monitor.c

   1 /* $OpenBSD: monitor.c,v 1.110 2010/09/09 10:45:45 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 #include "roaming.h"
  92
  93 #ifdef GSSAPI
  94 static Gssctxt *gsscontext = NULL;
  95 #endif
  96
  97 /* Imports */
  98 extern ServerOptions options;
  99 extern u_int utmp_len;
 100 extern Newkeys *current_keys[];
 101 extern z_stream incoming_stream;
 102 extern z_stream outgoing_stream;
 103 extern u_char session_id[];
 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         u_int64_t sent_bytes;
 130         u_int64_t recv_bytes;
 131 } child_state;
 132
 133 /* Functions on the monitor that answer unprivileged requests */
 134
 135 int mm_answer_moduli(int, Buffer *);
 136 int mm_answer_sign(int, Buffer *);
 137 int mm_answer_pwnamallow(int, Buffer *);
 138 int mm_answer_auth2_read_banner(int, Buffer *);
 139 int mm_answer_authserv(int, Buffer *);
 140 int mm_answer_authpassword(int, Buffer *);
 141 int mm_answer_bsdauthquery(int, Buffer *);
 142 int mm_answer_bsdauthrespond(int, Buffer *);
 143 int mm_answer_skeyquery(int, Buffer *);
 144 int mm_answer_skeyrespond(int, Buffer *);
 145 int mm_answer_keyallowed(int, Buffer *);
 146 int mm_answer_keyverify(int, Buffer *);
 147 int mm_answer_pty(int, Buffer *);
 148 int mm_answer_pty_cleanup(int, Buffer *);
 149 int mm_answer_term(int, Buffer *);
 150 int mm_answer_rsa_keyallowed(int, Buffer *);
 151 int mm_answer_rsa_challenge(int, Buffer *);
 152 int mm_answer_rsa_response(int, Buffer *);
 153 int mm_answer_sesskey(int, Buffer *);
 154 int mm_answer_sessid(int, Buffer *);
 155 int mm_answer_jpake_get_pwdata(int, Buffer *);
 156 int mm_answer_jpake_step1(int, Buffer *);
 157 int mm_answer_jpake_step2(int, Buffer *);
 158 int mm_answer_jpake_key_confirm(int, Buffer *);
 159 int mm_answer_jpake_check_confirm(int, Buffer *);
 160
 161 #ifdef USE_PAM
 162 int mm_answer_pam_start(int, Buffer *);
 163 int mm_answer_pam_account(int, Buffer *);
 164 int mm_answer_pam_init_ctx(int, Buffer *);
 165 int mm_answer_pam_query(int, Buffer *);
 166 int mm_answer_pam_respond(int, Buffer *);
 167 int mm_answer_pam_free_ctx(int, Buffer *);
 168 #endif
 169
 170 #ifdef GSSAPI
 171 int mm_answer_gss_setup_ctx(int, Buffer *);
 172 int mm_answer_gss_accept_ctx(int, Buffer *);
 173 int mm_answer_gss_userok(int, Buffer *);
 174 int mm_answer_gss_checkmic(int, Buffer *);
 175 #endif
 176
 177 #ifdef SSH_AUDIT_EVENTS
 178 int mm_answer_audit_event(int, Buffer *);
 179 int mm_answer_audit_command(int, Buffer *);
 180 #endif
 181
 182 static Authctxt *authctxt;
 183 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 184
 185 /* local state for key verify */
 186 static u_char *key_blob = NULL;
 187 static u_int key_bloblen = 0;
 188 static int key_blobtype = MM_NOKEY;
 189 static char *hostbased_cuser = NULL;
 190 static char *hostbased_chost = NULL;
 191 static char *auth_method = "unknown";
 192 static u_int session_id2_len = 0;
 193 static u_char *session_id2 = NULL;
 194 static pid_t monitor_child_pid;
 195
 196 struct mon_table {
 197         enum monitor_reqtype type;
 198         int flags;
 199         int (*f)(int, Buffer *);
 200 };
 201
 202 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 203 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 204 #define MON_ONCE        0x0010  /* Disable after calling */
 205 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 206
 207 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 208
 209 #define MON_PERMIT      0x1000  /* Request is permitted */
 210
 211 struct mon_table mon_dispatch_proto20[] = {
 212     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 213     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 214     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 215     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 216     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 217     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 218 #ifdef USE_PAM
 219     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 220     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 221     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 222     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 223     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 224     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 225 #endif
 226 #ifdef SSH_AUDIT_EVENTS
 227     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 228 #endif
 229 #ifdef BSD_AUTH
 230     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 231     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 232 #endif
 233 #ifdef SKEY
 234     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 235     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 236 #endif
 237     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 238     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 239 #ifdef GSSAPI
 240     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 241     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 242     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 243     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 244 #endif
 245 #ifdef JPAKE
 246     {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata},
 247     {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1},
 248     {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2},
 249     {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm},
 250     {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm},
 251 #endif
 252     {0, 0, NULL}
 253 };
 254
 255 struct mon_table mon_dispatch_postauth20[] = {
 256     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 257     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 258     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 259     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 260     {MONITOR_REQ_TERM, 0, mm_answer_term},
 261 #ifdef SSH_AUDIT_EVENTS
