public static void Decrypt(ZWaveAES aesEngine, byte[] encKey, byte[] iv, ref byte[] payload)
{
string pre = payload.GetHex();
aesEngine.AES_OFB(encKey, iv, payload, false);
string after = payload.GetHex();
"S0 {0} = {1}"._DLOG(after, pre);
}
/// <summary>
/// Decrypts the payload.
/// </summary>
/// <param name="networkKey">The network key.</param>
/// <param name="encryptedPayload">The encrypted payload.</param>
/// <param name="IV">The IV.</param>
/// <returns></returns>
public byte[] DecryptPayload(byte[] networkKey, byte[] encryptedPayload, byte[] IV)
{
try
{
/////////////////////////////
//byte[] authKey = new byte[16];
byte[] encKey = new byte[16];
//byte[] pattern = ZWaveAES.RepeatByte16(0x55);
//AES.AES_ECB(authData.Key, pattern, authKey); // K_A = AES(K_N,pattern)
byte[] pattern = ZWaveAES.RepeatByte16(0xAA);
Engine.AES_ECB(networkKey, pattern, encKey); // K_E = AES(K_N,pattern)
/////////////////////////////
byte[] output = new byte[0];
byte[] encPayload = new byte[0];
if (encryptedPayload.Length < 16)
{
output = ExpandEmptyArray(16);
encPayload = ExpandEmptyArray(16);
}
else
{
output = ExpandEmptyArray(encryptedPayload.Length);
encPayload = ExpandEmptyArray(encryptedPayload.Length);
}
for (int i = 0; i < encryptedPayload.Length; i++)
{
encPayload[i] = encryptedPayload[i];
}
Engine.AES_OFB(encKey, IV, encPayload, true);
byte[] decryptedPayload = new byte[encryptedPayload.Length];
for (int i = 0; i < encryptedPayload.Length; i++)
{
if (i < encPayload.Length)
{
decryptedPayload[i] = encPayload[i];
}
}
return(decryptedPayload);
}
catch (Exception ex)
{
throw new ApplicationException("SecurityException", ex);
}
}