[thirdparty/kernel/linux.git] / crypto / algapi.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/algapi.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/fips.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/workqueue.h>

#include "internal.h"

static LIST_HEAD(crypto_template_list);

static inline void crypto_check_module_sig(struct module *mod)
{
        if (fips_enabled && mod && !module_sig_ok(mod))
                panic("Module %s signature verification failed in FIPS mode\n",
                      module_name(mod));
}

static int crypto_check_alg(struct crypto_alg *alg)
{
        crypto_check_module_sig(alg->cra_module);

        if (!alg->cra_name[0] || !alg->cra_driver_name[0])
                return -EINVAL;

        if (alg->cra_alignmask & (alg->cra_alignmask + 1))
                return -EINVAL;

        /* General maximums for all algs. */
        if (alg->cra_alignmask > MAX_ALGAPI_ALIGNMASK)
                return -EINVAL;

        if (alg->cra_blocksize > MAX_ALGAPI_BLOCKSIZE)
                return -EINVAL;

        /* Lower maximums for specific alg types. */
        if (!alg->cra_type && (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
                               CRYPTO_ALG_TYPE_CIPHER) {
                if (alg->cra_alignmask > MAX_CIPHER_ALIGNMASK)
                        return -EINVAL;

                if (alg->cra_blocksize > MAX_CIPHER_BLOCKSIZE)
                        return -EINVAL;
        }

        if (alg->cra_priority < 0)
                return -EINVAL;

        refcount_set(&alg->cra_refcnt, 1);

        return 0;
}

static void crypto_free_instance(struct crypto_instance *inst)
{
        inst->alg.cra_type->free(inst);
}

static void crypto_destroy_instance_workfn(struct work_struct *w)
{
        struct crypto_template *tmpl = container_of(w, struct crypto_template,
                                                    free_work);
        struct crypto_instance *inst;
        struct hlist_node *n;
        HLIST_HEAD(list);

        down_write(&crypto_alg_sem);
        hlist_for_each_entry_safe(inst, n, &tmpl->dead, list) {
                if (refcount_read(&inst->alg.cra_refcnt) != -1)
                        continue;
                hlist_del(&inst->list);
                hlist_add_head(&inst->list, &list);
        }
        up_write(&crypto_alg_sem);

        hlist_for_each_entry_safe(inst, n, &list, list)
                crypto_free_instance(inst);
}

static void crypto_destroy_instance(struct crypto_alg *alg)
{
        struct crypto_instance *inst = container_of(alg,
                                                    struct crypto_instance,
                                                    alg);
        struct crypto_template *tmpl = inst->tmpl;

        refcount_set(&alg->cra_refcnt, -1);
        schedule_work(&tmpl->free_work);
}

/*
 * This function adds a spawn to the list secondary_spawns which
 * will be used at the end of crypto_remove_spawns to unregister
 * instances, unless the spawn happens to be one that is depended
 * on by the new algorithm (nalg in crypto_remove_spawns).
 *
 * This function is also responsible for resurrecting any algorithms
 * in the dependency chain of nalg by unsetting n->dead.
 */
static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
                                            struct list_head *stack,
                                            struct list_head *top,
                                            struct list_head *secondary_spawns)
{
        struct crypto_spawn *spawn, *n;

        spawn = list_first_entry_or_null(stack, struct crypto_spawn, list);
        if (!spawn)
                return NULL;

        n = list_prev_entry(spawn, list);
        list_move(&spawn->list, secondary_spawns);

        if (list_is_last(&n->list, stack))
                return top;

        n = list_next_entry(n, list);
        if (!spawn->dead)
                n->dead = false;

        return &n->inst->alg.cra_users;
}

static void crypto_remove_instance(struct crypto_instance *inst,
                                   struct list_head *list)
{
        struct crypto_template *tmpl = inst->tmpl;

        if (crypto_is_dead(&inst->alg))
                return;

        inst->alg.cra_flags |= CRYPTO_ALG_DEAD;

        if (!tmpl)
                return;

        list_del_init(&inst->alg.cra_list);
        hlist_del(&inst->list);
        hlist_add_head(&inst->list, &tmpl->dead);

