RSA加密和解密工具

import javax.crypto.Cipher;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;

import cn.com.hwqh.user.service.impl.UserServiceImpl;
import cn.com.hwqh.user.util.utility.MyConfiguration;
import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Map;

/** * @ClassName: RSAUtil * @version: 1.0 * @description: RSA加密和解密工具 **/
public class RSAUtil {
    
    private static Logger logger = LoggerFactory.getLogger(RSAUtil.class);
    /** * 数字签名，密钥算法 */
    private static final String RSA_KEY_ALGORITHM = "RSA";

    /** * 数字签名签名/验证算法 */
    private static final String SIGNATURE_ALGORITHM = "MD5withRSA";

    /** * RSA密钥长度，RSA算法的默认密钥长度是1024密钥长度必须是64的倍数，在512到65536位之间 */
    private static final int KEY_SIZE = 1024;
    /** * 私钥 */
    public static final String PRIVATE_KEY  = MyConfiguration.create().getString("private.key");



    /** * 生成密钥对 */
    private static Map<String, String> initKey() throws Exception {
    
        KeyPairGenerator keygen = KeyPairGenerator.getInstance(RSA_KEY_ALGORITHM);
        SecureRandom secrand = new SecureRandom();
        /** * 初始化随机产生器 */
        secrand.setSeed("initSeed".getBytes());
        /** * 初始化密钥生成器 */
        keygen.initialize(KEY_SIZE, secrand);
        KeyPair keys = keygen.genKeyPair();

        byte[] pub_key = keys.getPublic().getEncoded();
        String publicKeyString = Base64.encodeBase64String(pub_key);

        byte[] pri_key = keys.getPrivate().getEncoded();
        String privateKeyString = Base64.encodeBase64String(pri_key);

        Map<String, String> keyPairMap = new HashMap<>();
        keyPairMap.put("publicKeyString", publicKeyString);
        keyPairMap.put("privateKeyString", privateKeyString);

        return keyPairMap;
    }

    /** * 密钥转成字符串 * * @param key * @return */
    public static String encodeBase64String(byte[] key) {
    
        return Base64.encodeBase64String(key);
    }

    /** * 密钥转成byte[] * * @param key * @return */
    public static byte[] decodeBase64(String key) {
    
        return Base64.decodeBase64(key);
    }

    /** * 公钥加密 * * @param data 加密前的字符串 * @param publicKey 公钥 * @return 加密后的字符串 * @throws Exception */
    public static String encryptByPubKey(String data, String publicKey) throws Exception {
    
        byte[] pubKey = RSAUtil.decodeBase64(publicKey);
        byte[] enSign = encryptByPubKey(data.getBytes(), pubKey);
        return Base64.encodeBase64String(enSign);
    }

    /** * 公钥加密 * * @param data 待加密数据 * @param pubKey 公钥 * @return * @throws Exception */
    public static byte[] encryptByPubKey(byte[] data, byte[] pubKey) throws Exception {
    
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        return cipher.doFinal(data);
    }

    /** * 私钥加密 * * @param data 加密前的字符串 * @param privateKey 私钥 * @return 加密后的字符串 * @throws Exception */
    public static String encryptByPriKey(String data, String privateKey) throws Exception {
    
        byte[] priKey = RSAUtil.decodeBase64(privateKey);
        byte[] enSign = encryptByPriKey(data.getBytes(), priKey);
        return Base64.encodeBase64String(enSign);
    }

    /** * 私钥加密 * * @param data 待加密的数据 * @param priKey 私钥 * @return 加密后的数据 * @throws Exception */
    public static byte[] encryptByPriKey(byte[] data, byte[] priKey) throws Exception {
    
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        return cipher.doFinal(data);
    }

    /** * 公钥解密 * * @param data 待解密的数据 * @param pubKey 公钥 * @return 解密后的数据 * @throws Exception */
    public static byte[] decryptByPubKey(byte[] data, byte[] pubKey) throws Exception {
    
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        return cipher.doFinal(data);
    }

    /** * 公钥解密 * * @param data 解密前的字符串 * @param publicKey 公钥 * @return 解密后的字符串 * @throws Exception */
    public static String decryptByPubKey(String data, String publicKey) throws Exception {
    
        byte[] pubKey = RSAUtil.decodeBase64(publicKey);
        byte[] design = decryptByPubKey(Base64.decodeBase64(data), pubKey);
        return new String(design);
    }

    /** * 私钥解密 * * @param data 待解密的数据 * @param priKey 私钥 * @return * @throws Exception */
    public static byte[] decryptByPriKey(byte[] data, byte[] priKey) throws Exception {
    
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        return cipher.doFinal(data);
    }

    /** * 私钥解密 * * @param data 解密前的字符串 * @param privateKey 私钥 * @return 解密后的字符串 * @throws Exception */
    public static String decryptByPriKey(String data, String privateKey) throws Exception {
    
        byte[] priKey = RSAUtil.decodeBase64(privateKey);
        byte[] design = decryptByPriKey(Base64.decodeBase64(data), priKey);
        return new String(design);
    }
    /** * 私钥解密 * * @param data 解密前的字符串 * @param privateKey 私钥 * @return 解密后的字符串 * @throws Exception */
    public static String myDecryptByPriKey(String data) throws Exception {
    
        byte[] priKey = RSAUtil.decodeBase64(PRIVATE_KEY);
        byte[] design = decryptByPriKey(Base64.decodeBase64(data), priKey);
        return new String(design);
    }

    /** * RSA签名 * * @param data 待签名数据 * @param priKey 私钥 * @return 签名 * @throws Exception */
    public static String sign(byte[] data, byte[] priKey) throws Exception {
    
        // 取得私钥
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        // 生成私钥
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
        // 实例化Signature
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        // 初始化Signature
        signature.initSign(privateKey);
        // 更新
        signature.update(data);
        return Base64.encodeBase64String(signature.sign());
    }

    /** * RSA校验数字签名 * * @param data 待校验数据 * @param sign 数字签名 * @param pubKey 公钥 * @return boolean 校验成功返回true，失败返回false */
    public boolean verify(byte[] data, byte[] sign, byte[] pubKey) throws Exception {
    
        // 实例化密钥工厂
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        // 初始化公钥
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);
        // 产生公钥
        PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
        // 实例化Signature
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        // 初始化Signature
        signature.initVerify(publicKey);
        // 更新
        signature.update(data);
        // 验证
        return signature.verify(sign);
    }

    public static void main(String[] args) {
    
        try {
    
            Map<String, String> keyMap = initKey();
            String publicKeyString = keyMap.get("publicKeyString");
            String privateKeyString = keyMap.get("privateKeyString");
            logger.info("公钥:" + publicKeyString);
            logger.info("私钥:" + privateKeyString);

            // 待加密数据
            String data = "admin123";
            // 公钥加密
            String encrypt = RSAUtil.encryptByPubKey(data, publicKeyString);
            // 私钥解密
            String decrypt = RSAUtil.decryptByPriKey(encrypt, privateKeyString);

            logger.info("加密前:" + data);
            logger.info("加密后:" + encrypt);
            logger.info("解密后:" + decrypt);
        } catch (Exception e) {
    
            e.printStackTrace();
        }
    }

}