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34 * Context establishment state machine.
37 #include "gssapiP_eap.h"
40 #define SM_FLAG_TRANSITED 0x80000000
42 #define SM_ASSERT_VALID(ctx, status) do { \
43 assert(GSS_ERROR((status)) || \
44 ((status) == GSS_S_CONTINUE_NEEDED && ((ctx)->state > GSSEAP_STATE_INITIAL && (ctx)->state < GSSEAP_STATE_ESTABLISHED)) || \
45 ((status) == GSS_S_COMPLETE && (ctx)->state == GSSEAP_STATE_ESTABLISHED)); \
50 gssEapStateToString(enum gss_eap_state state)
55 case GSSEAP_STATE_INITIAL:
58 case GSSEAP_STATE_AUTHENTICATE:
61 case GSSEAP_STATE_INITIATOR_EXTS:
64 case GSSEAP_STATE_ACCEPTOR_EXTS:
67 #ifdef GSSEAP_ENABLE_REAUTH
68 case GSSEAP_STATE_REAUTHENTICATE:
72 case GSSEAP_STATE_ESTABLISHED:
84 gssEapSmTransition(gss_ctx_id_t ctx, enum gss_eap_state state)
86 assert(state >= GSSEAP_STATE_INITIAL);
87 assert(state <= GSSEAP_STATE_ESTABLISHED);
89 fprintf(stderr, "GSS-EAP: state transition %s->%s\n",
90 gssEapStateToString(GSSEAP_SM_STATE(ctx)),
91 gssEapStateToString(state));
95 #endif /* GSSEAP_DEBUG */
98 makeErrorToken(OM_uint32 *minor,
99 OM_uint32 majorStatus,
100 OM_uint32 minorStatus,
101 struct gss_eap_token_buffer_set *token)
103 OM_uint32 major, tmpMinor;
104 unsigned char errorData[8];
105 gss_buffer_desc errorBuffer;
107 assert(GSS_ERROR(majorStatus));
110 * Only return error codes that the initiator could have caused,
111 * to avoid information leakage.
113 if (IS_RADIUS_ERROR(minorStatus)) {
114 /* Squash RADIUS error codes */
115 minorStatus = GSSEAP_RADIUS_PROT_FAILURE;
116 } else if (!IS_WIRE_ERROR(minorStatus)) {
117 /* Don't return non-wire error codes */
118 return GSS_S_COMPLETE;
121 minorStatus -= ERROR_TABLE_BASE_eapg;
123 store_uint32_be(majorStatus, &errorData[0]);
124 store_uint32_be(minorStatus, &errorData[4]);
126 major = gssEapAllocInnerTokens(&tmpMinor, 1, token);
127 if (GSS_ERROR(major)) {
132 errorBuffer.length = sizeof(errorData);
133 errorBuffer.value = errorData;
135 major = duplicateBuffer(&tmpMinor, &errorBuffer, &token->buffers.elements[0]);
136 if (GSS_ERROR(major)) {
137 gssEapReleaseInnerTokens(&tmpMinor, token, 1);
142 token->types[0] = ITOK_TYPE_CONTEXT_ERR | ITOK_FLAG_CRITICAL;
145 return GSS_S_COMPLETE;
149 gssEapSmStep(OM_uint32 *minor,
156 gss_channel_bindings_t chanBindings,
157 gss_buffer_t inputToken,
158 gss_buffer_t outputToken,
159 struct gss_eap_sm *sm, /* ordered by state */
162 OM_uint32 major, tmpMajor, tmpMinor;
163 struct gss_eap_token_buffer_set inputTokens = { { 0, GSS_C_NO_BUFFER }, NULL };
164 struct gss_eap_token_buffer_set outputTokens = { { 0, GSS_C_NO_BUFFER }, NULL };
165 gss_buffer_desc unwrappedInputToken = GSS_C_EMPTY_BUFFER;
166 gss_buffer_desc unwrappedOutputToken = GSS_C_EMPTY_BUFFER;
167 unsigned int smFlags = 0;
169 int initialContextToken = 0;
170 enum gss_eap_token_type tokType;
176 outputToken->length = 0;
177 outputToken->value = NULL;
179 if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
180 major = gssEapVerifyToken(minor, ctx, inputToken, &tokType,
181 &unwrappedInputToken);
182 if (GSS_ERROR(major))
185 if (tokType != (CTX_IS_INITIATOR(ctx)
186 ? TOK_TYPE_ACCEPTOR_CONTEXT : TOK_TYPE_INITIATOR_CONTEXT)) {
187 major = GSS_S_DEFECTIVE_TOKEN;
188 *minor = GSSEAP_WRONG_TOK_ID;
191 } else if (!CTX_IS_INITIATOR(ctx) || ctx->state != GSSEAP_STATE_INITIAL) {
192 major = GSS_S_DEFECTIVE_TOKEN;
193 *minor = GSSEAP_WRONG_SIZE;
196 initialContextToken = 1;
199 if (CTX_IS_ESTABLISHED(ctx)) {
200 major = GSS_S_BAD_STATUS;
201 *minor = GSSEAP_CONTEXT_ESTABLISHED;
205 assert(ctx->state < GSSEAP_STATE_ESTABLISHED);
207 major = gssEapDecodeInnerTokens(minor, &unwrappedInputToken, &inputTokens);
208 if (GSS_ERROR(major))
211 major = gssEapAllocInnerTokens(minor, smCount, &outputTokens);
212 if (GSS_ERROR(major))
215 ctx->inputTokens = &inputTokens;
216 ctx->outputTokens = &outputTokens;
218 /* Process all the tokens that are valid for the current state. */
219 for (i = 0; i < smCount; i++) {
220 struct gss_eap_sm *smp = &sm[i];
221 int processToken = 0;
222 gss_buffer_t innerInputToken = GSS_C_NO_BUFFER;
223 OM_uint32 *inputTokenType = NULL;
224 gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
226 if ((smp->validStates & ctx->state) == 0)
