谷歌Google authenticator 整合到JAVA項目

前言:

     最近項目中,需要使用到谷歌的驗證碼,就採用了這種.....
     其實還可以使用reCaptcha來做,不過移動端還是採用authenticator 會方便點,

    如果想了解reCaptcha,移步到這裏:https://blog.csdn.net/baidu_38990811/article/details/86530350

原理:

1.客戶端每30秒使用密鑰『DPI45HKISEXU6HG7』和時間戳通過一種『算法』生成一個6位數字的一次性密碼

2.用戶登陸時輸入一次性密碼『684060』。

3.服務器端使用保存在數據庫中的密鑰『DPI45HKISEXU6HG7』和時間戳通過同一種『算法』生成一個6位數字的一次性密碼。大家都懂控制變量法，如果算法相同、密鑰相同，又是同一個時間（時間戳相同），那麼客戶端和服務器計算出的一次性密碼是一樣的。服務器驗證時如果一樣，就登錄成功了。

思路:

1.手機下載Google authenticator 驗證器

2.在app界面上,無論是掃碼還是手動添加都行,我是直接手動添加,
測試的話,賬號隨便輸入,正式的話,我都是採用用戶手機號,祕鑰是16位,生成方法,在下面,

3.工具類

import org.apache.commons.codec.binary.Base32;
import org.apache.commons.codec.binary.Base64;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

/**
 * 描述:
 * 〈谷歌驗證器工具類〉
 *
 * @author Monkey
 * @create 2020/5/4 18:32
 */
public class GoogleAuthenticator {

    // taken from Google pam docs - we probably don't need to mess with these  
    public static final int SECRET_SIZE = 10;

    public static final String SEED = "g8GjEvTbW5oVSV7avLBdwIHqGlUYNzKFI7izOF8GwLDVKs2m0QN7vxRs2im5MDaNCWGmcD2rvcZx";

    public static final String RANDOM_NUMBER_ALGORITHM = "SHA1PRNG";

    // default 3 - max 17 (from google docs)最多可偏移的時間
    int window_size = 3;

    public void setWindowSize(int s) {
        if (s >= 1 && s <= 17){
            window_size = s;
        }
    }


    public static Boolean authcode(String codes, String savedSecret) {
        // enter the code shown on device. Edit this and run it fast before the  
        // code expires!  
        long code = Long.parseLong(codes);
        long t = System.currentTimeMillis();
        GoogleAuthenticator ga = new GoogleAuthenticator();
        // should give 5 * 30 seconds of grace...
        ga.setWindowSize(15);
        boolean r = ga.check_code(savedSecret, code, t);
        return r;
    }

    public static String genSecret(String user) {
        String secret = GoogleAuthenticator.generateSecretKey();
        GoogleAuthenticator.getQRBarcodeURL(user,
                "testhost", secret);
        return secret;
    }

    public static String generateSecretKey() {
        SecureRandom sr = null;
        try {
            sr = SecureRandom.getInstance(RANDOM_NUMBER_ALGORITHM);
            sr.setSeed(Base64.decodeBase64(SEED));
            byte[] buffer = sr.generateSeed(SECRET_SIZE);
            Base32 codec = new Base32();
            byte[] bEncodedKey = codec.encode(buffer);
            String encodedKey = new String(bEncodedKey);
            return encodedKey;
        } catch (NoSuchAlgorithmException e) {
            // should never occur... configuration error  
        }
        return null;
    }


    public static String getQRBarcodeURL(String user, String host, String secret) {
        String format = "https://www.google.com/chart?chs=200x200&chld=M%%7C0&cht=qr&chl=otpauth://totp/%s@%s%%3Fsecret%%3D%s";
        return String.format(format, user, host, secret);
    }


    public boolean check_code(String secret, long code, long timeMsec) {
        Base32 codec = new Base32();
        byte[] decodedKey = codec.decode(secret);
        // convert unix msec time into a 30 second "window"  
        // this is per the TOTP spec (see the RFC for details)  
        long t = (timeMsec / 1000L) / 30L;
        // Window is used to check codes generated in the near past.  
        // You can use this value to tune how far you're willing to go.  
        for (int i = -window_size; i <= window_size; ++i) {
            long hash;
            try {
                hash = verify_code(decodedKey, t + i);
            } catch (Exception e) {
                // Yes, this is bad form - but  
                // the exceptions thrown would be rare and a static configuration problem  
                //e.printStackTrace();
                throw new RuntimeException(e.getMessage());
                //return false;
            }
            if (hash == code) {
                return true;
            }
        }
        // The validation code is invalid.  
        return false;
    }

    private static int verify_code(byte[] key, long t) throws NoSuchAlgorithmException, InvalidKeyException {
        byte[] data = new byte[8];
        long value = t;
        for (int i = 8; i-- > 0; value >>>= 8) {
            data[i] = (byte) value;
        }
        SecretKeySpec signKey = new SecretKeySpec(key, "HmacSHA1");
        Mac mac = Mac.getInstance("HmacSHA1");
        mac.init(signKey);
        byte[] hash = mac.doFinal(data);
        int offset = hash[20 - 1] & 0xF;
        // We're using a long because Java hasn't got unsigned int.  
        long truncatedHash = 0;
        for (int i = 0; i < 4; ++i) {
            truncatedHash <<= 8;
            // We are dealing with signed bytes:  
            // we just keep the first byte.  
            truncatedHash |= (hash[offset + i] & 0xFF);
        }
        truncatedHash &= 0x7FFFFFFF;
        truncatedHash %= 1000000;
        return (int) truncatedHash;
    }
}  

4.調用方法,生成祕鑰

GoogleAuthenticator.genSecret(user.getTel());

5.調用方法(參數爲手機號和驗證碼),進行驗證

GoogleAuthenticator.authcode(codes, userEntity.getPrivateKey());

大致流程:

    1. 用戶使用我們的產品,進行註冊,會生成祕鑰存到該用戶記錄上,然後用戶自己去下載谷歌驗證器,填入該祕鑰和手機號
    2.在業務需要的地方,讓用戶傳遞驗證碼(這個驗證碼是一次性的,每30s刷新一次)給我們,這個驗證碼則需要用戶自己登陸谷歌驗證器app中去查看