mech_eap/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 static OM_uint32
 187 peerConfigInit(OM_uint32 *minor,
 188                gss_cred_id_t cred,
 189                gss_ctx_id_t ctx,
 190                int loadConfig)
 191 {
 192     krb5_context krbContext;
 193     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
 194     krb5_error_code code;
 195     char *identity;
 196
 197     GSSEAP_KRB_INIT(&krbContext);
 198
 199     if (loadConfig) {
 200     }
 201
 202     code = krb5_unparse_name(krbContext, cred->name->krbPrincipal, &identity);
 203     if (code != 0) {
 204         *minor = code;
 205         return GSS_S_FAILURE;
 206     }
 207
 208     eapPeerConfig->identity = (unsigned char *)identity;
 209     eapPeerConfig->identity_len = strlen(identity);
 210     eapPeerConfig->password = (unsigned char *)cred->password.value;
 211     eapPeerConfig->password_len = cred->password.length;
 212
 213     return GSS_S_COMPLETE;
 214 }
 215
 216 static OM_uint32
 217 peerConfigFree(OM_uint32 *minor,
 218                gss_ctx_id_t ctx)
 219 {
 220     krb5_context krbContext;
 221     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
 222
 223     GSSEAP_KRB_INIT(&krbContext);
 224
 225     krb5_free_unparsed_name(krbContext, (char *)eapPeerConfig->identity);
 226
 227     return GSS_S_COMPLETE;
 228 }
 229
 230 static OM_uint32
 231 peerDeriveKey(OM_uint32 *minor,
 232               gss_ctx_id_t ctx)
 233 {
 234     OM_uint32 major;
 235     const unsigned char *key;
 236     size_t keyLength;
 237     krb5_context krbContext;
 238
 239     GSSEAP_KRB_INIT(&krbContext);
 240
 241     /* Cache encryption type derived from selected mechanism OID */
 242     major = gssEapOidToEnctype(minor, ctx->mechanismUsed, &ctx->encryptionType);
 243     if (GSS_ERROR(major))
 244         return major;
 245
 246     if (ctx->encryptionType != ENCTYPE_NULL &&
 247         eap_key_available(ctx->initiatorCtx.eap)) {
 248         key = eap_get_eapKeyData(ctx->initiatorCtx.eap, &keyLength);
 249
 250         major = gssEapDeriveRFC3961Key(minor, key, keyLength,
 251                                        ctx->encryptionType, &ctx->rfc3961Key);
 252         if (GSS_ERROR(major))
 253             return major;
 254     } else {
 255         /*
 256          * draft-howlett-eap-gss says that integrity/confidentialty should
 257          * always be advertised as available, but if we have no keying
 258          * material it seems confusing to the caller to advertise this.
 259          */
 260         ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
 261     }
 262
 263     return GSS_S_COMPLETE;
 264 }
 265
 266 static OM_uint32
 267 eapGssSmInitAuthenticate(OM_uint32 *minor,
 268                          gss_cred_id_t cred,
 269                          gss_ctx_id_t ctx,
 270                          gss_name_t target,
 271                          gss_OID mech,
 272                          OM_uint32 reqFlags,
 273                          OM_uint32 timeReq,
 274                          gss_channel_bindings_t chanBindings,
 275                          gss_buffer_t inputToken,
 276                          gss_buffer_t outputToken)
 277 {
 278     OM_uint32 major, tmpMinor;
 279     time_t now;
 280     int initialContextToken = 0, code;
 281
 282     initialContextToken = (inputToken == GSS_C_NO_BUFFER ||
 283                            inputToken->length == 0);
 284
 285     major = peerConfigInit(minor, cred, ctx, initialContextToken);
 286     if (GSS_ERROR(major))
 287         goto cleanup;
 288
 289     if (initialContextToken) {
 290         ctx->flags |= CTX_FLAG_EAP_PORT_ENABLED;
 291
 292         ctx->initiatorCtx.eap = eap_peer_sm_init(ctx,
 293                                                  &gssEapPolicyCallbacks,
 294                                                  ctx,
 295                                                  &ctx->initiatorCtx.eapConfig);
 296
 297         time(&now);
 298         if (timeReq == 0 || timeReq == GSS_C_INDEFINITE)
 299             ctx->expiryTime = 0;
 300         else
 301             ctx->expiryTime = now + timeReq;
 302
 303         major = gss_duplicate_name(minor, cred->name, &ctx->initiatorName);
 304         if (GSS_ERROR(major))
 305             goto cleanup;
 306
 307         major = gss_duplicate_name(minor, target, &ctx->acceptorName);
 308         if (GSS_ERROR(major))
 309             goto cleanup;
 310
 311         if (mech == GSS_C_NULL_OID || oidEqual(mech, GSS_EAP_MECHANISM)) {
