前段数据加密,后端解密

一.生成秘钥和公钥,(公钥加密,私钥解密)

1.添加依赖

        
            commons-codec
            commons-codec
            1.10
        

2.工具类代码(来源网络)

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

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

/**
 * Created by lake on 17-4-12.
 */
public class RSACoder {
    public static final String KEY_ALGORITHM = "RSA";
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

    private static final String PUBLIC_KEY = "RSAPublicKey";
    private static final String PRIVATE_KEY = "RSAPrivateKey";

    public static byte[] decryptBASE64(String key) {
        return Base64.decodeBase64(key);
    }

    public static String encryptBASE64(byte[] bytes) {
        return Base64.encodeBase64String(bytes);
    }

    /**
     * 用私钥对信息生成数字签名
     *
     * @param data       加密数据
     * @param privateKey 私钥
     * @return
     * @throws Exception
     */
    public static String sign(byte[] data, String privateKey) throws Exception {
        // 解密由base64编码的私钥
        byte[] keyBytes = decryptBASE64(privateKey);
        // 构造PKCS8EncodedKeySpec对象
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        // KEY_ALGORITHM 指定的加密算法
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        // 取私钥匙对象
        PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
        // 用私钥对信息生成数字签名
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initSign(priKey);
        signature.update(data);
        return encryptBASE64(signature.sign());
    }

    /**
     * 校验数字签名
     *
     * @param data      加密数据
     * @param publicKey 公钥
     * @param sign      数字签名
     * @return 校验成功返回true 失败返回false
     * @throws Exception
     */
    public static boolean verify(byte[] data, String publicKey, String sign)
            throws Exception {
        // 解密由base64编码的公钥
        byte[] keyBytes = decryptBASE64(publicKey);
        // 构造X509EncodedKeySpec对象
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        // KEY_ALGORITHM 指定的加密算法
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        // 取公钥匙对象
        PublicKey pubKey = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initVerify(pubKey);
        signature.update(data);
        // 验证签名是否正常
        return signature.verify(decryptBASE64(sign));
    }

    public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception{
        // 对密钥解密
        byte[] keyBytes = decryptBASE64(key);
        // 取得私钥
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
        // 对数据解密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        return cipher.doFinal(data);
    }

    /**
     * 解密

     * 用私钥解密
     *
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(String data, String key)
            throws Exception {
        return decryptByPrivateKey(decryptBASE64(data),key);
    }

    /**
     * 解密

     * 用公钥解密
     *
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPublicKey(byte[] data, String key)
            throws Exception {
        // 对密钥解密
        byte[] keyBytes = decryptBASE64(key);
        // 取得公钥
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicKey = keyFactory.generatePublic(x509KeySpec);
        // 对数据解密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        return cipher.doFinal(data);
    }

    /**
     * 加密

     * 用公钥加密
     *
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(String data, String key)
            throws Exception {
        // 对公钥解密
        byte[] keyBytes = decryptBASE64(key);
        // 取得公钥
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicKey = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        return cipher.doFinal(data.getBytes());
    }

    /**
     * 加密

     * 用私钥加密
     *
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, String key)
            throws Exception {
        // 对密钥解密
        byte[] keyBytes = decryptBASE64(key);
        // 取得私钥
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        return cipher.doFinal(data);
    }

    /**
     * 取得私钥
     *
     * @param keyMap
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return encryptBASE64(key.getEncoded());
    }

    /**
     * 取得公钥
     *
     * @param keyMap
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map keyMap)
            throws Exception {
        Key key = keyMap.get(PUBLIC_KEY);
        return encryptBASE64(key.getEncoded());
    }

    /**
     * 初始化密钥
     *
     * @return
     * @throws Exception
     */
    public static Map initKey() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator
                .getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        Map keyMap = new HashMap(2);
        keyMap.put(PUBLIC_KEY, keyPair.getPublic());// 公钥
        keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私钥
        return keyMap;
    }
}

3.使用工具类生成公钥和私钥(生成的秘钥要保存下来,后面要用)

public static void main(String[] args) throws Exception {
        Map stringKeyMap = RSACoder.initKey();
        String publicKey = RSACoder.getPublicKey(stringKeyMap);
        String privateKey = RSACoder.getPrivateKey(stringKeyMap);
        System.out.println("publicKey : " + publicKey);
        System.out.println("privateKey : " + privateKey);
}

二.前段加密

1.引入jsencrypt.min.js

2.取上文生成的公钥

3.进行加密

三.后端解密

public static void main(String[] args) throws Exception {
    //这里就是前段加密后的字符串
    String encrypted = "GBTCQj/Q/DjtP6GtdewYRRh4BEPd6S6DjxsshSk8lpIzxmkk++wsqeafkuqY4/jVRMipSaCihxZwOJj1xKdpv1zHwNG/Xx6NTY5MzFA01SbXMPpGVsUuKF/OjxUvRjWhJJDpXc7ECdQeUx26GgeD17PdBbb3eLrkZUBza4Y1s/I=";
    //这里是上文生成的私钥    
    String privateKey = "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";
    //执行解密
    byte[] bytes = RSACoder.decryptByPrivateKey(encrypted, privateKey);
        System.out.println(new String(bytes));//aaa123456
    }