go_totp

README

go_totp

go_totp is a Go package for generating Time-based One-Time Passwords (TOTP) conforming to RFC 6238. It supports multiple hash algorithms, including HMAC-SHA1, HMAC-SHA256, and HMAC-SHA512.

Features

• Supports HMAC-SHA1, HMAC-SHA256, and HMAC-SHA512 algorithms.
• Configurable TOTP parameters such as digit length, time step, and initial counter value.
• Easy-to-use interface for generating TOTPs.

Installation

To install the package, run:

go get github.com/michaelwp/go_totp

Usage

Here's a step-by-step guide on how to use the go_totp library to generate a TOTP.

Import the Package

First, import the package into your Go code:

import "github.com/michaelwp/go-totp"

Create a TOTP Instance

Create an instance of the Totp struct with the desired configuration. For example, to create a TOTP generator using HMAC-SHA256 with a 8-digit output:

totp := go_totp.Totp{
    Secret:    "rahasia",
    Digits:    8,
    Period:    15,
    Algorithm: go_totp.SHA256,
    T0:        0,
}

TOTP Struct

The Totp struct contains the following fields:

• Secret: The shared secret key used for generating the TOTP.
• Digits: The number of digits in the TOTP output.
• Period: The time step in seconds (default is 30 seconds).
• Algorithm: The hash algorithm to use (SHA1, SHA256, or SHA512).
• T0: The initial counter value (default is 0).

Generating the TOTP

To generate the TOTP, call the GenerateTOTP method on the Totp instance, passing the current Unix timestamp as the argument. This method returns the generated TOTP as a string.

Example

Here's a complete example demonstrating how to use the go_totp package:

package main

import (
	"fmt"
	"github.com/michaelwp/go-totp"
	"log"
	"time"
)

func main() {
	// Get the current Unix time
	timestamp := time.Now().Unix()

	// define the variables
	totp := go_totp.Totp{
		Secret:    "rahasia",
		Digits:    8,
		Period:    15,
		Algorithm: go_totp.SHA256,
		T0:        0,
	}

	// Generate the TOTP
	pass, err := totp.GenerateTOTP(timestamp)
	if err != nil {
		log.Println("GenerateTOTP error:", err)
	}

	// Print the TOTP
	fmt.Println("TOTP:", pass)
}

Running the Example

To run the example, save it to a file (e.g., main.go), and then run:

go run main.go

This will output a 8-digit TOTP based on the provided user ID and the current Unix time.

License

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

Contributing

Contributions are welcome! Please open an issue or submit a pull request with your changes.

Contact

For any questions or issues, please open an issue on GitHub.

Documentation

Index

• Constants
• type Totp
  • func (t Totp) GenerateTOTP(timestamp int64) (string, error)

Constants

const (
	SHA1 algorithm = iota
	SHA256
	SHA512
)

Types

type Totp

type Totp struct {
	Secret    string
	Digits    int
	Period    int64
	Algorithm algorithm
	T0        int64
}

func (Totp) GenerateTOTP

func (t Totp) GenerateTOTP(timestamp int64) (string, error)