 312             major = gssEapDefaultMech(minor, &ctx->mechanismUsed);
 313         } else if (gssEapIsConcreteMechanismOid(mech)) {
 314             if (!gssEapInternalizeOid(mech, &ctx->mechanismUsed))
 315                 major = duplicateOid(minor, mech, &ctx->mechanismUsed);
 316         } else {
 317             major = GSS_S_BAD_MECH;
 318         }
 319         if (GSS_ERROR(major))
 320             goto cleanup;
 321     }
 322
 323     wpabuf_set(&ctx->initiatorCtx.reqData,
 324                inputToken->value, inputToken->length);
 325
 326     code = eap_peer_sm_step(ctx->initiatorCtx.eap);
 327
 328     if (ctx->flags & CTX_FLAG_EAP_RESP) {
 329         struct wpabuf *resp;
 330         gss_buffer_desc buf;
 331
 332         ctx->flags &= ~(CTX_FLAG_EAP_RESP);
 333
 334         resp = eap_get_eapRespData(ctx->initiatorCtx.eap);
 335
 336         if (resp != NULL) {
 337             buf.length = wpabuf_len(resp);
 338             buf.value = (void *)wpabuf_head(resp);
 339
 340             major = duplicateBuffer(minor, &buf, outputToken);
 341             if (GSS_ERROR(major))
 342                 goto cleanup;
 343
 344             major = GSS_S_CONTINUE_NEEDED;
 345         }
 346     }
 347
 348     if (ctx->flags & CTX_FLAG_EAP_SUCCESS) {
 349         major = peerDeriveKey(minor, ctx);
 350         if (GSS_ERROR(major))
 351             goto cleanup;
 352
 353         ctx->state = EAP_STATE_ESTABLISHED;
 354     } else if (code == 0) {
 355         major = GSS_S_FAILURE;
 356     }
 357
 358 cleanup:
 359     wpabuf_set(&ctx->initiatorCtx.reqData, NULL, 0);
 360     peerConfigFree(&tmpMinor, ctx);
 361
 362     return major;
 363 }
 364
 365 static OM_uint32
 366 eapGssSmInitKeyTransport(OM_uint32 *minor,
 367                          gss_cred_id_t cred,
 368                          gss_ctx_id_t ctx,
 369                          gss_name_t target,
 370                          gss_OID mech,
 371                          OM_uint32 reqFlags,
 372                          OM_uint32 timeReq,
 373                          gss_channel_bindings_t chanBindings,
 374                          gss_buffer_t inputToken,
 375                          gss_buffer_t outputToken)
 376 {
 377     GSSEAP_NOT_IMPLEMENTED;
 378 }
 379
 380 static OM_uint32
 381 eapGssSmInitSecureAssoc(OM_uint32 *minor,
 382                         gss_cred_id_t cred,
 383                         gss_ctx_id_t ctx,
 384                         gss_name_t target,
 385                         gss_OID mech,
 386                         OM_uint32 reqFlags,
 387                         OM_uint32 timeReq,
 388                         gss_channel_bindings_t chanBindings,
 389                         gss_buffer_t inputToken,
 390                         gss_buffer_t outputToken)
 391 {
 392     GSSEAP_NOT_IMPLEMENTED;
 393 }
 394
 395 static OM_uint32
 396 eapGssSmInitGssChannelBindings(OM_uint32 *minor,
 397                                gss_cred_id_t cred,
 398                                gss_ctx_id_t ctx,
 399                                gss_name_t target,
 400                                gss_OID mech,
 401                                OM_uint32 reqFlags,
 402                                OM_uint32 timeReq,
 403                                gss_channel_bindings_t chanBindings,
 404                                gss_buffer_t inputToken,
 405                                gss_buffer_t outputToken)
 406 {
 407     GSSEAP_NOT_IMPLEMENTED;
 408 }
 409
 410 static OM_uint32
 411 eapGssSmInitEstablished(OM_uint32 *minor,
 412                         gss_cred_id_t cred,
 413                         gss_ctx_id_t ctx,
 414                         gss_name_t target,
 415                         gss_OID mech,
 416                         OM_uint32 reqFlags,
 417                         OM_uint32 timeReq,
 418                         gss_channel_bindings_t chanBindings,
 419                         gss_buffer_t inputToken,
 420                         gss_buffer_t outputToken)
 421 {
 422     /* Called with already established context */
 423     *minor = EINVAL;
 424     return GSS_S_BAD_STATUS;
 425 }
 426
 427 static struct eap_gss_initiator_sm {
 428     enum gss_eap_token_type inputTokenType;
 429     enum gss_eap_token_type outputTokenType;
 430     OM_uint32 (*processToken)(OM_uint32 *,
 431                               gss_cred_id_t,
 432                               gss_ctx_id_t,
 433                               gss_name_t,
 434                               gss_OID,
 435                               OM_uint32,
