1430159 - allow protocols to specify an argument validator that automatically gets executed

Status: NEW

(Core :: IPC, enhancement, P3)

Description

[Ben Kelly [:bkelly, not reviewing]]

A common IPC protocol hardening approach is to:

1. Validate arguments in the content process before sending the message.
2. Validate again in the parent process.  If they fail at that point we know we have a spoofed message and can KillHard the child.

It would be nice if there was a hook for a protocol implementation to register a validation method that Send*() and Recv*() could automatically run to do this kind of checking.  Many protocols will need more context to do proper validation, but there are probably a lot of places where simple checks would go a long way.

For example, an API taking a URL argument could:

1. Validate the URL parses.
2. Validate the URL has the expected scheme (perhaps chrome:// only, etc.)
3. Perhaps validate other know path/file extension limitations.