package com.dji.sample.droneairport.utils;

import org.bouncycastle.crypto.engines.SM4Engine;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.paddings.PKCS7Padding;

import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Base64;

public class SM4Util {


    /**
     * 生成一个随机的SM4加密密钥。
     *
     * SM4算法是一种对称加密算法，其密钥长度为128位（16字节）。
     * 本方法使用安全随机数生成器生成一个16字节的随机值作为SM4密钥，
     * 并将其转换为十六进制字符串格式以便于使用和存储。
     *
     * @return 返回一个表示SM4密钥的十六进制字符串。
     */
    public static String generateSM4Key() {
        SecureRandom secureRandom = new SecureRandom();
        byte[] sm4Key = new byte[8]; // SM4 密钥长度为 128 位（16 字节）
        secureRandom.nextBytes(sm4Key);
        String key = bytesToHex(sm4Key);
        return key;
    }


    private static String bytesToHex(byte[] bytes) {
        StringBuilder sb = new StringBuilder();
        for (byte b : bytes) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    }
    /**
     * 使用SM4算法加密输入数据。
     *
     * @param key 加密密钥，应符合SM4算法的密钥长度要求。
     * @param input 待加密的输入数据。
     * @return 加密后的数据，以Base64编码形式表示。
     */
    public static String encrypt(byte[] key, byte[] input) {
        // 创建并初始化SM4加密器
        PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new SM4Engine(), new PKCS7Padding());
        cipher.init(true, new KeyParameter(key));  // ECB模式下不需要IV

        // 用于存储加密后的数据
        byte[] output = new byte[cipher.getOutputSize(input.length)];
        // 处理输入数据，进行加密
        int length = cipher.processBytes(input, 0, input.length, output, 0);

        // 完成加密过程，处理可能剩余的数据
        try {
            length += cipher.doFinal(output, length);
        } catch (Exception e) {
            e.printStackTrace();
        }

        // 使用Base64编码加密后的字节数组，并返回
        String encoded = Base64.getEncoder().encodeToString(Arrays.copyOf(output, length));
        return encoded;
    }


    /**
     * 使用SM4算法对输入数据进行解密
     *
     * @param key 密钥字节数组，用于解密数据
     * @param input 待解密的字节数组
     * @return 解密后的字节数组
     */
    public static byte[] decrypt(byte[] key, byte[] input) {
        // 创建基于SM4算法的缓冲分组密码对象
        PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new SM4Engine(), new PKCS7Padding());
        // 初始化密码对象为解密模式，并设置密钥参数
        cipher.init(false, new KeyParameter(key));  // ECB模式下不需要IV
        // 根据输入数据长度计算解密后的字节数组长度
        byte[] output = new byte[cipher.getOutputSize(input.length)];
        // 处理字节数组，将输入数据解密到输出字节数组中
        int length = cipher.processBytes(input, 0, input.length, output, 0);
        try {
            // 完成最终的解密操作，并将长度累加到已处理字节数组中
            length += cipher.doFinal(output, length);
        } catch (Exception e) {
            // 捕获并处理解密过程中的异常
            e.printStackTrace();
        }
        // 返回解密后的字节数组
        return Arrays.copyOf(output, length);
    }

    public static String decrypt(String keys,String secert){
        byte[] key = keys.getBytes(StandardCharsets.UTF_8);
        byte[] ming= Base64.getDecoder().decode(secert);
        byte[] text=decrypt(key,ming);
        return new String(text, StandardCharsets.UTF_8);
    }

    public static String encrypt(String keys, String input){
        byte[] key = keys.getBytes(StandardCharsets.UTF_8);
        return encrypt(key,input.getBytes());
    }

    public static void main(String[] args) {
        System.out.println(generateSM4Key());
        byte[] key = "2bc304ccba171672".getBytes(StandardCharsets.UTF_8); // 16字节密钥

