Buffer *m)
1514 {
1515         Key *key = NULL;
1516         u_char *blob, *response;
1517         u_int blen, len;
1518         int success;
1519
1520         debug3("%s entering", __func__);
1521
1522         if (!authctxt->valid)
1523                 fatal("%s: authctxt not valid", __func__);
1524         if (ssh1_challenge == NULL)
1525                 fatal("%s: no ssh1_challenge", __func__);
1526
1527         blob = buffer_get_string(m, &blen);
1528         if (!monitor_allowed_key(blob, blen))
1529                 fatal("%s: bad key, not previously allowed", __func__);
1530         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1531                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1532         if ((key = key_from_blob(blob, blen)) == NULL)
1533                 fatal("%s: received bad key", __func__);
1534         response = buffer_get_string(m, &len);
1535         if (len != 16)
1536                 fatal("%s: received bad response to challenge", __func__);
1537         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1538
1539         xfree(blob);
1540         key_free(key);
1541         xfree(response);
1542
1543         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1544
1545         /* reset state */
1546         BN_clear_free(ssh1_challenge);
1547         ssh1_challenge = NULL;
1548         monitor_reset_key_state();
1549
1550         buffer_clear(m);
1551         buffer_put_int(m, success);
1552         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1553
1554         return (success);
1555 }
1556
1557 #ifdef KRB4
1558 int
1559 mm_answer_krb4(int socket, Buffer *m)
1560 {
1561         KTEXT_ST auth, reply;
1562         char  *client, *p;
1563         int success;
1564         u_int alen;
1565
1566         reply.length = auth.length = 0;
1567
1568         p = buffer_get_string(m, &alen);
1569         if (alen >=  MAX_KTXT_LEN)
1570                  fatal("%s: auth too large", __func__);
1571         memcpy(auth.dat, p, alen);
1572         auth.length = alen;
1573         memset(p, 0, alen);
1574         xfree(p);
1575
1576         success = options.kerberos_authentication &&
1577             authctxt->valid &&
1578             auth_krb4(authctxt, &auth, &client, &reply);
1579
1580         memset(auth.dat, 0, alen);
1581         buffer_clear(m);
1582         buffer_put_int(m, success);
1583
1584         if (success) {
1585                 buffer_put_cstring(m, client);
1586                 buffer_put_string(m, reply.dat, reply.length);
1587                 if (client)
1588                         xfree(client);
1589                 if (reply.length)
1590                         memset(reply.dat, 0, reply.length);
1591         }
1592
1593         debug3("%s: sending result %d", __func__, success);
1594         mm_request_send(socket, MONITOR_ANS_KRB4, m);
1595
1596         auth_method = "kerberos";
1597
1598         /* Causes monitor loop to terminate if authenticated */
1599         return (success);
1600 }
1601 #endif
1602
1603 #ifdef KRB5
1604 int
1605 mm_answer_krb5(int socket, Buffer *m)
1606 {
1607         krb5_data tkt, reply;
1608         char *client_user;
1609         u_int len;
1610         int success;
1611
1612         /* use temporary var to avoid size issues on 64bit arch */
1613         tkt.data = buffer_get_string(m, &len);
1614         tkt.length = len;
1615
1616         success = options.kerberos_authentication &&
1617             authctxt->valid &&
1618             auth_krb5(authctxt, &tkt, &client_user, &reply);
1619
1620         if (tkt.length)
1621                 xfree(tkt.data);
1622
1623         buffer_clear(m);
1624         buffer_put_int(m, success);
1625
1626         if (success) {
1627                 buffer_put_cstring(m, client_user);
1628                 buffer_put_string(m, reply.data, reply.length);
1629                 if (client_user)
1630                         xfree(client_user);
1631                 if (reply.length)
1632                         xfree(reply.data);
1633         }
1634         mm_request_send(socket, MONITOR_ANS_KRB5, m);
1635
1636         auth_method = "kerberos";
1637
1638         return success;
1639 }
1640 #endif
1641
1642 int
1643 mm_answer_term(int sock, Buffer *req)
1644 {
1645         extern struct monitor *pmonitor;
1646         int res, status;
1647
1648         debug3("%s: tearing down sessions", __func__);
1649
1650         /* The child is terminating */
1651         session_destroy_all(&mm_session_close);
1652
1653         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1654                 if (errno != EINTR)
1655                         exit(1);
1656
1657         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1658
1659         /* Terminate process */
1660         exit(res);
1661 }
1662
1663 void
1664 monitor_apply_keystate(struct monitor *pmonitor)
1665 {
1666         if (compat20) {
1667                 set_newkeys(MODE_IN);
