| /* |
| * Copyright (C) 2003 Jana Saout <jana@saout.de> |
| * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> |
| * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. |
| * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com> |
| * |
| * This file is released under the GPL. |
| */ |
| |
| #include <linux/completion.h> |
| #include <linux/err.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/bio.h> |
| #include <linux/blkdev.h> |
| #include <linux/mempool.h> |
| #include <linux/slab.h> |
| #include <linux/crypto.h> |
| #include <linux/workqueue.h> |
| #include <linux/kthread.h> |
| #include <linux/backing-dev.h> |
| #include <linux/atomic.h> |
| #include <linux/scatterlist.h> |
| #include <linux/rbtree.h> |
| #include <asm/page.h> |
| #include <asm/unaligned.h> |
| #include <crypto/hash.h> |
| #include <crypto/md5.h> |
| #include <crypto/algapi.h> |
| |
| #include <linux/device-mapper.h> |
| |
| #define DM_MSG_PREFIX "crypt" |
| |
| /* |
| * context holding the current state of a multi-part conversion |
| */ |
| struct convert_context { |
| struct completion restart; |
| struct bio *bio_in; |
| struct bio *bio_out; |
| struct bvec_iter iter_in; |
| struct bvec_iter iter_out; |
| sector_t cc_sector; |
| atomic_t cc_pending; |
| struct ablkcipher_request *req; |
| }; |
| |
| /* |
| * per bio private data |
| */ |
| struct dm_crypt_io { |
| struct crypt_config *cc; |
| struct bio *base_bio; |
| struct work_struct work; |
| |
| struct convert_context ctx; |
| |
| atomic_t io_pending; |
| int error; |
| sector_t sector; |
| |
| struct rb_node rb_node; |
| } CRYPTO_MINALIGN_ATTR; |
| |
| struct dm_crypt_request { |
| struct convert_context *ctx; |
| struct scatterlist sg_in; |
| struct scatterlist sg_out; |
| sector_t iv_sector; |
| }; |
| |
| struct crypt_config; |
| |
| struct crypt_iv_operations { |
| int (*ctr)(struct crypt_config *cc, struct dm_target *ti, |
| const char *opts); |
| void (*dtr)(struct crypt_config *cc); |
| int (*init)(struct crypt_config *cc); |
| int (*wipe)(struct crypt_config *cc); |
| int (*generator)(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq); |
| int (*post)(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq); |
| }; |
| |
| struct iv_essiv_private { |
| struct crypto_hash *hash_tfm; |
| u8 *salt; |
| }; |
| |
| struct iv_benbi_private { |
| int shift; |
| }; |
| |
| #define LMK_SEED_SIZE 64 /* hash + 0 */ |
| struct iv_lmk_private { |
| struct crypto_shash *hash_tfm; |
| u8 *seed; |
| }; |
| |
| #define TCW_WHITENING_SIZE 16 |
| struct iv_tcw_private { |
| struct crypto_shash *crc32_tfm; |
| u8 *iv_seed; |
| u8 *whitening; |
| }; |
| |
| /* |
| * Crypt: maps a linear range of a block device |
| * and encrypts / decrypts at the same time. |
| */ |
| enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, |
| DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD }; |
| |
| /* |
| * The fields in here must be read only after initialization. |
| */ |
| struct crypt_config { |
| struct dm_dev *dev; |
| sector_t start; |
| |
| /* |
| * pool for per bio private data, crypto requests and |
| * encryption requeusts/buffer pages |
| */ |
| mempool_t *req_pool; |
| mempool_t *page_pool; |
| struct bio_set *bs; |
| struct mutex bio_alloc_lock; |
| |
| struct workqueue_struct *io_queue; |
| struct workqueue_struct *crypt_queue; |
| |
| struct task_struct *write_thread; |
| wait_queue_head_t write_thread_wait; |
| struct rb_root write_tree; |
| |
| char *cipher; |
| char *cipher_string; |
| |
| struct crypt_iv_operations *iv_gen_ops; |
| union { |
| struct iv_essiv_private essiv; |
| struct iv_benbi_private benbi; |
| struct iv_lmk_private lmk; |
| struct iv_tcw_private tcw; |
| } iv_gen_private; |
| sector_t iv_offset; |
| unsigned int iv_size; |
| |
| /* ESSIV: struct crypto_cipher *essiv_tfm */ |
| void *iv_private; |
| struct crypto_ablkcipher **tfms; |
| unsigned tfms_count; |
| |
| /* |
| * Layout of each crypto request: |
| * |
| * struct ablkcipher_request |
| * context |
| * padding |
| * struct dm_crypt_request |
| * padding |
| * IV |
| * |
| * The padding is added so that dm_crypt_request and the IV are |
| * correctly aligned. |
| */ |
