Java-非对称加密算法RSA算法

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import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

import org.apache.commons.codec.binary.Base64;


/**
 * 非对称加密算法RSA算法组件
 * 非对称算法一般是用来传送对称加密算法的密钥来使用的，相对于DH算法，RSA算法只需要一方构造密钥，不需要
 * 大费周章的构造各自本地的密钥对了。DH算法只能算法非对称算法的底层实现。而RSA算法算法实现起来较为简单
 * @author 张昭
 * @time 2018/12/25 20:31
 */
public class RSASecurityUtil {
    static final String ALGORITHM_RSA = "RSA";
    static final String ALGORITHM_SIGN = "MD5withRSA";
    static final String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCMhoJ/mBHbkDRi+mVwUU7MXyJ5kZx+esx6WyfPIixcK5Z7sCDaoLve5pb1EHpsAq0oI2OlRqh+M44LfUD1GYYRHMzXwYTSeDDcyKjZc+zvsNfWf64h0Ne51BxBvc0DQjW2g6rwBBgu06mYHnsIxskXLTsY4b2npXwFtKmqQaIadQIDAQAB";
    static final String privteKey = "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";
   
    public static void main(String[] args) throws Exception {
        // 公钥加密
        String a = "admin阿斯顿发生发生";
        String target = encrypt(a, publicKey);
        // 私钥解密
        String sourc2e = decrypt(target, privteKey);

        System.out.println("t, 公钥加密后的数据： " + target);
        System.out.println("t, 私钥解密后的数据： " + sourc2e);

        /*System.out.println("--------------------------私钥加密并且签名，公钥验证签名并且解密------------------------------");
        // 私钥加密
        target = encryptionByPrivateKey(source, priKey);
        // 签名
        String sign = signByPrivateKey(target, priKey);
        // 验证签名
        verifyByPublicKey(target, sign, pubKey);
        // 公钥解密
        decryptionByPublicKey(target,pubKey);*/

    }

    /**
     * 生成密钥对
     * @throws Exception
     */
    static void generatorKeyPair() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(ALGORITHM_RSA);
        keyPairGen.initialize(1024);//可以更改1024，但是要是512的倍数，
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
        byte[] keyBs = rsaPublicKey.getEncoded();
        String publicKey = encodeBase64(keyBs);
        System.out.println("生成的公钥：\r\n" + publicKey);
        RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
        keyBs = rsaPrivateKey.getEncoded();
        String privateKey = encodeBase64(keyBs);
        System.out.println("生成的私钥：\r\n" + privateKey);
    }

    /**
     * 获取公钥
     * @return
     * @throws Exception
     */
    static PublicKey getPublicKey(String publicKey) throws Exception {
        X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(decodeBase64(publicKey));
        KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
        return keyFactory.generatePublic(publicKeySpec);
    }

    /**
     * 获取私钥
     * @return
     * @throws Exception
     */
    static PrivateKey getPrivateKey(String privateKey) throws Exception {
        PKCS8EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(decodeBase64(privateKey));
        KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
        return keyFactory.generatePrivate(privateKeySpec);
    }

    /**
     * 公钥加密
     * @param source
     * @return
     * @throws Exception
     */
    public static String encrypt(String source, String pubKey) throws Exception{
        PublicKey publicKey = getPublicKey(pubKey);
        Cipher cipher = Cipher.getInstance(publicKey.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        cipher.update(source.getBytes("UTF-8"));
        return encodeBase64(cipher.doFinal());
    }

    /**
     * 公钥解密
     * @param target
     * @throws Exception
     */
    static void decryptionByPublicKey(String target, String pubKey) throws Exception{
        PublicKey publicKey = getPublicKey(pubKey);
        Cipher cipher = Cipher.getInstance(publicKey.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        cipher.update(decodeBase64(target));
        String source = new String(cipher.doFinal(), "UTF-8");
        System.out.println("公钥解密后的数据：\r\n" + source);
    }

    /**
     * 公钥验证签名
     * @return
     * @throws Exception
     */
    static void verifyByPublicKey(String target, String sign, String pubKey) throws Exception{
        PublicKey publicKey = getPublicKey(pubKey);
        Signature signature = Signature.getInstance(ALGORITHM_SIGN);
        signature.initVerify(publicKey);
        signature.update(target.getBytes("UTF-8"));
        if (signature.verify(decodeBase64(sign))) {
            System.out.println("签名正确！");
        } else {
            System.out.println("签名错误！");
        }
    }

    /**
     * 私钥加密
     * @param source
     * @return
     * @throws Exception
     */
    static String encryptionByPrivateKey(String source, String priKey) throws Exception {
        PrivateKey privateKey = getPrivateKey(priKey);
        Cipher cipher = Cipher.getInstance(privateKey.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        cipher.update(source.getBytes("UTF-8"));
        String target = encodeBase64(cipher.doFinal());
        System.out.println("私钥加密后的数据：\r\n" + target);
        return target;
    }

    /**
     * 私钥解密
     * @param target
     * @throws Exception
     */
    public static String decrypt(String target, String priKey) throws Exception {
        PrivateKey privateKey = getPrivateKey(priKey);
        Cipher cipher = Cipher.getInstance(privateKey.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        cipher.update(decodeBase64(target));
        return new String(cipher.doFinal(), "UTF-8");
    }

    /**
     * 私钥签名
     * @param target
     * @return
     * @throws Exception
     */
    static String signByPrivateKey(String target, String priKey) throws Exception{
        PrivateKey privateKey = getPrivateKey(priKey);
        Signature signature = Signature.getInstance(ALGORITHM_SIGN);
        signature.initSign(privateKey);
        signature.update(target.getBytes("UTF-8"));
        String sign = encodeBase64(signature.sign());
        System.out.println("生成的签名：\r\n" + sign);
        return sign;
    }

    /**
     * base64编码
     * @param source
     * @return
     * @throws Exception
     */
    static String encodeBase64(byte[] source) throws Exception{
        return new String(Base64.encodeBase64(source), "UTF-8");
    }

    /**
     * Base64解码
     * @param target
     * @return
     * @throws Exception
     */
    static byte[] decodeBase64(String target) throws Exception{
        return Base64.decodeBase64(target.getBytes("UTF-8"));
    }
}