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 static krb5_error_code
  40 validate_keytab(krb5_context context, const char *name, krb5_keytab *id)
  41 {
  42     krb5_error_code ret;
  43
  44     ret = krb5_kt_resolve(context, name, id);
  45     if (ret)
  46         return ret;
  47
  48     ret = krb5_kt_have_content(context, *id);
  49     if (ret) {
  50         krb5_kt_close(context, *id);
  51         *id = NULL;
  52     }
  53
  54     return ret;
  55 }
  56
  57 OM_uint32
  58 _gsskrb5_register_acceptor_identity(OM_uint32 *min_stat, const char *identity)
  59 {
  60     krb5_context context;
  61     krb5_error_code ret;
  62
  63     *min_stat = 0;
  64
  65     ret = _gsskrb5_init(&context);
  66     if(ret)
  67         return GSS_S_FAILURE;
  68
  69     HEIMDAL_MUTEX_lock(&gssapi_keytab_mutex);
  70
  71     if(_gsskrb5_keytab != NULL) {
  72         krb5_kt_close(context, _gsskrb5_keytab);
  73         _gsskrb5_keytab = NULL;
  74     }
  75     if (identity == NULL) {
  76         ret = krb5_kt_default(context, &_gsskrb5_keytab);
  77     } else {
  78         /*
  79          * First check if we can the keytab as is and if it has content...
  80          */
  81         ret = validate_keytab(context, identity, &_gsskrb5_keytab);
  82         /*
  83          * if it doesn't, lets prepend FILE: and try again
  84          */
  85         if (ret) {
  86             char *p = NULL;
  87             ret = asprintf(&p, "FILE:%s", identity);
  88             if(ret < 0 || p == NULL) {
  89                 HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
  90                 return GSS_S_FAILURE;
  91             }
  92             ret = validate_keytab(context, p, &_gsskrb5_keytab);
  93             free(p);
  94         }
  95     }
  96     HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
  97     if(ret) {
  98         *min_stat = ret;
  99         return GSS_S_FAILURE;
 100     }
 101     return GSS_S_COMPLETE;
 102 }
 103
 104 void
 105 _gsskrb5i_is_cfx(krb5_context context, gsskrb5_ctx ctx, int acceptor)
 106 {
 107     krb5_keyblock *key;
 108
 109     if (acceptor) {
 110         if (ctx->auth_context->local_subkey)
 111             key = ctx->auth_context->local_subkey;
 112         else
 113             key = ctx->auth_context->remote_subkey;
 114     } else {
 115         if (ctx->auth_context->remote_subkey)
 116             key = ctx->auth_context->remote_subkey;
 117         else
 118             key = ctx->auth_context->local_subkey;
 119     }
 120     if (key == NULL)
 121         key = ctx->auth_context->keyblock;
 122
 123     if (key == NULL)
 124         return;
 125
 126     switch (key->keytype) {
 127     case ETYPE_DES_CBC_CRC:
 128     case ETYPE_DES_CBC_MD4:
 129     case ETYPE_DES_CBC_MD5:
 130     case ETYPE_DES3_CBC_MD5:
 131     case ETYPE_OLD_DES3_CBC_SHA1:
 132     case ETYPE_DES3_CBC_SHA1:
 133     case ETYPE_ARCFOUR_HMAC_MD5:
 134     case ETYPE_ARCFOUR_HMAC_MD5_56:
 135         break;
 136     default :
 137         ctx->more_flags |= IS_CFX;
 138
 139         if ((acceptor && ctx->auth_context->local_subkey) ||
 140             (!acceptor && ctx->auth_context->remote_subkey))
 141             ctx->more_flags |= ACCEPTOR_SUBKEY;
 142         break;
 143     }
 144     if (ctx->crypto)
 145         krb5_crypto_destroy(context, ctx->crypto);
 146     /* XXX We really shouldn't ignore this; will come back to this */
 147     (void) krb5_crypto_init(context, key, 0, &ctx->crypto);
 148 }
 149
 150
 151 static OM_uint32
 152 gsskrb5_accept_delegated_token(OM_uint32 *minor_status,
 153                                gsskrb5_ctx ctx,
 154                                krb5_context context,
 155                                gss_cred_id_t *delegated_cred_handle)
 156 {
 157     krb5_ccache ccache = NULL;
 158     krb5_error_code kret;
 159     int32_t ac_flags, ret = GSS_S_COMPLETE;
 160     gsskrb5_cred handle;
 161
 162     *minor_status = 0;
 163
 164     /* XXX Create a new delegated_cred_handle? */
 165     if (delegated_cred_handle == NULL)
 166         return GSS_S_COMPLETE;
 167
 168     *delegated_cred_handle = NULL;
 169     kret = krb5_cc_resolve(context, "MEMORY:anonymous", &ccache);
 170     if (kret == 0)
