accept_sec_context.c

   1 /*
   2  * Copyright (c) 2010, JANET(UK)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. Neither the name of JANET(UK) nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  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 != GSS_C_NO_CREDENTIAL && 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(krb5_princ_size(krbContext, krbPrinc) >= 2);
 201
 202     /* Acceptor-Service-Name */
 203     krbDataToGssBuffer(krb5_princ_component(krbContext, 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     krbDataToGssBuffer(krb5_princ_component(krbContext, 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 (krb5_princ_size(krbContext, krbPrinc) > 2) {
 223         /* Acceptor-Service-Specific */
 224         krb5_principal_data ssiPrinc = *krbPrinc;
 225         char *ssi;
 226
 227         krb5_princ_size(krbContext, &ssiPrinc) -= 2;
 228         krb5_princ_name(krbContext, &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     krbDataToGssBuffer(krb5_princ_realm(krbContext, 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 != GSS_C_NO_CREDENTIAL) {
 288         if (cred->radiusConfigFile != NULL)
 289             configFile = cred->radiusConfigFile;
 290         if (cred->radiusConfigStanza != NULL)
 291             configStanza = cred->radiusConfigStanza;
 292     }
 293
 294     ralloc.calloc  = GSSEAP_CALLOC;
 295     ralloc.malloc  = GSSEAP_MALLOC;
 296     ralloc.free    = GSSEAP_FREE;
 297     ralloc.realloc = GSSEAP_REALLOC;
 298
 299     rs_context_set_alloc_scheme(actx->radContext, &ralloc);
 300
 301     if (rs_context_read_config(actx->radContext, configFile) != 0) {
 302         err = rs_err_ctx_pop(actx->radContext);
 303         goto fail;
 304     }
 305
 306     if (rs_conn_create(actx->radContext, &actx->radConn, configStanza) != 0) {
 307         err = rs_err_conn_pop(actx->radConn);
 308         goto fail;
 309     }
 310
 311     if (actx->radServer != NULL) {
 312         if (rs_conn_select_server(actx->radConn, actx->radServer) != 0) {
 313             err = rs_err_conn_pop(actx->radConn);
 314             goto fail;
 315         }
 316     }
 317
 318     *minor = 0;
 319     return GSS_S_COMPLETE;
 320
 321 fail:
 322     return gssEapRadiusMapError(minor, err);
 323 }
 324
 325 /*
 326  * Process a EAP response from the initiator.
 327  */
 328 static OM_uint32
 329 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 330                            gss_ctx_id_t ctx,
 331                            gss_cred_id_t cred,
 332                            gss_buffer_t inputToken,
 333                            gss_channel_bindings_t chanBindings,
 334                            gss_buffer_t outputToken)
 335 {
 336     OM_uint32 major, tmpMinor;
 337     struct rs_connection *rconn;
 338     struct rs_request *request = NULL;
 339     struct rs_packet *req = NULL, *resp = NULL;
 340     struct radius_packet *frreq, *frresp;
 341     int sendAcceptorIdentity = 0;
 342
 343     if (ctx->acceptorCtx.radContext == NULL) {
 344         /* May be NULL from an imported partial context */
 345         major = createRadiusHandle(minor, cred, ctx);
 346         if (GSS_ERROR(major))
 347             goto cleanup;
 348
 349         sendAcceptorIdentity = 1;
 350     }
 351
 352     rconn = ctx->acceptorCtx.radConn;
 353
 354     if (rs_packet_create_acc_request(rconn, &req, NULL, NULL) != 0) {
