crypto/openssh/monitor.c

   1 /* $OpenBSD: monitor.c,v 1.115 2011/06/23 23:35:42 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 #ifdef HAVE_POLL_H
  48 #include <poll.h>
  49 #else
  50 # ifdef HAVE_SYS_POLL_H
  51 #  include <sys/poll.h>
  52 # endif
  53 #endif
  54
  55 #ifdef SKEY
  56 #include <skey.h>
  57 #endif
  58
  59 #include <openssl/dh.h>
  60
  61 #include "openbsd-compat/sys-queue.h"
  62 #include "atomicio.h"
  63 #include "xmalloc.h"
  64 #include "ssh.h"
  65 #include "key.h"
  66 #include "buffer.h"
  67 #include "hostfile.h"
  68 #include "auth.h"
  69 #include "cipher.h"
  70 #include "kex.h"
  71 #include "dh.h"
  72 #ifdef TARGET_OS_MAC    /* XXX Broken krb5 headers on Mac */
  73 #undef TARGET_OS_MAC
  74 #include "zlib.h"
  75 #define TARGET_OS_MAC 1
  76 #else
  77 #include "zlib.h"
  78 #endif
  79 #include "packet.h"
  80 #include "auth-options.h"
  81 #include "sshpty.h"
  82 #include "channels.h"
  83 #include "session.h"
  84 #include "sshlogin.h"
  85 #include "canohost.h"
  86 #include "log.h"
  87 #include "servconf.h"
  88 #include "monitor.h"
  89 #include "monitor_mm.h"
  90 #ifdef GSSAPI
  91 #include "ssh-gss.h"
  92 #endif
  93 #include "monitor_wrap.h"
  94 #include "monitor_fdpass.h"
  95 #include "misc.h"
  96 #include "compat.h"
  97 #include "ssh2.h"
  98 #include "jpake.h"
  99 #include "roaming.h"
 100
 101 #ifdef GSSAPI
 102 static Gssctxt *gsscontext = NULL;
 103 #endif
 104
 105 /* Imports */
 106 extern ServerOptions options;
 107 extern u_int utmp_len;
 108 extern Newkeys *current_keys[];
 109 extern z_stream incoming_stream;
 110 extern z_stream outgoing_stream;
 111 extern u_char session_id[];
 112 extern Buffer auth_debug;
 113 extern int auth_debug_init;
 114 extern Buffer loginmsg;
 115
 116 /* State exported from the child */
 117
 118 struct {
 119         z_stream incoming;
 120         z_stream outgoing;
 121         u_char *keyin;
 122         u_int keyinlen;
 123         u_char *keyout;
 124         u_int keyoutlen;
 125         u_char *ivin;
 126         u_int ivinlen;
 127         u_char *ivout;
 128         u_int ivoutlen;
 129         u_char *ssh1key;
 130         u_int ssh1keylen;
 131         int ssh1cipher;
 132         int ssh1protoflags;
 133         u_char *input;
 134         u_int ilen;
 135         u_char *output;
 136         u_int olen;
 137         u_int64_t sent_bytes;
 138         u_int64_t recv_bytes;
 139 } child_state;
 140
 141 /* Functions on the monitor that answer unprivileged requests */
 142
 143 int mm_answer_moduli(int, Buffer *);
 144 int mm_answer_sign(int, Buffer *);
 145 int mm_answer_pwnamallow(int, Buffer *);
 146 int mm_answer_auth2_read_banner(int, Buffer *);
 147 int mm_answer_authserv(int, Buffer *);
 148 int mm_answer_authpassword(int, Buffer *);
 149 int mm_answer_bsdauthquery(int, Buffer *);
 150 int mm_answer_bsdauthrespond(int, Buffer *);
 151 int mm_answer_skeyquery(int, Buffer *);
 152 int mm_answer_skeyrespond(int, Buffer *);
 153 int mm_answer_keyallowed(int, Buffer *);
 154 int mm_answer_keyverify(int, Buffer *);
 155 int mm_answer_pty(int, Buffer *);
 156 int mm_answer_pty_cleanup(int, Buffer *);
 157 int mm_answer_term(int, Buffer *);
 158 int mm_answer_rsa_keyallowed(int, Buffer *);
 159 int mm_answer_rsa_challenge(int, Buffer *);
 160 int mm_answer_rsa_response(int, Buffer *);
 161 int mm_answer_sesskey(int, Buffer *);
 162 int mm_answer_sessid(int, Buffer *);
 163 int mm_answer_jpake_get_pwdata(int, Buffer *);
 164 int mm_answer_jpake_step1(int, Buffer *);
 165 int mm_answer_jpake_step2(int, Buffer *);
 166 int mm_answer_jpake_key_confirm(int, Buffer *);
 167 int mm_answer_jpake_check_confirm(int, Buffer *);
 168
 169 #ifdef USE_PAM
 170 int mm_answer_pam_start(int, Buffer *);
 171 int mm_answer_pam_account(int, Buffer *);
 172 int mm_answer_pam_init_ctx(int, Buffer *);
 173 int mm_answer_pam_query(int, Buffer *);
 174 int mm_answer_pam_respond(int, Buffer *);
 175 int mm_answer_pam_free_ctx(int, Buffer *);
 176 #endif
 177
 178 #ifdef GSSAPI
 179 int mm_answer_gss_setup_ctx(int, Buffer *);
 180 int mm_answer_gss_accept_ctx(int, Buffer *);
 181 int mm_answer_gss_userok(int, Buffer *);
 182 int mm_answer_gss_checkmic(int, Buffer *);
 183 #endif
 184
 185 #ifdef SSH_AUDIT_EVENTS
 186 int mm_answer_audit_event(int, Buffer *);
 187 int mm_answer_audit_command(int, Buffer *);
 188 #endif
 189
 190 static int monitor_read_log(struct monitor *);
 191
 192 static Authctxt *authctxt;
 193 static BIGNUM *ssh1_challenge = NULL;   /* used for ssh1 rsa auth */
 194
 195 /* local state for key verify */
 196 static u_char *key_blob = NULL;
 197 static u_int key_bloblen = 0;
 198 static int key_blobtype = MM_NOKEY;
 199 static char *hostbased_cuser = NULL;
 200 static char *hostbased_chost = NULL;
 201 static char *auth_method = "unknown";
 202 static u_int session_id2_len = 0;
 203 static u_char *session_id2 = NULL;
 204 static pid_t monitor_child_pid;
 205
 206 struct mon_table {
 207         enum monitor_reqtype type;
 208         int flags;
 209         int (*f)(int, Buffer *);
 210 };
 211
 212 #define MON_ISAUTH      0x0004  /* Required for Authentication */
 213 #define MON_AUTHDECIDE  0x0008  /* Decides Authentication */
 214 #define MON_ONCE        0x0010  /* Disable after calling */
 215 #define MON_ALOG        0x0020  /* Log auth attempt without authenticating */
 216
 217 #define MON_AUTH        (MON_ISAUTH|MON_AUTHDECIDE)
 218
 219 #define MON_PERMIT      0x1000  /* Request is permitted */
 220
 221 struct mon_table mon_dispatch_proto20[] = {
 222     {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
 223     {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
 224     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 225     {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
 226     {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
 227     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 228 #ifdef USE_PAM
 229     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 230     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 231     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 232     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 233     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 234     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 235 #endif
 236 #ifdef SSH_AUDIT_EVENTS
 237     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 238 #endif
 239 #ifdef BSD_AUTH
 240     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 241     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 242 #endif
 243 #ifdef SKEY
 244     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 245     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 246 #endif
 247     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
 248     {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
 249 #ifdef GSSAPI
 250     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
 251     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
 252     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
 253     {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 254 #endif
 255 #ifdef JPAKE
 256     {MONITOR_REQ_JPAKE_GET_PWDATA, MON_ONCE, mm_answer_jpake_get_pwdata},
 257     {MONITOR_REQ_JPAKE_STEP1, MON_ISAUTH, mm_answer_jpake_step1},
 258     {MONITOR_REQ_JPAKE_STEP2, MON_ONCE, mm_answer_jpake_step2},
 259     {MONITOR_REQ_JPAKE_KEY_CONFIRM, MON_ONCE, mm_answer_jpake_key_confirm},
 260     {MONITOR_REQ_JPAKE_CHECK_CONFIRM, MON_AUTH, mm_answer_jpake_check_confirm},
 261 #endif
 262     {0, 0, NULL}
 263 };
 264
 265 struct mon_table mon_dispatch_postauth20[] = {
 266     {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
 267     {MONITOR_REQ_SIGN, 0, mm_answer_sign},
 268     {MONITOR_REQ_PTY, 0, mm_answer_pty},
 269     {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
 270     {MONITOR_REQ_TERM, 0, mm_answer_term},
 271 #ifdef SSH_AUDIT_EVENTS
 272     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 273     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
 274 #endif
 275     {0, 0, NULL}
 276 };
 277
 278 struct mon_table mon_dispatch_proto15[] = {
 279     {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
 280     {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
 281     {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
 282     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 283     {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
 284     {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
 285     {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
 286     {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
 287 #ifdef BSD_AUTH
 288     {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
 289     {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
 290 #endif
 291 #ifdef SKEY
 292     {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
 293     {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
 294 #endif
 295 #ifdef USE_PAM
 296     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
 297     {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
 298     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
 299     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
 300     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
 301     {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
 302 #endif
 303 #ifdef SSH_AUDIT_EVENTS
 304     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 305 #endif
 306     {0, 0, NULL}
 307 };
 308
 309 struct mon_table mon_dispatch_postauth15[] = {
 310     {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
