1=pod
2
3=head1 NAME
4
5OSSL_CRMF_pbm_new,
6OSSL_CRMF_pbmp_new
7- functions for producing Password-Based MAC (PBM)
8
9=head1 SYNOPSIS
10
11 #include <openssl/crmf.h>
12
13 int OSSL_CRMF_pbm_new(OSSL_LIB_CTX *libctx, const char *propq,
14                       const OSSL_CRMF_PBMPARAMETER *pbmp,
15                       const unsigned char *msg, size_t msglen,
16                       const unsigned char *sec, size_t seclen,
17                       unsigned char **mac, size_t *maclen);
18
19 OSSL_CRMF_PBMPARAMETER *OSSL_CRMF_pbmp_new(OSSL_LIB_CTX *libctx, size_t saltlen,
20                                            int owfnid, size_t itercnt,
21                                            int macnid);
22
23=head1 DESCRIPTION
24
25OSSL_CRMF_pbm_new() generates a PBM (Password-Based MAC) based on given PBM
26parameters I<pbmp>, message I<msg>, and secret I<sec>, along with the respective
27lengths I<msglen> and I<seclen>.
28The optional library context I<libctx> and I<propq> parameters may be used
29to influence the selection of the MAC algorithm referenced in the I<pbmp>;
30see L<crypto(7)/ALGORITHM FETCHING> for further information.
31On success writes the address of the newly
32allocated MAC via the I<mac> reference parameter and writes the length via the
33I<maclen> reference parameter unless it its NULL.
34
35OSSL_CRMF_pbmp_new() initializes and returns a new B<PBMParameter> structure
36with a new random salt of given length I<saltlen>,
37OWF (one-way function) NID I<owfnid>, OWF iteration count I<itercnt>,
38and MAC NID I<macnid>.
39The library context I<libctx> parameter may be used to select the provider
40for the random number generation (DRBG) and may be NULL for the default.
41
42=head1 NOTES
43
44The algorithms for the OWF (one-way function) and for the MAC (message
45authentication code) may be any with a NID defined in F<< <openssl/objects.h> >>.
46As specified by RFC 4210, these should include NID_hmac_sha1.
47
48RFC 4210 recommends that the salt SHOULD be at least 8 bytes (64 bits) long,
49where 16 bytes is common.
50
51The iteration count must be at least 100, as stipulated by RFC 4211, and is
52limited to at most 100000 to avoid DoS through manipulated or otherwise
53malformed input.
54
55=head1 RETURN VALUES
56
57OSSL_CRMF_pbm_new() returns 1 on success, 0 on error.
58
59OSSL_CRMF_pbmp_new() returns a new and initialized OSSL_CRMF_PBMPARAMETER
60structure, or NULL on error.
61
62=head1 EXAMPLES
63
64 OSSL_CRMF_PBMPARAMETER *pbm = NULL;
65 unsigned char *msg = "Hello";
66 unsigned char *sec = "SeCrEt";
67 unsigned char *mac = NULL;
68 size_t maclen;
69
70 if ((pbm = OSSL_CRMF_pbmp_new(16, NID_sha256, 500, NID_hmac_sha1) == NULL))
71     goto err;
72 if (!OSSL_CRMF_pbm_new(pbm, msg, 5, sec, 6, &mac, &maclen))
73     goto err;
74
75=head1 SEE ALSO
76
77RFC 4211 section 4.4
78
79=head1 HISTORY
80
81The OpenSSL CRMF support was added in OpenSSL 3.0.
82
83=head1 COPYRIGHT
84
85Copyright 2007-2021 The OpenSSL Project Authors. All Rights Reserved.
86
87Licensed under the Apache License 2.0 (the "License").  You may not use
88this file except in compliance with the License.  You can obtain a copy
89in the file LICENSE in the source distribution or at
90L<https://www.openssl.org/source/license.html>.
91
92=cut
93