crypto/openssh/monitor.c

   1 /* $OpenBSD: monitor.c,v 1.101 2009/02/12 03:26:22 djm Exp $ */
   2 /*
   3  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
   4  * Copyright 2002 Markus Friedl <markus@openbsd.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "includes.h"
  29
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32 #include <sys/socket.h>
  33 #include "openbsd-compat/sys-tree.h"
  34 #include <sys/wait.h>
  35
  36 #include <errno.h>
  37 #include <fcntl.h>
  38 #ifdef HAVE_PATHS_H
  39 #include <paths.h>
  40 #endif
  41 #include <pwd.h>
  42 #include <signal.h>
  43 #include <stdarg.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47
  48 #ifdef SKEY
  49 #include <skey.h>
  50 #endif
  51
  52 #include <openssl/dh.h>
  53
  54 #include "openbsd-compat/sys-queue.h"
  55 #include "xmalloc.h"
  56 #include "ssh.h"
  57 #include "key.h"
  58 #include "buffer.h"
  59 #include "hostfile.h"
  60 #include "auth.h"
  61 #include "cipher.h"
  62 #include "kex.h"
  63 #include "dh.h"
  64 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
  65 #undef TARGET_OS_MAC
  66 #include "zlib.h"
  67 #define TARGET_OS_MAC 1
  68 #else
  69 #include "zlib.h"
  70 #endif
  71 #include "packet.h"
  72 #include "auth-options.h"
  73 #include "sshpty.h"
  74 #include "channels.h"
  75 #include "session.h"
  76 #include "sshlogin.h"
  77 #include "canohost.h"
  78 #include "log.h"
  79 #include "servconf.h"
  80 #include "monitor.h"
  81 #include "monitor_mm.h"
  82 #ifdef GSSAPI
  83 #include "ssh-gss.h"
  84 #endif
  85 #include "monitor_wrap.h"
  86 #include "monitor_fdpass.h"
  87 #include "misc.h"
  88 #include "compat.h"
  89 #include "ssh2.h"
  90 #include "jpake.h"
  91
  92 #ifdef GSSAPI
  93 static Gssctxt *gsscontext = NULL;
  94 #endif
  95
  96 /* Imports */
  97 extern ServerOptions options;
  98 extern u_int utmp_len;
  99 extern Newkeys *current_keys[];
 100 extern z_stream incoming_stream;
 101 extern z_stream outgoing_stream;
 102 extern u_char session_id[];
 103 extern Buffer input, output;
 104 extern Buffer auth_debug;
 105 extern int auth_debug_init;
 106 extern Buffer loginmsg;
 107
 108 /* State exported from the child */
 109
 110 struct {
 111         z_stream incoming;
 112         z_stream outgoing;
 113         u_char *keyin;
 114         u_int keyinlen;
 115         u_char *keyout;
 116         u_int keyoutlen;
 117         u_char *ivin;
 118         u_int ivinlen;
 119         u_char *ivout;
 120         u_int ivoutlen;
 121         u_char *ssh1key;
 122         u_int ssh1keylen;
 123         int ssh1cipher;
 124         int ssh1protoflags;
 125         u_char *input;
 126         u_int ilen;
 127         u_char *output;
 128         u_int olen;
 129 } child_state;
 130
 131 /* Functions on the monitor that answer unprivileged requests */
 132
 133 int mm_answer_moduli(int, Buffer *);
 134 int mm_answer_sign(int, Buffer *);
 135 int mm_answer_pwnamallow(int, Buffer *);
 136 int mm_answer_auth2_read_banner(int, Buffer *);
 137 int mm_answer_authserv(int, Buffer *);
 138 int mm_answer_authpassword(int, Buffer *);
 139 int mm_answer_bsdauthquery(int, Buffer *);
 140 int mm_answer_bsdauthrespond(int, Buffer *);
 141 int mm_answer_skeyquery(int, Buffer *);
 142 int mm_answer_skeyrespond(int, Buffer *);
 143 int mm_answer_keyallowed(int, Buffer *);
 144 int mm_answer_keyverify(int, Buffer *);
 145 int mm_answer_pty(int, Buffer *);
 146 int mm_answer_pty_cleanup(int, Buffer *);
 147 int mm_answer_term(int, Buffer *);
 148 int mm_answer_rsa_keyallowed(int, Buffer *);
 149 int mm_answer_rsa_challenge(int, Buffer *);
 150 int mm_answer_rsa_response(int, Buffer *);
 151 int mm_answer_sesskey(int, Buffer *);
 152 int mm_answer_sessid(int, Buffer *);
 153 int mm_answer_jpake_get_pwdata(int, Buffer *);
 154 int mm_answer_jpake_step1(int, Buffer *);
 155 int mm_answer_jpake_step2(int, Buffer *);
 156 int mm_answer_jpake_key_confirm(int, Buffer *);
 157 int mm_answer_jpake_check_confirm(int, Buffer *);
 158
 159 #ifdef USE_PAM
 160 int mm_answer_pam_start(int, Buffer *);
 161 int mm_answer_pam_account(int, Buffer *);
 162 int mm_answer_pam_init_ctx(int, Buffer *);
 163 int mm_answer_pam_query(int, Buffer *);
 164 int mm_answer_pam_respond(int, Buffer *);
 165 int mm_answer_pam_free_ctx(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 #ifdef SSH_AUDIT_EVENTS
 176 int mm_answer_audit_event(int, Buffer *);
 177 int mm_answer_audit_command(int, Buffer *);
 178 #endif
 179
 180 static Authctxt *authctxt;
 181 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 182
 183 /* local state for key verify */
 184 static u_char *key_blob = NULL;
 185 static u_int key_bloblen = 0;
 186 static int key_blobtype = MM_NOKEY;
 187 static char *hostbased_cuser = NULL;
 188 static char *hostbased_chost = NULL;
 189 static char *auth_method = "unknown";
 190 static u_int session_id2_len = 0;
 191 static u_char *session_id2 = NULL;
 192 static pid_t monitor_child_pid;
 193
 194 struct mon_table {
 195         enum monitor_reqtype type;
 196         int flags;
 197         int (*f)(int, Buffer *);
 198 };
 199
 200 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 201 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 202 #define MON_ONCE        0x0010  /* Disable after calling */
 203 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 204
 205 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 206
 207 #define MON_PERMIT      0x1000  /* Request is permitted */
 208
 209 struct mon_table mon_dispatch_proto20[] = {
 210     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 211     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 212     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 213     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 214     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 215     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 216 #ifdef USE_PAM
 217     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 218     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 219     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 220     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 221     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 222     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 223 #endif
 224 #ifdef SSH_AUDIT_EVENTS
 225     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 226 #endif
 227 #ifdef BSD_AUTH
 228     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 229     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 230 #endif
 231 #ifdef SKEY
 232     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 233     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 234 #endif
 235     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 236     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 237 #ifdef GSSAPI
 238     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 239     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 240     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 241     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 242 #endif
 243 #ifdef JPAKE
 244     {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata},
 245     {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1},
 246     {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2},
 247     {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm},
 248     {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm},
 249 #endif
 250     {0, 0, NULL}
 251 };
 252
 253 struct mon_table mon_dispatch_postauth20[] = {
 254     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 255     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 256     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 257     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 258     {MONITOR_REQ_TERM, 0, mm_answer_term},
 259 #ifdef SSH_AUDIT_EVENTS
 260     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 261     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 262 #endif
 263     {0, 0, NULL}
 264 };
 265
 266 struct mon_table mon_dispatch_proto15[] = {
 267     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 268     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 269     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 270     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 271     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 272     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 273     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 274     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 275 #ifdef BSD_AUTH
 276     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 277     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 278 #endif
 279 #ifdef SKEY
 280     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 281     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 282 #endif
 283 #ifdef USE_PAM
 284     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 285     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 286     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 287     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 288     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 289     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 290 #endif