 171         kret = krb5_cc_initialize(context, ccache, ctx->source);
 172     if (kret == 0) {
 173         (void) krb5_auth_con_removeflags(context,
 174                                          ctx->auth_context,
 175                                          KRB5_AUTH_CONTEXT_DO_TIME,
 176                                          &ac_flags);
 177         kret = krb5_rd_cred2(context,
 178                              ctx->auth_context,
 179                              ccache,
 180                              &ctx->fwd_data);
 181         (void) krb5_auth_con_setflags(context,
 182                                       ctx->auth_context,
 183                                       ac_flags);
 184     }
 185     if (kret) {
 186         ctx->flags &= ~GSS_C_DELEG_FLAG;
 187         ret = GSS_S_FAILURE;
 188         *minor_status = kret;
 189         goto out;
 190     }
 191
 192     ret = _gsskrb5_krb5_import_cred(minor_status,
 193                                     &ccache,
 194                                     NULL,
 195                                     NULL,
 196                                     delegated_cred_handle);
 197     if (ret != GSS_S_COMPLETE)
 198         goto out;
 199
 200     handle = (gsskrb5_cred) *delegated_cred_handle;
 201     handle->cred_flags |= GSS_CF_DESTROY_CRED_ON_RELEASE;
 202
 203     /*
 204      * A root TGT is one of the form krbtgt/REALM@SAME-REALM.
 205      *
 206      * A destination TGT is a root TGT for the same realm as the acceptor
 207      * service's realm.
 208      *
 209      * Normally clients delegate a root TGT for the client's realm.
 210      *
 211      * In some deployments clients may want to delegate destination TGTs as
 212      * a form of constrained delegation: so that the destination service
 213      * cannot use the delegated credential to impersonate the client
 214      * principal to services in its home realm (due to KDC lineage/transit
 215      * checks).  In those deployments there may not even be a route back to
 216      * the KDCs of the client's realm, and attempting to use a
 217      * non-destination TGT might even lead to timeouts.
 218      *
 219      * We could simply pretend not to have obtained a credential, except
 220      * that a) we don't (yet) have an app name here for the appdefault we
 221      * need to check, b) the application really wants to be able to log a
 222      * message about the delegated credential being no good.
 223      *
 224      * Thus we leave it to _gsskrb5_store_cred_into2() to decide what to do
 225      * with non-destination TGTs.  To do that, it needs the realm of the
 226      * acceptor service, which we record here.
 227      */
 228     handle->destination_realm =
 229         strdup(krb5_principal_get_realm(context, ctx->target));
 230     if (handle->destination_realm == NULL) {
 231         _gsskrb5_release_cred(minor_status, delegated_cred_handle);
 232         *minor_status = krb5_enomem(context);
 233         ret = GSS_S_FAILURE;
 234         goto out;
 235     }
 236
 237 out:
 238     if (ccache) {
 239         krb5_cc_close(context, ccache);
 240     }
 241     return ret;
 242 }
 243
 244 static OM_uint32
 245 gsskrb5_acceptor_ready(OM_uint32 * minor_status,
 246                        gsskrb5_ctx ctx,
 247                        krb5_context context,
 248                        gss_cred_id_t *delegated_cred_handle)
 249 {
 250     OM_uint32 ret;
 251     int32_t seq_number;
 252     int is_cfx = 0;
 253
 254     krb5_auth_con_getremoteseqnumber (context,
 255                                       ctx->auth_context,
 256                                       &seq_number);
 257
 258     _gsskrb5i_is_cfx(context, ctx, 1);
 259     is_cfx = (ctx->more_flags & IS_CFX);
 260
 261     ret = _gssapi_msg_order_create(minor_status,
 262                                    &ctx->order,
 263                                    _gssapi_msg_order_f(ctx->flags),
 264                                    seq_number, 0, is_cfx);
 265     if (ret)
 266         return ret;
 267
 268     /*
 269      * If requested, set local sequence num to remote sequence if this
 270      * isn't a mutual authentication context
 271      */
 272     if (!(ctx->flags & GSS_C_MUTUAL_FLAG) && _gssapi_msg_order_f(ctx->flags)) {
