util_reauth.c

   1 /*
   2  * Copyright (c) 2010, JANET(UK)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. Neither the name of JANET(UK) nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "gssapiP_eap.h"
  34
  35 #include <dlfcn.h>
  36
  37 /*
  38  * Fast reauthentication support for EAP GSS.
  39  */
  40
  41 krb5_error_code
  42 krb5_encrypt_tkt_part(krb5_context, const krb5_keyblock *, krb5_ticket *);
  43
  44 krb5_error_code
  45 encode_krb5_ticket(const krb5_ticket *rep, krb5_data **code);
  46
  47 static OM_uint32
  48 gssDisplayName(OM_uint32 *minor,
  49                gss_name_t name,
  50                gss_buffer_t buffer,
  51                gss_OID *name_type);
  52
  53 static OM_uint32
  54 gssImportName(OM_uint32 *minor,
  55               gss_buffer_t buffer,
  56               gss_OID name_type,
  57               gss_name_t *name);
  58
  59 static krb5_error_code
  60 getAcceptorKey(krb5_context krbContext,
  61                gss_ctx_id_t ctx,
  62                gss_cred_id_t cred,
  63                krb5_principal *princ,
  64                krb5_keyblock *key)
  65 {
  66     krb5_error_code code;
  67     krb5_keytab keytab = NULL;
  68     krb5_keytab_entry ktent = { 0 };
  69     krb5_kt_cursor cursor = NULL;
  70
  71     *princ = NULL;
  72     memset(key, 0, sizeof(*key));
  73
  74     code = krb5_kt_default(krbContext, &keytab);
  75     if (code != 0)
  76         goto cleanup;
  77
  78     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
  79         code = krb5_kt_get_entry(krbContext, keytab,
  80                                  cred->name->krbPrincipal, 0,
  81                                  ctx->encryptionType, &ktent);
  82         if (code != 0)
  83             goto cleanup;
  84     } else {
  85         /*
  86          * It's not clear that looking encrypting the ticket in the
  87          * requested EAP enctype provides any value.
  88          */
  89         code = krb5_kt_start_seq_get(krbContext, keytab, &cursor);
  90         if (code != 0)
  91             goto cleanup;
  92
  93         while ((code = krb5_kt_next_entry(krbContext, keytab,
  94                                           &ktent, &cursor)) == 0) {
  95             if (ktent.key.enctype == ctx->encryptionType)
  96                 break;
  97             else
  98                 krb5_free_keytab_entry_contents(krbContext, &ktent);
  99         }
 100     }
 101
 102     if (code == 0) {
 103         *princ = ktent.principal;
 104         *key = ktent.key;
 105     }
 106
 107 cleanup:
 108     if (cred == GSS_C_NO_CREDENTIAL || cred->name == GSS_C_NO_NAME)
 109         krb5_kt_end_seq_get(krbContext, keytab, &cursor);
 110     krb5_kt_close(krbContext, keytab);
 111
 112     if (code != 0)
 113         krb5_free_keytab_entry_contents(krbContext, &ktent);
 114
 115     return code;
 116 }
 117
 118 static OM_uint32
 119 freezeAttrContext(OM_uint32 *minor,
 120                   gss_name_t initiatorName,
 121                   krb5_const_principal acceptorPrinc,
 122                   krb5_keyblock *session,
 123                   krb5_authdata ***authdata)
 124 {
 125     OM_uint32 major, tmpMinor;
 126     krb5_error_code code;
 127     gss_buffer_desc attrBuf = GSS_C_EMPTY_BUFFER;
 128     krb5_authdata *authData[2], authDatum = { 0 };
 129     krb5_context krbContext;
 130
 131     GSSEAP_KRB_INIT(&krbContext);
 132
 133     major = gssEapExportAttrContext(minor, initiatorName, &attrBuf);
 134     if (GSS_ERROR(major))
 135         return major;
 136
 137     authDatum.ad_type = KRB5_AUTHDATA_RADIUS_AVP;
 138     authDatum.length = attrBuf.length;
 139     authDatum.contents = attrBuf.value;
 140     authData[0] = &authDatum;
 141     authData[1] = NULL;
 142
 143     code = krb5_make_authdata_kdc_issued(krbContext, session, acceptorPrinc,
 144                                          authData, authdata);
 145     if (code != 0) {
 146         major = GSS_S_FAILURE;
 147         *minor = code;
 148     } else {
 149         major = GSS_S_COMPLETE;
 150     }
 151
 152     gss_release_buffer(&tmpMinor, &attrBuf);
 153
 154     return major;
 155 }
 156
 157 /*
 158  * Fabricate a ticket to ourselves given a GSS EAP context.
