From ef077ba0d2fa28fd1b481f80335bda723d3d1f20 Mon Sep 17 00:00:00 2001
From: Richard Levitte <levitte@openssl.org>
Date: Fri, 24 Jan 2020 18:14:06 +0100
Subject: [PATCH] Make SM3 a mandatory hash function for SM2.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/10942)
---
 crypto/ec/ec_ameth.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crypto/ec/ec_ameth.c b/crypto/ec/ec_ameth.c
index 6105e6b087..f38ab103ab 100644
--- a/crypto/ec/ec_ameth.c
+++ b/crypto/ec/ec_ameth.c
@@ -507,9 +507,9 @@ static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
         if (EVP_PKEY_id(pkey) == EVP_PKEY_SM2) {
             /* For SM2, the only valid digest-alg is SM3 */
             *(int *)arg2 = NID_sm3;
-        } else {
-            *(int *)arg2 = NID_sha256;
+            return 2;            /* Make it mandatory */
         }
+        *(int *)arg2 = NID_sha256;
         return 1;
 
     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT: