/*

 * Copyright 2016-2021 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

 */

#include <string.h>

#include <assert.h>

#include <openssl/err.h>

#include <openssl/lhash.h>

#include "internal/common.h"

#include "store_local.h"

static CRYPTO_RWLOCK *registry_lock;

static CRYPTO_ONCE registry_init = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(do_registry_init)

{

    registry_lock = CRYPTO_THREAD_lock_new();

    return registry_lock != NULL;

}

/*

 *  Functions for manipulating OSSL_STORE_LOADERs

 */

OSSL_STORE_LOADER *OSSL_STORE_LOADER_new(ENGINE *e, const char *scheme)

{

    OSSL_STORE_LOADER *res = NULL;

    if (!ossl_assert(e == NULL))

        return NULL;

    /*

     * We usually don't check NULL arguments.  For loaders, though, the

     * scheme is crucial and must never be NULL, or the user will get

     * mysterious errors when trying to register the created loader

     * later on.

     */

    if (scheme == NULL) {

        ERR_raise(ERR_LIB_OSSL_STORE, OSSL_STORE_R_INVALID_SCHEME);

        return NULL;

    }

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

        return NULL;

    res->scheme = scheme;

    return res;

}

const char *OSSL_STORE_LOADER_get0_scheme(const OSSL_STORE_LOADER *loader)

{

    return loader->scheme;

}

int OSSL_STORE_LOADER_set_open(OSSL_STORE_LOADER *loader,

    OSSL_STORE_open_fn open_function)

{

    loader->open = open_function;

    return 1;

}

int OSSL_STORE_LOADER_set_open_ex(OSSL_STORE_LOADER *loader,

    OSSL_STORE_open_ex_fn open_ex_function)

{

    loader->open_ex = open_ex_function;

    return 1;

}

int OSSL_STORE_LOADER_set_attach(OSSL_STORE_LOADER *loader,

    OSSL_STORE_attach_fn attach_function)

{

    loader->attach = attach_function;

    return 1;

}

int OSSL_STORE_LOADER_set_ctrl(OSSL_STORE_LOADER *loader,

    OSSL_STORE_ctrl_fn ctrl_function)

{

    loader->ctrl = ctrl_function;

    return 1;

}

int OSSL_STORE_LOADER_set_expect(OSSL_STORE_LOADER *loader,

    OSSL_STORE_expect_fn expect_function)

{

    loader->expect = expect_function;

    return 1;

}

int OSSL_STORE_LOADER_set_find(OSSL_STORE_LOADER *loader,

    OSSL_STORE_find_fn find_function)

{

    loader->find = find_function;

    return 1;

}

int OSSL_STORE_LOADER_set_load(OSSL_STORE_LOADER *loader,

    OSSL_STORE_load_fn load_function)

{

    loader->load = load_function;

    return 1;

}

int OSSL_STORE_LOADER_set_eof(OSSL_STORE_LOADER *loader,

    OSSL_STORE_eof_fn eof_function)

{

    loader->eof = eof_function;

    return 1;

}

int OSSL_STORE_LOADER_set_error(OSSL_STORE_LOADER *loader,

    OSSL_STORE_error_fn error_function)

{

    loader->error = error_function;

    return 1;

}

int OSSL_STORE_LOADER_set_close(OSSL_STORE_LOADER *loader,

    OSSL_STORE_close_fn close_function)

{

    loader->closefn = close_function;

    return 1;

}

/*

 *  Functions for registering OSSL_STORE_LOADERs

 */

static unsigned long store_loader_hash(const OSSL_STORE_LOADER *v)

{

    return OPENSSL_LH_strhash(v->scheme);

}

static int store_loader_cmp(const OSSL_STORE_LOADER *a,

    const OSSL_STORE_LOADER *b)

{

    assert(a->scheme != NULL && b->scheme != NULL);

    return strcmp(a->scheme, b->scheme);

}

static LHASH_OF(OSSL_STORE_LOADER) *loader_register = NULL;

static int ossl_store_register_init(void)

{

    if (loader_register == NULL) {

        loader_register = lh_OSSL_STORE_LOADER_new(store_loader_hash,

            store_loader_cmp);

    }

    return loader_register != NULL;

}

int ossl_store_register_loader_int(OSSL_STORE_LOADER *loader)

{

    const char *scheme = loader->scheme;

    int ok = 0;

    /*

     * Check that the given scheme conforms to correct scheme syntax as per

     * RFC 3986:

