init_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 #include "gssapiP_eap.h"
  34
  35 static OM_uint32
  36 policyVariableToFlag(enum eapol_bool_var variable)
  37 {
  38     OM_uint32 flag = 0;
  39
  40     switch (variable) {
  41     case EAPOL_eapSuccess:
  42         flag = CTX_FLAG_EAP_SUCCESS;
  43         break;
  44     case EAPOL_eapRestart:
  45         flag = CTX_FLAG_EAP_RESTART;
  46         break;
  47     case EAPOL_eapFail:
  48         flag = CTX_FLAG_EAP_FAIL;
  49         break;
  50     case EAPOL_eapResp:
  51         flag = CTX_FLAG_EAP_RESP;
  52         break;
  53     case EAPOL_eapNoResp:
  54         flag = CTX_FLAG_EAP_NO_RESP;
  55         break;
  56     case EAPOL_eapReq:
  57         flag = CTX_FLAG_EAP_REQ;
  58         break;
  59     case EAPOL_portEnabled:
  60         flag = CTX_FLAG_EAP_PORT_ENABLED;
  61         break;
  62     case EAPOL_altAccept:
  63         flag = CTX_FLAG_EAP_ALT_ACCEPT;
  64         break;
  65     case EAPOL_altReject:
  66         flag = CTX_FLAG_EAP_ALT_REJECT;
  67         break;
  68     }
  69
  70     return flag;
  71 }
  72
  73 static struct eap_peer_config *
  74 peerGetConfig(void *ctx)
  75 {
  76     gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
  77
  78     return &gssCtx->initiatorCtx.eapPeerConfig;
  79 }
  80
  81 static Boolean
  82 peerGetBool(void *data, enum eapol_bool_var variable)
  83 {
  84     gss_ctx_id_t ctx = data;
  85     OM_uint32 flag;
  86
  87     if (ctx == GSS_C_NO_CONTEXT)
  88         return FALSE;
  89
  90     flag = policyVariableToFlag(variable);
  91
  92     return ((ctx->flags & flag) != 0);
  93 }
  94
  95 static void
  96 peerSetBool(void *data, enum eapol_bool_var variable,
  97             Boolean value)
  98 {
  99     gss_ctx_id_t ctx = data;
 100     OM_uint32 flag;
 101
 102     if (ctx == GSS_C_NO_CONTEXT)
 103         return;
 104
 105     flag = policyVariableToFlag(variable);
 106
 107     if (value)
 108         ctx->flags |= flag;
 109     else
 110         ctx->flags &= ~(flag);
 111 }
 112
 113 static unsigned int
 114 peerGetInt(void *data, enum eapol_int_var variable)
 115 {
 116     gss_ctx_id_t ctx = data;
 117
 118     if (ctx == GSS_C_NO_CONTEXT)
 119         return FALSE;
 120
 121     assert(CTX_IS_INITIATOR(ctx));
 122
 123     switch (variable) {
 124     case EAPOL_idleWhile:
 125         return ctx->initiatorCtx.idleWhile;
 126         break;
 127     }
 128
 129     return 0;
 130 }
 131
 132 static void
 133 peerSetInt(void *data, enum eapol_int_var variable,
 134            unsigned int value)
 135 {
 136     gss_ctx_id_t ctx = data;
 137
 138     if (ctx == GSS_C_NO_CONTEXT)
 139         return;
 140
 141     assert(CTX_IS_INITIATOR(ctx));
 142
 143     switch (variable) {
 144     case EAPOL_idleWhile:
 145         ctx->initiatorCtx.idleWhile = value;
 146         break;
 147     }
 148 }
 149
 150 static struct wpabuf *
 151 peerGetEapReqData(void *ctx)
 152 {
 153     gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
 154
 155     return &gssCtx->initiatorCtx.reqData;
 156 }
 157
 158 static void
 159 peerSetConfigBlob(void *ctx, struct wpa_config_blob *blob)
 160 {
 161 }
 162
 163 static const struct wpa_config_blob *
 164 peerGetConfigBlob(void *ctx, const char *name)
 165 {
 166     return NULL;
 167 }
 168
 169 static void
 170 peerNotifyPending(void *ctx)