 311     {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
 312     {MONITOR_REQ_TERM, 0, mm_answer_term},
 313 #ifdef SSH_AUDIT_EVENTS
 314     {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
 315     {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
 316 #endif
 317     {0, 0, NULL}
 318 };
 319
 320 struct mon_table *mon_dispatch;
 321
 322 /* Specifies if a certain message is allowed at the moment */
 323
 324 static void
 325 monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
 326 {
 327         while (ent->f != NULL) {
 328                 if (ent->type == type) {
 329                         ent->flags &= ~MON_PERMIT;
 330                         ent->flags |= permit ? MON_PERMIT : 0;
 331                         return;
 332                 }
 333                 ent++;
 334         }
 335 }
 336
 337 static void
 338 monitor_permit_authentications(int permit)
 339 {
 340         struct mon_table *ent = mon_dispatch;
 341
 342         while (ent->f != NULL) {
 343                 if (ent->flags & MON_AUTH) {
 344                         ent->flags &= ~MON_PERMIT;
 345                         ent->flags |= permit ? MON_PERMIT : 0;
 346                 }
 347                 ent++;
 348         }
 349 }
 350
 351 void
 352 monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
 353 {
 354         struct mon_table *ent;
 355         int authenticated = 0;
 356
 357         debug3("preauth child monitor started");
 358
 359         close(pmonitor->m_recvfd);
 360         close(pmonitor->m_log_sendfd);
 361         pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
 362
 363         authctxt = _authctxt;
 364         memset(authctxt, 0, sizeof(*authctxt));
 365
 366         authctxt->loginmsg = &loginmsg;
 367
 368         if (compat20) {
 369                 mon_dispatch = mon_dispatch_proto20;
 370
 371                 /* Permit requests for moduli and signatures */
 372                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 373                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 374         } else {
 375                 mon_dispatch = mon_dispatch_proto15;
 376
 377                 monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
 378         }
 379
 380         /* The first few requests do not require asynchronous access */
 381         while (!authenticated) {
 382                 auth_method = "unknown";
 383                 authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1);
 384                 if (authenticated) {
 385                         if (!(ent->flags & MON_AUTHDECIDE))
 386                                 fatal("%s: unexpected authentication from %d",
 387                                     __func__, ent->type);
 388                         if (authctxt->pw->pw_uid == 0 &&
 389                             !auth_root_allowed(auth_method))
 390                                 authenticated = 0;
 391 #ifdef USE_PAM
 392                         /* PAM needs to perform account checks after auth */
 393                         if (options.use_pam && authenticated) {
 394                                 Buffer m;
 395
 396                                 buffer_init(&m);
 397                                 mm_request_receive_expect(pmonitor->m_sendfd,
 398                                     MONITOR_REQ_PAM_ACCOUNT, &m);
 399                                 authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
 400                                 buffer_free(&m);
 401                         }
 402 #endif
 403                 }
 404
 405                 if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
 406                         auth_log(authctxt, authenticated, auth_method,
 407                             compat20 ? " ssh2" : "");
 408                         if (!authenticated)
 409                                 authctxt->failures++;
 410                 }
 411 #ifdef JPAKE
 412                 /* Cleanup JPAKE context after authentication */
 413                 if (ent->flags & MON_AUTHDECIDE) {
 414                         if (authctxt->jpake_ctx != NULL) {
 415                                 jpake_free(authctxt->jpake_ctx);
 416                                 authctxt->jpake_ctx = NULL;
 417                         }
 418                 }
 419 #endif
 420         }
 421
 422         /* Drain any buffered messages from the child */
 423         while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
 424                 ;
 425
 426         if (!authctxt->valid)
 427                 fatal("%s: authenticated invalid user", __func__);
 428         if (strcmp(auth_method, "unknown") == 0)
 429                 fatal("%s: authentication method name unknown", __func__);
 430
 431         debug("%s: %s has been authenticated by privileged process",
 432             __func__, authctxt->user);
 433
 434         mm_get_keystate(pmonitor);
 435
 436         close(pmonitor->m_sendfd);
 437         close(pmonitor->m_log_recvfd);
 438         pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
 439 }
 440
 441 static void
 442 monitor_set_child_handler(pid_t pid)
 443 {
 444         monitor_child_pid = pid;
 445 }
 446
 447 static void
 448 monitor_child_handler(int sig)
 449 {
 450         kill(monitor_child_pid, sig);
 451 }
 452
 453 void
 454 monitor_child_postauth(struct monitor *pmonitor)
 455 {
 456         close(pmonitor->m_recvfd);
 457         pmonitor->m_recvfd = -1;
 458
 459         monitor_set_child_handler(pmonitor->m_pid);
 460         signal(SIGHUP, &monitor_child_handler);
 461         signal(SIGTERM, &monitor_child_handler);
 462         signal(SIGINT, &monitor_child_handler);
 463
 464         if (compat20) {
 465                 mon_dispatch = mon_dispatch_postauth20;
 466
 467                 /* Permit requests for moduli and signatures */
 468                 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
 469                 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
 470                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 471         } else {
 472                 mon_dispatch = mon_dispatch_postauth15;
 473                 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
 474         }
 475         if (!no_pty_flag) {
 476                 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
 477                 monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
 478         }
 479
 480         for (;;)
 481                 monitor_read(pmonitor, mon_dispatch, NULL);
 482
 483         close(pmonitor->m_sendfd);
 484         pmonitor->m_sendfd = -1;
 485 }
 486
 487 void
 488 monitor_sync(struct monitor *pmonitor)
 489 {
 490         if (options.compression) {
 491                 /* The member allocation is not visible, so sync it */
 492                 mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback);
 493         }
 494 }
 495
 496 static int
 497 monitor_read_log(struct monitor *pmonitor)
 498 {
 499         Buffer logmsg;
 500         u_int len, level;
 501         char *msg;
 502
 503         buffer_init(&logmsg);
 504
 505         /* Read length */
 506         buffer_append_space(&logmsg, 4);
 507         if (atomicio(read, pmonitor->m_log_recvfd,
 508             buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) {
 509                 if (errno == EPIPE) {
 510                         debug("%s: child log fd closed", __func__);
 511                         close(pmonitor->m_log_recvfd);
 512                         pmonitor->m_log_recvfd = -1;
 513                         return -1;
 514                 }
 515                 fatal("%s: log fd read: %s", __func__, strerror(errno));
 516         }
 517         len = buffer_get_int(&logmsg);
 518         if (len <= 4 || len > 8192)
 519                 fatal("%s: invalid log message length %u", __func__, len);
 520
 521         /* Read severity, message */
 522         buffer_clear(&logmsg);
 523         buffer_append_space(&logmsg, len);
 524         if (atomicio(read, pmonitor->m_log_recvfd,
 525             buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg))
 526                 fatal("%s: log fd read: %s", __func__, strerror(errno));
 527
 528         /* Log it */
 529         level = buffer_get_int(&logmsg);
 530         msg = buffer_get_string(&logmsg, NULL);
 531         if (log_level_name(level) == NULL)
 532                 fatal("%s: invalid log level %u (corrupted message?)",
 533                     __func__, level);
 534         do_log2(level, "%s [preauth]", msg);
 535
 536         buffer_free(&logmsg);
 537         xfree(msg);
 538
 539         return 0;
 540 }
 541
 542 int
 543 monitor_read(struct monitor *pmonitor, struct mon_table *ent,
 544     struct mon_table **pent)
 545 {
 546         Buffer m;
 547         int ret;
 548         u_char type;
 549         struct pollfd pfd[2];
 550
 551         for (;;) {
 552                 bzero(&pfd, sizeof(pfd));
 553                 pfd[0].fd = pmonitor->m_sendfd;
 554                 pfd[0].events = POLLIN;
 555                 pfd[1].fd = pmonitor->m_log_recvfd;
 556                 pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
 557                 if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
 558                         if (errno == EINTR || errno == EAGAIN)
 559                                 continue;
 560                         fatal("%s: poll: %s", __func__, strerror(errno));
 561                 }
 562                 if (pfd[1].revents) {
 563                         /*
 564                          * Drain all log messages before processing next
 565                          * monitor request.
