详解ASP.NET中加密和解密的方法
散列运算
mscorlib.dll下的System.Security.Cryptography下:
- 抽象类HashAlgorithm
- 抽象类MD5
- MD5CryptoServiceProvider
- SHA1
- SHA1CryptoServiceProvider密封类:调用Windows Crypto API
- SHA1Managed普通类:用托管代码写的
- SHA256
- SHA256CryptoServiceProvider
- SHA256Managed
- SHA384
- SHA512
- 抽象类MD5
对字节数组或流散列运算
class Program { static void Main(string[] args) { string str = "Hello World"; HashAlgorithm hashAlgorithm = HashAlgorithm.Create(HashAlgorithmType.SHA1); byte[] data = Encoding.Default.GetBytes(str); byte[] digest = hashAlgorithm.ComputeHash(data); foreach (byte b in digest) { Console.Write("{0:X}",b); } Console.ReadKey(); } } public class HashAlgorithmType { public const string SHA1 = "SHA1"; public const string SHA256 = "SHA256"; public const string SHA384 = "SHA384"; public const string SHA512 = "SHA512"; public const string MD5 = "MD5"; }
密匙散列运算
string key = "secret key"; byte[] data = Encoding.Default.GetBytes(key); KeyedHashAlgorithm kha = new HMACSHA1(); byte[] digest = kha.ComputeHash(data); foreach (byte b in digest) { Console.Write("{0:x}",b); }
对称加密和解密
- SymmetricAlgorithm
- DES
- DESCryptoServiceProvider
- TripleDES
- TripleDESCryptoServiceProvider
- Rijndael
- RijindaelManaged
- RC2
- RC2CryptoServiceProvider
- DES
IV:Initialization vector初始化向量:
- 为了解决加密字符串加密后仍然有重复部分,引入IV,加密字符串即使有重复,也会被打乱。
- IV值可以随意指定,但长度固定,通常为64位byte类型
- 密匙长度也是固定的,通常为128位或196位byte类型
使用Encoding类将字符串转换为byte[]:
- 如果使用UTF8,会变长编码
加密解密方法:
- 加密方法:CreateEncryptor(),返回ICryptoTransform接口类型
- 解密方法:CreateDecryptor(),返回ICrtyptoTransform接口类型
明文流和加密流的转换:
public CryptoStream(Stream stream, ICryptoTransform transform, CryptoStreamMode mode) class Program { static void Main(string[] args) { #region 对称加密和解密 string key = "secret key"; string str = "Hello World"; //加密 string encryptedText = SymmetricCryptoHelper.Encrypt(str, key); Console.WriteLine(encryptedText); //解密 string clearText = SymmetricCryptoHelper.Decrypt(encryptedText, key); Console.WriteLine(clearText); Console.ReadKey(); #endregion } } //对称加密帮助类 public class SymmetricCryptoHelper { private ICryptoTransform encryptor; //加密器对象 private ICryptoTransform decryptor; //解密器对象 private const int BufferSize = 1024; public SymmetricCryptoHelper(string algorithmName, byte[] key) { SymmetricAlgorithm provider = SymmetricAlgorithm.Create(algorithmName); provider.Key = key; provider.IV = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; encryptor = provider.CreateEncryptor(); decryptor = provider.CreateDecryptor(); } public SymmetricCryptoHelper(byte[] key) : this("TripleDES", key){} //加密算法 public string Encrypt(string clearText) { //创建明文流 byte[] clearBuffer = Encoding.UTF8.GetBytes(clearText); //byte[] clearBuffer = Encoding.Default.GetBytes(clearText); MemoryStream clearStream = new MemoryStream(clearBuffer); //创建空的密文流 MemoryStream encryptedStream = new MemoryStream(); //明文流和密文流转换流,准备写到密文流中 CryptoStream cryptoStream = new CryptoStream(encryptedStream, encryptor, CryptoStreamMode.Write); int bytesRead = 0; byte[] buffer = new byte[BufferSize]; do { //读取明文流到buffer中 bytesRead = clearStream.Read(buffer, 0, BufferSize); //通过CryptoStream将buffer中的明文流字节数组写到明文流中 cryptoStream.Write(buffer, 0, bytesRead); } while (bytesRead > 0); cryptoStream.FlushFinalBlock(); //获取加密后的字节数组 buffer = encryptedStream.ToArray(); //将加密后的字节数组转换成字符串 string encryptedText = Convert.ToBase64String(buffer); return encryptedText; } //解密算法 public string Decrypt(string encryptedText) { //把加密字符串转换为加密字节数组 byte[] encryptedBuffer = Convert.FromBase64String(encryptedText); //创建密文流 Stream encryptedStream = new MemoryStream(encryptedBuffer); //创建空的明文流 MemoryStream clearStream = new MemoryStream(); //创建明文流和密文流的转化流,读取密文流 CryptoStream cryptoStream = new CryptoStream(encryptedStream, decryptor, CryptoStreamMode.Read); int bytesRead = 0; byte[] buffer = new byte[BufferSize]; do { //通过CryptoStream读取密文流到Buffer bytesRead = cryptoStream.Read(buffer, 0, BufferSize); //把Buffer中的密文流写到明文流中 clearStream.Write(buffer, 0, bytesRead); } while (bytesRead > 0); //将明文流转换成字节数组 buffer = clearStream.GetBuffer(); string clearText = Encoding.UTF8.GetString(buffer, 0, (int)clearStream.Length); //string clearText = Encoding.Default.GetString(buffer, 0, (int)clearStream.Length); return