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     ctx->initiatorName->attrCtx = gssEapCreateAttrContext(cred, ctx);
 111
 112     *minor = 0;
 113     return GSS_S_COMPLETE;
 114 }
 115
 116 /*
 117  * Emit a identity EAP request to force the initiator (peer) to identify
 118  * itself.
 119  */
 120 static OM_uint32
 121 eapGssSmAcceptIdentity(OM_uint32 *minor,
 122                        gss_ctx_id_t ctx,
 123                        gss_cred_id_t cred,
 124                        gss_buffer_t inputToken,
 125                        gss_channel_bindings_t chanBindings,
 126                        gss_buffer_t outputToken)
 127 {
 128     OM_uint32 major;
 129     union {
 130         struct eap_hdr pdu;
 131         unsigned char data[5];
 132     } pkt;
 133     gss_buffer_desc pktBuffer;
 134
 135     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
 136         *minor = GSSEAP_WRONG_SIZE;
 137         return GSS_S_DEFECTIVE_TOKEN;
 138     }
 139
 140     assert(ctx->acceptorName == GSS_C_NO_NAME);
 141
 142     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
 143         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 144         if (GSS_ERROR(major))
 145             return major;
 146     }
 147
 148     pkt.pdu.code = EAP_CODE_REQUEST;
 149     pkt.pdu.identifier = 0;
 150     pkt.pdu.length = htons(sizeof(pkt.data));
 151     pkt.data[4] = EAP_TYPE_IDENTITY;
 152
 153     pktBuffer.length = sizeof(pkt.data);
 154     pktBuffer.value = pkt.data;
 155
 156     major = duplicateBuffer(minor, &pktBuffer, outputToken);
 157     if (GSS_ERROR(major))
 158         return major;
 159
 160     ctx->state = EAP_STATE_AUTHENTICATE;
 161
 162     *minor = 0;
 163     return GSS_S_CONTINUE_NEEDED;
 164 }
 165
 166 /*
 167  * Pass the asserted acceptor identity to the authentication server.
 168  */
 169 static OM_uint32
 170 setAcceptorIdentity(OM_uint32 *minor,
 171                     gss_ctx_id_t ctx,
 172                     VALUE_PAIR **vps)
 173 {
 174     OM_uint32 major;
 175     gss_buffer_desc nameBuf;
 176     krb5_context krbContext = NULL;
 177     krb5_principal krbPrinc;
 178     struct rs_context *rc = ctx->acceptorCtx.radContext;
 179
 180     assert(rc != NULL);
 181
 182     if (ctx->acceptorName == GSS_C_NO_NAME) {
 183         *minor = 0;
 184         return GSS_S_COMPLETE;
 185     }
 186
 187     if ((ctx->acceptorName->flags & NAME_FLAG_SERVICE) == 0) {
 188         *minor = GSSEAP_BAD_SERVICE_NAME;
 189         return GSS_S_BAD_NAME;
 190     }
 191
 192     GSSEAP_KRB_INIT(&krbContext);
 193
 194     krbPrinc = ctx->acceptorName->krbPrincipal;
 195     assert(krbPrinc != NULL);
 196     assert(krb5_princ_size(krbContext, krbPrinc) >= 2);
 197
 198     /* Acceptor-Service-Name */
 199     krbDataToGssBuffer(krb5_princ_component(krbContext, krbPrinc, 0), &nameBuf);
 200
 201     major = gssEapRadiusAddAvp(minor, vps,
 202                                PW_GSS_ACCEPTOR_SERVICE_NAME,
 203                                VENDORPEC_UKERNA,
 204                                &nameBuf);
 205     if (GSS_ERROR(major))
 206         return major;
 207
 208     /* Acceptor-Host-Name */
 209     krbDataToGssBuffer(krb5_princ_component(krbContext, krbPrinc, 1), &nameBuf);
 210
 211     major = gssEapRadiusAddAvp(minor, vps,
 212                                PW_GSS_ACCEPTOR_HOST_NAME,
 213                                VENDORPEC_UKERNA,
 214                                &nameBuf);
 215     if (GSS_ERROR(major))
