What is SecureOTP-Generator?

SecureOTP-Generator is a C# library for generating Time-based One-Time Passwords (TOTP) and HMAC-based One-Time Passwords (HOTP), in accordance with the standards specified in RFC 4226 and RFC 6238. These OTPs are commonly used in two-factor authentication (2FA) systems to enhance security.

Features

• TOTP Generation: Generate time-based OTPs with configurable time periods, algorithms, and digits.
• HOTP Generation: Generate counter-based OTPs with configurable counters, algorithms, and digits.
• Configurable Algorithms: Supports MD5, SHA1, SHA256, and SHA512 hashing algorithms.
• Base32 Secret Keys: Utilizes Base32-encoded secret keys for secure OTP generation.

Installation

To integrate this library into your project:

Download the lib from the latest releases: https://github.com/StillAching/SecureOTP-Generator/releases Then reference the file in your project.

OR

1. Clone the repository:

   git clone https://github.com/StillAching/SecureOTP-Generator.git

2. Add the .cs files from the cloned repository to your C# project.

Usage & Examples

TOTP Example

To generate a TOTP, instantiate the TOTP class and configure it as follows:

using System;

public class Program
{
    public static void Main()
    {
        var totp = new SecureOTPGenerator.TOTP
        {
            Secret = "PUT SECRET HERE!!!",                      // Required
            Digits = 6,                                         // Optional (default is 6)
            Algorithm = SecureOTPGenerator.HashAlgorithm.SHA1,  // Optional (default is SHA1)
            Period = 30,                                        // Optional (default is 30 seconds) [30 seconds period is common for TOTP]
            //UnixTime = 99999999999                            // Optional (default is current Unix time)
        };

        string otp = totp.Generate();
        Console.WriteLine($"Generated TOTP: {otp}");
    }
}

HOTP Example

To generate an HOTP, use the HOTP class:

using System;

public class Program
{
    public static void Main()
    {
        var hotp = new SecureOTPGenerator.HOTP
        {
            Secret = "PUT SECRET HERE!!!",  // Required
            Digits = 6,                     // Optional (default is 6)
            Counter = 0                     // Optional (default is 0)
        };

        string otp = hotp.Generate();
        Console.WriteLine($"Generated HOTP: {otp}");
    }
}

Configuration

TOTP Configuration

• Secret: Base32-encoded string used as the secret key. (Required)
• Digits: Number of digits in the OTP (default is 6).
• Algorithm: Hashing algorithm to use (MD5, SHA1, SHA256, SHA512). Default is set to SHA1.
• Period: Time period in seconds for the TOTP (default is 30 seconds).
• UnixTime: Unix timestamp for generating the OTP. Defaults to the current time.

HOTP Configuration

• Secret: Base32-encoded string used as the secret key. (Required)
• Digits: Number of digits in the OTP (default is 6).
• Counter: Counter value used for generating the OTP (default is 0).

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License. See the LICENSE file for details.