/*

 * Copyright 2020-2022 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 <openssl/crypto.h>

#include "crypto/store.h"

#include "internal/core.h"

#include "internal/namemap.h"

#include "internal/property.h"

#include "internal/provider.h"

#include "store_local.h"

#include "crypto/context.h"

int OSSL_STORE_LOADER_up_ref(OSSL_STORE_LOADER *loader)

{

    int ref = 0;

    if (loader->prov != NULL)

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

    return 1;

}

void OSSL_STORE_LOADER_free(OSSL_STORE_LOADER *loader)

{

    if (loader != NULL && loader->prov != NULL) {

        int i;

        CRYPTO_DOWN_REF(&loader->refcnt, &i, loader->lock);

        if (i > 0)

            return;

        ossl_provider_free(loader->prov);

        CRYPTO_THREAD_lock_free(loader->lock);

    }

    OPENSSL_free(loader);

}

/*

 * OSSL_STORE_LOADER_new() expects the scheme as a constant string,

 * which we currently don't have, so we need an alternative allocator.

 */

static OSSL_STORE_LOADER *new_loader(OSSL_PROVIDER *prov)

{

    OSSL_STORE_LOADER *loader;

    if ((loader = OPENSSL_zalloc(sizeof(*loader))) == NULL

        || (loader->lock = CRYPTO_THREAD_lock_new()) == NULL) {

        OPENSSL_free(loader);

        return NULL;

    }

    loader->prov = prov;

    ossl_provider_up_ref(prov);

    loader->refcnt = 1;

    return loader;

}

static int up_ref_loader(void *method)

{

    return OSSL_STORE_LOADER_up_ref(method);

}

static void free_loader(void *method)

{

    OSSL_STORE_LOADER_free(method);

}

/* Data to be passed through ossl_method_construct() */

struct loader_data_st {

    OSSL_LIB_CTX *libctx;

    int scheme_id;               /* For get_loader_from_store() */

    const char *scheme;          /* For get_loader_from_store() */

    const char *propquery;       /* For get_loader_from_store() */

    OSSL_METHOD_STORE *tmp_store; /* For get_tmp_loader_store() */

    unsigned int flag_construct_error_occurred : 1;

};

/*

 * Generic routines to fetch / create OSSL_STORE methods with

 * ossl_method_construct()

 */

/* Temporary loader method store, constructor and destructor */

static void *get_tmp_loader_store(void *data)

{

    struct loader_data_st *methdata = data;

    if (methdata->tmp_store == NULL)

        methdata->tmp_store = ossl_method_store_new(methdata->libctx);

    return methdata->tmp_store;

}

 static void dealloc_tmp_loader_store(void *store)

{

    if (store != NULL)

        ossl_method_store_free(store);

}

/* Get the permanent loader store */

static OSSL_METHOD_STORE *get_loader_store(OSSL_LIB_CTX *libctx)

{

    return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_STORE_LOADER_STORE_INDEX);

}

static int reserve_loader_store(void *store, void *data)

{

    struct loader_data_st *methdata = data;

    if (store == NULL

        && (store = get_loader_store(methdata->libctx)) == NULL)

        return 0;

    return ossl_method_lock_store(store);

}

static int unreserve_loader_store(void *store, void *data)

{

    struct loader_data_st *methdata = data;

    if (store == NULL

        && (store = get_loader_store(methdata->libctx)) == NULL)

        return 0;

    return ossl_method_unlock_store(store);

}

/* Get loader methods from a store, or put one in */

static void *get_loader_from_store(void *store, const OSSL_PROVIDER **prov,

                                   void *data)

{

    struct loader_data_st *methdata = data;

    void *method = NULL;

    int id;

    if ((id = methdata->scheme_id) == 0) {

        OSSL_NAMEMAP *namemap = ossl_namemap_stored(methdata->libctx);

        id = ossl_namemap_name2num(namemap, methdata->scheme);

    }

    if (store == NULL

        && (store = get_loader_store(methdata->libctx)) == NULL)

        return NULL;

    if (!ossl_method_store_fetch(store, id, methdata->propquery, prov, &method))

        return NULL;

    return method;

}

static int put_loader_in_store(void *store, void *method,

                               const OSSL_PROVIDER *prov,

                               const char *scheme, const char *propdef,

                               void *data)

{

    struct loader_data_st *methdata = data;

    OSSL_NAMEMAP *namemap;

    int id;

    if ((namemap = ossl_namemap_stored(methdata->libctx)) == NULL

        || (id = ossl_namemap_name2num(namemap, scheme)) == 0)

        return 0;

    if (store == NULL && (store = get_loader_store(methdata->libctx)) == NULL)

        return 0;

    return ossl_method_store_add(store, prov, id, propdef, method,

                                 up_ref_loader, free_loader);

}

static void *loader_from_algorithm(int scheme_id, const OSSL_ALGORITHM *algodef,

                                   OSSL_PROVIDER *prov)

