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 /*
  34  * Fast reauthentication support.
  35  */
  36
  37 #include "gssapiP_eap.h"
  38
  39 #include <dlfcn.h>
  40
  41 /*
  42  * Fast reauthentication support for EAP GSS.
  43  */
  44
  45 krb5_error_code
  46 krb5_encrypt_tkt_part(krb5_context, const krb5_keyblock *, krb5_ticket *);
  47
  48 krb5_error_code
  49 encode_krb5_ticket(const krb5_ticket *rep, krb5_data **code);
  50
  51 static OM_uint32
  52 gssDisplayName(OM_uint32 *minor,
  53                gss_name_t name,
  54                gss_buffer_t buffer,
  55                gss_OID *name_type);
  56
  57 static OM_uint32
  58 gssImportName(OM_uint32 *minor,
  59               gss_buffer_t buffer,
  60               gss_OID name_type,
  61               gss_name_t *name);
  62
  63 static krb5_error_code
  64 getAcceptorKey(krb5_context krbContext,
  65                gss_ctx_id_t ctx,
  66                gss_cred_id_t cred,
  67                krb5_principal *princ,
  68                krb5_keyblock *key)
  69 {
  70     krb5_error_code code;
  71     krb5_keytab keytab = NULL;
  72     krb5_keytab_entry ktent = { 0 };
  73 #ifdef HAVE_HEIMDAL_VERSION
  74     krb5_kt_cursor cursor = { 0 };
  75 #else
  76     krb5_kt_cursor cursor = NULL;
  77 #endif
  78
  79     *princ = NULL;
  80     memset(key, 0, sizeof(*key));
  81
  82     code = krb5_kt_default(krbContext, &keytab);
  83     if (code != 0)
  84         goto cleanup;
  85
  86     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
  87         code = krb5_kt_get_entry(krbContext, keytab,
  88                                  cred->name->krbPrincipal, 0,
  89                                  ctx->encryptionType, &ktent);
  90         if (code != 0)
  91             goto cleanup;
  92     } else {
  93         /*
  94          * It's not clear that looking encrypting the ticket in the
  95          * requested EAP enctype provides any value.
  96          */
  97         code = krb5_kt_start_seq_get(krbContext, keytab, &cursor);
  98         if (code != 0)
  99             goto cleanup;
 100
 101         while ((code = krb5_kt_next_entry(krbContext, keytab,
 102                                           &ktent, &cursor)) == 0) {
 103 #ifdef HAVE_HEIMDAL_VERSION
 104             if (ktent.keyblock.keytype == ctx->encryptionType)
 105                 break;
 106             else
 107                 krb5_kt_free_entry(krbContext, &ktent);
 108 #else
 109             if (ktent.key.enctype == ctx->encryptionType)
 110                 break;
 111             else
 112                 krb5_free_keytab_entry_contents(krbContext, &ktent);
 113 #endif
 114         }
 115     }
 116
 117     if (code == 0) {
 118         *princ = ktent.principal;
 119 #ifdef HAVE_HEIMDAL_VERSION
 120         *key = ktent.keyblock;
 121 #else
 122         *key = ktent.key;
 123 #endif
 124     }
 125
 126 cleanup:
 127     if (cred == GSS_C_NO_CREDENTIAL || cred->name == GSS_C_NO_NAME)
 128         krb5_kt_end_seq_get(krbContext, keytab, &cursor);
 129     krb5_kt_close(krbContext, keytab);
 130
 131     if (code != 0)
 132 #ifdef HAVE_HEIMDAL_VERSION
 133         krb5_kt_free_entry(krbContext, &ktent);
 134 #else
 135         krb5_free_keytab_entry_contents(krbContext, &ktent);
 136 #endif
 137
 138     return code;
 139 }
 140
 141 static OM_uint32
 142 freezeAttrContext(OM_uint32 *minor,
 143                   gss_name_t initiatorName,
 144                   krb5_const_principal acceptorPrinc,
 145                   krb5_keyblock *session,
 146 #ifdef HAVE_HEIMDAL_VERSION
 147                   krb5_authdata *authdata
 148 #else
 149                   krb5_authdata ***authdata
 150 #endif
 151                   )
 152 {
 153     OM_uint32 major, tmpMinor;
 154     krb5_error_code code;
 155     gss_buffer_desc attrBuf = GSS_C_EMPTY_BUFFER;
 156 #ifdef HAVE_HEIMDAL_VERSION
 157     AuthorizationData authDataBuf, *authData = &authDataBuf;
 158     AuthorizationDataElement authDatum = { 0 };
 159 #else
 160     krb5_authdata *authData[2], authDatum = { 0 };
 161 #endif
 162     krb5_context krbContext;
 163
 164     GSSEAP_KRB_INIT(&krbContext);
 165
 166     major = gssEapExportAttrContext(minor, initiatorName, &attrBuf);
 167     if (GSS_ERROR(major))
 168         return major;
 169
 170     authDatum.ad_type = KRB5_AUTHDATA_RADIUS_AVP;
 171 #ifdef HAVE_HEIMDAL_VERSION
 172     authDatum.ad_data.length = attrBuf.length;
 173     authDatum.ad_data.data = attrBuf.value;
 174     authData->len = 1;
 175     authData->val = &authDatum;
 176 #else
 177     authDatum.length = attrBuf.length;
 178     authDatum.contents = attrBuf.value;
 179     authData[0] = &authDatum;
 180     authData[1] = NULL;
 181 #endif
 182
 183     code = krbMakeAuthDataKdcIssued(krbContext, session, acceptorPrinc,
 184                                     authData, authdata);
 185     if (code != 0) {
 186         major = GSS_S_FAILURE;
 187         *minor = code;
 188     } else {
 189         major = GSS_S_COMPLETE;
 190     }
 191
 192     gss_release_buffer(&tmpMinor, &attrBuf);
 193
 194     return major;
 195 }
 196
 197 /*
 198  * Fabricate a ticket to ourselves given a GSS EAP context.
