This library implements HMAC-based One-Time Password (HOTP) and Time-based One-Time Password (TOTP) algorithms.

As this package hasn't reached v1 yet, its API shouldn't be considered stable and can change at any moment. However, it is unlikely to happen.

• HOTP (rfc 4226)
• TOTP (rfc 6238)

Using defaults :

code := otp.TOTP(secret, time.Now(), TOTPOptions{})

Using options :

code := otp.TOTP(secret, time.Now(), TOTPOptions{
  HOTPOptions: HOTPOptions{
    Digits: 8,
  },
  Period: 60,
  Step: -1,
})

Default options are :

• 6 digits
• 30 seconds time period
• SHA1 hash function