Modifies WindowProxy::setSecurityToken so that the frame's SecurityOrigin is taken into account whe…

Source/bindings/core/v8/WindowProxy.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
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  * notice, this list of conditions and the following disclaimer.
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@@ skipping 436 matching lines @@
     // origins that should only allow access to themselves. In this
     // case, we use the global object as the security token to avoid
     // calling canAccess when a script accesses its own objects.
     v8::HandleScope handleScope(m_isolate);
     v8::Local<v8::Context> context = m_scriptState->context();
     if (token.isEmpty() || token == "null") {
         context->UseDefaultSecurityToken();
         return;
     }
 
-    if (m_world->isPrivateScriptIsolatedWorld())
+    if (m_world->isPrivateScriptIsolatedWorld()) {
         token = "private-script://" + token;
+    } else if (m_world->isIsolatedWorld()) {
+        String frameSecurityToken = m_frame->securityContext()->securityOrigin()->toString();
+        if (frameSecurityToken.isEmpty() || frameSecurityToken == "null") {
+            context->UseDefaultSecurityToken();
+            return;
+        }
+        token = frameSecurityToken + token;

[haraken, 2015/09/10 23:34:20]

Just help me understand: Why do we need to add a per-frame information to the
token? What we need is to add a per-world information (e.g., world id) to the
token, isn't it?

[epertoso, 2015/09/11 13:18:22]

The rationale here is: the extension can access some domain, e.g.
'http://www.abc.de/*'. 

A page on abc.de has an iframe, whose source is still
'http://www.abc.de/something', so the extension script is injected in that frame
too.

IIUC, there are now two worlds for the same script, but the same-origin policy
doesn't prevent the iframe from accessing the content of the document in which
it is contained, because they have the same protocol, host and port.

+    }
 
     CString utf8Token = token.utf8();
     // NOTE: V8 does identity comparison in fast path, must use a symbol
     // as the security token.
     context->SetSecurityToken(v8AtomicString(m_isolate, utf8Token.data(), utf8Token.length()));
 }
 
 void WindowProxy::updateDocument()
 {
     ASSERT(m_world->isMainWorld());
@@ skipping 79 matching lines @@
 
 void WindowProxy::updateSecurityOrigin(SecurityOrigin* origin)
 {
     ASSERT(m_world->isMainWorld());
     if (!isContextInitialized())
         return;
     setSecurityToken(origin);
 }
 
 } // namespace blink