 159  */
 160 OM_uint32
 161 gssEapMakeReauthCreds(OM_uint32 *minor,
 162                       gss_ctx_id_t ctx,
 163                       gss_cred_id_t cred,
 164                       gss_buffer_t credBuf)
 165 {
 166     OM_uint32 major = GSS_S_COMPLETE;
 167     krb5_error_code code;
 168     krb5_context krbContext = NULL;
 169     krb5_ticket ticket = { 0 };
 170     krb5_keyblock session = { 0 }, acceptorKey = { 0 };
 171     krb5_enc_tkt_part enc_part = { 0 };
 172     krb5_data *ticketData = NULL, *credsData = NULL;
 173     krb5_creds creds = { 0 };
 174     krb5_auth_context authContext = NULL;
 175
 176     credBuf->length = 0;
 177     credBuf->value = NULL;
 178
 179     GSSEAP_KRB_INIT(&krbContext);
 180
 181     code = getAcceptorKey(krbContext, ctx, cred,
 182                           &ticket.server, &acceptorKey);
 183     if (code == KRB5_KT_NOTFOUND) {
 184         gss_buffer_desc emptyToken = { 0, "" };
 185
 186         /*
 187          * If we can't produce the KRB-CRED message, we need to
 188          * return an empty (not NULL) token to the caller so we
 189          * don't change the number of authentication legs.
 190          */
 191         return duplicateBuffer(minor, &emptyToken, credBuf);
 192     } else if (code != 0)
 193         goto cleanup;
 194
 195     enc_part.flags = TKT_FLG_INITIAL;
 196
 197     /*
 198      * Generate a random session key to place in the ticket and
 199      * sign the "KDC-Issued" authorization data element.
 200      */
 201     code = krb5_c_make_random_key(krbContext, ctx->encryptionType,
 202                                   &session);
 203     if (code != 0)
 204         goto cleanup;
 205
 206     enc_part.session = &session;
 207     enc_part.client = ctx->initiatorName->krbPrincipal;
 208     enc_part.times.authtime = time(NULL);
 209     enc_part.times.starttime = enc_part.times.authtime;
 210     enc_part.times.endtime = ctx->expiryTime
 211                              ? ctx->expiryTime
 212                              : KRB5_INT32_MAX;
 213     enc_part.times.renew_till = 0;
 214
 215     major = freezeAttrContext(minor, ctx->initiatorName, ticket.server,
 216                               &session, &enc_part.authorization_data);
 217     if (GSS_ERROR(major))
 218         goto cleanup;
 219
 220     ticket.enc_part2 = &enc_part;
 221
 222     code = krb5_encrypt_tkt_part(krbContext, &acceptorKey, &ticket);
 223     if (code != 0)
 224         goto cleanup;
 225
 226     code = encode_krb5_ticket(&ticket, &ticketData);
 227     if (code != 0)
 228         goto cleanup;
 229
 230     creds.client = enc_part.client;
 231     creds.server = ticket.server;
 232     creds.keyblock = session;
 233     creds.times = enc_part.times;
 234     creds.ticket_flags = enc_part.flags;
 235     creds.ticket = *ticketData;
 236     creds.authdata = enc_part.authorization_data;
 237
 238     code = krb5_auth_con_init(krbContext, &authContext);
 239     if (code != 0)
 240         goto cleanup;
 241
 242     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 243     if (code != 0)
 244         goto cleanup;
 245
 246     code = krb5_auth_con_setsendsubkey(krbContext, authContext,
 247                                        &ctx->rfc3961Key);
 248     if (code != 0)
 249         goto cleanup;
 250
 251     code = krb5_mk_1cred(krbContext, authContext, &creds, &credsData, NULL);
 252     if (code != 0)
 253         goto cleanup;
 254
 255     krbDataToGssBuffer(credsData, credBuf);
 256
 257 cleanup:
 258     if (ticket.enc_part.ciphertext.data != NULL)
 259         GSSEAP_FREE(ticket.enc_part.ciphertext.data);
 260     krb5_free_keyblock_contents(krbContext, &session);
 261     krb5_free_keyblock_contents(krbContext, &acceptorKey);
 262     krb5_free_data(krbContext, ticketData);
