www.project-moonshot.org Git - mech_eap.orig/blob - 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 RC_CONFIG_FILE      SYSCONFDIR "/radiusclient/radiusclient.conf"
  36
  37 /*
  38  * Mark a context as ready for cryptographic operations
  39  */
  40 static OM_uint32
  41 acceptReady(OM_uint32 *minor, gss_ctx_id_t ctx)
  42 {
  43     OM_uint32 major;
  44     VALUE_PAIR *vp;
  45     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
  46
  47     /* Cache encryption type derived from selected mechanism OID */
  48     major = gssEapOidToEnctype(minor, ctx->mechanismUsed,
  49                                &ctx->encryptionType);
  50     if (GSS_ERROR(major))
  51         return major;
  52
  53     vp = rc_avpair_get(ctx->acceptorCtx.avps, PW_USER_NAME, 0);
  54     if (vp != NULL) {
  55         nameBuf.length = vp->lvalue;
  56         nameBuf.value = vp->strvalue;
  57     } else {
  58         ctx->gssFlags |= GSS_C_ANON_FLAG;
  59     }
  60
  61     major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
  62                              &ctx->initiatorName);
  63     if (GSS_ERROR(major))
  64         return major;
  65
  66     vp = rc_avpair_get(ctx->acceptorCtx.avps, PW_MSCHAP2_SUCCESS, 0);
  67     if (ctx->encryptionType != ENCTYPE_NULL && vp != NULL) {
  68         major = gssEapDeriveRfc3961Key(minor,
  69                                        (unsigned char *)vp->strvalue,
  70                                        vp->lvalue,
  71                                        ctx->encryptionType,
  72                                        &ctx->rfc3961Key);
  73         if (GSS_ERROR(major))
  74             return major;
  75
  76         major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
  77                                            &ctx->checksumType);
  78         if (GSS_ERROR(major))
  79             return major;
  80     } else {
  81         /*
  82          * draft-howlett-eap-gss says that integrity/confidentialty should
  83          * always be advertised as available, but if we have no keying
  84          * material it seems confusing to the caller to advertise this.
  85          */
  86         ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
  87     }
  88
  89     major = sequenceInit(minor,
  90                          &ctx->seqState, ctx->recvSeq,
  91                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
  92                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
  93                          TRUE);
  94     if (GSS_ERROR(major))
  95         return major;
  96
  97     return GSS_S_COMPLETE;
  98 }
  99
 100 static OM_uint32
 101 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
 102                            gss_ctx_id_t ctx,
 103                            gss_cred_id_t cred,
 104                            gss_buffer_t inputToken,
 105                            gss_channel_bindings_t chanBindings,
 106                            gss_buffer_t outputToken)
 107 {
 108     OM_uint32 major;
 109     OM_uint32 service = PW_AUTHENTICATE_ONLY;
 110     int code;
 111     VALUE_PAIR *send = NULL;
 112     VALUE_PAIR *received = NULL;
 113     rc_handle *rh = ctx->acceptorCtx.radHandle;
 114     char msgBuffer[4096];
 115
 116     if (rh == NULL) {
 117         rh = ctx->acceptorCtx.radHandle = rc_read_config(RC_CONFIG_FILE);
 118         if (rh == NULL) {
 119             *minor = errno;
 120             major = GSS_S_FAILURE;
 121             goto cleanup;
 122         }
 123
 124         if (rc_read_dictionary(rh, rc_conf_str(rh, "dictionary")) != 0) {
 125             *minor = errno;
 126             major = GSS_S_FAILURE;
 127             goto cleanup;
 128         }
 129     }
 130
 131     if (ctx->acceptorName == GSS_C_NO_NAME &&
 132         cred != GSS_C_NO_CREDENTIAL &&
 133         cred->name != GSS_C_NO_NAME) {
 134         major = gss_duplicate_name(minor, cred->name, &ctx->acceptorName);
 135         if (GSS_ERROR(major))
 136             goto cleanup;
 137     }
 138
 139     if (rc_avpair_add(rh, &send, PW_EAP_MESSAGE,
 140                       inputToken->value, inputToken->length, 0) == NULL) {
 141         *minor = ENOMEM;
 142         major = GSS_S_FAILURE;
 143         goto cleanup;
 144     }
 145
 146     if (rc_avpair_add(rh, &send, PW_SERVICE_TYPE, &service, -1, 0) == NULL) {
