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 #include "gssapiP_eap.h"
  34
  35 #ifdef BUILTIN_EAP
  36 #define EAP_KEY_AVAILABLE(ctx)  ((ctx)->acceptorCtx.eapPolInterface->eapKeyAvailable)
  37 #define EAP_KEY_DATA(ctx)       ((ctx)->acceptorCtx.eapPolInterface->eapKeyData)
  38 #define EAP_KEY_LENGTH(ctx)     ((ctx)->acceptorCtx.eapPolInterface->eapKeyDataLen)
  39 #else
  40 #define EAP_KEY_AVAILABLE(ctx)  0
  41 #define EAP_KEY_DATA(ctx)       NULL
  42 #define EAP_KEY_LENGTH(ctx)     0
  43 #endif /* BUILTIN_EAP */
  44
  45 static OM_uint32
  46 acceptReady(OM_uint32 *minor, gss_ctx_id_t ctx);
  47
  48 #ifdef BUILTIN_EAP
  49 #define EAP_MAX_METHODS 8
  50
  51 #define EAP_TTLS_AUTH_PAP 1
  52 #define EAP_TTLS_AUTH_CHAP 2
  53 #define EAP_TTLS_AUTH_MSCHAP 4
  54 #define EAP_TTLS_AUTH_MSCHAPV2 8
  55
  56 struct eap_user {
  57         struct {
  58                 int vendor;
  59                 u32 method;
  60         } methods[EAP_MAX_METHODS];
  61         u8 *password;
  62         size_t password_len;
  63         int password_hash; /* whether password is hashed with
  64                             * nt_password_hash() */
  65         int phase2;
  66         int force_version;
  67         int ttls_auth; /* bitfield of
  68                         * EAP_TTLS_AUTH_{PAP,CHAP,MSCHAP,MSCHAPV2} */
  69 };
  70
  71 struct eap_eapol_interface {
  72         /* Lower layer to full authenticator variables */
  73         Boolean eapResp; /* shared with EAPOL Backend Authentication */
  74         struct wpabuf *eapRespData;
  75         Boolean portEnabled;
  76         int retransWhile;
  77         Boolean eapRestart; /* shared with EAPOL Authenticator PAE */
  78         int eapSRTT;
  79         int eapRTTVAR;
  80
  81         /* Full authenticator to lower layer variables */
  82         Boolean eapReq; /* shared with EAPOL Backend Authentication */
  83         Boolean eapNoReq; /* shared with EAPOL Backend Authentication */
  84         Boolean eapSuccess;
  85         Boolean eapFail;
  86         Boolean eapTimeout;
  87         struct wpabuf *eapReqData;
  88         u8 *eapKeyData;
  89         size_t eapKeyDataLen;
  90         Boolean eapKeyAvailable; /* called keyAvailable in IEEE 802.1X-2004 */
  91
  92         /* AAA interface to full authenticator variables */
  93         Boolean aaaEapReq;
  94         Boolean aaaEapNoReq;
  95         Boolean aaaSuccess;
  96         Boolean aaaFail;
  97         struct wpabuf *aaaEapReqData;
  98         u8 *aaaEapKeyData;
  99         size_t aaaEapKeyDataLen;
 100         Boolean aaaEapKeyAvailable;
 101         int aaaMethodTimeout;
 102
 103         /* Full authenticator to AAA interface variables */
 104         Boolean aaaEapResp;
 105         struct wpabuf *aaaEapRespData;
 106         /* aaaIdentity -> eap_get_identity() */
 107         Boolean aaaTimeout;
 108 };
 109
 110 #define eapol_callbacks     SERVER_eapol_callbacks
 111
 112 struct eapol_callbacks {
 113         int (*get_eap_user)(void *ctx, const u8 *identity, size_t identity_len,
 114                             int phase2, struct eap_user *user);
 115         const char * (*get_eap_req_id_text)(void *ctx, size_t *len);
 116 };
 117
