DH_new_by_nid, DH_get_nid - create or get DH named parameters

       Copyright 2017-2020 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance
       with the License.  You can obtain a copy in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.

3.5.0                                              2025-06-04                                DH_NEW_BY_NID(3SSL)

DH_new_by_nid() creates and returns a DH structure containing named parameters nid. Currently nid must be
       NID_ffdhe2048, NID_ffdhe3072, NID_ffdhe4096, NID_ffdhe6144, NID_ffdhe8192, NID_modp_1536, NID_modp_2048,
       NID_modp_3072, NID_modp_4096, NID_modp_6144 or NID_modp_8192.

       DH_get_nid() determines if the parameters contained in dh match any named safe prime group. It returns
       the NID corresponding to the matching parameters or NID_undef if there is no match.  This function is
       deprecated.

       All of these functions were deprecated in OpenSSL 3.0.

       DH_new_by_nid, DH_get_nid - create or get DH named parameters

DH_new_by_nid() returns a set of DH parameters or NULL if an error occurred.

       DH_get_nid() returns the NID of the matching set of parameters for p and g and optionally q, otherwise it
       returns NID_undef if there is no match.

        #include <openssl/dh.h>

       The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining
       OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):

        DH *DH_new_by_nid(int nid);

        int DH_get_nid(const DH *dh);