 263     krb5_auth_con_free(krbContext, authContext);
 264     krb5_free_authdata(krbContext, enc_part.authorization_data);
 265     if (credsData != NULL)
 266         GSSEAP_FREE(credsData);
 267
 268     if (major == GSS_S_COMPLETE) {
 269         *minor = code;
 270         major = code != 0 ? GSS_S_FAILURE : GSS_S_COMPLETE;
 271     }
 272
 273     return major;
 274 }
 275
 276 static int
 277 isTicketGrantingServiceP(krb5_context krbContext,
 278                          krb5_const_principal principal)
 279 {
 280     if (krb5_princ_size(krbContext, principal) == 2 &&
 281         krb5_princ_component(krbContext, principal, 0)->length == 6 &&
 282         memcmp(krb5_princ_component(krbContext,
 283                                     principal, 0)->data, "krbtgt", 6) == 0)
 284         return TRUE;
 285
 286     return FALSE;
 287 }
 288
 289 static int
 290 reauthUseCredsCache(krb5_context krbContext,
 291                     krb5_principal principal)
 292 {
 293     int reauthUseCCache;
 294
 295     /* if reauth_use_ccache, use default credentials cache if ticket is for us */
 296     krb5_appdefault_boolean(krbContext, "eap_gss",
 297                             krb5_princ_realm(krbContext, principal),
 298                             "reauth_use_ccache", 0, &reauthUseCCache);
 299
 300     return reauthUseCCache;
 301 }
 302
 303 static OM_uint32
 304 getReauthCredentials(OM_uint32 *minor,
 305                      gss_cred_id_t cred,
 306                      gss_name_t target,
 307                      time_t now,
 308                      OM_uint32 timeReq)
 309 {
 310     OM_uint32 major = GSS_S_CRED_UNAVAIL;
 311     krb5_context krbContext = NULL;
 312     krb5_error_code code;
 313     krb5_ccache ccache = NULL;
 314     krb5_creds match = { 0 };
 315     krb5_creds creds = { 0 };
 316
 317     GSSEAP_KRB_INIT(&krbContext);
 318
 319     assert(cred != GSS_C_NO_CREDENTIAL);
 320     assert(target != GSS_C_NO_NAME);
 321
 322     if (!reauthUseCredsCache(krbContext, cred->name->krbPrincipal))
 323         goto cleanup;
 324
 325     match.client = cred->name->krbPrincipal;
 326     match.server = target->krbPrincipal;
 327     if (timeReq != 0 && timeReq != GSS_C_INDEFINITE)
 328         match.times.endtime = now + timeReq;
 329
 330     code = krb5_cc_default(krbContext, &ccache);
 331     if (code != 0)
 332         goto cleanup;
 333
 334     code = krb5_cc_retrieve_cred(krbContext, ccache, 0, &match, &creds);
 335     if (code != 0)
 336         goto cleanup;
 337
 338     cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 339     cred->krbCredCache = ccache;
 340     ccache = NULL;
 341
 342     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 343                                  &cred->krbCred);
 344
 345 cleanup:
 346     if (major == GSS_S_CRED_UNAVAIL)
 347         *minor = code;
 348
 349     if (ccache != NULL)
 350         krb5_cc_close(krbContext, ccache);
 351     krb5_free_cred_contents(krbContext, &creds);
 352
 353     return major;
 354 }
 355
 356 int
 357 gssEapCanReauthP(gss_cred_id_t cred,
 358                  gss_name_t target,
 359                  OM_uint32 timeReq)
 360 {
 361     time_t now;
 362
 363     if (cred == GSS_C_NO_CREDENTIAL)
 364         return FALSE;
 365
 366     now = time(NULL);
 367
 368     if (cred->krbCredCache != NULL &&
 369         cred->expiryTime > time(NULL) + (timeReq ? timeReq : 0))
 370         return TRUE;
 371
 372     if (cred->name != GSS_C_NO_NAME) {
 373         OM_uint32 major, minor;
 374
 375         major = getReauthCredentials(&minor, cred, target, now, timeReq);
 376
 377         return !GSS_ERROR(major);
 378     }
 379
 380     return FALSE;
 381 }
 382
 383 /*
 384  * Store re-authentication (Kerberos) credentials in a credential handle.
