xref: /freebsd/crypto/heimdal/lib/gssapi/spnego/accept_sec_context.c (revision 7fc95c31f007ef01c53aa5f9d8802e9579f408ee)
1 /*
2  * Copyright (c) 1997 - 2006 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * Portions Copyright (c) 2004 PADL Software Pty Ltd.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "spnego_locl.h"
35 
36 static OM_uint32
37 send_reject (OM_uint32 *minor_status,
38 	     gss_buffer_t output_token)
39 {
40     NegotiationToken nt;
41     size_t size;
42 
43     nt.element = choice_NegotiationToken_negTokenResp;
44 
45     ALLOC(nt.u.negTokenResp.negResult, 1);
46     if (nt.u.negTokenResp.negResult == NULL) {
47 	*minor_status = ENOMEM;
48 	return GSS_S_FAILURE;
49     }
50     *(nt.u.negTokenResp.negResult)  = reject;
51     nt.u.negTokenResp.supportedMech = NULL;
52     nt.u.negTokenResp.responseToken = NULL;
53     nt.u.negTokenResp.mechListMIC   = NULL;
54 
55     ASN1_MALLOC_ENCODE(NegotiationToken,
56 		       output_token->value, output_token->length, &nt,
57 		       &size, *minor_status);
58     free_NegotiationToken(&nt);
59     if (*minor_status != 0)
60 	return GSS_S_FAILURE;
61 
62     return GSS_S_BAD_MECH;
63 }
64 
65 static OM_uint32
66 acceptor_approved(gss_name_t target_name, gss_OID mech)
67 {
68     gss_cred_id_t cred = GSS_C_NO_CREDENTIAL;
69     gss_OID_set oidset;
70     OM_uint32 junk, ret;
71 
72     if (target_name == GSS_C_NO_NAME)
73 	return GSS_S_COMPLETE;
74 
75     gss_create_empty_oid_set(&junk, &oidset);
76     gss_add_oid_set_member(&junk, mech, &oidset);
77 
78     ret = gss_acquire_cred(&junk, target_name, GSS_C_INDEFINITE, oidset,
79 			   GSS_C_ACCEPT, &cred, NULL, NULL);
80     gss_release_oid_set(&junk, &oidset);
81     if (ret != GSS_S_COMPLETE)
82 	return ret;
83     gss_release_cred(&junk, &cred);
84 
85     return GSS_S_COMPLETE;
86 }
87 
88 static OM_uint32
89 send_supported_mechs (OM_uint32 *minor_status,
90 		      gss_buffer_t output_token)
91 {
92     NegotiationTokenWin nt;
93     size_t buf_len = 0;
94     gss_buffer_desc data;
95     OM_uint32 ret;
96 
97     memset(&nt, 0, sizeof(nt));
98 
99     nt.element = choice_NegotiationTokenWin_negTokenInit;
100     nt.u.negTokenInit.reqFlags = NULL;
101     nt.u.negTokenInit.mechToken = NULL;
102     nt.u.negTokenInit.negHints = NULL;
103 
104     ret = _gss_spnego_indicate_mechtypelist(minor_status, GSS_C_NO_NAME,
105 					    acceptor_approved, 1, NULL,
106 					    &nt.u.negTokenInit.mechTypes, NULL);
107     if (ret != GSS_S_COMPLETE) {
108 	return ret;
109     }
110 
111     ALLOC(nt.u.negTokenInit.negHints, 1);
112     if (nt.u.negTokenInit.negHints == NULL) {
113 	*minor_status = ENOMEM;
114 	free_NegotiationTokenWin(&nt);
115 	return GSS_S_FAILURE;
116     }
117 
118     ALLOC(nt.u.negTokenInit.negHints->hintName, 1);
119     if (nt.u.negTokenInit.negHints->hintName == NULL) {
120 	*minor_status = ENOMEM;
121 	free_NegotiationTokenWin(&nt);
122 	return GSS_S_FAILURE;
123     }
124 
125     *nt.u.negTokenInit.negHints->hintName = strdup("not_defined_in_RFC4178@please_ignore");
