mech_eap/accept_sec_context.c

   1 /*
   2  * Copyright (c) 2011, JANET(UK)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. Neither the name of JANET(UK) nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * Establish a security context on the acceptor (server). These functions
  35  * wrap around libradsec and (thus) talk to a RADIUS server or proxy.
  36  */
  37
  38 #include "gssapiP_eap.h"
  39
  40 #ifdef GSSEAP_ENABLE_REAUTH
  41 static OM_uint32
  42 eapGssSmAcceptGssReauth(OM_uint32 *minor,
  43                         gss_cred_id_t cred,
  44                         gss_ctx_id_t ctx,
  45                         gss_name_t target,
  46                         gss_OID mech,
  47                         OM_uint32 reqFlags,
  48                         OM_uint32 timeReq,
  49                         gss_channel_bindings_t chanBindings,
  50                         gss_buffer_t inputToken,
  51                         gss_buffer_t outputToken,
  52                         OM_uint32 *smFlags);
  53 #endif
  54
  55 /*
  56  * Mark an acceptor context as ready for cryptographic operations
  57  */
  58 static OM_uint32
  59 acceptReadyEap(OM_uint32 *minor, gss_ctx_id_t ctx, gss_cred_id_t cred)
  60 {
  61     OM_uint32 major, tmpMinor;
  62     rs_const_avp *vp;
  63     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
  64
  65     /* Cache encryption type derived from selected mechanism OID */
  66     major = gssEapOidToEnctype(minor, ctx->mechanismUsed,
  67                                &ctx->encryptionType);
  68     if (GSS_ERROR(major))
  69         return major;
  70
  71     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
  72
  73     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
  74                                   PW_USER_NAME, 0, &vp);
  75     if (major == GSS_S_COMPLETE && rs_avp_length(vp) != 0) {
  76         rs_avp_octets_value_byref((rs_avp *)vp,
  77                                   (unsigned char **)&nameBuf.value,
  78                                   &nameBuf.length);
  79     } else {
  80         ctx->gssFlags |= GSS_C_ANON_FLAG;
  81     }
  82
  83     major = gssEapImportName(minor, &nameBuf,
  84                              (ctx->gssFlags & GSS_C_ANON_FLAG) ?
  85                                 GSS_C_NT_ANONYMOUS : GSS_C_NT_USER_NAME,
  86                              ctx->mechanismUsed,
  87                              &ctx->initiatorName);
  88     if (GSS_ERROR(major))
  89         return major;
  90
  91     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
  92                                   PW_MS_MPPE_SEND_KEY, VENDORPEC_MICROSOFT, &vp);
  93     if (GSS_ERROR(major)) {
  94         *minor = GSSEAP_KEY_UNAVAILABLE;
  95         return GSS_S_UNAVAILABLE;
  96     }
  97
  98     major = gssEapDeriveRfc3961Key(minor,
  99                                    rs_avp_octets_value_const_ptr(vp),
 100                                    rs_avp_length(vp),
 101                                    ctx->encryptionType,
 102                                    &ctx->rfc3961Key);
 103     if (GSS_ERROR(major))
 104         return major;
 105
 106     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 107                                        &ctx->checksumType);
 108     if (GSS_ERROR(major))
 109         return major;
 110
 111     major = sequenceInit(minor,
 112                          &ctx->seqState, ctx->recvSeq,
 113                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 114                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 115                          TRUE);
 116     if (GSS_ERROR(major))
 117         return major;
 118
 119     major = gssEapCreateAttrContext(minor, cred, ctx,
 120                                     &ctx->initiatorName->attrCtx,
 121                                     &ctx->expiryTime);
 122     if (GSS_ERROR(major))
 123         return major;
 124
 125     if (ctx->expiryTime != 0 && ctx->expiryTime < time(NULL)) {
 126         *minor = GSSEAP_CRED_EXPIRED;
 127         return GSS_S_CREDENTIALS_EXPIRED;
 128     }
 129
 130     *minor = 0;
 131     return GSS_S_COMPLETE;
 132 }
 133
 134 static OM_uint32
 135 eapGssSmAcceptAcceptorName(OM_uint32 *minor,
 136                            gss_cred_id_t cred GSSEAP_UNUSED,
 137                            gss_ctx_id_t ctx,
 138                            gss_name_t target GSSEAP_UNUSED,
 139                            gss_OID mech GSSEAP_UNUSED,
 140                            OM_uint32 reqFlags GSSEAP_UNUSED,
 141                            OM_uint32 timeReq GSSEAP_UNUSED,
 142                            gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 143                            gss_buffer_t inputToken GSSEAP_UNUSED,
 144                            gss_buffer_t outputToken,
 145                            OM_uint32 *smFlags GSSEAP_UNUSED)
 146 {
 147     OM_uint32 major;
 148
 149     /* XXX TODO import and validate name from inputToken */
 150
 151     if (ctx->acceptorName != GSS_C_NO_NAME) {
 152         /* Send desired target name to acceptor */
 153         major = gssEapDisplayName(minor, ctx->acceptorName,
 154                                   outputToken, NULL);
 155         if (GSS_ERROR(major))
 156             return major;
 157     }
 158
 159     return GSS_S_CONTINUE_NEEDED;
 160 }
 161
 162 #ifdef GSSEAP_DEBUG
 163 static OM_uint32
 164 eapGssSmAcceptVendorInfo(OM_uint32 *minor,
 165                          gss_cred_id_t cred GSSEAP_UNUSED,
 166                          gss_ctx_id_t ctx GSSEAP_UNUSED,
 167                          gss_name_t target GSSEAP_UNUSED,
 168                          gss_OID mech GSSEAP_UNUSED,
 169                          OM_uint32 reqFlags GSSEAP_UNUSED,
 170                          OM_uint32 timeReq GSSEAP_UNUSED,
 171                          gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 172                          gss_buffer_t inputToken,
 173                          gss_buffer_t outputToken GSSEAP_UNUSED,
 174                          OM_uint32 *smFlags GSSEAP_UNUSED)
 175 {
 176     fprintf(stderr, "GSS-EAP: vendor: %.*s\n",
 177             (int)inputToken->length, (char *)inputToken->value);
 178
 179     *minor = 0;
 180     return GSS_S_CONTINUE_NEEDED;
 181 }
 182 #endif
 183
 184
 185 /*
 186  * Emit a identity EAP request to force the initiator (peer) to identify
 187  * itself.