1668                 set_newkeys(MODE_OUT);
1669         } else {
1670                 packet_set_protocol_flags(child_state.ssh1protoflags);
1671                 packet_set_encryption_key(child_state.ssh1key,
1672                     child_state.ssh1keylen, child_state.ssh1cipher);
1673                 xfree(child_state.ssh1key);
1674         }
1675
1676         /* for rc4 and other stateful ciphers */
1677         packet_set_keycontext(MODE_OUT, child_state.keyout);
1678         xfree(child_state.keyout);
1679         packet_set_keycontext(MODE_IN, child_state.keyin);
1680         xfree(child_state.keyin);
1681
1682         if (!compat20) {
1683                 packet_set_iv(MODE_OUT, child_state.ivout);
1684                 xfree(child_state.ivout);
1685                 packet_set_iv(MODE_IN, child_state.ivin);
1686                 xfree(child_state.ivin);
1687         }
1688
1689         memcpy(&incoming_stream, &child_state.incoming,
1690             sizeof(incoming_stream));
1691         memcpy(&outgoing_stream, &child_state.outgoing,
1692             sizeof(outgoing_stream));
1693
1694         /* Update with new address */
1695         if (options.compression)
1696                 mm_init_compression(pmonitor->m_zlib);
1697
1698         /* Network I/O buffers */
1699         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1700         buffer_clear(packet_get_input());
1701         buffer_append(packet_get_input(), child_state.input, child_state.ilen);
1702         memset(child_state.input, 0, child_state.ilen);
1703         xfree(child_state.input);
1704
1705         buffer_clear(packet_get_output());
1706         buffer_append(packet_get_output(), child_state.output,
1707                       child_state.olen);
1708         memset(child_state.output, 0, child_state.olen);
1709         xfree(child_state.output);
1710
1711         /* Roaming */
1712         if (compat20)
1713                 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes);
1714 }
1715
1716 static Kex *
1717 mm_get_kex(Buffer *m)
1718 {
1719         Kex *kex;
1720         void *blob;
1721         u_int bloblen;
1722
1723         kex = xcalloc(1, sizeof(*kex));
1724         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1725         if ((session_id2 == NULL) ||
1726             (kex->session_id_len != session_id2_len) ||
1727             (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1728                 fatal("mm_get_get: internal error: bad session id");
1729         kex->we_need = buffer_get_int(m);
1730         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1731         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1732         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1733         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1734         kex->server = 1;
1735         kex->hostkey_type = buffer_get_int(m);
1736         kex->kex_type = buffer_get_int(m);
1737         blob = buffer_get_string(m, &bloblen);
1738         buffer_init(&kex->my);
1739         buffer_append(&kex->my, blob, bloblen);
1740         xfree(blob);
1741         blob = buffer_get_string(m, &bloblen);
1742         buffer_init(&kex->peer);
1743         buffer_append(&kex->peer, blob, bloblen);
1744         xfree(blob);
1745         kex->done = 1;
1746         kex->flags = buffer_get_int(m);
1747         kex->client_version_string = buffer_get_string(m, NULL);
1748         kex->server_version_string = buffer_get_string(m, NULL);
1749         kex->load_host_key=&get_hostkey_by_type;
1750         kex->host_key_index=&get_hostkey_index;
1751
1752         return (kex);
1753 }
1754
1755 /* This function requries careful sanity checking */
1756
1757 void
1758 mm_get_keystate(struct monitor *pmonitor)
1759 {
1760         Buffer m;
1761         u_char *blob, *p;
1762         u_int bloblen, plen;
1763         u_int32_t seqnr, packets;
1764         u_int64_t blocks, bytes;
1765
1766         debug3("%s: Waiting for new keys", __func__);
1767
1768         buffer_init(&m);
1769         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1770         if (!compat20) {
1771                 child_state.ssh1protoflags = buffer_get_int(&m);
1772                 child_state.ssh1cipher = buffer_get_int(&m);
1773                 child_state.ssh1key = buffer_get_string(&m,
1774                     &child_state.ssh1keylen);
1775                 child_state.ivout = buffer_get_string(&m,
1776                     &child_state.ivoutlen);
1777                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1778                 goto skip;
1779         } else {
1780                 /* Get the Kex for rekeying */
1781                 *pmonitor->m_pkex = mm_get_kex(&m);
1782         }
1783
1784         blob = buffer_get_string(&m, &bloblen);
1785         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1786         xfree(blob);
1787
1788         debug3("%s: Waiting for second key", __func__);