 199  */
 200 OM_uint32
 201 gssEapMakeReauthCreds(OM_uint32 *minor,
 202                       gss_ctx_id_t ctx,
 203                       gss_cred_id_t cred,
 204                       gss_buffer_t credBuf)
 205 {
 206     OM_uint32 major = GSS_S_COMPLETE;
 207     krb5_error_code code;
 208     krb5_context krbContext = NULL;
 209     krb5_keyblock session = { 0 }, acceptorKey = { 0 };
 210     krb5_principal server = NULL;
 211 #ifdef HAVE_HEIMDAL_VERSION
 212     Ticket ticket;
 213     EncTicketPart enc_part;
 214     AuthorizationData authData = { 0 };
 215     krb5_crypto krbCrypto = NULL;
 216     unsigned char *buf = NULL;
 217     size_t buf_size, len;
 218 #else
 219     krb5_ticket ticket;
 220     krb5_enc_tkt_part enc_part;
 221 #endif
 222     krb5_data *ticketData = NULL, credsData = { 0 };
 223     krb5_creds creds = { 0 };
 224     krb5_auth_context authContext = NULL;
 225
 226     memset(&ticket, 0, sizeof(ticket));
 227     memset(&enc_part, 0, sizeof(enc_part));
 228
 229     credBuf->length = 0;
 230     credBuf->value = NULL;
 231
 232     GSSEAP_KRB_INIT(&krbContext);
 233
 234     code = getAcceptorKey(krbContext, ctx, cred, &server, &acceptorKey);
 235     if (code == KRB5_KT_NOTFOUND) {
 236         *minor = code;
 237         return GSS_S_UNAVAILABLE;
 238     } else if (code != 0)
 239         goto cleanup;
 240
 241 #ifdef HAVE_HEIMDAL_VERSION
 242     ticket.realm = server->realm;
 243     ticket.sname = server->name;
 244 #else
 245     ticket.server = server;
 246 #endif
 247
 248     /*
 249      * Generate a random session key to place in the ticket and
 250      * sign the "KDC-Issued" authorization data element.
 251      */
 252     code = krb5_c_make_random_key(krbContext, ctx->encryptionType,
 253                                   &session);
 254     if (code != 0)
 255         goto cleanup;
 256
 257 #ifdef HAVE_HEIMDAL_VERSION
 258     enc_part.flags.initial = 1;
 259     enc_part.key = session;
 260     enc_part.crealm = ctx->initiatorName->krbPrincipal->realm;
 261     enc_part.cname = ctx->initiatorName->krbPrincipal->name;
 262     enc_part.authtime = time(NULL);
 263     enc_part.starttime = &enc_part.authtime;
 264     enc_part.endtime = (ctx->expiryTime != 0)
 265                        ? ctx->expiryTime : KRB_TIME_FOREVER;
 266     enc_part.renew_till = NULL;
 267     enc_part.authorization_data = &authData;
 268
 269     major = freezeAttrContext(minor, ctx->initiatorName, server,
 270                               &session, &authData);
 271     if (GSS_ERROR(major))
 272         goto cleanup;
 273
 274     ASN1_MALLOC_ENCODE(EncTicketPart, buf, buf_size, &enc_part, &len, code);
 275     if (code != 0)
 276         goto cleanup;
 277
 278     code = krb5_crypto_init(krbContext, &acceptorKey, 0, &krbCrypto);
 279     if (code != 0)
 280         goto cleanup;
 281
 282     code = krb5_encrypt_EncryptedData(krbContext,
 283                                       krbCrypto,
 284                                       KRB5_KU_TICKET,
 285                                       buf,
 286                                       len,
 287                                       0,
 288                                       &ticket.enc_part);
 289     if (code != 0)
 290         goto cleanup;
 291
 292     GSSEAP_FREE(buf);
 293     buf = NULL;
 294
 295     ASN1_MALLOC_ENCODE(Ticket, buf, buf_size, &ticket, &len, code);
 296     if (code != 0)
 297         goto cleanup;
 298 #else
 299     enc_part.flags = TKT_FLG_INITIAL;
 300     enc_part.session = &session;
 301     enc_part.client = ctx->initiatorName->krbPrincipal;
 302     enc_part.times.authtime = time(NULL);
 303     enc_part.times.starttime = enc_part.times.authtime;
 304     enc_part.times.endtime = (ctx->expiryTime != 0)
 305                              ? ctx->expiryTime
 306                              : KRB_TIME_FOREVER;
 307     enc_part.times.renew_till = 0;
 308
 309     major = freezeAttrContext(minor, ctx->initiatorName, server,
 310                               &session, &enc_part.authorization_data);
 311     if (GSS_ERROR(major))
 312         goto cleanup;
 313
 314     ticket.enc_part2 = &enc_part;
 315
 316     code = krb5_encrypt_tkt_part(krbContext, &acceptorKey, &ticket);
 317     if (code != 0)
 318         goto cleanup;
 319
 320     code = encode_krb5_ticket(&ticket, &ticketData);
 321     if (code != 0)
 322         goto cleanup;
 323 #endif /* HAVE_HEIMDAL_VERSION */
 324
 325     creds.client = ctx->initiatorName->krbPrincipal;
 326     creds.server = server;
 327 #ifdef HAVE_HEIMDAL_VERSION
 328     creds.session = session;
 329     creds.times.authtime = enc_part.authtime;
 330     creds.times.starttime = *enc_part.starttime;
 331     creds.times.endtime = enc_part.endtime;
 332     creds.times.renew_till = 0;
 333     creds.flags.b = enc_part.flags;
 334     creds.ticket = *ticketData;
 335     creds.authdata = authData;
 336 #else
 337     creds.keyblock = session;
 338     creds.times = enc_part.times;
