PKCS12_GEN_MAC(3)

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

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);

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. If the PKCS12 macdata contains PBMAC1 an error will occur if the related PBKDF2 parameters are missing, or if the associated key length is not in the range 1 to 64.

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 PBMAC1 with PBKDF2 is used for protection of the PKCS#12 object.

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

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

NOTES
If salt is NULL then a suitable salt will be generated and used.

If 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 passphrase-encoding(7) for more information.

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

ENVIRONMENT

LEGACY_GOST_PKCS12
    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 PKCS5_PBKDF2_HMAC(3) and not the whole sequence.

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

SEE ALSO
d2i_PKCS12(3), EVP_KDF-PKCS12KDF(7), PKCS12_create(3), passphrase-encoding(7)

HISTORY
The PKCS12_set_pbmac1_pbkdf2 function was added in OpenSSL 3.4.

COPYRIGHT
Copyright 2021-2026 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>.