 262     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 263     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 264 #endif
 265     {0, 0, NULL}
 266 };
 267
 268 struct mon_table mon_dispatch_proto15[] = {
 269     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 270     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 271     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 272     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 273     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 274     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 275     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 276     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 277 #ifdef BSD_AUTH
 278     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 279     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 280 #endif
 281 #ifdef SKEY
 282     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 283     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 284 #endif
 285 #ifdef USE_PAM
 286     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 287     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 288     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 289     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 290     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 291     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 292 #endif
 293 #ifdef SSH_AUDIT_EVENTS
 294     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 295 #endif
 296     {0, 0, NULL}
 297 };
 298
 299 struct mon_table mon_dispatch_postauth15[] = {
 300     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 301     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 302     {MONITOR_REQ_TERM, 0, mm_answer_term},
 303 #ifdef SSH_AUDIT_EVENTS
 304     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 305     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
 306 #endif
 307     {0, 0, NULL}
 308 };
 309
 310 struct mon_table *mon_dispatch;
 311
 312 /* Specifies if a certain message is allowed at the moment */
 313
 314 static void
 315 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 316 {
 317         while (ent->f != NULL) {
 318                 if (ent->type == type) {
 319                         ent->flags &= ~MON_PERMIT;
 320                         ent->flags |= permit ? MON_PERMIT : 0;
 321                         return;
 322                 }
 323                 ent++;
 324         }
 325 }
 326
 327 static void
 328 monitor_permit_authentications(int permit)
 329 {
 330         struct mon_table *ent = mon_dispatch;
 331
 332         while (ent->f != NULL) {
 333                 if (ent->flags & MON_AUTH) {
 334                         ent->flags &= ~MON_PERMIT;
 335                         ent->flags |= permit ? MON_PERMIT : 0;
 336                 }
 337                 ent++;
 338         }
 339 }
 340
 341 void
 342 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 343 {
 344         struct mon_table *ent;
 345         int authenticated = 0;
 346
 347         debug3("preauth child monitor started");
 348
 349         authctxt = _authctxt;
 350         memset(authctxt, 0, sizeof(*authctxt));
 351
 352         authctxt->loginmsg = &loginmsg;
 353
 354         if (compat20) {
 355                 mon_dispatch = mon_dispatch_proto20;
 356
 357                 /* Permit requests for moduli and signatures */
 358                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 359                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 360         } else {
 361                 mon_dispatch = mon_dispatch_proto15;
 362
 363                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 364         }
 365
 366         /* The first few requests do not require asynchronous access */
 367         while (!authenticated) {
 368                 auth_method = "unknown";
 369                 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
 370                 if (authenticated) {
 371                         if (!(ent->flags & MON_AUTHDECIDE))
 372                                 fatal("%s: unexpected authentication from %d",
 373                                     __func__, ent->type);
 374                         if (authctxt->pw->pw_uid == 0 &&
 375                             !auth_root_allowed(auth_method))
 376                                 authenticated = 0;
 377 #ifdef USE_PAM
 378                         /* PAM needs to perform account checks after auth */
 379                         if (options.use_pam && authenticated) {
 380                                 Buffer m;
 381
 382                                 buffer_init(&m);
 383                                 mm_request_receive_expect(pmonitor->m_sendfd,
 384                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 385                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 386                                 buffer_free(&m);
 387                         }
 388 #endif
 389                 }
 390
 391                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 392                         auth_log(authctxt, authenticated, auth_method,
 393                             compat20 ? " ssh2" : "");
 394                         if (!authenticated)
 395                                 authctxt->failures++;
 396                 }
 397 #ifdef JPAKE
 398                 /* Cleanup JPAKE context after authentication */
 399                 if (ent->flags & MON_AUTHDECIDE) {
 400                         if (authctxt->jpake_ctx != NULL) {
 401                                 jpake_free(authctxt->jpake_ctx);
 402                                 authctxt->jpake_ctx = NULL;
 403                         }
 404                 }
 405 #endif
 406         }
 407
 408         if (!authctxt->valid)
 409                 fatal("%s: authenticated invalid user", __func__);
