2 * Copyright 2014-2017 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 */
12 #include <openssl/ct.h>
13 #include "../ssl_locl.h"
14 #include "internal/cryptlib.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 if (parse_cb_wrap->parse_cb == NULL)
70 return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
71 parse_cb_wrap->parse_arg);
75 * Find a custom extension from the list. The |role| param is there to
76 * support the legacy API where custom extensions for client and server could
77 * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
78 * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
79 * client, or ENDPOINT_BOTH for either
81 custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
82 ENDPOINT role, unsigned int ext_type,
86 custom_ext_method *meth = exts->meths;
88 for (i = 0; i < exts->meths_count; i++, meth++) {
89 if (ext_type == meth->ext_type
90 && (role == ENDPOINT_BOTH || role == meth->role
91 || meth->role == ENDPOINT_BOTH)) {
101 * Initialise custom extensions flags to indicate neither sent nor received.
103 void custom_ext_init(custom_ext_methods *exts)
106 custom_ext_method *meth = exts->meths;
108 for (i = 0; i < exts->meths_count; i++, meth++)
112 /* Pass received custom extension data to the application for parsing. */
113 int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type,
114 const unsigned char *ext_data, size_t ext_size, X509 *x,
115 size_t chainidx, int *al)
117 custom_ext_methods *exts = &s->cert->custext;
118 custom_ext_method *meth;
119 ENDPOINT role = ENDPOINT_BOTH;
121 if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
122 role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;
124 meth = custom_ext_find(exts, role, ext_type, NULL);
125 /* If not found return success */
129 /* Check if extension is defined for our protocol. If not, skip */
130 if (!extension_is_relevant(s, meth->context, context))
133 if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
134 | SSL_EXT_TLS1_3_SERVER_HELLO
135 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
137 * If it's ServerHello or EncryptedExtensions we can't have any
138 * extensions not sent in ClientHello.
140 if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
141 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
147 * Extensions received in the ClientHello are marked with the
148 * SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
149 * extensions in the ServerHello/EncryptedExtensions message
151 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
152 meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;
154 /* If no parse function set return success */
158 return meth->parse_cb(s, ext_type, context, ext_data, ext_size, x, chainidx,
159 al, meth->parse_arg);
163 * Request custom extension data from the application and add to the return
166 int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx,
167 int maxversion, int *al)
169 custom_ext_methods *exts = &s->cert->custext;
170 custom_ext_method *meth;
173 for (i = 0; i < exts->meths_count; i++) {
174 const unsigned char *out = NULL;
177 meth = exts->meths + i;
179 if (!should_add_extension(s, meth->context, context, maxversion))
182 if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
183 | SSL_EXT_TLS1_3_SERVER_HELLO
184 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
185 | SSL_EXT_TLS1_3_CERTIFICATE
186 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
187 /* Only send extensions present in ClientHello. */
188 if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
192 * We skip it if the callback is absent - except for a ClientHello where
193 * we add an empty extension.
195 if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
198 if (meth->add_cb != NULL) {
199 int cb_retval = meth->add_cb(s, meth->ext_type, context, &out,
200 &outlen, x, chainidx, al,
204 return 0; /* error */
206 continue; /* skip this extension */
209 if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
210 || !WPACKET_start_sub_packet_u16(pkt)
211 || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
212 || !WPACKET_close(pkt)) {
213 *al = SSL_AD_INTERNAL_ERROR;
216 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
218 * We can't send duplicates: code logic should prevent this.
220 if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
221 *al = SSL_AD_INTERNAL_ERROR;
225 * Indicate extension has been sent: this is both a sanity check to
226 * ensure we don't send duplicate extensions and indicates that it
227 * is not an error if the extension is present in ServerHello.