 355         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 356         goto cleanup;
 357     }
 358     frreq = rs_packet_frpkt(req);
 359
 360     if (sendAcceptorIdentity) {
 361         major = setAcceptorIdentity(minor, ctx, &frreq->vps);
 362         if (GSS_ERROR(major))
 363             goto cleanup;
 364     }
 365
 366     major = gssEapRadiusAddAvp(minor, &frreq->vps,
 367                                PW_EAP_MESSAGE, 0, inputToken);
 368     if (GSS_ERROR(major))
 369         goto cleanup;
 370
 371     if (ctx->acceptorCtx.state.length != 0) {
 372         major = gssEapRadiusAddAvp(minor, &frreq->vps, PW_STATE, 0,
 373                                    &ctx->acceptorCtx.state);
 374         if (GSS_ERROR(major))
 375             goto cleanup;
 376
 377         gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
 378     }
 379
 380     if (rs_request_create(rconn, &request) != 0 ||
 381         rs_request_send(request, req, &resp) != 0) {
 382         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 383         goto cleanup;
 384     }
 385
 386     assert(resp != NULL);
 387
 388     frresp = rs_packet_frpkt(resp);
 389     switch (frresp->code) {
 390     case PW_AUTHENTICATION_ACK:
 391     case PW_ACCESS_CHALLENGE:
 392         major = GSS_S_CONTINUE_NEEDED;
 393         break;
 394     case PW_AUTHENTICATION_REJECT:
 395         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
 396         major = GSS_S_DEFECTIVE_CREDENTIAL;
 397         goto cleanup;
 398         break;
 399     default:
 400         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
 401         major = GSS_S_FAILURE;
 402         goto cleanup;
 403         break;
 404     }
 405
 406     major = gssEapRadiusGetAvp(minor, frresp->vps, PW_EAP_MESSAGE, 0,
 407                                outputToken, TRUE);
 408     if (major == GSS_S_UNAVAILABLE && frresp->code == PW_ACCESS_CHALLENGE) {
 409         *minor = GSSEAP_MISSING_EAP_REQUEST;
 410         major = GSS_S_DEFECTIVE_TOKEN;
 411         goto cleanup;
 412     } else if (GSS_ERROR(major))
 413         goto cleanup;
 414
 415     if (frresp->code == PW_ACCESS_CHALLENGE) {
 416         major = gssEapRadiusGetAvp(minor, frresp->vps, PW_STATE, 0,
 417                                    &ctx->acceptorCtx.state, TRUE);
 418         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
 419             goto cleanup;
 420     } else {
 421         ctx->acceptorCtx.vps = frresp->vps;
 422         frresp->vps = NULL;
 423
 424         rs_conn_destroy(ctx->acceptorCtx.radConn);
 425         ctx->acceptorCtx.radConn = NULL;
 426
 427         major = acceptReadyEap(minor, ctx, cred);
 428         if (GSS_ERROR(major))
 429             goto cleanup;
 430
 431         ctx->state = GSSEAP_STATE_EXTENSIONS_REQ;
 432     }
 433
 434     *minor = 0;
 435     major = GSS_S_CONTINUE_NEEDED;
 436
 437 cleanup:
 438     rs_request_destroy(request);
 439
 440     return major;
 441 }
 442
 443 static OM_uint32
 444 eapGssSmAcceptExtensionsReq(OM_uint32 *minor,
 445                             gss_ctx_id_t ctx,
 446                             gss_cred_id_t cred,
 447                             gss_buffer_t inputToken,
 448                             gss_channel_bindings_t chanBindings,
 449                             gss_buffer_t outputToken)
 450 {
 451     OM_uint32 major;
 452
 453     major = gssEapVerifyExtensions(minor, cred, ctx, chanBindings, inputToken);
 454     if (GSS_ERROR(major))
