sac/sf-vertx/src/main/java/com/sf/vertx/security/RSAUtil.java

package com.sf.vertx.security;

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
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.apache.commons.lang3.ArrayUtils;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class RSAUtil {

	// RSA最大加密明文大小
	  private static final int MAX_ENCRYPT_BLOCK = 117;

	  // RSA最大解密密文大小
	  private static final int MAX_DECRYPT_BLOCK = 128;

	  private RSAUtil() {
	  }

	  /**
	   * 获取公钥和私钥对，key为公钥，value为私钥
	   * 
	   * @return
	   * @throws NoSuchAlgorithmException
	   */
	  public static Map<String, String> genKeyPair() throws NoSuchAlgorithmException {
	    KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
	    keyPairGen.initialize(1024, new SecureRandom());
	    KeyPair keyPair = keyPairGen.generateKeyPair();
	    RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
	    RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
	    String publicKeyString = null;
	    String privateKeyString = null;

	    try {
	      publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()), "UTF-8");
	      privateKeyString = new String(Base64.encodeBase64(privateKey.getEncoded()), "UTF-8");
	    } catch (UnsupportedEncodingException var7) {
	      var7.printStackTrace();
	    }

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

	  public static String encrypt(String str, String publicKey) throws Exception {
	    byte[] decoded = Base64.decodeBase64(publicKey);
	    RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA")
	        .generatePublic(new X509EncodedKeySpec(decoded));
	    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
	    cipher.init(1, pubKey);
	    // 分段加密
	    // URLEncoder编码解决中文乱码问题
	    byte[] data = URLEncoder.encode(str, "UTF-8").getBytes("UTF-8");
	    // 加密时超过117字节就报错。为此采用分段加密的办法来加密
	    byte[] enBytes = null;
	    for (int i = 0; i < data.length; i += MAX_ENCRYPT_BLOCK) {
	      // 注意要使用2的倍数，否则会出现加密后的内容再解密时为乱码
	      byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_ENCRYPT_BLOCK));
	      enBytes = ArrayUtils.addAll(enBytes, doFinal);
	    }
	    String outStr = Base64.encodeBase64String(enBytes);
	    return outStr;
	  }

	  /**
	   * 公钥分段解密
	   * 
	   * @param str
	   * @param privateKey
	   * @return
	   * @throws Exception
	   */
	  public static String decrypt(String str, String privateKey) throws Exception {
	    // 获取公钥
	    byte[] decoded = Base64.decodeBase64(privateKey);
	    RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA")
	        .generatePrivate(new PKCS8EncodedKeySpec(decoded));
	    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
	    cipher.init(2, priKey);
	    byte[] data = Base64.decodeBase64(str.getBytes("UTF-8"));

	    // 返回UTF-8编码的解密信息
	    int inputLen = data.length;
	    ByteArrayOutputStream out = new ByteArrayOutputStream();
	    int offSet = 0;
	    byte[] cache;
	    int i = 0;
	    // 对数据分段解密
	    while (inputLen - offSet > 0) {
	      if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
	        cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
	      } else {
	        cache = cipher.doFinal(data, offSet, inputLen - offSet);
	      }
	      out.write(cache, 0, cache.length);
	      i++;
	      offSet = i * 128;
	    }
	    byte[] decryptedData = out.toByteArray();
	    out.close();
	    return URLDecoder.decode(new String(decryptedData, "UTF-8"), "UTF-8");
	  }

    public static void main(String[] args) throws Exception {
    	Map<String, String> keyMap = genKeyPair();
        String publicKey = keyMap.get("publicKey");
        String privateKey = keyMap.get("privateKey");
        privateKey = "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";
        publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCuIBxYMYWgIau1BKjTpM/9JhIHRnO4QoaiOrVJk+OFWAJFpFrZoDj3JYQF4ywD8uWOx28EBf+g+U8UIE0pS93IEvm/O47VOwSqSvc5tpXmrxHTVgHSqcXqXkm4+q64c525N5bhUbReXI/CSKU62EH7MWapjHD7vPKGVCwjg8RHCQIDAQAB"; 		
        log.info("publicKey = " + publicKey);
        log.info("privateKey = " + privateKey);
        String originValue = "{\n"
        		+ "    \"data\": {\n"
        		+ "        \"a\": 1,\n"
        		+ "        \"b\": \"dd\"\n"
        		+ "    },\n"
        		+ "    \"divideHttpUrl\": {\n"
        		+ "        \"company\": {\n"
        		+ "            \"aesKey\": \"dadddsdfadfadsfa33323223\"\n"
        		+ "        }\n"
        		+ "    }\n"
        		+ "}";
        // 加密前：原数据123456，测试一下
        System.out.println("加密前：" + originValue);

        String encrypt = encrypt(originValue, publicKey);
        log.info("加密后：" + encrypt);
        encrypt =  "Rk3UOW4UG+a/MmnddEvv03mdcv5B2+Rhu7A7mRuu9MgBTBTYrX8RVRgLwXkQq5Wuo8O33/b9n6qGhLX/GDWQ4unuO0IR4wkYwbL5EOXkOmozxScfSyiypu1zD+hSw+B4uMO5LZql+jRJeCtEjph9RZK5EFD186qktUWP1QcKHzGGIM7Ex1YZogWdn6g2I3iyYTStJrofWfUtMQzEj2UUbaAJ/KuCKSXBAJ1oBjmfT856R9TZrHxVXLf5+jNgoUQrSit6ca/hZ8HSZ+rRLf9r+pgAsU0zYLmifRVDc+F819I3XIdi/FNNm9fwNuX7ZpXyKAGP93j8V35uQ6p1ZMw+xQ==";
        String decrypt = decrypt(encrypt, privateKey);
        log.info("解密后：" + decrypt);
    }
}