more TLV cleanups
[mech_eap.git] / accept_sec_context.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  * Establish a security context on the acceptor (server). These functions
35  * wrap around libradsec and (thus) talk to a RADIUS server or proxy.
36  */
37
38 #include "gssapiP_eap.h"
39
40 #ifdef GSSEAP_ENABLE_REAUTH
41 static OM_uint32
42 eapGssSmAcceptGssReauth(OM_uint32 *minor,
43                         gss_cred_id_t cred,
44                         gss_ctx_id_t ctx,
45                         gss_name_t target __attribute__((__unused__)),
46                         gss_OID mech __attribute__((__unused__)),
47                         OM_uint32 reqFlags __attribute__((__unused__)),
48                         OM_uint32 timeReq __attribute__((__unused__)),
49                         gss_channel_bindings_t chanBindings,
50                         gss_buffer_t inputToken,
51                         gss_buffer_t outputToken,
52                         OM_uint32 *smFlags);
53 #endif
54
55 /*
56  * Mark an acceptor context as ready for cryptographic operations
57  */
58 static OM_uint32
59 acceptReadyEap(OM_uint32 *minor, gss_ctx_id_t ctx, gss_cred_id_t cred)
60 {
61     OM_uint32 major, tmpMinor;
62     VALUE_PAIR *vp;
63     gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
64
65     /* Cache encryption type derived from selected mechanism OID */
66     major = gssEapOidToEnctype(minor, ctx->mechanismUsed,
67                                &ctx->encryptionType);
68     if (GSS_ERROR(major))
69         return major;
70
71     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
72
73     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
74                                   PW_USER_NAME, 0, &vp);
75     if (major == GSS_S_COMPLETE) {
76         nameBuf.length = vp->length;
77         nameBuf.value = vp->vp_strvalue;
78     } else {
79         ctx->gssFlags |= GSS_C_ANON_FLAG;
80     }
81
82     major = gssEapImportName(minor, &nameBuf,
83                              (ctx->gssFlags & GSS_C_ANON_FLAG) ?
84                                 GSS_C_NT_ANONYMOUS : GSS_C_NT_USER_NAME,
85                              &ctx->initiatorName);
86     if (GSS_ERROR(major))
87         return major;
88
89     major = gssEapRadiusGetRawAvp(minor, ctx->acceptorCtx.vps,
90                                   PW_MS_MPPE_SEND_KEY, VENDORPEC_MS, &vp);
91     if (GSS_ERROR(major)) {
92         *minor = GSSEAP_KEY_UNAVAILABLE;
93         return GSS_S_UNAVAILABLE;
94     }
95
96     major = gssEapDeriveRfc3961Key(minor,
97                                    vp->vp_octets,
98                                    vp->length,
99                                    ctx->encryptionType,
100                                    &ctx->rfc3961Key);
101     if (GSS_ERROR(major))
102         return major;
103
104     major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
105                                        &ctx->checksumType);
106     if (GSS_ERROR(major))
107         return major;
108
109     major = sequenceInit(minor,
110                          &ctx->seqState, ctx->recvSeq,
111                          ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
112                          ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
113                          TRUE);
114     if (GSS_ERROR(major))
115         return major;
116
117     major = gssEapCreateAttrContext(minor, cred, ctx,
118                                     &ctx->initiatorName->attrCtx,
119                                     &ctx->expiryTime);
120     if (GSS_ERROR(major))
121         return major;
122
123     *minor = 0;
124     return GSS_S_COMPLETE;
125 }
126
127 /*
128  * Emit a identity EAP request to force the initiator (peer) to identify
129  * itself.
