package com.dy.pipIrrWechat.util;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.GCMParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

/**
 * @author ZhuBaoMin
 * @date 2024-07-15 10:18
 * @LastEditTime 2024-07-15 10:18
 * @Description
 */
public class AesUtil {
    static final int KEY_LENGTH_BYTE = 32;
    static final int TAG_LENGTH_BIT = 128;

    /**
     * 解密
     * @param apiV3Key apiV3密钥
     * @param associatedData 附加数据
     * @param nonce 随机串
     * @param ciphertext 数据密文
     * @return 解密后字符串
     * @throws GeneralSecurityException
     * @throws IOException
     */
    public static String decryptToString(byte[] apiV3Key, byte[] associatedData, byte[] nonce, String ciphertext) throws GeneralSecurityException, IOException {
        try {
            Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
            SecretKeySpec key = new SecretKeySpec(apiV3Key, "AES");
            GCMParameterSpec spec = new GCMParameterSpec(TAG_LENGTH_BIT, nonce);

            cipher.init(Cipher.DECRYPT_MODE, key, spec);
            cipher.updateAAD(associatedData);

            return new String(cipher.doFinal(Base64.getDecoder().decode(ciphertext)), "utf-8");
        } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {
            throw new IllegalStateException(e);
        } catch (InvalidKeyException | InvalidAlgorithmParameterException e) {
            throw new IllegalArgumentException(e);
        }
    }
}