 339     creds.ticket_flags = enc_part.flags;
 340     creds.ticket = *ticketData;
 341     creds.authdata = enc_part.authorization_data;
 342 #endif
 343
 344     code = krb5_auth_con_init(krbContext, &authContext);
 345     if (code != 0)
 346         goto cleanup;
 347
 348     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 349     if (code != 0)
 350         goto cleanup;
 351
 352     code = krb5_auth_con_setsendsubkey(krbContext, authContext,
 353                                        &ctx->rfc3961Key);
 354     if (code != 0)
 355         goto cleanup;
 356
 357     code = krbMakeCred(krbContext, authContext, &creds, &credsData);
 358     if (code != 0)
 359         goto cleanup;
 360
 361     krbDataToGssBuffer(&credsData, credBuf);
 362
 363 cleanup:
 364 #ifdef HAVE_HEIMDAL_VERSION
 365     if (krbCrypto != NULL)
 366         krb5_crypto_destroy(krbContext, krbCrypto);
 367     if (buf != NULL)
 368         GSSEAP_FREE(buf);
 369     free_AuthorizationData(&authData);
 370     free_EncryptedData(&ticket.enc_part);
 371 #else
 372     krb5_free_authdata(krbContext, enc_part.authorization_data);
 373     if (ticket.enc_part.ciphertext.data != NULL)
 374         GSSEAP_FREE(ticket.enc_part.ciphertext.data);
 375 #endif
 376     krb5_free_keyblock_contents(krbContext, &session);
 377     krb5_free_principal(krbContext, server);
 378     krb5_free_keyblock_contents(krbContext, &acceptorKey);
 379     krb5_free_data(krbContext, ticketData);
 380     krb5_auth_con_free(krbContext, authContext);
 381
 382     if (major == GSS_S_COMPLETE) {
 383         *minor = code;
 384         major = (code != 0) ? GSS_S_FAILURE : GSS_S_COMPLETE;
 385     }
 386
 387     return major;
 388 }
 389
 390 static int
 391 isTicketGrantingServiceP(krb5_context krbContext,
 392                          krb5_const_principal principal)
 393 {
 394     if (KRB_PRINC_LENGTH(principal) == 2 &&
 395 #ifdef HAVE_HEIMDAL_VERSION
 396         strcmp(KRB_PRINC_NAME(principal)[0], "krbtgt") == 0
 397 #else
 398         krb5_princ_component(krbContext, principal, 0)->length == 6 &&
 399         memcmp(krb5_princ_component(krbContext,
 400                                     principal, 0)->data, "krbtgt", 6) == 0
 401 #endif
 402         )
 403         return TRUE;
 404
 405     return FALSE;
 406 }
 407
 408 /*
 409  * Returns TRUE if the configuration variable reauth_use_ccache is
 410  * set in krb5.conf for the eap_gss application and the client realm.
 411  */
 412 static int
 413 reauthUseCredsCache(krb5_context krbContext,
 414                     krb5_principal principal)
 415 {
 416     int reauthUseCCache;
 417
 418     /* if reauth_use_ccache, use default credentials cache if ticket is for us */
 419     krb5_appdefault_boolean(krbContext, "eap_gss",
 420                             KRB_PRINC_REALM(principal),
 421                             "reauth_use_ccache", 0, &reauthUseCCache);
 422
 423     return reauthUseCCache;
 424 }
 425
 426 /*
 427  * Look in default credentials cache for reauthentication credentials,
 428  * if policy allows.
 429  */
 430 static OM_uint32
 431 getDefaultReauthCredentials(OM_uint32 *minor,
 432                             gss_cred_id_t cred,
 433                             gss_name_t target,
 434                             time_t now,
 435                             OM_uint32 timeReq)
 436 {
 437     OM_uint32 major = GSS_S_CRED_UNAVAIL;
 438     krb5_context krbContext = NULL;
 439     krb5_error_code code = 0;
 440     krb5_ccache ccache = NULL;
 441     krb5_creds match = { 0 };
 442     krb5_creds creds = { 0 };
 443
 444     GSSEAP_KRB_INIT(&krbContext);
 445
 446     assert(cred != GSS_C_NO_CREDENTIAL);
 447     assert(target != GSS_C_NO_NAME);
 448
 449     if (cred->name == GSS_C_NO_NAME ||
 450         !reauthUseCredsCache(krbContext, cred->name->krbPrincipal))
 451         goto cleanup;
 452
 453     match.client = cred->name->krbPrincipal;
 454     match.server = target->krbPrincipal;
 455     if (timeReq != 0 && timeReq != GSS_C_INDEFINITE)
 456         match.times.endtime = now + timeReq;
 457
 458     code = krb5_cc_default(krbContext, &ccache);
 459     if (code != 0)
 460         goto cleanup;
 461
 462     code = krb5_cc_retrieve_cred(krbContext, ccache, 0, &match, &creds);
 463     if (code != 0)
 464         goto cleanup;
 465
 466     cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 467     cred->krbCredCache = ccache;
 468     ccache = NULL;
 469
 470     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 471                                  &cred->krbCred);
 472
 473 cleanup:
 474     if (major == GSS_S_CRED_UNAVAIL)
 475         *minor = code;
 476
 477     if (ccache != NULL)
 478         krb5_cc_close(krbContext, ccache);
 479     krb5_free_cred_contents(krbContext, &creds);
 480
 481     return major;
 482 }
 483
 484 /*
 485  * Returns TRUE if the credential handle's reauth credentials are
 486  * valid or if we can use the default credentials cache. Credentials
 487  * handle must be locked.
