lib/gssapi/krb5/accept_sec_context.c

   1 /*
   2  * Copyright (c) 1997 - 2006 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "gsskrb5_locl.h"
  35
  36 HEIMDAL_MUTEX gssapi_keytab_mutex = HEIMDAL_MUTEX_INITIALIZER;
  37 krb5_keytab _gsskrb5_keytab;
  38
  39 OM_uint32
  40 _gsskrb5_register_acceptor_identity (const char *identity)
  41 {
  42     krb5_context context;
  43     krb5_error_code ret;
  44
  45     ret = _gsskrb5_init(&context);
  46     if(ret)
  47         return GSS_S_FAILURE;
  48
  49     HEIMDAL_MUTEX_lock(&gssapi_keytab_mutex);
  50
  51     if(_gsskrb5_keytab != NULL) {
  52         krb5_kt_close(context, _gsskrb5_keytab);
  53         _gsskrb5_keytab = NULL;
  54     }
  55     if (identity == NULL) {
  56         ret = krb5_kt_default(context, &_gsskrb5_keytab);
  57     } else {
  58         char *p;
  59
  60         asprintf(&p, "FILE:%s", identity);
  61         if(p == NULL) {
  62             HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
  63             return GSS_S_FAILURE;
  64         }
  65         ret = krb5_kt_resolve(context, p, &_gsskrb5_keytab);
  66         free(p);
  67     }
  68     HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
  69     if(ret)
  70         return GSS_S_FAILURE;
  71     return GSS_S_COMPLETE;
  72 }
  73
  74 void
  75 _gsskrb5i_is_cfx(krb5_context context, gsskrb5_ctx ctx, int acceptor)
  76 {
  77     krb5_error_code ret;
  78     krb5_keyblock *key;
  79
  80     if (acceptor) {
  81         if (ctx->auth_context->local_subkey)
  82             key = ctx->auth_context->local_subkey;
  83         else
  84             key = ctx->auth_context->remote_subkey;
  85     } else {
  86         if (ctx->auth_context->remote_subkey)
  87             key = ctx->auth_context->remote_subkey;
  88         else
  89             key = ctx->auth_context->local_subkey;
  90     }
  91     if (key == NULL)
  92         key = ctx->auth_context->keyblock;
  93
  94     if (key == NULL)
  95         return;
  96
  97     switch (key->keytype) {
  98     case ETYPE_DES_CBC_CRC:
  99     case ETYPE_DES_CBC_MD4:
 100     case ETYPE_DES_CBC_MD5:
 101     case ETYPE_DES3_CBC_MD5:
 102     case ETYPE_DES3_CBC_SHA1:
 103     case ETYPE_ARCFOUR_HMAC_MD5:
 104     case ETYPE_ARCFOUR_HMAC_MD5_56:
 105         break;
 106     default :
 107         ctx->more_flags |= IS_CFX;
 108
 109         if ((acceptor && ctx->auth_context->local_subkey) ||
 110             (!acceptor && ctx->auth_context->remote_subkey))
 111             ctx->more_flags |= ACCEPTOR_SUBKEY;
 112         break;
 113     }
 114     if (ctx->crypto)
 115         krb5_crypto_destroy(context, ctx->crypto);
 116     ret = krb5_crypto_init(context, key, 0, &ctx->crypto);
 117 }
 118
 119
 120 static OM_uint32
 121 gsskrb5_accept_delegated_token
 122 (OM_uint32 * minor_status,
 123  gsskrb5_ctx ctx,
 124  krb5_context context,
 125  gss_cred_id_t * delegated_cred_handle
 126     )
 127 {
 128     krb5_ccache ccache = NULL;
 129     krb5_error_code kret;
 130     int32_t ac_flags, ret = GSS_S_COMPLETE;
 131
 132     *minor_status = 0;
 133
 134     /* XXX Create a new delegated_cred_handle? */
 135     if (delegated_cred_handle == NULL) {
 136         kret = krb5_cc_default (context, &ccache);
 137     } else {
 138         *delegated_cred_handle = NULL;
 139         kret = krb5_cc_new_unique (context, krb5_cc_type_memory,
 140                                    NULL, &ccache);
 141     }
 142     if (kret) {
 143         ctx->flags &= ~GSS_C_DELEG_FLAG;
 144         goto out;
 145     }
 146
 147     kret = krb5_cc_initialize(context, ccache, ctx->source);
 148     if (kret) {
 149         ctx->flags &= ~GSS_C_DELEG_FLAG;
 150         goto out;
 151     }
 152
 153     krb5_auth_con_removeflags(context,
 154                               ctx->auth_context,
 155                               KRB5_AUTH_CONTEXT_DO_TIME,
 156                               &ac_flags);
 157     kret = krb5_rd_cred2(context,
 158                          ctx->auth_context,
 159                          ccache,
 160                          &ctx->fwd_data);
 161     krb5_auth_con_setflags(context,
 162                            ctx->auth_context,
 163                            ac_flags);
 164     if (kret) {
 165         ctx->flags &= ~GSS_C_DELEG_FLAG;
 166         ret = GSS_S_FAILURE;
 167         *minor_status = kret;
 168         goto out;
 169     }
 170
 171     if (delegated_cred_handle) {
 172         gsskrb5_cred handle;
 173
 174         ret = _gsskrb5_import_cred(minor_status,
 175                                    ccache,
 176                                    NULL,
 177                                    NULL,
 178                                    delegated_cred_handle);
 179         if (ret != GSS_S_COMPLETE)
 180             goto out;
 181
 182         handle = (gsskrb5_cred) *delegated_cred_handle;
 183
 184         handle->cred_flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
 185         krb5_cc_close(context, ccache);
 186         ccache = NULL;
 187     }
 188
 189 out:
 190     if (ccache) {
 191         /* Don't destroy the default cred cache */
 192         if (delegated_cred_handle == NULL)
 193             krb5_cc_close(context, ccache);
 194         else
 195             krb5_cc_destroy(context, ccache);
 196     }
 197     return ret;
 198 }
 199
 200 static OM_uint32
 201 gsskrb5_acceptor_ready(OM_uint32 * minor_status,
 202                        gsskrb5_ctx ctx,
 203                        krb5_context context,
 204                        gss_cred_id_t *delegated_cred_handle)
 205 {
 206     OM_uint32 ret;
 207     int32_t seq_number;
 208     int is_cfx = 0;
 209
 210     krb5_auth_getremoteseqnumber (context,
 211                                   ctx->auth_context,
 212                                   &seq_number);
 213
 214     _gsskrb5i_is_cfx(context, ctx, 1);
 215     is_cfx = (ctx->more_flags & IS_CFX);
 216
 217     ret = _gssapi_msg_order_create(minor_status,
 218                                    &ctx->order,
 219                                    _gssapi_msg_order_f(ctx->flags),
 220                                    seq_number, 0, is_cfx);
 221     if (ret)
 222         return ret;
 223
 224     /*
 225      * If requested, set local sequence num to remote sequence if this
 226      * isn't a mutual authentication context
 227      */
 228     if (!(ctx->flags & GSS_C_MUTUAL_FLAG) && _gssapi_msg_order_f(ctx->flags)) {
 229         krb5_auth_con_setlocalseqnumber(context,
 230                                         ctx->auth_context,
 231                                         seq_number);
 232     }
 233
 234     /*
 235      * We should handle the delegation ticket, in case it's there
 236      */
 237     if (ctx->fwd_data.length > 0 && (ctx->flags & GSS_C_DELEG_FLAG)) {
 238         ret = gsskrb5_accept_delegated_token(minor_status,
 239                                              ctx,
 240                                              context,
 241                                              delegated_cred_handle);
 242         if (ret)
 243             return ret;
 244     } else {
 245         /* Well, looks like it wasn't there after all */
 246         ctx->flags &= ~GSS_C_DELEG_FLAG;
 247     }
 248
 249     ctx->state = ACCEPTOR_READY;
 250     ctx->more_flags |= OPEN;
 251
 252     return GSS_S_COMPLETE;
 253 }
 254
 255 static OM_uint32
 256 send_error_token(OM_uint32 *minor_status,
 257                  krb5_context context,
 258                  krb5_error_code kret,
 259                  krb5_principal server,
 260                  krb5_data *indata,
 261                  gss_buffer_t output_token)
 262 {
 263     krb5_principal ap_req_server = NULL;
 264     krb5_error_code ret;
 265     krb5_data outbuf;
 266
 267     /* build server from request if the acceptor had not selected one */
 268     if (server == NULL) {
 269         AP_REQ ap_req;
 270
 271         ret = krb5_decode_ap_req(context, indata, &ap_req);
 272         if (ret) {
 273             *minor_status = ret;
 274             return GSS_S_FAILURE;
 275         }
 276         ret = _krb5_principalname2krb5_principal(context,
 277                                                   &ap_req_server,
 278                                                   ap_req.ticket.sname,