 566                          */
 567                         monitor_read_log(pmonitor);
 568                         continue;
 569                 }
 570                 if (pfd[0].revents)
 571                         break;  /* Continues below */
 572         }
 573
 574         buffer_init(&m);
 575
 576         mm_request_receive(pmonitor->m_sendfd, &m);
 577         type = buffer_get_char(&m);
 578
 579         debug3("%s: checking request %d", __func__, type);
 580
 581         while (ent->f != NULL) {
 582                 if (ent->type == type)
 583                         break;
 584                 ent++;
 585         }
 586
 587         if (ent->f != NULL) {
 588                 if (!(ent->flags & MON_PERMIT))
 589                         fatal("%s: unpermitted request %d", __func__,
 590                             type);
 591                 ret = (*ent->f)(pmonitor->m_sendfd, &m);
 592                 buffer_free(&m);
 593
 594                 /* The child may use this request only once, disable it */
 595                 if (ent->flags & MON_ONCE) {
 596                         debug2("%s: %d used once, disabling now", __func__,
 597                             type);
 598                         ent->flags &= ~MON_PERMIT;
 599                 }
 600
 601                 if (pent != NULL)
 602                         *pent = ent;
 603
 604                 return ret;
 605         }
 606
 607         fatal("%s: unsupported request: %d", __func__, type);
 608
 609         /* NOTREACHED */
 610         return (-1);
 611 }
 612
 613 /* allowed key state */
 614 static int
 615 monitor_allowed_key(u_char *blob, u_int bloblen)
 616 {
 617         /* make sure key is allowed */
 618         if (key_blob == NULL || key_bloblen != bloblen ||
 619             timingsafe_bcmp(key_blob, blob, key_bloblen))
 620                 return (0);
 621         return (1);
 622 }
 623
 624 static void
 625 monitor_reset_key_state(void)
 626 {
 627         /* reset state */
 628         if (key_blob != NULL)
 629                 xfree(key_blob);
 630         if (hostbased_cuser != NULL)
 631                 xfree(hostbased_cuser);
 632         if (hostbased_chost != NULL)
 633                 xfree(hostbased_chost);
 634         key_blob = NULL;
 635         key_bloblen = 0;
 636         key_blobtype = MM_NOKEY;
 637         hostbased_cuser = NULL;
 638         hostbased_chost = NULL;
 639 }
 640
 641 int
 642 mm_answer_moduli(int sock, Buffer *m)
 643 {
 644         DH *dh;
 645         int min, want, max;
 646
 647         min = buffer_get_int(m);
 648         want = buffer_get_int(m);
 649         max = buffer_get_int(m);
 650
 651         debug3("%s: got parameters: %d %d %d",
 652             __func__, min, want, max);
 653         /* We need to check here, too, in case the child got corrupted */
 654         if (max < min || want < min || max < want)
 655                 fatal("%s: bad parameters: %d %d %d",
 656                     __func__, min, want, max);
 657
 658         buffer_clear(m);
 659
 660         dh = choose_dh(min, want, max);
 661         if (dh == NULL) {
 662                 buffer_put_char(m, 0);
 663                 return (0);
 664         } else {
 665                 /* Send first bignum */
 666                 buffer_put_char(m, 1);
 667                 buffer_put_bignum2(m, dh->p);
 668                 buffer_put_bignum2(m, dh->g);
 669
 670                 DH_free(dh);
 671         }
 672         mm_request_send(sock, MONITOR_ANS_MODULI, m);
 673         return (0);
 674 }
 675
 676 int
 677 mm_answer_sign(int sock, Buffer *m)
 678 {
 679         Key *key;
 680         u_char *p;
 681         u_char *signature;
 682         u_int siglen, datlen;
 683         int keyid;
 684
 685         debug3("%s", __func__);
 686
 687         keyid = buffer_get_int(m);
 688         p = buffer_get_string(m, &datlen);
 689
 690         /*
 691          * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
 692          * SHA384 (48 bytes) and SHA512 (64 bytes).
 693          */
 694         if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64)
 695                 fatal("%s: data length incorrect: %u", __func__, datlen);
 696
 697         /* save session id, it will be passed on the first call */
 698         if (session_id2_len == 0) {
 699                 session_id2_len = datlen;
 700                 session_id2 = xmalloc(session_id2_len);
 701                 memcpy(session_id2, p, session_id2_len);
 702         }
 703
 704         if ((key = get_hostkey_by_index(keyid)) == NULL)
 705                 fatal("%s: no hostkey from index %d", __func__, keyid);
 706         if (key_sign(key, &signature, &siglen, p, datlen) < 0)
 707                 fatal("%s: key_sign failed", __func__);
 708
 709         debug3("%s: signature %p(%u)", __func__, signature, siglen);
 710
 711         buffer_clear(m);
 712         buffer_put_string(m, signature, siglen);
 713
 714         xfree(p);
 715         xfree(signature);
 716
 717         mm_request_send(sock, MONITOR_ANS_SIGN, m);
 718
 719         /* Turn on permissions for getpwnam */
 720         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
 721
 722         return (0);
 723 }
 724
 725 /* Retrieves the password entry and also checks if the user is permitted */
 726
 727 int
 728 mm_answer_pwnamallow(int sock, Buffer *m)
 729 {
 730         char *username;
 731         struct passwd *pwent;
 732         int allowed = 0;
 733         u_int i;
 734
 735         debug3("%s", __func__);
 736
 737         if (authctxt->attempt++ != 0)
 738                 fatal("%s: multiple attempts for getpwnam", __func__);
 739
 740         username = buffer_get_string(m, NULL);
 741
 742         pwent = getpwnamallow(username);
 743
 744         authctxt->user = xstrdup(username);
 745         setproctitle("%s [priv]", pwent ? username : "unknown");
 746         xfree(username);
 747
 748         buffer_clear(m);
 749
 750         if (pwent == NULL) {
 751                 buffer_put_char(m, 0);
 752                 authctxt->pw = fakepw();
 753                 goto out;
 754         }
 755
 756         allowed = 1;
 757         authctxt->pw = pwent;
 758         authctxt->valid = 1;
 759
 760         buffer_put_char(m, 1);
 761         buffer_put_string(m, pwent, sizeof(struct passwd));
 762         buffer_put_cstring(m, pwent->pw_name);
 763         buffer_put_cstring(m, "*");
 764         buffer_put_cstring(m, pwent->pw_gecos);
 765 #ifdef HAVE_PW_CLASS_IN_PASSWD
 766         buffer_put_cstring(m, pwent->pw_class);
 767 #endif
 768         buffer_put_cstring(m, pwent->pw_dir);
 769         buffer_put_cstring(m, pwent->pw_shell);
 770
 771  out:
 772         buffer_put_string(m, &options, sizeof(options));
 773
 774 #define M_CP_STROPT(x) do { \
 775                 if (options.x != NULL) \
 776                         buffer_put_cstring(m, options.x); \
 777         } while (0)
 778 #define M_CP_STRARRAYOPT(x, nx) do { \
 779                 for (i = 0; i < options.nx; i++) \
 780                         buffer_put_cstring(m, options.x[i]); \
 781         } while (0)
 782         /* See comment in servconf.h */
 783         COPY_MATCH_STRING_OPTS();
 784 #undef M_CP_STROPT
 785 #undef M_CP_STRARRAYOPT
 786
 787         debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
 788         mm_request_send(sock, MONITOR_ANS_PWNAM, m);
 789
 790         /* For SSHv1 allow authentication now */
 791         if (!compat20)
 792                 monitor_permit_authentications(1);
 793         else {
 794                 /* Allow service/style information on the auth context */
 795                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
 796                 monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
 797         }
 798 #ifdef USE_PAM
 799         if (options.use_pam)
 800                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
 801 #endif
 802
 803         return (0);
 804 }
 805
 806 int mm_answer_auth2_read_banner(int sock, Buffer *m)
 807 {
 808         char *banner;
 809
 810         buffer_clear(m);
 811         banner = auth2_read_banner();
 812         buffer_put_cstring(m, banner != NULL ? banner : "");
 813         mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
 814
 815         if (banner != NULL)
 816                 xfree(banner);
 817
 818         return (0);
 819 }
 820
 821 int
 822 mm_answer_authserv(int sock, Buffer *m)
 823 {
 824         monitor_permit_authentications(1);
 825
 826         authctxt->service = buffer_get_string(m, NULL);
 827         authctxt->style = buffer_get_string(m, NULL);
 828         debug3("%s: service=%s, style=%s",
 829             __func__, authctxt->service, authctxt->style);
 830
 831         if (strlen(authctxt->style) == 0) {
 832                 xfree(authctxt->style);
 833                 authctxt->style = NULL;
 834         }
 835
 836         return (0);
 837 }
 838
 839 int
 840 mm_answer_authpassword(int sock, Buffer *m)
 841 {
 842         static int call_count;
 843         char *passwd;
 844         int authenticated;
 845         u_int plen;
 846
 847         passwd = buffer_get_string(m, &plen);
 848         /* Only authenticate if the context is valid */
 849         authenticated = options.password_authentication &&
 850             auth_password(authctxt, passwd);
 851         memset(passwd, 0, strlen(passwd));
 852         xfree(passwd);
 853
 854         buffer_clear(m);
 855         buffer_put_int(m, authenticated);
 856
 857         debug3("%s: sending result %d", __func__, authenticated);
 858         mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
 859
 860         call_count++;
 861         if (plen == 0 && call_count == 1)
 862                 auth_method = "none";
 863         else
 864                 auth_method = "password";
 865
 866         /* Causes monitor loop to terminate if authenticated */
 867         return (authenticated);
