EVP_PKEY2PKCS8(3ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

🌸 EVP_PKEY2PKCS8(3ossl) — the OpenSSL glow-up where private keys get a PKCS8 makeover 💅

okay bestie, pull up a chair 🫶 this one is from the OpenSSL manual, section 3ossl, and it's literally the whole "turn my private key into a PKCS8 object and back again" situation. three functions, one very specific job. let's get into it ✨

✨ NAME ✨

EVP_PKEY2PKCS8, EVP_PKCS82PKEY_ex, EVP_PKCS82PKEY — convert a private key to/from PKCS8. that's the entire personality. 🎀

🌈 SYNOPSIS 🌈

#include <openssl/x509.h>

PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(const EVP_PKEY *pkey);
EVP_PKEY *EVP_PKCS82PKEY(const PKCS8_PRIV_KEY_INFO *p8);
EVP_PKEY *EVP_PKCS82PKEY_ex(const PKCS8_PRIV_KEY_INFO *p8, OSSL_LIB_CTX *libctx,
                            const char *propq);

like, look at those signatures. immaculate. no notes. 💖

🦋 DESCRIPTION 🦋

so here's the vibe, function by function:

  • EVP_PKEY2PKCS8() — takes your private key pkey and converts it into a returned PKCS8 object. one direction, clean, done. it's giving "packing your fave outfit into a suitcase" energy 🧳✨
  • EVP_PKCS82PKEY_ex() — the reverse trip, bestie. takes a PKCS8 object p8 and converts it into a returned private key. and here's the ex part (as in "extra", as in "she has options"): it uses libctx and propq when fetching algorithms. so you get to tell it which library context and which property query to use 🔥
  • EVP_PKCS82PKEY() — literally EVP_PKCS82PKEY_ex() but the low-effort cousin in the best way: it uses default values of NULL for the libctx and propq. no cap, that's the only difference 💀

👑 RETURN VALUES 👑

  • EVP_PKEY2PKCS8() returns a PKCS8 object on success. slay. 💅
  • EVP_PKCS82PKEY() and EVP_PKCS82PKEY_ex() return a private key on success. iconic. 🔥

and the sad part 😭 — all functions return NULL if the operation fails. so if you get NULL, do not pass go, do not collect your key, check your error stack.

🌟 SEE ALSO 🌟

go read that one too, it's part of the same friend group 🫶

Copyright 2020-2022 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>.

fr fr read the license before you go copying stuff, bestie. "not complying with the License" is not the main character arc you want 🙈

okay that's the whole page, no crumbs left 💖 this was OpenSSL 3.5.6, dated 2026-04-07 — stan a version number that shows up on time, periodt. mwah, go convert some keys 🎀✨🦋

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