 385  */
 386 OM_uint32
 387 gssEapStoreReauthCreds(OM_uint32 *minor,
 388                        gss_ctx_id_t ctx,
 389                        gss_cred_id_t cred,
 390                        gss_buffer_t credBuf)
 391 {
 392     OM_uint32 major = GSS_S_COMPLETE;
 393     krb5_error_code code;
 394     krb5_context krbContext = NULL;
 395     krb5_auth_context authContext = NULL;
 396     krb5_data credData = { 0 };
 397     krb5_creds **creds = NULL;
 398     krb5_principal canonPrinc;
 399     krb5_principal ccPrinc = NULL;
 400     int i;
 401
 402     if (credBuf->length == 0 || cred == GSS_C_NO_CREDENTIAL)
 403         return GSS_S_COMPLETE;
 404
 405     GSSEAP_KRB_INIT(&krbContext);
 406
 407     code = krb5_auth_con_init(krbContext, &authContext);
 408     if (code != 0)
 409         goto cleanup;
 410
 411     code = krb5_auth_con_setflags(krbContext, authContext, 0);
 412     if (code != 0)
 413         goto cleanup;
 414
 415     code = krb5_auth_con_setrecvsubkey(krbContext, authContext,
 416                                        &ctx->rfc3961Key);
 417     if (code != 0)
 418         goto cleanup;
 419
 420     gssBufferToKrbData(credBuf, &credData);
 421
 422     code = krb5_rd_cred(krbContext, authContext, &credData, &creds, NULL);
 423     if (code != 0)
 424         goto cleanup;
 425
 426     if (creds == NULL || creds[0] == NULL)
 427         goto cleanup;
 428
 429     code = krb5_copy_principal(krbContext, creds[0]->client, &canonPrinc);
 430     if (code != 0)
 431         goto cleanup;
 432
 433     krb5_free_principal(krbContext, cred->name->krbPrincipal);
 434     cred->name->krbPrincipal = canonPrinc;
 435
 436     cred->expiryTime = creds[0]->times.endtime;
 437
 438     if (cred->krbCredCache == NULL) {
 439         if (reauthUseCredsCache(krbContext, creds[0]->client) &&
 440             krb5_cc_default(krbContext, &cred->krbCredCache) == 0)
 441             cred->flags |= CRED_FLAG_DEFAULT_CCACHE;
 442     } else {
 443         /*
 444          * If we already have an associated credentials cache, possibly from
 445          * the last time we stored a reauthentication credential, then we
 446          * need to clear it out and release the associated GSS credential.
 447          */
 448         if (cred->flags & CRED_FLAG_DEFAULT_CCACHE) {
 449             krb5_cc_remove_cred(krbContext, cred->krbCredCache, 0, creds[0]);
 450         } else {
 451             krb5_cc_destroy(krbContext, cred->krbCredCache);
 452             cred->krbCredCache = NULL;
 453         }
 454         gssReleaseCred(minor, &cred->krbCred);
 455     }
 456
 457     if (cred->krbCredCache == NULL) {
 458         code = krb5_cc_new_unique(krbContext, "MEMORY", NULL, &cred->krbCredCache);
 459         if (code != 0)
 460             goto cleanup;
 461     }
 462
 463     if ((cred->flags & CRED_FLAG_DEFAULT_CCACHE) == 0 ||
 464         krb5_cc_get_principal(krbContext, cred->krbCredCache, &ccPrinc) != 0) {
 465         code = krb5_cc_initialize(krbContext, cred->krbCredCache,
 466                                   creds[0]->client);
 467         if (code != 0)
 468             goto cleanup;
 469     }
 470
 471     for (i = 0; creds[i] != NULL; i++) {
 472         krb5_creds kcred = *(creds[i]);
 473
 474         /*
 475          * Swap in the acceptor name the client asked for so
 476          * get_credentials() works. We're making the assumption that
 477          * any service tickets returned are for us. We'll need to
 478          * reflect some more on whether that is a safe assumption.