126     nt.u.negTokenInit.negHints->hintAddress = NULL;
127 
128     ASN1_MALLOC_ENCODE(NegotiationTokenWin,
129 		       data.value, data.length, &nt, &buf_len, ret);
130     free_NegotiationTokenWin(&nt);
131     if (ret) {
132 	*minor_status = ret;
133 	return GSS_S_FAILURE;
134     }
135     if (data.length != buf_len) {
136 	abort();
137         UNREACHABLE(return GSS_S_FAILURE);
138     }
139 
140     ret = gss_encapsulate_token(&data, GSS_SPNEGO_MECHANISM, output_token);
141 
142     free (data.value);
143 
144     if (ret != GSS_S_COMPLETE)
145 	return ret;
146 
147     *minor_status = 0;
148 
149     return GSS_S_CONTINUE_NEEDED;
150 }
151 
152 static OM_uint32
153 send_accept (OM_uint32 *minor_status,
154 	     gssspnego_ctx context_handle,
155 	     gss_buffer_t mech_token,
156 	     int initial_response,
157 	     gss_buffer_t mech_buf,
158 	     gss_buffer_t output_token)
159 {
160     NegotiationToken nt;
161     OM_uint32 ret;
162     gss_buffer_desc mech_mic_buf;
163     size_t size;
164 
165     memset(&nt, 0, sizeof(nt));
166 
167     nt.element = choice_NegotiationToken_negTokenResp;
168 
169     ALLOC(nt.u.negTokenResp.negResult, 1);
170     if (nt.u.negTokenResp.negResult == NULL) {
171 	*minor_status = ENOMEM;
172 	return GSS_S_FAILURE;
173     }
174 
175     if (context_handle->open) {
176 	if (mech_token != GSS_C_NO_BUFFER
177 	    && mech_token->length != 0
178 	    && mech_buf != GSS_C_NO_BUFFER)
179 	    *(nt.u.negTokenResp.negResult)  = accept_incomplete;
180 	else
181 	    *(nt.u.negTokenResp.negResult)  = accept_completed;
182     } else {
183 	if (initial_response && context_handle->require_mic)
184 	    *(nt.u.negTokenResp.negResult)  = request_mic;
185 	else
186 	    *(nt.u.negTokenResp.negResult)  = accept_incomplete;
187     }
188 
189     if (initial_response) {
190 	ALLOC(nt.u.negTokenResp.supportedMech, 1);
191 	if (nt.u.negTokenResp.supportedMech == NULL) {
192 	    free_NegotiationToken(&nt);
193 	    *minor_status = ENOMEM;
194 	    return GSS_S_FAILURE;
195 	}
196 
197 	ret = der_get_oid(context_handle->preferred_mech_type->elements,
198 			  context_handle->preferred_mech_type->length,
199 			  nt.u.negTokenResp.supportedMech,
200 			  NULL);
201 	if (ret) {
202 	    free_NegotiationToken(&nt);
203 	    *minor_status = ENOMEM;
204 	    return GSS_S_FAILURE;
205 	}
206     } else {
207 	nt.u.negTokenResp.supportedMech = NULL;
208     }
209 
210     if (mech_token != GSS_C_NO_BUFFER && mech_token->length != 0) {
211 	ALLOC(nt.u.negTokenResp.responseToken, 1);
212 	if (nt.u.negTokenResp.responseToken == NULL) {
213 	    free_NegotiationToken(&nt);
214 	    *minor_status = ENOMEM;
215 	    return GSS_S_FAILURE;
216 	}
217 	nt.u.negTokenResp.responseToken->length = mech_token->length;
218 	nt.u.negTokenResp.responseToken->data   = mech_token->value;
219 	mech_token->length = 0;
220 	mech_token->value  = NULL;
221     } else {
222 	nt.u.negTokenResp.responseToken = NULL;
223     }
224 
225     if (mech_buf != GSS_C_NO_BUFFER) {
226 	ret = gss_get_mic(minor_status,
227 			  context_handle->negotiated_ctx_id,
