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_REAUTHENTICATE:
  58         s = "REAUTHENTICATE";
  59         break;
  60     case GSSEAP_STATE_ESTABLISHED:
  61         s = "ESTABLISHED";
  62         break;
  63     default:
  64         s = "INVALID";
  65         break;
  66     }
  67
  68     return s;
  69 }
  70
  71 static OM_uint32
  72 makeErrorToken(OM_uint32 *minor,
  73                OM_uint32 majorStatus,
  74                OM_uint32 minorStatus,
  75                gss_buffer_set_t *outputToken)
  76 {
  77     unsigned char errorData[8];
  78     gss_buffer_desc errorBuffer;
  79
  80     assert(GSS_ERROR(majorStatus));
  81
  82     /*
  83      * Only return error codes that the initiator could have caused,
  84      * to avoid information leakage.
  85      */
  86     if (IS_RADIUS_ERROR(minorStatus)) {
  87         /* Squash RADIUS error codes */
  88         minorStatus = GSSEAP_RADIUS_PROT_FAILURE;
  89     } else if (!IS_WIRE_ERROR(minorStatus)) {
  90         /* Don't return non-wire error codes */
  91         return GSS_S_COMPLETE;
  92     }
  93
  94     minorStatus -= ERROR_TABLE_BASE_eapg;
  95
  96     store_uint32_be(majorStatus, &errorData[0]);
  97     store_uint32_be(minorStatus, &errorData[4]);
  98
  99     errorBuffer.length = sizeof(errorData);
 100     errorBuffer.value = errorData;
 101
 102     return gss_add_buffer_set_member(minor, &errorBuffer, outputToken);
 103 }
 104
 105 OM_uint32
 106 gssEapSmStep(OM_uint32 *minor,
 107              gss_cred_id_t cred,
 108              gss_ctx_id_t ctx,
 109              gss_name_t target,
 110              gss_OID mech,
 111              OM_uint32 reqFlags,
 112              OM_uint32 timeReq,
 113              gss_channel_bindings_t chanBindings,
 114              gss_buffer_t inputToken,
 115              gss_buffer_t outputToken,
 116              struct gss_eap_sm *sm,
 117              size_t smCount)
 118 {
 119     OM_uint32 major, tmpMajor, tmpMinor;
 120     gss_buffer_desc unwrappedInputToken = GSS_C_EMPTY_BUFFER;
 121     gss_buffer_desc unwrappedOutputToken = GSS_C_EMPTY_BUFFER;
 122     gss_buffer_set_t innerInputTokens = GSS_C_NO_BUFFER_SET;
 123     gss_buffer_set_t innerOutputTokens = GSS_C_NO_BUFFER_SET;
 124     OM_uint32 *inputTokenTypes = NULL, *outputTokenTypes = NULL;
 125     unsigned int smFlags = 0;
 126     size_t i, j;
 127     int initialContextToken = 0;
 128
 129     assert(smCount > 0);
 130
 131     *minor = 0;
 132
 133     outputToken->length = 0;
 134     outputToken->value = NULL;
 135
 136     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
 137         enum gss_eap_token_type tokType;
 138
 139         major = gssEapVerifyToken(minor, ctx, inputToken, &tokType,
 140                                   &unwrappedInputToken);
 141         if (GSS_ERROR(major))
 142             goto cleanup;
 143
 144         if (tokType != TOK_TYPE_ESTABLISH_CONTEXT) {
 145             major = GSS_S_DEFECTIVE_TOKEN;
 146             *minor = GSSEAP_WRONG_TOK_ID;
 147             goto cleanup;
 148         }
 149     } else if (!CTX_IS_INITIATOR(ctx) || ctx->state != GSSEAP_STATE_INITIAL) {
 150         major = GSS_S_DEFECTIVE_TOKEN;
 151         *minor = GSSEAP_WRONG_SIZE;
 152         goto cleanup;
 153     } else {
 154         initialContextToken = 1;
 155     }
 156
 157     if (ctx->state == GSSEAP_STATE_ESTABLISHED) {
 158         major = GSS_S_BAD_STATUS;
 159         *minor = GSSEAP_CONTEXT_ESTABLISHED;
 160         goto cleanup;
 161     }
 162
 163     assert(ctx->state < GSSEAP_STATE_ESTABLISHED);
 164
 165     major = gssEapDecodeInnerTokens(minor, &unwrappedInputToken,
 166                                     &innerInputTokens, &inputTokenTypes);
 167     if (GSS_ERROR(major))
 168         goto cleanup;
 169
 170     assert(innerInputTokens != GSS_C_NO_BUFFER_SET);
 171
 172     major = gss_create_empty_buffer_set(minor, &innerOutputTokens);
 173     if (GSS_ERROR(major))
 174         goto cleanup;
 175
 176     assert(innerOutputTokens->count == 0);
 177     assert(innerOutputTokens->elements == NULL);
 178
 179     innerOutputTokens->elements = (gss_buffer_desc *)GSSEAP_CALLOC(smCount,
 180                                                                    sizeof(gss_buffer_desc));
 181     if (innerOutputTokens->elements == NULL) {
 182         major = GSS_S_FAILURE;
 183         *minor = ENOMEM;
 184         goto cleanup;
 185     }
 186
 187     outputTokenTypes = (OM_uint32 *)GSSEAP_CALLOC(smCount, sizeof(OM_uint32));
 188     if (outputTokenTypes == NULL) {
 189         major = GSS_S_FAILURE;
 190         *minor = ENOMEM;
 191         goto cleanup;
 192     }
 193
 194     /*
 195      * Process all the tokens that are valid for the current state. If
 196      * the processToken function returns GSS_S_COMPLETE, the state is
 197      * advanced until there is a token to send or the ESTABLISHED state
 198      * is reached.