 171 {
 172 }
 173
 174 static struct eapol_callbacks gssEapPolicyCallbacks = {
 175     peerGetConfig,
 176     peerGetBool,
 177     peerSetBool,
 178     peerGetInt,
 179     peerSetInt,
 180     peerGetEapReqData,
 181     peerSetConfigBlob,
 182     peerGetConfigBlob,
 183     peerNotifyPending,
 184 };
 185
 186 extern int wpa_debug_level;
 187
 188 static OM_uint32
 189 peerConfigInit(OM_uint32 *minor,
 190                gss_cred_id_t cred,
 191                gss_ctx_id_t ctx)
 192 {
 193     krb5_context krbContext;
 194     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
 195     krb5_error_code code;
 196     char *identity;
 197
 198     GSSEAP_KRB_INIT(&krbContext);
 199
 200     eapPeerConfig->fragment_size = 1024;
 201     wpa_debug_level = 0;
 202
 203     code = krb5_unparse_name(krbContext, cred->name->krbPrincipal, &identity);
 204     if (code != 0) {
 205         *minor = code;
 206         return GSS_S_FAILURE;
 207     }
 208
 209     eapPeerConfig->identity = (unsigned char *)identity;
 210     eapPeerConfig->identity_len = strlen(identity);
 211     eapPeerConfig->password = (unsigned char *)cred->password.value;
 212     eapPeerConfig->password_len = cred->password.length;
 213
 214     return GSS_S_COMPLETE;
 215 }
 216
 217 static OM_uint32
 218 peerConfigFree(OM_uint32 *minor,
 219                gss_ctx_id_t ctx)
 220 {
 221     krb5_context krbContext;
 222     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
 223
 224     GSSEAP_KRB_INIT(&krbContext);
 225
 226     krb5_free_unparsed_name(krbContext, (char *)eapPeerConfig->identity);
 227
 228     return GSS_S_COMPLETE;
 229 }
 230
 231 static OM_uint32
 232 initReady(OM_uint32 *minor, gss_ctx_id_t ctx)
 233 {
 234     OM_uint32 major;
 235     const unsigned char *key;
 236     size_t keyLength;
 237     krb5_enctype encryptionType;
 238     int gotKey = 0;
 239
 240     /* Cache encryption type derived from selected mechanism OID */
 241     major = gssEapOidToEnctype(minor, ctx->mechanismUsed, &encryptionType);
 242     if (GSS_ERROR(major))
 243         return major;
 244
 245     if (encryptionType != ENCTYPE_NULL &&
 246         eap_key_available(ctx->initiatorCtx.eap)) {
 247         key = eap_get_eapKeyData(ctx->initiatorCtx.eap, &keyLength);
 248
 249         if (keyLength >= EAP_EMSK_LEN) {
 250             major = gssEapDeriveRfc3961Key(minor,
 251                                            &key[EAP_EMSK_LEN / 2],
 252                                            EAP_EMSK_LEN / 2,
 253                                            encryptionType,
 254                                            &ctx->rfc3961Key);
 255                if (GSS_ERROR(major))
 256                    return major;
 257
 258             major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 259                                               &ctx->checksumType);
 260             if (GSS_ERROR(major))
 261                 return major;
 262             gotKey++;
 263         }
 264     }
 265
 266     if (gotKey) {
 267         ctx->encryptionType = encryptionType;
 268     } else {
 269         /*
 270          * draft-howlett-eap-gss says that integrity/confidentialty should
 271          * always be advertised as available, but if we have no keying
 272          * material it seems confusing to the caller to advertise this.