 188  */
 189 static OM_uint32
 190 eapGssSmAcceptIdentity(OM_uint32 *minor,
 191                        gss_cred_id_t cred,
 192                        gss_ctx_id_t ctx,
 193                        gss_name_t target GSSEAP_UNUSED,
 194                        gss_OID mech GSSEAP_UNUSED,
 195                        OM_uint32 reqFlags GSSEAP_UNUSED,
 196                        OM_uint32 timeReq GSSEAP_UNUSED,
 197                        gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 198                        gss_buffer_t inputToken,
 199                        gss_buffer_t outputToken,
 200                        OM_uint32 *smFlags)
 201 {
 202     OM_uint32 major;
 203     struct wpabuf *reqData;
 204     gss_buffer_desc pktBuffer;
 205
 206     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 207         *minor = GSSEAP_CRED_MECH_MISMATCH;
 208         return GSS_S_BAD_MECH;
 209     }
 210
 211     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
 212         *minor = GSSEAP_WRONG_SIZE;
 213         return GSS_S_DEFECTIVE_TOKEN;
 214     }
 215
 216     reqData = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IDENTITY, 0,
 217                             EAP_CODE_REQUEST, 0);
 218     if (reqData == NULL) {
 219         *minor = ENOMEM;
 220         return GSS_S_FAILURE;
 221     }
 222
 223     pktBuffer.length = wpabuf_len(reqData);
 224     pktBuffer.value = (void *)wpabuf_head(reqData);
 225
 226     major = duplicateBuffer(minor, &pktBuffer, outputToken);
 227     if (GSS_ERROR(major))
 228         return major;
 229
 230     wpabuf_free(reqData);
 231
 232     GSSEAP_SM_TRANSITION_NEXT(ctx);
 233
 234     *minor = 0;
 235     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 236
 237     return GSS_S_CONTINUE_NEEDED;
 238 }
 239
 240 /*
 241  * Returns TRUE if the input token contains an EAP identity response.
 242  */
 243 static int
 244 isIdentityResponseP(gss_buffer_t inputToken)
 245 {
 246     struct wpabuf respData;
 247
 248     wpabuf_set(&respData, inputToken->value, inputToken->length);
 249
 250     return (eap_get_type(&respData) == EAP_TYPE_IDENTITY);
 251 }
 252
 253 /*
 254  * Save the asserted initiator identity from the EAP identity response.
 255  */
 256 static OM_uint32
 257 importInitiatorIdentity(OM_uint32 *minor,
 258                         gss_ctx_id_t ctx,
 259                         gss_buffer_t inputToken)
 260 {
 261     OM_uint32 tmpMinor;
 262     struct wpabuf respData;
 263     const unsigned char *pos;
 264     size_t len;
 265     gss_buffer_desc nameBuf;
 266
 267     wpabuf_set(&respData, inputToken->value, inputToken->length);
 268
 269     pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IDENTITY,
 270                            &respData, &len);
 271     if (pos == NULL) {
 272         *minor = GSSEAP_PEER_BAD_MESSAGE;
 273         return GSS_S_DEFECTIVE_TOKEN;
 274     }
 275
 276     nameBuf.value = (void *)pos;
 277     nameBuf.length = len;
 278
 279     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
 280
 281     return gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
 282                             ctx->mechanismUsed, &ctx->initiatorName);
 283 }
 284
 285 /*
 286  * Pass the asserted initiator identity to the authentication server.
 287  */
 288 static OM_uint32
 289 setInitiatorIdentity(OM_uint32 *minor,
 290                      gss_ctx_id_t ctx,
 291                      struct rs_packet *req)
 292 {
 293     OM_uint32 major, tmpMinor;
 294     gss_buffer_desc nameBuf;
 295
 296     /*
 297      * We should have got an EAP identity response, but if we didn't, then
 298      * we will just avoid sending User-Name. Note that radsecproxy requires
 299      * User-Name to be sent on every request (presumably so it can remain
 300      * stateless).
