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

namespace Common
{
    public class SecurityHelper
    {
        //开发员
        public static string Me = "VollYoung.com";

        ///   <summary>  
        ///   给一个字符串进行MD5加密  
        ///   </summary>  
        ///   <param   name="strText">待加密字符串</param>  
        ///   <returns>加密后的字符串</returns>  
        public static string Md5Encrypt(string strText)
        {
            using (MD5 md5Hash = MD5.Create())
            {
                string hash = GetMd5Hash(md5Hash, strText);

                return hash;
            }
        }

        static string GetMd5Hash(MD5 md5Hash, string input)
        {

            // Convert the input string to a byte array and compute the hash.
            byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));

            // Create a new Stringbuilder to collect the bytes
            // and create a string.
            StringBuilder sBuilder = new StringBuilder();

            // Loop through each byte of the hashed data 
            // and format each one as a hexadecimal string.
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }

            // Return the hexadecimal string.
            return sBuilder.ToString();
        }

        // Verify a hash against a string.
        static bool VerifyMd5Hash(MD5 md5Hash, string input, string hash)
        {
            // Hash the input.
            string hashOfInput = GetMd5Hash(md5Hash, input);

            // Create a StringComparer an compare the hashes.
            StringComparer comparer = StringComparer.OrdinalIgnoreCase;

            if (0 == comparer.Compare(hashOfInput, hash))
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}