228 			  0,
229 			  mech_buf,
230 			  &mech_mic_buf);
231 	if (ret == GSS_S_COMPLETE) {
232 	    ALLOC(nt.u.negTokenResp.mechListMIC, 1);
233 	    if (nt.u.negTokenResp.mechListMIC == NULL) {
234 		gss_release_buffer(minor_status, &mech_mic_buf);
235 		free_NegotiationToken(&nt);
236 		*minor_status = ENOMEM;
237 		return GSS_S_FAILURE;
238 	    }
239 	    nt.u.negTokenResp.mechListMIC->length = mech_mic_buf.length;
240 	    nt.u.negTokenResp.mechListMIC->data   = mech_mic_buf.value;
241 	} else if (ret == GSS_S_UNAVAILABLE) {
242 	    nt.u.negTokenResp.mechListMIC = NULL;
243 	} else {
244 	    free_NegotiationToken(&nt);
245 	    return ret;
246 	}
247 
248     } else
249 	nt.u.negTokenResp.mechListMIC = NULL;
250 
251     ASN1_MALLOC_ENCODE(NegotiationToken,
252 		       output_token->value, output_token->length,
253 		       &nt, &size, ret);
254     if (ret) {
255 	free_NegotiationToken(&nt);
256 	*minor_status = ret;
257 	return GSS_S_FAILURE;
258     }
259 
260     /*
261      * The response should not be encapsulated, because
262      * it is a SubsequentContextToken (note though RFC 1964
263      * specifies encapsulation for all _Kerberos_ tokens).
264      */
265 
266     if (*(nt.u.negTokenResp.negResult) == accept_completed)
267 	ret = GSS_S_COMPLETE;
268     else
269 	ret = GSS_S_CONTINUE_NEEDED;
270     free_NegotiationToken(&nt);
271     return ret;
272 }
273 
274 
275 static OM_uint32
276 verify_mechlist_mic
277 	   (OM_uint32 *minor_status,
278 	    gssspnego_ctx context_handle,
279 	    gss_buffer_t mech_buf,
280 	    heim_octet_string *mechListMIC
281 	   )
282 {
283     OM_uint32 ret;
284     gss_buffer_desc mic_buf;
285 
286     if (context_handle->verified_mic) {
287 	/* This doesn't make sense, we've already verified it? */
288 	*minor_status = 0;
289 	return GSS_S_DUPLICATE_TOKEN;
290     }
291 
292     if (mechListMIC == NULL) {
293 	*minor_status = 0;
294 	return GSS_S_DEFECTIVE_TOKEN;
295     }
296 
297     mic_buf.length = mechListMIC->length;
298     mic_buf.value  = mechListMIC->data;
299 
300     ret = gss_verify_mic(minor_status,
301 			 context_handle->negotiated_ctx_id,
302 			 mech_buf,
303 			 &mic_buf,
304 			 NULL);
305 
306     if (ret != GSS_S_COMPLETE)
307 	ret = GSS_S_DEFECTIVE_TOKEN;
308 
309     return ret;
310 }
311 
312 static OM_uint32
313 select_mech(OM_uint32 *minor_status, MechType *mechType, int verify_p,
314 	    gss_OID *mech_p)
315 {
316     char mechbuf[64];
317     size_t mech_len;
318     gss_OID_desc oid;
319     gss_OID oidp;
320     gss_OID_set mechs;
321     size_t i;
322     OM_uint32 ret, junk;
323 
324     ret = der_put_oid ((unsigned char *)mechbuf + sizeof(mechbuf) - 1,
325 		       sizeof(mechbuf),
326 		       mechType,
327 		       &mech_len);
328     if (ret) {
329 	return GSS_S_DEFECTIVE_TOKEN;
330     }
331 
332     oid.length   = mech_len;
333     oid.elements = mechbuf + sizeof(mechbuf) - mech_len;
334 
335     if (gss_oid_equal(&oid, GSS_SPNEGO_MECHANISM)) {
336 	return GSS_S_BAD_MECH;
337     }
338 
339     *minor_status = 0;