 301      */
 302     if (ctx->initiatorName != GSS_C_NO_NAME) {
 303         major = gssEapDisplayName(minor, ctx->initiatorName, &nameBuf, NULL);
 304         if (GSS_ERROR(major))
 305             return major;
 306
 307         major = gssEapRadiusAddAvp(minor, req, PW_USER_NAME, 0, &nameBuf);
 308         if (GSS_ERROR(major))
 309             return major;
 310
 311         gss_release_buffer(&tmpMinor, &nameBuf);
 312     }
 313
 314     *minor = 0;
 315     return GSS_S_COMPLETE;
 316 }
 317
 318 /*
 319  * Pass the asserted acceptor identity to the authentication server.
 320  */
 321 static OM_uint32
 322 setAcceptorIdentity(OM_uint32 *minor,
 323                     gss_ctx_id_t ctx,
 324                     struct rs_packet *req)
 325 {
 326     OM_uint32 major;
 327     gss_buffer_desc nameBuf;
 328     krb5_context krbContext = NULL;
 329     krb5_principal krbPrinc;
 330     struct rs_context *rc = ctx->acceptorCtx.radContext;
 331
 332     GSSEAP_ASSERT(rc != NULL);
 333
 334     if (ctx->acceptorName == GSS_C_NO_NAME) {
 335         *minor = 0;
 336         return GSS_S_COMPLETE;
 337     }
 338
 339     if ((ctx->acceptorName->flags & NAME_FLAG_SERVICE) == 0) {
 340         *minor = GSSEAP_BAD_SERVICE_NAME;
 341         return GSS_S_BAD_NAME;
 342     }
 343
 344     GSSEAP_KRB_INIT(&krbContext);
 345
 346     krbPrinc = ctx->acceptorName->krbPrincipal;
 347     GSSEAP_ASSERT(krbPrinc != NULL);
 348     GSSEAP_ASSERT(KRB_PRINC_LENGTH(krbPrinc) >= 2);
 349
 350     /* Acceptor-Service-Name */
 351     krbPrincComponentToGssBuffer(krbPrinc, 0, &nameBuf);
 352
 353     major = gssEapRadiusAddAvp(minor, req,
 354                                PW_GSS_ACCEPTOR_SERVICE_NAME,
 355                                0,
 356                                &nameBuf);
 357     if (GSS_ERROR(major))
 358         return major;
 359
 360     /* Acceptor-Host-Name */
 361     krbPrincComponentToGssBuffer(krbPrinc, 1, &nameBuf);
 362
 363     major = gssEapRadiusAddAvp(minor, req,
 364                                PW_GSS_ACCEPTOR_HOST_NAME,
 365                                0,
 366                                &nameBuf);
 367     if (GSS_ERROR(major))
 368         return major;
 369
 370     if (KRB_PRINC_LENGTH(krbPrinc) > 2) {
 371         /* Acceptor-Service-Specific */
 372         *minor = krbPrincUnparseServiceSpecifics(krbContext,
 373                                                  krbPrinc, &nameBuf);
 374         if (*minor != 0)
 375             return GSS_S_FAILURE;
 376
 377         major = gssEapRadiusAddAvp(minor, req,
 378                                    PW_GSS_ACCEPTOR_SERVICE_SPECIFICS,
 379                                    0,
 380                                    &nameBuf);
 381         krbFreeUnparsedName(krbContext, &nameBuf);
 382         if (GSS_ERROR(major))
 383             return major;
 384     }
 385
 386     krbPrincRealmToGssBuffer(krbPrinc, &nameBuf);
 387     if (nameBuf.length != 0) {
 388         /* Acceptor-Realm-Name */
 389         major = gssEapRadiusAddAvp(minor, req,
 390                                    PW_GSS_ACCEPTOR_REALM_NAME,
 391                                    0,
 392                                    &nameBuf);
 393         if (GSS_ERROR(major))
 394             return major;
 395     }
 396
 397     *minor = 0;
 398     return GSS_S_COMPLETE;
 399 }
 400
 401 /*
 402  * Allocate a RadSec handle
 403  */
 404 static OM_uint32
 405 createRadiusHandle(OM_uint32 *minor,
 406                    gss_cred_id_t cred,
 407                    gss_ctx_id_t ctx)
 408 {
 409     struct gss_eap_acceptor_ctx *actx = &ctx->acceptorCtx;
 410     struct rs_error *err;
 411     const char *configStanza = "gss-eap";
 412     OM_uint32 major;
 413
 414     GSSEAP_ASSERT(actx->radContext == NULL);
 415     GSSEAP_ASSERT(actx->radConn == NULL);
 416     GSSEAP_ASSERT(cred != GSS_C_NO_CREDENTIAL);
 417
 418     major = gssEapCreateRadiusContext(minor, cred, &actx->radContext);
 419     if (GSS_ERROR(major))
 420         return major;
 421
 422     if (cred->radiusConfigStanza.value != NULL)
 423         configStanza = (const char *)cred->radiusConfigStanza.value;
 424
 425     if (rs_conn_create(actx->radContext, &actx->radConn, configStanza) != 0) {
 426         err = rs_err_conn_pop(actx->radConn);
 427         return gssEapRadiusMapError(minor, err);
 428     }
 429
 430     if (actx->radServer != NULL) {
 431         if (rs_conn_select_peer(actx->radConn, actx->radServer) != 0) {
 432             err = rs_err_conn_pop(actx->radConn);
 433             return gssEapRadiusMapError(minor, err);
 434         }
 435     }
 436
 437     *minor = 0;
 438     return GSS_S_COMPLETE;
 439 }
 440
 441 /*
 442  * Process a EAP response from the initiator.
