From 4b83175fcab8caa4f1a863cc654f0d991b6ffb58 Mon Sep 17 00:00:00 2001
From: dweller <dweller@cabin.digital>
Date: Tue, 12 Mar 2024 00:50:55 +0200
Subject: disallow injection of args to $manbin via $query

---
 search.php | 122 ++++++++++++++++++++++++++++++++-----------------------------
 1 file changed, 65 insertions(+), 57 deletions(-)

(limited to 'search.php')

diff --git a/search.php b/search.php
index 12c1719..234aa9e 100644
--- a/search.php
+++ b/search.php
@@ -100,79 +100,87 @@
     if(!empty($arch))
         $arg_section .= " -S ". escapeshellarg($arch);
 
-    $found_man = false;
-    if($action === "man")
+    /* NOTE: This seems like it's a too ad hoc of a solution, but _theoretically_ escapeshellarg()
+     *       should take care of the rest. I need more testing.
+     */
+    if($query[0] === "-") $query = ltrim($query, "-\n\r\t\v\x00");
+    if(!empty($query))
     {
-        $res = exec("$manbin -M $manpath -T html -O fragment,toc $arg_section "
-             . escapeshellarg($query), $lines, $ret);
-        if($ret === 0)
+        $found_man = false;
+        if($action === "man")
         {
-            /* TODO: maybe hardcoding a line isn't such a good idea, but I don't wanna regex the
-             * whole thing */
-            preg_match('/.+<span class="head-ltitle">.+\((.).*\)<\/span>/iu', $lines[1], $sect);
+            $res = exec("$manbin -M $manpath -T html -O fragment,toc $arg_section "
+                 . escapeshellarg($query), $lines, $ret);
+            if($ret === 0)
+            {
+                /* TODO: maybe hardcoding a line isn't such a good idea, but I don't wanna regex the
+                 * whole thing */
+                preg_match('/.+<span class="head-ltitle">.+\((.).*\)<\/span>/iu', $lines[1], $sect);
 
-            $url = "$root/?query=". urlencode($query) ."&ampsection=". urlencode($sect[1])
-                ."&arch=". urlencode($arch) ."&action=lmmtfy";
+                $url = "$root/?query=". urlencode($query) ."&ampsection=". urlencode($sect[1])
+                    ."&arch=". urlencode($arch) ."&action=lmmtfy";
 
-            /* HACK: fucking mandoc just generates tons of useless <br>s that make <code> stuff
-             * look horrible. So I just remove it here.
-             * As you can see, they also decided to pepper the HTML with inline style coz they
-             * just absolutely hate me, so I strip it too.
-             */
-            for($i = 0; $i < count($lines); $i++)
-            {
-                $line = preg_replace('/\<br.\>/i', '', $lines[$i]);
-                $line = preg_replace('/style=".*"/i', '', $line);
-                if(!empty(trim($line))) $lines2[$i] = $line;
-            }
+                /* HACK: fucking mandoc just generates tons of useless <br>s that make <code> stuff
+                 * look horrible. So I just remove it here.
+                 * As you can see, they also decided to pepper the HTML with inline style coz they
+                 * just absolutely hate me, so I strip it too.
+                 */
+                for($i = 0; $i < count($lines); $i++)
+                {
+                    $line = preg_replace('/\<br.\>/i', '', $lines[$i]);
+                    $line = preg_replace('/style=".*"/i', '', $line);
+                    if(!empty(trim($line))) $lines2[$i] = $line;
+                }
 
-            echo "<nav id='lmmtfy'><div><div>";
-            echo " <label for='lmmtfy_url'>LmmtFy URL</label></div>";
-            echo " <textarea id='lmmtfy_url' wrap='off' rows='1' readonly>".$url."</textarea>";
-            echo " <button id='lmmtfy_copy' class='jsonly'>Copy</button></div></nav>";
-            echo "<article class='manpage'>". implode(PHP_EOL, $lines2) ."</article>";
-            echo "<script src='/js/copy.js'></script>";
+                echo "<nav id='lmmtfy'><div><div>";
+                echo " <label for='lmmtfy_url'>LmmtFy URL</label></div>";
+                echo " <textarea id='lmmtfy_url' wrap='off' rows='1' readonly>".$url."</textarea>";
+                echo " <button id='lmmtfy_copy' class='jsonly'>Copy</button></div></nav>";
+                echo "<article class='manpage'>". implode(PHP_EOL, $lines2) ."</article>";
+                echo "<script src='/js/copy.js'></script>";
 
-            $found_man = true;
+                $found_man = true;
+            }
         }
-    }
 
-    if(($action === "apropos") || !$found_man)
-    {
-        $res = exec("$manbin -M $manpath $arg_section -k " . escapeshellarg($query), $lines, $ret);
-        if($ret === 0)
+        if(($action === "apropos") || !$found_man)
         {
-            $n = count($lines);
-            $s = $n > 1 ? "s" : "";
-            echo "<p class='hint'> Found $n result$s</p>";
-
-            foreach($lines as $line)
+            $res = exec("$manbin -M $manpath $arg_section -k " . escapeshellarg($query), $lines, $ret);
+            if($ret === 0)
             {
-                preg_match('/^((.+)(?:,.+)*)\((.+)\)\s?-\s?(.*)$/Uu', $line, $matches);
-                $fname = $matches[1];
-                $name  = $matches[2];
-                $fsect = $matches[3];
-                $desc  = $matches[4];
-                $sect  = explode(',', $fsect);
-                $arch  = explode('/', end($sect));
-                $sect  = trim($arch[0]);
-                $arch  = trim(end($arch));
+                $n = count($lines);
+                $s = $n > 1 ? "s" : "";
+                echo "<p class='hint'> Found $n result$s</p>";
+
+                foreach($lines as $line)
+                {
+                    preg_match('/^((.+)(?:,.+)*)\((.+)\)\s?-\s?(.*)$/Uu', $line, $matches);
+                    $fname = $matches[1];
+                    $name  = $matches[2];
+                    $fsect = $matches[3];
+                    $desc  = $matches[4];
+                    $sect  = explode(',', $fsect);
+                    $arch  = explode('/', end($sect));
+                    $sect  = trim($arch[0]);
+                    $arch  = trim(end($arch));
 
-                $descl = strlen($desc);
-                if($descl > 320) $desc = substr($desc, 0, 320) . "...";
-                elseif($descl === 0) $desc = "No synopsis.";
+                    $descl = strlen($desc);
+                    if($descl > 320) $desc = substr($desc, 0, 320) . "...";
+                    elseif($descl === 0) $desc = "No synopsis.";
 
-                $url = "$root/search.php?query=". urlencode($name) ."&section=". urlencode($sect)
-                       ."&arch=". urlencode($arch) ."&action=man";
+                    $url = "$root/search.php?query=". urlencode($name) ."&section=". urlencode($sect)
+                           ."&arch=". urlencode($arch) ."&action=man";
 
-                echo '<dl>';
-                echo "  <dt><a href='".$url."'>$fname($fsect)</a></dt>";
-                echo "  <dd>$desc</dd>";
-                echo '</dl>';
+                    echo '<dl>';
+                    echo "  <dt><a href='".$url."'>$fname($fsect)</a></dt>";
+                    echo "  <dd>$desc</dd>";
+                    echo '</dl>';
+                }
             }
+            else echo "<p class='hint'> No results.</p>";
         }
-        else echo "<p class='hint'> No results.</p>";
     }
+    else echo "<p class='hint'> No input = no results.</p>";
 ?>
             </section>
             <footer>
-- 
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