www.project-moonshot.org Git - mech_eap.orig/blob - 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_ctx_id_t ctx,
  44                         gss_cred_id_t cred,
  45                         gss_buffer_t inputToken,
  46                         gss_channel_bindings_t chanBindings,
  47                         gss_buffer_t outputToken);
  48 #endif
  49
  50 /*
  51  * Mark an acceptor context as ready for cryptographic operations
  52  */
  53 static OM_uint32
  54 acceptReadyEap(OM_uint32 *minor, gss_ctx_id_t ctx, gss_cred_id_t cred)
  55 {
  56     OM_uint32 major, tmpMinor;
  57     VALUE_PAIR *vp;
  58     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
  59
  60     /* Cache encryption type derived from selected mechanism OID */
  61     major = gssEapOidToEnctype(minor, ctx->mechanismUsed,
  62                                &ctx->encryptionType);
  63     if (GSS_ERROR(major))
  64         return major;
  65
  66     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
  67
  68     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
  69                                   PW_USER_NAME, 0, &vp);
  70     if (major == GSS_S_COMPLETE) {
  71         nameBuf.length = vp->length;
  72         nameBuf.value = vp->vp_strvalue;
  73     } else {
  74         ctx->gssFlags |= GSS_C_ANON_FLAG;
  75     }
  76
  77     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
  78                              &ctx->initiatorName);
  79     if (GSS_ERROR(major))
  80         return major;
  81
  82     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
  83                                   PW_MS_MPPE_SEND_KEY, VENDORPEC_MS, &vp);
  84     if (GSS_ERROR(major)) {
  85         *minor = GSSEAP_KEY_UNAVAILABLE;
  86         return GSS_S_UNAVAILABLE;
  87     }
  88
  89     major = gssEapDeriveRfc3961Key(minor,
  90                                    vp->vp_octets,
  91                                    vp->length,
  92                                    ctx->encryptionType,
  93                                    &ctx->rfc3961Key);
  94     if (GSS_ERROR(major))
  95         return major;
  96
  97     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
  98                                        &ctx->checksumType);
  99     if (GSS_ERROR(major))
 100         return major;
 101
 102     major = sequenceInit(minor,
 103                          &ctx->seqState, ctx->recvSeq,
 104                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 105                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 106                          TRUE);
 107     if (GSS_ERROR(major))
 108         return major;
 109
 110     major = gssEapCreateAttrContext(minor, cred, ctx,
 111                                     &ctx->initiatorName->attrCtx,
 112                                     &ctx->expiryTime);
 113     if (GSS_ERROR(major))
 114         return major;
 115
 116     *minor = 0;
 117     return GSS_S_COMPLETE;
 118 }
 119
 120 /*
 121  * Emit a identity EAP request to force the initiator (peer) to identify
 122  * itself.
 123  */
 124 static OM_uint32
 125 eapGssSmAcceptIdentity(OM_uint32 *minor,
 126                        gss_ctx_id_t ctx,
 127                        gss_cred_id_t cred,
 128                        gss_buffer_t inputToken,
 129                        gss_channel_bindings_t chanBindings,
 130                        gss_buffer_t outputToken)
 131 {
 132     OM_uint32 major;
 133     union {
 134         struct eap_hdr pdu;
 135         unsigned char data[5];
 136     } pkt;
 137     gss_buffer_desc pktBuffer;
 138
 139     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
 140         *minor = GSSEAP_WRONG_SIZE;
 141         return GSS_S_DEFECTIVE_TOKEN;
 142     }
 143
 144     assert(ctx->acceptorName == GSS_C_NO_NAME);
 145
 146     if (cred->name != GSS_C_NO_NAME) {
 147         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 148         if (GSS_ERROR(major))
 149             return major;
 150     }
 151
 152     pkt.pdu.code = EAP_CODE_REQUEST;
 153     pkt.pdu.identifier = 0;
 154     pkt.pdu.length = htons(sizeof(pkt.data));
 155     pkt.data[4] = EAP_TYPE_IDENTITY;
 156
 157     pktBuffer.length = sizeof(pkt.data);
 158     pktBuffer.value = pkt.data;
 159
 160     major = duplicateBuffer(minor, &pktBuffer, outputToken);
 161     if (GSS_ERROR(major))
 162         return major;
 163
 164     ctx->state = GSSEAP_STATE_AUTHENTICATE;
 165
 166     *minor = 0;
 167     return GSS_S_CONTINUE_NEEDED;
 168 }
 169
 170 /*
 171  * Pass the asserted acceptor identity to the authentication server.
