Implement channel bindings
[cyrus-sasl.git] / mech_eap / 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
74 static struct eap_peer_config *
75 peerGetConfig(void *ctx)
76 {
77     gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
78
79     return &gssCtx->initiatorCtx.eapPeerConfig;
80 }
81
82 static Boolean
83 peerGetBool(void *data, enum eapol_bool_var variable)
84 {
85     gss_ctx_id_t ctx = data;
86     OM_uint32 flag;
87
88     if (ctx == GSS_C_NO_CONTEXT)
89         return FALSE;
90
91     flag = policyVariableToFlag(variable);
92
93     return ((ctx->flags & flag) != 0);
94 }
95
96 static void
97 peerSetBool(void *data, enum eapol_bool_var variable,
98             Boolean value)
99 {
100     gss_ctx_id_t ctx = data;
101     OM_uint32 flag;
102
103     if (ctx == GSS_C_NO_CONTEXT)
104         return;
105
106     flag = policyVariableToFlag(variable);
107
108     if (value)
109         ctx->flags |= flag;
110     else
111         ctx->flags &= ~(flag);
112 }
113
114 static unsigned int
115 peerGetInt(void *data, enum eapol_int_var variable)
116 {
117     gss_ctx_id_t ctx = data;
118
119     if (ctx == GSS_C_NO_CONTEXT)
120         return FALSE;
121
122     assert(CTX_IS_INITIATOR(ctx));
123
124     switch (variable) {
125     case EAPOL_idleWhile:
126         return ctx->initiatorCtx.idleWhile;
127         break;
128     }
129
130     return 0;
131 }
132
133 static void
134 peerSetInt(void *data, enum eapol_int_var variable,
135            unsigned int value)
136 {
137     gss_ctx_id_t ctx = data;
138
139     if (ctx == GSS_C_NO_CONTEXT)
140         return;
141
142     assert(CTX_IS_INITIATOR(ctx));
143
144     switch (variable) {
145     case EAPOL_idleWhile:
146         ctx->initiatorCtx.idleWhile = value;
147         break;
148     }
149 }
150
151 static struct wpabuf *
152 peerGetEapReqData(void *ctx)
153 {
154     gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
155
156     return &gssCtx->initiatorCtx.reqData;
157 }
158
159 static void
160 peerSetConfigBlob(void *ctx, struct wpa_config_blob *blob)
161 {
162 }
163
164 static const struct wpa_config_blob *
165 peerGetConfigBlob(void *ctx, const char *name)
166 {
167     return NULL;
168 }
169
170 static void
171 peerNotifyPending(void *ctx)
172 {
173 }
174
175 static struct eapol_callbacks gssEapPolicyCallbacks = {
176     peerGetConfig,
177     peerGetBool,
178     peerSetBool,
179     peerGetInt,
180     peerSetInt,
181     peerGetEapReqData,
182     peerSetConfigBlob,
183     peerGetConfigBlob,
184     peerNotifyPending,
185 };
186
187 extern int wpa_debug_level;
188
189 static OM_uint32
190 peerConfigInit(OM_uint32 *minor,
191                gss_cred_id_t cred,
192                gss_ctx_id_t ctx,
193                int loadConfig)
194 {
195     krb5_context krbContext;
196     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
197     krb5_error_code code;
198     char *identity;
199
200     GSSEAP_KRB_INIT(&krbContext);
201
202     if (loadConfig) {
203         eapPeerConfig->fragment_size = 1024;
204         wpa_debug_level = 0;
205     }
206
207     code = krb5_unparse_name(krbContext, cred->name->krbPrincipal, &identity);
208     if (code != 0) {
209         *minor = code;
210         return GSS_S_FAILURE;
211     }
212
213     eapPeerConfig->identity = (unsigned char *)identity;
214     eapPeerConfig->identity_len = strlen(identity);
215     eapPeerConfig->password = (unsigned char *)cred->password.value;
216     eapPeerConfig->password_len = cred->password.length;
217
218     return GSS_S_COMPLETE;
219 }
220
221 static OM_uint32
222 peerConfigFree(OM_uint32 *minor,
223                gss_ctx_id_t ctx)
224 {
225     krb5_context krbContext;
226     struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
227
228     GSSEAP_KRB_INIT(&krbContext);
