// SPDX-License-Identifier: GPL-2.0-or-later /* * CBC: Cipher Block Chaining mode * * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au> */ #include <crypto/algapi.h> #include <crypto/cbc.h> #include <crypto/internal/skcipher.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/log2.h> #include <linux/module.h> static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst) { crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src); } static int crypto_cbc_encrypt(struct skcipher_request *req) { return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one); } static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst) { crypto_cipher_decrypt_one(skcipher_cipher_simple(tfm), dst, src); } static int crypto_cbc_decrypt(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_walk walk; int err; err = skcipher_walk_virt(&walk, req, false); while (walk.nbytes) { err = crypto_cbc_decrypt_blocks(&walk, tfm, crypto_cbc_decrypt_one); err = skcipher_walk_done(&walk, err); } return err; } static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb) { struct skcipher_instance *inst; struct crypto_alg *alg; int err; inst = skcipher_alloc_instance_simple(tmpl, tb); if (IS_ERR(inst)) return PTR_ERR(inst); alg = skcipher_ialg_simple(inst); err = -EINVAL; if (!is_power_of_2(alg->cra_blocksize)) goto out_free_inst; inst->alg.encrypt = crypto_cbc_encrypt; inst->alg.decrypt = crypto_cbc_decrypt; err = skcipher_register_instance(tmpl, inst); if (err) { out_free_inst: inst->free(inst); } return err; } static struct crypto_template crypto_cbc_tmpl = { .name = "cbc", .create = crypto_cbc_create, .module = THIS_MODULE, }; static int __init crypto_cbc_module_init(void) { return crypto_register_template(&crypto_cbc_tmpl); } static void __exit crypto_cbc_module_exit(void) { crypto_unregister_template(&crypto_cbc_tmpl); } subsys_initcall(crypto_cbc_module_init); module_exit(crypto_cbc_module_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("CBC block cipher mode of operation"); MODULE_ALIAS_CRYPTO("cbc");