Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188// 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/internal/skcipher.h>#include <linux/err.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/log2.h>#include <linux/module.h>
static int crypto_cbc_encrypt_segment(struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned nbytes, u8 *iv){ unsigned int bsize = crypto_lskcipher_blocksize(tfm);
for (; nbytes >= bsize; src += bsize, dst += bsize, nbytes -= bsize) { crypto_xor(iv, src, bsize); crypto_lskcipher_encrypt(tfm, iv, dst, bsize, NULL); memcpy(iv, dst, bsize); }
return nbytes;}
static int crypto_cbc_encrypt_inplace(struct crypto_lskcipher *tfm, u8 *src, unsigned nbytes, u8 *oiv){ unsigned int bsize = crypto_lskcipher_blocksize(tfm); u8 *iv = oiv;
if (nbytes < bsize) goto out;
do { crypto_xor(src, iv, bsize); crypto_lskcipher_encrypt(tfm, src, src, bsize, NULL); iv = src;
src += bsize; } while ((nbytes -= bsize) >= bsize);
memcpy(oiv, iv, bsize);
out: return nbytes;}
static int crypto_cbc_encrypt(struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned len, u8 *iv, u32 flags){ struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm); bool final = flags & CRYPTO_LSKCIPHER_FLAG_FINAL; struct crypto_lskcipher *cipher = *ctx; int rem;
if (src == dst) rem = crypto_cbc_encrypt_inplace(cipher, dst, len, iv); else rem = crypto_cbc_encrypt_segment(cipher, src, dst, len, iv);
return rem && final ? -EINVAL : rem;}
static int crypto_cbc_decrypt_segment(struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned nbytes, u8 *oiv){ unsigned int bsize = crypto_lskcipher_blocksize(tfm); const u8 *iv = oiv;
if (nbytes < bsize) goto out;
do { crypto_lskcipher_decrypt(tfm, src, dst, bsize, NULL); crypto_xor(dst, iv, bsize); iv = src;
src += bsize; dst += bsize; } while ((nbytes -= bsize) >= bsize);
memcpy(oiv, iv, bsize);
out: return nbytes;}
static int crypto_cbc_decrypt_inplace(struct crypto_lskcipher *tfm, u8 *src, unsigned nbytes, u8 *iv){ unsigned int bsize = crypto_lskcipher_blocksize(tfm); u8 last_iv[MAX_CIPHER_BLOCKSIZE];
if (nbytes < bsize) goto out;
/* Start of the last block. */ src += nbytes - (nbytes & (bsize - 1)) - bsize; memcpy(last_iv, src, bsize);
for (;;) { crypto_lskcipher_decrypt(tfm, src, src, bsize, NULL); if ((nbytes -= bsize) < bsize) break; crypto_xor(src, src - bsize, bsize); src -= bsize; }
crypto_xor(src, iv, bsize); memcpy(iv, last_iv, bsize);
out: return nbytes;}
static int crypto_cbc_decrypt(struct crypto_lskcipher *tfm, const u8 *src, u8 *dst, unsigned len, u8 *iv, u32 flags){ struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm); bool final = flags & CRYPTO_LSKCIPHER_FLAG_FINAL; struct crypto_lskcipher *cipher = *ctx; int rem;
if (src == dst) rem = crypto_cbc_decrypt_inplace(cipher, dst, len, iv); else rem = crypto_cbc_decrypt_segment(cipher, src, dst, len, iv);
return rem && final ? -EINVAL : rem;}
static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb){ struct lskcipher_instance *inst; int err;
inst = lskcipher_alloc_instance_simple(tmpl, tb); if (IS_ERR(inst)) return PTR_ERR(inst);
err = -EINVAL; if (!is_power_of_2(inst->alg.co.base.cra_blocksize)) goto out_free_inst;
if (inst->alg.co.statesize) goto out_free_inst;
inst->alg.encrypt = crypto_cbc_encrypt; inst->alg.decrypt = crypto_cbc_decrypt;
err = lskcipher_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);}
module_init(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");