From: Frédéric Lécaille <flecaille@haproxy.com>
Date: Thu, 18 Nov 2021 12:54:43 +0000 (+0100)
Subject: MINOR: quic: Wrong value for version negotiation packet 'Unused' field
X-Git-Tag: v2.5-dev15~10
X-Git-Url: http://git.haproxy.org/?a=commitdiff_plain;h=ea78ee1adbedc1e13ce2433c3fcb04b877c3e281;p=haproxy-2.5.git

MINOR: quic: Wrong value for version negotiation packet 'Unused' field

The seven less significant bits of the first byte must be arbitrary.
Without this fix, QUIC tracker "version_negotiation" test could not pass.
---

diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 86c7ff8..6b45630 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -3551,8 +3551,10 @@ static int qc_send_version_negotiation(int fd, struct sockaddr_storage *addr,
 	 * header form
 	 * long header, fixed bit to 0 for Version Negotiation
 	 */
-	buf[i++] = '\x80';
+	if (RAND_bytes((unsigned char *)buf, 1) != 1)
+		return 1;
 
+	buf[i++] |= '\x80';
 	/* null version for Version Negotiation */
 	buf[i++] = '\x00';
 	buf[i++] = '\x00';