130  */
131 static OM_uint32
132 eapGssSmAcceptIdentity(OM_uint32 *minor,
133                        gss_cred_id_t cred,
134                        gss_ctx_id_t ctx,
135                        gss_name_t target __attribute__((__unused__)),
136                        gss_OID mech __attribute__((__unused__)),
137                        OM_uint32 reqFlags __attribute__((__unused__)),
138                        OM_uint32 timeReq __attribute__((__unused__)),
139                        gss_channel_bindings_t chanBindings __attribute__((__unused__)),
140                        gss_buffer_t inputToken,
141                        gss_buffer_t outputToken,
142                        OM_uint32 *smFlags)
143 {
144     OM_uint32 major;
145     struct wpabuf *reqData;
146     gss_buffer_desc pktBuffer;
147
148     if (!gssEapCredAvailable(cred, ctx->mechanismUsed)) {
149         *minor = GSSEAP_CRED_MECH_MISMATCH;
150         return GSS_S_BAD_MECH;
151     }
152
153     if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0) {
154         *minor = GSSEAP_WRONG_SIZE;
155         return GSS_S_DEFECTIVE_TOKEN;
156     }
157
158     assert(ctx->acceptorName == GSS_C_NO_NAME);
159
160     if (cred->name != GSS_C_NO_NAME) {
161         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
162         if (GSS_ERROR(major))
163             return major;
164     }
165
166     reqData = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IDENTITY, 0,
167                             EAP_CODE_REQUEST, 0);
168     if (reqData == NULL) {
169         *minor = ENOMEM;
170         return GSS_S_FAILURE;
171     }
172
173     pktBuffer.length = wpabuf_len(reqData);
174     pktBuffer.value = (void *)wpabuf_head(reqData);
175
176     major = duplicateBuffer(minor, &pktBuffer, outputToken);
177     if (GSS_ERROR(major))
178         return major;
179
180     wpabuf_free(reqData);
181
182     GSSEAP_SM_TRANSITION_NEXT(ctx);
183
184     *minor = 0;
185
186     return GSS_S_CONTINUE_NEEDED;
187 }
188
189 /*
190  * Returns TRUE if the input token contains an EAP identity response.
191  */
192 static int
193 isIdentityResponseP(gss_buffer_t inputToken)
194 {
195     struct wpabuf respData;
196
197     wpabuf_set(&respData, inputToken->value, inputToken->length);
198
199     return (eap_get_type(&respData) == EAP_TYPE_IDENTITY);
200 }
201
202 /*
203  * Save the asserted initiator identity from the EAP identity response.
204  */
205 static OM_uint32
206 importInitiatorIdentity(OM_uint32 *minor,
207                         gss_ctx_id_t ctx,
208                         gss_buffer_t inputToken)
209 {
210     OM_uint32 tmpMinor;
211     struct wpabuf respData;
212     const unsigned char *pos;
213     size_t len;
214     gss_buffer_desc nameBuf;
215
216     wpabuf_set(&respData, inputToken->value, inputToken->length);
217
218     pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_IDENTITY,
219                            &respData, &len);
220     if (pos == NULL) {
221         *minor = GSSEAP_PEER_BAD_MESSAGE;
222         return GSS_S_DEFECTIVE_TOKEN;
223     }
224
225     nameBuf.value = (void *)pos;
226     nameBuf.length = len;
227
228     gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
229
230     return gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
231                             &ctx->initiatorName);
232 }
233
234 /*
235  * Pass the asserted initiator identity to the authentication server.
236  */
237 static OM_uint32
238 setInitiatorIdentity(OM_uint32 *minor,
239                      gss_ctx_id_t ctx,
240                      VALUE_PAIR **vps)
241 {
242     OM_uint32 major, tmpMinor;
243     gss_buffer_desc nameBuf;
244
245     /*
246      * We should have got an EAP identity response, but if we didn't, then
247      * we will just avoid sending User-Name. Note that radsecproxy requires
248      * User-Name to be sent on every request (presumably so it can remain
249      * stateless).
250      */
251     if (ctx->initiatorName != GSS_C_NO_NAME) {
252         major = gssEapDisplayName(minor, ctx->initiatorName, &nameBuf, NULL);
253         if (GSS_ERROR(major))
254             return major;
255
256         major = gssEapRadiusAddAvp(minor, vps, PW_USER_NAME, 0, &nameBuf);
257         if (GSS_ERROR(major))
258             return major;
259
260         gss_release_buffer(&tmpMinor, &nameBuf);
261     }
262
263     *minor = 0;
264     return GSS_S_COMPLETE;
265 }
266
267 /*
268  * Pass the asserted acceptor identity to the authentication server.