| unsigned int dmreq_start; |
| |
| unsigned int per_bio_data_size; |
| |
| unsigned long flags; |
| unsigned int key_size; |
| unsigned int key_parts; /* independent parts in key buffer */ |
| unsigned int key_extra_size; /* additional keys length */ |
| u8 key[0]; |
| }; |
| |
| #define MIN_IOS 16 |
| |
| static void clone_init(struct dm_crypt_io *, struct bio *); |
| static void kcryptd_queue_crypt(struct dm_crypt_io *io); |
| static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq); |
| |
| /* |
| * Use this to access cipher attributes that are the same for each CPU. |
| */ |
| static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc) |
| { |
| return cc->tfms[0]; |
| } |
| |
| /* |
| * Different IV generation algorithms: |
| * |
| * plain: the initial vector is the 32-bit little-endian version of the sector |
| * number, padded with zeros if necessary. |
| * |
| * plain64: the initial vector is the 64-bit little-endian version of the sector |
| * number, padded with zeros if necessary. |
| * |
| * essiv: "encrypted sector|salt initial vector", the sector number is |
| * encrypted with the bulk cipher using a salt as key. The salt |
| * should be derived from the bulk cipher's key via hashing. |
| * |
| * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 |
| * (needed for LRW-32-AES and possible other narrow block modes) |
| * |
| * null: the initial vector is always zero. Provides compatibility with |
| * obsolete loop_fish2 devices. Do not use for new devices. |
| * |
| * lmk: Compatible implementation of the block chaining mode used |
| * by the Loop-AES block device encryption system |
| * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ |
| * It operates on full 512 byte sectors and uses CBC |
| * with an IV derived from the sector number, the data and |
| * optionally extra IV seed. |
| * This means that after decryption the first block |
| * of sector must be tweaked according to decrypted data. |
| * Loop-AES can use three encryption schemes: |
| * version 1: is plain aes-cbc mode |
| * version 2: uses 64 multikey scheme with lmk IV generator |
| * version 3: the same as version 2 with additional IV seed |
| * (it uses 65 keys, last key is used as IV seed) |
| * |
| * tcw: Compatible implementation of the block chaining mode used |
| * by the TrueCrypt device encryption system (prior to version 4.1). |
| * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat |
| * It operates on full 512 byte sectors and uses CBC |
| * with an IV derived from initial key and the sector number. |
| * In addition, whitening value is applied on every sector, whitening |
| * is calculated from initial key, sector number and mixed using CRC32. |
| * Note that this encryption scheme is vulnerable to watermarking attacks |
| * and should be used for old compatible containers access only. |
| * |
| * plumb: unimplemented, see: |
| * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 |
| */ |
| |
| static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq) |
| { |
| memset(iv, 0, cc->iv_size); |
| *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); |
| |
| return 0; |
| } |
| |
| static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq) |
| { |
| memset(iv, 0, cc->iv_size); |
| *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); |
| |
| return 0; |
| } |
| |
| /* Initialise ESSIV - compute salt but no local memory allocations */ |
| static int crypt_iv_essiv_init(struct crypt_config *cc) |
| { |
| struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; |
| struct hash_desc desc; |
| struct scatterlist sg; |
| struct crypto_cipher *essiv_tfm; |
| int err; |
| |
| sg_init_one(&sg, cc->key, cc->key_size); |
| desc.tfm = essiv->hash_tfm; |
| desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| |
| err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt); |
| if (err) |
| return err; |
| |
| essiv_tfm = cc->iv_private; |
| |
| err = crypto_cipher_setkey(essiv_tfm, essiv->salt, |
| crypto_hash_digestsize(essiv->hash_tfm)); |
| if (err) |
| return err; |
| |
| return 0; |
| } |
| |
| /* Wipe salt and reset key derived from volume key */ |
| static int crypt_iv_essiv_wipe(struct crypt_config *cc) |