 118 #define eap_config          SERVER_eap_config
 119
 120 struct eap_config {
 121         void *ssl_ctx;
 122         void *msg_ctx;
 123         void *eap_sim_db_priv;
 124         Boolean backend_auth;
 125         int eap_server;
 126         u8 *pac_opaque_encr_key;
 127         u8 *eap_fast_a_id;
 128         size_t eap_fast_a_id_len;
 129         char *eap_fast_a_id_info;
 130         int eap_fast_prov;
 131         int pac_key_lifetime;
 132         int pac_key_refresh_time;
 133         int eap_sim_aka_result_ind;
 134         int tnc;
 135         struct wps_context *wps;
 136         const struct wpabuf *assoc_wps_ie;
 137         const u8 *peer_addr;
 138         int fragment_size;
 139 };
 140
 141 struct eap_sm * eap_server_sm_init(void *eapol_ctx,
 142                                    struct eapol_callbacks *eapol_cb,
 143                                    struct eap_config *eap_conf);
 144 void eap_server_sm_deinit(struct eap_sm *sm);
 145 int eap_server_sm_step(struct eap_sm *sm);
 146 void eap_sm_notify_cached(struct eap_sm *sm);
 147 void eap_sm_pending_cb(struct eap_sm *sm);
 148 int eap_sm_method_pending(struct eap_sm *sm);
 149 const u8 * eap_get_identity(struct eap_sm *sm, size_t *len);
 150 struct eap_eapol_interface * eap_get_interface(struct eap_sm *sm);
 151
 152 #include <eap_server/eap_i.h>
 153
 154 static OM_uint32
 155 initTls(OM_uint32 *minor,
 156         gss_ctx_id_t ctx)
 157 {
 158     struct tls_config tconf;
 159     struct tls_connection_params tparams;
 160
 161     memset(&tconf, 0, sizeof(tconf));
 162     ctx->acceptorCtx.tlsContext = tls_init(&tconf);
 163     if (ctx->acceptorCtx.tlsContext == NULL)
 164         return GSS_S_FAILURE;
 165
 166     memset(&tparams, 0, sizeof(tparams));
 167     tparams.ca_cert = "ca.pem";
 168     tparams.client_cert = "server.pem";
 169     tparams.private_key = "server-key.pem";
 170
 171     if (tls_global_set_params(ctx->acceptorCtx.tlsContext, &tparams)) {
 172         return GSS_S_FAILURE;
 173     }
 174
 175     if (tls_global_set_verify(ctx->acceptorCtx.tlsContext, 0)) {
 176         return GSS_S_FAILURE;
 177     }
 178
 179     return GSS_S_COMPLETE;
 180 }
 181
 182 static int
 183 serverGetEapUser(void *ctx,
 184                  const unsigned char *identity,
 185                  size_t identityLength,
 186                  int phase2,
 187                  struct eap_user *user)
 188 {
 189     gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
 190     OM_uint32 major, minor;
 191     gss_buffer_desc buf;
 192
 193     memset(user, 0, sizeof(*user));
 194
 195     buf.length = identityLength;
 196     buf.value = (void *)identity;
 197
 198     if (phase2 == 0) {
 199         user->methods[0].vendor = EAP_VENDOR_IETF;
 200         user->methods[0].method = EAP_TYPE_PEAP;
 201         return 0;
 202     }
 203
 204     major = gssEapImportName(&minor, &buf, GSS_C_NT_USER_NAME,
 205                              &gssCtx->initiatorName);
 206     if (GSS_ERROR(major))
 207         return -1;
 208
 209     /*
 210      * OK, obviously there is no real security here, this is simply
 211      * for testing the token exchange; this code will be completely
 212      * replaced with libradsec once that library is available.
