DSA_DUP_DH(3SSL)

📦
version 4.0.3 · 14 versions
, in ubuntu stonking

💖 DSA_dup_DH — the OpenSSL manual, bestie edition 💖

okay so this is DSA_dup_DH(3SSL) from the OpenSSL crew, and before you get excited — this one is deprecated, bestie. she's retired. still, iykyk, let's go through it. 🎀

✨ NAME ✨

DSA_dup_DH — create a DH structure out of a DSA structure. yes literally that's the whole job. it's giving ✨structure glow-up✨.

🦋 SYNOPSIS 🦋

#include <openssl/dsa.h>

okay so warning you upfront: the following functions have been deprecated since OpenSSL 3.0, and you can hide them entirely by defining OPENSSL_API_COMPAT with a suitable version value — peep openssl_user_macros(7) for the deets. 👑

DH *DSA_dup_DH(const DSA *r);

🌸 DESCRIPTION 🌸

the function on this page is deprecated, full stop, no cap. and the plot twist? there is no direct replacement. applications should use the EVP_PKEY APIs for Diffie-Hellman operations instead. that's the move now. 💅

DSA_dup_DH() duplicates DSA parameters/keys as DH parameters/keys. and here's the part you cannot miss: q is lost during that conversion — gone, adios, not invited to the afterparty 🥲 — but the resulting DH parameters do contain its length. so her memory lives on in spirit, length-wise.

👑 RETURN VALUES 👑

DSA_dup_DH() returns the new DH structure, and NULL on error. if you need the error codes, you grab them with ERR_get_error(3). 😭

💀 NOTE 💀

be careful to avoid small subgroup attacks when using this. i'm serious. this is not the vibe to be careless about. 🙈

🔥 SEE ALSO 🔥

🌈 HISTORY 🌈

this function was deprecated in OpenSSL 3.0. she served her time. 🫶

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>.

and that's the whole page, bestie — OpenSSL 4.0.3, dated 2026-09-29, DSA_DUP_DH(3SSL) ✨ stay safe, avoid those small subgroup attacks, mwah 💖🎀

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