 488  */
 489 int
 490 gssEapCanReauthP(gss_cred_id_t cred,
 491                  gss_name_t target,
 492                  OM_uint32 timeReq)
 493 {
 494     time_t now, expiryReq;
 495     OM_uint32 minor;
 496
 497     assert(cred != GSS_C_NO_CREDENTIAL);
 498
 499     now = time(NULL);
 500     expiryReq = now;
 501     if (timeReq != GSS_C_INDEFINITE)
 502         expiryReq += timeReq;
 503
 504     if (cred->krbCredCache != NULL && cred->expiryTime > expiryReq)
 505         return TRUE;
 506
 507     if (getDefaultReauthCredentials(&minor, cred, target,
 508                                     now, timeReq) == GSS_S_COMPLETE)
 509         return TRUE;
 510
 511     return FALSE;
 512 }
 513
 514 /*
 515  * Store re-authentication (Kerberos) credentials in a credential handle.
 516  * Credentials handle must be locked.
 517  */
 518 OM_uint32
 519 gssEapStoreReauthCreds(OM_uint32 *minor,
 520                        gss_ctx_id_t ctx,
 521                        gss_cred_id_t cred,
 522                        gss_buffer_t credBuf)
 523 {
 524     OM_uint32 major = GSS_S_COMPLETE;
 525     krb5_error_code code;
 526     krb5_context krbContext = NULL;
 527     krb5_auth_context authContext = NULL;
 528     krb5_data credData = { 0 };
 529     krb5_creds **creds = NULL;
 530     krb5_principal canonPrinc;
 531     krb5_principal ccPrinc = NULL;
 532     int i;
 533
 534     if (credBuf->length == 0 || cred == GSS_C_NO_CREDENTIAL)
 535         return GSS_S_COMPLETE;
 536
 537     GSSEAP_KRB_INIT(&krbContext);
 538
 539     code = krb5_auth_con_init(krbContext, &authContext);
 540     if (code != 0)
 541         goto cleanup;
 542
 543     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 544     if (code != 0)
 545         goto cleanup;
 546
 547     code = krb5_auth_con_setrecvsubkey(krbContext, authContext,
 548                                        &ctx->rfc3961Key);
 549     if (code != 0)
 550         goto cleanup;
 551
 552     gssBufferToKrbData(credBuf, &credData);
 553
 554     code = krb5_rd_cred(krbContext, authContext, &credData, &creds, NULL);
 555     if (code != 0)
 556         goto cleanup;
 557
 558     if (creds == NULL || creds[0] == NULL)
 559         goto cleanup;
 560
 561     code = krb5_copy_principal(krbContext, creds[0]->client, &canonPrinc);
 562     if (code != 0)
 563         goto cleanup;
 564
 565     krb5_free_principal(krbContext, cred->name->krbPrincipal);
 566     cred->name->krbPrincipal = canonPrinc;
 567
 568     if (creds[0]->times.endtime == KRB_TIME_FOREVER)
 569         cred->expiryTime = 0;
 570     else
 571         cred->expiryTime = creds[0]->times.endtime;
 572
 573     if (cred->krbCredCache == NULL) {
 574         if (reauthUseCredsCache(krbContext, creds[0]->client) &&
 575             krb5_cc_default(krbContext, &cred->krbCredCache) == 0)
 576             cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 577     } else {
 578         /*
 579          * If we already have an associated credentials cache, possibly from
 580          * the last time we stored a reauthentication credential, then we
 581          * need to clear it out and release the associated GSS credential.
 582          */
 583         if (cred->flags & CRED_FLAG_DEFAULT_CCACHE) {
 584             krb5_cc_remove_cred(krbContext, cred->krbCredCache, 0, creds[0]);
 585         } else {
 586             krb5_cc_destroy(krbContext, cred->krbCredCache);
 587             cred->krbCredCache = NULL;
 588         }
 589         gssReleaseCred(minor, &cred->krbCred);
 590     }
 591
 592     if (cred->krbCredCache == NULL) {
 593         code = krb5_cc_new_unique(krbContext, "MEMORY", NULL, &cred->krbCredCache);
 594         if (code != 0)
 595             goto cleanup;
 596     }
 597
 598     if ((cred->flags & CRED_FLAG_DEFAULT_CCACHE) == 0 ||
 599         krb5_cc_get_principal(krbContext, cred->krbCredCache, &ccPrinc) != 0) {
 600         code = krb5_cc_initialize(krbContext, cred->krbCredCache,
 601                                   creds[0]->client);
 602         if (code != 0)
 603             goto cleanup;
 604     }
 605
 606     for (i = 0; creds[i] != NULL; i++) {
 607         krb5_creds kcred = *(creds[i]);
 608
 609         /*
 610          * Swap in the acceptor name the client asked for so
 611          * get_credentials() works. We're making the assumption that
 612          * any service tickets returned are for us. We'll need to
 613          * reflect some more on whether that is a safe assumption.
