<?php
# PodMail
# $Id$
# (C) 2006 Alkaloid Networks
# Released under the terms of the GPL.
# See included LICENSE file for more information.
#
# Released under terms of the GPL by Ben Klang <bklang@alkaloid.net>,
# Bryan Rite <brite@alkaloid.net>, and Jeff Smith <jsmith@alkaloid.net>
# on Wed, Jan 19, 2006.
#
# Visit projects.alkaloid.net or podmail.alkaloid.net for PodMail
# information and updates.
#
# PodMail brings together some of the best open source technology to
# create a new way of accessing voicemail through Asterisk. 
# With integration into Asterisk:LDAP or regular Asterisk voicemail,
# PodMail has the ability to offer the end-user their voicemail in a
# comfortable, popular, and "kewl" format: as a PodCast! 
#
# This is the perfect medium for voicemail as it allows for secure
# authentication as well as support on Windows and Mac through
# iTunes and Linux through Amarok.  Update your personal voicemail
# podcast and take your voicemails with you.  Update from anywhere
# with comfort and security; its faster then checking your email!

###
# START CONFIGURATION SECTION 
###
#
# PodMail Backend
#
# Choose from one of 'file', 'static' or 'ldap'.
# For more information on using LDAP see Asterisk::LDAP at
# http://projects.alkaloid.net
# To verify credentials an authenticated bind is attempted.  The user must
# have bind access and read access to at least their own 'voiceMailbox'
# attribute for PodMail to function correctly.
$conf['backend'] = 'ldap';
$conf['file']['location'] = '/etc/asterisk/voicemail.conf';
$conf['ldap']['host'] = 'picasso';
$conf['ldap']['basedn'] = 'ou=Customers,dc=alkaloid,dc=net';
$conf['ldap']['userkey'] = 'mail';
$conf['static']['user'] = '421';
# Don't forget to set $conf['force_context'] with static auth!

# Force authentication to a particular context
$conf['force_context'] = 'default';

# Set to the location of Asterisk's voicemail area
$conf['vmail_basedir'] = '/var/spool/asterisk/voicemail';

# Set to the location of LAME
$conf['lame'] = "/usr/bin/lame";

# Use this directory to hold the mp3 caches.  In this release of the code
# the cache is not managed so you'll have to clean it yourself
$conf['tmpdir'] = "/tmp/podmail/ldap";

#
# Podcast Metadata
#
# Below are podcast metadata settings.  Tune to your fancy.
# Don't worry about special characters, they will be converted before sending.
$conf['title'] = 'Alkaloid Networks PodMail: Now with LDAP!';
$conf['subtitle'] = 'This PodMail is integrated with LDAP';
$conf['ttl'] = '60';
$conf['link'] = 'http://projects.alkaloid.net/';
$conf['baseurl'] = 'http://podmail.alkaloid.net/ldap/';
$conf['copyright'] = '2006 Alkaloid Networks';
$conf['description'] = 'Your Voicemail as a Podcast!  Brought to you by the Alkaloid Networks';
$conf['author'] = 'Alkaloid Networks';
$conf['summary'] = 'Integrating the best of open source to deliver new ideas, Alkaloid Networks brings you PodMail: Hear your Voicemail as a podcast!';
$conf['owner']['name'] = 'Alkaloid Developers';
$conf['owner']['email'] = 'projects@alkaloid.net';
$conf['image']['url'] = 'http://podmail.alkaloid.net/podmail.png';

###
# END CONFIGURATION SECTION
###

if (!isset($_SERVER['PHP_AUTH_USER']) && !($conf['backend'] == 'static')) {
    notAuthenticated();
}


$context = false;
$messagelist = false;

// Input validation
// Only strip the context when using the file backend: LDAP may have a
// valid '@' in the username
if ($pos = strpos($_SERVER['PHP_AUTH_USER'], '@') &&
    $conf['backend'] == 'file') {
    $user = substr($_SERVER['PHP_AUTH_USER'], 0, $pos);
    $pos++; // Skip the '@'
} else {
    $user = $_SERVER['PHP_AUTH_USER'];
}

// If force_context is supplied we ignore the user-supplied data
if (!$conf['force_context'] && $pos) {
    $context = substr($_SERVER['PHP_AUTH_USER'], $pos);
} else {
    $context = $conf['force_context'];
}
// If we didn't find a context, oh well.  We won't be able to authenticate
// below.

