![Mikulas Patocka](/assets/img/avatar_default.png)
Change dm-crypt so that it uses auxiliary data allocated with the bio. Dm-crypt requires two allocations per request - struct dm_crypt_io and struct ablkcipher_request (with other data appended to it). It previously only used mempool allocations. Some requests may require more dm_crypt_ios and ablkcipher_requests, however most requests need just one of each of these two structures to complete. This patch changes it so that the first dm_crypt_io and ablkcipher_request are allocated with the bio (using target per_bio_data_size option). If the request needs additional values, they are allocated from the mempool. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015 lines
47 KiB
C
2015 lines
47 KiB
C
/*
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* Copyright (C) 2003 Jana Saout <jana@saout.de>
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* Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
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* Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.
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* Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
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*
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* This file is released under the GPL.
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*/
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#include <linux/completion.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/mempool.h>
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#include <linux/slab.h>
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#include <linux/crypto.h>
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#include <linux/workqueue.h>
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#include <linux/backing-dev.h>
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#include <linux/atomic.h>
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#include <linux/scatterlist.h>
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#include <asm/page.h>
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#include <asm/unaligned.h>
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#include <crypto/hash.h>
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#include <crypto/md5.h>
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#include <crypto/algapi.h>
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#include <linux/device-mapper.h>
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#define DM_MSG_PREFIX "crypt"
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/*
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* context holding the current state of a multi-part conversion
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*/
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struct convert_context {
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struct completion restart;
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struct bio *bio_in;
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struct bio *bio_out;
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struct bvec_iter iter_in;
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struct bvec_iter iter_out;
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sector_t cc_sector;
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atomic_t cc_pending;
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struct ablkcipher_request *req;
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};
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/*
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* per bio private data
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*/
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struct dm_crypt_io {
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struct crypt_config *cc;
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struct bio *base_bio;
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struct work_struct work;
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struct convert_context ctx;
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atomic_t io_pending;
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int error;
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sector_t sector;
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struct dm_crypt_io *base_io;
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} CRYPTO_MINALIGN_ATTR;
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struct dm_crypt_request {
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struct convert_context *ctx;
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struct scatterlist sg_in;
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struct scatterlist sg_out;
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sector_t iv_sector;
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};
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struct crypt_config;
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struct crypt_iv_operations {
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int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
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const char *opts);
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void (*dtr)(struct crypt_config *cc);
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int (*init)(struct crypt_config *cc);
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int (*wipe)(struct crypt_config *cc);
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int (*generator)(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq);
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int (*post)(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq);
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};
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struct iv_essiv_private {
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struct crypto_hash *hash_tfm;
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u8 *salt;
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};
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struct iv_benbi_private {
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int shift;
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};
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#define LMK_SEED_SIZE 64 /* hash + 0 */
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struct iv_lmk_private {
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struct crypto_shash *hash_tfm;
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u8 *seed;
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};
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#define TCW_WHITENING_SIZE 16
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struct iv_tcw_private {
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struct crypto_shash *crc32_tfm;
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u8 *iv_seed;
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u8 *whitening;
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};
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/*
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* Crypt: maps a linear range of a block device
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* and encrypts / decrypts at the same time.
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*/
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enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
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/*
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* The fields in here must be read only after initialization.
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*/
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struct crypt_config {
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struct dm_dev *dev;
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sector_t start;
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/*
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* pool for per bio private data, crypto requests and
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* encryption requeusts/buffer pages
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*/
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mempool_t *io_pool;
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mempool_t *req_pool;
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mempool_t *page_pool;
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struct bio_set *bs;
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struct workqueue_struct *io_queue;
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struct workqueue_struct *crypt_queue;
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char *cipher;
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char *cipher_string;
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struct crypt_iv_operations *iv_gen_ops;
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union {
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struct iv_essiv_private essiv;
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struct iv_benbi_private benbi;
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struct iv_lmk_private lmk;
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struct iv_tcw_private tcw;
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} iv_gen_private;
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sector_t iv_offset;
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unsigned int iv_size;
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/* ESSIV: struct crypto_cipher *essiv_tfm */
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void *iv_private;
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struct crypto_ablkcipher **tfms;
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unsigned tfms_count;
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/*
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* Layout of each crypto request:
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*
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* struct ablkcipher_request
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* context
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* padding
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* struct dm_crypt_request
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* padding
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* IV
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*
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* The padding is added so that dm_crypt_request and the IV are
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* correctly aligned.
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*/
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unsigned int dmreq_start;
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unsigned int per_bio_data_size;
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unsigned long flags;
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unsigned int key_size;
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unsigned int key_parts; /* independent parts in key buffer */
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unsigned int key_extra_size; /* additional keys length */
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u8 key[0];
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};
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#define MIN_IOS 16
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#define MIN_POOL_PAGES 32
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static struct kmem_cache *_crypt_io_pool;
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static void clone_init(struct dm_crypt_io *, struct bio *);
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static void kcryptd_queue_crypt(struct dm_crypt_io *io);
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static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
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/*
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* Use this to access cipher attributes that are the same for each CPU.
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*/
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static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
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{
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return cc->tfms[0];
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}
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/*
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* Different IV generation algorithms:
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*
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* plain: the initial vector is the 32-bit little-endian version of the sector
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* number, padded with zeros if necessary.
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*
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* plain64: the initial vector is the 64-bit little-endian version of the sector
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* number, padded with zeros if necessary.
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*
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* essiv: "encrypted sector|salt initial vector", the sector number is
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* encrypted with the bulk cipher using a salt as key. The salt
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* should be derived from the bulk cipher's key via hashing.
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*
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* benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
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* (needed for LRW-32-AES and possible other narrow block modes)
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*
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* null: the initial vector is always zero. Provides compatibility with
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* obsolete loop_fish2 devices. Do not use for new devices.
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*
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* lmk: Compatible implementation of the block chaining mode used
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* by the Loop-AES block device encryption system
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* designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
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* It operates on full 512 byte sectors and uses CBC
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* with an IV derived from the sector number, the data and
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* optionally extra IV seed.
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* This means that after decryption the first block
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* of sector must be tweaked according to decrypted data.
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* Loop-AES can use three encryption schemes:
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* version 1: is plain aes-cbc mode
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* version 2: uses 64 multikey scheme with lmk IV generator
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* version 3: the same as version 2 with additional IV seed
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* (it uses 65 keys, last key is used as IV seed)
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*
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* tcw: Compatible implementation of the block chaining mode used
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* by the TrueCrypt device encryption system (prior to version 4.1).
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* For more info see: http://www.truecrypt.org
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* It operates on full 512 byte sectors and uses CBC
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* with an IV derived from initial key and the sector number.
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* In addition, whitening value is applied on every sector, whitening
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* is calculated from initial key, sector number and mixed using CRC32.
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* Note that this encryption scheme is vulnerable to watermarking attacks
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* and should be used for old compatible containers access only.