 479          */
 480         if (!isTicketGrantingServiceP(krbContext, kcred.server))
 481             kcred.server = ctx->acceptorName->krbPrincipal;
 482
 483         code = krb5_cc_store_cred(krbContext, cred->krbCredCache, &kcred);
 484         if (code != 0)
 485             goto cleanup;
 486     }
 487
 488     major = gss_krb5_import_cred(minor, cred->krbCredCache, NULL, NULL,
 489                                  &cred->krbCred);
 490     if (GSS_ERROR(major))
 491         goto cleanup;
 492
 493 cleanup:
 494     *minor = code;
 495
 496     krb5_free_principal(krbContext, ccPrinc);
 497     krb5_auth_con_free(krbContext, authContext);
 498     if (creds != NULL) {
 499         for (i = 0; creds[i] != NULL; i++)
 500             krb5_free_creds(krbContext, creds[i]);
 501         GSSEAP_FREE(creds);
 502     }
 503     if (major == GSS_S_COMPLETE)
 504         major = *minor ? GSS_S_FAILURE : GSS_S_COMPLETE;
 505
 506     return major;
 507 }
 508
 509 static gss_buffer_desc radiusAvpKrbAttr = {
 510     sizeof("urn:authdata-radius-avp") - 1, "urn:authdata-radius-avp"
 511 };
 512
 513 /*
 514  * Unfortunately extracting an AD-KDCIssued authorization data element
 515  * is pretty implementation-dependent. It's not possible to verify the
 516  * signature ourselves because the ticket session key is not exposed
 517  * outside GSS. In an ideal world, all AD-KDCIssued elements would be
 518  * verified by the Kerberos library and authentication would fail if
 519  * verification failed. We're not quite there yet and as a result have
 520  * to go through some hoops to get this to work. The alternative would
 521  * be to sign the authorization data with our long-term key, but it
 522  * seems a pity to compromise the design because of current implementation
 523  * limitations.
 524  *
 525  * (Specifically, the hoops involve a libkrb5 authorisation data plugin
 526  * that exposes the verified and serialised attribute context through
 527  * the Kerberos GSS mechanism's naming extensions API.)
 528  */
 529 static OM_uint32
 530 defrostAttrContext(OM_uint32 *minor,
 531                    gss_name_t glueName,
 532                    gss_name_t mechName)
 533 {
 534     OM_uint32 major, tmpMinor;
 535     gss_buffer_desc authData = GSS_C_EMPTY_BUFFER;
 536     gss_buffer_desc authDataDisplay = GSS_C_EMPTY_BUFFER;
 537     int more = -1;
 538     int authenticated, complete;
 539
 540     major = gssGetNameAttribute(minor, glueName, &radiusAvpKrbAttr,
 541                                 &authenticated, &complete,
 542                                 &authData, &authDataDisplay, &more);
 543     if (major == GSS_S_COMPLETE) {
 544         if (authenticated == 0)
 545             major = GSS_S_BAD_NAME;
 546         else
 547             major = gssEapImportAttrContext(minor, &authData, mechName);
 548     } else if (major == GSS_S_UNAVAILABLE) {
 549         major = GSS_S_COMPLETE;
 550     }
 551
 552     gss_release_buffer(&tmpMinor, &authData);
 553     gss_release_buffer(&tmpMinor, &authDataDisplay);
 554
 555     return major;
 556 }
 557
 558 /*
 559  * Convert a mechanism glue to an EAP mechanism name by displaying and
 560  * importing it. This also handles the RADIUS attributes.
 561  */
 562 OM_uint32
 563 gssEapGlueToMechName(OM_uint32 *minor,
 564                      gss_name_t glueName,
 565                      gss_name_t *pMechName)
 566 {
 567     OM_uint32 major, tmpMinor;
 568     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 569
 570     *pMechName = GSS_C_NO_NAME;
 571
 572     major = gssDisplayName(minor, glueName, &nameBuf, NULL);
 573     if (GSS_ERROR(major))
 574         goto cleanup;
 575
 576     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 577                              pMechName);
 578     if (GSS_ERROR(major))
 579         goto cleanup;
 580
 581     major = defrostAttrContext(minor, glueName, *pMechName);
 582     if (GSS_ERROR(major))
 583         goto cleanup;
 584
 585 cleanup:
 586     if (GSS_ERROR(major)) {
 587         gssReleaseName(&tmpMinor, pMechName);
 588         *pMechName = GSS_C_NO_NAME;
 589     }
 590
 591     gss_release_buffer(&tmpMinor, &nameBuf);
 592
 593     return major;
 594 }
 595
 596 /*
 597  * Convert an EAP mechanism name to a mechanism glue name by displaying
 598  * and importing it.
