xref: /freebsd/crypto/openssl/ssl/statem/extensions_cust.c (revision e7be843b4a162e68651d3911f0357ed464915629)
1 /*
2  * Copyright 2014-2025 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 /* Custom extension utility functions */
11 
12 #include <openssl/ct.h>
13 #include "../ssl_local.h"
14 #include "internal/cryptlib.h"
15 #include "internal/ssl_unwrap.h"
16 #include "statem_local.h"
17 
18 typedef struct {
19     void *add_arg;
20     custom_ext_add_cb add_cb;
21     custom_ext_free_cb free_cb;
22 } custom_ext_add_cb_wrap;
23 
24 typedef struct {
25     void *parse_arg;
26     custom_ext_parse_cb parse_cb;
27 } custom_ext_parse_cb_wrap;
28 
29 /*
30  * Provide thin wrapper callbacks which convert new style arguments to old style
31  */
custom_ext_add_old_cb_wrap(SSL * s,unsigned int ext_type,unsigned int context,const unsigned char ** out,size_t * outlen,X509 * x,size_t chainidx,int * al,void * add_arg)32 static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type,
33                                       unsigned int context,
34                                       const unsigned char **out,
35                                       size_t *outlen, X509 *x, size_t chainidx,
36                                       int *al, void *add_arg)
37 {
38     custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
39 
40     if (add_cb_wrap->add_cb == NULL)
41         return 1;
42 
43     return add_cb_wrap->add_cb(s, ext_type, out, outlen, al,
44                                add_cb_wrap->add_arg);
45 }
46 
custom_ext_free_old_cb_wrap(SSL * s,unsigned int ext_type,unsigned int context,const unsigned char * out,void * add_arg)47 static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type,
48                                         unsigned int context,
49                                         const unsigned char *out, void *add_arg)
50 {
51     custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
52 
53     if (add_cb_wrap->free_cb == NULL)
54         return;
55 
56     add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg);
57 }
58 
custom_ext_parse_old_cb_wrap(SSL * s,unsigned int ext_type,unsigned int context,const unsigned char * in,size_t inlen,X509 * x,size_t chainidx,int * al,void * parse_arg)59 static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type,
60                                         unsigned int context,
61                                         const unsigned char *in,
62                                         size_t inlen, X509 *x, size_t chainidx,
63                                         int *al, void *parse_arg)
64 {
65     custom_ext_parse_cb_wrap *parse_cb_wrap =
66         (custom_ext_parse_cb_wrap *)parse_arg;
67 
68     if (parse_cb_wrap->parse_cb == NULL)
69         return 1;
70 
71     return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
72                                    parse_cb_wrap->parse_arg);
73 }
74 
75 /*
76  * Find a custom extension from the list. The |role| param is there to
77  * support the legacy API where custom extensions for client and server could
78  * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
79  * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
80  * client, or ENDPOINT_BOTH for either
81  */
custom_ext_find(const custom_ext_methods * exts,ENDPOINT role,unsigned int ext_type,size_t * idx)82 custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
83                                    ENDPOINT role, unsigned int ext_type,
84                                    size_t *idx)
85 {
86     size_t i;
87     custom_ext_method *meth = exts->meths;
88 
89     for (i = 0; i < exts->meths_count; i++, meth++) {
90         if (ext_type == meth->ext_type
91                 && (role == ENDPOINT_BOTH || role == meth->role
92                     || meth->role == ENDPOINT_BOTH)) {
93             if (idx != NULL)
94                 *idx = i;
95             return meth;
96         }
97     }
98     return NULL;
99 }
100 
101 /*
102  * Initialise custom extensions flags to indicate neither sent nor received.
