www.project-moonshot.org Git - mech_eap.orig/blob - 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     if (cred == GSS_C_NO_CREDENTIAL)
 489         return FALSE;
 490
 491     now = time(NULL);
 492     expiryReq = now;
 493     if (timeReq != GSS_C_INDEFINITE)
 494         expiryReq += timeReq;
 495
 496     if (cred->krbCredCache != NULL && cred->expiryTime > expiryReq)
 497         return TRUE;
 498
 499     if (getDefaultReauthCredentials(&minor, cred, target,
 500                                     now, timeReq) == GSS_S_COMPLETE)
 501         return TRUE;
 502
 503     return FALSE;
 504 }
 505
 506 /*
 507  * Store re-authentication (Kerberos) credentials in a credential handle.
 508  * Credentials handle must be locked.
 509  */
 510 OM_uint32
 511 gssEapStoreReauthCreds(OM_uint32 *minor,
 512                        gss_ctx_id_t ctx,
 513                        gss_cred_id_t cred,
 514                        gss_buffer_t credBuf)
 515 {
 516     OM_uint32 major = GSS_S_COMPLETE;
 517     krb5_error_code code;
 518     krb5_context krbContext = NULL;
 519     krb5_auth_context authContext = NULL;
 520     krb5_data credData = { 0 };
 521     krb5_creds **creds = NULL;
 522     krb5_principal canonPrinc;
 523     krb5_principal ccPrinc = NULL;
 524     int i;
 525
 526     if (credBuf->length == 0 || cred == GSS_C_NO_CREDENTIAL)
 527         return GSS_S_COMPLETE;
 528
 529     GSSEAP_KRB_INIT(&krbContext);
 530
 531     code = krb5_auth_con_init(krbContext, &authContext);
 532     if (code != 0)
 533         goto cleanup;
 534
 535     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 536     if (code != 0)
 537         goto cleanup;
 538
 539     code = krb5_auth_con_setrecvsubkey(krbContext, authContext,
 540                                        &ctx->rfc3961Key);
 541     if (code != 0)
 542         goto cleanup;
 543
 544     gssBufferToKrbData(credBuf, &credData);
 545
 546     code = krb5_rd_cred(krbContext, authContext, &credData, &creds, NULL);
 547     if (code != 0)
 548         goto cleanup;
 549
 550     if (creds == NULL || creds[0] == NULL)
 551         goto cleanup;
 552
 553     code = krb5_copy_principal(krbContext, creds[0]->client, &canonPrinc);
 554     if (code != 0)
 555         goto cleanup;
 556
 557     krb5_free_principal(krbContext, cred->name->krbPrincipal);
 558     cred->name->krbPrincipal = canonPrinc;
 559
 560     if (creds[0]->times.endtime == KRB_TIME_FOREVER)
 561         cred->expiryTime = 0;
 562     else
 563         cred->expiryTime = creds[0]->times.endtime;
 564
 565     if (cred->krbCredCache == NULL) {
 566         if (reauthUseCredsCache(krbContext, creds[0]->client) &&
 567             krb5_cc_default(krbContext, &cred->krbCredCache) == 0)
 568             cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 569     } else {
 570         /*
 571          * If we already have an associated credentials cache, possibly from
 572          * the last time we stored a reauthentication credential, then we
 573          * need to clear it out and release the associated GSS credential.
