/* | |
* 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 "mbedtls/ssl_internal.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; | |
ret = mbedtls_ssl_session_copy( session, &entry->session ); | |
if( ret != 0 ) | |
{ | |
ret = 1; | |
goto exit; | |
} | |
#if defined(MBEDTLS_X509_CRT_PARSE_C) && \ | |
defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) | |
/* | |
* Restore peer certificate (without rest of the original chain) | |
*/ | |
if( entry->peer_cert.p != NULL ) | |
{ | |
/* `session->peer_cert` is NULL after the call to | |
* mbedtls_ssl_session_copy(), because cache entries | |
* have the `peer_cert` field set to 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 && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ | |
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 = mbedtls_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 | |
} | |
#if defined(MBEDTLS_X509_CRT_PARSE_C) && \ | |
defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) | |
/* | |
* 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) ); | |
} | |
#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ | |
/* Copy the entire session; this temporarily makes a copy of the | |
* X.509 CRT structure even though we only want to store the raw CRT. | |
* This inefficiency will go away as soon as we implement on-demand | |
* parsing of CRTs, in which case there's no need for the `peer_cert` | |
* field anymore in the first place, and we're done after this call. */ | |
ret = mbedtls_ssl_session_copy( &cur->session, session ); | |
if( ret != 0 ) | |
{ | |
ret = 1; | |
goto exit; | |
} | |
#if defined(MBEDTLS_X509_CRT_PARSE_C) && \ | |
defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) | |
/* If present, free the X.509 structure and only store the raw CRT data. */ | |
if( cur->session.peer_cert != NULL ) | |
{ | |
cur->peer_cert.p = | |
mbedtls_calloc( 1, cur->session.peer_cert->raw.len ); | |
if( cur->peer_cert.p == NULL ) | |
{ | |
ret = 1; | |
goto exit; | |
} | |
memcpy( cur->peer_cert.p, | |
cur->session.peer_cert->raw.p, | |
cur->session.peer_cert->raw.len ); | |
cur->peer_cert.len = session->peer_cert->raw.len; | |
mbedtls_x509_crt_free( cur->session.peer_cert ); | |
mbedtls_free( cur->session.peer_cert ); | |
cur->session.peer_cert = NULL; | |
} | |
#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ | |
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) && \ | |
defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) | |
mbedtls_free( prv->peer_cert.p ); | |
#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ | |
mbedtls_free( prv ); | |
} | |
#if defined(MBEDTLS_THREADING_C) | |
mbedtls_mutex_free( &cache->mutex ); | |
#endif | |
cache->chain = NULL; | |
} | |
#endif /* MBEDTLS_SSL_CACHE_C */ |