2 * Copyright 2014-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
10 /* Custom extension utility functions */
13 #include <openssl/ct.h>
14 #include "../ssl_locl.h"
15 #include "statem_locl.h"
19 custom_ext_add_cb add_cb;
20 custom_ext_free_cb free_cb;
21 } custom_ext_add_cb_wrap;
25 custom_ext_parse_cb parse_cb;
26 } custom_ext_parse_cb_wrap;
29 * Provide thin wrapper callbacks which convert new style arguments to old style
31 static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type,
33 const unsigned char **out,
34 size_t *outlen, X509 *x, size_t chainidx,
35 int *al, void *add_arg)
37 custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
39 if (add_cb_wrap->add_cb == NULL)
42 return add_cb_wrap->add_cb(s, ext_type, out, outlen, al,
43 add_cb_wrap->add_arg);
46 static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type,
48 const unsigned char *out, void *add_arg)
50 custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
52 if (add_cb_wrap->free_cb == NULL)
55 add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg);
58 static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type,
60 const unsigned char *in,
61 size_t inlen, X509 *x, size_t chainidx,
62 int *al, void *parse_arg)
64 custom_ext_parse_cb_wrap *parse_cb_wrap =
65 (custom_ext_parse_cb_wrap *)parse_arg;
67 return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
68 parse_cb_wrap->parse_arg);
72 * Find a custom extension from the list. The |role| param is there to
73 * support the legacy API where custom extensions for client and server could
74 * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
75 * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
76 * client, or ENDPOINT_BOTH for either
78 custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
79 ENDPOINT role, unsigned int ext_type,
83 custom_ext_method *meth = exts->meths;
85 for (i = 0; i < exts->meths_count; i++, meth++) {
86 if (ext_type == meth->ext_type
87 && (role == ENDPOINT_BOTH || role == meth->role
88 || meth->role == ENDPOINT_BOTH)) {
98 * Initialise custom extensions flags to indicate neither sent nor received.
100 void custom_ext_init(custom_ext_methods *exts)
103 custom_ext_method *meth = exts->meths;
105 for (i = 0; i < exts->meths_count; i++, meth++)
109 /* Pass received custom extension data to the application for parsing. */
110 int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type,
111 const unsigned char *ext_data, size_t ext_size, X509 *x,
112 size_t chainidx, int *al)
114 custom_ext_methods *exts = &s->cert->custext;
115 custom_ext_method *meth;
116 ENDPOINT role = ENDPOINT_BOTH;
118 if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
119 role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;
121 meth = custom_ext_find(exts, role, ext_type, NULL);
122 /* If not found return success */
126 /* Check if extension is defined for our protocol. If not, skip */
127 if (!extension_is_relevant(s, meth->context, context))
130 if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
131 | SSL_EXT_TLS1_3_SERVER_HELLO
132 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
134 * If it's ServerHello or EncryptedExtensions we can't have any
135 * extensions not sent in ClientHello.
137 if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
138 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
144 * Extensions received in the ClientHello are marked with the
145 * SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
146 * extensions in the ServerHello/EncryptedExtensions message
148 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
149 meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;
151 /* If no parse function set return success */
155 return meth->parse_cb(s, ext_type, context, ext_data, ext_size, x, chainidx,
156 al, meth->parse_arg);
160 * Request custom extension data from the application and add to the return
163 int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx,
164 int maxversion, int *al)
166 custom_ext_methods *exts = &s->cert->custext;
167 custom_ext_method *meth;
170 for (i = 0; i < exts->meths_count; i++) {
171 const unsigned char *out = NULL;
174 meth = exts->meths + i;
176 if (!should_add_extension(s, meth->context, context, maxversion))
179 if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
180 | SSL_EXT_TLS1_3_SERVER_HELLO
181 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
183 * For ServerHello/EncryptedExtensions only send extensions present
186 if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
190 * We skip it if the callback is absent - except for a ClientHello where
191 * we add an empty extension.
