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_server(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_auth_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         rs_request_send(request, req, &resp) != 0) {
 380         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 381         goto cleanup;
 382     }
 383
 384     assert(resp != NULL);
 385
 386     frresp = rs_packet_frpkt(resp);
 387     switch (frresp->code) {
 388     case PW_AUTHENTICATION_ACK:
 389     case PW_ACCESS_CHALLENGE:
 390         major = GSS_S_CONTINUE_NEEDED;
 391         break;
 392     case PW_AUTHENTICATION_REJECT:
 393         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
 394         major = GSS_S_DEFECTIVE_CREDENTIAL;
 395         goto cleanup;
 396         break;
 397     default:
 398         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
 399         major = GSS_S_FAILURE;
 400         goto cleanup;
 401         break;
 402     }
 403
 404     major = gssEapRadiusGetAvp(minor, frresp->vps, PW_EAP_MESSAGE, 0,
 405                                outputToken, TRUE);
 406     if (major == GSS_S_UNAVAILABLE && frresp->code == PW_ACCESS_CHALLENGE) {
 407         *minor = GSSEAP_MISSING_EAP_REQUEST;
 408         major = GSS_S_DEFECTIVE_TOKEN;
 409         goto cleanup;
 410     } else if (GSS_ERROR(major))
 411         goto cleanup;
 412
 413     if (frresp->code == PW_ACCESS_CHALLENGE) {
 414         major = gssEapRadiusGetAvp(minor, frresp->vps, PW_STATE, 0,
 415                                    &ctx->acceptorCtx.state, TRUE);
 416         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
 417             goto cleanup;
 418     } else {
 419         ctx->acceptorCtx.vps = frresp->vps;
 420         frresp->vps = NULL;
 421
 422         rs_conn_destroy(ctx->acceptorCtx.radConn);
 423         ctx->acceptorCtx.radConn = NULL;
 424
 425         major = acceptReadyEap(minor, ctx, cred);
 426         if (GSS_ERROR(major))
 427             goto cleanup;
 428
 429         ctx->state = GSSEAP_STATE_EXTENSIONS_REQ;
 430     }
 431
 432     *minor = 0;
 433     major = GSS_S_CONTINUE_NEEDED;
 434
 435 cleanup:
 436     if (request)
 437       rs_request_destroy(request);
 438
 439     return major;
 440 }
 441
 442 static OM_uint32
 443 eapGssSmAcceptExtensionsReq(OM_uint32 *minor,
 444                             gss_ctx_id_t ctx,
 445                             gss_cred_id_t cred,
 446                             gss_buffer_t inputToken,
 447                             gss_channel_bindings_t chanBindings,
 448                             gss_buffer_t outputToken)
 449 {
 450     OM_uint32 major;
 451
 452     major = gssEapVerifyExtensions(minor, cred, ctx, chanBindings, inputToken);
 453     if (GSS_ERROR(major))
 454         return major;
 455
 456     outputToken->length = 0;
 457     outputToken->value = NULL;
 458
 459     ctx->state = GSSEAP_STATE_EXTENSIONS_RESP;
 460
 461     *minor = 0;
 462     return GSS_S_CONTINUE_NEEDED;
 463 }
 464
 465 static OM_uint32
 466 eapGssSmAcceptExtensionsResp(OM_uint32 *minor,
 467                              gss_ctx_id_t ctx,
 468                              gss_cred_id_t cred,
 469                              gss_buffer_t inputToken,
 470                              gss_channel_bindings_t chanBindings,
 471                              gss_buffer_t outputToken)
 472 {
 473     OM_uint32 major;
 474
 475     major = gssEapMakeExtensions(minor, cred, ctx, chanBindings, outputToken);
 476     if (GSS_ERROR(major))
 477         return major;
 478
 479     ctx->state = GSSEAP_STATE_ESTABLISHED;
 480
 481     *minor = 0;
 482     return GSS_S_COMPLETE;
 483 }
 484
 485 static OM_uint32
 486 eapGssSmAcceptEstablished(OM_uint32 *minor,
 487                           gss_ctx_id_t ctx,
 488                           gss_cred_id_t cred,
 489                           gss_buffer_t inputToken,
 490                           gss_channel_bindings_t chanBindings,
 491                           gss_buffer_t outputToken)
 492 {
 493     /* Called with already established context */
 494     *minor = GSSEAP_CONTEXT_ESTABLISHED;
 495     return GSS_S_BAD_STATUS;
 496 }
 497
 498 static OM_uint32
 499 makeErrorToken(OM_uint32 *minor,
 500                OM_uint32 majorStatus,
 501                OM_uint32 minorStatus,
 502                gss_buffer_t outputToken)
 503 {
 504     unsigned char errorData[8];
 505     gss_buffer_desc errorBuffer;
 506
 507     assert(GSS_ERROR(majorStatus));
 508
 509     /*
 510      * Only return error codes that the initiator could have caused,
 511      * to avoid information leakage.
