/* * 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/init.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/module.h> #include <linux/string.h> #include "internal.h" static LIST_HEAD(crypto_template_list); void crypto_larval_error(const char *name, u32 type, u32 mask) { struct crypto_alg *alg; down_read(&crypto_alg_sem); alg = __crypto_alg_lookup(name, type, mask); up_read(&crypto_alg_sem); if (alg) { if (crypto_is_larval(alg)) { struct crypto_larval *larval = (void *)alg; complete(&larval->completion); } crypto_mod_put(alg); } } EXPORT_SYMBOL_GPL(crypto_larval_error); 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 int crypto_check_alg(struct crypto_alg *alg) { if (alg->cra_alignmask & (alg->cra_alignmask + 1)) return -EINVAL; if (alg->cra_alignmask & alg->cra_blocksize) return -EINVAL; if (alg->cra_blocksize > PAGE_SIZE / 8) return -EINVAL; if (alg->cra_priority < 0) return -EINVAL; return crypto_set_driver_name(alg); } static void crypto_destroy_instance(struct crypto_alg *alg) { struct crypto_instance *inst = (void *)alg; struct crypto_template *tmpl = inst->tmpl; tmpl->free(inst); crypto_tmpl_put(tmpl); } static void crypto_remove_spawns(struct list_head *spawns, struct list_head *list) { struct crypto_spawn *spawn, *n; list_for_each_entry_safe(spawn, n, spawns, list) { struct crypto_instance *inst = spawn->inst; struct crypto_template *tmpl = inst->tmpl; list_del_init(&spawn->list); spawn->alg = NULL; if (crypto_is_dead(&inst->alg)) continue; inst->alg.cra_flags |= CRYPTO_ALG_DEAD; if (!tmpl || !crypto_tmpl_get(tmpl)) continue; 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; if (!list_empty(&inst->alg.cra_users)) { if (&n->list == spawns) n = list_entry(inst->alg.cra_users.next, typeof(*n), list); __list_splice(&inst->alg.cra_users, spawns->prev); } } } static int __crypto_register_alg(struct crypto_alg *alg, struct list_head *list) { struct crypto_alg *q; int ret = -EAGAIN; if (crypto_is_dead(alg)) goto out; INIT_LIST_HEAD(&alg->cra_users); ret = -EEXIST; atomic_set(&alg->cra_refcnt, 1); list_for_each_entry(q, &crypto_alg_list, cra_list) { if (q == alg) goto out; if (crypto_is_moribund(q)) continue; if (crypto_is_larval(q)) { struct crypto_larval *larval = (void *)q; if (strcmp(alg->cra_name, q->cra_name) && strcmp(alg->cra_driver_name, q->cra_name)) continue; if (larval->adult) continue; if ((q->cra_flags ^ alg->cra_flags) & larval->mask) continue; if (!crypto_mod_get(alg)) continue; larval->adult = alg; complete(&larval->completion); 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->cra_users, list); } list_add(&alg->cra_list, &crypto_alg_list); crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg); ret = 0; out: return ret; } static 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); } } int crypto_register_alg(struct crypto_alg *alg) { LIST_HEAD(list); int err; err = crypto_check_alg(alg); if (err) return err; down_write(&crypto_alg_sem); err = __crypto_register_alg(alg, &list); up_write(&crypto_alg_sem); crypto_remove_final(&list); return err; } 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; crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg); list_del_init(&alg->cra_list); crypto_remove_spawns(&alg->cra_users, list); return 0; } int 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 (ret) return ret; BUG_ON(atomic_read(&alg->cra_refcnt) != 1); if (alg->cra_destroy) alg->cra_destroy(alg); crypto_remove_final(&list); return 0; } EXPORT_SYMBOL_GPL(crypto_unregister_alg); int crypto_register_template(struct crypto_template *tmpl) { struct crypto_template *q; int err = -EEXIST; down_write(&crypto_alg_sem); list_for_each_entry(q, &crypto_template_list, list) { if (q == tmpl) goto out; } list_add(&tmpl->list, &crypto_template_list); crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl); err = 0; out: up_write(&crypto_alg_sem); return err; } EXPORT_SYMBOL_GPL(crypto_register_template); void crypto_unregister_template(struct crypto_template *tmpl) { struct crypto_instance *inst; struct hlist_node *p, *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, p, list, list) { int err = crypto_remove_alg(&inst->alg, &users); BUG_ON(err); } crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl); up_write(&crypto_alg_sem); hlist_for_each_entry_safe(inst, p, n, list, list) { BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1); tmpl->free(inst); } crypto_remove_final(&users); } EXPORT_SYMBOL_GPL(crypto_unregister_template); 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), name); } EXPORT_SYMBOL_GPL(crypto_lookup_template); int crypto_register_instance(struct crypto_template *tmpl, struct crypto_instance *inst) { LIST_HEAD(list); int err = -EINVAL; if (inst->alg.cra_destroy) goto err; err = crypto_check_alg(&inst->alg); if (err) goto err; inst->alg.cra_module = tmpl->module; down_write(&crypto_alg_sem); err = __crypto_register_alg(&inst->alg, &list); if (err) goto unlock; hlist_add_head(&inst->list, &tmpl->instances); inst->tmpl = tmpl; unlock: up_write(&crypto_alg_sem); crypto_remove_final(&list); err: return err; } EXPORT_SYMBOL_GPL(crypto_register_instance); int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg, struct crypto_instance *inst) { int err = -EAGAIN; spawn->inst = inst; down_write(&crypto_alg_sem); if (!crypto_is_moribund(alg)) { list_add(&spawn->list, &alg->cra_users); spawn->alg = alg; err = 0; } up_write(&crypto_alg_sem); return err; } EXPORT_SYMBOL_GPL(crypto_init_spawn); void crypto_drop_spawn(struct crypto_spawn *spawn) { down_write(&crypto_alg_sem); list_del(&spawn->list); up_write(&crypto_alg_sem); } EXPORT_SYMBOL_GPL(crypto_drop_spawn); struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn) { struct crypto_alg *alg; struct crypto_alg *alg2; struct crypto_tfm *tfm; down_read(&crypto_alg_sem); alg = spawn->alg; alg2 = alg; if (alg2) alg2 = crypto_mod_get(alg2); up_read(&crypto_alg_sem); if (!alg2) { if (alg) crypto_shoot_alg(alg); return ERR_PTR(-EAGAIN); } tfm = __crypto_alloc_tfm(alg, 0); if (IS_ERR(tfm)) crypto_mod_put(alg); return tfm; } EXPORT_SYMBOL_GPL(crypto_spawn_tfm); 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); static int __init crypto_algapi_init(void) { crypto_init_proc(); return 0; } static void __exit crypto_algapi_exit(void) { crypto_exit_proc(); } module_init(crypto_algapi_init); module_exit(crypto_algapi_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Cryptographic algorithms API");