 574          */
 575         if (cred->flags & CRED_FLAG_DEFAULT_CCACHE) {
 576             krb5_cc_remove_cred(krbContext, cred->krbCredCache, 0, creds[0]);
 577         } else {
 578             krb5_cc_destroy(krbContext, cred->krbCredCache);
 579             cred->krbCredCache = NULL;
 580         }
 581         gssReleaseCred(minor, &cred->reauthCred);
 582     }
 583
 584     if (cred->krbCredCache == NULL) {
 585         code = krb5_cc_new_unique(krbContext, "MEMORY", NULL, &cred->krbCredCache);
 586         if (code != 0)
 587             goto cleanup;
 588     }
 589
 590     if ((cred->flags & CRED_FLAG_DEFAULT_CCACHE) == 0 ||
 591         krb5_cc_get_principal(krbContext, cred->krbCredCache, &ccPrinc) != 0) {
 592         code = krb5_cc_initialize(krbContext, cred->krbCredCache,
 593                                   creds[0]->client);
 594         if (code != 0)
 595             goto cleanup;
 596     }
 597
 598     for (i = 0; creds[i] != NULL; i++) {
 599         krb5_creds kcred = *(creds[i]);
 600
 601         /*
 602          * Swap in the acceptor name the client asked for so
 603          * get_credentials() works. We're making the assumption that
 604          * any service tickets returned are for us. We'll need to
 605          * reflect some more on whether that is a safe assumption.
 606          */
 607         if (!isTicketGrantingServiceP(krbContext, kcred.server))
 608             kcred.server = ctx->acceptorName->krbPrincipal;
 609
 610         code = krb5_cc_store_cred(krbContext, cred->krbCredCache, &kcred);
 611         if (code != 0)
 612             goto cleanup;
 613     }
 614
 615     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 616                                  &cred->reauthCred);
 617     if (GSS_ERROR(major))
 618         goto cleanup;
 619
 620 cleanup:
 621     *minor = code;
 622
 623     krb5_free_principal(krbContext, ccPrinc);
 624     krb5_auth_con_free(krbContext, authContext);
 625     if (creds != NULL) {
 626         for (i = 0; creds[i] != NULL; i++)
 627             krb5_free_creds(krbContext, creds[i]);
 628         GSSEAP_FREE(creds);
 629     }
 630     if (major == GSS_S_COMPLETE)
 631         major = *minor ? GSS_S_FAILURE : GSS_S_COMPLETE;
 632
 633     return major;
 634 }
 635
 636 #ifndef HAVE_HEIMDAL_VERSION
 637 static gss_buffer_desc radiusAvpKrbAttr = {
 638     sizeof("urn:authdata-radius-avp") - 1, "urn:authdata-radius-avp"
 639 };
 640 #endif
 641
 642 /*
 643  * Unfortunately extracting an AD-KDCIssued authorization data element
 644  * is pretty implementation-dependent. It's not possible to verify the
 645  * signature ourselves because the ticket session key is not exposed
 646  * outside GSS. In an ideal world, all AD-KDCIssued elements would be
 647  * verified by the Kerberos library and authentication would fail if
 648  * verification failed. We're not quite there yet and as a result have
 649  * to go through some hoops to get this to work. The alternative would
 650  * be to sign the authorization data with our long-term key, but it
 651  * seems a pity to compromise the design because of current implementation
 652  * limitations.
 653  *
 654  * (Specifically, the hoops involve a libkrb5 authorisation data plugin
 655  * that exposes the verified and serialised attribute context through
 656  * the Kerberos GSS mechanism's naming extensions API.)