 410         if (strcmp(auth_method, "unknown") == 0)
 411                 fatal("%s: authentication method name unknown", __func__);
 412
 413         debug("%s: %s has been authenticated by privileged process",
 414             __func__, authctxt->user);
 415
 416         mm_get_keystate(pmonitor);
 417 }
 418
 419 static void
 420 monitor_set_child_handler(pid_t pid)
 421 {
 422         monitor_child_pid = pid;
 423 }
 424
 425 static void
 426 monitor_child_handler(int sig)
 427 {
 428         kill(monitor_child_pid, sig);
 429 }
 430
 431 void
 432 monitor_child_postauth(struct monitor *pmonitor)
 433 {
 434         monitor_set_child_handler(pmonitor->m_pid);
 435         signal(SIGHUP, &monitor_child_handler);
 436         signal(SIGTERM, &monitor_child_handler);
 437         signal(SIGINT, &monitor_child_handler);
 438
 439         if (compat20) {
 440                 mon_dispatch = mon_dispatch_postauth20;
 441
 442                 /* Permit requests for moduli and signatures */
 443                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 444                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 445                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 446         } else {
 447                 mon_dispatch = mon_dispatch_postauth15;
 448                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 449         }
 450         if (!no_pty_flag) {
 451                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 452                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 453         }
 454
 455         for (;;)
 456                 monitor_read(pmonitor, mon_dispatch, NULL);
 457 }
 458
 459 void
 460 monitor_sync(struct monitor *pmonitor)
 461 {
 462         if (options.compression) {
 463                 /* The member allocation is not visible, so sync it */
 464                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 465         }
 466 }
 467
 468 int
 469 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 470     struct mon_table **pent)
 471 {
 472         Buffer m;
 473         int ret;
 474         u_char type;
 475
 476         buffer_init(&m);
 477
 478         mm_request_receive(pmonitor->m_sendfd, &m);
 479         type = buffer_get_char(&m);
 480
 481         debug3("%s: checking request %d", __func__, type);
 482
 483         while (ent->f != NULL) {
 484                 if (ent->type == type)
 485                         break;
 486                 ent++;
 487         }
 488
 489         if (ent->f != NULL) {
 490                 if (!(ent->flags & MON_PERMIT))
 491                         fatal("%s: unpermitted request %d", __func__,
 492                             type);
 493                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 494                 buffer_free(&m);
 495
 496                 /* The child may use this request only once, disable it */
 497                 if (ent->flags & MON_ONCE) {
 498                         debug2("%s: %d used once, disabling now", __func__,
 499                             type);
 500                         ent->flags &= ~MON_PERMIT;
 501                 }
 502
 503                 if (pent != NULL)
 504                         *pent = ent;
 505
 506                 return ret;
 507         }
 508
 509         fatal("%s: unsupported request: %d", __func__, type);
 510
 511         /* NOTREACHED */
 512         return (-1);
 513 }
 514
 515 /* allowed key state */
 516 static int
 517 monitor_allowed_key(u_char *blob, u_int bloblen)
 518 {
 519         /* make sure key is allowed */
 520         if (key_blob == NULL || key_bloblen != bloblen ||
 521             timingsafe_bcmp(key_blob, blob, key_bloblen))
 522                 return (0);
 523         return (1);
 524 }
 525
 526 static void
 527 monitor_reset_key_state(void)
 528 {
 529         /* reset state */
 530         if (key_blob != NULL)
 531                 xfree(key_blob);
 532         if (hostbased_cuser != NULL)
 533                 xfree(hostbased_cuser);
 534         if (hostbased_chost != NULL)
 535                 xfree(hostbased_chost);
 536         key_blob = NULL;
 537         key_bloblen = 0;
 538         key_blobtype = MM_NOKEY;
 539         hostbased_cuser = NULL;
 540         hostbased_chost = NULL;
 541 }
 542
 543 int
 544 mm_answer_moduli(int sock, Buffer *m)
 545 {
 546         DH *dh;
 547         int min, want, max;
 548
 549         min = buffer_get_int(m);
 550         want = buffer_get_int(m);
 551         max = buffer_get_int(m);
 552
 553         debug3("%s: got parameters: %d %d %d",
 554             __func__, min, want, max);
 555         /* We need to check here, too, in case the child got corrupted */
 556         if (max < min || want < min || max < want)
 557                 fatal("%s: bad parameters: %d %d %d",
 558                     __func__, min, want, max);
 559
 560         buffer_clear(m);
 561
 562         dh = choose_dh(min, want, max);
 563         if (dh == NULL) {
 564                 buffer_put_char(m, 0);
 565                 return (0);
 566         } else {
 567                 /* Send first bignum */
 568                 buffer_put_char(m, 1);
 569                 buffer_put_bignum2(m, dh->p);
 570                 buffer_put_bignum2(m, dh->g);
 571
 572                 DH_free(dh);
 573         }
 574         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 575         return (0);
 576 }
 577
 578 int
 579 mm_answer_sign(int sock, Buffer *m)
 580 {
 581         Key *key;
 582         u_char *p;
 583         u_char *signature;
 584         u_int siglen, datlen;
 585         int keyid;
 586
 587         debug3("%s", __func__);
 588
 589         keyid = buffer_get_int(m);
 590         p = buffer_get_string(m, &datlen);
 591
 592         /*
 593          * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
 594          * SHA384 (48 bytes) and SHA512 (64 bytes).