 199      */
 200     do {
 201         major = GSS_S_COMPLETE;
 202
 203         for (i = 0; i < smCount; i++) {
 204             struct gss_eap_sm *smp = &sm[i];
 205             int processToken = 0;
 206             gss_buffer_t innerInputToken = GSS_C_NO_BUFFER;
 207             OM_uint32 *inputTokenType = NULL;
 208             gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
 209
 210             if ((smp->validStates & ctx->state) == 0)
 211                 continue;
 212
 213             if (smp->inputTokenType == ITOK_TYPE_NONE || initialContextToken) {
 214                 processToken = 1;
 215             } else if ((smFlags & SM_FLAG_TRANSITION) == 0) {
 216                 for (j = 0; j < innerInputTokens->count; j++) {
 217                     if ((inputTokenTypes[j] & ITOK_TYPE_MASK) == smp->inputTokenType) {
 218                         processToken = 1;
 219                         if (innerInputToken != GSS_C_NO_BUFFER) {
 220                             major = GSS_S_DEFECTIVE_TOKEN;
 221                             *minor = GSSEAP_DUPLICATE_ITOK;
 222                             break;
 223                         }
 224                     }
 225                     innerInputToken = &innerInputTokens->elements[j];
 226                     inputTokenType = &inputTokenTypes[j];
 227                 }
 228             }
 229
 230 #ifdef GSSEAP_DEBUG
 231             fprintf(stderr, "GSS-EAP: state %d processToken %d inputTokenType %08x "
 232                     "innerInputToken %p innerOutputTokensCount %zd\n",
 233                     ctx->state, processToken, smp->inputTokenType,
 234                     innerInputToken, innerOutputTokens->count);
 235 #endif
 236
 237             if (processToken) {
 238                 smFlags = 0;
 239
 240                 major = smp->processToken(minor, cred, ctx, target, mech, reqFlags,
 241                                          timeReq, chanBindings, innerInputToken,
 242                                          &innerOutputToken, &smFlags);
 243                 if (GSS_ERROR(major))
 244                     break;
 245
 246                 if (inputTokenType != NULL)
 247                     *inputTokenType |= ITOK_FLAG_VERIFIED;
 248
 249                 if (innerOutputToken.value != NULL) {
 250                     innerOutputTokens->elements[innerOutputTokens->count] = innerOutputToken;
 251                     assert(smp->outputTokenType != ITOK_TYPE_NONE);
 252                     outputTokenTypes[innerOutputTokens->count] = smp->outputTokenType;
 253                     if (smp->itokFlags & SM_ITOK_FLAG_CRITICAL)
 254                         outputTokenTypes[innerOutputTokens->count] |= ITOK_FLAG_CRITICAL;
 255                     innerOutputTokens->count++;
 256                 }
 257                 if (smFlags & SM_FLAG_STOP_EVAL)
 258                     break;
 259             } else if ((smp->itokFlags & SM_ITOK_FLAG_REQUIRED) &&
 260                 smp->inputTokenType != ITOK_TYPE_NONE) {
 261                 major = GSS_S_DEFECTIVE_TOKEN;
 262                 *minor = GSSEAP_MISSING_REQUIRED_ITOK;
 263                 break;
 264             }
 265         }
 266
 267         if (GSS_ERROR(major) || (smFlags & SM_FLAG_TRANSITION) == 0)
 268             break;
 269
 270         assert(ctx->state < GSSEAP_STATE_ESTABLISHED);
 271
 272 #ifdef GSSEAP_DEBUG
 273         fprintf(stderr, "GSS-EAP: state transition %s->%s\n",
 274                 gssEapStateToString(ctx->state),
 275                 gssEapStateToString(GSSEAP_STATE_NEXT(ctx->state)));