clearText; } //密匙加密 public static string Encrypt(string clearText, string key) { byte[] keyData = new byte[16]; //TripleDES密匙固定长度为16个字节 //把密匙字符串转换成字节数组 byte[] sourceData = Encoding.Default.GetBytes(key); int copyBytes = 16; if (sourceData.Length < 16) { copyBytes = sourceData.Length; } //把密匙数组复制到keyData字节数组中 Array.Copy(sourceData,keyData,copyBytes); SymmetricCryptoHelper helper = new SymmetricCryptoHelper(keyData); return helper.Encrypt(clearText); } //密匙解密 public static string Decrypt(string encryptedText, string key) { byte[] keyData = new byte[16]; byte[] sourceData = Encoding.Default.GetBytes(key); int copyBytes = 16; if (sourceData.Length < 16) { copyBytes = sourceData.Length; } Array.Copy(sourceData,keyData,copyBytes); SymmetricCryptoHelper helper = new SymmetricCryptoHelper(keyData); return helper.Decrypt(encryptedText); } }
非对称加密
- AsymmetricAlgorithm
- RSA
- RSACryptoServiceProvider
- DSA
- DSACryptoServiceProvider:只能进行认证模式,即数字签名
- RSA
对称加密中的密匙:
密匙为由开发者设定的字符串
非对称加密中的密匙:
- 通常是自动生成,不同的算法有不同的密匙格式
- 在创建RSACryptoServiceProvider实例时,会自动创建一个公/私密匙对。在实例上调用ToXmlString()方法获得。
RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); string publicPrivate = provider.ToXmlString(true);//获得公/私匙对 //string publicOnly = provider.ToXmlString(false); //只获得公匙 Console.Write(publicPrivate); Console.ReadKey();
非对称加密帮助类
//非对称加密帮助类 public class RSACryptoHelper { //加密 public static string Encrypt(string publicKeyXml, string plainText) { RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); provider.FromXmlString(publicKeyXml); //使用公匙初始化对象 byte[] plainData = Encoding.Default.GetBytes(plainText); byte[] encryptedData = provider.Encrypt(plainData, true); return Convert.ToBase64String(encryptedData); } //解密 public static string Decrypt(string privateKeyXml, string encryptedText) { RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); provider.FromXmlString(privateKeyXml); byte[] encryptedData = Convert.FromBase64String(encryptedText); byte[] plainData = provider.Decrypt(encryptedData, true); string plainText = Encoding.Default.GetString(plainData); return plainText; } }
数字签名
RSACryptoServiceProvider或DSACryptoServiceProvider
SignData()对摘要进行签名,并返回签名后的摘要。
VerifyData()得出本地摘要,并解密传递进来的原始摘要,对比返回bool类型结果。
数字签名帮助类
public class RSACryptoHelper { public static string SignData(string plainText, string privateKeyXml) { RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); provider.FromXmlString(privateKeyXml); byte[] plainData = Encoding.Default.GetBytes(plainText); //设置获取摘要的算法 HashAlgorithm sha1 = HashAlgorithm.Create("SHA1"); //获取签名过的摘要,是使用私匙加密过的摘要 byte[] signedDigest = provider.SignData(plainData, sha1); return Convert.ToBase64String(signedDigest); } public static bool VerifyData(string plainText, string signature, string publicKeyXml) { RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); provider.FromXmlString(publicKeyXml); byte[] plainData = Encoding.Default.GetBytes(plainText); byte[] signedDigest = Convert.FromBase64String(signature); HashAlgorithm sha1 = HashAlgorithm.Create("SHA1"); bool isDataIntact = provider.VerifyData(plainData, sha1, signedDigest); return isDataIntact; } //使用SingnHash public static string SignData2(string plainText, string privateKeyXml) { RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); provider.FromXmlString(privateKeyXml); byte[] plainData = Encoding.Default.GetBytes(plainText); //设置获取摘要的算法 HashAlgorithm sha1 = HashAlgorithm.Create("SHA1"); //获得原始摘要 byte[] digestData = sha1.ComputeHash(plainData); //对元素摘要进行签名 byte[] signedDigest = provider.SignHash(digestData, "SHA1"); return Convert.ToBase64String(signedDigest); } //使用VerifyHash public static bool VerifyData2(string plainText, string signedDigest, string publicKeyXml) { RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); provider.FromXmlString(publicKeyXml); byte[] plainData = Encoding.Default.GetBytes("SHA1"); byte[] signedDigestData = Convert.FromBase64String(signedDigest); //获得本地摘要 HashAlgorithm sha1 = HashAlgorithm.Create("SHA1"); byte[] digest = sha1.ComputeHash(plainData); //解密签名 bool isDataIntact = provider.VerifyHash(digest, "SHA1", signedDigestData); return isDataIntact; } }
到此这篇关于ASP.NET加密和解密的文章就介绍到这了。希望对大家的学习有所帮助,也希望大家多多支持我们。
赞 (0)