 512      */
 513     if (IS_RADIUS_ERROR(minorStatus)) {
 514         /* Squash RADIUS error codes */
 515         minorStatus = GSSEAP_RADIUS_PROT_FAILURE;
 516     } else if (!IS_WIRE_ERROR(minorStatus)) {
 517         /* Don't return non-wire error codes */
 518         return GSS_S_COMPLETE;
 519     }
 520
 521     minorStatus -= ERROR_TABLE_BASE_eapg;
 522
 523     store_uint32_be(majorStatus, &errorData[0]);
 524     store_uint32_be(minorStatus, &errorData[4]);
 525
 526     errorBuffer.length = sizeof(errorData);
 527     errorBuffer.value = errorData;
 528
 529     return duplicateBuffer(minor, &errorBuffer, outputToken);
 530 }
 531
 532 static struct gss_eap_acceptor_sm {
 533     enum gss_eap_token_type inputTokenType;
 534     enum gss_eap_token_type outputTokenType;
 535     OM_uint32 (*processToken)(OM_uint32 *,
 536                               gss_ctx_id_t,
 537                               gss_cred_id_t,
 538                               gss_buffer_t,
 539                               gss_channel_bindings_t,
 540                               gss_buffer_t);
 541 } eapGssAcceptorSm[] = {
 542     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptIdentity           },
 543     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptAuthenticate       },
 544     { TOK_TYPE_EXT_REQ,     TOK_TYPE_NONE,          eapGssSmAcceptExtensionsReq      },
 545     { TOK_TYPE_NONE,        TOK_TYPE_EXT_RESP,      eapGssSmAcceptExtensionsResp     },
 546     { TOK_TYPE_NONE,        TOK_TYPE_NONE,          eapGssSmAcceptEstablished        },
 547     { TOK_TYPE_NONE,        TOK_TYPE_CONTEXT_ERR,   NULL                             },
 548 #ifdef GSSEAP_ENABLE_REAUTH
 549     { TOK_TYPE_GSS_REAUTH,  TOK_TYPE_GSS_REAUTH,    eapGssSmAcceptGssReauth          },
 550 #endif
 551 };
 552
 553 OM_uint32
 554 gss_accept_sec_context(OM_uint32 *minor,
 555                        gss_ctx_id_t *context_handle,
 556                        gss_cred_id_t cred,
 557                        gss_buffer_t input_token,
 558                        gss_channel_bindings_t input_chan_bindings,
 559                        gss_name_t *src_name,
 560                        gss_OID *mech_type,
 561                        gss_buffer_t output_token,
 562                        OM_uint32 *ret_flags,
 563                        OM_uint32 *time_rec,
 564                        gss_cred_id_t *delegated_cred_handle)
 565 {
 566     OM_uint32 major;
 567     OM_uint32 tmpMajor, tmpMinor;
 568     gss_ctx_id_t ctx = *context_handle;
 569     struct gss_eap_acceptor_sm *sm = NULL;
 570     gss_buffer_desc innerInputToken = GSS_C_EMPTY_BUFFER;
 571     gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 572     enum gss_eap_token_type tokType;
 573     int initialContextToken = 0;
 574
 575     *minor = 0;
 576
 577     output_token->length = 0;
 578     output_token->value = NULL;
 579
 580     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
 581         *minor = GSSEAP_TOK_TRUNC;
 582         return GSS_S_DEFECTIVE_TOKEN;
 583     }
 584
 585     if (ctx == GSS_C_NO_CONTEXT) {
 586         major = gssEapAllocContext(minor, &ctx);
 587         if (GSS_ERROR(major))
 588             return major;
 589
 590         initialContextToken = 1;
 591         *context_handle = ctx;
 592     }
 593
 594     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 595
 596     if (cred == GSS_C_NO_CREDENTIAL) {
 597         if (ctx->defaultCred == GSS_C_NO_CREDENTIAL) {
 598             major = gssEapAcquireCred(minor,
 599                                       GSS_C_NO_NAME,
 600                                       GSS_C_NO_BUFFER,
 601                                       GSS_C_INDEFINITE,
 602                                       GSS_C_NO_OID_SET,
 603                                       GSS_C_ACCEPT,
 604                                       &ctx->defaultCred,
 605                                       NULL,
 606                                       NULL);
 607             if (GSS_ERROR(major))
 608                 goto cleanup;
 609         }
 610
 611         cred = ctx->defaultCred;
 612     }
 613
 614     GSSEAP_MUTEX_LOCK(&cred->mutex);
 615
 616     sm = &eapGssAcceptorSm[ctx->state];
 617
 618     major = gssEapVerifyToken(minor, ctx, input_token,
 619                               &tokType, &innerInputToken);
 620     if (GSS_ERROR(major))
 621         goto cleanup;
 622
 623     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 624         *minor = GSSEAP_CRED_MECH_MISMATCH;
 625         major = GSS_S_BAD_MECH;
 626         goto cleanup;
 627     }
 628
 629 #ifdef GSSEAP_ENABLE_REAUTH
 630     /*
 631      * If we're built with fast reauthentication support, it's valid
 632      * for an initiator to send a GSS reauthentication token as its
 633      * initial context token, causing us to short-circuit the state
 634      * machine and process Kerberos GSS messages instead.
