mech_eap/accept_sec_context.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  * Establish a security context on the acceptor (server). These functions
  35  * wrap around libradsec and (thus) talk to a RADIUS server or proxy.
  36  */
  37
  38 #include "gssapiP_eap.h"
  39
  40 #ifdef GSSEAP_ENABLE_REAUTH
  41 static OM_uint32
  42 eapGssSmAcceptGssReauth(OM_uint32 *minor,
  43                         gss_cred_id_t cred,
  44                         gss_ctx_id_t ctx,
  45                         gss_name_t target,
  46                         gss_OID mech,
  47                         OM_uint32 reqFlags,
  48                         OM_uint32 timeReq,
  49                         gss_channel_bindings_t chanBindings,
  50                         gss_buffer_t inputToken,
  51                         gss_buffer_t outputToken,
  52                         OM_uint32 *smFlags);
  53 #endif
  54
  55 /*
  56  * Mark an acceptor context as ready for cryptographic operations
  57  */
  58 static OM_uint32
  59 acceptReadyEap(OM_uint32 *minor, gss_ctx_id_t ctx, gss_cred_id_t cred)
  60 {
  61     OM_uint32 major, tmpMinor;
  62     rs_const_avp *vp;
  63     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
  64
  65     /* Cache encryption type derived from selected mechanism OID */
  66     major = gssEapOidToEnctype(minor, ctx->mechanismUsed,
  67                                &ctx->encryptionType);
  68     if (GSS_ERROR(major))
  69         return major;
  70
  71     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
  72
  73     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
  74                                   PW_USER_NAME, 0, &vp);
  75     if (major == GSS_S_COMPLETE && rs_avp_length(vp) != 0) {
  76         rs_avp_octets_value_byref((rs_avp *)vp,
  77                                   (unsigned char **)&nameBuf.value,
  78                                   &nameBuf.length);
  79     } else {
  80         ctx->gssFlags |= GSS_C_ANON_FLAG;
  81     }
  82
  83     major = gssEapImportName(minor, &nameBuf,
  84                              (ctx->gssFlags & GSS_C_ANON_FLAG) ?
  85                                 GSS_C_NT_ANONYMOUS : GSS_C_NT_USER_NAME,
  86                              ctx->mechanismUsed,
  87                              &ctx->initiatorName);
  88     if (GSS_ERROR(major))
  89         return major;
  90
  91     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
  92                                   PW_MS_MPPE_SEND_KEY, VENDORPEC_MICROSOFT, &vp);
  93     if (GSS_ERROR(major)) {
  94         *minor = GSSEAP_KEY_UNAVAILABLE;
  95         return GSS_S_UNAVAILABLE;
  96     }
  97
  98     major = gssEapDeriveRfc3961Key(minor,
  99                                    rs_avp_octets_value_const_ptr(vp),
 100                                    rs_avp_length(vp),
 101                                    ctx->encryptionType,
 102                                    &ctx->rfc3961Key);
 103     if (GSS_ERROR(major))
 104         return major;
 105
 106     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 107                                        &ctx->checksumType);
 108     if (GSS_ERROR(major))
 109         return major;
 110
 111     major = sequenceInit(minor,
 112                          &ctx->seqState, ctx->recvSeq,
 113                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 114                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 115                          TRUE);
 116     if (GSS_ERROR(major))
 117         return major;
 118
 119     major = gssEapCreateAttrContext(minor, cred, ctx,
 120                                     &ctx->initiatorName->attrCtx,
 121                                     &ctx->expiryTime);
 122     if (GSS_ERROR(major))
 123         return major;
 124
 125     if (ctx->expiryTime != 0 && ctx->expiryTime < time(NULL)) {
 126         *minor = GSSEAP_CRED_EXPIRED;
 127         return GSS_S_CREDENTIALS_EXPIRED;
 128     }
 129
 130     *minor = 0;
 131     return GSS_S_COMPLETE;
 132 }
 133
 134 static OM_uint32
 135 eapGssSmAcceptAcceptorName(OM_uint32 *minor,
 136                            gss_cred_id_t cred GSSEAP_UNUSED,
 137                            gss_ctx_id_t ctx,
 138                            gss_name_t target GSSEAP_UNUSED,
 139                            gss_OID mech GSSEAP_UNUSED,
 140                            OM_uint32 reqFlags GSSEAP_UNUSED,
 141                            OM_uint32 timeReq GSSEAP_UNUSED,
 142                            gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 143                            gss_buffer_t inputToken GSSEAP_UNUSED,
 144                            gss_buffer_t outputToken,
 145                            OM_uint32 *smFlags GSSEAP_UNUSED)
 146 {
 147     OM_uint32 major;
 148
 149     /* XXX TODO import and validate name from inputToken */
 150
 151     if (ctx->acceptorName != GSS_C_NO_NAME) {
 152         /* Send desired target name to acceptor */
 153         major = gssEapDisplayName(minor, ctx->acceptorName,
 154                                   outputToken, NULL);
 155         if (GSS_ERROR(major))
 156             return major;
 157     }
 158
 159     return GSS_S_CONTINUE_NEEDED;
 160 }
 161
 162 #ifdef GSSEAP_DEBUG
 163 static OM_uint32
 164 eapGssSmAcceptVendorInfo(OM_uint32 *minor,
 165                          gss_cred_id_t cred GSSEAP_UNUSED,
 166                          gss_ctx_id_t ctx GSSEAP_UNUSED,
 167                          gss_name_t target GSSEAP_UNUSED,
 168                          gss_OID mech GSSEAP_UNUSED,
 169                          OM_uint32 reqFlags GSSEAP_UNUSED,
 170                          OM_uint32 timeReq GSSEAP_UNUSED,
 171                          gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 172                          gss_buffer_t inputToken,
 173                          gss_buffer_t outputToken GSSEAP_UNUSED,
 174                          OM_uint32 *smFlags GSSEAP_UNUSED)
 175 {
 176     fprintf(stderr, "GSS-EAP: vendor: %.*s\n",
 177             (int)inputToken->length, (char *)inputToken->value);
 178
 179     *minor = 0;
 180     return GSS_S_CONTINUE_NEEDED;
 181 }
 182 #endif
 183
 184
 185 /*
 186  * Emit a identity EAP request to force the initiator (peer) to identify
 187  * itself.
 188  */
 189 static OM_uint32
 190 eapGssSmAcceptIdentity(OM_uint32 *minor,
 191                        gss_cred_id_t cred,
 192                        gss_ctx_id_t ctx,
 193                        gss_name_t target GSSEAP_UNUSED,
 194                        gss_OID mech GSSEAP_UNUSED,
 195                        OM_uint32 reqFlags GSSEAP_UNUSED,
 196                        OM_uint32 timeReq GSSEAP_UNUSED,
 197                        gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 198                        gss_buffer_t inputToken,
 199                        gss_buffer_t outputToken,
 200                        OM_uint32 *smFlags)
 201 {
 202     OM_uint32 major;
 203     struct wpabuf *reqData;
 204     gss_buffer_desc pktBuffer;
 205
 206     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 207         *minor = GSSEAP_CRED_MECH_MISMATCH;
 208         return GSS_S_BAD_MECH;
 209     }
 210
 211     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
 212         *minor = GSSEAP_WRONG_SIZE;
 213         return GSS_S_DEFECTIVE_TOKEN;
 214     }
 215
 216     reqData = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IDENTITY, 0,
 217                             EAP_CODE_REQUEST, 0);
 218     if (reqData == NULL) {
 219         *minor = ENOMEM;
 220         return GSS_S_FAILURE;
 221     }
 222
 223     pktBuffer.length = wpabuf_len(reqData);
 224     pktBuffer.value = (void *)wpabuf_head(reqData);
 225
 226     major = duplicateBuffer(minor, &pktBuffer, outputToken);
 227     if (GSS_ERROR(major))
 228         return major;
 229
 230     wpabuf_free(reqData);
 231
 232     GSSEAP_SM_TRANSITION_NEXT(ctx);
 233
 234     *minor = 0;
 235     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 236
 237     return GSS_S_CONTINUE_NEEDED;
 238 }
 239
 240 /*
 241  * Returns TRUE if the input token contains an EAP identity response.
 242  */
 243 static int
 244 isIdentityResponseP(gss_buffer_t inputToken)
 245 {
 246     struct wpabuf respData;
 247
 248     wpabuf_set(&respData, inputToken->value, inputToken->length);
 249
 250     return (eap_get_type(&respData) == EAP_TYPE_IDENTITY);
 251 }
 252
 253 /*
 254  * Save the asserted initiator identity from the EAP identity response.
 255  */
 256 static OM_uint32
 257 importInitiatorIdentity(OM_uint32 *minor,
 258                         gss_ctx_id_t ctx,
 259                         gss_buffer_t inputToken)
 260 {
 261     OM_uint32 tmpMinor;
 262     struct wpabuf respData;
 263     const unsigned char *pos;
 264     size_t len;
 265     gss_buffer_desc nameBuf;
 266
 267     wpabuf_set(&respData, inputToken->value, inputToken->length);
 268
 269     pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IDENTITY,
 270                            &respData, &len);
 271     if (pos == NULL) {
 272         *minor = GSSEAP_PEER_BAD_MESSAGE;
 273         return GSS_S_DEFECTIVE_TOKEN;
 274     }
 275
 276     nameBuf.value = (void *)pos;
 277     nameBuf.length = len;
 278
 279     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
 280
 281     return gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 282                             ctx->mechanismUsed, &ctx->initiatorName);
 283 }
 284
 285 /*
 286  * Pass the asserted initiator identity to the authentication server.
 287  */
 288 static OM_uint32
 289 setInitiatorIdentity(OM_uint32 *minor,
 290                      gss_ctx_id_t ctx,
 291                      struct rs_packet *req)
 292 {
 293     OM_uint32 major, tmpMinor;
 294     gss_buffer_desc nameBuf;
 295
 296     /*
 297      * We should have got an EAP identity response, but if we didn't, then
 298      * we will just avoid sending User-Name. Note that radsecproxy requires
 299      * User-Name to be sent on every request (presumably so it can remain
 300      * stateless).
 301      */
 302     if (ctx->initiatorName != GSS_C_NO_NAME) {
 303         major = gssEapDisplayName(minor, ctx->initiatorName, &nameBuf, NULL);
 304         if (GSS_ERROR(major))
 305             return major;
 306
 307         major = gssEapRadiusAddAvp(minor, req, PW_USER_NAME, 0, &nameBuf);
 308         if (GSS_ERROR(major))
 309             return major;
 310
 311         gss_release_buffer(&tmpMinor, &nameBuf);
 312     }
 313
 314     *minor = 0;
 315     return GSS_S_COMPLETE;
 316 }
 317
 318 /*
 319  * Pass the asserted acceptor identity to the authentication server.
 320  */
 321 static OM_uint32
 322 setAcceptorIdentity(OM_uint32 *minor,
 323                     gss_ctx_id_t ctx,
 324                     struct rs_packet *req)
 325 {
 326     OM_uint32 major;
 327     gss_buffer_desc nameBuf;
 328     krb5_context krbContext = NULL;
 329     krb5_principal krbPrinc;
 330     struct rs_context *rc = ctx->acceptorCtx.radContext;
 331
 332     GSSEAP_ASSERT(rc != NULL);
 333
 334     if (ctx->acceptorName == GSS_C_NO_NAME) {
 335         *minor = 0;
 336         return GSS_S_COMPLETE;
 337     }
 338
 339     if ((ctx->acceptorName->flags & NAME_FLAG_SERVICE) == 0) {
 340         *minor = GSSEAP_BAD_SERVICE_NAME;
 341         return GSS_S_BAD_NAME;
 342     }
 343
 344     GSSEAP_KRB_INIT(&krbContext);
 345
 346     krbPrinc = ctx->acceptorName->krbPrincipal;
 347     GSSEAP_ASSERT(krbPrinc != NULL);
 348     GSSEAP_ASSERT(KRB_PRINC_LENGTH(krbPrinc) >= 2);
 349
 350     /* Acceptor-Service-Name */
 351     krbPrincComponentToGssBuffer(krbPrinc, 0, &nameBuf);
 352
 353     major = gssEapRadiusAddAvp(minor, req,
 354                                PW_GSS_ACCEPTOR_SERVICE_NAME,
 355                                0,
 356                                &nameBuf);
 357     if (GSS_ERROR(major))
 358         return major;
 359
 360     /* Acceptor-Host-Name */
 361     krbPrincComponentToGssBuffer(krbPrinc, 1, &nameBuf);
 362
 363     major = gssEapRadiusAddAvp(minor, req,
 364                                PW_GSS_ACCEPTOR_HOST_NAME,
 365                                0,
 366                                &nameBuf);
 367     if (GSS_ERROR(major))
 368         return major;
 369
 370     if (KRB_PRINC_LENGTH(krbPrinc) > 2) {
 371         /* Acceptor-Service-Specific */
 372         *minor = krbPrincUnparseServiceSpecifics(krbContext,
 373                                                  krbPrinc, &nameBuf);
 374         if (*minor != 0)
 375             return GSS_S_FAILURE;
 376
 377         major = gssEapRadiusAddAvp(minor, req,
 378                                    PW_GSS_ACCEPTOR_SERVICE_SPECIFICS,
 379                                    0,
 380                                    &nameBuf);
 381 #ifdef HAVE_HEIMDAL_VERSION
 382         krb5_xfree(ssi);
 383 #else
 384         krb5_free_unparsed_name(krbContext, ssi);
 385 #endif
 386         if (GSS_ERROR(major))
 387             return major;
 388     }
 389
 390     krbPrincRealmToGssBuffer(krbPrinc, &nameBuf);
 391     if (nameBuf.length != 0) {
 392         /* Acceptor-Realm-Name */
 393         major = gssEapRadiusAddAvp(minor, req,
 394                                    PW_GSS_ACCEPTOR_REALM_NAME,
 395                                    0,
 396                                    &nameBuf);
 397         if (GSS_ERROR(major))
 398             return major;
 399     }
 400
 401     *minor = 0;
 402     return GSS_S_COMPLETE;
 403 }
 404
 405 /*
 406  * Allocate a RadSec handle
 407  */
 408 static OM_uint32
 409 createRadiusHandle(OM_uint32 *minor,
 410                    gss_cred_id_t cred,
 411                    gss_ctx_id_t ctx)
 412 {
 413     struct gss_eap_acceptor_ctx *actx = &ctx->acceptorCtx;
 414     struct rs_error *err;
 415     const char *configStanza = "gss-eap";
 416     OM_uint32 major;
 417
 418     GSSEAP_ASSERT(actx->radContext == NULL);
 419     GSSEAP_ASSERT(actx->radConn == NULL);
 420     GSSEAP_ASSERT(cred != GSS_C_NO_CREDENTIAL);
 421
 422     major = gssEapCreateRadiusContext(minor, cred, &actx->radContext);
 423     if (GSS_ERROR(major))
 424         return major;
 425
 426     if (cred->radiusConfigStanza.value != NULL)
 427         configStanza = (const char *)cred->radiusConfigStanza.value;
 428
 429     if (rs_conn_create(actx->radContext, &actx->radConn, configStanza) != 0) {
 430         err = rs_err_conn_pop(actx->radConn);
 431         return gssEapRadiusMapError(minor, err);
 432     }
 433
 434     if (actx->radServer != NULL) {
 435         if (rs_conn_select_peer(actx->radConn, actx->radServer) != 0) {
 436             err = rs_err_conn_pop(actx->radConn);
 437             return gssEapRadiusMapError(minor, err);
 438         }
 439     }
 440
 441     *minor = 0;
 442     return GSS_S_COMPLETE;
 443 }
 444
 445 /*
 446  * Process a EAP response from the initiator.