 436                               OM_uint32,
 437                               gss_channel_bindings_t,
 438                               gss_buffer_t,
 439                               gss_buffer_t);
 440 } eapGssInitiatorSm[] = {
 441     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitAuthenticate        },
 442     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitKeyTransport        },
 443     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitSecureAssoc         },
 444     { TOK_TYPE_GSS_CB,  TOK_TYPE_NONE,      eapGssSmInitGssChannelBindings  },
 445     { TOK_TYPE_NONE,    TOK_TYPE_NONE,      eapGssSmInitEstablished         },
 446 };
 447
 448 OM_uint32
 449 gss_init_sec_context(OM_uint32 *minor,
 450                      gss_cred_id_t cred,
 451                      gss_ctx_id_t *context_handle,
 452                      gss_name_t target_name,
 453                      gss_OID mech_type,
 454                      OM_uint32 req_flags,
 455                      OM_uint32 time_req,
 456                      gss_channel_bindings_t input_chan_bindings,
 457                      gss_buffer_t input_token,
 458                      gss_OID *actual_mech_type,
 459                      gss_buffer_t output_token,
 460                      OM_uint32 *ret_flags,
 461                      OM_uint32 *time_rec)
 462 {
 463     OM_uint32 major, tmpMinor;
 464     gss_ctx_id_t ctx = *context_handle;
 465     struct eap_gss_initiator_sm *sm = NULL;
 466     gss_buffer_desc innerInputToken, innerOutputToken;
 467
 468     *minor = 0;
 469
 470     innerOutputToken.length = 0;
 471     innerOutputToken.value = NULL;
 472
 473     output_token->length = 0;
 474     output_token->value = NULL;
 475
 476     if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_INITIATE)) {
 477         return GSS_S_NO_CRED;
 478     }
 479
 480     if (ctx == GSS_C_NO_CONTEXT) {
 481         if (input_token != GSS_C_NO_BUFFER && input_token->length != 0) {
 482             return GSS_S_DEFECTIVE_TOKEN;
 483         }
 484
 485         major = gssEapAllocContext(minor, &ctx);
 486         if (GSS_ERROR(major))
 487             return major;
 488
 489         ctx->flags |= CTX_FLAG_INITIATOR;
 490
 491         *context_handle = ctx;
 492     }
 493
 494     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 495
 496     sm = &eapGssInitiatorSm[ctx->state];
 497
 498     if (input_token != GSS_C_NO_BUFFER) {
 499         major = gssEapVerifyToken(minor, ctx, input_token,
 500                                   sm->inputTokenType, &innerInputToken);
 501         if (GSS_ERROR(major))
 502             goto cleanup;
 503     } else {
 504         innerInputToken.length = 0;
 505         innerInputToken.value = NULL;
 506     }
 507
 508     /*
 509      * Advance through state machine whilst empty tokens are emitted and
 510      * the status is not GSS_S_COMPLETE or an error status.
 511      */
 512     do {
 513         major = (sm->processToken)(minor,
 514                                    cred,
 515                                    ctx,
 516                                    target_name,
 517                                    mech_type,
 518                                    req_flags,
 519                                    time_req,
 520                                    input_chan_bindings,
 521                                    &innerInputToken,
 522                                    &innerOutputToken);
 523         if (GSS_ERROR(major))
 524             goto cleanup;
 525     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 526
 527     if (actual_mech_type != NULL) {
 528         if (!gssEapInternalizeOid(ctx->mechanismUsed, actual_mech_type))
 529             duplicateOid(&tmpMinor, ctx->mechanismUsed, actual_mech_type);
 530     }
 531     if (innerOutputToken.length != 0) {
 532         major = gssEapMakeToken(minor, ctx, &innerOutputToken,
 533                                 sm->outputTokenType, output_token);
 534         if (GSS_ERROR(major))
 535             goto cleanup;
 536     }
 537     if (ret_flags != NULL)
 538         *ret_flags = ctx->gssFlags;
 539     if (time_rec != NULL)
 540         gss_context_time(&tmpMinor, ctx, time_rec);
 541
 542     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 543
 544 cleanup:
 545     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 546
 547     if (GSS_ERROR(major))
 548         gssEapReleaseContext(&tmpMinor, context_handle);
 549
 550     gss_release_buffer(&tmpMinor, &innerOutputToken);
 551
 552     return major;
 553 }