MD5 and SHA1 hash calculation tool.

Hash.cs

using System;
using System.Text;
using System.Security.Cryptography;
 
static class Hash
{
    public static string SHA1(string text)
    {
        byte[] buffer = Encoding.UTF8.GetBytes(text);
        var sha1 = new SHA1CryptoServiceProvider();
        return BitConverter.ToString(sha1.ComputeHash(buffer)).Replace("-", "");
    }
    
    private static string MD5(string text)
    {
        var md5 = new MD5CryptoServiceProvider();
        byte[] data = md5.ComputeHash(Encoding.Default.GetBytes(text));
        var sb = new StringBuilder(32);
        for (int i = 0; i < data.Length; i++)
            sb.Append(data[i].ToString("x2"));
        return sb.ToString();
    }
    
    private static void PrintUsage(bool full)
    {
        if (full)
        {
            Console.WriteLine("Computes MD5 or SHA1 hash of a string.");
            Console.WriteLine("https://gist.github.com/ishahid/4948899");
        }
        
        Console.WriteLine();
        Console.WriteLine("Usage: hash [[OPTION] <string>]");
        Console.WriteLine();
        Console.WriteLine("Options:");
        Console.WriteLine("    -md5          Calculate MD5 hash of the string.");
        Console.WriteLine("                  Default option if no option is specified.");
        Console.WriteLine("    -sha1         Calculate SHA1 hash of the string.");
    }
    
    public static int Main(string[] args)
    {
        string hash = "";
        
        switch(args.Length)
        {
            case 0:
                PrintUsage(true);
                break;
            
            case 1:
                hash = MD5(args[0]);
                Console.WriteLine(hash.ToLower());
                break;
            
            case 2:
                if (args[0] == "-md5")
                {
                    hash = MD5(args[1]);
                    Console.WriteLine(hash.ToLower());
                } else {
                    if (args[0] == "-sha1")
                    {
                        hash = SHA1(args[1]);
                        Console.WriteLine(hash.ToLower());
                    } else {
                        Console.WriteLine("Invalid switch.");
                        PrintUsage(false);
                    }
                }
                break;
            
            default:
                Console.WriteLine("Invalid switch.");
                PrintUsage(false);
            	break;
        }
    	
        return 0;
    }
}