 447  */
 448 static OM_uint32
 449 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 450                            gss_cred_id_t cred,
 451                            gss_ctx_id_t ctx,
 452                            gss_name_t target GSSEAP_UNUSED,
 453                            gss_OID mech GSSEAP_UNUSED,
 454                            OM_uint32 reqFlags GSSEAP_UNUSED,
 455                            OM_uint32 timeReq GSSEAP_UNUSED,
 456                            gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 457                            gss_buffer_t inputToken,
 458                            gss_buffer_t outputToken,
 459                            OM_uint32 *smFlags)
 460 {
 461     OM_uint32 major, tmpMinor;
 462     struct rs_connection *rconn;
 463     struct rs_request *request = NULL;
 464     struct rs_packet *req = NULL, *resp = NULL;
 465     int isAccessChallenge;
 466
 467     if (ctx->acceptorCtx.radContext == NULL) {
 468         /* May be NULL from an imported partial context */
 469         major = createRadiusHandle(minor, cred, ctx);
 470         if (GSS_ERROR(major))
 471             goto cleanup;
 472     }
 473
 474     if (isIdentityResponseP(inputToken)) {
 475         major = importInitiatorIdentity(minor, ctx, inputToken);
 476         if (GSS_ERROR(major))
 477             return major;
 478     }
 479
 480     rconn = ctx->acceptorCtx.radConn;
 481
 482     if (rs_packet_create_authn_request(rconn, &req, NULL, NULL) != 0) {
 483         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 484         goto cleanup;
 485     }
 486
 487     major = setInitiatorIdentity(minor, ctx, req);
 488     if (GSS_ERROR(major))
 489         goto cleanup;
 490
 491     major = setAcceptorIdentity(minor, ctx, req);
 492     if (GSS_ERROR(major))
 493         goto cleanup;
 494
 495     major = gssEapRadiusAddAvp(minor, req,
 496                                PW_EAP_MESSAGE, 0, inputToken);
 497     if (GSS_ERROR(major))
 498         goto cleanup;
 499
 500     if (ctx->acceptorCtx.state.length != 0) {
 501         major = gssEapRadiusAddAvp(minor, req, PW_STATE, 0,
 502                                    &ctx->acceptorCtx.state);
 503         if (GSS_ERROR(major))
 504             goto cleanup;
 505
 506         gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
 507     }
 508
 509     if (rs_request_create(rconn, &request) != 0) {
 510         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 511         goto cleanup;
 512     }
 513
 514     rs_request_add_reqpkt(request, req);
 515     req = NULL;
 516
 517     if (rs_request_send(request, &resp) != 0) {
 518         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 519         goto cleanup;
 520     }
 521
 522     GSSEAP_ASSERT(resp != NULL);
 523
 524     isAccessChallenge = 0;
 525
 526     switch (rs_packet_code(resp)) {
 527     case PW_ACCESS_CHALLENGE:
 528         isAccessChallenge = 1;
 529         break;
 530     case PW_ACCESS_ACCEPT:
 531         break;
 532     case PW_ACCESS_REJECT:
 533         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
 534         major = GSS_S_DEFECTIVE_CREDENTIAL;
 535         goto cleanup;
 536         break;
 537     default:
 538         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
 539         major = GSS_S_FAILURE;
 540         goto cleanup;
 541         break;
 542     }
 543
 544     major = gssEapRadiusGetAvp(minor, resp, PW_EAP_MESSAGE, 0,
 545                                outputToken, TRUE);
 546     if (major == GSS_S_UNAVAILABLE && isAccessChallenge) {
 547         *minor = GSSEAP_MISSING_EAP_REQUEST;
 548         major = GSS_S_DEFECTIVE_TOKEN;
 549         goto cleanup;
 550     } else if (GSS_ERROR(major))
 551         goto cleanup;
 552
 553     if (isAccessChallenge) {
 554         major = gssEapRadiusGetAvp(minor, resp, PW_STATE, 0,
 555                                    &ctx->acceptorCtx.state, TRUE);
 556         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
 557             goto cleanup;
 558     } else {
 559         rs_avp **vps;
 560
 561         rs_packet_avps(resp, &vps);
 562
 563         ctx->acceptorCtx.vps = *vps;
 564         *vps = NULL;
 565
 566         major = acceptReadyEap(minor, ctx, cred);
 567         if (GSS_ERROR(major))
 568             goto cleanup;
 569
 570         GSSEAP_SM_TRANSITION_NEXT(ctx);
 571     }
 572
 573     major = GSS_S_CONTINUE_NEEDED;
 574     *minor = 0;
 575     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 576
 577 cleanup:
 578     if (request != NULL)