340 
341     /* Translate broken MS Kebreros OID */
342     if (gss_oid_equal(&oid, &_gss_spnego_mskrb_mechanism_oid_desc))
343 	    oidp = &_gss_spnego_krb5_mechanism_oid_desc;
344     else
345 	    oidp = &oid;
346 
347 
348     ret = gss_indicate_mechs(&junk, &mechs);
349     if (ret)
350 	    return (ret);
351 
352     for (i = 0; i < mechs->count; i++)
353 	    if (gss_oid_equal(&mechs->elements[i], oidp))
354 		    break;
355 
356     if (i == mechs->count) {
357 	    gss_release_oid_set(&junk, &mechs);
358 	    return GSS_S_BAD_MECH;
359     }
360     gss_release_oid_set(&junk, &mechs);
361 
362     ret = gss_duplicate_oid(minor_status,
363 			    &oid, /* possibly this should be oidp */
364 			    mech_p);
365 
366     if (verify_p) {
367 	gss_name_t name = GSS_C_NO_NAME;
368 	gss_buffer_desc namebuf;
369 	char *str = NULL, *host, hostname[MAXHOSTNAMELEN];
370 
371 	host = getenv("GSSAPI_SPNEGO_NAME");
372 	if (host == NULL || issuid()) {
373 	    int rv;
374 	    if (gethostname(hostname, sizeof(hostname)) != 0) {
375 		*minor_status = errno;
376 		return GSS_S_FAILURE;
377 	    }
378 	    rv = asprintf(&str, "host@%s", hostname);
379 	    if (rv < 0 || str == NULL) {
380 		*minor_status = ENOMEM;
381 		return GSS_S_FAILURE;
382 	    }
383 	    host = str;
384 	}
385 
386 	namebuf.length = strlen(host);
387 	namebuf.value = host;
388 
389 	ret = gss_import_name(minor_status, &namebuf,
390 			      GSS_C_NT_HOSTBASED_SERVICE, &name);
391 	if (str)
392 	    free(str);
393 	if (ret != GSS_S_COMPLETE)
394 	    return ret;
395 
396 	ret = acceptor_approved(name, *mech_p);
397 	gss_release_name(&junk, &name);
398     }
399 
400     return ret;
401 }
402 
403 
404 static OM_uint32
405 acceptor_complete(OM_uint32 * minor_status,
406 		  gssspnego_ctx ctx,
407 		  int *get_mic,
408 		  gss_buffer_t mech_buf,
409 		  gss_buffer_t mech_input_token,
410 		  gss_buffer_t mech_output_token,
411 		  heim_octet_string *mic,
412 		  gss_buffer_t output_token)
413 {
414     OM_uint32 ret;
415     int require_mic, verify_mic;
416 
417     ret = _gss_spnego_require_mechlist_mic(minor_status, ctx, &require_mic);
418     if (ret)
419 	return ret;
420 
421     ctx->require_mic = require_mic;
422 
423     if (mic != NULL)
424 	require_mic = 1;
425 
426     if (ctx->open && require_mic) {
427 	if (mech_input_token == GSS_C_NO_BUFFER) { /* Even/One */
428 	    verify_mic = 1;
429 	    *get_mic = 0;
430 	} else if (mech_output_token != GSS_C_NO_BUFFER &&
431 		   mech_output_token->length == 0) { /* Odd */
432 	    *get_mic = verify_mic = 1;
433 	} else { /* Even/One */
434 	    verify_mic = 0;
435 	    *get_mic = 1;
436 	}
437 
438 	if (verify_mic || *get_mic) {
439 	    int eret;
440 	    size_t buf_len = 0;
441 
442 	    ASN1_MALLOC_ENCODE(MechTypeList,
443 			       mech_buf->value, mech_buf->length,
444 			       &ctx->initiator_mech_types, &buf_len, eret);
445 	    if (eret) {
446 		*minor_status = eret;
447 		return GSS_S_FAILURE;
448 	    }
449 	    heim_assert(mech_buf->length == buf_len, "Internal ASN.1 error");
