www.project-moonshot.org Git - mech_eap.orig/blob - util_sm.c

   1 /*
   2  * Copyright (c) 2011, 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 /*
  34  * Context establishment state machine.
  35  */
  36
  37 #include "gssapiP_eap.h"
  38
  39 static const char *
  40 gssEapStateToString(enum gss_eap_state state)
  41 {
  42     const char *s;
  43
  44     switch (state) {
  45     case GSSEAP_STATE_INITIAL:
  46         s = "INITIAL";
  47         break;
  48     case GSSEAP_STATE_AUTHENTICATE:
  49         s = "AUTHENTICATE";
  50         break;
  51     case GSSEAP_STATE_INITIATOR_EXTS:
  52         s = "INITIATOR_EXTS";
  53         break;
  54     case GSSEAP_STATE_ACCEPTOR_EXTS:
  55         s = "ACCEPTOR_EXTS";
  56         break;
  57     case GSSEAP_STATE_ESTABLISHED:
  58         s = "ESTABLISHED";
  59         break;
  60     default:
  61         s = "INVALID";
  62         break;
  63     }
  64
  65     return s;
  66 }
  67
  68 static OM_uint32
  69 makeErrorToken(OM_uint32 *minor,
  70                OM_uint32 majorStatus,
  71                OM_uint32 minorStatus,
  72                gss_buffer_set_t *outputToken)
  73 {
  74     unsigned char errorData[8];
  75     gss_buffer_desc errorBuffer;
  76
  77     assert(GSS_ERROR(majorStatus));
  78
  79     /*
  80      * Only return error codes that the initiator could have caused,
  81      * to avoid information leakage.
  82      */
  83     if (IS_RADIUS_ERROR(minorStatus)) {
  84         /* Squash RADIUS error codes */
  85         minorStatus = GSSEAP_RADIUS_PROT_FAILURE;
  86     } else if (!IS_WIRE_ERROR(minorStatus)) {
  87         /* Don't return non-wire error codes */
  88         return GSS_S_COMPLETE;
  89     }
  90
  91     minorStatus -= ERROR_TABLE_BASE_eapg;
  92
  93     store_uint32_be(majorStatus, &errorData[0]);
  94     store_uint32_be(minorStatus, &errorData[4]);
  95
  96     errorBuffer.length = sizeof(errorData);
  97     errorBuffer.value = errorData;
  98
  99     return gss_add_buffer_set_member(minor, &errorBuffer, outputToken);
 100 }
 101
 102 OM_uint32
 103 gssEapSmStep(OM_uint32 *minor,
 104              gss_cred_id_t cred,
 105              gss_ctx_id_t ctx,
 106              gss_name_t target,
 107              gss_OID mech,
 108              OM_uint32 reqFlags,
 109              OM_uint32 timeReq,
 110              gss_channel_bindings_t chanBindings,
 111              gss_buffer_t inputToken,
 112              gss_buffer_t outputToken,
 113              struct gss_eap_sm *sm,
 114              size_t smCount)
 115 {
 116     OM_uint32 major, tmpMajor, tmpMinor;
 117     gss_buffer_desc unwrappedInputToken = GSS_C_EMPTY_BUFFER;
 118     gss_buffer_desc unwrappedOutputToken = GSS_C_EMPTY_BUFFER;
 119     gss_buffer_set_t innerInputTokens = GSS_C_NO_BUFFER_SET;
 120     gss_buffer_set_t innerOutputTokens = GSS_C_NO_BUFFER_SET;
 121     OM_uint32 *inputTokenTypes = NULL, *outputTokenTypes = NULL;
 122     unsigned int smFlags = 0;
 123     size_t i, j;
 124     int initialContextToken = 0;
 125
 126     assert(smCount > 0);
 127
 128     *minor = 0;
 129
 130     outputToken->length = 0;
 131     outputToken->value = NULL;
 132
 133     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
 134         enum gss_eap_token_type tokType;
 135
 136         major = gssEapVerifyToken(minor, ctx, inputToken, &tokType,
 137                                   &unwrappedInputToken);
 138         if (GSS_ERROR(major))
 139             goto cleanup;
 140
 141         if (tokType != TOK_TYPE_ESTABLISH_CONTEXT) {
 142             major = GSS_S_DEFECTIVE_TOKEN;
 143             *minor = GSSEAP_WRONG_TOK_ID;
 144             goto cleanup;
 145         }
 146     } else if (!CTX_IS_INITIATOR(ctx) || ctx->state != GSSEAP_STATE_INITIAL) {
 147         major = GSS_S_DEFECTIVE_TOKEN;
 148         *minor = GSSEAP_WRONG_SIZE;
 149         goto cleanup;
 150     } else {
 151         initialContextToken = 1;
 152     }
 153
 154     if (ctx->state == GSSEAP_STATE_ESTABLISHED) {
 155         major = GSS_S_BAD_STATUS;
 156         *minor = GSSEAP_CONTEXT_ESTABLISHED;
 157         goto cleanup;
 158     }
 159
 160     assert(ctx->state < GSSEAP_STATE_ESTABLISHED);
 161
 162     major = gssEapDecodeInnerTokens(minor, &unwrappedInputToken,
 163                                     &innerInputTokens, &inputTokenTypes);
 164     if (GSS_ERROR(major))
 165         goto cleanup;
 166
 167     assert(innerInputTokens != GSS_C_NO_BUFFER_SET);
 168
 169     major = gss_create_empty_buffer_set(minor, &innerOutputTokens);
 170     if (GSS_ERROR(major))
 171         goto cleanup;
 172
 173     assert(innerOutputTokens->count == 0);
 174     assert(innerOutputTokens->elements == NULL);
 175
 176     innerOutputTokens->elements = (gss_buffer_desc *)GSSEAP_CALLOC(smCount,
 177                                                                    sizeof(gss_buffer_desc));
 178     if (innerOutputTokens->elements == NULL) {
 179         major = GSS_S_FAILURE;
 180         *minor = ENOMEM;
 181         goto cleanup;
 182     }
 183
 184     outputTokenTypes = (OM_uint32 *)GSSEAP_CALLOC(smCount, sizeof(OM_uint32));
 185     if (outputTokenTypes == NULL) {
 186         major = GSS_S_FAILURE;
 187         *minor = ENOMEM;
 188         goto cleanup;
 189     }
 190
 191     /*
 192      * Process all the tokens that are valid for the current state. If
 193      * the processToken function returns GSS_S_COMPLETE, the state is
 194      * advanced until there is a token to send or the ESTABLISHED state
 195      * is reached.
 196      */
 197     do {
 198         major = GSS_S_COMPLETE;
 199
 200         for (i = 0; i < smCount; i++) {
 201             struct gss_eap_sm *smp = &sm[i];
 202             int processToken = 0;
 203             gss_buffer_t innerInputToken = GSS_C_NO_BUFFER;
 204             OM_uint32 *inputTokenType = NULL;
 205             gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 206
 207             if ((smp->validStates & ctx->state) == 0)
 208                 continue;
 209
 210             if (smp->inputTokenType == ITOK_TYPE_NONE || initialContextToken) {
 211                 processToken = 1;
 212             } else if ((smFlags & SM_FLAG_TRANSITION) == 0) {
 213                 for (j = 0; j < innerInputTokens->count; j++) {
 214                     if ((inputTokenTypes[j] & ITOK_TYPE_MASK) == smp->inputTokenType) {
 215                         processToken = 1;
 216                         if (innerInputToken != GSS_C_NO_BUFFER) {
 217                             major = GSS_S_DEFECTIVE_TOKEN;
 218                             *minor = GSSEAP_DUPLICATE_ITOK;
 219                             break;
 220                         }
 221                     }
 222                     innerInputToken = &innerInputTokens->elements[j];
 223                     inputTokenType = &inputTokenTypes[j];
 224                 }
 225             }
 226
 227 #ifdef GSSEAP_DEBUG
 228             fprintf(stderr, "GSS-EAP: state %d processToken %d inputTokenType %08x "
 229                     "innerInputToken %p innerOutputTokensCount %zd\n",
 230                     ctx->state, processToken, smp->inputTokenType,
 231                     innerInputToken, innerOutputTokens->count);
 232 #endif
 233
 234             if (processToken) {
 235                 smFlags = 0;
 236
 237                 major = smp->processToken(minor, cred, ctx, target, mech, reqFlags,
 238                                          timeReq, chanBindings, innerInputToken,
 239                                          &innerOutputToken, &smFlags);
 240                 if (GSS_ERROR(major))
 241                     break;
 242
 243                 if (inputTokenType != NULL)
 244                     *inputTokenType |= ITOK_FLAG_VERIFIED;
 245
 246                 if (innerOutputToken.value != NULL) {
 247                     innerOutputTokens->elements[innerOutputTokens->count] = innerOutputToken;
 248                     assert(smp->outputTokenType != ITOK_TYPE_NONE);
 249                     outputTokenTypes[innerOutputTokens->count] = smp->outputTokenType;
 250                     if (smp->critical)
 251                         outputTokenTypes[innerOutputTokens->count] |= ITOK_FLAG_CRITICAL;
 252                     innerOutputTokens->count++;
 253                 }
 254                 if (smFlags & SM_FLAG_STOP_EVAL)
