From 8fd19b20beca97a2ef804058f099cf54f12f7614 Mon Sep 17 00:00:00 2001
From: "Dr. Stephen Henson" <steve@openssl.org>
Date: Fri, 10 Feb 2017 04:22:18 +0000
Subject: [PATCH] Check index >= 0 as 0 is a valid index.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2587)
---
 ssl/t1_lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 43340d4d49..d6a841a82f 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1601,7 +1601,7 @@ int tls1_process_sigalgs(SSL *s)
         if (SSL_IS_TLS13(s) && sigptr->sig == EVP_PKEY_RSA)
             continue;
         idx = tls12_get_pkey_idx(sigptr->sig);
-        if (idx > 0 && pmd[idx] == NULL) {
+        if (idx >= 0 && pmd[idx] == NULL) {
             md = ssl_md(sigptr->hash_idx);
             pmd[idx] = md;
             pvalid[idx] = CERT_PKEY_EXPLICIT_SIGN;
-- 
2.25.1