openssl/crypto/dh/dh_kdf.c
Shane Lontis 1aec7716c1 Add X9.42 KDF.
Move the KDF code for CMS DH key agreement into an EVP_KDF object.
There are 2 specifications for X9.42 KDF. This implementation uses DER for
otherinfo which embeds the KDF loop counter inside the DER object.

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8898)
2019-07-09 09:33:18 +10:00

52 lines
1.5 KiB
C

/*
* Copyright 2013-2019 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
*/
#include "e_os.h"
#ifndef OPENSSL_NO_CMS
# include <string.h>
# include <openssl/dh.h>
# include <openssl/evp.h>
# include <openssl/asn1.h>
# include <openssl/kdf.h>
int DH_KDF_X9_42(unsigned char *out, size_t outlen,
const unsigned char *Z, size_t Zlen,
ASN1_OBJECT *key_oid,
const unsigned char *ukm, size_t ukmlen, const EVP_MD *md)
{
int ret = 0, nid;
EVP_KDF_CTX *kctx = NULL;
const EVP_KDF *kdf = NULL;
const char *oid_sn;
nid = OBJ_obj2nid(key_oid);
if (nid == NID_undef)
return 0;
oid_sn = OBJ_nid2sn(nid);
if (oid_sn == NULL)
return 0;
kdf = EVP_get_kdfbyname(SN_x942kdf);
if (kdf == NULL)
goto err;
kctx = EVP_KDF_CTX_new(kdf);
ret =
kctx != NULL
&& EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, md) > 0
&& EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_KEY, Z, Zlen) > 0
&& (ukm == NULL
|| EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_UKM, ukm, ukmlen) > 0)
&& EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_CEK_ALG, oid_sn) > 0
&& EVP_KDF_derive(kctx, out, outlen) > 0;
err:
EVP_KDF_CTX_free(kctx);
return ret;
}
#endif /* OPENSSL_NO_CMS */