 657  */
 658 static OM_uint32
 659 defrostAttrContext(OM_uint32 *minor,
 660 #ifdef HAVE_HEIMDAL_VERSION
 661                    gss_ctx_id_t glueContext,
 662 #else
 663                    gss_name_t glueName,
 664 #endif
 665                    gss_name_t mechName)
 666 {
 667     OM_uint32 major, tmpMinor;
 668 #ifdef HAVE_HEIMDAL_VERSION
 669     gss_OID_desc oid = { 0 };
 670     gss_buffer_set_t authData = GSS_C_NO_BUFFER_SET;
 671 #else
 672     gss_buffer_desc authData = GSS_C_EMPTY_BUFFER;
 673     gss_buffer_desc authDataDisplay = GSS_C_EMPTY_BUFFER;
 674     int more = -1;
 675     int authenticated, complete;
 676 #endif
 677
 678 #ifdef HAVE_HEIMDAL_VERSION
 679     major = composeOid(minor,
 680                        GSS_KRB5_EXTRACT_AUTHZ_DATA_FROM_SEC_CONTEXT_X->elements,
 681                        GSS_KRB5_EXTRACT_AUTHZ_DATA_FROM_SEC_CONTEXT_X->length,
 682                        KRB5_AUTHDATA_RADIUS_AVP, &oid);
 683     if (GSS_ERROR(major))
 684         return major;
 685
 686     /* XXX we are assuming that this verifies AD-KDCIssued signature */
 687     major = gssInquireSecContextByOid(minor, glueContext,
 688                                       &oid, &authData);
 689     if (major == GSS_S_COMPLETE) {
 690         if (authData == GSS_C_NO_BUFFER_SET || authData->count != 1)
 691             major = GSS_S_FAILURE;
 692         else
 693             major = gssEapImportAttrContext(minor, authData->elements, mechName);
 694     } else if (major == GSS_S_FAILURE && *minor == ENOENT) {
 695         /* This is the equivalent of GSS_S_UNAVAILABLE for MIT attr APIs */
 696         *minor = 0;
 697         major = GSS_S_COMPLETE;
 698     }
 699
 700     gss_release_buffer_set(&tmpMinor, &authData);
 701     GSSEAP_FREE(oid.elements);
 702 #else
 703     major = gssGetNameAttribute(minor, glueName, &radiusAvpKrbAttr,
 704                                 &authenticated, &complete,
 705                                 &authData, &authDataDisplay, &more);
 706     if (major == GSS_S_COMPLETE) {
 707         if (authenticated == 0)
 708             major = GSS_S_BAD_NAME;
 709         else
 710             major = gssEapImportAttrContext(minor, &authData, mechName);
 711     } else if (major == GSS_S_UNAVAILABLE) {
 712         major = GSS_S_COMPLETE;
 713     }
 714
 715     gss_release_buffer(&tmpMinor, &authData);
 716     gss_release_buffer(&tmpMinor, &authDataDisplay);
 717 #endif /* HAVE_HEIMDAL_VERSION */
 718
 719     return major;
 720 }
 721
 722 /*
 723  * Convert a mechanism glue to an EAP mechanism name by displaying and
 724  * importing it. This also handles the RADIUS attributes.
 725  */
 726 OM_uint32
 727 gssEapGlueToMechName(OM_uint32 *minor,
 728                      gss_ctx_id_t ctx,
 729                      gss_name_t glueName,
 730                      gss_name_t *pMechName)
 731 {
 732     OM_uint32 major, tmpMinor;
 733     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 734
 735     *pMechName = GSS_C_NO_NAME;
 736
 737     major = gssDisplayName(minor, glueName, &nameBuf, NULL);
 738     if (GSS_ERROR(major))
 739         goto cleanup;
 740
 741     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 742                              ctx->mechanismUsed, pMechName);
 743     if (GSS_ERROR(major))
 744         goto cleanup;
 745
 746     major = defrostAttrContext(minor,
 747 #ifdef HAVE_HEIMDAL_VERSION
 748                                ctx->reauthCtx,
 749 #else
 750                                glueName,
 751 #endif
 752                                *pMechName);
 753     if (GSS_ERROR(major))
 754         goto cleanup;
 755
 756 cleanup:
 757     if (GSS_ERROR(major)) {
 758         gssReleaseName(&tmpMinor, pMechName);
 759         *pMechName = GSS_C_NO_NAME;
 760     }
 761
 762     gss_release_buffer(&tmpMinor, &nameBuf);
 763
 764     return major;
 765 }
 766
 767 /*
 768  * Convert an EAP mechanism name to a mechanism glue name by displaying
 769  * and importing it.
