mbedtls/library/ssl_cache.c
Simon Butcher b5b6af2663 Puts platform time abstraction into its own header
Separates platform time abstraction into it's own header from the
general platform abstraction as both depend on different build options.
(MBEDTLS_PLATFORM_C vs MBEDTLS_HAVE_TIME)
2016-07-13 14:46:18 +01:00

327 lines
8.0 KiB
C

/*
* SSL session cache implementation
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* 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.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* 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_CACHE_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/ssl_cache.h"
#include <string.h>
void mbedtls_ssl_cache_init( mbedtls_ssl_cache_context *cache )
{
memset( cache, 0, sizeof( mbedtls_ssl_cache_context ) );
cache->timeout = MBEDTLS_SSL_CACHE_DEFAULT_TIMEOUT;
cache->max_entries = MBEDTLS_SSL_CACHE_DEFAULT_MAX_ENTRIES;
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init( &cache->mutex );
#endif
}
int mbedtls_ssl_cache_get( void *data, mbedtls_ssl_session *session )
{
int ret = 1;
#if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t t = mbedtls_time( NULL );
#endif
mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
mbedtls_ssl_cache_entry *cur, *entry;
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &cache->mutex ) != 0 )
return( 1 );
#endif
cur = cache->chain;
entry = NULL;
while( cur != NULL )
{
entry = cur;
cur = cur->next;
#if defined(MBEDTLS_HAVE_TIME)
if( cache->timeout != 0 &&
(int) ( t - entry->timestamp ) > cache->timeout )
continue;
#endif
if( session->ciphersuite != entry->session.ciphersuite ||
session->compression != entry->session.compression ||
session->id_len != entry->session.id_len )
continue;
if( memcmp( session->id, entry->session.id,
entry->session.id_len ) != 0 )
continue;
memcpy( session->master, entry->session.master, 48 );
session->verify_result = entry->session.verify_result;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
/*
* Restore peer certificate (without rest of the original chain)
*/
if( entry->peer_cert.p != NULL )
{
if( ( session->peer_cert = mbedtls_calloc( 1,
sizeof(mbedtls_x509_crt) ) ) == NULL )
{
ret = 1;
goto exit;
}
mbedtls_x509_crt_init( session->peer_cert );
if( mbedtls_x509_crt_parse( session->peer_cert, entry->peer_cert.p,
entry->peer_cert.len ) != 0 )
{
mbedtls_free( session->peer_cert );
session->peer_cert = NULL;
ret = 1;
goto exit;
}
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
ret = 0;
goto exit;
}
exit:
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &cache->mutex ) != 0 )
ret = 1;
#endif
return( ret );
}
int mbedtls_ssl_cache_set( void *data, const mbedtls_ssl_session *session )
{
int ret = 1;
#if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t t = time( NULL ), oldest = 0;
mbedtls_ssl_cache_entry *old = NULL;
#endif
mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
mbedtls_ssl_cache_entry *cur, *prv;
int count = 0;
#if defined(MBEDTLS_THREADING_C)
if( ( ret = mbedtls_mutex_lock( &cache->mutex ) ) != 0 )
return( ret );
#endif
cur = cache->chain;
prv = NULL;
while( cur != NULL )
{
count++;
#if defined(MBEDTLS_HAVE_TIME)
if( cache->timeout != 0 &&
(int) ( t - cur->timestamp ) > cache->timeout )
{
cur->timestamp = t;
break; /* expired, reuse this slot, update timestamp */
}
#endif
if( memcmp( session->id, cur->session.id, cur->session.id_len ) == 0 )
break; /* client reconnected, keep timestamp for session id */
#if defined(MBEDTLS_HAVE_TIME)
if( oldest == 0 || cur->timestamp < oldest )
{
oldest = cur->timestamp;
old = cur;
}
#endif
prv = cur;
cur = cur->next;
}
if( cur == NULL )
{
#if defined(MBEDTLS_HAVE_TIME)
/*
* Reuse oldest entry if max_entries reached
*/
if( count >= cache->max_entries )
{
if( old == NULL )
{
ret = 1;
goto exit;
}
cur = old;
}
#else /* MBEDTLS_HAVE_TIME */
/*
* Reuse first entry in chain if max_entries reached,
* but move to last place
*/
if( count >= cache->max_entries )
{
if( cache->chain == NULL )
{
ret = 1;
goto exit;
}
cur = cache->chain;
cache->chain = cur->next;
cur->next = NULL;
prv->next = cur;
}
#endif /* MBEDTLS_HAVE_TIME */
else
{
/*
* max_entries not reached, create new entry
*/
cur = mbedtls_calloc( 1, sizeof(mbedtls_ssl_cache_entry) );
if( cur == NULL )
{
ret = 1;
goto exit;
}
if( prv == NULL )
cache->chain = cur;
else
prv->next = cur;
}
#if defined(MBEDTLS_HAVE_TIME)
cur->timestamp = t;
#endif
}
memcpy( &cur->session, session, sizeof( mbedtls_ssl_session ) );
#if defined(MBEDTLS_X509_CRT_PARSE_C)
/*
* If we're reusing an entry, free its certificate first
*/
if( cur->peer_cert.p != NULL )
{
mbedtls_free( cur->peer_cert.p );
memset( &cur->peer_cert, 0, sizeof(mbedtls_x509_buf) );
}
/*
* Store peer certificate
*/
if( session->peer_cert != NULL )
{
cur->peer_cert.p = mbedtls_calloc( 1, session->peer_cert->raw.len );
if( cur->peer_cert.p == NULL )
{
ret = 1;
goto exit;
}
memcpy( cur->peer_cert.p, session->peer_cert->raw.p,
session->peer_cert->raw.len );
cur->peer_cert.len = session->peer_cert->raw.len;
cur->session.peer_cert = NULL;
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
ret = 0;
exit:
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &cache->mutex ) != 0 )
ret = 1;
#endif
return( ret );
}
#if defined(MBEDTLS_HAVE_TIME)
void mbedtls_ssl_cache_set_timeout( mbedtls_ssl_cache_context *cache, int timeout )
{
if( timeout < 0 ) timeout = 0;
cache->timeout = timeout;
}
#endif /* MBEDTLS_HAVE_TIME */
void mbedtls_ssl_cache_set_max_entries( mbedtls_ssl_cache_context *cache, int max )
{
if( max < 0 ) max = 0;
cache->max_entries = max;
}
void mbedtls_ssl_cache_free( mbedtls_ssl_cache_context *cache )
{
mbedtls_ssl_cache_entry *cur, *prv;
cur = cache->chain;
while( cur != NULL )
{
prv = cur;
cur = cur->next;
mbedtls_ssl_session_free( &prv->session );
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_free( prv->peer_cert.p );
#endif /* MBEDTLS_X509_CRT_PARSE_C */
mbedtls_free( prv );
}
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_free( &cache->mutex );
#endif
}
#endif /* MBEDTLS_SSL_CACHE_C */