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I manage a server with two-factor authentication. I have to use the Google Authenticator iPhone app to get the 6-digit verification code to enter after entering the normal server password. The setup is described here:

I would like a way to get the verification code using just my laptop and not from my iphone. There must be a way to seed a command line app that generates these verification codes and gives you the code for the current 30-second window.

Is there a program that can do this?

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up vote 10 down vote accepted

Yes, oauthtool can do this. You'll need to seed it with the shared secret from your server.

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Is this compatible with the Google Authenticator PAM module? It seems like a different (though functionally equivalent) beast... – voretaq7 Jul 1 '13 at 16:31
Yep - with the --totp flag, it implements the same standards-compliant TOTP alg that Google Authenticator does. – EEAA Jul 1 '13 at 16:37
It's oathtool. In many cases you need both --totp and -b flag (base32 decoding) – Zouppen Feb 5 at 13:51

As far as I'm aware Google only releases the Authenticator application for phones (iOS, Android).
(This poses a problem for paranoid folks like me, who don't really trust Google's history of discontinuing services with little notice, and would prefer a token generator we can see inside of.)

You could consider other alternatives, like a one-time password pad system.

Honestly, getting the verification code from your laptop kind of defeats the two-factor authentication aspect (anyone who captures the laptop now has the code generator - that's part of what Authenticator is supposed to protect against).

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There's many 3rd party Authenticator implementations. Check out the list on the wikipedia page. For instance, you may be able to use onetimepass (which is written in Python) for command line usage.

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There is also a go implementation on github at

This one uses a config file ~/.config/gauth.csv to store the tokens in a the following format abcd efg hijk lmno
aws-account: mygauthtoken

And the output is rather friendly too:

$ gauth
           prev   curr   next
AWS        315306 135387 483601
Airbnb     563728 339206 904549
Google     453564 477615 356846
Github     911264 548790 784099
[=======                      ]
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