C# MD5 vs MD5sum

From: chis2k (sfd_at_sdf.com)
Date: 07/25/03 

Date: Fri, 25 Jul 2003 12:06:55 -0700

I am trying to figure out how to get the MD5 sum of a file that is like the
result from the MD5sum.exe program that is readily available on the
internet. I tried the following but it gives me something completely
different.... Any ideas?

MD5sum.exe output = c37a2719bd83ba766b29d8f83cee6258
My program output = w3onGb2DunZrKdj4PO5iWA==

public string GetMD5Hash( byte[] input_buffer) {
    // create implementation of MD5
    MD5 md5 = new MD5CryptoServiceProvider();
    // get hash
    return System.Convert.ToBase64String(md5.ComputeHash(input_buffer));
}