 599  */
 600 OM_uint32
 601 gssEapMechToGlueName(OM_uint32 *minor,
 602                      gss_name_t mechName,
 603                      gss_name_t *pGlueName)
 604 {
 605     OM_uint32 major, tmpMinor;
 606     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
 607
 608     *pGlueName = GSS_C_NO_NAME;
 609
 610     major = gssEapDisplayName(minor, mechName, &nameBuf, NULL);
 611     if (GSS_ERROR(major))
 612         goto cleanup;
 613
 614     major = gssImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 615                           pGlueName);
 616     if (GSS_ERROR(major))
 617         goto cleanup;
 618
 619 cleanup:
 620     gss_release_buffer(&tmpMinor, &nameBuf);
 621
 622     return major;
 623 }
 624
 625 /*
 626  * Suck out the analgous elements of a Kerberos GSS context into an EAP
 627  * one so that the application doesn't know the difference.
 628  */
 629 OM_uint32
 630 gssEapReauthComplete(OM_uint32 *minor,
 631                     gss_ctx_id_t ctx,
 632                     gss_cred_id_t cred,
 633                     const gss_OID mech,
 634                     OM_uint32 timeRec)
 635 {
 636     OM_uint32 major, tmpMinor;
 637     gss_buffer_set_t keyData = GSS_C_NO_BUFFER_SET;
 638
 639     if (!oidEqual(mech, gss_mech_krb5)) {
 640         major = GSS_S_BAD_MECH;
 641         goto cleanup;
 642     }
 643
 644     /* Get the raw subsession key and encryption type*/
 645     major = gssInquireSecContextByOid(minor, ctx->kerberosCtx,
 646                                       GSS_C_INQ_SSPI_SESSION_KEY, &keyData);
 647     if (GSS_ERROR(major))
 648         goto cleanup;
 649
 650     {
 651         gss_OID_desc oid;
 652         int suffix;
 653
 654         oid.length = keyData->elements[1].length;
 655         oid.elements = keyData->elements[1].value;
 656
 657         /* GSS_KRB5_SESSION_KEY_ENCTYPE_OID */
 658         major = decomposeOid(minor,
 659                              "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04",
 660                              10, &oid, &suffix);
 661         if (GSS_ERROR(major))
 662             goto cleanup;
 663
 664         ctx->encryptionType = suffix;
 665     }
 666
 667     {
 668         krb5_context krbContext = NULL;
 669         krb5_keyblock key;
 670
 671         GSSEAP_KRB_INIT(&krbContext);
 672
 673         KRB_KEY_LENGTH(&key) = keyData->elements[0].length;
 674         KRB_KEY_DATA(&key)   = keyData->elements[0].value;
 675         KRB_KEY_TYPE(&key)   = ctx->encryptionType;
 676
 677         *minor = krb5_copy_keyblock_contents(krbContext,
 678                                              &key, &ctx->rfc3961Key);
 679         if (*minor != 0) {
 680             major = GSS_S_FAILURE;
 681             goto cleanup;
 682         }
 683     }
 684
 685     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 686                                       &ctx->checksumType);
 687     if (GSS_ERROR(major))
 688         goto cleanup;
 689
 690     if (timeRec != GSS_C_INDEFINITE)
 691         ctx->expiryTime = time(NULL) + timeRec;
 692
 693     /* Initialize our sequence state */
 694     major = sequenceInit(minor,
 695                          &ctx->seqState, ctx->recvSeq,
 696                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 697                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 698                          TRUE);
 699     if (GSS_ERROR(major))
 700         goto cleanup;
 701
 702     major = GSS_S_COMPLETE;
 703
 704 cleanup:
 705     gss_release_buffer_set(&tmpMinor, &keyData);
 706
 707     return major;
 708 }
 709
 710 /*
 711  * The remainder of this file consists of wrappers so we can call into the
 712  * mechanism glue without calling ourselves.
