moonshot/mech_eap/util_reauth.c

   1 /*
   2  * Copyright (c) 2011, 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     krb5_kt_cursor cursor;
  74
  75     *princ = NULL;
  76     memset(key, 0, sizeof(*key));
  77     memset(&cursor, 0, sizeof(cursor));
  78
  79     code = krb5_kt_default(krbContext, &keytab);
  80     if (code != 0)
  81         goto cleanup;
  82
  83     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
  84         code = krb5_kt_get_entry(krbContext, keytab,
  85                                  cred->name->krbPrincipal, 0,
  86                                  ctx->encryptionType, &ktent);
  87         if (code != 0)
  88             goto cleanup;
  89     } else {
  90         /*
  91          * It's not clear that looking encrypting the ticket in the
  92          * requested EAP enctype provides any value.
  93          */
  94         code = krb5_kt_start_seq_get(krbContext, keytab, &cursor);
  95         if (code != 0)
  96             goto cleanup;
  97
  98         while ((code = krb5_kt_next_entry(krbContext, keytab,
  99                                           &ktent, &cursor)) == 0) {
 100             if (KRB_KEY_TYPE(KRB_KT_ENT_KEYBLOCK(&ktent)) == ctx->encryptionType)
 101                 break;
 102             else
 103                 KRB_KT_ENT_FREE(krbContext, &ktent);
 104         }
 105     }
 106
 107     if (code == 0) {
 108         *princ = ktent.principal;
 109         *key = *KRB_KT_ENT_KEYBLOCK(&ktent);
 110     }
 111
 112 cleanup:
 113     if (cred == GSS_C_NO_CREDENTIAL || cred->name == GSS_C_NO_NAME)
 114         krb5_kt_end_seq_get(krbContext, keytab, &cursor);
 115     krb5_kt_close(krbContext, keytab);
 116     if (code != 0)
 117         KRB_KT_ENT_FREE(krbContext, &ktent);
 118
 119     return code;
 120 }
 121
 122 static OM_uint32
 123 freezeAttrContext(OM_uint32 *minor,
 124                   gss_name_t initiatorName,
 125                   krb5_const_principal acceptorPrinc,
 126                   krb5_keyblock *session,
 127 #ifdef HAVE_HEIMDAL_VERSION
 128                   krb5_authdata *kdcIssuedAuthData
 129 #else
 130                   krb5_authdata ***kdcIssuedAuthData
 131 #endif
 132                   )
 133 {
 134     OM_uint32 major, tmpMinor;
 135     krb5_error_code code;
 136     krb5_context krbContext;
 137     gss_buffer_desc attrBuf = GSS_C_EMPTY_BUFFER;
 138 #ifdef HAVE_HEIMDAL_VERSION
 139     krb5_authdata authDataBuf, *authData = &authDataBuf;
 140     AuthorizationDataElement authDatum = { 0 };
 141 #else
 142     krb5_authdata *authData[2], authDatum = { 0 };
 143 #endif
 144
 145     memset(kdcIssuedAuthData, 0, sizeof(*kdcIssuedAuthData));
 146
 147     GSSEAP_KRB_INIT(&krbContext);
 148
 149     major = gssEapExportAttrContext(minor, initiatorName, &attrBuf);
 150     if (GSS_ERROR(major))
 151         return major;
 152
 153     authDatum.ad_type = KRB5_AUTHDATA_RADIUS_AVP;
 154 #ifdef HAVE_HEIMDAL_VERSION
 155     authDatum.ad_data.length = attrBuf.length;
 156     authDatum.ad_data.data = attrBuf.value;
 157     authData->len = 1;
 158     authData->val = &authDatum;
 159 #else
 160     authDatum.length = attrBuf.length;
 161     authDatum.contents = attrBuf.value;
 162     authData[0] = &authDatum;
 163     authData[1] = NULL;
 164 #endif
 165
 166     code = krbMakeAuthDataKdcIssued(krbContext, session, acceptorPrinc,
 167                                     authData, kdcIssuedAuthData);
 168     if (code != 0) {
 169         major = GSS_S_FAILURE;
 170         *minor = code;
 171     } else {
 172         major = GSS_S_COMPLETE;
 173     }
 174
 175     gss_release_buffer(&tmpMinor, &attrBuf);
 176
 177     return major;
 178 }
 179
 180 /*
 181  * Fabricate a ticket to ourselves given a GSS EAP context.