$pass = $_SERVER['PHP_AUTH_PW'];


switch($conf['backend']) {

##
# File based authentication (voicemail.conf)
##
case 'file':
    authFile($user, $pass, $context) ?
        $messagelist = authenticated($user, $context) :
        notAuthenticated("Invalid credentials");
    break;

##
# LDAP based authentication
##
case 'ldap':
    if ($user = authLDAP($user, $pass, $context)) {
        $messagelist = authenticated($user, $context);
    } else {
        notAuthenticated("Invalid credentials");
    }
    break;

case 'static':
    $messagelist = authenticated($conf['static']['user'], $context);
    break;
}

# At this point we should be authenticated and have a messagelist,
# though it may be of 0 length
if ($_REQUEST['guid']) {
    # A file was requested
    sendFile($messagelist, $_REQUEST['guid']);
} else {
    renderPodcast($messagelist);
}

###
# End of main logic
###

###
# Begin subroutines
###
function notAuthenticated($msg = "")
{
    global $conf;

    header('WWW-Authenticate: Basic realm="'.$conf['title'].'"');
    header('HTTP/1.0 401 Unauthorized');
    echo "<html>\n";
    echo "<head><title>Bad Authentication</title></head>\n";
    echo "<body>\n";
    echo "You are not authorized for this service.<br />";
    echo $msg;
    echo "</body>\n";
    echo "</html>\n";
    exit;
}

function authenticated($user, $context)
{
    global $conf;
    $mailbox = $conf['vmail_basedir'].'/'.$context.'/'.$user.'/INBOX';
    $messagelist = parseMailbox($mailbox);
    return $messagelist;
}

function parseMailbox($mailbox)
{

$dh = opendir($mailbox) or
    notAuthenticated("Unable to open mailbox $mailbox");
    #FIXME Return audio error
    #die ("Unable to open mailbox $mailbox");

    $messagelist = array();
    $i = 0;
    
    while (($file = readdir($dh)) != false) {
        if (preg_match('/\.txt$/i', $file)) {
            $fh = fopen($mailbox.'/'.$file, 'r') or
                notAuthenticated("Unable to open file $mailbox/$file");
                #die ("Unable to open voicemail metadata: $file");
    
            while (!feof($fh)) {
                $line = fgets($fh, 4096);
    
                $token = strpos($line, '=');
                if ($token) {
                    $var = substr($line, 0, $token);
                    $value = preg_replace('/\n$/', '',
                        substr($line, $token + 1));
        
                    $messagelist[$i][$var] = $value;
                }
                
            }
            fclose($fh);
            $messagelist[$i]['file'] = $mailbox.'/'.preg_replace('/txt$/',
                'wav', $file);

            # Generate a GUID for this message
            $messagelist[$i]['guid'] = md5(
                $messagelist[$i]['origtime'].
                $messagelist[$i]['callerchan'].
                $messagelist[$i]['sender']
            );
            $i++;
         }
    }
    return $messagelist;
}


function renderPodcast($messagelist = array())
{
    require 'XML/Util.php';
    global $conf;
    
    header("Content-type: text/xml");
    echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
    ?>
  <rss xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" version="2.0">
    <channel>
        <description><?php
            echo XML_Util::replaceEntities($conf['description']);
        ?></description>
        <ttl><?php echo XML_Util::replaceEntities($conf['ttl']); ?></ttl>
        <title><?php echo XML_Util::replaceEntities($conf['title']); ?></title>
        <link><?php echo XML_Util::replaceEntities($conf['link']); ?></link>
        <language>en-US</language>
        <copyright>&#xA9; <?php
            echo XML_Util::replaceEntities($conf['copyright']);
        ?></copyright>
        <itunes:subtitle><?php
            echo XML_Util::replaceEntities($conf['subtitle']);
        ?></itunes:subtitle>
        <itunes:author><?php
            echo XML_Util::replaceEntities($conf['author']);
        ?></itunes:author>
        <itunes:summary><?php
            echo XML_Util::replaceEntities($conf['summary']);
        ?></itunes:summary>
        <itunes:owner>
            <itunes:name><?php
                echo XML_Util::replaceEntities($conf['owner']['name']);
            ?></itunes:name>
            <itunes:email><?php
                echo XML_Util::replaceEntities($conf['owner']['email']);
            ?></itunes:email>
        </itunes:owner>
        <itunes:image href="<?php
            echo XML_Util::replaceEntities($conf['image']['url']);
        ?>" />
        <itunes:explicit>Clean</itunes:explicit>
        <itunes:category text="Technology">
            <itunes:category text="Gadgets"/>
        </itunes:category>
    
