Cryptography加密和解密

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Security.Cryptography;
using System.Text;
using System.IO;

namespace WeiXin.Core
{
    public class Cryptography
    {
        #region SHA1加密
        public static string SHA1_EncryptToFormat(string str)
        {
            SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
            StringBuilder encryptText = new StringBuilder();
            byte[] strRes = Encoding.Default.GetBytes(str);
            strRes = sha1.ComputeHash(strRes);
            foreach (byte iByte in strRes)
            {
                encryptText.AppendFormat("{0:x2}", iByte);
            }
            sha1.Dispose();
            return encryptText.ToString();
        }

        public static string SHA1_EncryptToBase64String(string str)
        {
            SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
            byte[] strRes = Encoding.UTF8.GetBytes(str);
            strRes = sha1.ComputeHash(strRes);
            sha1.Dispose();
            return Convert.ToBase64String(strRes);
        }
        public static byte[] SHA1_Encrypt(byte[] str)
        {
            SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
            byte[] strHash = sha1.ComputeHash(str);
            sha1.Dispose();
            return strHash;
        }
        #endregion


        #region 对称加密

        /// <summary>
        /// 对称算法，机密字符串
        /// </summary>
        /// <param name="Value">要加密的字符串</param>
        /// <returns>covert成ToBase64String类型的加密字符串</returns>
        public static string DataEncrypt(string Value)
        {
            try
            {
                byte[] buffer1 = Convert.FromBase64String("iw/k5uRzMdk=");
                byte[] buffer2 = Convert.FromBase64String("c/DP9HnKryk=");
                DESCryptoServiceProvider provider1 = new DESCryptoServiceProvider();//实例化des对称加密标准
                provider1.Key = buffer1;//机密密钥
                provider1.IV = buffer2; //初始化向量         
                ICryptoTransform transform1 = provider1.CreateEncryptor(provider1.Key, provider1.IV);//定义基本的加密转换运算
                byte[] buffer3 = Encoding.UTF8.GetBytes(Value);//将要加密的字符串编码为一个字节序列
                MemoryStream stream1 = new MemoryStream();//内存流
                CryptoStream stream2 = new CryptoStream(stream1, transform1, CryptoStreamMode.Write);//加密流
                stream2.Write(buffer3, 0, buffer3.Length);
                stream2.FlushFinalBlock();//用缓冲区的当前状态更新基础数据源或储存库，随后清除缓冲区。
                stream2.Close();//关闭当前流并释放与之关联的所有资源（如套接字和文件句柄）
                return Convert.ToBase64String(stream1.ToArray());
            }
            catch
            {
                return "error";
            }
        }

        /// <summary>
        /// 对称算法，解密字符串
        /// </summary>
        /// <param name="Value">需要解密的字符串</param>
        /// <returns>将解密后的流写入字节数组，然后将字节数组解码为一个字符串</returns>
        public static string DataDecrypt(string Value)
        {
            try
            {
                byte[] buffer1 = Convert.FromBase64String("iw/k5uRzMdk=");
                byte[] buffer2 = Convert.FromBase64String("c/DP9HnKryk=");
                DESCryptoServiceProvider provider1 = new DESCryptoServiceProvider();
                provider1.Key = buffer1;
                provider1.IV = buffer2;
                ICryptoTransform transform1 = provider1.CreateDecryptor(provider1.Key, provider1.IV);//定义基本解密转换运算
                byte[] buffer3 = Convert.FromBase64String(Value);
                MemoryStream stream1 = new MemoryStream();
                CryptoStream stream2 = new CryptoStream(stream1, transform1, CryptoStreamMode.Write);//CryptoStreamMode.Write对加密流的写访问
                stream2.Write(buffer3, 0, buffer3.Length);//按照transform1解密算法向流中写入需要解密的字符串
                stream2.FlushFinalBlock();
                stream2.Close();
                return Encoding.UTF8.GetString(stream1.ToArray());//将流写入字节数组，然后将字节数组解码为一个字符串
            }
            catch
            {
                return "error";
            }
        }
        #endregion

    }
}