=pod

=head1 NAME

X509V3_set_ctx,
X509V3_set_issuer_pkey - X.509 v3 extension generation utilities

=head1 SYNOPSIS

 #include <openssl/x509v3.h>

 void X509V3_set_ctx(X509V3_CTX *ctx, X509 *issuer, X509 *subject,
                     X509_REQ *req, X509_CRL *crl, int flags);
 int X509V3_set_issuer_pkey(X509V3_CTX *ctx, EVP_PKEY *pkey);

=head1 DESCRIPTION

X509V3_set_ctx() fills in the basic fields of I<ctx> of type B<X509V3_CTX>,
providing details potentially needed by functions producing X509 v3 extensions.
These may make use of fields of the certificate I<subject>, the certification
request I<req>, or the certificate revocation list I<crl>.
At most one of these three parameters can be non-NULL.
When constructing the subject key identifier of a certificate by computing a
hash value of its public key, the public key is taken from I<subject> or I<req>.
Similarly, when constructing subject alternative names from any email addresses
contained in a subject DN, the subject DN is taken from I<subject> or I<req>.
If I<subject> or I<crl> is provided, I<issuer> should point to its issuer, for
instance as a reference for generating the authority key identifier extension.
I<issuer> may be the same pointer value as I<subject> (which usually is an
indication that the I<subject> certificate is self-issued or even self-signed).
In this case the fallback source for generating the authority key identifier
extension will be taken from any value provided using X509V3_set_issuer_pkey().
I<flags> may be 0
or contain B<X509V3_CTX_TEST>, which means that just the syntax of
extension definitions is to be checked without actually producing any extension,
or B<X509V3_CTX_REPLACE>, which means that each X.509v3 extension added as
defined in some configuration section shall replace any already existing
extension with the same OID.

X509V3_set_issuer_pkey() explicitly sets the issuer private key of
the subject certificate that has been provided in I<ctx>.
This should be done in case the I<issuer> and I<subject> arguments to
X509V3_set_ctx() have the same pointer value
to provide fallback data for the authority key identifier extension.

=head1 RETURN VALUES

X509V3_set_issuer_pkey() returns 1 on success and 0 on error.

=head1 SEE ALSO

L<X509_add_ext(3)>

=head1 HISTORY

X509V3_set_issuer_pkey() was added in OpenSSL 3.0.

CTX_TEST was deprecated in OpenSSL 3.0; use X509V3_CTX_TEST instead.

=head1 COPYRIGHT

Copyright 2015-2025 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
L<https://www.openssl.org/source/license.html>.

=cut