 279                                                   ap_req.ticket.realm);
 280         free_AP_REQ(&ap_req);
 281         if (ret) {
 282             *minor_status = ret;
 283             return GSS_S_FAILURE;
 284         }
 285         server = ap_req_server;
 286     }
 287
 288     ret = krb5_mk_error(context, kret, NULL, NULL, NULL,
 289                         server, NULL, NULL, &outbuf);
 290     if (ap_req_server)
 291         krb5_free_principal(context, ap_req_server);
 292     if (ret) {
 293         *minor_status = ret;
 294         return GSS_S_FAILURE;
 295     }
 296
 297     ret = _gsskrb5_encapsulate(minor_status,
 298                                &outbuf,
 299                                output_token,
 300                                "\x03\x00",
 301                                GSS_KRB5_MECHANISM);
 302     krb5_data_free (&outbuf);
 303     if (ret)
 304         return ret;
 305
 306     *minor_status = 0;
 307     return GSS_S_CONTINUE_NEEDED;
 308 }
 309
 310
 311 static OM_uint32
 312 gsskrb5_acceptor_start(OM_uint32 * minor_status,
 313                        gsskrb5_ctx ctx,
 314                        krb5_context context,
 315                        const gss_cred_id_t acceptor_cred_handle,
 316                        const gss_buffer_t input_token_buffer,
 317                        const gss_channel_bindings_t input_chan_bindings,
 318                        gss_name_t * src_name,
 319                        gss_OID * mech_type,
 320                        gss_buffer_t output_token,
 321                        OM_uint32 * ret_flags,
 322                        OM_uint32 * time_rec,
 323                        gss_cred_id_t * delegated_cred_handle)
 324 {
 325     krb5_error_code kret;
 326     OM_uint32 ret = GSS_S_COMPLETE;
 327     krb5_data indata;
 328     krb5_flags ap_options;
 329     krb5_keytab keytab = NULL;
 330     int is_cfx = 0;
 331     const gsskrb5_cred acceptor_cred = (gsskrb5_cred)acceptor_cred_handle;
 332
 333     /*
 334      * We may, or may not, have an escapsulation.
 335      */
 336     ret = _gsskrb5_decapsulate (minor_status,
 337                                 input_token_buffer,
 338                                 &indata,
 339                                 "\x01\x00",
 340                                 GSS_KRB5_MECHANISM);
 341
 342     if (ret) {
 343         /* Assume that there is no OID wrapping. */
 344         indata.length   = input_token_buffer->length;
 345         indata.data     = input_token_buffer->value;
 346     }
 347
 348     /*
 349      * We need to get our keytab
 350      */
 351     if (acceptor_cred == NULL) {
 352         if (_gsskrb5_keytab != NULL)
 353             keytab = _gsskrb5_keytab;
 354     } else if (acceptor_cred->keytab != NULL) {
 355         keytab = acceptor_cred->keytab;
 356     }
 357
 358     /*
 359      * We need to check the ticket and create the AP-REP packet
 360      */
 361
 362     {
 363         krb5_rd_req_in_ctx in = NULL;
 364         krb5_rd_req_out_ctx out = NULL;
 365         krb5_principal server = NULL;
 366
 367         if (acceptor_cred)
 368             server = acceptor_cred->principal;
 369
 370         kret = krb5_rd_req_in_ctx_alloc(context, &in);
 371         if (kret == 0)
 372             kret = krb5_rd_req_in_set_keytab(context, in, keytab);
 373         if (kret) {
 374             if (in)
 375                 krb5_rd_req_in_ctx_free(context, in);
 376             *minor_status = kret;
 377             return GSS_S_FAILURE;
 378         }
 379
 380         kret = krb5_rd_req_ctx(context,
 381                                &ctx->auth_context,
 382                                &indata,
 383                                server,
 384                                in, &out);
 385         krb5_rd_req_in_ctx_free(context, in);
 386         if (kret == KRB5KRB_AP_ERR_SKEW || kret == KRB5KRB_AP_ERR_TKT_NYV) {
 387             /*
 388              * No reply in non-MUTUAL mode, but we don't know that its
 389              * non-MUTUAL mode yet, thats inside the 8003 checksum, so
 390              * lets only send the error token on clock skew, that
 391              * limit when send error token for non-MUTUAL.
