<?php
/*
 *  Jirafeau, your web file repository
 *  Copyright (C) 2008  Julien "axolotl" BERNARD <axolotl@magieeternelle.org>
 *  Copyright (C) 2015  Jerome Jutteau <j.jutteau@gmail.com>
 *  Copyright (C) 2015  Nicola Spanti (RyDroid) <dev@nicola-spanti.info>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as
 *  published by the Free Software Foundation, either version 3 of the
 *  License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

/**
 * Transform a string in a path by seperating each letters by a '/'.
 * @return path finishing with a '/'
 */
function s2p($s)
{
    $p = '';
    for ($i = 0; $i < strlen($s); $i++) {
        $p .= $s{$i} . '/';
    }
    return $p;
}

/**
 * Convert base 16 to base 64
 * @returns A string based on 64 characters (0-9, a-z, A-Z, "-" and "_")
 */
function base_16_to_64($num)
{
    $m = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_';
    $hex2bin = array('0000',  # 0
                      '0001',  # 1
                      '0010',  # 2
                      '0011',  # 3
                      '0100',  # 4
                      '0101',  # 5
                      '0110',  # 6
                      '0111',  # 7
                      '1000',  # 8
                      '1001',  # 9
                      '1010',  # a
                      '1011',  # b
                      '1100',  # c
                      '1101',  # d
                      '1110',  # e
                      '1111'); # f
    $o = '';
    $b = '';
    $i = 0;
    # Convert long hex string to bin.
    $size = strlen($num);
    for ($i = 0; $i < $size; $i++) {
        $b .= $hex2bin{hexdec($num{$i})};
    }
    # Convert long bin to base 64.
    $size *= 4;
    for ($i = $size - 6; $i >= 0; $i -= 6) {
        $o = $m{bindec(substr($b, $i, 6))} . $o;
    }
    # Some few bits remaining ?
    if ($i < 0 && $i > -6) {
        $o = $m{bindec(substr($b, 0, $i + 6))} . $o;
    }
    return $o;
}

/**
  * Generate a random code.
  * @param $l code length
  * @return  random code.
  */
function jirafeau_gen_random($l)
{
    if ($l <= 0) {
        return 42;
    }

    $code="";
    for ($i = 0; $i < $l; $i++) {
        $code .= dechex(rand(0, 15));
    }

    return $code;
}

function is_ssl()
{
    if (isset($_SERVER['HTTPS'])) {
        if ('on' == strtolower($_SERVER['HTTPS']) ||
             '1' == $_SERVER['HTTPS']) {
            return true;
        }
    } elseif (isset($_SERVER['SERVER_PORT']) && ('443' == $_SERVER['SERVER_PORT'])) {
        return true;
    } elseif (isset($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
        if ($_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') {
            return true;
        }
    }
    return false;
}

function jirafeau_human_size($octets)
{
    $u = array('B', 'KB', 'MB', 'GB', 'TB');
    $o = max($octets, 0);
    $p = min(floor(($o ? log($o) : 0) / log(1024)), count($u) - 1);
    $o /= pow(1024, $p);
    return round($o, 1) . $u[$p];
}

function jirafeau_clean_rm_link($link)
{
    $p = s2p("$link");
    if (file_exists(VAR_LINKS . $p . $link)) {
        unlink(VAR_LINKS . $p . $link);
    }
    $parse = VAR_LINKS . $p;
    $scan = array();
    while (file_exists($parse)
           && ($scan = scandir($parse))
           && count($scan) == 2 // '.' and '..' folders => empty.
           && basename($parse) != basename(VAR_LINKS)) {
        rmdir($parse);
        $parse = substr($parse, 0, strlen($parse) - strlen(basename($parse)) - 1);
    }
}

function jirafeau_clean_rm_file($md5)
{
    $p = s2p("$md5");
    $f = VAR_FILES . $p . $md5;
    if (file_exists($f) && is_file($f)) {
        unlink($f);
    }
    if (file_exists($f . '_count') && is_file($f . '_count')) {
        unlink($f . '_count');
    }
    $parse = VAR_FILES . $p;
    $scan = array();
    while (file_exists($parse)
           && ($scan = scandir($parse))
           && count($scan) == 2 // '.' and '..' folders => empty.
           && basename($parse) != basename(VAR_FILES)) {
        rmdir($parse);
        $parse = substr($parse, 0, strlen($parse) - strlen(basename($parse)) - 1);
    }
}

/**
 * transforms a php.ini string representing a value in an integer
 * @param $value the value from php.ini
 * @returns an integer for this value
 */
function jirafeau_ini_to_bytes($value)
{
    $modifier = substr($value, -1);
    $bytes = substr($value, 0, -1);
    switch (strtoupper($modifier)) {
    case 'P':
        $bytes *= 1024;
    case 'T':
        $bytes *= 1024;
    case 'G':
        $bytes *= 1024;
    case 'M':
        $bytes *= 1024;
    case 'K':
        $bytes *= 1024;
    }
    return $bytes;
}

/**
 * gets the maximum upload size according to php.ini
 * @returns the maximum upload size in bytes
 */
function jirafeau_get_max_upload_size_bytes()
{
    return min(jirafeau_ini_to_bytes(ini_get('post_max_size')),
                jirafeau_ini_to_bytes(ini_get('upload_max_filesize')));
}