{

    OSSL_STORE_LOADER *loader = NULL;

    const OSSL_DISPATCH *fns = algodef->implementation;

    if ((loader = new_loader(prov)) == NULL)

        return NULL;

    loader->scheme_id = scheme_id;

    loader->propdef = algodef->property_definition;

    loader->description = algodef->algorithm_description;

    for (; fns->function_id != 0; fns++) {

        switch (fns->function_id) {

        case OSSL_FUNC_STORE_OPEN:

            if (loader->p_open == NULL)

                loader->p_open = OSSL_FUNC_store_open(fns);

            break;

        case OSSL_FUNC_STORE_ATTACH:

            if (loader->p_attach == NULL)

                loader->p_attach = OSSL_FUNC_store_attach(fns);

            break;

        case OSSL_FUNC_STORE_SETTABLE_CTX_PARAMS:

            if (loader->p_settable_ctx_params == NULL)

                loader->p_settable_ctx_params =

                    OSSL_FUNC_store_settable_ctx_params(fns);

            break;

        case OSSL_FUNC_STORE_SET_CTX_PARAMS:

            if (loader->p_set_ctx_params == NULL)

                loader->p_set_ctx_params = OSSL_FUNC_store_set_ctx_params(fns);

            break;

        case OSSL_FUNC_STORE_LOAD:

            if (loader->p_load == NULL)

                loader->p_load = OSSL_FUNC_store_load(fns);

            break;

        case OSSL_FUNC_STORE_EOF:

            if (loader->p_eof == NULL)

                loader->p_eof = OSSL_FUNC_store_eof(fns);

            break;

        case OSSL_FUNC_STORE_CLOSE:

            if (loader->p_close == NULL)

                loader->p_close = OSSL_FUNC_store_close(fns);

            break;

        case OSSL_FUNC_STORE_EXPORT_OBJECT:

            if (loader->p_export_object == NULL)

                loader->p_export_object = OSSL_FUNC_store_export_object(fns);

            break;

        }

    }

    if ((loader->p_open == NULL && loader->p_attach == NULL)

        || loader->p_load == NULL

        || loader->p_eof == NULL

        || loader->p_close == NULL) {

        /* Only set_ctx_params is optionaal */

        OSSL_STORE_LOADER_free(loader);

        ERR_raise(ERR_LIB_OSSL_STORE, OSSL_STORE_R_LOADER_INCOMPLETE);

        return NULL;

    }

    return loader;

}

/*

 * The core fetching functionality passes the scheme of the implementation.

 * This function is responsible to getting an identity number for them,

 * then call loader_from_algorithm() with that identity number.

 */

static void *construct_loader(const OSSL_ALGORITHM *algodef,

                              OSSL_PROVIDER *prov, void *data)

{

    /*

     * This function is only called if get_loader_from_store() returned

     * NULL, so it's safe to say that of all the spots to create a new

     * namemap entry, this is it.  Should the scheme already exist there, we

     * know that ossl_namemap_add() will return its corresponding number.

     */

    struct loader_data_st *methdata = data;

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(prov);

    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

    const char *scheme = algodef->algorithm_names;

    int id = ossl_namemap_add_name(namemap, 0, scheme);

    void *method = NULL;

    if (id != 0)

        method = loader_from_algorithm(id, algodef, prov);

    /*

     * Flag to indicate that there was actual construction errors.  This

     * helps inner_loader_fetch() determine what error it should

     * record on inaccessible algorithms.

     */

    if (method == NULL)

        methdata->flag_construct_error_occurred = 1;

    return method;

}

/* Intermediary function to avoid ugly casts, used below */

static void destruct_loader(void *method, void *data)

{

    OSSL_STORE_LOADER_free(method);

}

/* Fetching support.  Can fetch by numeric identity or by scheme */

static OSSL_STORE_LOADER *

inner_loader_fetch(struct loader_data_st *methdata,

                   const char *scheme, const char *properties)

{

    OSSL_METHOD_STORE *store = get_loader_store(methdata->libctx);

    OSSL_NAMEMAP *namemap = ossl_namemap_stored(methdata->libctx);

    const char *const propq = properties != NULL ? properties : "";

    void *method = NULL;

    int unsupported, id;

    if (store == NULL || namemap == NULL) {

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_INVALID_ARGUMENT);

        return NULL;

    }

    /* If we haven't received a name id yet, try to get one for the name */

    id = scheme != NULL ? ossl_namemap_name2num(namemap, scheme) : 0;

    /*

     * If we haven't found the name yet, chances are that the algorithm to

     * be fetched is unsupported.

     */

    unsupported = id == 0;

    if (id == 0

        || !ossl_method_store_cache_get(store, NULL, id, propq, &method)) {

        OSSL_METHOD_CONSTRUCT_METHOD mcm = {

            get_tmp_loader_store,

            reserve_loader_store,

            unreserve_loader_store,

            get_loader_from_store,

            put_loader_in_store,

            construct_loader,

            destruct_loader

        };

        OSSL_PROVIDER *prov = NULL;

        methdata->scheme_id = id;

        methdata->scheme = scheme;

        methdata->propquery = propq;

        methdata->flag_construct_error_occurred = 0;

        if ((method = ossl_method_construct(methdata->libctx, OSSL_OP_STORE,

                                            &prov, 0 /* !force_cache */,

                                            &mcm, methdata)) != NULL) {

            /*

             * If construction did create a method for us, we know that there

             * is a correct scheme_id, since those have already been calculated

             * in get_loader_from_store() and put_loader_in_store() above.