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*
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* plumb: unimplemented, see:
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* http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
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*/
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static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq)
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{
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memset(iv, 0, cc->iv_size);
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*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
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return 0;
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}
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static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq)
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{
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memset(iv, 0, cc->iv_size);
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*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
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return 0;
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}
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/* Initialise ESSIV - compute salt but no local memory allocations */
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static int crypt_iv_essiv_init(struct crypt_config *cc)
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{
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struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
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struct hash_desc desc;
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struct scatterlist sg;
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struct crypto_cipher *essiv_tfm;
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int err;
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sg_init_one(&sg, cc->key, cc->key_size);
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desc.tfm = essiv->hash_tfm;
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desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
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err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
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if (err)
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return err;
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essiv_tfm = cc->iv_private;
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err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
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crypto_hash_digestsize(essiv->hash_tfm));
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if (err)
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return err;
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return 0;
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}
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/* Wipe salt and reset key derived from volume key */
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static int crypt_iv_essiv_wipe(struct crypt_config *cc)
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{
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struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
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unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
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struct crypto_cipher *essiv_tfm;
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int r, err = 0;
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memset(essiv->salt, 0, salt_size);
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essiv_tfm = cc->iv_private;
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r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
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if (r)
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err = r;
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return err;
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}
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/* Set up per cpu cipher state */
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static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
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struct dm_target *ti,
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u8 *salt, unsigned saltsize)
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{
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struct crypto_cipher *essiv_tfm;
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int err;
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/* Setup the essiv_tfm with the given salt */
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essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
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if (IS_ERR(essiv_tfm)) {
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ti->error = "Error allocating crypto tfm for ESSIV";
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return essiv_tfm;
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}
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if (crypto_cipher_blocksize(essiv_tfm) !=
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crypto_ablkcipher_ivsize(any_tfm(cc))) {
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ti->error = "Block size of ESSIV cipher does "
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"not match IV size of block cipher";
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crypto_free_cipher(essiv_tfm);
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return ERR_PTR(-EINVAL);
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}
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err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
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if (err) {
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ti->error = "Failed to set key for ESSIV cipher";
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crypto_free_cipher(essiv_tfm);
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return ERR_PTR(err);
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}
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return essiv_tfm;
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}
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static void crypt_iv_essiv_dtr(struct crypt_config *cc)
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{
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struct crypto_cipher *essiv_tfm;
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struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
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crypto_free_hash(essiv->hash_tfm);
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essiv->hash_tfm = NULL;
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kzfree(essiv->salt);
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essiv->salt = NULL;
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essiv_tfm = cc->iv_private;
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if (essiv_tfm)
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crypto_free_cipher(essiv_tfm);
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cc->iv_private = NULL;
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}
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static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
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const char *opts)
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{
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struct crypto_cipher *essiv_tfm = NULL;
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struct crypto_hash *hash_tfm = NULL;
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u8 *salt = NULL;
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int err;
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if (!opts) {
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ti->error = "Digest algorithm missing for ESSIV mode";
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return -EINVAL;
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}
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/* Allocate hash algorithm */
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hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
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if (IS_ERR(hash_tfm)) {
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ti->error = "Error initializing ESSIV hash";
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err = PTR_ERR(hash_tfm);
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goto bad;
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}
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salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
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if (!salt) {
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ti->error = "Error kmallocing salt storage in ESSIV";
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err = -ENOMEM;
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goto bad;
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}
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cc->iv_gen_private.essiv.salt = salt;
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cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
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essiv_tfm = setup_essiv_cpu(cc, ti, salt,
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crypto_hash_digestsize(hash_tfm));
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if (IS_ERR(essiv_tfm)) {
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crypt_iv_essiv_dtr(cc);
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return PTR_ERR(essiv_tfm);
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}
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cc->iv_private = essiv_tfm;
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return 0;
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bad:
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if (hash_tfm && !IS_ERR(hash_tfm))
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crypto_free_hash(hash_tfm);
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kfree(salt);
