StringBuilder b = new StringBuilder();
for (int i = 0; i < 8; i++)
{
b.Append(stringToConvert[i % stringToConvert.Length]);
}
stringToConvert = b.ToString();
byte[] key = Encoding.Unicode.GetBytes(stringToConvert);//key size is 16 bytes = 128 bits
Even better (without a StringBuilder
):
byte[] key = new byte[16];
for (int i = 0; i < 16; i+=2)
{
byte[] unicodeBytes = BitConverter.GetBytes(stringToConvert[i % stringToConvert.Length]);
Array.Copy(unicodeBytes, 0, key, i, 2);
}