X-Git-Url: https://git.p6c8.net/jirafeau.git/blobdiff_plain/33c3f08cac2785129f87e93fd754e5b872a9b3b5..eacea40554f17e8cbf38d5adf2c60904e44a5b95:/lib/functions.php?ds=sidebyside

diff --git a/lib/functions.php b/lib/functions.php
index b417769..1dd03e5 100644
--- a/lib/functions.php
+++ b/lib/functions.php
@@ -25,9 +25,16 @@
  */
 function s2p($s)
 {
+    $block_size = 8;
     $p = '';
     for ($i = 0; $i < strlen($s); $i++) {
-        $p .= $s{$i} . '/';
+        $p .= $s{$i};
+        if (($i + 1) % $block_size == 0) {
+            $p .= '/';
+        }
+    }
+    if (strlen($s) % $block_size != 0) {
+        $p .= '/';
     }
     return $p;
 }
@@ -152,10 +159,10 @@ function jirafeau_clean_rm_link($link)
     }
 }
 
-function jirafeau_clean_rm_file($md5)
+function jirafeau_clean_rm_file($hash)
 {
-    $p = s2p("$md5");
-    $f = VAR_FILES . $p . $md5;
+    $p = s2p("$hash");
+    $f = VAR_FILES . $p . $hash;
     if (file_exists($f) && is_file($f)) {
         unlink($f);
     }
@@ -204,7 +211,7 @@ function jirafeau_ini_to_bytes($value)
 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')));
+               jirafeau_ini_to_bytes(ini_get('upload_max_filesize')));
 }
 
 /**
@@ -213,9 +220,7 @@ function jirafeau_get_max_upload_size_bytes()
  */
 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'))));
+    return jirafeau_human_size(jirafeau_get_max_upload_size_bytes());
 }
 
 /**
@@ -256,31 +261,31 @@ function jirafeau_delete_link($link)
 
     jirafeau_clean_rm_link($link);
 
-    $md5 = $l['md5'];
-    $p = s2p("$md5");
+    $hash = $l['hash'];
+    $p = s2p("$hash");
 
     $counter = 1;
-    if (file_exists(VAR_FILES . $p . $md5. '_count')) {
-        $content = file(VAR_FILES . $p . $md5. '_count');
+    if (file_exists(VAR_FILES . $p . $hash. '_count')) {
+        $content = file(VAR_FILES . $p . $hash. '_count');
         $counter = trim($content[0]);
     }
     $counter--;
 
     if ($counter >= 1) {
-        $handle = fopen(VAR_FILES . $p . $md5. '_count', 'w');
+        $handle = fopen(VAR_FILES . $p . $hash. '_count', 'w');
         fwrite($handle, $counter);
         fclose($handle);
     }
 
     if ($counter == 0) {
-        jirafeau_clean_rm_file($md5);
+        jirafeau_clean_rm_file($hash);
     }
 }
 
 /**
  * Delete a file and it's links.
  */
-function jirafeau_delete_file($md5)
+function jirafeau_delete_file($hash)
 {
     $count = 0;
     /* Get all links files. */
@@ -303,17 +308,69 @@ function jirafeau_delete_file($md5)
                 if (!count($l)) {
                     continue;
                 }
-                if ($l['md5'] == $md5) {
+                if ($l['hash'] == $hash) {
                     $count++;
                     jirafeau_delete_link($node);
                 }
             }
         }
     }
-    jirafeau_clean_rm_file($md5);
+    jirafeau_clean_rm_file($hash);
     return $count;
 }
 