 392              */
 393             return send_error_token(minor_status, context, kret,
 394                                     server, &indata, output_token);
 395         } else if (kret) {
 396             *minor_status = kret;
 397             return GSS_S_FAILURE;
 398         }
 399
 400         /*
 401          * we need to remember some data on the context_handle.
 402          */
 403         kret = krb5_rd_req_out_get_ap_req_options(context, out,
 404                                                   &ap_options);
 405         if (kret == 0)
 406             kret = krb5_rd_req_out_get_ticket(context, out,
 407                                               &ctx->ticket);
 408         if (kret == 0)
 409             kret = krb5_rd_req_out_get_keyblock(context, out,
 410                                                 &ctx->service_keyblock);
 411         ctx->lifetime = ctx->ticket->ticket.endtime;
 412
 413         krb5_rd_req_out_ctx_free(context, out);
 414         if (kret) {
 415             ret = GSS_S_FAILURE;
 416             *minor_status = kret;
 417             return ret;
 418         }
 419     }
 420
 421
 422     /*
 423      * We need to copy the principal names to the context and the
 424      * calling layer.
 425      */
 426     kret = krb5_copy_principal(context,
 427                                ctx->ticket->client,
 428                                &ctx->source);
 429     if (kret) {
 430         ret = GSS_S_FAILURE;
 431         *minor_status = kret;
 432     }
 433
 434     kret = krb5_copy_principal(context,
 435                                ctx->ticket->server,
 436                                &ctx->target);
 437     if (kret) {
 438         ret = GSS_S_FAILURE;
 439         *minor_status = kret;
 440         return ret;
 441     }
 442
 443     /*
 444      * We need to setup some compat stuff, this assumes that
 445      * context_handle->target is already set.
 446      */
 447     ret = _gss_DES3_get_mic_compat(minor_status, ctx, context);
 448     if (ret)
 449         return ret;
 450
 451     if (src_name != NULL) {
 452         kret = krb5_copy_principal (context,
 453                                     ctx->ticket->client,
 454                                     (gsskrb5_name*)src_name);
 455         if (kret) {
 456             ret = GSS_S_FAILURE;
 457             *minor_status = kret;
 458             return ret;
 459         }
 460     }
 461
 462     /*
 463      * We need to get the flags out of the 8003 checksum.
 464      */
 465     {
 466         krb5_authenticator authenticator;
 467
 468         kret = krb5_auth_con_getauthenticator(context,
 469                                               ctx->auth_context,
 470                                               &authenticator);
 471         if(kret) {
 472             ret = GSS_S_FAILURE;
 473             *minor_status = kret;
 474             return ret;
 475         }
 476
 477         if (authenticator->cksum->cksumtype == CKSUMTYPE_GSSAPI) {
 478             ret = _gsskrb5_verify_8003_checksum(minor_status,
 479                                                 input_chan_bindings,
 480                                                 authenticator->cksum,
 481                                                 &ctx->flags,
 482                                                 &ctx->fwd_data);
 483
 484             krb5_free_authenticator(context, &authenticator);
 485             if (ret) {
 486                 return ret;
 487             }
 488         } else {
 489             krb5_crypto crypto;
 490
 491             kret = krb5_crypto_init(context,
 492                                     ctx->auth_context->keyblock,
 493                                     0, &crypto);
 494             if(kret) {
 495                 krb5_free_authenticator(context, &authenticator);
 496
 497                 ret = GSS_S_FAILURE;
 498                 *minor_status = kret;
 499                 return ret;
 500             }
 501
 502             /*
 503              * Windows accepts Samba3's use of a kerberos, rather than
 504              * GSSAPI checksum here
 505              */
 506
 507             kret = krb5_verify_checksum(context,
 508                                         crypto, KRB5_KU_AP_REQ_AUTH_CKSUM, NULL, 0,
 509                                         authenticator->cksum);
 510             krb5_free_authenticator(context, &authenticator);
 511             krb5_crypto_destroy(context, crypto);
 512
 513             if(kret) {
 514                 ret = GSS_S_BAD_SIG;
 515                 *minor_status = kret;
 516                 return ret;
 517             }
 518
 519             /*
 520              * Samba style get some flags (but not DCE-STYLE), use
 521              * ap_options to guess the mutual flag.
