<ahref="https://en.wikipedia.org/wiki/Universal_2nd_Factor"class="urlextern"title="https://en.wikipedia.org/wiki/Universal_2nd_Factor"rel="nofollow">Universal 2nd Factor</a> (U2F) is an open authentication standard that strengthens and simplifies two-factor authentication using specialized USB or NFC devices.
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<p>
LLNG can propose to users to register their keys. When done, registered user can't login without using its key.
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<divclass="notetip">Note that it's a second factor, not an authentication module. Users are authenticated by both login form and U2F form.
<h2class="sectionedit2"id="prerequisites_and_dependencies">Prerequisites and dependencies</h2>
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This feature uses <ahref="https://metacpan.org/pod/Crypt::U2F::Server::Simple"class="urlextern"title="https://metacpan.org/pod/Crypt::U2F::Server::Simple"rel="nofollow">Crypt::U2F::Server::Simple</a> that is available only via CPAN for now. Before compiling it, you must install Yubico's C library headers (called libu2f-server-dev on Debian).
<liclass="level1"><divclass="li"> U2F ⇒ Self registration: set it to “on” <em>(to display this application on the menu, create an application that points to <ahref="https://auth.your.domain/u2fregister.html"class="urlextern"title="https://auth.your.domain/u2fregister.html"rel="nofollow">https://auth.your.domain/u2fregister.html</a>)</em></div>
<liclass="level1"><divclass="li"> U2F ⇒ Authentication level: you can overwrite here auth level for U2F registered users. Leave it blank keeps auth level provided by first authentication module <em>(default: 2 for user/password based modules)</em></div>
<divclass="noteimportant">If you want to use a custom rule for “activation” and want to keep self-registration, you must include this in your rule: <code>$_u2fKeyHandle and $_u2fUserKey</code>, else U2F will be required even if users are not registered. This is automatically done when “activation” is simply set to “on”.
<liclass="level2"><divclass="li"> 38 to 56 with <ahref="https://addons.mozilla.org/fr/firefox/addon/u2f-support-add-on/"class="urlextern"title="https://addons.mozilla.org/fr/firefox/addon/u2f-support-add-on/"rel="nofollow">U2F Support Add-on</a></div>
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<liclass="level2"><divclass="li"> 57 to 58, with “security.webauth.u2f” set to “true” in “about:config” <em>(see <ahref="https://www.yubico.com/2017/11/how-to-navigate-fido-u2f-in-firefox-quantum/"class="urlextern"title="https://www.yubico.com/2017/11/how-to-navigate-fido-u2f-in-firefox-quantum/"rel="nofollow">Yubico explanations</a>)</em></div>
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<liclass="level2"><divclass="li"> probably enabled by default for versions >= 59</div>
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</ul>
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<liclass="level1"><divclass="li"> Opera >= 40</div>