+
+/** hash file's content
+ * @param $method hash method, see 'file_hash' option. Valid methods are 'md5', 'md5_outside' or 'random'
+ * @param $file_path file to hash
+ * @returns hash string
+ */
+function jirafeau_hash_file($method, $file_path)
+{
+    switch ($method) {
+        case 'md5_outside':
+            return jirafeau_md5_outside($file_path);
+        case 'md5':
+            return md5_file($file_path);
+        case 'random':
+            return jirafeau_gen_random(32);
+    }
+    return md5_file($file_path);
+}
+
+/** hash part of file: start, end and size.
+ * This is a partial file hash, faster but weaker.
+ * @param $file_path file to hash
+ * @returns hash string
+ */
+function jirafeau_md5_outside($file_path)
+{
+    $out = false;
+    $handle = fopen($file_path, "r");
+    if ($handle === false) {
+        return false;
+    }
+    $size = filesize($file_path);
+    if ($size === false) {
+        goto err;
+    }
+    $first = fread($handle, 64);
+    if ($first === false) {
+        goto err;
+    }
+    if (fseek($handle, $size < 64 ? 0 : $size - 64) == -1) {
+        goto err;
+    }
+    $last = fread($handle, 64);
+    if ($last === false) {
+        goto err;
+    }
+    $out = md5($first . $last . $size);
+    err:
+    fclose($handle);
+    return $out;
+}
+
 /**
  * handles an uploaded file
  * @param $file the file struct given by $_FILE[]
@@ -328,7 +385,7 @@ function jirafeau_delete_file($md5)
  *   '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, $link_name_length)
+function jirafeau_upload($file, $one_time_download, $key, $time, $ip, $crypt, $link_name_length, $file_hash_method)
 {
     if (empty($file['tmp_name']) || !is_uploaded_file($file['tmp_name'])) {
         return (array(
@@ -356,18 +413,18 @@ function jirafeau_upload($file, $one_time_download, $key, $time, $ip, $crypt, $l
     }
 
     /* file informations */
-    $md5 = md5_file($file['tmp_name']);
+    $hash = jirafeau_hash_file($file_hash_method, $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)) {
+    $p = s2p("$hash");
+    if (file_exists(VAR_FILES . $p .  $hash)) {
         $rc = unlink($file['tmp_name']);
     } elseif ((file_exists(VAR_FILES . $p) || @mkdir(VAR_FILES . $p, 0755, true))
-            && move_uploaded_file($file['tmp_name'], VAR_FILES . $p . $md5)) {
+            && move_uploaded_file($file['tmp_name'], VAR_FILES . $p . $hash)) {
         $rc = true;
     }
     if (!$rc) {
@@ -381,47 +438,47 @@ function jirafeau_upload($file, $one_time_download, $key, $time, $ip, $crypt, $l
 
     /* Increment or create count file. */
     $counter = 0;
-    if (file_exists(VAR_FILES . $p . $md5 . '_count')) {
-        $content = file(VAR_FILES . $p . $md5. '_count');
+    if (file_exists(VAR_FILES . $p . $hash . '_count')) {
+        $content = file(VAR_FILES . $p . $hash. '_count');
         $counter = trim($content[0]);
     }
     $counter++;
-    $handle = fopen(VAR_FILES . $p . $md5. '_count', 'w');
+    $handle = fopen(VAR_FILES . $p . $hash. '_count', 'w');
     fwrite($handle, $counter);
     fclose($handle);
 
     /* Create delete code. */
     $delete_link_code = jirafeau_gen_random(5);
 
-    /* md5 password or empty. */
+    /* hash password or empty. */
     $password = '';
     if (!empty($key)) {
         $password = md5($key);
     }
 
     /* create link file */
-    $link_tmp_name =  VAR_LINKS . $md5 . rand(0, 10000) . '.tmp';
+    $link_tmp_name =  VAR_LINKS . $hash . 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 . $hash. NL . ($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");
+    $hash_link = substr(base_16_to_64(md5_file($link_tmp_name)), 0, $link_name_length);
+    $l = s2p("$hash_link");
     if (!@mkdir(VAR_LINKS . $l, 0755, true) ||
-        !rename($link_tmp_name, VAR_LINKS . $l . $md5_link)) {
+        !rename($link_tmp_name, VAR_LINKS . $l . $hash_link)) {
         if (file_exists($link_tmp_name)) {
             unlink($link_tmp_name);
         }
 