 455         return major;
 456
 457     outputToken->length = 0;
 458     outputToken->value = NULL;
 459
 460     ctx->state = GSSEAP_STATE_EXTENSIONS_RESP;
 461
 462     *minor = 0;
 463     return GSS_S_CONTINUE_NEEDED;
 464 }
 465
 466 static OM_uint32
 467 eapGssSmAcceptExtensionsResp(OM_uint32 *minor,
 468                              gss_ctx_id_t ctx,
 469                              gss_cred_id_t cred,
 470                              gss_buffer_t inputToken,
 471                              gss_channel_bindings_t chanBindings,
 472                              gss_buffer_t outputToken)
 473 {
 474     OM_uint32 major;
 475
 476     major = gssEapMakeExtensions(minor, cred, ctx, chanBindings, outputToken);
 477     if (GSS_ERROR(major))
 478         return major;
 479
 480     ctx->state = GSSEAP_STATE_ESTABLISHED;
 481
 482     *minor = 0;
 483     return GSS_S_COMPLETE;
 484 }
 485
 486 static OM_uint32
 487 eapGssSmAcceptEstablished(OM_uint32 *minor,
 488                           gss_ctx_id_t ctx,
 489                           gss_cred_id_t cred,
 490                           gss_buffer_t inputToken,
 491                           gss_channel_bindings_t chanBindings,
 492                           gss_buffer_t outputToken)
 493 {
 494     /* Called with already established context */
 495     *minor = GSSEAP_CONTEXT_ESTABLISHED;
 496     return GSS_S_BAD_STATUS;
 497 }
 498
 499 static OM_uint32
 500 makeErrorToken(OM_uint32 *minor,
 501                OM_uint32 majorStatus,
 502                OM_uint32 minorStatus,
 503                gss_buffer_t outputToken)
 504 {
 505     unsigned char errorData[8];
 506     gss_buffer_desc errorBuffer;
 507
 508     assert(GSS_ERROR(majorStatus));
 509
 510     /*
 511      * Only return error codes that the initiator could have caused,
 512      * to avoid information leakage.
 513      */
 514     switch (minorStatus) {
 515     case GSSEAP_WRONG_SIZE:
 516     case GSSEAP_WRONG_MECH:
 517     case GSSEAP_BAD_TOK_HEADER:
 518     case GSSEAP_TOK_TRUNC:
 519     case GSSEAP_BAD_DIRECTION:
 520     case GSSEAP_WRONG_TOK_ID:
 521     case GSSEAP_CRIT_EXT_UNAVAILABLE:
 522     case GSSEAP_MISSING_REQUIRED_EXT:
 523     case GSSEAP_KEY_UNAVAILABLE:
 524     case GSSEAP_KEY_TOO_SHORT:
 525     case GSSEAP_RADIUS_AUTH_FAILURE:
 526     case GSSEAP_UNKNOWN_RADIUS_CODE:
 527     case GSSEAP_MISSING_EAP_REQUEST:
 528         break;
 529     default:
 530         if (IS_RADIUS_ERROR(minorStatus))
 531             /* Squash RADIUS error codes */
 532             minorStatus = GSSEAP_RADIUS_PROT_FAILURE;
 533         else
 534             /* Don't return system error codes */
 535             return GSS_S_COMPLETE;
 536     }
 537
 538     minorStatus -= ERROR_TABLE_BASE_eapg;
 539
 540     store_uint32_be(majorStatus, &errorData[0]);
 541     store_uint32_be(minorStatus, &errorData[4]);
 542
 543     errorBuffer.length = sizeof(errorData);
 544     errorBuffer.value = errorData;
 545
 546     return duplicateBuffer(minor, &errorBuffer, outputToken);
 547 }
 548
 549 static struct gss_eap_acceptor_sm {
 550     enum gss_eap_token_type inputTokenType;
 551     enum gss_eap_token_type outputTokenType;
 552     OM_uint32 (*processToken)(OM_uint32 *,
 553                               gss_ctx_id_t,
 554                               gss_cred_id_t,
 555                               gss_buffer_t,
 556                               gss_channel_bindings_t,