 182  */
 183 OM_uint32
 184 gssEapMakeReauthCreds(OM_uint32 *minor,
 185                       gss_ctx_id_t ctx,
 186                       gss_cred_id_t cred,
 187                       gss_buffer_t credBuf)
 188 {
 189     OM_uint32 major = GSS_S_COMPLETE;
 190     krb5_error_code code;
 191     krb5_context krbContext = NULL;
 192     krb5_keyblock session = { 0 }, acceptorKey = { 0 };
 193     krb5_principal server = NULL;
 194 #ifdef HAVE_HEIMDAL_VERSION
 195     Ticket ticket;
 196     EncTicketPart enc_part;
 197     AuthorizationData authData = { 0 };
 198     krb5_crypto krbCrypto = NULL;
 199     krb5_data ticketData = { 0 };
 200     krb5_data encPartData = { 0 };
 201     size_t len;
 202 #else
 203     krb5_ticket ticket;
 204     krb5_enc_tkt_part enc_part;
 205     krb5_data *ticketData = NULL;
 206 #endif
 207     krb5_data credsData = { 0 };
 208     krb5_creds creds = { 0 };
 209     krb5_auth_context authContext = NULL;
 210
 211     memset(&ticket, 0, sizeof(ticket));
 212     memset(&enc_part, 0, sizeof(enc_part));
 213
 214     credBuf->length = 0;
 215     credBuf->value = NULL;
 216
 217     GSSEAP_KRB_INIT(&krbContext);
 218
 219     code = getAcceptorKey(krbContext, ctx, cred, &server, &acceptorKey);
 220     if (code != 0) {
 221         *minor = code;
 222         return GSS_S_UNAVAILABLE;
 223     }
 224
 225     /*
 226      * Generate a random session key to place in the ticket and
 227      * sign the "KDC-Issued" authorization data element.
 228      */
 229 #ifdef HAVE_HEIMDAL_VERSION
 230     ticket.realm = server->realm;
 231     ticket.sname = server->name;
 232
 233     code = krb5_generate_random_keyblock(krbContext, ctx->encryptionType,
 234                                          &session);
 235     if (code != 0)
 236         goto cleanup;
 237
 238     enc_part.flags.initial = 1;
 239     enc_part.key = session;
 240     enc_part.crealm = ctx->initiatorName->krbPrincipal->realm;
 241     enc_part.cname = ctx->initiatorName->krbPrincipal->name;
 242     enc_part.authtime = time(NULL);
 243     enc_part.starttime = &enc_part.authtime;
 244     enc_part.endtime = (ctx->expiryTime != 0)
 245                        ? ctx->expiryTime : KRB_TIME_FOREVER;
 246     enc_part.renew_till = NULL;
 247     enc_part.authorization_data = &authData;
 248
 249     major = freezeAttrContext(minor, ctx->initiatorName, server,
 250                               &session, &authData);
 251     if (GSS_ERROR(major))
 252         goto cleanup;
 253
 254     ASN1_MALLOC_ENCODE(EncTicketPart, encPartData.data, encPartData.length,
 255                        &enc_part, &len, code);
 256     if (code != 0)
 257         goto cleanup;
 258
 259     code = krb5_crypto_init(krbContext, &acceptorKey, 0, &krbCrypto);
 260     if (code != 0)
 261         goto cleanup;
 262
 263     code = krb5_encrypt_EncryptedData(krbContext,
 264                                       krbCrypto,
 265                                       KRB5_KU_TICKET,
 266                                       encPartData.data,
 267                                       encPartData.length,
 268                                       0,
 269                                       &ticket.enc_part);
 270     if (code != 0)
 271         goto cleanup;
 272
 273     ASN1_MALLOC_ENCODE(Ticket, ticketData.data, ticketData.length,
 274                        &ticket, &len, code);
 275     if (code != 0)
 276         goto cleanup;
 277 #else
 278     ticket.server = server;
 279
 280     code = krb5_c_make_random_key(krbContext, ctx->encryptionType,
 281                                   &session);
 282     if (code != 0)
 283         goto cleanup;
 284
 285     enc_part.flags = TKT_FLG_INITIAL;
 286     enc_part.session = &session;
 287     enc_part.client = ctx->initiatorName->krbPrincipal;
 288     enc_part.times.authtime = time(NULL);
 289     enc_part.times.starttime = enc_part.times.authtime;