450 	    UNREACHABLE(return GSS_S_FAILURE);
451 	}
452 
453 	if (verify_mic) {
454 	    ret = verify_mechlist_mic(minor_status, ctx, mech_buf, mic);
455 	    if (ret) {
456 		if (*get_mic)
457 		    send_reject (minor_status, output_token);
458 		return ret;
459 	    }
460 	    ctx->verified_mic = 1;
461 	}
462     } else
463 	*get_mic = 0;
464 
465     return GSS_S_COMPLETE;
466 }
467 
468 
469 static OM_uint32 GSSAPI_CALLCONV
470 acceptor_start
471 	   (OM_uint32 * minor_status,
472 	    gss_ctx_id_t * context_handle,
473 	    const gss_cred_id_t acceptor_cred_handle,
474 	    const gss_buffer_t input_token_buffer,
475 	    const gss_channel_bindings_t input_chan_bindings,
476 	    gss_name_t * src_name,
477 	    gss_OID * mech_type,
478 	    gss_buffer_t output_token,
479 	    OM_uint32 * ret_flags,
480 	    OM_uint32 * time_rec,
481 	    gss_cred_id_t *delegated_cred_handle
482 	   )
483 {
484     OM_uint32 ret, junk;
485     NegotiationToken nt;
486     size_t nt_len;
487     NegTokenInit *ni;
488     gss_buffer_desc data;
489     gss_buffer_t mech_input_token = GSS_C_NO_BUFFER;
490     gss_buffer_desc mech_output_token;
491     gss_buffer_desc mech_buf;
492     gss_OID preferred_mech_type = GSS_C_NO_OID;
493     gssspnego_ctx ctx;
494     int get_mic = 0;
495     int first_ok = 0;
496 
497     mech_output_token.value = NULL;
498     mech_output_token.length = 0;
499     mech_buf.value = NULL;
500 
501     if (input_token_buffer->length == 0)
502 	return send_supported_mechs (minor_status, output_token);
503 
504     ret = _gss_spnego_alloc_sec_context(minor_status, context_handle);
505     if (ret != GSS_S_COMPLETE)
506 	return ret;
507 
508     ctx = (gssspnego_ctx)*context_handle;
509 
510     /*
511      * The GSS-API encapsulation is only present on the initial
512      * context token (negTokenInit).
513      */
514     ret = gss_decapsulate_token (input_token_buffer,
515 				 GSS_SPNEGO_MECHANISM,
516 				 &data);
517     if (ret)
518 	return ret;
519 
520     ret = decode_NegotiationToken(data.value, data.length, &nt, &nt_len);
521     gss_release_buffer(minor_status, &data);
522     if (ret) {
523 	*minor_status = ret;
524 	return GSS_S_DEFECTIVE_TOKEN;
525     }
526     if (nt.element != choice_NegotiationToken_negTokenInit) {
527 	*minor_status = 0;
528 	return GSS_S_DEFECTIVE_TOKEN;
529     }
530     ni = &nt.u.negTokenInit;
531 
532     if (ni->mechTypes.len < 1) {
533 	free_NegotiationToken(&nt);
534 	*minor_status = 0;
535 	return GSS_S_DEFECTIVE_TOKEN;
536     }
537 
538     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
539 
540     ret = copy_MechTypeList(&ni->mechTypes, &ctx->initiator_mech_types);
541     if (ret) {
542 	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
543 	free_NegotiationToken(&nt);
544 	*minor_status = ret;
545 	return GSS_S_FAILURE;
546     }
547 
548     /*
549      * First we try the opportunistic token if we have support for it,
550      * don't try to verify we have credential for the token,
551      * gss_accept_sec_context() will (hopefully) tell us that.