 291 #ifdef SSH_AUDIT_EVENTS
 292     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 293 #endif
 294     {0, 0, NULL}
 295 };
 296
 297 struct mon_table mon_dispatch_postauth15[] = {
 298     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 299     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 300     {MONITOR_REQ_TERM, 0, mm_answer_term},
 301 #ifdef SSH_AUDIT_EVENTS
 302     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 303     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
 304 #endif
 305     {0, 0, NULL}
 306 };
 307
 308 struct mon_table *mon_dispatch;
 309
 310 /* Specifies if a certain message is allowed at the moment */
 311
 312 static void
 313 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 314 {
 315         while (ent->f != NULL) {
 316                 if (ent->type == type) {
 317                         ent->flags &= ~MON_PERMIT;
 318                         ent->flags |= permit ? MON_PERMIT : 0;
 319                         return;
 320                 }
 321                 ent++;
 322         }
 323 }
 324
 325 static void
 326 monitor_permit_authentications(int permit)
 327 {
 328         struct mon_table *ent = mon_dispatch;
 329
 330         while (ent->f != NULL) {
 331                 if (ent->flags & MON_AUTH) {
 332                         ent->flags &= ~MON_PERMIT;
 333                         ent->flags |= permit ? MON_PERMIT : 0;
 334                 }
 335                 ent++;
 336         }
 337 }
 338
 339 void
 340 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 341 {
 342         struct mon_table *ent;
 343         int authenticated = 0;
 344
 345         debug3("preauth child monitor started");
 346
 347         authctxt = _authctxt;
 348         memset(authctxt, 0, sizeof(*authctxt));
 349
 350         authctxt->loginmsg = &loginmsg;
 351
 352         if (compat20) {
 353                 mon_dispatch = mon_dispatch_proto20;
 354
 355                 /* Permit requests for moduli and signatures */
 356                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 357                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 358         } else {
 359                 mon_dispatch = mon_dispatch_proto15;
 360
 361                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 362         }
 363
 364         /* The first few requests do not require asynchronous access */
 365         while (!authenticated) {
 366                 auth_method = "unknown";
 367                 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
 368                 if (authenticated) {
 369                         if (!(ent->flags & MON_AUTHDECIDE))
 370                                 fatal("%s: unexpected authentication from %d",
 371                                     __func__, ent->type);
 372                         if (authctxt->pw->pw_uid == 0 &&
 373                             !auth_root_allowed(auth_method))
 374                                 authenticated = 0;
 375 #ifdef USE_PAM
 376                         /* PAM needs to perform account checks after auth */
 377                         if (options.use_pam && authenticated) {
 378                                 Buffer m;
 379
 380                                 buffer_init(&m);
 381                                 mm_request_receive_expect(pmonitor->m_sendfd,
 382                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 383                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 384                                 buffer_free(&m);
 385                         }
 386 #endif
 387                 }
 388
 389                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 390                         auth_log(authctxt, authenticated, auth_method,
 391                             compat20 ? " ssh2" : "");
 392                         if (!authenticated)
 393                                 authctxt->failures++;
 394                 }
 395 #ifdef JPAKE
 396                 /* Cleanup JPAKE context after authentication */
 397                 if (ent->flags & MON_AUTHDECIDE) {
 398                         if (authctxt->jpake_ctx != NULL) {
 399                                 jpake_free(authctxt->jpake_ctx);
 400                                 authctxt->jpake_ctx = NULL;
 401                         }
 402                 }
 403 #endif
 404         }
 405
 406         if (!authctxt->valid)
 407                 fatal("%s: authenticated invalid user", __func__);
 408         if (strcmp(auth_method, "unknown") == 0)
 409                 fatal("%s: authentication method name unknown", __func__);
 410
 411         debug("%s: %s has been authenticated by privileged process",
 412             __func__, authctxt->user);
 413
 414         mm_get_keystate(pmonitor);
 415 }
 416
 417 static void
 418 monitor_set_child_handler(pid_t pid)
 419 {
 420         monitor_child_pid = pid;
 421 }
 422
 423 static void
 424 monitor_child_handler(int sig)
 425 {
 426         kill(monitor_child_pid, sig);
 427 }
 428
 429 void
 430 monitor_child_postauth(struct monitor *pmonitor)
 431 {
 432         monitor_set_child_handler(pmonitor->m_pid);
 433         signal(SIGHUP, &monitor_child_handler);
 434         signal(SIGTERM, &monitor_child_handler);
 435         signal(SIGINT, &monitor_child_handler);
 436
 437         if (compat20) {
 438                 mon_dispatch = mon_dispatch_postauth20;
 439
 440                 /* Permit requests for moduli and signatures */
 441                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 442                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 443                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 444         } else {
 445                 mon_dispatch = mon_dispatch_postauth15;
 446                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 447         }
 448         if (!no_pty_flag) {
 449                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 450                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 451         }
 452
 453         for (;;)
 454                 monitor_read(pmonitor, mon_dispatch, NULL);
 455 }
 456
 457 void
 458 monitor_sync(struct monitor *pmonitor)
 459 {
 460         if (options.compression) {
 461                 /* The member allocation is not visible, so sync it */
 462                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 463         }
 464 }
 465
 466 int
 467 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 468     struct mon_table **pent)
 469 {
 470         Buffer m;
 471         int ret;
 472         u_char type;
 473
 474         buffer_init(&m);
 475
 476         mm_request_receive(pmonitor->m_sendfd, &m);
 477         type = buffer_get_char(&m);
 478
 479         debug3("%s: checking request %d", __func__, type);
 480
 481         while (ent->f != NULL) {
 482                 if (ent->type == type)
 483                         break;
 484                 ent++;
 485         }
 486
 487         if (ent->f != NULL) {
 488                 if (!(ent->flags & MON_PERMIT))
 489                         fatal("%s: unpermitted request %d", __func__,
 490                             type);
 491                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 492                 buffer_free(&m);
 493
 494                 /* The child may use this request only once, disable it */
 495                 if (ent->flags & MON_ONCE) {
 496                         debug2("%s: %d used once, disabling now", __func__,
 497                             type);
 498                         ent->flags &= ~MON_PERMIT;
 499                 }
 500
 501                 if (pent != NULL)
 502                         *pent = ent;
 503
 504                 return ret;
 505         }
 506
 507         fatal("%s: unsupported request: %d", __func__, type);
 508
 509         /* NOTREACHED */
 510         return (-1);
 511 }
 512
 513 /* allowed key state */
 514 static int
 515 monitor_allowed_key(u_char *blob, u_int bloblen)
 516 {
 517         /* make sure key is allowed */
 518         if (key_blob == NULL || key_bloblen != bloblen ||
 519             memcmp(key_blob, blob, key_bloblen))
 520                 return (0);
 521         return (1);
 522 }
 523
 524 static void
 525 monitor_reset_key_state(void)
 526 {
 527         /* reset state */
 528         if (key_blob != NULL)
 529                 xfree(key_blob);
 530         if (hostbased_cuser != NULL)
 531                 xfree(hostbased_cuser);
 532         if (hostbased_chost != NULL)
 533                 xfree(hostbased_chost);
 534         key_blob = NULL;
 535         key_bloblen = 0;
 536         key_blobtype = MM_NOKEY;
 537         hostbased_cuser = NULL;
 538         hostbased_chost = NULL;
 539 }
 540
 541 int
 542 mm_answer_moduli(int sock, Buffer *m)
 543 {
 544         DH *dh;
 545         int min, want, max;
 546
 547         min = buffer_get_int(m);
 548         want = buffer_get_int(m);
 549         max = buffer_get_int(m);
 550
 551         debug3("%s: got parameters: %d %d %d",
 552             __func__, min, want, max);
 553         /* We need to check here, too, in case the child got corrupted */
