EVP_MD-BLAKE2(7ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

💅 EVP_MD-BLAKE2 💅

okay so bestie, welcome to EVP_MD-BLAKE2(7ossl) — the glow-up page for the BLAKE2 EVP_MD implementation ✨ this is the OpenSSL corner of the universe where BLAKE2 lives, and i'm gonna walk you through it like we're texting at 2am 🫶

🌸 DESCRIPTION 🌸

so basically: this is support for computing BLAKE2 digests through the EVP_MD API. that's the whole vibe 💫

🦋 Identities 🦋

okay so this implementation? it's exclusive — only available with the default provider, no gatecrashing from other providers 💅 and it includes the following varieties:

  • BLAKE2S-256 — known names are "BLAKE2S-256" and "BLAKE2s256" ⭐
  • BLAKE2B-512 — known names are "BLAKE2B-512" and "BLAKE2b512" 🌈

like, those are the names it answers to. it's giving dual identity, main character energy 👑

🎀 Settable Parameters 🎀

"BLAKE2B-512" supports the following EVP_MD_CTX_set_params() key described in "PARAMETERS" in EVP_DigestInit(3) — go check that out for the full tea 🍓

  • "size" (OSSL_DIGEST_PARAM_SIZE) <unsigned integer> — yep, that's the one 💜

🧚 Gettable Parameters 🧚

this implementation supports the common gettable parameters described in EVP_MD-common(7). nothing extra, nothing dramatic, just the usual lineup ✨

🌸 Settable Context Parameters 🌸

the implementation supports the following OSSL_PARAM(3) entries which are settable for an EVP_MD_CTX with EVP_DigestInit_ex2(3) or EVP_MD_CTX_set_params(3):

  • "size" (OSSL_DIGEST_PARAM_SIZE) <unsigned integer> — sets a different digest length for the EVP_DigestFinal(3) output. lowkey this one has rules bestie, so listen up 👂 the value of the "size" parameter must not exceed the default digest length of the respective BLAKE2 algorithm variants — that's 64 for BLAKE2B-512 and 32 for BLAKE2S-256. periodt 💅
fr fr though — the parameter must be set with the EVP_DigestInit_ex2(3) call to have an immediate effect. when set with EVP_MD_CTX_set_params(3) it will have an effect only if the EVP_MD_CTX context is reinitialized 🙈 don't say i didn't warn you, that's the sneaky part 💀

🔥 SEE ALSO 🔥

go read those too, i promise they're worth it 💖

⭐ HISTORY ⭐

this functionality was added in OpenSSL 3.0 — iconic behavior honestly 👑

the variable size support was added in OpenSSL 3.2 for BLAKE2B-512 and in OpenSSL 3.3 for BLAKE2S-256 🌱 look at it grow, we love an evolving queen 💅

Copyright 2020-2024 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, no cap 🫶 this was the 3.5.6 version, dated 2026-04-07 — the EVP_MD-BLAKE2(7ossl) manual page, wrapped up and looking cute 🎀 slay, go hash something ✨💖

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