 172  */
 173 static OM_uint32
 174 setAcceptorIdentity(OM_uint32 *minor,
 175                     gss_ctx_id_t ctx,
 176                     VALUE_PAIR **vps)
 177 {
 178     OM_uint32 major;
 179     gss_buffer_desc nameBuf;
 180     krb5_context krbContext = NULL;
 181     krb5_principal krbPrinc;
 182     struct rs_context *rc = ctx->acceptorCtx.radContext;
 183
 184     assert(rc != NULL);
 185
 186     if (ctx->acceptorName == GSS_C_NO_NAME) {
 187         *minor = 0;
 188         return GSS_S_COMPLETE;
 189     }
 190
 191     if ((ctx->acceptorName->flags & NAME_FLAG_SERVICE) == 0) {
 192         *minor = GSSEAP_BAD_SERVICE_NAME;
 193         return GSS_S_BAD_NAME;
 194     }
 195
 196     GSSEAP_KRB_INIT(&krbContext);
 197
 198     krbPrinc = ctx->acceptorName->krbPrincipal;
 199     assert(krbPrinc != NULL);
 200     assert(KRB_PRINC_LENGTH(krbPrinc) >= 2);
 201
 202     /* Acceptor-Service-Name */
 203     krbPrincComponentToGssBuffer(krbPrinc, 0, &nameBuf);
 204
 205     major = gssEapRadiusAddAvp(minor, vps,
 206                                PW_GSS_ACCEPTOR_SERVICE_NAME,
 207                                VENDORPEC_UKERNA,
 208                                &nameBuf);
 209     if (GSS_ERROR(major))
 210         return major;
 211
 212     /* Acceptor-Host-Name */
 213     krbPrincComponentToGssBuffer(krbPrinc, 1, &nameBuf);
 214
 215     major = gssEapRadiusAddAvp(minor, vps,
 216                                PW_GSS_ACCEPTOR_HOST_NAME,
 217                                VENDORPEC_UKERNA,
 218                                &nameBuf);
 219     if (GSS_ERROR(major))
 220         return major;
 221
 222     if (KRB_PRINC_LENGTH(krbPrinc) > 2) {
 223         /* Acceptor-Service-Specific */
 224         krb5_principal_data ssiPrinc = *krbPrinc;
 225         char *ssi;
 226
 227         KRB_PRINC_LENGTH(&ssiPrinc) -= 2;
 228         KRB_PRINC_NAME(&ssiPrinc) += 2;
 229
 230         *minor = krb5_unparse_name_flags(krbContext, &ssiPrinc,
 231                                          KRB5_PRINCIPAL_UNPARSE_NO_REALM, &ssi);
 232         if (*minor != 0)
 233             return GSS_S_FAILURE;
 234
 235         nameBuf.value = ssi;
 236         nameBuf.length = strlen(ssi);
 237
 238         major = gssEapRadiusAddAvp(minor, vps,
 239                                    PW_GSS_ACCEPTOR_SERVICE_SPECIFIC,
 240                                    VENDORPEC_UKERNA,
 241                                    &nameBuf);
 242
 243         if (GSS_ERROR(major)) {
 244             krb5_free_unparsed_name(krbContext, ssi);
 245             return major;
 246         }
 247         krb5_free_unparsed_name(krbContext, ssi);
 248     }
 249
 250     krbPrincRealmToGssBuffer(krbPrinc, &nameBuf);
 251     if (nameBuf.length != 0) {
 252         /* Acceptor-Realm-Name */
 253         major = gssEapRadiusAddAvp(minor, vps,
 254                                    PW_GSS_ACCEPTOR_REALM_NAME,
 255                                    VENDORPEC_UKERNA,
 256                                    &nameBuf);
 257         if (GSS_ERROR(major))
 258             return major;
 259     }
 260
 261     *minor = 0;
 262     return GSS_S_COMPLETE;
 263 }
 264
 265 /*
 266  * Allocate a RadSec handle
 267  */
 268 static OM_uint32
 269 createRadiusHandle(OM_uint32 *minor,
 270                    gss_cred_id_t cred,