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return err;
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}
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static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq)
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{
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struct crypto_cipher *essiv_tfm = cc->iv_private;
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memset(iv, 0, cc->iv_size);
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*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
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crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
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return 0;
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}
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static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
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const char *opts)
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{
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unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
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int log = ilog2(bs);
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/* we need to calculate how far we must shift the sector count
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* to get the cipher block count, we use this shift in _gen */
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if (1 << log != bs) {
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ti->error = "cypher blocksize is not a power of 2";
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return -EINVAL;
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}
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if (log > 9) {
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ti->error = "cypher blocksize is > 512";
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return -EINVAL;
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}
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cc->iv_gen_private.benbi.shift = 9 - log;
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return 0;
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}
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static void crypt_iv_benbi_dtr(struct crypt_config *cc)
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{
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}
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static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq)
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{
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__be64 val;
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memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
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val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
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put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
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return 0;
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}
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static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
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struct dm_crypt_request *dmreq)
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{
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memset(iv, 0, cc->iv_size);
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return 0;
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}
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static void crypt_iv_lmk_dtr(struct crypt_config *cc)
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{
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struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
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if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
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crypto_free_shash(lmk->hash_tfm);
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lmk->hash_tfm = NULL;
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kzfree(lmk->seed);
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lmk->seed = NULL;
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}
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static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
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const char *opts)
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{
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struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
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lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
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if (IS_ERR(lmk->hash_tfm)) {
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ti->error = "Error initializing LMK hash";
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return PTR_ERR(lmk->hash_tfm);
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}
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/* No seed in LMK version 2 */
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if (cc->key_parts == cc->tfms_count) {
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lmk->seed = NULL;
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return 0;
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}
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lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
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if (!lmk->seed) {
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crypt_iv_lmk_dtr(cc);
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ti->error = "Error kmallocing seed storage in LMK";
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return -ENOMEM;
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}
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return 0;
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}
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static int crypt_iv_lmk_init(struct crypt_config *cc)
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{
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struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
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int subkey_size = cc->key_size / cc->key_parts;
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/* LMK seed is on the position of LMK_KEYS + 1 key */
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if (lmk->seed)
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memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
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crypto_shash_digestsize(lmk->hash_tfm));
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return 0;
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}
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|
|
static int crypt_iv_lmk_wipe(struct crypt_config *cc)
|
|
{
|
|
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
|
|
|
|
if (lmk->seed)
|
|
memset(lmk->seed, 0, LMK_SEED_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
|
|
struct dm_crypt_request *dmreq,
|
|
u8 *data)
|
|
{
|
|
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
|
|
struct {
|
|
struct shash_desc desc;
|
|
char ctx[crypto_shash_descsize(lmk->hash_tfm)];
|
|
} sdesc;
|
|
struct md5_state md5state;
|
|
__le32 buf[4];
|
|
int i, r;
|
|
|
|
sdesc.desc.tfm = lmk->hash_tfm;
|
|
sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
|
|
|
|
r = crypto_shash_init(&sdesc.desc);
|
|
if (r)
|
|
return r;
|
|
|
|
if (lmk->seed) {
|
|
r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
|
|
if (r)
|
|
return r;
|
|
}
|
|
|
|
/* Sector is always 512B, block size 16, add data of blocks 1-31 */
|
|
r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
|
|
if (r)
|
|
return r;
|
|
|
|
/* Sector is cropped to 56 bits here */
|
|
buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
|
|
buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
|
|
buf[2] = cpu_to_le32(4024);
|
|
buf[3] = 0;
|
|
r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
|
|
if (r)
|
|
return r;
|
|
|
|
/* No MD5 padding here */
|
|
r = crypto_shash_export(&sdesc.desc, &md5state);
|
|
if (r)
|
|
return r;
|
|
|
|
for (i = 0; i < MD5_HASH_WORDS; i++)
|
|
__cpu_to_le32s(&md5state.hash[i]);
|
|
memcpy(iv, &md5state.hash, cc->iv_size);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
|
|
struct dm_crypt_request *dmreq)
|
|
{
|
|
u8 *src;
|
|
int r = 0;
|
|
|
|
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
|
|
src = kmap_atomic(sg_page(&dmreq->sg_in));
|
|
r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
|
|
kunmap_atomic(src);
|
|
} else
|
|
memset(iv, 0, cc->iv_size);
|
|
|
|
return r;
|
|
}
|
|
|
|
static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
|
|
struct dm_crypt_request *dmreq)
|
|
{
|
|
u8 *dst;
|
|
int r;
|
|
|
|
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
|
|
return 0;
|
|
|
|
dst = kmap_atomic(sg_page(&dmreq->sg_out));
|
|
r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
|
|
|
|
/* Tweak the first block of plaintext sector */
|
|
if (!r)
|
|
crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
|
|
|
|
kunmap_atomic(dst);
|
|
return r;
|
|
}
|
|
|
|
static void crypt_iv_tcw_dtr(struct crypt_config *cc)
|
|
{
|
|
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
|
|
|
|
kzfree(tcw->iv_seed);
|
|
tcw->iv_seed = NULL;
|
|
kzfree(tcw->whitening);
|
|
tcw->whitening = NULL;
|
|
|
|
if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
|
|
crypto_free_shash(tcw->crc32_tfm);
|
|
tcw->crc32_tfm = NULL;
|
|
}
|
|
|
|
static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
|
|
const char *opts)
|
|
{
|
|
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
|
|
|
|
if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
|
|
ti->error = "Wrong key size for TCW";
|
|
return -EINVAL;
|
|
}
|
|
|
|
tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
|
|
if (IS_ERR(tcw->crc32_tfm)) {
|
|
ti->error = "Error initializing CRC32 in TCW";
|
|
return PTR_ERR(tcw->crc32_tfm);
|
|
}
|
|
|
|
tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
|
|
tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
|
|
if (!tcw->iv_seed || !tcw->whitening) {
|
|
crypt_iv_tcw_dtr(cc);
|
|