 868 }
 869
 870 #ifdef BSD_AUTH
 871 int
 872 mm_answer_bsdauthquery(int sock, Buffer *m)
 873 {
 874         char *name, *infotxt;
 875         u_int numprompts;
 876         u_int *echo_on;
 877         char **prompts;
 878         u_int success;
 879
 880         success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
 881             &prompts, &echo_on) < 0 ? 0 : 1;
 882
 883         buffer_clear(m);
 884         buffer_put_int(m, success);
 885         if (success)
 886                 buffer_put_cstring(m, prompts[0]);
 887
 888         debug3("%s: sending challenge success: %u", __func__, success);
 889         mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
 890
 891         if (success) {
 892                 xfree(name);
 893                 xfree(infotxt);
 894                 xfree(prompts);
 895                 xfree(echo_on);
 896         }
 897
 898         return (0);
 899 }
 900
 901 int
 902 mm_answer_bsdauthrespond(int sock, Buffer *m)
 903 {
 904         char *response;
 905         int authok;
 906
 907         if (authctxt->as == 0)
 908                 fatal("%s: no bsd auth session", __func__);
 909
 910         response = buffer_get_string(m, NULL);
 911         authok = options.challenge_response_authentication &&
 912             auth_userresponse(authctxt->as, response, 0);
 913         authctxt->as = NULL;
 914         debug3("%s: <%s> = <%d>", __func__, response, authok);
 915         xfree(response);
 916
 917         buffer_clear(m);
 918         buffer_put_int(m, authok);
 919
 920         debug3("%s: sending authenticated: %d", __func__, authok);
 921         mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
 922
 923         auth_method = "bsdauth";
 924
 925         return (authok != 0);
 926 }
 927 #endif
 928
 929 #ifdef SKEY
 930 int
 931 mm_answer_skeyquery(int sock, Buffer *m)
 932 {
 933         struct skey skey;
 934         char challenge[1024];
 935         u_int success;
 936
 937         success = _compat_skeychallenge(&skey, authctxt->user, challenge,
 938             sizeof(challenge)) < 0 ? 0 : 1;
 939
 940         buffer_clear(m);
 941         buffer_put_int(m, success);
 942         if (success)
 943                 buffer_put_cstring(m, challenge);
 944
 945         debug3("%s: sending challenge success: %u", __func__, success);
 946         mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m);
 947
 948         return (0);
 949 }
 950
 951 int
 952 mm_answer_skeyrespond(int sock, Buffer *m)
 953 {
 954         char *response;
 955         int authok;
 956
 957         response = buffer_get_string(m, NULL);
 958
 959         authok = (options.challenge_response_authentication &&
 960             authctxt->valid &&
 961             skey_haskey(authctxt->pw->pw_name) == 0 &&
 962             skey_passcheck(authctxt->pw->pw_name, response) != -1);
 963
 964         xfree(response);
 965
 966         buffer_clear(m);
 967         buffer_put_int(m, authok);
 968
 969         debug3("%s: sending authenticated: %d", __func__, authok);
 970         mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m);
 971
 972         auth_method = "skey";
 973
 974         return (authok != 0);
 975 }
 976 #endif
 977
 978 #ifdef USE_PAM
 979 int
 980 mm_answer_pam_start(int sock, Buffer *m)
 981 {
 982         if (!options.use_pam)
 983                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 984
 985         start_pam(authctxt);
 986
 987         monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 988
 989         return (0);
 990 }
 991
 992 int
 993 mm_answer_pam_account(int sock, Buffer *m)
 994 {
 995         u_int ret;
 996
 997         if (!options.use_pam)
 998                 fatal("UsePAM not set, but ended up in %s anyway", __func__);
 999
1000         ret = do_pam_account();
1001
1002         buffer_put_int(m, ret);
1003         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1004
1005         mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
1006
1007         return (ret);
1008 }
1009
1010 static void *sshpam_ctxt, *sshpam_authok;
1011 extern KbdintDevice sshpam_device;
1012
1013 int
1014 mm_answer_pam_init_ctx(int sock, Buffer *m)
1015 {
1016
1017         debug3("%s", __func__);
1018         authctxt->user = buffer_get_string(m, NULL);
1019         sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
1020         sshpam_authok = NULL;
1021         buffer_clear(m);
1022         if (sshpam_ctxt != NULL) {
1023                 monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
1024                 buffer_put_int(m, 1);
1025         } else {
1026                 buffer_put_int(m, 0);
1027         }
1028         mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
1029         return (0);
1030 }
1031
1032 int
1033 mm_answer_pam_query(int sock, Buffer *m)
1034 {
1035         char *name = NULL, *info = NULL, **prompts = NULL;
1036         u_int i, num = 0, *echo_on = 0;
1037         int ret;
1038
1039         debug3("%s", __func__);
1040         sshpam_authok = NULL;
1041         ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on);
1042         if (ret == 0 && num == 0)
1043                 sshpam_authok = sshpam_ctxt;
1044         if (num > 1 || name == NULL || info == NULL)
1045                 ret = -1;
1046         buffer_clear(m);
1047         buffer_put_int(m, ret);
1048         buffer_put_cstring(m, name);
1049         xfree(name);
1050         buffer_put_cstring(m, info);
1051         xfree(info);
1052         buffer_put_int(m, num);
1053         for (i = 0; i < num; ++i) {
1054                 buffer_put_cstring(m, prompts[i]);
1055                 xfree(prompts[i]);
1056                 buffer_put_int(m, echo_on[i]);
1057         }
1058         if (prompts != NULL)
1059                 xfree(prompts);
1060         if (echo_on != NULL)
1061                 xfree(echo_on);
1062         auth_method = "keyboard-interactive/pam";
1063         mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
1064         return (0);
1065 }
1066
1067 int
1068 mm_answer_pam_respond(int sock, Buffer *m)
1069 {
1070         char **resp;
1071         u_int i, num;
1072         int ret;
1073
1074         debug3("%s", __func__);
1075         sshpam_authok = NULL;
1076         num = buffer_get_int(m);
1077         if (num > 0) {
1078                 resp = xcalloc(num, sizeof(char *));
1079                 for (i = 0; i < num; ++i)
1080                         resp[i] = buffer_get_string(m, NULL);
1081                 ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
1082                 for (i = 0; i < num; ++i)
1083                         xfree(resp[i]);
1084                 xfree(resp);
1085         } else {
1086                 ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
1087         }
1088         buffer_clear(m);
1089         buffer_put_int(m, ret);
1090         mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
1091         auth_method = "keyboard-interactive/pam";
1092         if (ret == 0)
1093                 sshpam_authok = sshpam_ctxt;
1094         return (0);
1095 }
1096
1097 int
1098 mm_answer_pam_free_ctx(int sock, Buffer *m)
1099 {
1100
1101         debug3("%s", __func__);
1102         (sshpam_device.free_ctx)(sshpam_ctxt);
1103         buffer_clear(m);
1104         mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
1105         auth_method = "keyboard-interactive/pam";
1106         return (sshpam_authok == sshpam_ctxt);
1107 }
1108 #endif
1109
1110 int
1111 mm_answer_keyallowed(int sock, Buffer *m)
1112 {
1113         Key *key;
1114         char *cuser, *chost;
1115         u_char *blob;
1116         u_int bloblen;
1117         enum mm_keytype type = 0;
1118         int allowed = 0;
1119
1120         debug3("%s entering", __func__);
1121
1122         type = buffer_get_int(m);
1123         cuser = buffer_get_string(m, NULL);
1124         chost = buffer_get_string(m, NULL);
1125         blob = buffer_get_string(m, &bloblen);
1126
1127         key = key_from_blob(blob, bloblen);
1128
1129         if ((compat20 && type == MM_RSAHOSTKEY) ||
1130             (!compat20 && type != MM_RSAHOSTKEY))
1131                 fatal("%s: key type and protocol mismatch", __func__);
1132
1133         debug3("%s: key_from_blob: %p", __func__, key);
1134
1135         if (key != NULL && authctxt->valid) {
1136                 switch (type) {
1137                 case MM_USERKEY:
1138                         allowed = options.pubkey_authentication &&
1139                             user_key_allowed(authctxt->pw, key);
1140                         auth_method = "publickey";
1141                         if (options.pubkey_authentication && allowed != 1)
1142                                 auth_clear_options();
1143                         break;
1144                 case MM_HOSTKEY:
1145                         allowed = options.hostbased_authentication &&
1146                             hostbased_key_allowed(authctxt->pw,
1147                             cuser, chost, key);
1148                         auth_method = "hostbased";
1149                         break;
1150                 case MM_RSAHOSTKEY:
1151                         key->type = KEY_RSA1; /* XXX */
1152                         allowed = options.rhosts_rsa_authentication &&
1153                             auth_rhosts_rsa_key_allowed(authctxt->pw,
1154                             cuser, chost, key);
1155                         if (options.rhosts_rsa_authentication && allowed != 1)
1156                                 auth_clear_options();
1157                         auth_method = "rsa";
1158                         break;
1159                 default:
1160                         fatal("%s: unknown key type %d", __func__, type);
1161                         break;
1162                 }
1163         }
1164         if (key != NULL)
1165                 key_free(key);
1166
