package com.fzzy.api.utils;

;

import org.apache.commons.codec.binary.Base64;


import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

/**
 * date: 2022-08-31
 * 上海是平台接口人员提供
 */
public class ShRSAUtils {
	
	// 数字签名，密钥算法
	private static final String RSA_KEY_ALGORITHM = "RSA";
	// 数字签名签名/验证算法
	private static final String SIGNATURE_ALGORITHM = "MD5withRSA";
	//分段加密大小
	public static int MAX_ENCRYPT_BLOCK  = 117;
	//分段解密大小
	public static int MAX_DECRYPT_BLOCK = 128;
	//密钥大小
	public static int KEY_SIZE = 1024;

	/**
	 * 初始化RSA密钥对
	 */
	@SuppressWarnings("unused")
	private static Map<String, String> initKey(String str) throws Exception {
		KeyPairGenerator keygen = KeyPairGenerator.getInstance(RSA_KEY_ALGORITHM);
		SecureRandom secrand = new SecureRandom();
		secrand.setSeed(str.getBytes());// 初始化随机产生器
		keygen.initialize(KEY_SIZE, secrand); // 初始化密钥生成器
		KeyPair keys = keygen.genKeyPair();
		String pub_key = new String(Base64.encodeBase64(keys.getPublic().getEncoded()),"utf-8");
		String pri_key = new String(Base64.encodeBase64(keys.getPrivate().getEncoded()),"utf-8");
		Map<String, String> keyMap = new HashMap<String, String>();
		System.out.println("公钥：" + pub_key);
		System.out.println("私钥：" + pri_key);
		return keyMap;
	}
	
	/**
	 * 数字签名
	 */
	public static String sign(String text, String pri_key) throws Exception {
		byte[] data = text.getBytes();
		// 取得私钥
		byte[] pri_key_bytes = Base64.decodeBase64(pri_key.getBytes());
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(pri_key_bytes);
		KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
		// 生成私钥
		PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
		// 实例化Signature
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		// 初始化Signature
		signature.initSign(priKey);
		// 更新
		signature.update(data);
		return new String(Base64.encodeBase64(signature.sign()),"utf-8");
	}

	

	/**
	 * 公钥加密
	 * @param data 待加密数据
	 * @param pub_key 公钥
	 * @return 密文
	 * @throws Exception 抛出异常
	 */
	private static byte[] encryptByPubKey(byte[] data, byte[] pub_key) throws Exception {
		// 取得公钥
		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pub_key);
		KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
		PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
		// 对数据加密
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.ENCRYPT_MODE, publicKey);
//		return cipher.doFinal(data);
		
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
	}
	/**
     * RSA校验数字签名
     */
    public static boolean verify(byte[] data, byte[] sign, String pub_key) throws Exception {
        // 转换公钥材料
        // 实例化密钥工厂
        byte[] pub_key_bytes = Base64.decodeBase64(pub_key.getBytes());
        KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);
        // 初始化公钥
        // 密钥材料转换
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pub_key_bytes);
        // 产生公钥
        PublicKey pubKey = keyFactory.generatePublic(x509KeySpec);
        // 实例化Signature
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        // 初始化Signature
        signature.initVerify(pubKey);
        // 更新
        signature.update(data);
        // 验证
        return signature.verify(sign);
    }
	public static boolean InspecdataSign(String data,String accessToken,String pubkey){
        String sign = data;
        try {
            if(ShRSAUtils.verify(sign.getBytes(), Base64.decodeBase64(accessToken.getBytes()), pubkey)){
                return true;
            }else{
                return false;
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return false;
        }
    }
	/**
	 * 公钥加密
	 * @param data 待加密数据
	 * @param pub_key 公钥
	 * @return 密文
	 * @throws Exception 抛出异常
	 */
	public static String encryptByPubKey(String data, String pub_key) throws Exception {

		byte[] pub_key_bytes = Base64.decodeBase64(pub_key.getBytes("utf-8"));
		byte[] enSign = encryptByPubKey(data.getBytes("utf-8"), pub_key_bytes);
		return new String(Base64.encodeBase64(enSign),"utf-8");
	}

	
	
	public static void main(String[] args) throws Exception{
//        initKey("嘉定区智慧粮库接口2023");
        String signStr = "310114_2022-09-18";
        String pri_key = "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";
        String pub_key = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCRsamMiP5Op2JJtp3+IIJADFYhL256ZW0KsOkMHruJ3hVwgvoimPHKuUWRI/CS365v4BwUzzfBRdbECMFsLA1e1FHPPA0uSsAIuSVwRzHXG4drX7ZCDa9GFZ+qyIFAU25j2e2PC9olvKbGLBfZ8cL1FLXGxSVyDCX4t/UMZdDULwIDAQAB";
        String access_token = ShRSAUtils.sign(signStr, pri_key);
        System.out.println(access_token);
        System.out.println(InspecdataSign(signStr,access_token,pub_key));
    }
	
}