         $counter--;
         if ($counter >= 1) {
-            $handle = fopen(VAR_FILES . $p . $md5. '_count', 'w');
+            $handle = fopen(VAR_FILES . $p . $hash. '_count', 'w');
             fwrite($handle, $counter);
             fclose($handle);
         } else {
-            jirafeau_clean_rm_file($md5_link);
+            jirafeau_clean_rm_file($hash_link);
         }
         return array(
                  'error' =>
@@ -431,7 +488,7 @@ function jirafeau_upload($file, $one_time_download, $key, $time, $ip, $crypt, $l
                  'delete_link' => '');
     }
     return array( 'error' => $noerr,
-                  'link' => $md5_link,
+                  'link' => $hash_link,
                   'delete_link' => $delete_link_code,
                   'crypt_key' => $crypt_key);
 }
@@ -500,16 +557,13 @@ function check_errors($cfg)
         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);
+        add_error(t('FILE_DIR_W'), VAR_FILES);
     }
 
     if (!is_writable(VAR_LINKS)) {
-        add_error(t('The link directory is not writable!'), VAR_LINKS);
+        add_error(t('LINK_DIR_W'), VAR_LINKS);
     }
 
     if (!is_writable(VAR_ASYNC)) {
@@ -536,7 +590,7 @@ function jirafeau_get_link($hash)
     $out['file_size'] = trim($c[2]);
     $out['key'] = trim($c[3], NL);
     $out['time'] = trim($c[4]);
-    $out['md5'] = trim($c[5]);
+    $out['hash'] = trim($c[5]);
     $out['onetime'] = trim($c[6]);
     $out['upload_date'] = trim($c[7]);
     $out['ip'] = trim($c[8]);
@@ -553,28 +607,28 @@ function jirafeau_admin_list($name, $file_hash, $link_hash)
 {
     echo '<fieldset><legend>';
     if (!empty($name)) {
-        echo t('FILENAME') . ": $name ";
+        echo t('FILENAME') . ": " . jirafeau_escape($name);
     }
     if (!empty($file_hash)) {
-        echo t('FILE') . ": $file_hash ";
+        echo t('FILE') . ": " . jirafeau_escape($file_hash);
     }
     if (!empty($link_hash)) {
-        echo t('LINK') . ": $link_hash ";
+        echo t('LINK') . ": " . jirafeau_escape($link_hash);
     }
     if (empty($name) && empty($file_hash) && empty($link_hash)) {
         echo t('LS_FILES');
     }
     echo '</legend>';
-    echo '<table>';
+    echo '<table border="1" width="1100">';
     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 '<th>' . t('FILENAME') . '</th>';
+    echo '<th>' . t('TYPE') . '</th>';
+    echo '<th>' . t('SIZE') . '</th>';
+    echo '<th>' . t('EXPIRE') . '</th>';
+    echo '<th>' . t('ONETIME') . '</th>';
+    echo '<th>' . t('UPLOAD_DATE') . '</th>';
+    echo '<th>' . t('ORIGIN') . '</th>';
+    echo '<th>' . t('ACTION') . '</th>';
     echo '</tr>';
 
     /* Get all links files. */
@@ -597,10 +651,10 @@ function jirafeau_admin_list($name, $file_hash, $link_hash)
                 }
 
                 /* Filter. */
-                if (!empty($name) && !preg_match("/$name/i", jirafeau_escape($l['file_name']))) {
+                if (!empty($name) && !@preg_match("/$name/i", jirafeau_escape($l['file_name']))) {
                     continue;
                 }
-                if (!empty($file_hash) && $file_hash != $l['md5']) {
+                if (!empty($file_hash) && $file_hash != $l['hash']) {
                     continue;
                 }
                 if (!empty($link_hash) && $link_hash != $node) {
@@ -612,7 +666,7 @@ function jirafeau_admin_list($name, $file_hash, $link_hash)
                 '<strong><a id="upload_link" href="f.php?h='. jirafeau_escape($node) .'" title="' .
                     t('DL_PAGE') . '">' . jirafeau_escape($l['file_name']) . '</a></strong>';
                 echo '</td>';
-                echo '<td>' . $l['mime_type'] . '</td>';
+                echo '<td>' . jirafeau_escape($l['mime_type']) . '</td>';
                 echo '<td>' . jirafeau_human_size($l['file_size']) . '</td>';
                 echo '<td>' . ($l['time'] == -1 ? '∞' : jirafeau_get_datetimefield($l['time'])) . '</td>';
                 echo '<td>';
@@ -628,16 +682,19 @@ function jirafeau_admin_list($name, $file_hash, $link_hash)
                 '<form method="post">' .
                 '<input type = "hidden" name = "action" value = "download"/>' .
                 '<input type = "hidden" name = "link" value = "' . $node . '"/>' .
+                jirafeau_admin_csrf_field() .
                 '<input type = "submit" value = "' . t('DL') . '" />' .
                 '</form>' .
                 '<form method="post">' .
                 '<input type = "hidden" name = "action" value = "delete_link"/>' .
                 '<input type = "hidden" name = "link" value = "' . $node . '"/>' .
+                jirafeau_admin_csrf_field() .
                 '<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 = "hidden" name = "hash" value = "' . $l['hash'] . '"/>' .
+                jirafeau_admin_csrf_field() .
                 '<input type = "submit" value = "' . t('DEL_FILE_LINKS') . '" />' .
                 '</form>' .
                 '</td>';
@@ -675,10 +732,10 @@ function jirafeau_admin_clean()
                 if (!count($l)) {
                     continue;
                 }
-                $p = s2p($l['md5']);
+                $p = s2p($l['hash']);
                 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
+                    !file_exists(VAR_FILES . $p . $l['hash']) || // invalid
+                    !file_exists(VAR_FILES . $p . $l['hash'] . '_count')) { // invalid
                     jirafeau_delete_link($node);
                     $count++;
                 }
@@ -888,7 +945,7 @@ function jirafeau_async_push($ref, $data, $code, $max_file_size)
   * @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, $link_name_length)
+function jirafeau_async_end($ref, $code, $crypt, $link_name_length, $file_hash_method)
 {
     /* Get async infos. */
     $a = jirafeau_get_async_ref($ref);
@@ -912,48 +969,48 @@ function jirafeau_async_end($ref, $code, $crypt, $link_name_length)
         }
     }
 
