string input = "asd";

System.Security.Cryptography.MD5 alg = System.Security.Cryptography.MD5.Create();
System.Text.UTF8Encoding enc = new System.Text.UTF8Encoding();


byte[] hash = alg.ComputeHash(enc.GetBytes(input));
string output = Convert.ToBase64String(hash);

// outputs:   eBVpbsvxyW5olLd5RW0zDg==
Console.WriteLine(output);

$input = "asd";
$output = HashSomething($input);
echo $output;

$hashValue = base64_encode(md5(utf8_decode($inputString)))