1789         blob = buffer_get_string(&m, &bloblen);
1790         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1791         xfree(blob);
1792
1793         /* Now get sequence numbers for the packets */
1794         seqnr = buffer_get_int(&m);
1795         blocks = buffer_get_int64(&m);
1796         packets = buffer_get_int(&m);
1797         bytes = buffer_get_int64(&m);
1798         packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1799         seqnr = buffer_get_int(&m);
1800         blocks = buffer_get_int64(&m);
1801         packets = buffer_get_int(&m);
1802         bytes = buffer_get_int64(&m);
1803         packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1804
1805  skip:
1806         /* Get the key context */
1807         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1808         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1809
1810         debug3("%s: Getting compression state", __func__);
1811         /* Get compression state */
1812         p = buffer_get_string(&m, &plen);
1813         if (plen != sizeof(child_state.outgoing))
1814                 fatal("%s: bad request size", __func__);
1815         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1816         xfree(p);
1817
1818         p = buffer_get_string(&m, &plen);
1819         if (plen != sizeof(child_state.incoming))
1820                 fatal("%s: bad request size", __func__);
1821         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1822         xfree(p);
1823
1824         /* Network I/O buffers */
1825         debug3("%s: Getting Network I/O buffers", __func__);
1826         child_state.input = buffer_get_string(&m, &child_state.ilen);
1827         child_state.output = buffer_get_string(&m, &child_state.olen);
1828
1829         /* Roaming */
1830         if (compat20) {
1831                 child_state.sent_bytes = buffer_get_int64(&m);
1832                 child_state.recv_bytes = buffer_get_int64(&m);
1833         }
1834
1835         buffer_free(&m);
1836 }
1837
1838
1839 /* Allocation functions for zlib */
1840 void *
1841 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1842 {
1843         size_t len = (size_t) size * ncount;
1844         void *address;
1845
1846         if (len == 0 || ncount > SIZE_T_MAX / size)
1847                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1848
1849         address = mm_malloc(mm, len);
1850
1851         return (address);
1852 }
1853
1854 void
1855 mm_zfree(struct mm_master *mm, void *address)
1856 {
1857         mm_free(mm, address);
1858 }
1859
1860 void
1861 mm_init_compression(struct mm_master *mm)
1862 {
1863         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1864         outgoing_stream.zfree = (free_func)mm_zfree;
1865         outgoing_stream.opaque = mm;
1866
1867         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1868         incoming_stream.zfree = (free_func)mm_zfree;
1869         incoming_stream.opaque = mm;
1870 }
1871
1872 /* XXX */
1873
1874 #define FD_CLOSEONEXEC(x) do { \
1875         if (fcntl(x, F_SETFD, 1) == -1) \
1876                 fatal("fcntl(%d, F_SETFD)", x); \
1877 } while (0)
1878
1879 static void
1880 monitor_socketpair(int *pair)
1881 {
1882         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1883                 fatal("%s: socketpair", __func__);
1884         FD_CLOSEONEXEC(pair[0]);
1885         FD_CLOSEONEXEC(pair[1]);
1886 }
1887
1888 #define MM_MEMSIZE      65536
1889
1890 struct monitor *
1891 monitor_init(void)
1892 {
1893         struct monitor *mon;
1894         int pair[2];
1895
1896         mon = xcalloc(1, sizeof(*mon));
1897
1898         monitor_socketpair(pair);
1899
1900         mon->m_recvfd = pair[0];
1901         mon->m_sendfd = pair[1];
1902
1903         /* Used to share zlib space across processes */
1904         if (options.compression) {
1905                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1906                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1907
1908                 /* Compression needs to share state across borders */
1909                 mm_init_compression(mon->m_zlib);
1910         }
1911
1912         return mon;
1913 }
1914
1915 void
1916 monitor_reinit(struct monitor *mon)
1917 {
1918         int pair[2];
1919
1920         monitor_socketpair(pair);
1921
1922         mon->m_recvfd = pair[0];
1923         mon->m_sendfd = pair[1];
1924 }
1925
1926 #ifdef GSSAPI
1927 int
1928 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1929 {
1930         gss_OID_desc goid;
1931         OM_uint32 major;
1932         u_int len;
1933
1934         goid.elements = buffer_get_string(m, &len);
1935         goid.length = len;
1936
1937         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1938
1939         xfree(goid.elements);
1940
1941         buffer_clear(m);
1942         buffer_put_int(m, major);
1943
1944         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1945