 271                    gss_ctx_id_t ctx)
 272 {
 273     struct gss_eap_acceptor_ctx *actx = &ctx->acceptorCtx;
 274     const char *configFile = RS_CONFIG_FILE;
 275     const char *configStanza = "gss-eap";
 276     struct rs_alloc_scheme ralloc;
 277     struct rs_error *err;
 278
 279     assert(actx->radContext == NULL);
 280     assert(actx->radConn == NULL);
 281
 282     if (rs_context_create(&actx->radContext, RS_DICT_FILE) != 0) {
 283         *minor = GSSEAP_RADSEC_CONTEXT_FAILURE;
 284         return GSS_S_FAILURE;
 285     }
 286
 287     if (cred->radiusConfigFile != NULL)
 288         configFile = cred->radiusConfigFile;
 289     if (cred->radiusConfigStanza != NULL)
 290         configStanza = cred->radiusConfigStanza;
 291
 292     ralloc.calloc  = GSSEAP_CALLOC;
 293     ralloc.malloc  = GSSEAP_MALLOC;
 294     ralloc.free    = GSSEAP_FREE;
 295     ralloc.realloc = GSSEAP_REALLOC;
 296
 297     rs_context_set_alloc_scheme(actx->radContext, &ralloc);
 298
 299     if (rs_context_read_config(actx->radContext, configFile) != 0) {
 300         err = rs_err_ctx_pop(actx->radContext);
 301         goto fail;
 302     }
 303
 304     if (rs_conn_create(actx->radContext, &actx->radConn, configStanza) != 0) {
 305         err = rs_err_conn_pop(actx->radConn);
 306         goto fail;
 307     }
 308
 309     if (actx->radServer != NULL) {
 310         if (rs_conn_select_peer(actx->radConn, actx->radServer) != 0) {
 311             err = rs_err_conn_pop(actx->radConn);
 312             goto fail;
 313         }
 314     }
 315
 316     *minor = 0;
 317     return GSS_S_COMPLETE;
 318
 319 fail:
 320     return gssEapRadiusMapError(minor, err);
 321 }
 322
 323 /*
 324  * Process a EAP response from the initiator.
 325  */
 326 static OM_uint32
 327 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 328                            gss_ctx_id_t ctx,
 329                            gss_cred_id_t cred,
 330                            gss_buffer_t inputToken,
 331                            gss_channel_bindings_t chanBindings,
 332                            gss_buffer_t outputToken)
 333 {
 334     OM_uint32 major, tmpMinor;
 335     struct rs_connection *rconn;
 336     struct rs_request *request = NULL;
 337     struct rs_packet *req = NULL, *resp = NULL;
 338     struct radius_packet *frreq, *frresp;
 339     int sendAcceptorIdentity = 0;
 340
 341     if (ctx->acceptorCtx.radContext == NULL) {
 342         /* May be NULL from an imported partial context */
 343         major = createRadiusHandle(minor, cred, ctx);
 344         if (GSS_ERROR(major))
 345             goto cleanup;
 346
 347         sendAcceptorIdentity = 1;
 348     }
 349
 350     rconn = ctx->acceptorCtx.radConn;
 351
 352     if (rs_packet_create_authn_request(rconn, &req, NULL, NULL) != 0) {
 353         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 354         goto cleanup;
 355     }
 356     frreq = rs_packet_frpkt(req);
 357
 358     if (sendAcceptorIdentity) {
 359         major = setAcceptorIdentity(minor, ctx, &frreq->vps);
 360         if (GSS_ERROR(major))
 361             goto cleanup;
 362     }
 363
 364     major = gssEapRadiusAddAvp(minor, &frreq->vps,
 365                                PW_EAP_MESSAGE, 0, inputToken);
 366     if (GSS_ERROR(major))
 367         goto cleanup;
 368
