C#中常用的加密算法的封装

目录

前言：一、DES加密二、MD5加密三、RSA加密

前言：

一、DES加密

DES加密是对称加密算法， 对称加密算法的优点是速度快，缺点是密钥管理不方便，要求共享密钥

public class DesEncrypt { private readonly byte[] _rgbKey; private readonly byte[] _rgbIV; /// <summary> /// Ctor /// </summary> /// <param name="rgbKey">用于对称算法的密钥</param> /// <param name="rgbIV">用于对称算法的初始化向量</param> public DesEncrypt(string rgbKey, string rgbIV) { _rgbKey = Encoding.ASCII.GetBytes(rgbKey.Substring(0, 8)); _rgbIV = Encoding.ASCII.GetBytes(rgbIV.Insert(0, "w").Substring(0, 8)); } /// <summary> /// DES加密 /// </summary> /// <param name="text">需要加密的值</param> /// <returns>加密后的结果</returns> public string Encrypt(string text) { var desCrypto = new DESCryptoServiceProvider(); using (var memoryStream = new MemoryStream()) { var crypStream = new CryptoStream( memoryStream, desCrypto.CreateEncryptor(_rgbKey, _rgbIV), CryptoStreamMode.Write); var sWriter = new StreamWriter(crypStream); sWriter.Write(text); sWriter.Flush(); crypStream.FlushFinalBlock(); memoryStream.Flush(); return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length); } } /// <summary> /// DES解密 /// </summary> /// <param name="encryptText">需要解密的值</param> /// <returns>解密后的结果</returns> public string Decrypt(string encryptText) { var desCrypto = new DESCryptoServiceProvider(); var buffer = Convert.FromBase64String(encryptText); using (var memoryStream = new MemoryStream()) { var crypStream = new CryptoStream( memoryStream, desCrypto.CreateDecryptor(_rgbKey, _rgbIV), CryptoStreamMode.Write); crypStream.Write(buffer, 0, buffer.Length); crypStream.FlushFinalBlock(); return Encoding.UTF8.GetString(memoryStream.ToArray()); } } }

二、MD5加密

MD5加密是不可逆加密 防止被篡改 防止明文存储 防止抵赖，数字签名

public class MD5Encrypt { /// <summary> /// 加密 /// </summary> /// <param name="source">需要加密的字符串</param> /// <param name="length">密文长度</param> /// <returns>密文</returns> public string Encrypt(string source, int length = 32) { if (string.IsNullOrEmpty(source)) return string.Empty; var provider = CryptoConfig.CreateFromName("MD5") as HashAlgorithm; // 这里需要区别编码的 var sourceBytes = Encoding.UTF8.GetBytes(source); var hashValue = provider.ComputeHash(sourceBytes); var cipher = new StringBuilder(); switch (length) { case 16: for (int i = 4; i < 12; i++) { cipher.Append(hashValue[i].ToString("x2")); } break; case 32: for (int i = 0; i < 16; i++) { cipher.Append(hashValue[i].ToString("x2")); } break; default: for (int i = 0; i < hashValue.Length; i++) { cipher.Append(hashValue[i].ToString("x2")); } break; } return cipher.ToString(); } }

也可以对文件进行加密，获得文件的MD5密文 根据MD5密码，可以判断文件是否被篡改，例如百度网盘的急速秒传。

/// <summary> /// 获取文件的MD5摘要 /// </summary> /// <param name="fileName"></param> /// <returns></returns> public string AbstractFile(string fileName) { using (var file = new FileStream(fileName, FileMode.Open)) { return AbstractFile(file); } } /// <summary> /// 根据stream获取文件摘要 /// </summary> /// <param name="stream"></param> /// <returns></returns> public static string AbstractFile(Stream stream) { var md5 = new MD5CryptoServiceProvider(); var computeHash = md5.ComputeHash(stream); var cipher = new StringBuilder(); for (int i = 0; i < computeHash.Length; i++) { cipher.Append(computeHash[i].ToString("x2")); } return cipher.ToString(); } }

三、RSA加密

RSA加密是可逆非对称加密 非对称加密算法的优点是密钥管理很方便，缺点是速度慢。

/// <summary> /// 可逆非对称加密 /// 非对称加密算法的优点是密钥管理很方便，缺点是速度慢。 /// </summary> public class RsaEncrypt { /// <summary> /// 获取密钥对 /// </summary> /// <returns></returns> public KeyValuePair<string, string> GetKeyPair() { var rsaCryptoService = new RSACryptoServiceProvider(); var publicKey = rsaCryptoService.ToXmlString(false); var privateKey = rsaCryptoService.ToXmlString(true); return new KeyValuePair<string, string>(publicKey, privateKey); } /// <summary> /// 加密 /// </summary> /// <param name="content">需要加密的内容</param> /// <param name="encryptKey">加密的密钥</param> /// <returns></returns> public string Encrypt(string content, string encryptKey) { var rsaCryptoService = new RSACryptoServiceProvider(); rsaCryptoService.FromXmlString(encryptKey); byte[] dataToEncrypt = Encoding.UTF8.GetBytes(content); byte[] resultBytes = rsaCryptoService.Encrypt(dataToEncrypt, false); return Convert.ToBase64String(resultBytes); } /// <summary> /// 解密 /// </summary> /// <param name="content">需要解密的内容</param> /// <param name="decryptKey">解密的密钥</param> /// <returns></returns> public string Decrypt(string content, string decryptKey) { var rsaCryptoService = new RSACryptoServiceProvider(); rsaCryptoService.FromXmlString(decryptKey); byte[] dataToDecrypt = Convert.FromBase64String(content); byte[] resultBytes = rsaCryptoService.Decrypt(dataToDecrypt, false); return Encoding.UTF8.GetString(resultBytes); } }