 216         return major;
 217
 218     if (krb5_princ_size(krbContext, krbPrinc) > 2) {
 219         /* Acceptor-Service-Specific */
 220         krb5_principal_data ssiPrinc = *krbPrinc;
 221         char *ssi;
 222
 223         krb5_princ_size(krbContext, &ssiPrinc) -= 2;
 224         krb5_princ_name(krbContext, &ssiPrinc) += 2;
 225
 226         *minor = krb5_unparse_name_flags(krbContext, &ssiPrinc,
 227                                          KRB5_PRINCIPAL_UNPARSE_NO_REALM, &ssi);
 228         if (*minor != 0)
 229             return GSS_S_FAILURE;
 230
 231         nameBuf.value = ssi;
 232         nameBuf.length = strlen(ssi);
 233
 234         major = gssEapRadiusAddAvp(minor, vps,
 235                                    PW_GSS_ACCEPTOR_SERVICE_SPECIFIC,
 236                                    VENDORPEC_UKERNA,
 237                                    &nameBuf);
 238
 239         if (GSS_ERROR(major)) {
 240             krb5_free_unparsed_name(krbContext, ssi);
 241             return major;
 242         }
 243         krb5_free_unparsed_name(krbContext, ssi);
 244     }
 245
 246     krbDataToGssBuffer(krb5_princ_realm(krbContext, krbPrinc), &nameBuf);
 247     if (nameBuf.length != 0) {
 248         /* Acceptor-Realm-Name */
 249         major = gssEapRadiusAddAvp(minor, vps,
 250                                    PW_GSS_ACCEPTOR_REALM_NAME,
 251                                    VENDORPEC_UKERNA,
 252                                    &nameBuf);
 253         if (GSS_ERROR(major))
 254             return major;
 255     }
 256
 257     *minor = 0;
 258     return GSS_S_COMPLETE;
 259 }
 260
 261 /*
 262  * Allocate a RadSec handle
 263  */
 264 static OM_uint32
 265 createRadiusHandle(OM_uint32 *minor,
 266                    gss_cred_id_t cred,
 267                    gss_ctx_id_t ctx)
 268 {
 269     struct gss_eap_acceptor_ctx *actx = &ctx->acceptorCtx;
 270     const char *configFile = RS_CONFIG_FILE;
 271     const char *configStanza = "gss-eap";
 272     struct rs_alloc_scheme ralloc;
 273     struct rs_error *err;
 274
 275     assert(actx->radContext == NULL);
 276     assert(actx->radConn == NULL);
 277
 278     if (rs_context_create(&actx->radContext, RS_DICT_FILE) != 0) {
 279         *minor = GSSEAP_RADSEC_CONTEXT_FAILURE;
 280         return GSS_S_FAILURE;
 281     }
 282
 283     if (cred != GSS_C_NO_CREDENTIAL) {
 284         if (cred->radiusConfigFile != NULL)
 285             configFile = cred->radiusConfigFile;
 286         if (cred->radiusConfigStanza != NULL)
 287             configStanza = cred->radiusConfigStanza;
 288     }
 289
 290     ralloc.calloc  = GSSEAP_CALLOC;
 291     ralloc.malloc  = GSSEAP_MALLOC;
 292     ralloc.free    = GSSEAP_FREE;
 293     ralloc.realloc = GSSEAP_REALLOC;
 294
 295     rs_context_set_alloc_scheme(actx->radContext, &ralloc);
 296
 297     if (rs_context_read_config(actx->radContext, configFile) != 0) {
 298         err = rs_err_ctx_pop(actx->radContext);
 299         goto fail;
 300     }
 301
 302     if (rs_conn_create(actx->radContext, &actx->radConn, configStanza) != 0) {
 303         err = rs_err_conn_pop(actx->radConn);
 304         goto fail;
 305     }
 306
 307     /* XXX TODO rs_conn_select_server does not exist yet */
 308 #if 0
 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 #endif
 316
 317     *minor = 0;
 318     return GSS_S_COMPLETE;
 319
 320 fail:
 321     return gssEapRadiusMapError(minor, err);
 322 }
 323
 324 /*
 325  * Process a EAP response from the initiator.
