X509_GET_PUBKEY(3)

NAME
X509_get_pubkey, X509_get0_pubkey, X509_set_pubkey, X509_get_X509_PUBKEY, X509_REQ_get_pubkey, X509_REQ_set_pubkey - get or set certificate or certificate request public key

SYNOPSIS
#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(X509 *x);
EVP_PKEY *
X509_REQ_get_pubkey(X509_REQ *req);
int
X509_REQ_set_pubkey(X509_REQ *x, EVP_PKEY *pkey);

DESCRIPTION
X509_get_pubkey() attempts to decode the public key for certificate x. If successful it returns the public key as an EVP_PKEY pointer with its reference count incremented: this means the returned key must be freed up after use. X509_get0_pubkey() is similar except that it does not increment the reference count of the returned EVP_PKEY, so it must not be freed up after use.

X509_get_X509_PUBKEY() returns 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_get_X509_PUBKEY() is implemented as a macro.

X509_set_pubkey() attempts to set the public key for certificate x to pkey. The key pkey should be freed up after use.

X509_REQ_get_pubkey() and X509_REQ_set_pubkey() are similar but operate on certificate request req.

The first time a public key is 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.

RETURN VALUES
X509_get_pubkey(), X509_get0_pubkey(), X509_get_X509_PUBKEY(), and X509_REQ_get_pubkey() return a public key or NULL if an error occurred.

X509_set_pubkey() and X509_REQ_set_pubkey() return 1 for success or 0 for failure.

In some cases of failure of X509_get0_pubkey(), X509_set_pubkey(), X509_REQ_get_pubkey(), and X509_REQ_set_pubkey(), the reason can be determined with ERR_get_error(3).

SEE ALSO
d2i_X509(3), X509_CRL_get0_by_serial(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_PUBKEY_new(3), X509_REQ_new(3), X509_sign(3), X509_verify_cert(3), X509V3_get_d2i(3)

HISTORY
X509_get_pubkey(), X509_set_pubkey(), X509_REQ_get_pubkey(), and X509_REQ_set_pubkey() first appeared in SSLeay 0.6.5. X509_get_X509_PUBKEY() first appeared in SSLeay 0.8.0. These functions have been available since OpenBSD 2.4.

X509_get0_pubkey() first appeared in OpenSSL 1.1.0 and has been available since OpenBSD 6.3.