Initial commit

LICENSE

+Copyright 2017 Anton Sarukhanov
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

+# Un-Safelinks
+
+A Thunderbird add-on to revert the link rewriting done by Office 365's Advanced
+Threat Protection feature.
+
+ATP makes links illegible and provides questionable security benefit
+<sup>
+[[1]](https://blog.tylerbickford.com/2016/06/16/microsoft-advanced-threat-protection-is-a-disaster/)
+[[2]](https://emtunc.org/blog/03/2017/bypassing-safe-links-exchange-online-advanced-threat-protection/)
+[[3]](https://halon.io/blog/fooled-microsofts-safe-link-technology/)</sup>.
+This add-on will revert those links to their original state.
+
+Only the message view pane is affected; actual emails (local and remote) will be
+untouched. Replies to messages containing rewritten links will still contain
+rewritten links.
+
+# License
+
+This add-on is released under the MIT license. Link icon from [MDI](https://materialdesignicons.com/).

chrome.manifest

+content     unsafelinks    chrome/content/
+overlay chrome://messenger/content/messenger.xul chrome://unsafelinks/content/unsafelinks.xul
\ No newline at end of file

chrome/content/unsafelinks.js

+// Listen for the "window loaded" event and initialize.
+window.addEventListener("load", function load(event) {
+    window.removeEventListener("load", load, false);
+    unsafelinks.init();
+}, false);
+
+var unsafelinks = {
+    init: function() {
+        // Listen for the "message loaded" event, if this is a message window.
+        var messagepane = document.getElementById("messagepane");
+        if (messagepane) {
+            messagepane.addEventListener("load", unsafelinks.onMessageLoad, true);
+        }
+    },
+
+    onMessageLoad: function(event) {
+        // Replace each safelinks URL in the message body with the original URL.
+        var body = event.originalTarget.body;
+        body.innerHTML = body.innerHTML.replace(unsafelinks.urlRegex, unsafelinks.replacer);
+    },
+
+    // Regular expression matching a safelinks-encoded URL.
+    urlRegex: /https?:\/\/(?:.+?\.)?safelinks\.protection\.outlook\.com\/([A-Za-z0-9\-\._~:\/\?#\[\]@!$&'\(\)\*\+,;\=%]*)/gi,
+
+    replacer: function(url, queryString){
+        // Extract the "url" parameter from the URL, if it exists.
+        var params = new URLSearchParams(queryString);
+        if (params.has('url')) {
+            return params.get('url');
+        } else {
+            return url;
+        }
+    },
+};

chrome/content/unsafelinks.xul

+<?xml version="1.0"?>
+<overlay id="unsafelinks" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+<script type="application/javascript" src="chrome://unsafelinks/content/unsafelinks.js"/>
+</overlay>

install.rdf

+<?xml version="1.0"?>
+<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+     xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+  <Description about="urn:mozilla:install-manifest">
+    <em:id>unsafelinks@ant.sr</em:id>
+    <em:name>Un-Safelinks</em:name>
+    <em:description>Replace URLs which have been rewritten by Office 365 Advanced Threat Protection with the original URL.</em:description>
+    <em:version>1.0</em:version>
+	<em:homepageURL>https://ant.sr/unsafelinks</em:homepageURL>
+    <em:targetApplication>
+      <Description>
+        <em:id>{3550f703-e582-4d05-9a08-453d09bdfdc6}</em:id>
+        <em:minVersion>45.8.0</em:minVersion>
+        <em:maxVersion>52.*</em:maxVersion>
+      </Description>
+    </em:targetApplication>
+  </Description>
+</RDF>