 557                               gss_buffer_t);
 558 } eapGssAcceptorSm[] = {
 559     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptIdentity           },
 560     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptAuthenticate       },
 561     { TOK_TYPE_EXT_REQ,     TOK_TYPE_NONE,          eapGssSmAcceptExtensionsReq      },
 562     { TOK_TYPE_NONE,        TOK_TYPE_EXT_RESP,      eapGssSmAcceptExtensionsResp     },
 563     { TOK_TYPE_NONE,        TOK_TYPE_NONE,          eapGssSmAcceptEstablished        },
 564     { TOK_TYPE_NONE,        TOK_TYPE_CONTEXT_ERR,   NULL                             },
 565 #ifdef GSSEAP_ENABLE_REAUTH
 566     { TOK_TYPE_GSS_REAUTH,  TOK_TYPE_GSS_REAUTH,    eapGssSmAcceptGssReauth          },
 567 #endif
 568 };
 569
 570 OM_uint32
 571 gss_accept_sec_context(OM_uint32 *minor,
 572                        gss_ctx_id_t *context_handle,
 573                        gss_cred_id_t cred,
 574                        gss_buffer_t input_token,
 575                        gss_channel_bindings_t input_chan_bindings,
 576                        gss_name_t *src_name,
 577                        gss_OID *mech_type,
 578                        gss_buffer_t output_token,
 579                        OM_uint32 *ret_flags,
 580                        OM_uint32 *time_rec,
 581                        gss_cred_id_t *delegated_cred_handle)
 582 {
 583     OM_uint32 major;
 584     OM_uint32 tmpMajor, tmpMinor;
 585     gss_ctx_id_t ctx = *context_handle;
 586     struct gss_eap_acceptor_sm *sm = NULL;
 587     gss_buffer_desc innerInputToken = GSS_C_EMPTY_BUFFER;
 588     gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 589     enum gss_eap_token_type tokType;
 590     int initialContextToken = 0;
 591
 592     *minor = 0;
 593
 594     output_token->length = 0;
 595     output_token->value = NULL;
 596
 597     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
 598         *minor = GSSEAP_TOK_TRUNC;
 599         return GSS_S_DEFECTIVE_TOKEN;
 600     }
 601
 602     if (ctx == GSS_C_NO_CONTEXT) {
 603         major = gssEapAllocContext(minor, &ctx);
 604         if (GSS_ERROR(major))
 605             return major;
 606
 607         initialContextToken = 1;
 608         *context_handle = ctx;
 609     }
 610
 611     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 612
 613     /* Validate and lock credentials */
 614     if (cred != GSS_C_NO_CREDENTIAL) {
 615         GSSEAP_MUTEX_LOCK(&cred->mutex);
 616
 617         if ((cred->flags & CRED_FLAG_ACCEPT) == 0) {
 618             *minor = GSSEAP_CRED_USAGE_MISMATCH;
 619             major = GSS_S_NO_CRED;
 620             goto cleanup;
 621         }
 622     }
 623
 624     sm = &eapGssAcceptorSm[ctx->state];
 625
 626     major = gssEapVerifyToken(minor, ctx, input_token,
 627                               &tokType, &innerInputToken);
 628     if (GSS_ERROR(major))
 629         goto cleanup;
 630
 631     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 632         *minor = GSSEAP_CRED_MECH_MISMATCH;
 633         major = GSS_S_BAD_MECH;
 634         goto cleanup;
 635     }
 636
 637 #ifdef GSSEAP_ENABLE_REAUTH
 638     /*
 639      * If we're built with fast reauthentication support, it's valid
 640      * for an initiator to send a GSS reauthentication token as its
 641      * initial context token, causing us to short-circuit the state
 642      * machine and process Kerberos GSS messages instead.
