Simple CLI app that generates tokens compatible with Google Authenticator. I implemented this mainly to understand how it works, you should probably not use this.

Example output:

$ go run main.go -secret "<your key>"
934523 (17 second(s) remaining)

Relevant RFCs:

• http://tools.ietf.org/html/rfc4226
• http://tools.ietf.org/html/rfc6238