        BUG_ON(!list_empty(&inst->alg.cra_users));

        crypto_alg_put(&inst->alg);
}

/*
 * Given an algorithm alg, remove all algorithms that depend on it
 * through spawns.  If nalg is not null, then exempt any algorithms
 * that is depended on by nalg.  This is useful when nalg itself
 * depends on alg.
 */
void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
                          struct crypto_alg *nalg)
{
        u32 new_type = (nalg ?: alg)->cra_flags;
        struct crypto_spawn *spawn, *n;
        LIST_HEAD(secondary_spawns);
        struct list_head *spawns;
        LIST_HEAD(stack);
        LIST_HEAD(top);

        spawns = &alg->cra_users;
        list_for_each_entry_safe(spawn, n, spawns, list) {
                if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
                        continue;

                list_move(&spawn->list, &top);
        }

        /*
         * Perform a depth-first walk starting from alg through
         * the cra_users tree.  The list stack records the path
         * from alg to the current spawn.
         */
        spawns = &top;
        do {
                while (!list_empty(spawns)) {
                        struct crypto_instance *inst;

                        spawn = list_first_entry(spawns, struct crypto_spawn,
                                                 list);
                        inst = spawn->inst;

                        list_move(&spawn->list, &stack);
                        spawn->dead = !spawn->registered || &inst->alg != nalg;

                        if (!spawn->registered)
                                break;

                        BUG_ON(&inst->alg == alg);

                        if (&inst->alg == nalg)
                                break;

                        spawns = &inst->alg.cra_users;

                        /*
                         * Even if spawn->registered is true, the
                         * instance itself may still be unregistered.
                         * This is because it may have failed during
                         * registration.  Therefore we still need to
                         * make the following test.
                         *
                         * We may encounter an unregistered instance here, since
                         * an instance's spawns are set up prior to the instance
                         * being registered.  An unregistered instance will have
                         * NULL ->cra_users.next, since ->cra_users isn't
                         * properly initialized until registration.  But an
                         * unregistered instance cannot have any users, so treat
                         * it the same as ->cra_users being empty.
                         */
                        if (spawns->next == NULL)
                                break;
                }
        } while ((spawns = crypto_more_spawns(alg, &stack, &top,
                                              &secondary_spawns)));

        /*
         * Remove all instances that are marked as dead.  Also
         * complete the resurrection of the others by moving them
         * back to the cra_users list.
         */
        list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
                if (!spawn->dead)
                        list_move(&spawn->list, &spawn->alg->cra_users);
                else if (spawn->registered)
                        crypto_remove_instance(spawn->inst, list);
        }
}
EXPORT_SYMBOL_GPL(crypto_remove_spawns);

static void crypto_alg_finish_registration(struct crypto_alg *alg,
                                           struct list_head *algs_to_put)
{
        struct crypto_alg *q;

        list_for_each_entry(q, &crypto_alg_list, cra_list) {
                if (q == alg)
                        continue;

                if (crypto_is_moribund(q))
                        continue;

                if (crypto_is_larval(q))
                        continue;

                if (strcmp(alg->cra_name, q->cra_name))
                        continue;

                if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
                    q->cra_priority > alg->cra_priority)
                        continue;

                crypto_remove_spawns(q, algs_to_put, alg);
        }

        crypto_notify(CRYPTO_MSG_ALG_LOADED, alg);
}

static struct crypto_larval *crypto_alloc_test_larval(struct crypto_alg *alg)
{
        struct crypto_larval *larval;

        if (!IS_ENABLED(CONFIG_CRYPTO_SELFTESTS) ||
            (alg->cra_flags & CRYPTO_ALG_INTERNAL))
                return NULL; /* No self-test needed */

        larval = crypto_larval_alloc(alg->cra_name,
                                     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
        if (IS_ERR(larval))
                return larval;

        larval->adult = crypto_mod_get(alg);
        if (!larval->adult) {
                kfree(larval);
                return ERR_PTR(-ENOENT);
        }

        refcount_set(&larval->alg.cra_refcnt, 1);
        memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
               CRYPTO_MAX_ALG_NAME);
        larval->alg.cra_priority = alg->cra_priority;

        return larval;
}

static struct crypto_larval *
__crypto_register_alg(struct crypto_alg *alg, struct list_head *algs_to_put)
{
        struct crypto_alg *q;
        struct crypto_larval *larval;
        int ret = -EAGAIN;

        if (crypto_is_dead(alg))
                goto err;