 554         if (max < min || want < min || max < want)
 555                 fatal("%s: bad parameters: %d %d %d",
 556                     __func__, min, want, max);
 557
 558         buffer_clear(m);
 559
 560         dh = choose_dh(min, want, max);
 561         if (dh == NULL) {
 562                 buffer_put_char(m, 0);
 563                 return (0);
 564         } else {
 565                 /* Send first bignum */
 566                 buffer_put_char(m, 1);
 567                 buffer_put_bignum2(m, dh->p);
 568                 buffer_put_bignum2(m, dh->g);
 569
 570                 DH_free(dh);
 571         }
 572         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 573         return (0);
 574 }
 575
 576 int
 577 mm_answer_sign(int sock, Buffer *m)
 578 {
 579         Key *key;
 580         u_char *p;
 581         u_char *signature;
 582         u_int siglen, datlen;
 583         int keyid;
 584
 585         debug3("%s", __func__);
 586
 587         keyid = buffer_get_int(m);
 588         p = buffer_get_string(m, &datlen);
 589
 590         /*
 591          * Supported KEX types will only return SHA1 (20 byte) or
 592          * SHA256 (32 byte) hashes
 593          */
 594         if (datlen != 20 && datlen != 32)
 595                 fatal("%s: data length incorrect: %u", __func__, datlen);
 596
 597         /* save session id, it will be passed on the first call */
 598         if (session_id2_len == 0) {
 599                 session_id2_len = datlen;
 600                 session_id2 = xmalloc(session_id2_len);
 601                 memcpy(session_id2, p, session_id2_len);
 602         }
 603
 604         if ((key = get_hostkey_by_index(keyid)) == NULL)
 605                 fatal("%s: no hostkey from index %d", __func__, keyid);
 606         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 607                 fatal("%s: key_sign failed", __func__);
 608
 609         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 610
 611         buffer_clear(m);
 612         buffer_put_string(m, signature, siglen);
 613
 614         xfree(p);
 615         xfree(signature);
 616
 617         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 618
 619         /* Turn on permissions for getpwnam */
 620         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 621
 622         return (0);
 623 }
 624
 625 /* Retrieves the password entry and also checks if the user is permitted */
 626
 627 int
 628 mm_answer_pwnamallow(int sock, Buffer *m)
 629 {
 630         char *username;
 631         struct passwd *pwent;
 632         int allowed = 0;
 633
 634         debug3("%s", __func__);
 635
 636         if (authctxt->attempt++ != 0)
 637                 fatal("%s: multiple attempts for getpwnam", __func__);
 638
 639         username = buffer_get_string(m, NULL);
 640
 641         pwent = getpwnamallow(username);
 642
 643         authctxt->user = xstrdup(username);
 644         setproctitle("%s [priv]", pwent ? username : "unknown");
 645         xfree(username);
 646
 647         buffer_clear(m);
 648
 649         if (pwent == NULL) {
 650                 buffer_put_char(m, 0);
 651                 authctxt->pw = fakepw();
 652                 goto out;
 653         }
 654
 655         allowed = 1;
 656         authctxt->pw = pwent;
 657         authctxt->valid = 1;
 658
 659         buffer_put_char(m, 1);
 660         buffer_put_string(m, pwent, sizeof(struct passwd));
 661         buffer_put_cstring(m, pwent->pw_name);
 662         buffer_put_cstring(m, "*");
 663         buffer_put_cstring(m, pwent->pw_gecos);
 664 #ifdef HAVE_PW_CLASS_IN_PASSWD
 665         buffer_put_cstring(m, pwent->pw_class);
 666 #endif
 667         buffer_put_cstring(m, pwent->pw_dir);
 668         buffer_put_cstring(m, pwent->pw_shell);
 669
 670  out:
 671         buffer_put_string(m, &options, sizeof(options));
 672         if (options.banner != NULL)
 673                 buffer_put_cstring(m, options.banner);
 674         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 675         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 676
 677         /* For SSHv1 allow authentication now */
 678         if (!compat20)
 679                 monitor_permit_authentications(1);
 680         else {
 681                 /* Allow service/style information on the auth context */
 682                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 683                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 684         }
 685
 686 #ifdef USE_PAM
 687         if (options.use_pam)
 688                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 689 #endif
 690
 691         return (0);
 692 }
 693
 694 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 695 {
 696         char *banner;
 697
 698         buffer_clear(m);
 699         banner = auth2_read_banner();
 700         buffer_put_cstring(m, banner != NULL ? banner : "");
 701         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 702
 703         if (banner != NULL)
 704                 xfree(banner);
 705
 706         return (0);
 707 }
 708
 709 int
 710 mm_answer_authserv(int sock, Buffer *m)
 711 {
 712         monitor_permit_authentications(1);
 713
 714         authctxt->service = buffer_get_string(m, NULL);
 715         authctxt->style = buffer_get_string(m, NULL);
 716         debug3("%s: service=%s, style=%s",
 717             __func__, authctxt->service, authctxt->style);
 718
 719         if (strlen(authctxt->style) == 0) {
 720                 xfree(authctxt->style);
 721                 authctxt->style = NULL;
 722         }
 723
 724         return (0);
 725 }
 726
 727 int
 728 mm_answer_authpassword(int sock, Buffer *m)
 729 {
 730         static int call_count;
 731         char *passwd;
 732         int authenticated;
 733         u_int plen;
 734
 735         passwd = buffer_get_string(m, &plen);
 736         /* Only authenticate if the context is valid */
 737         authenticated = options.password_authentication &&
 738             auth_password(authctxt, passwd);
 739         memset(passwd, 0, strlen(passwd));
 740         xfree(passwd);
 741
 742         buffer_clear(m);
 743         buffer_put_int(m, authenticated);
 744
 745         debug3("%s: sending result %d", __func__, authenticated);
 746         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 747
 748         call_count++;
 749         if (plen == 0 && call_count == 1)
 750                 auth_method = "none";
 751         else
 752                 auth_method = "password";
 753
 754         /* Causes monitor loop to terminate if authenticated */
 755         return (authenticated);
 756 }
 757
 758 #ifdef BSD_AUTH
 759 int
 760 mm_answer_bsdauthquery(int sock, Buffer *m)
 761 {
 762         char *name, *infotxt;
 763         u_int numprompts;
 764         u_int *echo_on;
 765         char **prompts;
 766         u_int success;
 767
 768         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 769             &prompts, &echo_on) < 0 ? 0 : 1;
 770
 771         buffer_clear(m);
 772         buffer_put_int(m, success);
 773         if (success)
 774                 buffer_put_cstring(m, prompts[0]);
 775
 776         debug3("%s: sending challenge success: %u", __func__, success);
 777         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 778
 779         if (success) {
 780                 xfree(name);
 781                 xfree(infotxt);
 782                 xfree(prompts);
 783                 xfree(echo_on);
 784         }
 785
 786         return (0);
 787 }
 788
 789 int
 790 mm_answer_bsdauthrespond(int sock, Buffer *m)
 791 {
 792         char *response;
 793         int authok;
 794
 795         if (authctxt->as == 0)
 796                 fatal("%s: no bsd auth session", __func__);
 797
 798         response = buffer_get_string(m, NULL);
 799         authok = options.challenge_response_authentication &&
 800             auth_userresponse(authctxt->as, response, 0);
 801         authctxt->as = NULL;
 802         debug3("%s: <%s> = <%d>", __func__, response, authok);
 803         xfree(response);
 804
 805         buffer_clear(m);
 806         buffer_put_int(m, authok);
 807
 808         debug3("%s: sending authenticated: %d", __func__, authok);
 809         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 810
 811         auth_method = "bsdauth";
 812
 813         return (authok != 0);
 814 }
 815 #endif
 816
 817 #ifdef SKEY
 818 int
 819 mm_answer_skeyquery(int sock, Buffer *m)
 820 {
 821         struct skey skey;
 822         char challenge[1024];
 823         u_int success;
 824
 825         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 826             sizeof(challenge)) < 0 ? 0 : 1;
 827
 828         buffer_clear(m);
 829         buffer_put_int(m, success);
 830         if (success)
 831                 buffer_put_cstring(m, challenge);
 832
 833         debug3("%s: sending challenge success: %u", __func__, success);
 834         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 835
 836         return (0);
 837 }
 838
 839 int
 840 mm_answer_skeyrespond(int sock, Buffer *m)
 841 {
 842         char *response;
 843         int authok;
 844
 845         response = buffer_get_string(m, NULL);
 846