 369     if (ctx->acceptorCtx.state.length != 0) {
 370         major = gssEapRadiusAddAvp(minor, &frreq->vps, PW_STATE, 0,
 371                                    &ctx->acceptorCtx.state);
 372         if (GSS_ERROR(major))
 373             goto cleanup;
 374
 375         gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
 376     }
 377
 378     if (rs_request_create(rconn, &request) != 0) {
 379         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 380         goto cleanup;
 381     }
 382
 383     rs_request_add_reqpkt(request, req);
 384     req = NULL;
 385
 386     if (rs_request_send(request, &resp) != 0) {
 387         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 388         goto cleanup;
 389     }
 390
 391     assert(resp != NULL);
 392
 393     frresp = rs_packet_frpkt(resp);
 394     switch (frresp->code) {
 395     case PW_AUTHENTICATION_ACK:
 396     case PW_ACCESS_CHALLENGE:
 397         major = GSS_S_CONTINUE_NEEDED;
 398         break;
 399     case PW_AUTHENTICATION_REJECT:
 400         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
 401         major = GSS_S_DEFECTIVE_CREDENTIAL;
 402         goto cleanup;
 403         break;
 404     default:
 405         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
 406         major = GSS_S_FAILURE;
 407         goto cleanup;
 408         break;
 409     }
 410
 411     major = gssEapRadiusGetAvp(minor, frresp->vps, PW_EAP_MESSAGE, 0,
 412                                outputToken, TRUE);
 413     if (major == GSS_S_UNAVAILABLE && frresp->code == PW_ACCESS_CHALLENGE) {
 414         *minor = GSSEAP_MISSING_EAP_REQUEST;
 415         major = GSS_S_DEFECTIVE_TOKEN;
 416         goto cleanup;
 417     } else if (GSS_ERROR(major))
 418         goto cleanup;
 419
 420     if (frresp->code == PW_ACCESS_CHALLENGE) {
 421         major = gssEapRadiusGetAvp(minor, frresp->vps, PW_STATE, 0,
 422                                    &ctx->acceptorCtx.state, TRUE);
 423         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
 424             goto cleanup;
 425     } else {
 426         ctx->acceptorCtx.vps = frresp->vps;
 427         frresp->vps = NULL;
 428
 429         rs_conn_destroy(ctx->acceptorCtx.radConn);
 430         ctx->acceptorCtx.radConn = NULL;
 431
 432         major = acceptReadyEap(minor, ctx, cred);
 433         if (GSS_ERROR(major))
 434             goto cleanup;
 435
 436         ctx->state = GSSEAP_STATE_EXTENSIONS_REQ;
 437     }
 438
 439     *minor = 0;
 440     major = GSS_S_CONTINUE_NEEDED;
 441
 442 cleanup:
 443     if (request != NULL)
 444         rs_request_destroy(request);
 445     if (req != NULL)
 446         rs_packet_destroy(req);
 447
 448     return major;
 449 }
 450
 451 static OM_uint32
 452 eapGssSmAcceptExtensionsReq(OM_uint32 *minor,
 453                             gss_ctx_id_t ctx,
 454                             gss_cred_id_t cred,
 455                             gss_buffer_t inputToken,
 456                             gss_channel_bindings_t chanBindings,
 457                             gss_buffer_t outputToken)
 458 {
 459     OM_uint32 major;
 460
 461     major = gssEapVerifyExtensions(minor, cred, ctx, chanBindings, inputToken);
 462     if (GSS_ERROR(major))
 463         return major;
 464
 465     outputToken->length = 0;
 466     outputToken->value = NULL;
 467
