JAVA实现非对称加密：DH、RSA、ELGamal（相关API的应用）

本文主要是介绍JAVA实现非对称加密：DH、RSA、ELGamal（相关API的应用），希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

DH算法

import org.apache.commons.codec.binary.Hex;import javax.crypto.Cipher;
import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;
import javax.crypto.interfaces.DHPublicKey;
import javax.crypto.spec.DHParameterSpec;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PublicKey;
import java.security.spec.X509EncodedKeySpec;/*** 非对称加密 - DH算法** @author liuming* @create 2018/4/13*/
public class DH {private static String srcMsg = "imooc security dh";public static void main(String[] args) {jdkDH(srcMsg);}public static void jdkDH(String srcMsg) {try {// 初始化发送方密钥KeyPairGenerator senderKeyPairGenerator = KeyPairGenerator.getInstance("DH");senderKeyPairGenerator.initialize(512);KeyPair senderKeyPair = senderKeyPairGenerator.generateKeyPair();// 发送发公钥，需要发送给接收方byte[] senderPublicKeyEnc = senderKeyPair.getPublic().getEncoded();// 初始化接收方密钥KeyFactory receiverKeyFactory = KeyFactory.getInstance("DH");X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(senderPublicKeyEnc);PublicKey receiverPublicKey = receiverKeyFactory.generatePublic(x509EncodedKeySpec);DHParameterSpec dhParameterSpec = ((DHPublicKey) receiverPublicKey).getParams();KeyPairGenerator receiverKeyPairGenerator = KeyPairGenerator.getInstance("DH");receiverKeyPairGenerator.initialize(dhParameterSpec);KeyPair receiverKeyPair = receiverKeyPairGenerator.generateKeyPair();byte[] receiverPublicKeyEnc = receiverKeyPair.getPublic().getEncoded();// 密钥构建KeyAgreement receiverKeyAgreement = KeyAgreement.getInstance("DH");receiverKeyAgreement.init(receiverKeyPair.getPrivate());receiverKeyAgreement.doPhase(receiverPublicKey, true);SecretKey receiverDesKey = receiverKeyAgreement.generateSecret("DES");KeyFactory senderKeyFactory = KeyFactory.getInstance("DH");x509EncodedKeySpec = new X509EncodedKeySpec(receiverPublicKeyEnc);PublicKey senderPublicKey = senderKeyFactory.generatePublic(x509EncodedKeySpec);KeyAgreement senderKeyAgreement = KeyAgreement.getInstance("DH");senderKeyAgreement.init(senderKeyPair.getPrivate());senderKeyAgreement.doPhase(senderPublicKey, true);SecretKey senderDesKey = senderKeyAgreement.generateSecret("DES");// encryptCipher cipher = Cipher.getInstance("DES");cipher.init(Cipher.ENCRYPT_MODE, senderDesKey);byte[] bytes = cipher.doFinal(srcMsg.getBytes());// outputString encodedMsg = Hex.encodeHexString(bytes);System.out.println(encodedMsg);System.out.println(org.apache.commons.codec.binary.Base64.encodeBase64String(bytes));// decryptcipher.init(Cipher.DECRYPT_MODE, receiverDesKey);bytes = cipher.doFinal(bytes);// outputSystem.out.println(new String(bytes));} catch (Exception e) {e.printStackTrace();}}}

但是jdk1.8.0_161版本及以上，执行SecretKey receiverDesKey = receiverKeyAgreement.generateSecret("DES");会报如下错误：

java.security.NoSuchAlgorithmException: Unsupported secret key algorithm: DESat com.sun.crypto.provider.DHKeyAgreement.engineGenerateSecret(DHKeyAgreement.java:387)at javax.crypto.KeyAgreement.generateSecret(KeyAgreement.java:648)at DH.jdkDH(DH.java:53)at DH.main(DH.java:26)