 614          */
 615         if (!isTicketGrantingServiceP(krbContext, kcred.server))
 616             kcred.server = ctx->acceptorName->krbPrincipal;
 617
 618         code = krb5_cc_store_cred(krbContext, cred->krbCredCache, &kcred);
 619         if (code != 0)
 620             goto cleanup;
 621     }
 622
 623     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 624                                  &cred->krbCred);
 625     if (GSS_ERROR(major))
 626         goto cleanup;
 627
 628 cleanup:
 629     *minor = code;
 630
 631     krb5_free_principal(krbContext, ccPrinc);
 632     krb5_auth_con_free(krbContext, authContext);
 633     if (creds != NULL) {
 634         for (i = 0; creds[i] != NULL; i++)
 635             krb5_free_creds(krbContext, creds[i]);
 636         GSSEAP_FREE(creds);
 637     }
 638     if (major == GSS_S_COMPLETE)
 639         major = *minor ? GSS_S_FAILURE : GSS_S_COMPLETE;
 640
 641     return major;
 642 }
 643
 644 #ifndef HAVE_HEIMDAL_VERSION
 645 static gss_buffer_desc radiusAvpKrbAttr = {
 646     sizeof("urn:authdata-radius-avp") - 1, "urn:authdata-radius-avp"
 647 };
 648 #endif
 649
 650 /*
 651  * Unfortunately extracting an AD-KDCIssued authorization data element
 652  * is pretty implementation-dependent. It's not possible to verify the
 653  * signature ourselves because the ticket session key is not exposed
 654  * outside GSS. In an ideal world, all AD-KDCIssued elements would be
 655  * verified by the Kerberos library and authentication would fail if
 656  * verification failed. We're not quite there yet and as a result have
 657  * to go through some hoops to get this to work. The alternative would
 658  * be to sign the authorization data with our long-term key, but it
 659  * seems a pity to compromise the design because of current implementation
 660  * limitations.
 661  *
 662  * (Specifically, the hoops involve a libkrb5 authorisation data plugin
 663  * that exposes the verified and serialised attribute context through
 664  * the Kerberos GSS mechanism's naming extensions API.)
 665  */
 666 static OM_uint32
 667 defrostAttrContext(OM_uint32 *minor,
 668                    gss_ctx_id_t glueContext,
 669                    gss_name_t glueName,
 670                    gss_name_t mechName)
 671 {
 672     OM_uint32 major, tmpMinor;
 673 #ifdef HAVE_HEIMDAL_VERSION
 674     gss_OID_desc oid = { 0 };
 675     gss_buffer_set_t authData = GSS_C_NO_BUFFER_SET;
 676 #else
 677     gss_buffer_desc authData = GSS_C_EMPTY_BUFFER;
 678     gss_buffer_desc authDataDisplay = GSS_C_EMPTY_BUFFER;
 679     int more = -1;
 680     int authenticated, complete;
 681 #endif
 682
 683 #ifdef HAVE_HEIMDAL_VERSION
 684     major = composeOid(minor,
 685                        GSS_KRB5_EXTRACT_AUTHZ_DATA_FROM_SEC_CONTEXT_X->elements,
 686                        GSS_KRB5_EXTRACT_AUTHZ_DATA_FROM_SEC_CONTEXT_X->length,
 687                        KRB5_AUTHDATA_RADIUS_AVP, &oid);
 688     if (GSS_ERROR(major))
 689         return major;
 690
 691     /* XXX we are assuming that this verifies AD-KDCIssued signature */
 692     major = gssInquireSecContextByOid(minor, glueContext,
 693                                       &oid, &authData);
 694     if (major == GSS_S_COMPLETE) {
 695         if (authData == GSS_C_NO_BUFFER_SET || authData->count != 1)
 696             major = GSS_S_FAILURE;
 697         else
 698             major = gssEapImportAttrContext(minor, authData->elements, mechName);
 699     } else if (major == GSS_S_FAILURE && *minor == ENOENT) {
 700         /* This is the equivalent of GSS_S_UNAVAILABLE for MIT attr APIs */
 701         *minor = 0;
 702         major = GSS_S_COMPLETE;
 703     }
 704
 705     gss_release_buffer_set(&tmpMinor, &authData);
 706     GSSEAP_FREE(oid.elements);
 707 #else
 708     major = gssGetNameAttribute(minor, glueName, &radiusAvpKrbAttr,
 709                                 &authenticated, &complete,
 710                                 &authData, &authDataDisplay, &more);
 711     if (major == GSS_S_COMPLETE) {
 712         if (authenticated == 0)
 713             major = GSS_S_BAD_NAME;
 714         else
 715             major = gssEapImportAttrContext(minor, &authData, mechName);
 716     } else if (major == GSS_S_UNAVAILABLE) {
 717         major = GSS_S_COMPLETE;
 718     }
 719
 720     gss_release_buffer(&tmpMinor, &authData);
 721     gss_release_buffer(&tmpMinor, &authDataDisplay);
 722 #endif /* HAVE_HEIMDAL_VERSION */
 723
 724     return major;
 725 }
 726
 727 /*
 728  * Convert a mechanism glue to an EAP mechanism name by displaying and
 729  * importing it. This also handles the RADIUS attributes.