 847         authok = (options.challenge_response_authentication &&
 848             authctxt->valid &&
 849             skey_haskey(authctxt->pw->pw_name) == 0 &&
 850             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 851
 852         xfree(response);
 853
 854         buffer_clear(m);
 855         buffer_put_int(m, authok);
 856
 857         debug3("%s: sending authenticated: %d", __func__, authok);
 858         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 859
 860         auth_method = "skey";
 861
 862         return (authok != 0);
 863 }
 864 #endif
 865
 866 #ifdef USE_PAM
 867 int
 868 mm_answer_pam_start(int sock, Buffer *m)
 869 {
 870         if (!options.use_pam)
 871                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 872
 873         start_pam(authctxt);
 874
 875         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 876
 877         return (0);
 878 }
 879
 880 int
 881 mm_answer_pam_account(int sock, Buffer *m)
 882 {
 883         u_int ret;
 884
 885         if (!options.use_pam)
 886                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 887
 888         ret = do_pam_account();
 889
 890         buffer_put_int(m, ret);
 891         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 892
 893         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 894
 895         return (ret);
 896 }
 897
 898 static void *sshpam_ctxt, *sshpam_authok;
 899 extern KbdintDevice sshpam_device;
 900
 901 int
 902 mm_answer_pam_init_ctx(int sock, Buffer *m)
 903 {
 904
 905         debug3("%s", __func__);
 906         authctxt->user = buffer_get_string(m, NULL);
 907         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 908         sshpam_authok = NULL;
 909         buffer_clear(m);
 910         if (sshpam_ctxt != NULL) {
 911                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 912                 buffer_put_int(m, 1);
 913         } else {
 914                 buffer_put_int(m, 0);
 915         }
 916         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 917         return (0);
 918 }
 919
 920 int
 921 mm_answer_pam_query(int sock, Buffer *m)
 922 {
 923         char *name, *info, **prompts;
 924         u_int i, num, *echo_on;
 925         int ret;
 926
 927         debug3("%s", __func__);
 928         sshpam_authok = NULL;
 929         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 930         if (ret == 0 && num == 0)
 931                 sshpam_authok = sshpam_ctxt;
 932         if (num > 1 || name == NULL || info == NULL)
 933                 ret = -1;
 934         buffer_clear(m);
 935         buffer_put_int(m, ret);
 936         buffer_put_cstring(m, name);
 937         xfree(name);
 938         buffer_put_cstring(m, info);
 939         xfree(info);
 940         buffer_put_int(m, num);
 941         for (i = 0; i < num; ++i) {
 942                 buffer_put_cstring(m, prompts[i]);
 943                 xfree(prompts[i]);
 944                 buffer_put_int(m, echo_on[i]);
 945         }
 946         if (prompts != NULL)
 947                 xfree(prompts);
 948         if (echo_on != NULL)
 949                 xfree(echo_on);
 950         auth_method = "keyboard-interactive/pam";
 951         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 952         return (0);
 953 }
 954
 955 int
 956 mm_answer_pam_respond(int sock, Buffer *m)
 957 {
 958         char **resp;
 959         u_int i, num;
 960         int ret;
 961
 962         debug3("%s", __func__);
 963         sshpam_authok = NULL;
 964         num = buffer_get_int(m);
 965         if (num > 0) {
 966                 resp = xcalloc(num, sizeof(char *));
 967                 for (i = 0; i < num; ++i)
 968                         resp[i] = buffer_get_string(m, NULL);
 969                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 970                 for (i = 0; i < num; ++i)
 971                         xfree(resp[i]);
 972                 xfree(resp);
 973         } else {
 974                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 975         }
 976         buffer_clear(m);
 977         buffer_put_int(m, ret);
 978         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 979         auth_method = "keyboard-interactive/pam";
 980         if (ret == 0)
 981                 sshpam_authok = sshpam_ctxt;
 982         return (0);
 983 }
 984
 985 int
 986 mm_answer_pam_free_ctx(int sock, Buffer *m)
 987 {
 988
 989         debug3("%s", __func__);
 990         (sshpam_device.free_ctx)(sshpam_ctxt);
 991         buffer_clear(m);
 992         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 993         auth_method = "keyboard-interactive/pam";
 994         return (sshpam_authok == sshpam_ctxt);
 995 }
 996 #endif
 997
 998 static void
 999 mm_append_debug(Buffer *m)
1000 {
1001         if (auth_debug_init && buffer_len(&auth_debug)) {
1002                 debug3("%s: Appending debug messages for child", __func__);
1003                 buffer_append(m, buffer_ptr(&auth_debug),
1004                     buffer_len(&auth_debug));
1005                 buffer_clear(&auth_debug);
1006         }
1007 }
1008
1009 int
1010 mm_answer_keyallowed(int sock, Buffer *m)
1011 {
1012         Key *key;
1013         char *cuser, *chost;
1014         u_char *blob;
1015         u_int bloblen;
1016         enum mm_keytype type = 0;
1017         int allowed = 0;
1018
1019         debug3("%s entering", __func__);
1020
1021         type = buffer_get_int(m);
1022         cuser = buffer_get_string(m, NULL);
1023         chost = buffer_get_string(m, NULL);
1024         blob = buffer_get_string(m, &bloblen);
1025
1026         key = key_from_blob(blob, bloblen);
1027
1028         if ((compat20 && type == MM_RSAHOSTKEY) ||
1029             (!compat20 && type != MM_RSAHOSTKEY))
1030                 fatal("%s: key type and protocol mismatch", __func__);
1031
1032         debug3("%s: key_from_blob: %p", __func__, key);
1033
1034         if (key != NULL && authctxt->valid) {
1035                 switch (type) {
1036                 case MM_USERKEY:
1037                         allowed = options.pubkey_authentication &&
1038                             user_key_allowed(authctxt->pw, key);
1039                         auth_method = "publickey";
1040                         if (options.pubkey_authentication && allowed != 1)
1041                                 auth_clear_options();
1042                         break;
1043                 case MM_HOSTKEY:
1044                         allowed = options.hostbased_authentication &&
1045                             hostbased_key_allowed(authctxt->pw,
1046                             cuser, chost, key);
1047                         auth_method = "hostbased";
1048                         break;
1049                 case MM_RSAHOSTKEY:
1050                         key->type = KEY_RSA1; /* XXX */
1051                         allowed = options.rhosts_rsa_authentication &&
1052                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1053                             cuser, chost, key);
1054                         if (options.rhosts_rsa_authentication && allowed != 1)
1055                                 auth_clear_options();
1056                         auth_method = "rsa";
1057                         break;
1058                 default:
1059                         fatal("%s: unknown key type %d", __func__, type);
1060                         break;
1061                 }
1062         }
1063         if (key != NULL)
1064                 key_free(key);
1065
1066         /* clear temporarily storage (used by verify) */
1067         monitor_reset_key_state();
1068
1069         if (allowed) {
1070                 /* Save temporarily for comparison in verify */
1071                 key_blob = blob;
1072                 key_bloblen = bloblen;
1073                 key_blobtype = type;
1074                 hostbased_cuser = cuser;
1075                 hostbased_chost = chost;
1076         } else {
1077                 /* Log failed attempt */
1078                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1079                 xfree(blob);
1080                 xfree(cuser);
1081                 xfree(chost);
1082         }
1083
1084         debug3("%s: key %p is %s",
1085             __func__, key, allowed ? "allowed" : "not allowed");
1086
1087         buffer_clear(m);
1088         buffer_put_int(m, allowed);
1089         buffer_put_int(m, forced_command != NULL);
1090
1091         mm_append_debug(m);
1092
1093         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1094
1095         if (type == MM_RSAHOSTKEY)
1096                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1097
1098         return (0);
1099 }
1100
1101 static int
1102 monitor_valid_userblob(u_char *data, u_int datalen)
1103 {
1104         Buffer b;
1105         char *p;
1106         u_int len;
1107         int fail = 0;
1108
1109         buffer_init(&b);
1110         buffer_append(&b, data, datalen);
1111
1112         if (datafellows & SSH_OLD_SESSIONID) {
1113                 p = buffer_ptr(&b);
1114                 len = buffer_len(&b);
1115                 if ((session_id2 == NULL) ||
1116                     (len < session_id2_len) ||
