企业级 - RSA加解密工具

留给读者

RAS非对称加密在企业加密中应用是比较广泛的，针对非对称加密另外做了数字签名和验证。

一、介绍

二、代码

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.Arrays;
import java.util.HashMap;
import java.util.Map;


public class RSACoder {
  public static final String KEY_ALGORITHM = "RSA";
  public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

  // 只作为 生成 真正的 key 使用，不当成 秘钥使用
  private static final String PUBLIC_KEY = "RSAPublicKey";
  // 只作为 生成 真正的 key 使用，不当成 秘钥使用
  private static final String PRIVATE_KEY = "RSAPrivateKey";
  
  // 使用 初始化、获取秘钥方法 再对公钥和秘钥再写入
  public static final String LOGIN_PUBLIC_KEY = "";
  // 使用 初始化、获取秘钥方法 再对公钥和秘钥再写入
  public static final String LOGIN_PRIVATE_KEY = "";
  

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

  public static void main(String[] args) throws Exception {
    String signData = sign("abcdefg".getBytes(), LOGIN_PRIVATE_KEY);
    boolean verify = verify("abcdefg".getBytes(), LOGIN_PUBLIC_KEY, signData);
    System.out.println(verify);

    byte[] bytes = encryptByPrivateKey("abcdefg".getBytes(), LOGIN_PRIVATE_KEY);
    byte[] bytes1 = decryptByPublicKey(bytes, LOGIN_PUBLIC_KEY);
    System.out.println(new String(bytes1));
  }

}

三、总结

简洁、高效、严谨！