 326  */
 327 static OM_uint32
 328 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 329                            gss_ctx_id_t ctx,
 330                            gss_cred_id_t cred,
 331                            gss_buffer_t inputToken,
 332                            gss_channel_bindings_t chanBindings,
 333                            gss_buffer_t outputToken)
 334 {
 335     OM_uint32 major, tmpMinor;
 336     struct rs_connection *rconn;
 337     struct rs_request *request = NULL;
 338     struct rs_packet *req = NULL, *resp = NULL;
 339     struct radius_packet *frreq, *frresp;
 340     int sendAcceptorIdentity = 0;
 341
 342     if (ctx->acceptorCtx.radContext == NULL) {
 343         /* May be NULL from an imported partial context */
 344         major = createRadiusHandle(minor, cred, ctx);
 345         if (GSS_ERROR(major))
 346             goto cleanup;
 347
 348         sendAcceptorIdentity = 1;
 349     }
 350
 351     rconn = ctx->acceptorCtx.radConn;
 352
 353     if (rs_packet_create_acc_request(rconn, &req, NULL, NULL) != 0) {
 354         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 355         goto cleanup;
 356     }
 357     frreq = rs_packet_frpkt(req);
 358
 359     if (sendAcceptorIdentity) {
 360         major = setAcceptorIdentity(minor, ctx, &frreq->vps);
 361         if (GSS_ERROR(major))
 362             goto cleanup;
 363     }
 364
 365     major = gssEapRadiusAddAvp(minor, &frreq->vps,
 366                                PW_EAP_MESSAGE, 0, inputToken);
 367     if (GSS_ERROR(major))
 368         goto cleanup;
 369
 370     if (ctx->acceptorCtx.state.length != 0) {
 371         major = gssEapRadiusAddAvp(minor, &frreq->vps, PW_STATE, 0,
 372                                    &ctx->acceptorCtx.state);
 373         if (GSS_ERROR(major))
 374             goto cleanup;
 375
 376         gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
 377     }
 378
 379     if (rs_request_create(rconn, &request) != 0 ||
 380         rs_request_send(request, req, &resp) != 0) {
 381         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 382         goto cleanup;
 383     }
 384
 385     assert(resp != NULL);
 386
 387     frresp = rs_packet_frpkt(resp);
 388     switch (frresp->code) {
 389     case PW_AUTHENTICATION_ACK:
 390     case PW_ACCESS_CHALLENGE:
 391         major = GSS_S_CONTINUE_NEEDED;
 392         break;
 393     case PW_AUTHENTICATION_REJECT:
 394         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
 395         major = GSS_S_DEFECTIVE_CREDENTIAL;
 396         goto cleanup;
 397         break;
 398     default:
 399         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
 400         major = GSS_S_FAILURE;
 401         goto cleanup;
 402         break;
 403     }
 404
 405     major = gssEapRadiusGetAvp(minor, frresp->vps, PW_EAP_MESSAGE, 0,
 406                                outputToken, TRUE);
 407     if (major == GSS_S_UNAVAILABLE && frresp->code == PW_ACCESS_CHALLENGE) {
 408         *minor = GSSEAP_MISSING_EAP_REQUEST;
