openssl/crypto/core_fetch.c

/*
 * Copyright 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 <stddef.h>

#include <openssl/core.h>
#include "internal/cryptlib.h"
#include "internal/core.h"
#include "internal/property.h"
#include "internal/provider.h"

struct construct_data_st {
    OPENSSL_CTX *libctx;
    OSSL_METHOD_STORE *store;
    int operation_id;
    int force_store;
    OSSL_METHOD_CONSTRUCT_METHOD *mcm;
    void *mcm_data;
};

static int ossl_method_construct_this(OSSL_PROVIDER *provider, void *cbdata)
{
    struct construct_data_st *data = cbdata;
    int no_store = 0;    /* Assume caching is ok */
    const OSSL_ALGORITHM *map =
        ossl_provider_query_operation(provider, data->operation_id, &no_store);

    while (map->algorithm_name != NULL) {
        const OSSL_ALGORITHM *thismap = map++;
        void *method = NULL;

        if ((method = data->mcm->construct(thismap->algorithm_name,
                                           thismap->implementation, provider,
                                           data->mcm_data)) == NULL)
            continue;

        /*
         * Note regarding putting the method in stores:
         *
         * we don't need to care if it actually got in or not here.
         * If it didn't get in, it will simply not be available when
         * ossl_method_construct() tries to get it from the store.
         *
         * It is *expected* that the put function increments the refcnt
         * of the passed method.
         */

        if (data->force_store || !no_store) {
            /*
             * If we haven't been told not to store,
             * add to the global store
             */
            data->mcm->put(data->libctx, NULL,
                           thismap->property_definition,
                           method, data->mcm_data);
        }

        data->mcm->put(data->libctx, data->store,
                       thismap->property_definition,
                       method, data->mcm_data);

        /* refcnt-- because we're dropping the reference */
        data->mcm->destruct(method, data->mcm_data);
    }

    return 1;
}

void *ossl_method_construct(OPENSSL_CTX *libctx, int operation_id,
                            const char *name, const char *propquery,
                            int force_store,
                            OSSL_METHOD_CONSTRUCT_METHOD *mcm, void *mcm_data)
{
    void *method = NULL;

    if ((method = mcm->get(libctx, NULL, propquery, mcm_data)) == NULL) {
        struct construct_data_st cbdata;

        /*
         * We have a temporary store to be able to easily search among new
         * items, or items that should find themselves in the global store.
         */
        if ((cbdata.store = mcm->alloc_tmp_store(libctx)) == NULL)
            goto fin;

        cbdata.libctx = libctx;
        cbdata.operation_id = operation_id;
        cbdata.force_store = force_store;
        cbdata.mcm = mcm;
        cbdata.mcm_data = mcm_data;
        ossl_provider_forall_loaded(libctx, ossl_method_construct_this,
                                    &cbdata);

        method = mcm->get(libctx, cbdata.store, propquery, mcm_data);
        mcm->dealloc_tmp_store(cbdata.store);
    }

 fin:
    return method;
}