/**
 * gets the maximum upload size according to php.ini
 * @returns the maximum upload size string
 */
function jirafeau_get_max_upload_size()
{
    return jirafeau_human_size(
            min(jirafeau_ini_to_bytes(ini_get('post_max_size')),
                 jirafeau_ini_to_bytes(ini_get('upload_max_filesize'))));
}

/**
 * gets a string explaining the error
 * @param $code the error code
 * @returns a string explaining the error
 */
function jirafeau_upload_errstr($code)
{
    switch ($code) {
    case UPLOAD_ERR_INI_SIZE:
    case UPLOAD_ERR_FORM_SIZE:
        return t('Your file exceeds the maximum authorized file size. ');

    case UPLOAD_ERR_PARTIAL:
    case UPLOAD_ERR_NO_FILE:
        return
            t('Your file was not uploaded correctly. You may succeed in retrying. ');

    case UPLOAD_ERR_NO_TMP_DIR:
    case UPLOAD_ERR_CANT_WRITE:
    case UPLOAD_ERR_EXTENSION:
        return t('Internal error. You may not succeed in retrying. ');
    }
    return t('Unknown error. ');
}

/** Remove link and it's file
 * @param $link the link's name (hash)
 */

function jirafeau_delete_link($link)
{
    $l = jirafeau_get_link($link);
    if (!count($l)) {
        return;
    }

    jirafeau_clean_rm_link($link);

    $md5 = $l['md5'];
    $p = s2p("$md5");

    $counter = 1;
    if (file_exists(VAR_FILES . $p . $md5. '_count')) {
        $content = file(VAR_FILES . $p . $md5. '_count');
        $counter = trim($content[0]);
    }
    $counter--;

    if ($counter >= 1) {
        $handle = fopen(VAR_FILES . $p . $md5. '_count', 'w');
        fwrite($handle, $counter);
        fclose($handle);
    }

    if ($counter == 0) {
        jirafeau_clean_rm_file($md5);
    }
}

/**
 * Delete a file and it's links.
 */
function jirafeau_delete_file($md5)
{
    $count = 0;
    /* Get all links files. */
    $stack = array(VAR_LINKS);
    while (($d = array_shift($stack)) && $d != null) {
        $dir = scandir($d);

        foreach ($dir as $node) {
            if (strcmp($node, '.') == 0 || strcmp($node, '..') == 0 ||
                preg_match('/\.tmp/i', "$node")) {
                continue;
            }

            if (is_dir($d . $node)) {
                /* Push new found directory. */
                $stack[] = $d . $node . '/';
            } elseif (is_file($d . $node)) {
                /* Read link informations. */
                $l = jirafeau_get_link(basename($node));
                if (!count($l)) {
                    continue;
                }
                if ($l['md5'] == $md5) {
                    $count++;
                    jirafeau_delete_link($node);
                }
            }
        }
    }
    jirafeau_clean_rm_file($md5);
    return $count;
}

/**
 * handles an uploaded file
 * @param $file the file struct given by $_FILE[]
 * @param $one_time_download is the file a one time download ?
 * @param $key if not empty, protect the file with this key
 * @param $time the time of validity of the file
 * @param $ip uploader's ip
 * @param $crypt boolean asking to crypt or not
 * @param $link_name_length size of the link name
 * @returns an array containing some information
 *   'error' => information on possible errors
 *   'link' => the link name of the uploaded file
 *   'delete_link' => the link code to delete file
 */
function jirafeau_upload($file, $one_time_download, $key, $time, $ip, $crypt, $link_name_length)
{
    if (empty($file['tmp_name']) || !is_uploaded_file($file['tmp_name'])) {
        return (array(
                 'error' =>
                   array('has_error' => true,
                          'why' => jirafeau_upload_errstr($file['error'])),
                 'link' => '',
                 'delete_link' => ''));
    }

    /* array representing no error */
    $noerr = array('has_error' => false, 'why' => '');

    /* Crypt file if option is enabled. */
    $crypted = false;
    $crypt_key = '';
    if ($crypt == true && !(extension_loaded('mcrypt') == true)) {
        error_log("PHP extension mcrypt not loaded, won't encrypt in Jirafeau");
    }
    if ($crypt == true && extension_loaded('mcrypt') == true) {
        $crypt_key = jirafeau_encrypt_file($file['tmp_name'], $file['tmp_name']);
        if (strlen($crypt_key) > 0) {
            $crypted = true;
        }
    }

    /* file informations */
    $md5 = md5_file($file['tmp_name']);
    $name = str_replace(NL, '', trim($file['name']));
    $mime_type = $file['type'];
    $size = $file['size'];

    /* does file already exist ? */
    $rc = false;
    $p = s2p("$md5");
    if (file_exists(VAR_FILES . $p .  $md5)) {
        $rc = unlink($file['tmp_name']);
    } elseif ((file_exists(VAR_FILES . $p) || @mkdir(VAR_FILES . $p, 0755, true))
            && move_uploaded_file($file['tmp_name'], VAR_FILES . $p . $md5)) {
        $rc = true;
    }
    if (!$rc) {
        return (array(
                 'error' =>
                   array('has_error' => true,
                          'why' => t('Internal error during file creation.')),
                 'link' =>'',
                 'delete_link' => ''));
    }