269  */
270 static OM_uint32
271 setAcceptorIdentity(OM_uint32 *minor,
272                     gss_ctx_id_t ctx,
273                     VALUE_PAIR **vps)
274 {
275     OM_uint32 major;
276     gss_buffer_desc nameBuf;
277     krb5_context krbContext = NULL;
278     krb5_principal krbPrinc;
279     struct rs_context *rc = ctx->acceptorCtx.radContext;
280
281     assert(rc != NULL);
282
283     if (ctx->acceptorName == GSS_C_NO_NAME) {
284         *minor = 0;
285         return GSS_S_COMPLETE;
286     }
287
288     if ((ctx->acceptorName->flags & NAME_FLAG_SERVICE) == 0) {
289         *minor = GSSEAP_BAD_SERVICE_NAME;
290         return GSS_S_BAD_NAME;
291     }
292
293     GSSEAP_KRB_INIT(&krbContext);
294
295     krbPrinc = ctx->acceptorName->krbPrincipal;
296     assert(krbPrinc != NULL);
297     assert(KRB_PRINC_LENGTH(krbPrinc) >= 2);
298
299     /* Acceptor-Service-Name */
300     krbPrincComponentToGssBuffer(krbPrinc, 0, &nameBuf);
301
302     major = gssEapRadiusAddAvp(minor, vps,
303                                PW_GSS_ACCEPTOR_SERVICE_NAME,
304                                VENDORPEC_UKERNA,
305                                &nameBuf);
306     if (GSS_ERROR(major))
307         return major;
308
309     /* Acceptor-Host-Name */
310     krbPrincComponentToGssBuffer(krbPrinc, 1, &nameBuf);
311
312     major = gssEapRadiusAddAvp(minor, vps,
313                                PW_GSS_ACCEPTOR_HOST_NAME,
314                                VENDORPEC_UKERNA,
315                                &nameBuf);
316     if (GSS_ERROR(major))
317         return major;
318
319     if (KRB_PRINC_LENGTH(krbPrinc) > 2) {
320         /* Acceptor-Service-Specific */
321         krb5_principal_data ssiPrinc = *krbPrinc;
322         char *ssi;
323
324         KRB_PRINC_LENGTH(&ssiPrinc) -= 2;
325         KRB_PRINC_NAME(&ssiPrinc) += 2;
326
327         *minor = krb5_unparse_name_flags(krbContext, &ssiPrinc,
328                                          KRB5_PRINCIPAL_UNPARSE_NO_REALM, &ssi);
329         if (*minor != 0)
330             return GSS_S_FAILURE;
331
332         nameBuf.value = ssi;
333         nameBuf.length = strlen(ssi);
334
335         major = gssEapRadiusAddAvp(minor, vps,
336                                    PW_GSS_ACCEPTOR_SERVICE_SPECIFIC,
337                                    VENDORPEC_UKERNA,
338                                    &nameBuf);
339
340         if (GSS_ERROR(major)) {
341             krb5_free_unparsed_name(krbContext, ssi);
342             return major;
343         }
344         krb5_free_unparsed_name(krbContext, ssi);
345     }
346
347     krbPrincRealmToGssBuffer(krbPrinc, &nameBuf);
348     if (nameBuf.length != 0) {
349         /* Acceptor-Realm-Name */
350         major = gssEapRadiusAddAvp(minor, vps,
351                                    PW_GSS_ACCEPTOR_REALM_NAME,
352                                    VENDORPEC_UKERNA,
353                                    &nameBuf);
354         if (GSS_ERROR(major))
355             return major;
356     }
357
358     *minor = 0;
359     return GSS_S_COMPLETE;
360 }
361
362 /*
363  * Allocate a RadSec handle
364  */
365 static OM_uint32
366 createRadiusHandle(OM_uint32 *minor,
367                    gss_cred_id_t cred,
368                    gss_ctx_id_t ctx)
369 {
370     struct gss_eap_acceptor_ctx *actx = &ctx->acceptorCtx;
371     const char *configFile = RS_CONFIG_FILE;
372     const char *configStanza = "gss-eap";
373     struct rs_alloc_scheme ralloc;
374     struct rs_error *err;
375
376     assert(actx->radContext == NULL);
377     assert(actx->radConn == NULL);
378
379     if (rs_context_create(&actx->radContext, RS_DICT_FILE) != 0) {
380         *minor = GSSEAP_RADSEC_CONTEXT_FAILURE;
381         return GSS_S_FAILURE;