 443  */
 444 static OM_uint32
 445 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 446                            gss_cred_id_t cred,
 447                            gss_ctx_id_t ctx,
 448                            gss_name_t target GSSEAP_UNUSED,
 449                            gss_OID mech GSSEAP_UNUSED,
 450                            OM_uint32 reqFlags GSSEAP_UNUSED,
 451                            OM_uint32 timeReq GSSEAP_UNUSED,
 452                            gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 453                            gss_buffer_t inputToken,
 454                            gss_buffer_t outputToken,
 455                            OM_uint32 *smFlags)
 456 {
 457     OM_uint32 major, tmpMinor;
 458     struct rs_connection *rconn;
 459     struct rs_request *request = NULL;
 460     struct rs_packet *req = NULL, *resp = NULL;
 461     int isAccessChallenge;
 462
 463     if (ctx->acceptorCtx.radContext == NULL) {
 464         /* May be NULL from an imported partial context */
 465         major = createRadiusHandle(minor, cred, ctx);
 466         if (GSS_ERROR(major))
 467             goto cleanup;
 468     }
 469
 470     if (isIdentityResponseP(inputToken)) {
 471         major = importInitiatorIdentity(minor, ctx, inputToken);
 472         if (GSS_ERROR(major))
 473             return major;
 474     }
 475
 476     rconn = ctx->acceptorCtx.radConn;
 477
 478     if (rs_packet_create_authn_request(rconn, &req, NULL, NULL) != 0) {
 479         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 480         goto cleanup;
 481     }
 482
 483     major = setInitiatorIdentity(minor, ctx, req);
 484     if (GSS_ERROR(major))
 485         goto cleanup;
 486
 487     major = setAcceptorIdentity(minor, ctx, req);
 488     if (GSS_ERROR(major))
 489         goto cleanup;
 490
 491     major = gssEapRadiusAddAvp(minor, req,
 492                                PW_EAP_MESSAGE, 0, inputToken);
 493     if (GSS_ERROR(major))
 494         goto cleanup;
 495
 496     if (ctx->acceptorCtx.state.length != 0) {
 497         major = gssEapRadiusAddAvp(minor, req, PW_STATE, 0,
 498                                    &ctx->acceptorCtx.state);
 499         if (GSS_ERROR(major))
 500             goto cleanup;
 501
 502         gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
 503     }
 504
 505     if (rs_request_create(rconn, &request) != 0) {
 506         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 507         goto cleanup;
 508     }
 509
 510     rs_request_add_reqpkt(request, req);
 511     req = NULL;
 512
 513     if (rs_request_send(request, &resp) != 0) {
 514         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
 515         goto cleanup;
 516     }
 517
 518     GSSEAP_ASSERT(resp != NULL);
 519
 520     isAccessChallenge = 0;
 521
 522     switch (rs_packet_code(resp)) {
 523     case PW_ACCESS_CHALLENGE:
 524         isAccessChallenge = 1;
 525         break;
 526     case PW_ACCESS_ACCEPT:
 527         break;
 528     case PW_ACCESS_REJECT:
 529         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
 530         major = GSS_S_DEFECTIVE_CREDENTIAL;
 531         goto cleanup;
 532         break;
 533     default:
 534         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
 535         major = GSS_S_FAILURE;
 536         goto cleanup;
 537         break;
 538     }
 539
 540     major = gssEapRadiusGetAvp(minor, resp, PW_EAP_MESSAGE, 0,
 541                                outputToken, TRUE);
 542     if (major == GSS_S_UNAVAILABLE && isAccessChallenge) {
 543         *minor = GSSEAP_MISSING_EAP_REQUEST;
 544         major = GSS_S_DEFECTIVE_TOKEN;
 545         goto cleanup;
 546     } else if (GSS_ERROR(major))
 547         goto cleanup;
 548
 549     if (isAccessChallenge) {
 550         major = gssEapRadiusGetAvp(minor, resp, PW_STATE, 0,
 551                                    &ctx->acceptorCtx.state, TRUE);
 552         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
 553             goto cleanup;
 554     } else {
 555         rs_avp **vps;
 556
 557         rs_packet_avps(resp, &vps);
 558
 559         ctx->acceptorCtx.vps = *vps;
 560         *vps = NULL;
 561
 562         major = acceptReadyEap(minor, ctx, cred);
 563         if (GSS_ERROR(major))
 564             goto cleanup;
 565
 566         GSSEAP_SM_TRANSITION_NEXT(ctx);
 567     }
 568
 569     major = GSS_S_CONTINUE_NEEDED;
 570     *minor = 0;
 571     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 572
 573 cleanup:
 574     if (request != NULL)
