2020-11-16 10:42:18 +08:00
|
|
|
=pod
|
|
|
|
|
|
|
|
=head1 NAME
|
|
|
|
|
|
|
|
EVP_KDF-X942-ASN1 - The X9.42-2003 asn1 EVP_KDF implementation
|
|
|
|
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
|
|
|
|
The EVP_KDF-X942-ASN1 algorithm implements the key derivation function
|
|
|
|
X942KDF-ASN1. It is used by DH KeyAgreement, to derive a key using input such as
|
|
|
|
a shared secret key and other info. The other info is DER encoded data that
|
|
|
|
contains a 32 bit counter as well as optional fields for "partyu-info",
|
|
|
|
"partyv-info", "supp-pubinfo" and "supp-privinfo".
|
|
|
|
This kdf is used by Cryptographic Message Syntax (CMS).
|
|
|
|
|
|
|
|
=head2 Identity
|
|
|
|
|
|
|
|
"X942KDF-ASN1" or "X942KDF" is the name for this implementation; it
|
|
|
|
can be used with the EVP_KDF_fetch() function.
|
|
|
|
|
|
|
|
=head2 Supported parameters
|
|
|
|
|
|
|
|
The supported parameters are:
|
|
|
|
|
|
|
|
=over 4
|
|
|
|
|
|
|
|
=item "properties" (B<OSSL_KDF_PARAM_PROPERTIES>) <UTF8 string>
|
|
|
|
|
|
|
|
=item "digest" (B<OSSL_KDF_PARAM_DIGEST>) <UTF8 string>
|
|
|
|
|
|
|
|
These parameters work as described in L<EVP_KDF(3)/PARAMETERS>.
|
|
|
|
|
|
|
|
=item "key" (B<OSSL_KDF_PARAM_KEY>) <octet string>
|
|
|
|
|
|
|
|
The shared secret used for key derivation. This parameter sets the secret.
|
|
|
|
|
2021-02-05 15:45:39 +08:00
|
|
|
=item "acvp-info" (B<OSSL_KDF_PARAM_X942_ACVPINFO>) <octet string>
|
|
|
|
|
|
|
|
This value should not be used in production and should only be used for ACVP
|
|
|
|
testing. It is an optional octet string containing a combined DER encoded blob
|
|
|
|
of any of the optional fields related to "partyu-info", "partyv-info",
|
|
|
|
"supp-pubinfo" and "supp-privinfo". If it is specified then none of these other
|
|
|
|
fields should be used.
|
|
|
|
|
2020-11-16 10:42:18 +08:00
|
|
|
=item "partyu-info" (B<OSSL_KDF_PARAM_X942_PARTYUINFO>) <octet string>
|
|
|
|
|
|
|
|
An optional octet string containing public info contributed by the initiator.
|
|
|
|
|
|
|
|
=item "ukm" (B<OSSL_KDF_PARAM_UKM>) <octet string>
|
|
|
|
|
|
|
|
An alias for "partyu-info".
|
|
|
|
In CMS this is the user keying material.
|
|
|
|
|
|
|
|
=item "partyv-info" (B<OSSL_KDF_PARAM_X942_PARTYVINFO>) <octet string>
|
|
|
|
|
|
|
|
An optional octet string containing public info contributed by the responder.
|
|
|
|
|
|
|
|
=item "supp-pubinfo" (B<OSSL_KDF_PARAM_X942_SUPP_PUBINFO>) <octet string>
|
|
|
|
|
|
|
|
An optional octet string containing some additional, mutually-known public
|
|
|
|
information. Setting this value also sets "use-keybits" to 0.
|
|
|
|
|
|
|
|
=item "use-keybits" (B<OSSL_KDF_PARAM_X942_SUPP_PRIVINFO>) <integer>
|
|
|
|
|
|
|
|
The default value of 1 will use the KEK key length (in bits) as the
|
|
|
|
"supp-pubinfo". A value of 0 disables setting the "supp-pubinfo".
|
|
|
|
|
|
|
|
=item "supp-privinfo" (B<OSSL_KDF_PARAM_X942_SUPP_PRIVINFO>) <octet string>
|
|
|
|
|
|
|
|
An optional octet string containing some additional, mutually-known private
|
|
|
|
information.