 255                     break;
 256             } else if (smp->required && smp->inputTokenType != ITOK_TYPE_NONE) {
 257                 major = GSS_S_DEFECTIVE_TOKEN;
 258                 *minor = GSSEAP_MISSING_REQUIRED_ITOK;
 259                 break;
 260             }
 261         }
 262
 263         if (GSS_ERROR(major) || (smFlags & SM_FLAG_TRANSITION) == 0)
 264             break;
 265
 266         assert(ctx->state < GSSEAP_STATE_ESTABLISHED);
 267
 268 #ifdef GSSEAP_DEBUG
 269         fprintf(stderr, "GSS-EAP: state transition %s->%s\n",
 270                 gssEapStateToString(ctx->state),
 271                 gssEapStateToString(GSSEAP_STATE_NEXT(ctx->state)));
 272 #endif
 273
 274         ctx->state = GSSEAP_STATE_NEXT(ctx->state);
 275
 276         if (innerOutputTokens->count != 0 || (smFlags & SM_FLAG_FORCE_SEND_TOKEN)) {
 277             assert(major == GSS_S_CONTINUE_NEEDED || ctx->state == GSSEAP_STATE_ESTABLISHED);
 278             break; /* send any tokens if we have them */
 279         }
 280     } while (ctx->state != GSSEAP_STATE_ESTABLISHED);
 281
 282     assert(innerOutputTokens->count <= smCount);
 283
 284     /* Check we understood all critical tokens */
 285     if (!GSS_ERROR(major)) {
 286         for (j = 0; j < innerInputTokens->count; j++) {
 287             if ((inputTokenTypes[j] & ITOK_FLAG_CRITICAL) &&
 288                 (inputTokenTypes[j] & ITOK_FLAG_VERIFIED) == 0) {
 289                 major = GSS_S_UNAVAILABLE;
 290                 *minor = GSSEAP_CRIT_ITOK_UNAVAILABLE;
 291                 goto cleanup;
 292             }
 293         }
 294     }
 295
 296     /* Emit an error token if we are the acceptor */
 297     if (GSS_ERROR(major)) {
 298         if (CTX_IS_INITIATOR(ctx))
 299             goto cleanup; /* return error directly to caller */
 300
 301         /* replace any emitted tokens with error token */
 302         gss_release_buffer_set(&tmpMinor, &innerOutputTokens);
 303
 304         tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &innerOutputTokens);
 305         if (GSS_ERROR(tmpMajor)) {
 306             major = tmpMajor;
 307             *minor = tmpMinor;
 308             goto cleanup;
 309         }
 310
 311         outputTokenTypes[0] = ITOK_TYPE_CONTEXT_ERR | ITOK_FLAG_CRITICAL;
 312     }
 313
 314 #ifdef GSSEAP_DEBUG
 315     for (i = 0; i < innerOutputTokens->count; i++) {
 316         fprintf(stderr, "GSS-EAP: type %08x length %zd value %p\n",
 317                 outputTokenTypes[i],
 318                 innerOutputTokens->elements[i].length,
 319                 innerOutputTokens->elements[i].value);
 320     }
 321 #endif
 322
 323     /* Format composite output token */
 324     if (innerOutputTokens->count != 0 ||            /* inner tokens to send */
 325         !CTX_IS_INITIATOR(ctx) ||                   /* any leg acceptor */
 326         ctx->state != GSSEAP_STATE_ESTABLISHED) {   /* non-last leg initiator */
 327         tmpMajor = gssEapEncodeInnerTokens(&tmpMinor, innerOutputTokens,
 328                                            outputTokenTypes, &unwrappedOutputToken);
 329         if (tmpMajor == GSS_S_COMPLETE) {
 330             tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &unwrappedOutputToken,
 331                                        TOK_TYPE_ESTABLISH_CONTEXT, outputToken);
 332             if (GSS_ERROR(tmpMajor)) {
 333                 major = tmpMajor;
 334                 *minor = tmpMinor;
 335                 goto cleanup;
 336             }
 337         }
 338     }
 339
 340     assert(GSS_ERROR(major) ||
 341            (major == GSS_S_CONTINUE_NEEDED && (ctx->state > GSSEAP_STATE_INITIAL && ctx->state < GSSEAP_STATE_ESTABLISHED)) ||
 342            (major == GSS_S_COMPLETE && ctx->state == GSSEAP_STATE_ESTABLISHED));
 343
 344 cleanup:
 345     gss_release_buffer_set(&tmpMinor, &innerInputTokens);
 346     gss_release_buffer_set(&tmpMinor, &innerOutputTokens);
 347     if (inputTokenTypes != NULL)
 348         GSSEAP_FREE(inputTokenTypes);
 349     if (outputTokenTypes != NULL)
 350     gss_release_buffer(&tmpMinor, &unwrappedOutputToken);
 351         GSSEAP_FREE(outputTokenTypes);
 352
 353     return major;
 354 }