Commit 5df22060 authored by Matt Caswell's avatar Matt Caswell
Browse files

Improve fallback protection 



A client that has fallen back could detect an inappropriate fallback if
the TLSv1.3 downgrade protection sentinels are present.

Fixes #6756

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6894)
parent f460e839

ssl/statem/statem_lib.c

+3 −0
Original line number Diff line number Diff line
@@ -1914,6 +1914,9 @@ int ssl_choose_client_version(SSL *s, int version, RAW_EXTENSION *extensions) 
        if (highver != 0 && s->version != vent->version)

            continue;



        if (highver == 0 && (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) != 0)

            highver = vent->version;



        method = vent->cmeth();

        err = ssl_method_error(s, method);

        if (err != 0) {