 213      */
 214     user->methods[0].vendor = EAP_VENDOR_IETF;
 215     user->methods[0].method = EAP_TYPE_MSCHAPV2;
 216     user->password = (unsigned char *)strdup(" ");
 217     user->password_len = 1;
 218
 219     return 0;
 220 }
 221
 222 static const char *
 223 serverGetEapReqIdText(void *ctx,
 224                       size_t *len)
 225 {
 226     *len = 0;
 227     return NULL;
 228 }
 229
 230 static OM_uint32
 231 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 232                            gss_ctx_id_t ctx,
 233                            gss_cred_id_t cred,
 234                            gss_buffer_t inputToken,
 235                            gss_channel_bindings_t chanBindings,
 236                            gss_buffer_t outputToken)
 237 {
 238     OM_uint32 major;
 239     OM_uint32 tmpMinor, tmpMajor;
 240     int code;
 241     struct wpabuf respData;
 242     static struct eapol_callbacks cb = { serverGetEapUser, serverGetEapReqIdText };
 243     if (ctx->acceptorCtx.eap == NULL) {
 244         struct eap_config eapConfig;
 245
 246         major = initTls(minor, ctx);
 247         if (GSS_ERROR(major))
 248             goto cleanup;
 249
 250         memset(&eapConfig, 0, sizeof(eapConfig));
 251         eapConfig.eap_server = 1;
 252         eapConfig.ssl_ctx = ctx->acceptorCtx.tlsContext;
 253
 254         ctx->acceptorCtx.eap = eap_server_sm_init(ctx, &cb, &eapConfig);
 255         if (ctx->acceptorCtx.eap == NULL) {
 256             major = GSS_S_FAILURE;
 257             goto cleanup;
 258         }
 259
 260         ctx->acceptorCtx.eapPolInterface = eap_get_interface(ctx->acceptorCtx.eap);
 261         ctx->acceptorCtx.eapPolInterface->portEnabled = TRUE;
 262         ctx->acceptorCtx.eapPolInterface->eapRestart = TRUE;
 263     }
 264
 265     if (ctx->acceptorName == GSS_C_NO_NAME &&
 266         cred != GSS_C_NO_CREDENTIAL &&
 267         cred->name != GSS_C_NO_NAME) {
 268         major = gss_duplicate_name(minor, cred->name, &ctx->acceptorName);
 269         if (GSS_ERROR(major))
 270             goto cleanup;
 271     }
 272
 273     wpabuf_set(&respData, inputToken->value, inputToken->length);
 274     ctx->acceptorCtx.eapPolInterface->eapRespData = &respData;
 275     ctx->acceptorCtx.eapPolInterface->eapResp = TRUE;
 276
 277     code = eap_server_sm_step(ctx->acceptorCtx.eap);
 278
 279     if (ctx->acceptorCtx.eapPolInterface->eapReq) {
 280         ctx->acceptorCtx.eapPolInterface->eapReq = 0;
 281         major = GSS_S_CONTINUE_NEEDED;
 282     }
 283
 284     if (ctx->acceptorCtx.eapPolInterface->eapSuccess) {
 285         ctx->acceptorCtx.eapPolInterface->eapSuccess = 0;
 286         major = acceptReady(minor, ctx);
 287         if (GSS_ERROR(major))
 288             goto cleanup;
 289
 290         ctx->state = EAP_STATE_GSS_CHANNEL_BINDINGS;
 291         major = GSS_S_CONTINUE_NEEDED;
 292     } else if (ctx->acceptorCtx.eapPolInterface->eapFail) {
 293         ctx->acceptorCtx.eapPolInterface->eapFail = 0;
 294         major = GSS_S_FAILURE;
 295     } else if (code == 0) {
 296         major = GSS_S_FAILURE;
 297     }
 298
 299     if (ctx->acceptorCtx.eapPolInterface->eapReqData != NULL) {
 300         gss_buffer_desc buf;
 301
 302         buf.length = wpabuf_len(ctx->acceptorCtx.eapPolInterface->eapReqData);
 303         buf.value = (void *)wpabuf_head(ctx->acceptorCtx.eapPolInterface->eapReqData);
 304
 305         tmpMajor = duplicateBuffer(&tmpMinor, &buf, outputToken);
 306         if (GSS_ERROR(tmpMajor)) {
 307             major = tmpMajor;
 308             *minor = tmpMinor;
 309             goto cleanup;
 310         }
 311     }
 312
 313 cleanup:
 314     ctx->acceptorCtx.eapPolInterface->eapRespData = NULL;
 315
 316     return major;
 317 }
 318 #else
 319 static OM_uint32
 320 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 321                            gss_ctx_id_t ctx,
 322                            gss_cred_id_t cred,
 323                            gss_buffer_t inputToken,
 324                            gss_channel_bindings_t chanBindings,
 325                            gss_buffer_t outputToken)
 326 {
 327     OM_uint32 major, tmpMinor;
 328
 329 cleanup:
 330     return major;
 331 }
 332 #endif /* BUILTIN_EAP */
 333
 334 static OM_uint32
 335 eapGssSmAcceptGssChannelBindings(OM_uint32 *minor,
 336                                  gss_ctx_id_t ctx,
 337                                  gss_cred_id_t cred,
