java token自定义实现

import com.example.newsmanager.model.Token;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TokenUtil {

    public static final String TOKEN_NAME = "token";

    private TokenUtil() {}

    public static void addToken(HttpServletResponse response, String data) {
        Token token = new Token(data);
        Cookie cookie = new Cookie(TOKEN_NAME,token.toString());
        cookie.setMaxAge((int) (token.getDuration() / 1000 - 10));
        cookie.setHttpOnly(true);
        response.addCookie(cookie);
    }

    public static boolean verify(HttpServletRequest request) {
        Token token = getTokenFromCookie(request);
        return token != null && token.verify();
    }

    public static boolean verify(HttpServletRequest request, boolean head) {
        if (!verify(request)) {
            return false;
        }else if(head) {
            Token token = getTokenFromHeader(request);
            return token != null && token.verify();
        }else {
            return true;
        }
    }

    private static Token getTokenFromCookie(HttpServletRequest request) {
        Cookie[] cookies = request.getCookies();
        if (cookies != null) {
            for (Cookie cookie : cookies) {
                if (TOKEN_NAME.equals(cookie.getName())) {
                    return Token.valueOf(cookie.getValue());
                }
            }
        }
        return null;
    }

    private static Token getTokenFromHeader(HttpServletRequest request) {
        String tokenStr = request.getHeader(TOKEN_NAME);
        return Token.valueOf(tokenStr);
    }

    public static void deleteToken(HttpServletResponse response) {
        Cookie cookie = new Cookie(TOKEN_NAME,"");
        cookie.setMaxAge(0);
        cookie.setHttpOnly(true);
        response.addCookie(cookie);
    }
}

import com.example.newsmanager.props.TokenProps;
import com.example.newsmanager.util.RSAUtil;
import lombok.Data;

import java.nio.charset.StandardCharsets;
import java.util.Base64;

@Data
public class Token {
    private String data;
    private long timestamp = System.currentTimeMillis();
    private long duration = 43200000L;//one day
    private String sign;

    public Token(String data, long timestamp, long duration, String sign) {
        this.data = data;
        this.timestamp = timestamp;
        this.duration = duration;
        this.sign = sign;
    }

    public Token(String data, long timestamp, long duration) {
        this.data = data;
        this.timestamp = timestamp;
        this.duration = duration;
        initSign();
    }

    public Token(String data) {
        this.data = data;
        initSign();
    }

    public Token(String data, long duration) {
        this.data = data;
        this.duration = duration;
        initSign();
    }

    private void initSign() {
        try {
            this.sign = RSAUtil.sign(data+","+timestamp+","+duration, TokenProps.getPriKey());
        }catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public String toString() {
        return Base64.getEncoder().encodeToString((data+"\n"+timestamp+"\n"+duration+"\n"+sign).getBytes(StandardCharsets.UTF_8));
    }

    public boolean verify() {
        boolean flag = false;
        try {
            flag = RSAUtil.verify(data+","+timestamp+","+duration, TokenProps.getPubKey(),sign);
            if (flag) {
                long curTime = System.currentTimeMillis();
                flag = timestamp + duration > curTime;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return flag;
    }

    public static Token valueOf(String token) {
        if (token != null && token .length() > 0) {
            try {
                byte[] bytes = Base64.getDecoder().decode(token);
                String data = new String(bytes);
                String[] arr = data.split("\n");
                return new Token(arr[0],Long.parseLong(arr[1]),Long.parseLong(arr[2]),arr[3]);
            }catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

public class RSAUtil {

    private static final int KEY_SIZE = 512;
    private static final String SIGN_TYPE = "MD5withRSA";

    private static final int MAX_DECRYPT_BLOCK = KEY_SIZE >> 3;
    private static final int MAX_ENCRYPT_BLOCK = MAX_DECRYPT_BLOCK - 11;

    public static void generateKeyPair() throws NoSuchAlgorithmException {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(KEY_SIZE);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        Key publicKey = keyPair.getPublic();
        Key privateKey = keyPair.getPrivate();
        String publicKeyStr = Base64.getEncoder().encodeToString(publicKey.getEncoded());
        String privateKeyStr = Base64.getEncoder().encodeToString(privateKey.getEncoded());
        System.out.println("pub:" + publicKeyStr);
        System.out.println("pri:" + privateKeyStr);
    }

    public static PrivateKey getPrivateKey(String privateKey) throws Exception {
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        byte[] decodedKey = Base64.getDecoder().decode(privateKey.getBytes());
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(decodedKey);
        return keyFactory.generatePrivate(keySpec);
    }

    public static PublicKey getPublicKey(String publicKey) throws Exception {
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        byte[] decodedKey = Base64.getDecoder().decode(publicKey.getBytes());
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(decodedKey);
        return keyFactory.generatePublic(keySpec);
    }

    public static String encrypt(String data, String pubKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, getPublicKey(pubKey));
        int inputLen = data.getBytes().length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offset = 0;
        byte[] cache;
        int i = 0;
        while (inputLen - offset > 0) {
            if (inputLen - offset > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data.getBytes(), offset, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data.getBytes(), offset, inputLen - offset);
            }
            out.write(cache, 0, cache.length);
            i++;
            offset = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return Base64.getEncoder().encodeToString(encryptedData);
    }

    public static String decrypt(String data, String priKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, getPrivateKey(priKey));
        byte[] dataBytes = Base64.getDecoder().decode(data);
        int inputLen = dataBytes.length;
        try(ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            int offset = 0;
            byte[] cache;
            int i = 0;
            while (inputLen - offset > 0) {
                if (inputLen - offset > MAX_DECRYPT_BLOCK) {
                    cache = cipher.doFinal(dataBytes, offset, MAX_DECRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(dataBytes, offset, inputLen - offset);
                }
                out.write(cache, 0, cache.length);
                i++;
                offset = i * MAX_DECRYPT_BLOCK;
            }
            return out.toString("UTF-8");
        }catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public static String sign(String data, String priKey) throws Exception {
        Signature signature = Signature.getInstance(SIGN_TYPE);
        signature.initSign(getPrivateKey(priKey));
        signature.update(data.getBytes());
        return Base64.getEncoder().encodeToString(signature.sign());
    }

    public static boolean verify(String srcData, String pubKey, String sign) throws Exception {
        Signature signature = Signature.getInstance(SIGN_TYPE);
        signature.initVerify(getPublicKey(pubKey));
        signature.update(srcData.getBytes());
        return signature.verify(Base64.getDecoder().decode(sign));
    }
}