 147         *minor = ENOMEM;
 148         major = GSS_S_FAILURE;
 149         goto cleanup;
 150     }
 151
 152     code = rc_auth(rh, 0, send, &received, msgBuffer);
 153     if (code != 0) {
 154         *minor = errno;
 155         major = GSS_S_UNAVAILABLE;
 156         goto cleanup;
 157     }
 158
 159     if (code == OK_RC || code == PW_ACCESS_CHALLENGE) {
 160         VALUE_PAIR *eapResponse;
 161         gss_buffer_desc eapBuf = GSS_C_EMPTY_BUFFER;
 162
 163         eapResponse = rc_avpair_get(received, PW_EAP_MESSAGE, 0);
 164         if (eapResponse != NULL) {
 165             eapBuf.length = eapResponse->lvalue;
 166             eapBuf.value = eapResponse->strvalue;
 167         }
 168
 169         major = duplicateBuffer(minor, &eapBuf, outputToken);
 170         if (GSS_ERROR(major))
 171             goto cleanup;
 172
 173         major = GSS_S_CONTINUE_NEEDED;
 174     } else {
 175         major = GSS_S_FAILURE;
 176         goto cleanup;
 177     }
 178
 179     if (code == OK_RC) {
 180         ctx->acceptorCtx.avps = received;
 181         received = NULL;
 182
 183         major = acceptReady(minor, ctx);
 184         if (GSS_ERROR(major))
 185             goto cleanup;
 186
 187         ctx->state = EAP_STATE_GSS_CHANNEL_BINDINGS;
 188         major = GSS_S_CONTINUE_NEEDED;
 189     }
 190
 191 cleanup:
 192     if (received != NULL)
 193         rc_avpair_free(received);
 194
 195     return major;
 196 }
 197
 198 static OM_uint32
 199 eapGssSmAcceptGssChannelBindings(OM_uint32 *minor,
 200                                  gss_ctx_id_t ctx,
 201                                  gss_cred_id_t cred,
 202                                  gss_buffer_t inputToken,
 203                                  gss_channel_bindings_t chanBindings,
 204                                  gss_buffer_t outputToken)
 205 {
 206     OM_uint32 major, tmpMinor;
 207     gss_iov_buffer_desc iov[2];
 208
 209     outputToken->length = 0;
 210     outputToken->value = NULL;
 211
 212     if (chanBindings == GSS_C_NO_CHANNEL_BINDINGS) {
 213         ctx->state = EAP_STATE_ESTABLISHED;
 214         return GSS_S_COMPLETE;
 215     }
 216
 217     if (inputToken->length < 14) {
 218         return GSS_S_DEFECTIVE_TOKEN;
 219     }
 220
 221     iov[0].type = GSS_IOV_BUFFER_TYPE_DATA;
 222     iov[0].buffer.length = 0;
 223     iov[0].buffer.value = NULL;
 224
 225     if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS)
 226         iov[0].buffer = chanBindings->application_data;
 227
 228     iov[1].type = GSS_IOV_BUFFER_TYPE_HEADER;
 229     iov[1].buffer.length = 16;
 230     iov[1].buffer.value = (unsigned char *)inputToken->value - 2;
 231
 232     assert(load_uint16_be(iov[1].buffer.value) == TOK_TYPE_GSS_CB);
 233
 234     iov[2].type = GSS_IOV_BUFFER_TYPE_TRAILER;
 235     iov[2].buffer.length = inputToken->length - 14;
 236     iov[2].buffer.value = (unsigned char *)inputToken->value + 14;
 237
 238     major = gssEapUnwrapOrVerifyMIC(minor, ctx, NULL, NULL,
 239                                     iov, 3, TOK_TYPE_GSS_CB);
 240     if (major == GSS_S_COMPLETE) {
 241         ctx->state = EAP_STATE_ESTABLISHED;
 242     }
 243
 244 #if 0
 245     gss_release_buffer(&tmpMinor, &iov[0].buffer);
 246 #endif
 247
 248     return major;
 249 }
 250
 251 static OM_uint32
 252 eapGssSmAcceptEstablished(OM_uint32 *minor,
 253                           gss_ctx_id_t ctx,
 254                           gss_cred_id_t cred,
 255                           gss_buffer_t inputToken,
 256                           gss_channel_bindings_t chanBindings,
 257                           gss_buffer_t outputToken)
 258 {
 259     /* Called with already established context */
 260     *minor = EINVAL;
 261     return GSS_S_BAD_STATUS;
 262 }
 263
 264 static struct gss_eap_acceptor_sm {
 265     enum gss_eap_token_type inputTokenType;
 266     enum gss_eap_token_type outputTokenType;
 267     OM_uint32 (*processToken)(OM_uint32 *,
 268                               gss_ctx_id_t,
 269                               gss_cred_id_t,
 270                               gss_buffer_t,
 271                               gss_channel_bindings_t,
 272                               gss_buffer_t);
 273 } eapGssAcceptorSm[] = {
 274     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,  eapGssSmAcceptAuthenticate       },
 275 #if 0