 290     enc_part.times.endtime = (ctx->expiryTime != 0)
 291                              ? ctx->expiryTime
 292                              : KRB_TIME_FOREVER;
 293     enc_part.times.renew_till = 0;
 294
 295     major = freezeAttrContext(minor, ctx->initiatorName, server,
 296                               &session, &enc_part.authorization_data);
 297     if (GSS_ERROR(major))
 298         goto cleanup;
 299
 300     ticket.enc_part2 = &enc_part;
 301
 302     code = krb5_encrypt_tkt_part(krbContext, &acceptorKey, &ticket);
 303     if (code != 0)
 304         goto cleanup;
 305
 306     code = encode_krb5_ticket(&ticket, &ticketData);
 307     if (code != 0)
 308         goto cleanup;
 309 #endif /* HAVE_HEIMDAL_VERSION */
 310
 311     creds.client = ctx->initiatorName->krbPrincipal;
 312     creds.server = server;
 313 #ifdef HAVE_HEIMDAL_VERSION
 314     creds.session = session;
 315     creds.times.authtime = enc_part.authtime;
 316     creds.times.starttime = *enc_part.starttime;
 317     creds.times.endtime = enc_part.endtime;
 318     creds.times.renew_till = 0;
 319     creds.flags.b = enc_part.flags;
 320     creds.ticket = ticketData;
 321     creds.authdata = authData;
 322 #else
 323     creds.keyblock = session;
 324     creds.times = enc_part.times;
 325     creds.ticket_flags = enc_part.flags;
 326     creds.ticket = *ticketData;
 327     creds.authdata = enc_part.authorization_data;
 328 #endif
 329
 330     code = krb5_auth_con_init(krbContext, &authContext);
 331     if (code != 0)
 332         goto cleanup;
 333
 334     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 335     if (code != 0)
 336         goto cleanup;
 337
 338 #ifdef HAVE_HEIMDAL_VERSION
 339     code = krb5_auth_con_setlocalsubkey(krbContext, authContext,
 340                                         &ctx->rfc3961Key);
 341 #else
 342     code = krb5_auth_con_setsendsubkey(krbContext, authContext,
 343                                        &ctx->rfc3961Key);
 344 #endif
 345     if (code != 0)
 346         goto cleanup;
 347
 348     code = krbMakeCred(krbContext, authContext, &creds, &credsData);
 349     if (code != 0)
 350         goto cleanup;
 351
 352     krbDataToGssBuffer(&credsData, credBuf);
 353
 354 cleanup:
 355 #ifdef HAVE_HEIMDAL_VERSION
 356     if (krbCrypto != NULL)
 357         krb5_crypto_destroy(krbContext, krbCrypto);
 358     free_AuthorizationData(&authData);
 359     free_EncryptedData(&ticket.enc_part);
 360     krb5_data_free(&ticketData);
 361     krb5_data_free(&encPartData);
 362 #else
 363     krb5_free_authdata(krbContext, enc_part.authorization_data);
 364     if (ticket.enc_part.ciphertext.data != NULL)
 365         GSSEAP_FREE(ticket.enc_part.ciphertext.data);
 366     krb5_free_data(krbContext, ticketData);
 367 #endif
 368     krb5_free_keyblock_contents(krbContext, &session);
 369     krb5_free_principal(krbContext, server);
 370     krb5_free_keyblock_contents(krbContext, &acceptorKey);
 371     krb5_auth_con_free(krbContext, authContext);
 372
 373     if (major == GSS_S_COMPLETE) {
 374         *minor = code;
 375         major = (code != 0) ? GSS_S_FAILURE : GSS_S_COMPLETE;
 376     }
 377
 378     return major;
 379 }
 380
 381 static int
 382 isTicketGrantingServiceP(krb5_context krbContext GSSEAP_UNUSED,
 383                          krb5_const_principal principal)
 384 {
 385     if (KRB_PRINC_LENGTH(principal) == 2 &&
 386 #ifdef HAVE_HEIMDAL_VERSION
 387         strcmp(KRB_PRINC_NAME(principal)[0], "krbtgt") == 0
 388 #else
 389         krb5_princ_component(krbContext, principal, 0)->length == 6 &&
 390         memcmp(krb5_princ_component(krbContext,
 391                                     principal, 0)->data, "krbtgt", 6) == 0
 392 #endif
 393         )
 394         return TRUE;
 395
 396     return FALSE;
 397 }
 398
 399 /*
 400  * Returns TRUE if the configuration variable reauth_use_ccache is
 401  * set in krb5.conf for the eap_gss application and the client realm.