    /* Increment or create count file. */
    $counter = 0;
    if (file_exists(VAR_FILES . $p . $md5 . '_count')) {
        $content = file(VAR_FILES . $p . $md5. '_count');
        $counter = trim($content[0]);
    }
    $counter++;
    $handle = fopen(VAR_FILES . $p . $md5. '_count', 'w');
    fwrite($handle, $counter);
    fclose($handle);

    /* Create delete code. */
    $delete_link_code = jirafeau_gen_random(5);

    /* md5 password or empty. */
    $password = '';
    if (!empty($key)) {
        $password = md5($key);
    }

    /* create link file */
    $link_tmp_name =  VAR_LINKS . $md5 . rand(0, 10000) . '.tmp';
    $handle = fopen($link_tmp_name, 'w');
    fwrite($handle,
            $name . NL. $mime_type . NL. $size . NL. $password . NL. $time .
            NL . $md5. NL . ($one_time_download ? 'O' : 'R') . NL . time() .
            NL . $ip . NL. $delete_link_code . NL . ($crypted ? 'C' : 'O'));
    fclose($handle);
    $md5_link = substr(base_16_to_64(md5_file($link_tmp_name)), 0, $link_name_length);
    $l = s2p("$md5_link");
    if (!@mkdir(VAR_LINKS . $l, 0755, true) ||
        !rename($link_tmp_name, VAR_LINKS . $l . $md5_link)) {
        if (file_exists($link_tmp_name)) {
            unlink($link_tmp_name);
        }

        $counter--;
        if ($counter >= 1) {
            $handle = fopen(VAR_FILES . $p . $md5. '_count', 'w');
            fwrite($handle, $counter);
            fclose($handle);
        } else {
            jirafeau_clean_rm_file($md5_link);
        }
        return array(
                 'error' =>
                   array('has_error' => true,
                          'why' => t('Internal error during file creation. ')),
                 'link' =>'',
                 'delete_link' => '');
    }
    return array( 'error' => $noerr,
                  'link' => $md5_link,
                  'delete_link' => $delete_link_code,
                  'crypt_key' => $crypt_key);
}

/**
 * Tells if a mime-type is viewable in a browser
 * @param $mime the mime type
 * @returns a boolean telling if a mime type is viewable
 */
function jirafeau_is_viewable($mime)
{
    if (!empty($mime)) {
        /* Actually, verify if mime-type is an image or a text. */
        $viewable = array('image', 'text', 'video', 'audio');
        $decomposed = explode('/', $mime);
        return in_array($decomposed[0], $viewable);
    }
    return false;
}

// Error handling functions.
//! Global array that contains all registered errors.
$error_list = array();

/**
 * Adds an error to the list of errors.
 * @param $title the error's title
 * @param $description is a human-friendly description of the problem.
 */
function add_error($title, $description)
{
    global $error_list;
    $error_list[] = '<p>' . $title. '<br />' . $description. '</p>';
}

/**
 * Informs whether any error has been registered yet.
 * @return true if there are errors.
 */
function has_error()
{
    global $error_list;
    return !empty($error_list);
}

/**
 * Displays all the errors.
 */
function show_errors()
{
    if (has_error()) {
        global $error_list;
        echo '<div class="error">';
        foreach ($error_list as $error) {
            echo $error;
        }
        echo '</div>';
    }
}

function check_errors($cfg)
{
    if (file_exists(JIRAFEAU_ROOT . 'install.php')
        && !($cfg['installation_done'] === true)) {
        header('Location: install.php');
        exit;
    }

    /* check if the destination dirs are writable */
    $writable = is_writable(VAR_FILES) && is_writable(VAR_LINKS);

    /* Checking for errors. */
    if (!is_writable(VAR_FILES)) {
        add_error(t('The file directory is not writable!'), VAR_FILES);
    }

    if (!is_writable(VAR_LINKS)) {
        add_error(t('The link directory is not writable!'), VAR_LINKS);
    }

    if (!is_writable(VAR_ASYNC)) {
        add_error(t('The async directory is not writable!'), VAR_ASYNC);
    }
}

/**
 * Read link informations
 * @return array containing informations.
 */
function jirafeau_get_link($hash)
{
    $out = array();
    $link = VAR_LINKS . s2p("$hash") . $hash;

    if (!file_exists($link)) {
        return $out;
    }

    $c = file($link);
    $out['file_name'] = trim($c[0]);
    $out['mime_type'] = trim($c[1]);
    $out['file_size'] = trim($c[2]);
    $out['key'] = trim($c[3], NL);
    $out['time'] = trim($c[4]);
    $out['md5'] = trim($c[5]);
    $out['onetime'] = trim($c[6]);
    $out['upload_date'] = trim($c[7]);
    $out['ip'] = trim($c[8]);
    $out['link_code'] = trim($c[9]);
    $out['crypted'] = trim($c[10]) == 'C';