552      * If that failes,
553      */
554 
555     ret = select_mech(minor_status,
556 		      &ni->mechTypes.val[0],
557 		      0,
558 		      &preferred_mech_type);
559 
560     if (ret == 0 && ni->mechToken != NULL) {
561 	gss_buffer_desc ibuf;
562 
563 	ibuf.length = ni->mechToken->length;
564 	ibuf.value = ni->mechToken->data;
565 	mech_input_token = &ibuf;
566 
567 	if (ctx->mech_src_name != GSS_C_NO_NAME)
568 	    gss_release_name(&junk, &ctx->mech_src_name);
569 
570 	ret = gss_accept_sec_context(minor_status,
571 				     &ctx->negotiated_ctx_id,
572 				     acceptor_cred_handle,
573 				     mech_input_token,
574 				     input_chan_bindings,
575 				     &ctx->mech_src_name,
576 				     &ctx->negotiated_mech_type,
577 				     &mech_output_token,
578 				     &ctx->mech_flags,
579 				     &ctx->mech_time_rec,
580 				     delegated_cred_handle);
581 
582 	if (ret == GSS_S_COMPLETE || ret == GSS_S_CONTINUE_NEEDED) {
583 	    ctx->preferred_mech_type = preferred_mech_type;
584 	    if (ret == GSS_S_COMPLETE)
585 		ctx->open = 1;
586 
587 	    ret = acceptor_complete(minor_status,
588 				    ctx,
589 				    &get_mic,
590 				    &mech_buf,
591 				    mech_input_token,
592 				    &mech_output_token,
593 				    ni->mechListMIC,
594 				    output_token);
595 	    if (ret != GSS_S_COMPLETE)
596 		goto out;
597 
598 	    first_ok = 1;
599 	} else {
600 	    gss_mg_collect_error(preferred_mech_type, ret, *minor_status);
601 	}
602     }
603 
604     /*
605      * If opportunistic token failed, lets try the other mechs.
606      */
607 
608     if (!first_ok) {
609 	size_t j;
610 
611 	preferred_mech_type = GSS_C_NO_OID;
612 
613 	/* Call glue layer to find first mech we support */
614 	for (j = 1; j < ni->mechTypes.len; ++j) {
615 	    ret = select_mech(minor_status,
616 			      &ni->mechTypes.val[j],
617 			      1,
618 			      &preferred_mech_type);
619 	    if (ret == 0)
620 		break;
621 	}
622     }
623 
624     ctx->preferred_mech_type = preferred_mech_type;
625 
626     if (preferred_mech_type == GSS_C_NO_OID) {
627         send_reject(minor_status, output_token);
628         HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
629         free_NegotiationToken(&nt);
630         return ret;
631     }
632 
633     /*
634      * The initial token always have a response
635      */
636 
637     ret = send_accept (minor_status,
638 		       ctx,
639 		       &mech_output_token,
640 		       1,
641 		       get_mic ? &mech_buf : NULL,
642 		       output_token);
643     if (ret)
644 	goto out;
645 
646 out:
647     if (mech_output_token.value != NULL)
648 	gss_release_buffer(&junk, &mech_output_token);
649     if (mech_buf.value != NULL) {
650 	free(mech_buf.value);
651 	mech_buf.value = NULL;
652     }
653     free_NegotiationToken(&nt);
654 
655 
656     if (ret == GSS_S_COMPLETE) {
657 	if (src_name != NULL && ctx->mech_src_name != NULL) {
658 	    spnego_name name;
659 
660 	    name = calloc(1, sizeof(*name));
661 	    if (name) {
662 		name->mech = ctx->mech_src_name;
663 		ctx->mech_src_name = NULL;
664 		*src_name = (gss_name_t)name;
665 	    }
666 	}
667     }
668 
669     if (mech_type != NULL)
670 	*mech_type = ctx->negotiated_mech_type;
671     if (ret_flags != NULL)
672 	*ret_flags = ctx->mech_flags;
673     if (time_rec != NULL)
674 	*time_rec = ctx->mech_time_rec;
675 
676     if (ret == GSS_S_COMPLETE || ret == GSS_S_CONTINUE_NEEDED) {
677 	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
678  	return ret;
679     }
680 
681     _gss_spnego_internal_delete_sec_context(&junk, context_handle,
682 					    GSS_C_NO_BUFFER);
683 
684     return ret;
685 }
686 
687 
688 static OM_uint32 GSSAPI_CALLCONV
689 acceptor_continue
690 	   (OM_uint32 * minor_status,
691 	    gss_ctx_id_t * context_handle,
692 	    const gss_cred_id_t acceptor_cred_handle,
693 	    const gss_buffer_t input_token_buffer,
694 	    const gss_channel_bindings_t input_chan_bindings,
695 	    gss_name_t * src_name,
696 	    gss_OID * mech_type,
697 	    gss_buffer_t output_token,
698 	    OM_uint32 * ret_flags,
699 	    OM_uint32 * time_rec,
700 	    gss_cred_id_t *delegated_cred_handle
701 	   )
702 {
703     OM_uint32 ret, ret2, minor;
704     NegotiationToken nt;
705     size_t nt_len;
706     NegTokenResp *na;
707     unsigned int negResult = accept_incomplete;
708     gss_buffer_t mech_input_token = GSS_C_NO_BUFFER;
709     gss_buffer_t mech_output_token = GSS_C_NO_BUFFER;
710     gss_buffer_desc mech_buf;
711     gssspnego_ctx ctx;
712 
713     mech_buf.value = NULL;
714 
715     ctx = (gssspnego_ctx)*context_handle;
716 
717     /*
718      * The GSS-API encapsulation is only present on the initial
719      * context token (negTokenInit).
