public StreamEncryptor(byte[] key, byte[] deviceSeed, byte[] phoneSeed)
{
Debug.Assert(key != null && key.Length == BtleLinkTypes.ENCRYPTED_BLOCK_SIZE);
Debug.Assert(deviceSeed != null && deviceSeed.Length > 0);
Debug.Assert(phoneSeed != null && phoneSeed.Length > 0);
// For use to send data, Encrypt
_encyptedRxStream = new EncryptedStreamGenerator(key, deviceSeed);
// For use to receive data, Decrypt
_encyptedTxStream = new EncryptedStreamGenerator(key, phoneSeed);
IsEnabled = true;
}
private byte[] Xor(byte[] data, int index, int len, EncryptedStreamGenerator encryptor)
{
Debug.Assert(data != null && data.Length > 0);
Debug.Assert(index >= 0 && len > 0);
Debug.Assert(index + len <= data.Length);
Debug.Assert(encryptor != null, "Encryptor is NULL");
byte[] result = new byte[len];
byte[] encryptedBlock = encryptor.Generate(len);
for (int i = 0; i < len; i++)
{
result[i] = (byte)(data[index + i] ^ encryptedBlock[i]);
// Eitan, Just for debug: 0x84 - New Battery Reading
//if ( i == 0 && result[ 0 ] == 0x84 )
// {
// // Just to detect the Battery record
// Debug.WriteLine( " Found it: result[ 0 ] == 0x84" );
// }
}
return(result);
}