www.project-moonshot.org Git - mech_eap.orig/blob - util_reauth.c

   1 /*
   2  * Copyright (c) 2010, JANET(UK)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  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  * 3. Neither the name of JANET(UK) nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "gssapiP_eap.h"
  34
  35 #include <dlfcn.h>
  36
  37 /*
  38  * Fast reauthentication support for EAP GSS.
  39  */
  40
  41 krb5_error_code
  42 krb5_encrypt_tkt_part(krb5_context, const krb5_keyblock *, krb5_ticket *);
  43
  44 krb5_error_code
  45 encode_krb5_ticket(const krb5_ticket *rep, krb5_data **code);
  46
  47 static krb5_error_code
  48 getAcceptorKey(krb5_context krbContext,
  49                gss_ctx_id_t ctx,
  50                gss_cred_id_t cred,
  51                krb5_principal *princ,
  52                krb5_keyblock *key)
  53 {
  54     krb5_error_code code;
  55     krb5_keytab keytab = NULL;
  56     krb5_keytab_entry ktent = { 0 };
  57     krb5_kt_cursor cursor = NULL;
  58
  59     *princ = NULL;
  60     memset(key, 0, sizeof(*key));
  61
  62     code = krb5_kt_default(krbContext, &keytab);
  63     if (code != 0)
  64         goto cleanup;
  65
  66     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
  67         code = krb5_kt_get_entry(krbContext, keytab,
  68                                  cred->name->krbPrincipal, 0,
  69                                  ctx->encryptionType, &ktent);
  70         if (code != 0)
  71             goto cleanup;
  72     } else {
  73         code = krb5_kt_start_seq_get(krbContext, keytab, &cursor);
  74         if (code != 0)
  75             goto cleanup;
  76
  77         while ((code = krb5_kt_next_entry(krbContext, keytab,
  78                                           &ktent, &cursor)) == 0) {
  79             if (ktent.key.enctype == ctx->encryptionType)
  80                 break;
  81             else
  82                 krb5_free_keytab_entry_contents(krbContext, &ktent);
  83         }
  84     }
  85
  86     if (code == 0) {
  87         *princ = ktent.principal;
  88         *key = ktent.key;
  89     }
  90
  91 cleanup:
  92     if (cred == GSS_C_NO_CREDENTIAL || cred->name == GSS_C_NO_NAME)
  93         krb5_kt_end_seq_get(krbContext, keytab, &cursor);
  94     krb5_kt_close(krbContext, keytab);
  95
  96     if (code != 0)
  97         krb5_free_keytab_entry_contents(krbContext, &ktent);
  98
  99     return code;
 100 }
 101
 102 static OM_uint32
 103 freezeAttrContext(OM_uint32 *minor,
 104                   gss_name_t initiatorName,
 105                   krb5_const_principal acceptorPrinc,
 106                   krb5_keyblock *session,
 107                   krb5_authdata ***authdata)
 108 {
 109     OM_uint32 major, tmpMinor;
 110     krb5_error_code code;
 111     gss_buffer_desc attrBuf = GSS_C_EMPTY_BUFFER;
 112     krb5_authdata *authData[2], authDatum = { 0 };
 113     krb5_context krbContext;
 114
 115     GSSEAP_KRB_INIT(&krbContext);
 116
 117     major = gssEapExportAttrContext(minor, initiatorName, &attrBuf);
 118     if (GSS_ERROR(major))
 119         return major;
 120
 121     authDatum.ad_type = KRB5_AUTHDATA_RADIUS_AVP;
 122     authDatum.length = attrBuf.length;
 123     authDatum.contents = attrBuf.value;
 124     authData[0] = &authDatum;
 125     authData[1] = NULL;
 126
 127     code = krb5_make_authdata_kdc_issued(krbContext, session, acceptorPrinc,
 128                                          authData, authdata);
 129     if (code != 0) {
 130         major = GSS_S_FAILURE;
 131         *minor = code;
 132     } else {
 133         major = GSS_S_COMPLETE;
 134     }
 135
 136     gss_release_buffer(&tmpMinor, &attrBuf);
 137
 138     return major;
 139 }
 140
 141 OM_uint32
 142 gssEapMakeReauthCreds(OM_uint32 *minor,
 143                       gss_ctx_id_t ctx,
 144                       gss_cred_id_t cred,
 145                       gss_buffer_t credBuf)
 146 {
 147     OM_uint32 major = GSS_S_COMPLETE;
 148     krb5_error_code code;
 149     krb5_context krbContext = NULL;
 150     krb5_ticket ticket = { 0 };
 151     krb5_keyblock session = { 0 }, acceptorKey = { 0 };
 152     krb5_enc_tkt_part enc_part = { 0 };
 153     krb5_data *ticketData = NULL, *credsData = NULL;
 154     krb5_creds creds = { 0 };
 155     krb5_auth_context authContext = NULL;
 156
 157     credBuf->length = 0;
 158     credBuf->value = NULL;
 159
 160     GSSEAP_KRB_INIT(&krbContext);
 161
 162     code = getAcceptorKey(krbContext, ctx, cred,
 163                           &ticket.server, &acceptorKey);
 164     if (code == KRB5_KT_NOTFOUND) {
 165         gss_buffer_desc emptyToken = { 0, "" };
 166
 167         /*
 168          * If we can't produce the KRB-CRED message, we need to
 169          * return an empty (not NULL) token to the caller so we
 170          * don't change the number of authentication legs.
