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     return NULL;
 154 }
 155
 156 static void
 157 peerSetConfigBlob(void *ctx, struct wpa_config_blob *blob)
 158 {
 159 }
 160
 161 static const struct wpa_config_blob *
 162 peerGetConfigBlob(void *ctx, const char *name)
 163 {
 164     return NULL;
 165 }
 166
 167 static void
 168 peerNotifyPending(void *ctx)
 169 {
 170 }
 171
 172 static struct eapol_callbacks gssEapPolicyCallbacks = {
 173     peerGetConfig,
 174     peerGetBool,
 175     peerSetBool,
 176     peerGetInt,
 177     peerSetInt,
 178     peerGetEapReqData,
 179     peerSetConfigBlob,
 180     peerGetConfigBlob,
 181     peerNotifyPending,
 182 };
 183
 184 static OM_uint32
 185 peerConfigInit(OM_uint32 *minor,
 186                gss_cred_id_t cred,
 187                gss_ctx_id_t ctx,
 188                int loadConfig)
 189 {
 190     krb5_context krbContext;
 191     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
 192     krb5_error_code code;
 193     char *identity;
 194
 195     GSSEAP_KRB_INIT(&krbContext);
 196
 197     if (loadConfig) {
 198     }
 199
 200     code = krb5_unparse_name(krbContext, cred->name->krbPrincipal, &identity);
 201     if (code != 0) {
 202         *minor = code;
 203         return GSS_S_FAILURE;
 204     }
 205
 206     eapPeerConfig->identity = (unsigned char *)identity;
 207     eapPeerConfig->identity_len = strlen(identity);
 208     eapPeerConfig->password = (unsigned char *)cred->password.value;
 209     eapPeerConfig->password_len = cred->password.length;
 210
 211     return GSS_S_COMPLETE;
 212 }
 213
 214 static OM_uint32
 215 peerConfigFree(OM_uint32 *minor,
 216                gss_ctx_id_t ctx)
 217 {
 218     krb5_context krbContext;
 219     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
 220
 221     GSSEAP_KRB_INIT(&krbContext);
 222
 223     krb5_free_unparsed_name(krbContext, (char *)eapPeerConfig->identity);
 224
 225     return GSS_S_COMPLETE;
 226 }
 227
 228 static OM_uint32
 229 peerDeriveKey(OM_uint32 *minor,
 230               gss_ctx_id_t ctx)
 231 {
 232     OM_uint32 major;
 233     const unsigned char *key;
 234     size_t keyLength;
 235     krb5_context krbContext;
 236
 237     GSSEAP_KRB_INIT(&krbContext);
 238
 239     /* Cache encryption type derived from selected mechanism OID */
 240     major = gssEapOidToEnctype(minor, ctx->mechanismUsed, &ctx->encryptionType);
 241     if (GSS_ERROR(major))
 242         return major;
 243
 244     if (ctx->encryptionType != ENCTYPE_NULL &&
 245         eap_key_available(ctx->initiatorCtx.eap)) {
 246         key = eap_get_eapKeyData(ctx->initiatorCtx.eap, &keyLength);
 247
 248         major = gssEapDeriveRFC3961Key(minor, key, keyLength,
 249                                        ctx->encryptionType, &ctx->rfc3961Key);
 250         if (GSS_ERROR(major))
 251             return major;
 252     } else {
 253         /*
 254          * draft-howlett-eap-gss says that integrity/confidentialty should
 255          * always be advertised as available, but if we have no keying
 256          * material it seems confusing to the caller to advertise this.
