core: Allow loopback hosts for admin endpoint (fix #5650) (#5664)

This commit is contained in:
Matt Holt
2023-08-02 11:13:52 -06:00
committed by GitHub
parent 5c51c1db2c
commit f66493efef
2 changed files with 43 additions and 14 deletions

View File

@ -318,7 +318,32 @@ func (admin AdminConfig) allowedOrigins(addr NetworkAddress) []*url.URL {
// messages. If the requested URI does not include an Internet host
// name for the service being requested, then the Host header field MUST
// be given with an empty value."
//
// UPDATE July 2023: Go broke this by patching a minor security bug in 1.20.6.
// Understandable, but frustrating. See:
// https://github.com/golang/go/issues/60374
// See also the discussion here:
// https://github.com/golang/go/issues/61431
//
// We can no longer conform to RFC 2616 Section 14.26 from either Go or curl
// in purity. (Curl allowed no host between 7.40 and 7.50, but now requires a
// bogus host; see https://superuser.com/a/925610.) If we disable Host/Origin
// security checks, the infosec community assures me that it is secure to do
// so, because:
// 1) Browsers do not allow access to unix sockets
// 2) DNS is irrelevant to unix sockets
//
// I am not quite ready to trust either of those external factors, so instead
// of disabling Host/Origin checks, we now allow specific Host values when
// accessing the admin endpoint over unix sockets. I definitely don't trust
// DNS (e.g. I don't trust 'localhost' to always resolve to the local host),
// and IP shouldn't even be used, but if it is for some reason, I think we can
// at least be reasonably assured that 127.0.0.1 and ::1 route to the local
// machine, meaning that a hypothetical browser origin would have to be on the
// local machine as well.
uniqueOrigins[""] = struct{}{}
uniqueOrigins["127.0.0.1"] = struct{}{}
uniqueOrigins["::1"] = struct{}{}
} else {
uniqueOrigins[net.JoinHostPort("localhost", addr.port())] = struct{}{}
uniqueOrigins[net.JoinHostPort("::1", addr.port())] = struct{}{}