=pod

=head1 NAME

CMS_add0_cert, CMS_add1_cert, CMS_get1_certs,
CMS_add0_crl, CMS_add1_crl, CMS_get1_crls
- CMS certificate and CRL utility functions

=head1 SYNOPSIS

 #include <openssl/cms.h>

 int CMS_add0_cert(CMS_ContentInfo *cms, X509 *cert);
 int CMS_add1_cert(CMS_ContentInfo *cms, X509 *cert);
 STACK_OF(X509) *CMS_get1_certs(CMS_ContentInfo *cms);

 int CMS_add0_crl(CMS_ContentInfo *cms, X509_CRL *crl);
 int CMS_add1_crl(CMS_ContentInfo *cms, X509_CRL *crl);
 STACK_OF(X509_CRL) *CMS_get1_crls(CMS_ContentInfo *cms);

=head1 DESCRIPTION

CMS_add0_cert() and CMS_add1_cert() add certificate I<cert> to I<cms>
unless it is already present.
This is used by L<CMS_sign_ex(3)> and L<CMS_sign(3)> and may be used before
calling L<CMS_verify(3)> to help chain building in certificate validation.
As the 0 implies, CMS_add0_cert() adds I<cert> internally to I<cms>
and on success it must not be freed up by the caller.
In contrast, the caller of CMS_add1_cert() must free I<cert>.
I<cms> must be of type signed data or (authenticated) enveloped data.
For signed data, such a certificate can be used when signing or verifying
to fill in the signer certificate or to provide an extra CA certificate
that may be needed for chain building in certificate validation.

CMS_get1_certs() returns all certificates in I<cms>.

CMS_add0_crl() and CMS_add1_crl() add CRL I<crl> to I<cms>.
I<cms> must be of type signed data or (authenticated) enveloped data.
For signed data, such a CRL may be used in certificate validation
with L<CMS_verify(3)>.
It may be given both for inclusion when signing a CMS message
and when verifying a signed CMS message.

CMS_get1_crls() returns all CRLs in I<cms>.

=head1 NOTES

The CMS_ContentInfo structure I<cms> must be of type signed data or enveloped
data or authenticated enveloped data or an error will be returned.

For signed data, certificates and CRLs are added to the I<certificates> and
I<crls> fields of SignedData structure.
For enveloped data they are added to B<OriginatorInfo>.

=head1 RETURN VALUES

CMS_add0_cert(), CMS_add1_cert() and CMS_add0_crl() and CMS_add1_crl() return
1 for success and 0 for failure.

CMS_get1_certs() and CMS_get1_crls() return the STACK of certificates or CRLs,
which is empty if there are none. They return NULL on error.
Besides out-of-memory, the only error which will occur
in practice is if the I<cms> type is invalid.

=head1 SEE ALSO

L<ERR_get_error(3)>,
L<CMS_sign(3)>, L<CMS_sign_ex(3)>, L<CMS_verify(3)>,
L<CMS_encrypt(3)>

=head1 HISTORY

CMS_add0_cert() and CMS_add1_cert() have been changed in OpenSSL 3.2
not to throw an error if a certificate to be added is already present.

=head1 COPYRIGHT

Copyright 2008-2024 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