1167         /* clear temporarily storage (used by verify) */
1168         monitor_reset_key_state();
1169
1170         if (allowed) {
1171                 /* Save temporarily for comparison in verify */
1172                 key_blob = blob;
1173                 key_bloblen = bloblen;
1174                 key_blobtype = type;
1175                 hostbased_cuser = cuser;
1176                 hostbased_chost = chost;
1177         } else {
1178                 /* Log failed attempt */
1179                 auth_log(authctxt, 0, auth_method, compat20 ? " ssh2" : "");
1180                 xfree(blob);
1181                 xfree(cuser);
1182                 xfree(chost);
1183         }
1184
1185         debug3("%s: key %p is %s",
1186             __func__, key, allowed ? "allowed" : "not allowed");
1187
1188         buffer_clear(m);
1189         buffer_put_int(m, allowed);
1190         buffer_put_int(m, forced_command != NULL);
1191
1192         mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
1193
1194         if (type == MM_RSAHOSTKEY)
1195                 monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1196
1197         return (0);
1198 }
1199
1200 static int
1201 monitor_valid_userblob(u_char *data, u_int datalen)
1202 {
1203         Buffer b;
1204         char *p;
1205         u_int len;
1206         int fail = 0;
1207
1208         buffer_init(&b);
1209         buffer_append(&b, data, datalen);
1210
1211         if (datafellows & SSH_OLD_SESSIONID) {
1212                 p = buffer_ptr(&b);
1213                 len = buffer_len(&b);
1214                 if ((session_id2 == NULL) ||
1215                     (len < session_id2_len) ||
1216                     (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1217                         fail++;
1218                 buffer_consume(&b, session_id2_len);
1219         } else {
1220                 p = buffer_get_string(&b, &len);
1221                 if ((session_id2 == NULL) ||
1222                     (len != session_id2_len) ||
1223                     (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1224                         fail++;
1225                 xfree(p);
1226         }
1227         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1228                 fail++;
1229         p = buffer_get_string(&b, NULL);
1230         if (strcmp(authctxt->user, p) != 0) {
1231                 logit("wrong user name passed to monitor: expected %s != %.100s",
1232                     authctxt->user, p);
1233                 fail++;
1234         }
1235         xfree(p);
1236         buffer_skip_string(&b);
1237         if (datafellows & SSH_BUG_PKAUTH) {
1238                 if (!buffer_get_char(&b))
1239                         fail++;
1240         } else {
1241                 p = buffer_get_string(&b, NULL);
1242                 if (strcmp("publickey", p) != 0)
1243                         fail++;
1244                 xfree(p);
1245                 if (!buffer_get_char(&b))
1246                         fail++;
1247                 buffer_skip_string(&b);
1248         }
1249         buffer_skip_string(&b);
1250         if (buffer_len(&b) != 0)
1251                 fail++;
1252         buffer_free(&b);
1253         return (fail == 0);
1254 }
1255
1256 static int
1257 monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
1258     char *chost)
1259 {
1260         Buffer b;
1261         char *p;
1262         u_int len;
1263         int fail = 0;
1264
1265         buffer_init(&b);
1266         buffer_append(&b, data, datalen);
1267
1268         p = buffer_get_string(&b, &len);
1269         if ((session_id2 == NULL) ||
1270             (len != session_id2_len) ||
1271             (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
1272                 fail++;
1273         xfree(p);
1274
1275         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
1276                 fail++;
1277         p = buffer_get_string(&b, NULL);
1278         if (strcmp(authctxt->user, p) != 0) {
1279                 logit("wrong user name passed to monitor: expected %s != %.100s",
1280                     authctxt->user, p);
1281                 fail++;
1282         }
1283         xfree(p);
1284         buffer_skip_string(&b); /* service */
1285         p = buffer_get_string(&b, NULL);
1286         if (strcmp(p, "hostbased") != 0)
1287                 fail++;
1288         xfree(p);
1289         buffer_skip_string(&b); /* pkalg */
1290         buffer_skip_string(&b); /* pkblob */
1291
1292         /* verify client host, strip trailing dot if necessary */
1293         p = buffer_get_string(&b, NULL);
1294         if (((len = strlen(p)) > 0) && p[len - 1] == '.')
1295                 p[len - 1] = '\0';
1296         if (strcmp(p, chost) != 0)
1297                 fail++;
1298         xfree(p);
1299
1300         /* verify client user */
1301         p = buffer_get_string(&b, NULL);
1302         if (strcmp(p, cuser) != 0)
1303                 fail++;
1304         xfree(p);
1305
1306         if (buffer_len(&b) != 0)
1307                 fail++;
1308         buffer_free(&b);
1309         return (fail == 0);
1310 }
1311
1312 int
1313 mm_answer_keyverify(int sock, Buffer *m)
1314 {
1315         Key *key;
1316         u_char *signature, *data, *blob;
1317         u_int signaturelen, datalen, bloblen;
1318         int verified = 0;
1319         int valid_data = 0;
1320
1321         blob = buffer_get_string(m, &bloblen);
1322         signature = buffer_get_string(m, &signaturelen);
1323         data = buffer_get_string(m, &datalen);
1324
1325         if (hostbased_cuser == NULL || hostbased_chost == NULL ||
1326           !monitor_allowed_key(blob, bloblen))
1327                 fatal("%s: bad key, not previously allowed", __func__);
1328
1329         key = key_from_blob(blob, bloblen);
1330         if (key == NULL)
1331                 fatal("%s: bad public key blob", __func__);
1332
1333         switch (key_blobtype) {
1334         case MM_USERKEY:
1335                 valid_data = monitor_valid_userblob(data, datalen);
1336                 break;
1337         case MM_HOSTKEY:
1338                 valid_data = monitor_valid_hostbasedblob(data, datalen,
1339                     hostbased_cuser, hostbased_chost);
1340                 break;
1341         default:
1342                 valid_data = 0;
1343                 break;
1344         }
1345         if (!valid_data)
1346                 fatal("%s: bad signature data blob", __func__);
1347
1348         verified = key_verify(key, signature, signaturelen, data, datalen);
1349         debug3("%s: key %p signature %s",
1350             __func__, key, (verified == 1) ? "verified" : "unverified");
1351
1352         key_free(key);
1353         xfree(blob);
1354         xfree(signature);
1355         xfree(data);
1356
1357         auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased";
1358
1359         monitor_reset_key_state();
1360
1361         buffer_clear(m);
1362         buffer_put_int(m, verified);
1363         mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
1364
1365         return (verified == 1);
1366 }
1367
1368 static void
1369 mm_record_login(Session *s, struct passwd *pw)
1370 {
1371         socklen_t fromlen;
1372         struct sockaddr_storage from;
1373
1374         /*
1375          * Get IP address of client. If the connection is not a socket, let
1376          * the address be 0.0.0.0.
1377          */
1378         memset(&from, 0, sizeof(from));
1379         fromlen = sizeof(from);
1380         if (packet_connection_is_on_socket()) {
1381                 if (getpeername(packet_get_connection_in(),
1382                     (struct sockaddr *)&from, &fromlen) < 0) {
1383                         debug("getpeername: %.100s", strerror(errno));
1384                         cleanup_exit(255);
1385                 }
1386         }
1387         /* Record that there was a login on that tty from the remote host. */
1388         record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
1389             get_remote_name_or_ip(utmp_len, options.use_dns),
1390             (struct sockaddr *)&from, fromlen);
1391 }
1392
1393 static void
1394 mm_session_close(Session *s)
1395 {
1396         debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid);
1397         if (s->ttyfd != -1) {
1398                 debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd);
1399                 session_pty_cleanup2(s);
1400         }
1401         session_unused(s->self);
1402 }
1403
1404 int
1405 mm_answer_pty(int sock, Buffer *m)
1406 {
1407         extern struct monitor *pmonitor;
1408         Session *s;
1409         int res, fd0;
1410
1411         debug3("%s entering", __func__);
1412
1413         buffer_clear(m);
1414         s = session_new();
1415         if (s == NULL)
1416                 goto error;
1417         s->authctxt = authctxt;
1418         s->pw = authctxt->pw;
1419         s->pid = pmonitor->m_pid;
1420         res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
1421         if (res == 0)
1422                 goto error;
1423         pty_setowner(authctxt->pw, s->tty);
1424
1425         buffer_put_int(m, 1);
1426         buffer_put_cstring(m, s->tty);
1427
1428         /* We need to trick ttyslot */
1429         if (dup2(s->ttyfd, 0) == -1)
1430                 fatal("%s: dup2", __func__);
1431
1432         mm_record_login(s, authctxt->pw);
1433
1434         /* Now we can close the file descriptor again */
1435         close(0);
1436
1437         /* send messages generated by record_login */
1438         buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
1439         buffer_clear(&loginmsg);
1440
1441         mm_request_send(sock, MONITOR_ANS_PTY, m);
1442
1443         if (mm_send_fd(sock, s->ptyfd) == -1 ||
1444             mm_send_fd(sock, s->ttyfd) == -1)
1445                 fatal("%s: send fds failed", __func__);
1446
1447         /* make sure nothing uses fd 0 */
1448         if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