 273          */
 274         ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
 275     }
 276
 277     major = sequenceInit(minor,
 278                          &ctx->seqState,
 279                          ctx->recvSeq,
 280                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 281                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 282                          TRUE);
 283     if (GSS_ERROR(major))
 284         return major;
 285
 286     return GSS_S_COMPLETE;
 287 }
 288
 289 static OM_uint32
 290 eapGssSmInitIdentity(OM_uint32 *minor,
 291                      gss_cred_id_t cred,
 292                      gss_ctx_id_t ctx,
 293                      gss_name_t target,
 294                      gss_OID mech,
 295                      OM_uint32 reqFlags,
 296                      OM_uint32 timeReq,
 297                      gss_channel_bindings_t chanBindings,
 298                      gss_buffer_t inputToken,
 299                      gss_buffer_t outputToken)
 300 {
 301     time_t now;
 302     OM_uint32 major;
 303     int initialContextToken;
 304
 305     initialContextToken = (inputToken == GSS_C_NO_BUFFER ||
 306                            inputToken->length == 0);
 307     if (!initialContextToken)
 308         return GSS_S_DEFECTIVE_TOKEN;
 309
 310     time(&now);
 311     if (timeReq == 0 || timeReq == GSS_C_INDEFINITE)
 312         ctx->expiryTime = 0;
 313     else
 314         ctx->expiryTime = now + timeReq;
 315
 316     major = gssEapDuplicateName(minor, cred->name, &ctx->initiatorName);
 317     if (GSS_ERROR(major))
 318         return major;
 319
 320     major = gssEapDuplicateName(minor, target, &ctx->acceptorName);
 321     if (GSS_ERROR(major))
 322         return major;
 323
 324     if (mech == GSS_C_NULL_OID || oidEqual(mech, GSS_EAP_MECHANISM)) {
 325         major = gssEapDefaultMech(minor, &ctx->mechanismUsed);
 326     } else if (gssEapIsConcreteMechanismOid(mech)) {
 327         if (!gssEapInternalizeOid(mech, &ctx->mechanismUsed))
 328             major = duplicateOid(minor, mech, &ctx->mechanismUsed);
 329     } else {
 330         major = GSS_S_BAD_MECH;
 331     }
 332     if (GSS_ERROR(major))
 333         return major;
 334
 335     /* If credentials were provided, check they're usable with this mech */
 336     if (!gssEapCredAvailable(cred, ctx->mechanismUsed))
 337         return GSS_S_BAD_MECH;
 338
 339     ctx->state = EAP_STATE_AUTHENTICATE;
 340
 341     return GSS_S_CONTINUE_NEEDED;
 342 }
 343
 344 static struct wpabuf emptyWpaBuffer;
 345
 346 static OM_uint32
 347 eapGssSmInitAuthenticate(OM_uint32 *minor,
 348                          gss_cred_id_t cred,
 349                          gss_ctx_id_t ctx,
 350                          gss_name_t target,
 351                          gss_OID mech,
 352                          OM_uint32 reqFlags,
 353                          OM_uint32 timeReq,
 354                          gss_channel_bindings_t chanBindings,
 355                          gss_buffer_t inputToken,
 356                          gss_buffer_t outputToken)
 357 {
 358     OM_uint32 major;
 359     OM_uint32 tmpMinor;
 360     int code;
 361     struct wpabuf *resp = NULL;
 362     int initialContextToken;
 363
 364     initialContextToken = (inputToken == GSS_C_NO_BUFFER ||
 365                            inputToken->length == 0);
 366
 367     major = peerConfigInit(minor, cred, ctx);
 368     if (GSS_ERROR(major))
 369         goto cleanup;
 370
 371     if (ctx->initiatorCtx.eap == NULL) {
 372         struct eap_config eapConfig;
 373
 374         memset(&eapConfig, 0, sizeof(eapConfig));
 375
 376         ctx->initiatorCtx.eap = eap_peer_sm_init(ctx,
 377                                                  &gssEapPolicyCallbacks,
 378                                                  ctx,
 379                                                  &eapConfig);
 380         if (ctx->initiatorCtx.eap == NULL) {
 381             major = GSS_S_FAILURE;
 382             goto cleanup;
 383         }
 384
 385         ctx->flags |= CTX_FLAG_EAP_RESTART | CTX_FLAG_EAP_PORT_ENABLED;
 386     }
 387
 388     ctx->flags |= CTX_FLAG_EAP_REQ; /* we have a Request from the acceptor */
 389
 390     wpabuf_set(&ctx->initiatorCtx.reqData,
 391                inputToken->value, inputToken->length);
 392
