public static byte[] FromBase64CharArray (char[] inArray, int offset, int length)
{
if (inArray == null)
throw new ArgumentNullException ("inArray");
if (offset < 0)
throw new ArgumentOutOfRangeException ("offset < 0");
if (length < 0)
throw new ArgumentOutOfRangeException ("length < 0");
// avoid integer overflow
if (offset > inArray.Length - length)
throw new ArgumentOutOfRangeException ("offset + length > array.Length");
return InternalFromBase64CharArray (inArray, offset, length);
}