密码加密两种办法

一：Hash +Salt 撒盐法

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

namespace PasswordHash
{
    /// <summary>
    /// 咸的密码散列pbkdf2-sha1。
    /// Compatibility: .NET 3.0 and later.
    /// </summary>
    public class PasswordHash
    {
        // 下列常数可以在不破坏现有的哈希值的变化。
        public const int SALT_BYTE_SIZE = 24;
        public const int HASH_BYTE_SIZE = 24;
        public const int PBKDF2_ITERATIONS = 1000;

        public const int ITERATION_INDEX = 0;
        public const int SALT_INDEX = 1;
        public const int PBKDF2_INDEX = 2;

        /// <summary>
        /// 创建一个咸PBKDF2散列密码。
        /// </summary>
        /// <param name="password">散列密码。</param>
        /// <returns>密码的散列。</returns>
        public static string CreateHash(string password)
        {
            // 产生一个随机的盐
            RNGCryptoServiceProvider csprng = new RNGCryptoServiceProvider();
            byte[] salt = new byte[SALT_BYTE_SIZE];
            csprng.GetBytes(salt);

            // 散列密码，并对参数进行编码
            byte[] hash = PBKDF2(password, salt, PBKDF2_ITERATIONS, HASH_BYTE_SIZE);
            return PBKDF2_ITERATIONS + ":" +
                Convert.ToBase64String(salt) + ":" +
                Convert.ToBase64String(hash);
        }

        /// <summary>
        /// 验证给定一个正确的哈希的密码。
        /// </summary>
        /// <param name="password">检查密码。</param>
        /// <param name="correctHash">正确密码的散列。</param>
        /// <returns>如果密码正确的话。否则为假。</returns>
        public static bool ValidatePassword(string password, string correctHash)
        {
            // 从散列中提取参数
            char[] delimiter = { ':' };
            string[] split = correctHash.Split(delimiter);
            int iterations = Int32.Parse(split[ITERATION_INDEX]);
            byte[] salt = Convert.FromBase64String(split[SALT_INDEX]);
            byte[] hash = Convert.FromBase64String(split[PBKDF2_INDEX]);

            byte[] testHash = PBKDF2(password, salt, iterations, hash.Length);
            return SlowEquals(hash, testHash);
        }

        /// <summary>
        /// 比较两个字节数组的长度常数时间。这种比较
        /// 方法是用这样的密码哈希值不能提取
        /// 上线系统使用定时攻击，然后攻击离线。
        /// </summary>
        /// <param name="a">第一字节数组。</param>
        /// <param name="b">第二字节数组。</param>
        /// <returns>如果两个字节数组都相等，则为真。否则为假。</returns>
        private static bool SlowEquals(byte[] a, byte[] b)
        {
            uint diff = (uint)a.Length ^ (uint)b.Length;
            for (int i = 0; i < a.Length && i < b.Length; i++)
                diff |= (uint)(a[i] ^ b[i]);
            return diff == 0;
        }

        /// <summary>
        /// 计算密码的哈希pbkdf2-sha1。
        /// </summary>
        /// <param name="password">散列密码。</param>
        /// <param name="salt">盐。</param>
        /// <param name="iterations">该PBKDF2迭代次数。</param>
        /// <param name="outputBytes">散列来生成的长度，以字节为单位的。</param>
        /// <returns>密码的散列。</returns>
        private static byte[] PBKDF2(string password, byte[] salt, int iterations, int outputBytes)
        {
            Rfc2898DeriveBytes pbkdf2 = new Rfc2898DeriveBytes(password, salt);
            pbkdf2.IterationCount = iterations;
            return pbkdf2.GetBytes(outputBytes);
        }
    }
}

二：对PassWord进行MD5单向加密

1）：

System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(msg, "MD5")

2）：

/// <summary>
/// MD5散列
/// </summary>
public static string MD5(string inputStr)
{
　　MD5 md5 = new MD5CryptoServiceProvider();
　　byte[] hashByte = md5.ComputeHash(Encoding.UTF8.GetBytes(inputStr));
　　StringBuilder sb = new StringBuilder();
　　foreach (byte item in hashByte)
　　　　sb.Append(item.ToString("x").PadLeft(2, '0'));
　　return sb.ToString();
}