 338                                  gss_buffer_t inputToken,
 339                                  gss_channel_bindings_t chanBindings,
 340                                  gss_buffer_t outputToken)
 341 {
 342     OM_uint32 major, tmpMinor;
 343     gss_iov_buffer_desc iov[2];
 344
 345     outputToken->length = 0;
 346     outputToken->value = NULL;
 347
 348     if (chanBindings == GSS_C_NO_CHANNEL_BINDINGS) {
 349         ctx->state = EAP_STATE_ESTABLISHED;
 350         return GSS_S_COMPLETE;
 351     }
 352
 353     if (inputToken->length < 14) {
 354         return GSS_S_DEFECTIVE_TOKEN;
 355     }
 356
 357     iov[0].type = GSS_IOV_BUFFER_TYPE_DATA;
 358     iov[0].buffer.length = 0;
 359     iov[0].buffer.value = NULL;
 360
 361     if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS)
 362         iov[0].buffer = chanBindings->application_data;
 363
 364     iov[1].type = GSS_IOV_BUFFER_TYPE_HEADER;
 365     iov[1].buffer.length = 16;
 366     iov[1].buffer.value = (unsigned char *)inputToken->value - 2;
 367
 368     assert(load_uint16_be(iov[1].buffer.value) == TOK_TYPE_GSS_CB);
 369
 370     iov[2].type = GSS_IOV_BUFFER_TYPE_TRAILER;
 371     iov[2].buffer.length = inputToken->length - 14;
 372     iov[2].buffer.value = (unsigned char *)inputToken->value + 14;
 373
 374     major = gssEapUnwrapOrVerifyMIC(minor, ctx, NULL, NULL,
 375                                     iov, 3, TOK_TYPE_GSS_CB);
 376     if (major == GSS_S_COMPLETE) {
 377         ctx->state = EAP_STATE_ESTABLISHED;
 378     }
 379
 380 #if 0
 381     gss_release_buffer(&tmpMinor, &iov[0].buffer);
 382 #endif
 383
 384     return major;
 385 }
 386
 387 static OM_uint32
 388 eapGssSmAcceptEstablished(OM_uint32 *minor,
 389                           gss_ctx_id_t ctx,
 390                           gss_cred_id_t cred,
 391                           gss_buffer_t inputToken,
 392                           gss_channel_bindings_t chanBindings,
 393                           gss_buffer_t outputToken)
 394 {
 395     /* Called with already established context */
 396     *minor = EINVAL;
 397     return GSS_S_BAD_STATUS;
 398 }
 399
 400 static struct eap_gss_acceptor_sm {
 401     enum gss_eap_token_type inputTokenType;
 402     enum gss_eap_token_type outputTokenType;
 403     OM_uint32 (*processToken)(OM_uint32 *,
 404                               gss_ctx_id_t,
 405                               gss_cred_id_t,
 406                               gss_buffer_t,
 407                               gss_channel_bindings_t,
 408                               gss_buffer_t);
 409 } eapGssAcceptorSm[] = {
 410     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,  eapGssSmAcceptAuthenticate       },
 411 #if 0
 412     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,  NULL                             },
 413     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,  NULL                             },
 414 #endif
 415     { TOK_TYPE_GSS_CB,      TOK_TYPE_NONE,     eapGssSmAcceptGssChannelBindings },
 416     { TOK_TYPE_NONE,        TOK_TYPE_NONE,     eapGssSmAcceptEstablished        },
 417 };
 418
 419 OM_uint32
 420 gss_accept_sec_context(OM_uint32 *minor,
 421                        gss_ctx_id_t *context_handle,
 422                        gss_cred_id_t cred,
 423                        gss_buffer_t input_token,
 424                        gss_channel_bindings_t input_chan_bindings,
 425                        gss_name_t *src_name,
 426                        gss_OID *mech_type,
 427                        gss_buffer_t output_token,
 428                        OM_uint32 *ret_flags,
 429                        OM_uint32 *time_rec,
 430                        gss_cred_id_t *delegated_cred_handle)
 431 {
 432     OM_uint32 major;
 433     OM_uint32 tmpMajor, tmpMinor;
 434     gss_ctx_id_t ctx = *context_handle;
 435     struct eap_gss_acceptor_sm *sm = NULL;
 436     gss_buffer_desc innerInputToken, innerOutputToken;
 437
 438     *minor = 0;
 439
 440     innerOutputToken.length = 0;
 441     innerOutputToken.value = NULL;
 442
 443     output_token->length = 0;
 444     output_token->value = NULL;
 445
 446     if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_ACCEPT)) {
 447         return GSS_S_NO_CRED;
 448     }
 449
 450     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
 451         return GSS_S_DEFECTIVE_TOKEN;
 452     }
 453
 454     if (ctx == GSS_C_NO_CONTEXT) {
 455         major = gssEapAllocContext(minor, &ctx);