229
230     krb5_free_unparsed_name(krbContext, (char *)eapPeerConfig->identity);
231
232     return GSS_S_COMPLETE;
233 }
234
235 static OM_uint32
236 initReady(OM_uint32 *minor, gss_ctx_id_t ctx)
237 {
238     OM_uint32 major;
239     const unsigned char *key;
240     size_t keyLength;
241     krb5_context krbContext;
242
243     GSSEAP_KRB_INIT(&krbContext);
244
245     /* Cache encryption type derived from selected mechanism OID */
246     major = gssEapOidToEnctype(minor, ctx->mechanismUsed, &ctx->encryptionType);
247     if (GSS_ERROR(major))
248         return major;
249
250     if (ctx->encryptionType != ENCTYPE_NULL &&
251         eap_key_available(ctx->initiatorCtx.eap)) {
252         key = eap_get_eapKeyData(ctx->initiatorCtx.eap, &keyLength);
253
254         major = gssEapDeriveRFC3961Key(minor, key, keyLength,
255                                        ctx->encryptionType, &ctx->rfc3961Key);
256         if (GSS_ERROR(major))
257             return major;
258     } else {
259         /*
260          * draft-howlett-eap-gss says that integrity/confidentialty should
261          * always be advertised as available, but if we have no keying
262          * material it seems confusing to the caller to advertise this.
263          */
264         ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
265     }
266
267     sequenceInit(&ctx->seqState, ctx->recvSeq,
268                  ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
269                  ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
270                  TRUE);
271
272     return GSS_S_COMPLETE;
273 }
274
275 static OM_uint32
276 eapGssSmInitAuthenticate(OM_uint32 *minor,
277                          gss_cred_id_t cred,
278                          gss_ctx_id_t ctx,
279                          gss_name_t target,
280                          gss_OID mech,
281                          OM_uint32 reqFlags,
282                          OM_uint32 timeReq,
283                          gss_channel_bindings_t chanBindings,
284                          gss_buffer_t inputToken,
285                          gss_buffer_t outputToken)
286 {
287     OM_uint32 major;
288     OM_uint32 tmpMajor, tmpMinor;
289     time_t now;
290     int initialContextToken = 0, code;
291     gss_buffer_desc respBuf;
292
293     respBuf.length = 0;
294     respBuf.value = NULL;
295
296     initialContextToken = (inputToken == GSS_C_NO_BUFFER ||
297                            inputToken->length == 0);
298
299     major = peerConfigInit(minor, cred, ctx, initialContextToken);
300     if (GSS_ERROR(major))
301         goto cleanup;
302
303     if (initialContextToken) {
304         struct eap_config eapConfig;
305
306         memset(&eapConfig, 0, sizeof(eapConfig));
307         ctx->flags |= CTX_FLAG_EAP_PORT_ENABLED;
308
309         ctx->initiatorCtx.eap = eap_peer_sm_init(ctx,
310                                                  &gssEapPolicyCallbacks,
311                                                  ctx,
312                                                  &eapConfig);
313
314         time(&now);
315         if (timeReq == 0 || timeReq == GSS_C_INDEFINITE)
316             ctx->expiryTime = 0;
317         else
318             ctx->expiryTime = now + timeReq;
319
320         major = gss_duplicate_name(minor, cred->name, &ctx->initiatorName);
321         if (GSS_ERROR(major))
322             goto cleanup;
323
324         major = gss_duplicate_name(minor, target, &ctx->acceptorName);
325         if (GSS_ERROR(major))
326             goto cleanup;
327
328         if (mech == GSS_C_NULL_OID || oidEqual(mech, GSS_EAP_MECHANISM)) {
329             major = gssEapDefaultMech(minor, &ctx->mechanismUsed);
330         } else if (gssEapIsConcreteMechanismOid(mech)) {
