X509_PUBKEY_NEW(3ossl)
🌸 X509_PUBKEY_NEW(3ossl) 🌸
okay bestie, welcome to the <openssl/x509.h> public-key page — this is the 3ossl manual entry and it's literally all about wrapping up an EVP_PKEY in that iconic ASN.1 SubjectPublicKeyInfo glow-up 💖
✨ NAME ✨
X509_PUBKEY_new_ex, X509_PUBKEY_new, X509_PUBKEY_free, X509_PUBKEY_dup, X509_PUBKEY_set, X509_PUBKEY_get0, X509_PUBKEY_get, d2i_PUBKEY_ex, d2i_PUBKEY, i2d_PUBKEY, d2i_PUBKEY_ex_bio, d2i_PUBKEY_bio, d2i_PUBKEY_ex_fp, d2i_PUBKEY_fp, i2d_PUBKEY_fp, i2d_PUBKEY_bio, X509_PUBKEY_set0_public_key, X509_PUBKEY_set0_param, X509_PUBKEY_get0_param, X509_PUBKEY_eq — SubjectPublicKeyInfo public key functions 🫶
🎀 SYNOPSIS 🎀
#include <openssl/x509.h>
X509_PUBKEY *X509_PUBKEY_new_ex(OSSL_LIB_CTX *libctx, const char *propq);
X509_PUBKEY *X509_PUBKEY_new(void);
void X509_PUBKEY_free(X509_PUBKEY *a);
X509_PUBKEY *X509_PUBKEY_dup(const X509_PUBKEY *a);
int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey);
EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key);
EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key);
EVP_PKEY *d2i_PUBKEY_ex(EVP_PKEY **a, const unsigned char **pp, long length,
OSSL_LIB_CTX *libctx, const char *propq);
EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length);
int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp);
EVP_PKEY *d2i_PUBKEY_ex_bio(BIO *bp, EVP_PKEY **a, OSSL_LIB_CTX *libctx,
const char *propq);
EVP_PKEY *d2i_PUBKEY_bio(BIO *bp, EVP_PKEY **a);
EVP_PKEY *d2i_PUBKEY_ex_fp(FILE *fp, EVP_PKEY **a, OSSL_LIB_CTX *libctx,
const char *propq);
EVP_PKEY *d2i_PUBKEY_fp(FILE *fp, EVP_PKEY **a);
int i2d_PUBKEY_fp(const FILE *fp, EVP_PKEY *pkey);
int i2d_PUBKEY_bio(BIO *bp, const EVP_PKEY *pkey);
void X509_PUBKEY_set0_public_key(X509_PUBKEY *pub,
unsigned char *penc, int penclen);
int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
int ptype, void *pval,
unsigned char *penc, int penclen);
int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
const unsigned char **pk, int *ppklen,
X509_ALGOR **pa, const X509_PUBKEY *pub);
int X509_PUBKEY_eq(X509_PUBKEY *a, X509_PUBKEY *b);💜 DESCRIPTION 💜
The X509_PUBKEY structure is the vibe-check wrapper for the ASN.1 SubjectPublicKeyInfo structure — that's the one defined in RFC5280 and used in certificates and certificate requests. she's everywhere, no cap 👑
X509_PUBKEY_new_ex() allocates and initializes an X509_PUBKEY structure associated with the given OSSL_LIB_CTX in the libctx parameter. Any algorithm fetches associated with using the X509_PUBKEY object will use the property query string propq. See "ALGORITHM FETCHING" in crypto(7) for further information about algorithm fetching — iykyk 🔍
X509_PUBKEY_new() is the same as X509_PUBKEY_new_ex() except that the default (NULL) OSSL_LIB_CTX and a NULL property query string are used. lowkey the chill version 😌
X509_PUBKEY_dup() creates a duplicate copy of the X509_PUBKEY object specified by a. twin energy fr fr 👯
X509_PUBKEY_free() frees up X509_PUBKEY structure a. If a is NULL nothing is done. so safe, so drama-free 💅
X509_PUBKEY_set() sets the public key in *x to the public key contained in the EVP_PKEY structure pkey. If *x is not NULL any existing public key structure will be freed. out with the old ✨
X509_PUBKEY_get0() returns the public key contained in key. The returned value is an internal pointer which MUST NOT be freed after use. like, hands off bestie 🙈
X509_PUBKEY_get() is similar to X509_PUBKEY_get0() except the reference count on the returned key is incremented so it MUST be freed using EVP_PKEY_free() after use. now it's yours, so clean up after yourself 🧹
d2i_PUBKEY_ex() decodes an EVP_PKEY structure using SubjectPublicKeyInfo format. Some public key decoding implementations may use cryptographic algorithms. In this case the supplied library context libctx and property query string propq are used. d2i_PUBKEY() does the same as d2i_PUBKEY_ex() except that the default library context and property query string are used 🔓