 468     ctx->state = GSSEAP_STATE_EXTENSIONS_RESP;
 469
 470     *minor = 0;
 471     return GSS_S_CONTINUE_NEEDED;
 472 }
 473
 474 static OM_uint32
 475 eapGssSmAcceptExtensionsResp(OM_uint32 *minor,
 476                              gss_ctx_id_t ctx,
 477                              gss_cred_id_t cred,
 478                              gss_buffer_t inputToken,
 479                              gss_channel_bindings_t chanBindings,
 480                              gss_buffer_t outputToken)
 481 {
 482     OM_uint32 major;
 483
 484     major = gssEapMakeExtensions(minor, cred, ctx, chanBindings, outputToken);
 485     if (GSS_ERROR(major))
 486         return major;
 487
 488     ctx->state = GSSEAP_STATE_ESTABLISHED;
 489
 490     *minor = 0;
 491     return GSS_S_COMPLETE;
 492 }
 493
 494 static OM_uint32
 495 eapGssSmAcceptEstablished(OM_uint32 *minor,
 496                           gss_ctx_id_t ctx,
 497                           gss_cred_id_t cred,
 498                           gss_buffer_t inputToken,
 499                           gss_channel_bindings_t chanBindings,
 500                           gss_buffer_t outputToken)
 501 {
 502     /* Called with already established context */
 503     *minor = GSSEAP_CONTEXT_ESTABLISHED;
 504     return GSS_S_BAD_STATUS;
 505 }
 506
 507 static OM_uint32
 508 makeErrorToken(OM_uint32 *minor,
 509                OM_uint32 majorStatus,
 510                OM_uint32 minorStatus,
 511                gss_buffer_t outputToken)
 512 {
 513     unsigned char errorData[8];
 514     gss_buffer_desc errorBuffer;
 515
 516     assert(GSS_ERROR(majorStatus));
 517
 518     /*
 519      * Only return error codes that the initiator could have caused,
 520      * to avoid information leakage.
 521      */
 522     if (IS_RADIUS_ERROR(minorStatus)) {
 523         /* Squash RADIUS error codes */
 524         minorStatus = GSSEAP_RADIUS_PROT_FAILURE;
 525     } else if (!IS_WIRE_ERROR(minorStatus)) {
 526         /* Don't return non-wire error codes */
 527         return GSS_S_COMPLETE;
 528     }
 529
 530     minorStatus -= ERROR_TABLE_BASE_eapg;
 531
 532     store_uint32_be(majorStatus, &errorData[0]);
 533     store_uint32_be(minorStatus, &errorData[4]);
 534
 535     errorBuffer.length = sizeof(errorData);
 536     errorBuffer.value = errorData;
 537
 538     return duplicateBuffer(minor, &errorBuffer, outputToken);
 539 }
 540
 541 static struct gss_eap_acceptor_sm {
 542     enum gss_eap_token_type inputTokenType;
 543     enum gss_eap_token_type outputTokenType;
 544     OM_uint32 (*processToken)(OM_uint32 *,
 545                               gss_ctx_id_t,
 546                               gss_cred_id_t,
 547                               gss_buffer_t,
 548                               gss_channel_bindings_t,
 549                               gss_buffer_t);
 550 } eapGssAcceptorSm[] = {
 551     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptIdentity           },
 552     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptAuthenticate       },
 553     { TOK_TYPE_EXT_REQ,     TOK_TYPE_NONE,          eapGssSmAcceptExtensionsReq      },
 554     { TOK_TYPE_NONE,        TOK_TYPE_EXT_RESP,      eapGssSmAcceptExtensionsResp     },
 555     { TOK_TYPE_NONE,        TOK_TYPE_NONE,          eapGssSmAcceptEstablished        },
