Java实现微信小程序加密数据解密算法

野性酷女 2022-04-06 13:48 615阅读 0赞

**一.概述**

微信推出了小程序，很多公司的客户端应用不仅具有了APP、H5、还接入了小程序开发。但是，小程序中竟然没有提供Java版本的加密数据解密算法。

微信小程序提供的加密数据解密算法链接为：[https://mp.weixin.qq.com/debug/wxadoc/dev/api/signature.html][https_mp.weixin.qq.com_debug_wxadoc_dev_api_signature.html]

我们下载的算法示例如下：

![9ccce6ea-020d-3221-b9e2-3ebb82bc731b.png][]  
　　真的没有java实现示例。

**二.实现Java版本的微信小程序加密数据解密算法**

**1.创建项目**

这里，我们创建一个Maven工程，具体创建步骤略。

**2.配置pom.xml**

我们在pom.xml中加入如下配置，其中bcprov-jdk15on是为了支持AES的BouncyCastleProvider，而commons-codec则是为了顺利的对session\_key,iv,encryptData进行Base64的编解码。

<dependency>
        <groupId>org.bouncycastle</groupId>
        <artifactId>bcprov-jdk16</artifactId>
        <version>1.46</version>
    </dependency>
    
    <dependency>
      	<groupId>commons-codec</groupId>
      	<artifactId>commons-codec</artifactId>
      	<version>1.10</version>
    </dependency>
    
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.29</version>
    </dependency>

**3.实现AES类**

package com.bijian.test;
    
    import java.security.AlgorithmParameters;
    import java.security.InvalidAlgorithmParameterException;
    import java.security.InvalidKeyException;
    import java.security.Key;
    import java.security.NoSuchAlgorithmException;
    import java.security.NoSuchProviderException;
    import java.security.Security;
     
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.spec.IvParameterSpec;
    import javax.crypto.spec.SecretKeySpec;
    import org.bouncycastle.jce.provider.BouncyCastleProvider;
     
    /**
     * AES加密
     */
    public class AES {
    	
    	public static boolean initialized = false;
     
    	/**
    	 * AES解密
    	 * 
    	 * @param content
    	 *            密文
    	 * @return
    	 * @throws InvalidAlgorithmParameterException
    	 * @throws NoSuchProviderException
    	 */
    	public byte[] decrypt(byte[] content, byte[] keyByte, byte[] ivByte) throws InvalidAlgorithmParameterException {
    		initialize();
    		try {
    			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
    			Key sKeySpec = new SecretKeySpec(keyByte, "AES");
    			cipher.init(Cipher.DECRYPT_MODE, sKeySpec, generateIV(ivByte));// 初始化
    			byte[] result = cipher.doFinal(content);
    			return result;
    		} catch (NoSuchAlgorithmException e) {
    			e.printStackTrace();
    		} catch (NoSuchPaddingException e) {
    			e.printStackTrace();
    		} catch (InvalidKeyException e) {
    			e.printStackTrace();
    		} catch (IllegalBlockSizeException e) {
    			e.printStackTrace();
    		} catch (BadPaddingException e) {
    			e.printStackTrace();
    		} catch (NoSuchProviderException e) {
    			e.printStackTrace();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
     
    	public static void initialize() {
    		if (initialized)
    			return;
    		Security.addProvider(new BouncyCastleProvider());
    		initialized = true;
    	}
     
    	// 生成iv
    	public static AlgorithmParameters generateIV(byte[] iv) throws Exception {
    		AlgorithmParameters params = AlgorithmParameters.getInstance("AES");
    		params.init(new IvParameterSpec(iv));
    		return params;
    	}
    }

**4.实现WxPKCS7Encoder类**

package com.bijian.test;
    
    import java.nio.charset.Charset;
    import java.util.Arrays;
    
    /**
     * 微信小程序加解密
     */
    public class WxPKCS7Encoder {
    	private static final Charset CHARSET = Charset.forName("utf-8");
    	private static final int BLOCK_SIZE = 32;
     
    	/**
    	 * 获得对明文进行补位填充的字节.
    	 *
    	 * @param count
    	 *            需要进行填充补位操作的明文字节个数
    	 * @return 补齐用的字节数组
    	 */
    	public static byte[] encode(int count) {
    		// 计算需要填充的位数
    		int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE);
    		if (amountToPad == 0) {
    			amountToPad = BLOCK_SIZE;
    		}
    		// 获得补位所用的字符
    		char padChr = chr(amountToPad);
    		String tmp = new String();
    		for (int index = 0; index < amountToPad; index++) {
    			tmp += padChr;
    		}
    		return tmp.getBytes(CHARSET);
    	}
     
    	/**
    	 * 删除解密后明文的补位字符
    	 *
    	 * @param decrypted
    	 *            解密后的明文
    	 * @return 删除补位字符后的明文
    	 */
    	public static byte[] decode(byte[] decrypted) {
    		int pad = decrypted[decrypted.length - 1];
    		if (pad < 1 || pad > 32) {
    			pad = 0;
    		}
    		return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad);
    	}
     
