This is an implementation of Open Authentication(http://www.openauthentication.org) OTP (One Time Password) specifications in go.
rfc4226 - HOTP: An HMAC-Based One-Time Password Algorithm (http://www.ietf.org/rfc/rfc4226.txt)
rfc6238 - TOTP: Time-Based One-Time Password Algorithm (http://tools.ietf.org/html/rfc6238)