 276     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,  NULL                             },
 277     { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,  NULL                             },
 278 #endif
 279     { TOK_TYPE_GSS_CB,      TOK_TYPE_NONE,     eapGssSmAcceptGssChannelBindings },
 280     { TOK_TYPE_NONE,        TOK_TYPE_NONE,     eapGssSmAcceptEstablished        },
 281 };
 282
 283 OM_uint32
 284 gss_accept_sec_context(OM_uint32 *minor,
 285                        gss_ctx_id_t *context_handle,
 286                        gss_cred_id_t cred,
 287                        gss_buffer_t input_token,
 288                        gss_channel_bindings_t input_chan_bindings,
 289                        gss_name_t *src_name,
 290                        gss_OID *mech_type,
 291                        gss_buffer_t output_token,
 292                        OM_uint32 *ret_flags,
 293                        OM_uint32 *time_rec,
 294                        gss_cred_id_t *delegated_cred_handle)
 295 {
 296     OM_uint32 major;
 297     OM_uint32 tmpMajor, tmpMinor;
 298     gss_ctx_id_t ctx = *context_handle;
 299     struct gss_eap_acceptor_sm *sm = NULL;
 300     gss_buffer_desc innerInputToken = GSS_C_EMPTY_BUFFER;
 301     gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 302
 303     *minor = 0;
 304
 305     output_token->length = 0;
 306     output_token->value = NULL;
 307
 308     if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_ACCEPT)) {
 309         return GSS_S_NO_CRED;
 310     }
 311
 312     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
 313         return GSS_S_DEFECTIVE_TOKEN;
 314     }
 315
 316     if (ctx == GSS_C_NO_CONTEXT) {
 317         major = gssEapAllocContext(minor, &ctx);
 318         if (GSS_ERROR(major))
 319             return major;
 320
 321         *context_handle = ctx;
 322     }
 323
 324     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 325
 326     sm = &eapGssAcceptorSm[ctx->state];
 327
 328     major = gssEapVerifyToken(minor, ctx, input_token,
 329                               sm->inputTokenType, &innerInputToken);
 330     if (GSS_ERROR(major))
 331         goto cleanup;
 332
 333     /* If credentials were provided, check they're usable with this mech */
 334     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
 335         major = GSS_S_BAD_MECH;
 336         goto cleanup;
 337     }
 338
 339     do {
 340         sm = &eapGssAcceptorSm[ctx->state];
 341
 342         major = (sm->processToken)(minor,
 343                                    ctx,
 344                                    cred,
 345                                    &innerInputToken,
 346                                    input_chan_bindings,
 347                                    &innerOutputToken);
 348         if (GSS_ERROR(major))
 349             goto cleanup;
 350     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 351
 352     if (mech_type != NULL) {
 353         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
 354             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
 355     }
 356     if (innerOutputToken.length != 0) {
 357         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
 358                                    sm->outputTokenType, output_token);
 359         if (GSS_ERROR(tmpMajor)) {
 360             major = tmpMajor;
 361             *minor = tmpMinor;
 362             goto cleanup;
 363         }
 364     }
 365     if (ret_flags != NULL)
 366         *ret_flags = ctx->gssFlags;
 367     if (delegated_cred_handle != NULL)
 368         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 369
 370     if (major == GSS_S_COMPLETE) {
 371         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
 372             major = gss_duplicate_name(&tmpMinor, ctx->initiatorName, src_name);
 373             if (GSS_ERROR(major))
 374                 goto cleanup;
 375         }
 376         if (time_rec != NULL)
 377             gss_context_time(&tmpMinor, ctx, time_rec);
 378     }
 379
 380     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 381
 382 cleanup:
 383     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 384
 385     if (GSS_ERROR(major))
 386         gssEapReleaseContext(&tmpMinor, context_handle);
 387
 388     gss_release_buffer(&tmpMinor, &innerOutputToken);
 389
 390     return major;
 391 }
 392