-    $md5 = md5_file($p);
+    $hash = jirafeau_hash_file($file_hash_method, $p);
     $size = filesize($p);
-    $np = s2p($md5);
+    $np = s2p($hash);
     $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);
+    if (!file_exists(VAR_FILES . $np . $hash)) {
+        rename($p, VAR_FILES . $np . $hash);
     }
 
     /* Increment or create count file. */
     $counter = 0;
-    if (file_exists(VAR_FILES . $np . $md5 . '_count')) {
-        $content = file(VAR_FILES . $np . $md5. '_count');
+    if (file_exists(VAR_FILES . $np . $hash . '_count')) {
+        $content = file(VAR_FILES . $np . $hash. '_count');
         $counter = trim($content[0]);
     }
     $counter++;
-    $handle = fopen(VAR_FILES . $np . $md5. '_count', 'w');
+    $handle = fopen(VAR_FILES . $np . $hash. '_count', 'w');
     fwrite($handle, $counter);
     fclose($handle);
 
     /* Create link. */
-    $link_tmp_name =  VAR_LINKS . $md5 . rand(0, 10000) . '.tmp';
+    $link_tmp_name =  VAR_LINKS . $hash . 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 .
+            $a['key'] . NL . $a['time'] . NL . $hash . 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");
+    $hash_link = substr(base_16_to_64(md5_file($link_tmp_name)), 0, $link_name_length);
+    $l = s2p("$hash_link");
     if (!@mkdir(VAR_LINKS . $l, 0755, true) ||
-        !rename($link_tmp_name, VAR_LINKS . $l . $md5_link)) {
+        !rename($link_tmp_name, VAR_LINKS . $l . $hash_link)) {
         echo "Error";
     }
 
     /* Clean async upload. */
     jirafeau_async_delete($ref);
-    return $md5_link . NL . $delete_link_code . NL . urlencode($crypt_key);
+    return $hash_link . NL . $delete_link_code . NL . urlencode($crypt_key);
 }
 
 function jirafeau_crypt_create_iv($base, $size)
@@ -983,10 +1040,10 @@ function jirafeau_encrypt_file($fp_src, $fp_dst)
     $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));
+    $hash_key = md5($crypt_key);
+    $iv = jirafeau_crypt_create_iv($hash_key, mcrypt_enc_get_iv_size($m));
     /* Init module. */
-    mcrypt_generic_init($m, $md5_key, $iv);
+    mcrypt_generic_init($m, $hash_key, $iv);
     /* Crypt file. */
     $r = fopen($fp_src, 'r');
     $w = fopen($fp_dst, 'c');
@@ -1022,8 +1079,8 @@ function jirafeau_decrypt_file($fp_src, $fp_dst, $k)
     $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));
+    $hash_key = md5($crypt_key);
+    $iv = jirafeau_crypt_create_iv($hash_key, mcrypt_enc_get_iv_size($m));
     /* Decrypt file. */
     $r = fopen($fp_src, 'r');
     $w = fopen($fp_dst, 'c');
@@ -1069,19 +1126,14 @@ function jirafeau_challenge_upload_password($cfg, $password)
 }
 