 402  */
 403 static int
 404 reauthUseCredsCache(krb5_context krbContext,
 405                     krb5_principal principal)
 406 {
 407     int reauthUseCCache;
 408
 409     /* if reauth_use_ccache, use default credentials cache if ticket is for us */
 410     krb5_appdefault_boolean(krbContext, "eap_gss",
 411                             KRB_PRINC_REALM(principal),
 412                             "reauth_use_ccache", 0, &reauthUseCCache);
 413
 414     return reauthUseCCache;
 415 }
 416
 417 /*
 418  * Look in default credentials cache for reauthentication credentials,
 419  * if policy allows.
 420  */
 421 static OM_uint32
 422 getDefaultReauthCredentials(OM_uint32 *minor,
 423                             gss_cred_id_t cred,
 424                             gss_name_t target,
 425                             time_t now,
 426                             OM_uint32 timeReq)
 427 {
 428     OM_uint32 major = GSS_S_CRED_UNAVAIL;
 429     krb5_context krbContext = NULL;
 430     krb5_error_code code = 0;
 431     krb5_ccache ccache = NULL;
 432     krb5_creds match = { 0 };
 433     krb5_creds creds = { 0 };
 434
 435     GSSEAP_KRB_INIT(&krbContext);
 436
 437     GSSEAP_ASSERT(cred != GSS_C_NO_CREDENTIAL);
 438     GSSEAP_ASSERT(target != GSS_C_NO_NAME);
 439
 440     if (cred->name == GSS_C_NO_NAME ||
 441         !reauthUseCredsCache(krbContext, cred->name->krbPrincipal))
 442         goto cleanup;
 443
 444     match.client = cred->name->krbPrincipal;
 445     match.server = target->krbPrincipal;
 446     if (timeReq != 0 && timeReq != GSS_C_INDEFINITE)
 447         match.times.endtime = now + timeReq;
 448
 449     code = krb5_cc_default(krbContext, &ccache);
 450     if (code != 0)
 451         goto cleanup;
 452
 453     code = krb5_cc_retrieve_cred(krbContext, ccache, 0, &match, &creds);
 454     if (code != 0)
 455         goto cleanup;
 456
 457     cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 458     cred->krbCredCache = ccache;
 459     ccache = NULL;
 460
 461     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 462                                  &cred->reauthCred);
 463
 464 cleanup:
 465     if (major == GSS_S_CRED_UNAVAIL)
 466         *minor = code;
 467
 468     if (ccache != NULL)
 469         krb5_cc_close(krbContext, ccache);
 470     krb5_free_cred_contents(krbContext, &creds);
 471
 472     return major;
 473 }
 474
 475 /*
 476  * Returns TRUE if the credential handle's reauth credentials are
 477  * valid or if we can use the default credentials cache. Credentials
 478  * handle must be locked.
 479  */
 480 int
 481 gssEapCanReauthP(gss_cred_id_t cred,
 482                  gss_name_t target,
 483                  OM_uint32 timeReq)
 484 {
 485     time_t now, expiryReq;
 486     OM_uint32 minor;
 487
 488     GSSEAP_ASSERT(cred != GSS_C_NO_CREDENTIAL);
 489
 490     now = time(NULL);
 491     expiryReq = now;
 492     if (timeReq != GSS_C_INDEFINITE)
 493         expiryReq += timeReq;
 494
 495     if (cred->krbCredCache != NULL && cred->expiryTime > expiryReq)
 496         return TRUE;
 497
 498     if (getDefaultReauthCredentials(&minor, cred, target,
 499                                     now, timeReq) == GSS_S_COMPLETE)
 500         return TRUE;
 501
 502     return FALSE;
 503 }
 504
 505 /*
 506  * Store re-authentication (Kerberos) credentials in a credential handle.