 409         major = GSS_S_DEFECTIVE_TOKEN;
 410         goto cleanup;
 411     } else if (GSS_ERROR(major))
 412         goto cleanup;
 413
 414     if (frresp->code == PW_ACCESS_CHALLENGE) {
 415         major = gssEapRadiusGetAvp(minor, frresp->vps, PW_STATE, 0,
 416                                    &ctx->acceptorCtx.state, TRUE);
 417         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
 418             goto cleanup;
 419     } else {
 420         ctx->acceptorCtx.vps = frresp->vps;
 421         frresp->vps = NULL;
 422
 423         rs_conn_destroy(ctx->acceptorCtx.radConn);
 424         ctx->acceptorCtx.radConn = NULL;
 425
 426         major = acceptReadyEap(minor, ctx, cred);
 427         if (GSS_ERROR(major))
 428             goto cleanup;
 429
 430         ctx->state = EAP_STATE_EXTENSIONS_REQ;
 431     }
 432
 433     *minor = 0;
 434     major = GSS_S_CONTINUE_NEEDED;
 435
 436 cleanup:
 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 = EAP_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 = EAP_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     switch (minorStatus) {
 514     case GSSEAP_WRONG_SIZE:
 515     case GSSEAP_WRONG_MECH:
 516     case GSSEAP_BAD_TOK_HEADER:
 517     case GSSEAP_TOK_TRUNC:
 518     case GSSEAP_BAD_DIRECTION:
 519     case GSSEAP_WRONG_TOK_ID:
 520     case GSSEAP_CRIT_EXT_UNAVAILABLE:
 521     case GSSEAP_MISSING_REQUIRED_EXT:
 522     case GSSEAP_KEY_UNAVAILABLE:
 523     case GSSEAP_KEY_TOO_SHORT:
 524     case GSSEAP_RADIUS_AUTH_FAILURE:
 525     case GSSEAP_UNKNOWN_RADIUS_CODE:
 526     case GSSEAP_MISSING_EAP_REQUEST:
 527         break;
 528     default:
 529         if (IS_RADIUS_ERROR(minorStatus))
 530             /* Squash RADIUS error codes */
 531             minorStatus = GSSEAP_GENERIC_RADIUS_ERROR;
 532         else
 533             /* Don't return system error codes */
 534             return GSS_S_COMPLETE;
 535     }
 536
 537     minorStatus -= ERROR_TABLE_BASE_eapg;
 538
 539     store_uint32_be(majorStatus, &errorData[0]);
 540     store_uint32_be(minorStatus, &errorData[4]);
 541
 542     errorBuffer.length = sizeof(errorData);
 543     errorBuffer.value = errorData;
 544
 545     return duplicateBuffer(minor, &errorBuffer, outputToken);
 546 }
 547
 548 static struct gss_eap_acceptor_sm {
 549     enum gss_eap_token_type inputTokenType;
 550     enum gss_eap_token_type outputTokenType;
 551     OM_uint32 (*processToken)(OM_uint32 *,
 552                               gss_ctx_id_t,
 553                               gss_cred_id_t,
 554                               gss_buffer_t,
 555                               gss_channel_bindings_t,
 556                               gss_buffer_t);
 557 } eapGssAcceptorSm[] = {
 558     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptIdentity           },
 559     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,       eapGssSmAcceptAuthenticate       },
 560     { TOK_TYPE_EXT_REQ,     TOK_TYPE_NONE,          eapGssSmAcceptExtensionsReq      },
