Back to loading mathjax via blob urls

Fucking stupid Content Security Policy

src/calibre/gui2/viewer2/mathjax.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python2
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
+
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+PATCHED_MATHJAX = '''
+
+function postprocess_mathjax(link_uid) {
+    Array.prototype.forEach.call(document.getElementsByTagName('a'), function(a) {
+        var href = a.getAttribute('href');
+        if (href && href.startsWith('#')) {
+            a.setAttribute('href', 'javascript: void(0)')
+            a.setAttribute('data-' + link_uid, JSON.stringify({'frag':href.slice(1)}))
+        }
+    });
+    document.documentElement.dispatchEvent(new CustomEvent("calibre-mathjax-init-done"));
+}
+
+function monkeypatch(mathjax_files) {
+    var orig = window.MathJax.Ajax.fileURL.bind(window.MathJax.Ajax);
+
+    window.MathJax.Ajax.fileURL = function(mathjax_name) {
+        var ans = orig(mathjax_name);
+        var name = ans.replace(/^\\//g, '');
+        if (name.startsWith('../fonts')) name = name.slice(3);
+        ans = mathjax_files[name];
+        if (!ans) ans = '';
+        if (typeof ans !== 'string') {
+            mathjax_files[name] = window.URL.createObjectURL(ans);
+            ans = mathjax_files[name];
+        }
+        if (ans === name && !name.startsWith('blob:')) {
+            if (ans.endsWith('.eot') || ans.endsWith('.otf')) return '';
+            console.log('WARNING: Failed to resolve MathJax file: ' + mathjax_name);
+        }
+        return ans;
+    }
+    window.MathJax.Ajax.fileRev = function(mathjax_name) { return ''; }
+}
+
+function init_mathjax(link_uid, mathjax_files) {
+    monkeypatch(mathjax_files);
+    window.MathJax.Hub.Register.StartupHook("End", postprocess_mathjax.bind(this, link_uid))
+}
+
+document.documentElement.addEventListener("calibre-mathjax-init", function(ev) {
+
+window.MathJax = ev.detail.MathJax;
+window.MathJax.AuthorInit = init_mathjax.bind(this, ev.detail.link_uid, ev.detail.mathjax_files);
+
+__SRC__
+});
+'''
+
+
+def monkeypatch_mathjax(src):
+    return PATCHED_MATHJAX.replace('__SRC__', src, 1)

src/calibre/gui2/viewer2/web_view.py

@@ -62,7 +62,7 @@ class UrlSchemeHandler(QWebEngineUrlSchemeHandler):
 
     def __init__(self, parent=None):
         QWebEngineUrlSchemeHandler.__init__(self, parent)
-        self.mathjax_tdir = None
+        self.mathjax_tdir = self.mathjax_manifest = None
 
     def requestStarted(self, rq):
         if bytes(rq.requestMethod()) != b'GET':
@@ -99,16 +99,28 @@ class UrlSchemeHandler(QWebEngineUrlSchemeHandler):
             data = b'[' + manifest + b',' + metadata + b']'
             self.send_reply(rq, mime_type, data)
         elif name.startswith('mathjax/'):
-            if self.mathjax_tdir is None:
-                from calibre.srv.books import get_mathjax_manifest
-                self.mathjax_tdir = PersistentTemporaryDirectory(prefix='v2mjx-')
-                get_mathjax_manifest(self.mathjax_tdir)
-
+            from calibre.gui2.viewer2.mathjax import monkeypatch_mathjax
+            if name == 'mathjax/manifest.json':
+                if self.mathjax_tdir is None:
+                    import json
+                    from calibre.srv.books import get_mathjax_manifest
+                    self.mathjax_tdir = PersistentTemporaryDirectory(prefix='v2mjx-')
+                    self.mathjax_manifest = json.dumps(get_mathjax_manifest(self.mathjax_tdir)['files'])
+                    self.send_reply(rq, 'application/json', self.mathjax_manifest)
+                    return
             path = os.path.abspath(os.path.join(self.mathjax_tdir, name))
             if path.startswith(self.mathjax_tdir):
                 mt = guess_type(name)
-                with lopen(path, 'rb') as f:
-                    raw = f.read()
+                try:
+                    with lopen(path, 'rb') as f:
+                        raw = f.read()
+                except EnvironmentError as err:
+                    prints("Failed to get mathjax file: {} with error: {}".format(name, err))
+                    rq.fail(rq.RequestFailed)
+                    return
+                if 'MathJax.js' in name:
+                    raw = monkeypatch_mathjax(raw.decode('utf-8')).encode('utf-8')
+
                 self.send_reply(rq, mt, raw)
 
     def send_reply(self, rq, mime_type, data):

src/pyj/read_book/mathjax.pyj

@@ -15,6 +15,7 @@ def get_url(mathjax_files, name):
         ans = mathjax_files[name] = window.URL.createObjectURL(ans)
     return ans
 
+
 def monkeypatch(mathjax_files):
     StyleString = window.MathJax.Ajax.StyleString.bind(window.MathJax.Ajax)
 
@@ -72,7 +73,18 @@ def apply_mathjax(mathjax_files, link_uid, proceed):
     script = E.script(type='text/javascript')
     document.head.appendChild(script)
     if runtime.is_standalone_viewer:
-        script.src = f'{runtime.FAKE_PROTOCOL}://{runtime.FAKE_HOST}/mathjax/MathJax.js'
+        script.onload = def():
+            ev = new CustomEvent("calibre-mathjax-init", {
+                'detail': {
+                    'MathJax': m,
+                    'link_uid': link_uid,
+                    'mathjax_files': mathjax_files,
+                }
+            })
+            document.documentElement.dispatchEvent(ev)
+        document.documentElement.addEventListener("calibre-mathjax-init-done", def(ev):
+            proceed()
+        )
     else:
         m.AuthorInit = init_mathjax.bind(this, mathjax_files, link_uid, proceed)
-        script.src = get_url(mathjax_files, 'MathJax.js')
+    script.src = get_url(mathjax_files, 'MathJax.js')

src/pyj/read_book/view.pyj

@@ -168,7 +168,7 @@ class View:
             'human_scroll': self.on_human_scroll,
         }
         entry_point = None if runtime.is_standalone_viewer else 'read_book.iframe'
-        self.iframe_wrapper = IframeWrapper(handlers, document.getElementById(iframe_id), entry_point, _('Bootstrapping book reader...'))
+        self.iframe_wrapper = IframeWrapper(handlers, document.getElementById(iframe_id), entry_point, _('Bootstrapping book reader...'), runtime.FAKE_PROTOCOL, runtime.FAKE_HOST)
         self.search_overlay = SearchOverlay(self)
         self.content_popup_overlay = ContentPopupOverlay(self)
         self.overlay = Overlay(self)

src/pyj/viewer-main.pyj

@@ -59,9 +59,57 @@ def get_file(book, name, proceed):
         xhr.responseType = 'blob'
     xhr.send()
 
+def mathjax_file_received(name, proceed, end_type, xhr, ev):
+    if end_type is 'abort':
+        return
+    if end_type is not 'load':
+        show_error(_('Failed to load MathJax file'), _(
+            'Could not load the file: {} with error: {}').format(name, xhr.error_html))
+        return
+    if not xhr.responseType or xhr.responseType is 'text':
+        result = xhr.responseText
+    else if xhr.responseType is 'blob' or xhr.responseType is 'json':
+        result = xhr.response
+    else:
+        show_error(_('Failed to load MathJax file'), _(
+            'Could not load the file: {} unknown response type: {}')
+.format(name, xhr.responseType))
+        return
+    if name is 'manifest.json':
+        get_mathjax_files.manifest = result
+        get_mathjax_files_stage2.files_to_get = list(Object.keys(result))
+        get_mathjax_files_stage2.file_data = {}
+        get_mathjax_files_stage2(proceed)
+        return
+
+    get_mathjax_files_stage2.file_data[name] = result
+    get_mathjax_files_stage2.files_to_get.remove(name)
+    if not get_mathjax_files_stage2.files_to_get.length:
+        proceed(get_mathjax_files_stage2.file_data)
+
+def get_mathjax_manifest(proceed):
+    xhr = ajax('mathjax/manifest.json', mathjax_file_received.bind(None, 'manifest.json', proceed), ok_code=0)
+    xhr.responseType = 'json'
+    xhr.send()
+
+
+def get_mathjax_files_stage2(proceed):
+    if not get_mathjax_files_stage2.files_to_get.length:
+        proceed(get_mathjax_files_stage2.file_data)
+        return
+    for filename in get_mathjax_files_stage2.files_to_get:
+        xhr = ajax(f'mathjax/{filename}', mathjax_file_received.bind(None, filename, proceed), ok_code=0)
+        xhr.responseType = 'blob'
+        xhr.send()
+
+
 
 def get_mathjax_files(proceed):
-    proceed({})
+    if not get_mathjax_files.manifest:
+        get_mathjax_manifest(proceed)
+    else:
+        get_mathjax_files_stage2(proceed)
+
 
 
 def update_url_state(replace):