 713  */
 714 static OM_uint32
 715 (*gssInitSecContextNext)(OM_uint32 *,
 716                          gss_cred_id_t,
 717                          gss_ctx_id_t *,
 718                          gss_name_t,
 719                          gss_OID,
 720                          OM_uint32,
 721                          OM_uint32,
 722                          gss_channel_bindings_t,
 723                          gss_buffer_t,
 724                          gss_OID *,
 725                          gss_buffer_t,
 726                          OM_uint32 *,
 727                          OM_uint32 *);
 728
 729 static OM_uint32
 730 (*gssAcceptSecContextNext)(OM_uint32 *,
 731                            gss_ctx_id_t *,
 732                            gss_cred_id_t,
 733                            gss_buffer_t,
 734                            gss_channel_bindings_t,
 735                            gss_name_t *,
 736                            gss_OID *,
 737                            gss_buffer_t,
 738                            OM_uint32 *,
 739                            OM_uint32 *,
 740                            gss_cred_id_t *);
 741
 742 static OM_uint32
 743 (*gssReleaseCredNext)(OM_uint32 *, gss_cred_id_t *);
 744
 745 static OM_uint32
 746 (*gssReleaseNameNext)(OM_uint32 *, gss_name_t *);
 747
 748 static OM_uint32
 749 (*gssInquireSecContextByOidNext)(OM_uint32 *,
 750                                  const gss_ctx_id_t,
 751                                  const gss_OID,
 752                                  gss_buffer_set_t *);
 753
 754 static OM_uint32
 755 (*gssDeleteSecContextNext)(OM_uint32 *,
 756                           gss_ctx_id_t *,
 757                           gss_buffer_t);
 758
 759 static OM_uint32
 760 (*gssDisplayNameNext)(OM_uint32 *,
 761                       gss_name_t,
 762                       gss_buffer_t,
 763                       gss_OID *);
 764
 765 static OM_uint32
 766 (*gssImportNameNext)(OM_uint32 *,
 767                      gss_buffer_t,
 768                      gss_OID,
 769                      gss_name_t *);
 770
 771 static OM_uint32
 772 (*gssStoreCredNext)(OM_uint32 *,
 773                     const gss_cred_id_t,
 774                     gss_cred_usage_t,
 775                     const gss_OID,
 776                     OM_uint32,
 777                     OM_uint32,
 778                     gss_OID_set *,
 779                     gss_cred_usage_t *);
 780
 781 static OM_uint32
 782 (*gssGetNameAttributeNext)(OM_uint32 *,
 783                           gss_name_t,
 784                           gss_buffer_t,
 785                           int *,
 786                           int *,
 787                           gss_buffer_t,
 788                           gss_buffer_t,
 789                           int *);
 790
 791 #define NEXT_SYMBOL(local, global)  ((local) = dlsym(RTLD_NEXT, (global)))
 792
 793 OM_uint32
 794 gssEapReauthInitialize(OM_uint32 *minor)
 795 {
 796     NEXT_SYMBOL(gssInitSecContextNext,         "gss_init_sec_context");
 797     NEXT_SYMBOL(gssAcceptSecContextNext,       "gss_accept_sec_context");
 798     NEXT_SYMBOL(gssReleaseCredNext,            "gss_release_cred");
 799     NEXT_SYMBOL(gssReleaseNameNext,            "gss_release_name");
 800     NEXT_SYMBOL(gssInquireSecContextByOidNext, "gss_inquire_sec_context_by_oid");
 801     NEXT_SYMBOL(gssDeleteSecContextNext,       "gss_delete_sec_context");
 802     NEXT_SYMBOL(gssDisplayNameNext,            "gss_display_name");
 803     NEXT_SYMBOL(gssImportNameNext,             "gss_import_name");
 804     NEXT_SYMBOL(gssStoreCredNext,              "gss_store_cred");
 805     NEXT_SYMBOL(gssGetNameAttributeNext,       "gss_get_name_attribute");
 806
 807     return GSS_S_COMPLETE;
 808 }
 809
 810 OM_uint32
 811 gssInitSecContext(OM_uint32 *minor,
 812                   gss_cred_id_t cred,
 813                   gss_ctx_id_t *context_handle,
 814                   gss_name_t target_name,
 815                   gss_OID mech_type,
 816                   OM_uint32 req_flags,
 817                   OM_uint32 time_req,
 818                   gss_channel_bindings_t input_chan_bindings,
 819                   gss_buffer_t input_token,
 820                   gss_OID *actual_mech_type,
 821                   gss_buffer_t output_token,
 822                   OM_uint32 *ret_flags,
 823                   OM_uint32 *time_rec)
 824 {
 825     if (gssInitSecContextNext == NULL)
 826         return GSS_S_UNAVAILABLE;
 827
 828     return gssInitSecContextNext(minor, cred, context_handle,
 829                                  target_name, mech_type, req_flags,
 830                                  time_req, input_chan_bindings,
 831                                  input_token, actual_mech_type,
 832                                  output_token, ret_flags, time_rec);
 833 }
 834
 835 OM_uint32
 836 gssAcceptSecContext(OM_uint32 *minor,
 837                     gss_ctx_id_t *context_handle,
 838                     gss_cred_id_t cred,
 839                     gss_buffer_t input_token,
 840                     gss_channel_bindings_t input_chan_bindings,
 841                     gss_name_t *src_name,
 842                     gss_OID *mech_type,
 843                     gss_buffer_t output_token,
 844                     OM_uint32 *ret_flags,
 845                     OM_uint32 *time_rec,
 846                     gss_cred_id_t *delegated_cred_handle)
 847 {
 848     if (gssAcceptSecContextNext == NULL)
 849         return GSS_S_UNAVAILABLE;
 850
 851     return gssAcceptSecContextNext(minor, context_handle, cred,
 852                                    input_token, input_chan_bindings,
 853                                    src_name, mech_type, output_token,
 854                                    ret_flags, time_rec, delegated_cred_handle);
 855 }
 856
 857 OM_uint32
 858 gssReleaseCred(OM_uint32 *minor,
 859                gss_cred_id_t *cred_handle)
 860 {
 861     if (gssReleaseCredNext == NULL)
 862         return GSS_S_UNAVAILABLE;
 863
 864     return gssReleaseCredNext(minor, cred_handle);
 865 }
 866
 867 OM_uint32
 868 gssReleaseName(OM_uint32 *minor,
 869                gss_name_t *name)
 870 {
 871     if (gssReleaseName == NULL)
 872         return GSS_S_UNAVAILABLE;
 873
 874     return gssReleaseNameNext(minor, name);
 875 }
 876
 877 OM_uint32
 878 gssDeleteSecContext(OM_uint32 *minor,
 879                     gss_ctx_id_t *context_handle,
 880                     gss_buffer_t output_token)
 881 {
 882     if (gssDeleteSecContextNext == NULL)
 883         return GSS_S_UNAVAILABLE;
 884
 885     return gssDeleteSecContextNext(minor, context_handle, output_token);
 886 }
 887
 888 static OM_uint32
 889 gssDisplayName(OM_uint32 *minor,
 890                gss_name_t name,
 891                gss_buffer_t buffer,
 892                gss_OID *name_type)
 893 {
 894     if (gssDisplayNameNext == NULL)
 895         return GSS_S_UNAVAILABLE;
 896
 897     return gssDisplayNameNext(minor, name, buffer, name_type);
 898 }
 899
 900 static OM_uint32
 901 gssImportName(OM_uint32 *minor,
 902               gss_buffer_t buffer,
 903               gss_OID name_type,
 904               gss_name_t *name)
 905 {
 906     if (gssImportNameNext == NULL)
 907         return GSS_S_UNAVAILABLE;
 908
 909     return gssImportNameNext(minor, buffer, name_type, name);
 910 }
 911
 912 OM_uint32
 913 gssInquireSecContextByOid(OM_uint32 *minor,
 914                           const gss_ctx_id_t context_handle,
 915                           const gss_OID desired_object,
 916                           gss_buffer_set_t *data_set)
 917 {
 918     if (gssInquireSecContextByOidNext == NULL)
 919         return GSS_S_UNAVAILABLE;
 920
 921     return gssInquireSecContextByOidNext(minor, context_handle,
 922                                          desired_object, data_set);
 923 }
 924
 925 OM_uint32
 926 gssStoreCred(OM_uint32 *minor,
 927              const gss_cred_id_t input_cred_handle,
 928              gss_cred_usage_t input_usage,
 929              const gss_OID desired_mech,
 930              OM_uint32 overwrite_cred,
 931              OM_uint32 default_cred,
 932              gss_OID_set *elements_stored,
 933              gss_cred_usage_t *cred_usage_stored)
 934 {
 935     if (gssStoreCredNext == NULL)
 936         return GSS_S_UNAVAILABLE;
 937
 938     return gssStoreCredNext(minor, input_cred_handle, input_usage,
 939                             desired_mech, overwrite_cred, default_cred,
 940                             elements_stored, cred_usage_stored);
 941 }
 942
 943 OM_uint32
 944 gssGetNameAttribute(OM_uint32 *minor,
 945                     gss_name_t name,
 946                     gss_buffer_t attr,
 947                     int *authenticated,
 948                     int *complete,
 949                     gss_buffer_t value,
 950                     gss_buffer_t display_value,
 951                     int *more)
 952 {
 953     if (gssGetNameAttributeNext == NULL)
 954         return GSS_S_UNAVAILABLE;
 955
 956     return gssGetNameAttributeNext(minor, name, attr, authenticated, complete,
 957                                    value, display_value, more);
 958 }