 575         rs_request_destroy(request);
 576     if (req != NULL)
 577         rs_packet_destroy(req);
 578     if (resp != NULL)
 579         rs_packet_destroy(resp);
 580     if (GSSEAP_SM_STATE(ctx) == GSSEAP_STATE_INITIATOR_EXTS) {
 581         GSSEAP_ASSERT(major == GSS_S_CONTINUE_NEEDED);
 582
 583         rs_conn_destroy(ctx->acceptorCtx.radConn);
 584         ctx->acceptorCtx.radConn = NULL;
 585     }
 586
 587     return major;
 588 }
 589
 590 static OM_uint32
 591 eapGssSmAcceptGssFlags(OM_uint32 *minor,
 592                        gss_cred_id_t cred GSSEAP_UNUSED,
 593                        gss_ctx_id_t ctx,
 594                        gss_name_t target GSSEAP_UNUSED,
 595                        gss_OID mech GSSEAP_UNUSED,
 596                        OM_uint32 reqFlags GSSEAP_UNUSED,
 597                        OM_uint32 timeReq GSSEAP_UNUSED,
 598                        gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 599                        gss_buffer_t inputToken,
 600                        gss_buffer_t outputToken GSSEAP_UNUSED,
 601                        OM_uint32 *smFlags GSSEAP_UNUSED)
 602 {
 603     unsigned char *p;
 604     OM_uint32 initiatorGssFlags;
 605
 606     GSSEAP_ASSERT((ctx->flags & CTX_FLAG_KRB_REAUTH) == 0);
 607
 608     if (inputToken->length < 4) {
 609         *minor = GSSEAP_TOK_TRUNC;
 610         return GSS_S_DEFECTIVE_TOKEN;
 611     }
 612
 613     /* allow flags to grow for future expansion */
 614     p = (unsigned char *)inputToken->value + inputToken->length - 4;
 615
 616     initiatorGssFlags = load_uint32_be(p);
 617     initiatorGssFlags &= GSSEAP_WIRE_FLAGS_MASK;
 618
 619     ctx->gssFlags |= initiatorGssFlags;
 620
 621     return GSS_S_CONTINUE_NEEDED;
 622 }
 623
 624 static OM_uint32
 625 eapGssSmAcceptGssChannelBindings(OM_uint32 *minor,
 626                                  gss_cred_id_t cred GSSEAP_UNUSED,
 627                                  gss_ctx_id_t ctx,
 628                                  gss_name_t target GSSEAP_UNUSED,
 629                                  gss_OID mech GSSEAP_UNUSED,
 630                                  OM_uint32 reqFlags GSSEAP_UNUSED,
 631                                  OM_uint32 timeReq GSSEAP_UNUSED,
 632                                  gss_channel_bindings_t chanBindings,
 633                                  gss_buffer_t inputToken,
 634                                  gss_buffer_t outputToken GSSEAP_UNUSED,
 635                                  OM_uint32 *smFlags GSSEAP_UNUSED)
 636 {
 637     krb5_error_code code;
 638     krb5_context krbContext;
 639     krb5_data data;
 640     krb5_checksum cksum;
 641     krb5_boolean valid = FALSE;
 642
 643     if (chanBindings == GSS_C_NO_CHANNEL_BINDINGS ||
 644         chanBindings->application_data.length == 0)
 645         return GSS_S_CONTINUE_NEEDED;
 646
 647     GSSEAP_KRB_INIT(&krbContext);
 648
 649     KRB_DATA_INIT(&data);
 650
 651     gssBufferToKrbData(&chanBindings->application_data, &data);
 652
 653     KRB_CHECKSUM_INIT(&cksum, ctx->checksumType, inputToken);
 654
 655     code = krb5_c_verify_checksum(krbContext, &ctx->rfc3961Key,
 656                                   KEY_USAGE_GSSEAP_CHBIND_MIC,
 657                                   &data, &cksum, &valid);
 658     if (code != 0) {
 659         *minor = code;
 660         return GSS_S_FAILURE;
 661     }
 662
 663     if (valid == FALSE) {
 664         *minor = GSSEAP_BINDINGS_MISMATCH;
 665         return GSS_S_BAD_BINDINGS;
 666     }
 667
 668     ctx->flags |= CTX_FLAG_CHANNEL_BINDINGS_VERIFIED;
 669
 670     *minor = 0;
 671     return GSS_S_CONTINUE_NEEDED;
 672 }
 673
 674 static OM_uint32
 675 eapGssSmAcceptInitiatorMIC(OM_uint32 *minor,
 676                            gss_cred_id_t cred GSSEAP_UNUSED,
 677                            gss_ctx_id_t ctx,
 678                            gss_name_t target GSSEAP_UNUSED,
 679                            gss_OID mech GSSEAP_UNUSED,
 680                            OM_uint32 reqFlags GSSEAP_UNUSED,
 681                            OM_uint32 timeReq GSSEAP_UNUSED,
 682                            gss_channel_bindings_t chanBindings,
 683                            gss_buffer_t inputToken,
 684                            gss_buffer_t outputToken GSSEAP_UNUSED,
 685                            OM_uint32 *smFlags GSSEAP_UNUSED)
 686 {
 687     OM_uint32 major;
 688
 689     /*
 690      * The channel binding token is optional, however if the caller indicated
 691      * bindings we must raise an error if it was absent.
