每日一得--对称加密算法之（DES）

最新推荐文章于 2024-10-18 15:14:13 发布

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本文介绍了对称加密算法DES的两种实现方式，包括使用Java默认库（JDK）和BouncyCastle库（bcprov-jdk15-133.jar）。通过示例代码展示了DES的加密和解密过程，强调了DES的安全性问题。

一，实现对称加密算法的方式：jdk实现方式和bcprov-jdk15-133.jar（简称bc）实现方式

import java.security.Key;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

//DES 安全性不高
public class DESMain {
private static String str= "husq DES test";
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
jdkDES();
bcDES();
}

//jdk DES
public static void jdkDES(){
try{
//生成key
KeyGenerator keyGenerator = KeyGenerator.getInstance("DES");
keyGenerator.init(56);
SecretKey secretKey = keyGenerator.generateKey();
byte[] byteKey = secretKey.getEncoded();

//key转换
DESKeySpec desKeySpec = new DESKeySpec(byteKey);
SecretKeyFactory factory = SecretKeyFactory.getInstance("DES");
Key convertSecretKey = factory.generateSecret(desKeySpec);

//加密
Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, convertSecretKey);
byte[] result = cipher.doFinal(str.getBytes());
System.out.println("jdk des encrypt="+Hex.encodeHexString(result));

//解密
cipher.init(Cipher.DECRYPT_MODE, convertSecretKey);
byte[] dsign = cipher.doFinal(result);

System.out.println("jdk des decrypt="+new String(dsign));

System.out.println("==========================================");
}catch(Exception e){
e.printStackTrace();
}

}

//bcprov-jdk15-133.jar DES
public static void bcDES(){
try{
Security.addProvider(new BouncyCastleProvider());

//生成key
KeyGenerator keyGenerator = KeyGenerator.getInstance("DES","BC");
keyGenerator.getProvider();
keyGenerator.init(56);
SecretKey secretKey = keyGenerator.generateKey();
byte[] byteKey = secretKey.getEncoded();

//key转换
DESKeySpec desKeySpec = new DESKeySpec(byteKey);
SecretKeyFactory factory = SecretKeyFactory.getInstance("DES");
Key convertSecretKey = factory.generateSecret(desKeySpec);

//加密
Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, convertSecretKey);
byte[] result = cipher.doFinal(str.getBytes());
System.out.println("bc des encrypt="+Hex.encodeHexString(result));

//解密
cipher.init(Cipher.DECRYPT_MODE, convertSecretKey);
byte[] dsign = cipher.doFinal(result);

System.out.println("bc des decrypt="+new String(dsign));
}catch(Exception e){
e.printStackTrace();
}

}

}