Google Authenticator 2FA 总是返回 True

Question

我在 ASP.NET 应用程序中使用GoogleAuthenticator nuget 包进行2FA 身份验证。问题是函数ValidateTwoFactorPIN 总是返回true，即使验证器应用程序已经更改了TOTP 代码。 Nuget Package

public TwoFactorSetupResponse Enable(string email)
        {
            var accountSecretKey = $"{SecretCode}-{email}";
            var setupInfo = _twoFactorAuthenticator.GenerateSetupCode("App", email, Encoding.ASCII.GetBytes(accountSecretKey));

            return new TwoFactorSetupResponse()
            {
                Account = setupInfo.Account,
                ManualEntryKey = setupInfo.ManualEntryKey,
                QrCodeSetupImageUrl = setupInfo.QrCodeSetupImageUrl,
            };
        }

        public bool IsCodeValid(string email, string code)
        {
            var accountSecretKey = $"{SecretCode}-{email}";
            return _twoFactorAuthenticator.ValidateTwoFactorPIN(accountSecretKey, code);
        }

Answer 1

那个包的默认drift tolerance是five minutes，所以要么用较小的容差进行测试，要么等到容差窗口过去。