 692      *
 693      * In the future, we might use a context option to allow the caller to
 694      * indicate that missing bindings are acceptable.
 695      */
 696     if (chanBindings != NULL &&
 697         chanBindings->application_data.length != 0 &&
 698         (ctx->flags & CTX_FLAG_CHANNEL_BINDINGS_VERIFIED) == 0) {
 699         *minor = GSSEAP_MISSING_BINDINGS;
 700         return GSS_S_BAD_BINDINGS;
 701     }
 702
 703     major = gssEapVerifyTokenMIC(minor, ctx, inputToken);
 704     if (GSS_ERROR(major))
 705         return major;
 706
 707     GSSEAP_SM_TRANSITION_NEXT(ctx);
 708
 709     *minor = 0;
 710     return GSS_S_CONTINUE_NEEDED;
 711 }
 712
 713 #ifdef GSSEAP_ENABLE_REAUTH
 714 static OM_uint32
 715 eapGssSmAcceptReauthCreds(OM_uint32 *minor,
 716                           gss_cred_id_t cred,
 717                           gss_ctx_id_t ctx,
 718                           gss_name_t target GSSEAP_UNUSED,
 719                           gss_OID mech GSSEAP_UNUSED,
 720                           OM_uint32 reqFlags GSSEAP_UNUSED,
 721                           OM_uint32 timeReq GSSEAP_UNUSED,
 722                           gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 723                           gss_buffer_t inputToken GSSEAP_UNUSED,
 724                           gss_buffer_t outputToken,
 725                           OM_uint32 *smFlags GSSEAP_UNUSED)
 726 {
 727     OM_uint32 major;
 728
 729     /*
 730      * If we're built with fast reauthentication enabled, then
 731      * fabricate a ticket from the initiator to ourselves.
 732      */
 733     major = gssEapMakeReauthCreds(minor, ctx, cred, outputToken);
 734     if (major == GSS_S_UNAVAILABLE)
 735         major = GSS_S_COMPLETE;
 736     if (major == GSS_S_COMPLETE)
 737         major = GSS_S_CONTINUE_NEEDED;
 738
 739     return major;
 740 }
 741 #endif
 742
 743 static OM_uint32
 744 eapGssSmAcceptAcceptorMIC(OM_uint32 *minor,
 745                           gss_cred_id_t cred GSSEAP_UNUSED,
 746                           gss_ctx_id_t ctx,
 747                           gss_name_t target GSSEAP_UNUSED,
 748                           gss_OID mech GSSEAP_UNUSED,
 749                           OM_uint32 reqFlags GSSEAP_UNUSED,
 750                           OM_uint32 timeReq GSSEAP_UNUSED,
 751                           gss_channel_bindings_t chanBindings GSSEAP_UNUSED,
 752                           gss_buffer_t inputToken GSSEAP_UNUSED,
 753                           gss_buffer_t outputToken,
 754                           OM_uint32 *smFlags)
 755 {
 756     OM_uint32 major;
 757
 758     major = gssEapMakeTokenMIC(minor, ctx, outputToken);
 759     if (GSS_ERROR(major))
 760         return major;
 761
 762     GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
 763
 764     *minor = 0;
 765     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 766
 767     return GSS_S_COMPLETE;
 768 }
 769
 770 static struct gss_eap_sm eapGssAcceptorSm[] = {
 771     {
 772         ITOK_TYPE_ACCEPTOR_NAME_REQ,
 773         ITOK_TYPE_ACCEPTOR_NAME_RESP,
 774         GSSEAP_STATE_INITIAL,
 775         0,
 776         eapGssSmAcceptAcceptorName
 777     },
 778 #ifdef GSSEAP_DEBUG
 779     {
 780         ITOK_TYPE_VENDOR_INFO,
 781         ITOK_TYPE_NONE,
 782         GSSEAP_STATE_INITIAL,
 783         0,
 784         eapGssSmAcceptVendorInfo,
 785     },
 786 #endif
 787 #ifdef GSSEAP_ENABLE_REAUTH
 788     {
 789         ITOK_TYPE_REAUTH_REQ,
 790         ITOK_TYPE_REAUTH_RESP,
 791         GSSEAP_STATE_INITIAL,
 792         0,
 793         eapGssSmAcceptGssReauth,
 794     },
 795 #endif
 796     {
 797         ITOK_TYPE_NONE,
 798         ITOK_TYPE_EAP_REQ,
 799         GSSEAP_STATE_INITIAL,
 800         SM_ITOK_FLAG_REQUIRED,
 801         eapGssSmAcceptIdentity,
 802     },
 803     {
 804         ITOK_TYPE_EAP_RESP,
 805         ITOK_TYPE_EAP_REQ,
 806         GSSEAP_STATE_AUTHENTICATE,
 807         SM_ITOK_FLAG_REQUIRED,
 808         eapGssSmAcceptAuthenticate
 809     },
 810     {
 811         ITOK_TYPE_GSS_FLAGS,
 812         ITOK_TYPE_NONE,
 813         GSSEAP_STATE_INITIATOR_EXTS,
 814         0,
 815         eapGssSmAcceptGssFlags
 816     },
 817     {
 818         ITOK_TYPE_GSS_CHANNEL_BINDINGS,
 819         ITOK_TYPE_NONE,
 820         GSSEAP_STATE_INITIATOR_EXTS,
 821         0,
 822         eapGssSmAcceptGssChannelBindings,
 823     },
 824     {
 825         ITOK_TYPE_INITIATOR_MIC,
 826         ITOK_TYPE_NONE,
 827         GSSEAP_STATE_INITIATOR_EXTS,
 828         SM_ITOK_FLAG_REQUIRED,
 829         eapGssSmAcceptInitiatorMIC,
 830     },
 831 #ifdef GSSEAP_ENABLE_REAUTH
 832     {
 833         ITOK_TYPE_NONE,