 770  */
 771 OM_uint32
 772 gssEapMechToGlueName(OM_uint32 *minor,
 773                      gss_name_t mechName,
 774                      gss_name_t *pGlueName)
 775 {
 776     OM_uint32 major, tmpMinor;
 777     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 778
 779     *pGlueName = GSS_C_NO_NAME;
 780
 781     major = gssEapDisplayName(minor, mechName, &nameBuf, NULL);
 782     if (GSS_ERROR(major))
 783         goto cleanup;
 784
 785     major = gssImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 786                           pGlueName);
 787     if (GSS_ERROR(major))
 788         goto cleanup;
 789
 790 cleanup:
 791     gss_release_buffer(&tmpMinor, &nameBuf);
 792
 793     return major;
 794 }
 795
 796 /*
 797  * Suck out the analgous elements of a Kerberos GSS context into an EAP
 798  * one so that the application doesn't know the difference.
 799  */
 800 OM_uint32
 801 gssEapReauthComplete(OM_uint32 *minor,
 802                      gss_ctx_id_t ctx,
 803                      gss_cred_id_t cred GSSEAP_UNUSED,
 804                      const gss_OID mech,
 805                      OM_uint32 timeRec)
 806 {
 807     OM_uint32 major, tmpMinor;
 808     gss_buffer_set_t keyData = GSS_C_NO_BUFFER_SET;
 809     krb5_context krbContext = NULL;
 810 #ifdef HAVE_HEIMDAL_VERSION
 811     krb5_storage *sp = NULL;
 812 #endif
 813
 814     GSSEAP_KRB_INIT(&krbContext);
 815
 816     if (!oidEqual(mech, gss_mech_krb5)) {
 817         major = GSS_S_BAD_MECH;
 818         goto cleanup;
 819     }
 820
 821     /* Get the raw subsession key and encryption type */
 822 #ifdef HAVE_HEIMDAL_VERSION
 823 #define KRB_GSS_SUBKEY_COUNT    1 /* encoded session key */
 824     major = gssInquireSecContextByOid(minor, ctx->reauthCtx,
 825                                       GSS_KRB5_GET_SUBKEY_X, &keyData);
 826 #else
 827 #define KRB_GSS_SUBKEY_COUNT    2 /* raw session key, enctype OID */
 828     major = gssInquireSecContextByOid(minor, ctx->reauthCtx,
 829                                       GSS_C_INQ_SSPI_SESSION_KEY, &keyData);
 830 #endif
 831     if (GSS_ERROR(major))
 832         goto cleanup;
 833
 834     if (keyData == GSS_C_NO_BUFFER_SET || keyData->count < KRB_GSS_SUBKEY_COUNT) {
 835         *minor = GSSEAP_KEY_UNAVAILABLE;
 836         major = GSS_S_FAILURE;
 837         goto cleanup;
 838     }
 839
 840 #ifdef HAVE_HEIMDAL_VERSION
 841     sp = krb5_storage_from_mem(keyData->elements[0].value,
 842                                keyData->elements[0].length);
 843     if (sp == NULL) {
 844         *minor = ENOMEM;
 845         major = GSS_S_FAILURE;
 846         goto cleanup;
 847     }
 848
 849     *minor = krb5_ret_keyblock(sp, &ctx->rfc3961Key);
 850     if (*minor != 0) {
 851         major = GSS_S_FAILURE;
 852         goto cleanup;
 853     }
 854 #else
 855     {
 856         gss_OID_desc oid;
 857         int suffix;
 858
 859         oid.length = keyData->elements[1].length;
 860         oid.elements = keyData->elements[1].value;
 861
 862         /* GSS_KRB5_SESSION_KEY_ENCTYPE_OID */
 863         major = decomposeOid(minor,
 864                              "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04",
 865                              10, &oid, &suffix);
 866         if (GSS_ERROR(major))
 867             goto cleanup;
 868
 869         ctx->encryptionType = suffix;
 870     }
 871
 872     {
 873         krb5_keyblock key;
 874
 875         KRB_KEY_LENGTH(&key) = keyData->elements[0].length;
 876         KRB_KEY_DATA(&key)   = keyData->elements[0].value;
 877         KRB_KEY_TYPE(&key)   = ctx->encryptionType;
 878
 879         *minor = krb5_copy_keyblock_contents(krbContext,
 880                                              &key, &ctx->rfc3961Key);
 881         if (*minor != 0) {
 882             major = GSS_S_FAILURE;
 883             goto cleanup;