        INIT_LIST_HEAD(&alg->cra_users);

        ret = -EEXIST;

        list_for_each_entry(q, &crypto_alg_list, cra_list) {
                if (q == alg)
                        goto err;

                if (crypto_is_moribund(q))
                        continue;

                if (crypto_is_larval(q)) {
                        if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
                                goto err;
                        continue;
                }

                if (!strcmp(q->cra_driver_name, alg->cra_name) ||
                    !strcmp(q->cra_driver_name, alg->cra_driver_name) ||
                    !strcmp(q->cra_name, alg->cra_driver_name))
                        goto err;
        }

        larval = crypto_alloc_test_larval(alg);
        if (IS_ERR(larval))
                goto out;

        list_add(&alg->cra_list, &crypto_alg_list);

        if (larval) {
                /* No cheating! */
                alg->cra_flags &= ~CRYPTO_ALG_TESTED;

                list_add(&larval->alg.cra_list, &crypto_alg_list);
        } else {
                alg->cra_flags |= CRYPTO_ALG_TESTED;
                crypto_alg_finish_registration(alg, algs_to_put);
        }

out:
        return larval;

err:
        larval = ERR_PTR(ret);
        goto out;
}

void crypto_alg_tested(const char *name, int err)
{
        struct crypto_larval *test;
        struct crypto_alg *alg;
        struct crypto_alg *q;
        LIST_HEAD(list);

        down_write(&crypto_alg_sem);
        list_for_each_entry(q, &crypto_alg_list, cra_list) {
                if (crypto_is_moribund(q) || !crypto_is_larval(q))
                        continue;

                test = (struct crypto_larval *)q;

                if (!strcmp(q->cra_driver_name, name))
                        goto found;
        }

        pr_err("alg: Unexpected test result for %s: %d\n", name, err);
        up_write(&crypto_alg_sem);
        return;

found:
        q->cra_flags |= CRYPTO_ALG_DEAD;
        alg = test->adult;

        if (crypto_is_dead(alg))
                goto complete;

        if (err == -ECANCELED)
                alg->cra_flags |= CRYPTO_ALG_FIPS_INTERNAL;
        else if (err)
                goto complete;
        else
                alg->cra_flags &= ~CRYPTO_ALG_FIPS_INTERNAL;

        alg->cra_flags |= CRYPTO_ALG_TESTED;

        crypto_alg_finish_registration(alg, &list);

complete:
        list_del_init(&test->alg.cra_list);
        complete_all(&test->completion);

        up_write(&crypto_alg_sem);

        crypto_alg_put(&test->alg);
        crypto_remove_final(&list);
}
EXPORT_SYMBOL_GPL(crypto_alg_tested);

void crypto_remove_final(struct list_head *list)
{
        struct crypto_alg *alg;
        struct crypto_alg *n;

        list_for_each_entry_safe(alg, n, list, cra_list) {
                list_del_init(&alg->cra_list);
                crypto_alg_put(alg);
        }
}
EXPORT_SYMBOL_GPL(crypto_remove_final);

static void crypto_free_alg(struct crypto_alg *alg)
{
        unsigned int algsize = alg->cra_type->algsize;
        u8 *p = (u8 *)alg - algsize;

        crypto_destroy_alg(alg);
        kfree(p);
}

int crypto_register_alg(struct crypto_alg *alg)
{
        struct crypto_larval *larval;
        bool test_started = false;
        LIST_HEAD(algs_to_put);
        int err;

        alg->cra_flags &= ~CRYPTO_ALG_DEAD;
        err = crypto_check_alg(alg);
        if (err)
                return err;

        if (alg->cra_flags & CRYPTO_ALG_DUP_FIRST &&
            !WARN_ON_ONCE(alg->cra_destroy)) {
                unsigned int algsize = alg->cra_type->algsize;
                u8 *p = (u8 *)alg - algsize;

                p = kmemdup(p, algsize + sizeof(*alg), GFP_KERNEL);
                if (!p)
                        return -ENOMEM;

                alg = (void *)(p + algsize);
                alg->cra_destroy = crypto_free_alg;
        }