 834         ITOK_TYPE_REAUTH_CREDS,
 835         GSSEAP_STATE_ACCEPTOR_EXTS,
 836         0,
 837         eapGssSmAcceptReauthCreds,
 838     },
 839 #endif
 840     {
 841         ITOK_TYPE_NONE,
 842         ITOK_TYPE_ACCEPTOR_NAME_RESP,
 843         GSSEAP_STATE_ACCEPTOR_EXTS,
 844         0,
 845         eapGssSmAcceptAcceptorName
 846     },
 847     {
 848         ITOK_TYPE_NONE,
 849         ITOK_TYPE_ACCEPTOR_MIC,
 850         GSSEAP_STATE_ACCEPTOR_EXTS,
 851         0,
 852         eapGssSmAcceptAcceptorMIC
 853     },
 854 };
 855
 856 OM_uint32
 857 gssEapAcceptSecContext(OM_uint32 *minor,
 858                        gss_ctx_id_t ctx,
 859                        gss_cred_id_t cred,
 860                        gss_buffer_t input_token,
 861                        gss_channel_bindings_t input_chan_bindings,
 862                        gss_name_t *src_name,
 863                        gss_OID *mech_type,
 864                        gss_buffer_t output_token,
 865                        OM_uint32 *ret_flags,
 866                        OM_uint32 *time_rec,
 867                        gss_cred_id_t *delegated_cred_handle)
 868 {
 869     OM_uint32 major, tmpMinor;
 870
 871     if (cred == GSS_C_NO_CREDENTIAL) {
 872         if (ctx->cred == GSS_C_NO_CREDENTIAL) {
 873             major = gssEapAcquireCred(minor,
 874                                       GSS_C_NO_NAME,
 875                                       GSS_C_INDEFINITE,
 876                                       GSS_C_NO_OID_SET,
 877                                       GSS_C_ACCEPT,
 878                                       &ctx->cred,
 879                                       NULL,
 880                                       NULL);
 881             if (GSS_ERROR(major))
 882                 goto cleanup;
 883         }
 884
 885         cred = ctx->cred;
 886     }
 887
 888     /*
 889      * Previously we acquired the credential mutex here, but it should not be
 890      * necessary as the acceptor does not access any mutable elements of the
 891      * credential handle.
 892      */
 893
 894     if (cred->name != GSS_C_NO_NAME) {
 895         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
 896         if (GSS_ERROR(major))
 897             goto cleanup;
 898     }
 899
 900     major = gssEapSmStep(minor,
 901                          cred,
 902                          ctx,
 903                          GSS_C_NO_NAME,
 904                          GSS_C_NO_OID,
 905                          0,
 906                          GSS_C_INDEFINITE,
 907                          input_chan_bindings,
 908                          input_token,
 909                          output_token,
 910                          eapGssAcceptorSm,
 911                          sizeof(eapGssAcceptorSm) / sizeof(eapGssAcceptorSm[0]));
 912     if (GSS_ERROR(major))
 913         goto cleanup;
 914
 915     if (mech_type != NULL) {
 916         OM_uint32 tmpMajor;
 917
 918         tmpMajor = gssEapCanonicalizeOid(&tmpMinor, ctx->mechanismUsed, 0, mech_type);
 919         if (GSS_ERROR(tmpMajor)) {
 920             major = tmpMajor;
 921             *minor = tmpMinor;
 922             goto cleanup;
 923         }
 924     }
 925     if (ret_flags != NULL)
 926         *ret_flags = ctx->gssFlags;
 927     if (delegated_cred_handle != NULL)
 928         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 929
 930     if (major == GSS_S_COMPLETE) {
 931         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 932             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
 933             if (GSS_ERROR(major))
 934                 goto cleanup;
 935         }
 936         if (time_rec != NULL) {
 937             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
 938             if (GSS_ERROR(major))
 939                 goto cleanup;
 940         }
 941     }
 942
 943     GSSEAP_ASSERT(CTX_IS_ESTABLISHED(ctx) || major == GSS_S_CONTINUE_NEEDED);
 944
 945 cleanup:
 946     return major;
 947 }
 948
 949 #ifdef GSSEAP_ENABLE_REAUTH
 950 static OM_uint32
 951 acceptReadyKrb(OM_uint32 *minor,
 952                gss_ctx_id_t ctx,
 953                gss_cred_id_t cred,
 954                const gss_name_t initiator,
 955                const gss_OID mech,
 956                OM_uint32 timeRec)
 957 {
 958     OM_uint32 major;
 959
 960     major = gssEapGlueToMechName(minor, ctx, initiator, &ctx->initiatorName);
 961     if (GSS_ERROR(major))
 962         return major;
 963
 964     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 965     if (GSS_ERROR(major))
 966         return major;
 967
 968     *minor = 0;
 969     return GSS_S_COMPLETE;