 556     { TOK_TYPE_NONE,        TOK_TYPE_CONTEXT_ERR,   NULL                             },
 557 #ifdef GSSEAP_ENABLE_REAUTH
 558     { TOK_TYPE_GSS_REAUTH,  TOK_TYPE_GSS_REAUTH,    eapGssSmAcceptGssReauth          },
 559 #endif
 560 };
 561
 562 OM_uint32
 563 gss_accept_sec_context(OM_uint32 *minor,
 564                        gss_ctx_id_t *context_handle,
 565                        gss_cred_id_t cred,
 566                        gss_buffer_t input_token,
 567                        gss_channel_bindings_t input_chan_bindings,
 568                        gss_name_t *src_name,
 569                        gss_OID *mech_type,
 570                        gss_buffer_t output_token,
 571                        OM_uint32 *ret_flags,
 572                        OM_uint32 *time_rec,
 573                        gss_cred_id_t *delegated_cred_handle)
 574 {
 575     OM_uint32 major;
 576     OM_uint32 tmpMajor, tmpMinor;
 577     gss_ctx_id_t ctx = *context_handle;
 578     struct gss_eap_acceptor_sm *sm = NULL;
 579     gss_buffer_desc innerInputToken = GSS_C_EMPTY_BUFFER;
 580     gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 581     enum gss_eap_token_type tokType;
 582     int initialContextToken = 0;
 583
 584     *minor = 0;
 585
 586     output_token->length = 0;
 587     output_token->value = NULL;
 588
 589     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
 590         *minor = GSSEAP_TOK_TRUNC;
 591         return GSS_S_DEFECTIVE_TOKEN;
 592     }
 593
 594     if (ctx == GSS_C_NO_CONTEXT) {
 595         major = gssEapAllocContext(minor, &ctx);
 596         if (GSS_ERROR(major))
 597             return major;
 598
 599         initialContextToken = 1;
 600         *context_handle = ctx;
 601     }
 602
 603     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 604
 605     if (cred == GSS_C_NO_CREDENTIAL) {
 606         if (ctx->defaultCred == GSS_C_NO_CREDENTIAL) {
 607             major = gssEapAcquireCred(minor,
 608                                       GSS_C_NO_NAME,
 609                                       GSS_C_NO_BUFFER,
 610                                       GSS_C_INDEFINITE,
 611                                       GSS_C_NO_OID_SET,
 612                                       GSS_C_ACCEPT,
 613                                       &ctx->defaultCred,
 614                                       NULL,
 615                                       NULL);
 616             if (GSS_ERROR(major))
 617                 goto cleanup;
 618         }
 619
 620         cred = ctx->defaultCred;
 621     }
 622
 623     GSSEAP_MUTEX_LOCK(&cred->mutex);
 624
 625     sm = &eapGssAcceptorSm[ctx->state];
 626
 627     major = gssEapVerifyToken(minor, ctx, input_token,
 628                               &tokType, &innerInputToken);
 629     if (GSS_ERROR(major))
 630         goto cleanup;
 631
 632     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 633         *minor = GSSEAP_CRED_MECH_MISMATCH;
 634         major = GSS_S_BAD_MECH;
 635         goto cleanup;
 636     }
 637
 638 #ifdef GSSEAP_ENABLE_REAUTH
 639     /*
 640      * If we're built with fast reauthentication support, it's valid
 641      * for an initiator to send a GSS reauthentication token as its
 642      * initial context token, causing us to short-circuit the state
 643      * machine and process Kerberos GSS messages instead.
