微信小程序加密数据解密算法 java

获取用户头像、昵称、手机号等授权信息，需解密

java 微信小程序加密数据解密算法

    /**
     * 加密数据解密
     *
     * @param encryptedData
     * @param sessionKey
     * @param iv
     * @return
     */
    private String decrypt(String encryptedData, String sessionKey, String iv) {
        String result = "";
        try {
            byte[] resultByte = AES.decrypt(Base64.decodeBase64(encryptedData),
                    Base64.decodeBase64(sessionKey),
                    Base64.decodeBase64(iv));
            if (null != resultByte && resultByte.length > 0) {
                result = new String(resultByte, "UTF-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

AES 解密工具类

import org.bouncycastle.jce.provider.BouncyCastleProvider;

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 java.security.*;

public class AES {
    public static boolean initialized = false;

    /**
     * AES解密
     *
     * @param content
     *            密文
     * @return
     * @throws InvalidAlgorithmParameterException
     * @throws NoSuchProviderException
     */
    public static 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) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            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;
    }
}

以下情况，有可能导致解密失效：

1、短时间的多次 wx.login

2、授权回调里，又再次 wx.login

也就是，没事不要瞎调用 wx.login