 507  * Credentials handle must be locked.
 508  */
 509 OM_uint32
 510 gssEapStoreReauthCreds(OM_uint32 *minor,
 511                        gss_ctx_id_t ctx,
 512                        gss_cred_id_t cred,
 513                        gss_buffer_t credBuf)
 514 {
 515     OM_uint32 major = GSS_S_COMPLETE;
 516     krb5_error_code code;
 517     krb5_context krbContext = NULL;
 518     krb5_auth_context authContext = NULL;
 519     krb5_data credData = { 0 };
 520     krb5_creds **creds = NULL;
 521     krb5_principal canonPrinc;
 522     krb5_principal ccPrinc = NULL;
 523     int i;
 524
 525     if (credBuf->length == 0 || cred == GSS_C_NO_CREDENTIAL)
 526         return GSS_S_COMPLETE;
 527
 528     GSSEAP_KRB_INIT(&krbContext);
 529
 530     code = krb5_auth_con_init(krbContext, &authContext);
 531     if (code != 0)
 532         goto cleanup;
 533
 534     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 535     if (code != 0)
 536         goto cleanup;
 537
 538     code = krb5_auth_con_setrecvsubkey(krbContext, authContext,
 539                                        &ctx->rfc3961Key);
 540     if (code != 0)
 541         goto cleanup;
 542
 543     gssBufferToKrbData(credBuf, &credData);
 544
 545     code = krb5_rd_cred(krbContext, authContext, &credData, &creds, NULL);
 546     if (code != 0)
 547         goto cleanup;
 548
 549     if (creds == NULL || creds[0] == NULL)
 550         goto cleanup;
 551
 552     code = krb5_copy_principal(krbContext, creds[0]->client, &canonPrinc);
 553     if (code != 0)
 554         goto cleanup;
 555
 556     krb5_free_principal(krbContext, cred->name->krbPrincipal);
 557     cred->name->krbPrincipal = canonPrinc;
 558
 559     if (creds[0]->times.endtime == KRB_TIME_FOREVER)
 560         cred->expiryTime = 0;
 561     else
 562         cred->expiryTime = creds[0]->times.endtime;
 563
 564     if (cred->krbCredCache == NULL) {
 565         if (reauthUseCredsCache(krbContext, creds[0]->client) &&
 566             krb5_cc_default(krbContext, &cred->krbCredCache) == 0)
 567             cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 568     } else {
 569         /*
 570          * If we already have an associated credentials cache, possibly from
 571          * the last time we stored a reauthentication credential, then we
 572          * need to clear it out and release the associated GSS credential.
 573          */
 574         if (cred->flags & CRED_FLAG_DEFAULT_CCACHE) {
 575             krb5_cc_remove_cred(krbContext, cred->krbCredCache, 0, creds[0]);
 576         } else {
 577             krb5_cc_destroy(krbContext, cred->krbCredCache);
 578             cred->krbCredCache = NULL;
 579         }
 580         gssReleaseCred(minor, &cred->reauthCred);
 581     }
 582
 583     if (cred->krbCredCache == NULL) {
 584         code = krb5_cc_new_unique(krbContext, "MEMORY", NULL, &cred->krbCredCache);
 585         if (code != 0)
 586             goto cleanup;
 587     }
 588
 589     if ((cred->flags & CRED_FLAG_DEFAULT_CCACHE) == 0 ||
 590         krb5_cc_get_principal(krbContext, cred->krbCredCache, &ccPrinc) != 0) {
 591         code = krb5_cc_initialize(krbContext, cred->krbCredCache,
 592                                   creds[0]->client);
 593         if (code != 0)
 594             goto cleanup;
 595     }
 596
 597     for (i = 0; creds[i] != NULL; i++) {
 598         krb5_creds kcred = *(creds[i]);
 599
 600         /*
 601          * Swap in the acceptor name the client asked for so
 602          * get_credentials() works. We're making the assumption that
 603          * any service tickets returned are for us. We'll need to
 604          * reflect some more on whether that is a safe assumption.