229 meth->ext_flags |= SSL_EXT_FLAG_SENT;
231 if (meth->free_cb != NULL)
232 meth->free_cb(s, meth->ext_type, context, out, meth->add_arg);
237 /* Copy the flags from src to dst for any extensions that exist in both */
238 int custom_exts_copy_flags(custom_ext_methods *dst,
239 const custom_ext_methods *src)
242 custom_ext_method *methsrc = src->meths;
244 for (i = 0; i < src->meths_count; i++, methsrc++) {
245 custom_ext_method *methdst = custom_ext_find(dst, methsrc->role,
246 methsrc->ext_type, NULL);
251 methdst->ext_flags = methsrc->ext_flags;
257 /* Copy table of custom extensions */
258 int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
263 if (src->meths_count > 0) {
265 OPENSSL_memdup(src->meths,
266 sizeof(*src->meths) * src->meths_count);
267 if (dst->meths == NULL)
269 dst->meths_count = src->meths_count;
271 for (i = 0; i < src->meths_count; i++) {
272 custom_ext_method *methsrc = src->meths + i;
273 custom_ext_method *methdst = dst->meths + i;
275 if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
279 * We have found an old style API wrapper. We need to copy the
284 methdst->add_arg = NULL;
285 methdst->parse_arg = NULL;
289 methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
290 sizeof(custom_ext_add_cb_wrap));
291 methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
292 sizeof(custom_ext_parse_cb_wrap));
294 if (methdst->add_arg == NULL || methdst->parse_arg == NULL)
300 custom_exts_free(dst);
307 void custom_exts_free(custom_ext_methods *exts)
310 custom_ext_method *meth;
312 for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
313 if (meth->add_cb != custom_ext_add_old_cb_wrap)
316 /* Old style API wrapper. Need to free the arguments too */
317 OPENSSL_free(meth->add_arg);
318 OPENSSL_free(meth->parse_arg);
320 OPENSSL_free(exts->meths);
323 /* Return true if a client custom extension exists, false otherwise */
324 int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
326 return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
330 static int add_custom_ext_intern(SSL_CTX *ctx, ENDPOINT role,
331 unsigned int ext_type,
332 unsigned int context,
333 SSL_custom_ext_add_cb_ex add_cb,
334 SSL_custom_ext_free_cb_ex free_cb,
336 SSL_custom_ext_parse_cb_ex parse_cb,
339 custom_ext_methods *exts = &ctx->cert->custext;
340 custom_ext_method *meth, *tmp;
343 * Check application error: if add_cb is not set free_cb will never be
346 if (add_cb == NULL && free_cb != NULL)
349 #ifndef OPENSSL_NO_CT
351 * We don't want applications registering callbacks for SCT extensions
352 * whilst simultaneously using the built-in SCT validation features, as
353 * these two things may not play well together.
355 if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
356 && (context & SSL_EXT_CLIENT_HELLO) != 0
357 && SSL_CTX_ct_is_enabled(ctx))
362 * Don't add if extension supported internally, but make exception
363 * for extension types that previously were not supported, but now are.
365 if (SSL_extension_supported(ext_type)
366 && ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
369 /* Extension type must fit in 16 bits */
370 if (ext_type > 0xffff)
372 /* Search for duplicate */
373 if (custom_ext_find(exts, role, ext_type, NULL))
375 tmp = OPENSSL_realloc(exts->meths,
376 (exts->meths_count + 1) * sizeof(custom_ext_method));
381 meth = exts->meths + exts->meths_count;
382 memset(meth, 0, sizeof(*meth));
384 meth->context = context;
385 meth->parse_cb = parse_cb;