 595          */
 596         if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64)
 597                 fatal("%s: data length incorrect: %u", __func__, datlen);
 598
 599         /* save session id, it will be passed on the first call */
 600         if (session_id2_len == 0) {
 601                 session_id2_len = datlen;
 602                 session_id2 = xmalloc(session_id2_len);
 603                 memcpy(session_id2, p, session_id2_len);
 604         }
 605
 606         if ((key = get_hostkey_by_index(keyid)) == NULL)
 607                 fatal("%s: no hostkey from index %d", __func__, keyid);
 608         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 609                 fatal("%s: key_sign failed", __func__);
 610
 611         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 612
 613         buffer_clear(m);
 614         buffer_put_string(m, signature, siglen);
 615
 616         xfree(p);
 617         xfree(signature);
 618
 619         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 620
 621         /* Turn on permissions for getpwnam */
 622         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 623
 624         return (0);
 625 }
 626
 627 /* Retrieves the password entry and also checks if the user is permitted */
 628
 629 int
 630 mm_answer_pwnamallow(int sock, Buffer *m)
 631 {
 632         char *username;
 633         struct passwd *pwent;
 634         int allowed = 0;
 635
 636         debug3("%s", __func__);
 637
 638         if (authctxt->attempt++ != 0)
 639                 fatal("%s: multiple attempts for getpwnam", __func__);
 640
 641         username = buffer_get_string(m, NULL);
 642
 643         pwent = getpwnamallow(username);
 644
 645         authctxt->user = xstrdup(username);
 646         setproctitle("%s [priv]", pwent ? username : "unknown");
 647         xfree(username);
 648
 649         buffer_clear(m);
 650
 651         if (pwent == NULL) {
 652                 buffer_put_char(m, 0);
 653                 authctxt->pw = fakepw();
 654                 goto out;
 655         }
 656
 657         allowed = 1;
 658         authctxt->pw = pwent;
 659         authctxt->valid = 1;
 660
 661         buffer_put_char(m, 1);
 662         buffer_put_string(m, pwent, sizeof(struct passwd));
 663         buffer_put_cstring(m, pwent->pw_name);
 664         buffer_put_cstring(m, "*");
 665         buffer_put_cstring(m, pwent->pw_gecos);
 666 #ifdef HAVE_PW_CLASS_IN_PASSWD
 667         buffer_put_cstring(m, pwent->pw_class);
 668 #endif
 669         buffer_put_cstring(m, pwent->pw_dir);
 670         buffer_put_cstring(m, pwent->pw_shell);
 671
 672  out:
 673         buffer_put_string(m, &options, sizeof(options));
 674         if (options.banner != NULL)
 675                 buffer_put_cstring(m, options.banner);
 676         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 677         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 678
 679         /* For SSHv1 allow authentication now */
 680         if (!compat20)
 681                 monitor_permit_authentications(1);
 682         else {
 683                 /* Allow service/style information on the auth context */
 684                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 685                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 686         }
 687
 688 #ifdef USE_PAM
 689         if (options.use_pam)
 690                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 691 #endif
 692
 693         return (0);
 694 }
 695
 696 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 697 {
 698         char *banner;
 699
 700         buffer_clear(m);
 701         banner = auth2_read_banner();
 702         buffer_put_cstring(m, banner != NULL ? banner : "");
 703         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 704
 705         if (banner != NULL)
 706                 xfree(banner);
 707
 708         return (0);
 709 }
 710
 711 int
 712 mm_answer_authserv(int sock, Buffer *m)
 713 {
 714         monitor_permit_authentications(1);
 715
 716         authctxt->service = buffer_get_string(m, NULL);
 717         authctxt->style = buffer_get_string(m, NULL);
 718         debug3("%s: service=%s, style=%s",
 719             __func__, authctxt->service, authctxt->style);
 720
 721         if (strlen(authctxt->style) == 0) {
 722                 xfree(authctxt->style);
 723                 authctxt->style = NULL;
 724         }
 725
 726         return (0);
 727 }
 728
 729 int
 730 mm_answer_authpassword(int sock, Buffer *m)
 731 {
 732         static int call_count;
 733         char *passwd;
 734         int authenticated;
 735         u_int plen;
 736
 737         passwd = buffer_get_string(m, &plen);
 738         /* Only authenticate if the context is valid */
 739         authenticated = options.password_authentication &&
 740             auth_password(authctxt, passwd);
 741         memset(passwd, 0, strlen(passwd));
 742         xfree(passwd);
 743
 744         buffer_clear(m);
 745         buffer_put_int(m, authenticated);
 746
 747         debug3("%s: sending result %d", __func__, authenticated);
 748         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 749
 750         call_count++;
 751         if (plen == 0 && call_count == 1)
 752                 auth_method = "none";
 753         else
 754                 auth_method = "password";
 755
 756         /* Causes monitor loop to terminate if authenticated */
 757         return (authenticated);
 758 }
 759
 760 #ifdef BSD_AUTH
 761 int
 762 mm_answer_bsdauthquery(int sock, Buffer *m)
 763 {
 764         char *name, *infotxt;
 765         u_int numprompts;
 766         u_int *echo_on;
 767         char **prompts;
 768         u_int success;
 769