1946         /* Now we have a context, enable the step */
1947         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1948
1949         return (0);
1950 }
1951
1952 int
1953 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1954 {
1955         gss_buffer_desc in;
1956         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1957         OM_uint32 major, minor;
1958         OM_uint32 flags = 0; /* GSI needs this */
1959         u_int len;
1960
1961         in.value = buffer_get_string(m, &len);
1962         in.length = len;
1963         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1964         xfree(in.value);
1965
1966         buffer_clear(m);
1967         buffer_put_int(m, major);
1968         buffer_put_string(m, out.value, out.length);
1969         buffer_put_int(m, flags);
1970         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1971
1972         gss_release_buffer(&minor, &out);
1973
1974         if (major == GSS_S_COMPLETE) {
1975                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1976                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1977                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1978         }
1979         return (0);
1980 }
1981
1982 int
1983 mm_answer_gss_checkmic(int sock, Buffer *m)
1984 {
1985         gss_buffer_desc gssbuf, mic;
1986         OM_uint32 ret;
1987         u_int len;
1988
1989         gssbuf.value = buffer_get_string(m, &len);
1990         gssbuf.length = len;
1991         mic.value = buffer_get_string(m, &len);
1992         mic.length = len;
1993
1994         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1995
1996         xfree(gssbuf.value);
1997         xfree(mic.value);
1998
1999         buffer_clear(m);
2000         buffer_put_int(m, ret);
2001
2002         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
2003
2004         if (!GSS_ERROR(ret))
2005                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2006
2007         return (0);
2008 }
2009
2010 int
2011 mm_answer_gss_userok(int sock, Buffer *m)
2012 {
2013         int authenticated;
2014
2015         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2016
2017         buffer_clear(m);
2018         buffer_put_int(m, authenticated);
2019
2020         debug3("%s: sending result %d", __func__, authenticated);
2021         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
2022
2023         auth_method = "gssapi-with-mic";
2024
2025         /* Monitor loop will terminate if authenticated */
2026         return (authenticated);
2027 }
2028 #endif /* GSSAPI */
2029
2030 #ifdef JPAKE
2031 int
2032 mm_answer_jpake_step1(int sock, Buffer *m)
2033 {
2034         struct jpake_ctx *pctx;
2035         u_char *x3_proof, *x4_proof;
2036         u_int x3_proof_len, x4_proof_len;
2037
2038         if (!options.zero_knowledge_password_authentication)
2039                 fatal("zero_knowledge_password_authentication disabled");
2040
2041         if (authctxt->jpake_ctx != NULL)
2042                 fatal("%s: authctxt->jpake_ctx already set (%p)",
2043                     __func__, authctxt->jpake_ctx);
2044         authctxt->jpake_ctx = pctx = jpake_new();
2045
2046         jpake_step1(pctx->grp,
2047             &pctx->server_id, &pctx->server_id_len,
2048             &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4,
2049             &x3_proof, &x3_proof_len,
2050             &x4_proof, &x4_proof_len);
2051
2052         JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__));
2053
2054         buffer_clear(m);
2055
2056         buffer_put_string(m, pctx->server_id, pctx->server_id_len);
2057         buffer_put_bignum2(m, pctx->g_x3);
2058         buffer_put_bignum2(m, pctx->g_x4);
2059         buffer_put_string(m, x3_proof, x3_proof_len);
2060         buffer_put_string(m, x4_proof, x4_proof_len);
2061
2062         debug3("%s: sending step1", __func__);
2063         mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m);
2064
2065         bzero(x3_proof, x3_proof_len);
2066         bzero(x4_proof, x4_proof_len);
2067         xfree(x3_proof);
2068         xfree(x4_proof);
2069
2070         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1);
2071         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0);
2072
2073         return 0;
2074 }
2075
2076 int
2077 mm_answer_jpake_get_pwdata(int sock, Buffer *m)
2078 {
2079         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2080         char *hash_scheme, *salt;
2081
2082         if (pctx == NULL)
2083                 fatal("%s: pctx == NULL", __func__);
2084
2085         auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt);
2086
2087         buffer_clear(m);
2088         /* pctx->s is sensitive, not returned to slave */
2089         buffer_put_cstring(m, hash_scheme);
2090         buffer_put_cstring(m, salt);
2091
2092         debug3("%s: sending pwdata", __func__);
2093         mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m);
