Fix coverity issue: CID - Improper use of Negative value in dh_ctrl.c
@@ -500,6 +500,9 @@ int EVP_PKEY_CTX_set0_dh_kdf_ukm(EVP_PKEY_CTX *ctx, unsigned char *ukm, int len)
int ret;
OSSL_PARAM params[2], *p = params;
+ if (len <= 0)
+ return -1;
+
ret = dh_param_derive_check(ctx);
if (ret != 1)
return ret;