331             if (!gssEapInternalizeOid(mech, &ctx->mechanismUsed))
332                 major = duplicateOid(minor, mech, &ctx->mechanismUsed);
333         } else {
334             major = GSS_S_BAD_MECH;
335         }
336         if (GSS_ERROR(major))
337             goto cleanup;
338
339         /* If credentials were provided, check they're usable with this mech */
340         if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
341             major = GSS_S_BAD_MECH;
342             goto cleanup;
343         }
344
345         respBuf.value = ""; /* emit empty inner token */
346         major = GSS_S_CONTINUE_NEEDED;
347         goto cleanup;
348     } else {
349         ctx->flags |= CTX_FLAG_EAP_REQ; /* we have a Request from the acceptor */
350     }
351
352     wpabuf_set(&ctx->initiatorCtx.reqData,
353                inputToken->value, inputToken->length);
354
355     major = GSS_S_CONTINUE_NEEDED;
356
357     code = eap_peer_sm_step(ctx->initiatorCtx.eap);
358     if (ctx->flags & CTX_FLAG_EAP_RESP) {
359         struct wpabuf *resp;
360
361         ctx->flags &= ~(CTX_FLAG_EAP_RESP);
362
363         resp = eap_get_eapRespData(ctx->initiatorCtx.eap);
364         if (resp != NULL) {
365             respBuf.length = wpabuf_len(resp);
366             respBuf.value = (void *)wpabuf_head(resp);
367         }
368     } else if (ctx->flags & CTX_FLAG_EAP_SUCCESS) {
369         major = initReady(minor, ctx);
370         if (GSS_ERROR(major))
371             goto cleanup;
372
373         ctx->flags &= ~(CTX_FLAG_EAP_SUCCESS);
374         major = GSS_S_CONTINUE_NEEDED;
375         ctx->state = EAP_STATE_GSS_CHANNEL_BINDINGS;
376     } else if ((ctx->flags & CTX_FLAG_EAP_FAIL) || code == 0) {
377         major = GSS_S_FAILURE;
378     }
379
380 cleanup:
381     if (respBuf.value != NULL) {
382         OM_uint32 tmpMajor;
383
384         assert(major == GSS_S_CONTINUE_NEEDED);
385
386         tmpMajor = duplicateBuffer(&tmpMinor, &respBuf, outputToken);
387         if (GSS_ERROR(tmpMajor)) {
388             major = tmpMajor;
389             *minor = tmpMinor;
390         }
391     }
392
393     wpabuf_set(&ctx->initiatorCtx.reqData, NULL, 0);
394     peerConfigFree(&tmpMinor, ctx);
395
396     return major;
397 }
398
399 #if 0
400 static OM_uint32
401 eapGssSmInitKeyTransport(OM_uint32 *minor,
402                          gss_cred_id_t cred,
403                          gss_ctx_id_t ctx,
404                          gss_name_t target,
405                          gss_OID mech,
406                          OM_uint32 reqFlags,
407                          OM_uint32 timeReq,
408                          gss_channel_bindings_t chanBindings,
409                          gss_buffer_t inputToken,
410                          gss_buffer_t outputToken)
411 {
412     GSSEAP_NOT_IMPLEMENTED;
413 }
414
415 static OM_uint32
416 eapGssSmInitSecureAssoc(OM_uint32 *minor,
417                         gss_cred_id_t cred,
418                         gss_ctx_id_t ctx,
419                         gss_name_t target,
420                         gss_OID mech,
421                         OM_uint32 reqFlags,
422                         OM_uint32 timeReq,
423                         gss_channel_bindings_t chanBindings,
424                         gss_buffer_t inputToken,
425                         gss_buffer_t outputToken)
426 {
427     GSSEAP_NOT_IMPLEMENTED;
428 }
429 #endif
430
431 static OM_uint32
432 eapGssSmInitGssChannelBindings(OM_uint32 *minor,
433                                gss_cred_id_t cred,
434                                gss_ctx_id_t ctx,
435                                gss_name_t target,
436                                gss_OID mech,
437                                OM_uint32 reqFlags,
