A simple, correct TOTP library.

Time-based One-time Passwords are a useful way to authenticate a client, since a valid password expires long before it could ever be guessed by an attacker. This library provides an implementation of TOTP that matches its specification RFC6238, along with a simple interface.

The Totp function is likely what you need. It uses the default time step of 30 seconds and produces 8 digits of output:

 // Negotiated between you and the authenticating service.
 password := []byte("secret")

 // The number of seconds since the Unix Epoch.
 seconds := uint64(time.Now().Unix())

 // Specify the desired Hash algorithm from the Standard Library.
 // For TOTP, sha1 and sha256 are also valid.
 totp := Totp(sha512.New, password, seconds)

For full control over how the algorithm is configured, consider TotpCustom.

• RFC6238: TOTP
• RFC6238 Errata

License: MIT