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

namespace GTech.Solution.Api.Common
{
    public static class EncryptHelper
    {
        #region 创建字符串的MD5哈希值
        /// <summary>
        /// 创建字符串的MD5哈希值
        /// </summary>
        /// <param name="inputString"></param>
        /// <returns>字符串MD5哈希值的十六进制字符串</returns>
        public static string StringToMD5Hash(string inputString)
        {
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] encryptedBytes = md5.ComputeHash(Encoding.ASCII.GetBytes(inputString));
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < encryptedBytes.Length; i++)
            {
                sb.AppendFormat("{0:x2}", encryptedBytes[i]);
            }
            return sb.ToString();
        }
        #endregion

        #region  1、一般可逆加密解密
        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="data">加密数据</param>
        /// <param name="KEY_64">密钥</param>
        /// <param name="IV_64">加密向量</param>
        /// <returns>加密数据结果</returns>
        public static string Encode(string data, string KEY_64, string IV_64)
        {
            byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
            byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            int i = cryptoProvider.KeySize;
            MemoryStream ms = new MemoryStream();
            CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

            StreamWriter sw = new StreamWriter(cst);
            sw.Write(data);
            sw.Flush();
            cst.FlushFinalBlock();
            sw.Flush();
            return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);
        }
        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="data">解密数据</param>
        /// <param name="KEY_64">密钥</param>
        /// <param name="IV_64">加密向量</param>
        /// <returns>解密数据结果</returns>
        public static string Decode(string data, string KEY_64, string IV_64)
        {
            byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
            byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

            byte[] byEnc;
            try
            {
                byEnc = Convert.FromBase64String(data);
            }
            catch
            {
                return null;
            }

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream ms = new MemoryStream(byEnc);
            CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cst);
            return sr.ReadToEnd();
        }
        #endregion
        
        #region 3、DES加密解密
        /// <summary>
        /// DES 加密
        /// </summary>
        /// <param name="str">加密字符串</param>
        /// <param name="encrytKey">密钥，要求八位</param>
        /// <param name="strDESIV">向量</param>
        /// <returns></returns>
        public static string DESEncode(string str, string strDESKey, string strDESIV)
        {
            return DESEncrytion.DESEncrypt(str, strDESKey, strDESIV);
        }
        /// <summary>
        /// DES 解密
        /// </summary>
        /// <param name="str">解密字符串</param>
        /// <param name="encrytKey">密钥，要求八位</param>
        /// <param name="strDESIV">向量</param>
        /// <returns></returns>
        public static string DESDecode(string str, string strDESKey, string strDESIV)
        {
            return DESEncrytion.DESDecrypt(str, strDESKey, strDESIV);
        }

        /// <summary>
        /// DES 加密  加密向量默认
        /// </summary>
        /// <param name="str">加密字符串</param>
        /// <param name="encrytKey">密钥，要求八位</param>
        /// <returns></returns>
        public static string DESEncode(string str, string encrytKey)
        {
            return DESEncrytion.EncryptDES(str, encrytKey);
        }
        /// <summary>
        /// DES 解密  加密向量默认
        /// </summary>
        /// <param name="str">待解密字符串</param>
        /// <param name="encrytKey">解密密钥,要求为8位,和加密密钥相同</param>
        /// <returns></returns>
        public static string DESDecode(string str, string encrytKey)
        {
            return DESEncrytion.DecryptDES(str, encrytKey);
        }
        #endregion

        #region 4、文件加密解密

        /// <summary>
        /// 加密文件 
        /// </summary>
        /// <param name="inName">源文件全名称</param>
        /// <param name="outName">加密后文件保存全名称</param>
        /// <param name="desKey">加密密钥</param>
        /// <param name="desIV">加密向量</param>
        private static void EncryptData(String inName, String outName, byte[] desKey, byte[] desIV)
        {
            FileEncrytion.EncryptData(inName, outName, desKey, desIV);
        }

        /// <summary>
        /// 解密文件 
        /// </summary>
        /// <param name="inName">源文件全名称</param>
        /// <param name="outName">解密文件全名称</param>
        /// <param name="desKey">解密密钥</param>
        /// <param name="desIV">解密向量</param>
        private static void DecryptData(String inName, String outName, byte[] desKey, byte[] desIV)
        {
            FileEncrytion.DecryptData(inName, outName, desKey, desIV);
        }

        #endregion
        
        #region 6、对称加密

        /// <summary>    
        /// 加密方法    
        /// </summary>    
        /// <param name="Source">待加密的串</param>    
        /// <returns>经过加密的串</returns>    
        public static string Encrypto(string Source)
        {
            return SymmetricEncrytion.Encrypto(Source);
        }
        /// <summary>    
        /// 解密方法    
        /// </summary>    
        /// <param name="Source">待解密的串</param>    
        /// <returns>经过解密的串</returns>    
        public static string Decrypto(string Source)
        {
            return SymmetricEncrytion.Decrypto(Source);
        }
        #endregion
    }
}