ti->error = "Error allocating seed storage in TCW";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_iv_tcw_init(struct crypt_config *cc)
|
|
{
|
|
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
|
|
int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
|
|
|
|
memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
|
|
memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
|
|
TCW_WHITENING_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_iv_tcw_wipe(struct crypt_config *cc)
|
|
{
|
|
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
|
|
|
|
memset(tcw->iv_seed, 0, cc->iv_size);
|
|
memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_iv_tcw_whitening(struct crypt_config *cc,
|
|
struct dm_crypt_request *dmreq,
|
|
u8 *data)
|
|
{
|
|
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
|
|
u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
|
|
u8 buf[TCW_WHITENING_SIZE];
|
|
struct {
|
|
struct shash_desc desc;
|
|
char ctx[crypto_shash_descsize(tcw->crc32_tfm)];
|
|
} sdesc;
|
|
int i, r;
|
|
|
|
/* xor whitening with sector number */
|
|
memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
|
|
crypto_xor(buf, (u8 *)§or, 8);
|
|
crypto_xor(&buf[8], (u8 *)§or, 8);
|
|
|
|
/* calculate crc32 for every 32bit part and xor it */
|
|
sdesc.desc.tfm = tcw->crc32_tfm;
|
|
sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
|
|
for (i = 0; i < 4; i++) {
|
|
r = crypto_shash_init(&sdesc.desc);
|
|
if (r)
|
|
goto out;
|
|
r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4);
|
|
if (r)
|
|
goto out;
|
|
r = crypto_shash_final(&sdesc.desc, &buf[i * 4]);
|
|
if (r)
|
|
goto out;
|
|
}
|
|
crypto_xor(&buf[0], &buf[12], 4);
|
|
crypto_xor(&buf[4], &buf[8], 4);
|
|
|
|
/* apply whitening (8 bytes) to whole sector */
|
|
for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
|
|
crypto_xor(data + i * 8, buf, 8);
|
|
out:
|
|
memset(buf, 0, sizeof(buf));
|
|
return r;
|
|
}
|
|
|
|
static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
|
|
struct dm_crypt_request *dmreq)
|
|
{
|
|
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
|
|
u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
|
|
u8 *src;
|
|
int r = 0;
|
|
|
|
/* Remove whitening from ciphertext */
|
|
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
|
|
src = kmap_atomic(sg_page(&dmreq->sg_in));
|
|
r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
|
|
kunmap_atomic(src);
|
|
}
|
|
|
|
/* Calculate IV */
|
|
memcpy(iv, tcw->iv_seed, cc->iv_size);
|
|
crypto_xor(iv, (u8 *)§or, 8);
|
|
if (cc->iv_size > 8)
|
|
crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
|
|
|
|
return r;
|
|
}
|
|
|
|
static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
|
|
struct dm_crypt_request *dmreq)
|
|
{
|
|
u8 *dst;
|
|
int r;
|
|
|
|
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
|
|
return 0;
|
|
|
|
/* Apply whitening on ciphertext */
|
|
dst = kmap_atomic(sg_page(&dmreq->sg_out));
|
|
r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
|
|
kunmap_atomic(dst);
|
|
|
|
return r;
|
|
}
|
|
|
|
static struct crypt_iv_operations crypt_iv_plain_ops = {
|
|
.generator = crypt_iv_plain_gen
|
|
};
|
|
|
|
static struct crypt_iv_operations crypt_iv_plain64_ops = {
|
|
.generator = crypt_iv_plain64_gen
|
|
};
|
|
|
|
static struct crypt_iv_operations crypt_iv_essiv_ops = {
|
|
.ctr = crypt_iv_essiv_ctr,
|
|
.dtr = crypt_iv_essiv_dtr,
|
|
.init = crypt_iv_essiv_init,
|
|
.wipe = crypt_iv_essiv_wipe,
|
|
.generator = crypt_iv_essiv_gen
|
|
};
|
|
|
|
static struct crypt_iv_operations crypt_iv_benbi_ops = {
|
|
.ctr = crypt_iv_benbi_ctr,
|
|
.dtr = crypt_iv_benbi_dtr,
|
|
.generator = crypt_iv_benbi_gen
|
|
};
|
|
|
|
static struct crypt_iv_operations crypt_iv_null_ops = {
|
|
.generator = crypt_iv_null_gen
|
|
};
|
|
|
|
static struct crypt_iv_operations crypt_iv_lmk_ops = {
|
|
.ctr = crypt_iv_lmk_ctr,
|
|
.dtr = crypt_iv_lmk_dtr,
|
|
.init = crypt_iv_lmk_init,
|
|
.wipe = crypt_iv_lmk_wipe,
|
|
.generator = crypt_iv_lmk_gen,
|
|
.post = crypt_iv_lmk_post
|
|
};
|
|
|
|
static struct crypt_iv_operations crypt_iv_tcw_ops = {
|
|
.ctr = crypt_iv_tcw_ctr,
|
|
.dtr = crypt_iv_tcw_dtr,
|
|
.init = crypt_iv_tcw_init,
|
|
.wipe = crypt_iv_tcw_wipe,
|
|
.generator = crypt_iv_tcw_gen,
|
|
.post = crypt_iv_tcw_post
|
|
};
|
|
|
|
static void crypt_convert_init(struct crypt_config *cc,
|
|
struct convert_context *ctx,
|
|
struct bio *bio_out, struct bio *bio_in,
|
|
sector_t sector)
|
|
{
|
|
ctx->bio_in = bio_in;
|
|
ctx->bio_out = bio_out;
|
|
if (bio_in)
|
|
ctx->iter_in = bio_in->bi_iter;
|
|
if (bio_out)
|
|
ctx->iter_out = bio_out->bi_iter;
|
|
ctx->cc_sector = sector + cc->iv_offset;
|
|
init_completion(&ctx->restart);
|
|
}
|
|
|
|
static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
|
|
struct ablkcipher_request *req)
|
|
{
|
|
return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
|
|
}
|
|
|
|
static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
|
|
struct dm_crypt_request *dmreq)
|
|
{
|
|
return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
|
|
}
|
|
|
|
static u8 *iv_of_dmreq(struct crypt_config *cc,
|
|
struct dm_crypt_request *dmreq)
|
|
{
|
|
return (u8 *)ALIGN((unsigned long)(dmreq + 1),
|
|
crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
|
|
}
|
|
|
|
static int crypt_convert_block(struct crypt_config *cc,
|
|
struct convert_context *ctx,
|
|
struct ablkcipher_request *req)
|
|
{
|
|
struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
|
|
struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
|
|
struct dm_crypt_request *dmreq;
|
|
u8 *iv;
|
|
int r;
|
|
|
|
dmreq = dmreq_of_req(cc, req);
|
|
iv = iv_of_dmreq(cc, dmreq);
|
|
|
|
dmreq->iv_sector = ctx->cc_sector;
|
|
dmreq->ctx = ctx;
|
|
sg_init_table(&dmreq->sg_in, 1);
|
|
sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
|
|
bv_in.bv_offset);
|
|
|
|
sg_init_table(&dmreq->sg_out, 1);
|
|
sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
|
|
bv_out.bv_offset);
|
|
|
|
bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
|
|
bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
|
|
|
|
if (cc->iv_gen_ops) {
|
|
r = cc->iv_gen_ops->generator(cc, iv, dmreq);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
|
|
1 << SECTOR_SHIFT, iv);
|
|
|
|
if (bio_data_dir(ctx->bio_in) == WRITE)
|
|
r = crypto_ablkcipher_encrypt(req);
|
|
else
|
|
r = crypto_ablkcipher_decrypt(req);
|
|
|
|
if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
|
|
r = cc->iv_gen_ops->post(cc, iv, dmreq);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void kcryptd_async_done(struct crypto_async_request *async_req,
|
|
int error);
|
|
|
|
static void crypt_alloc_req(struct crypt_config *cc,
|
|
struct convert_context *ctx)
|
|
{
|
|
unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
|
|
|
|
if (!ctx->req)
|
|
ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
|
|
|
|
ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
|
|
ablkcipher_request_set_callback(ctx->req,
|
|
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
kcryptd_async_done, dmreq_of_req(cc, ctx->req));
|
|
}
|
|
|
|
static void crypt_free_req(struct crypt_config *cc,
|
|
struct ablkcipher_request *req, struct bio *base_bio)
|
|
{
|
|
struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
|
|
|
|
if ((struct ablkcipher_request *)(io + 1) != req)
|
|
mempool_free(req, cc->req_pool);
|
|
}
|
|
|
|
/*
|
|
* Encrypt / decrypt data from one bio to another one (can be the same one)
|
|
*/
|
|
static int crypt_convert(struct crypt_config *cc,
|
|
struct convert_context *ctx)
|
|
{
|
|
int r;
|
|
|
|
atomic_set(&ctx->cc_pending, 1);
|
|
|
|
while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
|
|
|
|
crypt_alloc_req(cc, ctx);
|
|
|
|
atomic_inc(&ctx->cc_pending);
|
|
|
|
r = crypt_convert_block(cc, ctx, ctx->req);
|
|
|
|
switch (r) {
|
|
/* async */
|
|
case -EBUSY:
|
|
wait_for_completion(&ctx->restart);
|
|
reinit_completion(&ctx->restart);
|
|
/* fall through*/
|
|
case -EINPROGRESS:
|
|
ctx->req = NULL;
|
|
ctx->cc_sector++;
|
|
continue;
|
|
|
|
/* sync */
|
|
case 0:
|
|
atomic_dec(&ctx->cc_pending);
|
|
ctx->cc_sector++;
|
|
cond_resched();
|
|
continue;
|
|
|
|
/* error */
|
|
default:
|
|
atomic_dec(&ctx->cc_pending);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Generate a new unfragmented bio with the given size
|
|
* This should never violate the device limitations
|
|
* May return a smaller bio when running out of pages, indicated by
|
|
* *out_of_pages set to 1.
|
|
*/
|
|
static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
|
|
unsigned *out_of_pages)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
struct bio *clone;
|
|
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
|
|
unsigned i, len;
|
|
struct page *page;
|
|
|
|
clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
|
|
if (!clone)
|
|
return NULL;
|
|
|
|
clone_init(io, clone);
|
|
*out_of_pages = 0;
|
|
|
|
for (i = 0; i < nr_iovecs; i++) {
|
|
page = mempool_alloc(cc->page_pool, gfp_mask);
|
|
if (!page) {
|
|
*out_of_pages = 1;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If additional pages cannot be allocated without waiting,
|
|
* return a partially-allocated bio. The caller will then try
|
|
* to allocate more bios while submitting this partial bio.
|
|
*/
|
|
gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
|
|
|
|
len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
|
|
|
|
if (!bio_add_page(clone, page, len, 0)) {
|
|
mempool_free(page, cc->page_pool);
|
|
break;
|
|
}
|
|
|
|
size -= len;
|
|
}
|
|
|
|
if (!clone->bi_iter.bi_size) {
|
|
bio_put(clone);
|
|
return NULL;
|
|
}
|
|
|
|
return clone;
|
|
}
|
|
|
|
static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
|
|
{
|
|
unsigned int i;
|
|
struct bio_vec *bv;
|
|
|
|
bio_for_each_segment_all(bv, clone, i) {
|
|
BUG_ON(!bv->bv_page);
|
|
mempool_free(bv->bv_page, cc->page_pool);
|
|
bv->bv_page = NULL;
|
|
}
|
|
}
|
|
|
|
static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
|
|
struct bio *bio, sector_t sector)
|
|
{
|
|
io->cc = cc;
|
|
io->base_bio = bio;
|
|
io->sector = sector;
|
|
io->error = 0;
|
|
io->base_io = NULL;
|
|
io->ctx.req = NULL;
|
|
atomic_set(&io->io_pending, 0);
|
|
}
|
|
|
|
static void crypt_inc_pending(struct dm_crypt_io *io)
|
|
{
|
|
atomic_inc(&io->io_pending);
|
|
}
|
|
|
|
/*
|
|
* One of the bios was finished. Check for completion of
|
|
* the whole request and correctly clean up the buffer.
|
|
* If base_io is set, wait for the last fragment to complete.
