c# 谷歌动态口令对接

https://www.cnblogs.com/easyauthor/p/11054869.html

Google 身份验证器与两步验证功能配合，可在您登录 Google 帐户时为您平添一重安全保障。

启用两步验证之后，当您登录帐户时，需要提供密码和此应用生成的验证码。配置完成后，无需网络连接或蜂窝连接即可获得验证码。

功能包括：

- 通过 QR 码自动设置

- 支持多帐户登录

- 支持基于时间和基于计数器生成验证码

要使用 Google 身份验证器，需要先为您的 Google 帐户启用两步验证。访问 http://www.google.com/2step 即可立即启用。

demo：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace GoogleAuthenticator
{
    class Program
    {
        static void Main(string[] args)
        {
            long duration = ;
            string key = "xeon997@foxmail.com";
            GoogleAuthenticator authenticator = new GoogleAuthenticator(duration, key);
            var mobileKey = authenticator.GetMobilePhoneKey();

            while (true)
            {

                Console.WriteLine("手机端秘钥为：" + mobileKey);

                var code = authenticator.GenerateCode();
                Console.WriteLine("动态验证码为：" + code);

                Console.WriteLine("刷新倒计时：" + authenticator.EXPIRE_SECONDS);

                System.Threading.Thread.Sleep();
                Console.Clear();
            }
        }
    }
}

认证器：

using GoogleAuthorization;
using System;
using System.Security.Cryptography;
using System.Text;
namespace GoogleAuthenticator
{
    public class GoogleAuthenticator
    {
        /// <summary>
        /// 初始化验证码生成规则
        /// </summary>
        /// <param name="key">秘钥(手机使用Base32码)</param>
        /// <param name="duration">验证码间隔多久刷新一次（默认30秒和google同步）</param>
        public GoogleAuthenticator(long duration = , string key = "xeon997@foxmail.com")
        {
            this.SERECT_KEY = key;
            this.SERECT_KEY_MOBILE = Base32.ToString(Encoding.UTF8.GetBytes(key));
            this.DURATION_TIME = duration;
        }

        /// <summary>
        /// 间隔时间
        /// </summary>
        private long DURATION_TIME { get; set; }

        /// <summary>
        /// 迭代次数
        /// </summary>
        private long COUNTER
        {
            get
            {
                return (long)(DateTime.UtcNow - new DateTime(, , , , , , DateTimeKind.Utc)).TotalSeconds / DURATION_TIME;
            }
        }

        /// <summary>
        /// 秘钥
        /// </summary>
        private string SERECT_KEY { get; set; }

        /// <summary>
        /// 手机端输入的秘钥
        /// </summary>
        private string SERECT_KEY_MOBILE { get; set; }

        /// <summary>
        /// 到期秒数
        /// </summary>
        public long EXPIRE_SECONDS
        {
            get
            {
                return (DURATION_TIME - (long)(DateTime.UtcNow - new DateTime(, , , , , , DateTimeKind.Utc)).TotalSeconds % DURATION_TIME);
            }
        }

        /// <summary>
        /// 获取手机端秘钥
        /// </summary>
        /// <returns></returns>
        public string GetMobilePhoneKey()
        {
            if (SERECT_KEY_MOBILE == null)
                throw new ArgumentNullException("SERECT_KEY_MOBILE");
            return SERECT_KEY_MOBILE;
        }

        /// <summary>
        /// 生成认证码
        /// </summary>
        /// <returns>返回验证码</returns>
        public string GenerateCode()
        {
            return GenerateHashedCode(SERECT_KEY, COUNTER);
        }

        /// <summary>
        /// 按照次数生成哈希编码
        /// </summary>
        /// <param name="secret">秘钥</param>
        /// <param name="iterationNumber">迭代次数</param>
        /// <param name="digits">生成位数</param>
        /// <returns>返回验证码</returns>
        private string GenerateHashedCode(string secret, long iterationNumber, int digits = )
        {
            byte[] counter = BitConverter.GetBytes(iterationNumber);

            if (BitConverter.IsLittleEndian)
                Array.Reverse(counter);

            byte[] key = Encoding.ASCII.GetBytes(secret);

            HMACSHA1 hmac = new HMACSHA1(key, true);

            byte[] hash = hmac.ComputeHash(counter);

            int offset = hash[hash.Length - ] & 0xf;

            int binary =
                ((hash[offset] & 0x7f) << )
                | ((hash[offset + ] & 0xff) << )
                | ((hash[offset + ] & 0xff) << )
                | (hash[offset + ] & 0xff);

            int password = binary % (int)Math.Pow(, digits); // 6 digits

            return password.ToString(new string('', digits));
        }
    }
}

 Base32转码类

using System;
namespace GoogleAuthorization
{
    public static class Base32
    {
        public static byte[] ToBytes(string input)
        {
            if (string.IsNullOrEmpty(input))
            {
                throw new ArgumentNullException("input");
            }

            input = input.TrimEnd('=');
            int byteCount = input.Length *  / ;
            byte[] returnArray = new byte[byteCount];

            byte curByte = , bitsRemaining = ;
            int mask = , arrayIndex = ;

            foreach (char c in input)
            {
                int cValue = CharToValue(c);

                if (bitsRemaining > )
                {
                    mask = cValue << (bitsRemaining - );
                    curByte = (byte)(curByte | mask);
                    bitsRemaining -= ;
                }
                else
                {
                    mask = cValue >> ( - bitsRemaining);
                    curByte = (byte)(curByte | mask);
                    returnArray[arrayIndex++] = curByte;
                    curByte = (byte)(cValue << ( + bitsRemaining));
                    bitsRemaining += ;
                }
            }

            if (arrayIndex != byteCount)
            {
                returnArray[arrayIndex] = curByte;
            }

            return returnArray;
        }

        public static string ToString(byte[] input)
        {
            if (input == null || input.Length == )
            {
                throw new ArgumentNullException("input");
            }

            int charCount = (int)Math.Ceiling(input.Length / 5d) * ;
            char[] returnArray = new char[charCount];

            byte nextChar = , bitsRemaining = ;
            int arrayIndex = ;

            foreach (byte b in input)
            {
                nextChar = (byte)(nextChar | (b >> ( - bitsRemaining)));
                returnArray[arrayIndex++] = ValueToChar(nextChar);

                if (bitsRemaining < )
                {
                    nextChar = (byte)((b >> ( - bitsRemaining)) & );
                    returnArray[arrayIndex++] = ValueToChar(nextChar);
                    bitsRemaining += ;
                }

                bitsRemaining -= ;
                nextChar = (byte)((b << bitsRemaining) & );
            }

            if (arrayIndex != charCount)
            {
                returnArray[arrayIndex++] = ValueToChar(nextChar);
                while (arrayIndex != charCount) returnArray[arrayIndex++] = '=';
            }

            return new string(returnArray);
        }

        private static int CharToValue(char c)
        {
            var value = (int)c;

            if (value <  && value > )
            {
                return value - ;
            }
            if (value <  && value > )
            {
                return value - ;
            }
            if (value <  && value > )
            {
                return value - ;
            }

            throw new ArgumentException("Character is not a Base32 character.", "c");
        }

        private static char ValueToChar(byte b)
        {
            if (b < )
            {
                return (char)(b + );
            }

            if (b < )
            {
                return (char)(b + );
            }

            throw new ArgumentException("Byte is not a value Base32 value.", "b");
        }
    }
}

关于二维码的内容：

 String format = "otpauth://totp/帐号?secret=密钥";
生成二维码就可以了。

有用的请点赞下 谢谢。