Implementation of script hashes for CSP.

Source/core/dom/ScriptLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 290 matching lines @@
     if (sourceCode.isEmpty())
         return;
 
     RefPtr<Document> elementDocument = &m_element->document();
     RefPtr<Document> contextDocument = elementDocument->contextDocument().get();
     if (!contextDocument)
         return;
 
     Frame* frame = contextDocument->frame();
 
-    bool shouldBypassMainWorldContentSecurityPolicy = (frame && frame->script()->shouldBypassMainWorldContentSecurityPolicy()) || elementDocument->contentSecurityPolicy()->allowScriptNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr));
+    bool shouldBypassMainWorldContentSecurityPolicy = (frame && frame->script()->shouldBypassMainWorldContentSecurityPolicy()) || elementDocument->contentSecurityPolicy()->allowScriptNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr)) || elementDocument->contentSecurityPolicy()->allowScriptHash(sourceCode.source());

[Mike West, 2013/10/16 14:53:02]

This is getting pretty ugly. I shouldn't have added the nonce bits here in the
first place, but adding hash really makes it visibly wrong. Ideally, we'd
refactor this in a separate CL so that the
'shouldBypassMainWorldContentSecurityPolicy' variable did what it said.

[jww, 2013/10/16 21:49:21]

I'm a little confused about what you'd like to see here. How about I break up
all of these calls into separate booleans and we can just || them all together.
That should make it quite a bit more readable, yes? I suppose the only problem
is short circuiting extraneous checks, but that's what compilers are for, I
suppose :-)

 
     if (!m_isExternalScript && (!shouldBypassMainWorldContentSecurityPolicy && !elementDocument->contentSecurityPolicy()->allowInlineScript(elementDocument->url(), m_startLineNumber)))
         return;
 
     if (m_isExternalScript && m_resource && !m_resource->mimeTypeAllowedByNosniff()) {
         contextDocument->addConsoleMessage(SecurityMessageSource, ErrorMessageLevel, "Refused to execute script from '" + m_resource->url().elidedString() + "' because its MIME type ('" + m_resource->mimeType() + "') is not executable, and strict MIME type checking is enabled.");
         return;
     }
 
     if (frame) {
@@ skipping 112 matching lines @@
     if (isHTMLScriptLoader(element))
         return toHTMLScriptElement(element)->loader();
 
     if (isSVGScriptLoader(element))
         return toSVGScriptElement(element)->loader();
 
     return 0;
 }
 
 }