        down_write(&crypto_alg_sem);
        larval = __crypto_register_alg(alg, &algs_to_put);
        if (!IS_ERR_OR_NULL(larval)) {
                test_started = crypto_boot_test_finished();
                larval->test_started = test_started;
        }
        up_write(&crypto_alg_sem);

        if (IS_ERR(larval)) {
                crypto_alg_put(alg);
                return PTR_ERR(larval);
        }

        if (test_started)
                crypto_schedule_test(larval);
        else
                crypto_remove_final(&algs_to_put);

        return 0;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);

static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
{
        if (unlikely(list_empty(&alg->cra_list)))
                return -ENOENT;

        alg->cra_flags |= CRYPTO_ALG_DEAD;

        list_del_init(&alg->cra_list);
        crypto_remove_spawns(alg, list, NULL);

        return 0;
}

void crypto_unregister_alg(struct crypto_alg *alg)
{
        int ret;
        LIST_HEAD(list);

        down_write(&crypto_alg_sem);
        ret = crypto_remove_alg(alg, &list);
        up_write(&crypto_alg_sem);

        if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name))
                return;

        WARN_ON(!alg->cra_destroy && refcount_read(&alg->cra_refcnt) != 1);

        list_add(&alg->cra_list, &list);
        crypto_remove_final(&list);
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);

int crypto_register_algs(struct crypto_alg *algs, int count)
{
        int i, ret;

        for (i = 0; i < count; i++) {
                ret = crypto_register_alg(&algs[i]);
                if (ret)
                        goto err;
        }

        return 0;

err:
        for (--i; i >= 0; --i)
                crypto_unregister_alg(&algs[i]);

        return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_algs);

void crypto_unregister_algs(struct crypto_alg *algs, int count)
{
        int i;

        for (i = 0; i < count; i++)
                crypto_unregister_alg(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_algs);

int crypto_register_template(struct crypto_template *tmpl)
{
        struct crypto_template *q;
        int err = -EEXIST;

        INIT_WORK(&tmpl->free_work, crypto_destroy_instance_workfn);

        down_write(&crypto_alg_sem);

        crypto_check_module_sig(tmpl->module);

        list_for_each_entry(q, &crypto_template_list, list) {
                if (q == tmpl)
                        goto out;
        }

        list_add(&tmpl->list, &crypto_template_list);
        err = 0;
out:
        up_write(&crypto_alg_sem);
        return err;
}
EXPORT_SYMBOL_GPL(crypto_register_template);

int crypto_register_templates(struct crypto_template *tmpls, int count)
{
        int i, err;

        for (i = 0; i < count; i++) {
                err = crypto_register_template(&tmpls[i]);
                if (err)
                        goto out;
        }
        return 0;

out:
        for (--i; i >= 0; --i)
                crypto_unregister_template(&tmpls[i]);
        return err;
}
EXPORT_SYMBOL_GPL(crypto_register_templates);

void crypto_unregister_template(struct crypto_template *tmpl)
{
        struct crypto_instance *inst;
        struct hlist_node *n;
        struct hlist_head *list;
        LIST_HEAD(users);

        down_write(&crypto_alg_sem);

        BUG_ON(list_empty(&tmpl->list));
        list_del_init(&tmpl->list);

        list = &tmpl->instances;
        hlist_for_each_entry(inst, list, list) {
                int err = crypto_remove_alg(&inst->alg, &users);

                BUG_ON(err);
        }

        up_write(&crypto_alg_sem);

        hlist_for_each_entry_safe(inst, n, list, list) {
                BUG_ON(refcount_read(&inst->alg.cra_refcnt) != 1);
                crypto_free_instance(inst);
        }
        crypto_remove_final(&users);

        flush_work(&tmpl->free_work);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);

void crypto_unregister_templates(struct crypto_template *tmpls, int count)
{
        int i;

        for (i = count - 1; i >= 0; --i)
                crypto_unregister_template(&tmpls[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_templates);

static struct crypto_template *__crypto_lookup_template(const char *name)
{
        struct crypto_template *q, *tmpl = NULL;

        down_read(&crypto_alg_sem);
        list_for_each_entry(q, &crypto_template_list, list) {
                if (strcmp(q->name, name))
                        continue;
                if (unlikely(!crypto_tmpl_get(q)))
                        continue;