230 * We special case the first call to gss_init_sec_context so that
231 * all token providers have the opportunity to generate an initial
232 * context token. Providers where inputTokenType is ITOK_TYPE_NONE
233 * are always called and generally act on state transition boundaries,
234 * for example to advance the state after a series of optional tokens
235 * (as is the case with the extension token exchange) or to generate
236 * a new token after the state was advanced by a provider which did
239 if (smp->inputTokenType == ITOK_TYPE_NONE || initialContextToken) {
241 } else if ((smFlags & SM_FLAG_TRANSITED) == 0) {
242 /* Don't regurgitate a token which belonds to a previous state. */
243 for (j = 0; j < inputTokens.buffers.count; j++) {
244 if ((inputTokens.types[j] & ITOK_TYPE_MASK) == smp->inputTokenType) {
246 /* Check for duplicate inner tokens */
247 major = GSS_S_DEFECTIVE_TOKEN;
248 *minor = GSSEAP_DUPLICATE_ITOK;
252 innerInputToken = &inputTokens.buffers.elements[j];
253 inputTokenType = &inputTokens.types[j];
256 if (GSS_ERROR(major))
261 enum gss_eap_state oldState = ctx->state;
264 if (inputTokenType != NULL && (*inputTokenType & ITOK_FLAG_CRITICAL))
265 smFlags |= SM_FLAG_INPUT_TOKEN_CRITICAL;
267 major = smp->processToken(minor, cred, ctx, target, mech, reqFlags,
268 timeReq, chanBindings, innerInputToken,
269 &innerOutputToken, &smFlags);
270 if (GSS_ERROR(major))
273 if (inputTokenType != NULL)
274 *inputTokenType |= ITOK_FLAG_VERIFIED;
275 if (ctx->state < oldState)
277 else if (ctx->state != oldState)
278 smFlags |= SM_FLAG_TRANSITED;
280 if (innerOutputToken.value != NULL) {
281 outputTokens.buffers.elements[outputTokens.buffers.count] = innerOutputToken;
282 assert(smp->outputTokenType != ITOK_TYPE_NONE);
283 outputTokens.types[outputTokens.buffers.count] = smp->outputTokenType;
284 if (smFlags & SM_FLAG_OUTPUT_TOKEN_CRITICAL)
285 outputTokens.types[outputTokens.buffers.count] |= ITOK_FLAG_CRITICAL;
286 outputTokens.buffers.count++;
289 * Break out if we made a state transition and have some tokens to send.
291 if ((smFlags & SM_FLAG_TRANSITED) &&
292 ((smFlags & SM_FLAG_FORCE_SEND_TOKEN) || outputTokens.buffers.count != 0)) {
293 SM_ASSERT_VALID(ctx, major);
296 } else if ((smp->itokFlags & SM_ITOK_FLAG_REQUIRED) &&
297 smp->inputTokenType != ITOK_TYPE_NONE) {
298 /* Check for required inner tokens */
299 major = GSS_S_DEFECTIVE_TOKEN;
300 *minor = GSSEAP_MISSING_REQUIRED_ITOK;
305 assert(outputTokens.buffers.count <= smCount);
307 /* Check we understood all critical tokens sent by peer */
308 if (!GSS_ERROR(major)) {
309 for (j = 0; j < inputTokens.buffers.count; j++) {
310 if ((inputTokens.types[j] & ITOK_FLAG_CRITICAL) &&
311 (inputTokens.types[j] & ITOK_FLAG_VERIFIED) == 0) {
312 major = GSS_S_UNAVAILABLE;
313 *minor = GSSEAP_CRIT_ITOK_UNAVAILABLE;
319 /* Optionaly emit an error token if we are the acceptor */
320 if (GSS_ERROR(major)) {
321 if (CTX_IS_INITIATOR(ctx))
322 goto cleanup; /* return error directly to caller */
324 /* replace any emitted tokens with error token */
325 gssEapReleaseInnerTokens(&tmpMinor, &outputTokens, 1);
327 tmpMajor = makeErrorToken(&tmpMinor, major, *minor, &outputTokens);
328 if (GSS_ERROR(tmpMajor)) {
335 /* Format output token from inner tokens */
336 if (outputTokens.buffers.count != 0 || /* inner tokens to send */
337 !CTX_IS_INITIATOR(ctx) || /* any leg acceptor */
338 !CTX_IS_ESTABLISHED(ctx)) { /* non-last leg initiator */
339 tmpMajor = gssEapEncodeInnerTokens(&tmpMinor, &outputTokens, &unwrappedOutputToken);
340 if (tmpMajor == GSS_S_COMPLETE) {
341 if (CTX_IS_INITIATOR(ctx))
342 tokType = TOK_TYPE_INITIATOR_CONTEXT;
344 tokType = TOK_TYPE_ACCEPTOR_CONTEXT;
346 tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &unwrappedOutputToken,
347 tokType, outputToken);
348 if (GSS_ERROR(tmpMajor)) {
356 /* If the context is established, empty tokens only to be emitted by initiator */
357 assert(!CTX_IS_ESTABLISHED(ctx) || ((outputToken->length == 0) == CTX_IS_INITIATOR(ctx)));
359 SM_ASSERT_VALID(ctx, major);
362 gssEapReleaseInnerTokens(&tmpMinor, &inputTokens, 0);
363 gssEapReleaseInnerTokens(&tmpMinor, &inputTokens, 1);
365 gss_release_buffer(&tmpMinor, &unwrappedOutputToken);
367 ctx->inputTokens = NULL;
368 ctx->outputTokens = NULL;