 770         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 771             &prompts, &echo_on) < 0 ? 0 : 1;
 772
 773         buffer_clear(m);
 774         buffer_put_int(m, success);
 775         if (success)
 776                 buffer_put_cstring(m, prompts[0]);
 777
 778         debug3("%s: sending challenge success: %u", __func__, success);
 779         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 780
 781         if (success) {
 782                 xfree(name);
 783                 xfree(infotxt);
 784                 xfree(prompts);
 785                 xfree(echo_on);
 786         }
 787
 788         return (0);
 789 }
 790
 791 int
 792 mm_answer_bsdauthrespond(int sock, Buffer *m)
 793 {
 794         char *response;
 795         int authok;
 796
 797         if (authctxt->as == 0)
 798                 fatal("%s: no bsd auth session", __func__);
 799
 800         response = buffer_get_string(m, NULL);
 801         authok = options.challenge_response_authentication &&
 802             auth_userresponse(authctxt->as, response, 0);
 803         authctxt->as = NULL;
 804         debug3("%s: <%s> = <%d>", __func__, response, authok);
 805         xfree(response);
 806
 807         buffer_clear(m);
 808         buffer_put_int(m, authok);
 809
 810         debug3("%s: sending authenticated: %d", __func__, authok);
 811         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 812
 813         auth_method = "bsdauth";
 814
 815         return (authok != 0);
 816 }
 817 #endif
 818
 819 #ifdef SKEY
 820 int
 821 mm_answer_skeyquery(int sock, Buffer *m)
 822 {
 823         struct skey skey;
 824         char challenge[1024];
 825         u_int success;
 826
 827         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 828             sizeof(challenge)) < 0 ? 0 : 1;
 829
 830         buffer_clear(m);
 831         buffer_put_int(m, success);
 832         if (success)
 833                 buffer_put_cstring(m, challenge);
 834
 835         debug3("%s: sending challenge success: %u", __func__, success);
 836         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 837
 838         return (0);
 839 }
 840
 841 int
 842 mm_answer_skeyrespond(int sock, Buffer *m)
 843 {
 844         char *response;
 845         int authok;
 846
 847         response = buffer_get_string(m, NULL);
 848
 849         authok = (options.challenge_response_authentication &&
 850             authctxt->valid &&
 851             skey_haskey(authctxt->pw->pw_name) == 0 &&
 852             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 853
 854         xfree(response);
 855
 856         buffer_clear(m);
 857         buffer_put_int(m, authok);
 858
 859         debug3("%s: sending authenticated: %d", __func__, authok);
 860         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 861
 862         auth_method = "skey";
 863
 864         return (authok != 0);
 865 }
 866 #endif
 867
 868 #ifdef USE_PAM
 869 int
 870 mm_answer_pam_start(int sock, Buffer *m)
 871 {
 872         if (!options.use_pam)
 873                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 874
 875         start_pam(authctxt);
 876
 877         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 878
 879         return (0);
 880 }
 881
 882 int
 883 mm_answer_pam_account(int sock, Buffer *m)
 884 {
 885         u_int ret;
 886
 887         if (!options.use_pam)
 888                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 889
 890         ret = do_pam_account();
 891
 892         buffer_put_int(m, ret);
 893         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
 894
 895         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
 896
 897         return (ret);
 898 }
 899
 900 static void *sshpam_ctxt, *sshpam_authok;
 901 extern KbdintDevice sshpam_device;
 902
 903 int
 904 mm_answer_pam_init_ctx(int sock, Buffer *m)
 905 {
 906
 907         debug3("%s", __func__);
 908         authctxt->user = buffer_get_string(m, NULL);
 909         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
 910         sshpam_authok = NULL;
 911         buffer_clear(m);
 912         if (sshpam_ctxt != NULL) {
 913                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
 914                 buffer_put_int(m, 1);
 915         } else {
 916                 buffer_put_int(m, 0);
 917         }
 918         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
 919         return (0);
 920 }
 921
 922 int
 923 mm_answer_pam_query(int sock, Buffer *m)
 924 {
 925         char *name = NULL, *info = NULL, **prompts = NULL;
 926         u_int i, num = 0, *echo_on = 0;
 927         int ret;
 928
 929         debug3("%s", __func__);
 930         sshpam_authok = NULL;
 931         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
 932         if (ret == 0 && num == 0)
 933                 sshpam_authok = sshpam_ctxt;
 934         if (num > 1 || name == NULL || info == NULL)
 935                 ret = -1;
 936         buffer_clear(m);
 937         buffer_put_int(m, ret);
 938         buffer_put_cstring(m, name);
 939         xfree(name);
 940         buffer_put_cstring(m, info);
 941         xfree(info);
 942         buffer_put_int(m, num);
 943         for (i = 0; i < num; ++i) {
 944                 buffer_put_cstring(m, prompts[i]);
 945                 xfree(prompts[i]);
 946                 buffer_put_int(m, echo_on[i]);
 947         }
 948         if (prompts != NULL)
 949                 xfree(prompts);
 950         if (echo_on != NULL)
 951                 xfree(echo_on);
 952         auth_method = "keyboard-interactive/pam";
 953         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
 954         return (0);
 955 }
 956
 957 int
 958 mm_answer_pam_respond(int sock, Buffer *m)
 959 {
 960         char **resp;
 961         u_int i, num;
 962         int ret;
