Diff: source/ssl_cache.c

Revision:

1:24750b9ad5ef

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/ssl_cache.c	Fri Jan 22 16:44:49 2016 -0600
@@ -0,0 +1,326 @@
+/*
+ *  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)
+
+#include "mbedtls/ssl_cache.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc    calloc
+#define mbedtls_free       free
+#endif
+
+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)
+    time_t t = 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)
+    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 */