From: dtucker <dtucker@openbsd.org>
Date: Fri, 9 Jun 2017 04:40:04 +0000 (+0000)
Subject: Add comments referring to the relevant RFC sections for rekeying
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=dd78c617373b7392af0e6625d69e2fcfe4017285;p=openbsd

Add comments referring to the relevant RFC sections for rekeying
behaviour.
---

diff --git a/usr.bin/ssh/packet.c b/usr.bin/ssh/packet.c
index ab25778bdae..a3e20652b55 100644
--- a/usr.bin/ssh/packet.c
+++ b/usr.bin/ssh/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.260 2017/06/06 09:12:17 dtucker Exp $ */
+/* $OpenBSD: packet.c,v 1.261 2017/06/09 04:40:04 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -890,6 +890,7 @@ ssh_set_newkeys(struct ssh *ssh, int mode)
 	/*
 	 * The 2^(blocksize*2) limit is too expensive for 3DES,
 	 * so enforce a 1GB limit for small blocksizes.
+	 * See RFC4344 section 3.2.
 	 */
 	if (enc->block_size >= 16)
 		*max_blocks = (u_int64_t)1 << (enc->block_size*2);
@@ -933,7 +934,10 @@ ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
 	    (int64_t)state->rekey_time + state->rekey_interval <= monotime())
 		return 1;
 
-	/* Always rekey when MAX_PACKETS sent in either direction */
+	/*
+	 * Always rekey when MAX_PACKETS sent in either direction 
+	 * As per RFC4344 section 3.1 we do this after 2^31 packets.
+	 */
 	if (state->p_send.packets > MAX_PACKETS ||
 	    state->p_read.packets > MAX_PACKETS)
 		return 1;