103  */
custom_ext_init(custom_ext_methods * exts)104 void custom_ext_init(custom_ext_methods *exts)
105 {
106     size_t i;
107     custom_ext_method *meth = exts->meths;
108 
109     for (i = 0; i < exts->meths_count; i++, meth++)
110         meth->ext_flags &= ~(SSL_EXT_FLAG_SENT | SSL_EXT_FLAG_RECEIVED);
111 }
112 
113 /* Pass received custom extension data to the application for parsing. */
custom_ext_parse(SSL_CONNECTION * s,unsigned int context,unsigned int ext_type,const unsigned char * ext_data,size_t ext_size,X509 * x,size_t chainidx)114 int custom_ext_parse(SSL_CONNECTION *s, unsigned int context,
115                      unsigned int ext_type,
116                      const unsigned char *ext_data, size_t ext_size, X509 *x,
117                      size_t chainidx)
118 {
119     int al = 0;
120     custom_ext_methods *exts = &s->cert->custext;
121     custom_ext_method *meth;
122     ENDPOINT role = ENDPOINT_BOTH;
123 
124     if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
125         role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;
126 
127     meth = custom_ext_find(exts, role, ext_type, NULL);
128     /* If not found return success */
129     if (!meth)
130         return 1;
131 
132     /* Check if extension is defined for our protocol. If not, skip */
133     if (!extension_is_relevant(s, meth->context, context))
134         return 1;
135 
136     if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
137                     | SSL_EXT_TLS1_3_SERVER_HELLO
138                     | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
139         /*
140          * If it's ServerHello or EncryptedExtensions we can't have any
141          * extensions not sent in ClientHello.
142          */
143         if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
144             SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_R_BAD_EXTENSION);
145             return 0;
146         }
147     }
148 
149     /*
150      * Extensions received in the ClientHello or CertificateRequest are marked
151      * with the SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
152      * extensions in the response messages
153      */
154     if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST))
155             != 0)
156         meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;
157 
158     /* If no parse function set return success */
159     if (meth->parse_cb == NULL)
160         return 1;
161 
162     if (meth->parse_cb(SSL_CONNECTION_GET_USER_SSL(s), ext_type, context, ext_data,
163                        ext_size, x, chainidx, &al, meth->parse_arg) <= 0) {
164         SSLfatal(s, al, SSL_R_BAD_EXTENSION);
165         return 0;
166     }
167 
168     return 1;
169 }
170 
171 /*
172  * Request custom extension data from the application and add to the return
173  * buffer.
174  */
custom_ext_add(SSL_CONNECTION * s,int context,WPACKET * pkt,X509 * x,size_t chainidx,int maxversion)175 int custom_ext_add(SSL_CONNECTION *s, int context, WPACKET *pkt, X509 *x,
176                    size_t chainidx, int maxversion)
177 {
178     custom_ext_methods *exts = &s->cert->custext;
179     custom_ext_method *meth;
180     size_t i;
181     int al;
182     int for_comp = (context & SSL_EXT_TLS1_3_CERTIFICATE_COMPRESSION) != 0;
183 
184     for (i = 0; i < exts->meths_count; i++) {
185         const unsigned char *out = NULL;
186         size_t outlen = 0;
187 
188         meth = exts->meths + i;
189 
190         if (!should_add_extension(s, meth->context, context, maxversion))
191             continue;
192 
193         if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
194                         | SSL_EXT_TLS1_3_SERVER_HELLO
195                         | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
196                         | SSL_EXT_TLS1_3_CERTIFICATE
197                         | SSL_EXT_TLS1_3_RAW_PUBLIC_KEY
198                         | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
199             /* Only send extensions present in ClientHello/CertificateRequest */
200             if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
201                 continue;
202         }
203         /*
204          * We skip it if the callback is absent - except for a ClientHello where
205          * we add an empty extension.
