From 02119faee397565525151eb2ce39c424d129d287 Mon Sep 17 00:00:00 2001
From: tangyiqun <tangyiqun@uniontech.com>
Date: Tue, 12 Apr 2022 16:07:17 +0800
Subject: [PATCH] Check the return of EVP_KDF_fetch()

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18096)
---
 crypto/dh/dh_kdf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/crypto/dh/dh_kdf.c b/crypto/dh/dh_kdf.c
index eda3d3998ad..045936b7304 100644
--- a/crypto/dh/dh_kdf.c
+++ b/crypto/dh/dh_kdf.c
@@ -39,6 +39,8 @@ int ossl_dh_kdf_X9_42_asn1(unsigned char *out, size_t outlen,
     const char *mdname = EVP_MD_get0_name(md);
 
     kdf = EVP_KDF_fetch(libctx, OSSL_KDF_NAME_X942KDF_ASN1, propq);
+    if (kdf == NULL)
+        return 0;
     kctx = EVP_KDF_CTX_new(kdf);
     if (kctx == NULL)
         goto err;
-- 
2.47.3