using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;
using System.IO;
namespace Epost.Common
{
    #region 加解密
    /// <summary>
    /// 加解密
    /// </summary>
    public class EncryptHelper
    {
        #region 全局变量
        /// <summary>
        /// 加密密钥必须为8位字符串
        /// </summary>
        protected static string Key = "12345678";
        #endregion

        #region 方法

        #region MD5

        #region MD5加密 16位
        /// <summary>
        /// MD5加密 16位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string EncryptMD5By16(string str)
        {
            return str;
        }
        #endregion

        #region MD5加密 32位
        /// <summary>
        /// MD5加密 32位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string EncryptMD5By32(string str)
        {
            //MD5加密
            var md5 = MD5.Create();
            var bs = md5.ComputeHash(Encoding.UTF8.GetBytes(str));
            var sb = new StringBuilder();
            foreach (byte b in bs)
            {
                sb.Append(b.ToString("x2"));
            }
            //所有字符转为大写
            return sb.ToString();
        }
        #endregion

        #region MD5解密 16位
        /// <summary>
        /// MD5解密 16位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string DecryptMD5By16(string str)
        {
            return str;
        }
        #endregion

        #region MD5解密 32位
        /// <summary>
        /// MD5解密 32位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string DecryptMD5By32(string str)
        {
            return str;
        }
        #endregion

        #endregion

        #region DES

        #region DES加密 16位
        /// <summary>
        /// DES加密 16位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string EncryptDESBy16(string str)
        {
            return str;
        }
        #endregion

        #region DES加密 32位
        /// <summary>
        /// DES加密 32位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string EncryptDESBy32(string str)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.Default.GetBytes(str);
            des.Key = ASCIIEncoding.ASCII.GetBytes(Key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(Key);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            ret.ToString();
            return ret.ToString();
        }

        /// <summary>
        /// DES加密 32位
        /// </summary>
        /// <param name="str"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string EncryptDESBy32(string str, string key)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray;
            inputByteArray = Encoding.Default.GetBytes(str);
            des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(key);
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            return ret.ToString();

            //DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            //byte[] inputByteArray = Encoding.Default.GetBytes(str);
            //des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            //des.IV = ASCIIEncoding.ASCII.GetBytes(key);
            //MemoryStream ms = new MemoryStream();
            //CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            //cs.Write(inputByteArray, 0, inputByteArray.Length);
            //cs.FlushFinalBlock();
            //StringBuilder ret = new StringBuilder();
            //foreach (byte b in ms.ToArray())
            //{
            //    ret.AppendFormat("{0:X2}", b);
            //}
            //ret.ToString();
            //return ret.ToString();
        }
        #endregion

        #region DES解密 16位
        /// <summary>
        /// DES解密 16位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string DecryptDESBy16(string str)
        {
            return str;
        }
        #endregion

        #region DES解密 32位
        /// <summary>
        /// DES解密 32位
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string DecryptDESBy32(string str)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = new byte[str.Length / 2];
            for (int x = 0; x < str.Length / 2; x++)
            {
                int i = (Convert.ToInt32(str.Substring(x * 2, 2), 16));
                inputByteArray[x] = (byte)i;
            }
            des.Key = ASCIIEncoding.ASCII.GetBytes(Key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(Key);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            return System.Text.Encoding.Default.GetString(ms.ToArray());
        }

        /// <summary>
        /// DES解密 32位
        /// </summary>
        /// <param name="str"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string DecryptDESBy32(string str, string key)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            int len;
            len = str.Length / 2;
            byte[] inputByteArray = new byte[len];
            int x, i;
            for (x = 0; x < len; x++)
            {
                i = Convert.ToInt32(str.Substring(x * 2, 2), 16);
                inputByteArray[x] = (byte)i;
            }
            des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(key);
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return Encoding.Default.GetString(ms.ToArray());
        }
        #endregion

        #endregion

        #endregion

        #region 对字符串进行Base64编码

        /// <summary>
        /// 对字符串进行Base64编码
        /// </summary>
        /// <param name="source"></param>
        /// <returns>string</returns>
        public static string Base64EnCode(string source)
        {
            byte[] bytes = UTF8Encoding.UTF8.GetBytes(source);
            return Convert.ToBase64String(bytes);
        }

        #endregion

        #region 对字符串进行Base64解码

        /// <summary>
        /// 对字符串进行Base64解码
        /// </summary>
        /// <param name="source"></param>
        /// <returns>string</returns>
        public static string Base64Decode(string source)
        {
            byte[] bytes = Convert.FromBase64String(source);
            return UTF8Encoding.UTF8.GetString(bytes);
        }

        #endregion
    }
    #endregion
}