                tmpl = q;
                break;
        }
        up_read(&crypto_alg_sem);

        return tmpl;
}

struct crypto_template *crypto_lookup_template(const char *name)
{
        return try_then_request_module(__crypto_lookup_template(name),
                                       "crypto-%s", name);
}
EXPORT_SYMBOL_GPL(crypto_lookup_template);

int crypto_register_instance(struct crypto_template *tmpl,
                             struct crypto_instance *inst)
{
        struct crypto_larval *larval;
        struct crypto_spawn *spawn;
        u32 fips_internal = 0;
        LIST_HEAD(algs_to_put);
        int err;

        err = crypto_check_alg(&inst->alg);
        if (err)
                return err;

        inst->alg.cra_module = tmpl->module;
        inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE;
        inst->alg.cra_destroy = crypto_destroy_instance;

        down_write(&crypto_alg_sem);

        larval = ERR_PTR(-EAGAIN);
        for (spawn = inst->spawns; spawn;) {
                struct crypto_spawn *next;

                if (spawn->dead)
                        goto unlock;

                next = spawn->next;
                spawn->inst = inst;
                spawn->registered = true;

                fips_internal |= spawn->alg->cra_flags;

                crypto_mod_put(spawn->alg);

                spawn = next;
        }

        inst->alg.cra_flags |= (fips_internal & CRYPTO_ALG_FIPS_INTERNAL);

        larval = __crypto_register_alg(&inst->alg, &algs_to_put);
        if (IS_ERR(larval))
                goto unlock;
        else if (larval)
                larval->test_started = true;

        hlist_add_head(&inst->list, &tmpl->instances);
        inst->tmpl = tmpl;

unlock:
        up_write(&crypto_alg_sem);

        if (IS_ERR(larval))
                return PTR_ERR(larval);

        if (larval)
                crypto_schedule_test(larval);
        else
                crypto_remove_final(&algs_to_put);

        return 0;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);

void crypto_unregister_instance(struct crypto_instance *inst)
{
        LIST_HEAD(list);

        down_write(&crypto_alg_sem);

        crypto_remove_spawns(&inst->alg, &list, NULL);
        crypto_remove_instance(inst, &list);

        up_write(&crypto_alg_sem);

        crypto_remove_final(&list);
}
EXPORT_SYMBOL_GPL(crypto_unregister_instance);

int crypto_grab_spawn(struct crypto_spawn *spawn, struct crypto_instance *inst,
                      const char *name, u32 type, u32 mask)
{
        struct crypto_alg *alg;
        int err = -EAGAIN;

        if (WARN_ON_ONCE(inst == NULL))
                return -EINVAL;

        /* Allow the result of crypto_attr_alg_name() to be passed directly */
        if (IS_ERR(name))
                return PTR_ERR(name);

        alg = crypto_find_alg(name, spawn->frontend,
                              type | CRYPTO_ALG_FIPS_INTERNAL, mask);
        if (IS_ERR(alg))
                return PTR_ERR(alg);

        down_write(&crypto_alg_sem);
        if (!crypto_is_moribund(alg)) {
                list_add(&spawn->list, &alg->cra_users);
                spawn->alg = alg;
                spawn->mask = mask;
                spawn->next = inst->spawns;
                inst->spawns = spawn;
                inst->alg.cra_flags |=
                        (alg->cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
                err = 0;
        }
        up_write(&crypto_alg_sem);
        if (err)
                crypto_mod_put(alg);
        return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_spawn);

void crypto_drop_spawn(struct crypto_spawn *spawn)
{
        if (!spawn->alg) /* not yet initialized? */
                return;

        down_write(&crypto_alg_sem);
        if (!spawn->dead)
                list_del(&spawn->list);
        up_write(&crypto_alg_sem);

        if (!spawn->registered)
                crypto_mod_put(spawn->alg);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);

static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
{
        struct crypto_alg *alg = ERR_PTR(-EAGAIN);
        struct crypto_alg *target;
        bool shoot = false;

        down_read(&crypto_alg_sem);
        if (!spawn->dead) {
                alg = spawn->alg;
                if (!crypto_mod_get(alg)) {
                        target = crypto_alg_get(alg);
                        shoot = true;
                        alg = ERR_PTR(-EAGAIN);
                }
        }
        up_read(&crypto_alg_sem);