 393     major = GSS_S_CONTINUE_NEEDED;
 394
 395     code = eap_peer_sm_step(ctx->initiatorCtx.eap);
 396     if (ctx->flags & CTX_FLAG_EAP_RESP) {
 397         ctx->flags &= ~(CTX_FLAG_EAP_RESP);
 398
 399         resp = eap_get_eapRespData(ctx->initiatorCtx.eap);
 400     } else if (ctx->flags & CTX_FLAG_EAP_SUCCESS) {
 401         major = initReady(minor, ctx);
 402         if (GSS_ERROR(major))
 403             goto cleanup;
 404
 405         ctx->flags &= ~(CTX_FLAG_EAP_SUCCESS);
 406         major = GSS_S_CONTINUE_NEEDED;
 407         ctx->state = EAP_STATE_GSS_CHANNEL_BINDINGS;
 408     } else if (ctx->flags & CTX_FLAG_EAP_FAIL) {
 409         major = GSS_S_DEFECTIVE_CREDENTIAL;
 410     } else if (code == 0 && initialContextToken) {
 411         resp = &emptyWpaBuffer;
 412         major = GSS_S_CONTINUE_NEEDED;
 413     } else {
 414         major = GSS_S_DEFECTIVE_TOKEN;
 415     }
 416
 417 cleanup:
 418     if (resp != NULL) {
 419         OM_uint32 tmpMajor;
 420         gss_buffer_desc respBuf;
 421
 422         assert(major == GSS_S_CONTINUE_NEEDED);
 423
 424         respBuf.length = wpabuf_len(resp);
 425         respBuf.value = (void *)wpabuf_head(resp);
 426
 427         tmpMajor = duplicateBuffer(&tmpMinor, &respBuf, outputToken);
 428         if (GSS_ERROR(tmpMajor)) {
 429             major = tmpMajor;
 430             *minor = tmpMinor;
 431         }
 432     }
 433
 434     wpabuf_set(&ctx->initiatorCtx.reqData, NULL, 0);
 435     peerConfigFree(&tmpMinor, ctx);
 436
 437     return major;
 438 }
 439
 440 static OM_uint32
 441 eapGssSmInitGssChannelBindings(OM_uint32 *minor,
 442                                gss_cred_id_t cred,
 443                                gss_ctx_id_t ctx,
 444                                gss_name_t target,
 445                                gss_OID mech,
 446                                OM_uint32 reqFlags,
 447                                OM_uint32 timeReq,
 448                                gss_channel_bindings_t chanBindings,
 449                                gss_buffer_t inputToken,
 450                                gss_buffer_t outputToken)
 451 {
 452     OM_uint32 major;
 453     gss_iov_buffer_desc iov[2];
 454     gss_buffer_desc buf;
 455
 456     iov[0].type = GSS_IOV_BUFFER_TYPE_DATA;
 457     iov[0].buffer.length = 0;
 458     iov[0].buffer.value = NULL;
 459
 460     iov[1].type = GSS_IOV_BUFFER_TYPE_HEADER | GSS_IOV_BUFFER_FLAG_ALLOCATE;
 461     iov[1].buffer.length = 0;
 462     iov[1].buffer.value = NULL;
 463
 464     if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS)
 465         iov[0].buffer = chanBindings->application_data;
 466
 467     major = gssEapWrapOrGetMIC(minor, ctx, FALSE, FALSE, iov, 2,
 468                                TOK_TYPE_GSS_CB);
 469     if (GSS_ERROR(major))
 470         goto cleanup;
 471
 472     /* Skip past token ID */
 473     assert(iov[1].buffer.length > 2);
 474     assert(load_uint16_be(iov[1].buffer.value) == TOK_TYPE_GSS_CB);
 475
 476     buf.length = iov[1].buffer.length - 2;
 477     buf.value = (unsigned char *)iov[1].buffer.value + 2;
 478
 479     major = duplicateBuffer(minor, &buf, outputToken);
 480     if (GSS_ERROR(major))
 481         goto cleanup;
 482
 483     major = GSS_S_CONTINUE_NEEDED;
 484     ctx->state = EAP_STATE_KRB_REAUTH_CRED;
 485
 486 cleanup:
 487     gssEapReleaseIov(iov, 2);
 488
 489     return major;
 490 }
 491
 492 static OM_uint32
 493 eapGssSmInitKrbReauthCred(OM_uint32 *minor,
 494                           gss_cred_id_t cred,
 495                           gss_ctx_id_t ctx,
 496                           gss_name_t target,
 497                           gss_OID mech,
 498                           OM_uint32 reqFlags,
 499                           OM_uint32 timeReq,
 500                           gss_channel_bindings_t chanBindings,
 501                           gss_buffer_t inputToken,
 502                           gss_buffer_t outputToken)
 503 {
 504     OM_uint32 major;
 505
 506     major = gssEapStoreReauthCreds(minor, ctx, cred, inputToken);
 507     if (GSS_ERROR(major))
 508         return major;
 509
 510     ctx->state = EAP_STATE_ESTABLISHED;
 511
 512     return GSS_S_COMPLETE;
 513 }
 514
 515 static OM_uint32
 516 eapGssSmInitEstablished(OM_uint32 *minor,
 517                         gss_cred_id_t cred,