382     }
383
384     if (cred->radiusConfigFile != NULL)
385         configFile = cred->radiusConfigFile;
386     if (cred->radiusConfigStanza != NULL)
387         configStanza = cred->radiusConfigStanza;
388
389     ralloc.calloc  = GSSEAP_CALLOC;
390     ralloc.malloc  = GSSEAP_MALLOC;
391     ralloc.free    = GSSEAP_FREE;
392     ralloc.realloc = GSSEAP_REALLOC;
393
394     rs_context_set_alloc_scheme(actx->radContext, &ralloc);
395
396     if (rs_context_read_config(actx->radContext, configFile) != 0) {
397         err = rs_err_ctx_pop(actx->radContext);
398         goto fail;
399     }
400
401     if (rs_conn_create(actx->radContext, &actx->radConn, configStanza) != 0) {
402         err = rs_err_conn_pop(actx->radConn);
403         goto fail;
404     }
405
406     if (actx->radServer != NULL) {
407         if (rs_conn_select_peer(actx->radConn, actx->radServer) != 0) {
408             err = rs_err_conn_pop(actx->radConn);
409             goto fail;
410         }
411     }
412
413     *minor = 0;
414     return GSS_S_COMPLETE;
415
416 fail:
417     return gssEapRadiusMapError(minor, err);
418 }
419
420 /*
421  * Process a EAP response from the initiator.
422  */
423 static OM_uint32
424 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
425                            gss_cred_id_t cred,
426                            gss_ctx_id_t ctx,
427                            gss_name_t target __attribute__((__unused__)),
428                            gss_OID mech __attribute__((__unused__)),
429                            OM_uint32 reqFlags __attribute__((__unused__)),
430                            OM_uint32 timeReq __attribute__((__unused__)),
431                            gss_channel_bindings_t chanBindings,
432                            gss_buffer_t inputToken,
433                            gss_buffer_t outputToken,
434                            OM_uint32 *smFlags)
435 {
436     OM_uint32 major, tmpMinor;
437     struct rs_connection *rconn;
438     struct rs_request *request = NULL;
439     struct rs_packet *req = NULL, *resp = NULL;
440     struct radius_packet *frreq, *frresp;
441
442     if (ctx->acceptorCtx.radContext == NULL) {
443         /* May be NULL from an imported partial context */
444         major = createRadiusHandle(minor, cred, ctx);
445         if (GSS_ERROR(major))
446             goto cleanup;
447     }
448
449     if (isIdentityResponseP(inputToken)) {
450         major = importInitiatorIdentity(minor, ctx, inputToken);
451         if (GSS_ERROR(major))
452             return major;
453     }
454
455     rconn = ctx->acceptorCtx.radConn;
456
457     if (rs_packet_create_authn_request(rconn, &req, NULL, NULL) != 0) {
458         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
459         goto cleanup;
460     }
461     frreq = rs_packet_frpkt(req);
462
463     major = setInitiatorIdentity(minor, ctx, &frreq->vps);
464     if (GSS_ERROR(major))
465         goto cleanup;
466
467     major = setAcceptorIdentity(minor, ctx, &frreq->vps);
468     if (GSS_ERROR(major))
469         goto cleanup;
470
471     major = gssEapRadiusAddAvp(minor, &frreq->vps,
472                                PW_EAP_MESSAGE, 0, inputToken);
473     if (GSS_ERROR(major))
474         goto cleanup;
475
476     if (ctx->acceptorCtx.state.length != 0) {
477         major = gssEapRadiusAddAvp(minor, &frreq->vps, PW_STATE, 0,
478                                    &ctx->acceptorCtx.state);
479         if (GSS_ERROR(major))
480             goto cleanup;
481
482         gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
483     }
484
485     if (rs_request_create(rconn, &request) != 0) {
486         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
487         goto cleanup;
