Bug 228324

Summary:	Investigate removing Referrer in all HTTPS -> HTTP cases
Product:	WebKit	Reporter:	Sam Sneddon [:gsnedders] <gsnedders>
Component:	Page Loading	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	achristensen, beidson, webkit-bug-importer, wilander
Priority:	P2	Keywords:	InRadar
Version:	WebKit Local Build
Hardware:	Unspecified
OS:	Unspecified

Description Sam Sneddon [:gsnedders] 2021-07-27 08:03:41 PDT

While less useful in the short term due to SNI providing leakage of the cross-site origin anyway, once ECH has more support the only data available to a passive monitor is the IP address of the secure origin; as such, at that point, it would become a big shame to then be leaking it through the Referer header when navigating to an insecure origin.

This doesn't happen by default on ToT, given the Referrer-Policy default of strict-origin-when-cross-origin means we don't send a Referer in the HTTPS -> HTTP case anyway, but we should probably investigate making all the Referrer-Policy behave like this. (See Bug 228323, which is related insofar as it suggests overriding the policy in other ways.)

Comment 1 Radar WebKit Bug Importer 2021-07-28 04:03:24 PDT

<rdar://problem/81210169>