|
|
*/
|
|
static void crypt_dec_pending(struct dm_crypt_io *io)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
struct bio *base_bio = io->base_bio;
|
|
struct dm_crypt_io *base_io = io->base_io;
|
|
int error = io->error;
|
|
|
|
if (!atomic_dec_and_test(&io->io_pending))
|
|
return;
|
|
|
|
if (io->ctx.req)
|
|
crypt_free_req(cc, io->ctx.req, base_bio);
|
|
if (io != dm_per_bio_data(base_bio, cc->per_bio_data_size))
|
|
mempool_free(io, cc->io_pool);
|
|
|
|
if (likely(!base_io))
|
|
bio_endio(base_bio, error);
|
|
else {
|
|
if (error && !base_io->error)
|
|
base_io->error = error;
|
|
crypt_dec_pending(base_io);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* kcryptd/kcryptd_io:
|
|
*
|
|
* Needed because it would be very unwise to do decryption in an
|
|
* interrupt context.
|
|
*
|
|
* kcryptd performs the actual encryption or decryption.
|
|
*
|
|
* kcryptd_io performs the IO submission.
|
|
*
|
|
* They must be separated as otherwise the final stages could be
|
|
* starved by new requests which can block in the first stages due
|
|
* to memory allocation.
|
|
*
|
|
* The work is done per CPU global for all dm-crypt instances.
|
|
* They should not depend on each other and do not block.
|
|
*/
|
|
static void crypt_endio(struct bio *clone, int error)
|
|
{
|
|
struct dm_crypt_io *io = clone->bi_private;
|
|
struct crypt_config *cc = io->cc;
|
|
unsigned rw = bio_data_dir(clone);
|
|
|
|
if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
|
|
error = -EIO;
|
|
|
|
/*
|
|
* free the processed pages
|
|
*/
|
|
if (rw == WRITE)
|
|
crypt_free_buffer_pages(cc, clone);
|
|
|
|
bio_put(clone);
|
|
|
|
if (rw == READ && !error) {
|
|
kcryptd_queue_crypt(io);
|
|
return;
|
|
}
|
|
|
|
if (unlikely(error))
|
|
io->error = error;
|
|
|
|
crypt_dec_pending(io);
|
|
}
|
|
|
|
static void clone_init(struct dm_crypt_io *io, struct bio *clone)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
|
|
clone->bi_private = io;
|
|
clone->bi_end_io = crypt_endio;
|
|
clone->bi_bdev = cc->dev->bdev;
|
|
clone->bi_rw = io->base_bio->bi_rw;
|
|
}
|
|
|
|
static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
struct bio *base_bio = io->base_bio;
|
|
struct bio *clone;
|
|
|
|
/*
|
|
* The block layer might modify the bvec array, so always
|
|
* copy the required bvecs because we need the original
|
|
* one in order to decrypt the whole bio data *afterwards*.
|
|
*/
|
|
clone = bio_clone_bioset(base_bio, gfp, cc->bs);
|
|
if (!clone)
|
|
return 1;
|
|
|
|
crypt_inc_pending(io);
|
|
|
|
clone_init(io, clone);
|
|
clone->bi_iter.bi_sector = cc->start + io->sector;
|
|
|
|
generic_make_request(clone);
|
|
return 0;
|
|
}
|
|
|
|
static void kcryptd_io_write(struct dm_crypt_io *io)
|
|
{
|
|
struct bio *clone = io->ctx.bio_out;
|
|
generic_make_request(clone);
|
|
}
|
|
|
|
static void kcryptd_io(struct work_struct *work)
|
|
{
|
|
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
|
|
|
|
if (bio_data_dir(io->base_bio) == READ) {
|
|
crypt_inc_pending(io);
|
|
if (kcryptd_io_read(io, GFP_NOIO))
|
|
io->error = -ENOMEM;
|
|
crypt_dec_pending(io);
|
|
} else
|
|
kcryptd_io_write(io);
|
|
}
|
|
|
|
static void kcryptd_queue_io(struct dm_crypt_io *io)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
|
|
INIT_WORK(&io->work, kcryptd_io);
|
|
queue_work(cc->io_queue, &io->work);
|
|
}
|
|
|
|
static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
|
|
{
|
|
struct bio *clone = io->ctx.bio_out;
|
|
struct crypt_config *cc = io->cc;
|
|
|
|
if (unlikely(io->error < 0)) {
|
|
crypt_free_buffer_pages(cc, clone);
|
|
bio_put(clone);
|
|
crypt_dec_pending(io);
|
|
return;
|
|
}
|
|
|
|
/* crypt_convert should have filled the clone bio */
|
|
BUG_ON(io->ctx.iter_out.bi_size);
|
|
|
|
clone->bi_iter.bi_sector = cc->start + io->sector;
|
|
|
|
if (async)
|
|
kcryptd_queue_io(io);
|
|
else
|
|
generic_make_request(clone);
|
|
}
|
|
|
|
static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
struct bio *clone;
|
|
struct dm_crypt_io *new_io;
|
|
int crypt_finished;
|
|
unsigned out_of_pages = 0;
|
|
unsigned remaining = io->base_bio->bi_iter.bi_size;
|
|
sector_t sector = io->sector;
|
|
int r;
|
|
|
|
/*
|
|
* Prevent io from disappearing until this function completes.
|
|
*/
|
|
crypt_inc_pending(io);
|
|
crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
|
|
|
|
/*
|
|
* The allocated buffers can be smaller than the whole bio,
|
|
* so repeat the whole process until all the data can be handled.
|
|
*/
|
|
while (remaining) {
|
|
clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
|
|
if (unlikely(!clone)) {
|
|
io->error = -ENOMEM;
|
|
break;
|
|
}
|
|
|
|
io->ctx.bio_out = clone;
|
|
io->ctx.iter_out = clone->bi_iter;
|
|
|
|
remaining -= clone->bi_iter.bi_size;
|
|
sector += bio_sectors(clone);
|
|
|
|
crypt_inc_pending(io);
|
|
|
|
r = crypt_convert(cc, &io->ctx);
|
|
if (r < 0)
|
|
io->error = -EIO;
|
|
|
|
crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
|
|
|
|
/* Encryption was already finished, submit io now */
|
|
if (crypt_finished) {
|
|
kcryptd_crypt_write_io_submit(io, 0);
|
|
|
|
/*
|
|
* If there was an error, do not try next fragments.
|
|
* For async, error is processed in async handler.
|
|
*/
|
|
if (unlikely(r < 0))
|
|
break;
|
|
|
|
io->sector = sector;
|
|
}
|
|
|
|
/*
|
|
* Out of memory -> run queues
|
|
* But don't wait if split was due to the io size restriction
|
|
*/
|
|
if (unlikely(out_of_pages))
|
|
congestion_wait(BLK_RW_ASYNC, HZ/100);
|
|
|
|
/*
|
|
* With async crypto it is unsafe to share the crypto context
|
|
* between fragments, so switch to a new dm_crypt_io structure.
|
|
*/
|
|
if (unlikely(!crypt_finished && remaining)) {
|
|
new_io = mempool_alloc(cc->io_pool, GFP_NOIO);
|
|
crypt_io_init(new_io, io->cc, io->base_bio, sector);
|
|
crypt_inc_pending(new_io);
|
|
crypt_convert_init(cc, &new_io->ctx, NULL,
|
|
io->base_bio, sector);
|
|
new_io->ctx.iter_in = io->ctx.iter_in;
|
|
|
|
/*
|
|
* Fragments after the first use the base_io
|
|
* pending count.