1117                     (memcmp(p, session_id2, session_id2_len) != 0))
1118                         fail++;
1119                 buffer_consume(&b, session_id2_len);
1120         } else {
1121                 p = buffer_get_string(&b, &len);
1122                 if ((session_id2 == NULL) ||
1123                     (len != session_id2_len) ||
1124                     (memcmp(p, session_id2, session_id2_len) != 0))
1125                         fail++;
1126                 xfree(p);
1127         }
1128         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1129                 fail++;
1130         p = buffer_get_string(&b, NULL);
1131         if (strcmp(authctxt->user, p) != 0) {
1132                 logit("wrong user name passed to monitor: expected %s != %.100s",
1133                     authctxt->user, p);
1134                 fail++;
1135         }
1136         xfree(p);
1137         buffer_skip_string(&b);
1138         if (datafellows & SSH_BUG_PKAUTH) {
1139                 if (!buffer_get_char(&b))
1140                         fail++;
1141         } else {
1142                 p = buffer_get_string(&b, NULL);
1143                 if (strcmp("publickey", p) != 0)
1144                         fail++;
1145                 xfree(p);
1146                 if (!buffer_get_char(&b))
1147                         fail++;
1148                 buffer_skip_string(&b);
1149         }
1150         buffer_skip_string(&b);
1151         if (buffer_len(&b) != 0)
1152                 fail++;
1153         buffer_free(&b);
1154         return (fail == 0);
1155 }
1156
1157 static int
1158 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1159     char *chost)
1160 {
1161         Buffer b;
1162         char *p;
1163         u_int len;
1164         int fail = 0;
1165
1166         buffer_init(&b);
1167         buffer_append(&b, data, datalen);
1168
1169         p = buffer_get_string(&b, &len);
1170         if ((session_id2 == NULL) ||
1171             (len != session_id2_len) ||
1172             (memcmp(p, session_id2, session_id2_len) != 0))
1173                 fail++;
1174         xfree(p);
1175
1176         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1177                 fail++;
1178         p = buffer_get_string(&b, NULL);
1179         if (strcmp(authctxt->user, p) != 0) {
1180                 logit("wrong user name passed to monitor: expected %s != %.100s",
1181                     authctxt->user, p);
1182                 fail++;
1183         }
1184         xfree(p);
1185         buffer_skip_string(&b); /* service */
1186         p = buffer_get_string(&b, NULL);
1187         if (strcmp(p, "hostbased") != 0)
1188                 fail++;
1189         xfree(p);
1190         buffer_skip_string(&b); /* pkalg */
1191         buffer_skip_string(&b); /* pkblob */
1192
1193         /* verify client host, strip trailing dot if necessary */
1194         p = buffer_get_string(&b, NULL);
1195         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1196                 p[len - 1] = '\0';
1197         if (strcmp(p, chost) != 0)
1198                 fail++;
1199         xfree(p);
1200
1201         /* verify client user */
1202         p = buffer_get_string(&b, NULL);
1203         if (strcmp(p, cuser) != 0)
1204                 fail++;
1205         xfree(p);
1206
1207         if (buffer_len(&b) != 0)
1208                 fail++;
1209         buffer_free(&b);
1210         return (fail == 0);
1211 }
1212
1213 int
1214 mm_answer_keyverify(int sock, Buffer *m)
1215 {
1216         Key *key;
1217         u_char *signature, *data, *blob;
1218         u_int signaturelen, datalen, bloblen;
1219         int verified = 0;
1220         int valid_data = 0;
1221
1222         blob = buffer_get_string(m, &bloblen);
1223         signature = buffer_get_string(m, &signaturelen);
1224         data = buffer_get_string(m, &datalen);
1225
1226         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1227           !monitor_allowed_key(blob, bloblen))
1228                 fatal("%s: bad key, not previously allowed", __func__);
1229
1230         key = key_from_blob(blob, bloblen);
1231         if (key == NULL)
1232                 fatal("%s: bad public key blob", __func__);
1233
1234         switch (key_blobtype) {
1235         case MM_USERKEY:
1236                 valid_data = monitor_valid_userblob(data, datalen);
1237                 break;
1238         case MM_HOSTKEY:
1239                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1240                     hostbased_cuser, hostbased_chost);
1241                 break;
1242         default:
1243                 valid_data = 0;
1244                 break;
1245         }
1246         if (!valid_data)
1247                 fatal("%s: bad signature data blob", __func__);
1248
1249         verified = key_verify(key, signature, signaturelen, data, datalen);
1250         debug3("%s: key %p signature %s",
1251             __func__, key, (verified == 1) ? "verified" : "unverified");
1252
1253         key_free(key);
1254         xfree(blob);
1255         xfree(signature);
1256         xfree(data);
1257
1258         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1259
1260         monitor_reset_key_state();
1261
1262         buffer_clear(m);
1263         buffer_put_int(m, verified);
1264         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1265
1266         return (verified == 1);
1267 }
1268
1269 static void
1270 mm_record_login(Session *s, struct passwd *pw)
1271 {
1272         socklen_t fromlen;
1273         struct sockaddr_storage from;
1274
1275         /*
1276          * Get IP address of client. If the connection is not a socket, let
1277          * the address be 0.0.0.0.
1278          */
1279         memset(&from, 0, sizeof(from));
1280         fromlen = sizeof(from);
1281         if (packet_connection_is_on_socket()) {
1282                 if (getpeername(packet_get_connection_in(),
1283                     (struct sockaddr *)&from, &fromlen) < 0) {
1284                         debug("getpeername: %.100s", strerror(errno));
1285                         cleanup_exit(255);
1286                 }
1287         }
1288         /* Record that there was a login on that tty from the remote host. */
1289         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1290             get_remote_name_or_ip(utmp_len, options.use_dns),
1291             (struct sockaddr *)&from, fromlen);
1292 }
1293
1294 static void
1295 mm_session_close(Session *s)
1296 {
1297         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1298         if (s->ttyfd != -1) {
1299                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1300                 session_pty_cleanup2(s);
1301         }
1302         session_unused(s->self);
1303 }
1304
1305 int
1306 mm_answer_pty(int sock, Buffer *m)
1307 {
1308         extern struct monitor *pmonitor;
1309         Session *s;
1310         int res, fd0;
1311
1312         debug3("%s entering", __func__);
1313
1314         buffer_clear(m);
1315         s = session_new();
1316         if (s == NULL)
1317                 goto error;
1318         s->authctxt = authctxt;
1319         s->pw = authctxt->pw;
1320         s->pid = pmonitor->m_pid;
1321         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1322         if (res == 0)
1323                 goto error;
1324         pty_setowner(authctxt->pw, s->tty);
1325
1326         buffer_put_int(m, 1);
1327         buffer_put_cstring(m, s->tty);
1328
1329         /* We need to trick ttyslot */
1330         if (dup2(s->ttyfd, 0) == -1)
1331                 fatal("%s: dup2", __func__);
1332
1333         mm_record_login(s, authctxt->pw);
1334
1335         /* Now we can close the file descriptor again */
1336         close(0);
1337
1338         /* send messages generated by record_login */
1339         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1340         buffer_clear(&loginmsg);
1341
1342         mm_request_send(sock, MONITOR_ANS_PTY, m);
1343
1344         if (mm_send_fd(sock, s->ptyfd) == -1 ||
1345             mm_send_fd(sock, s->ttyfd) == -1)
1346                 fatal("%s: send fds failed", __func__);
1347
1348         /* make sure nothing uses fd 0 */
1349         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1350                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1351         if (fd0 != 0)
1352                 error("%s: fd0 %d != 0", __func__, fd0);
1353
1354         /* slave is not needed */
1355         close(s->ttyfd);
1356         s->ttyfd = s->ptyfd;
1357         /* no need to dup() because nobody closes ptyfd */
1358         s->ptymaster = s->ptyfd;
1359
1360         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1361
1362         return (0);
1363
1364  error:
1365         if (s != NULL)
1366                 mm_session_close(s);
1367         buffer_put_int(m, 0);
1368         mm_request_send(sock, MONITOR_ANS_PTY, m);
1369         return (0);
1370 }
1371
1372 int
1373 mm_answer_pty_cleanup(int sock, Buffer *m)
1374 {
1375         Session *s;
1376         char *tty;
1377
1378         debug3("%s entering", __func__);
1379
1380         tty = buffer_get_string(m, NULL);
1381         if ((s = session_by_tty(tty)) != NULL)
1382                 mm_session_close(s);