 273         krb5_auth_con_setlocalseqnumber(context,
 274                                         ctx->auth_context,
 275                                         seq_number);
 276     }
 277
 278     /*
 279      * We should handle the delegation ticket, in case it's there
 280      */
 281     if (ctx->fwd_data.length > 0 && (ctx->flags & GSS_C_DELEG_FLAG)) {
 282         ret = gsskrb5_accept_delegated_token(minor_status,
 283                                              ctx,
 284                                              context,
 285                                              delegated_cred_handle);
 286         if (ret != GSS_S_COMPLETE)
 287             return ret;
 288     } else {
 289         /* Well, looks like it wasn't there after all */
 290         ctx->flags &= ~GSS_C_DELEG_FLAG;
 291     }
 292
 293     ctx->state = ACCEPTOR_READY;
 294     ctx->more_flags |= OPEN;
 295
 296     return GSS_S_COMPLETE;
 297 }
 298
 299 static OM_uint32
 300 send_error_token(OM_uint32 *minor_status,
 301                  krb5_context context,
 302                  krb5_error_code kret,
 303                  krb5_principal server,
 304                  krb5_data *indata,
 305                  gss_buffer_t output_token)
 306 {
 307     krb5_principal ap_req_server = NULL;
 308     krb5_error_code ret;
 309     krb5_data outbuf;
 310     /* this e_data value encodes KERB_AP_ERR_TYPE_SKEW_RECOVERY which
 311        tells windows to try again with the corrected timestamp. See
 312        [MS-KILE] 2.2.1 KERB-ERROR-DATA */
 313     krb5_data e_data = { 7, rk_UNCONST("\x30\x05\xa1\x03\x02\x01\x02") };
 314
 315     /* build server from request if the acceptor had not selected one */
 316     if (server == NULL) {
 317         AP_REQ ap_req;
 318
 319         ret = krb5_decode_ap_req(context, indata, &ap_req);
 320         if (ret) {
 321             *minor_status = ret;
 322             return GSS_S_FAILURE;
 323         }
 324         ret = _krb5_principalname2krb5_principal(context,
 325                                                   &ap_req_server,
 326                                                   ap_req.ticket.sname,
 327                                                   ap_req.ticket.realm);
 328         free_AP_REQ(&ap_req);
 329         if (ret) {
 330             *minor_status = ret;
 331             return GSS_S_FAILURE;
 332         }
 333         server = ap_req_server;
 334     }
 335
 336     ret = krb5_mk_error(context, kret, NULL, &e_data, NULL,
 337                         server, NULL, NULL, &outbuf);
 338     if (ap_req_server)
 339         krb5_free_principal(context, ap_req_server);
 340     if (ret) {
 341         *minor_status = ret;
 342         return GSS_S_FAILURE;
 343     }
 344
 345     ret = _gsskrb5_encapsulate(minor_status,
 346                                &outbuf,
 347                                output_token,
 348                                "\x03\x00",
 349                                GSS_KRB5_MECHANISM);
 350     krb5_data_free (&outbuf);
 351     if (ret)
 352         return ret;
 353
 354     *minor_status = 0;
 355     return GSS_S_CONTINUE_NEEDED;
 356 }
 357
 358
 359 static OM_uint32
 360 gsskrb5_acceptor_start(OM_uint32 * minor_status,
 361                        gsskrb5_ctx ctx,
 362                        krb5_context context,
 363                        gss_const_cred_id_t acceptor_cred_handle,
 364                        const gss_buffer_t input_token_buffer,
 365                        const gss_channel_bindings_t input_chan_bindings,
 366                        gss_name_t * src_name,
 367                        gss_OID * mech_type,
 368                        gss_buffer_t output_token,
 369                        OM_uint32 * ret_flags,
 370                        OM_uint32 * time_rec,
 371                        gss_cred_id_t * delegated_cred_handle)
 372 {
 373     krb5_error_code kret;
 374     OM_uint32 ret = GSS_S_COMPLETE;
 375     krb5_data indata;
 376     krb5_flags ap_options;
 377     krb5_keytab keytab = NULL;
 378     int is_cfx = 0;
 379     int close_kt = 0;
 380     const gsskrb5_cred acceptor_cred = (gsskrb5_cred)acceptor_cred_handle;
 381
 382     /*
 383      * We may, or may not, have an escapsulation.