 730  */
 731 OM_uint32
 732 gssEapGlueToMechName(OM_uint32 *minor,
 733                      gss_ctx_id_t glueContext,
 734                      gss_name_t glueName,
 735                      gss_name_t *pMechName)
 736 {
 737     OM_uint32 major, tmpMinor;
 738     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 739
 740     *pMechName = GSS_C_NO_NAME;
 741
 742     major = gssDisplayName(minor, glueName, &nameBuf, NULL);
 743     if (GSS_ERROR(major))
 744         goto cleanup;
 745
 746     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 747                              pMechName);
 748     if (GSS_ERROR(major))
 749         goto cleanup;
 750
 751     major = defrostAttrContext(minor, glueContext, glueName, *pMechName);
 752     if (GSS_ERROR(major))
 753         goto cleanup;
 754
 755 cleanup:
 756     if (GSS_ERROR(major)) {
 757         gssReleaseName(&tmpMinor, pMechName);
 758         *pMechName = GSS_C_NO_NAME;
 759     }
 760
 761     gss_release_buffer(&tmpMinor, &nameBuf);
 762
 763     return major;
 764 }
 765
 766 /*
 767  * Convert an EAP mechanism name to a mechanism glue name by displaying
 768  * and importing it.
 769  */
 770 OM_uint32
 771 gssEapMechToGlueName(OM_uint32 *minor,
 772                      gss_name_t mechName,
 773                      gss_name_t *pGlueName)
 774 {
 775     OM_uint32 major, tmpMinor;
 776     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 777
 778     *pGlueName = GSS_C_NO_NAME;
 779
 780     major = gssEapDisplayName(minor, mechName, &nameBuf, NULL);
 781     if (GSS_ERROR(major))
 782         goto cleanup;
 783
 784     major = gssImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 785                           pGlueName);
 786     if (GSS_ERROR(major))
 787         goto cleanup;
 788
 789 cleanup:
 790     gss_release_buffer(&tmpMinor, &nameBuf);
 791
 792     return major;
 793 }
 794
 795 /*
 796  * Suck out the analgous elements of a Kerberos GSS context into an EAP
 797  * one so that the application doesn't know the difference.
 798  */
 799 OM_uint32
 800 gssEapReauthComplete(OM_uint32 *minor,
 801                     gss_ctx_id_t ctx,
 802                     gss_cred_id_t cred,
 803                     const gss_OID mech,
 804                     OM_uint32 timeRec)
 805 {
 806     OM_uint32 major, tmpMinor;
 807     gss_buffer_set_t keyData = GSS_C_NO_BUFFER_SET;
 808     krb5_context krbContext = NULL;
 809 #ifdef HAVE_HEIMDAL_VERSION
 810     krb5_storage *sp = NULL;
 811 #endif
 812
 813     GSSEAP_KRB_INIT(&krbContext);
 814
 815     if (!oidEqual(mech, gss_mech_krb5)) {
 816         major = GSS_S_BAD_MECH;
 817         goto cleanup;
 818     }
 819
 820     /* Get the raw subsession key and encryption type */
 821 #ifdef HAVE_HEIMDAL_VERSION
 822 #define KRB_GSS_SUBKEY_COUNT    1 /* encoded session key */
 823     major = gssInquireSecContextByOid(minor, ctx->kerberosCtx,
 824                                       GSS_KRB5_GET_SUBKEY_X, &keyData);
 825 #else
 826 #define KRB_GSS_SUBKEY_COUNT    2 /* raw session key, enctype OID */
 827     major = gssInquireSecContextByOid(minor, ctx->kerberosCtx,
 828                                       GSS_C_INQ_SSPI_SESSION_KEY, &keyData);
 829 #endif
 830     if (GSS_ERROR(major))
 831         goto cleanup;
 832
 833     if (keyData == GSS_C_NO_BUFFER_SET || keyData->count < KRB_GSS_SUBKEY_COUNT) {
 834         *minor = GSSEAP_KEY_UNAVAILABLE;
 835         major = GSS_S_FAILURE;
 836         goto cleanup;
 837     }
 838
 839 #ifdef HAVE_HEIMDAL_VERSION
 840     sp = krb5_storage_from_mem(keyData->elements[0].value,
 841                                keyData->elements[0].length);
 842     if (sp == NULL) {
 843         *minor = ENOMEM;
 844         major = GSS_S_FAILURE;
 845         goto cleanup;
 846     }
 847
 848     *minor = krb5_ret_keyblock(sp, &ctx->rfc3961Key);
 849     if (*minor != 0) {
 850         major = GSS_S_FAILURE;
 851         goto cleanup;
 852     }
 853 #else
 854     {
 855         gss_OID_desc oid;
 856         int suffix;
 857
 858         oid.length = keyData->elements[1].length;
 859         oid.elements = keyData->elements[1].value;
 860
 861         /* GSS_KRB5_SESSION_KEY_ENCTYPE_OID */
 862         major = decomposeOid(minor,
 863                              "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04",
 864                              10, &oid, &suffix);
 865         if (GSS_ERROR(major))
 866             goto cleanup;
 867
 868         ctx->encryptionType = suffix;
 869     }
 870
 871     {
 872         krb5_keyblock key;
 873
 874         KRB_KEY_LENGTH(&key) = keyData->elements[0].length;
 875         KRB_KEY_DATA(&key)   = keyData->elements[0].value;
 876         KRB_KEY_TYPE(&key)   = ctx->encryptionType;
 877
 878         *minor = krb5_copy_keyblock_contents(krbContext,
 879                                              &key, &ctx->rfc3961Key);
 880         if (*minor != 0) {
 881             major = GSS_S_FAILURE;
 882             goto cleanup;
 883         }
 884     }
 885 #endif /* HAVE_HEIMDAL_VERSION */
 886
 887     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 888                                       &ctx->checksumType);
 889     if (GSS_ERROR(major))
 890         goto cleanup;
 891
 892     if (timeRec != GSS_C_INDEFINITE)
 893         ctx->expiryTime = time(NULL) + timeRec;
 894
 895     /* Initialize our sequence state */
 896     major = sequenceInit(minor,
 897                          &ctx->seqState, ctx->recvSeq,
 898                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 899                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 900                          TRUE);
 901     if (GSS_ERROR(major))
 902         goto cleanup;
 903
 904     major = GSS_S_COMPLETE;
 905
 906 cleanup:
 907 #ifdef HAVE_HEIMDAL_VERSION
 908     if (sp != NULL)
 909         krb5_storage_free(sp);
 910 #endif
 911     gss_release_buffer_set(&tmpMinor, &keyData);
 912
 913     return major;
 914 }
 915
 916 /*
 917  * The remainder of this file consists of wrappers so we can call into the
 918  * mechanism glue without calling ourselves.
