From: markus@openbsd.org <markus@openbsd.org>
Date: Tue, 12 Nov 2019 19:34:00 +0000 (+0000)
Subject: upstream: check sig_r and sig_s for ssh-sk keys; ok djm
X-Git-Tag: V_8_2_P1~336
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3fcf69ace19e75cf9dcd7206f396adfcb29611a8;p=thirdparty%2Fopenssh-portable.git

upstream: check sig_r and sig_s for ssh-sk keys; ok djm

OpenBSD-Commit-ID: 1a1e6a85b5f465d447a3800f739e35c5b74e0abc
---

diff --git a/ssh-sk.c b/ssh-sk.c
index a9da765eb..7a4bf8c6b 100644
--- a/ssh-sk.c
+++ b/ssh-sk.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-sk.c,v 1.7 2019/11/12 19:32:30 markus Exp $ */
+/* $OpenBSD: ssh-sk.c,v 1.8 2019/11/12 19:34:00 markus Exp $ */
 /*
  * Copyright (c) 2019 Google LLC
  *
@@ -365,6 +365,12 @@ sshsk_ecdsa_inner_sig(struct sk_sign_response *resp, struct sshbuf **retp)
 	int r = SSH_ERR_INTERNAL_ERROR;
 
 	*retp = NULL;
+	/* Check response validity */
+	if (resp->sig_r == NULL || resp->sig_r == NULL) {
+		error("%s: sk_sign response invalid", __func__);
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
 	if ((inner_sig = sshbuf_new()) == NULL) {
 		r = SSH_ERR_ALLOC_FAIL;
 		goto out;
@@ -400,6 +406,12 @@ sshsk_ed25519_inner_sig(struct sk_sign_response *resp, struct sshbuf **retp)
 	int r = SSH_ERR_INTERNAL_ERROR;
 
 	*retp = NULL;
+	/* Check response validity */
+	if (resp->sig_r == NULL) {
+		error("%s: sk_sign response invalid", __func__);
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
 	if ((inner_sig = sshbuf_new()) == NULL) {
 		r = SSH_ERR_ALLOC_FAIL;
 		goto out;