1/*
2 * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License").  You may not use
5 * this file except in compliance with the License.  You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10/*
11 * This implemments a dummy key manager for legacy KDFs that still support the
12 * old way of performing a KDF via EVP_PKEY_derive(). New KDFs should not be
13 * implemented this way. In reality there is no key data for such KDFs, so this
14 * key manager does very little.
15 */
16
17#include <openssl/core_dispatch.h>
18#include <openssl/core_names.h>
19#include <openssl/err.h>
20#include "prov/implementations.h"
21#include "prov/providercommon.h"
22#include "prov/provider_ctx.h"
23#include "prov/kdfexchange.h"
24
25static OSSL_FUNC_keymgmt_new_fn kdf_newdata;
26static OSSL_FUNC_keymgmt_free_fn kdf_freedata;
27static OSSL_FUNC_keymgmt_has_fn kdf_has;
28
29KDF_DATA *ossl_kdf_data_new(void *provctx)
30{
31    KDF_DATA *kdfdata;
32
33    if (!ossl_prov_is_running())
34        return NULL;
35
36    kdfdata = OPENSSL_zalloc(sizeof(*kdfdata));
37    if (kdfdata == NULL)
38        return NULL;
39
40    kdfdata->lock = CRYPTO_THREAD_lock_new();
41    if (kdfdata->lock == NULL) {
42        OPENSSL_free(kdfdata);
43        return NULL;
44    }
45    kdfdata->libctx = PROV_LIBCTX_OF(provctx);
46    kdfdata->refcnt = 1;
47
48    return kdfdata;
49}
50
51void ossl_kdf_data_free(KDF_DATA *kdfdata)
52{
53    int ref = 0;
54
55    if (kdfdata == NULL)
56        return;
57
58    CRYPTO_DOWN_REF(&kdfdata->refcnt, &ref, kdfdata->lock);
59    if (ref > 0)
60        return;
61
62    CRYPTO_THREAD_lock_free(kdfdata->lock);
63    OPENSSL_free(kdfdata);
64}
65
66int ossl_kdf_data_up_ref(KDF_DATA *kdfdata)
67{
68    int ref = 0;
69
70    /* This is effectively doing a new operation on the KDF_DATA and should be
71     * adequately guarded again modules' error states.  However, both current
72     * calls here are guarded propery in exchange/kdf_exch.c.  Thus, it
73     * could be removed here.  The concern is that something in the future
74     * might call this function without adequate guards.  It's a cheap call,
75     * it seems best to leave it even though it is currently redundant.
76     */
77    if (!ossl_prov_is_running())
78        return 0;
79
80    CRYPTO_UP_REF(&kdfdata->refcnt, &ref, kdfdata->lock);
81    return 1;
82}
83
84static void *kdf_newdata(void *provctx)
85{
86    return ossl_kdf_data_new(provctx);
87}
88
89static void kdf_freedata(void *kdfdata)
90{
91    ossl_kdf_data_free(kdfdata);
92}
93
94static int kdf_has(const void *keydata, int selection)
95{
96    return 1; /* nothing is missing */
97}
98
99const OSSL_DISPATCH ossl_kdf_keymgmt_functions[] = {
100    { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))kdf_newdata },
101    { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))kdf_freedata },
102    { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))kdf_has },
103    { 0, NULL }
104};
105