NAME

       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, X509_REQ_get_X509_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(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() 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 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_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(), X509_REQ_get0_pubkey(), X509_REQ_set_pubkey() and X509_REQ_get_X509_PUBKEY() are
       similar but operate on certificate request req.

NOTES

       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(), 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

       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

       Copyright 2015-2021 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>.