 518                         gss_ctx_id_t ctx,
 519                         gss_name_t target,
 520                         gss_OID mech,
 521                         OM_uint32 reqFlags,
 522                         OM_uint32 timeReq,
 523                         gss_channel_bindings_t chanBindings,
 524                         gss_buffer_t inputToken,
 525                         gss_buffer_t outputToken)
 526 {
 527     /* Called with already established context */
 528     *minor = EINVAL;
 529     return GSS_S_BAD_STATUS;
 530 }
 531
 532 static int
 533 canReauthP(gss_cred_id_t cred)
 534 {
 535     return (cred != GSS_C_NO_CREDENTIAL &&
 536             cred->krbCred != GSS_C_NO_CREDENTIAL &&
 537             cred->expiryTime > time(NULL));
 538 }
 539
 540 static OM_uint32
 541 initReadyKrb(OM_uint32 *minor,
 542             gss_ctx_id_t ctx,
 543             gss_cred_id_t cred,
 544             const gss_name_t target,
 545             const gss_OID mech,
 546             OM_uint32 timeRec)
 547 {
 548     OM_uint32 major;
 549
 550     major = gssEapGlueToMechName(minor, target, &ctx->acceptorName);
 551     if (GSS_ERROR(major))
 552         return major;
 553
 554     major = gssEapDuplicateName(minor, cred->name, &ctx->initiatorName);
 555     if (GSS_ERROR(major))
 556         return major;
 557
 558     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
 559     if (GSS_ERROR(major))
 560         return major;
 561
 562     ctx->state = EAP_STATE_ESTABLISHED;
 563
 564     return GSS_S_COMPLETE;
 565 }
 566
 567 static OM_uint32
 568 eapGssSmInitGssReauth(OM_uint32 *minor,
 569                       gss_cred_id_t cred,
 570                       gss_ctx_id_t ctx,
 571                       gss_name_t target,
 572                       gss_OID mech,
 573                       OM_uint32 reqFlags,
 574                       OM_uint32 timeReq,
 575                       gss_channel_bindings_t chanBindings,
 576                       gss_buffer_t inputToken,
 577                       gss_buffer_t outputToken)
 578 {
 579     OM_uint32 major, tmpMinor;
 580     gss_name_t mechTarget = GSS_C_NO_NAME;
 581     gss_OID actualMech = GSS_C_NO_OID;
 582     OM_uint32 timeRec;
 583
 584     assert(cred != GSS_C_NO_CREDENTIAL);
 585
 586     ctx->flags |= CTX_FLAG_KRB_REAUTH_GSS;
 587
 588     major = gssEapMechToGlueName(minor, target, &mechTarget);
 589     if (GSS_ERROR(major))
 590         goto cleanup;
 591
 592     major = gssInitSecContext(minor,
 593                               cred->krbCred,
 594                               &ctx->kerberosCtx,
 595                               mechTarget,
 596                               (gss_OID)gss_mech_krb5,
 597                               reqFlags,
 598                               timeReq,
 599                               chanBindings,
 600                               inputToken,
 601                               &actualMech,
 602                               outputToken,
 603                               &ctx->gssFlags,
 604                               &timeRec);
 605     if (GSS_ERROR(major))
 606         goto cleanup;
 607
 608 cleanup:
 609     gssReleaseName(&tmpMinor, &mechTarget);
 610
 611     return major;
 612 }
 613
 614 static struct gss_eap_initiator_sm {
 615     enum gss_eap_token_type inputTokenType;
 616     enum gss_eap_token_type outputTokenType;
 617     OM_uint32 (*processToken)(OM_uint32 *,
 618                               gss_cred_id_t,
 619                               gss_ctx_id_t,
 620                               gss_name_t,
 621                               gss_OID,
 622                               OM_uint32,
 623                               OM_uint32,
 624                               gss_channel_bindings_t,
 625                               gss_buffer_t,
 626                               gss_buffer_t);
 627 } eapGssInitiatorSm[] = {
 628     { TOK_TYPE_NONE,    TOK_TYPE_EAP_RESP,      eapGssSmInitIdentity            },
 629     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,      eapGssSmInitAuthenticate        },
 630     { TOK_TYPE_NONE,    TOK_TYPE_GSS_CB,        eapGssSmInitGssChannelBindings  },
 631     { TOK_TYPE_KRB_CRED,TOK_TYPE_NONE,          eapGssSmInitKrbReauthCred       },
 632     { TOK_TYPE_NONE,    TOK_TYPE_NONE,          eapGssSmInitEstablished         },
