===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/digest-openssl.c,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- src/usr.bin/ssh/digest-openssl.c	2014/12/21 22:27:56	1.5
+++ src/usr.bin/ssh/digest-openssl.c	2017/03/10 02:59:51	1.6
@@ -1,4 +1,4 @@
-/* $OpenBSD: digest-openssl.c,v 1.5 2014/12/21 22:27:56 djm Exp $ */
+/* $OpenBSD: digest-openssl.c,v 1.6 2017/03/10 02:59:51 dtucker Exp $ */
 /*
  * Copyright (c) 2013 Damien Miller <djm@mindrot.org>
  *
@@ -141,7 +141,7 @@
 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
 	u_int l = dlen;
 
-	if (dlen > UINT_MAX)
+	if (digest == NULL || dlen > UINT_MAX)
 		return SSH_ERR_INVALID_ARGUMENT;
 	if (dlen < digest->digest_len) /* No truncation allowed */
 		return SSH_ERR_INVALID_ARGUMENT;