X509_GET_PUBKEY(3ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

💖 NAME 💖

okay bestie, welcome to X509_GET_PUBKEY(3ossl) — the OpenSSL manual page for X509_get_pubkey, X509_get0_pubkey, X509_set_pubkey, X509_get_X509_PUBKEY, X509_REQ_get_pubkey, X509_REQ_get0_pubkey, X509_REQ_set_pubkey, and X509_REQ_get_X509_PUBKEY — together they get or set the public key for a certificate or a certificate request. slay. ✨

🦋 SYNOPSIS 🦋

copy these exactly, no cap:

#include <openssl/x509.h>

EVP_PKEY *X509_get_pubkey(X509 *x);
EVP_PKEY *X509_get0_pubkey(const X509 *x);
int X509_set_pubkey(X509 *x, EVP_PKEY *pkey);
X509_PUBKEY *X509_get_X509_PUBKEY(const X509 *x);

EVP_PKEY *X509_REQ_get_pubkey(X509_REQ *req);
EVP_PKEY *X509_REQ_get0_pubkey(X509_REQ *req);
int X509_REQ_set_pubkey(X509_REQ *x, EVP_PKEY *pkey);
X509_PUBKEY *X509_REQ_get_X509_PUBKEY(X509_REQ *x);

🌸 DESCRIPTION 🌸

  • X509_get_pubkey() — tries to decode the public key for certificate x. If it works, you get the public key back as an EVP_PKEY pointer with its reference count incremented; that means you must free the returned key after use. 💅
  • X509_get0_pubkey() — same idea, except it does not increment the reference count of the returned EVP_PKEY, so you must not free it after use. no cap. 🙈
  • X509_get_X509_PUBKEY() — hands you an internal pointer to the X509_PUBKEY structure which encodes the certificate of x. The returned value must not be freed up after use. 🎀
  • X509_set_pubkey() — tries to set the public key for certificate x to pkey. The key pkey should be freed up after use. 🦋
  • X509_REQ_get_pubkey(), X509_REQ_get0_pubkey(), X509_REQ_set_pubkey(), and X509_REQ_get_X509_PUBKEY() — same vibes, but they operate on certificate request req. ✨

🔥 NOTES 🔥

the first time a public key gets decoded, the EVP_PKEY structure is cached in the certificate or certificate request itself. Subsequent calls return the cached structure with its reference count incremented to improve performance. that's the whole point, bestie — performance slay. ⭐

💀 RETURN VALUES 💀

  • X509_get_pubkey(), X509_get0_pubkey(), X509_get_X509_PUBKEY(), X509_REQ_get_pubkey(), and X509_REQ_get_X509_PUBKEY() return a public key, or NULL if an error occurred. 😭
  • X509_set_pubkey() and X509_REQ_set_pubkey() return 1 for success and 0 for failure. ✅

🌈 SEE ALSO 🌈

go read these next, bestie: d2i_X509(3), ERR_get_error(3), X509_CRL_get0_by_serial(3), X509_get0_signature(3), X509_get_ext_d2i(3), X509_get_extension_flags(3), X509_get_subject_name(3), X509_get_version(3), X509_NAME_add_entry_by_txt(3), X509_NAME_ENTRY_get_object(3), X509_NAME_get_index_by_NID(3), X509_NAME_print_ex(3), X509_new(3), X509_sign(3), X509V3_get_d2i(3), X509_verify_cert(3). 💜

Copyright 2015-2016 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>. 🫶

this page is from OpenSSL 3.5.6, dated 2026-04-07 — bye bestie, go get those pubkeys 💖

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