--- /dev/null
+/*
+ * Common and shared functions used by multiple modules in the Mbed TLS
+ * library.
+ *
+ * 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.
+ *
+ * **********
+ */
+
+/*
+ * Ensure gmtime_r is available even with -std=c99; must be defined before
+ * config.h, which pulls in glibc's features.h. Harmless on other platforms.
+ */
+#if !defined(_POSIX_C_SOURCE)
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include "mbedtls/platform_util.h"
+#include "mbedtls/platform.h"
+#include "mbedtls/threading.h"
+
+#include <stddef.h>
+#include <string.h>
+
+#if !defined(MBEDTLS_PLATFORM_ZEROIZE_ALT)
+/*
+ * This implementation should never be optimized out by the compiler
+ *
+ * This implementation for mbedtls_platform_zeroize() was inspired from Colin
+ * Percival's blog article at:
+ *
+ * http://www.daemonology.net/blog/2014-09-04-how-to-zero-a-buffer.html
+ *
+ * It uses a volatile function pointer to the standard memset(). Because the
+ * pointer is volatile the compiler expects it to change at
+ * any time and will not optimize out the call that could potentially perform
+ * other operations on the input buffer instead of just setting it to 0.
+ * Nevertheless, as pointed out by davidtgoldblatt on Hacker News
+ * (refer to http://www.daemonology.net/blog/2014-09-05-erratum.html for
+ * details), optimizations of the following form are still possible:
+ *
+ * if( memset_func != memset )
+ * memset_func( buf, 0, len );
+ *
+ * Note that it is extremely difficult to guarantee that
+ * mbedtls_platform_zeroize() will not be optimized out by aggressive compilers
+ * in a portable way. For this reason, Mbed TLS also provides the configuration
+ * option MBEDTLS_PLATFORM_ZEROIZE_ALT, which allows users to configure
+ * mbedtls_platform_zeroize() to use a suitable implementation for their
+ * platform and needs.
+ */
+static void * (* const volatile memset_func)( void *, int, size_t ) = memset;
+
+void mbedtls_platform_zeroize( void *buf, size_t len )
+{
+ MBEDTLS_INTERNAL_VALIDATE( len == 0 || buf != NULL );
+
+ if( len > 0 )
+ memset_func( buf, 0, len );
+}
+#endif /* MBEDTLS_PLATFORM_ZEROIZE_ALT */
+
+#if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_R_ALT)
+#include <time.h>
+#if !defined(_WIN32) && (defined(unix) || \
+ defined(__unix) || defined(__unix__) || (defined(__APPLE__) && \
+ defined(__MACH__)))
+#include <unistd.h>
+#endif /* !_WIN32 && (unix || __unix || __unix__ ||
+ * (__APPLE__ && __MACH__)) */
+
+#if !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) || \
+ ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) && \
+ _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) )
+/*
+ * This is a convenience shorthand macro to avoid checking the long
+ * preprocessor conditions above. Ideally, we could expose this macro in
+ * platform_util.h and simply use it in platform_util.c, threading.c and
+ * threading.h. However, this macro is not part of the Mbed TLS public API, so
+ * we keep it private by only defining it in this file
+ */
+#if ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) )
+#define PLATFORM_UTIL_USE_GMTIME
+#endif /* ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) ) */
+
+#endif /* !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) || \
+ ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) && \
+ _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) ) */
+
+struct tm *mbedtls_platform_gmtime_r( const mbedtls_time_t *tt,
+ struct tm *tm_buf )
+{
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+ return( ( gmtime_s( tm_buf, tt ) == 0 ) ? tm_buf : NULL );
+#elif !defined(PLATFORM_UTIL_USE_GMTIME)
+ return( gmtime_r( tt, tm_buf ) );
+#else
+ struct tm *lt;
+
+#if defined(MBEDTLS_THREADING_C)
+ if( mbedtls_mutex_lock( &mbedtls_threading_gmtime_mutex ) != 0 )
+ return( NULL );
+#endif /* MBEDTLS_THREADING_C */
+
+ lt = gmtime( tt );
+
+ if( lt != NULL )
+ {
+ memcpy( tm_buf, lt, sizeof( struct tm ) );
+ }
+
+#if defined(MBEDTLS_THREADING_C)
+ if( mbedtls_mutex_unlock( &mbedtls_threading_gmtime_mutex ) != 0 )
+ return( NULL );
+#endif /* MBEDTLS_THREADING_C */
+
+ return( ( lt == NULL ) ? NULL : tm_buf );
+#endif /* _WIN32 && !EFIX64 && !EFI32 */
+}
+#endif /* MBEDTLS_HAVE_TIME_DATE && MBEDTLS_PLATFORM_GMTIME_R_ALT */
projects / reactos.git / blobdiff