 605          */
 606         if (!isTicketGrantingServiceP(krbContext, kcred.server))
 607             kcred.server = ctx->acceptorName->krbPrincipal;
 608
 609         code = krb5_cc_store_cred(krbContext, cred->krbCredCache, &kcred);
 610         if (code != 0)
 611             goto cleanup;
 612     }
 613
 614     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 615                                  &cred->reauthCred);
 616     if (GSS_ERROR(major))
 617         goto cleanup;
 618
 619 cleanup:
 620     *minor = code;
 621
 622     krb5_free_principal(krbContext, ccPrinc);
 623     krb5_auth_con_free(krbContext, authContext);
 624     if (creds != NULL) {
 625         for (i = 0; creds[i] != NULL; i++)
 626             krb5_free_creds(krbContext, creds[i]);
 627         GSSEAP_FREE(creds);
 628     }
 629     if (major == GSS_S_COMPLETE)
 630         major = *minor ? GSS_S_FAILURE : GSS_S_COMPLETE;
 631
 632     return major;
 633 }
 634
 635 #ifndef HAVE_HEIMDAL_VERSION
 636 static gss_buffer_desc radiusAvpKrbAttr = {
 637     sizeof("urn:authdata-radius-avp") - 1, "urn:authdata-radius-avp"
 638 };
 639 #endif
 640
 641 /*
 642  * Unfortunately extracting an AD-KDCIssued authorization data element
 643  * is pretty implementation-dependent. It's not possible to verify the
 644  * signature ourselves because the ticket session key is not exposed
 645  * outside GSS. In an ideal world, all AD-KDCIssued elements would be
 646  * verified by the Kerberos library and authentication would fail if
 647  * verification failed. We're not quite there yet and as a result have
 648  * to go through some hoops to get this to work. The alternative would
 649  * be to sign the authorization data with our long-term key, but it
 650  * seems a pity to compromise the design because of current implementation
 651  * limitations.
 652  *
 653  * (Specifically, the hoops involve a libkrb5 authorisation data plugin
 654  * that exposes the verified and serialised attribute context through
 655  * the Kerberos GSS mechanism's naming extensions API.)
 656  */
 657 static OM_uint32
 658 defrostAttrContext(OM_uint32 *minor,
 659 #ifdef HAVE_HEIMDAL_VERSION
 660                    gss_ctx_id_t glueContext,
 661 #else
 662                    gss_name_t glueName,
 663 #endif
 664                    gss_name_t mechName)
 665 {
 666     OM_uint32 major, tmpMinor;
 667 #ifdef HAVE_HEIMDAL_VERSION
 668     gss_OID_desc oid = { 0 };
 669     gss_buffer_set_t authData = GSS_C_NO_BUFFER_SET;
 670 #else
 671     gss_buffer_desc authData = GSS_C_EMPTY_BUFFER;
 672     gss_buffer_desc authDataDisplay = GSS_C_EMPTY_BUFFER;
 673     int more = -1;
 674     int authenticated, complete;
 675 #endif
 676
 677 #ifdef HAVE_HEIMDAL_VERSION
 678     major = composeOid(minor,
 679                        GSS_KRB5_EXTRACT_AUTHZ_DATA_FROM_SEC_CONTEXT_X->elements,
 680                        GSS_KRB5_EXTRACT_AUTHZ_DATA_FROM_SEC_CONTEXT_X->length,
 681                        KRB5_AUTHDATA_RADIUS_AVP, &oid);
 682     if (GSS_ERROR(major))
 683         return major;
 684
 685     /* XXX we are assuming that this verifies AD-KDCIssued signature */
 686     major = gssInquireSecContextByOid(minor, glueContext,
 687                                       &oid, &authData);
 688     if (major == GSS_S_COMPLETE) {
 689         if (authData == GSS_C_NO_BUFFER_SET || authData->count != 1)
 690             major = GSS_S_FAILURE;
 691         else
 692             major = gssEapImportAttrContext(minor, authData->elements, mechName);
 693     } else if (major == GSS_S_FAILURE && *minor == ENOENT) {
 694         /* This is the equivalent of GSS_S_UNAVAILABLE for MIT attr APIs */
 695         *minor = 0;
 696         major = GSS_S_COMPLETE;
 697     }
 698
 699     gss_release_buffer_set(&tmpMinor, &authData);
 700     GSSEAP_FREE(oid.elements);
 701 #else
 702     major = gssGetNameAttribute(minor, glueName, &radiusAvpKrbAttr,
 703                                 &authenticated, &complete,
 704                                 &authData, &authDataDisplay, &more);
 705     if (major == GSS_S_COMPLETE) {
 706         if (authenticated == 0)
 707             major = GSS_S_BAD_NAME;
 708         else
 709             major = gssEapImportAttrContext(minor, &authData, mechName);
 710     } else if (major == GSS_S_UNAVAILABLE) {
 711         major = GSS_S_COMPLETE;
 712     }
 713
 714     gss_release_buffer(&tmpMinor, &authData);
 715     gss_release_buffer(&tmpMinor, &authDataDisplay);
 716 #endif /* HAVE_HEIMDAL_VERSION */
 717
 718     return major;
 719 }
 720
 721 /*
 722  * Convert a mechanism glue to an EAP mechanism name by displaying and
 723  * importing it. This also handles the RADIUS attributes.