206          */
207         if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
208             continue;
209 
210         if (meth->add_cb != NULL) {
211             int cb_retval = meth->add_cb(SSL_CONNECTION_GET_USER_SSL(s),
212                                          meth->ext_type, context, &out,
213                                          &outlen, x, chainidx, &al,
214                                          meth->add_arg);
215 
216             if (cb_retval < 0) {
217                 if (!for_comp)
218                     SSLfatal(s, al, SSL_R_CALLBACK_FAILED);
219                 return 0;       /* error */
220             }
221             if (cb_retval == 0)
222                 continue;       /* skip this extension */
223         }
224 
225         if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
226                 || !WPACKET_start_sub_packet_u16(pkt)
227                 || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
228                 || !WPACKET_close(pkt)) {
229             if (meth->free_cb != NULL)
230                 meth->free_cb(SSL_CONNECTION_GET_USER_SSL(s), meth->ext_type,
231                               context, out, meth->add_arg);
232             if (!for_comp)
233                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
234             return 0;
235         }
236         if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
237             /*
238              * We can't send duplicates: code logic should prevent this.
239              */
240             if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
241                 if (meth->free_cb != NULL)
242                     meth->free_cb(SSL_CONNECTION_GET_USER_SSL(s), meth->ext_type,
243                                   context, out, meth->add_arg);
244                 if (!for_comp)
245                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
246                 return 0;
247             }
248             /*
249              * Indicate extension has been sent: this is both a sanity check to
250              * ensure we don't send duplicate extensions and indicates that it
251              * is not an error if the extension is present in ServerHello.
252              */
253             meth->ext_flags |= SSL_EXT_FLAG_SENT;
254         }
255         if (meth->free_cb != NULL)
256             meth->free_cb(SSL_CONNECTION_GET_USER_SSL(s), meth->ext_type,
257                           context, out, meth->add_arg);
258     }
259     return 1;
260 }
261 
262 /* Copy the flags from src to dst for any extensions that exist in both */
custom_exts_copy_flags(custom_ext_methods * dst,const custom_ext_methods * src)263 int custom_exts_copy_flags(custom_ext_methods *dst,
264                            const custom_ext_methods *src)
265 {
266     size_t i;
267     custom_ext_method *methsrc = src->meths;
268 
269     for (i = 0; i < src->meths_count; i++, methsrc++) {
270         custom_ext_method *methdst = custom_ext_find(dst, methsrc->role,
271                                                      methsrc->ext_type, NULL);
272 
273         if (methdst == NULL)
274             continue;
275 
276         methdst->ext_flags = methsrc->ext_flags;
277     }
278 
279     return 1;
280 }
281 
282 /* Copy old style API wrapper arguments */
custom_ext_copy_old_cb(custom_ext_method * methdst,const custom_ext_method * methsrc,int * err)283 static void custom_ext_copy_old_cb(custom_ext_method *methdst,
284                                    const custom_ext_method *methsrc,
285                                    int *err)
286 {
287     if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
288         return;
289 
290     if (*err) {
291         methdst->add_arg = NULL;
292         methdst->parse_arg = NULL;
293         return;
294     }
295 
296     methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
297                                       sizeof(custom_ext_add_cb_wrap));
298     methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
299                                         sizeof(custom_ext_parse_cb_wrap));
300 
301     if (methdst->add_arg == NULL || methdst->parse_arg == NULL)
302         *err = 1;
303 
304     return;
305 }
306 
307 /* Copy table of custom extensions */
custom_exts_copy(custom_ext_methods * dst,const custom_ext_methods * src)308 int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
309 {
310     size_t i;
311     int err = 0;
312 
313     if (src->meths_count > 0) {
314         dst->meths =
315             OPENSSL_memdup(src->meths,
316                            sizeof(*src->meths) * src->meths_count);
317         if (dst->meths == NULL)
318             return 0;
319         dst->meths_count = src->meths_count;