        // 原始明文
        String plaintext = "{\n" +
                "  \"deviceid\": [\n" +
                "    \"1581F6QAD241800B6V95\",\n" +
                "    \"1581F6QAD241500BDZ3J\"\n" +
                "  ],\n" +
                "  \"bizidname\": \"test\",\n" +
                "  \"tasklist\": [\n" +
                "    {\n" +
                "      \"bsm\": \"20281071717177177\",\n" +
                "      \"xzqdm\": \"31000\",\n" +
                "      \"dkbh\": \"ndbg20110210711\",\n" +
                "      \"dklx\": \"ndbg2774\",\n" +
                "      \"dkmc\": \"桥头\",\n" +
                "      \"dkmj\": 20.574,\n" +
                "      \"dkfw\": \"POLYGON((116.0216 25.8926,116.0217 25.8921,116.0205 25.8919,116.0204 25.8928,116.0214 25.8931,116.0216 25.8926))\"\n" +
                "    }  ]\n" +
                "}";
        String secert =encrypt(key,plaintext.getBytes());
//        System.out.println(secert);


        byte[] ming= Base64.getDecoder().decode(secert);
        byte[] text=decrypt(key,ming);
//        System.out.println(new String(text, StandardCharsets.UTF_8));
        System.out.println(encrypt("2bc304ccba171672",plaintext));
//        System.out.println(generateSM4Key());
//        System.out.println("封装"+decrypt("8a217699714b0fc0","N0KrVFiFdPlpoRF/pugsgOFjDSymxnhUHe9xbuF4XhO3/uVYC83dCixg9estZC67YdP3R/H9oGQ3uDV1OuSV/dYTnli8nb6hMBCcMhcGMeY0UOoWL00tMOqJMaQQ903C9BaozQ1AjdUu1zaA3uisNdkj3O0jMBZRv7JVWuOYpjaPAElRehLFf25wbDxjAtz8p13OWoUZuCfawcfL2B45H2OOUFzr/a91X26NJvkkRrr4dEngeubTldC53JXF+poD92xfw0f9e+7weLcB4QR01F2mpCNTW4nEdj/aBQxoLtt+zVYOBWFSEBsqu5ExdpRxpRTyN7Sh1inEUVYN0f9OT3mzeF8oaRe/AyI2I50dQrh1pBvNH7uCzjPtSrl8HvhKzv5l+G++3VFb2fDWqconrmt9AOCyxLhOkso6yC8MH9ZtEAVhB20LLVYN0qQrdZHIzJNXgWTDXlTVcPcGUjkTYbKYDk8q/+ToLg7BNCsMVKjwCE/ehbS4aU/3/M3rdXlRxXSuNylT1MZYKy1giRbkVnVHHl4Dw4ZYe5ydm6y1VRS1fcAkEhlcKrmgHGcWDf0i9mBjUqXGRs0ZmD7gsTXDf5/I4Pwhwk7VAJAIQqYElOWnopE4uzjIsY/NzZ6PnBsmLwBuwSvOL+ooZbRTenfmWK7r42dxJNuSkKUl78+igxyYGkD70DsLtx2SlVR+W0Kac2T3Atl4aYxVSBIDn81ngQdLCze+BuzN9L4DRDzsFc0ACg3zoDcvDeWWi39KgJNqjMW25gio7jLQaHRM//sVsVFWf3IFzIjfpYcvPBlqlRZNOTvcSarfQWKECKVP7ltI0RqRx8AiRkLWjI6zntIW+JPHt8PHIXDukMWiOU+uMsMdf4R1zV18XcM6VgtNMiLCO2f8sR5OIM8UfEuNCXyyHiHGRxXrv5SRdTU/FRh1h+dcxI+TvCDmADKf+19KK5owTcLy8LsP08hYOFmkayDXQm3C8ZqUjF5Bxaz0Tz50hrUfwVhd3vifAEZbTjVuYqWaOghpXdl6e/I/vkSbcDT3IuL2WzMIvl+ZoL7U9zKEPFmghBBDhGieJQ0Lq+5Cd961+hBooSeOxletN735xp27DhAllU4Ps+qA0m3gSzDWnSWjd2eHvFDAG2Zd99E0CYUVk7jzAhEg6ihVU56Dxs9b9LfzE0IO6mMl+mpPEhuJWgnHdANGGiwgyAKBdey73f1D0NR9R3X42RgSIJeZSp6YJKmNqZOjWQI3IUKywL0lKsN5zACZYmw0maaK//tRt+ab1jxvh2fkwaQe4Y7EB9brZomYEhUzoHOH6uUK9sMs9ICVFAmV+5eFEpVcFF3mbYTsXaakI1NbicR2P9oFDGgu2/Zw0e9m619q6A3RSYVp5/JiEjwP/3gg7CZTrjR4k52FP9d0WjMeUKWMAfjLMvC3IxA5pmpzsihicdt6Nl0jRyEVpL22sUHYfsXro4JG0AlN3OA2x+8VxffiEv/A9zHbgkjwMC1Ygod4hAlF5/c0rnyBppnRxbk6WEvxwc2rtI4Kv7kYGkomdzYEFrhmlSfLgpL+mfE/TVWR15Abv7Wt2ZfrU140MoH43j0J6fWn1m1HK7sq+Ww2+HH8G6ucPgxsr7zoj1UlP2LF0o3z5kz8upGIzGn2jnJse3M0VFMmLxVicesbgPkxPiYbvnFR6iI0ND24HMMxRtZIWLlg+TGs8BQh0RRm3uTEwtyBs2z9bjsFQhioPDXuyWwyXx90RXJlrli3gMIpTR8lYgfOVGFBi5lIIFAakKMEL4cu/odxCCLEoqYQAkO53hyi9zJ5fO/aaKH7k7CTUgviLLofJUgh9aaHdR1MNpIx+dfO4g3TPVnofCb7/PPOa9U0U87wjb7kTGRx5yK494qfslNofwpRZa9bKT3aZl04XVVQ/v1/zTs49VqxWnv2C0uwg+KT4HWcA5+UyXy2uC8LLBmdYI3h8qmzG57K50wL/AJ7ZMN/MFeKD8ulg1CPupAJxlduH/Zu40F6y1fFqinQfqeVOhXX7lNJoWEycdo0XGsVGq3kdEay0mpLVHUPQVW+wDxN/O7tWdJqS1R1D0FVvsA8Tfzu7VmQyL9Eq3f7OvmqAdFHzQkFQFyd4KpMAlWySab4tCbL+4YVOYfaRysmmui2NZdUW2GcFtceaROR6KNL0KeROxrehgxZeKBn25gneLP9G40kiXhkGRk0ufZ2DGBoHQ7/y9DTwVYGonvJBsJcvM4Kg5Abhy25CzIH75dRVThNHSiWaVAao9yMrQEQFz4PJwysIJnu1jYkrCvQ32t+NkBMN5nZOj8XEyOqtaYh9mVl0oeAfz/XdFozHlCljAH4yzLwtyMQOaZqc7IoYnHbejZdI0chNiZteN46775aU0MC+weqGLYUq4ehBXxq3Yd5ds2Tx+RcxI+TvCDmADKf+19KK5owV2APRlFTvPv6tyO8vu/c0EvSEPMPotb7wtVEOuBGd7+iJ5aKPkiG62ikXLqYAjbDe238+pAN1hCVRcUEkdmzhgN7MdMdB1OSJJ+CC4Om7GZv2xRIYYE3cEOrHCIYlRCT7d5TCatHmJN5Y7HEg2AgSl2/6CoCZbGQaCj8qsqnS7I="));
        String encryptedBase64 = encrypt(key, plaintext.getBytes(StandardCharsets.UTF_8));
//        System.out.println("Encrypted (Base64): " + encryptedBase64);
//        System.out.println(generateSM4Key());
        // 直接解密
        byte[] decoded = Base64.getDecoder().decode(encryptedBase64);
        byte[] decrypted = decrypt(key, decoded);

//        // 输出结果
//        System.out.println("Plaintext: " + plaintext);
//        System.out.println("Decrypted: " + new String(decrypted, StandardCharsets.UTF_8));
    }
}