 171          */
 172         return duplicateBuffer(minor, &emptyToken, credBuf);
 173     } else if (code != 0)
 174         goto cleanup;
 175
 176     enc_part.flags = TKT_FLG_INITIAL;
 177
 178     /*
 179      * Generate a random session key to place in the ticket and
 180      * sign the "KDC-Issued" authorization data element.
 181      */
 182     code = krb5_c_make_random_key(krbContext, ctx->encryptionType,
 183                                   &session);
 184     if (code != 0)
 185         goto cleanup;
 186
 187     enc_part.session = &session;
 188     enc_part.client = ctx->initiatorName->krbPrincipal;
 189     enc_part.times.authtime = time(NULL);
 190     enc_part.times.starttime = enc_part.times.authtime;
 191     enc_part.times.endtime = ctx->expiryTime
 192                              ? ctx->expiryTime
 193                              : KRB5_INT32_MAX;
 194     enc_part.times.renew_till = 0;
 195
 196     major = freezeAttrContext(minor, ctx->initiatorName, ticket.server,
 197                               &session, &enc_part.authorization_data);
 198     if (GSS_ERROR(major))
 199         goto cleanup;
 200
 201     ticket.enc_part2 = &enc_part;
 202
 203     code = krb5_encrypt_tkt_part(krbContext, &acceptorKey, &ticket);
 204     if (code != 0)
 205         goto cleanup;
 206
 207     code = encode_krb5_ticket(&ticket, &ticketData);
 208     if (code != 0)
 209         goto cleanup;
 210
 211     creds.client = enc_part.client;
 212     creds.server = ticket.server;
 213     creds.keyblock = session;
 214     creds.times = enc_part.times;
 215     creds.ticket_flags = enc_part.flags;
 216     creds.ticket = *ticketData;
 217     creds.authdata = enc_part.authorization_data;
 218
 219     code = krb5_auth_con_init(krbContext, &authContext);
 220     if (code != 0)
 221         goto cleanup;
 222
 223     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 224     if (code != 0)
 225         goto cleanup;
 226
 227     code = krb5_auth_con_setsendsubkey(krbContext, authContext,
 228                                        &ctx->rfc3961Key);
 229     if (code != 0)
 230         goto cleanup;
 231
 232     code = krb5_mk_1cred(krbContext, authContext, &creds, &credsData, NULL);
 233     if (code != 0)
 234         goto cleanup;
 235
 236     krbDataToGssBuffer(credsData, credBuf);
 237
 238 cleanup:
 239     if (ticket.enc_part.ciphertext.data != NULL)
 240         GSSEAP_FREE(ticket.enc_part.ciphertext.data);
 241     krb5_free_keyblock_contents(krbContext, &session);
 242     krb5_free_keyblock_contents(krbContext, &acceptorKey);
 243     krb5_free_data(krbContext, ticketData);
 244     krb5_auth_con_free(krbContext, authContext);
 245     krb5_free_authdata(krbContext, enc_part.authorization_data);
 246     if (credsData != NULL)
 247         GSSEAP_FREE(credsData);
 248
 249     if (major == GSS_S_COMPLETE) {
 250         *minor = code;
 251         major = code != 0 ? GSS_S_FAILURE : GSS_S_COMPLETE;
 252     }
 253
 254     return major;
 255 }
 256
 257 static int
 258 isTicketGrantingServiceP(krb5_context krbContext,
 259                          krb5_const_principal principal)
 260 {