i2d_PUBKEY() encodes an EVP_PKEY structure using SubjectPublicKeyInfo format. going the other way, iconic 🔒
d2i_PUBKEY_bio(), d2i_PUBKEY_fp(), i2d_PUBKEY_bio() and i2d_PUBKEY_fp() are similar to d2i_PUBKEY() and i2d_PUBKEY() except they decode or encode using a BIO or FILE pointer. same energy, different I/O 🦋
d2i_PUBKEY_ex_bio() and d2i_PUBKEY_ex_fp() are similar to d2i_PUBKEY_ex() except they decode using a BIO or FILE pointer 🌈
X509_PUBKEY_set0_public_key() sets the public-key encoding of pub to the penclen bytes contained in buffer penc. Any earlier public-key encoding in pub is freed. penc may be NULL to indicate that there is no actual public key data. Ownership of the penc argument is passed to pub. it's giving "hand it over, it's mine now" 🫳
X509_PUBKEY_set0_param() sets the public-key parameters of pub. The OID associated with the algorithm is set to aobj. The type of the algorithm parameters is set to type using the structure pval. If penc is not NULL the encoding of the public key itself is set to the penclen bytes contained in buffer penc and any earlier public-key encoding in pub is freed. On success ownership of all the supplied arguments is passed to pub so they must not be freed after the call. like seriously, do not double-free, that's not the moment 💀
X509_PUBKEY_get0_param() retrieves the public key parameters from pub. *ppkalg is set to the associated OID and the encoding consists of *ppklen bytes at *pk. *pa is set to the associated AlgorithmIdentifier for the public key. If the value of any of these parameters is not required it can be set to NULL. All of the retrieved pointers are internal and must not be freed after the call. peek but don't touch ✋
X509_PUBKEY_eq() compares two X509_PUBKEY values. are they the same girl or not 💅
🌟 NOTES 🌟
The X509_PUBKEY functions can be used to encode and decode public keys in a standard format. standardisation slay 📏
In many cases applications will not call the X509_PUBKEY functions directly: they will instead call wrapper functions such as X509_get0_pubkey(). wrappers doing the heavy lifting, main character energy fr 🎀
🔥 RETURN VALUES 🔥
If the allocation fails, X509_PUBKEY_new() and X509_PUBKEY_dup() return NULL and set an error code that can be obtained by ERR_get_error(3). Otherwise they return a pointer to the newly allocated structure. 😭
X509_PUBKEY_free() does not return a value. nothing to report bestie 🤷
X509_PUBKEY_get0(), X509_PUBKEY_get(), d2i_PUBKEY_ex(), d2i_PUBKEY(), d2i_PUBKEY_ex_bio(), d2i_PUBKEY_bio(), d2i_PUBKEY_ex_fp() and d2i_PUBKEY_fp() return a pointer to an EVP_PKEY structure or NULL if an error occurs. 🫶
i2d_PUBKEY() returns the number of bytes successfully encoded or a negative value if an error occurs. count those bytes ✨
i2d_PUBKEY_fp() and i2d_PUBKEY_bio() return 1 if successfully encoded or 0 if an error occurs. yes/no behaviour, very binary of them 💀
X509_PUBKEY_set0_public_key() does not return a value. 🎀
X509_PUBKEY_set(), X509_PUBKEY_set0_param() and X509_PUBKEY_get0_param() return 1 for success and 0 if an error occurred. classic 1-or-0 🌸
X509_PUBKEY_eq() returns 1 for equal, 0 for different, and < 0 on error. the three moods 💜
🦋 SEE ALSO 🦋
👑 HISTORY 👑
The X509_PUBKEY_new_ex() and X509_PUBKEY_eq() functions were added in OpenSSL 3.0. glow-up era ✨
The X509_PUBKEY_set0_public_key(), d2i_PUBKEY_ex_bio() and d2i_PUBKEY_ex_fp() functions were added in OpenSSL 3.2. newer additions, still iconic 🎀
💖 COPYRIGHT 💖
Copyright 2016-2022 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>.
and that's the whole page, bestie 🫶 legal said include the license link and I said periodt.
kisses, this was X509_PUBKEY_NEW(3ossl) from OpenSSL 3.5.6, dated 2026-04-07 — mwah 💋
📦 where this page comes from
- freebsd 15.1: base 15.1
- 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms