b3c16bfc6a
This patch introduces the skcipher_ialg_simple helper which fetches the crypto_alg structure from a simple skcipher instance's spawn. This allows us to remove the third argument from the function skcipher_alloc_instance_simple. In doing so the reference count to the algorithm is now maintained by the Crypto API and the caller no longer needs to drop the alg refcount. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* CBC: Cipher Block Chaining mode
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*
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* Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>
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*/
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#include <crypto/algapi.h>
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#include <crypto/cbc.h>
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#include <crypto/internal/skcipher.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/log2.h>
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#include <linux/module.h>
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static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
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const u8 *src, u8 *dst)
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{
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crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src);
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}
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static int crypto_cbc_encrypt(struct skcipher_request *req)
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{
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return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
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}
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static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
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const u8 *src, u8 *dst)
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{
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crypto_cipher_decrypt_one(skcipher_cipher_simple(tfm), dst, src);
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}
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static int crypto_cbc_decrypt(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct skcipher_walk walk;
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int err;
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err = skcipher_walk_virt(&walk, req, false);
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while (walk.nbytes) {
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err = crypto_cbc_decrypt_blocks(&walk, tfm,
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crypto_cbc_decrypt_one);
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err = skcipher_walk_done(&walk, err);
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}
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return err;
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}
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static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
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{
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struct skcipher_instance *inst;
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struct crypto_alg *alg;
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int err;
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inst = skcipher_alloc_instance_simple(tmpl, tb);
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if (IS_ERR(inst))
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return PTR_ERR(inst);
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alg = skcipher_ialg_simple(inst);
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err = -EINVAL;
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if (!is_power_of_2(alg->cra_blocksize))
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goto out_free_inst;
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inst->alg.encrypt = crypto_cbc_encrypt;
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inst->alg.decrypt = crypto_cbc_decrypt;
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err = skcipher_register_instance(tmpl, inst);
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if (err) {
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out_free_inst:
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inst->free(inst);
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}
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return err;
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}
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static struct crypto_template crypto_cbc_tmpl = {
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.name = "cbc",
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.create = crypto_cbc_create,
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.module = THIS_MODULE,
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};
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static int __init crypto_cbc_module_init(void)
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{
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return crypto_register_template(&crypto_cbc_tmpl);
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}
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static void __exit crypto_cbc_module_exit(void)
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{
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crypto_unregister_template(&crypto_cbc_tmpl);
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}
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subsys_initcall(crypto_cbc_module_init);
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module_exit(crypto_cbc_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("CBC block cipher mode of operation");
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MODULE_ALIAS_CRYPTO("cbc");
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