 384      */
 385     ret = _gsskrb5_decapsulate (minor_status,
 386                                 input_token_buffer,
 387                                 &indata,
 388                                 "\x01\x00",
 389                                 GSS_KRB5_MECHANISM);
 390
 391     if (ret) {
 392         /* Could be a raw AP-REQ (check for APPLICATION tag) */
 393         if (input_token_buffer->length == 0 ||
 394             ((const uint8_t *)input_token_buffer->value)[0] != 0x6E) {
 395             *minor_status = ASN1_MISPLACED_FIELD;
 396             return GSS_S_DEFECTIVE_TOKEN;
 397         }
 398
 399         /* Assume that there is no OID wrapping. */
 400         indata.length   = input_token_buffer->length;
 401         indata.data     = input_token_buffer->value;
 402     }
 403
 404     /*
 405      * We need to get our keytab
 406      */
 407     if (acceptor_cred == NULL) {
 408         HEIMDAL_MUTEX_lock(&gssapi_keytab_mutex);
 409         if (_gsskrb5_keytab != NULL) {
 410             char *name = NULL;
 411             kret = krb5_kt_get_full_name(context, _gsskrb5_keytab, &name);
 412             if (kret == 0) {
 413                 kret = krb5_kt_resolve(context, name, &keytab);
 414                 krb5_xfree(name);
 415             }
 416             if (kret == 0)
 417                 close_kt = 1;
 418             else
 419                 keytab = NULL;
 420         }
 421         HEIMDAL_MUTEX_unlock(&gssapi_keytab_mutex);
 422     } else if (acceptor_cred->keytab != NULL) {
 423         keytab = acceptor_cred->keytab;
 424     }
 425
 426     /*
 427      * We need to check the ticket and create the AP-REP packet
 428      */
 429
 430     {
 431         krb5_rd_req_in_ctx in = NULL;
 432         krb5_rd_req_out_ctx out = NULL;
 433         krb5_principal server = NULL;
 434
 435         if (acceptor_cred)
 436             server = acceptor_cred->principal;
 437
 438         kret = krb5_rd_req_in_ctx_alloc(context, &in);
 439         if (kret == 0)
 440             kret = krb5_rd_req_in_set_keytab(context, in, keytab);
 441         if (kret) {
 442             if (in)
 443                 krb5_rd_req_in_ctx_free(context, in);
 444             if (close_kt)
 445                 krb5_kt_close(context, keytab);
 446             *minor_status = kret;
 447             return GSS_S_FAILURE;
 448         }
 449
 450         kret = krb5_rd_req_ctx(context,
 451                                &ctx->auth_context,
 452                                &indata,
 453                                server,
 454                                in, &out);
 455         krb5_rd_req_in_ctx_free(context, in);
 456         if (close_kt)
 457             krb5_kt_close(context, keytab);
 458         if (kret == KRB5KRB_AP_ERR_SKEW || kret == KRB5KRB_AP_ERR_TKT_NYV) {
 459             /*
 460              * No reply in non-MUTUAL mode, but we don't know that its
 461              * non-MUTUAL mode yet, thats inside the 8003 checksum, so
 462              * lets only send the error token on clock skew, that
 463              * limit when send error token for non-MUTUAL.
 464              */
 465             krb5_auth_con_free(context, ctx->auth_context);
 466             krb5_auth_con_free(context, ctx->deleg_auth_context);
 467             ctx->deleg_auth_context = NULL;
 468             ctx->auth_context = NULL;
 469             return send_error_token(minor_status, context, kret,
 470                                     server, &indata, output_token);
 471         } else if (kret) {
 472             *minor_status = kret;
 473             return GSS_S_FAILURE;
 474         }
 475
 476         /*
 477          * we need to remember some data on the context_handle.
