path: root/crypto/algapi.c

/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#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 "internal.h"

static LIST_HEAD(crypto_template_list);

static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
	static const char suffix[] = "-generic";
	char *driver_name = alg->cra_driver_name;
	int len;

	if (*driver_name)
		return 0;

	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	memcpy(driver_name + len, suffix, sizeof(suffix));
	return 0;
}

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

	if (alg->cra_blocksize > PAGE_SIZE / 8)
		return -EINVAL;

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

	atomic_set(&alg->cra_refcnt, 1);

	return crypto_set_driver_name(alg);
}

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

	inst->alg.cra_type->free(inst);
}

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

	crypto_free_instance(inst);
	crypto_tmpl_put(tmpl);
}

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;

	if (list_empty(stack))
		return NULL;

	spawn = list_first_entry(stack, struct crypto_spawn, list);
	n = list_entry(spawn->list.next, struct crypto_spawn, list);

	if (spawn->alg && &n->list != stack && !n->alg)
		n->alg = (n->list.next == stack) ? alg :
			 &list_entry(n->list.next, struct crypto_spawn,
				     list)->inst->alg;

	list_move(&spawn->list, secondary_spawns);

	return &n->list == stack ? top : &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 (hlist_unhashed(&inst->list))
		return;

	if (!tmpl || !crypto_tmpl_get(tmpl))
		return;

	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
	list_move(&inst->alg.cra_list, list);
	hlist_del(&inst->list);
	inst->alg.cra_destroy = crypto_destroy_instance;

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

void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
			  struct crypto_alg *nalg)
{
	u32 new_type = (nalg