需要在执行时添加VM option内容为-Djdk.crypto.KeyAgreement.legacyKDF=true再执行即可。

RSA

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;import javax.crypto.Cipher;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;/*** RSA** @author liuming* @create 2018/4/13*/
public class RSA {private static String srcMsg = "imooc security rsa";public static void main(String[] args) {jdkRSA(srcMsg);}public static void jdkRSA(String srcMsg) {try {// 初始化发送方密钥KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");keyPairGenerator.initialize(512);KeyPair keyPair = keyPairGenerator.generateKeyPair();RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();System.out.println(Base64.encodeBase64String(rsaPublicKey.getEncoded()));System.out.println(Base64.encodeBase64String(rsaPrivateKey.getEncoded()));// 私钥加密PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());KeyFactory keyFactory = KeyFactory.getInstance("RSA");PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);// encryptCipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.ENCRYPT_MODE, privateKey);byte[] bytes = cipher.doFinal(srcMsg.getBytes());// outputString encodedMsg = Hex.encodeHexString(bytes);System.out.println(encodedMsg);System.out.println(org.apache.commons.codec.binary.Base64.encodeBase64String(bytes));// 公钥解密X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());keyFactory = KeyFactory.getInstance("RSA");PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);// decryptcipher.init(Cipher.DECRYPT_MODE, publicKey);bytes = cipher.doFinal(bytes);// outputSystem.out.println(new String(bytes));// 公钥加密x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());keyFactory = KeyFactory.getInstance("RSA");publicKey = keyFactory.generatePublic(x509EncodedKeySpec);cipher.init(Cipher.ENCRYPT_MODE, publicKey);bytes = cipher.doFinal(srcMsg.getBytes());// outputencodedMsg = Hex.encodeHexString(bytes);System.out.println(encodedMsg);System.out.println(org.apache.commons.codec.binary.Base64.encodeBase64String(bytes));// 私钥解密pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());keyFactory = KeyFactory.getInstance("RSA");privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);// encryptcipher = Cipher.getInstance("RSA");cipher.init(Cipher.DECRYPT_MODE, privateKey);bytes = cipher.doFinal(bytes);// outputSystem.out.println(new String(bytes));} catch (Exception e) {e.printStackTrace();}}}

ELGamal

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jce.provider.BouncyCastleProvider;import javax.crypto.Cipher;
import javax.crypto.spec.DHParameterSpec;
import java.security.AlgorithmParameterGenerator;
import java.security.AlgorithmParameters;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Security;/*** ELGamal** @author liuming* @create 2018/4/13*/
public class ELGamal {private static String srcMsg = "imooc security elgamal";public static void main(String[] args) {jdkELGamal(srcMsg);}public static void jdkELGamal(String srcMsg) {try {Security.addProvider(new BouncyCastleProvider());// 初始化密钥AlgorithmParameterGenerator algorithmParameterGenerator = AlgorithmParameterGenerator.getInstance("ELGamal");algorithmParameterGenerator.init(256);AlgorithmParameters algorithmParameters = algorithmParameterGenerator.generateParameters();DHParameterSpec dhParameterSpec = algorithmParameters.getParameterSpec(DHParameterSpec.class);KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("ELGamal");System.out.println(keyPairGenerator.getProvider().getInfo());keyPairGenerator.initialize(dhParameterSpec, new SecureRandom());KeyPair keyPair = keyPairGenerator.generateKeyPair();PublicKey publicKey = keyPair.getPublic();PrivateKey privateKey = keyPair.getPrivate();System.out.println(Base64.encodeBase64String(publicKey.getEncoded()));System.out.println(Base64.encodeBase64String(privateKey.getEncoded()));// 公钥加密// encryptCipher cipher = Cipher.getInstance("ELGamal");cipher.init(Cipher.ENCRYPT_MODE, publicKey);byte[] bytes = cipher.doFinal(srcMsg.getBytes());// outputString encodedMsg = Hex.encodeHexString(bytes);System.out.println(encodedMsg);System.out.println(Base64.encodeBase64String(bytes));// 私钥解密// decryptcipher = Cipher.getInstance("ELGamal");cipher.init(Cipher.DECRYPT_MODE, privateKey);bytes = cipher.doFinal(bytes);// outputSystem.out.println(new String(bytes));} catch (Exception e) {e.printStackTrace();}}}