488     }
489
490     rs_request_add_reqpkt(request, req);
491     req = NULL;
492
493     if (rs_request_send(request, &resp) != 0) {
494         major = gssEapRadiusMapError(minor, rs_err_conn_pop(rconn));
495         goto cleanup;
496     }
497
498     assert(resp != NULL);
499
500     frresp = rs_packet_frpkt(resp);
501     switch (frresp->code) {
502     case PW_AUTHENTICATION_ACK:
503     case PW_ACCESS_CHALLENGE:
504         break;
505     case PW_AUTHENTICATION_REJECT:
506         *minor = GSSEAP_RADIUS_AUTH_FAILURE;
507         major = GSS_S_DEFECTIVE_CREDENTIAL;
508         goto cleanup;
509         break;
510     default:
511         *minor = GSSEAP_UNKNOWN_RADIUS_CODE;
512         major = GSS_S_FAILURE;
513         goto cleanup;
514         break;
515     }
516
517     major = gssEapRadiusGetAvp(minor, frresp->vps, PW_EAP_MESSAGE, 0,
518                                outputToken, TRUE);
519     if (major == GSS_S_UNAVAILABLE && frresp->code == PW_ACCESS_CHALLENGE) {
520         *minor = GSSEAP_MISSING_EAP_REQUEST;
521         major = GSS_S_DEFECTIVE_TOKEN;
522         goto cleanup;
523     } else if (GSS_ERROR(major))
524         goto cleanup;
525
526     if (frresp->code == PW_ACCESS_CHALLENGE) {
527         major = gssEapRadiusGetAvp(minor, frresp->vps, PW_STATE, 0,
528                                    &ctx->acceptorCtx.state, TRUE);
529         if (GSS_ERROR(major) && *minor != GSSEAP_NO_SUCH_ATTR)
530             goto cleanup;
531     } else {
532         ctx->acceptorCtx.vps = frresp->vps;
533         frresp->vps = NULL;
534
535         rs_conn_destroy(ctx->acceptorCtx.radConn);
536         ctx->acceptorCtx.radConn = NULL;
537
538         major = acceptReadyEap(minor, ctx, cred);
539         if (GSS_ERROR(major))
540             goto cleanup;
541
542         GSSEAP_SM_TRANSITION_NEXT(ctx);
543     }
544
545     major = GSS_S_CONTINUE_NEEDED;
546     *minor = 0;
547
548 cleanup:
549     if (request != NULL)
550         rs_request_destroy(request);
551     if (req != NULL)
552         rs_packet_destroy(req);
553
554     return major;
555 }
556
557 static OM_uint32
558 eapGssSmAcceptGssChannelBindings(OM_uint32 *minor,
559                                  gss_cred_id_t cred,
560                                  gss_ctx_id_t ctx,
561                                  gss_name_t target __attribute__((__unused__)),
562                                  gss_OID mech __attribute__((__unused__)),
563                                  OM_uint32 reqFlags __attribute__((__unused__)),
564                                  OM_uint32 timeReq __attribute__((__unused__)),
565                                  gss_channel_bindings_t chanBindings,
566                                  gss_buffer_t inputToken,
567                                  gss_buffer_t outputToken,
568                                  OM_uint32 *smFlags)
569 {
570     OM_uint32 major, tmpMinor;
571     gss_iov_buffer_desc iov[2];
572
573     iov[0].type = GSS_IOV_BUFFER_TYPE_DATA | GSS_IOV_BUFFER_FLAG_ALLOCATE;
574     iov[0].buffer.length = 0;
575     iov[0].buffer.value = NULL;
576
577     iov[1].type = GSS_IOV_BUFFER_TYPE_STREAM;
578     iov[1].buffer = *inputToken;
579
580     major = gssEapUnwrapOrVerifyMIC(minor, ctx, NULL, NULL,
581                                     iov, 2, TOK_TYPE_WRAP);
582     if (GSS_ERROR(major))
583         return GSS_S_BAD_BINDINGS;
584
585     if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS &&
586         !bufferEqual(&iov[0].buffer, &chanBindings->application_data)) {
587         major = GSS_S_BAD_BINDINGS;
588         *minor = GSSEAP_BINDINGS_MISMATCH;
589     } else {
590         major = GSS_S_CONTINUE_NEEDED;
591         *minor = 0;
592     }
593
594     gss_release_buffer(&tmpMinor, &iov[0].buffer);
