Commit b04f9479 authored by Kazuki Yamaguchi's avatar Kazuki Yamaguchi Committed by Matt Caswell
Browse files

Fix NPN protocol name list validation 

Since 50932c4a "PACKETise ServerHello processing",
ssl_next_proto_validate() incorrectly allows empty protocol name.
draft-agl-tls-nextprotoneg-04[1] says "Implementations MUST ensure that
the empty string is not included and that no byte strings are
truncated."
This patch restores the old correct behavior.

[1] https://tools.ietf.org/html/draft-agl-tls-nextprotoneg-04



Reviewed-by: default avatarEmilia Käsper <emilia@openssl.org>
Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
parent c5ebfcab

ssl/t1_lib.c

+3 −3
Original line number Diff line number Diff line
@@ -2339,11 +2339,11 @@ int ssl_parse_clienthello_tlsext(SSL *s, PACKET *pkt) 
 */

static char ssl_next_proto_validate(PACKET *pkt)

{

    unsigned int len;

    PACKET tmp_protocol;



    while (PACKET_remaining(pkt)) {

        if (!PACKET_get_1(pkt, &len)

                || !PACKET_forward(pkt, len))

        if (!PACKET_get_length_prefixed_1(pkt, &tmp_protocol)

                || PACKET_remaining(&tmp_protocol) == 0)

            return 0;

    }