|
|
*/
|
|
if (!io->base_io)
|
|
new_io->base_io = io;
|
|
else {
|
|
new_io->base_io = io->base_io;
|
|
crypt_inc_pending(io->base_io);
|
|
crypt_dec_pending(io);
|
|
}
|
|
|
|
io = new_io;
|
|
}
|
|
}
|
|
|
|
crypt_dec_pending(io);
|
|
}
|
|
|
|
static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
|
|
{
|
|
crypt_dec_pending(io);
|
|
}
|
|
|
|
static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
int r = 0;
|
|
|
|
crypt_inc_pending(io);
|
|
|
|
crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
|
|
io->sector);
|
|
|
|
r = crypt_convert(cc, &io->ctx);
|
|
if (r < 0)
|
|
io->error = -EIO;
|
|
|
|
if (atomic_dec_and_test(&io->ctx.cc_pending))
|
|
kcryptd_crypt_read_done(io);
|
|
|
|
crypt_dec_pending(io);
|
|
}
|
|
|
|
static void kcryptd_async_done(struct crypto_async_request *async_req,
|
|
int error)
|
|
{
|
|
struct dm_crypt_request *dmreq = async_req->data;
|
|
struct convert_context *ctx = dmreq->ctx;
|
|
struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
|
|
struct crypt_config *cc = io->cc;
|
|
|
|
if (error == -EINPROGRESS) {
|
|
complete(&ctx->restart);
|
|
return;
|
|
}
|
|
|
|
if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
|
|
error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
|
|
|
|
if (error < 0)
|
|
io->error = -EIO;
|
|
|
|
crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
|
|
|
|
if (!atomic_dec_and_test(&ctx->cc_pending))
|
|
return;
|
|
|
|
if (bio_data_dir(io->base_bio) == READ)
|
|
kcryptd_crypt_read_done(io);
|
|
else
|
|
kcryptd_crypt_write_io_submit(io, 1);
|
|
}
|
|
|
|
static void kcryptd_crypt(struct work_struct *work)
|
|
{
|
|
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
|
|
|
|
if (bio_data_dir(io->base_bio) == READ)
|
|
kcryptd_crypt_read_convert(io);
|
|
else
|
|
kcryptd_crypt_write_convert(io);
|
|
}
|
|
|
|
static void kcryptd_queue_crypt(struct dm_crypt_io *io)
|
|
{
|
|
struct crypt_config *cc = io->cc;
|
|
|
|
INIT_WORK(&io->work, kcryptd_crypt);
|
|
queue_work(cc->crypt_queue, &io->work);
|
|
}
|
|
|
|
/*
|
|
* Decode key from its hex representation
|
|
*/
|
|
static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
|
|
{
|
|
char buffer[3];
|
|
unsigned int i;
|
|
|
|
buffer[2] = '\0';
|
|
|
|
for (i = 0; i < size; i++) {
|
|
buffer[0] = *hex++;
|
|
buffer[1] = *hex++;
|
|
|
|
if (kstrtou8(buffer, 16, &key[i]))
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (*hex != '\0')
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void crypt_free_tfms(struct crypt_config *cc)
|
|
{
|
|
unsigned i;
|
|
|
|
if (!cc->tfms)
|
|
return;
|
|
|
|
for (i = 0; i < cc->tfms_count; i++)
|
|
if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
|
|
crypto_free_ablkcipher(cc->tfms[i]);
|
|
cc->tfms[i] = NULL;
|
|
}
|
|
|
|
kfree(cc->tfms);
|
|
cc->tfms = NULL;
|
|
}
|
|
|
|
static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
|
|
{
|
|
unsigned i;
|
|
int err;
|
|
|
|
cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *),
|
|
GFP_KERNEL);
|
|
if (!cc->tfms)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < cc->tfms_count; i++) {
|
|
cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
|
|
if (IS_ERR(cc->tfms[i])) {
|
|
err = PTR_ERR(cc->tfms[i]);
|
|
crypt_free_tfms(cc);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int crypt_setkey_allcpus(struct crypt_config *cc)
|
|
{
|
|
unsigned subkey_size;
|
|
int err = 0, i, r;
|
|
|
|
/* Ignore extra keys (which are used for IV etc) */
|
|
subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
|
|
|
|
for (i = 0; i < cc->tfms_count; i++) {
|
|
r = crypto_ablkcipher_setkey(cc->tfms[i],
|
|
cc->key + (i * subkey_size),
|
|
subkey_size);
|
|
if (r)
|
|
err = r;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int crypt_set_key(struct crypt_config *cc, char *key)
|
|
{
|
|
int r = -EINVAL;
|
|
int key_string_len = strlen(key);
|
|
|
|
/* The key size may not be changed. */
|
|
if (cc->key_size != (key_string_len >> 1))
|
|
goto out;
|
|
|
|
/* Hyphen (which gives a key_size of zero) means there is no key. */
|
|
if (!cc->key_size && strcmp(key, "-"))
|
|
goto out;
|
|
|
|
if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
|
|
goto out;
|
|
|
|
set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
|
|
|
|
r = crypt_setkey_allcpus(cc);
|
|
|
|
out:
|
|
/* Hex key string not needed after here, so wipe it. */
|
|
memset(key, '0', key_string_len);
|
|
|
|
return r;
|
|
}
|
|
|
|
static int crypt_wipe_key(struct crypt_config *cc)
|
|
{
|
|
clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
|
|
memset(&cc->key, 0, cc->key_size * sizeof(u8));
|
|
|
|
return crypt_setkey_allcpus(cc);
|
|
}
|
|
|
|
static void crypt_dtr(struct dm_target *ti)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
|
|
ti->private = NULL;
|
|
|
|
if (!cc)
|
|
return;
|
|
|
|
if (cc->io_queue)
|
|
destroy_workqueue(cc->io_queue);
|
|
if (cc->crypt_queue)
|
|
destroy_workqueue(cc->crypt_queue);
|
|
|
|
crypt_free_tfms(cc);
|
|
|
|
if (cc->bs)
|
|
bioset_free(cc->bs);
|
|
|
|
if (cc->page_pool)
|
|
mempool_destroy(cc->page_pool);
|
|
if (cc->req_pool)
|
|
mempool_destroy(cc->req_pool);
|
|
if (cc->io_pool)
|
|
mempool_destroy(cc->io_pool);
|
|
|
|
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
|
|
cc->iv_gen_ops->dtr(cc);
|
|
|
|
if (cc->dev)
|
|
dm_put_device(ti, cc->dev);
|
|
|
|
kzfree(cc->cipher);
|
|
kzfree(cc->cipher_string);
|
|
|
|
/* Must zero key material before freeing */
|
|
kzfree(cc);
|
|
}
|
|
|
|
static int crypt_ctr_cipher(struct dm_target *ti,
|
|
char *cipher_in, char *key)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
|
|
char *cipher_api = NULL;
|
|
int ret = -EINVAL;
|
|
char dummy;
|
|
|
|
/* Convert to crypto api definition? */
|
|
if (strchr(cipher_in, '(')) {
|
|
ti->error = "Bad cipher specification";
|
|
return -EINVAL;
|
|
}
|
|
|
|
cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
|
|
if (!cc->cipher_string)
|
|
goto bad_mem;
|
|
|
|
/*
|
|
* Legacy dm-crypt cipher specification
|
|
* cipher[:keycount]-mode-iv:ivopts
|
|
*/
|
|
tmp = cipher_in;
|
|
keycount = strsep(&tmp, "-");
|
|
cipher = strsep(&keycount, ":");
|
|
|
|
if (!keycount)
|
|
cc->tfms_count = 1;
|
|
else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
|
|
!is_power_of_2(cc->tfms_count)) {
|
|
ti->error = "Bad cipher key count specification";
|
|
return -EINVAL;
|
|
}
|
|
cc->key_parts = cc->tfms_count;
|
|
cc->key_extra_size = 0;
|
|
|
|
cc->cipher = kstrdup(cipher, GFP_KERNEL);
|
|
if (!cc->cipher)
|
|
goto bad_mem;
|
|
|
|
chainmode = strsep(&tmp, "-");
|
|
ivopts = strsep(&tmp, "-");
|
|
ivmode = strsep(&ivopts, ":");
|
|
|
|
if (tmp)
|
|
DMWARN("Ignoring unexpected additional cipher options");
|
|
|
|
/*
|
|
* For compatibility with the original dm-crypt mapping format, if
|
|
* only the cipher name is supplied, use cbc-plain.
