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