Adding support to symmetric encryption

Author: Luigi Gubello

src/Encryption.cpp

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2019 Arduino SA. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "Encryption.h"
+
+EncryptionClass::EncryptionClass(int blockSize, int digestSize) :
+  _blockSize(blockSize),
+  _digestSize(digestSize)
+{
+  _data = (uint8_t*)malloc(_digestSize);
+  _secret = (uint8_t*)malloc(_blockSize);
+  _ivector = (uint8_t*)malloc(_blockSize);
+}
+
+EncryptionClass::~EncryptionClass()
+{
+  if (_secret) {
+    free(_secret);
+    _secret = NULL;
+  }
+
+  if (_data) {
+    free(_data);
+    _data = NULL;
+  }
+
+  if (_ivector) {
+    free(_ivector);
+    _ivector = NULL;
+  }
+}
+
+int EncryptionClass::runEnc(uint8_t *_secret, size_t _secretLength, uint8_t *_data, size_t _dataLength, uint8_t *_ivector)
+{
+  return runEncryption(_secret, _secretLength, _data, _dataLength, _ivector);
+}
+
+int EncryptionClass::runDec(uint8_t *_secret, size_t _secretLength, uint8_t *_data, size_t _dataLength, uint8_t *_ivector)
+{
+  return runDecryption(_secret, _secretLength, _data, _dataLength, _ivector);
+}

src/Encryption.h

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2019 Arduino SA. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef ENCRYPTION_H
+#define ENCRYPTION_H
+
+#include <Arduino.h>
+
+class EncryptionClass {
+
+public:
+  EncryptionClass(int blockSize, int digestSize);
+  virtual ~EncryptionClass();
+
+  int runEnc(uint8_t *_secret, size_t _secretLength, uint8_t *_data, size_t _dataLength, uint8_t *_ivector);
+  int runDec(uint8_t *_secret, size_t _secretLength, uint8_t *_data, size_t _dataLength, uint8_t *_ivector);
+
+protected:
+  virtual int runEncryption(uint8_t *key, size_t size, uint8_t *input, size_t block_size, uint8_t *iv) = 0;
+  virtual int runDecryption(uint8_t *key, size_t size, uint8_t *input, size_t block_size, uint8_t *iv) = 0;
+
+private:
+  int _blockSize;
+  int _digestSize;
+
+  uint8_t* _secret;
+  int _secretLength;
+  uint8_t* _ivector;
+  int _ivectorLength;
+  uint8_t* _data;
+  int _dataLength;
+};
+
+#endif