一、四种加密方式
1、MD5不可逆加密
2、Des对称可逆加密
3、RSA非对称可逆加密
4、数字证书SSL
二、详解
1、MD5加密
public class MD5Encrypt { public static string Encrypt(string source, int length = 32) { if (string.IsNullOrEmpty(source)) return string.Empty; HashAlgorithm provider = CryptoConfig.CreateFromName("MD5") as HashAlgorithm; byte[] bytes = Encoding.UTF8.GetBytes(source); byte[] hashValue = provider.ComputeHash(bytes); StringBuilder sb = new StringBuilder(); switch (length) { case 16: for (int i = 4; i < 12; i++) { sb.Append(hashValue[i].ToString("x2")); } break; case 32: for (int i = 0; i < 16; i++) { sb.Append(hashValue[i].ToString("x2")); } break; default: for (int i = 0; i < hashValue.Length; i++) { sb.Append(hashValue[i].ToString("x2")); } break; } return sb.ToString(); } public static string AbstractFile(string filePath) { using (FileStream file = new FileStream(filePath, FileMode.Open)) { return AbstractFile(file); } } public static string AbstractFile(Stream stream) { MD5 md5 = new MD5CryptoServiceProvider(); byte[] retVal = md5.ComputeHash(stream); StringBuilder sb = new StringBuilder(); for (int i = 0; i < retVal.Length; i++) { sb.Append(retVal[i].ToString("x2")); } return sb.ToString(); } }调用
//字符串MD5 Console.WriteLine(MD5Encrypt.Encrypt("1")); Console.WriteLine(MD5Encrypt.Encrypt("1")); Console.WriteLine(MD5Encrypt.Encrypt("12")); Console.WriteLine(MD5Encrypt.Encrypt("1fsdfasd")); Console.WriteLine(MD5Encrypt.Encrypt("晚上发范德萨飞洒登封市大锅饭大锅饭电话")); //文件MD5 Console.WriteLine(MD5Encrypt.AbstractFile("C:\\Users\\Daschow\\Desktop\\01.txt")); Console.WriteLine(MD5Encrypt.AbstractFile("C:\\Users\\Daschow\\Desktop\\01 - 副本.txt"));得出结果
* 通过上面结果可以得出规律
MD5可以得到一串定长的随机编码
传入的字符串或者文件相同，得到的编码是相同的
只要稍微有一点不同得到的MD5都是不同的
用处：
1、账号登陆，数据库内防止看到密码明文
(1)注册密码
(2)MD5一下,保存
(3)登陆的时候,输入的密码也md5一下，比对2、疑问：
md5不能解密？
不能解密 网上的解密都是基于样本比对，只能解密简单的密码
密码最好设置复杂点，也加盐（密码+后缀 再MD5）（双MD5）
2、Des加密（可逆对称加密）
1、可逆对称加密
2、数据传输 加密速度快。
3、因为要把密钥发给别人，密钥的安全是问题
4、公开算法，即使拿到密文，也推算不了密钥，也推算不了原文
public class DesEncrypt { private static byte[] _rgbKey = ASCIIEncoding.ASCII.GetBytes(Constant.DesKey.Substring(0, 8)); private static byte[] _rgbIV = ASCIIEncoding.ASCII.GetBytes(Constant.DesKey.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 static string Encrypt(string text) { DESCryptoServiceProvider dsp = new DESCryptoServiceProvider(); using (MemoryStream memStream = new MemoryStream()) { CryptoStream crypStream = new CryptoStream(memStream, dsp.CreateEncryptor(_rgbKey, _rgbIV), CryptoStreamMode.Write); StreamWriter sWriter = new StreamWriter(crypStream); sWriter.Write(text); sWriter.Flush(); crypStream.FlushFinalBlock(); memStream.Flush(); return Convert.ToBase64String(memStream.GetBuffer(), 0, (int)memStream.Length); } } /// <summary> /// DES解密 /// </summary> /// <param name="encryptText"></param> /// <returns>解密后的结果</returns> public static string Decrypt(string encryptText) { DESCryptoServiceProvider dsp = new DESCryptoServiceProvider(); byte[] buffer = Convert.FromBase64String(encryptText); using (MemoryStream memStream = new MemoryStream()) { CryptoStream crypStream = new CryptoStream(memStream, dsp.CreateDecryptor(_rgbKey, _rgbIV), CryptoStreamMode.Write); crypStream.Write(buffer, 0, buffer.Length); crypStream.FlushFinalBlock(); return ASCIIEncoding.UTF8.GetString(memStream.ToArray()); } } }
3、Rsa加密（可逆非对称加密）
1、如图，任何人都可以随意获取公钥，并且可以在拿到私钥后解析Eleven说的话。
但是这种方式保证了消息一定是来自于Eleven。
2、加密钥作为私钥，解密钥作为公钥。别人只能解密由Eleven加密的东西
3、如果反过来，加密钥作为公钥，解密钥作为私钥。那东西只有Eleven能看
4、如果合起来准备两套，一套保证签名安全，一套保证信息安全（即只有Elevent能加密并且只有Elevent能看）
public class RsaEncrypt { /// <summary> /// 获取加密/解密对 /// 给你一个，是无法推算出另外一个的 /// /// Encrypt Decrypt /// </summary> /// <returns>Encrypt Decrypt</returns> public static KeyValuePair<string, string> GetKeyPair() { RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(); string publicKey = RSA.ToXmlString(false); string privateKey = RSA.ToXmlString(true); return new KeyValuePair<string, string>(publicKey, privateKey); } /// <summary> /// 加密：内容+加密key /// </summary> /// <param name="content"></param> /// <param name="encryptKey">加密key</param> /// <returns></returns> public static string Encrypt(string content, string encryptKey) { RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); rsa.FromXmlString(encryptKey); UnicodeEncoding ByteConverter = new UnicodeEncoding(); byte[] DataToEncrypt = ByteConverter.GetBytes(content); byte[] resultBytes = rsa.Encrypt(DataToEncrypt, false); return Convert.ToBase64String(resultBytes); } /// <summary> /// 解密 内容+解密key /// </summary> /// <param name="content"></param> /// <param name="decryptKey">解密key</param> /// <returns></returns> public static string Decrypt(string content, string decryptKey) { byte[] dataToDecrypt = Convert.FromBase64String(content); RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(); RSA.FromXmlString(decryptKey); byte[] resultBytes = RSA.Decrypt(dataToDecrypt, false); UnicodeEncoding ByteConverter = new UnicodeEncoding(); return ByteConverter.GetString(resultBytes); } /// <summary> /// 可以合并在一起的，，每次产生一组新的密钥 /// </summary> /// <param name="content"></param> /// <param name="encryptKey">加密key</param> /// <param name="decryptKey">解密key</param> /// <returns>加密后结果</returns> private static string Encrypt(string content, out string publicKey, out string privateKey) { RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider(); publicKey = rsaProvider.ToXmlString(false); privateKey = rsaProvider.ToXmlString(true); UnicodeEncoding ByteConverter = new UnicodeEncoding(); byte[] DataToEncrypt = ByteConverter.GetBytes(content); byte[] resultBytes = rsaProvider.Encrypt(DataToEncrypt, false); return Convert.ToBase64String(resultBytes); } }KeyValuePair<string, string> encryptDecrypt = RsaEncrypt.GetKeyPair(); string rsaEn1 = RsaEncrypt.Encrypt("net", encryptDecrypt.Key); //key加密 string rsaDel = RsaEncrypt.Decrypt(rsaEn1, encryptDecrypt.Value); //value解密