 261     if (krb5_princ_size(krbContext, principal) == 2 &&
 262         krb5_princ_component(krbContext, principal, 0)->length == 6 &&
 263         memcmp(krb5_princ_component(krbContext,
 264                                     principal, 0)->data, "krbtgt", 6) == 0)
 265         return TRUE;
 266
 267     return FALSE;
 268 }
 269
 270 OM_uint32
 271 gssEapStoreReauthCreds(OM_uint32 *minor,
 272                        gss_ctx_id_t ctx,
 273                        gss_cred_id_t cred,
 274                        gss_buffer_t credBuf)
 275 {
 276     OM_uint32 major = GSS_S_COMPLETE, code;
 277     krb5_context krbContext = NULL;
 278     krb5_auth_context authContext = NULL;
 279     krb5_data credData = { 0 };
 280     krb5_creds **creds = NULL;
 281     krb5_principal canonPrinc;
 282     int i;
 283
 284     if (credBuf->length == 0 || cred == GSS_C_NO_CREDENTIAL)
 285         return GSS_S_COMPLETE;
 286
 287     GSSEAP_KRB_INIT(&krbContext);
 288
 289     code = krb5_auth_con_init(krbContext, &authContext);
 290     if (code != 0)
 291         goto cleanup;
 292
 293     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 294     if (code != 0)
 295         goto cleanup;
 296
 297     code = krb5_auth_con_setrecvsubkey(krbContext, authContext,
 298                                        &ctx->rfc3961Key);
 299     if (code != 0)
 300         goto cleanup;
 301
 302     gssBufferToKrbData(credBuf, &credData);
 303
 304     code = krb5_rd_cred(krbContext, authContext, &credData, &creds, NULL);
 305     if (code != 0)
 306         goto cleanup;
 307
 308     if (creds == NULL || creds[0] == NULL)
 309         goto cleanup;
 310
 311     code = krb5_copy_principal(krbContext, creds[0]->client, &canonPrinc);
 312     if (code != 0)
 313         goto cleanup;
 314
 315     krb5_free_principal(krbContext, cred->name->krbPrincipal);
 316     cred->name->krbPrincipal = canonPrinc;
 317
 318     cred->expiryTime = creds[0]->times.endtime;
 319
 320     code = krb5_cc_new_unique(krbContext, "MEMORY", NULL, &cred->krbCredCache);
 321     if (code != 0)
 322         goto cleanup;
 323
 324     code = krb5_cc_initialize(krbContext, cred->krbCredCache,
 325                               creds[0]->client);
 326     if (code != 0)
 327         goto cleanup;
 328
 329     for (i = 0; creds[i] != NULL; i++) {
 330         krb5_creds kcred = *(creds[i]);
 331
 332         /*
 333          * Swap in the acceptor name the client asked for so
 334          * get_credentials() works. We're making the assumption that
 335          * any service tickets returned are for us. We'll need to
 336          * reflect some more on whether that is a safe assumption.
 337          */
 338         if (!isTicketGrantingServiceP(krbContext, kcred.server))
 339             kcred.server = ctx->acceptorName->krbPrincipal;
 340
 341         code = krb5_cc_store_cred(krbContext, cred->krbCredCache, &kcred);
 342         if (code != 0)
 343             goto cleanup;
 344     }
 345
 346     /*
 347      * To turn a credentials cache into a GSS credentials handle, we
 348      * require the gss_krb5_import_cred() API (present in Heimdal, but
 349      * not shipped in MIT yet).