 963
 964         debug3("%s", __func__);
 965         sshpam_authok = NULL;
 966         num = buffer_get_int(m);
 967         if (num > 0) {
 968                 resp = xcalloc(num, sizeof(char *));
 969                 for (i = 0; i < num; ++i)
 970                         resp[i] = buffer_get_string(m, NULL);
 971                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
 972                 for (i = 0; i < num; ++i)
 973                         xfree(resp[i]);
 974                 xfree(resp);
 975         } else {
 976                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
 977         }
 978         buffer_clear(m);
 979         buffer_put_int(m, ret);
 980         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
 981         auth_method = "keyboard-interactive/pam";
 982         if (ret == 0)
 983                 sshpam_authok = sshpam_ctxt;
 984         return (0);
 985 }
 986
 987 int
 988 mm_answer_pam_free_ctx(int sock, Buffer *m)
 989 {
 990
 991         debug3("%s", __func__);
 992         (sshpam_device.free_ctx)(sshpam_ctxt);
 993         buffer_clear(m);
 994         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
 995         auth_method = "keyboard-interactive/pam";
 996         return (sshpam_authok == sshpam_ctxt);
 997 }
 998 #endif
 999
1000 int
1001 mm_answer_keyallowed(int sock, Buffer *m)
1002 {
1003         Key *key;
1004         char *cuser, *chost;
1005         u_char *blob;
1006         u_int bloblen;
1007         enum mm_keytype type = 0;
1008         int allowed = 0;
1009
1010         debug3("%s entering", __func__);
1011
1012         type = buffer_get_int(m);
1013         cuser = buffer_get_string(m, NULL);
1014         chost = buffer_get_string(m, NULL);
1015         blob = buffer_get_string(m, &bloblen);
1016
1017         key = key_from_blob(blob, bloblen);
1018
1019         if ((compat20 && type == MM_RSAHOSTKEY) ||
1020             (!compat20 && type != MM_RSAHOSTKEY))
1021                 fatal("%s: key type and protocol mismatch", __func__);
1022
1023         debug3("%s: key_from_blob: %p", __func__, key);
1024
1025         if (key != NULL && authctxt->valid) {
1026                 switch (type) {
1027                 case MM_USERKEY:
1028                         allowed = options.pubkey_authentication &&
1029                             user_key_allowed(authctxt->pw, key);
1030                         auth_method = "publickey";
1031                         if (options.pubkey_authentication && allowed != 1)
1032                                 auth_clear_options();
1033                         break;
1034                 case MM_HOSTKEY:
1035                         allowed = options.hostbased_authentication &&
1036                             hostbased_key_allowed(authctxt->pw,
1037                             cuser, chost, key);
1038                         auth_method = "hostbased";
1039                         break;
1040                 case MM_RSAHOSTKEY:
1041                         key->type = KEY_RSA1; /* XXX */
1042                         allowed = options.rhosts_rsa_authentication &&
1043                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1044                             cuser, chost, key);
1045                         if (options.rhosts_rsa_authentication && allowed != 1)
1046                                 auth_clear_options();
1047                         auth_method = "rsa";
1048                         break;
1049                 default:
1050                         fatal("%s: unknown key type %d", __func__, type);
1051                         break;
1052                 }
1053         }
1054         if (key != NULL)
1055                 key_free(key);
1056
1057         /* clear temporarily storage (used by verify) */
1058         monitor_reset_key_state();
1059
1060         if (allowed) {
1061                 /* Save temporarily for comparison in verify */
1062                 key_blob = blob;
1063                 key_bloblen = bloblen;
1064                 key_blobtype = type;
1065                 hostbased_cuser = cuser;
1066                 hostbased_chost = chost;
1067         } else {
1068                 /* Log failed attempt */
1069                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1070                 xfree(blob);
1071                 xfree(cuser);
1072                 xfree(chost);
1073         }
1074
1075         debug3("%s: key %p is %s",
1076             __func__, key, allowed ? "allowed" : "not allowed");
1077
1078         buffer_clear(m);
1079         buffer_put_int(m, allowed);
1080         buffer_put_int(m, forced_command != NULL);
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                     (timingsafe_bcmp(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                     (timingsafe_bcmp(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             (timingsafe_bcmp(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_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1466
1467         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1468         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1469         return (0);
1470 }
1471
1472 int
1473 mm_answer_rsa_challenge(int sock, Buffer *m)
1474 {
1475         Key *key = NULL;
1476         u_char *blob;
1477         u_int blen;
1478
1479         debug3("%s entering", __func__);
1480
1481         if (!authctxt->valid)
1482                 fatal("%s: authctxt not valid", __func__);
1483         blob = buffer_get_string(m, &blen);
1484         if (!monitor_allowed_key(blob, blen))
1485                 fatal("%s: bad key, not previously allowed", __func__);
1486         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1487                 fatal("%s: key type mismatch", __func__);