| { |
| struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; |
| unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm); |
| struct crypto_cipher *essiv_tfm; |
| int r, err = 0; |
| |
| memset(essiv->salt, 0, salt_size); |
| |
| essiv_tfm = cc->iv_private; |
| r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size); |
| if (r) |
| err = r; |
| |
| return err; |
| } |
| |
| /* Set up per cpu cipher state */ |
| static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc, |
| struct dm_target *ti, |
| u8 *salt, unsigned saltsize) |
| { |
| struct crypto_cipher *essiv_tfm; |
| int err; |
| |
| /* Setup the essiv_tfm with the given salt */ |
| essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
| if (IS_ERR(essiv_tfm)) { |
| ti->error = "Error allocating crypto tfm for ESSIV"; |
| return essiv_tfm; |
| } |
| |
| if (crypto_cipher_blocksize(essiv_tfm) != |
| crypto_ablkcipher_ivsize(any_tfm(cc))) { |
| ti->error = "Block size of ESSIV cipher does " |
| "not match IV size of block cipher"; |
| crypto_free_cipher(essiv_tfm); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); |
| if (err) { |
| ti->error = "Failed to set key for ESSIV cipher"; |
| crypto_free_cipher(essiv_tfm); |
| return ERR_PTR(err); |
| } |
| |
| return essiv_tfm; |
| } |
| |
| static void crypt_iv_essiv_dtr(struct crypt_config *cc) |
| { |
| struct crypto_cipher *essiv_tfm; |
| struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; |
| |
| crypto_free_hash(essiv->hash_tfm); |
| essiv->hash_tfm = NULL; |
| |
| kzfree(essiv->salt); |
| essiv->salt = NULL; |
| |
| essiv_tfm = cc->iv_private; |
| |
| if (essiv_tfm) |
| crypto_free_cipher(essiv_tfm); |
| |
| cc->iv_private = NULL; |
| } |
| |
| static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, |
| const char *opts) |
| { |
| struct crypto_cipher *essiv_tfm = NULL; |
| struct crypto_hash *hash_tfm = NULL; |
| u8 *salt = NULL; |
| int err; |
| |
| if (!opts) { |
| ti->error = "Digest algorithm missing for ESSIV mode"; |
| return -EINVAL; |
| } |
| |
| /* Allocate hash algorithm */ |
| hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); |
| if (IS_ERR(hash_tfm)) { |
| ti->error = "Error initializing ESSIV hash"; |
| err = PTR_ERR(hash_tfm); |
| goto bad; |
| } |
| |
| salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL); |
| if (!salt) { |
| ti->error = "Error kmallocing salt storage in ESSIV"; |
| err = -ENOMEM; |
| goto bad; |
| } |
| |
| cc->iv_gen_private.essiv.salt = salt; |
| cc->iv_gen_private.essiv.hash_tfm = hash_tfm; |
| |
| essiv_tfm = setup_essiv_cpu(cc, ti, salt, |
| crypto_hash_digestsize(hash_tfm)); |
| if (IS_ERR(essiv_tfm)) { |
| crypt_iv_essiv_dtr(cc); |
| return PTR_ERR(essiv_tfm); |
| } |
| cc->iv_private = essiv_tfm; |
| |
| return 0; |
| |
| bad: |
| if (hash_tfm && !IS_ERR(hash_tfm)) |
| crypto_free_hash(hash_tfm); |
| kfree(salt); |
| return err; |
| } |
| |
| static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq) |
| { |
| struct crypto_cipher *essiv_tfm = cc->iv_private; |
| |
| memset(iv, 0, cc->iv_size); |
| *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); |
| crypto_cipher_encrypt_one(essiv_tfm, iv, iv); |
| |
| return 0; |
| } |
| |
| static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, |
| const char *opts) |
| { |
| unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc)); |
| int log = ilog2(bs); |
| |
| /* we need to calculate how far we must shift the sector count |
| * to get the cipher block count, we use this shift in _gen */ |
| |
| if (1 << log != bs) { |
| ti->error = "cypher blocksize is not a power of 2"; |
| return -EINVAL; |
| } |
| |
| if (log > 9) { |
| ti->error = "cypher blocksize is > 512"; |
| return -EINVAL; |
| } |
| |
| cc->iv_gen_private.benbi.shift = 9 - log; |
| |
| return 0; |
| } |
| |
| static void crypt_iv_benbi_dtr(struct crypt_config *cc) |
| { |
| } |
| |
| static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq) |
| { |
| __be64 val; |
| |
| memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ |
| |
| val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); |
| put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); |
