279 lines
8 KiB
C
279 lines
8 KiB
C
/*
|
|
* DTLS cookie callbacks implementation
|
|
*
|
|
* Copyright The Mbed TLS Contributors
|
|
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
|
|
*
|
|
* This file is provided under the Apache License 2.0, or the
|
|
* GNU General Public License v2.0 or later.
|
|
*
|
|
* **********
|
|
* Apache License 2.0:
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
* not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* **********
|
|
*
|
|
* **********
|
|
* GNU General Public License v2.0 or later:
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* **********
|
|
*/
|
|
/*
|
|
* These session callbacks use a simple chained list
|
|
* to store and retrieve the session information.
|
|
*/
|
|
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "mbedtls/config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_SSL_COOKIE_C)
|
|
|
|
#if defined(MBEDTLS_PLATFORM_C)
|
|
#include "mbedtls/platform.h"
|
|
#else
|
|
#define mbedtls_calloc calloc
|
|
#define mbedtls_free free
|
|
#endif
|
|
|
|
#include "mbedtls/ssl_cookie.h"
|
|
#include "mbedtls/ssl_internal.h"
|
|
#include "mbedtls/platform_util.h"
|
|
|
|
#include <string.h>
|
|
|
|
/*
|
|
* If DTLS is in use, then at least one of SHA-1, SHA-256, SHA-512 is
|
|
* available. Try SHA-256 first, 512 wastes resources since we need to stay
|
|
* with max 32 bytes of cookie for DTLS 1.0
|
|
*/
|
|
#if defined(MBEDTLS_SHA256_C)
|
|
#define COOKIE_MD MBEDTLS_MD_SHA224
|
|
#define COOKIE_MD_OUTLEN 32
|
|
#define COOKIE_HMAC_LEN 28
|
|
#elif defined(MBEDTLS_SHA512_C)
|
|
#define COOKIE_MD MBEDTLS_MD_SHA384
|
|
#define COOKIE_MD_OUTLEN 48
|
|
#define COOKIE_HMAC_LEN 28
|
|
#elif defined(MBEDTLS_SHA1_C)
|
|
#define COOKIE_MD MBEDTLS_MD_SHA1
|
|
#define COOKIE_MD_OUTLEN 20
|
|
#define COOKIE_HMAC_LEN 20
|
|
#else
|
|
#error "DTLS hello verify needs SHA-1 or SHA-2"
|
|
#endif
|
|
|
|
/*
|
|
* Cookies are formed of a 4-bytes timestamp (or serial number) and
|
|
* an HMAC of timestemp and client ID.
|
|
*/
|
|
#define COOKIE_LEN ( 4 + COOKIE_HMAC_LEN )
|
|
|
|
void mbedtls_ssl_cookie_init( mbedtls_ssl_cookie_ctx *ctx )
|
|
{
|
|
mbedtls_md_init( &ctx->hmac_ctx );
|
|
#if !defined(MBEDTLS_HAVE_TIME)
|
|
ctx->serial = 0;
|
|
#endif
|
|
ctx->timeout = MBEDTLS_SSL_COOKIE_TIMEOUT;
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
mbedtls_mutex_init( &ctx->mutex );
|
|
#endif
|
|
}
|
|
|
|
void mbedtls_ssl_cookie_set_timeout( mbedtls_ssl_cookie_ctx *ctx, unsigned long delay )
|
|
{
|
|
ctx->timeout = delay;
|
|
}
|
|
|
|
void mbedtls_ssl_cookie_free( mbedtls_ssl_cookie_ctx *ctx )
|
|
{
|
|
mbedtls_md_free( &ctx->hmac_ctx );
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
mbedtls_mutex_free( &ctx->mutex );
|
|
#endif
|
|
|
|
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ssl_cookie_ctx ) );
|
|
}
|
|
|
|
int mbedtls_ssl_cookie_setup( mbedtls_ssl_cookie_ctx *ctx,
|
|
int (*f_rng)(void *, unsigned char *, size_t),
|
|
void *p_rng )
|
|
{
|
|
int ret;
|
|
unsigned char key[COOKIE_MD_OUTLEN];
|
|
|
|
if( ( ret = f_rng( p_rng, key, sizeof( key ) ) ) != 0 )
|
|
return( ret );
|
|
|
|
ret = mbedtls_md_setup( &ctx->hmac_ctx, mbedtls_md_info_from_type( COOKIE_MD ), 1 );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
ret = mbedtls_md_hmac_starts( &ctx->hmac_ctx, key, sizeof( key ) );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