 644      */
 645     if (tokType == TOK_TYPE_GSS_REAUTH && initialContextToken) {
 646         ctx->state = GSSEAP_STATE_KRB_REAUTH;
 647     } else
 648 #endif
 649     if (tokType != sm->inputTokenType) {
 650         *minor = GSSEAP_WRONG_TOK_ID;
 651         major = GSS_S_DEFECTIVE_TOKEN;
 652         goto cleanup;
 653     }
 654
 655     do {
 656         sm = &eapGssAcceptorSm[ctx->state];
 657
 658         major = (sm->processToken)(minor,
 659                                    ctx,
 660                                    cred,
 661                                    &innerInputToken,
 662                                    input_chan_bindings,
 663                                    &innerOutputToken);
 664         if (GSS_ERROR(major)) {
 665             /* Possibly generate an error token */
 666             tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &innerOutputToken);
 667             if (GSS_ERROR(tmpMajor)) {
 668                 major = tmpMajor;
 669                 goto cleanup;
 670             }
 671
 672             sm = &eapGssAcceptorSm[GSSEAP_STATE_ERROR];
 673             goto send_token;
 674         }
 675     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 676
 677     if (mech_type != NULL) {
 678         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
 679             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
 680     }
 681     if (ret_flags != NULL)
 682         *ret_flags = ctx->gssFlags;
 683     if (delegated_cred_handle != NULL)
 684         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 685
 686     if (major == GSS_S_COMPLETE) {
 687         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 688             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
 689             if (GSS_ERROR(major))
 690                 goto cleanup;
 691         }
 692         if (time_rec != NULL) {
 693             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
 694             if (GSS_ERROR(major))
 695                 goto cleanup;
 696         }
 697     }
 698
 699     assert(ctx->state == GSSEAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 700
 701 send_token:
 702     if (innerOutputToken.value != NULL) {
 703         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 704                                    sm->outputTokenType, output_token);
 705         if (GSS_ERROR(tmpMajor)) {
 706             major = tmpMajor;
 707             *minor = tmpMinor;
 708             goto cleanup;
 709         }
 710     }
 711
 712 cleanup:
 713     if (cred != GSS_C_NO_CREDENTIAL)
 714         GSSEAP_MUTEX_UNLOCK(&cred->mutex);
 715     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 716
 717     if (GSS_ERROR(major))
 718         gssEapReleaseContext(&tmpMinor, context_handle);
 719
 720     gss_release_buffer(&tmpMinor, &innerOutputToken);
 721
 722     return major;
 723 }
 724
 725 #ifdef GSSEAP_ENABLE_REAUTH
 726 static OM_uint32
 727 acceptReadyKrb(OM_uint32 *minor,
 728                gss_ctx_id_t ctx,
 729                gss_cred_id_t cred,
 730                const gss_name_t initiator,
 731                const gss_OID mech,
 732                OM_uint32 timeRec)
 733 {
 734     OM_uint32 major;
 735
 736     major = gssEapGlueToMechName(minor, ctx, initiator, &ctx->initiatorName);
 737     if (GSS_ERROR(major))
 738         return major;
 739
 740     if (cred->name != GSS_C_NO_NAME) {
 741         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 742         if (GSS_ERROR(major))
 743             return major;
 744     }
 745
 746     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 747     if (GSS_ERROR(major))
 748         return major;
 749
 750     ctx->state = GSSEAP_STATE_ESTABLISHED;
 751
 752     *minor = 0;
 753     return GSS_S_COMPLETE;
 754 }
 755
 756 static OM_uint32
 757 eapGssSmAcceptGssReauth(OM_uint32 *minor,
 758                         gss_ctx_id_t ctx,
 759                         gss_cred_id_t cred,
 760                         gss_buffer_t inputToken,
 761                         gss_channel_bindings_t chanBindings,
 762                         gss_buffer_t outputToken)
 763 {
 764     OM_uint32 major, tmpMinor;
 765     gss_name_t krbInitiator = GSS_C_NO_NAME;
 766     gss_OID mech = GSS_C_NO_OID;
 767     OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
 768
 769     ctx->flags |= CTX_FLAG_KRB_REAUTH;
 770
 771     major = gssAcceptSecContext(minor,
 772                                 &ctx->kerberosCtx,
 773                                 cred->krbCred,
 774                                 inputToken,
 775                                 chanBindings,
 776                                 &krbInitiator,
 777                                 &mech,
 778                                 outputToken,
 779                                 &gssFlags,
 780                                 &timeRec,
 781                                 NULL);
 782     if (major == GSS_S_COMPLETE) {
 783         major = acceptReadyKrb(minor, ctx, cred,
 784                                krbInitiator, mech, timeRec);
 785     }
 786
 787     ctx->gssFlags = gssFlags;
 788
 789     gssReleaseName(&tmpMinor, &krbInitiator);
 790
 791     return major;
 792 }
 793 #endif /* GSSEAP_ENABLE_REAUTH */