using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace CCTVRigthsCenter.Util
{
    public class EncryptHelper
    {
        /// <summary>
        /// MD5 hash加密
        /// </summary>
        /// <param name="s"></param>
        /// <returns></returns>
        public static string MD5(string s)
        {
            var md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            var result = BitConverter.ToString(md5.ComputeHash(UnicodeEncoding.UTF8.GetBytes(s.Trim())));
            return result;
        }

        public static string GetMD5HashFromFile(Stream file)
        {
            try
            {
                System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
                byte[] retVal = md5.ComputeHash(file);

                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < retVal.Length; i++)
                {
                    sb.Append(retVal[i].ToString("x2"));
                }
                return sb.ToString();
            }
            catch (Exception ex)
            {
                throw new Exception("GetMD5HashFromFile() fail,error:" + ex.Message);
            }
        }


        #region DES加密解密
        //默认密钥向量
        private static byte[] keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

        /// <summary>
        /// DES加密字符串
        /// </summary>
        /// <param name="encryptString">待加密的字符串</param>
        /// <param name="encryptKey">加密密钥,要求为8位</param>
        /// <returns>加密成功返回加密后的字符串,失败返回源串</returns>
        public static string Encode(string encryptString, string encryptKey = "cmyprint")
        {
            encryptKey = encryptKey.Substring(0, 8);
            encryptKey = encryptKey.PadRight(8, ‘ ‘);
            byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
            byte[] rgbIV = keys;
            byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
            DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
            MemoryStream mStream = new MemoryStream();
            CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
            cStream.Write(inputByteArray, 0, inputByteArray.Length);
            cStream.FlushFinalBlock();
            return Convert.ToBase64String(mStream.ToArray());

        }

        /// <summary>
        /// WebApi的basic认证里的加密
        /// </summary>
        /// <param name="data"></param>
        /// <param name="application"></param>
        /// <param name="key"></param>
        /// <param name="IV"></param>
        /// <returns></returns>
        public static string Encode(string data, string application = "IOS", string key = "swkj1111", string IV = "swkj1111")
        {
            byte[] inputByteArray = Encoding.UTF8.GetBytes(data);
            byte[] rgbKey = Encoding.UTF8.GetBytes(key);
            byte[] rgbIV = Encoding.UTF8.GetBytes(IV);

            DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
            MemoryStream mStream = new MemoryStream();
            CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
            cStream.Write(inputByteArray, 0, inputByteArray.Length);
            cStream.FlushFinalBlock();

            string desString = Convert.ToBase64String(mStream.ToArray());

            return EncodeBase64(Encoding.UTF8, application + ":" + desString);
        }

        /// <summary>
        /// DES解密字符串
        /// </summary>
        /// <param name="decryptString">待解密的字符串</param>
        /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>
        /// <returns>解密成功返回解密后的字符串,失败返源串</returns>
        public static string Decode(string decryptString, string decryptKey = "cmyprint")
        {
            try
            {
                decryptKey = decryptKey.Substring(0, 8);
                decryptKey = decryptKey.PadRight(8, ‘ ‘);
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
                byte[] rgbIV = keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();

                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return "";
            }

        }
        #endregion

        #region Base64加解密
        /// <summary>
        /// Base64加密
        /// </summary>
        /// <param name="codeName">加密采用的编码方式</param>
        /// <param name="source">待加密的明文</param>
        /// <returns></returns>
        private static string EncodeBase64(Encoding encode, string source)
        {
            string strRulst;
            byte[] bytes = encode.GetBytes(source);
            try
            {
                strRulst = Convert.ToBase64String(bytes);
            }
            catch
            {
                strRulst = source;
            }
            return strRulst;
        }

        /// <summary>
        /// Base64加密，采用utf8编码方式加密
        /// </summary>
        /// <param name="source">待加密的明文</param>
        /// <returns>加密后的字符串</returns>
        public static string EncodeBase64(string source)
        {
            return EncodeBase64(Encoding.UTF8, source);
        }

        /// <summary>
        /// Base64解密
        /// </summary>
        /// <param name="codeName">解密采用的编码方式，注意和加密时采用的方式一致</param>
        /// <param name="result">待解密的密文</param>
        /// <returns>解密后的字符串</returns>
        private static string DecodeBase64(Encoding encode, string result)
        {
            string decode = "";
            byte[] bytes = Convert.FromBase64String(result);
            try
            {
                decode = encode.GetString(bytes);
            }
            catch
            {
                decode = result;
            }
            return decode;
        }

        /// <summary>
        /// Base64解密，采用utf8编码方式解密
        /// </summary>
        /// <param name="result">待解密的密文</param>
        /// <returns>解密后的字符串</returns>
        public static string DecodeBase64(string result)
        {
            return DecodeBase64(Encoding.UTF8, result);
        }
        #endregion


        #region BEGIN 新增加密 add by show 2016-10-10 16:09:20

        /// <summary>
        /// DES加密字符串
        /// </summary>
        /// <param name="encryptString">待加密的字符串</param>
        /// <param name="application">应用名称</param>
        /// <param name="key">加密密钥,要求为8位</param>
        /// <param name="IV">加密密钥,要求为8位</param>
        /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>
        public static string EncryptApplicationAndURL(string encryptString, string application, string key, string IV)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(key);
                byte[] rgbIV = Encoding.UTF8.GetBytes(IV);
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                string desString = Convert.ToBase64String(mStream.ToArray());

                return EncryptHelper.EncodeBase64(application + ":" + desString);
            }
            catch
            {
                throw;
            }
        }

        /// <summary>
        /// 描述：Base64URLSafe解密
        /// 作者：show
        /// 时间：2016-10-10 09:07:20
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string Base64URLSafeDecode(string text)
        {
            if (String.IsNullOrEmpty(text))
                return "";

            text = text.Replace(‘-‘, ‘+‘).Replace(‘_‘, ‘/‘);

            var yu = text.Length % 4;

            if (yu > 0)
            {
                text = text.PadRight(text.Length + 4 - yu, ‘=‘);
            }

            return Encoding.UTF8.GetString(Convert.FromBase64String(text));
        }

        /// <summary>
        /// 描述：URL安全的base64编码
        /// 作者：show
        /// 时间：2016-10-10 15:50:20
        /// </summary>
        /// <param name="text">要编码的字符串</param>
        /// <returns></returns>
        public static string ToBase64URLSafe(string text)
        {
            if (String.IsNullOrEmpty(text))
                return "";

            byte[] bs = Encoding.UTF8.GetBytes(text);
            var encodedStr = Convert.ToBase64String(bs);
            encodedStr = encodedStr.Replace(‘+‘, ‘-‘).Replace(‘/‘, ‘_‘).TrimEnd(‘=‘);

            return encodedStr;
        }

        #endregion END 新增加密
    }
}

加解密封装