 257          */
 258         ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
 259     }
 260
 261     return GSS_S_COMPLETE;
 262 }
 263
 264 static OM_uint32
 265 eapGssSmInitAuthenticate(OM_uint32 *minor,
 266                          gss_cred_id_t cred,
 267                          gss_ctx_id_t ctx,
 268                          gss_name_t target,
 269                          gss_OID mech,
 270                          OM_uint32 reqFlags,
 271                          OM_uint32 timeReq,
 272                          gss_channel_bindings_t chanBindings,
 273                          gss_buffer_t inputToken,
 274                          gss_buffer_t outputToken)
 275 {
 276     OM_uint32 major, tmpMinor;
 277     time_t now;
 278     int initialContextToken = 0, code;
 279
 280     initialContextToken = (inputToken == GSS_C_NO_BUFFER ||
 281                            inputToken->length == 0);
 282
 283     major = peerConfigInit(minor, cred, ctx, initialContextToken);
 284     if (GSS_ERROR(major))
 285         goto cleanup;
 286
 287     if (initialContextToken) {
 288         ctx->flags |= CTX_FLAG_EAP_PORT_ENABLED;
 289
 290         ctx->initiatorCtx.eap = eap_peer_sm_init(ctx,
 291                                                  &gssEapPolicyCallbacks,
 292                                                  ctx,
 293                                                  &ctx->initiatorCtx.eapConfig);
 294
 295         time(&now);
 296         if (timeReq == 0 || timeReq == GSS_C_INDEFINITE)
 297             ctx->expiryTime = 0;
 298         else
 299             ctx->expiryTime = now + timeReq;
 300
 301         major = gss_duplicate_name(minor, cred->name, &ctx->initiatorName);
 302         if (GSS_ERROR(major))
 303             goto cleanup;
 304
 305         major = gss_duplicate_name(minor, target, &ctx->acceptorName);
 306         if (GSS_ERROR(major))
 307             goto cleanup;
 308
 309         if (mech == GSS_C_NULL_OID || oidEqual(mech, GSS_EAP_MECHANISM)) {
 310             major = gssEapDefaultMech(minor, &ctx->mechanismUsed);
 311         } else if (gssEapIsConcreteMechanismOid(mech)) {
 312             if (!gssEapInternalizeOid(mech, &ctx->mechanismUsed))
 313                 major = duplicateOid(minor, mech, &ctx->mechanismUsed);
 314         } else {
 315             major = GSS_S_BAD_MECH;
 316         }
 317         if (GSS_ERROR(major))
 318             goto cleanup;
 319     }
 320
 321     code = eap_peer_sm_step(ctx->initiatorCtx.eap);
 322
 323     if (ctx->flags & CTX_FLAG_EAP_RESP) {
 324         struct wpabuf *resp;
 325         gss_buffer_desc buf;
 326
 327         ctx->flags &= ~(CTX_FLAG_EAP_RESP);
 328
 329         resp = eap_get_eapRespData(ctx->initiatorCtx.eap);
 330
 331         if (resp != NULL) {
 332             buf.length = wpabuf_len(resp);
 333             buf.value = (void *)wpabuf_head(resp);
 334
 335             major = duplicateBuffer(minor, &buf, outputToken);
 336             if (GSS_ERROR(major))
 337                 goto cleanup;
 338
 339             major = GSS_S_CONTINUE_NEEDED;
 340         }
 341     }
 342
 343     if (ctx->flags & CTX_FLAG_EAP_SUCCESS) {
 344         major = peerDeriveKey(minor, ctx);
 345         if (GSS_ERROR(major))
 346             goto cleanup;
 347
 348         ctx->state = EAP_STATE_ESTABLISHED;
 349     } else if (code == 0) {
 350         major = GSS_S_FAILURE;
 351     }
 352
 353 cleanup:
 354     peerConfigFree(&tmpMinor, ctx);
 355
 356     return major;
 357 }
 358
 359 static OM_uint32
 360 eapGssSmInitKeyTransport(OM_uint32 *minor,
 361                          gss_cred_id_t cred,
 362                          gss_ctx_id_t ctx,
 363                          gss_name_t target,
 364                          gss_OID mech,
 365                          OM_uint32 reqFlags,
 366                          OM_uint32 timeReq,
 367                          gss_channel_bindings_t chanBindings,
 368                          gss_buffer_t inputToken,
 369                          gss_buffer_t outputToken)
 370 {
 371     GSSEAP_NOT_IMPLEMENTED;
 372 }
 373
 374 static OM_uint32
 375 eapGssSmInitSecureAssoc(OM_uint32 *minor,
 376                         gss_cred_id_t cred,
 377                         gss_ctx_id_t ctx,
 378                         gss_name_t target,
 379                         gss_OID mech,
 380                         OM_uint32 reqFlags,
 381                         OM_uint32 timeReq,
 382                         gss_channel_bindings_t chanBindings,
 383                         gss_buffer_t inputToken,
 384                         gss_buffer_t outputToken)
 385 {
 386     GSSEAP_NOT_IMPLEMENTED;
 387 }
 388
 389 static OM_uint32
 390 eapGssSmInitGssChannelBindings(OM_uint32 *minor,
 391                                gss_cred_id_t cred,
 392                                gss_ctx_id_t ctx,
 393                                gss_name_t target,
 394                                gss_OID mech,
 395                                OM_uint32 reqFlags,
 396                                OM_uint32 timeReq,
 397                                gss_channel_bindings_t chanBindings,
 398                                gss_buffer_t inputToken,
 399                                gss_buffer_t outputToken)
 400 {
 401     GSSEAP_NOT_IMPLEMENTED;
 402 }
 403
 404 static OM_uint32