 643      */
 644     if (tokType == TOK_TYPE_GSS_REAUTH && initialContextToken) {
 645         ctx->state = GSSEAP_STATE_KRB_REAUTH;
 646     } else
 647 #endif
 648     if (tokType != sm->inputTokenType) {
 649         *minor = GSSEAP_WRONG_TOK_ID;
 650         major = GSS_S_DEFECTIVE_TOKEN;
 651         goto cleanup;
 652     }
 653
 654     do {
 655         sm = &eapGssAcceptorSm[ctx->state];
 656
 657         major = (sm->processToken)(minor,
 658                                    ctx,
 659                                    cred,
 660                                    &innerInputToken,
 661                                    input_chan_bindings,
 662                                    &innerOutputToken);
 663         if (GSS_ERROR(major)) {
 664             /* Possibly generate an error token */
 665             tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &innerOutputToken);
 666             if (GSS_ERROR(tmpMajor)) {
 667                 major = tmpMajor;
 668                 goto cleanup;
 669             }
 670
 671             sm = &eapGssAcceptorSm[GSSEAP_STATE_ERROR];
 672             goto send_token;
 673         }
 674     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 675
 676     if (mech_type != NULL) {
 677         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
 678             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
 679     }
 680     if (ret_flags != NULL)
 681         *ret_flags = ctx->gssFlags;
 682     if (delegated_cred_handle != NULL)
 683         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 684
 685     if (major == GSS_S_COMPLETE) {
 686         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 687             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
 688             if (GSS_ERROR(major))
 689                 goto cleanup;
 690         }
 691         if (time_rec != NULL) {
 692             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
 693             if (GSS_ERROR(major))
 694                 goto cleanup;
 695         }
 696     }
 697
 698     assert(ctx->state == GSSEAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 699
 700 send_token:
 701     if (innerOutputToken.value != NULL) {
 702         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 703                                    sm->outputTokenType, output_token);
 704         if (GSS_ERROR(tmpMajor)) {
 705             major = tmpMajor;
 706             *minor = tmpMinor;
 707             goto cleanup;
 708         }
 709     }
 710
 711 cleanup:
 712     if (cred != GSS_C_NO_CREDENTIAL)
 713         GSSEAP_MUTEX_UNLOCK(&cred->mutex);
 714     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 715
 716     if (GSS_ERROR(major))
 717         gssEapReleaseContext(&tmpMinor, context_handle);
 718
 719     gss_release_buffer(&tmpMinor, &innerOutputToken);
 720
 721     return major;
 722 }
 723
 724 #ifdef GSSEAP_ENABLE_REAUTH
 725 static OM_uint32
 726 acceptReadyKrb(OM_uint32 *minor,
 727                gss_ctx_id_t ctx,
 728                gss_cred_id_t cred,
 729                const gss_name_t initiator,
 730                const gss_OID mech,
 731                OM_uint32 timeRec)
 732 {
 733     OM_uint32 major;
 734
 735     major = gssEapGlueToMechName(minor, initiator, &ctx->initiatorName);
 736     if (GSS_ERROR(major))
 737         return major;
 738
 739     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
 740         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 741         if (GSS_ERROR(major))
 742             return major;
 743     }
 744
 745     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 746     if (GSS_ERROR(major))
 747         return major;
 748
 749     ctx->state = GSSEAP_STATE_ESTABLISHED;
 750
 751     *minor = 0;
 752     return GSS_S_COMPLETE;
 753 }
 754
 755 static OM_uint32
 756 eapGssSmAcceptGssReauth(OM_uint32 *minor,
 757                         gss_ctx_id_t ctx,
 758                         gss_cred_id_t cred,
 759                         gss_buffer_t inputToken,
 760                         gss_channel_bindings_t chanBindings,
 761                         gss_buffer_t outputToken)
 762 {
 763     OM_uint32 major, tmpMinor;
 764     gss_cred_id_t krbCred = GSS_C_NO_CREDENTIAL;
 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     if (cred != GSS_C_NO_CREDENTIAL)
 772         krbCred = cred->krbCred;
 773
 774     major = gssAcceptSecContext(minor,
 775                                 &ctx->kerberosCtx,
 776                                 krbCred,
 777                                 inputToken,
 778                                 chanBindings,
 779                                 &krbInitiator,
 780                                 &mech,
 781                                 outputToken,
 782                                 &gssFlags,
 783                                 &timeRec,
 784                                 NULL);
 785     if (major == GSS_S_COMPLETE) {
 786         major = acceptReadyKrb(minor, ctx, cred,
 787                                krbInitiator, mech, timeRec);
 788     }
 789
 790     ctx->gssFlags = gssFlags;
 791
 792     gssReleaseName(&tmpMinor, &krbInitiator);
 793
 794     return major;
 795 }
 796 #endif /* GSSEAP_ENABLE_REAUTH */