 884         }
 885     }
 886 #endif /* HAVE_HEIMDAL_VERSION */
 887
 888     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 889                                       &ctx->checksumType);
 890     if (GSS_ERROR(major))
 891         goto cleanup;
 892
 893     if (timeRec != GSS_C_INDEFINITE)
 894         ctx->expiryTime = time(NULL) + timeRec;
 895
 896     /* Initialize our sequence state */
 897     major = sequenceInit(minor,
 898                          &ctx->seqState, ctx->recvSeq,
 899                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 900                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 901                          TRUE);
 902     if (GSS_ERROR(major))
 903         goto cleanup;
 904
 905     major = GSS_S_COMPLETE;
 906
 907 cleanup:
 908 #ifdef HAVE_HEIMDAL_VERSION
 909     if (sp != NULL)
 910         krb5_storage_free(sp);
 911 #endif
 912     gss_release_buffer_set(&tmpMinor, &keyData);
 913
 914     return major;
 915 }
 916
 917 /*
 918  * The remainder of this file consists of wrappers so we can call into the
 919  * mechanism glue without calling ourselves.
 920  */
 921 static OM_uint32
 922 (*gssInitSecContextNext)(OM_uint32 *,
 923                          gss_cred_id_t,
 924                          gss_ctx_id_t *,
 925                          gss_name_t,
 926                          gss_OID,
 927                          OM_uint32,
 928                          OM_uint32,
 929                          gss_channel_bindings_t,
 930                          gss_buffer_t,
 931                          gss_OID *,
 932                          gss_buffer_t,
 933                          OM_uint32 *,
 934                          OM_uint32 *);
 935
 936 static OM_uint32
 937 (*gssAcceptSecContextNext)(OM_uint32 *,
 938                            gss_ctx_id_t *,
 939                            gss_cred_id_t,
 940                            gss_buffer_t,
 941                            gss_channel_bindings_t,
 942                            gss_name_t *,
 943                            gss_OID *,
 944                            gss_buffer_t,
 945                            OM_uint32 *,
 946                            OM_uint32 *,
 947                            gss_cred_id_t *);
 948
 949 static OM_uint32
 950 (*gssReleaseCredNext)(OM_uint32 *, gss_cred_id_t *);
 951
 952 static OM_uint32
 953 (*gssReleaseNameNext)(OM_uint32 *, gss_name_t *);
 954
 955 static OM_uint32
 956 (*gssInquireSecContextByOidNext)(OM_uint32 *,
 957                                  const gss_ctx_id_t,
 958                                  const gss_OID,
 959                                  gss_buffer_set_t *);
 960
 961 static OM_uint32
 962 (*gssDeleteSecContextNext)(OM_uint32 *,
 963                           gss_ctx_id_t *,
 964                           gss_buffer_t);
 965
 966 static OM_uint32
 967 (*gssDisplayNameNext)(OM_uint32 *,
 968                       gss_name_t,
 969                       gss_buffer_t,
 970                       gss_OID *);
 971
 972 static OM_uint32
 973 (*gssImportNameNext)(OM_uint32 *,
 974                      gss_buffer_t,
 975                      gss_OID,
 976                      gss_name_t *);
 977
 978 static OM_uint32
 979 (*gssStoreCredNext)(OM_uint32 *,
 980                     const gss_cred_id_t,
 981                     gss_cred_usage_t,
 982                     const gss_OID,
 983                     OM_uint32,
 984                     OM_uint32,
 985                     gss_OID_set *,
 986                     gss_cred_usage_t *);
 987
 988 static OM_uint32
 989 (*gssGetNameAttributeNext)(OM_uint32 *,
 990                           gss_name_t,
 991                           gss_buffer_t,
 992                           int *,
 993                           int *,
 994                           gss_buffer_t,