    	/**
    	 * 将数字转化成ASCII码对应的字符，用于对明文进行补码
    	 *
    	 * @param a
    	 *            需要转化的数字
    	 * @return 转化得到的字符
    	 */
    	public static char chr(int a) {
    		byte target = (byte) (a & 0xFF);
    		return (char) target;
    	}
    }

**5.实现WXCore类**

package com.bijian.test;
    
    import org.apache.commons.codec.binary.Base64;
    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONObject;
    
    /**
     * 封装对外访问方法
     */
    public class WXCore {
    
    	private static final String WATERMARK = "watermark";
    	private static final String APPID = "appid";
    
    	/**
    	 * 解密数据
    	 * 
    	 * @return
    	 * @throws Exception
    	 */
    	public static String decrypt(String appId, String encryptedData,
    			String sessionKey, String iv) {
    		String result = "";
    		try {
    			AES aes = new AES();
    			byte[] resultByte = aes.decrypt(Base64.decodeBase64(encryptedData), Base64.decodeBase64(sessionKey), Base64.decodeBase64(iv));
    			if (null != resultByte && resultByte.length > 0) {
    				result = new String(WxPKCS7Encoder.decode(resultByte));
    				JSONObject jsonObject = JSON.parseObject(result);
    				String decryptAppid = jsonObject.getJSONObject(WATERMARK)
    						.getString(APPID);
    				if (!appId.equals(decryptAppid)) {
    					result = "";
    				}
    			}
    		} catch (Exception e) {
    			result = "";
    			e.printStackTrace();
    		}
    		return result;
    	}
    
    	public static void main(String[] args) throws Exception {
    
    		String appId = "wx4f4bc4dec97d474b";
    		String encryptedData = "CiyLU1Aw2KjvrjMdj8YKliAjtP4gsMZMQmRzooG2xrDcvSnxIMXFufNstNGTyaGS9uT5geRa0W4oTOb1WT7fJlAC+oNPdbB+3hVbJSRgv+4lGOETKUQz6OYStslQ142dNCuabNPGBzlooOmB231qMM85d2/fV6ChevvXvQP8Hkue1poOFtnEtpyxVLW1zAo6/1Xx1COxFvrc2d7UL/lmHInNlxuacJXwu0fjpXfz/YqYzBIBzD6WUfTIF9GRHpOn/Hz7saL8xz+W//FRAUid1OksQaQx4CMs8LOddcQhULW4ucetDf96JcR3g0gfRK4PC7E/r7Z6xNrXd2UIeorGj5Ef7b1pJAYB6Y5anaHqZ9J6nKEBvB4DnNLIVWSgARns/8wR2SiRS7MNACwTyrGvt9ts8p12PKFdlqYTopNHR1Vf7XjfhQlVsAJdNiKdYmYVoKlaRv85IfVunYzO0IKXsyl7JCUjCpoG20f0a04COwfneQAGGwd5oa+T8yO5hzuyDb/XcxxmK01EpqOyuxINew==";
    		String sessionKey = "tiihtNczf5v6AKRyjwEUhQ==";
    		String iv = "r7BXXKkLb8qrSNn05n0qiA==";
    		System.out.println(decrypt(appId, encryptedData, sessionKey, iv));
    	}
    }

这个类主要是对具体算法的封装，统一对外提供方法。

**三.测试**

**1.运行Java版微信小程序加密数据解密算法**

这里我就直接运行WXcore类的main方法，这里的测试数据都是从Node.js版微信小程序加密数据解密算法的示例程序中提出来的。我们的运行结果如下：

{"openId":"oGZUI0egBJY1zhBYw2KhdUfwVJJE","nickName":"Band","gender":1,"language":"zh_CN","city":"Guangzhou","province":"Guangdong","country":"CN","avatarUrl":"http://wx.qlogo.cn/mmopen/vi_32/aSKcBBPpibyKNicHNTMM0qJVh8Kjgiak2AHWr8MHM4WgMEm7GFhsf8OYrySdbvAMvTsw3mo8ibKicsnfN5pRjl1p8HQ/0","unionId":"ocMvos6NjeKLIBqg5Mr9QjxrP1FA","watermark":{"timestamp":1477314187,"appid":"wx4f4bc4dec97d474b"}}

**2.运行Node.js版微信小程序加密数据解密算法**

我在Node.js环境中直接运行微信官方提供的Node.js版小程序加密数据解密算法，结果如下：

![35ea825d-da9d-336d-9382-b7d4623d444f.png][]  
　　通过对比以上结果可知，我们自行使用Java实现的Java版微信小程序加密数据解密算法与微信官方提供的Node.js版小程序加密数据解密算法结果一致。