1488         if ((key = key_from_blob(blob, blen)) == NULL)
1489                 fatal("%s: received bad key", __func__);
1490         if (key->type != KEY_RSA)
1491                 fatal("%s: received bad key type %d", __func__, key->type);
1492         key->type = KEY_RSA1;
1493         if (ssh1_challenge)
1494                 BN_clear_free(ssh1_challenge);
1495         ssh1_challenge = auth_rsa_generate_challenge(key);
1496
1497         buffer_clear(m);
1498         buffer_put_bignum2(m, ssh1_challenge);
1499
1500         debug3("%s sending reply", __func__);
1501         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1502
1503         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1504
1505         xfree(blob);
1506         key_free(key);
1507         return (0);
1508 }
1509
1510 int
1511 mm_answer_rsa_response(int sock, Buffer *m)
1512 {
1513         Key *key = NULL;
1514         u_char *blob, *response;
1515         u_int blen, len;
1516         int success;
1517
1518         debug3("%s entering", __func__);
1519
1520         if (!authctxt->valid)
1521                 fatal("%s: authctxt not valid", __func__);
1522         if (ssh1_challenge == NULL)
1523                 fatal("%s: no ssh1_challenge", __func__);
1524
1525         blob = buffer_get_string(m, &blen);
1526         if (!monitor_allowed_key(blob, blen))
1527                 fatal("%s: bad key, not previously allowed", __func__);
1528         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1529                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1530         if ((key = key_from_blob(blob, blen)) == NULL)
1531                 fatal("%s: received bad key", __func__);
1532         response = buffer_get_string(m, &len);
1533         if (len != 16)
1534                 fatal("%s: received bad response to challenge", __func__);
1535         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1536
1537         xfree(blob);
1538         key_free(key);
1539         xfree(response);
1540
1541         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1542
1543         /* reset state */
1544         BN_clear_free(ssh1_challenge);
1545         ssh1_challenge = NULL;
1546         monitor_reset_key_state();
1547
1548         buffer_clear(m);
1549         buffer_put_int(m, success);
1550         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1551
1552         return (success);
1553 }
1554
1555 int
1556 mm_answer_term(int sock, Buffer *req)
1557 {
1558         extern struct monitor *pmonitor;
1559         int res, status;
1560
1561         debug3("%s: tearing down sessions", __func__);
1562
1563         /* The child is terminating */
1564         session_destroy_all(&mm_session_close);
1565
1566 #ifdef USE_PAM
1567         if (options.use_pam)
1568                 sshpam_cleanup();
1569 #endif
1570
1571         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1572                 if (errno != EINTR)
1573                         exit(1);
1574
1575         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1576
1577         /* Terminate process */
1578         exit(res);
1579 }
1580
1581 #ifdef SSH_AUDIT_EVENTS
1582 /* Report that an audit event occurred */
1583 int
1584 mm_answer_audit_event(int socket, Buffer *m)
1585 {
1586         ssh_audit_event_t event;
1587
1588         debug3("%s entering", __func__);
1589
1590         event = buffer_get_int(m);
1591         switch(event) {
1592         case SSH_AUTH_FAIL_PUBKEY:
1593         case SSH_AUTH_FAIL_HOSTBASED:
1594         case SSH_AUTH_FAIL_GSSAPI:
1595         case SSH_LOGIN_EXCEED_MAXTRIES:
1596         case SSH_LOGIN_ROOT_DENIED:
1597         case SSH_CONNECTION_CLOSE:
1598         case SSH_INVALID_USER:
1599                 audit_event(event);
1600                 break;
1601         default:
1602                 fatal("Audit event type %d not permitted", event);
1603         }
1604
1605         return (0);
1606 }
1607
1608 int
1609 mm_answer_audit_command(int socket, Buffer *m)
1610 {
1611         u_int len;
1612         char *cmd;
1613
1614         debug3("%s entering", __func__);
1615         cmd = buffer_get_string(m, &len);
1616         /* sanity check command, if so how? */
1617         audit_run_command(cmd);
1618         xfree(cmd);
1619         return (0);
1620 }
1621 #endif /* SSH_AUDIT_EVENTS */
1622
1623 void
1624 monitor_apply_keystate(struct monitor *pmonitor)
1625 {
1626         if (compat20) {
1627                 set_newkeys(MODE_IN);
1628                 set_newkeys(MODE_OUT);
1629         } else {
1630                 packet_set_protocol_flags(child_state.ssh1protoflags);
1631                 packet_set_encryption_key(child_state.ssh1key,
1632                     child_state.ssh1keylen, child_state.ssh1cipher);
1633                 xfree(child_state.ssh1key);
1634         }
1635
1636         /* for rc4 and other stateful ciphers */
1637         packet_set_keycontext(MODE_OUT, child_state.keyout);
1638         xfree(child_state.keyout);
1639         packet_set_keycontext(MODE_IN, child_state.keyin);
1640         xfree(child_state.keyin);
1641
1642         if (!compat20) {
1643                 packet_set_iv(MODE_OUT, child_state.ivout);
1644                 xfree(child_state.ivout);
1645                 packet_set_iv(MODE_IN, child_state.ivin);
1646                 xfree(child_state.ivin);
1647         }
1648
1649         memcpy(&incoming_stream, &child_state.incoming,
1650             sizeof(incoming_stream));
1651         memcpy(&outgoing_stream, &child_state.outgoing,
1652             sizeof(outgoing_stream));
1653
1654         /* Update with new address */
1655         if (options.compression)
1656                 mm_init_compression(pmonitor->m_zlib);
1657
1658         /* Network I/O buffers */
