901695 - Limit TLS intolerance fallback to sites that are not HSTS

Status: RESOLVED INCOMPLETE

(Core :: Security: PSM, defect)

Description

[Brian Smith (:briansmith, :bsmith, use NEEDINFO?)]

HSTS should stop us from doing TLS intolerance fallback, since the purpose of HSTS is to make TLS-related errors fatal.

Comment 1

[Brian Smith (:briansmith, :bsmith, use NEEDINFO?)]

We may need to continue to allow TLS 1.2 -> TLS 1.1 -> TLS 1.0 fallback in response to connection resets in order to work around some intermediaries that reset TLS 1.2 and TLS 1.1 connections, based on my understanding of GOogle's findings. However, we should at least prevent the fallback to SSL 3.0 for HSTS sites.

Adding dependency on bug 775370 since that will make it easier for us to get the HSTS state during the TLS connection. CC'ing keeler in case he wants to do this after bug 775370 is done.

Comment 2

[Wim Lewis]

Duplicate of bug 643894?

Comment 3

[Florian Bender]

Given Bug 643894 is specifically about disabling TLS -> SSL fallback (and not inter-TLS), I marked this as a dependancy. But feel free to dupe.

Comment 5

[Brian Smith (:briansmith, :bsmith, use NEEDINFO?)]

Not necessary after bug 1084025 is fixed.