<?php
namespace Otp;
/**
* Interface for HOTP and TOTP
*
* HMAC-Based One-time Password(HOTP) algorithm specified in RFC 4226
* @link https://tools.ietf.org/html/rfc4226
*
* Time-based One-time Password (TOTP) algorithm specified in RFC 6238
* @link https://tools.ietf.org/html/rfc6238
*
* @author Christian Riesen <chris.riesen@gmail.com>
* @link http://christianriesen.com
* @license MIT License see LICENSE file
*/
interface OtpInterface
{
/**
* Returns OTP using the HOTP algorithm (counter based)
*
* @param string $secret Base32 Secret String
* @param integer $counter Counter
*
* @return string One Time Password
*/
function hotp($secret, $counter);
/**
* Returns OTP using the TOTP algorithm (time based)
*
* @param string $secret Base32 Secret String
* @param integer $timecounter Optional: Uses current time if null
*
* @return string One Time Password
*/
function totp($secret, $timecounter = null);
/**
* Checks Hotp against a key
*
* This is a helper function, but is here to ensure the Totp can be checked
* in the same manner.
*
* @param string $secret Base32 Secret String
* @param integer $counter Counter
* @param string $key User supplied key
*
* @return boolean True if key is correct
*/
function checkHotp($secret, $counter, $key);
/**
* Checks Hotp against a key for a provided counter window
*
* @param string $secret Base32 Secret String
* @param integer $counter Counter
* @param string $key User supplied key
* @param integer $counterwindow (optional) Size of the look-ahead window. Default value is 2
*
* @return int|boolean the counter if key is correct else false
*/
function checkHotpResync($secret, $counter, $key, $counterwindow = 2);
/**
* Checks Totp against a key
*
* @param string $secret Base32 Secret String
* @param string $key User supplied key
* @param integer $timedrift How large a drift to use beyond exact match
*
* @return boolean True if key is correct within time drift
*/
function checkTotp($secret, $key, $timedrift = 1);
}