 522              */
 523             ctx->flags = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG;
 524             if (ap_options & AP_OPTS_MUTUAL_REQUIRED)
 525                 ctx->flags |= GSS_C_MUTUAL_FLAG;
 526         }
 527     }
 528
 529     if(ctx->flags & GSS_C_MUTUAL_FLAG) {
 530         krb5_data outbuf;
 531         int use_subkey = 0;
 532
 533         _gsskrb5i_is_cfx(context, ctx, 1);
 534         is_cfx = (ctx->more_flags & IS_CFX);
 535
 536         if (is_cfx || (ap_options & AP_OPTS_USE_SUBKEY)) {
 537             use_subkey = 1;
 538         } else {
 539             krb5_keyblock *rkey;
 540
 541             /*
 542              * If there is a initiator subkey, copy that to acceptor
 543              * subkey to match Windows behavior
 544              */
 545             kret = krb5_auth_con_getremotesubkey(context,
 546                                                  ctx->auth_context,
 547                                                  &rkey);
 548             if (kret == 0) {
 549                 kret = krb5_auth_con_setlocalsubkey(context,
 550                                                     ctx->auth_context,
 551                                                     rkey);
 552                 if (kret == 0)
 553                     use_subkey = 1;
 554                 krb5_free_keyblock(context, rkey);
 555             }
 556         }
 557         if (use_subkey) {
 558             ctx->more_flags |= ACCEPTOR_SUBKEY;
 559             krb5_auth_con_addflags(context, ctx->auth_context,
 560                                    KRB5_AUTH_CONTEXT_USE_SUBKEY,
 561                                    NULL);
 562         }
 563
 564         kret = krb5_mk_rep(context,
 565                            ctx->auth_context,
 566                            &outbuf);
 567         if (kret) {
 568             *minor_status = kret;
 569             return GSS_S_FAILURE;
 570         }
 571
 572         if (IS_DCE_STYLE(ctx)) {
 573             output_token->length = outbuf.length;
 574             output_token->value = outbuf.data;
 575         } else {
 576             ret = _gsskrb5_encapsulate(minor_status,
 577                                        &outbuf,
 578                                        output_token,
 579                                        "\x02\x00",
 580                                        GSS_KRB5_MECHANISM);
 581             krb5_data_free (&outbuf);
 582             if (ret)
 583                 return ret;
 584         }
 585     }
 586
 587     ctx->flags |= GSS_C_TRANS_FLAG;
 588
 589     /* Remember the flags */
 590
 591     ctx->lifetime = ctx->ticket->ticket.endtime;
 592     ctx->more_flags |= OPEN;
 593
 594     if (mech_type)
 595         *mech_type = GSS_KRB5_MECHANISM;
 596
 597     if (time_rec) {
 598         ret = _gsskrb5_lifetime_left(minor_status,
 599                                      context,
 600                                      ctx->lifetime,
 601                                      time_rec);
 602         if (ret) {
 603             return ret;
 604         }
 605     }
 606
 607     /*
 608      * When GSS_C_DCE_STYLE is in use, we need ask for a AP-REP from
 609      * the client.