 350      */
 351     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 352                                  &cred->krbCred);
 353     if (GSS_ERROR(major))
 354         goto cleanup;
 355
 356 cleanup:
 357     *minor = code;
 358
 359     krb5_auth_con_free(krbContext, authContext);
 360     if (creds != NULL) {
 361         for (i = 0; creds[i] != NULL; i++)
 362             krb5_free_creds(krbContext, creds[i]);
 363     }
 364     if (major == GSS_S_COMPLETE)
 365         major = *minor ? GSS_S_FAILURE : GSS_S_COMPLETE;
 366
 367     return major;
 368 }
 369
 370 static OM_uint32
 371 (*gssInitSecContextNext)(OM_uint32 *,
 372                          gss_cred_id_t,
 373                          gss_ctx_id_t *,
 374                          gss_name_t,
 375                          gss_OID,
 376                          OM_uint32,
 377                          OM_uint32,
 378                          gss_channel_bindings_t,
 379                          gss_buffer_t,
 380                          gss_OID *,
 381                          gss_buffer_t,
 382                          OM_uint32 *,
 383                          OM_uint32 *);
 384
 385 static OM_uint32
 386 (*gssAcceptSecContextNext)(OM_uint32 *,
 387                            gss_ctx_id_t *,
 388                            gss_cred_id_t,
 389                            gss_buffer_t,
 390                            gss_channel_bindings_t,
 391                            gss_name_t *,
 392                            gss_OID *,
 393                            gss_buffer_t,
 394                            OM_uint32 *,
 395                            OM_uint32 *,
 396                            gss_cred_id_t *);
 397
 398 static OM_uint32
 399 (*gssReleaseCredNext)(OM_uint32 *, gss_cred_id_t *);
 400
 401 static OM_uint32
 402 (*gssReleaseNameNext)(OM_uint32 *, gss_name_t *);
 403
 404 static OM_uint32
 405 (*gssInquireSecContextByOidNext)(OM_uint32 *,
 406                                  const gss_ctx_id_t,
 407                                  const gss_OID,
 408                                  gss_buffer_set_t *);
 409
 410 static OM_uint32
 411 (*gssDeleteSecContextNext)(OM_uint32 *,
 412                           gss_ctx_id_t *,
 413                           gss_buffer_t);
 414
 415 static OM_uint32
 416 (*gssDisplayNameNext)(OM_uint32 *,
 417                       gss_name_t,
 418                       gss_buffer_t,
 419                       gss_OID *);
 420
 421 static OM_uint32
 422 (*gssImportNameNext)(OM_uint32 *,
 423                      gss_buffer_t,
 424                      gss_OID,
 425                      gss_name_t *);
 426
 427 static OM_uint32
 428 (*gssStoreCredNext)(OM_uint32 *,
 429                     const gss_cred_id_t,
 430                     gss_cred_usage_t,
 431                     const gss_OID,
 432                     OM_uint32,
 433                     OM_uint32,
 434                     gss_OID_set *,
 435                     gss_cred_usage_t *);
 436
 437 static OM_uint32
 438 (*gssGetNameAttributeNext)(OM_uint32 *,
 439                           gss_name_t,
 440                           gss_buffer_t,
 441                           int *,
 442                           int *,
 443                           gss_buffer_t,
 444                           gss_buffer_t,
 445                           int *);
 446
 447 #define NEXT_SYMBOL(local, global)  ((local) = dlsym(RTLD_NEXT, (global)))
 448
 449 OM_uint32
 450 gssEapReauthInitialize(OM_uint32 *minor)
 451 {
 452     NEXT_SYMBOL(gssInitSecContextNext,                    "gss_init_sec_context");
 453     NEXT_SYMBOL(gssAcceptSecContextNext,                  "gss_accept_sec_context");
 454     NEXT_SYMBOL(gssReleaseCredNext,                       "gss_release_cred");
 455     NEXT_SYMBOL(gssReleaseNameNext,                       "gss_release_name");
 456     NEXT_SYMBOL(gssInquireSecContextByOidNext,            "gss_inquire_sec_context_by_oid");
 457     NEXT_SYMBOL(gssDeleteSecContextNext,                  "gss_delete_sec_context");
 458     NEXT_SYMBOL(gssDisplayNameNext,                       "gss_display_name");
