=pod

=head1 NAME

PKCS12_gen_mac, PKCS12_setup_mac, PKCS12_set_mac,
PKCS12_set_pbmac1_pbkdf2, PKCS12_verify_mac, PKCS12_get0_mac -
Functions to create and manipulate a PKCS#12 MAC structure

=head1 SYNOPSIS

 #include <openssl/pkcs12.h>

 int PKCS12_gen_mac(PKCS12 *p12, const char *pass, int passlen,
                    unsigned char *mac, unsigned int *maclen);
 int PKCS12_verify_mac(PKCS12 *p12, const char *pass, int passlen);
 int PKCS12_set_mac(PKCS12 *p12, const char *pass, int passlen,
                    unsigned char *salt, int saltlen, int iter,
                    const EVP_MD *md_type);
 int PKCS12_set_pbmac1_pbkdf2(PKCS12 *p12, const char *pass, int passlen,
                                   unsigned char *salt, int saltlen, int iter,
                                   const EVP_MD *md_type,
                                   const char *prf_md_name);
 int PKCS12_setup_mac(PKCS12 *p12, int iter, unsigned char *salt,
                      int saltlen, const EVP_MD *md_type);

 void PKCS12_get0_mac(const ASN1_OCTET_STRING **pmac,
                      const X509_ALGOR **pmacalg,
                      const ASN1_OCTET_STRING **psalt,
                      const ASN1_INTEGER **piter,
                      const PKCS12 *p12);

=head1 DESCRIPTION

PKCS12_gen_mac() generates an HMAC over the entire PKCS#12 object using the
supplied password along with a set of already configured parameters.
The default key generation mechanism used is PKCS12KDF.

PKCS12_verify_mac() verifies the PKCS#12 object's HMAC using the supplied
password.

PKCS12_setup_mac() sets the MAC part of the PKCS#12 structure with the supplied
parameters.

PKCS12_set_mac() sets the MAC and MAC parameters into the PKCS#12 object.
PKCS12_set_pbmac1_pbkdf2() sets the MAC and MAC parameters into the PKCS#12
object when B<PBMAC1> with PBKDF2 is used for protection of the PKCS#12 object.

I<pass> is the passphrase to use in the HMAC. I<salt> is the salt value to use,
I<iter> is the iteration count and I<md_type> is the message digest function to
use. I<prf_md_name> specifies the digest used for the PBKDF2 in PBMAC1 KDF.

PKCS12_get0_mac() retrieves any included MAC value, B<X509_ALGOR> object,
I<salt>, and I<iter> count from the PKCS12 object.

=head1 NOTES

If I<salt> is NULL then a suitable salt will be generated and used.

If I<iter> is 1 then an iteration count will be omitted from the PKCS#12
structure.

PKCS12_gen_mac(), PKCS12_verify_mac(), PKCS12_set_mac() and
PKCS12_set_pbmac1_pbkdf2() make assumptions regarding the encoding of the
given passphrase. See L<passphrase-encoding(7)> for more information.

=head1 RETURN VALUES

All functions returning an integer return 1 on success and 0 if an error occurred.

=head1 ENVIRONMENT

=over 4

=item B<LEGACY_GOST_PKCS12>

=for comment
https://tc26.ru/standarts/metodicheskie-rekomendatsii/transportnyy-klyuchevoy-konteyner.html section 5.1
https://tc26.ru/standard/rs/%D0%A0%2050.1.112-2016.pdf section 5
https://meganorm.ru/mega_doc/norm/prikaz/25/r_1323565_1_041-2022_rekomendatsii_po_standartizatsii.html section 7.1

If this environment variable is set, MAC generation that utilises
GOST R 34.11-94 or GOST 34.11-2012 hashing algorithms is performed the usual
way and not in accordance with the specification provided in the methodical
recommendation MP 26.2.002-2012 (or in its later versions, standardisation
recommendation P 50.1.112-2016 or P 1323565.1.041-2022)
of Technical Committee 26, that specifies that the key used for MAC
generation should be the last 32 bytes of the 96-byte sequence generated
by L<PKCS5_PBKDF2_HMAC(3)> and not the whole sequence.

=back

=head1 CONFORMING TO

IETF RFC 7292 (L<https://tools.ietf.org/html/rfc7292>)
IETF RFC 9579 (L<https://tools.ietf.org/html/rfc9579>)

=head1 SEE ALSO

L<d2i_PKCS12(3)>,
L<EVP_KDF-PKCS12KDF(7)>,
L<PKCS12_create(3)>,
L<passphrase-encoding(7)>

=head1 HISTORY

The I<PKCS12_set_pbmac1_pbkdf2> function was added in OpenSSL 3.4.

=head1 COPYRIGHT

Copyright 2021-2025 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