2094
2095         bzero(hash_scheme, strlen(hash_scheme));
2096         bzero(salt, strlen(salt));
2097         xfree(hash_scheme);
2098         xfree(salt);
2099
2100         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1);
2101
2102         return 0;
2103 }
2104
2105 int
2106 mm_answer_jpake_step2(int sock, Buffer *m)
2107 {
2108         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2109         u_char *x1_proof, *x2_proof, *x4_s_proof;
2110         u_int x1_proof_len, x2_proof_len, x4_s_proof_len;
2111
2112         if (pctx == NULL)
2113                 fatal("%s: pctx == NULL", __func__);
2114
2115         if ((pctx->g_x1 = BN_new()) == NULL ||
2116             (pctx->g_x2 = BN_new()) == NULL)
2117                 fatal("%s: BN_new", __func__);
2118         buffer_get_bignum2(m, pctx->g_x1);
2119         buffer_get_bignum2(m, pctx->g_x2);
2120         pctx->client_id = buffer_get_string(m, &pctx->client_id_len);
2121         x1_proof = buffer_get_string(m, &x1_proof_len);
2122         x2_proof = buffer_get_string(m, &x2_proof_len);
2123
2124         jpake_step2(pctx->grp, pctx->s, pctx->g_x3,
2125             pctx->g_x1, pctx->g_x2, pctx->x4,
2126             pctx->client_id, pctx->client_id_len,
2127             pctx->server_id, pctx->server_id_len,
2128             x1_proof, x1_proof_len,
2129             x2_proof, x2_proof_len,
2130             &pctx->b,
2131             &x4_s_proof, &x4_s_proof_len);
2132
2133         JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__));
2134
2135         bzero(x1_proof, x1_proof_len);
2136         bzero(x2_proof, x2_proof_len);
2137         xfree(x1_proof);
2138         xfree(x2_proof);
2139
2140         buffer_clear(m);
2141
2142         buffer_put_bignum2(m, pctx->b);
2143         buffer_put_string(m, x4_s_proof, x4_s_proof_len);
2144
2145         debug3("%s: sending step2", __func__);
2146         mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m);
2147
2148         bzero(x4_s_proof, x4_s_proof_len);
2149         xfree(x4_s_proof);
2150
2151         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1);
2152
2153         return 0;
2154 }
2155
2156 int
2157 mm_answer_jpake_key_confirm(int sock, Buffer *m)
2158 {
2159         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2160         u_char *x2_s_proof;
2161         u_int x2_s_proof_len;
2162
2163         if (pctx == NULL)
2164                 fatal("%s: pctx == NULL", __func__);
2165
2166         if ((pctx->a = BN_new()) == NULL)
2167                 fatal("%s: BN_new", __func__);
2168         buffer_get_bignum2(m, pctx->a);
2169         x2_s_proof = buffer_get_string(m, &x2_s_proof_len);
2170
2171         jpake_key_confirm(pctx->grp, pctx->s, pctx->a,
2172             pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2,
2173             pctx->server_id, pctx->server_id_len,
2174             pctx->client_id, pctx->client_id_len,
2175             session_id2, session_id2_len,
2176             x2_s_proof, x2_s_proof_len,
2177             &pctx->k,
2178             &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len);
2179
2180         JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__));
2181
2182         bzero(x2_s_proof, x2_s_proof_len);
2183         buffer_clear(m);
2184
2185         /* pctx->k is sensitive, not sent */
2186         buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len);
2187
2188         debug3("%s: sending confirmation hash", __func__);
2189         mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m);
2190
2191         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1);
2192
2193         return 0;
2194 }
2195
2196 int
2197 mm_answer_jpake_check_confirm(int sock, Buffer *m)
2198 {
2199         int authenticated = 0;
2200         u_char *peer_confirm_hash;
2201         u_int peer_confirm_hash_len;
2202         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2203
2204         if (pctx == NULL)
2205                 fatal("%s: pctx == NULL", __func__);
2206
2207         peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len);
2208
2209         authenticated = jpake_check_confirm(pctx->k,
2210             pctx->client_id, pctx->client_id_len,
2211             session_id2, session_id2_len,
2212             peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid;
2213
2214         JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__));
2215
2216         bzero(peer_confirm_hash, peer_confirm_hash_len);
2217         xfree(peer_confirm_hash);
2218
2219         buffer_clear(m);
2220         buffer_put_int(m, authenticated);
2221
2222         debug3("%s: sending result %d", __func__, authenticated);
2223         mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m);
2224
2225         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1);
2226
2227         auth_method = "jpake-01@openssh.com";
2228         return authenticated;
2229 }
2230
2231 #endif /* JPAKE */