Inherits from AGOtp : NSObject
Declared in AGTotp.h
AGTotp.m

Overview

The Totp class generates a one-time password (OTP) using the Time-based One-time Password Algorithm described in: http://tools.ietf.org/html/draft-mraihi-totp-timebased

Basically, we define TOTP as TOTP = HOTP(K, T) where T is an integer and represents the number of time steps between the initial counter time T0 and the current Unix time (i.e. the number of seconds elapsed since midnight UTC of January 1, 1970).

More specifically T = (Current Unix time – T0) / X where:

  • X represents the time step in seconds (default value X = 30 seconds) and is a system parameter;

  • T0 is the Unix time to start counting time steps (default value is 0, Unix epoch) and is also a system parameter.

Tasks

Other Methods

  • – initWithSecret:

    Returns an AGTotp object initialized with a secret specified by the given string.
  • – now

    Generate an TOTP token using the current time.
  • – now:

    Generate an TOTP token using the specified AGClock.

Other Methods

Instance Methods

generateOTP

Entry point to generate an OTP token.

- (NSString *)generateOTP

Return Value

An NSString that contains the token with leading zero-padding as required.

Discussion

Entry point to generate an OTP token.

NOTE: Subclasses should override this method.

Declared In

AGOtp.h

initWithSecret:

Returns an AGTotp object initialized with a secret specified by the given string.

- (id)initWithSecret:(NSData *)secret

Parameters

secret

The secret to use.

Return Value

An AGTotp object initialized by the specified secret.

Discussion

Returns an AGTotp object initialized with a secret specified by the given string.

Declared In

AGTotp.h

now

Generate an TOTP token using the current time.

- (NSString *)now

Return Value

An NSString that contains the token with leading zero-padding as required.

Discussion

Generate an TOTP token using the current time.

Declared In

AGTotp.h

now:

Generate an TOTP token using the specified AGClock.

- (NSString *)now:(AGClock *)clock

Parameters

clock

The AGClock object to use.

Return Value

An NSString that contains the token with leading zero-padding as required.

Discussion

Generate an TOTP token using the specified AGClock.

Declared In

AGTotp.h