move from polarssl to mbedtls (#708)

* update polarssl to mbedtls
* fix a warning in armsrc/iso15693
* added random generator and ecdsa test
* added signature check to test
* move crypto lib to client directory

common/mbedtls/platform_util.h

@@ -0,0 +1,64 @@
+/**
+ * \file platform_util.h
+ *
+ * \brief Common and shared functions used by multiple modules in the Mbed TLS
+ *        library.
+ */
+/*
+ *  Copyright (C) 2018, Arm Limited, All Rights Reserved
+ *  SPDX-License-Identifier: GPL-2.0
+ *
+ *  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.
+ *
+ *  This file is part of Mbed TLS (https://tls.mbed.org)
+ */
+#ifndef MBEDTLS_PLATFORM_UTIL_H
+#define MBEDTLS_PLATFORM_UTIL_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief       Securely zeroize a buffer
+ *
+ *              The function is meant to wipe the data contained in a buffer so
+ *              that it can no longer be recovered even if the program memory
+ *              is later compromised. Call this function on sensitive data
+ *              stored on the stack before returning from a function, and on
+ *              sensitive data stored on the heap before freeing the heap
+ *              object.
+ *
+ *              It is extremely difficult to guarantee that calls to
+ *              mbedtls_platform_zeroize() are not removed by aggressive
+ *              compiler optimizations in a portable way. For this reason, Mbed
+ *              TLS 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
+ *
+ * \param buf   Buffer to be zeroized
+ * \param len   Length of the buffer in bytes
+ *
+ */
+void mbedtls_platform_zeroize( void *buf, size_t len );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MBEDTLS_PLATFORM_UTIL_H */