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C#对称加密(3des)和非对称加密(rsa)算法

时间:2015-11-11 17:55:37      阅读:321      评论:0      收藏:0      [点我收藏+]

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3DES加密/解密算法的C#实现:(实现的方式很多,仅供参考)

public static bool DecryptFromBase64(string base64String, string key,out string DecryptString)
        {
            DecryptString = "";
            try
            {
                // encode to bytes
                byte[] KEY = HexStringToByteArray(key);
                byte[] CRYPTSTRING = Convert.FromBase64String(base64String);

                //set iv and key
                byte[] tmpiv = { 49, 50, 51, 52, 53, 54, 55, 56 };
                byte[] tmpkey = { 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7 };


                for (int ii = 0; ii < 24; ii++)
                {
                    tmpkey[ii] = KEY[ii];
                }

                TripleDESCryptoServiceProvider dsp = new TripleDESCryptoServiceProvider();
                dsp.Mode = System.Security.Cryptography.CipherMode.CBC;
                dsp.Padding = System.Security.Cryptography.PaddingMode.PKCS7;

                ICryptoTransform tridesencrypt = dsp.CreateDecryptor(tmpkey, tmpiv);

                using (var ms = new MemoryStream(CRYPTSTRING))
                {
                    using (var cs = new CryptoStream(ms, tridesencrypt, CryptoStreamMode.Read))
                    {
                        var sr = new StreamReader(cs, Encoding.UTF8);
                        // 2015/11/11 修改 读取全部内容,而不是只读第一行,此问题乃是算法的bug
                        DecryptString = sr.ReadToEnd();// sr.ReadLine();
                    }
                }

                dsp.Clear();
                return true;
            }
            catch (Exception e)
            {
                return false;
            }
        }

        public static bool Crypt3DESToBase64(string CryptString, string Key, out string DecryptString)
        {
            DecryptString = "";
            try
            {
                // encode to bytes
                byte[] KEY = HexStringToByteArray(Key);
                byte[] CRYPTSTRING = System.Text.Encoding.UTF8.GetBytes(CryptString);

                //set iv and key
                byte[] tmpiv = { 49, 50, 51, 52, 53, 54, 55, 56 };
                byte[] tmpkey = { 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7 };


                for (int ii = 0; ii < 24; ii++)
                {
                    tmpkey[ii] = KEY[ii];
                }

                TripleDESCryptoServiceProvider dsp = new TripleDESCryptoServiceProvider();
                dsp.Mode = System.Security.Cryptography.CipherMode.CBC;
                dsp.Padding = System.Security.Cryptography.PaddingMode.PKCS7;

                ICryptoTransform tridesencrypt = dsp.CreateEncryptor(tmpkey, tmpiv);

                byte[] results = tridesencrypt.TransformFinalBlock(CRYPTSTRING, 0, CRYPTSTRING.Length);

                DecryptString = Convert.ToBase64String(results);

                dsp.Clear();

                return true;
            }
            catch (Exception e)
            {
                return false;
            }
        }

        public static byte[] HexStringToByteArray(string s)
        {
            Byte[] buf = new byte[s.Length / 2];
            for (int i = 0; i < buf.Length; i++)
            {
                buf[i] = (byte)(chr2hex(s.Substring(i * 2, 1)) * 0x10 + chr2hex(s.Substring(i * 2 + 1, 1)));
            }
            return buf;
        }

        private static byte chr2hex(string chr)
        {
            switch (chr)
            {
                case "0":
                    return 0x00;
                case "1":
                    return 0x01;
                case "2":
                    return 0x02;
                case "3":
                    return 0x03;
                case "4":
                    return 0x04;
                case "5":
                    return 0x05;
                case "6":
                    return 0x06;
                case "7":
                    return 0x07;
                case "8":
                    return 0x08;
                case "9":
                    return 0x09;
                case "A":
                    return 0x0a;
                case "B":
                    return 0x0b;
                case "C":
                    return 0x0c;
                case "D":
                    return 0x0d;
                case "E":
                    return 0x0e;
                case "F":
                    return 0x0f;
            }
            return 0x00;
        }

  在以上算法中,key为一个48位的字符串,别的就没特别要注意的了。

RSA加密算法(根据MSDN文档实现):

        /// <summary>
        /// 使用rsa非对称加密算法加密文本内容
        /// </summary>
        /// <param name="contentBytes">待加密内容byte数组</param>
        /// <param name="publicKey">公开密钥</param>
        /// <param name="DoOAEPPadding">建议为false</param>
        /// <returns>加密后的byte[]</returns>
        public static byte[] RSAEncryptContent(byte[]contentBytes,RSAParameters publicKey,bool DoOAEPPadding)
        {
            try
            {
                byte[] encryptedData;
                using (RSACryptoServiceProvider provider = new RSACryptoServiceProvider())
                {
                    provider.ImportParameters(publicKey);

                    encryptedData = provider.Encrypt(contentBytes, DoOAEPPadding);
                }
                return encryptedData;
            }
            catch (Exception e)
            {
                return null;
            }
        }

        /// <summary>
        /// 使用rsa非对称加密算法进行解密
        /// </summary>
        /// <param name="cryptContentBytes">加密后的字节数组</param>
        /// <param name="privateKey">私有密钥</param>
        /// <param name="DoOAEPPadding">建议为false</param>
        /// <returns>解密后的内容数组</returns>
        public static byte[] RSADescryptContent(byte[]cryptContentBytes,RSAParameters privateKey,bool DoOAEPPadding)
        {
            try
            {
                byte[] decryptData;
                using (RSACryptoServiceProvider provider = new RSACryptoServiceProvider())
                {
                    provider.ImportParameters(privateKey);

                    decryptData = provider.Decrypt(cryptContentBytes, DoOAEPPadding);
                }
                return decryptData;
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                return null;
            }
        }

  使用RSA加密/解密算法的方法:

       
//content为要进行加密的字符串
byte[] contentBytes = byteConverter.GetBytes(content); byte[] encryptBytes; byte[] decryptBytes; //待加密的字节数不能超过密钥的长度值除以 8 再减去 11(即:RSACryptoServiceProvider.KeySize / 8 - 11) int maxBlockSize; using(RSACryptoServiceProvider provider=new RSACryptoServiceProvider()) { maxBlockSize = provider.KeySize / 8 - 11; RSAParameters publicKey = provider.ExportParameters(false); // 小于最大块值,直接加密 if (contentBytes.Length <= maxBlockSize) { encryptBytes = EncryptContent(contentBytes, publicKey, false); } else { // 分块儿加密 using(MemoryStream plaintStream=new MemoryStream(contentBytes)) using(MemoryStream cryptStream=new MemoryStream()) { byte[] buffer = new byte[maxBlockSize]; int blockSize = plaintStream.Read(buffer, 0, maxBlockSize); while(blockSize>0) { byte[] encryptBlock = new byte[blockSize]; Array.Copy(buffer, encryptBlock, blockSize); byte[]encryptedBlock=EncryptContent(encryptBlock,publicKey,false); cryptStream.Write(encryptedBlock, 0, encryptedBlock.Length); blockSize = plaintStream.Read(buffer, 0, maxBlockSize); } encryptBytes = cryptStream.ToArray(); } } //加密后的字符串 string encryptString = byteConverter.GetString(encryptBytes); Console.WriteLine("加密结束"); Console.ReadLine(); Console.ReadLine();
// 以下为解密过程,解密过程也会有长度限制,可参考加密的方式进行解密 //string encryptString = byteConverter.GetString(encryptBytes); //RSAParameters privateKey = provider.ExportParameters(true); //decryptBytes = DecryptContent(encryptBytes, privateKey, false); //string decryptString = byteConverter.GetString(decryptBytes); //Console.WriteLine(decryptString); }

  

C#对称加密(3des)和非对称加密(rsa)算法

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原文地址:http://www.cnblogs.com/Pure-Land/p/4956650.html

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