438                                OM_uint32 timeReq,
439                                gss_channel_bindings_t chanBindings,
440                                gss_buffer_t inputToken,
441                                gss_buffer_t outputToken)
442 {
443     OM_uint32 major, tmpMinor;
444     gss_iov_buffer_desc iov[2];
445     gss_buffer_desc buf;
446
447     iov[0].type = GSS_IOV_BUFFER_TYPE_DATA;
448     iov[0].buffer.length = 0;
449     iov[0].buffer.value = NULL;
450
451     iov[1].type = GSS_IOV_BUFFER_TYPE_HEADER | GSS_IOV_BUFFER_FLAG_ALLOCATE;
452     iov[1].buffer.length = 0;
453     iov[1].buffer.value = NULL;
454
455     if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS) {
456         major = gssEapEncodeGssChannelBindings(minor, chanBindings,
457                                                 &iov[0].buffer);
458         if (GSS_ERROR(major))
459             goto cleanup;
460
461         iov[0].type |= GSS_IOV_BUFFER_FLAG_ALLOCATED;
462     } else {
463         iov[0].buffer.length = sizeof("NO_CHANNEL_BINDINGS") - 1;
464         iov[0].buffer.value = "NO_CHANNEL_BINDINGS";
465     }
466
467     major = gssEapWrapOrGetMIC(minor, ctx, FALSE, FALSE, iov, 2,
468                                TOK_TYPE_GSS_CB);
469     if (GSS_ERROR(major))
470         goto cleanup;
471
472     /* Skip past token ID */
473     assert(iov[1].buffer.length > 2);
474     assert(load_uint16_be(iov[1].buffer.value) == TOK_TYPE_GSS_CB);
475
476     buf.length = iov[1].buffer.length - 2;
477     buf.value = (unsigned char *)iov[1].buffer.value + 2;
478
479     major = duplicateBuffer(minor, &buf, outputToken);
480     if (GSS_ERROR(major))
481         goto cleanup;
482
483     major = GSS_S_COMPLETE;
484     ctx->state = EAP_STATE_ESTABLISHED;
485
486 cleanup:
487     gssEapReleaseIov(iov, 2);
488
489     return major;
490 }
491
492 static OM_uint32
493 eapGssSmInitEstablished(OM_uint32 *minor,
494                         gss_cred_id_t cred,
495                         gss_ctx_id_t ctx,
496                         gss_name_t target,
497                         gss_OID mech,
498                         OM_uint32 reqFlags,
499                         OM_uint32 timeReq,
500                         gss_channel_bindings_t chanBindings,
501                         gss_buffer_t inputToken,
502                         gss_buffer_t outputToken)
503 {
504     /* Called with already established context */
505     *minor = EINVAL;
506     return GSS_S_BAD_STATUS;
507 }
508
509 static struct eap_gss_initiator_sm {
510     enum gss_eap_token_type inputTokenType;
511     enum gss_eap_token_type outputTokenType;
512     OM_uint32 (*processToken)(OM_uint32 *,
513                               gss_cred_id_t,
514                               gss_ctx_id_t,
515                               gss_name_t,
516                               gss_OID,
517                               OM_uint32,
518                               OM_uint32,
519                               gss_channel_bindings_t,
520                               gss_buffer_t,
521                               gss_buffer_t);
522 } eapGssInitiatorSm[] = {
523     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitAuthenticate        },
524 #if 0
525     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitKeyTransport        },
526     { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,  eapGssSmInitSecureAssoc         },
527 #endif
528     { TOK_TYPE_NONE,    TOK_TYPE_GSS_CB,    eapGssSmInitGssChannelBindings  },
529     { TOK_TYPE_NONE,    TOK_TYPE_NONE,      eapGssSmInitEstablished         },
530 };
531
532 OM_uint32
533 gss_init_sec_context(OM_uint32 *minor,
534                      gss_cred_id_t cred,
535                      gss_ctx_id_t *context_handle,
536                      gss_name_t target_name,