320 
321         for (i = 0; i < src->meths_count; i++)
322             custom_ext_copy_old_cb(&dst->meths[i], &src->meths[i], &err);
323     }
324 
325     if (err) {
326         custom_exts_free(dst);
327         return 0;
328     }
329 
330     return 1;
331 }
332 
333 /* Copy custom extensions that were set on connection */
custom_exts_copy_conn(custom_ext_methods * dst,const custom_ext_methods * src)334 int custom_exts_copy_conn(custom_ext_methods *dst,
335                           const custom_ext_methods *src)
336 {
337     size_t i;
338     int err = 0;
339 
340     if (src->meths_count > 0) {
341         size_t meths_count = 0;
342 
343         for (i = 0; i < src->meths_count; i++)
344             if ((src->meths[i].ext_flags & SSL_EXT_FLAG_CONN) != 0)
345                 meths_count++;
346 
347         if (meths_count > 0) {
348             custom_ext_method *methdst =
349                 OPENSSL_realloc(dst->meths,
350                                 (dst->meths_count + meths_count) *
351                                 sizeof(custom_ext_method));
352 
353             if (methdst == NULL)
354                 return 0;
355 
356             for (i = 0; i < dst->meths_count; i++)
357                 custom_ext_copy_old_cb(&methdst[i], &dst->meths[i], &err);
358 
359             dst->meths = methdst;
360             methdst += dst->meths_count;
361 
362             for (i = 0; i < src->meths_count; i++) {
363                 custom_ext_method *methsrc = &src->meths[i];
364 
365                 if ((methsrc->ext_flags & SSL_EXT_FLAG_CONN) == 0)
366                     continue;
367 
368                 memcpy(methdst, methsrc, sizeof(custom_ext_method));
369                 custom_ext_copy_old_cb(methdst, methsrc, &err);
370                 methdst++;
371             }
372 
373             dst->meths_count += meths_count;
374         }
375     }
376 
377     if (err) {
378         custom_exts_free(dst);
379         return 0;
380     }
381 
382     return 1;
383 }
384 
custom_exts_free(custom_ext_methods * exts)385 void custom_exts_free(custom_ext_methods *exts)
386 {
387     size_t i;
388     custom_ext_method *meth;
389 
390     for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
391         if (meth->add_cb != custom_ext_add_old_cb_wrap)
392             continue;
393 
394         /* Old style API wrapper. Need to free the arguments too */
395         OPENSSL_free(meth->add_arg);
396         OPENSSL_free(meth->parse_arg);
397     }
398     OPENSSL_free(exts->meths);
399     exts->meths = NULL;
400     exts->meths_count = 0;
401 }
402 
403 /* Return true if a client custom extension exists, false otherwise */
SSL_CTX_has_client_custom_ext(const SSL_CTX * ctx,unsigned int ext_type)404 int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
405 {
406     return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
407                            NULL) != NULL;
408 }
409 
ossl_tls_add_custom_ext_intern(SSL_CTX * ctx,custom_ext_methods * exts,ENDPOINT role,unsigned int ext_type,unsigned int context,SSL_custom_ext_add_cb_ex add_cb,SSL_custom_ext_free_cb_ex free_cb,void * add_arg,SSL_custom_ext_parse_cb_ex parse_cb,void * parse_arg)410 int ossl_tls_add_custom_ext_intern(SSL_CTX *ctx, custom_ext_methods *exts,
411                                    ENDPOINT role, unsigned int ext_type,
412                                    unsigned int context,
413                                    SSL_custom_ext_add_cb_ex add_cb,
414                                    SSL_custom_ext_free_cb_ex free_cb,
415                                    void *add_arg,
416                                    SSL_custom_ext_parse_cb_ex parse_cb,
417                                    void *parse_arg)
418 {
419     custom_ext_method *meth, *tmp;
420 
421     /*
422      * Check application error: if add_cb is not set free_cb will never be
423      * called.
424      */
425     if (add_cb == NULL && free_cb != NULL)
426         return 0;
427 
428     if (exts == NULL)
429         exts = &ctx->cert->custext;
430 
431 #ifndef OPENSSL_NO_CT
432     /*
433      * We don't want applications registering callbacks for SCT extensions
434      * whilst simultaneously using the built-in SCT validation features, as
435      * these two things may not play well together.
436      */
437     if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
438             && (context & SSL_EXT_CLIENT_HELLO) != 0
439             && ctx != NULL
440             && SSL_CTX_ct_is_enabled(ctx))
441         return 0;
442 #endif
443 
444     /*
445      * Don't add if extension supported internally, but make exception
446      * for extension types that previously were not supported, but now are.