             */

            if (id == 0)

                id = ossl_namemap_name2num(namemap, scheme);

            ossl_method_store_cache_set(store, prov, id, propq, method,

                                        up_ref_loader, free_loader);

        }

        /*

         * If we never were in the constructor, the algorithm to be fetched

         * is unsupported.

         */

        unsupported = !methdata->flag_construct_error_occurred;

    }

    if ((id != 0 || scheme != NULL) && method == NULL) {

        int code = unsupported ? ERR_R_UNSUPPORTED : ERR_R_FETCH_FAILED;

        const char *helpful_msg =

            unsupported

            ? ( "No store loader found. For standard store loaders you need "

                "at least one of the default or base providers available. "

                "Did you forget to load them? Info: " )

            : "";

        if (scheme == NULL)

            scheme = ossl_namemap_num2name(namemap, id, 0);

        ERR_raise_data(ERR_LIB_OSSL_STORE, code,

                       "%s%s, Scheme (%s : %d), Properties (%s)",

                       helpful_msg,

                       ossl_lib_ctx_get_descriptor(methdata->libctx),

                       scheme == NULL ? "<null>" : scheme, id,

                       properties == NULL ? "<null>" : properties);

    }

    return method;

}

OSSL_STORE_LOADER *OSSL_STORE_LOADER_fetch(OSSL_LIB_CTX *libctx,

                                           const char *scheme,

                                           const char *properties)

{

    struct loader_data_st methdata;

    void *method;

    methdata.libctx = libctx;

    methdata.tmp_store = NULL;

    method = inner_loader_fetch(&methdata, scheme, properties);

    dealloc_tmp_loader_store(methdata.tmp_store);

    return method;

}

int ossl_store_loader_store_cache_flush(OSSL_LIB_CTX *libctx)

{

    OSSL_METHOD_STORE *store = get_loader_store(libctx);

    if (store != NULL)

        return ossl_method_store_cache_flush_all(store);

    return 1;

}

int ossl_store_loader_store_remove_all_provided(const OSSL_PROVIDER *prov)

{

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(prov);

    OSSL_METHOD_STORE *store = get_loader_store(libctx);

    if (store != NULL)

        return ossl_method_store_remove_all_provided(store, prov);

    return 1;

}

/*

 * Library of basic method functions

 */

const OSSL_PROVIDER *OSSL_STORE_LOADER_get0_provider(const OSSL_STORE_LOADER *loader)

{

    if (!ossl_assert(loader != NULL)) {

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return loader->prov;

}

const char *OSSL_STORE_LOADER_get0_properties(const OSSL_STORE_LOADER *loader)

{

    if (!ossl_assert(loader != NULL)) {

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return loader->propdef;

}

int ossl_store_loader_get_number(const OSSL_STORE_LOADER *loader)

{

    if (!ossl_assert(loader != NULL)) {

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return loader->scheme_id;

}

const char *OSSL_STORE_LOADER_get0_description(const OSSL_STORE_LOADER *loader)

{

    return loader->description;

}

int OSSL_STORE_LOADER_is_a(const OSSL_STORE_LOADER *loader, const char *name)

{

    if (loader->prov != NULL) {

        OSSL_LIB_CTX *libctx = ossl_provider_libctx(loader->prov);

        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

        return ossl_namemap_name2num(namemap, name) == loader->scheme_id;

    }

    return 0;

}

struct do_one_data_st {

    void (*user_fn)(OSSL_STORE_LOADER *loader, void *arg);

    void *user_arg;

};

static void do_one(ossl_unused int id, void *method, void *arg)

{

    struct do_one_data_st *data = arg;

    data->user_fn(method, data->user_arg);

}

void OSSL_STORE_LOADER_do_all_provided(OSSL_LIB_CTX *libctx,

                                       void (*user_fn)(OSSL_STORE_LOADER *loader,

                                                       void *arg),

                                       void *user_arg)

{

    struct loader_data_st methdata;

    struct do_one_data_st data;

    methdata.libctx = libctx;

    methdata.tmp_store = NULL;

    (void)inner_loader_fetch(&methdata, NULL, NULL /* properties */);

    data.user_fn = user_fn;

    data.user_arg = user_arg;

    if (methdata.tmp_store != NULL)

        ossl_method_store_do_all(methdata.tmp_store, &do_one, &data);

    ossl_method_store_do_all(get_loader_store(libctx), &do_one, &data);

    dealloc_tmp_loader_store(methdata.tmp_store);

}

int OSSL_STORE_LOADER_names_do_all(const OSSL_STORE_LOADER *loader,

                                   void (*fn)(const char *name, void *data),

                                   void *data)

{

    if (loader == NULL)

        return 0;

    if (loader->prov != NULL) {

        OSSL_LIB_CTX *libctx = ossl_provider_libctx(loader->prov);

        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

        return ossl_namemap_doall_names(namemap, loader->scheme_id, fn, data);

    }

    return 1;

}