 635      */
 636     if (tokType == TOK_TYPE_GSS_REAUTH && initialContextToken) {
 637         ctx->state = GSSEAP_STATE_KRB_REAUTH;
 638     } else
 639 #endif
 640     if (tokType != sm->inputTokenType) {
 641         *minor = GSSEAP_WRONG_TOK_ID;
 642         major = GSS_S_DEFECTIVE_TOKEN;
 643         goto cleanup;
 644     }
 645
 646     do {
 647         sm = &eapGssAcceptorSm[ctx->state];
 648
 649         major = (sm->processToken)(minor,
 650                                    ctx,
 651                                    cred,
 652                                    &innerInputToken,
 653                                    input_chan_bindings,
 654                                    &innerOutputToken);
 655         if (GSS_ERROR(major)) {
 656             /* Possibly generate an error token */
 657             tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &innerOutputToken);
 658             if (GSS_ERROR(tmpMajor)) {
 659                 major = tmpMajor;
 660                 goto cleanup;
 661             }
 662
 663             sm = &eapGssAcceptorSm[GSSEAP_STATE_ERROR];
 664             goto send_token;
 665         }
 666     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 667
 668     if (mech_type != NULL) {
 669         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
 670             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
 671     }
 672     if (ret_flags != NULL)
 673         *ret_flags = ctx->gssFlags;
 674     if (delegated_cred_handle != NULL)
 675         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 676
 677     if (major == GSS_S_COMPLETE) {
 678         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 679             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
 680             if (GSS_ERROR(major))
 681                 goto cleanup;
 682         }
 683         if (time_rec != NULL) {
 684             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
 685             if (GSS_ERROR(major))
 686                 goto cleanup;
 687         }
 688     }
 689
 690     assert(ctx->state == GSSEAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 691
 692 send_token:
 693     if (innerOutputToken.value != NULL) {
 694         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 695                                    sm->outputTokenType, output_token);
 696         if (GSS_ERROR(tmpMajor)) {
 697             major = tmpMajor;
 698             *minor = tmpMinor;
 699             goto cleanup;
 700         }
 701     }
 702
 703 cleanup:
 704     if (cred != GSS_C_NO_CREDENTIAL)
 705         GSSEAP_MUTEX_UNLOCK(&cred->mutex);
 706     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 707
 708     if (GSS_ERROR(major))
 709         gssEapReleaseContext(&tmpMinor, context_handle);
 710
 711     gss_release_buffer(&tmpMinor, &innerOutputToken);
 712
 713     return major;
 714 }
 715
 716 #ifdef GSSEAP_ENABLE_REAUTH
 717 static OM_uint32
 718 acceptReadyKrb(OM_uint32 *minor,
 719                gss_ctx_id_t ctx,
 720                gss_cred_id_t cred,
 721                const gss_name_t initiator,
 722                const gss_OID mech,
 723                OM_uint32 timeRec)
 724 {
 725     OM_uint32 major;
 726
 727     major = gssEapGlueToMechName(minor, ctx, initiator, &ctx->initiatorName);
 728     if (GSS_ERROR(major))
 729         return major;
 730
 731     if (cred->name != GSS_C_NO_NAME) {
 732         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 733         if (GSS_ERROR(major))
 734             return major;
 735     }
 736
 737     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 738     if (GSS_ERROR(major))
 739         return major;
 740
 741     ctx->state = GSSEAP_STATE_ESTABLISHED;
 742
 743     *minor = 0;
 744     return GSS_S_COMPLETE;
 745 }
 746
 747 static OM_uint32
 748 eapGssSmAcceptGssReauth(OM_uint32 *minor,
 749                         gss_ctx_id_t ctx,
 750                         gss_cred_id_t cred,
 751                         gss_buffer_t inputToken,
 752                         gss_channel_bindings_t chanBindings,
 753                         gss_buffer_t outputToken)
 754 {
 755     OM_uint32 major, tmpMinor;
 756     gss_name_t krbInitiator = GSS_C_NO_NAME;
 757     gss_OID mech = GSS_C_NO_OID;
 758     OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
 759
 760     ctx->flags |= CTX_FLAG_KRB_REAUTH;
 761
 762     major = gssAcceptSecContext(minor,
 763                                 &ctx->kerberosCtx,
 764                                 cred->krbCred,
 765                                 inputToken,
 766                                 chanBindings,
 767                                 &krbInitiator,
 768                                 &mech,
 769                                 outputToken,
 770                                 &gssFlags,
 771                                 &timeRec,
 772                                 NULL);
 773     if (major == GSS_S_COMPLETE) {
 774         major = acceptReadyKrb(minor, ctx, cred,
 775                                krbInitiator, mech, timeRec);
 776     }
 777
 778     ctx->gssFlags = gssFlags;
 779
 780     gssReleaseName(&tmpMinor, &krbInitiator);
 781
 782     return major;
 783 }
 784 #endif /* GSSEAP_ENABLE_REAUTH */