1383         buffer_clear(m);
1384         xfree(tty);
1385         return (0);
1386 }
1387
1388 int
1389 mm_answer_sesskey(int sock, Buffer *m)
1390 {
1391         BIGNUM *p;
1392         int rsafail;
1393
1394         /* Turn off permissions */
1395         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1396
1397         if ((p = BN_new()) == NULL)
1398                 fatal("%s: BN_new", __func__);
1399
1400         buffer_get_bignum2(m, p);
1401
1402         rsafail = ssh1_session_key(p);
1403
1404         buffer_clear(m);
1405         buffer_put_int(m, rsafail);
1406         buffer_put_bignum2(m, p);
1407
1408         BN_clear_free(p);
1409
1410         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1411
1412         /* Turn on permissions for sessid passing */
1413         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1414
1415         return (0);
1416 }
1417
1418 int
1419 mm_answer_sessid(int sock, Buffer *m)
1420 {
1421         int i;
1422
1423         debug3("%s entering", __func__);
1424
1425         if (buffer_len(m) != 16)
1426                 fatal("%s: bad ssh1 session id", __func__);
1427         for (i = 0; i < 16; i++)
1428                 session_id[i] = buffer_get_char(m);
1429
1430         /* Turn on permissions for getpwnam */
1431         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1432
1433         return (0);
1434 }
1435
1436 int
1437 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1438 {
1439         BIGNUM *client_n;
1440         Key *key = NULL;
1441         u_char *blob = NULL;
1442         u_int blen = 0;
1443         int allowed = 0;
1444
1445         debug3("%s entering", __func__);
1446
1447         auth_method = "rsa";
1448         if (options.rsa_authentication && authctxt->valid) {
1449                 if ((client_n = BN_new()) == NULL)
1450                         fatal("%s: BN_new", __func__);
1451                 buffer_get_bignum2(m, client_n);
1452                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1453                 BN_clear_free(client_n);
1454         }
1455         buffer_clear(m);
1456         buffer_put_int(m, allowed);
1457         buffer_put_int(m, forced_command != NULL);
1458
1459         /* clear temporarily storage (used by generate challenge) */
1460         monitor_reset_key_state();
1461
1462         if (allowed && key != NULL) {
1463                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1464                 if (key_to_blob(key, &blob, &blen) == 0)
1465                         fatal("%s: key_to_blob failed", __func__);
1466                 buffer_put_string(m, blob, blen);
1467
1468                 /* Save temporarily for comparison in verify */
1469                 key_blob = blob;
1470                 key_bloblen = blen;
1471                 key_blobtype = MM_RSAUSERKEY;
1472         }
1473         if (key != NULL)
1474                 key_free(key);
1475
1476         mm_append_debug(m);
1477
1478         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1479
1480         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1481         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1482         return (0);
1483 }
1484
1485 int
1486 mm_answer_rsa_challenge(int sock, Buffer *m)
1487 {
1488         Key *key = NULL;
1489         u_char *blob;
1490         u_int blen;
1491
1492         debug3("%s entering", __func__);
1493
1494         if (!authctxt->valid)
1495                 fatal("%s: authctxt not valid", __func__);
1496         blob = buffer_get_string(m, &blen);
1497         if (!monitor_allowed_key(blob, blen))
1498                 fatal("%s: bad key, not previously allowed", __func__);
1499         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1500                 fatal("%s: key type mismatch", __func__);
1501         if ((key = key_from_blob(blob, blen)) == NULL)
1502                 fatal("%s: received bad key", __func__);
1503         if (key->type != KEY_RSA)
1504                 fatal("%s: received bad key type %d", __func__, key->type);
1505         key->type = KEY_RSA1;
1506         if (ssh1_challenge)
1507                 BN_clear_free(ssh1_challenge);
1508         ssh1_challenge = auth_rsa_generate_challenge(key);
1509
1510         buffer_clear(m);
1511         buffer_put_bignum2(m, ssh1_challenge);
1512
1513         debug3("%s sending reply", __func__);
1514         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1515
1516         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1517
1518         xfree(blob);
1519         key_free(key);
1520         return (0);
1521 }
1522
1523 int
1524 mm_answer_rsa_response(int sock, Buffer *m)
1525 {
1526         Key *key = NULL;
1527         u_char *blob, *response;
1528         u_int blen, len;
1529         int success;
1530
1531         debug3("%s entering", __func__);
1532
1533         if (!authctxt->valid)
1534                 fatal("%s: authctxt not valid", __func__);
1535         if (ssh1_challenge == NULL)
1536                 fatal("%s: no ssh1_challenge", __func__);
1537
1538         blob = buffer_get_string(m, &blen);
1539         if (!monitor_allowed_key(blob, blen))
1540                 fatal("%s: bad key, not previously allowed", __func__);
1541         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1542                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1543         if ((key = key_from_blob(blob, blen)) == NULL)
1544                 fatal("%s: received bad key", __func__);
1545         response = buffer_get_string(m, &len);
1546         if (len != 16)
1547                 fatal("%s: received bad response to challenge", __func__);
1548         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1549
1550         xfree(blob);
1551         key_free(key);
1552         xfree(response);
1553
1554         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1555
1556         /* reset state */
1557         BN_clear_free(ssh1_challenge);
1558         ssh1_challenge = NULL;
1559         monitor_reset_key_state();
1560
1561         buffer_clear(m);
1562         buffer_put_int(m, success);
1563         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1564
1565         return (success);
1566 }
1567
1568 int
1569 mm_answer_term(int sock, Buffer *req)
1570 {
1571         extern struct monitor *pmonitor;
1572         int res, status;
1573
1574         debug3("%s: tearing down sessions", __func__);
1575
1576         /* The child is terminating */
1577         session_destroy_all(&mm_session_close);
1578
1579 #ifdef USE_PAM
1580         if (options.use_pam)
1581                 sshpam_cleanup();
1582 #endif
1583
1584         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1585                 if (errno != EINTR)
1586                         exit(1);
1587
1588         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1589
1590         /* Terminate process */
1591         exit(res);
1592 }
1593
1594 #ifdef SSH_AUDIT_EVENTS
1595 /* Report that an audit event occurred */
1596 int
1597 mm_answer_audit_event(int socket, Buffer *m)
1598 {
1599         ssh_audit_event_t event;
1600
1601         debug3("%s entering", __func__);
1602
1603         event = buffer_get_int(m);
1604         switch(event) {
1605         case SSH_AUTH_FAIL_PUBKEY:
1606         case SSH_AUTH_FAIL_HOSTBASED:
1607         case SSH_AUTH_FAIL_GSSAPI:
1608         case SSH_LOGIN_EXCEED_MAXTRIES:
1609         case SSH_LOGIN_ROOT_DENIED:
1610         case SSH_CONNECTION_CLOSE:
1611         case SSH_INVALID_USER:
1612                 audit_event(event);
1613                 break;
1614         default:
1615                 fatal("Audit event type %d not permitted", event);
1616         }
1617
1618         return (0);
1619 }
1620
1621 int
1622 mm_answer_audit_command(int socket, Buffer *m)
1623 {
1624         u_int len;
1625         char *cmd;
1626
1627         debug3("%s entering", __func__);
1628         cmd = buffer_get_string(m, &len);
1629         /* sanity check command, if so how? */
1630         audit_run_command(cmd);
1631         xfree(cmd);
1632         return (0);
1633 }
1634 #endif /* SSH_AUDIT_EVENTS */
1635
1636 void
1637 monitor_apply_keystate(struct monitor *pmonitor)
1638 {
1639         if (compat20) {
1640                 set_newkeys(MODE_IN);
1641                 set_newkeys(MODE_OUT);
1642         } else {
1643                 packet_set_protocol_flags(child_state.ssh1protoflags);
1644                 packet_set_encryption_key(child_state.ssh1key,
1645                     child_state.ssh1keylen, child_state.ssh1cipher);
1646                 xfree(child_state.ssh1key);
1647         }
1648
1649         /* for rc4 and other stateful ciphers */
1650         packet_set_keycontext(MODE_OUT, child_state.keyout);
1651         xfree(child_state.keyout);
1652         packet_set_keycontext(MODE_IN, child_state.keyin);
1653         xfree(child_state.keyin);
1654
1655         if (!compat20) {
1656                 packet_set_iv(MODE_OUT, child_state.ivout);
1657                 xfree(child_state.ivout);
1658                 packet_set_iv(MODE_IN, child_state.ivin);
1659                 xfree(child_state.ivin);
1660         }
1661
1662         memcpy(&incoming_stream, &child_state.incoming,
1663             sizeof(incoming_stream));