447      */
448     if (SSL_extension_supported(ext_type)
449             && ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
450         return 0;
451 
452     /* Extension type must fit in 16 bits */
453     if (ext_type > 0xffff)
454         return 0;
455     /* Search for duplicate */
456     if (custom_ext_find(exts, role, ext_type, NULL))
457         return 0;
458     tmp = OPENSSL_realloc(exts->meths,
459                           (exts->meths_count + 1) * sizeof(custom_ext_method));
460     if (tmp == NULL)
461         return 0;
462 
463     exts->meths = tmp;
464     meth = exts->meths + exts->meths_count;
465     memset(meth, 0, sizeof(*meth));
466     meth->role = role;
467     meth->context = context;
468     meth->parse_cb = parse_cb;
469     meth->add_cb = add_cb;
470     meth->free_cb = free_cb;
471     meth->ext_type = ext_type;
472     meth->ext_flags = (ctx == NULL) ? SSL_EXT_FLAG_CONN : 0;
473     meth->add_arg = add_arg;
474     meth->parse_arg = parse_arg;
475     exts->meths_count++;
476     return 1;
477 }
478 
add_old_custom_ext(SSL_CTX * ctx,ENDPOINT role,unsigned int ext_type,unsigned int context,custom_ext_add_cb add_cb,custom_ext_free_cb free_cb,void * add_arg,custom_ext_parse_cb parse_cb,void * parse_arg)479 static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
480                               unsigned int ext_type,
481                               unsigned int context,
482                               custom_ext_add_cb add_cb,
483                               custom_ext_free_cb free_cb,
484                               void *add_arg,
485                               custom_ext_parse_cb parse_cb, void *parse_arg)
486 {
487     custom_ext_add_cb_wrap *add_cb_wrap
488         = OPENSSL_malloc(sizeof(*add_cb_wrap));
489     custom_ext_parse_cb_wrap *parse_cb_wrap
490         = OPENSSL_malloc(sizeof(*parse_cb_wrap));
491     int ret;
492 
493     if (add_cb_wrap == NULL || parse_cb_wrap == NULL) {
494         OPENSSL_free(add_cb_wrap);
495         OPENSSL_free(parse_cb_wrap);
496         return 0;
497     }
498 
499     add_cb_wrap->add_arg = add_arg;
500     add_cb_wrap->add_cb = add_cb;
501     add_cb_wrap->free_cb = free_cb;
502     parse_cb_wrap->parse_arg = parse_arg;
503     parse_cb_wrap->parse_cb = parse_cb;
504 
505     ret = ossl_tls_add_custom_ext_intern(ctx, NULL, role, ext_type,
506                                          context,
507                                          custom_ext_add_old_cb_wrap,
508                                          custom_ext_free_old_cb_wrap,
509                                          add_cb_wrap,
510                                          custom_ext_parse_old_cb_wrap,
511                                          parse_cb_wrap);
512 
513     if (!ret) {
514         OPENSSL_free(add_cb_wrap);
515         OPENSSL_free(parse_cb_wrap);
516     }
517 
518     return ret;
519 }
520 
521 /* Application level functions to add the old custom extension callbacks */
SSL_CTX_add_client_custom_ext(SSL_CTX * ctx,unsigned int ext_type,custom_ext_add_cb add_cb,custom_ext_free_cb free_cb,void * add_arg,custom_ext_parse_cb parse_cb,void * parse_arg)522 int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
523                                   custom_ext_add_cb add_cb,
524                                   custom_ext_free_cb free_cb,
525                                   void *add_arg,
526                                   custom_ext_parse_cb parse_cb, void *parse_arg)
527 {
528     return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
529                               SSL_EXT_TLS1_2_AND_BELOW_ONLY
