By default, only the configured authentication backend is available for users.
</p>
<p>
Contrary to <ahref="authmulti.html"class="wikilink1"title="documentation:2.0:authmulti">multiple backend stacking</a>, backend choice will present all available authentication methods to users, who will choose the one they want.
In Manager, go in <code>General Parameters</code>><code>Authentication modules</code> and choose Choice for authentication.
</p>
<divclass="noteimportant">When <code>Choice</code> is selected for authentication, values for Users and Password modules are also forced to <code>Choice</code>.
</div>
<p>
Then, go in <code>Choice Parameters</code>:
</p>
<ul>
<liclass="level1"><divclass="li"><strong><abbrtitle="Uniform Resource Locator">URL</abbr> parameter</strong>: parameter name used to set choice value (default: <code>lmAuth</code>)</div>
<liclass="level1"><divclass="li"><strong><abbrtitle="Uniform Resource Locator">URL</abbr></strong>: optional, can be used to redirect on another <abbrtitle="Uniform Resource Locator">URL</abbr> (for example <ahref="https://authssl.example.com"class="urlextern"title="https://authssl.example.com"rel="nofollow">https://authssl.example.com</a>). This is mandatory if you want to use an Apache authentication module, which is run by Apache before showing the LemonLDAP::NG portal page.</div>
<liclass="level1"><divclass="li"><strong>Condition</strong>: optional, can be used to evaluate an expression to display the tab. For example, to display a tab only if redirected by Handler from application <code>test1.example.com</code>, you can set this condition:</div>
<divclass="noteclassic">Authentication request to an another <abbrtitle="Uniform Resource Locator">URL</abbr> than Portal <abbrtitle="Uniform Resource Locator">URL</abbr> can lead to a persistent loop between Portal and a redirection <abbrtitle="Uniform Resource Locator">URL</abbr> (pdata is not removed because domains mismatch). To avoid this, you have to set pdata cookie domain by editing <code>lemonldap-ng.ini</code> in section [portal]:<preclass="code file ini"><spanclass="re0"><spanclass="br0">[</span>portal<spanclass="br0">]</span></span>
</div><divclass="notetip">You can prefix the key name with a digit to order them. The digit will not be shown on portal page. Underscore characters are also replaced by spaces.
</div><divclass="notetip">You can also override some LLNG parameters for each chain. See <ahref="parameterlist.html"class="wikilink1"title="documentation:2.0:parameterlist">Parameter list</a> to have the key names to use