1664         memcpy(&outgoing_stream, &child_state.outgoing,
1665             sizeof(outgoing_stream));
1666
1667         /* Update with new address */
1668         if (options.compression)
1669                 mm_init_compression(pmonitor->m_zlib);
1670
1671         /* Network I/O buffers */
1672         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1673         buffer_clear(&input);
1674         buffer_append(&input, child_state.input, child_state.ilen);
1675         memset(child_state.input, 0, child_state.ilen);
1676         xfree(child_state.input);
1677
1678         buffer_clear(&output);
1679         buffer_append(&output, child_state.output, child_state.olen);
1680         memset(child_state.output, 0, child_state.olen);
1681         xfree(child_state.output);
1682 }
1683
1684 static Kex *
1685 mm_get_kex(Buffer *m)
1686 {
1687         Kex *kex;
1688         void *blob;
1689         u_int bloblen;
1690
1691         kex = xcalloc(1, sizeof(*kex));
1692         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1693         if ((session_id2 == NULL) ||
1694             (kex->session_id_len != session_id2_len) ||
1695             (memcmp(kex->session_id, session_id2, session_id2_len) != 0))
1696                 fatal("mm_get_get: internal error: bad session id");
1697         kex->we_need = buffer_get_int(m);
1698         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1699         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1700         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1701         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1702         kex->server = 1;
1703         kex->hostkey_type = buffer_get_int(m);
1704         kex->kex_type = buffer_get_int(m);
1705         blob = buffer_get_string(m, &bloblen);
1706         buffer_init(&kex->my);
1707         buffer_append(&kex->my, blob, bloblen);
1708         xfree(blob);
1709         blob = buffer_get_string(m, &bloblen);
1710         buffer_init(&kex->peer);
1711         buffer_append(&kex->peer, blob, bloblen);
1712         xfree(blob);
1713         kex->done = 1;
1714         kex->flags = buffer_get_int(m);
1715         kex->client_version_string = buffer_get_string(m, NULL);
1716         kex->server_version_string = buffer_get_string(m, NULL);
1717         kex->load_host_key=&get_hostkey_by_type;
1718         kex->host_key_index=&get_hostkey_index;
1719
1720         return (kex);
1721 }
1722
1723 /* This function requries careful sanity checking */
1724
1725 void
1726 mm_get_keystate(struct monitor *pmonitor)
1727 {
1728         Buffer m;
1729         u_char *blob, *p;
1730         u_int bloblen, plen;
1731         u_int32_t seqnr, packets;
1732         u_int64_t blocks, bytes;
1733
1734         debug3("%s: Waiting for new keys", __func__);
1735
1736         buffer_init(&m);
1737         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1738         if (!compat20) {
1739                 child_state.ssh1protoflags = buffer_get_int(&m);
1740                 child_state.ssh1cipher = buffer_get_int(&m);
1741                 child_state.ssh1key = buffer_get_string(&m,
1742                     &child_state.ssh1keylen);
1743                 child_state.ivout = buffer_get_string(&m,
1744                     &child_state.ivoutlen);
1745                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1746                 goto skip;
1747         } else {
1748                 /* Get the Kex for rekeying */
1749                 *pmonitor->m_pkex = mm_get_kex(&m);
1750         }
1751
1752         blob = buffer_get_string(&m, &bloblen);
1753         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1754         xfree(blob);
1755
1756         debug3("%s: Waiting for second key", __func__);
1757         blob = buffer_get_string(&m, &bloblen);
1758         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1759         xfree(blob);
1760
1761         /* Now get sequence numbers for the packets */
1762         seqnr = buffer_get_int(&m);
1763         blocks = buffer_get_int64(&m);
1764         packets = buffer_get_int(&m);
1765         bytes = buffer_get_int64(&m);
1766         packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1767         seqnr = buffer_get_int(&m);
1768         blocks = buffer_get_int64(&m);
1769         packets = buffer_get_int(&m);
1770         bytes = buffer_get_int64(&m);
1771         packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1772
1773  skip:
1774         /* Get the key context */
1775         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1776         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1777
1778         debug3("%s: Getting compression state", __func__);
1779         /* Get compression state */
1780         p = buffer_get_string(&m, &plen);
1781         if (plen != sizeof(child_state.outgoing))
1782                 fatal("%s: bad request size", __func__);
1783         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1784         xfree(p);
1785
1786         p = buffer_get_string(&m, &plen);
1787         if (plen != sizeof(child_state.incoming))
1788                 fatal("%s: bad request size", __func__);
1789         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1790         xfree(p);
1791
1792         /* Network I/O buffers */
1793         debug3("%s: Getting Network I/O buffers", __func__);
1794         child_state.input = buffer_get_string(&m, &child_state.ilen);
1795         child_state.output = buffer_get_string(&m, &child_state.olen);
1796
1797         buffer_free(&m);
1798 }
1799
1800
1801 /* Allocation functions for zlib */
1802 void *
1803 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1804 {
1805         size_t len = (size_t) size * ncount;
1806         void *address;
1807
1808         if (len == 0 || ncount > SIZE_T_MAX / size)
1809                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1810
1811         address = mm_malloc(mm, len);
1812
1813         return (address);
1814 }
1815
1816 void
1817 mm_zfree(struct mm_master *mm, void *address)
1818 {
1819         mm_free(mm, address);
1820 }
1821
1822 void
1823 mm_init_compression(struct mm_master *mm)
1824 {
1825         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1826         outgoing_stream.zfree = (free_func)mm_zfree;
1827         outgoing_stream.opaque = mm;
1828
1829         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1830         incoming_stream.zfree = (free_func)mm_zfree;
1831         incoming_stream.opaque = mm;
1832 }
1833
1834 /* XXX */
1835
1836 #define FD_CLOSEONEXEC(x) do { \
1837         if (fcntl(x, F_SETFD, 1) == -1) \
1838                 fatal("fcntl(%d, F_SETFD)", x); \
1839 } while (0)
1840
1841 static void
1842 monitor_socketpair(int *pair)
1843 {
1844 #ifdef HAVE_SOCKETPAIR
1845         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1846                 fatal("%s: socketpair", __func__);
1847 #else
1848         fatal("%s: UsePrivilegeSeparation=yes not supported",
1849             __func__);
1850 #endif
1851         FD_CLOSEONEXEC(pair[0]);
1852         FD_CLOSEONEXEC(pair[1]);
1853 }
1854
1855 #define MM_MEMSIZE      65536
1856
1857 struct monitor *
1858 monitor_init(void)
1859 {
1860         struct monitor *mon;
1861         int pair[2];
1862
1863         mon = xcalloc(1, sizeof(*mon));
1864
1865         monitor_socketpair(pair);
1866
1867         mon->m_recvfd = pair[0];
1868         mon->m_sendfd = pair[1];
1869
1870         /* Used to share zlib space across processes */
1871         if (options.compression) {
1872                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1873                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1874
1875                 /* Compression needs to share state across borders */
1876                 mm_init_compression(mon->m_zlib);
1877         }
1878
1879         return mon;
1880 }
1881
1882 void
1883 monitor_reinit(struct monitor *mon)
1884 {
1885         int pair[2];
1886
1887         monitor_socketpair(pair);
1888
1889         mon->m_recvfd = pair[0];
1890         mon->m_sendfd = pair[1];
1891 }
1892
1893 #ifdef GSSAPI
1894 int
1895 mm_answer_gss_setup_ctx(int sock, Buffer *m)
1896 {
1897         gss_OID_desc goid;
1898         OM_uint32 major;
1899         u_int len;
1900
1901         goid.elements = buffer_get_string(m, &len);
1902         goid.length = len;
1903
1904         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
1905
1906         xfree(goid.elements);
1907
1908         buffer_clear(m);
1909         buffer_put_int(m, major);
1910
1911         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
1912
1913         /* Now we have a context, enable the step */
1914         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
1915
1916         return (0);
1917 }
1918
1919 int
1920 mm_answer_gss_accept_ctx(int sock, Buffer *m)
1921 {
1922         gss_buffer_desc in;
1923         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
1924         OM_uint32 major, minor;
1925         OM_uint32 flags = 0; /* GSI needs this */
1926         u_int len;
1927
1928         in.value = buffer_get_string(m, &len);
1929         in.length = len;
1930         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
1931         xfree(in.value);
1932