    return $out;
}

/**
 * List files in admin interface.
 */
function jirafeau_admin_list($name, $file_hash, $link_hash)
{
    echo '<fieldset><legend>';
    if (!empty($name)) {
        echo t('Filename') . ": $name ";
    }
    if (!empty($file_hash)) {
        echo t('file') . ": $file_hash ";
    }
    if (!empty($link_hash)) {
        echo t('link') . ": $link_hash ";
    }
    if (empty($name) && empty($file_hash) && empty($link_hash)) {
        echo t('List all files');
    }
    echo '</legend>';
    echo '<table>';
    echo '<tr>';
    echo '<td>' . t('Filename') . '</td>';
    echo '<td>' . t('Type') . '</td>';
    echo '<td>' . t('Size') . '</td>';
    echo '<td>' . t('Expire') . '</td>';
    echo '<td>' . t('Onetime') . '</td>';
    echo '<td>' . t('Upload date') . '</td>';
    echo '<td>' . t('Origin') . '</td>';
    echo '<td>' . t('Action') . '</td>';
    echo '</tr>';

    /* Get all links files. */
    $stack = array(VAR_LINKS);
    while (($d = array_shift($stack)) && $d != null) {
        $dir = scandir($d);
        foreach ($dir as $node) {
            if (strcmp($node, '.') == 0 || strcmp($node, '..') == 0 ||
                preg_match('/\.tmp/i', "$node")) {
                continue;
            }
            if (is_dir($d . $node)) {
                /* Push new found directory. */
                $stack[] = $d . $node . '/';
            } elseif (is_file($d . $node)) {
                /* Read link informations. */
                $l = jirafeau_get_link($node);
                if (!count($l)) {
                    continue;
                }

                /* Filter. */
                if (!empty($name) && !preg_match("/$name/i", htmlspecialchars($l['file_name']))) {
                    continue;
                }
                if (!empty($file_hash) && $file_hash != $l['md5']) {
                    continue;
                }
                if (!empty($link_hash) && $link_hash != $node) {
                    continue;
                }
                /* Print link informations. */
                echo '<tr>';
                echo '<td>' .
                '<strong><a id="upload_link" href="' . JIRAFEAU_ABSPREFIX . 'f.php?h='. htmlspecialchars($node) .'" title="' .
                    t('Download page') . '">' . htmlspecialchars($l['file_name']) . '</a></strong>';
                echo '</td>';
                echo '<td>' . $l['mime_type'] . '</td>';
                echo '<td>' . jirafeau_human_size($l['file_size']) . '</td>';
                echo '<td>' . ($l['time'] == -1 ? '' : strftime('%c', $l['time'])) .
                     '</td>';
                echo '<td>';
                if ($l['onetime'] == 'O') {
                    echo 'Y';
                } else {
                    echo 'N';
                }
                echo '</td>';
                echo '<td>' . strftime('%c', $l['upload_date']) . '</td>';
                echo '<td>' . $l['ip'] . '</td>';
                echo '<td>' .
                '<form method="post">' .
                '<input type = "hidden" name = "action" value = "download"/>' .
                '<input type = "hidden" name = "link" value = "' . $node . '"/>' .
                '<input type = "submit" value = "' . t('Download') . '" />' .
                '</form>' .
                '<form method="post">' .
                '<input type = "hidden" name = "action" value = "delete_link"/>' .
                '<input type = "hidden" name = "link" value = "' . $node . '"/>' .
                '<input type = "submit" value = "' . t('Del link') . '" />' .
                '</form>' .
                '<form method="post">' .
                '<input type = "hidden" name = "action" value = "delete_file"/>' .
                '<input type = "hidden" name = "md5" value = "' . $l['md5'] . '"/>' .
                '<input type = "submit" value = "' . t('Del file and links') . '" />' .
                '</form>' .
                '</td>';
                echo '</tr>';
            }
        }
    }
    echo '</table></fieldset>';
}

/**
 * Clean expired files.
 * @return number of cleaned files.
 */
function jirafeau_admin_clean()
{
    $count = 0;
    /* Get all links files. */
    $stack = array(VAR_LINKS);
    while (($d = array_shift($stack)) && $d != null) {
        $dir = scandir($d);

        foreach ($dir as $node) {
            if (strcmp($node, '.') == 0 || strcmp($node, '..') == 0 ||
                preg_match('/\.tmp/i', "$node")) {
                continue;
            }

            if (is_dir($d . $node)) {
                /* Push new found directory. */
                $stack[] = $d . $node . '/';
            } elseif (is_file($d . $node)) {
                /* Read link informations. */
                $l = jirafeau_get_link(basename($node));
                if (!count($l)) {
                    continue;
                }
                $p = s2p($l['md5']);
                if ($l['time'] > 0 && $l['time'] < time() || // expired
                    !file_exists(VAR_FILES . $p . $l['md5']) || // invalid
                    !file_exists(VAR_FILES . $p . $l['md5'] . '_count')) { // invalid
                    jirafeau_delete_link($node);
                    $count++;
                }
            }
        }
    }
    return $count;
}


/**
 * Clean old async transferts.
 * @return number of cleaned files.
 */
function jirafeau_admin_clean_async()
{
    $count = 0;
    /* Get all links files. */
    $stack = array(VAR_ASYNC);
    while (($d = array_shift($stack)) && $d != null) {
        $dir = scandir($d);

        foreach ($dir as $node) {
            if (strcmp($node, '.') == 0 || strcmp($node, '..') == 0 ||
                preg_match('/\.tmp/i', "$node")) {
                continue;
            }

            if (is_dir($d . $node)) {
                /* Push new found directory. */
                $stack[] = $d . $node . '/';
            } elseif (is_file($d . $node)) {
                /* Read async informations. */
                $a = jirafeau_get_async_ref(basename($node));
                if (!count($a)) {
                    continue;
                }
                /* Delete transferts older than 1 hour. */
                if (time() - $a['last_edited'] > 3600) {
                    jirafeau_async_delete(basename($node));
                    $count++;
                }
            }
        }
    }
    return $count;
}
/**
 * Read async transfert informations
 * @return array containing informations.
 */
function jirafeau_get_async_ref($ref)
{
    $out = array();
    $refinfos = VAR_ASYNC . s2p("$ref") . "$ref";

    if (!file_exists($refinfos)) {
        return $out;
    }

    $c = file($refinfos);
    $out['file_name'] = trim($c[0]);
    $out['mime_type'] = trim($c[1]);
    $out['key'] = trim($c[2], NL);
    $out['time'] = trim($c[3]);
    $out['onetime'] = trim($c[4]);
    $out['ip'] = trim($c[5]);
    $out['last_edited'] = trim($c[6]);
    $out['next_code'] = trim($c[7]);
    return $out;
}

/**
 * Delete async transfert informations
 */
function jirafeau_async_delete($ref)
{
    $p = s2p("$ref");
    if (file_exists(VAR_ASYNC . $p . $ref)) {
        unlink(VAR_ASYNC . $p . $ref);
    }
    if (file_exists(VAR_ASYNC . $p . $ref . '_data')) {
        unlink(VAR_ASYNC . $p . $ref . '_data');
    }
    $parse = VAR_ASYNC . $p;
    $scan = array();
    while (file_exists($parse)
           && ($scan = scandir($parse))
           && count($scan) == 2 // '.' and '..' folders => empty.
           && basename($parse) != basename(VAR_ASYNC)) {
        rmdir($parse);
        $parse = substr($parse, 0, strlen($parse) - strlen(basename($parse)) - 1);
    }
}

/**
  * Init a new asynchronous upload.
  * @param $finename Name of the file to send
  * @param $one_time One time upload parameter
  * @param $key eventual password (or blank)
  * @param $time time limit
  * @param $ip ip address of the client
  * @return a string containing a temporary reference followed by a code or the string 'Error'
  */
function jirafeau_async_init($filename, $type, $one_time, $key, $time, $ip)
{
    $res = 'Error';

    /* Create temporary folder. */
    $ref;
    $p;
    $code = jirafeau_gen_random(4);
    do {
        $ref = jirafeau_gen_random(32);
        $p = VAR_ASYNC . s2p($ref);
    } while (file_exists($p));
    @mkdir($p, 0755, true);
    if (!file_exists($p)) {
        echo 'Error';
        return;
    }

    /* md5 password or empty */
    $password = '';
    if (!empty($key)) {
        $password = md5($key);
    }

    /* Store informations. */
    $p .= $ref;
    $handle = fopen($p, 'w');
    fwrite($handle,
            str_replace(NL, '', trim($filename)) . NL .
            str_replace(NL, '', trim($type)) . NL . $password . NL .
            $time . NL . ($one_time ? 'O' : 'R') . NL . $ip . NL .
            time() . NL . $code . NL);
    fclose($handle);

    return $ref . NL . $code ;
}

/**
  * Append a piece of file on the asynchronous upload.
  * @param $ref asynchronous upload reference
  * @param $file piece of data
  * @param $code client code for this operation
  * @param $max_file_size maximum allowed file size
  * @return a string containing a next code to use or the string "Error"
  */
function jirafeau_async_push($ref, $data, $code, $max_file_size)
{
    /* Get async infos. */
    $a = jirafeau_get_async_ref($ref);

    /* Check some errors. */
    if (count($a) == 0
        || $a['next_code'] != "$code"
        || empty($data['tmp_name'])
        || !is_uploaded_file($data['tmp_name'])) {
        return 'Error';
    }

    $p = s2p($ref);

    /* File path. */
    $r_path = $data['tmp_name'];
    $w_path = VAR_ASYNC . $p . $ref . '_data';

    /* Check that file size is not above upload limit. */
    if ($max_file_size > 0 &&
        filesize($r_path) + filesize($w_path) > $max_file_size * 1024 * 1024) {
        jirafeau_async_delete($ref);
        return 'Error';
    }

    /* Concatenate data. */
    $r = fopen($r_path, 'r');
    $w = fopen($w_path, 'a');
    while (!feof($r)) {
        if (fwrite($w, fread($r, 1024)) === false) {
            fclose($r);
            fclose($w);
            jirafeau_async_delete($ref);
            return 'Error';
        }
    }
    fclose($r);
    fclose($w);
    unlink($r_path);

    /* Update async file. */
    $code = jirafeau_gen_random(4);
    $handle = fopen(VAR_ASYNC . $p . $ref, 'w');
    fwrite($handle,
            $a['file_name'] . NL. $a['mime_type'] . NL. $a['key'] . NL .
            $a['time'] . NL . $a['onetime'] . NL . $a['ip'] . NL .
            time() . NL . $code . NL);
    fclose($handle);
    return $code;
}