        if (shoot) {
                crypto_shoot_alg(target);
                crypto_alg_put(target);
        }

        return alg;
}

struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
                                    u32 mask)
{
        struct crypto_alg *alg;
        struct crypto_tfm *tfm;

        alg = crypto_spawn_alg(spawn);
        if (IS_ERR(alg))
                return ERR_CAST(alg);

        tfm = ERR_PTR(-EINVAL);
        if (unlikely((alg->cra_flags ^ type) & mask))
                goto out_put_alg;

        tfm = __crypto_alloc_tfm(alg, type, mask);
        if (IS_ERR(tfm))
                goto out_put_alg;

        return tfm;

out_put_alg:
        crypto_mod_put(alg);
        return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm);

void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
{
        struct crypto_alg *alg;
        struct crypto_tfm *tfm;

        alg = crypto_spawn_alg(spawn);
        if (IS_ERR(alg))
                return ERR_CAST(alg);

        tfm = crypto_create_tfm(alg, spawn->frontend);
        if (IS_ERR(tfm))
                goto out_put_alg;

        return tfm;

out_put_alg:
        crypto_mod_put(alg);
        return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);

int crypto_register_notifier(struct notifier_block *nb)
{
        return blocking_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);

int crypto_unregister_notifier(struct notifier_block *nb)
{
        return blocking_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);

struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
{
        struct rtattr *rta = tb[0];
        struct crypto_attr_type *algt;

        if (!rta)
                return ERR_PTR(-ENOENT);
        if (RTA_PAYLOAD(rta) < sizeof(*algt))
                return ERR_PTR(-EINVAL);
        if (rta->rta_type != CRYPTOA_TYPE)
                return ERR_PTR(-EINVAL);

        algt = RTA_DATA(rta);

        return algt;
}
EXPORT_SYMBOL_GPL(crypto_get_attr_type);

/**
 * crypto_check_attr_type() - check algorithm type and compute inherited mask
 * @tb: the template parameters
 * @type: the algorithm type the template would be instantiated as
 * @mask_ret: (output) the mask that should be passed to crypto_grab_*()
 *            to restrict the flags of any inner algorithms
 *
 * Validate that the algorithm type the user requested is compatible with the
 * one the template would actually be instantiated as.  E.g., if the user is
 * doing crypto_alloc_shash("cbc(aes)", ...), this would return an error because
 * the "cbc" template creates an "skcipher" algorithm, not an "shash" algorithm.
 *
 * Also compute the mask to use to restrict the flags of any inner algorithms.
 *
 * Return: 0 on success; -errno on failure
 */
int crypto_check_attr_type(struct rtattr **tb, u32 type, u32 *mask_ret)
{
        struct crypto_attr_type *algt;

        algt = crypto_get_attr_type(tb);
        if (IS_ERR(algt))
                return PTR_ERR(algt);

        if ((algt->type ^ type) & algt->mask)
                return -EINVAL;

        *mask_ret = crypto_algt_inherited_mask(algt);
        return 0;
}
EXPORT_SYMBOL_GPL(crypto_check_attr_type);

const char *crypto_attr_alg_name(struct rtattr *rta)
{
        struct crypto_attr_alg *alga;

        if (!rta)
                return ERR_PTR(-ENOENT);
        if (RTA_PAYLOAD(rta) < sizeof(*alga))
                return ERR_PTR(-EINVAL);
        if (rta->rta_type != CRYPTOA_ALG)
                return ERR_PTR(-EINVAL);

        alga = RTA_DATA(rta);
        alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;

        return alga->name;
}
EXPORT_SYMBOL_GPL(crypto_attr_alg_name);

int __crypto_inst_setname(struct crypto_instance *inst, const char *name,
                          const char *driver, struct crypto_alg *alg)
{
        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
                     alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
                return -ENAMETOOLONG;

