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=head1 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

=head1 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);

 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);

=head1 DESCRIPTION

X509_get_pubkey() attempts to decode the public key for certificate B<x>. If

successful it returns the public key as an B<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 B<not> increment

the reference count of the returned B<EVP_PKEY> so it must not be freed up

after use.

X509_get_X509_PUBKEY() returns an internal pointer to the B<X509_PUBKEY>

structure which encodes the certificate of B<x>. The returned value

must not be freed up after use.

X509_set_pubkey() attempts to set the public key for certificate B<x> to

B<pkey>. The key B<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 B<req>.

=head1 NOTES

The first time a public key is decoded the B<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.

=head1 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

B<NULL> if an error occurred.

X509_set_pubkey() and X509_REQ_set_pubkey() return 1 for success and 0

for failure.

=head1 SEE ALSO

L<d2i_X509(3)>,

L<ERR_get_error(3)>,

L<X509_CRL_get0_by_serial(3)>,

L<X509_get0_signature(3)>,

L<X509_get_ext_d2i(3)>,

L<X509_get_extension_flags(3)>,

L<X509_get_subject_name(3)>,

L<X509_get_version(3)>,

L<X509_NAME_add_entry_by_txt(3)>,

L<X509_NAME_ENTRY_get_object(3)>,

L<X509_NAME_get_index_by_NID(3)>,

L<X509_NAME_print_ex(3)>,

L<X509_new(3)>,

L<X509_sign(3)>,

L<X509V3_get_d2i(3)>,

L<X509_verify_cert(3)>

=head1 COPYRIGHT

Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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

L<https://www.openssl.org/source/license.html>.

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