diff options
Diffstat (limited to 'lib/mbedtls-2.27.0/library/ssl_cookie.c')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/ssl_cookie.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/lib/mbedtls-2.27.0/library/ssl_cookie.c b/lib/mbedtls-2.27.0/library/ssl_cookie.c new file mode 100644 index 0000000..69d1b32 --- /dev/null +++ b/lib/mbedtls-2.27.0/library/ssl_cookie.c @@ -0,0 +1,249 @@ +/* + * DTLS cookie callbacks implementation + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-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. + */ +/* + * These session callbacks use a simple chained list + * to store and retrieve the session information. + */ + +#include "common.h" + +#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/error.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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + 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_ERR_ERROR_CORRUPTION_DETECTED; + 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_ERROR_ADD( 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_ERROR_ADD( 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_ERROR_ADD( 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_ERROR_ADD( 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 */ |