/**
  * Finalyze an asynchronous upload.
  * @param $ref asynchronous upload reference
  * @param $code client code for this operation
  * @param $crypt boolean asking to crypt or not
  * @param $link_name_length link name length
  * @return a string containing the download reference followed by a delete code or the string 'Error'
  */
function jirafeau_async_end($ref, $code, $crypt, $link_name_length)
{
    /* Get async infos. */
    $a = jirafeau_get_async_ref($ref);
    if (count($a) == 0
        || $a['next_code'] != "$code") {
        return "Error";
    }

    /* Generate link infos. */
    $p = VAR_ASYNC . s2p($ref) . $ref . "_data";
    if (!file_exists($p)) {
        return 'Error';
    }

    $crypted = false;
    $crypt_key = '';
    if ($crypt == true && extension_loaded('mcrypt') == true) {
        $crypt_key = jirafeau_encrypt_file($p, $p);
        if (strlen($crypt_key) > 0) {
            $crypted = true;
        }
    }

    $md5 = md5_file($p);
    $size = filesize($p);
    $np = s2p($md5);
    $delete_link_code = jirafeau_gen_random(5);

    /* File already exist ? */
    if (!file_exists(VAR_FILES . $np)) {
        @mkdir(VAR_FILES . $np, 0755, true);
    }
    if (!file_exists(VAR_FILES . $np . $md5)) {
        rename($p, VAR_FILES . $np . $md5);
    }

    /* Increment or create count file. */
    $counter = 0;
    if (file_exists(VAR_FILES . $np . $md5 . '_count')) {
        $content = file(VAR_FILES . $np . $md5. '_count');
        $counter = trim($content[0]);
    }
    $counter++;
    $handle = fopen(VAR_FILES . $np . $md5. '_count', 'w');
    fwrite($handle, $counter);
    fclose($handle);

    /* Create link. */
    $link_tmp_name =  VAR_LINKS . $md5 . rand(0, 10000) . '.tmp';
    $handle = fopen($link_tmp_name, 'w');
    fwrite($handle,
            $a['file_name'] . NL . $a['mime_type'] . NL . $size . NL .
            $a['key'] . NL . $a['time'] . NL . $md5 . NL . $a['onetime'] . NL .
            time() . NL . $a['ip'] . NL . $delete_link_code . NL . ($crypted ? 'C' : 'O'));
    fclose($handle);
    $md5_link = substr(base_16_to_64(md5_file($link_tmp_name)), 0, $link_name_length);
    $l = s2p("$md5_link");
    if (!@mkdir(VAR_LINKS . $l, 0755, true) ||
        !rename($link_tmp_name, VAR_LINKS . $l . $md5_link)) {
        echo "Error";
    }

    /* Clean async upload. */
    jirafeau_async_delete($ref);
    return $md5_link . NL . $delete_link_code . NL . urlencode($crypt_key);
}

function jirafeau_crypt_create_iv($base, $size)
{
    $iv = '';
    while (strlen($iv) < $size) {
        $iv = $iv . $base;
    }
    $iv = substr($iv, 0, $size);
    return $iv;
}

/**
 * Crypt file and returns decrypt key.
 * @param $fp_src file path to the file to crypt.
 * @param $fp_dst file path to the file to write crypted file (could be the same).
 * @return decrypt key composed of the key and the iv separated by a point ('.')
 */
function jirafeau_encrypt_file($fp_src, $fp_dst)
{
    $fs = filesize($fp_src);
    if ($fs === false || $fs == 0 || !(extension_loaded('mcrypt') == true)) {
        return '';
    }

    /* Prepare module. */
    $m = mcrypt_module_open('rijndael-256', '', 'ofb', '');
    /* Generate key. */
    $crypt_key = jirafeau_gen_random(10);
    $md5_key = md5($crypt_key);
    $iv = jirafeau_crypt_create_iv($md5_key, mcrypt_enc_get_iv_size($m));
    /* Init module. */
    mcrypt_generic_init($m, $md5_key, $iv);
    /* Crypt file. */
    $r = fopen($fp_src, 'r');
    $w = fopen($fp_dst, 'c');
    while (!feof($r)) {
        $enc = mcrypt_generic($m, fread($r, 1024));
        if (fwrite($w, $enc) === false) {
            return '';
        }
    }
    fclose($r);
    fclose($w);
    /* Cleanup. */
    mcrypt_generic_deinit($m);
    mcrypt_module_close($m);
    return $crypt_key;
}

/**
 * Decrypt file.
 * @param $fp_src file path to the file to decrypt.
 * @param $fp_dst file path to the file to write decrypted file (could be the same).
 * @param $k string composed of the key and the iv separated by a point ('.')
 * @return key used to decrypt. a string of length 0 is returned if failed.
 */
function jirafeau_decrypt_file($fp_src, $fp_dst, $k)
{
    $fs = filesize($fp_src);
    if ($fs === false || $fs == 0 || extension_loaded('mcrypt') == false) {
        return false;
    }