mbedtls_platform_zeroize( key, sizeof( key ) );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Generate the HMAC part of a cookie
|
|
*/
|
|
static int ssl_cookie_hmac( mbedtls_md_context_t *hmac_ctx,
|
|
const unsigned char time[4],
|
|
unsigned char **p, unsigned char *end,
|
|
const unsigned char *cli_id, size_t cli_id_len )
|
|
{
|
|
unsigned char hmac_out[COOKIE_MD_OUTLEN];
|
|
|
|
MBEDTLS_SSL_CHK_BUF_PTR( *p, end, COOKIE_HMAC_LEN );
|
|
|
|
if( mbedtls_md_hmac_reset( hmac_ctx ) != 0 ||
|
|
mbedtls_md_hmac_update( hmac_ctx, time, 4 ) != 0 ||
|
|
mbedtls_md_hmac_update( hmac_ctx, cli_id, cli_id_len ) != 0 ||
|
|
mbedtls_md_hmac_finish( hmac_ctx, hmac_out ) != 0 )
|
|
{
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
}
|
|
|
|
memcpy( *p, hmac_out, COOKIE_HMAC_LEN );
|
|
*p += COOKIE_HMAC_LEN;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Generate cookie for DTLS ClientHello verification
|
|
*/
|
|
int mbedtls_ssl_cookie_write( void *p_ctx,
|
|
unsigned char **p, unsigned char *end,
|
|
const unsigned char *cli_id, size_t cli_id_len )
|
|
{
|
|
int ret;
|
|
mbedtls_ssl_cookie_ctx *ctx = (mbedtls_ssl_cookie_ctx *) p_ctx;
|
|
unsigned long t;
|
|
|
|
if( ctx == NULL || cli_id == NULL )
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
|
|
MBEDTLS_SSL_CHK_BUF_PTR( *p, end, COOKIE_LEN );
|
|
|
|
#if defined(MBEDTLS_HAVE_TIME)
|
|
t = (unsigned long) mbedtls_time( NULL );
|
|
#else
|
|
t = ctx->serial++;
|
|
#endif
|
|
|
|
(*p)[0] = (unsigned char)( t >> 24 );
|
|
(*p)[1] = (unsigned char)( t >> 16 );
|
|
(*p)[2] = (unsigned char)( t >> 8 );
|
|
(*p)[3] = (unsigned char)( t );
|
|
*p += 4;
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
|
|
#endif
|
|
|
|
ret = ssl_cookie_hmac( &ctx->hmac_ctx, *p - 4,
|
|
p, end, cli_id, cli_id_len );
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
|
|
MBEDTLS_ERR_THREADING_MUTEX_ERROR );
|
|
#endif
|
|
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Check a cookie
|
|
*/
|
|
int mbedtls_ssl_cookie_check( void *p_ctx,
|
|
const unsigned char *cookie, size_t cookie_len,
|
|
const unsigned char *cli_id, size_t cli_id_len )
|
|
{
|
|
unsigned char ref_hmac[COOKIE_HMAC_LEN];
|
|
int ret = 0;
|
|
unsigned char *p = ref_hmac;
|
|
mbedtls_ssl_cookie_ctx *ctx = (mbedtls_ssl_cookie_ctx *) p_ctx;
|
|
unsigned long cur_time, cookie_time;
|
|
|
|
if( ctx == NULL || cli_id == NULL )
|
|
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
|
|
|
if( cookie_len != COOKIE_LEN )
|
|
return( -1 );
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
|
|
#endif
|
|
|
|
if( ssl_cookie_hmac( &ctx->hmac_ctx, cookie,
|
|
&p, p + sizeof( ref_hmac ),
|
|
cli_id, cli_id_len ) != 0 )
|
|
ret = -1;
|
|
|
|
#if defined(MBEDTLS_THREADING_C)
|
|
if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
|
|
MBEDTLS_ERR_THREADING_MUTEX_ERROR );
|
|
#endif
|
|
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
if( mbedtls_ssl_safer_memcmp( cookie + 4, ref_hmac, sizeof( ref_hmac ) ) != 0 )
|
|
return( -1 );
|
|
|
|
#if defined(MBEDTLS_HAVE_TIME)
|
|
cur_time = (unsigned long) mbedtls_time( NULL );
|
|
#else
|
|
cur_time = ctx->serial;
|
|
#endif
|
|
|
|
cookie_time = ( (unsigned long) cookie[0] << 24 ) |
|
|
( (unsigned long) cookie[1] << 16 ) |
|
|
( (unsigned long) cookie[2] << 8 ) |
|
|
( (unsigned long) cookie[3] );
|
|
|
|
if( ctx->timeout != 0 && cur_time - cookie_time > ctx->timeout )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_COOKIE_C */
|