private static int GetOTRDataLenType(OTR_DATA_LEN_TYPE otr_data_type)
{
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_CTR)
return OTRConstants.TYPE_LEN_CTR;
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_INT)
return OTRConstants.TYPE_LEN_INT;
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_MAC)
return OTRConstants.TYPE_LEN_MAC;
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_MPI)
return OTRConstants.TYPE_LEN_MPI;
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_SHORT)
return OTRConstants.TYPE_LEN_SHORT;
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_DATA)
return OTRConstants.TYPE_LEN_DATA;
if (otr_data_type == OTR_DATA_LEN_TYPE.TYPE_BYTE)
return OTRConstants.TYPE_LEN_BYTE;
return -1;
}
private static void EncodeOTRBytes(byte[] in_byte_array, OTR_DATA_LEN_TYPE otr_data_len_type, ref byte[] out_byte_array)
{
if (in_byte_array == null || in_byte_array.Length < 1)
throw new ArgumentException("EncodeOTRBytes: In byte array cannot be null/empty");
if (otr_data_len_type == OTR_DATA_LEN_TYPE.INVALID)
throw new ArgumentException("EncodeOTRBytes: The OTR data len type is invalid");
int _type_length = GetOTRDataLenType(otr_data_len_type);
if (in_byte_array.Length > _type_length)
throw new ArgumentException("EncodeOTRBytes: In byte length cannot greater than " + _type_length.ToString());
out_byte_array = new byte[_type_length];
Buffer.BlockCopy(in_byte_array, 0, out_byte_array, 0, out_byte_array.Length);
if (BitConverter.IsLittleEndian == true)
Array.Reverse(out_byte_array);
}
private static int DecoupleTypeFromBytes(byte[] in_byte_array, int start_index, OTR_DATA_LEN_TYPE otr_data_len_type, ref byte[] out_byte_array)
{
if (in_byte_array == null || in_byte_array.Length < 1)
throw new ArgumentException("DecoupleTypeFromBytes: In byte array cannot be null/empty");
if (otr_data_len_type == OTR_DATA_LEN_TYPE.INVALID)
throw new ArgumentException("DecoupleTypeFromBytes: The OTR data len type is invalid");
if (start_index < 0)
throw new ArgumentException("DecoupleTypeFromBytes: The start index cannot be less than 0");
int _type_length = GetOTRDataLenType(otr_data_len_type);
if (in_byte_array.Length < _type_length + 1)
throw new ArgumentException("DecoupleTypeFromBytes: In byte array length cannot be less than specified type length of " + _type_length.ToString());
int _next_start_index = 0;
byte[] _length_byte_array = new byte[_type_length];
Buffer.BlockCopy(in_byte_array, start_index, _length_byte_array, 0, _type_length);
if (BitConverter.IsLittleEndian)
Array.Reverse(_length_byte_array);
byte[] _int_32_length = new byte[4];
Buffer.BlockCopy(_length_byte_array, 0, _int_32_length, 0, _length_byte_array.Length);
int _data_array_length = BitConverter.ToInt32(_int_32_length, 0);
if (_data_array_length < 1)
throw new InvalidDataException("DecoupleTypeFromBytes: The length of the data sub array in the in byte array is less than 1");
_next_start_index = _data_array_length + start_index + _type_length;
if (_next_start_index > in_byte_array.Length)
throw new InvalidDataException("DecoupleTypeFromBytes: The extracted data length value exceeds the length of the byte array");
out_byte_array = new byte[_data_array_length + _type_length];
Buffer.BlockCopy(in_byte_array, start_index, out_byte_array, 0, out_byte_array.Length);
if (_next_start_index == in_byte_array.Length)
_next_start_index = -1;
return _next_start_index;
}
private static void EncodeBytesBE(byte[] in_byte_array, OTR_DATA_LEN_TYPE otr_data_len_type, ref byte[] out_byte_array)
{
if (in_byte_array == null || in_byte_array.Length < 1)
throw new ArgumentException("EncodeBytesBE: In byte array cannot be null/empty");
if (otr_data_len_type == OTR_DATA_LEN_TYPE.INVALID)
throw new ArgumentException("EncodeBytesBE: The OTR data len type is invalid");
int _type_length = GetOTRDataLenType(otr_data_len_type);
byte[] _byte_array = new byte[in_byte_array.Length];
Buffer.BlockCopy(in_byte_array, 0, _byte_array, 0, _byte_array.Length);
byte[] _length_byte_array = new byte[_type_length];
byte[] _length_temp_array = BitConverter.GetBytes(_byte_array.Length);
if (BitConverter.IsLittleEndian == false)
Array.Reverse(_length_temp_array);
Buffer.BlockCopy(_length_temp_array, 0, _length_byte_array, 0, _length_byte_array.Length);
if (BitConverter.IsLittleEndian)
Array.Reverse(_length_byte_array);
out_byte_array = new byte[_length_byte_array.Length + _byte_array.Length];
Buffer.BlockCopy(_length_byte_array, 0, out_byte_array, 0, _type_length);
Buffer.BlockCopy(_byte_array, 0, out_byte_array, _type_length, _byte_array.Length);
}
private static int DecodeOTRBytes(byte[] in_byte_array, int start_index, OTR_DATA_LEN_TYPE otr_data_len_type, ref byte[] out_byte_array)
{
/* Assumes in byte array is big-endian */
if (in_byte_array == null || in_byte_array.Length < 1)
throw new ArgumentException("DecodeOTRBytes: In byte array cannot be null/empty");
if (otr_data_len_type == OTR_DATA_LEN_TYPE.INVALID)
throw new ArgumentException("DecodeOTRBytes: The OTR data len type is invalid");
if (start_index < 0)
throw new ArgumentException("DecodeOTRBytes: The start index cannot be less than 0");
int _type_length = GetOTRDataLenType(otr_data_len_type);
int _next_start_index = start_index + _type_length;
out_byte_array = new byte [_type_length];
Buffer.BlockCopy(in_byte_array, start_index, out_byte_array, 0, out_byte_array.Length);
if (BitConverter.IsLittleEndian == true)
Array.Reverse(out_byte_array);
if (_next_start_index == in_byte_array.Length)
_next_start_index = -1;
return _next_start_index;
}
