Improve granluarity and defaults of security.allow-outbound-http
Ref T6755. This is a partial fix, but:
- Allow netblocks to be blacklisted instead of making the feature all-or-nothing.
- Default to disallow requests to all reserved private/local/special IP blocks. This should generally be a "safe" setting.
- Explain the risks better.
- Improve the errors rasied by Macro when failing.
- Removed security.allow-outbound-http, as it is superseded by this setting and is somewhat misleading.
- We still make outbound HTTP requests to OAuth.
- We still make outbound HTTP requests for repositories.
From a technical perspective:
- Add the default blacklist.
- Be more careful with response data in Macro fetching, and don't let the user see it if it isn't ultimately valid.
- I want to do this check before pulling repositories, but that's enough of a mess that it should go in a separate diff.
- The future implementation of T4190 needs to perform the fetch check.
- Fetched a valid macro.
- Fetched a non-image, verified it didn't result in a viewable file.
- Fetched a private-ip-space image, got an error.
- Fetched a 404, got a useful-enough error without additional revealing response content (which is usually HTML anyway and not useful).
- Fetched a bad protocol, got an error.
- Linked to a local resource, a phriction page, a valid remote site, all worked.
- Linked to private IP space, which worked fine (we want to let you link and redierect to other private services, just not fetch them).
- Added and executed unit tests.
Reviewed By: btrahan
Maniphest Tasks: T6755
Differential Revision: https://secure.phabricator.com/D12136