970453 - Potential False Negative for TLS safe renegotiation detection

Status: RESOLVED INVALID

(Core :: Security: PSM, defect)

Description

[JR Conlin [:jrconlin,:jconlin]]

Users connecting to a golang based TLS server will see the following message:

   E/GeckoConsole(  301): [JavaScript Error: "push.services.mozilla.com : server does not support RFC 5746, see CVE-2009-3555"]

Looking at the history for this bug, it appears that there was an issue surrounding cert renegotiations:

https://bugzilla.mozilla.org/show_bug.cgi?id=526689#c8

the golang TLS code does not support any renegotiations, opting to error the connection if one is attempted:

http://golang.org/src/pkg/crypto/tls/conn.go#518

I believe that the flag detection only looks to see if the server supports safe renegotiation to indicate that there is a potential issue. 

http://dxr.mozilla.org/mozilla-central/source/security/manager/ssl/src/nsNSSCallbacks.cpp#1180

It may be necessary to amend the detection to also permit servers that provide no renegotiation, since this would also prevent any renegotiation based attacks.

Comment 1

[JR Conlin [:jrconlin,:jconlin]]

Ping? We're seeing mobile devices being effected by this bug. Can I please have some resolution?

Comment 3

[Dana Keeler (she/her) [:keeler]]

We can't assume the server is doing the right thing in these cases (see https://tools.ietf.org/html/rfc5746#section-4.1 ).