MFA多因素驗證-java實現

依據谷歌官方的算法實現mfa認證：

谷歌mfa算法工具(直接copy后改了下)：

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 RANDOM_NUMBER_ALGORITHM = "SHA1PRNG";

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

    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();
        ga.setWindowSize(15); // should give 5 * 30 seconds of grace...
        boolean r = ga.check_code(savedSecret, code, t);
        return r;
    }

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

    public static String generateSecretKey(String name) {
        SecureRandom sr = null;
        try {
            sr = SecureRandom.getInstance(RANDOM_NUMBER_ALGORITHM);
            sr.setSeed(Base64.decodeBase64(UUID.randomUUID().toString()+name));
            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;
    }

　　//獲取二維碼的url
    public static String getQRBarcodeURL(String user, String host, String secret) {
        String format = "otpauth://totp/%s@%s?secret=%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 Exception {
        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;
    }
}

使用方法：

    @Test
    public void genSecretTest() {
　　　　  //生成secret
        String secret = GoogleAuthenticator.generateSecretKey("test");
　　　　  //生成二維碼url
        String url = GoogleAuthenticator.getQRBarcodeURL("test", "testhost", secret);
        QrConfig qrConfig = new QrConfig();
        qrConfig.setErrorCorrection(ErrorCorrectionLevel.L);
        qrConfig.setWidth(200);
        qrConfig.setHeight(200);
　　　　　//生成二維碼，生成后需要手機下載谷歌或者微軟的Authenticator進行掃描綁定
        QrCodeUtil.generate(url, qrConfig, FileUtil.file("d:/qrcode.jpg"));
        System.out.println("Please register " + url);
        System.out.println("Secret key is " + secret);
    }

    //在測試之前保存上一步生成的secret.
    static String savedSecret = "XLFAQII7HRRMZEP3";

    @Test
    public void authTest() {
        //code碼為0開頭的去掉0再進行驗證,否則類型超范圍
        long code = 驗證器的驗證碼;
        long t = System.currentTimeMillis();
        GoogleAuthenticator ga = new GoogleAuthenticator();
        ga.setWindowSize(5); //寬限時間5*30秒
        boolean r = ga.check_code(savedSecret, code, t);
        System.out.println("Check code = " + r);
    }