Otp.NET库TOTP验证窗口配置异常问题求助

我使用Otp.NET库实现TOTP生成与验证，需求是让生成的TOTP验证码有效期可达7天，但测试代码未达到预期效果。

测试代码 #

using OtpNet;
using System;

// 用于TOTP的密钥（所有测试需保持一致）
byte[] secretKey = Base32Encoding.ToBytes("JBSWY3DPEHPK3PXP");

// 创建Totp实例
Totp totpGenerator = new Totp(secretKey);

// 模拟在当前时间生成TOTP
DateTime generationTime = DateTime.Now;
string totpCode = totpGenerator.ComputeTotp(generationTime);
Console.WriteLine($"TOTP generated on {generationTime}: {totpCode}");

// 测试不同时间点的验证结果
TestTotpValidity(totpCode, generationTime.AddDays(5)); // 5天后验证，预期有效但实际无效
TestTotpValidity(totpCode, generationTime.AddDays(-5)); // 5天前验证，预期无效但实际有效
TestTotpValidity(totpCode, generationTime.AddDays(7)); // 7天后验证，预期有效但实际无效
TestTotpValidity(totpCode, generationTime.AddDays(-7)); // 7天前验证，预期无效但实际有效
TestTotpValidity(totpCode, generationTime.AddDays(8)); // 8天后验证，预期无效且实际无效
TestTotpValidity(totpCode, generationTime.AddDays(-8)); // 8天前验证，预期无效且实际无效

void TestTotpValidity(string totpCode, DateTime verificationTime)
{
    var validator = new Totp(secretKey);
    long timeStepMatched;
    // 自定义验证窗口：每天2880个时间步长，预期覆盖7天有效期
    bool isValid = validator.VerifyTotp(verificationTime, totpCode, out timeStepMatched, new VerificationWindow(previous: 2, future: 2880 * 7));

    Console.ForegroundColor = isValid ? ConsoleColor.DarkGreen : ConsoleColor.DarkRed;
    Console.WriteLine($"Verifying TOTP on {verificationTime} (time step matched {timeStepMatched}): {isValid}");
    Console.ResetColor();
}

控制台输出 #

TOTP generated on 05/16/2024 10:08:22: 935002
39;49mVerifying TOTP on 05/21/2024 10:08:22 (time step matched 0): False
[39;49m[39;49mVerifying TOTP on 05/11/2024 10:08:22 (time step matched 57195136): True
[39;49m[39;49mVerifying TOTP on 05/23/2024 10:08:22 (time step matched 0): False
[39;49m[39;49mVerifying TOTP on 05/09/2024 10:08:22 (time step matched 57195136): True
[39;49m[39;49mVerifying TOTP on 05/24/2024 10:08:22 (time step matched 0): False
[39;49m[39;49mVerifying TOTP on 05/08/2024 10:08:22 (time step matched 0): False
[39;49m

补充说明 #

• 生成与验证使用不同的Totp实例，理论上应支持任意时间点的验证
• 最终需求是实现单次验证，但当前需先确保验证窗口配置正确，预期当日生成的TOTP可在7天内有效

请问我是否误解了库的文档内容，或是代码存在错误？

内容的提问来源于stack exchange，提问作者Iker Ocio Zuazo