/*

 * Copyright 2019-2021 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

 */

/*

 * This implemments a dummy key manager for legacy KDFs that still support the

 * old way of performing a KDF via EVP_PKEY_derive(). New KDFs should not be

 * implemented this way. In reality there is no key data for such KDFs, so this

 * key manager does very little.

 */

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/err.h>

#include "prov/implementations.h"

#include "prov/providercommon.h"

#include "prov/provider_ctx.h"

#include "prov/kdfexchange.h"

static OSSL_FUNC_keymgmt_new_fn kdf_newdata;

static OSSL_FUNC_keymgmt_free_fn kdf_freedata;

static OSSL_FUNC_keymgmt_has_fn kdf_has;

KDF_DATA *ossl_kdf_data_new(void *provctx)

{

    KDF_DATA *kdfdata;

    if (!ossl_prov_is_running())

        return NULL;

    kdfdata = OPENSSL_zalloc(sizeof(*kdfdata));

    if (kdfdata == NULL)

        return NULL;

    kdfdata->lock = CRYPTO_THREAD_lock_new();

    if (kdfdata->lock == NULL) {

        OPENSSL_free(kdfdata);

        return NULL;

    }

    kdfdata->libctx = PROV_LIBCTX_OF(provctx);

    kdfdata->refcnt = 1;

    return kdfdata;

}

void ossl_kdf_data_free(KDF_DATA *kdfdata)

{

    int ref = 0;

    if (kdfdata == NULL)

        return;

    CRYPTO_DOWN_REF(&kdfdata->refcnt, &ref, kdfdata->lock);

    if (ref > 0)

        return;

    CRYPTO_THREAD_lock_free(kdfdata->lock);

    OPENSSL_free(kdfdata);

}

int ossl_kdf_data_up_ref(KDF_DATA *kdfdata)

{

    int ref = 0;

    /* This is effectively doing a new operation on the KDF_DATA and should be

     * adequately guarded again modules' error states.  However, both current

     * calls here are guarded propery in exchange/kdf_exch.c.  Thus, it

     * could be removed here.  The concern is that something in the future

     * might call this function without adequate guards.  It's a cheap call,

     * it seems best to leave it even though it is currently redundant.

     */

    if (!ossl_prov_is_running())

        return 0;

    CRYPTO_UP_REF(&kdfdata->refcnt, &ref, kdfdata->lock);

    return 1;

}

static void *kdf_newdata(void *provctx)

{

    return ossl_kdf_data_new(provctx);

}

static void kdf_freedata(void *kdfdata)

{

    ossl_kdf_data_free(kdfdata);

}

static int kdf_has(const void *keydata, int selection)

{

    return 1; /* nothing is missing */

}

const OSSL_DISPATCH ossl_kdf_keymgmt_functions[] = {

    { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))kdf_newdata },

    { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))kdf_freedata },

    { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))kdf_has },

    { 0, NULL }

};