530                               | SSL_EXT_CLIENT_HELLO
531                               | SSL_EXT_TLS1_2_SERVER_HELLO
532                               | SSL_EXT_IGNORE_ON_RESUMPTION,
533                               add_cb, free_cb, add_arg, parse_cb, parse_arg);
534 }
535 
SSL_CTX_add_server_custom_ext(SSL_CTX * ctx,unsigned int ext_type,custom_ext_add_cb add_cb,custom_ext_free_cb free_cb,void * add_arg,custom_ext_parse_cb parse_cb,void * parse_arg)536 int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
537                                   custom_ext_add_cb add_cb,
538                                   custom_ext_free_cb free_cb,
539                                   void *add_arg,
540                                   custom_ext_parse_cb parse_cb, void *parse_arg)
541 {
542     return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
543                               SSL_EXT_TLS1_2_AND_BELOW_ONLY
544                               | SSL_EXT_CLIENT_HELLO
545                               | SSL_EXT_TLS1_2_SERVER_HELLO
546                               | SSL_EXT_IGNORE_ON_RESUMPTION,
547                               add_cb, free_cb, add_arg, parse_cb, parse_arg);
548 }
549 
SSL_CTX_add_custom_ext(SSL_CTX * ctx,unsigned int ext_type,unsigned int context,SSL_custom_ext_add_cb_ex add_cb,SSL_custom_ext_free_cb_ex free_cb,void * add_arg,SSL_custom_ext_parse_cb_ex parse_cb,void * parse_arg)550 int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
551                            unsigned int context,
552                            SSL_custom_ext_add_cb_ex add_cb,
553                            SSL_custom_ext_free_cb_ex free_cb,
554                            void *add_arg,
555                            SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
556 {
557     return ossl_tls_add_custom_ext_intern(ctx, NULL, ENDPOINT_BOTH, ext_type,
558                                           context, add_cb, free_cb, add_arg,
559                                           parse_cb, parse_arg);
560 }
561 
SSL_extension_supported(unsigned int ext_type)562 int SSL_extension_supported(unsigned int ext_type)
563 {
564     switch (ext_type) {
565         /* Internally supported extensions. */
566     case TLSEXT_TYPE_application_layer_protocol_negotiation:
567     case TLSEXT_TYPE_ec_point_formats:
568     case TLSEXT_TYPE_supported_groups:
569     case TLSEXT_TYPE_key_share:
570 #ifndef OPENSSL_NO_NEXTPROTONEG
571     case TLSEXT_TYPE_next_proto_neg:
572 #endif
573     case TLSEXT_TYPE_padding:
574     case TLSEXT_TYPE_renegotiate:
575     case TLSEXT_TYPE_max_fragment_length:
576     case TLSEXT_TYPE_server_name:
577     case TLSEXT_TYPE_session_ticket:
578     case TLSEXT_TYPE_signature_algorithms:
579 #ifndef OPENSSL_NO_SRP
580     case TLSEXT_TYPE_srp:
581 #endif
582 #ifndef OPENSSL_NO_OCSP
583     case TLSEXT_TYPE_status_request:
584 #endif
585 #ifndef OPENSSL_NO_CT
586     case TLSEXT_TYPE_signed_certificate_timestamp:
587 #endif
588 #ifndef OPENSSL_NO_SRTP
589     case TLSEXT_TYPE_use_srtp:
590 #endif
591     case TLSEXT_TYPE_encrypt_then_mac:
592     case TLSEXT_TYPE_supported_versions:
593     case TLSEXT_TYPE_extended_master_secret:
594     case TLSEXT_TYPE_psk_kex_modes:
595     case TLSEXT_TYPE_cookie:
596     case TLSEXT_TYPE_early_data:
597     case TLSEXT_TYPE_certificate_authorities:
598     case TLSEXT_TYPE_psk:
599     case TLSEXT_TYPE_post_handshake_auth:
600     case TLSEXT_TYPE_compress_certificate:
601     case TLSEXT_TYPE_client_cert_type:
602     case TLSEXT_TYPE_server_cert_type:
603         return 1;
604     default:
605         return 0;
606     }
607 }
608