 459     NEXT_SYMBOL(gssImportNameNext,                        "gss_import_name");
 460     NEXT_SYMBOL(gssStoreCredNext,                         "gss_store_cred");
 461     NEXT_SYMBOL(gssGetNameAttributeNext,                  "gss_get_name_attribute");
 462
 463     return GSS_S_COMPLETE;
 464 }
 465
 466 OM_uint32
 467 gssInitSecContext(OM_uint32 *minor,
 468                   gss_cred_id_t cred,
 469                   gss_ctx_id_t *context_handle,
 470                   gss_name_t target_name,
 471                   gss_OID mech_type,
 472                   OM_uint32 req_flags,
 473                   OM_uint32 time_req,
 474                   gss_channel_bindings_t input_chan_bindings,
 475                   gss_buffer_t input_token,
 476                   gss_OID *actual_mech_type,
 477                   gss_buffer_t output_token,
 478                   OM_uint32 *ret_flags,
 479                   OM_uint32 *time_rec)
 480 {
 481     if (gssInitSecContextNext == NULL)
 482         return GSS_S_UNAVAILABLE;
 483
 484     return gssInitSecContextNext(minor, cred, context_handle,
 485                                  target_name, mech_type, req_flags,
 486                                  time_req, input_chan_bindings,
 487                                  input_token, actual_mech_type,
 488                                  output_token, ret_flags, time_rec);
 489 }
 490
 491 OM_uint32
 492 gssAcceptSecContext(OM_uint32 *minor,
 493                     gss_ctx_id_t *context_handle,
 494                     gss_cred_id_t cred,
 495                     gss_buffer_t input_token,
 496                     gss_channel_bindings_t input_chan_bindings,
 497                     gss_name_t *src_name,
 498                     gss_OID *mech_type,
 499                     gss_buffer_t output_token,
 500                     OM_uint32 *ret_flags,
 501                     OM_uint32 *time_rec,
 502                     gss_cred_id_t *delegated_cred_handle)
 503 {
 504     if (gssAcceptSecContextNext == NULL)
 505         return GSS_S_UNAVAILABLE;
 506
 507     return gssAcceptSecContextNext(minor, context_handle, cred,
 508                                    input_token, input_chan_bindings,
 509                                    src_name, mech_type, output_token,
 510                                    ret_flags, time_rec, delegated_cred_handle);
 511 }
 512
 513 OM_uint32
 514 gssReleaseCred(OM_uint32 *minor,
 515                gss_cred_id_t *cred_handle)
 516 {
 517     if (gssReleaseCredNext == NULL)
 518         return GSS_S_UNAVAILABLE;
 519
 520     return gssReleaseCredNext(minor, cred_handle);
 521 }
 522
 523 OM_uint32
 524 gssReleaseName(OM_uint32 *minor,
 525                gss_name_t *name)
 526 {
 527     if (gssReleaseName == NULL)
 528         return GSS_S_UNAVAILABLE;
 529
 530     return gssReleaseNameNext(minor, name);
 531 }
 532
 533 OM_uint32
 534 gssDeleteSecContext(OM_uint32 *minor,
 535                     gss_ctx_id_t *context_handle,
 536                     gss_buffer_t output_token)
 537 {
 538     if (gssDeleteSecContextNext == NULL)
 539         return GSS_S_UNAVAILABLE;
 540
 541     return gssDeleteSecContextNext(minor, context_handle, output_token);
 542 }
 543
 544 static OM_uint32
 545 gssDisplayName(OM_uint32 *minor,
 546                gss_name_t name,
 547                gss_buffer_t buffer,
 548                gss_OID *name_type)
 549 {
 550     if (gssDisplayNameNext == NULL)
 551         return GSS_S_UNAVAILABLE;
 552
 553     return gssDisplayNameNext(minor, name, buffer, name_type);
 554 }
 555
 556 static OM_uint32
 557 gssImportName(OM_uint32 *minor,
 558               gss_buffer_t buffer,
 559               gss_OID name_type,
 560               gss_name_t *name)
 561 {
 562     if (gssImportNameNext == NULL)
 563         return GSS_S_UNAVAILABLE;
 564
 565     return gssImportNameNext(minor, buffer, name_type, name);
 566 }
 567
 568 OM_uint32
 569 gssInquireSecContextByOid(OM_uint32 *minor,
 570                           const gss_ctx_id_t context_handle,
 571                           const gss_OID desired_object,