720      */
721 
722     ret = decode_NegotiationToken(input_token_buffer->value,
723 				  input_token_buffer->length,
724 				  &nt, &nt_len);
725     if (ret) {
726 	*minor_status = ret;
727 	return GSS_S_DEFECTIVE_TOKEN;
728     }
729     if (nt.element != choice_NegotiationToken_negTokenResp) {
730 	*minor_status = 0;
731 	return GSS_S_DEFECTIVE_TOKEN;
732     }
733     na = &nt.u.negTokenResp;
734 
735     if (na->negResult != NULL) {
736 	negResult = *(na->negResult);
737     }
738 
739     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
740 
741     {
742 	gss_buffer_desc ibuf, obuf;
743 	int require_mic, get_mic = 0;
744 	int require_response;
745 	heim_octet_string *mic;
746 
747 	if (na->responseToken != NULL) {
748 	    ibuf.length = na->responseToken->length;
749 	    ibuf.value = na->responseToken->data;
750 	    mech_input_token = &ibuf;
751 	} else {
752 	    ibuf.value = NULL;
753 	    ibuf.length = 0;
754 	}
755 
756 	if (mech_input_token != GSS_C_NO_BUFFER) {
757 
758 	    if (ctx->mech_src_name != GSS_C_NO_NAME)
759 		gss_release_name(&minor, &ctx->mech_src_name);
760 
761 	    ret = gss_accept_sec_context(&minor,
762 					 &ctx->negotiated_ctx_id,
763 					 acceptor_cred_handle,
764 					 mech_input_token,
765 					 input_chan_bindings,
766 					 &ctx->mech_src_name,
767 					 &ctx->negotiated_mech_type,
768 					 &obuf,
769 					 &ctx->mech_flags,
770 					 &ctx->mech_time_rec,
771 					 delegated_cred_handle);
772 
773 	    if (ret == GSS_S_COMPLETE || ret == GSS_S_CONTINUE_NEEDED) {
774 		mech_output_token = &obuf;
775 	    }
776 	    if (ret != GSS_S_COMPLETE && ret != GSS_S_CONTINUE_NEEDED) {
777 		free_NegotiationToken(&nt);
778 		gss_mg_collect_error(ctx->negotiated_mech_type, ret, minor);
779 		send_reject (minor_status, output_token);
780 		HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
781 		return ret;
782 	    }
783 	    if (ret == GSS_S_COMPLETE)
784 		ctx->open = 1;
785 	} else
786 	    ret = GSS_S_COMPLETE;
787 
788 	ret2 = _gss_spnego_require_mechlist_mic(minor_status,
789 						ctx,
790 						&require_mic);
791 	if (ret2)
792 	    goto out;
793 
794 	ctx->require_mic = require_mic;
795 
796 	mic = na->mechListMIC;
797 	if (mic != NULL)
798 	    require_mic = 1;
799 
800 	if (ret == GSS_S_COMPLETE)
801 	    ret = acceptor_complete(minor_status,
802 				    ctx,
803 				    &get_mic,
804 				    &mech_buf,
805 				    mech_input_token,
806 				    mech_output_token,
807 				    na->mechListMIC,
808 				    output_token);
809 
810 	if (ctx->mech_flags & GSS_C_DCE_STYLE)
811 	    require_response = (negResult != accept_completed);
812 	else
813 	    require_response = 0;
814 
815 	/*
816 	 * Check whether we need to send a result: there should be only
817 	 * one accept_completed response sent in the entire negotiation
818 	 */
819 	if ((mech_output_token != GSS_C_NO_BUFFER &&