 579         rs_request_destroy(request);
 580     if (req != NULL)
 581         rs_packet_destroy(req);
 582     if (resp != NULL)
 583         rs_packet_destroy(resp);
 584     if (GSSEAP_SM_STATE(ctx) == GSSEAP_STATE_INITIATOR_EXTS) {
 585         GSSEAP_ASSERT(major == GSS_S_CONTINUE_NEEDED);
 586
 587         rs_conn_destroy(ctx->acceptorCtx.radConn);
 588         ctx->acceptorCtx.radConn = NULL;
 589     }
 590
 591     return major;
 592 }
 593
 594 static OM_uint32
 595 eapGssSmAcceptGssFlags(OM_uint32 *minor,
 596                        gss_cred_id_t cred GSSEAP_UNUSED,
 597                        gss_ctx_id_t ctx,
 598                        gss_name_t target GSSEAP_UNUSED,
 599                        gss_OID mech GSSEAP_UNUSED,
 600                        OM_uint32 reqFlags GSSEAP_UNUSED,
 601                        OM_uint32 timeReq GSSEAP_UNUSED,
 602                        gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 603                        gss_buffer_t inputToken,
 604                        gss_buffer_t outputToken GSSEAP_UNUSED,
 605                        OM_uint32 *smFlags GSSEAP_UNUSED)
 606 {
 607     unsigned char *p;
 608     OM_uint32 initiatorGssFlags;
 609
 610     GSSEAP_ASSERT((ctx->flags & CTX_FLAG_KRB_REAUTH) == 0);
 611
 612     if (inputToken->length < 4) {
 613         *minor = GSSEAP_TOK_TRUNC;
 614         return GSS_S_DEFECTIVE_TOKEN;
 615     }
 616
 617     /* allow flags to grow for future expansion */
 618     p = (unsigned char *)inputToken->value + inputToken->length - 4;
 619
 620     initiatorGssFlags = load_uint32_be(p);
 621     initiatorGssFlags &= GSSEAP_WIRE_FLAGS_MASK;
 622
 623     ctx->gssFlags |= initiatorGssFlags;
 624
 625     return GSS_S_CONTINUE_NEEDED;
 626 }
 627
 628 static OM_uint32
 629 eapGssSmAcceptGssChannelBindings(OM_uint32 *minor,
 630                                  gss_cred_id_t cred GSSEAP_UNUSED,
 631                                  gss_ctx_id_t ctx,
 632                                  gss_name_t target GSSEAP_UNUSED,
 633                                  gss_OID mech GSSEAP_UNUSED,
 634                                  OM_uint32 reqFlags GSSEAP_UNUSED,
 635                                  OM_uint32 timeReq GSSEAP_UNUSED,
 636                                  gss_channel_bindings_t chanBindings,
 637                                  gss_buffer_t inputToken,
 638                                  gss_buffer_t outputToken GSSEAP_UNUSED,
 639                                  OM_uint32 *smFlags GSSEAP_UNUSED)
 640 {
 641     krb5_error_code code;
 642     krb5_context krbContext;
 643     krb5_data data;
 644     krb5_checksum cksum;
 645     krb5_boolean valid = FALSE;
 646
 647     if (chanBindings == GSS_C_NO_CHANNEL_BINDINGS ||
 648         chanBindings->application_data.length == 0)
 649         return GSS_S_CONTINUE_NEEDED;
 650
 651     GSSEAP_KRB_INIT(&krbContext);
 652
 653     KRB_DATA_INIT(&data);
 654
 655     gssBufferToKrbData(&chanBindings->application_data, &data);
 656
 657     KRB_CHECKSUM_INIT(&cksum, ctx->checksumType, inputToken);
 658
 659     code = krb5_c_verify_checksum(krbContext, &ctx->rfc3961Key,
 660                                   KEY_USAGE_GSSEAP_CHBIND_MIC,
 661                                   &data, &cksum, &valid);
 662     if (code != 0) {
 663         *minor = code;
 664         return GSS_S_FAILURE;
 665     }
 666
 667     if (valid == FALSE) {
 668         *minor = GSSEAP_BINDINGS_MISMATCH;
 669         return GSS_S_BAD_BINDINGS;
 670     }
 671
 672     ctx->flags |= CTX_FLAG_CHANNEL_BINDINGS_VERIFIED;
 673
 674     *minor = 0;
 675     return GSS_S_CONTINUE_NEEDED;
 676 }
 677
 678 static OM_uint32
 679 eapGssSmAcceptInitiatorMIC(OM_uint32 *minor,
 680                            gss_cred_id_t cred GSSEAP_UNUSED,
 681                            gss_ctx_id_t ctx,
 682                            gss_name_t target GSSEAP_UNUSED,
 683                            gss_OID mech GSSEAP_UNUSED,
 684                            OM_uint32 reqFlags GSSEAP_UNUSED,
 685                            OM_uint32 timeReq GSSEAP_UNUSED,
 686                            gss_channel_bindings_t chanBindings,
 687                            gss_buffer_t inputToken,
 688                            gss_buffer_t outputToken GSSEAP_UNUSED,
 689                            OM_uint32 *smFlags GSSEAP_UNUSED)
 690 {
 691     OM_uint32 major;
 692
 693     /*
 694      * The channel binding token is optional, however if the caller indicated
 695      * bindings we must raise an error if it was absent.