 919  */
 920 static OM_uint32
 921 (*gssInitSecContextNext)(OM_uint32 *,
 922                          gss_cred_id_t,
 923                          gss_ctx_id_t *,
 924                          gss_name_t,
 925                          gss_OID,
 926                          OM_uint32,
 927                          OM_uint32,
 928                          gss_channel_bindings_t,
 929                          gss_buffer_t,
 930                          gss_OID *,
 931                          gss_buffer_t,
 932                          OM_uint32 *,
 933                          OM_uint32 *);
 934
 935 static OM_uint32
 936 (*gssAcceptSecContextNext)(OM_uint32 *,
 937                            gss_ctx_id_t *,
 938                            gss_cred_id_t,
 939                            gss_buffer_t,
 940                            gss_channel_bindings_t,
 941                            gss_name_t *,
 942                            gss_OID *,
 943                            gss_buffer_t,
 944                            OM_uint32 *,
 945                            OM_uint32 *,
 946                            gss_cred_id_t *);
 947
 948 static OM_uint32
 949 (*gssReleaseCredNext)(OM_uint32 *, gss_cred_id_t *);
 950
 951 static OM_uint32
 952 (*gssReleaseNameNext)(OM_uint32 *, gss_name_t *);
 953
 954 static OM_uint32
 955 (*gssInquireSecContextByOidNext)(OM_uint32 *,
 956                                  const gss_ctx_id_t,
 957                                  const gss_OID,
 958                                  gss_buffer_set_t *);
 959
 960 static OM_uint32
 961 (*gssDeleteSecContextNext)(OM_uint32 *,
 962                           gss_ctx_id_t *,
 963                           gss_buffer_t);
 964
 965 static OM_uint32
 966 (*gssDisplayNameNext)(OM_uint32 *,
 967                       gss_name_t,
 968                       gss_buffer_t,
 969                       gss_OID *);
 970
 971 static OM_uint32
 972 (*gssImportNameNext)(OM_uint32 *,
 973                      gss_buffer_t,
 974                      gss_OID,
 975                      gss_name_t *);
 976
 977 static OM_uint32
 978 (*gssStoreCredNext)(OM_uint32 *,
 979                     const gss_cred_id_t,
 980                     gss_cred_usage_t,
 981                     const gss_OID,
 982                     OM_uint32,
 983                     OM_uint32,
 984                     gss_OID_set *,
 985                     gss_cred_usage_t *);
 986
 987 static OM_uint32
 988 (*gssGetNameAttributeNext)(OM_uint32 *,
 989                           gss_name_t,
 990                           gss_buffer_t,
 991                           int *,
 992                           int *,
 993                           gss_buffer_t,
 994                           gss_buffer_t,
 995                           int *);
 996
 997 #define NEXT_SYMBOL(local, global)  do {        \
 998         ((local) = dlsym(RTLD_NEXT, (global))); \
 999         if ((local) == NULL) {                  \
1000             *minor = GSSEAP_NO_MECHGLUE_SYMBOL; \
1001             major = GSS_S_UNAVAILABLE;          \
1002             /* but continue */                  \
1003         }                                       \
1004     } while (0)
1005
1006 OM_uint32
1007 gssEapReauthInitialize(OM_uint32 *minor)
1008 {
1009     OM_uint32 major = GSS_S_COMPLETE;
1010
1011     NEXT_SYMBOL(gssInitSecContextNext,         "gss_init_sec_context");
1012     NEXT_SYMBOL(gssAcceptSecContextNext,       "gss_accept_sec_context");
1013     NEXT_SYMBOL(gssReleaseCredNext,            "gss_release_cred");
1014     NEXT_SYMBOL(gssReleaseNameNext,            "gss_release_name");
1015     NEXT_SYMBOL(gssInquireSecContextByOidNext, "gss_inquire_sec_context_by_oid");
1016     NEXT_SYMBOL(gssDeleteSecContextNext,       "gss_delete_sec_context");
1017     NEXT_SYMBOL(gssDisplayNameNext,            "gss_display_name");
1018     NEXT_SYMBOL(gssImportNameNext,             "gss_import_name");
1019     NEXT_SYMBOL(gssStoreCredNext,              "gss_store_cred");
1020     NEXT_SYMBOL(gssGetNameAttributeNext,       "gss_get_name_attribute");
1021
1022     return major;
1023 }
1024
1025 OM_uint32
1026 gssInitSecContext(OM_uint32 *minor,
1027                   gss_cred_id_t cred,
1028                   gss_ctx_id_t *context_handle,
1029                   gss_name_t target_name,
1030                   gss_OID mech_type,
1031                   OM_uint32 req_flags,
1032                   OM_uint32 time_req,
1033                   gss_channel_bindings_t input_chan_bindings,
1034                   gss_buffer_t input_token,
1035                   gss_OID *actual_mech_type,
1036                   gss_buffer_t output_token,
1037                   OM_uint32 *ret_flags,
1038                   OM_uint32 *time_rec)
1039 {
1040     if (gssInitSecContextNext == NULL) {
1041         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1042         return GSS_S_UNAVAILABLE;
1043     }
1044
1045     return gssInitSecContextNext(minor, cred, context_handle,
1046                                  target_name, mech_type, req_flags,
1047                                  time_req, input_chan_bindings,
1048                                  input_token, actual_mech_type,