820 	     mech_output_token->length != 0)
821 	    || (ctx->open && negResult == accept_incomplete)
822 	    || require_response
823 	    || get_mic) {
824 	    ret2 = send_accept (minor_status,
825 				ctx,
826 				mech_output_token,
827 				0,
828 				get_mic ? &mech_buf : NULL,
829 				output_token);
830 	    if (ret2)
831 		goto out;
832 	}
833 
834      out:
835 	if (ret2 != GSS_S_COMPLETE)
836 	    ret = ret2;
837 	if (mech_output_token != NULL)
838 	    gss_release_buffer(&minor, mech_output_token);
839 	if (mech_buf.value != NULL)
840 	    free(mech_buf.value);
841 	free_NegotiationToken(&nt);
842     }
843 
844     if (ret == GSS_S_COMPLETE) {
845 	if (src_name != NULL && ctx->mech_src_name != NULL) {
846 	    spnego_name name;
847 
848 	    name = calloc(1, sizeof(*name));
849 	    if (name) {
850 		name->mech = ctx->mech_src_name;
851 		ctx->mech_src_name = NULL;
852 		*src_name = (gss_name_t)name;
853 	    }
854 	}
855     }
856 
857     if (mech_type != NULL)
858 	*mech_type = ctx->negotiated_mech_type;
859     if (ret_flags != NULL)
860 	*ret_flags = ctx->mech_flags;
861     if (time_rec != NULL)
862 	*time_rec = ctx->mech_time_rec;
863 
864     if (ret == GSS_S_COMPLETE || ret == GSS_S_CONTINUE_NEEDED) {
865 	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
866  	return ret;
867     }
868 
869     _gss_spnego_internal_delete_sec_context(&minor, context_handle,
870 				   GSS_C_NO_BUFFER);
871 
872     return ret;
873 }
874 
875 OM_uint32 GSSAPI_CALLCONV
876 _gss_spnego_accept_sec_context
877 	   (OM_uint32 * minor_status,
878 	    gss_ctx_id_t * context_handle,
879 	    const gss_cred_id_t acceptor_cred_handle,
880 	    const gss_buffer_t input_token_buffer,
881 	    const gss_channel_bindings_t input_chan_bindings,
882 	    gss_name_t * src_name,
883 	    gss_OID * mech_type,
884 	    gss_buffer_t output_token,
885 	    OM_uint32 * ret_flags,
886 	    OM_uint32 * time_rec,
887 	    gss_cred_id_t *delegated_cred_handle
888 	   )
889 {
890     _gss_accept_sec_context_t *func;
891 
892     *minor_status = 0;
893 
894     output_token->length = 0;
895     output_token->value  = NULL;
896 
897     if (src_name != NULL)
898 	*src_name = GSS_C_NO_NAME;
899     if (mech_type != NULL)
900 	*mech_type = GSS_C_NO_OID;
901     if (ret_flags != NULL)
902 	*ret_flags = 0;
903     if (time_rec != NULL)
904 	*time_rec = 0;
905     if (delegated_cred_handle != NULL)
906 	*delegated_cred_handle = GSS_C_NO_CREDENTIAL;
907 
908 
909     if (*context_handle == GSS_C_NO_CONTEXT)
910 	func = acceptor_start;
911     else
912 	func = acceptor_continue;
913 
914 
915     return (*func)(minor_status, context_handle, acceptor_cred_handle,
916 		   input_token_buffer, input_chan_bindings,
917 		   src_name, mech_type, output_token, ret_flags,
918 		   time_rec, delegated_cred_handle);
919 }
920