1449                 fatal("%s: open(/dev/null): %s", __func__, strerror(errno));
1450         if (fd0 != 0)
1451                 error("%s: fd0 %d != 0", __func__, fd0);
1452
1453         /* slave is not needed */
1454         close(s->ttyfd);
1455         s->ttyfd = s->ptyfd;
1456         /* no need to dup() because nobody closes ptyfd */
1457         s->ptymaster = s->ptyfd;
1458
1459         debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd);
1460
1461         return (0);
1462
1463  error:
1464         if (s != NULL)
1465                 mm_session_close(s);
1466         buffer_put_int(m, 0);
1467         mm_request_send(sock, MONITOR_ANS_PTY, m);
1468         return (0);
1469 }
1470
1471 int
1472 mm_answer_pty_cleanup(int sock, Buffer *m)
1473 {
1474         Session *s;
1475         char *tty;
1476
1477         debug3("%s entering", __func__);
1478
1479         tty = buffer_get_string(m, NULL);
1480         if ((s = session_by_tty(tty)) != NULL)
1481                 mm_session_close(s);
1482         buffer_clear(m);
1483         xfree(tty);
1484         return (0);
1485 }
1486
1487 int
1488 mm_answer_sesskey(int sock, Buffer *m)
1489 {
1490         BIGNUM *p;
1491         int rsafail;
1492
1493         /* Turn off permissions */
1494         monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
1495
1496         if ((p = BN_new()) == NULL)
1497                 fatal("%s: BN_new", __func__);
1498
1499         buffer_get_bignum2(m, p);
1500
1501         rsafail = ssh1_session_key(p);
1502
1503         buffer_clear(m);
1504         buffer_put_int(m, rsafail);
1505         buffer_put_bignum2(m, p);
1506
1507         BN_clear_free(p);
1508
1509         mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
1510
1511         /* Turn on permissions for sessid passing */
1512         monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
1513
1514         return (0);
1515 }
1516
1517 int
1518 mm_answer_sessid(int sock, Buffer *m)
1519 {
1520         int i;
1521
1522         debug3("%s entering", __func__);
1523
1524         if (buffer_len(m) != 16)
1525                 fatal("%s: bad ssh1 session id", __func__);
1526         for (i = 0; i < 16; i++)
1527                 session_id[i] = buffer_get_char(m);
1528
1529         /* Turn on permissions for getpwnam */
1530         monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
1531
1532         return (0);
1533 }
1534
1535 int
1536 mm_answer_rsa_keyallowed(int sock, Buffer *m)
1537 {
1538         BIGNUM *client_n;
1539         Key *key = NULL;
1540         u_char *blob = NULL;
1541         u_int blen = 0;
1542         int allowed = 0;
1543
1544         debug3("%s entering", __func__);
1545
1546         auth_method = "rsa";
1547         if (options.rsa_authentication && authctxt->valid) {
1548                 if ((client_n = BN_new()) == NULL)
1549                         fatal("%s: BN_new", __func__);
1550                 buffer_get_bignum2(m, client_n);
1551                 allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
1552                 BN_clear_free(client_n);
1553         }
1554         buffer_clear(m);
1555         buffer_put_int(m, allowed);
1556         buffer_put_int(m, forced_command != NULL);
1557
1558         /* clear temporarily storage (used by generate challenge) */
1559         monitor_reset_key_state();
1560
1561         if (allowed && key != NULL) {
1562                 key->type = KEY_RSA;    /* cheat for key_to_blob */
1563                 if (key_to_blob(key, &blob, &blen) == 0)
1564                         fatal("%s: key_to_blob failed", __func__);
1565                 buffer_put_string(m, blob, blen);
1566
1567                 /* Save temporarily for comparison in verify */
1568                 key_blob = blob;
1569                 key_bloblen = blen;
1570                 key_blobtype = MM_RSAUSERKEY;
1571         }
1572         if (key != NULL)
1573                 key_free(key);
1574
1575         mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
1576
1577         monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
1578         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
1579         return (0);
1580 }
1581
1582 int
1583 mm_answer_rsa_challenge(int sock, Buffer *m)
1584 {
1585         Key *key = NULL;
1586         u_char *blob;
1587         u_int blen;
1588
1589         debug3("%s entering", __func__);
1590
1591         if (!authctxt->valid)
1592                 fatal("%s: authctxt not valid", __func__);
1593         blob = buffer_get_string(m, &blen);
1594         if (!monitor_allowed_key(blob, blen))
1595                 fatal("%s: bad key, not previously allowed", __func__);
1596         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1597                 fatal("%s: key type mismatch", __func__);
1598         if ((key = key_from_blob(blob, blen)) == NULL)
1599                 fatal("%s: received bad key", __func__);
1600         if (key->type != KEY_RSA)
1601                 fatal("%s: received bad key type %d", __func__, key->type);
1602         key->type = KEY_RSA1;
1603         if (ssh1_challenge)
1604                 BN_clear_free(ssh1_challenge);
1605         ssh1_challenge = auth_rsa_generate_challenge(key);
1606
1607         buffer_clear(m);
1608         buffer_put_bignum2(m, ssh1_challenge);
1609
1610         debug3("%s sending reply", __func__);
1611         mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
1612
1613         monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
1614
1615         xfree(blob);
1616         key_free(key);
1617         return (0);
1618 }
1619
1620 int
1621 mm_answer_rsa_response(int sock, Buffer *m)
1622 {
1623         Key *key = NULL;
1624         u_char *blob, *response;
1625         u_int blen, len;
1626         int success;
1627
1628         debug3("%s entering", __func__);
1629
1630         if (!authctxt->valid)
1631                 fatal("%s: authctxt not valid", __func__);
1632         if (ssh1_challenge == NULL)
1633                 fatal("%s: no ssh1_challenge", __func__);
1634
1635         blob = buffer_get_string(m, &blen);
1636         if (!monitor_allowed_key(blob, blen))
1637                 fatal("%s: bad key, not previously allowed", __func__);
1638         if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
1639                 fatal("%s: key type mismatch: %d", __func__, key_blobtype);
1640         if ((key = key_from_blob(blob, blen)) == NULL)
1641                 fatal("%s: received bad key", __func__);
1642         response = buffer_get_string(m, &len);
1643         if (len != 16)
1644                 fatal("%s: received bad response to challenge", __func__);
1645         success = auth_rsa_verify_response(key, ssh1_challenge, response);
1646
1647         xfree(blob);
1648         key_free(key);
1649         xfree(response);
1650
1651         auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
1652
1653         /* reset state */
1654         BN_clear_free(ssh1_challenge);
1655         ssh1_challenge = NULL;
1656         monitor_reset_key_state();
1657
1658         buffer_clear(m);
1659         buffer_put_int(m, success);
1660         mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
1661
1662         return (success);
1663 }
1664
1665 int
1666 mm_answer_term(int sock, Buffer *req)
1667 {
1668         extern struct monitor *pmonitor;
1669         int res, status;
1670
1671         debug3("%s: tearing down sessions", __func__);
1672
1673         /* The child is terminating */
1674         session_destroy_all(&mm_session_close);
1675
1676 #ifdef USE_PAM
1677         if (options.use_pam)
1678                 sshpam_cleanup();
1679 #endif
1680
1681         while (waitpid(pmonitor->m_pid, &status, 0) == -1)
1682                 if (errno != EINTR)
1683                         exit(1);
1684
1685         res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
1686
1687         /* Terminate process */
1688         exit(res);
1689 }
1690
1691 #ifdef SSH_AUDIT_EVENTS
1692 /* Report that an audit event occurred */
1693 int
1694 mm_answer_audit_event(int socket, Buffer *m)
1695 {
1696         ssh_audit_event_t event;
1697
1698         debug3("%s entering", __func__);
1699
1700         event = buffer_get_int(m);
1701         switch(event) {
1702         case SSH_AUTH_FAIL_PUBKEY:
1703         case SSH_AUTH_FAIL_HOSTBASED:
1704         case SSH_AUTH_FAIL_GSSAPI:
1705         case SSH_LOGIN_EXCEED_MAXTRIES:
1706         case SSH_LOGIN_ROOT_DENIED:
1707         case SSH_CONNECTION_CLOSE:
1708         case SSH_INVALID_USER:
1709                 audit_event(event);
1710                 break;
1711         default:
1712                 fatal("Audit event type %d not permitted", event);
1713         }
1714
1715         return (0);
1716 }
1717
1718 int
1719 mm_answer_audit_command(int socket, Buffer *m)
1720 {
1721         u_int len;
1722         char *cmd;
1723
1724         debug3("%s entering", __func__);
1725         cmd = buffer_get_string(m, &len);
1726         /* sanity check command, if so how? */
1727         audit_run_command(cmd);
1728         xfree(cmd);
1729         return (0);
1730 }
1731 #endif /* SSH_AUDIT_EVENTS */
1732
1733 void
1734 monitor_apply_keystate(struct monitor *pmonitor)
1735 {
1736         if (compat20) {
1737                 set_newkeys(MODE_IN);
1738                 set_newkeys(MODE_OUT);
1739         } else {
1740                 packet_set_protocol_flags(child_state.ssh1protoflags);
1741                 packet_set_encryption_key(child_state.ssh1key,
1742                     child_state.ssh1keylen, child_state.ssh1cipher);
1743                 xfree(child_state.ssh1key);
1744         }
1745
1746         /* for rc4 and other stateful ciphers */
1747         packet_set_keycontext(MODE_OUT, child_state.keyout);
1748         xfree(child_state.keyout);
1749         packet_set_keycontext(MODE_IN, child_state.keyin);
1750         xfree(child_state.keyin);