193 if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
196 if (meth->add_cb != NULL) {
197 int cb_retval = meth->add_cb(s, meth->ext_type, context, &out,
198 &outlen, x, chainidx, al,
202 return 0; /* error */
204 continue; /* skip this extension */
207 if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
208 || !WPACKET_start_sub_packet_u16(pkt)
209 || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
210 || !WPACKET_close(pkt)) {
211 *al = SSL_AD_INTERNAL_ERROR;
214 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
216 * We can't send duplicates: code logic should prevent this.
218 assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0);
220 * Indicate extension has been sent: this is both a sanity check to
221 * ensure we don't send duplicate extensions and indicates that it
222 * is not an error if the extension is present in ServerHello.
224 meth->ext_flags |= SSL_EXT_FLAG_SENT;
226 if (meth->free_cb != NULL)
227 meth->free_cb(s, meth->ext_type, context, out, meth->add_arg);
232 /* Copy table of custom extensions */
233 int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
238 if (src->meths_count > 0) {
240 OPENSSL_memdup(src->meths,
241 sizeof(*src->meths) * src->meths_count);
242 if (dst->meths == NULL)
244 dst->meths_count = src->meths_count;
246 for (i = 0; i < src->meths_count; i++) {
247 custom_ext_method *methsrc = src->meths + i;
248 custom_ext_method *methdst = dst->meths + i;
250 if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
254 * We have found an old style API wrapper. We need to copy the
259 methdst->add_arg = NULL;
260 methdst->parse_arg = NULL;
264 methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
265 sizeof(custom_ext_add_cb_wrap));
266 methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
267 sizeof(custom_ext_parse_cb_wrap));
269 if (methdst->add_arg == NULL || methdst->parse_arg == NULL)
275 custom_exts_free(dst);
282 void custom_exts_free(custom_ext_methods *exts)
285 custom_ext_method *meth;
287 for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
288 if (meth->add_cb != custom_ext_add_old_cb_wrap)
291 /* Old style API wrapper. Need to free the arguments too */
292 OPENSSL_free(meth->add_arg);
293 OPENSSL_free(meth->parse_arg);
295 OPENSSL_free(exts->meths);
298 /* Return true if a client custom extension exists, false otherwise */
299 int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
301 return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
305 static int add_custom_ext_intern(SSL_CTX *ctx, ENDPOINT role,
306 unsigned int ext_type,
307 unsigned int context,
308 SSL_custom_ext_add_cb_ex add_cb,
309 SSL_custom_ext_free_cb_ex free_cb,
311 SSL_custom_ext_parse_cb_ex parse_cb,
314 custom_ext_methods *exts = &ctx->cert->custext;
315 custom_ext_method *meth, *tmp;
318 * Check application error: if add_cb is not set free_cb will never be
321 if (add_cb == NULL && free_cb != NULL)
324 #ifndef OPENSSL_NO_CT
326 * We don't want applications registering callbacks for SCT extensions
327 * whilst simultaneously using the built-in SCT validation features, as
328 * these two things may not play well together.
330 if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
331 && (context & SSL_EXT_CLIENT_HELLO) != 0
332 && SSL_CTX_ct_is_enabled(ctx))
337 * Don't add if extension supported internally, but make exception
338 * for extension types that previously were not supported, but now are.