    /* Init module */
    $m = mcrypt_module_open('rijndael-256', '', 'ofb', '');
    /* Extract key and iv. */
    $crypt_key = $k;
    $md5_key = md5($crypt_key);
    $iv = jirafeau_crypt_create_iv($md5_key, mcrypt_enc_get_iv_size($m));
    /* Decrypt file. */
    $r = fopen($fp_src, 'r');
    $w = fopen($fp_dst, 'c');
    while (!feof($r)) {
        $dec = mdecrypt_generic($m, fread($r, 1024));
        if (fwrite($w, $dec) === false) {
            return false;
        }
    }
    fclose($r);
    fclose($w);
    /* Cleanup. */
    mcrypt_generic_deinit($m);
    mcrypt_module_close($m);
    return true;
}

/**
 * Check if Jirafeau is password protected for visitors.
 * @return true if Jirafeau is password protected, false otherwise.
 */
function jirafeau_has_upload_password($cfg)
{
    return count($cfg['upload_password']) > 0;
}

/**
 * Challenge password for a visitor.
 * @param $password password to be challenged
 * @return true if password is valid, false otherwise.
 */
function jirafeau_challenge_upload_password($cfg, $password)
{
    if (!jirafeau_has_upload_password($cfg)) {
        return false;
    }
    foreach ($cfg['upload_password'] as $p) {
        if ($password == $p) {
            return true;
        }
    }
    return false;
}

/**
 * Test if visitor's IP is authorized to upload.
 * @param $ip IP to be challenged
 * @return true if IP is authorized, false otherwise.
 */
function jirafeau_challenge_upload_ip($cfg, $ip)
{
    if (count($cfg['upload_ip']) == 0) {
        return true;
    }
    foreach ($cfg['upload_ip'] as $i) {
        if ($i == $ip) {
            return true;
        }
        // CIDR test for IPv4 only.
        if (strpos($i, '/') !== false) {
            list($subnet, $mask) = explode('/', $i);
            if ((ip2long($ip) & ~((1 << (32 - $mask)) - 1)) == ip2long($subnet)) {
                return true;
            }
        }
    }
    return false;
}

/**
 * Test if visitor's IP is authorized or password is supplied and authorized
 * @param $ip IP to be challenged
 * @param $password password to be challenged
 * @return true if access is valid, false otherwise.
 */
function jirafeau_challenge_upload ($cfg, $ip, $password)
{
    // Allow if no ip restrictaion and no password restriction
    if ((count ($cfg['upload_ip']) == 0) and (count ($cfg['upload_password']) == 0)) {
        return true;
    }

    // Allow if ip is in array
    foreach ($cfg['upload_ip'] as $i) {
        if ($i == $ip) {
            return true;
        }
        // CIDR test for IPv4 only.
        if (strpos ($i, '/') !== false)
        {
            list ($subnet, $mask) = explode('/', $i);
            if ((ip2long ($ip) & ~((1 << (32 - $mask)) - 1) ) == ip2long ($subnet)) {
                return true;
            }
        }
    }
    if (!jirafeau_has_upload_password($cfg)) {
        return false;
    }
    
    foreach ($cfg['upload_password'] as $p) {
        if ($password == $p) {
            return true;
        }
    }
    return false;
}

/** Tell if we have some HTTP headers generated by a proxy */
function has_http_forwarded()
{
    return
        !empty($_SERVER['HTTP_X_FORWARDED_FOR']) ||
        !empty($_SERVER['http_X_forwarded_for']);
}

/**
 * Generate IP list from HTTP headers generated by a proxy
 * @return  array of IP strings
 */
function get_ip_list_http_forwarded()
{
    $ip_list = array();
    if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
        $l = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
        if ($l === false) {
            return array();
        }
        foreach ($l as $ip) {
            array_push($ip_list, preg_replace('/\s+/', '', $ip));
        }
    }
    if (!empty($_SERVER['http_X_forwarded_for'])) {
        $l = explode(',', $_SERVER['http_X_forwarded_for']);
        foreach ($l as $ip) {
            // Separate IP from port
            $ipa = explode(':', $ip);
            if ($ipa === false) {
                continue;
            }
            $ip = $ipa[0];
            array_push($ip_list, preg_replace('/\s+/', '', $ip));
        }
    }
    return $ip_list;
}

/**
 * Get the ip address of the client from REMOTE_ADDR
 * or from HTTP_X_FORWARDED_FOR if behind a proxy
 * @returns the client ip address
 */
function get_ip_address($cfg)
{
    $remote = $_SERVER['REMOTE_ADDR'];
    if (count($cfg['proxy_ip']) == 0 || !has_http_forwarded()) {
        return $remote;
    }

    $ip_list = get_ip_list_http_forwarded();
    if (count($ip_list) == 0) {
        return $remote;
    }

    foreach ($cfg['proxy_ip'] as $proxy_ip) {
        if ($remote != $proxy_ip) {
            continue;
        }
        // Take the last IP (the one which has been set by the defined proxy).
        return end($ip_list);
    }
    return $remote;
}

/**
 * Convert hexadecimal string to base64
 */
function hex_to_base64($hex)
{
    $b = '';
    foreach (str_split($hex, 2) as $pair) {
        $b .= chr(hexdec($pair));
    }
    return base64_encode($b);
}