1751
1752         if (!compat20) {
1753                 packet_set_iv(MODE_OUT, child_state.ivout);
1754                 xfree(child_state.ivout);
1755                 packet_set_iv(MODE_IN, child_state.ivin);
1756                 xfree(child_state.ivin);
1757         }
1758
1759         memcpy(&incoming_stream, &child_state.incoming,
1760             sizeof(incoming_stream));
1761         memcpy(&outgoing_stream, &child_state.outgoing,
1762             sizeof(outgoing_stream));
1763
1764         /* Update with new address */
1765         if (options.compression)
1766                 mm_init_compression(pmonitor->m_zlib);
1767
1768         /* Network I/O buffers */
1769         /* XXX inefficient for large buffers, need: buffer_init_from_string */
1770         buffer_clear(packet_get_input());
1771         buffer_append(packet_get_input(), child_state.input, child_state.ilen);
1772         memset(child_state.input, 0, child_state.ilen);
1773         xfree(child_state.input);
1774
1775         buffer_clear(packet_get_output());
1776         buffer_append(packet_get_output(), child_state.output,
1777                       child_state.olen);
1778         memset(child_state.output, 0, child_state.olen);
1779         xfree(child_state.output);
1780
1781         /* Roaming */
1782         if (compat20)
1783                 roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes);
1784 }
1785
1786 static Kex *
1787 mm_get_kex(Buffer *m)
1788 {
1789         Kex *kex;
1790         void *blob;
1791         u_int bloblen;
1792
1793         kex = xcalloc(1, sizeof(*kex));
1794         kex->session_id = buffer_get_string(m, &kex->session_id_len);
1795         if (session_id2 == NULL ||
1796             kex->session_id_len != session_id2_len ||
1797             timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0)
1798                 fatal("mm_get_get: internal error: bad session id");
1799         kex->we_need = buffer_get_int(m);
1800         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1801         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1802         kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1803         kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1804         kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1805         kex->server = 1;
1806         kex->hostkey_type = buffer_get_int(m);
1807         kex->kex_type = buffer_get_int(m);
1808         blob = buffer_get_string(m, &bloblen);
1809         buffer_init(&kex->my);
1810         buffer_append(&kex->my, blob, bloblen);
1811         xfree(blob);
1812         blob = buffer_get_string(m, &bloblen);
1813         buffer_init(&kex->peer);
1814         buffer_append(&kex->peer, blob, bloblen);
1815         xfree(blob);
1816         kex->done = 1;
1817         kex->flags = buffer_get_int(m);
1818         kex->client_version_string = buffer_get_string(m, NULL);
1819         kex->server_version_string = buffer_get_string(m, NULL);
1820         kex->load_host_public_key=&get_hostkey_public_by_type;
1821         kex->load_host_private_key=&get_hostkey_private_by_type;
1822         kex->host_key_index=&get_hostkey_index;
1823
1824         return (kex);
1825 }
1826
1827 /* This function requries careful sanity checking */
1828
1829 void
1830 mm_get_keystate(struct monitor *pmonitor)
1831 {
1832         Buffer m;
1833         u_char *blob, *p;
1834         u_int bloblen, plen;
1835         u_int32_t seqnr, packets;
1836         u_int64_t blocks, bytes;
1837
1838         debug3("%s: Waiting for new keys", __func__);
1839
1840         buffer_init(&m);
1841         mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m);
1842         if (!compat20) {
1843                 child_state.ssh1protoflags = buffer_get_int(&m);
1844                 child_state.ssh1cipher = buffer_get_int(&m);
1845                 child_state.ssh1key = buffer_get_string(&m,
1846                     &child_state.ssh1keylen);
1847                 child_state.ivout = buffer_get_string(&m,
1848                     &child_state.ivoutlen);
1849                 child_state.ivin = buffer_get_string(&m, &child_state.ivinlen);
1850                 goto skip;
1851         } else {
1852                 /* Get the Kex for rekeying */
1853                 *pmonitor->m_pkex = mm_get_kex(&m);
1854         }
1855
1856         blob = buffer_get_string(&m, &bloblen);
1857         current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen);
1858         xfree(blob);
1859
1860         debug3("%s: Waiting for second key", __func__);
1861         blob = buffer_get_string(&m, &bloblen);
1862         current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen);
1863         xfree(blob);
1864
1865         /* Now get sequence numbers for the packets */
1866         seqnr = buffer_get_int(&m);
1867         blocks = buffer_get_int64(&m);
1868         packets = buffer_get_int(&m);
1869         bytes = buffer_get_int64(&m);
1870         packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes);
1871         seqnr = buffer_get_int(&m);
1872         blocks = buffer_get_int64(&m);
1873         packets = buffer_get_int(&m);
1874         bytes = buffer_get_int64(&m);
1875         packet_set_state(MODE_IN, seqnr, blocks, packets, bytes);
1876
1877  skip:
1878         /* Get the key context */
1879         child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen);
1880         child_state.keyin  = buffer_get_string(&m, &child_state.keyinlen);
1881
1882         debug3("%s: Getting compression state", __func__);
1883         /* Get compression state */
1884         p = buffer_get_string(&m, &plen);
1885         if (plen != sizeof(child_state.outgoing))
1886                 fatal("%s: bad request size", __func__);
1887         memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing));
1888         xfree(p);
1889
1890         p = buffer_get_string(&m, &plen);
1891         if (plen != sizeof(child_state.incoming))
1892                 fatal("%s: bad request size", __func__);
1893         memcpy(&child_state.incoming, p, sizeof(child_state.incoming));
1894         xfree(p);
1895
1896         /* Network I/O buffers */
1897         debug3("%s: Getting Network I/O buffers", __func__);
1898         child_state.input = buffer_get_string(&m, &child_state.ilen);
1899         child_state.output = buffer_get_string(&m, &child_state.olen);
1900
1901         /* Roaming */
1902         if (compat20) {
1903                 child_state.sent_bytes = buffer_get_int64(&m);
1904                 child_state.recv_bytes = buffer_get_int64(&m);
1905         }
1906
1907         buffer_free(&m);
1908 }
1909
1910
1911 /* Allocation functions for zlib */
1912 void *
1913 mm_zalloc(struct mm_master *mm, u_int ncount, u_int size)
1914 {
1915         size_t len = (size_t) size * ncount;
1916         void *address;
1917
1918         if (len == 0 || ncount > SIZE_T_MAX / size)
1919                 fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size);
1920
1921         address = mm_malloc(mm, len);
1922
1923         return (address);
1924 }
1925
1926 void
1927 mm_zfree(struct mm_master *mm, void *address)
1928 {
1929         mm_free(mm, address);
1930 }
1931
1932 void
1933 mm_init_compression(struct mm_master *mm)
1934 {
1935         outgoing_stream.zalloc = (alloc_func)mm_zalloc;
1936         outgoing_stream.zfree = (free_func)mm_zfree;
1937         outgoing_stream.opaque = mm;
1938
1939         incoming_stream.zalloc = (alloc_func)mm_zalloc;
1940         incoming_stream.zfree = (free_func)mm_zfree;
1941         incoming_stream.opaque = mm;
1942 }
1943
1944 /* XXX */
1945
1946 #define FD_CLOSEONEXEC(x) do { \
1947         if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
1948                 fatal("fcntl(%d, F_SETFD)", x); \
1949 } while (0)
1950
1951 static void
1952 monitor_openfds(struct monitor *mon, int do_logfds)
1953 {
1954         int pair[2];
1955
1956         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
1957                 fatal("%s: socketpair: %s", __func__, strerror(errno));
1958         FD_CLOSEONEXEC(pair[0]);
1959         FD_CLOSEONEXEC(pair[1]);
1960         mon->m_recvfd = pair[0];
1961         mon->m_sendfd = pair[1];
1962
1963         if (do_logfds) {
1964                 if (pipe(pair) == -1)
1965                         fatal("%s: pipe: %s", __func__, strerror(errno));
1966                 FD_CLOSEONEXEC(pair[0]);
1967                 FD_CLOSEONEXEC(pair[1]);
1968                 mon->m_log_recvfd = pair[0];
1969                 mon->m_log_sendfd = pair[1];
1970         } else
1971                 mon->m_log_recvfd = mon->m_log_sendfd = -1;
1972 }
1973
1974 #define MM_MEMSIZE      65536
1975
1976 struct monitor *
1977 monitor_init(void)
1978 {
1979         struct monitor *mon;
1980
1981         mon = xcalloc(1, sizeof(*mon));
1982
1983         monitor_openfds(mon, 1);
1984
1985         /* Used to share zlib space across processes */
1986         if (options.compression) {
1987                 mon->m_zback = mm_create(NULL, MM_MEMSIZE);
1988                 mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE);
1989
1990                 /* Compression needs to share state across borders */
1991                 mm_init_compression(mon->m_zlib);
1992         }
1993
1994         return mon;
1995 }
1996
1997 void
1998 monitor_reinit(struct monitor *mon)
1999 {
2000         monitor_openfds(mon, 0);
2001 }
2002
2003 #ifdef GSSAPI
2004 int
2005 mm_answer_gss_setup_ctx(int sock, Buffer *m)
2006 {
2007         gss_OID_desc goid;
2008         OM_uint32 major;
2009         u_int len;
2010
2011         goid.elements = buffer_get_string(m, &len);
2012         goid.length = len;
2013
2014         major = ssh_gssapi_server_ctx(&gsscontext, &goid);
2015
2016         xfree(goid.elements);
2017
2018         buffer_clear(m);
2019         buffer_put_int(m, major);
2020
2021         mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
2022