 572                           gss_buffer_set_t *data_set)
 573 {
 574     if (gssInquireSecContextByOidNext == NULL)
 575         return GSS_S_UNAVAILABLE;
 576
 577     return gssInquireSecContextByOidNext(minor, context_handle,
 578                                          desired_object, data_set);
 579 }
 580
 581 OM_uint32
 582 gssStoreCred(OM_uint32 *minor,
 583              const gss_cred_id_t input_cred_handle,
 584              gss_cred_usage_t input_usage,
 585              const gss_OID desired_mech,
 586              OM_uint32 overwrite_cred,
 587              OM_uint32 default_cred,
 588              gss_OID_set *elements_stored,
 589              gss_cred_usage_t *cred_usage_stored)
 590 {
 591     if (gssStoreCredNext == NULL)
 592         return GSS_S_UNAVAILABLE;
 593
 594     return gssStoreCredNext(minor, input_cred_handle, input_usage,
 595                             desired_mech, overwrite_cred, default_cred,
 596                             elements_stored, cred_usage_stored);
 597 }
 598
 599 OM_uint32
 600 gssGetNameAttribute(OM_uint32 *minor,
 601                     gss_name_t name,
 602                     gss_buffer_t attr,
 603                     int *authenticated,
 604                     int *complete,
 605                     gss_buffer_t value,
 606                     gss_buffer_t display_value,
 607                     int *more)
 608 {
 609     if (gssGetNameAttributeNext == NULL)
 610         return GSS_S_UNAVAILABLE;
 611
 612     return gssGetNameAttributeNext(minor, name, attr, authenticated, complete,
 613                                    value, display_value, more);
 614 }
 615
 616 static gss_buffer_desc radiusAvpKrbAttr = {
 617     sizeof("urn:authdata-radius-avp") - 1, "urn:authdata-radius-avp"
 618 };
 619
 620 /*
 621  * Unfortunately extracting an AD-KDCIssued authorization data element
 622  * is pretty implementation-dependent. It's not possible to verify the
 623  * signature ourselves because the ticket session key is not exposed
 624  * outside GSS. In an ideal world, all AD-KDCIssued elements would be
 625  * verified by the Kerberos library and authentication would fail if
 626  * verification failed. We're not quite there yet and as a result have
 627  * to go through some hoops to get this to work. The alternative would
 628  * be to sign the authorization data with our long-term key, but it
 629  * seems a pity to compromise the design because of current implementation
 630  * limitations.
 631  *
 632  * (Specifically, the hoops involve a libkrb5 authorisation data plugin
 633  * that exposes the verified and serialised attribute context through
 634  * the Kerberos GSS mechanism's naming extensions API.)
 635  */
 636 static OM_uint32
 637 defrostAttrContext(OM_uint32 *minor,
 638                    gss_name_t glueName,
 639                    gss_name_t mechName)
 640 {
 641     OM_uint32 major, tmpMinor;
 642     gss_buffer_desc authData = GSS_C_EMPTY_BUFFER;
 643     gss_buffer_desc authDataDisplay = GSS_C_EMPTY_BUFFER;
 644     int more = -1;
 645     int authenticated, complete;
 646
 647     major = gssGetNameAttribute(minor, glueName, &radiusAvpKrbAttr,
 648                                 &authenticated, &complete,
 649                                 &authData, &authDataDisplay, &more);
 650     if (major == GSS_S_COMPLETE) {
 651         if (authenticated == 0)
 652             major = GSS_S_BAD_NAME;
 653         else
 654             major = gssEapImportAttrContext(minor, &authData, mechName);
 655     } else if (major == GSS_S_UNAVAILABLE) {
 656         major = GSS_S_COMPLETE;
 657     }
 658
 659     gss_release_buffer(&tmpMinor, &authData);
 660     gss_release_buffer(&tmpMinor, &authDataDisplay);
 661
 662     return major;
 663 }
 664
 665 OM_uint32
 666 gssEapGlueToMechName(OM_uint32 *minor,
 667                      gss_name_t glueName,
 668                      gss_name_t *pMechName)
 669 {
 670     OM_uint32 major, tmpMinor;
 671     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 672
 673     *pMechName = GSS_C_NO_NAME;
 674
 675     major = gssDisplayName(minor, glueName, &nameBuf, NULL);
 676     if (GSS_ERROR(major))