/**
 * Read alias informations
 * @return array containing informations.
 */
function jirafeau_get_alias($hash)
{
    $out = array();
    $link = VAR_ALIAS . s2p("$hash") . $hash;

    if (!file_exists($link)) {
        return $out;
    }

    $c = file($link);
    $out['md5_password'] = trim($c[0]);
    $out['ip'] = trim($c[1]);
    $out['update_date'] = trim($c[2]);
    $out['destination'] = trim($c[3], NL);

    return $out;
}

/** Create an alias to a jirafeau's link.
 * @param $alias alias name
 * @param $destination reference of the destination
 * @param $password password to protect alias
 * @param $ip client's IP
 * @return  a string containing the edit code of the alias or the string "Error"
 */
function jirafeau_alias_create($alias, $destination, $password, $ip)
{
    /* Check that alias and password are long enough. */
    if (strlen($alias) < 8 ||
        strlen($alias) > 32 ||
        strlen($password) < 8 ||
        strlen($password) > 32) {
        return 'Error';
    }

    /* Check that destination exists. */
    $l = jirafeau_get_link($destination);
    if (!count($l)) {
        return 'Error';
    }

    /* Check that alias does not already exists. */
    $alias = md5($alias);
    $p = VAR_ALIAS . s2p($alias);
    if (file_exists($p)) {
        return 'Error';
    }

    /* Create alias folder. */
    @mkdir($p, 0755, true);
    if (!file_exists($p)) {
        return 'Error';
    }

    /* Generate password. */
    $md5_password = md5($password);

    /* Store informations. */
    $p .= $alias;
    $handle = fopen($p, 'w');
    fwrite($handle,
            $md5_password . NL .
            $ip . NL .
            time() . NL .
            $destination . NL);
    fclose($handle);

    return 'Ok';
}

/** Update an alias.
 * @param $alias alias to update
 * @param $destination reference of the new destination
 * @param $password password to protect alias
 * @param $new_password optional new password to protect alias
 * @param $ip client's IP
 * @return "Ok" or "Error" string
 */
function jirafeau_alias_update($alias, $destination, $password,
                       $new_password, $ip)
{
    $alias = md5($alias);
    /* Check that alias exits. */
    $a = jirafeau_get_alias($alias);
    if (!count($a)) {
        return 'Error';
    }

    /* Check that destination exists. */
    $l = jirafeau_get_link($a["destination"]);
    if (!count($l)) {
        return 'Error';
    }

    /* Check password. */
    if ($a["md5_password"] != md5($password)) {
        return 'Error';
    }

    $p = $a['md5_password'];
    if (strlen($new_password) >= 8 &&
        strlen($new_password) <= 32) {
        $p = md5($new_password);
    } elseif (strlen($new_password) > 0) {
        return 'Error';
    }

    /* Rewrite informations. */
    $p = VAR_ALIAS . s2p($alias) . $alias;
    $handle = fopen($p, 'w');
    fwrite($handle,
            $p . NL .
            $ip . NL .
            time() . NL .
            $destination . NL);
    fclose($handle);
    return 'Ok';
}

/** Get an alias.
 * @param $alias alias to get
 * @return alias destination or "Error" string
 */
function jirafeau_alias_get($alias)
{
    $alias = md5($alias);
    /* Check that alias exits. */
    $a = jirafeau_get_alias($alias);
    if (!count($a)) {
        return 'Error';
    }

    return $a['destination'];
}

function jirafeau_clean_rm_alias($alias)
{
    $p = s2p("$alias");
    if (file_exists(VAR_ALIAS . $p . $alias)) {
        unlink(VAR_ALIAS . $p . $alias);
    }
    $parse = VAR_ALIAS . $p;
    $scan = array();
    while (file_exists($parse)
           && ($scan = scandir($parse))
           && count($scan) == 2 // '.' and '..' folders => empty.
           && basename($parse) != basename(VAR_ALIAS)) {
        rmdir($parse);
        $parse = substr($parse, 0, strlen($parse) - strlen(basename($parse)) - 1);
    }
}

/** Delete an alias.
 * @param $alias alias to delete
 * @param $password password to protect alias
 * @return "Ok" or "Error" string
 */
function jirafeau_alias_delete($alias, $password)
{
    $alias = md5($alias);
    /* Check that alias exits. */
    $a = jirafeau_get_alias($alias);
    if (!count($a)) {
        return "Error";
    }

    /* Check password. */
    if ($a["md5_password"] != md5($password)) {
        return 'Error';
    }

    jirafeau_clean_rm_alias($alias);
    return 'Ok';
}

/**
 * Replace markers in templates.
 *
 * Available markers have the scheme "###MARKERNAME###".
 *
 * @param $content string Template text with markers
 * @param $htmllinebreaks boolean Convert linebreaks to BR-Tags
 * @return Template with replaced markers
 */
function jirafeau_replace_markers($content, $htmllinebreaks = false)
{
    $patterns = array(
        '/###ORGANISATION###/',
        '/###CONTACTPERSON###/',
        '/###WEBROOT###/'
    );
    $replacements = array(
        $GLOBALS['cfg']['organisation'],
        $GLOBALS['cfg']['contactperson'],
        $GLOBALS['cfg']['web_root']
    );
    $content = preg_replace($patterns, $replacements, $content);

    if (true === $htmllinebreaks) {
        $content = nl2br($content);
    }

    return $content;
}