595
596     return major;
597 }
598
599 #ifdef GSSEAP_ENABLE_REAUTH
600 static OM_uint32
601 eapGssSmAcceptReauthCreds(OM_uint32 *minor,
602                           gss_cred_id_t cred,
603                           gss_ctx_id_t ctx,
604                           gss_name_t target __attribute__((__unused__)),
605                           gss_OID mech __attribute__((__unused__)),
606                           OM_uint32 reqFlags __attribute__((__unused__)),
607                           OM_uint32 timeReq __attribute__((__unused__)),
608                           gss_channel_bindings_t chanBindings __attribute__((__unused__)),
609                           gss_buffer_t inputToken,
610                           gss_buffer_t outputToken,
611                           OM_uint32 *smFlags)
612 {
613     OM_uint32 major;
614
615     /*
616      * If we're built with fast reauthentication enabled, then
617      * fabricate a ticket from the initiator to ourselves.
618      */
619     major = gssEapMakeReauthCreds(minor, ctx, cred, outputToken);
620     if (GSS_ERROR(major))
621         return major;
622
623     return major;
624 }
625 #endif
626
627 static OM_uint32
628 eapGssSmAcceptCompleteInitiatorExts(OM_uint32 *minor,
629                                     gss_cred_id_t cred,
630                                     gss_ctx_id_t ctx,
631                                     gss_name_t target,
632                                     gss_OID mech,
633                                     OM_uint32 reqFlags,
634                                     OM_uint32 timeReq,
635                                     gss_channel_bindings_t chanBindings,
636                                     gss_buffer_t inputToken,
637                                     gss_buffer_t outputToken,
638                                     OM_uint32 *smFlags)
639 {
640     GSSEAP_SM_TRANSITION_NEXT(ctx);
641
642     *minor = 0;
643
644     return GSS_S_CONTINUE_NEEDED;
645 }
646
647 static OM_uint32
648 eapGssSmAcceptCompleteAcceptorExts(OM_uint32 *minor,
649                                    gss_cred_id_t cred,
650                                    gss_ctx_id_t ctx,
651                                    gss_name_t target,
652                                    gss_OID mech,
653                                    OM_uint32 reqFlags,
654                                    OM_uint32 timeReq,
655                                    gss_channel_bindings_t chanBindings,
656                                    gss_buffer_t inputToken,
657                                    gss_buffer_t outputToken,
658                                    OM_uint32 *smFlags)
659 {
660     GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
661
662     *minor = 0;
663     *smFlags |= SM_FLAG_FORCE_SEND_TOKEN;
664
665     return GSS_S_COMPLETE;
666 }
667
668 static struct gss_eap_sm eapGssAcceptorSm[] = {
669 #ifdef GSSEAP_ENABLE_REAUTH
670     {
671         ITOK_TYPE_REAUTH_REQ,
672         ITOK_TYPE_REAUTH_RESP,
673         GSSEAP_STATE_INITIAL,
674         0,
675         eapGssSmAcceptGssReauth,
676     },
677 #endif
678     {
679         ITOK_TYPE_NONE,
680         ITOK_TYPE_EAP_REQ,
681         GSSEAP_STATE_INITIAL,
682         SM_ITOK_FLAG_CRITICAL | SM_ITOK_FLAG_REQUIRED,
683         eapGssSmAcceptIdentity,
684     },
685     {
686         ITOK_TYPE_EAP_RESP,
687         ITOK_TYPE_EAP_REQ,
688         GSSEAP_STATE_AUTHENTICATE,
689         SM_ITOK_FLAG_CRITICAL | SM_ITOK_FLAG_REQUIRED,
690         eapGssSmAcceptAuthenticate
691     },
692     {
693         ITOK_TYPE_GSS_CHANNEL_BINDINGS,
694         ITOK_TYPE_NONE,
695         GSSEAP_STATE_INITIATOR_EXTS,
696         SM_ITOK_FLAG_CRITICAL | SM_ITOK_FLAG_REQUIRED,