| |
| return 0; |
| } |
| |
| static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, |
| struct dm_crypt_request *dmreq) |
| { |
| memset(iv, 0, cc->iv_size); |
| |
| return 0; |
| } |
| |
| static void crypt_iv_lmk_dtr(struct crypt_config *cc) |
| { |
| struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| |
| if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) |
| crypto_free_shash(lmk->hash_tfm); |
| lmk->hash_tfm = NULL; |
| |
| kzfree(lmk->seed); |
| lmk->seed = NULL; |
| } |
| |
| static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, |
| const char *opts) |
| { |
| struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| |
| lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); |
| if (IS_ERR(lmk->hash_tfm)) { |
| ti->error = "Error initializing LMK hash"; |
| return PTR_ERR(lmk->hash_tfm); |
| } |
| |
| /* No seed in LMK version 2 */ |
| if (cc->key_parts == cc->tfms_count) { |
| lmk->seed = NULL; |
| return 0; |
| } |
| |
| lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); |
| if (!lmk->seed) { |
| crypt_iv_lmk_dtr(cc); |
| ti->error = "Error kmallocing seed storage in LMK"; |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static int crypt_iv_lmk_init(struct crypt_config *cc) |
| { |
| struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| int subkey_size = cc->key_size / cc->key_parts; |
| |
| /* LMK seed is on the position of LMK_KEYS + 1 key */ |
| if (lmk->seed) |
| memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), |
| crypto_shash_digestsize(lmk->hash_tfm)); |
| |
| return 0; |
| } |
| |
| 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; |
| SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); |
| struct md5_state md5state; |
| __le32 buf[4]; |
| int i, r; |
| |
| desc->tfm = lmk->hash_tfm; |
| desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| |
| r = crypto_shash_init(desc); |
| if (r) |
| return r; |
| |
| if (lmk->seed) { |
| r = crypto_shash_update(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(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(desc, (u8 *)buf, sizeof(buf)); |
| if (r) |
| return r; |
| |
| /* No MD5 padding here */ |
| r = crypto_shash_export(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]; |
| SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); |
| 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 */ |
| desc->tfm = tcw->crc32_tfm; |
| desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| for (i = 0; i < 4; i++) { |
| r = crypto_shash_init(desc); |
| if (r) |
| goto out; |
| r = crypto_shash_update(desc, &buf[i * 4], 4); |
| if (r) |
| goto out; |
| r = crypto_shash_final(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: |
| memzero_explicit(buf, 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; |
| } |
| |
| static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); |
| |
| /* |
| * Generate a new unfragmented bio with the given size |
| * This should never violate the device limitations (but only because |
| * max_segment_size is being constrained to PAGE_SIZE). |
| * |
| * This function may be called concurrently. If we allocate from the mempool |
| * concurrently, there is a possibility of deadlock. For example, if we have |
| * mempool of 256 pages, two processes, each wanting 256, pages allocate from |
| * the mempool concurrently, it may deadlock in a situation where both processes |
| * have allocated 128 pages and the mempool is exhausted. |
| * |
| * In order to avoid this scenario we allocate the pages under a mutex. |
| * |
| * In order to not degrade performance with excessive locking, we try |
| * non-blocking allocations without a mutex first but on failure we fallback |
| * to blocking allocations with a mutex. |
| */ |
| static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) |
| { |
| struct crypt_config *cc = io->cc; |
| struct bio *clone; |
| unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; |
| unsigned i, len, remaining_size; |
| struct page *page; |
| struct bio_vec *bvec; |
| |
| retry: |
| if (unlikely(gfp_mask & __GFP_WAIT)) |
| mutex_lock(&cc->bio_alloc_lock); |
| |
| clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); |