 /**
- * Test if visitor's IP is authorized to upload.
+ * Test if the given IP is whitelisted by the given list.
  *
  * @param $allowedIpList array of allowed IPs
  * @param $challengedIp IP to be challenged
  * @return true if IP is authorized, false otherwise.
  */
-function jirafeau_challenge_upload_ip($allowedIpList, $challengedIp)
+function jirafeau_challenge_ip($allowedIpList, $challengedIp)
 {
-    // skip if list is empty = all IPs allowed
-    if (count($allowedIpList) == 0) {
-        return true;
-    }
-    // test given IP against each allowed IP
     foreach ($allowedIpList as $i) {
         if ($i == $challengedIp) {
             return true;
@@ -1097,6 +1149,42 @@ function jirafeau_challenge_upload_ip($allowedIpList, $challengedIp)
     return false;
 }
 
+/**
+ * Check if Jirafeau has a restriction on the IP address for uploading.
+ * @return true if uploading is IP restricted, false otherwise.
+ */
+function jirafeau_upload_has_ip_restriction($cfg) {
+    return count($cfg['upload_ip']) > 0;
+}
+
+/**
+ * Test if visitor's IP is authorized to upload at all.
+ *
+ * @param $cfg configuration
+ * @param $challengedIp IP to be challenged
+ * @return true if IP is authorized, false otherwise.
+ */
+function jirafeau_challenge_upload_ip($cfg, $challengedIp)
+{
+    // If no IP address have been listed, allow upload from any IP
+    if (!jirafeau_upload_has_ip_restriction($cfg)) {
+        return true;
+    }
+    return jirafeau_challenge_ip($cfg['upload_ip'], $challengedIp);
+}
+
+/**
+ * Test if visitor's IP is authorized to upload without a password.
+ *
+ * @param $cfg configuration
+ * @param $challengedIp IP to be challenged
+ * @return true if IP is authorized, false otherwise.
+ */
+function jirafeau_challenge_upload_ip_without_password($cfg, $challengedIp)
+{
+    return jirafeau_challenge_ip($cfg['upload_ip_nopassword'], $challengedIp);
+}
+
 /**
  * Test if visitor's IP is authorized or password is supplied and authorized
  * @param $ip IP to be challenged
@@ -1105,35 +1193,9 @@ function jirafeau_challenge_upload_ip($allowedIpList, $challengedIp)
  */
 function jirafeau_challenge_upload ($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 == $p) {
-            return true;
-        }
-    }
-    return false;
+    return jirafeau_challenge_upload_ip_without_password($cfg, $ip) ||
+            (!jirafeau_has_upload_password($cfg) && !jirafeau_upload_has_ip_restriction($cfg)) ||
+            (jirafeau_challenge_upload_password($cfg, $password) && jirafeau_challenge_upload_ip($cfg, $ip));
 }
 
 /** Tell if we have some HTTP headers generated by a proxy */
@@ -1248,3 +1310,29 @@ function jirafeau_escape($string)
 {
     return htmlspecialchars($string, ENT_QUOTES);
 }
+
+function jirafeau_admin_session_start()
+{
+    $_SESSION['admin_auth'] = true;
+    $_SESSION['admin_csrf'] = md5(uniqid(mt_rand(), true));
+}
+
+function jirafeau_admin_session_end()
+{
+    $_SESSION = array();
+    session_destroy();
+}
+
+function jirafeau_admin_session_logged()
+{
+    return isset($_SESSION['admin_auth']) &&
+           isset($_SESSION['admin_csrf']) &&
+           isset($_POST['admin_csrf']) &&
+           $_SESSION['admin_auth'] === true &&
+           $_SESSION['admin_csrf'] === $_POST['admin_csrf'];
+}
+
+function jirafeau_admin_csrf_field()
+{
+    return "<input type='hidden' name='admin_csrf' value='". $_SESSION['admin_csrf'] . "'/>";
+}