 405 eapGssSmInitEstablished(OM_uint32 *minor,
 406                         gss_cred_id_t cred,
 407                         gss_ctx_id_t ctx,
 408                         gss_name_t target,
 409                         gss_OID mech,
 410                         OM_uint32 reqFlags,
 411                         OM_uint32 timeReq,
 412                         gss_channel_bindings_t chanBindings,
 413                         gss_buffer_t inputToken,
 414                         gss_buffer_t outputToken)
 415 {
 416     /* Called with already established context */
 417     *minor = EINVAL;
 418     return GSS_S_BAD_STATUS;
 419 }
 420
 421 static struct eap_gss_initiator_sm {
 422     enum gss_eap_token_type inputTokenType;
 423     enum gss_eap_token_type outputTokenType;
 424     OM_uint32 (*processToken)(OM_uint32 *,
 425                               gss_cred_id_t,
 426                               gss_ctx_id_t,
 427                               gss_name_t,
 428                               gss_OID,
 429                               OM_uint32,
 430                               OM_uint32,
 431                               gss_channel_bindings_t,
 432                               gss_buffer_t,
 433                               gss_buffer_t);
 434 } eapGssInitiatorSm[] = {
 435     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitAuthenticate        },
 436     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitKeyTransport        },
 437     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitSecureAssoc         },
 438     { TOK_TYPE_GSS_CB,  TOK_TYPE_NONE,      eapGssSmInitGssChannelBindings  },
 439     { TOK_TYPE_NONE,    TOK_TYPE_NONE,      eapGssSmInitEstablished         },
 440 };
 441
 442 OM_uint32
 443 gss_init_sec_context(OM_uint32 *minor,
 444                      gss_cred_id_t cred,
 445                      gss_ctx_id_t *context_handle,
 446                      gss_name_t target_name,
 447                      gss_OID mech_type,
 448                      OM_uint32 req_flags,
 449                      OM_uint32 time_req,
 450                      gss_channel_bindings_t input_chan_bindings,
 451                      gss_buffer_t input_token,
 452                      gss_OID *actual_mech_type,
 453                      gss_buffer_t output_token,
 454                      OM_uint32 *ret_flags,
 455                      OM_uint32 *time_rec)
 456 {
 457     OM_uint32 major, tmpMinor;
 458     gss_ctx_id_t ctx = *context_handle;
 459     struct eap_gss_initiator_sm *sm = NULL;
 460     gss_buffer_desc innerInputToken, innerOutputToken;
 461
 462     *minor = 0;
 463
 464     innerOutputToken.length = 0;
 465     innerOutputToken.value = NULL;
 466
 467     output_token->length = 0;
 468     output_token->value = NULL;
 469
 470     if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_INITIATE)) {
 471         return GSS_S_NO_CRED;
 472     }
 473
 474     if (ctx == GSS_C_NO_CONTEXT) {
 475         if (input_token != GSS_C_NO_BUFFER && input_token->length != 0) {
 476             return GSS_S_DEFECTIVE_TOKEN;
 477         }
 478
 479         major = gssEapAllocContext(minor, &ctx);
 480         if (GSS_ERROR(major))
 481             return major;
 482
 483         ctx->flags |= CTX_FLAG_INITIATOR;
 484
 485         *context_handle = ctx;
 486     }
 487
 488     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 489
 490     sm = &eapGssInitiatorSm[ctx->state];
 491
 492     if (input_token != GSS_C_NO_BUFFER) {
 493         major = gssEapVerifyToken(minor, ctx, input_token,
 494                                   sm->inputTokenType, &innerInputToken);
 495         if (GSS_ERROR(major))
 496             goto cleanup;
 497     } else {
 498         innerInputToken.length = 0;
 499         innerInputToken.value = NULL;
 500     }
 501
 502     major = (sm->processToken)(minor,
 503                                cred,
 504                                ctx,
 505                                target_name,
 506                                mech_type,
 507                                req_flags,
 508                                time_req,
 509                                input_chan_bindings,
 510                                &innerInputToken,
 511                                &innerOutputToken);
 512     if (GSS_ERROR(major))
 513         goto cleanup;
 514
 515     if (actual_mech_type != NULL) {
 516         if (!gssEapInternalizeOid(ctx->mechanismUsed, actual_mech_type))
 517             duplicateOid(&tmpMinor, ctx->mechanismUsed, actual_mech_type);
 518     }
 519     if (innerOutputToken.length != 0) {
 520         major = gssEapMakeToken(minor, ctx, &innerOutputToken,
 521                                 sm->outputTokenType, output_token);
 522         if (GSS_ERROR(major))
 523             goto cleanup;
 524     }
 525     if (ret_flags != NULL)
 526         *ret_flags = ctx->gssFlags;
 527     if (time_rec != NULL)
 528         gss_context_time(&tmpMinor, ctx, time_rec);
 529
 530     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 531
 532 cleanup:
 533     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 534
 535     if (GSS_ERROR(major))
 536         gssEapReleaseContext(&tmpMinor, context_handle);
 537
 538     gss_release_buffer(&tmpMinor, &innerOutputToken);
 539
 540     return major;
 541 }