 276 #endif
 277
 278         ctx->state = GSSEAP_STATE_NEXT(ctx->state);
 279
 280         if (innerOutputTokens->count != 0 || (smFlags & SM_FLAG_FORCE_SEND_TOKEN)) {
 281             assert(major == GSS_S_CONTINUE_NEEDED || ctx->state == GSSEAP_STATE_ESTABLISHED);
 282             break; /* send any tokens if we have them */
 283         }
 284     } while (ctx->state != GSSEAP_STATE_ESTABLISHED);
 285
 286     assert(innerOutputTokens->count <= smCount);
 287
 288     /* Check we understood all critical tokens */
 289     if (!GSS_ERROR(major)) {
 290         for (j = 0; j < innerInputTokens->count; j++) {
 291             if ((inputTokenTypes[j] & ITOK_FLAG_CRITICAL) &&
 292                 (inputTokenTypes[j] & ITOK_FLAG_VERIFIED) == 0) {
 293                 major = GSS_S_UNAVAILABLE;
 294                 *minor = GSSEAP_CRIT_ITOK_UNAVAILABLE;
 295                 goto cleanup;
 296             }
 297         }
 298     }
 299
 300     /* Emit an error token if we are the acceptor */
 301     if (GSS_ERROR(major)) {
 302         if (CTX_IS_INITIATOR(ctx))
 303             goto cleanup; /* return error directly to caller */
 304
 305         /* replace any emitted tokens with error token */
 306         gss_release_buffer_set(&tmpMinor, &innerOutputTokens);
 307
 308         tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &innerOutputTokens);
 309         if (GSS_ERROR(tmpMajor)) {
 310             major = tmpMajor;
 311             *minor = tmpMinor;
 312             goto cleanup;
 313         }
 314
 315         outputTokenTypes[0] = ITOK_TYPE_CONTEXT_ERR | ITOK_FLAG_CRITICAL;
 316     }
 317
 318 #ifdef GSSEAP_DEBUG
 319     for (i = 0; i < innerOutputTokens->count; i++) {
 320         fprintf(stderr, "GSS-EAP: type %08x length %zd value %p\n",
 321                 outputTokenTypes[i],
 322                 innerOutputTokens->elements[i].length,
 323                 innerOutputTokens->elements[i].value);
 324     }
 325 #endif
 326
 327     /* Format composite output token */
 328     if (innerOutputTokens->count != 0 ||            /* inner tokens to send */
 329         !CTX_IS_INITIATOR(ctx) ||                   /* any leg acceptor */
 330         ctx->state != GSSEAP_STATE_ESTABLISHED) {   /* non-last leg initiator */
 331         tmpMajor = gssEapEncodeInnerTokens(&tmpMinor, innerOutputTokens,
 332                                            outputTokenTypes, &unwrappedOutputToken);
 333         if (tmpMajor == GSS_S_COMPLETE) {
 334             tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &unwrappedOutputToken,
 335                                        TOK_TYPE_ESTABLISH_CONTEXT, outputToken);
 336             if (GSS_ERROR(tmpMajor)) {
 337                 major = tmpMajor;
 338                 *minor = tmpMinor;
 339                 goto cleanup;
 340             }
 341         }
 342     }
 343
 344     assert(GSS_ERROR(major) ||
 345            (major == GSS_S_CONTINUE_NEEDED && (ctx->state > GSSEAP_STATE_INITIAL && ctx->state < GSSEAP_STATE_ESTABLISHED)) ||
 346            (major == GSS_S_COMPLETE && ctx->state == GSSEAP_STATE_ESTABLISHED));
 347
 348 cleanup:
 349     gss_release_buffer_set(&tmpMinor, &innerInputTokens);
 350     gss_release_buffer_set(&tmpMinor, &innerOutputTokens);
 351     if (inputTokenTypes != NULL)
 352         GSSEAP_FREE(inputTokenTypes);
 353     if (outputTokenTypes != NULL)
 354     gss_release_buffer(&tmpMinor, &unwrappedOutputToken);
 355         GSSEAP_FREE(outputTokenTypes);
 356
 357     return major;
 358 }