PHP and C# HMAC SHA256

Question

I need to convert the following php code in C#:

$res = mac256($ent, $key);
$result = encodeBase64($res);

where

function enc         


        

Answer 1

This code should do the trick:

static byte[] hmacSHA256(String data, String key)
{
    using (HMACSHA256 hmac = new HMACSHA256(Encoding.ASCII.GetBytes(key)))
    {
        return hmac.ComputeHash(Encoding.ASCII.GetBytes(data));
    }
}

If I call this code:

Console.WriteLine(BitConverter.ToString(hmacSHA256("1234", "1234")).Replace("-", "").ToLower());

It returns:

4e4feaea959d426155a480dc07ef92f4754ee93edbe56d993d74f131497e66fb

When I run this in PHP:

echo hash_hmac('sha256', "1234", "1234", false);

It returns

4e4feaea959d426155a480dc07ef92f4754ee93edbe56d993d74f131497e66fb