2023         /* Now we have a context, enable the step */
2024         monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
2025
2026         return (0);
2027 }
2028
2029 int
2030 mm_answer_gss_accept_ctx(int sock, Buffer *m)
2031 {
2032         gss_buffer_desc in;
2033         gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
2034         OM_uint32 major, minor;
2035         OM_uint32 flags = 0; /* GSI needs this */
2036         u_int len;
2037
2038         in.value = buffer_get_string(m, &len);
2039         in.length = len;
2040         major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
2041         xfree(in.value);
2042
2043         buffer_clear(m);
2044         buffer_put_int(m, major);
2045         buffer_put_string(m, out.value, out.length);
2046         buffer_put_int(m, flags);
2047         mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
2048
2049         gss_release_buffer(&minor, &out);
2050
2051         if (major == GSS_S_COMPLETE) {
2052                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
2053                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2054                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
2055         }
2056         return (0);
2057 }
2058
2059 int
2060 mm_answer_gss_checkmic(int sock, Buffer *m)
2061 {
2062         gss_buffer_desc gssbuf, mic;
2063         OM_uint32 ret;
2064         u_int len;
2065
2066         gssbuf.value = buffer_get_string(m, &len);
2067         gssbuf.length = len;
2068         mic.value = buffer_get_string(m, &len);
2069         mic.length = len;
2070
2071         ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
2072
2073         xfree(gssbuf.value);
2074         xfree(mic.value);
2075
2076         buffer_clear(m);
2077         buffer_put_int(m, ret);
2078
2079         mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
2080
2081         if (!GSS_ERROR(ret))
2082                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2083
2084         return (0);
2085 }
2086
2087 int
2088 mm_answer_gss_userok(int sock, Buffer *m)
2089 {
2090         int authenticated;
2091
2092         authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2093
2094         buffer_clear(m);
2095         buffer_put_int(m, authenticated);
2096
2097         debug3("%s: sending result %d", __func__, authenticated);
2098         mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
2099
2100         auth_method = "gssapi-with-mic";
2101
2102         /* Monitor loop will terminate if authenticated */
2103         return (authenticated);
2104 }
2105 #endif /* GSSAPI */
2106
2107 #ifdef JPAKE
2108 int
2109 mm_answer_jpake_step1(int sock, Buffer *m)
2110 {
2111         struct jpake_ctx *pctx;
2112         u_char *x3_proof, *x4_proof;
2113         u_int x3_proof_len, x4_proof_len;
2114
2115         if (!options.zero_knowledge_password_authentication)
2116                 fatal("zero_knowledge_password_authentication disabled");
2117
2118         if (authctxt->jpake_ctx != NULL)
2119                 fatal("%s: authctxt->jpake_ctx already set (%p)",
2120                     __func__, authctxt->jpake_ctx);
2121         authctxt->jpake_ctx = pctx = jpake_new();
2122
2123         jpake_step1(pctx->grp,
2124             &pctx->server_id, &pctx->server_id_len,
2125             &pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4,
2126             &x3_proof, &x3_proof_len,
2127             &x4_proof, &x4_proof_len);
2128
2129         JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__));
2130
2131         buffer_clear(m);
2132
2133         buffer_put_string(m, pctx->server_id, pctx->server_id_len);
2134         buffer_put_bignum2(m, pctx->g_x3);
2135         buffer_put_bignum2(m, pctx->g_x4);
2136         buffer_put_string(m, x3_proof, x3_proof_len);
2137         buffer_put_string(m, x4_proof, x4_proof_len);
2138
2139         debug3("%s: sending step1", __func__);
2140         mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m);
2141
2142         bzero(x3_proof, x3_proof_len);
2143         bzero(x4_proof, x4_proof_len);
2144         xfree(x3_proof);
2145         xfree(x4_proof);
2146
2147         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1);
2148         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0);
2149
2150         return 0;
2151 }
2152
2153 int
2154 mm_answer_jpake_get_pwdata(int sock, Buffer *m)
2155 {
2156         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2157         char *hash_scheme, *salt;
2158
2159         if (pctx == NULL)
2160                 fatal("%s: pctx == NULL", __func__);
2161
2162         auth2_jpake_get_pwdata(authctxt, &pctx->s, &hash_scheme, &salt);
2163
2164         buffer_clear(m);
2165         /* pctx->s is sensitive, not returned to slave */
2166         buffer_put_cstring(m, hash_scheme);
2167         buffer_put_cstring(m, salt);
2168
2169         debug3("%s: sending pwdata", __func__);
2170         mm_request_send(sock, MONITOR_ANS_JPAKE_GET_PWDATA, m);
2171
2172         bzero(hash_scheme, strlen(hash_scheme));
2173         bzero(salt, strlen(salt));
2174         xfree(hash_scheme);
2175         xfree(salt);
2176
2177         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP2, 1);
2178
2179         return 0;
2180 }
2181
2182 int
2183 mm_answer_jpake_step2(int sock, Buffer *m)
2184 {
2185         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2186         u_char *x1_proof, *x2_proof, *x4_s_proof;
2187         u_int x1_proof_len, x2_proof_len, x4_s_proof_len;
2188
2189         if (pctx == NULL)
2190                 fatal("%s: pctx == NULL", __func__);
2191
2192         if ((pctx->g_x1 = BN_new()) == NULL ||
2193             (pctx->g_x2 = BN_new()) == NULL)
2194                 fatal("%s: BN_new", __func__);
2195         buffer_get_bignum2(m, pctx->g_x1);
2196         buffer_get_bignum2(m, pctx->g_x2);
2197         pctx->client_id = buffer_get_string(m, &pctx->client_id_len);
2198         x1_proof = buffer_get_string(m, &x1_proof_len);
2199         x2_proof = buffer_get_string(m, &x2_proof_len);
2200
2201         jpake_step2(pctx->grp, pctx->s, pctx->g_x3,
2202             pctx->g_x1, pctx->g_x2, pctx->x4,
2203             pctx->client_id, pctx->client_id_len,
2204             pctx->server_id, pctx->server_id_len,
2205             x1_proof, x1_proof_len,
2206             x2_proof, x2_proof_len,
2207             &pctx->b,
2208             &x4_s_proof, &x4_s_proof_len);
2209
2210         JPAKE_DEBUG_CTX((pctx, "step2 done in %s", __func__));
2211
2212         bzero(x1_proof, x1_proof_len);
2213         bzero(x2_proof, x2_proof_len);
2214         xfree(x1_proof);
2215         xfree(x2_proof);
2216
2217         buffer_clear(m);
2218
2219         buffer_put_bignum2(m, pctx->b);
2220         buffer_put_string(m, x4_s_proof, x4_s_proof_len);
2221
2222         debug3("%s: sending step2", __func__);
2223         mm_request_send(sock, MONITOR_ANS_JPAKE_STEP2, m);
2224
2225         bzero(x4_s_proof, x4_s_proof_len);
2226         xfree(x4_s_proof);
2227
2228         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_KEY_CONFIRM, 1);
2229
2230         return 0;
2231 }
2232
2233 int
2234 mm_answer_jpake_key_confirm(int sock, Buffer *m)
2235 {
2236         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2237         u_char *x2_s_proof;
2238         u_int x2_s_proof_len;
2239
2240         if (pctx == NULL)
2241                 fatal("%s: pctx == NULL", __func__);
2242
2243         if ((pctx->a = BN_new()) == NULL)
2244                 fatal("%s: BN_new", __func__);
2245         buffer_get_bignum2(m, pctx->a);
2246         x2_s_proof = buffer_get_string(m, &x2_s_proof_len);
2247
2248         jpake_key_confirm(pctx->grp, pctx->s, pctx->a,
2249             pctx->x4, pctx->g_x3, pctx->g_x4, pctx->g_x1, pctx->g_x2,
2250             pctx->server_id, pctx->server_id_len,
2251             pctx->client_id, pctx->client_id_len,
2252             session_id2, session_id2_len,
2253             x2_s_proof, x2_s_proof_len,
2254             &pctx->k,
2255             &pctx->h_k_sid_sessid, &pctx->h_k_sid_sessid_len);
2256
2257         JPAKE_DEBUG_CTX((pctx, "key_confirm done in %s", __func__));
2258
2259         bzero(x2_s_proof, x2_s_proof_len);
2260         buffer_clear(m);
2261
2262         /* pctx->k is sensitive, not sent */
2263         buffer_put_string(m, pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len);
2264
2265         debug3("%s: sending confirmation hash", __func__);
2266         mm_request_send(sock, MONITOR_ANS_JPAKE_KEY_CONFIRM, m);
2267
2268         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_CHECK_CONFIRM, 1);
2269
2270         return 0;
2271 }
2272
2273 int
2274 mm_answer_jpake_check_confirm(int sock, Buffer *m)
2275 {
2276         int authenticated = 0;
2277         u_char *peer_confirm_hash;
2278         u_int peer_confirm_hash_len;
2279         struct jpake_ctx *pctx = authctxt->jpake_ctx;
2280
2281         if (pctx == NULL)
2282                 fatal("%s: pctx == NULL", __func__);
2283
2284         peer_confirm_hash = buffer_get_string(m, &peer_confirm_hash_len);
2285
2286         authenticated = jpake_check_confirm(pctx->k,
2287             pctx->client_id, pctx->client_id_len,
2288             session_id2, session_id2_len,
2289             peer_confirm_hash, peer_confirm_hash_len) && authctxt->valid;
2290
2291         JPAKE_DEBUG_CTX((pctx, "check_confirm done in %s", __func__));
2292
2293         bzero(peer_confirm_hash, peer_confirm_hash_len);
2294         xfree(peer_confirm_hash);
2295
2296         buffer_clear(m);
2297         buffer_put_int(m, authenticated);
2298
2299         debug3("%s: sending result %d", __func__, authenticated);
2300         mm_request_send(sock, MONITOR_ANS_JPAKE_CHECK_CONFIRM, m);
2301
2302         monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 1);
2303
2304         auth_method = "jpake-01@openssh.com";
2305         return authenticated;
2306 }
2307
2308 #endif /* JPAKE */