Two Factor Authentication
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Background
At identityVector, we are always working to provide the most secure services possible. We're pleased to offer user-initiated Two Factor Authentication to our SSH, SCP, and SFTP users. This service is OPTIONAL, and can be added or removed as you like. Note that this is considered an advanced feature, so please don't configure it without fully understanding the potential impacts.
Two-factor authentication (2FA) is an authentication mechanism that requires information from a physical token of some kind in addition to your password before granting access. This means that successful 2FA requires both "something you know" (password) and "something you have" (the token). identityVector has evaluated several solutions, and selected Google Authenticator as our 2FA provider. With the Google Authenticator 2FA system, you can use an iOS, Android, Windows, Blackberry device as a token, as well as several others.
- For more information on 2FA in general, you may want to consult the Wikipedia page at http://en.wikipedia.org/wiki/Two-factor_authentication
- For more information on the Google Authenticator solution, consult the Wikipedia page at http://en.wikipedia.org/wiki/Google_Authenticator
- The code used for our Google Authenticator 2FA can be reviewed at http://code.google.com/p/google-authenticator/
Caveats
- Currently, key-based authentication overrides 2FA on our systems. If you have a valid SSH key authorized for your IVS SSH account, 2FA is ignored entirely.
- Our 2FA configuration is enabled for SSH, SCP, and SFTP access only. No other services have been configured to support 2FA at this time.
- Client-specific nuances will be added to this page as they are discovered. If you find a particular client is not working, but one of our supported clients works with 2FA, please let us know the name of the client software.
- The setup process will generate emergency scratch codes that will allow you to access IVS servers without the token. These should be maintained in a safe place. They may only be used once each. If you exhaust your emergency scratch codes, just re-accomplish the setup process.
Escape Clauses
- If you wish to stop using 2FA with your IVS account, simply remove the "~/.google_authenticator" file at any time. Use one of your emergency scratch codes to access the system if needed. If you don't have access to the emergency scratch codes, contact us for help. Be advised that we'll need to authenticate you via phone or other similar means before disabling 2FA for your account. This may take several hours.
- To start over, just remove the "~/.google_authenticator" file and re-accomplish the setup steps detailed below.
Setup Process
To enable 2FA for SSH access to the IVS system, follow these steps:
- SSH to the identityVector system:
Philip-Hagens-iMac:~ phil$ ssh phil@sftp.identityvector.com
This is a private computer system. Unauthorized users are hereby notified that
there is no expectation of privacy for their actions on this system, and
authorize the system administrators to record all unauthorized traffic for the
purposes of subsequent law enforcement actions.
-IdentityVector Solutions, LLC
Last login: Sat May 5 15:18:03 2012 from c-98-252-9-205.hsd1.de.comcast.net
[phil@quaff ~]$
- Run the "google-authenticator" utility. You'll be asked several questions - the following indicates our supported configuration. You can select any options you like, but you're on your own.
[phil@quaff ~]$ google-authenticator Do you want authentication tokens to be time-based (y/n) y https://www.google.com/chart?chs=200x200&chld=M|0&cht=qr&chl=otpauth://totp/phil@quaff.identityvector.com%3Fsecret%3D<redacted2> Your new secret key is: <redacted1> Your verification code is <redacted2> Your emergency scratch codes are: <code1> <code2> <code3> <code4> <code5> Do you want me to update your "/home/phil/.google_authenticator" file (y/n) y Do you want to disallow multiple uses of the same authentication token? This restricts you to one login about every 30s, but it increases your chances to notice or even prevent man-in-the-middle attacks (y/n) n By default, tokens are good for 30 seconds and in order to compensate for possible time-skew between the client and the server, we allow an extra token before and after the current time. If you experience problems with poor time synchronization, you can increase the window from its default size of 1:30min to about 4min. Do you want to do so (y/n) n If the computer that you are logging into isn't hardened against brute-force login attempts, you can enable rate-limiting for the authentication module. By default, this limits attackers to no more than 3 login attempts every 30s. Do you want to enable rate-limiting (y/n) n
- Save this output - you'll need it to set up the token on your mobile device. Emergency scratch codes should be kept in a safe place in case you lose access to your token and need to access the IVS systems.
- KEEP THIS SSH SESSION OPEN! You'll need it in case something goes wrong. Your failsafe is to remove the "~/.google_authenticator" file from this original SSH session.
- (Optional) Copy the Google URL from the "google-authenticator" command and paste it into a web browser. You'll see a two-dimensional barcode like this:
- Install the Google Authenticator application to your mobile device. Consult your device's App Store for full details. Note that these applications are not provided by IVS - we provide the links strictly as a convenience.
- Open the Google Authenticator application on your mobile device and add a new token. The screenshots below are from an iOS device, so your screens may differ.
- Screen 1: "Add Token"
- Either scan the two-dimensional barcode from your web browser, or enter the account name (free-form text) and Secret Key from the "google-authenticator" command. At this point, you'll see a new 6-digit token on your mobile device's screen.
- Screen 2: Token list
- From a separate session on your local machine, open another SSH to the IVS system. You'll be asked for a "Verification code" before a "Password". The verification code is your six-digit token, your password is your system account's normal password. After entering both values correctly, you'll be granted shell access as usual.
Philip-Hagens-iMac:~ phil$ ssh phil@sftp.identityvector.com
This is a private computer system. Unauthorized users are hereby notified that
there is no expectation of privacy for their actions on this system, and
authorize the system administrators to record all unauthorized traffic for the
purposes of subsequent law enforcement actions.
-IdentityVector Solutions, LLC
Verification code: <not echoed>
Password: <not echoed>
Last login: Sat May 5 15:24:27 2012 from c-98-252-9-205.hsd1.de.comcast.net
[phil@quaff ~]$