1933         buffer_clear(m);
1934         buffer_put_int(m, major);
1935         buffer_put_string(m, out.value, out.length);
1936         buffer_put_int(m, flags);
1937         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
1938
1939         gss_release_buffer(&minor, &out);
1940
1941         if (major == GSS_S_COMPLETE) {
1942                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
1943                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1944                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
1945         }
1946         return (0);
1947 }
1948
1949 int
1950 mm_answer_gss_checkmic(int sock, Buffer *m)
1951 {
1952         gss_buffer_desc gssbuf, mic;
1953         OM_uint32 ret;
1954         u_int len;
1955
1956         gssbuf.value = buffer_get_string(m, &len);
1957         gssbuf.length = len;
1958         mic.value = buffer_get_string(m, &len);
1959         mic.length = len;
1960
1961         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
1962
1963         xfree(gssbuf.value);
1964         xfree(mic.value);
1965
1966         buffer_clear(m);
1967         buffer_put_int(m, ret);
1968
1969         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
1970
1971         if (!GSS_ERROR(ret))
1972                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
1973
1974         return (0);
1975 }
1976
1977 int
1978 mm_answer_gss_userok(int sock, Buffer *m)
1979 {
1980         int authenticated;
1981
1982         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
1983
1984         buffer_clear(m);
1985         buffer_put_int(m, authenticated);
1986
1987         debug3("%s: sending result %d", __func__, authenticated);
1988         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
1989
1990         auth_method = "gssapi-with-mic";
1991
1992         /* Monitor loop will terminate if authenticated */
1993         return (authenticated);
1994 }
1995 #endif /* GSSAPI */
1996
1997 #ifdef JPAKE
1998 int
1999 mm_answer_jpake_step1(int sock, Buffer *m)
2000 {
2001         struct jpake_ctx *pctx;
2002         u_char *x3_proof, *x4_proof;
2003         u_int x3_proof_len, x4_proof_len;
2004
2005         if (!options.zero_knowledge_password_authentication)
2006                 fatal("zero_knowledge_password_authentication disabled");
2007
2008         if (authctxt->jpake_ctx != NULL)
2009                 fatal("%s: authctxt->jpake_ctx already set (%p)",
2010                     __func__, authctxt->jpake_ctx);
2011         authctxt->jpake_ctx = pctx = jpake_new();
2012
2013         jpake_step1(pctx->grp,
2014             &pctx->server_id, &pctx->server_id_len,
2015             &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4,
2016             &x3_proof, &x3_proof_len,
2017             &x4_proof, &x4_proof_len);
2018
2019         JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__));
2020
2021         buffer_clear(m);
2022
2023         buffer_put_string(m, pctx->server_id, pctx->server_id_len);
2024         buffer_put_bignum2(m, pctx->g_x3);
2025         buffer_put_bignum2(m, pctx->g_x4);
2026         buffer_put_string(m, x3_proof, x3_proof_len);
2027         buffer_put_string(m, x4_proof, x4_proof_len);
2028
2029         debug3("%s: sending step1", __func__);
2030         mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m);
2031
2032         bzero(x3_proof, x3_proof_len);
2033         bzero(x4_proof, x4_proof_len);
2034         xfree(x3_proof);
2035         xfree(x4_proof);
2036
2037         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1);
2038         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0);
2039
2040         return 0;
2041 }
2042
2043 int
2044 mm_answer_jpake_get_pwdata(int sock, Buffer *m)
2045 {
2046         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2047         char *hash_scheme, *salt;
2048
2049         if (pctx == NULL)
2050                 fatal("%s: pctx == NULL", __func__);
2051
2052         auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt);
2053
2054         buffer_clear(m);
2055         /* pctx->s is sensitive, not returned to slave */
2056         buffer_put_cstring(m, hash_scheme);
2057         buffer_put_cstring(m, salt);
2058
2059         debug3("%s: sending pwdata", __func__);
2060         mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m);
2061
2062         bzero(hash_scheme, strlen(hash_scheme));
2063         bzero(salt, strlen(salt));
2064         xfree(hash_scheme);
2065         xfree(salt);
2066
2067         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1);
2068
2069         return 0;
2070 }
2071
2072 int
2073 mm_answer_jpake_step2(int sock, Buffer *m)
2074 {
2075         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2076         u_char *x1_proof, *x2_proof, *x4_s_proof;
2077         u_int x1_proof_len, x2_proof_len, x4_s_proof_len;
2078
2079         if (pctx == NULL)
2080                 fatal("%s: pctx == NULL", __func__);
2081
2082         if ((pctx->g_x1 = BN_new()) == NULL ||
2083             (pctx->g_x2 = BN_new()) == NULL)
2084                 fatal("%s: BN_new", __func__);
2085         buffer_get_bignum2(m, pctx->g_x1);
2086         buffer_get_bignum2(m, pctx->g_x2);
2087         pctx->client_id = buffer_get_string(m, &pctx->client_id_len);
2088         x1_proof = buffer_get_string(m, &x1_proof_len);
2089         x2_proof = buffer_get_string(m, &x2_proof_len);
2090
2091         jpake_step2(pctx->grp, pctx->s, pctx->g_x3,
2092             pctx->g_x1, pctx->g_x2, pctx->x4,
2093             pctx->client_id, pctx->client_id_len,
2094             pctx->server_id, pctx->server_id_len,
2095             x1_proof, x1_proof_len,
2096             x2_proof, x2_proof_len,
2097             &pctx->b,
2098             &x4_s_proof, &x4_s_proof_len);
2099
2100         JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__));
2101
2102         bzero(x1_proof, x1_proof_len);
2103         bzero(x2_proof, x2_proof_len);
2104         xfree(x1_proof);
2105         xfree(x2_proof);
2106
2107         buffer_clear(m);
2108
2109         buffer_put_bignum2(m, pctx->b);
2110         buffer_put_string(m, x4_s_proof, x4_s_proof_len);
2111
2112         debug3("%s: sending step2", __func__);
2113         mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m);
2114
2115         bzero(x4_s_proof, x4_s_proof_len);
2116         xfree(x4_s_proof);
2117
2118         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1);
2119
2120         return 0;
2121 }
2122
2123 int
2124 mm_answer_jpake_key_confirm(int sock, Buffer *m)
2125 {
2126         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2127         u_char *x2_s_proof;
2128         u_int x2_s_proof_len;
2129
2130         if (pctx == NULL)
2131                 fatal("%s: pctx == NULL", __func__);
2132
2133         if ((pctx->a = BN_new()) == NULL)
2134                 fatal("%s: BN_new", __func__);
2135         buffer_get_bignum2(m, pctx->a);
2136         x2_s_proof = buffer_get_string(m, &x2_s_proof_len);
2137
2138         jpake_key_confirm(pctx->grp, pctx->s, pctx->a,
2139             pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2,
2140             pctx->server_id, pctx->server_id_len,
2141             pctx->client_id, pctx->client_id_len,
2142             session_id2, session_id2_len,
2143             x2_s_proof, x2_s_proof_len,
2144             &pctx->k,
2145             &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len);
2146
2147         JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__));
2148
2149         bzero(x2_s_proof, x2_s_proof_len);
2150         buffer_clear(m);
2151
2152         /* pctx->k is sensitive, not sent */
2153         buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len);
2154
2155         debug3("%s: sending confirmation hash", __func__);
2156         mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m);
2157
2158         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1);
2159
2160         return 0;
2161 }
2162
2163 int
2164 mm_answer_jpake_check_confirm(int sock, Buffer *m)
2165 {
2166         int authenticated = 0;
2167         u_char *peer_confirm_hash;
2168         u_int peer_confirm_hash_len;
2169         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2170
2171         if (pctx == NULL)
2172                 fatal("%s: pctx == NULL", __func__);
2173
2174         peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len);
2175
2176         authenticated = jpake_check_confirm(pctx->k,
2177             pctx->client_id, pctx->client_id_len,
2178             session_id2, session_id2_len,
2179             peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid;
2180
2181         JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__));
2182
2183         bzero(peer_confirm_hash, peer_confirm_hash_len);
2184         xfree(peer_confirm_hash);
2185
2186         buffer_clear(m);
2187         buffer_put_int(m, authenticated);
2188
2189         debug3("%s: sending result %d", __func__, authenticated);
2190         mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m);
2191
2192         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1);
2193
2194         auth_method = "jpake-01@openssh.com";
2195         return authenticated;
2196 }
2197
2198 #endif /* JPAKE */