README
¶
onetime
An one-time password generation library written in Go, implementing HOTP (RFC-4226) and TOTP (RFC-6238).
Example usage
Simple 6-digit HOTP code:
import "onetime"
var secret = []byte("SOME_SECRET")
var counter = 123456
var otp = onetime.Simple(6)
var code = otp.HOTP(secret, counter)
Google authenticator style 8-digit TOTP code:
import "onetime"
var secret = []byte("SOME_SECRET")
var otp = onetime.Simple(8)
var code = otp.TOTP(secret)
9-digit 5-second-step TOTP starting on midnight 2000-01-01 UTC, using SHA-256:
import (
"crypto/sha256"
"onetime"
"time"
)
var secret = []byte("SOME_SECRET")
var ts, _ = time.ParseDuration("5s")
var t = time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
var otp = onetime.OneTimePassword{Digit: 9, TimeStep: ts, BaseTime: t, Hash: sha256.New}
var code = otp.TOTP(secret)
Documentation
Package doc can be found at pkgdoc.org.
License
This library is released under a simplified BSD license.
Documentation
¶
Overview ¶
Package onetime provides a library for one-time password generation, implementing the HOTP and TOTP algorithms as specified by IETF RFC-4226 and RFC-6238.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type OneTimePassword ¶
type OneTimePassword struct {
Digit int // Length of code generated
TimeStep time.Duration // Length of each time step for TOTP
BaseTime time.Time // The start time for TOTP step calculation
Hash func() hash.Hash // Hash algorithm used with HMAC
}
OneTimePassword stores the configuration values relevant to HOTP/TOTP calculations.
func Simple ¶
func Simple(digit int) (otp OneTimePassword, err error)
Simple returns a new OneTimePassword with the specified HTOP code length, SHA-1 as the HMAC hash algorithm, the Unix epoch as the base time, and 30 seconds as the step length.
func (*OneTimePassword) HOTP ¶
func (otp *OneTimePassword) HOTP(secret []byte, count uint64) uint
HOTP returns a HOTP code with the given secret and counter.
func (*OneTimePassword) TOTP ¶
func (otp *OneTimePassword) TOTP(secret []byte) uint
TOTP returns a TOTP code calculated with the current time and the given secret.
Source Files