 995                           gss_buffer_t,
 996                           int *);
 997
 998 #define NEXT_SYMBOL(local, global)  do {        \
 999         ((local) = dlsym(RTLD_NEXT, (global))); \
1000         if ((local) == NULL) {                  \
1001             *minor = GSSEAP_NO_MECHGLUE_SYMBOL; \
1002             major = GSS_S_UNAVAILABLE;          \
1003             /* but continue */                  \
1004         }                                       \
1005     } while (0)
1006
1007 OM_uint32
1008 gssEapReauthInitialize(OM_uint32 *minor)
1009 {
1010     OM_uint32 major = GSS_S_COMPLETE;
1011
1012     NEXT_SYMBOL(gssInitSecContextNext,         "gss_init_sec_context");
1013     NEXT_SYMBOL(gssAcceptSecContextNext,       "gss_accept_sec_context");
1014     NEXT_SYMBOL(gssReleaseCredNext,            "gss_release_cred");
1015     NEXT_SYMBOL(gssReleaseNameNext,            "gss_release_name");
1016     NEXT_SYMBOL(gssInquireSecContextByOidNext, "gss_inquire_sec_context_by_oid");
1017     NEXT_SYMBOL(gssDeleteSecContextNext,       "gss_delete_sec_context");
1018     NEXT_SYMBOL(gssDisplayNameNext,            "gss_display_name");
1019     NEXT_SYMBOL(gssImportNameNext,             "gss_import_name");
1020     NEXT_SYMBOL(gssStoreCredNext,              "gss_store_cred");
1021 #ifndef HAVE_HEIMDAL_VERSION
1022     NEXT_SYMBOL(gssGetNameAttributeNext,       "gss_get_name_attribute");
1023 #endif
1024
1025     return major;
1026 }
1027
1028 OM_uint32
1029 gssInitSecContext(OM_uint32 *minor,
1030                   gss_cred_id_t cred,
1031                   gss_ctx_id_t *context_handle,
1032                   gss_name_t target_name,
1033                   gss_OID mech_type,
1034                   OM_uint32 req_flags,
1035                   OM_uint32 time_req,
1036                   gss_channel_bindings_t input_chan_bindings,
1037                   gss_buffer_t input_token,
1038                   gss_OID *actual_mech_type,
1039                   gss_buffer_t output_token,
1040                   OM_uint32 *ret_flags,
1041                   OM_uint32 *time_rec)
1042 {
1043     if (gssInitSecContextNext == NULL) {
1044         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1045         return GSS_S_UNAVAILABLE;
1046     }
1047
1048     return gssInitSecContextNext(minor, cred, context_handle,
1049                                  target_name, mech_type, req_flags,
1050                                  time_req, input_chan_bindings,
1051                                  input_token, actual_mech_type,
1052                                  output_token, ret_flags, time_rec);
1053 }
1054
1055 OM_uint32
1056 gssAcceptSecContext(OM_uint32 *minor,
1057                     gss_ctx_id_t *context_handle,
1058                     gss_cred_id_t cred,
1059                     gss_buffer_t input_token,
1060                     gss_channel_bindings_t input_chan_bindings,
1061                     gss_name_t *src_name,
1062                     gss_OID *mech_type,
1063                     gss_buffer_t output_token,
1064                     OM_uint32 *ret_flags,
1065                     OM_uint32 *time_rec,
1066                     gss_cred_id_t *delegated_cred_handle)
1067 {
1068     if (gssAcceptSecContextNext == NULL) {
1069         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1070         return GSS_S_UNAVAILABLE;
1071     }
1072
1073     return gssAcceptSecContextNext(minor, context_handle, cred,
1074                                    input_token, input_chan_bindings,
1075                                    src_name, mech_type, output_token,
1076                                    ret_flags, time_rec, delegated_cred_handle);
1077 }
1078
1079 OM_uint32
1080 gssReleaseCred(OM_uint32 *minor,
1081                gss_cred_id_t *cred_handle)
1082 {
1083     if (gssReleaseCredNext == NULL) {