1049                                  output_token, ret_flags, time_rec);
1050 }
1051
1052 OM_uint32
1053 gssAcceptSecContext(OM_uint32 *minor,
1054                     gss_ctx_id_t *context_handle,
1055                     gss_cred_id_t cred,
1056                     gss_buffer_t input_token,
1057                     gss_channel_bindings_t input_chan_bindings,
1058                     gss_name_t *src_name,
1059                     gss_OID *mech_type,
1060                     gss_buffer_t output_token,
1061                     OM_uint32 *ret_flags,
1062                     OM_uint32 *time_rec,
1063                     gss_cred_id_t *delegated_cred_handle)
1064 {
1065     if (gssAcceptSecContextNext == NULL) {
1066         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1067         return GSS_S_UNAVAILABLE;
1068     }
1069
1070     return gssAcceptSecContextNext(minor, context_handle, cred,
1071                                    input_token, input_chan_bindings,
1072                                    src_name, mech_type, output_token,
1073                                    ret_flags, time_rec, delegated_cred_handle);
1074 }
1075
1076 OM_uint32
1077 gssReleaseCred(OM_uint32 *minor,
1078                gss_cred_id_t *cred_handle)
1079 {
1080     if (gssReleaseCredNext == NULL) {
1081         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1082         return GSS_S_UNAVAILABLE;
1083     }
1084
1085     return gssReleaseCredNext(minor, cred_handle);
1086 }
1087
1088 OM_uint32
1089 gssReleaseName(OM_uint32 *minor,
1090                gss_name_t *name)
1091 {
1092     if (gssReleaseName == NULL) {
1093         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1094         return GSS_S_UNAVAILABLE;
1095     }
1096
1097     return gssReleaseNameNext(minor, name);
1098 }
1099
1100 OM_uint32
1101 gssDeleteSecContext(OM_uint32 *minor,
1102                     gss_ctx_id_t *context_handle,
1103                     gss_buffer_t output_token)
1104 {
1105     if (gssDeleteSecContextNext == NULL) {
1106         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1107         return GSS_S_UNAVAILABLE;
1108     }
1109
1110     return gssDeleteSecContextNext(minor, context_handle, output_token);
1111 }
1112
1113 static OM_uint32
1114 gssDisplayName(OM_uint32 *minor,
1115                gss_name_t name,
1116                gss_buffer_t buffer,
1117                gss_OID *name_type)
1118 {
1119     if (gssDisplayNameNext == NULL) {
1120         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1121         return GSS_S_UNAVAILABLE;
1122     }
1123
1124     return gssDisplayNameNext(minor, name, buffer, name_type);
1125 }
1126
1127 static OM_uint32
1128 gssImportName(OM_uint32 *minor,
1129               gss_buffer_t buffer,
1130               gss_OID name_type,
1131               gss_name_t *name)
1132 {
1133     if (gssImportNameNext == NULL) {
1134         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1135         return GSS_S_UNAVAILABLE;
1136     }
1137
1138     return gssImportNameNext(minor, buffer, name_type, name);
1139 }
1140
1141 OM_uint32
1142 gssInquireSecContextByOid(OM_uint32 *minor,
1143                           const gss_ctx_id_t context_handle,
1144                           const gss_OID desired_object,
1145                           gss_buffer_set_t *data_set)
1146 {
1147     if (gssInquireSecContextByOidNext == NULL) {
1148         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1149         return GSS_S_UNAVAILABLE;
1150     }
1151
1152     return gssInquireSecContextByOidNext(minor, context_handle,
1153                                          desired_object, data_set);
1154 }
1155
1156 OM_uint32
1157 gssStoreCred(OM_uint32 *minor,
1158              const gss_cred_id_t input_cred_handle,
1159              gss_cred_usage_t input_usage,
1160              const gss_OID desired_mech,
1161              OM_uint32 overwrite_cred,
1162              OM_uint32 default_cred,
1163              gss_OID_set *elements_stored,
1164              gss_cred_usage_t *cred_usage_stored)
1165 {
1166     if (gssStoreCredNext == NULL) {
1167         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1168         return GSS_S_UNAVAILABLE;
1169     }
1170
1171     return gssStoreCredNext(minor, input_cred_handle, input_usage,
1172                             desired_mech, overwrite_cred, default_cred,
1173                             elements_stored, cred_usage_stored);
1174 }
1175
1176 OM_uint32
1177 gssGetNameAttribute(OM_uint32 *minor,
1178                     gss_name_t name,
1179                     gss_buffer_t attr,
1180                     int *authenticated,
1181                     int *complete,
1182                     gss_buffer_t value,
1183                     gss_buffer_t display_value,
1184                     int *more)
1185 {
1186     if (gssGetNameAttributeNext == NULL) {
1187         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1188         return GSS_S_UNAVAILABLE;
1189     }
1190
1191     return gssGetNameAttributeNext(minor, name, attr, authenticated, complete,
1192                                    value, display_value, more);
1193 }