 724  */
 725 OM_uint32
 726 gssEapGlueToMechName(OM_uint32 *minor,
 727                      gss_ctx_id_t ctx,
 728                      gss_name_t glueName,
 729                      gss_name_t *pMechName)
 730 {
 731     OM_uint32 major, tmpMinor;
 732     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 733
 734     *pMechName = GSS_C_NO_NAME;
 735
 736     major = gssDisplayName(minor, glueName, &nameBuf, NULL);
 737     if (GSS_ERROR(major))
 738         goto cleanup;
 739
 740     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 741                              ctx->mechanismUsed, pMechName);
 742     if (GSS_ERROR(major))
 743         goto cleanup;
 744
 745     major = defrostAttrContext(minor,
 746 #ifdef HAVE_HEIMDAL_VERSION
 747                                ctx->reauthCtx,
 748 #else
 749                                glueName,
 750 #endif
 751                                *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 GSSEAP_UNUSED,
 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->reauthCtx,
 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->reauthCtx,
 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 #ifndef HAVE_HEIMDAL_VERSION
1021     NEXT_SYMBOL(gssGetNameAttributeNext,       "gss_get_name_attribute");
1022 #endif
1023
1024     return major;
1025 }
1026
1027 OM_uint32
1028 gssInitSecContext(OM_uint32 *minor,
1029                   gss_cred_id_t cred,
1030                   gss_ctx_id_t *context_handle,
1031                   gss_name_t target_name,
1032                   gss_OID mech_type,
1033                   OM_uint32 req_flags,
1034                   OM_uint32 time_req,
1035                   gss_channel_bindings_t input_chan_bindings,
1036                   gss_buffer_t input_token,
1037                   gss_OID *actual_mech_type,
1038                   gss_buffer_t output_token,
1039                   OM_uint32 *ret_flags,
1040                   OM_uint32 *time_rec)
1041 {
1042     if (gssInitSecContextNext == NULL) {
1043         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1044         return GSS_S_UNAVAILABLE;
1045     }
1046
1047     return gssInitSecContextNext(minor, cred, context_handle,
1048                                  target_name, mech_type, req_flags,
1049                                  time_req, input_chan_bindings,
1050                                  input_token, actual_mech_type,
1051                                  output_token, ret_flags, time_rec);
1052 }
1053
1054 OM_uint32
1055 gssAcceptSecContext(OM_uint32 *minor,
1056                     gss_ctx_id_t *context_handle,
1057                     gss_cred_id_t cred,
1058                     gss_buffer_t input_token,
1059                     gss_channel_bindings_t input_chan_bindings,
1060                     gss_name_t *src_name,
1061                     gss_OID *mech_type,
1062                     gss_buffer_t output_token,
1063                     OM_uint32 *ret_flags,
1064                     OM_uint32 *time_rec,
1065                     gss_cred_id_t *delegated_cred_handle)
1066 {
1067     if (gssAcceptSecContextNext == NULL) {
1068         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1069         return GSS_S_UNAVAILABLE;
1070     }
1071
1072     return gssAcceptSecContextNext(minor, context_handle, cred,
1073                                    input_token, input_chan_bindings,
1074                                    src_name, mech_type, output_token,
1075                                    ret_flags, time_rec, delegated_cred_handle);
1076 }
1077
1078 OM_uint32
1079 gssReleaseCred(OM_uint32 *minor,
1080                gss_cred_id_t *cred_handle)
1081 {
1082     if (gssReleaseCredNext == NULL) {
1083         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1084         return GSS_S_UNAVAILABLE;