 478          */
 479         kret = krb5_rd_req_out_get_ap_req_options(context, out,
 480                                                   &ap_options);
 481         if (kret == 0)
 482             kret = krb5_rd_req_out_get_ticket(context, out,
 483                                               &ctx->ticket);
 484         if (kret == 0)
 485             kret = krb5_rd_req_out_get_keyblock(context, out,
 486                                                 &ctx->service_keyblock);
 487         ctx->endtime = ctx->ticket->ticket.endtime;
 488
 489         krb5_rd_req_out_ctx_free(context, out);
 490         if (kret) {
 491             ret = GSS_S_FAILURE;
 492             *minor_status = kret;
 493             return ret;
 494         }
 495     }
 496
 497
 498     /*
 499      * We need to copy the principal names to the context and the
 500      * calling layer.
 501      */
 502     kret = krb5_copy_principal(context,
 503                                ctx->ticket->client,
 504                                &ctx->source);
 505     if (kret) {
 506         ret = GSS_S_FAILURE;
 507         *minor_status = kret;
 508         return ret;
 509     }
 510
 511     kret = krb5_copy_principal(context,
 512                                ctx->ticket->server,
 513                                &ctx->target);
 514     if (kret) {
 515         ret = GSS_S_FAILURE;
 516         *minor_status = kret;
 517         return ret;
 518     }
 519
 520     /*
 521      * We need to setup some compat stuff, this assumes that
 522      * context_handle->target is already set.
 523      */
 524     ret = _gss_DES3_get_mic_compat(minor_status, ctx, context);
 525     if (ret)
 526         return ret;
 527
 528     if (src_name != NULL) {
 529         kret = krb5_copy_principal (context,
 530                                     ctx->ticket->client,
 531                                     (gsskrb5_name*)src_name);
 532         if (kret) {
 533             ret = GSS_S_FAILURE;
 534             *minor_status = kret;
 535             return ret;
 536         }
 537     }
 538
 539     /*
 540      * We need to get the flags out of the 8003 checksum.
 541      */
 542
 543     {
 544         krb5_authenticator authenticator;
 545
 546         kret = krb5_auth_con_getauthenticator(context,
 547                                               ctx->auth_context,
 548                                               &authenticator);
 549         if(kret) {
 550             ret = GSS_S_FAILURE;
 551             *minor_status = kret;
 552             return ret;
 553         }
 554
 555         if (authenticator->cksum != NULL
 556             && authenticator->cksum->cksumtype == CKSUMTYPE_GSSAPI) {
 557             ret = _gsskrb5_verify_8003_checksum(context,
 558                                                 minor_status,
 559                                                 input_chan_bindings,
 560                                                 authenticator,
 561                                                 &ctx->flags,
 562                                                 &ctx->fwd_data);
 563
 564             if (ret) {
 565                 krb5_free_authenticator(context, &authenticator);
 566                 return ret;
 567             }
 568         } else {
 569             if (authenticator->cksum != NULL) {
 570                 krb5_crypto crypto;
 571
 572                 kret = krb5_crypto_init(context,
 573                                         ctx->auth_context->keyblock,
 574                                         0, &crypto);
 575                 if (kret) {
 576                     krb5_free_authenticator(context, &authenticator);
 577                     ret = GSS_S_FAILURE;
 578                     *minor_status = kret;
 579                     return ret;
 580                 }
 581
 582                 /*
 583                  * Windows accepts Samba3's use of a kerberos, rather than
 584                  * GSSAPI checksum here
 585                  */
 586
 587                 _krb5_crypto_set_flags(context, crypto, KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM);
 588                 kret = krb5_verify_checksum(context,
 589                                             crypto, KRB5_KU_AP_REQ_AUTH_CKSUM, NULL, 0,
 590                                             authenticator->cksum);
 591                 krb5_crypto_destroy(context, crypto);
 592
 593                 if (kret) {
 594                     krb5_free_authenticator(context, &authenticator);
 595                     ret = GSS_S_BAD_SIG;
 596                     *minor_status = kret;
 597                     return ret;
 598                 }
 599             }
 600
 601             /*
 602              * If there is no checksum or a kerberos checksum (which Windows
 603              * and Samba accept), we use the ap_options to guess the mutual
 604              * flag.