        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
                     driver, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
                return -ENAMETOOLONG;

        return 0;
}
EXPORT_SYMBOL_GPL(__crypto_inst_setname);

void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
{
        INIT_LIST_HEAD(&queue->list);
        queue->backlog = &queue->list;
        queue->qlen = 0;
        queue->max_qlen = max_qlen;
}
EXPORT_SYMBOL_GPL(crypto_init_queue);

int crypto_enqueue_request(struct crypto_queue *queue,
                           struct crypto_async_request *request)
{
        int err = -EINPROGRESS;

        if (unlikely(queue->qlen >= queue->max_qlen)) {
                if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) {
                        err = -ENOSPC;
                        goto out;
                }
                err = -EBUSY;
                if (queue->backlog == &queue->list)
                        queue->backlog = &request->list;
        }

        queue->qlen++;
        list_add_tail(&request->list, &queue->list);

out:
        return err;
}
EXPORT_SYMBOL_GPL(crypto_enqueue_request);

void crypto_enqueue_request_head(struct crypto_queue *queue,
                                 struct crypto_async_request *request)
{
        if (unlikely(queue->qlen >= queue->max_qlen))
                queue->backlog = queue->backlog->prev;

        queue->qlen++;
        list_add(&request->list, &queue->list);
}
EXPORT_SYMBOL_GPL(crypto_enqueue_request_head);

struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
{
        struct list_head *request;

        if (unlikely(!queue->qlen))
                return NULL;

        queue->qlen--;

        if (queue->backlog != &queue->list)
                queue->backlog = queue->backlog->next;

        request = queue->list.next;
        list_del_init(request);

        return list_entry(request, struct crypto_async_request, list);
}
EXPORT_SYMBOL_GPL(crypto_dequeue_request);

static inline void crypto_inc_byte(u8 *a, unsigned int size)
{
        u8 *b = (a + size);
        u8 c;

        for (; size; size--) {
                c = *--b + 1;
                *b = c;
                if (c)
                        break;
        }
}

void crypto_inc(u8 *a, unsigned int size)
{
        __be32 *b = (__be32 *)(a + size);
        u32 c;

        if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ||
            IS_ALIGNED((unsigned long)b, __alignof__(*b)))
                for (; size >= 4; size -= 4) {
                        c = be32_to_cpu(*--b) + 1;
                        *b = cpu_to_be32(c);
                        if (likely(c))
                                return;
                }

        crypto_inc_byte(a, size);
}
EXPORT_SYMBOL_GPL(crypto_inc);

unsigned int crypto_alg_extsize(struct crypto_alg *alg)
{
        return alg->cra_ctxsize +
               (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
}
EXPORT_SYMBOL_GPL(crypto_alg_extsize);

int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
                        u32 type, u32 mask)
{
        int ret = 0;
        struct crypto_alg *alg = crypto_find_alg(name, frontend, type, mask);

        if (!IS_ERR(alg)) {
                crypto_mod_put(alg);
                ret = 1;
        }

        return ret;
}
EXPORT_SYMBOL_GPL(crypto_type_has_alg);

static void __init crypto_start_tests(void)
{
        if (!IS_BUILTIN(CONFIG_CRYPTO_ALGAPI))
                return;

        if (!IS_ENABLED(CONFIG_CRYPTO_SELFTESTS))
                return;

        set_crypto_boot_test_finished();

        for (;;) {
                struct crypto_larval *larval = NULL;
                struct crypto_alg *q;

                down_write(&crypto_alg_sem);

                list_for_each_entry(q, &crypto_alg_list, cra_list) {
                        struct crypto_larval *l;

                        if (!crypto_is_larval(q))
                                continue;

                        l = (void *)q;

                        if (!crypto_is_test_larval(l))
                                continue;

                        if (l->test_started)
                                continue;

                        l->test_started = true;
                        larval = l;
                        break;
                }

                up_write(&crypto_alg_sem);

                if (!larval)
                        break;

                crypto_schedule_test(larval);
        }
}

static int __init crypto_algapi_init(void)
{
        crypto_init_proc();
        crypto_start_tests();
        return 0;
}

static void __exit crypto_algapi_exit(void)
{
        crypto_exit_proc();
}

/*
 * We run this at late_initcall so that all the built-in algorithms
 * have had a chance to register themselves first.
 */
late_initcall(crypto_algapi_init);
module_exit(crypto_algapi_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cryptographic algorithms API");
MODULE_SOFTDEP("pre: cryptomgr");