298 lines
10 KiB
C
298 lines
10 KiB
C
/* ssl/t1_ext.c */
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/* ====================================================================
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* Copyright (c) 2014 The OpenSSL Project. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* 3. All advertising materials mentioning features or use of this
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* software must display the following acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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*
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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* endorse or promote products derived from this software without
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* prior written permission. For written permission, please contact
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* openssl-core@openssl.org.
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*
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* 5. Products derived from this software may not be called "OpenSSL"
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* nor may "OpenSSL" appear in their names without prior written
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* permission of the OpenSSL Project.
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*
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* 6. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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*
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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* ====================================================================
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*
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* This product includes cryptographic software written by Eric Young
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* (eay@cryptsoft.com). This product includes software written by Tim
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* Hudson (tjh@cryptsoft.com).
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*
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*/
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/* Custom extension utility functions */
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#include "ssl_locl.h"
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#ifndef OPENSSL_NO_TLSEXT
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/* Find a custom extension from the list. */
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static custom_ext_method *custom_ext_find(custom_ext_methods *exts,
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unsigned int ext_type)
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{
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size_t i;
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custom_ext_method *meth = exts->meths;
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for (i = 0; i < exts->meths_count; i++, meth++) {
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if (ext_type == meth->ext_type)
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return meth;
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}
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return NULL;
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}
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/*
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* Initialise custom extensions flags to indicate neither sent nor received.
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*/
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void custom_ext_init(custom_ext_methods *exts)
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{
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size_t i;
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custom_ext_method *meth = exts->meths;
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for (i = 0; i < exts->meths_count; i++, meth++)
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meth->ext_flags = 0;
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}
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/* Pass received custom extension data to the application for parsing. */
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int custom_ext_parse(SSL *s, int server,
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unsigned int ext_type,
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const unsigned char *ext_data, size_t ext_size, int *al)
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{
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custom_ext_methods *exts = server ? &s->cert->srv_ext : &s->cert->cli_ext;
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custom_ext_method *meth;
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meth = custom_ext_find(exts, ext_type);
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/* If not found return success */
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if (!meth)
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return 1;
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if (!server) {
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/*
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* If it's ServerHello we can't have any extensions not sent in
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* ClientHello.
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*/
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if (!(meth->ext_flags & SSL_EXT_FLAG_SENT)) {
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*al = TLS1_AD_UNSUPPORTED_EXTENSION;
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return 0;
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}
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}
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/* If already present it's a duplicate */
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if (meth->ext_flags & SSL_EXT_FLAG_RECEIVED) {
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*al = TLS1_AD_DECODE_ERROR;
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return 0;
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}
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meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;
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/* If no parse function set return success */
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if (!meth->parse_cb)
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return 1;
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return meth->parse_cb(s, ext_type, ext_data, ext_size, al,
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meth->parse_arg);
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}
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/*
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* Request custom extension data from the application and add to the return
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* buffer.
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*/
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int custom_ext_add(SSL *s, int server,
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unsigned char **pret, unsigned char *limit, int *al)
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{
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custom_ext_methods *exts = server ? &s->cert->srv_ext : &s->cert->cli_ext;
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custom_ext_method *meth;
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unsigned char *ret = *pret;
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size_t i;
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for (i = 0; i < exts->meths_count; i++) {
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const unsigned char *out = NULL;
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size_t outlen = 0;
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meth = exts->meths + i;
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if (server) {
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/*
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* For ServerHello only send extensions present in ClientHello.
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*/
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if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
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continue;
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/* If callback absent for server skip it */
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if (!meth->add_cb)
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continue;
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}
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if (meth->add_cb) {
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int cb_retval = 0;
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cb_retval = meth->add_cb(s, meth->ext_type,
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&out, &outlen, al, meth->add_arg);
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if (cb_retval < 0)
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return 0; /* error */
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if (cb_retval == 0)
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continue; /* skip this extension */
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}
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if (4 > limit - ret || outlen > (size_t)(limit - ret - 4))
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return 0;
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s2n(meth->ext_type, ret);
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s2n(outlen, ret);
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if (outlen) {
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memcpy(ret, out, outlen);
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ret += outlen;
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}
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/*
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* We can't send duplicates: code logic should prevent this.
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*/
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OPENSSL_assert(!(meth->ext_flags & SSL_EXT_FLAG_SENT));
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/*
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* Indicate extension has been sent: this is both a sanity check to
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* ensure we don't send duplicate extensions and indicates that it is
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* not an error if the extension is present in ServerHello.
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*/
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meth->ext_flags |= SSL_EXT_FLAG_SENT;
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if (meth->free_cb)
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meth->free_cb(s, meth->ext_type, out, meth->add_arg);
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}
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*pret = ret;
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return 1;
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}
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/* Copy table of custom extensions */
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int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
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{
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if (src->meths_count) {
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dst->meths =
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BUF_memdup(src->meths,
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sizeof(custom_ext_method) * src->meths_count);
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if (dst->meths == NULL)
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return 0;
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dst->meths_count = src->meths_count;
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}
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return 1;
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}
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void custom_exts_free(custom_ext_methods *exts)
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{
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if (exts->meths)
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OPENSSL_free(exts->meths);
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}
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/* Set callbacks for a custom extension. */
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static int custom_ext_meth_add(custom_ext_methods *exts,
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unsigned int ext_type,
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custom_ext_add_cb add_cb,
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custom_ext_free_cb free_cb,
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void *add_arg,
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custom_ext_parse_cb parse_cb, void *parse_arg)
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{
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custom_ext_method *meth;
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/*
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* Check application error: if add_cb is not set free_cb will never be
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* called.
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*/
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if (!add_cb && free_cb)
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return 0;
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/* Don't add if extension supported internally. */
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if (SSL_extension_supported(ext_type))
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return 0;
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/* Extension type must fit in 16 bits */
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if (ext_type > 0xffff)
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return 0;
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/* Search for duplicate */
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if (custom_ext_find(exts, ext_type))
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return 0;
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exts->meths = OPENSSL_realloc(exts->meths,
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(exts->meths_count +
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1) * sizeof(custom_ext_method));
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if (!exts->meths) {
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exts->meths_count = 0;
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return 0;
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}
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meth = exts->meths + exts->meths_count;
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memset(meth, 0, sizeof(custom_ext_method));
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meth->parse_cb = parse_cb;
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meth->add_cb = add_cb;
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meth->free_cb = free_cb;
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meth->ext_type = ext_type;
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meth->add_arg = add_arg;
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meth->parse_arg = parse_arg;
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exts->meths_count++;
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return 1;
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}
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/* Application level functions to add custom extension callbacks */
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int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
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custom_ext_add_cb add_cb,
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custom_ext_free_cb free_cb,
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void *add_arg,
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custom_ext_parse_cb parse_cb,
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void *parse_arg)
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{
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return custom_ext_meth_add(&ctx->cert->cli_ext, ext_type,
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add_cb, free_cb, add_arg, parse_cb, parse_arg);
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}
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int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
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custom_ext_add_cb add_cb,
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custom_ext_free_cb free_cb,
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void *add_arg,
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custom_ext_parse_cb parse_cb,
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void *parse_arg)
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{
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return custom_ext_meth_add(&ctx->cert->srv_ext, ext_type,
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add_cb, free_cb, add_arg, parse_cb, parse_arg);
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}
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int SSL_extension_supported(unsigned int ext_type)
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{
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switch (ext_type) {
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/* Internally supported extensions. */
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case TLSEXT_TYPE_application_layer_protocol_negotiation:
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case TLSEXT_TYPE_ec_point_formats:
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case TLSEXT_TYPE_elliptic_curves:
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case TLSEXT_TYPE_heartbeat:
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case TLSEXT_TYPE_next_proto_neg:
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case TLSEXT_TYPE_padding:
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case TLSEXT_TYPE_renegotiate:
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case TLSEXT_TYPE_server_name:
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case TLSEXT_TYPE_session_ticket:
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case TLSEXT_TYPE_signature_algorithms:
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case TLSEXT_TYPE_srp:
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case TLSEXT_TYPE_status_request:
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case TLSEXT_TYPE_use_srtp:
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# ifdef TLSEXT_TYPE_opaque_prf_input
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case TLSEXT_TYPE_opaque_prf_input:
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# endif
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# ifdef TLSEXT_TYPE_encrypt_then_mac
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case TLSEXT_TYPE_encrypt_then_mac:
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# endif
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return 1;
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default:
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return 0;
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}
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}
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#endif
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