 605              */
 606
 607             ctx->flags = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG;
 608             if (ap_options & AP_OPTS_MUTUAL_REQUIRED)
 609                 ctx->flags |= GSS_C_MUTUAL_FLAG;
 610         }
 611         krb5_free_authenticator(context, &authenticator);
 612     }
 613
 614     if(ctx->flags & GSS_C_MUTUAL_FLAG) {
 615         krb5_data outbuf;
 616         int use_subkey = 0;
 617
 618         _gsskrb5i_is_cfx(context, ctx, 1);
 619         is_cfx = (ctx->more_flags & IS_CFX);
 620
 621         if (is_cfx || (ap_options & AP_OPTS_USE_SUBKEY)) {
 622             use_subkey = 1;
 623         } else {
 624             krb5_keyblock *rkey;
 625
 626             /*
 627              * If there is a initiator subkey, copy that to acceptor
 628              * subkey to match Windows behavior
 629              */
 630             kret = krb5_auth_con_getremotesubkey(context,
 631                                                  ctx->auth_context,
 632                                                  &rkey);
 633             if (kret == 0) {
 634                 kret = krb5_auth_con_setlocalsubkey(context,
 635                                                     ctx->auth_context,
 636                                                     rkey);
 637                 if (kret == 0)
 638                     use_subkey = 1;
 639             }
 640             krb5_free_keyblock(context, rkey);
 641         }
 642         if (use_subkey) {
 643             ctx->more_flags |= ACCEPTOR_SUBKEY;
 644             krb5_auth_con_addflags(context, ctx->auth_context,
 645                                    KRB5_AUTH_CONTEXT_USE_SUBKEY,
 646                                    NULL);
 647         }
 648
 649         kret = krb5_mk_rep(context,
 650                            ctx->auth_context,
 651                            &outbuf);
 652         if (kret) {
 653             *minor_status = kret;
 654             return GSS_S_FAILURE;
 655         }
 656
 657         if (IS_DCE_STYLE(ctx)) {
 658             output_token->length = outbuf.length;
 659             output_token->value = outbuf.data;
 660         } else {
 661             ret = _gsskrb5_encapsulate(minor_status,
 662                                        &outbuf,
 663                                        output_token,
 664                                        "\x02\x00",
 665                                        GSS_KRB5_MECHANISM);
 666             krb5_data_free (&outbuf);
 667             if (ret)
 668                 return ret;
 669         }
 670     }
 671
 672     ctx->flags |= GSS_C_TRANS_FLAG;
 673
 674     /* Remember the flags */
 675
 676     ctx->endtime = ctx->ticket->ticket.endtime;
 677     ctx->more_flags |= OPEN;
 678
 679     if (mech_type)
 680         *mech_type = GSS_KRB5_MECHANISM;
 681
 682     if (time_rec) {
 683         ret = _gsskrb5_lifetime_left(minor_status,
 684                                      context,
 685                                      ctx->endtime,
 686                                      time_rec);
 687         if (ret) {
 688             return ret;
 689         }
 690     }
 691
 692     /*
 693      * When GSS_C_DCE_STYLE is in use, we need ask for a AP-REP from
 694      * the client.
 695      */
 696     if (IS_DCE_STYLE(ctx)) {
 697         /*
 698          * Return flags to caller, but we haven't processed
 699          * delgations yet
 700          */
 701         if (ret_flags)
 702             *ret_flags = (ctx->flags & ~GSS_C_DELEG_FLAG);
 703
 704         ctx->state = ACCEPTOR_WAIT_FOR_DCESTYLE;
 705         return GSS_S_CONTINUE_NEEDED;
 706     }
 707
 708     ret = gsskrb5_acceptor_ready(minor_status, ctx, context,
 709                                  delegated_cred_handle);
 710
 711     if (ret_flags)
 712         *ret_flags = ctx->flags;
 713
 714     return ret;
 715 }
 716
 717 static OM_uint32
 718 acceptor_wait_for_dcestyle(OM_uint32 * minor_status,
 719                            gsskrb5_ctx ctx,
 720                            krb5_context context,
 721                            gss_const_cred_id_t acceptor_cred_handle,
 722                            const gss_buffer_t input_token_buffer,
 723                            const gss_channel_bindings_t input_chan_bindings,
 724                            gss_name_t * src_name,
 725                            gss_OID * mech_type,
 726                            gss_buffer_t output_token,
 727                            OM_uint32 * ret_flags,
 728                            OM_uint32 * time_rec,
 729                            gss_cred_id_t * delegated_cred_handle)
 730 {
 731     OM_uint32 ret;
 732     krb5_error_code kret;
 733     krb5_data inbuf;
 734     int32_t r_seq_number, l_seq_number;
 735
 736     /*
 737      * We know it's GSS_C_DCE_STYLE so we don't need to decapsulate the AP_REP
 738      */
 739
 740     inbuf.length = input_token_buffer->length;
 741     inbuf.data = input_token_buffer->value;
 742
 743     /*
 744      * We need to remeber the old remote seq_number, then check if the
 745      * client has replied with our local seq_number, and then reset
 746      * the remote seq_number to the old value
 747      */
 748     {
 749         kret = krb5_auth_con_getlocalseqnumber(context,
 750                                                ctx->auth_context,
 751                                                &l_seq_number);
 752         if (kret) {
 753             *minor_status = kret;
 754             return GSS_S_FAILURE;
 755         }
 756
 757         kret = krb5_auth_con_getremoteseqnumber(context,
 758                                                 ctx->auth_context,
 759                                                 &r_seq_number);
 760         if (kret) {
 761             *minor_status = kret;
 762             return GSS_S_FAILURE;
 763         }
 764
 765         kret = krb5_auth_con_setremoteseqnumber(context,
 766                                                 ctx->auth_context,
 767                                                 l_seq_number);
 768         if (kret) {
 769             *minor_status = kret;
 770             return GSS_S_FAILURE;
 771         }
 772     }
 773
 774     /*
 775      * We need to verify the AP_REP, but we need to flag that this is
 776      * DCE_STYLE, so don't check the timestamps this time, but put the
 777      * flag DO_TIME back afterward.
 778     */
 779     {
 780         krb5_ap_rep_enc_part *repl;
 781         int32_t auth_flags;
 782
 783         krb5_auth_con_removeflags(context,
 784                                   ctx->auth_context,
 785                                   KRB5_AUTH_CONTEXT_DO_TIME,
 786                                   &auth_flags);
 787
 788         kret = krb5_rd_rep(context, ctx->auth_context, &inbuf, &repl);
 789         if (kret) {
 790             *minor_status = kret;
 791             return GSS_S_FAILURE;
 792         }
 793         krb5_free_ap_rep_enc_part(context, repl);
 794         krb5_auth_con_setflags(context, ctx->auth_context, auth_flags);
 795     }
 796
 797     /* We need to check the liftime */
 798     {
 799         OM_uint32 lifetime_rec;
 800
 801         ret = _gsskrb5_lifetime_left(minor_status,
 802                                      context,
 803                                      ctx->endtime,
 804                                      &lifetime_rec);
 805         if (ret) {
 806             return ret;
 807         }
 808         if (lifetime_rec == 0) {
 809             return GSS_S_CONTEXT_EXPIRED;
 810         }
 811
 812         if (time_rec) *time_rec = lifetime_rec;
 813     }
 814
 815     /* We need to give the caller the flags which are in use */
 816     if (ret_flags) *ret_flags = ctx->flags;
 817
 818     if (src_name) {
 819         kret = krb5_copy_principal(context,
 820                                    ctx->source,
 821                                    (gsskrb5_name*)src_name);
 822         if (kret) {
 823             *minor_status = kret;
 824             return GSS_S_FAILURE;
 825         }
 826     }
 827
 828     /*
 829      * After the krb5_rd_rep() the remote and local seq_number should
 830      * be the same, because the client just replies the seq_number
 831      * from our AP-REP in its AP-REP, but then the client uses the
 832      * seq_number from its AP-REQ for GSS_wrap()
 833      */
 834     {
 835         int32_t tmp_r_seq_number, tmp_l_seq_number;
 836
 837         kret = krb5_auth_con_getremoteseqnumber(context,
 838                                                 ctx->auth_context,
