I use the following C# code to calculate a MD5 hash from a string. It works well and generates a 32-character hex string like this: 900150983cd24fb0d6963f7d28e17f72
900150983cd24fb0d6963f7d28e17f72
Here is my utility function for UTF8, which can be replaced with ASCII if desired:
UTF8
ASCII
public static byte[] MD5Hash(string message) { return MD5.Create().ComputeHash(Encoding.UTF8.GetBytes(message)); }