340 if (SSL_extension_supported(ext_type)
341 && ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
344 /* Extension type must fit in 16 bits */
345 if (ext_type > 0xffff)
347 /* Search for duplicate */
348 if (custom_ext_find(exts, role, ext_type, NULL))
350 tmp = OPENSSL_realloc(exts->meths,
351 (exts->meths_count + 1) * sizeof(custom_ext_method));
356 meth = exts->meths + exts->meths_count;
357 memset(meth, 0, sizeof(*meth));
359 meth->context = context;
360 meth->parse_cb = parse_cb;
361 meth->add_cb = add_cb;
362 meth->free_cb = free_cb;
363 meth->ext_type = ext_type;
364 meth->add_arg = add_arg;
365 meth->parse_arg = parse_arg;
370 static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
371 unsigned int ext_type,
372 unsigned int context,
373 custom_ext_add_cb add_cb,
374 custom_ext_free_cb free_cb,
376 custom_ext_parse_cb parse_cb, void *parse_arg)
378 custom_ext_add_cb_wrap *add_cb_wrap
379 = OPENSSL_malloc(sizeof(*add_cb_wrap));
380 custom_ext_parse_cb_wrap *parse_cb_wrap
381 = OPENSSL_malloc(sizeof(*parse_cb_wrap));
384 if (add_cb_wrap == NULL || parse_cb_wrap == NULL) {
385 OPENSSL_free(add_cb_wrap);
386 OPENSSL_free(parse_cb_wrap);
390 add_cb_wrap->add_arg = add_arg;
391 add_cb_wrap->add_cb = add_cb;
392 add_cb_wrap->free_cb = free_cb;
393 parse_cb_wrap->parse_arg = parse_arg;
394 parse_cb_wrap->parse_cb = parse_cb;
396 ret = add_custom_ext_intern(ctx, role, ext_type,
398 custom_ext_add_old_cb_wrap,
399 custom_ext_free_old_cb_wrap,
401 custom_ext_parse_old_cb_wrap,
405 OPENSSL_free(add_cb_wrap);
406 OPENSSL_free(parse_cb_wrap);
412 /* Application level functions to add the old custom extension callbacks */
413 int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
414 custom_ext_add_cb add_cb,
415 custom_ext_free_cb free_cb,
417 custom_ext_parse_cb parse_cb, void *parse_arg)
419 return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
420 SSL_EXT_TLS1_2_AND_BELOW_ONLY
421 | SSL_EXT_CLIENT_HELLO
422 | SSL_EXT_TLS1_2_SERVER_HELLO
423 | SSL_EXT_IGNORE_ON_RESUMPTION,
424 add_cb, free_cb, add_arg, parse_cb, parse_arg);
427 int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
428 custom_ext_add_cb add_cb,
429 custom_ext_free_cb free_cb,
431 custom_ext_parse_cb parse_cb, void *parse_arg)
433 return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
434 SSL_EXT_TLS1_2_AND_BELOW_ONLY
435 | SSL_EXT_CLIENT_HELLO
436 | SSL_EXT_TLS1_2_SERVER_HELLO
437 | SSL_EXT_IGNORE_ON_RESUMPTION,
438 add_cb, free_cb, add_arg, parse_cb, parse_arg);
441 int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
442 unsigned int context,
443 SSL_custom_ext_add_cb_ex add_cb,
444 SSL_custom_ext_free_cb_ex free_cb,
446 SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
448 return add_custom_ext_intern(ctx, ENDPOINT_BOTH, ext_type, context, add_cb,
449 free_cb, add_arg, parse_cb, parse_arg);
452 int SSL_extension_supported(unsigned int ext_type)
455 /* Internally supported extensions. */
456 case TLSEXT_TYPE_application_layer_protocol_negotiation:
457 #ifndef OPENSSL_NO_EC
458 case TLSEXT_TYPE_ec_point_formats:
459 case TLSEXT_TYPE_supported_groups:
460 case TLSEXT_TYPE_key_share:
462 #ifndef OPENSSL_NO_NEXTPROTONEG
463 case TLSEXT_TYPE_next_proto_neg:
465 case TLSEXT_TYPE_padding:
466 case TLSEXT_TYPE_renegotiate:
467 case TLSEXT_TYPE_server_name:
468 case TLSEXT_TYPE_session_ticket:
469 case TLSEXT_TYPE_signature_algorithms:
470 #ifndef OPENSSL_NO_SRP
471 case TLSEXT_TYPE_srp:
473 #ifndef OPENSSL_NO_OCSP
474 case TLSEXT_TYPE_status_request:
476 #ifndef OPENSSL_NO_CT
477 case TLSEXT_TYPE_signed_certificate_timestamp:
479 #ifndef OPENSSL_NO_SRTP
480 case TLSEXT_TYPE_use_srtp:
482 case TLSEXT_TYPE_encrypt_then_mac:
483 case TLSEXT_TYPE_supported_versions:
484 case TLSEXT_TYPE_extended_master_secret:
485 case TLSEXT_TYPE_psk_kex_modes:
486 case TLSEXT_TYPE_cookie:
487 case TLSEXT_TYPE_early_data:
488 case TLSEXT_TYPE_certificate_authorities:
489 case TLSEXT_TYPE_psk: