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/*
* Copyright (C) 2017 Red Hat, Inc.
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GnuTLS.
*
* The GnuTLS is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>
*
*/
#ifndef GNUTLS_LIB_EXTV_H
#define GNUTLS_LIB_EXTV_H
#include <gnutls/gnutls.h>
#include "str.h"
/* Iterates through all TLS-type extensions in data, and
* calls the callback function for each of them. The ctx, flags
* and parse_type are passed verbatim to callback. */
int _gnutls_extv_parse(void *ctx, gnutls_ext_raw_process_func cb,
const uint8_t *data, int data_size);
inline static int _gnutls_extv_append_init(gnutls_buffer_st *buf)
{
unsigned pos;
int ret;
pos = buf->length;
ret = _gnutls_buffer_append_prefix(buf, 16, 0);
if (ret < 0)
return gnutls_assert_val(ret);
return pos;
}
/* its input is the buffer and the return value of _gnutls_extv_append_init()
* @is_hello: should be true for client and server hello messages.
*/
inline static int _gnutls_extv_append_final(gnutls_buffer_st *buf,
unsigned init, unsigned is_hello)
{
unsigned size = buf->length - init - 2;
if (size > UINT16_MAX) /* sent too many extensions */
return gnutls_assert_val(GNUTLS_E_HANDSHAKE_TOO_LARGE);
if (size > 0)
_gnutls_write_uint16(size, &buf->data[init]);
else if (is_hello && size == 0) {
/* there is no point to send empty extension bytes, and
* they are known to break certain clients */
buf->length -= 2;
}
return 0;
}
typedef int (*extv_append_func)(void *ctx, gnutls_buffer_st *buf);
int _gnutls_extv_append(gnutls_buffer_st *buf, uint16_t tls_id, void *ctx,
extv_append_func cb);
#endif /* GNUTLS_LIB_EXTV_H */
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