 696      *
 697      * In the future, we might use a context option to allow the caller to
 698      * indicate that missing bindings are acceptable.
 699      */
 700     if (chanBindings != NULL &&
 701         chanBindings->application_data.length != 0 &&
 702         (ctx->flags & CTX_FLAG_CHANNEL_BINDINGS_VERIFIED) == 0) {
 703         *minor = GSSEAP_MISSING_BINDINGS;
 704         return GSS_S_BAD_BINDINGS;
 705     }
 706
 707     major = gssEapVerifyTokenMIC(minor, ctx, inputToken);
 708     if (GSS_ERROR(major))
 709         return major;
 710
 711     GSSEAP_SM_TRANSITION_NEXT(ctx);
 712
 713     *minor = 0;
 714     return GSS_S_CONTINUE_NEEDED;
 715 }
 716
 717 #ifdef GSSEAP_ENABLE_REAUTH
 718 static OM_uint32
 719 eapGssSmAcceptReauthCreds(OM_uint32 *minor,
 720                           gss_cred_id_t cred,
 721                           gss_ctx_id_t ctx,
 722                           gss_name_t target GSSEAP_UNUSED,
 723                           gss_OID mech GSSEAP_UNUSED,
 724                           OM_uint32 reqFlags GSSEAP_UNUSED,
 725                           OM_uint32 timeReq GSSEAP_UNUSED,
 726                           gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 727                           gss_buffer_t inputToken GSSEAP_UNUSED,
 728                           gss_buffer_t outputToken,
 729                           OM_uint32 *smFlags GSSEAP_UNUSED)
 730 {
 731     OM_uint32 major;
 732
 733     /*
 734      * If we're built with fast reauthentication enabled, then
 735      * fabricate a ticket from the initiator to ourselves.
 736      */
 737     major = gssEapMakeReauthCreds(minor, ctx, cred, outputToken);
 738     if (major == GSS_S_UNAVAILABLE)
 739         major = GSS_S_COMPLETE;
 740     if (major == GSS_S_COMPLETE)
 741         major = GSS_S_CONTINUE_NEEDED;
 742
 743     return major;
 744 }
 745 #endif
 746
 747 static OM_uint32
 748 eapGssSmAcceptAcceptorMIC(OM_uint32 *minor,
 749                           gss_cred_id_t cred GSSEAP_UNUSED,
 750                           gss_ctx_id_t ctx,
 751                           gss_name_t target GSSEAP_UNUSED,
 752                           gss_OID mech GSSEAP_UNUSED,
 753                           OM_uint32 reqFlags GSSEAP_UNUSED,
 754                           OM_uint32 timeReq GSSEAP_UNUSED,
 755                           gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 756                           gss_buffer_t inputToken GSSEAP_UNUSED,
 757                           gss_buffer_t outputToken,
 758                           OM_uint32 *smFlags)
 759 {
 760     OM_uint32 major;
 761
 762     major = gssEapMakeTokenMIC(minor, ctx, outputToken);
 763     if (GSS_ERROR(major))
 764         return major;
 765
 766     GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
 767
 768     *minor = 0;
 769     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 770
 771     return GSS_S_COMPLETE;
 772 }
 773
 774 static struct gss_eap_sm eapGssAcceptorSm[] = {
 775     {
 776         ITOK_TYPE_ACCEPTOR_NAME_REQ,
 777         ITOK_TYPE_ACCEPTOR_NAME_RESP,
 778         GSSEAP_STATE_INITIAL,
 779         0,
 780         eapGssSmAcceptAcceptorName
 781     },
 782 #ifdef GSSEAP_DEBUG
 783     {
 784         ITOK_TYPE_VENDOR_INFO,
 785         ITOK_TYPE_NONE,
 786         GSSEAP_STATE_INITIAL,
 787         0,
 788         eapGssSmAcceptVendorInfo,
 789     },
 790 #endif
 791 #ifdef GSSEAP_ENABLE_REAUTH
 792     {
 793         ITOK_TYPE_REAUTH_REQ,
 794         ITOK_TYPE_REAUTH_RESP,
 795         GSSEAP_STATE_INITIAL,
 796         0,
 797         eapGssSmAcceptGssReauth,
 798     },
 799 #endif
 800     {
 801         ITOK_TYPE_NONE,
 802         ITOK_TYPE_EAP_REQ,
 803         GSSEAP_STATE_INITIAL,
 804         SM_ITOK_FLAG_REQUIRED,
 805         eapGssSmAcceptIdentity,
 806     },
 807     {
 808         ITOK_TYPE_EAP_RESP,
 809         ITOK_TYPE_EAP_REQ,
 810         GSSEAP_STATE_AUTHENTICATE,
 811         SM_ITOK_FLAG_REQUIRED,
 812         eapGssSmAcceptAuthenticate
 813     },
 814     {
 815         ITOK_TYPE_GSS_FLAGS,
 816         ITOK_TYPE_NONE,
 817         GSSEAP_STATE_INITIATOR_EXTS,
 818         0,
 819         eapGssSmAcceptGssFlags
 820     },
 821     {
 822         ITOK_TYPE_GSS_CHANNEL_BINDINGS,
 823         ITOK_TYPE_NONE,
 824         GSSEAP_STATE_INITIATOR_EXTS,
 825         0,
 826         eapGssSmAcceptGssChannelBindings,
 827     },
 828     {
 829         ITOK_TYPE_INITIATOR_MIC,
 830         ITOK_TYPE_NONE,
 831         GSSEAP_STATE_INITIATOR_EXTS,
 832         SM_ITOK_FLAG_REQUIRED,
 833         eapGssSmAcceptInitiatorMIC,
 834     },
 835 #ifdef GSSEAP_ENABLE_REAUTH
 836     {
 837         ITOK_TYPE_NONE,
 838         ITOK_TYPE_REAUTH_CREDS,
 839         GSSEAP_STATE_ACCEPTOR_EXTS,
 840         0,
 841         eapGssSmAcceptReauthCreds,
 842     },
 843 #endif
 844     {
 845         ITOK_TYPE_NONE,
 846         ITOK_TYPE_ACCEPTOR_NAME_RESP,
 847         GSSEAP_STATE_ACCEPTOR_EXTS,
 848         0,
 849         eapGssSmAcceptAcceptorName
 850     },
 851     {
 852         ITOK_TYPE_NONE,
 853         ITOK_TYPE_ACCEPTOR_MIC,
 854         GSSEAP_STATE_ACCEPTOR_EXTS,
 855         0,
 856         eapGssSmAcceptAcceptorMIC
 857     },
 858 };
 859
 860 OM_uint32
 861 gssEapAcceptSecContext(OM_uint32 *minor,
 862                        gss_ctx_id_t ctx,
 863                        gss_cred_id_t cred,
 864                        gss_buffer_t input_token,
 865                        gss_channel_bindings_t input_chan_bindings,
 866                        gss_name_t *src_name,
 867                        gss_OID *mech_type,
 868                        gss_buffer_t output_token,
 869                        OM_uint32 *ret_flags,
 870                        OM_uint32 *time_rec,
 871                        gss_cred_id_t *delegated_cred_handle)
 872 {
 873     OM_uint32 major, tmpMinor;
 874
 875     if (cred == GSS_C_NO_CREDENTIAL) {
 876         if (ctx->cred == GSS_C_NO_CREDENTIAL) {
 877             major = gssEapAcquireCred(minor,
 878                                       GSS_C_NO_NAME,
 879                                       GSS_C_INDEFINITE,
 880                                       GSS_C_NO_OID_SET,
 881                                       GSS_C_ACCEPT,
 882                                       &ctx->cred,
 883                                       NULL,
 884                                       NULL);
 885             if (GSS_ERROR(major))
 886                 goto cleanup;
 887         }
 888
 889         cred = ctx->cred;
 890     }
 891
 892     /*
 893      * Previously we acquired the credential mutex here, but it should not be
 894      * necessary as the acceptor does not access any mutable elements of the
 895      * credential handle.
 896      */
 897
 898     if (cred->name != GSS_C_NO_NAME) {
 899         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 900         if (GSS_ERROR(major))
 901             goto cleanup;
 902     }
 903
 904     major = gssEapSmStep(minor,
 905                          cred,
 906                          ctx,
 907                          GSS_C_NO_NAME,
 908                          GSS_C_NO_OID,
 909                          0,
 910                          GSS_C_INDEFINITE,
 911                          input_chan_bindings,
 912                          input_token,
 913                          output_token,
 914                          eapGssAcceptorSm,
 915                          sizeof(eapGssAcceptorSm) / sizeof(eapGssAcceptorSm[0]));
 916     if (GSS_ERROR(major))
 917         goto cleanup;
 918
 919     if (mech_type != NULL) {
 920         OM_uint32 tmpMajor;
 921
 922         tmpMajor = gssEapCanonicalizeOid(&tmpMinor, ctx->mechanismUsed, 0, mech_type);
 923         if (GSS_ERROR(tmpMajor)) {
 924             major = tmpMajor;
 925             *minor = tmpMinor;
 926             goto cleanup;
 927         }
 928     }
 929     if (ret_flags != NULL)
 930         *ret_flags = ctx->gssFlags;
 931     if (delegated_cred_handle != NULL)
 932         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 933
 934     if (major == GSS_S_COMPLETE) {
 935         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 936             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
 937             if (GSS_ERROR(major))
 938                 goto cleanup;
 939         }
 940         if (time_rec != NULL) {
 941             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
 942             if (GSS_ERROR(major))
 943                 goto cleanup;
 944         }
 945     }
 946
 947     GSSEAP_ASSERT(CTX_IS_ESTABLISHED(ctx) || major == GSS_S_CONTINUE_NEEDED);
 948
 949 cleanup:
 950     return major;
 951 }
 952
 953 #ifdef GSSEAP_ENABLE_REAUTH
 954 static OM_uint32
 955 acceptReadyKrb(OM_uint32 *minor,
 956                gss_ctx_id_t ctx,
 957                gss_cred_id_t cred,
 958                const gss_name_t initiator,
 959                const gss_OID mech,
 960                OM_uint32 timeRec)
 961 {
 962     OM_uint32 major;
 963
 964     major = gssEapGlueToMechName(minor, ctx, initiator, &ctx->initiatorName);
 965     if (GSS_ERROR(major))
 966         return major;
 967
 968     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 969     if (GSS_ERROR(major))
 970         return major;
 971
 972     *minor = 0;
 973     return GSS_S_COMPLETE;
 974 }
 975
 976 static OM_uint32
 977 eapGssSmAcceptGssReauth(OM_uint32 *minor,
 978                         gss_cred_id_t cred,
 979                         gss_ctx_id_t ctx,
 980                         gss_name_t target GSSEAP_UNUSED,
 981                         gss_OID mech,
 982                         OM_uint32 reqFlags GSSEAP_UNUSED,
 983                         OM_uint32 timeReq GSSEAP_UNUSED,
 984                         gss_channel_bindings_t chanBindings,
 985                         gss_buffer_t inputToken,
 986                         gss_buffer_t outputToken,
 987                         OM_uint32 *smFlags)
 988 {
 989     OM_uint32 major, tmpMinor;
 990     gss_name_t krbInitiator = GSS_C_NO_NAME;
 991     OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
 992
 993     /*
 994      * If we're built with fast reauthentication support, it's valid
 995      * for an initiator to send a GSS reauthentication token as its
 996      * initial context token, causing us to short-circuit the state
 997      * machine and process Kerberos GSS messages instead.
 998      */
 999
1000     ctx->flags |= CTX_FLAG_KRB_REAUTH;
1001
1002     major = gssAcceptSecContext(minor,
1003                                 &ctx->reauthCtx,
1004                                 cred->reauthCred,
1005                                 inputToken,
1006                                 chanBindings,
1007                                 &krbInitiator,
1008                                 &mech,
1009                                 outputToken,
1010                                 &gssFlags,
1011                                 &timeRec,
1012                                 NULL);
1013     if (major == GSS_S_COMPLETE) {
1014         major = acceptReadyKrb(minor, ctx, cred,
1015                                krbInitiator, mech, timeRec);
1016         if (major == GSS_S_COMPLETE) {
1017             GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
1018         }
1019         ctx->gssFlags = gssFlags;
1020     } else if (GSS_ERROR(major) &&
1021         (*smFlags & SM_FLAG_INPUT_TOKEN_CRITICAL) == 0) {
1022         /* pretend reauthentication attempt never happened */
1023         gssDeleteSecContext(&tmpMinor, &ctx->reauthCtx, GSS_C_NO_BUFFER);
1024         ctx->flags &= ~(CTX_FLAG_KRB_REAUTH);
1025         GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_INITIAL);
1026         major = GSS_S_CONTINUE_NEEDED;
1027     }
1028
1029     gssReleaseName(&tmpMinor, &krbInitiator);
1030
1031     return major;
1032 }
1033 #endif /* GSSEAP_ENABLE_REAUTH */
1034
1035 OM_uint32 GSSAPI_CALLCONV
1036 gss_accept_sec_context(OM_uint32 *minor,
1037                        gss_ctx_id_t *context_handle,
1038                        gss_cred_id_t cred,
1039                        gss_buffer_t input_token,
1040                        gss_channel_bindings_t input_chan_bindings,
1041                        gss_name_t *src_name,
1042                        gss_OID *mech_type,
1043                        gss_buffer_t output_token,
1044                        OM_uint32 *ret_flags,
1045                        OM_uint32 *time_rec,
1046                        gss_cred_id_t *delegated_cred_handle)
1047 {
1048     OM_uint32 major, tmpMinor;
1049     gss_ctx_id_t ctx = *context_handle;
1050
1051     *minor = 0;
1052
1053     output_token->length = 0;
1054     output_token->value = NULL;
1055
1056     if (src_name != NULL)
1057         *src_name = GSS_C_NO_NAME;
1058
1059     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
1060         *minor = GSSEAP_TOK_TRUNC;
1061         return GSS_S_DEFECTIVE_TOKEN;
1062     }
1063
1064     if (ctx == GSS_C_NO_CONTEXT) {
1065         major = gssEapAllocContext(minor, &ctx);
1066         if (GSS_ERROR(major))
1067             return major;
1068
1069         *context_handle = ctx;
1070     }
1071
1072     GSSEAP_MUTEX_LOCK(&ctx->mutex);
1073
1074     major = gssEapAcceptSecContext(minor,
1075                                    ctx,
1076                                    cred,
1077                                    input_token,
1078                                    input_chan_bindings,
1079                                    src_name,
1080                                    mech_type,
1081                                    output_token,
1082                                    ret_flags,
1083                                    time_rec,
1084                                    delegated_cred_handle);
1085
1086     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
1087
1088     if (GSS_ERROR(major))
1089         gssEapReleaseContext(&tmpMinor, context_handle);
1090
1091     return major;
1092 }