 610      */
 611     if (IS_DCE_STYLE(ctx)) {
 612         /*
 613          * Return flags to caller, but we haven't processed
 614          * delgations yet
 615          */
 616         if (ret_flags)
 617             *ret_flags = (ctx->flags & ~GSS_C_DELEG_FLAG);
 618
 619         ctx->state = ACCEPTOR_WAIT_FOR_DCESTYLE;
 620         return GSS_S_CONTINUE_NEEDED;
 621     }
 622
 623     ret = gsskrb5_acceptor_ready(minor_status, ctx, context,
 624                                  delegated_cred_handle);
 625
 626     if (ret_flags)
 627         *ret_flags = ctx->flags;
 628
 629     return ret;
 630 }
 631
 632 static OM_uint32
 633 acceptor_wait_for_dcestyle(OM_uint32 * minor_status,
 634                            gsskrb5_ctx ctx,
 635                            krb5_context context,
 636                            const gss_cred_id_t acceptor_cred_handle,
 637                            const gss_buffer_t input_token_buffer,
 638                            const gss_channel_bindings_t input_chan_bindings,
 639                            gss_name_t * src_name,
 640                            gss_OID * mech_type,
 641                            gss_buffer_t output_token,
 642                            OM_uint32 * ret_flags,
 643                            OM_uint32 * time_rec,
 644                            gss_cred_id_t * delegated_cred_handle)
 645 {
 646     OM_uint32 ret;
 647     krb5_error_code kret;
 648     krb5_data inbuf;
 649     int32_t r_seq_number, l_seq_number;
 650
 651     /*
 652      * We know it's GSS_C_DCE_STYLE so we don't need to decapsulate the AP_REP
 653      */
 654
 655     inbuf.length = input_token_buffer->length;
 656     inbuf.data = input_token_buffer->value;
 657
 658     /*
 659      * We need to remeber the old remote seq_number, then check if the
 660      * client has replied with our local seq_number, and then reset
 661      * the remote seq_number to the old value
 662      */
 663     {
 664         kret = krb5_auth_con_getlocalseqnumber(context,
 665                                                ctx->auth_context,
 666                                                &l_seq_number);
 667         if (kret) {
 668             *minor_status = kret;
 669             return GSS_S_FAILURE;
 670         }
 671
 672         kret = krb5_auth_getremoteseqnumber(context,
 673                                             ctx->auth_context,
 674                                             &r_seq_number);
 675         if (kret) {
 676             *minor_status = kret;
 677             return GSS_S_FAILURE;
 678         }
 679
 680         kret = krb5_auth_con_setremoteseqnumber(context,
 681                                                 ctx->auth_context,
 682                                                 l_seq_number);
 683         if (kret) {
 684             *minor_status = kret;
 685             return GSS_S_FAILURE;
 686         }
 687     }
 688
 689     /*
 690      * We need to verify the AP_REP, but we need to flag that this is
 691      * DCE_STYLE, so don't check the timestamps this time, but put the
 692      * flag DO_TIME back afterward.
 693     */
 694     {
 695         krb5_ap_rep_enc_part *repl;
 696         int32_t auth_flags;
 697
 698         krb5_auth_con_removeflags(context,
 699                                   ctx->auth_context,
 700                                   KRB5_AUTH_CONTEXT_DO_TIME,
 701                                   &auth_flags);
 702
 703         kret = krb5_rd_rep(context, ctx->auth_context, &inbuf, &repl);
 704         if (kret) {
 705             *minor_status = kret;
 706             return GSS_S_FAILURE;
 707         }
 708         krb5_free_ap_rep_enc_part(context, repl);
 709         krb5_auth_con_setflags(context, ctx->auth_context, auth_flags);
 710     }
 711
 712     /* We need to check the liftime */
 713     {
 714         OM_uint32 lifetime_rec;
 715
 716         ret = _gsskrb5_lifetime_left(minor_status,
 717                                      context,
 718                                      ctx->lifetime,
 719                                      &lifetime_rec);
 720         if (ret) {
 721             return ret;
 722         }
 723         if (lifetime_rec == 0) {
 724             return GSS_S_CONTEXT_EXPIRED;
 725         }
 726
 727         if (time_rec) *time_rec = lifetime_rec;
 728     }
 729
 730     /* We need to give the caller the flags which are in use */
 731     if (ret_flags) *ret_flags = ctx->flags;
 732
 733     if (src_name) {
 734         kret = krb5_copy_principal(context,
 735                                    ctx->source,
 736                                    (gsskrb5_name*)src_name);
 737         if (kret) {
 738             *minor_status = kret;
 739             return GSS_S_FAILURE;
 740         }
 741     }
 742
 743     /*
 744      * After the krb5_rd_rep() the remote and local seq_number should
 745      * be the same, because the client just replies the seq_number
 746      * from our AP-REP in its AP-REP, but then the client uses the
 747      * seq_number from its AP-REQ for GSS_wrap()
 748      */
 749     {
 750         int32_t tmp_r_seq_number, tmp_l_seq_number;
 751
 752         kret = krb5_auth_getremoteseqnumber(context,
 753                                             ctx->auth_context,
