web页面使用js加密敏感信息，java端解密

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/zqz_zqz/article/details/81839156

为了保证安全，现在web应用中，大部分都使用https了，但是https只对传输通道进行加密，一旦通道被破，明文数据就被攻击者获取了，为了保证数据传输过程中的安全性，需要对敏感数据传输前做一次加密，下面演示如何通过RSA加密，做到前后端数据的安全传输：

首先我们需要一个前端js加密工具，这个工具叫JSEncrypt，

官方主页：http://travistidwell.com/jsencrypt/

下载地址：https://github.com/travist/jsencrypt/archive/master.zip

要缩包里面有个jsencrypt.min.js文件，就是我们要导入的文件，首先jsp页面导入这个js文件；

<script src="js/jsencrypt.min.js"></script>
<script>
    var encrypt = new JSEncrypt();
    encrypt.setPublicKey("<%=RSAUtil.publicKey%>");
    console.log("这是123456的密文："+encrypt.encrypt("123456"));
</script>

java端解密：

System.out.println( RSACoder.decryptBase64AndRSAByPrivateKey("这里输入密文") );

RSAUtil是一个java工具类：

import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;

import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

 
/**
 * 敏感信息加密
 * @author  zqz 20180818
 */
public class RSACoder {
	
	private static Logger logger = LoggerFactory.getLogger(RSACoder.class);
	
	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";
  
	/**公钥，请换掉这里的key，乱写的**/
	public static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKsSDFQDGtwz9qRQC6PLuShXMfaRUY9Or4CwqQTiTiukU8rTjmk6xcWGarieJNTjLkGRUbTjzkSzcDtGt1AItLUbS0hZvsd4K7BsrkT67/oNI3xZ9f5mw8SPfvyZnnMvNTy9KkkssMz/TnXrZLg4FI3U5yNRZQVOUVSPIYcGFc1Z6zQIFwIDAQAB";
	/**私钥，请换掉这里的key，乱写的**/
	public static String privateKey = "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";
  
	static {
		init();
	}
	
	public static void init() {
		/**
		 * 生成key
		 */
//		Map<String, Key> keyMap;
//		try {
//			keyMap = RSACoder.initKey();
//			publicKey = RSACoder.getPublicKey(keyMap);
//			privateKey = RSACoder.getPrivateKey(keyMap);
//		} catch (Exception e) {
//			// TODO Auto-generated catch block
//			logger.error("初始化前端js加密秘钥失败：",e);
//		}
		logger.info("公钥: \n\r" + publicKey);
		logger.info("私钥： \n\r" + privateKey);
	}
  
	public static byte[] decryptBASE64(String key) {
		return Base64.decodeBase64(key);
	}
 
	public static String encryptBASE64(byte[] bytes) {
		return Base64.encodeBase64String(bytes);
	}
	
	public static byte[] decryptBase64AndRSAByPrivateKey(String data)throws Exception{
		return decryptByPrivateKey(RSACoder.decryptBASE64(data),privateKey);
	}
	
	/**
	 * 私钥解密
	 * @param data  要解密的base64编码的数据；
	 * @param key   私钥的base64编码数据；
	 * @return
	 * @throws Exception
	 */
	public static byte[] decryptAndBase64ByPrivateKey(String data, String key) throws Exception{
		return decryptByPrivateKey(RSACoder.decryptBASE64(data),key);
	}
  
	/**
	 * 公钥加密
	 * 返回base64字符串
	 * @param data
	 * @param key
	 * @return
	 * @throws Exception
	 */
	public static String encryptAndBase64ByPublicKey(String data,String key) throws Exception {
		return encryptBASE64(encryptByPublicKey(data,key));
	}
 
  /**
   * 
   * 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));
  }
  
  /**
   * 使用私钥解密
   * @param data
   * @param privateKey
   * @return
   * @throws Exception
   */
  public static byte[] decryptByPrivateKey(byte[] data,  Key privateKey) throws Exception{
	  // 对数据解密
	  Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
	  cipher.init(Cipher.DECRYPT_MODE, privateKey);
	  return cipher.doFinal(data);
  }
  
  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);
	  return decryptByPrivateKey(data,privateKey);
  }
 
  /**
   * 解密<br>
   * 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<br>
   * 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<br>
   * 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<br>
   * 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<String, Key> 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<String, Key> keyMap)
      throws Exception {
    Key key = keyMap.get(PUBLIC_KEY);
    return encryptBASE64(key.getEncoded());
  }
 
  /**
   * 初始化密钥
   *
   * @return
 * @throws NoSuchAlgorithmException 
   * @throws Exception
   */
  public static Map<String, Key> initKey() throws NoSuchAlgorithmException {
    KeyPairGenerator keyPairGen = KeyPairGenerator
        .getInstance(KEY_ALGORITHM);
    keyPairGen.initialize(1024);
    KeyPair keyPair = keyPairGen.generateKeyPair();
    Map<String, Key> keyMap = new HashMap<String, Key>(2);
    keyMap.put(PUBLIC_KEY, keyPair.getPublic());// 公钥
    keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私钥
    return keyMap;
  }
}