386 meth->add_cb = add_cb;
387 meth->free_cb = free_cb;
388 meth->ext_type = ext_type;
389 meth->add_arg = add_arg;
390 meth->parse_arg = parse_arg;
395 static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
396 unsigned int ext_type,
397 unsigned int context,
398 custom_ext_add_cb add_cb,
399 custom_ext_free_cb free_cb,
401 custom_ext_parse_cb parse_cb, void *parse_arg)
403 custom_ext_add_cb_wrap *add_cb_wrap
404 = OPENSSL_malloc(sizeof(*add_cb_wrap));
405 custom_ext_parse_cb_wrap *parse_cb_wrap
406 = OPENSSL_malloc(sizeof(*parse_cb_wrap));
409 if (add_cb_wrap == NULL || parse_cb_wrap == NULL) {
410 OPENSSL_free(add_cb_wrap);
411 OPENSSL_free(parse_cb_wrap);
415 add_cb_wrap->add_arg = add_arg;
416 add_cb_wrap->add_cb = add_cb;
417 add_cb_wrap->free_cb = free_cb;
418 parse_cb_wrap->parse_arg = parse_arg;
419 parse_cb_wrap->parse_cb = parse_cb;
421 ret = add_custom_ext_intern(ctx, role, ext_type,
423 custom_ext_add_old_cb_wrap,
424 custom_ext_free_old_cb_wrap,
426 custom_ext_parse_old_cb_wrap,
430 OPENSSL_free(add_cb_wrap);
431 OPENSSL_free(parse_cb_wrap);
437 /* Application level functions to add the old custom extension callbacks */
438 int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
439 custom_ext_add_cb add_cb,
440 custom_ext_free_cb free_cb,
442 custom_ext_parse_cb parse_cb, void *parse_arg)
444 return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
445 SSL_EXT_TLS1_2_AND_BELOW_ONLY
446 | SSL_EXT_CLIENT_HELLO
447 | SSL_EXT_TLS1_2_SERVER_HELLO
448 | SSL_EXT_IGNORE_ON_RESUMPTION,
449 add_cb, free_cb, add_arg, parse_cb, parse_arg);
452 int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
453 custom_ext_add_cb add_cb,
454 custom_ext_free_cb free_cb,
456 custom_ext_parse_cb parse_cb, void *parse_arg)
458 return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
459 SSL_EXT_TLS1_2_AND_BELOW_ONLY
460 | SSL_EXT_CLIENT_HELLO
461 | SSL_EXT_TLS1_2_SERVER_HELLO
462 | SSL_EXT_IGNORE_ON_RESUMPTION,
463 add_cb, free_cb, add_arg, parse_cb, parse_arg);
466 int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
467 unsigned int context,
468 SSL_custom_ext_add_cb_ex add_cb,
469 SSL_custom_ext_free_cb_ex free_cb,
471 SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
473 return add_custom_ext_intern(ctx, ENDPOINT_BOTH, ext_type, context, add_cb,
474 free_cb, add_arg, parse_cb, parse_arg);
477 int SSL_extension_supported(unsigned int ext_type)
480 /* Internally supported extensions. */
481 case TLSEXT_TYPE_application_layer_protocol_negotiation:
482 #ifndef OPENSSL_NO_EC
483 case TLSEXT_TYPE_ec_point_formats:
484 case TLSEXT_TYPE_supported_groups:
485 case TLSEXT_TYPE_key_share:
487 #ifndef OPENSSL_NO_NEXTPROTONEG
488 case TLSEXT_TYPE_next_proto_neg:
490 case TLSEXT_TYPE_padding:
491 case TLSEXT_TYPE_renegotiate:
492 case TLSEXT_TYPE_max_fragment_length:
493 case TLSEXT_TYPE_server_name:
494 case TLSEXT_TYPE_session_ticket:
495 case TLSEXT_TYPE_signature_algorithms:
496 #ifndef OPENSSL_NO_SRP
497 case TLSEXT_TYPE_srp:
499 #ifndef OPENSSL_NO_OCSP
500 case TLSEXT_TYPE_status_request:
502 #ifndef OPENSSL_NO_CT
503 case TLSEXT_TYPE_signed_certificate_timestamp:
505 #ifndef OPENSSL_NO_SRTP
506 case TLSEXT_TYPE_use_srtp:
508 case TLSEXT_TYPE_encrypt_then_mac:
509 case TLSEXT_TYPE_supported_versions:
510 case TLSEXT_TYPE_extended_master_secret:
511 case TLSEXT_TYPE_psk_kex_modes:
512 case TLSEXT_TYPE_cookie:
513 case TLSEXT_TYPE_early_data:
514 case TLSEXT_TYPE_certificate_authorities:
515 case TLSEXT_TYPE_psk: