本文列举了 数据加密算法（Data Encryption Algorithm，DEA） 密码学中的高级加密标准（Advanced EncryptionStandard，AES）RSA公钥加密算法 的加密解密 .NET实现以及 安全哈希算法（Secure Hash Algorithm）和MD5的实现。
实现如下
using System; usingSystem.Security.Cryptography; usingSystem.IO; usingSystem.Text; usingSystem.Globalization; usingSystem.Xml.Linq; usingSystem.Collections.Generic; namespaceEncriptSample { /// <summary> /// 加密、解密 /// </summary> class Encrypter { //DES默认密钥向量 private static byte[] DES_IV = { 0x12,0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; //AES默认密钥向量 public static readonly byte[] AES_IV ={ 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF, 0x12, 0x34, 0x56, 0x78, 0x90,0xAB, 0xCD, 0xEF }; #region MD5 /// <summary> /// MD5加密为32字符长度的16进制字符串 /// </summary> /// <paramname="input"></param> /// <returns></returns> public static stringEncryptByMD5(string input) { MD5 md5Hasher = MD5.Create(); byte[] data =md5Hasher.ComputeHash(Encoding.UTF8.GetBytes(input)); StringBuilder sBuilder = newStringBuilder(); //将每个字节转为16进制 for (int i = 0; i < data.Length;i++) { sBuilder.Append(data[i].ToString("x2")); } return sBuilder.ToString(); } #endregion #region SHA1 /// <summary> /// SHA1加密 /// </summary> /// <paramname="input"></param> /// <returns></returns> public static stringEncryptBySHA1(string input) { SHA1 sha = new SHA1CryptoServiceProvider(); byte[] bytes =Encoding.Unicode.GetBytes(input); byte[] result =sha.ComputeHash(bytes); returnBitConverter.ToString(result); } #endregion #region DES /// <summary> /// 加密方法 /// </summary> /// <paramname="input"></param> /// <paramname="key"></param> /// <returns></returns> public static stringEncryptByDES(string input, string key) { byte[] inputBytes =Encoding.UTF8.GetBytes(input); //Encoding.UTF8.GetBytes(input); byte[] keyBytes =ASCIIEncoding.UTF8.GetBytes(key); byte[] encryptBytes =EncryptByDES(inputBytes, keyBytes, keyBytes); //string result =Encoding.UTF8.GetString(encryptBytes); //无法解码,其加密结果中文出现乱码：d\"?e????(??uπ?W??-??,_?\nJn7 //原因：如果明文为中文，UTF8编码两个字节标识一个中文字符，但是加密后，两个字节密文，不一定还是中文字符。 using (DES des = newDESCryptoServiceProvider()) { using (MemoryStream ms = newMemoryStream()) { using (CryptoStream cs =new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write)) { using (StreamWriterwriter = new StreamWriter(cs)) { writer.Write(inputBytes); } } } } string result =Convert.ToBase64String(encryptBytes); return result; } /// <summary> /// DES加密 /// </summary> /// <paramname="inputBytes">输入byte数组</param> /// <param name="key">密钥，只能是英文字母或数字</param> /// <param name="IV">偏移向量</param> /// <returns></returns> public static byte[]EncryptByDES(byte[] inputBytes, byte[] key, byte[] IV) { DES des = newDESCryptoServiceProvider(); //建立加密对象的密钥和偏移量 des.Key = key; des.IV = IV; string result = string.Empty; //1、如果通过CryptoStreamMode.Write方式进行加密，然后CryptoStreamMode.Read方式进行解密，解密成功。 using (MemoryStream ms = newMemoryStream()) { using (CryptoStream cs = newCryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write)) { cs.Write(inputBytes, 0,inputBytes.Length); } return ms.ToArray(); } //2、如果通过CryptoStreamMode.Write方式进行加密，然后再用CryptoStreamMode.Write方式进行解密，可以得到正确结果 //3、如果通过CryptoStreamMode.Read方式进行加密，然后再用CryptoStreamMode.Read方式进行解密，无法解密，Error：要解密的数据的长度无效。 //4、如果通过CryptoStreamMode.Read方式进行加密，然后再用CryptoStreamMode.Write方式进行解密,无法解密，Error：要解密的数据的长度无效。 //using (MemoryStream ms = newMemoryStream(inputBytes)) //{ // using (CryptoStream cs = newCryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Read)) // { // using (StreamReader reader = newStreamReader(cs)) // { // result = reader.ReadToEnd(); // returnEncoding.UTF8.GetBytes(result); // } // } //} } /// <summary> /// 解密 /// </summary> /// <paramname="input"></param> /// <paramname="key"></param> /// <returns></returns> public static stringDecryptByDES(string input, string key) { //UTF8无法解密，Error:要解密的数据的长度无效。 //byte[] inputBytes =Encoding.UTF8.GetBytes(input);//UTF8乱码，见加密算法 byte[] inputBytes =Convert.FromBase64String(input); byte[] keyBytes =ASCIIEncoding.UTF8.GetBytes(key); byte[] resultBytes = DecryptByDES(inputBytes,keyBytes, keyBytes); string result =Encoding.UTF8.GetString(resultBytes); return result; } /// <summary> /// 解密方法 /// </summary> /// <param name="inputBytes"></param> /// <paramname="key"></param> /// <paramname="iv"></param> /// <returns></returns> public static byte[]DecryptByDES(byte[] inputBytes, byte[] key, byte[] iv) { DESCryptoServiceProvider des = newDESCryptoServiceProvider(); //建立加密对象的密钥和偏移量，此值重要，不能修改 des.Key = key; des.IV = iv; //通过write方式解密 //using (MemoryStream ms = newMemoryStream()) //{ // using (CryptoStream cs = newCryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write)) // { // cs.Write(inputBytes, 0,inputBytes.Length); // } // return ms.ToArray(); //} //通过read方式解密 using (MemoryStream ms = newMemoryStream(inputBytes)) { using (CryptoStream cs = newCryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Read)) { using (StreamReader reader = newStreamReader(cs)) { string result =reader.ReadToEnd(); returnEncoding.UTF8.GetBytes(result); } } } //错误写法,注意哪个是输出流的位置，如果范围ms，与原文不一致。 //using (MemoryStream ms = newMemoryStream(inputBytes)) //{ // using (CryptoStream cs = newCryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Read)) // { // cs.Read(inputBytes, 0,inputBytes.Length); // } // return ms.ToArray(); //} } /// <summary> /// 加密字符串 /// </summary> /// <param name="input"></param> /// <paramname="sKey"></param> /// <returns></returns> public static stringEncryptString(string input, string sKey) { byte[] data =Encoding.UTF8.GetBytes(input); using (DESCryptoServiceProvider des= new DESCryptoServiceProvider()) { des.Key =ASCIIEncoding.ASCII.GetBytes(sKey); des.IV =ASCIIEncoding.ASCII.GetBytes(sKey); ICryptoTransform desencrypt = des.CreateEncryptor(); byte[] result =desencrypt.TransformFinalBlock(data, 0, data.Length); returnBitConverter.ToString(result); } } /// <summary> /// 解密字符串 /// </summary> /// <paramname="input"></param> /// <paramname="sKey"></param> /// <returns></returns> public static stringDecryptString(string input, string sKey) { string[] sInput =input.Split("-".ToCharArray()); byte[] data = new byte[sInput.Length]; for (int i = 0; i <sInput.Length; i++) { data[i] = byte.Parse(sInput[i],NumberStyles.HexNumber); } using (DESCryptoServiceProvider des= new DESCryptoServiceProvider()) { des.Key =ASCIIEncoding.ASCII.GetBytes(sKey); des.IV =ASCIIEncoding.ASCII.GetBytes(sKey); ICryptoTransform desencrypt =des.CreateDecryptor(); byte[] result =desencrypt.TransformFinalBlock(data, 0, data.Length); returnEncoding.UTF8.GetString(result); } } #endregion #region AES /// <summary> /// AES加密算法 /// </summary> /// <paramname="input">明文字符串</param> /// <param name="key">密钥</param> /// <returns>字符串</returns> public static stringEncryptByAES(string input, string key) { byte[] keyBytes =Encoding.UTF8.GetBytes(key.Substring(0, 32)); using (AesCryptoServiceProvideraesAlg = new AesCryptoServiceProvider()) { aesAlg.Key = keyBytes; aesAlg.IV = AES_IV; ICryptoTransform encryptor =aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV); using (MemoryStream msEncrypt =new MemoryStream()) { using (CryptoStreamcsEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) { using (StreamWriterswEncrypt = new StreamWriter(csEncrypt)) { swEncrypt.Write(input); } byte[] bytes =msEncrypt.ToArray(); //returnConvert.ToBase64String(bytes);//此方法不可用 returnBitConverter.ToString(bytes); } } } } /// <summary> /// AES解密 /// </summary> /// <paramname="input">密文字节数组</param> /// <param name="key">密钥</param> /// <returns>返回解密后的字符串</returns> public static stringDecryptByAES(string input, string key) { //byte[] inputBytes =Convert.FromBase64String(input); //Encoding.UTF8.GetBytes(input); string[] sInput =input.Split("-".ToCharArray()); byte[] inputBytes = newbyte[sInput.Length]; for (int i = 0; i <sInput.Length; i++) { inputBytes[i] =byte.Parse(sInput[i], NumberStyles.HexNumber); } byte[] keyBytes =Encoding.UTF8.GetBytes(key.Substring(0, 32)); using (AesCryptoServiceProvideraesAlg = new AesCryptoServiceProvider()) { aesAlg.Key = keyBytes; aesAlg.IV = AES_IV; ICryptoTransform decryptor =aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV); using (MemoryStream msEncrypt =new MemoryStream(inputBytes)) { using (CryptoStreamcsEncrypt = new CryptoStream(msEncrypt, decryptor, CryptoStreamMode.Read)) { using (StreamReadersrEncrypt = new StreamReader(csEncrypt)) { returnsrEncrypt.ReadToEnd(); } } } } } /// <summary> /// AES加密 /// </summary> /// <param name="inputdata">输入的数据</param> /// <param name="iv">向量128位</param> /// <param name="strKey">加密密钥</param> /// <returns></returns> public static byte[]EncryptByAES(byte[] inputdata, byte[] key, byte[] iv) { ////分组加密算法 //Aes aes = newAesCryptoServiceProvider(); ////设置密钥及密钥向量 //aes.Key = key; //aes.IV = iv; //using (MemoryStream ms = newMemoryStream()) //{ // using (CryptoStream cs = newCryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write)) // { // using (StreamWriter writer = newStreamWriter(cs)) // { // writer.Write(inputdata); // } // return ms.ToArray(); // } //} using (AesCryptoServiceProvideraesAlg = new AesCryptoServiceProvider()) { aesAlg.Key = key; aesAlg.IV = iv; ICryptoTransform encryptor =aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV); using (MemoryStream msEncrypt =new MemoryStream()) { using (CryptoStreamcsEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)) { using (StreamWriterswEncrypt = new StreamWriter(csEncrypt)) { swEncrypt.Write(inputdata); } byte[] encrypted =msEncrypt.ToArray(); return encrypted; } } } } /// <summary> /// AES解密 /// </summary> /// <param name="inputdata">输入的数据</param> /// <param name="key">key</param> /// <param name="iv">向量128</param> /// <returns></returns> public static byte[]DecryptByAES(byte[] inputBytes, byte[] key, byte[] iv) { Aes aes = newAesCryptoServiceProvider(); aes.Key = key; aes.IV = iv; byte[] decryptBytes; using (MemoryStream ms = newMemoryStream(inputBytes)) { using (CryptoStream cs = newCryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Read)) { using (StreamReader reader= new StreamReader(cs)) { string result =reader.ReadToEnd(); decryptBytes =Encoding.UTF8.GetBytes(result); } } } return decryptBytes; } #endregion #region DSA #endregion #region RSA /// <summary> /// RSA加密 /// </summary> /// <paramname="plaintext">明文</param> /// <paramname="publicKey">公钥</param> /// <returns>密文字符串</returns> public static stringEncryptByRSA(string plaintext, string publicKey) { UnicodeEncoding ByteConverter = newUnicodeEncoding(); byte[] dataToEncrypt =ByteConverter.GetBytes(plaintext); using (RSACryptoServiceProvider RSA= new RSACryptoServiceProvider()) { RSA.FromXmlString(publicKey); byte[] encryptedData =RSA.Encrypt(dataToEncrypt, false); return Convert.ToBase64String(encryptedData); } } /// <summary> /// RSA解密 /// </summary> /// <paramname="ciphertext">密文</param> /// <paramname="privateKey">私钥</param> /// <returns>明文字符串</returns> public static stringDecryptByRSA(string ciphertext, string privateKey) { UnicodeEncoding byteConverter = newUnicodeEncoding(); using (RSACryptoServiceProvider RSA= new RSACryptoServiceProvider()) { RSA.FromXmlString(privateKey); byte[] encryptedData =Convert.FromBase64String(ciphertext); byte[] decryptedData =RSA.Decrypt(encryptedData, false); returnbyteConverter.GetString(decryptedData); } } //public static string signByRSA(stringplaintext, string privateKey) //{ // UnicodeEncoding ByteConverter = new UnicodeEncoding(); // byte[] dataToEncrypt = ByteConverter.GetBytes(plaintext); // using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider()) // { // RSA.FromXmlString(privateKey); // byte[] encryptedData =RSA.SignData(dataToEncrypt,); // return Convert.ToBase64String(encryptedData); // } //} /// <summary> /// 数字签名 /// </summary> /// <paramname="plaintext">原文</param> /// <paramname="privateKey">私钥</param> /// <returns>签名</returns> public static stringHashAndSignString(string plaintext, string privateKey) { UnicodeEncoding ByteConverter = newUnicodeEncoding(); byte[] dataToEncrypt =ByteConverter.GetBytes(plaintext); using (RSACryptoServiceProviderRSAalg = new RSACryptoServiceProvider()) { RSAalg.FromXmlString(privateKey); //使用SHA1进行摘要算法，生成签名 byte[] encryptedData =RSAalg.SignData(dataToEncrypt, new SHA1CryptoServiceProvider()); returnConvert.ToBase64String(encryptedData); } } /// <summary> /// 验证签名 /// </summary> /// <paramname="plaintext">原文</param> /// <paramname="SignedData">签名</param> /// <paramname="publicKey">公钥</param> /// <returns></returns> public static bool VerifySigned(stringplaintext, string SignedData, string publicKey) { using (RSACryptoServiceProviderRSAalg = new RSACryptoServiceProvider()) { RSAalg.FromXmlString(publicKey); UnicodeEncoding ByteConverter =new UnicodeEncoding(); byte[] dataToVerifyBytes =ByteConverter.GetBytes(plaintext); byte[] signedDataBytes =Convert.FromBase64String(SignedData); returnRSAalg.VerifyData(dataToVerifyBytes, new SHA1CryptoServiceProvider(),signedDataBytes); } } /// <summary> /// 获取Key /// 键为公钥，值为私钥 /// </summary> /// <returns></returns> public static KeyValuePair<string,string> CreateRSAKey() { RSACryptoServiceProvider RSA = newRSACryptoServiceProvider(); string privateKey =RSA.ToXmlString(true); string publicKey =RSA.ToXmlString(false); return new KeyValuePair<string,string>(publicKey, privateKey); } #endregion #region other /// <summary> /// /// </summary> /// <param name="input"></param> /// <returns></returns> public static byte[] GetBytes(stringinput) { string[] sInput =input.Split("-".ToCharArray()); byte[] inputBytes = newbyte[sInput.Length]; for (int i = 0; i <sInput.Length; i++) { inputBytes[i] =byte.Parse(sInput[i], NumberStyles.HexNumber); } return inputBytes; } #endregion } }