using System;

using System.Security.Cryptography;

using System.Text;  

public class Program

{

    public void Main()

    {

        string privateKey = "au6RRBKcqrmSnh9RN8KNEBaKBEEEDcwwKbChTWb7FPxsZMtsUzuvQWGXCj8V87QnpBWYrHtVfKK6csfAKJaxW7w58NdZ2jXMBnNrsRfdJnWhXzLXU52Lddc8Sfss35kn";

        string publicKey = "4LDVS4Kv5S5sxT83FNHp5LzDcKb9wnkE";

        string urlAuthorize = "https://preprod.api.catalizr.io/authorize/";

        string urlGetInvestor = "https://preprod.api.catalizr.io/papi/investors/email/sophie.willmann@creditmutuel.fr";

        string nonceAuthorize = GetNonce();

        string signatureAuthorize = GetSignatureAuthorize(privateKey, publicKey, nonceAuthorize, urlAuthorize);     

        string nonceGetInvestor = GetNonce();

        string signatureGetInvestor = GetSignatureGetInvestor(privateKey, publicKey, nonceGetInvestor, urlGetInvestor);

        Console.WriteLine("Public key : " + publicKey);     

        Console.WriteLine("");

        Console.WriteLine("Signature authorize : " + signatureAuthorize);

        Console.WriteLine("Nonce authorize : " + nonceAuthorize);

        Console.WriteLine("");

        Console.WriteLine("Signature getInvestor : " + signatureAuthorize);

        Console.WriteLine("Nonce getInvestor : " + nonceGetInvestor);       

    }

    private string GetNonce()

    {

        var ts = DateTime.UtcNow - new DateTime(1970,1,1);

        return ts.TotalMilliseconds.ToString().Substring(0, 13);

    }

    private string GetSignatureAuthorize(string privateKey, string publicKey, string nonce, string url)

    {

        HMACSHA512 hmac = new HMACSHA512(Encoding.ASCII.GetBytes(privateKey));          

        byte[] computedHash = hmac.ComputeHash(Encoding.UTF8.GetBytes(nonce + url + "{\"apiPublicKey\": \"" + publicKey + "\"}"));

        return BitConverter.ToString(computedHash).Replace("-", string.Empty).ToLower();

    }

    private string GetSignatureGetInvestor(string privateKey, string publicKey, string nonce, string url)

    {

        HMACSHA512 hmac = new HMACSHA512(Encoding.ASCII.GetBytes(privateKey));          

        byte[] computedHash = hmac.ComputeHash(Encoding.UTF8.GetBytes(nonce + url));

        return BitConverter.ToString(computedHash).Replace("-", string.Empty).ToLower();

    }

}