|
|
*/
|
|
if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
|
|
chainmode = "cbc";
|
|
ivmode = "plain";
|
|
}
|
|
|
|
if (strcmp(chainmode, "ecb") && !ivmode) {
|
|
ti->error = "IV mechanism required";
|
|
return -EINVAL;
|
|
}
|
|
|
|
cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
|
|
if (!cipher_api)
|
|
goto bad_mem;
|
|
|
|
ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
|
|
"%s(%s)", chainmode, cipher);
|
|
if (ret < 0) {
|
|
kfree(cipher_api);
|
|
goto bad_mem;
|
|
}
|
|
|
|
/* Allocate cipher */
|
|
ret = crypt_alloc_tfms(cc, cipher_api);
|
|
if (ret < 0) {
|
|
ti->error = "Error allocating crypto tfm";
|
|
goto bad;
|
|
}
|
|
|
|
/* Initialize IV */
|
|
cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
|
|
if (cc->iv_size)
|
|
/* at least a 64 bit sector number should fit in our buffer */
|
|
cc->iv_size = max(cc->iv_size,
|
|
(unsigned int)(sizeof(u64) / sizeof(u8)));
|
|
else if (ivmode) {
|
|
DMWARN("Selected cipher does not support IVs");
|
|
ivmode = NULL;
|
|
}
|
|
|
|
/* Choose ivmode, see comments at iv code. */
|
|
if (ivmode == NULL)
|
|
cc->iv_gen_ops = NULL;
|
|
else if (strcmp(ivmode, "plain") == 0)
|
|
cc->iv_gen_ops = &crypt_iv_plain_ops;
|
|
else if (strcmp(ivmode, "plain64") == 0)
|
|
cc->iv_gen_ops = &crypt_iv_plain64_ops;
|
|
else if (strcmp(ivmode, "essiv") == 0)
|
|
cc->iv_gen_ops = &crypt_iv_essiv_ops;
|
|
else if (strcmp(ivmode, "benbi") == 0)
|
|
cc->iv_gen_ops = &crypt_iv_benbi_ops;
|
|
else if (strcmp(ivmode, "null") == 0)
|
|
cc->iv_gen_ops = &crypt_iv_null_ops;
|
|
else if (strcmp(ivmode, "lmk") == 0) {
|
|
cc->iv_gen_ops = &crypt_iv_lmk_ops;
|
|
/*
|
|
* Version 2 and 3 is recognised according
|
|
* to length of provided multi-key string.
|
|
* If present (version 3), last key is used as IV seed.
|
|
* All keys (including IV seed) are always the same size.
|
|
*/
|
|
if (cc->key_size % cc->key_parts) {
|
|
cc->key_parts++;
|
|
cc->key_extra_size = cc->key_size / cc->key_parts;
|
|
}
|
|
} else if (strcmp(ivmode, "tcw") == 0) {
|
|
cc->iv_gen_ops = &crypt_iv_tcw_ops;
|
|
cc->key_parts += 2; /* IV + whitening */
|
|
cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
|
|
} else {
|
|
ret = -EINVAL;
|
|
ti->error = "Invalid IV mode";
|
|
goto bad;
|
|
}
|
|
|
|
/* Initialize and set key */
|
|
ret = crypt_set_key(cc, key);
|
|
if (ret < 0) {
|
|
ti->error = "Error decoding and setting key";
|
|
goto bad;
|
|
}
|
|
|
|
/* Allocate IV */
|
|
if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
|
|
ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
|
|
if (ret < 0) {
|
|
ti->error = "Error creating IV";
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
/* Initialize IV (set keys for ESSIV etc) */
|
|
if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
|
|
ret = cc->iv_gen_ops->init(cc);
|
|
if (ret < 0) {
|
|
ti->error = "Error initialising IV";
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
bad:
|
|
kfree(cipher_api);
|
|
return ret;
|
|
|
|
bad_mem:
|
|
ti->error = "Cannot allocate cipher strings";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* Construct an encryption mapping:
|
|
* <cipher> <key> <iv_offset> <dev_path> <start>
|
|
*/
|
|
static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
|
|
{
|
|
struct crypt_config *cc;
|
|
unsigned int key_size, opt_params;
|
|
unsigned long long tmpll;
|
|
int ret;
|
|
struct dm_arg_set as;
|
|
const char *opt_string;
|
|
char dummy;
|
|
|
|
static struct dm_arg _args[] = {
|
|
{0, 1, "Invalid number of feature args"},
|
|
};
|
|
|
|
if (argc < 5) {
|
|
ti->error = "Not enough arguments";
|
|
return -EINVAL;
|
|
}
|
|
|
|
key_size = strlen(argv[1]) >> 1;
|
|
|
|
cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
|
|
if (!cc) {
|
|
ti->error = "Cannot allocate encryption context";
|
|
return -ENOMEM;
|
|
}
|
|
cc->key_size = key_size;
|
|
|
|
ti->private = cc;
|
|
ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
|
|
if (ret < 0)
|
|
goto bad;
|
|
|
|
ret = -ENOMEM;
|
|
cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
|
|
if (!cc->io_pool) {
|
|
ti->error = "Cannot allocate crypt io mempool";
|
|
goto bad;
|
|
}
|
|
|
|
cc->dmreq_start = sizeof(struct ablkcipher_request);
|
|
cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
|
|
cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
|
|
cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) &
|
|
~(crypto_tfm_ctx_alignment() - 1);
|
|
|
|
cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
|
|
sizeof(struct dm_crypt_request) + cc->iv_size);
|
|
if (!cc->req_pool) {
|
|
ti->error = "Cannot allocate crypt request mempool";
|
|
goto bad;
|
|
}
|
|
|
|
cc->per_bio_data_size = ti->per_bio_data_size =
|
|
sizeof(struct dm_crypt_io) + cc->dmreq_start +
|
|
sizeof(struct dm_crypt_request) + cc->iv_size;
|
|
|
|
cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
|
|
if (!cc->page_pool) {
|
|
ti->error = "Cannot allocate page mempool";
|
|
goto bad;
|
|
}
|
|
|
|
cc->bs = bioset_create(MIN_IOS, 0);
|
|
if (!cc->bs) {
|
|
ti->error = "Cannot allocate crypt bioset";
|
|
goto bad;
|
|
}
|
|
|
|
ret = -EINVAL;
|
|
if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
|
|
ti->error = "Invalid iv_offset sector";
|
|
goto bad;
|
|
}
|
|
cc->iv_offset = tmpll;
|
|
|
|
if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
|
|
ti->error = "Device lookup failed";
|
|
goto bad;
|
|
}
|
|
|
|
if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
|
|
ti->error = "Invalid device sector";
|
|
goto bad;
|
|
}
|
|
cc->start = tmpll;
|
|
|
|
argv += 5;
|
|
argc -= 5;
|
|
|
|
/* Optional parameters */
|
|
if (argc) {
|
|
as.argc = argc;
|
|
as.argv = argv;
|
|
|
|
ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
|
|
if (ret)
|
|
goto bad;
|
|
|
|
opt_string = dm_shift_arg(&as);
|
|
|