697         eapGssSmAcceptGssChannelBindings,
698     },
699     {
700         ITOK_TYPE_NONE,
701         ITOK_TYPE_NONE,
702         GSSEAP_STATE_INITIATOR_EXTS,
703         0,
704         eapGssSmAcceptCompleteInitiatorExts,
705     },
706 #ifdef GSSEAP_ENABLE_REAUTH
707     {
708         ITOK_TYPE_NONE,
709         ITOK_TYPE_REAUTH_CREDS,
710         GSSEAP_STATE_ACCEPTOR_EXTS,
711         0,
712         eapGssSmAcceptReauthCreds,
713     },
714 #endif
715     {
716         ITOK_TYPE_NONE,
717         ITOK_TYPE_NONE,
718         GSSEAP_STATE_ACCEPTOR_EXTS,
719         0,
720         eapGssSmAcceptCompleteAcceptorExts
721     },
722 };
723
724 OM_uint32
725 gss_accept_sec_context(OM_uint32 *minor,
726                        gss_ctx_id_t *context_handle,
727                        gss_cred_id_t cred,
728                        gss_buffer_t input_token,
729                        gss_channel_bindings_t input_chan_bindings,
730                        gss_name_t *src_name,
731                        gss_OID *mech_type,
732                        gss_buffer_t output_token,
733                        OM_uint32 *ret_flags,
734                        OM_uint32 *time_rec,
735                        gss_cred_id_t *delegated_cred_handle)
736 {
737     OM_uint32 major, tmpMinor;
738     gss_ctx_id_t ctx = *context_handle;
739
740     *minor = 0;
741
742     output_token->length = 0;
743     output_token->value = NULL;
744
745     if (src_name != NULL)
746         *src_name = GSS_C_NO_NAME;
747
748     if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
749         *minor = GSSEAP_TOK_TRUNC;
750         return GSS_S_DEFECTIVE_TOKEN;
751     }
752
753     if (ctx == GSS_C_NO_CONTEXT) {
754         major = gssEapAllocContext(minor, &ctx);
755         if (GSS_ERROR(major))
756             return major;
757
758         *context_handle = ctx;
759     }
760
761     GSSEAP_MUTEX_LOCK(&ctx->mutex);
762
763     if (cred == GSS_C_NO_CREDENTIAL) {
764         if (ctx->defaultCred == GSS_C_NO_CREDENTIAL) {
765             major = gssEapAcquireCred(minor,
766                                       GSS_C_NO_NAME,
767                                       GSS_C_NO_BUFFER,
768                                       GSS_C_INDEFINITE,
769                                       GSS_C_NO_OID_SET,
770                                       GSS_C_ACCEPT,
771                                       &ctx->defaultCred,
772                                       NULL,
773                                       NULL);
774             if (GSS_ERROR(major))
775                 goto cleanup;
776         }
777
778         cred = ctx->defaultCred;
779     }
780
781     GSSEAP_MUTEX_LOCK(&cred->mutex);
782
783     major = gssEapSmStep(minor,
784                          cred,
785                          ctx,
786                          GSS_C_NO_NAME,
787                          GSS_C_NO_OID,
788                          0,
789                          GSS_C_INDEFINITE,
790                          input_chan_bindings,
791                          input_token,
792                          output_token,
793                          eapGssAcceptorSm,
794                          sizeof(eapGssAcceptorSm) / sizeof(eapGssAcceptorSm[0]));
795     if (GSS_ERROR(major))
796         goto cleanup;
797
798     if (mech_type != NULL) {
799         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
800             duplicateOid(&tmpMinor, ctx->mechanismUsed, mech_type);
801     }
802     if (ret_flags != NULL)
803         *ret_flags = ctx->gssFlags;
804     if (delegated_cred_handle != NULL)
805         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
806
807     if (major == GSS_S_COMPLETE) {
808         if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
