DSA_DUP_DH(3ossl)

💖 NAME 💖

okay so bestie, welcome to DSA_DUP_DH(3ossl) — the OpenSSL manual page for DSA_dup_DH, which is literally about creating a DH structure out of a DSA structure. yes, that's the whole vibe. 🦋

✨ SYNOPSIS ✨

First, include the header:

#include <openssl/dsa.h>

Now the important part: 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 *DSA_dup_DH(const DSA *r);

🌸 DESCRIPTION 🌸

The function described on this page is deprecated. There is no direct replacement, applications should use the EVP_PKEY APIs for Diffie-Hellman operations.

DSA_dup_DH() duplicates DSA parameters/keys as DH parameters/keys. q is lost during that conversion, but the resulting DH parameters contain its length. 🎀

💅 RETURN VALUES 💅

DSA_dup_DH() returns the new DH structure, and NULL on error. The error codes can be obtained by ERR_get_error(3). 😭

⚠️ NOTE ⚠️

Be careful to avoid small subgroup attacks when using this. no cap, that's the warning, bestie. 🫶

👑 SEE ALSO 👑

DH_new(3), DSA_new(3), ERR_get_error(3)

🦋 HISTORY 🦋

This function was deprecated in OpenSSL 3.0.

💜 COPYRIGHT 💜

Copyright 2000-2020 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>.

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that's the whole page, bestie. source/version: OpenSSL 3.5.6; date: 2026-04-07; manual: DSA_DUP_DH(3ossl). slay. 💖✨