 456         if (GSS_ERROR(major))
 457             return major;
 458
 459         *context_handle = ctx;
 460     }
 461
 462     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 463
 464     sm = &eapGssAcceptorSm[ctx->state];
 465
 466     major = gssEapVerifyToken(minor, ctx, input_token,
 467                               sm->inputTokenType, &innerInputToken);
 468     if (GSS_ERROR(major))
 469         goto cleanup;
 470
 471     /* If credentials were provided, check they're usable with this mech */
 472     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 473         major = GSS_S_BAD_MECH;
 474         goto cleanup;
 475     }
 476
 477     do {
 478         sm = &eapGssAcceptorSm[ctx->state];
 479
 480         major = (sm->processToken)(minor,
 481                                    ctx,
 482                                    cred,
 483                                    &innerInputToken,
 484                                    input_chan_bindings,
 485                                    &innerOutputToken);
 486         if (GSS_ERROR(major))
 487             goto cleanup;
 488     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 489
 490     if (mech_type != NULL) {
 491         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
 492             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
 493     }
 494     if (innerOutputToken.length != 0) {
 495         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 496                                    sm->outputTokenType, output_token);
 497         if (GSS_ERROR(tmpMajor)) {
 498             major = tmpMajor;
 499             *minor = tmpMinor;
 500             goto cleanup;
 501         }
 502     }
 503     if (ret_flags != NULL)
 504         *ret_flags = ctx->gssFlags;
 505     if (delegated_cred_handle != NULL)
 506         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 507
 508     if (major == GSS_S_COMPLETE) {
 509         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 510             major = gss_duplicate_name(&tmpMinor, ctx->initiatorName, src_name);
 511             if (GSS_ERROR(major))
 512                 goto cleanup;
 513         }
 514         if (time_rec != NULL)
 515             gss_context_time(&tmpMinor, ctx, time_rec);
 516     }
 517
 518     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 519
 520 cleanup:
 521     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 522
 523     if (GSS_ERROR(major))
 524         gssEapReleaseContext(&tmpMinor, context_handle);
 525
 526     gss_release_buffer(&tmpMinor, &innerOutputToken);
 527
 528     return major;
 529 }
 530
 531 /*
 532  * Mark a context as ready for cryptographic operations
 533  */
 534 static OM_uint32
 535 acceptReady(OM_uint32 *minor, gss_ctx_id_t ctx)
 536 {
 537     OM_uint32 major;
 538
 539     /* Cache encryption type derived from selected mechanism OID */
 540     major = gssEapOidToEnctype(minor, ctx->mechanismUsed, &ctx->encryptionType);
 541     if (GSS_ERROR(major))
 542         return major;
 543
 544     if (ctx->encryptionType != ENCTYPE_NULL &&
 545         EAP_KEY_AVAILABLE(ctx)) {
 546         major = gssEapDeriveRfc3961Key(minor,
 547                                        EAP_KEY_DATA(ctx),
 548                                        EAP_KEY_LENGTH(ctx),
 549                                        ctx->encryptionType,
 550                                        &ctx->rfc3961Key);
 551         if (GSS_ERROR(major))
 552             return major;
 553
 554         major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
 555                                            &ctx->checksumType);
 556         if (GSS_ERROR(major))
 557             return major;
 558     } else {
 559         /*
 560          * draft-howlett-eap-gss says that integrity/confidentialty should
 561          * always be advertised as available, but if we have no keying
 562          * material it seems confusing to the caller to advertise this.
 563          */
 564         ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
 565     }
 566
 567     major = sequenceInit(minor,
 568                          &ctx->seqState, ctx->recvSeq,
 569                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
 570                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
 571                          TRUE);
 572     if (GSS_ERROR(major))
 573         return major;
 574
 575     return GSS_S_COMPLETE;
 576 }