 633     { TOK_TYPE_GSS_REAUTH, TOK_TYPE_GSS_REAUTH, eapGssSmInitGssReauth           },
 634 };
 635
 636 OM_uint32
 637 gss_init_sec_context(OM_uint32 *minor,
 638                      gss_cred_id_t cred,
 639                      gss_ctx_id_t *context_handle,
 640                      gss_name_t target_name,
 641                      gss_OID mech_type,
 642                      OM_uint32 req_flags,
 643                      OM_uint32 time_req,
 644                      gss_channel_bindings_t input_chan_bindings,
 645                      gss_buffer_t input_token,
 646                      gss_OID *actual_mech_type,
 647                      gss_buffer_t output_token,
 648                      OM_uint32 *ret_flags,
 649                      OM_uint32 *time_rec)
 650 {
 651     OM_uint32 major;
 652     OM_uint32 tmpMajor, tmpMinor;
 653     gss_ctx_id_t ctx = *context_handle;
 654     struct gss_eap_initiator_sm *sm = NULL;
 655     gss_buffer_desc innerInputToken;
 656     gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 657     enum gss_eap_token_type tokType;
 658
 659     *minor = 0;
 660
 661     output_token->length = 0;
 662     output_token->value = NULL;
 663
 664     if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_INITIATE)) {
 665         return GSS_S_NO_CRED;
 666     }
 667
 668     if (ctx == GSS_C_NO_CONTEXT) {
 669         if (input_token != GSS_C_NO_BUFFER && input_token->length != 0) {
 670             return GSS_S_DEFECTIVE_TOKEN;
 671         }
 672
 673         major = gssEapAllocContext(minor, &ctx);
 674         if (GSS_ERROR(major))
 675             return major;
 676
 677         ctx->flags |= CTX_FLAG_INITIATOR;
 678
 679         if (canReauthP(cred))
 680             ctx->state = EAP_STATE_KRB_REAUTH_GSS;
 681
 682         *context_handle = ctx;
 683     }
 684
 685     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 686
 687     sm = &eapGssInitiatorSm[ctx->state];
 688
 689     if (input_token != GSS_C_NO_BUFFER) {
 690         major = gssEapVerifyToken(minor, ctx, input_token,
 691                                   sm->inputTokenType,
 692                                   &tokType, &innerInputToken);
 693         if (GSS_ERROR(major))
 694             goto cleanup;
 695     } else {
 696         innerInputToken.length = 0;
 697         innerInputToken.value = NULL;
 698     }
 699
 700     /*
 701      * Advance through state machine whilst empty tokens are emitted and
 702      * the status is not GSS_S_COMPLETE or an error status.
 703      */
 704     do {
 705         sm = &eapGssInitiatorSm[ctx->state];
 706
 707         major = (sm->processToken)(minor,
 708                                    cred,
 709                                    ctx,
 710                                    target_name,
 711                                    mech_type,
 712                                    req_flags,
 713                                    time_req,
 714                                    input_chan_bindings,
 715                                    &innerInputToken,
 716                                    &innerOutputToken);
 717         if (GSS_ERROR(major))
 718             goto cleanup;
 719     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.value == NULL);
 720
 721     if (actual_mech_type != NULL) {
 722         if (!gssEapInternalizeOid(ctx->mechanismUsed, actual_mech_type))
 723             duplicateOid(&tmpMinor, ctx->mechanismUsed, actual_mech_type);
 724     }
 725     if (innerOutputToken.value != NULL) {
 726         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 727                                    sm->outputTokenType, output_token);
 728         if (GSS_ERROR(tmpMajor)) {
 729             major = tmpMajor;
 730             *minor = tmpMinor;
 731             goto cleanup;
 732         }
 733     }
 734     if (ret_flags != NULL)
 735         *ret_flags = ctx->gssFlags;
 736     if (time_rec != NULL)
 737         gssEapContextTime(&tmpMinor, ctx, time_rec);
 738
 739     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 740
 741 cleanup:
 742     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 743
 744     if (GSS_ERROR(major))
 745         gssEapReleaseContext(&tmpMinor, context_handle);
 746
 747     gss_release_buffer(&tmpMinor, &innerOutputToken);
 748
 749     return major;
 750 }