微信小程序根据code获取session_key和openid以及后端解密获取手机号

需要添加的依赖

  
           cn.hutool
           hutool-all
        5.3.9
       

        
        
            commons-codec
            commons-codec
            1.10
        

        
            org.bouncycastle
            bcprov-jdk16
            1.46
        

配置信息

      /**
 * wx 配置文件
 * */
public class WxConstant {

     //appid
    public static final String appid = "";
    //appsecret
    public static final String secret = "";
    public static final String authApi = "https://api.weixin.qq.com/sns/jscode2session";

    public static final String AES = "AES";
    public static final String AES_CBC_PADDING = "AES/CBC/PKCS7Padding";
}

import cn.hutool.http.HttpUtil;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.AlgorithmParameters;
import java.security.Key;
import java.security.Security;

public class WxUtils {

    public static String wxDecrypt(String encrypted, String session_key, String iv) {
        String result = null;
        byte[] encrypted64 = Base64.decodeBase64(encrypted);
        byte[] key64 = Base64.decodeBase64(session_key);
        byte[] iv64 = Base64.decodeBase64(iv);
        try {
            init();
            result = new String(decrypt(encrypted64, key64, generateIV(iv64)));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    /**
     *    * 初始化密钥
     *
     */

    public static void init() throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        KeyGenerator.getInstance(WxConstant.AES).init(128);
    }

    /**
     *    * 生成iv
     *
     */
    public static AlgorithmParameters generateIV(byte[] iv) throws Exception {
        // iv 为一个 16 字节的数组，这里采用和 iOS 端一样的构造方法，数据全为0
        // Arrays.fill(iv, (byte) 0x00);
        AlgorithmParameters params = AlgorithmParameters.getInstance(WxConstant.AES);
        params.init(new IvParameterSpec(iv));
        return params;
    }

    /**
     *    * 生成解密
     *
     */
    public static byte[] decrypt(byte[] encryptedData, byte[] keyBytes, AlgorithmParameters iv)
            throws Exception {
        Key key = new SecretKeySpec(keyBytes, WxConstant.AES);
        Cipher cipher = Cipher.getInstance(WxConstant.AES_CBC_PADDING);
        // 设置为解密模式
        cipher.init(Cipher.DECRYPT_MODE, key, iv);
        return cipher.doFinal(encryptedData);
    }

    /**
     * 根据code获取
     * @param code
     * @return
     */
    public static String getLoginInfo(String code){
        String url = WxConstant.authApi+"?" +
                "appid="+WxConstant.appid +
                "&secret="+WxConstant.secret+
                "&js_code="+code+
                "&grant_type=authorization_code";
        String result = HttpUtil.createGet(url)
                .execute()
                .charset("utf-8")
                .body();
        return result;
    }
}