 561     { TOK_TYPE_NONE,        TOK_TYPE_EXT_RESP,      eapGssSmAcceptExtensionsResp     },
 562     { TOK_TYPE_NONE,        TOK_TYPE_NONE,          eapGssSmAcceptEstablished        },
 563     { TOK_TYPE_NONE,        TOK_TYPE_CONTEXT_ERR,   NULL                             },
 564 #ifdef GSSEAP_ENABLE_REAUTH
 565     { TOK_TYPE_GSS_REAUTH,  TOK_TYPE_GSS_REAUTH,    eapGssSmAcceptGssReauth          },
 566 #endif
 567 };
 568
 569 OM_uint32
 570 gss_accept_sec_context(OM_uint32 *minor,
 571                        gss_ctx_id_t *context_handle,
 572                        gss_cred_id_t cred,
 573                        gss_buffer_t input_token,
 574                        gss_channel_bindings_t input_chan_bindings,
 575                        gss_name_t *src_name,
 576                        gss_OID *mech_type,
 577                        gss_buffer_t output_token,
 578                        OM_uint32 *ret_flags,
 579                        OM_uint32 *time_rec,
 580                        gss_cred_id_t *delegated_cred_handle)
 581 {
 582     OM_uint32 major;
 583     OM_uint32 tmpMajor, tmpMinor;
 584     gss_ctx_id_t ctx = *context_handle;
 585     struct gss_eap_acceptor_sm *sm = NULL;
 586     gss_buffer_desc innerInputToken = GSS_C_EMPTY_BUFFER;
 587     gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 588     enum gss_eap_token_type tokType;
 589     int initialContextToken = 0;
 590
 591     *minor = 0;
 592
 593     output_token->length = 0;
 594     output_token->value = NULL;
 595
 596     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
 597         *minor = GSSEAP_TOK_TRUNC;
 598         return GSS_S_DEFECTIVE_TOKEN;
 599     }
 600
 601     if (ctx == GSS_C_NO_CONTEXT) {
 602         major = gssEapAllocContext(minor, &ctx);
 603         if (GSS_ERROR(major))
 604             return major;
 605
 606         initialContextToken = 1;
 607         *context_handle = ctx;
 608     }
 609
 610     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 611
 612     /* Validate and lock credentials */
 613     if (cred != GSS_C_NO_CREDENTIAL) {
 614         GSSEAP_MUTEX_LOCK(&cred->mutex);
 615
 616         if ((cred->flags & CRED_FLAG_ACCEPT) == 0) {
 617             *minor = GSSEAP_CRED_USAGE_MISMATCH;
 618             major = GSS_S_NO_CRED;
 619             goto cleanup;
 620         }
 621     }
 622
 623     sm = &eapGssAcceptorSm[ctx->state];
 624
 625     major = gssEapVerifyToken(minor, ctx, input_token,
 626                               &tokType, &innerInputToken);
 627     if (GSS_ERROR(major))
 628         goto cleanup;
 629
 630     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 631         *minor = GSSEAP_CRED_MECH_MISMATCH;
 632         major = GSS_S_BAD_MECH;
 633         goto cleanup;
 634     }
 635
 636 #ifdef GSSEAP_ENABLE_REAUTH
 637     /*
 638      * If we're built with fast reauthentication support, it's valid
 639      * for an initiator to send a GSS reauthentication token as its
 640      * initial context token, causing us to short-circuit the state
 641      * machine and process Kerberos GSS messages instead.