 754                                             &tmp_r_seq_number);
 755         if (kret) {
 756             *minor_status = kret;
 757             return GSS_S_FAILURE;
 758         }
 759
 760         kret = krb5_auth_con_getlocalseqnumber(context,
 761                                                ctx->auth_context,
 762                                                &tmp_l_seq_number);
 763         if (kret) {
 764
 765             *minor_status = kret;
 766             return GSS_S_FAILURE;
 767         }
 768
 769         /*
 770          * Here we check if the client has responsed with our local seq_number,
 771          */
 772         if (tmp_r_seq_number != tmp_l_seq_number) {
 773             return GSS_S_UNSEQ_TOKEN;
 774         }
 775     }
 776
 777     /*
 778      * We need to reset the remote seq_number, because the client will use,
 779      * the old one for the GSS_wrap() calls
 780      */
 781     {
 782         kret = krb5_auth_con_setremoteseqnumber(context,
 783                                                 ctx->auth_context,
 784                                                 r_seq_number);
 785         if (kret) {
 786             *minor_status = kret;
 787             return GSS_S_FAILURE;
 788         }
 789     }
 790
 791     return gsskrb5_acceptor_ready(minor_status, ctx, context,
 792                                   delegated_cred_handle);
 793 }
 794
 795
 796 OM_uint32
 797 _gsskrb5_accept_sec_context(OM_uint32 * minor_status,
 798                             gss_ctx_id_t * context_handle,
 799                             const gss_cred_id_t acceptor_cred_handle,
 800                             const gss_buffer_t input_token_buffer,
 801                             const gss_channel_bindings_t input_chan_bindings,
 802                             gss_name_t * src_name,
 803                             gss_OID * mech_type,
 804                             gss_buffer_t output_token,
 805                             OM_uint32 * ret_flags,
 806                             OM_uint32 * time_rec,
 807                             gss_cred_id_t * delegated_cred_handle)
 808 {
 809     krb5_context context;
 810     OM_uint32 ret;
 811     gsskrb5_ctx ctx;
 812
 813     GSSAPI_KRB5_INIT(&context);
 814
 815     output_token->length = 0;
 816     output_token->value = NULL;
 817
 818     if (src_name != NULL)
 819         *src_name = NULL;
 820     if (mech_type)
 821         *mech_type = GSS_KRB5_MECHANISM;
 822
 823     if (*context_handle == GSS_C_NO_CONTEXT) {
 824         ret = _gsskrb5_create_ctx(minor_status,
 825                                   context_handle,
 826                                   context,
 827                                   input_chan_bindings,
 828                                   ACCEPTOR_START);
 829         if (ret)
 830             return ret;
 831     }
 832
 833     ctx = (gsskrb5_ctx)*context_handle;
 834
 835
 836     /*
 837      * TODO: check the channel_bindings
 838      * (above just sets them to krb5 layer)
 839      */
 840
 841     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
 842
 843     switch (ctx->state) {
 844     case ACCEPTOR_START:
 845         ret = gsskrb5_acceptor_start(minor_status,
 846                                      ctx,
 847                                      context,
 848                                      acceptor_cred_handle,
 849                                      input_token_buffer,
 850                                      input_chan_bindings,
 851                                      src_name,
 852                                      mech_type,
 853                                      output_token,
 854                                      ret_flags,
 855                                      time_rec,
 856                                      delegated_cred_handle);
 857         break;
 858     case ACCEPTOR_WAIT_FOR_DCESTYLE:
 859         ret = acceptor_wait_for_dcestyle(minor_status,
 860                                          ctx,
 861                                          context,
 862                                          acceptor_cred_handle,
 863                                          input_token_buffer,
 864                                          input_chan_bindings,
 865                                          src_name,
 866                                          mech_type,
 867                                          output_token,
 868                                          ret_flags,
 869                                          time_rec,
 870                                          delegated_cred_handle);
 871         break;
 872     case ACCEPTOR_READY:
 873         /*
 874          * If we get there, the caller have called
 875          * gss_accept_sec_context() one time too many.
 876          */
 877         ret =  GSS_S_BAD_STATUS;
 878         break;
 879     default:
 880         /* TODO: is this correct here? --metze */
 881         ret =  GSS_S_BAD_STATUS;
 882         break;
 883     }
 884
 885     HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 886
 887     if (GSS_ERROR(ret)) {
 888         OM_uint32 min2;
 889         _gsskrb5_delete_sec_context(&min2, context_handle, GSS_C_NO_BUFFER);
 890     }
 891
 892     return ret;
 893 }