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)
	__must_hold(&crypto_alg_sem)
{
	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)
	__must_hold(&crypto_alg_sem)
{
	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) {
			crypto_unregister_algs(algs, i);
			return ret;
		}
	}

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_register_algs);

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

	for (i = count - 1; i >= 0; --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");