Google 谷歌身份验证器 JAVA

package com.mange.sys.util;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base32;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;

import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Base64;
import java.util.List;

public class GoogleAuthUtil {
    /**
     * 获取当前时间
     * @return
     */
    public static long get_cur_time(){
        long ctime = System.currentTimeMillis() / 1000 / 30;
        return ctime;
    }

    /**
     * 获取上一个时间
     * @return
     */
    public static long get_pri_time(){
        return GoogleAuthUtil.get_cur_time() - 1;
    }

    /**
     * 获取下一个时间
     * @return
     */
    public static long get_next_time(){
        return GoogleAuthUtil.get_cur_time() + 1;
    }

    /**
     * 获取秘钥
     * @return
     */
    public static byte[] get_key(){
        SecureRandom secureRandom = new SecureRandom();
        return secureRandom.generateSeed(32);
    }

    /**
     * 获取秘钥  base32
     * @return
     */
    public static String get_key_base32(){
        Base32 base32 = new Base32();
        return base32.encodeAsString(GoogleAuthUtil.get_key());
    }

    /**
     * 验证动态面是否正确
     * @param base64_key
     * @param code
     * @return
     */
    public static boolean auth_code(String base64_key,String code){
        long cur_time = GoogleAuthUtil.get_cur_time();
        long pri_time = GoogleAuthUtil.get_pri_time();
        long next_time = GoogleAuthUtil.get_next_time();
        List<Long> times = Arrays.asList(cur_time, pri_time, next_time);
        byte[] hash = null;
        byte[] key_byte = Base64.getDecoder().decode(base64_key);
        for (Long time : times) {
            hash = GoogleAuthUtil.get_hash( GoogleAuthUtil.get_time_byte(time),key_byte);
            if (GoogleAuthUtil.get_code(hash).equals(code)){
                return true;
            }
        }
        return false;
    }

    /**
     * 生成url
     * @param name
     * @param key
     * @return
     */
    public static String get_qrcode_url(String name,byte [] key){
        Base32 base32 = new Base32();
        String str = base32.encodeAsString(key);
        return "otpauth://totp/"+name+"?secret=" + str;
    }

    public static String get_qrcode_url(String name){
        Base32 base32 = new Base32();
        String str = base32.encodeAsString(GoogleAuthUtil.get_key());
        return "otpauth://totp/"+name+"?secret=" + str;
    }
    
    /**
     * 获取时间byte
     * @param ctime
     * @return
     */
    public static byte[] get_time_byte(long ctime){
        //hex 长度补齐
        String hex = Long.toHexString(ctime);
        while (hex.length() < 16) hex = "0" + hex;
        byte[] time_byte = null;
        try {
            time_byte = Hex.decodeHex(hex);
        } catch (DecoderException e) {
            e.printStackTrace();
        }
        return time_byte;
    }

    /**
     * 根据时间 keu 获得hahs值
     * @param time
     * @param key_byte
     * @return
     */
    public static byte[] get_hash(byte[] time,byte[] key_byte){
        SHA1Digest digest = new SHA1Digest();
        HMac hMac = new HMac(digest);
        hMac.init( new KeyParameter(key_byte));
        hMac.update(time,0,time.length);
        byte [] result = new byte[hMac.getMacSize()];
        hMac.doFinal(result,0);
        return result;
    }

    /**
     * 根据hash组织计算动态密码
     * @param hash
     * @return
     */
    public static String get_code(byte[] hash){
        //偏移量
        int offset = hash[20 - 1] & 0xF;
        //java 中的int 类型没有无符号类型 所以使用long进行代替
        long trunHash = 0;
        for (int i = 0; i < 4; ++i) {
            trunHash <<= 8;
            //处理有符号类型byte 保留第一个字节
            trunHash |= (hash[offset + i] & 0xFF);
        }
        trunHash &= 0x7FFFFFFF;
        //取值六位动态密码 0 - 999999
        trunHash %= 1000000;
        return String.format("%06d", trunHash);
    }
}