1085     }
1086
1087     return gssReleaseCredNext(minor, cred_handle);
1088 }
1089
1090 OM_uint32
1091 gssReleaseName(OM_uint32 *minor,
1092                gss_name_t *name)
1093 {
1094     if (gssReleaseName == NULL) {
1095         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1096         return GSS_S_UNAVAILABLE;
1097     }
1098
1099     return gssReleaseNameNext(minor, name);
1100 }
1101
1102 OM_uint32
1103 gssDeleteSecContext(OM_uint32 *minor,
1104                     gss_ctx_id_t *context_handle,
1105                     gss_buffer_t output_token)
1106 {
1107     if (gssDeleteSecContextNext == NULL) {
1108         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1109         return GSS_S_UNAVAILABLE;
1110     }
1111
1112     return gssDeleteSecContextNext(minor, context_handle, output_token);
1113 }
1114
1115 static OM_uint32
1116 gssDisplayName(OM_uint32 *minor,
1117                gss_name_t name,
1118                gss_buffer_t buffer,
1119                gss_OID *name_type)
1120 {
1121     if (gssDisplayNameNext == NULL) {
1122         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1123         return GSS_S_UNAVAILABLE;
1124     }
1125
1126     return gssDisplayNameNext(minor, name, buffer, name_type);
1127 }
1128
1129 static OM_uint32
1130 gssImportName(OM_uint32 *minor,
1131               gss_buffer_t buffer,
1132               gss_OID name_type,
1133               gss_name_t *name)
1134 {
1135     if (gssImportNameNext == NULL) {
1136         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1137         return GSS_S_UNAVAILABLE;
1138     }
1139
1140     return gssImportNameNext(minor, buffer, name_type, name);
1141 }
1142
1143 OM_uint32
1144 gssInquireSecContextByOid(OM_uint32 *minor,
1145                           const gss_ctx_id_t context_handle,
1146                           const gss_OID desired_object,
1147                           gss_buffer_set_t *data_set)
1148 {
1149     if (gssInquireSecContextByOidNext == NULL) {
1150         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1151         return GSS_S_UNAVAILABLE;
1152     }
1153
1154     return gssInquireSecContextByOidNext(minor, context_handle,
1155                                          desired_object, data_set);
1156 }
1157
1158 OM_uint32
1159 gssStoreCred(OM_uint32 *minor,
1160              const gss_cred_id_t input_cred_handle,
1161              gss_cred_usage_t input_usage,
1162              const gss_OID desired_mech,
1163              OM_uint32 overwrite_cred,
1164              OM_uint32 default_cred,
1165              gss_OID_set *elements_stored,
1166              gss_cred_usage_t *cred_usage_stored)
1167 {
1168     if (gssStoreCredNext == NULL) {
1169         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1170         return GSS_S_UNAVAILABLE;
1171     }
1172
1173     return gssStoreCredNext(minor, input_cred_handle, input_usage,
1174                             desired_mech, overwrite_cred, default_cred,
1175                             elements_stored, cred_usage_stored);
1176 }
1177
1178 OM_uint32
1179 gssGetNameAttribute(OM_uint32 *minor,
1180                     gss_name_t name,
1181                     gss_buffer_t attr,
1182                     int *authenticated,
1183                     int *complete,
1184                     gss_buffer_t value,
1185                     gss_buffer_t display_value,
1186                     int *more)
1187 {
1188     if (gssGetNameAttributeNext == NULL) {
1189         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1190         return GSS_S_UNAVAILABLE;
1191     }
1192
1193     return gssGetNameAttributeNext(minor, name, attr, authenticated, complete,
1194                                    value, display_value, more);
1195 }