**四.javax.crypto.Cipher实现**

package com.bijian.test;
    
    import org.apache.commons.codec.binary.Base64;
    import org.bouncycastle.jce.provider.BouncyCastleProvider;
    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONObject;
    
    import javax.crypto.*;
    import javax.crypto.spec.IvParameterSpec;
    import javax.crypto.spec.SecretKeySpec;
    
    import java.security.*;
    
    public class Test {
    	
    	private static final String WATERMARK = "watermark";
    	private static final String APPID = "appid";
    	
    	private static boolean hasInited = false;
    
        public static void init() {
            if (hasInited) {
                return;
            }
            Security.addProvider(new BouncyCastleProvider());
            hasInited = true;
        }
    
        public static String decrypt(String session_key, String iv, String encryptData) {
        	
            String decryptString = "";
            init();
            byte[] sessionKeyByte = Base64.decodeBase64(session_key);
            byte[] ivByte = Base64.decodeBase64(iv);
            byte[] encryptDataByte = Base64.decodeBase64(encryptData);
            try {
                Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
                Key key = new SecretKeySpec(sessionKeyByte, "AES");
                AlgorithmParameters algorithmParameters = AlgorithmParameters.getInstance("AES");
                algorithmParameters.init(new IvParameterSpec(ivByte));
                cipher.init(Cipher.DECRYPT_MODE, key, algorithmParameters);
                byte[] bytes = cipher.doFinal(encryptDataByte);
                decryptString = new String(bytes);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return decryptString;
        }
        
        public static void main(String[] args) {
        	String appId = "wx4f4bc4dec97d474b";
            String session_key = "tiihtNczf5v6AKRyjwEUhQ==";
            String iv = "r7BXXKkLb8qrSNn05n0qiA==";
            String encryptData = 
            		"CiyLU1Aw2KjvrjMdj8YKliAjtP4gsMZM"+
            		"QmRzooG2xrDcvSnxIMXFufNstNGTyaGS"+
            		"9uT5geRa0W4oTOb1WT7fJlAC+oNPdbB+"+
            		"3hVbJSRgv+4lGOETKUQz6OYStslQ142d"+
            		"NCuabNPGBzlooOmB231qMM85d2/fV6Ch"+
            		"evvXvQP8Hkue1poOFtnEtpyxVLW1zAo6"+
            		"/1Xx1COxFvrc2d7UL/lmHInNlxuacJXw"+
            		"u0fjpXfz/YqYzBIBzD6WUfTIF9GRHpOn"+
            		"/Hz7saL8xz+W//FRAUid1OksQaQx4CMs"+
            		"8LOddcQhULW4ucetDf96JcR3g0gfRK4P"+
            		"C7E/r7Z6xNrXd2UIeorGj5Ef7b1pJAYB"+
            		"6Y5anaHqZ9J6nKEBvB4DnNLIVWSgARns"+
            		"/8wR2SiRS7MNACwTyrGvt9ts8p12PKFd"+
            		"lqYTopNHR1Vf7XjfhQlVsAJdNiKdYmYV"+
            		"oKlaRv85IfVunYzO0IKXsyl7JCUjCpoG"+
            		"20f0a04COwfneQAGGwd5oa+T8yO5hzuy"+
            		"Db/XcxxmK01EpqOyuxINew==";
            String decrypt = decrypt(session_key, iv, encryptData);
            JSONObject jsonObject = JSON.parseObject(decrypt);
        	String decryptAppid = jsonObject.getJSONObject(WATERMARK).getString(APPID);
        	if(!appId.equals(decryptAppid)){
        		decrypt = "";
        	}
            System.out.println(decrypt);
        }
    }

运行结果和上面的运行结果是一致的。

附：

jar包下载地址：[http://mvnrepository.com/artifact/org.bouncycastle/bcprov-jdk16/1.46][http_mvnrepository.com_artifact_org.bouncycastle_bcprov-jdk16_1.46]

文章来源：

[https://blog.csdn.net/l1028386804/article/details/79450115][https_blog.csdn.net_l1028386804_article_details_79450115]

[https://blog.csdn.net/u013187628/article/details/80665574][https_blog.csdn.net_u013187628_article_details_80665574]

[https_mp.weixin.qq.com_debug_wxadoc_dev_api_signature.html]: https://mp.weixin.qq.com/debug/wxadoc/dev/api/signature.html
[9ccce6ea-020d-3221-b9e2-3ebb82bc731b.png]: /images/20220406/487fd941153a43b9beecd5f0659ab8ae.png
[35ea825d-da9d-336d-9382-b7d4623d444f.png]: /images/20220406/6ba084f293a34f56a50ac040219e1dbb.png
[http_mvnrepository.com_artifact_org.bouncycastle_bcprov-jdk16_1.46]: http://mvnrepository.com/artifact/org.bouncycastle/bcprov-jdk16/1.46
[https_blog.csdn.net_l1028386804_article_details_79450115]: https://blog.csdn.net/l1028386804/article/details/79450115
[https_blog.csdn.net_u013187628_article_details_80665574]: https://blog.csdn.net/u013187628/article/details/80665574