 677         goto cleanup;
 678
 679     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 680                              pMechName);
 681     if (GSS_ERROR(major))
 682         goto cleanup;
 683
 684     major = defrostAttrContext(minor, glueName, *pMechName);
 685     if (GSS_ERROR(major))
 686         goto cleanup;
 687
 688 cleanup:
 689     if (GSS_ERROR(major)) {
 690         gssReleaseName(&tmpMinor, pMechName);
 691         *pMechName = GSS_C_NO_NAME;
 692     }
 693
 694     gss_release_buffer(&tmpMinor, &nameBuf);
 695
 696     return major;
 697 }
 698
 699 OM_uint32
 700 gssEapMechToGlueName(OM_uint32 *minor,
 701                      gss_name_t mechName,
 702                      gss_name_t *pGlueName)
 703 {
 704     OM_uint32 major, tmpMinor;
 705     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 706
 707     *pGlueName = GSS_C_NO_NAME;
 708
 709     major = gssEapDisplayName(minor, mechName, &nameBuf, NULL);
 710     if (GSS_ERROR(major))
 711         goto cleanup;
 712
 713     major = gssImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 714                           pGlueName);
 715     if (GSS_ERROR(major))
 716         goto cleanup;
 717
 718 cleanup:
 719     gss_release_buffer(&tmpMinor, &nameBuf);
 720
 721     return major;
 722 }
 723
 724 /*
 725  * Suck out the analgous elements of a Kerberos GSS context into an EAP
 726  * one so that the application doesn't know the difference.
 727  */
 728 OM_uint32
 729 gssEapReauthComplete(OM_uint32 *minor,
 730                     gss_ctx_id_t ctx,
 731                     gss_cred_id_t cred,
 732                     const gss_OID mech,
 733                     OM_uint32 timeRec)
 734 {
 735     OM_uint32 major, tmpMinor;
 736     gss_buffer_set_t keyData = GSS_C_NO_BUFFER_SET;
 737
 738     if (!oidEqual(mech, gss_mech_krb5)) {
 739         major = GSS_S_BAD_MECH;
 740         goto cleanup;
 741     }
 742
 743     /* Get the raw subsession key and encryptino type*/
 744     major = gssInquireSecContextByOid(minor, ctx->kerberosCtx,
 745                                       GSS_C_INQ_SSPI_SESSION_KEY, &keyData);
 746     if (GSS_ERROR(major))
 747         goto cleanup;
 748
 749     {
 750         gss_OID_desc oid;
 751         int suffix;
 752
 753         oid.length = keyData->elements[1].length;
 754         oid.elements = keyData->elements[1].value;
 755
 756         /* GSS_KRB5_SESSION_KEY_ENCTYPE_OID */
 757         major = decomposeOid(minor,
 758                              "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04",
 759                              10, &oid, &suffix);
 760         if (GSS_ERROR(major))
 761             goto cleanup;
 762
 763         ctx->encryptionType = suffix;
 764     }
 765
 766     {
 767         krb5_context krbContext = NULL;
 768         krb5_keyblock key;
 769
 770         GSSEAP_KRB_INIT(&krbContext);
 771
 772         KRB_KEY_LENGTH(&key) = keyData->elements[0].length;
 773         KRB_KEY_DATA(&key)   = keyData->elements[0].value;
 774         KRB_KEY_TYPE(&key)   = ctx->encryptionType;
 775
 776         *minor = krb5_copy_keyblock_contents(krbContext,
 777                                              &key, &ctx->rfc3961Key);
 778         if (*minor != 0) {
 779             major = GSS_S_FAILURE;
 780             goto cleanup;
 781         }
 782     }
 783
 784     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 785                                       &ctx->checksumType);
 786     if (GSS_ERROR(major))
 787         goto cleanup;
 788
 789     if (timeRec != GSS_C_INDEFINITE)
 790         ctx->expiryTime = time(NULL) + timeRec;
 791
 792     major = sequenceInit(minor,
 793                          &ctx->seqState, ctx->recvSeq,
 794                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 795                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 796                          TRUE);
 797     if (GSS_ERROR(major))
 798         goto cleanup;
 799
 800     major = GSS_S_COMPLETE;
 801
 802 cleanup:
 803     gss_release_buffer_set(&tmpMinor, &keyData);
 804
 805     return major;
 806 }