1659         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1660         buffer_clear(packet_get_input());
1661         buffer_append(packet_get_input(), child_state.input, child_state.ilen);
1662         memset(child_state.input, 0, child_state.ilen);
1663         xfree(child_state.input);
1664
1665         buffer_clear(packet_get_output());
1666         buffer_append(packet_get_output(), child_state.output,
1667                       child_state.olen);
1668         memset(child_state.output, 0, child_state.olen);
1669         xfree(child_state.output);
1670
1671         /* Roaming */
1672         if (compat20)
1673                 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes);
1674 }
1675
1676 static Kex *
1677 mm_get_kex(Buffer *m)
1678 {
1679         Kex *kex;
1680         void *blob;
1681         u_int bloblen;
1682
1683         kex = xcalloc(1, sizeof(*kex));
1684         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1685         if (session_id2 == NULL ||
1686             kex->session_id_len != session_id2_len ||
1687             timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0)
1688                 fatal("mm_get_get: internal error: bad session id");
1689         kex->we_need = buffer_get_int(m);
1690         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1691         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1692         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1693         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1694         kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1695         kex->server = 1;
1696         kex->hostkey_type = buffer_get_int(m);
1697         kex->kex_type = buffer_get_int(m);
1698         blob = buffer_get_string(m, &bloblen);
1699         buffer_init(&kex->my);
1700         buffer_append(&kex->my, blob, bloblen);
1701         xfree(blob);
1702         blob = buffer_get_string(m, &bloblen);
1703         buffer_init(&kex->peer);
1704         buffer_append(&kex->peer, blob, bloblen);
1705         xfree(blob);
1706         kex->done = 1;
1707         kex->flags = buffer_get_int(m);
1708         kex->client_version_string = buffer_get_string(m, NULL);
1709         kex->server_version_string = buffer_get_string(m, NULL);
1710         kex->load_host_public_key=&get_hostkey_public_by_type;
1711         kex->load_host_private_key=&get_hostkey_private_by_type;
1712         kex->host_key_index=&get_hostkey_index;
1713
1714         return (kex);
1715 }
1716
1717 /* This function requries careful sanity checking */
1718
1719 void
1720 mm_get_keystate(struct monitor *pmonitor)
1721 {
1722         Buffer m;
1723         u_char *blob, *p;
1724         u_int bloblen, plen;
1725         u_int32_t seqnr, packets;
1726         u_int64_t blocks, bytes;
1727
1728         debug3("%s: Waiting for new keys", __func__);
1729
1730         buffer_init(&m);
1731         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1732         if (!compat20) {
1733                 child_state.ssh1protoflags = buffer_get_int(&m);
1734                 child_state.ssh1cipher = buffer_get_int(&m);
1735                 child_state.ssh1key = buffer_get_string(&m,
1736                     &child_state.ssh1keylen);
1737                 child_state.ivout = buffer_get_string(&m,
1738                     &child_state.ivoutlen);
1739                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1740                 goto skip;
1741         } else {
1742                 /* Get the Kex for rekeying */
1743                 *pmonitor->m_pkex = mm_get_kex(&m);
1744         }
1745
1746         blob = buffer_get_string(&m, &bloblen);
1747         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1748         xfree(blob);
1749
1750         debug3("%s: Waiting for second key", __func__);
1751         blob = buffer_get_string(&m, &bloblen);
1752         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1753         xfree(blob);
1754
1755         /* Now get sequence numbers for the packets */
1756         seqnr = buffer_get_int(&m);
1757         blocks = buffer_get_int64(&m);
1758         packets = buffer_get_int(&m);
1759         bytes = buffer_get_int64(&m);
1760         packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1761         seqnr = buffer_get_int(&m);
1762         blocks = buffer_get_int64(&m);
1763         packets = buffer_get_int(&m);
1764         bytes = buffer_get_int64(&m);
1765         packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1766
1767  skip:
1768         /* Get the key context */
1769         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1770         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1771
1772         debug3("%s: Getting compression state", __func__);
1773         /* Get compression state */
1774         p = buffer_get_string(&m, &plen);
1775         if (plen != sizeof(child_state.outgoing))
1776                 fatal("%s: bad request size", __func__);
1777         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1778         xfree(p);
1779
1780         p = buffer_get_string(&m, &plen);
1781         if (plen != sizeof(child_state.incoming))
1782                 fatal("%s: bad request size", __func__);
1783         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1784         xfree(p);
1785
1786         /* Network I/O buffers */
1787         debug3("%s: Getting Network I/O buffers", __func__);
1788         child_state.input = buffer_get_string(&m, &child_state.ilen);
1789         child_state.output = buffer_get_string(&m, &child_state.olen);
1790
1791         /* Roaming */
1792         if (compat20) {
1793                 child_state.sent_bytes = buffer_get_int64(&m);
1794                 child_state.recv_bytes = buffer_get_int64(&m);
1795         }
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 */