 839                                                 &tmp_r_seq_number);
 840         if (kret) {
 841             *minor_status = kret;
 842             return GSS_S_FAILURE;
 843         }
 844
 845         kret = krb5_auth_con_getlocalseqnumber(context,
 846                                                ctx->auth_context,
 847                                                &tmp_l_seq_number);
 848         if (kret) {
 849
 850             *minor_status = kret;
 851             return GSS_S_FAILURE;
 852         }
 853
 854         /*
 855          * Here we check if the client has responsed with our local seq_number,
 856          */
 857         if (tmp_r_seq_number != tmp_l_seq_number) {
 858             return GSS_S_UNSEQ_TOKEN;
 859         }
 860     }
 861
 862     /*
 863      * We need to reset the remote seq_number, because the client will use,
 864      * the old one for the GSS_wrap() calls
 865      */
 866     {
 867         kret = krb5_auth_con_setremoteseqnumber(context,
 868                                                 ctx->auth_context,
 869                                                 r_seq_number);
 870         if (kret) {
 871             *minor_status = kret;
 872             return GSS_S_FAILURE;
 873         }
 874     }
 875
 876     return gsskrb5_acceptor_ready(minor_status, ctx, context,
 877                                   delegated_cred_handle);
 878 }
 879
 880
 881 OM_uint32 GSSAPI_CALLCONV
 882 _gsskrb5_accept_sec_context(OM_uint32 * minor_status,
 883                             gss_ctx_id_t * context_handle,
 884                             gss_const_cred_id_t acceptor_cred_handle,
 885                             const gss_buffer_t input_token_buffer,
 886                             const gss_channel_bindings_t input_chan_bindings,
 887                             gss_name_t * src_name,
 888                             gss_OID * mech_type,
 889                             gss_buffer_t output_token,
 890                             OM_uint32 * ret_flags,
 891                             OM_uint32 * time_rec,
 892                             gss_cred_id_t * delegated_cred_handle)
 893 {
 894     krb5_context context;
 895     OM_uint32 ret;
 896     gsskrb5_ctx ctx;
 897
 898     GSSAPI_KRB5_INIT(&context);
 899
 900     output_token->length = 0;
 901     output_token->value = NULL;
 902
 903     if (src_name != NULL)
 904         *src_name = NULL;
 905     if (mech_type)
 906         *mech_type = GSS_KRB5_MECHANISM;
 907
 908     if (*context_handle == GSS_C_NO_CONTEXT) {
 909         ret = _gsskrb5_create_ctx(minor_status,
 910                                   context_handle,
 911                                   context,
 912                                   input_chan_bindings,
 913                                   ACCEPTOR_START);
 914         if (ret)
 915             return ret;
 916     }
 917
 918     ctx = (gsskrb5_ctx)*context_handle;
 919
 920
 921     /*
 922      * TODO: check the channel_bindings
 923      * (above just sets them to krb5 layer)
 924      */
 925
 926     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
 927
 928     switch (ctx->state) {
 929     case ACCEPTOR_START:
 930         ret = gsskrb5_acceptor_start(minor_status,
 931                                      ctx,
 932                                      context,
 933                                      acceptor_cred_handle,
 934                                      input_token_buffer,
 935                                      input_chan_bindings,
 936                                      src_name,
 937                                      mech_type,
 938                                      output_token,
 939                                      ret_flags,
 940                                      time_rec,
 941                                      delegated_cred_handle);
 942         break;
 943     case ACCEPTOR_WAIT_FOR_DCESTYLE:
 944         ret = acceptor_wait_for_dcestyle(minor_status,
 945                                          ctx,
 946                                          context,
 947                                          acceptor_cred_handle,
 948                                          input_token_buffer,
 949                                          input_chan_bindings,
 950                                          src_name,
 951                                          mech_type,
 952                                          output_token,
 953                                          ret_flags,
 954                                          time_rec,
 955                                          delegated_cred_handle);
 956         break;
 957     case ACCEPTOR_READY:
 958         /*
 959          * If we get there, the caller have called
 960          * gss_accept_sec_context() one time too many.
 961          */
 962         ret =  GSS_S_BAD_STATUS;
 963         break;
 964     default:
 965         /* TODO: is this correct here? --metze */
 966         ret =  GSS_S_BAD_STATUS;
 967         break;
 968     }
 969
 970     HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
 971
 972     if (GSS_ERROR(ret)) {
 973         OM_uint32 min2;
 974         _gsskrb5_delete_sec_context(&min2, context_handle, GSS_C_NO_BUFFER);
 975     }
 976
 977     return ret;
 978 }