DES加密解密

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

namespace RG3.PF.AbstractionsBasis
{
    /// <summary>
    /// DES加密 解密
    /// 1.Java密钥为8字节，或8的倍数。2.只支持加密字符串为128位以内的字符加密，如果超过128位要分段进行加密
    /// </summary>
    public static class DESUtil
    {
        #region DES加密 ECB 
        /// <summary>
        /// DES加密 ECB  密钥8位
        /// </summary>
        /// <param name="encryptString"></param>
        /// <param name="sKey"></param>
        /// <returns></returns>
        public static string EncryptEcb(string encryptString, string sKey)
        {
            try
            {
                string key;
                //密钥为8位
                if (sKey.Length <= 8)
                {
                    key = sKey.PadRight(8, '0');
                }
                else
                {
                    key = sKey.Substring(0, 8);
                }

                byte[] keyBytes = Encoding.Default.GetBytes(key);
                byte[] keyIV = keyBytes;
                byte[] encryptBytes = Encoding.Default.GetBytes(encryptString);
                var desProvider = DES.Create();
                // 使用ECB方式
                desProvider.Mode = CipherMode.ECB;
                // PKCS7padding
                desProvider.Padding = PaddingMode.PKCS7;
                MemoryStream memStream = new MemoryStream();
                //CreateEncryptor(keyBytes, keyIV)类似于OpenSSL中的密钥置换
                CryptoStream crypStream = new CryptoStream(memStream, desProvider.CreateEncryptor(keyBytes, keyIV), CryptoStreamMode.Write);
                crypStream.Write(encryptBytes, 0, encryptBytes.Length);
                crypStream.FlushFinalBlock();
                byte[] cipherBytes = memStream.ToArray();
                return Convert.ToBase64String(cipherBytes);
            }
            catch
            {
                return encryptString;
            }
        }
        #endregion DES加密 ECB 


        #region DEC解密 ECB
        /// <summary>
        /// DEC解密 ECB  密钥8位
        /// </summary>
        /// <param name="decryptString"></param>
        /// <param name="sKey"></param>
        /// <returns></returns>
        public static string DecryptEcb(string decryptString, string sKey)
        {
            //key为8位
            string key;
            if (sKey.Length <= 8)
            {
                key = sKey.PadRight(8, '0');
            }
            else
            {
                key = sKey.Substring(0, 8);
            }
            byte[] keyBytes = Encoding.Default.GetBytes(key);
            byte[] keyIV = keyBytes;// Encoding.Default.GetBytes(iv);// keyBytes;
            byte[] inputByteArray = Convert.FromBase64String(decryptString);

            var desProvider = DES.Create();
            desProvider.Mode = CipherMode.ECB;
            MemoryStream memStream = new MemoryStream();
            CryptoStream crypStream = new CryptoStream(memStream, desProvider.CreateDecryptor(keyBytes, keyIV), CryptoStreamMode.Write);
            crypStream.Write(inputByteArray, 0, inputByteArray.Length);
            crypStream.FlushFinalBlock();

            return Encoding.Default.GetString(memStream.ToArray());
        }
        #endregion DEC解密 ECB
    }
}