 642      */
 643     if (tokType == TOK_TYPE_GSS_REAUTH && initialContextToken) {
 644         ctx->state = EAP_STATE_KRB_REAUTH_GSS;
 645     } else
 646 #endif
 647     if (tokType != sm->inputTokenType) {
 648         *minor = GSSEAP_WRONG_TOK_ID;
 649         major = GSS_S_DEFECTIVE_TOKEN;
 650         goto cleanup;
 651     }
 652
 653     do {
 654         sm = &eapGssAcceptorSm[ctx->state];
 655
 656         major = (sm->processToken)(minor,
 657                                    ctx,
 658                                    cred,
 659                                    &innerInputToken,
 660                                    input_chan_bindings,
 661                                    &innerOutputToken);
 662         if (GSS_ERROR(major)) {
 663             /* Possibly generate an error token */
 664             tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &innerOutputToken);
 665             if (GSS_ERROR(tmpMajor)) {
 666                 major = tmpMajor;
 667                 goto cleanup;
 668             }
 669
 670             sm = &eapGssAcceptorSm[EAP_STATE_ERROR];
 671             goto send_token;
 672         }
 673     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 674
 675     if (mech_type != NULL) {
 676         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
 677             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
 678     }
 679     if (ret_flags != NULL)
 680         *ret_flags = ctx->gssFlags;
 681     if (delegated_cred_handle != NULL)
 682         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 683
 684     if (major == GSS_S_COMPLETE) {
 685         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 686             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
 687             if (GSS_ERROR(major))
 688                 goto cleanup;
 689         }
 690         if (time_rec != NULL) {
 691             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
 692             if (GSS_ERROR(major))
 693                 goto cleanup;
 694         }
 695     }
 696
 697     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 698
 699 send_token:
 700     if (innerOutputToken.value != NULL) {
 701         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 702                                    sm->outputTokenType, output_token);
 703         if (GSS_ERROR(tmpMajor)) {
 704             major = tmpMajor;
 705             *minor = tmpMinor;
 706             goto cleanup;
 707         }
 708     }
 709
 710 cleanup:
 711     if (cred != GSS_C_NO_CREDENTIAL)
 712         GSSEAP_MUTEX_UNLOCK(&cred->mutex);
 713     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 714
 715     if (GSS_ERROR(major))
 716         gssEapReleaseContext(&tmpMinor, context_handle);
 717
 718     gss_release_buffer(&tmpMinor, &innerOutputToken);
 719
 720     return major;
 721 }
 722
 723 #ifdef GSSEAP_ENABLE_REAUTH
 724 static OM_uint32
 725 acceptReadyKrb(OM_uint32 *minor,
 726                gss_ctx_id_t ctx,
 727                gss_cred_id_t cred,
 728                const gss_name_t initiator,
 729                const gss_OID mech,
 730                OM_uint32 timeRec)
 731 {
 732     OM_uint32 major;
 733
 734     major = gssEapGlueToMechName(minor, initiator, &ctx->initiatorName);
 735     if (GSS_ERROR(major))
 736         return major;
 737
 738     if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
 739         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 740         if (GSS_ERROR(major))
 741             return major;
 742     }
 743
 744     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 745     if (GSS_ERROR(major))
 746         return major;
 747
 748     ctx->state = EAP_STATE_ESTABLISHED;
 749
 750     *minor = 0;
 751     return GSS_S_COMPLETE;
 752 }
 753
 754 static OM_uint32
 755 eapGssSmAcceptGssReauth(OM_uint32 *minor,
 756                         gss_ctx_id_t ctx,
 757                         gss_cred_id_t cred,
 758                         gss_buffer_t inputToken,
 759                         gss_channel_bindings_t chanBindings,
 760                         gss_buffer_t outputToken)
 761 {
 762     OM_uint32 major, tmpMinor;
 763     gss_cred_id_t krbCred = GSS_C_NO_CREDENTIAL;
 764     gss_name_t krbInitiator = GSS_C_NO_NAME;
 765     gss_OID mech = GSS_C_NO_OID;
 766     OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
 767
 768     ctx->flags |= CTX_FLAG_KRB_REAUTH_GSS;
 769
 770     if (cred != GSS_C_NO_CREDENTIAL)
 771         krbCred = cred->krbCred;
 772
 773     major = gssAcceptSecContext(minor,
 774                                 &ctx->kerberosCtx,
 775                                 krbCred,
 776                                 inputToken,
 777                                 chanBindings,
 778                                 &krbInitiator,
 779                                 &mech,
 780                                 outputToken,
 781                                 &gssFlags,
 782                                 &timeRec,
 783                                 NULL);
 784     if (major == GSS_S_COMPLETE) {
 785         major = acceptReadyKrb(minor, ctx, cred,
 786                                krbInitiator, mech, timeRec);
 787     }
 788
 789     ctx->gssFlags = gssFlags;
 790
 791     gssReleaseName(&tmpMinor, &krbInitiator);
 792
 793     return major;
 794 }
 795 #endif /* GSSEAP_ENABLE_REAUTH */