upstream commit
Skip passwords longer than 1k in length so clients can't
easily DoS sshd by sending very long passwords, causing it to spend CPU
hashing them. feedback djm@, ok markus@.
Brought to our attention by tomas.kuthan at oracle.com, shilei-c at
360.cn and coredump at autistici.org
Upstream-ID: d0af7d4a2190b63ba1d38eec502bc4be0be9e333
diff --git a/auth-passwd.c b/auth-passwd.c
index 530b5d4..996c2cf 100644
--- a/auth-passwd.c
+++ b/auth-passwd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-passwd.c,v 1.44 2014/07/15 15:54:14 millert Exp $ */
+/* $OpenBSD: auth-passwd.c,v 1.45 2016/07/21 01:39:35 dtucker Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -66,6 +66,8 @@
#define DAY (24L * 60 * 60) /* 1 day in seconds */
#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */
+#define MAX_PASSWORD_LEN 1024
+
void
disable_forwarding(void)
{
@@ -87,6 +89,9 @@
static int expire_checked = 0;
#endif
+ if (strlen(password) > MAX_PASSWORD_LEN)
+ return 0;
+
#ifndef HAVE_CYGWIN
if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
ok = 0;