|
|
|
|
|
|
|
|
=item "cekalg" (B<OSSL_KDF_PARAM_CEK_ALG>) <UTF8 string>
|
|
|
|
|
|
|
|
This parameter sets the CEK wrapping algorithm name.
|
|
|
|
Valid values are "AES-128-WRAP", "AES-192-WRAP", "AES-256-WRAP" and "DES3-WRAP".
|
|
|
|
|
|
|
|
=back
|
|
|
|
|
|
|
|
=head1 NOTES
|
|
|
|
|
|
|
|
A context for X942KDF can be obtained by calling:
|
|
|
|
|
|
|
|
EVP_KDF *kdf = EVP_KDF_fetch(NULL, "X942KDF", NULL);
|
|
|
|
EVP_KDF_CTX *kctx = EVP_KDF_CTX_new(kdf);
|
|
|
|
|
|
|
|
The output length of an X942KDF is specified via the I<keylen>
|
|
|
|
parameter to the L<EVP_KDF_derive(3)> function.
|
|
|
|
|
|
|
|
=head1 EXAMPLES
|
|
|
|
|
|
|
|
This example derives 24 bytes, with the secret key "secret" and random user
|
|
|
|
keying material:
|
|
|
|
|
|
|
|
EVP_KDF_CTX *kctx;
|
|
|
|
EVP_KDF_CTX *kctx;
|
|
|
|
unsigned char out[192/8];
|
|
|
|
unsignred char ukm[64];
|
|
|
|
OSSL_PARAM params[5], *p = params;
|
|
|
|
|
|
|
|
if (RAND_bytes(ukm, sizeof(ukm)) <= 0)
|
|
|
|
error("RAND_bytes");
|
|
|
|
|
|
|
|
kdf = EVP_KDF_fetch(NULL, "X942KDF", NULL);
|
|
|
|
if (kctx == NULL)
|
|
|
|
error("EVP_KDF_fetch");
|
|
|
|
kctx = EVP_KDF_CTX_new(kdf);
|
|
|
|
EVP_KDF_free(kdf);
|
|
|
|
if (kctx == NULL)
|
|
|
|
error("EVP_KDF_CTX_new");
|
|
|
|
|
|
|
|
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST, "SHA256", 0);
|
|
|
|
*p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SECRET,
|
|
|
|
"secret", (size_t)6);
|
|
|
|
*p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_UKM, ukm, sizeof(ukm));
|
|
|
|
*p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_CEK_ALG, "AES-256-WRAP, 0);
|
|
|
|
*p = OSSL_PARAM_construct_end();
|
|
|
|
if (EVP_KDF_CTX_set_params(kctx, params) <= 0)
|
|
|
|
error("EVP_KDF_CTX_set_params");
|
|
|
|
|
|
|
|
if (EVP_KDF_derive(kctx, out, sizeof(out)) <= 0)
|
|
|
|
error("EVP_KDF_derive");
|
|
|
|
|
|
|
|
EVP_KDF_CTX_free(kctx);
|
|
|
|
|
|
|
|
=head1 CONFORMING TO
|
|
|
|
|
|
|
|
ANS1 X9.42-2003
|
|
|
|
RFC 2631
|
|
|
|
|
|
|
|
=head1 SEE ALSO
|
|
|
|
|
|
|
|
L<EVP_KDF(3)>,
|
|
|
|
L<EVP_KDF_CTX_new(3)>,
|
|
|
|
L<EVP_KDF_CTX_free(3)>,
|
|
|
|
L<EVP_KDF_CTX_set_params(3)>,
|
|
|
|
L<EVP_KDF_CTX_get_kdf_size(3)>,
|
|
|
|
L<EVP_KDF_derive(3)>,
|
|
|
|
L<EVP_KDF(3)/PARAMETERS>
|
|
|
|
|
|
|
|
=head1 HISTORY
|
|
|
|
|
|
|
|
This functionality was added to OpenSSL 3.0.
|
|
|
|
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
|
2021-02-18 22:57:13 +08:00
|
|
|
Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
|
2020-11-16 10:42:18 +08:00
|
|
|
|
|
|
|
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
|