EVP_SIGNATURE-HMAC(7ossl)

💖 NAME 💖

EVP_SIGNATURE-HMAC, EVP_SIGNATURE-Siphash, EVP_SIGNATURE-Poly1305, EVP_SIGNATURE-CMAC — the legacy EVP_PKEY MAC signature implementations. This is OpenSSL’s EVP_SIGNATURE-HMAC(7ossl) page, bestie 💅.

✨ DESCRIPTION ✨

Okay so listen: the algorithms described here have legacy support for creating MACs using EVP_DigestSignInit(3) and related functions. That is not the preferred way of creating MACs — instead you should use the newer EVP_MAC_init(3) functions. This mechanism is provided for backwards compatibility with older versions of OpenSSL. iykyk 🫶

The same signature parameters can be set using EVP_PKEY_CTX_set_params() as can be set via EVP_MAC_CTX_set_params() for the underlying EVP_MAC. See EVP_MAC-HMAC(7), EVP_MAC-Siphash(7), EVP_MAC-Poly1305(7) and EVP_MAC-CMAC(7) for details ✨.

Also, see L<EVP_PKEY-HMAC(7)>, L<EVP_PKEY-Siphash(7)>, L<EVP_PKEY-Poly1305(7)> or L<EVP_PKEY-CMAC(7)> for details about parameters that are supported during the creation of an EVP_PKEY 💜.

🚨 Real talk: this is the legacy route — it’s here for backwards compatibility, and the preferred glow-up is EVP_MAC_init(3). Periodt.

🌈 SEE ALSO 🌈

• EVP_MAC_init(3)
• EVP_DigestSignInit(3)
• EVP_PKEY-HMAC(7)
• EVP_PKEY-Siphash(7)
• EVP_PKEY-Poly1305(7)
• EVP_PKEY-CMAC(7)
• EVP_MAC-HMAC(7)
• EVP_MAC-Siphash(7)
• EVP_MAC-Poly1305(7)
• EVP_MAC-CMAC(7)
• provider-signature(7)

🎀 COPYRIGHT 🎀

Copyright 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>.

mwah 💋 — this was OpenSSL 3.0.21, dated 2026-06-09, page EVP_SIGNATURE-HMAC(7ossl). Slay and read the docs 🦋👑