|
if (opt_params == 1 && opt_string &&
|
|
!strcasecmp(opt_string, "allow_discards"))
|
|
ti->num_discard_bios = 1;
|
|
else if (opt_params) {
|
|
ret = -EINVAL;
|
|
ti->error = "Invalid feature arguments";
|
|
goto bad;
|
|
}
|
|
}
|
|
|
|
ret = -ENOMEM;
|
|
cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
|
|
if (!cc->io_queue) {
|
|
ti->error = "Couldn't create kcryptd io queue";
|
|
goto bad;
|
|
}
|
|
|
|
cc->crypt_queue = alloc_workqueue("kcryptd",
|
|
WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
|
|
if (!cc->crypt_queue) {
|
|
ti->error = "Couldn't create kcryptd queue";
|
|
goto bad;
|
|
}
|
|
|
|
ti->num_flush_bios = 1;
|
|
ti->discard_zeroes_data_unsupported = true;
|
|
|
|
return 0;
|
|
|
|
bad:
|
|
crypt_dtr(ti);
|
|
return ret;
|
|
}
|
|
|
|
static int crypt_map(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct dm_crypt_io *io;
|
|
struct crypt_config *cc = ti->private;
|
|
|
|
/*
|
|
* If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
|
|
* - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
|
|
* - for REQ_DISCARD caller must use flush if IO ordering matters
|
|
*/
|
|
if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
|
|
bio->bi_bdev = cc->dev->bdev;
|
|
if (bio_sectors(bio))
|
|
bio->bi_iter.bi_sector = cc->start +
|
|
dm_target_offset(ti, bio->bi_iter.bi_sector);
|
|
return DM_MAPIO_REMAPPED;
|
|
}
|
|
|
|
io = dm_per_bio_data(bio, cc->per_bio_data_size);
|
|
crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
|
|
io->ctx.req = (struct ablkcipher_request *)(io + 1);
|
|
|
|
if (bio_data_dir(io->base_bio) == READ) {
|
|
if (kcryptd_io_read(io, GFP_NOWAIT))
|
|
kcryptd_queue_io(io);
|
|
} else
|
|
kcryptd_queue_crypt(io);
|
|
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
static void crypt_status(struct dm_target *ti, status_type_t type,
|
|
unsigned status_flags, char *result, unsigned maxlen)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
unsigned i, sz = 0;
|
|
|
|
switch (type) {
|
|
case STATUSTYPE_INFO:
|
|
result[0] = '\0';
|
|
break;
|
|
|
|
case STATUSTYPE_TABLE:
|
|
DMEMIT("%s ", cc->cipher_string);
|
|
|
|
if (cc->key_size > 0)
|
|
for (i = 0; i < cc->key_size; i++)
|
|
DMEMIT("%02x", cc->key[i]);
|
|
else
|
|
DMEMIT("-");
|
|
|
|
DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
|
|
cc->dev->name, (unsigned long long)cc->start);
|
|
|
|
if (ti->num_discard_bios)
|
|
DMEMIT(" 1 allow_discards");
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void crypt_postsuspend(struct dm_target *ti)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
|
|
set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
|
|
}
|
|
|
|
static int crypt_preresume(struct dm_target *ti)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
|
|
if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
|
|
DMERR("aborting resume - crypt key is not set.");
|
|
return -EAGAIN;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void crypt_resume(struct dm_target *ti)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
|
|
clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
|
|
}
|
|
|
|
/* Message interface
|
|
* key set <key>
|
|
* key wipe
|
|
*/
|
|
static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
int ret = -EINVAL;
|
|
|
|
if (argc < 2)
|
|
goto error;
|
|
|
|
if (!strcasecmp(argv[0], "key")) {
|
|
if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
|
|
DMWARN("not suspended during key manipulation.");
|
|
return -EINVAL;
|
|
}
|
|
if (argc == 3 && !strcasecmp(argv[1], "set")) {
|
|
ret = crypt_set_key(cc, argv[2]);
|
|
if (ret)
|
|
return ret;
|
|
if (cc->iv_gen_ops && cc->iv_gen_ops->init)
|
|
ret = cc->iv_gen_ops->init(cc);
|
|
return ret;
|
|
}
|
|
if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
|
|
if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
|
|
ret = cc->iv_gen_ops->wipe(cc);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
return crypt_wipe_key(cc);
|
|
}
|
|
}
|
|
|
|
error:
|
|
DMWARN("unrecognised message received.");
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
|
|
struct bio_vec *biovec, int max_size)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
struct request_queue *q = bdev_get_queue(cc->dev->bdev);
|
|
|
|
if (!q->merge_bvec_fn)
|
|
return max_size;
|
|
|
|
bvm->bi_bdev = cc->dev->bdev;
|
|
bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
|
|
|
|
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
|
|
}
|
|
|
|
static int crypt_iterate_devices(struct dm_target *ti,
|
|
iterate_devices_callout_fn fn, void *data)
|
|
{
|
|
struct crypt_config *cc = ti->private;
|
|
|
|
return fn(ti, cc->dev, cc->start, ti->len, data);
|
|
}
|
|
|
|
static struct target_type crypt_target = {
|
|
.name = "crypt",
|
|
.version = {1, 13, 0},
|
|
.module = THIS_MODULE,
|
|
.ctr = crypt_ctr,
|
|
.dtr = crypt_dtr,
|
|
.map = crypt_map,
|
|
.status = crypt_status,
|
|
.postsuspend = crypt_postsuspend,
|
|
.preresume = crypt_preresume,
|
|
.resume = crypt_resume,
|
|
.message = crypt_message,
|
|
.merge = crypt_merge,
|
|
.iterate_devices = crypt_iterate_devices,
|
|
};
|
|
|
|
static int __init dm_crypt_init(void)
|
|
{
|
|
int r;
|
|
|
|
_crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
|
|
if (!_crypt_io_pool)
|
|
return -ENOMEM;
|
|
|
|
r = dm_register_target(&crypt_target);
|
|
if (r < 0) {
|
|
DMERR("register failed %d", r);
|
|
kmem_cache_destroy(_crypt_io_pool);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
static void __exit dm_crypt_exit(void)
|
|
{
|
|
dm_unregister_target(&crypt_target);
|
|
kmem_cache_destroy(_crypt_io_pool);
|
|
}
|
|
|
|
module_init(dm_crypt_init);
|
|
module_exit(dm_crypt_exit);
|
|
|
|
MODULE_AUTHOR("Jana Saout <jana@saout.de>");
|
|
MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
|
|
MODULE_LICENSE("GPL");
|