From 9d2d6c1e3693239d2283279f74ed70818a325931 Mon Sep 17 00:00:00 2001
From: Han-Wen Nienhuys <hanwen@google.com>
Date: Tue, 31 Jan 2017 11:14:16 +0100
Subject: [PATCH] ssh: handle error from prepareKeyChange.

Fixes #18850.

Change-Id: Id3ae89233f9e95ec3238462bf2ecda3e0c515f88
Reviewed-on: https://go-review.googlesource.com/36051
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
---
 ssh/handshake.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ssh/handshake.go b/ssh/handshake.go
index 1b63ba8a6d..b9a207127d 100644
--- a/ssh/handshake.go
+++ b/ssh/handshake.go
@@ -574,7 +574,9 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
 	}
 	result.SessionID = t.sessionID
 
-	t.conn.prepareKeyChange(t.algorithms, result)
+	if err := t.conn.prepareKeyChange(t.algorithms, result); err != nil {
+		return err
+	}
 	if err = t.conn.writePacket([]byte{msgNewKeys}); err != nil {
 		return err
 	}