     *

     * scheme        = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )

     */

    OSSL_SKIP_SCHEME(scheme);

    if (*loader->scheme == '\0' || *scheme != '\0') {

        ERR_raise_data(ERR_LIB_OSSL_STORE, OSSL_STORE_R_INVALID_SCHEME,

            "scheme=%s", loader->scheme);

        return 0;

    }

    /* Check that functions we absolutely require are present */

    if (loader->open == NULL || loader->load == NULL || loader->eof == NULL

        || loader->error == NULL || loader->closefn == NULL) {

        ERR_raise(ERR_LIB_OSSL_STORE, OSSL_STORE_R_LOADER_INCOMPLETE);

        return 0;

    }

    if (!RUN_ONCE(&registry_init, do_registry_init)) {

        /* Should this error be raised in do_registry_init()? */

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_CRYPTO_LIB);

        return 0;

    }

    if (!CRYPTO_THREAD_write_lock(registry_lock))

        return 0;

    if (ossl_store_register_init()

        && (lh_OSSL_STORE_LOADER_insert(loader_register, loader) != NULL

            || lh_OSSL_STORE_LOADER_error(loader_register) == 0))

        ok = 1;

    CRYPTO_THREAD_unlock(registry_lock);

    return ok;

}

int OSSL_STORE_register_loader(OSSL_STORE_LOADER *loader)

{

    return ossl_store_register_loader_int(loader);

}

const OSSL_STORE_LOADER *ossl_store_get0_loader_int(const char *scheme)

{

    OSSL_STORE_LOADER template;

    OSSL_STORE_LOADER *loader = NULL;

    template.scheme = scheme;

    template.open = NULL;

    template.load = NULL;

    template.eof = NULL;

    template.closefn = NULL;

    template.open_ex = NULL;

    if (!RUN_ONCE(&registry_init, do_registry_init)) {

        /* Should this error be raised in do_registry_init()? */

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_CRYPTO_LIB);

        return NULL;

    }

    if (!CRYPTO_THREAD_write_lock(registry_lock))

        return NULL;

    if (!ossl_store_register_init())

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_INTERNAL_ERROR);

    else if ((loader = lh_OSSL_STORE_LOADER_retrieve(loader_register,

                  &template))

        == NULL)

        ERR_raise_data(ERR_LIB_OSSL_STORE, OSSL_STORE_R_UNREGISTERED_SCHEME,

            "scheme=%s", scheme);

    CRYPTO_THREAD_unlock(registry_lock);

    return loader;

}

OSSL_STORE_LOADER *ossl_store_unregister_loader_int(const char *scheme)

{

    OSSL_STORE_LOADER template;

    OSSL_STORE_LOADER *loader = NULL;

    template.scheme = scheme;

    template.open = NULL;

    template.load = NULL;

    template.eof = NULL;

    template.closefn = NULL;

    if (!RUN_ONCE(&registry_init, do_registry_init)) {

        /* Should this error be raised in do_registry_init()? */

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_CRYPTO_LIB);

        return NULL;

    }

    if (!CRYPTO_THREAD_write_lock(registry_lock))

        return NULL;

    if (!ossl_store_register_init())

        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_INTERNAL_ERROR);

    else if ((loader = lh_OSSL_STORE_LOADER_delete(loader_register,

                  &template))

        == NULL)

        ERR_raise_data(ERR_LIB_OSSL_STORE, OSSL_STORE_R_UNREGISTERED_SCHEME,

            "scheme=%s", scheme);

    CRYPTO_THREAD_unlock(registry_lock);

    return loader;

}

OSSL_STORE_LOADER *OSSL_STORE_unregister_loader(const char *scheme)

{

    return ossl_store_unregister_loader_int(scheme);

}

void ossl_store_destroy_loaders_int(void)

{

    lh_OSSL_STORE_LOADER_free(loader_register);

    loader_register = NULL;

    CRYPTO_THREAD_lock_free(registry_lock);

    registry_lock = NULL;

}

/*

 *  Functions to list OSSL_STORE loaders

 */

IMPLEMENT_LHASH_DOALL_ARG_CONST(OSSL_STORE_LOADER, void);

int OSSL_STORE_do_all_loaders(void (*do_function)(const OSSL_STORE_LOADER

                                                      *loader,

                                  void *do_arg),

    void *do_arg)

{

    if (ossl_store_register_init())

        lh_OSSL_STORE_LOADER_doall_void(loader_register, do_function, do_arg);

    return 1;

}