PasswordVerificator-good.cs

using System;
using System.Security.Cryptography;
using System.Text;

public class PasswordVerificator
{
	public static void Main()
	{
	string AuthenticationResult = AuthenticateUser("admin", "supersecretpassword")?"User authenticated!":"Access denied!";
		Console.WriteLine(AuthenticationResult);
	}

	public static string HexStringFromBytes(byte[] bytes)
	{
		var sb = new StringBuilder();
		foreach (byte b in bytes)
		{
			var hex = b.ToString("x2");
			sb.Append(hex);
		}
		return sb.ToString();
	}
	
	public static string SHA1Hash(string s)
	{
		byte[] bytes = Encoding.UTF8.GetBytes(s);
		var sha1 = SHA1.Create();
		byte[] hashBytes = sha1.ComputeHash(bytes);
		return HexStringFromBytes(hashBytes);
	}
	
	public static bool AuthenticateUser(string user, string password)
	{
		return (user=="admin" && SHA1Hash(password)=="18960546905b75c869e7de63961dc185f9a0a7c9");
	}
}