1084         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1085         return GSS_S_UNAVAILABLE;
1086     }
1087
1088     return gssReleaseCredNext(minor, cred_handle);
1089 }
1090
1091 OM_uint32
1092 gssReleaseName(OM_uint32 *minor,
1093                gss_name_t *name)
1094 {
1095     if (gssReleaseName == NULL) {
1096         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1097         return GSS_S_UNAVAILABLE;
1098     }
1099
1100     return gssReleaseNameNext(minor, name);
1101 }
1102
1103 OM_uint32
1104 gssDeleteSecContext(OM_uint32 *minor,
1105                     gss_ctx_id_t *context_handle,
1106                     gss_buffer_t output_token)
1107 {
1108     if (gssDeleteSecContextNext == NULL) {
1109         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1110         return GSS_S_UNAVAILABLE;
1111     }
1112
1113     return gssDeleteSecContextNext(minor, context_handle, output_token);
1114 }
1115
1116 static OM_uint32
1117 gssDisplayName(OM_uint32 *minor,
1118                gss_name_t name,
1119                gss_buffer_t buffer,
1120                gss_OID *name_type)
1121 {
1122     if (gssDisplayNameNext == NULL) {
1123         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1124         return GSS_S_UNAVAILABLE;
1125     }
1126
1127     return gssDisplayNameNext(minor, name, buffer, name_type);
1128 }
1129
1130 static OM_uint32
1131 gssImportName(OM_uint32 *minor,
1132               gss_buffer_t buffer,
1133               gss_OID name_type,
1134               gss_name_t *name)
1135 {
1136     if (gssImportNameNext == NULL) {
1137         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1138         return GSS_S_UNAVAILABLE;
1139     }
1140
1141     return gssImportNameNext(minor, buffer, name_type, name);
1142 }
1143
1144 OM_uint32
1145 gssInquireSecContextByOid(OM_uint32 *minor,
1146                           const gss_ctx_id_t context_handle,
1147                           const gss_OID desired_object,
1148                           gss_buffer_set_t *data_set)
1149 {
1150     if (gssInquireSecContextByOidNext == NULL) {
1151         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1152         return GSS_S_UNAVAILABLE;
1153     }
1154
1155     return gssInquireSecContextByOidNext(minor, context_handle,
1156                                          desired_object, data_set);
1157 }
1158
1159 OM_uint32
1160 gssStoreCred(OM_uint32 *minor,
1161              const gss_cred_id_t input_cred_handle,
1162              gss_cred_usage_t input_usage,
1163              const gss_OID desired_mech,
1164              OM_uint32 overwrite_cred,
1165              OM_uint32 default_cred,
1166              gss_OID_set *elements_stored,
1167              gss_cred_usage_t *cred_usage_stored)
1168 {
1169     if (gssStoreCredNext == NULL) {
1170         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1171         return GSS_S_UNAVAILABLE;
1172     }
1173
1174     return gssStoreCredNext(minor, input_cred_handle, input_usage,
1175                             desired_mech, overwrite_cred, default_cred,
1176                             elements_stored, cred_usage_stored);
1177 }
1178
1179 OM_uint32
1180 gssGetNameAttribute(OM_uint32 *minor,
1181                     gss_name_t name,
1182                     gss_buffer_t attr,
1183                     int *authenticated,
1184                     int *complete,
1185                     gss_buffer_t value,
1186                     gss_buffer_t display_value,
1187                     int *more)
1188 {
1189     if (gssGetNameAttributeNext == NULL) {
1190         *minor = GSSEAP_NO_MECHGLUE_SYMBOL;
1191         return GSS_S_UNAVAILABLE;
1192     }
1193
1194     return gssGetNameAttributeNext(minor, name, attr, authenticated, complete,
1195                                    value, display_value, more);
1196 }