private static byte[] ComputeM(AKEKeys ake_keys, byte[] my_public_key_mpi_byte_array, byte[] their_public_key_mpi_byte_array, byte[] dsa_public_key_bytes_encoded, byte[] key_id_byte_array, bool is_top_half_keys)
{
if (my_public_key_mpi_byte_array == null || my_public_key_mpi_byte_array.Length < 1)
throw new ArgumentException("ComputeM: My public key mpi byte array cannot be null/empty");
if (their_public_key_mpi_byte_array == null || their_public_key_mpi_byte_array.Length < 1)
throw new ArgumentException("ComputeM: Their public key mpi byte array cannot be null/empty");
if (key_id_byte_array == null || key_id_byte_array.Length < 1)
throw new ArgumentException("ComputeM: The id byte array cannot be null/empty");
if (dsa_public_key_bytes_encoded == null || dsa_public_key_bytes_encoded.Length < 1)
throw new ArgumentException("ComputeM: The encoded DSA public key byte array cannot be null/empty");
if (ake_keys == null)
throw new ArgumentException("ComputeM: AKE keys object cannot be null");
byte[] _encoded_key_id_byte_array = null;
try
{
Utility.EncodeOTRInt(key_id_byte_array, ref _encoded_key_id_byte_array);
}
catch (Exception ex)
{
throw new InvalidDataException("ComputeM:" + ex.ToString());
}
int _m_data_array_length = _encoded_key_id_byte_array.Length + my_public_key_mpi_byte_array.Length +
their_public_key_mpi_byte_array.Length +
dsa_public_key_bytes_encoded.Length;
byte [] _m_data_array = new byte[_m_data_array_length];
Buffer.BlockCopy(my_public_key_mpi_byte_array, 0, _m_data_array, 0, my_public_key_mpi_byte_array.Length);
Buffer.BlockCopy(their_public_key_mpi_byte_array, 0, _m_data_array, my_public_key_mpi_byte_array.Length, their_public_key_mpi_byte_array.Length);
Buffer.BlockCopy(dsa_public_key_bytes_encoded, 0, _m_data_array, my_public_key_mpi_byte_array.Length + their_public_key_mpi_byte_array.Length, dsa_public_key_bytes_encoded.Length);
Buffer.BlockCopy(_encoded_key_id_byte_array, 0, _m_data_array, my_public_key_mpi_byte_array.Length + their_public_key_mpi_byte_array.Length + dsa_public_key_bytes_encoded.Length, _encoded_key_id_byte_array.Length);
if (is_top_half_keys == true && (ake_keys.GetMACKey1() == null || ake_keys.GetMACKey1().Length < 1))
throw new ArgumentException("ComputeM: The AKE MAC key 1 cannot be null/empty");
if (is_top_half_keys == false && (ake_keys.GetMACKey3() == null || ake_keys.GetMACKey3().Length < 1))
throw new ArgumentException("ComputeM: The AKE MAC key 3 cannot be null/empty");
if (is_top_half_keys == true)
return Utility.SHA256GetKeyedHash(ake_keys.GetMACKey1(),_m_data_array);
else
return Utility.SHA256GetKeyedHash(ake_keys.GetMACKey3(), _m_data_array);
}
