xref: /freebsd-src/crypto/openssl/doc/man3/EVP_PKEY_todata.pod (revision b077aed33b7b6aefca7b17ddb250cf521f938613)
1*b077aed3SPierre Pronchery=pod
2*b077aed3SPierre Pronchery
3*b077aed3SPierre Pronchery=head1 NAME
4*b077aed3SPierre Pronchery
5*b077aed3SPierre ProncheryEVP_PKEY_todata, EVP_PKEY_export
6*b077aed3SPierre Pronchery- functions to return keys as an array of key parameters
7*b077aed3SPierre Pronchery
8*b077aed3SPierre Pronchery=head1 SYNOPSIS
9*b077aed3SPierre Pronchery
10*b077aed3SPierre Pronchery #include <openssl/evp.h>
11*b077aed3SPierre Pronchery
12*b077aed3SPierre Pronchery int EVP_PKEY_todata(const EVP_PKEY *pkey, int selection, OSSL_PARAM **params);
13*b077aed3SPierre Pronchery int EVP_PKEY_export(const EVP_PKEY *pkey, int selection,
14*b077aed3SPierre Pronchery                     OSSL_CALLBACK *export_cb, void *export_cbarg);
15*b077aed3SPierre Pronchery
16*b077aed3SPierre Pronchery=head1 DESCRIPTION
17*b077aed3SPierre Pronchery
18*b077aed3SPierre ProncheryThe functions described here are used to extract B<EVP_PKEY> key values as an
19*b077aed3SPierre Proncheryarray of L<OSSL_PARAM(3)>.
20*b077aed3SPierre Pronchery
21*b077aed3SPierre ProncheryEVP_PKEY_todata() extracts values from a key I<pkey> using the I<selection>.
22*b077aed3SPierre ProncheryI<selection> is described in L<EVP_PKEY_fromdata(3)/Selections>.
23*b077aed3SPierre ProncheryL<OSSL_PARAM_free(3)> should be used to free the returned parameters in
24*b077aed3SPierre ProncheryI<*params>.
25*b077aed3SPierre Pronchery
26*b077aed3SPierre ProncheryEVP_PKEY_export() is similiar to EVP_PKEY_todata() but uses a callback
27*b077aed3SPierre ProncheryI<export_cb> that gets passed the value of I<export_cbarg>.
28*b077aed3SPierre ProncherySee L<openssl-core.h(7)> for more information about the callback. Note that the
29*b077aed3SPierre ProncheryL<OSSL_PARAM(3)> array that is passed to the callback is not persistent after the
30*b077aed3SPierre Proncherycallback returns. The user must preserve the items of interest, or use
31*b077aed3SPierre ProncheryEVP_PKEY_todata() if persistence is required.
32*b077aed3SPierre Pronchery
33*b077aed3SPierre Pronchery=head1 NOTES
34*b077aed3SPierre Pronchery
35*b077aed3SPierre ProncheryThese functions only work with key management methods coming from a provider.
36*b077aed3SPierre ProncheryThis is the mirror function to L<EVP_PKEY_fromdata(3)>.
37*b077aed3SPierre Pronchery
38*b077aed3SPierre Pronchery=head1 RETURN VALUES
39*b077aed3SPierre Pronchery
40*b077aed3SPierre ProncheryEVP_PKEY_todata() and EVP_PKEY_export() return 1 for success and 0 for failure.
41*b077aed3SPierre Pronchery
42*b077aed3SPierre Pronchery=head1 SEE ALSO
43*b077aed3SPierre Pronchery
44*b077aed3SPierre ProncheryL<OSSL_PARAM(3)>, L<openssl-core.h(7)>,
45*b077aed3SPierre ProncheryL<EVP_PKEY_fromdata(3)>,
46*b077aed3SPierre ProncheryL<EVP_PKEY-RSA(7)>, L<EVP_PKEY-DSA(7)>, L<EVP_PKEY-DH(7)>, L<EVP_PKEY-EC(7)>,
47*b077aed3SPierre ProncheryL<EVP_PKEY-ED448(7)>, L<EVP_PKEY-X25519(7)>, L<EVP_PKEY-X448(7)>,
48*b077aed3SPierre ProncheryL<EVP_PKEY-ED25519(7)>
49*b077aed3SPierre Pronchery
50*b077aed3SPierre Pronchery=head1 HISTORY
51*b077aed3SPierre Pronchery
52*b077aed3SPierre ProncheryThese functions were added in OpenSSL 3.0.
53*b077aed3SPierre Pronchery
54*b077aed3SPierre Pronchery=head1 COPYRIGHT
55*b077aed3SPierre Pronchery
56*b077aed3SPierre ProncheryCopyright 2021 The OpenSSL Project Authors. All Rights Reserved.
57*b077aed3SPierre Pronchery
58*b077aed3SPierre ProncheryLicensed under the Apache License 2.0 (the "License").  You may not use
59*b077aed3SPierre Proncherythis file except in compliance with the License.  You can obtain a copy
60*b077aed3SPierre Proncheryin the file LICENSE in the source distribution or at
61*b077aed3SPierre ProncheryL<https://www.openssl.org/source/license.html>.
62*b077aed3SPierre Pronchery
63*b077aed3SPierre Pronchery=cut
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