Check os for NULL before dereferencing it

Avoids a segfault when both priv == NULL and os == NULL.

ok miod

diff --git a/lib/libcrypto/hmac/hm_ameth.c b/lib/libcrypto/hmac/hm_ameth.c
index faaa04b..818fec7 100644 (file)
--- a/lib/libcrypto/hmac/hm_ameth.c
+++ b/lib/libcrypto/hmac/hm_ameth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: hm_ameth.c,v 1.15 2022/11/18 15:10:51 tb Exp $ */
+/* $OpenBSD: hm_ameth.c,v 1.16 2022/11/18 20:03:36 tb Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2007.
  */
@@ -142,17 +142,17 @@ hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv, size_t len)
 static int
 hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv, size_t *len)
 {
-       ASN1_OCTET_STRING *os = pkey->pkey.ptr;
+       ASN1_OCTET_STRING *os;
        CBS cbs;
 
+       if ((os = pkey->pkey.ptr) == NULL)
+               return 0;
+
        if (priv == NULL) {
                *len = os->length;
                return 1;
        }
 
-       if (os == NULL)
-               return 0;
-
        CBS_init(&cbs, os->data, os->length);
        return CBS_write_bytes(&cbs, priv, *len, len);
 }