totp

README

totp-go

TOTP (Time-based one-time password) for GO according to RFC 6238 (https://datatracker.ietf.org/doc/html/rfc6238).

Supports SHA1, SHA256 and SHA512 hashing. Generates 6,8 or 8 digits long passwords.

Example usage

package main

import (
	"fmt"
	"os"

	"github.com/ironsys-pl/totp-go"
)

func main() {
    secret := "1234567890"
    timeStepSize := 30 // 30 seconds, recommended in RFC
    hashAlgo := totp.HashAlgoSha1
    digits := 6
    // produces 6 digit password, different output every 30 seconds
    pass  := totp.Totp([]byte(secret), time.Now(), timeStepSize, hashAlgo, digits)
}

Documentation

Index

• Constants
• func Totp(secret []byte, t time.Time, timeStepSize int, hashAlgo string, digits int) string

Constants

const (
	HashAlgoSha1   = "SHA1"
	HashAlgoSha256 = "SHA256"
	HashAlgoSha512 = "SHA512"
)

const TimeStepSizeDefault = 30

const TimeStepSizeMax = 31622400

const TimeStepSizeMin = 1

Functions

func Totp

func Totp(secret []byte, t time.Time, timeStepSize int, hashAlgo string, digits int) string

Totp calculates time based one time password as described in RFC 6238.

Password is calculated based on secret, time, timeStepSize (in seconds, 30 is the recommended value, has to be in range of [1, 31622400]), hashing algorithm (SHA1, SHA256 and SHA512 are accepted) and digits (6, 7 or 8). Digits parameter also determines result password length.