    <?php
        if (count($messagelist) && gettype($messagelist) == 'array') {
            foreach ($messagelist as $message) {
                $minutes = (int)($message['duration'] / 60);
                $seconds = (int)($message['duration'] % 60);
                if ($seconds < 10) { $seconds = '0'.$seconds; };
                $message['duration'] = $minutes.':'.$seconds;
        ?>
            <item>
                <title>From: <?php
                    echo XML_Util::replaceEntities($message['callerid']);
                ?></title>
                <itunes:author><?php
                    echo XML_Util::replaceEntities($conf['author']);
                ?></itunes:author>
                <itunes:subtitle>Voicemail recieved on <?php
                    echo date("D, d M Y G:i", $message["origtime"]);
                ?>, from: <?php
                    echo XML_Util::replaceEntities($message["callerid"]);
                ?></itunes:subtitle>
                <itunes:summary>From <?php
                    echo XML_Util::replaceEntities($message["callerid"]);
                ?></itunes:summary>
                <enclosure url="<?php
                    echo $conf['baseurl'].$message["guid"];
                ?>.mp3" type="audio/mpeg" />
                <guid><?php
                    echo $conf['baseurl'].$message["guid"];
                ?>.mp3</guid>
                <pubDate><?php
                    echo date("r", $message["origtime"]);
                ?></pubDate>
                <itunes:duration><?php
                    echo $message["duration"];
                ?></itunes:duration>
                <itunes:keywords>Alkaloid%20Networks,podmail</itunes:keywords>
                <itunes:explicit>Clean</itunes:explicit>
            </item>
        <?php
            }
        }
        ?>
    </channel>
    </rss>
    <?php
}

function sendFile($messagelist, $guid)
{
    global $conf;
    $file = false;

    foreach($messagelist as $vm) {
        if ($vm['guid'] == $guid) {

            $file = $vm['file'];
            break;
        }
        # Something isn't right...we didn't find a guid that matched.
        # FIXME: Send an error MP3 instead!
    }
    if (!$file) {
        notAuthenticated("Unknown GUID");
    }
    
    # Paranoia
    if (!preg_match('/^[A-Fa-f0-9]+$/', $guid)) {
        notAuthenticated("Internal Error: Bad GUID");
    }

    $stat = @stat($conf['tmpdir'].'/'.$guid.'.mp3');

    if (!$stat || $stat['size'] == 0) {
        $tmpfile = tempnam($conf['tmpdir'], $guid) or
            notAuthenticated("Internal Error: Unable to create tmpfile");

        exec($conf['lame'].  ' '.$file.' '.$tmpfile) or
            notAuthenticated("Internal Error: Error creating cache");

        rename($tmpfile, $conf['tmpdir'].'/'.$guid.'.mp3') or
            notAuthenticated("Internal Error: Unable to rename tmpfile");
    }
    $fh = fopen($conf['tmpdir'].'/'.$guid.'.mp3', "r") or
        notAuthenticated("Cache Error: Please try again later");

    header('Content-type: audio/mpeg');
    ob_start();
    fpassthru($fh) or notAuthenticated("Internal Error: Unable to send file");
    header('Content-length: '.ob_get_length());
    ob_end_flush();

}

function authFile($user, $pass, $context)
{
    global $conf;
 

    $fh = @fopen($conf['file']['location'], 'r') or notAuthenticated("Unable to open voicemail.conf");

    while(!feof($fh)) {
        $line = fgets($fh, 4096);

        if (preg_match('/^\[(.*)]/', $line, $matches)) {
            $curcontext = $matches[1];
            continue;
        }
        // Only check for extensions once we have the right context
        if (!$curcontext || $curcontext != $context) {
            continue;
        }


        // Look for a user definition like "101 => 1234,"
        if (preg_match('/^([0-9\*#]+)\s+=>\s+([0-9\*#]+),/', $line, $matches)) {
            if ($user == $matches[1] && $pass == $matches[2]) {
                return(true);
                break;
            }
        }
    }
    if ($messagelist === false) {
        notAuthenticated("Invalid message list");
    }
}

function authLDAP($user, $pass, $context)
{
    global $conf;

    $user = sanitizeQueryStr($user);
    $pass = sanitizeQueryStr($pass);
    $context = sanitizeQueryStr($context);

    $filter  = '(&';
    $filter .=   '(context='.$context.')';
    $filter .=   '('.$conf['ldap']['userkey'].'='.$user.')';
    $filter .= ')';

    $attributes = array('voiceMailbox');

    $ldap = @ldap_connect($conf['ldap']['host']) or
        notAuthenticated("Could not connect to LDAP");

    @ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3) or 
        notAuthenticated("Unable to start LDAPv3");

    $binddn = $conf['ldap']['userkey'].'='.$user.','.$conf['ldap']['basedn'];


    @ldap_bind($ldap, $binddn, $pass) or
        notAuthenticated("Unable to bind to LDAP");

    $res = @ldap_list($ldap, $conf['ldap']['basedn'], $filter, $attributes) or
        notAuthenticated("Unable to search LDAP");

    $res = @ldap_first_entry($ldap, $res) or
        notAuthenticated('Invalid Credentials or LDAP error');

    $res = @ldap_get_attributes($ldap, $res) or
        notAuthenticated('Internal Error');

    return ($res['voiceMailbox'][0]);
    
}

# This is not the way I want to handle this.  From everythign I can tell
# these are the only characters that need escaping.  I may be wrong but if I am
# then someone please tell me a library or function call to use instead?
function sanitizeQueryStr($str)
{
    return( preg_replace(
            array('/\*/',   '/\(/',   '/\)/',   '/\x00/'),
            array('\2a', '\28', '\29', '\00'),
            $str)
    );
}