809             major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
810             if (GSS_ERROR(major))
811                 goto cleanup;
812         }
813         if (time_rec != NULL) {
814             major = gssEapContextTime(&tmpMinor, ctx, time_rec);
815             if (GSS_ERROR(major))
816                 goto cleanup;
817         }
818     }
819
820     assert(ctx->state == GSSEAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
821
822 cleanup:
823     if (cred != GSS_C_NO_CREDENTIAL)
824         GSSEAP_MUTEX_UNLOCK(&cred->mutex);
825     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
826
827     if (GSS_ERROR(major))
828         gssEapReleaseContext(&tmpMinor, context_handle);
829
830     return major;
831 }
832
833 #ifdef GSSEAP_ENABLE_REAUTH
834 static OM_uint32
835 acceptReadyKrb(OM_uint32 *minor,
836                gss_ctx_id_t ctx,
837                gss_cred_id_t cred,
838                const gss_name_t initiator,
839                const gss_OID mech,
840                OM_uint32 timeRec)
841 {
842     OM_uint32 major;
843
844     major = gssEapGlueToMechName(minor, ctx, initiator, &ctx->initiatorName);
845     if (GSS_ERROR(major))
846         return major;
847
848     if (cred->name != GSS_C_NO_NAME) {
849         major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
850         if (GSS_ERROR(major))
851             return major;
852     }
853
854     major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
855     if (GSS_ERROR(major))
856         return major;
857
858     *minor = 0;
859     return GSS_S_COMPLETE;
860 }
861
862 static OM_uint32
863 eapGssSmAcceptGssReauth(OM_uint32 *minor,
864                         gss_cred_id_t cred,
865                         gss_ctx_id_t ctx,
866                         gss_name_t target __attribute__((__unused__)),
867                         gss_OID mech,
868                         OM_uint32 reqFlags __attribute__((__unused__)),
869                         OM_uint32 timeReq __attribute__((__unused__)),
870                         gss_channel_bindings_t chanBindings,
871                         gss_buffer_t inputToken,
872                         gss_buffer_t outputToken,
873                         OM_uint32 *smFlags)
874 {
875     OM_uint32 major, tmpMinor;
876     gss_name_t krbInitiator = GSS_C_NO_NAME;
877     OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
878
879     /*
880      * If we're built with fast reauthentication support, it's valid
881      * for an initiator to send a GSS reauthentication token as its
882      * initial context token, causing us to short-circuit the state
883      * machine and process Kerberos GSS messages instead.
884      */
885
886     ctx->flags |= CTX_FLAG_KRB_REAUTH;
887
888     major = gssAcceptSecContext(minor,
889                                 &ctx->kerberosCtx,
890                                 cred->krbCred,
891                                 inputToken,
892                                 chanBindings,
893                                 &krbInitiator,
894                                 &mech,
895                                 outputToken,
896                                 &gssFlags,
897                                 &timeRec,
898                                 NULL);
899     if (major == GSS_S_COMPLETE) {
900         major = acceptReadyKrb(minor, ctx, cred,
901                                krbInitiator, mech, timeRec);
902         if (major == GSS_S_COMPLETE) {
903             GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
904         }
905     }
906
907     ctx->gssFlags = gssFlags;
908
909     gssReleaseName(&tmpMinor, &krbInitiator);
910
911     return major;
912 }
913 #endif /* GSSEAP_ENABLE_REAUTH */