537                      gss_OID mech_type,
538                      OM_uint32 req_flags,
539                      OM_uint32 time_req,
540                      gss_channel_bindings_t input_chan_bindings,
541                      gss_buffer_t input_token,
542                      gss_OID *actual_mech_type,
543                      gss_buffer_t output_token,
544                      OM_uint32 *ret_flags,
545                      OM_uint32 *time_rec)
546 {
547     OM_uint32 major;
548     OM_uint32 tmpMajor, tmpMinor;
549     gss_ctx_id_t ctx = *context_handle;
550     struct eap_gss_initiator_sm *sm = NULL;
551     gss_buffer_desc innerInputToken, innerOutputToken;
552
553     *minor = 0;
554
555     innerOutputToken.length = 0;
556     innerOutputToken.value = NULL;
557
558     output_token->length = 0;
559     output_token->value = NULL;
560
561     if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_INITIATE)) {
562         return GSS_S_NO_CRED;
563     }
564
565     if (ctx == GSS_C_NO_CONTEXT) {
566         if (input_token != GSS_C_NO_BUFFER && input_token->length != 0) {
567             return GSS_S_DEFECTIVE_TOKEN;
568         }
569
570         major = gssEapAllocContext(minor, &ctx);
571         if (GSS_ERROR(major))
572             return major;
573
574         ctx->flags |= CTX_FLAG_INITIATOR;
575
576         *context_handle = ctx;
577     }
578
579     GSSEAP_MUTEX_LOCK(&ctx->mutex);
580
581     sm = &eapGssInitiatorSm[ctx->state];
582
583     if (input_token != GSS_C_NO_BUFFER) {
584         major = gssEapVerifyToken(minor, ctx, input_token,
585                                   sm->inputTokenType, &innerInputToken);
586         if (GSS_ERROR(major))
587             goto cleanup;
588     } else {
589         innerInputToken.length = 0;
590         innerInputToken.value = NULL;
591     }
592
593     /*
594      * Advance through state machine whilst empty tokens are emitted and
595      * the status is not GSS_S_COMPLETE or an error status.
596      */
597     do {
598         sm = &eapGssInitiatorSm[ctx->state];
599
600         major = (sm->processToken)(minor,
601                                    cred,
602                                    ctx,
603                                    target_name,
604                                    mech_type,
605                                    req_flags,
606                                    time_req,
607                                    input_chan_bindings,
608                                    &innerInputToken,
609                                    &innerOutputToken);
610         if (GSS_ERROR(major))
611             goto cleanup;
612     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.value == NULL);
613
614     if (actual_mech_type != NULL) {
615         if (!gssEapInternalizeOid(ctx->mechanismUsed, actual_mech_type))
616             duplicateOid(&tmpMinor, ctx->mechanismUsed, actual_mech_type);
617     }
618     if (innerOutputToken.value != NULL) {
619         tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
620                                    sm->outputTokenType, output_token);
621         if (GSS_ERROR(tmpMajor)) {
622             major = tmpMajor;
623             *minor = tmpMinor;
624             goto cleanup;
625         }
626     }
627     if (ret_flags != NULL)
628         *ret_flags = ctx->gssFlags;
629     if (time_rec != NULL)
630         gss_context_time(&tmpMinor, ctx, time_rec);
631
632     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
633
634 cleanup:
635     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
636
637     if (GSS_ERROR(major))
638         gssEapReleaseContext(&tmpMinor, context_handle);
639
640     gss_release_buffer(&tmpMinor, &innerOutputToken);
641
642     return major;
643 }