Adding class for calculating SHA256 using BearSSL

Author: aentinger

src/tls/utility/SHA256.cpp

@@ -0,0 +1,41 @@
+/*
+   This file is part of ArduinoIoTCloud.
+
+   Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+
+   This software is released under the GNU General Public License version 3,
+   which covers the main part of arduino-cli.
+   The terms of this license can be found at:
+   https://www.gnu.org/licenses/gpl-3.0.en.html
+
+   You can be released from the requirements of the above licenses by purchasing
+   a commercial license. Buying such a license is mandatory if you want to modify or
+   otherwise use the software for commercial activities involving the Arduino
+   software without disclosing the source code of your own applications. To purchase
+   a commercial license, send an email to [email protected].
+*/
+
+/******************************************************************************
+ * INCLUDE
+ ******************************************************************************/
+
+#include "SHA256.h"
+
+/******************************************************************************
+ * PUBLIC MEMBER FUNCTIONS
+ ******************************************************************************/
+
+void SHA256::begin()
+{
+  br_sha256_init(&_ctx);
+}
+
+void SHA256::update(uint8_t const * data, size_t const len)
+{
+  br_sha256_update(&_ctx, data, len);
+}
+
+void SHA256::finalize(char * hash)
+{
+  br_sha256_out(&_ctx, hash);
+}

src/tls/utility/SHA256.h

@@ -0,0 +1,46 @@
+/*
+   This file is part of ArduinoIoTCloud.
+
+   Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+
+   This software is released under the GNU General Public License version 3,
+   which covers the main part of arduino-cli.
+   The terms of this license can be found at:
+   https://www.gnu.org/licenses/gpl-3.0.en.html
+
+   You can be released from the requirements of the above licenses by purchasing
+   a commercial license. Buying such a license is mandatory if you want to modify or
+   otherwise use the software for commercial activities involving the Arduino
+   software without disclosing the source code of your own applications. To purchase
+   a commercial license, send an email to [email protected].
+*/
+
+#ifndef ARDUINO_TLS_UTILITY_SHA256_H_
+#define ARDUINO_TLS_UTILITY_SHA256_H_
+
+/******************************************************************************
+ * INCLUDE
+ ******************************************************************************/
+
+#include "../bearssl/bearssl_hash.h"
+
+/******************************************************************************
+ * CLASS DECLARATION
+ ******************************************************************************/
+
+class SHA256
+{
+
+public:
+
+  void begin   ();
+  void update  (uint8_t const * data, size_t const len);
+  void finalize(char * hash);
+
+private:
+
+  br_sha256_context _ctx;
+
+};
+
+#endif /* ARDUINO_TLS_UTILITY_SHA256_H_ */