 970 }
 971
 972 static OM_uint32
 973 eapGssSmAcceptGssReauth(OM_uint32 *minor,
 974                         gss_cred_id_t cred,
 975                         gss_ctx_id_t ctx,
 976                         gss_name_t target GSSEAP_UNUSED,
 977                         gss_OID mech,
 978                         OM_uint32 reqFlags GSSEAP_UNUSED,
 979                         OM_uint32 timeReq GSSEAP_UNUSED,
 980                         gss_channel_bindings_t chanBindings,
 981                         gss_buffer_t inputToken,
 982                         gss_buffer_t outputToken,
 983                         OM_uint32 *smFlags)
 984 {
 985     OM_uint32 major, tmpMinor;
 986     gss_name_t krbInitiator = GSS_C_NO_NAME;
 987     OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
 988
 989     /*
 990      * If we're built with fast reauthentication support, it's valid
 991      * for an initiator to send a GSS reauthentication token as its
 992      * initial context token, causing us to short-circuit the state
 993      * machine and process Kerberos GSS messages instead.
 994      */
 995
 996     ctx->flags |= CTX_FLAG_KRB_REAUTH;
 997
 998     major = gssAcceptSecContext(minor,
 999                                 &ctx->reauthCtx,
1000                                 cred->reauthCred,
1001                                 inputToken,
1002                                 chanBindings,
1003                                 &krbInitiator,
1004                                 &mech,
1005                                 outputToken,
1006                                 &gssFlags,
1007                                 &timeRec,
1008                                 NULL);
1009     if (major == GSS_S_COMPLETE) {
1010         major = acceptReadyKrb(minor, ctx, cred,
1011                                krbInitiator, mech, timeRec);
1012         if (major == GSS_S_COMPLETE) {
1013             GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
1014         }
1015         ctx->gssFlags = gssFlags;
1016     } else if (GSS_ERROR(major) &&
1017         (*smFlags & SM_FLAG_INPUT_TOKEN_CRITICAL) == 0) {
1018         /* pretend reauthentication attempt never happened */
1019         gssDeleteSecContext(&tmpMinor, &ctx->reauthCtx, GSS_C_NO_BUFFER);
1020         ctx->flags &= ~(CTX_FLAG_KRB_REAUTH);
1021         GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_INITIAL);
1022         major = GSS_S_CONTINUE_NEEDED;
1023     }
1024
1025     gssReleaseName(&tmpMinor, &krbInitiator);
1026
1027     return major;
1028 }
1029 #endif /* GSSEAP_ENABLE_REAUTH */
1030
1031 OM_uint32 GSSAPI_CALLCONV
1032 gss_accept_sec_context(OM_uint32 *minor,
1033                        gss_ctx_id_t *context_handle,
1034                        gss_cred_id_t cred,
1035                        gss_buffer_t input_token,
1036                        gss_channel_bindings_t input_chan_bindings,
1037                        gss_name_t *src_name,
1038                        gss_OID *mech_type,
1039                        gss_buffer_t output_token,
1040                        OM_uint32 *ret_flags,
1041                        OM_uint32 *time_rec,
1042                        gss_cred_id_t *delegated_cred_handle)
1043 {
1044     OM_uint32 major, tmpMinor;
1045     gss_ctx_id_t ctx = *context_handle;
1046
1047     *minor = 0;
1048
1049     output_token->length = 0;
1050     output_token->value = NULL;
1051
1052     if (src_name != NULL)
1053         *src_name = GSS_C_NO_NAME;
1054
1055     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
1056         *minor = GSSEAP_TOK_TRUNC;
1057         return GSS_S_DEFECTIVE_TOKEN;
1058     }
1059
1060     if (ctx == GSS_C_NO_CONTEXT) {
1061         major = gssEapAllocContext(minor, &ctx);
1062         if (GSS_ERROR(major))
1063             return major;
1064
1065         *context_handle = ctx;
1066     }
1067
1068     GSSEAP_MUTEX_LOCK(&ctx->mutex);
1069
1070     major = gssEapAcceptSecContext(minor,
1071                                    ctx,
1072                                    cred,
1073                                    input_token,
1074                                    input_chan_bindings,
1075                                    src_name,
1076                                    mech_type,
1077                                    output_token,
1078                                    ret_flags,
1079                                    time_rec,
1080                                    delegated_cred_handle);
1081
1082     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
1083
1084     if (GSS_ERROR(major))
1085         gssEapReleaseContext(&tmpMinor, context_handle);
1086
1087     return major;
1088 }