From a571dbcc7b7b25371174569b13df5159bc4c6c7a Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Tue, 4 Oct 2016 21:34:40 +0000 Subject: [PATCH] upstream commit add a comment about implicitly-expected checks to sshkey_ec_validate_public() Upstream-ID: 74a7f71c28f7c13a50f89fc78e7863b9cd61713f --- sshkey.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/sshkey.c b/sshkey.c index f7197726c..25a360b7b 100644 --- a/sshkey.c +++ b/sshkey.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshkey.c,v 1.39 2016/09/26 21:16:11 djm Exp $ */ +/* $OpenBSD: sshkey.c,v 1.40 2016/10/04 21:34:40 djm Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * Copyright (c) 2008 Alexander von Gernler. All rights reserved. @@ -2864,6 +2864,14 @@ sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public) BIGNUM *order, *x, *y, *tmp; int ret = SSH_ERR_KEY_INVALID_EC_VALUE; + /* + * NB. This assumes OpenSSL has already verified that the public + * point lies on the curve. This is done by EC_POINT_oct2point() + * implicitly calling EC_POINT_is_on_curve(). If this code is ever + * reachable with public points not unmarshalled using + * EC_POINT_oct2point then the caller will need to explicitly check. + */ + if ((bnctx = BN_CTX_new()) == NULL) return SSH_ERR_ALLOC_FAIL; BN_CTX_start(bnctx);