| if (!clone) |
| goto return_clone; |
| |
| clone_init(io, clone); |
| |
| remaining_size = size; |
| |
| for (i = 0; i < nr_iovecs; i++) { |
| page = mempool_alloc(cc->page_pool, gfp_mask); |
| if (!page) { |
| crypt_free_buffer_pages(cc, clone); |
| bio_put(clone); |
| gfp_mask |= __GFP_WAIT; |
| goto retry; |
| } |
| |
| len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; |
| |
| bvec = &clone->bi_io_vec[clone->bi_vcnt++]; |
| bvec->bv_page = page; |
| bvec->bv_len = len; |
| bvec->bv_offset = 0; |
| |
| clone->bi_iter.bi_size += len; |
| |
| remaining_size -= len; |
| } |
| |
| return_clone: |
| if (unlikely(gfp_mask & __GFP_WAIT)) |
| mutex_unlock(&cc->bio_alloc_lock); |
| |
| 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->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. |
| */ |
| static void crypt_dec_pending(struct dm_crypt_io *io) |
| { |
| struct crypt_config *cc = io->cc; |
| struct bio *base_bio = io->base_bio; |
| 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); |
| |
| bio_endio(base_bio, error); |
| } |
| |
| /* |
| * 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 *clone; |
| |
| /* |
| * We need the original biovec array in order to decrypt |
| * the whole bio data *afterwards* -- thanks to immutable |
| * biovecs we don't need to worry about the block layer |
| * modifying the biovec array; so leverage bio_clone_fast(). |
| */ |
| clone = bio_clone_fast(io->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_read_work(struct work_struct *work) |
| { |
| struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
| |
| crypt_inc_pending(io); |
| if (kcryptd_io_read(io, GFP_NOIO)) |
| io->error = -ENOMEM; |
| crypt_dec_pending(io); |
| } |
| |
| static void kcryptd_queue_read(struct dm_crypt_io *io) |
| { |
| struct crypt_config *cc = io->cc; |
| |
| INIT_WORK(&io->work, kcryptd_io_read_work); |
| queue_work(cc->io_queue, &io->work); |
| } |
| |
| static void kcryptd_io_write(struct dm_crypt_io *io) |
| { |
| struct bio *clone = io->ctx.bio_out; |
| |
| generic_make_request(clone); |
| } |
| |
| #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) |
| |
| static int dmcrypt_write(void *data) |
| { |
| struct crypt_config *cc = data; |
| struct dm_crypt_io *io; |
| |
| while (1) { |
| struct rb_root write_tree; |
| struct blk_plug plug; |
| |
| DECLARE_WAITQUEUE(wait, current); |
| |
| spin_lock_irq(&cc->write_thread_wait.lock); |
| continue_locked: |
| |
| if (!RB_EMPTY_ROOT(&cc->write_tree)) |
| goto pop_from_list; |
| |
| __set_current_state(TASK_INTERRUPTIBLE); |
| __add_wait_queue(&cc->write_thread_wait, &wait); |
| |
| spin_unlock_irq(&cc->write_thread_wait.lock); |
| |
| if (unlikely(kthread_should_stop())) { |
| set_task_state(current, TASK_RUNNING); |
| remove_wait_queue(&cc->write_thread_wait, &wait); |
| break; |
| } |
| |
| schedule(); |
| |
| set_task_state(current, TASK_RUNNING); |
| spin_lock_irq(&cc->write_thread_wait.lock); |
| __remove_wait_queue(&cc->write_thread_wait, &wait); |
| goto continue_locked; |
| |
| pop_from_list: |
| write_tree = cc->write_tree; |
| cc->write_tree = RB_ROOT; |
| spin_unlock_irq(&cc->write_thread_wait.lock); |
| |
| BUG_ON(rb_parent(write_tree.rb_node)); |
| |
| /* |
| * Note: we cannot walk the tree here with rb_next because |
| * the structures may be freed when kcryptd_io_write is called. |
| */ |
| blk_start_plug(&plug); |
| do { |
| io = crypt_io_from_node(rb_first(&write_tree)); |
| rb_erase(&io->rb_node, &write_tree); |
| kcryptd_io_write(io); |
| } while (!RB_EMPTY_ROOT(&write_tree)); |
| blk_finish_plug(&plug); |
| } |
| return 0; |
| } |
| |
| 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; |
| unsigned long flags; |
| sector_t sector; |
| struct rb_node **rbp, *parent; |
| |
| 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 (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) { |
| generic_make_request(clone); |
| return; |
| } |
| |
| spin_lock_irqsave(&cc->write_thread_wait.lock, flags); |
| rbp = &cc->write_tree.rb_node; |
| parent = NULL; |
| sector = io->sector; |
| while (*rbp) { |
| parent = *rbp; |
| if (sector < crypt_io_from_node(parent)->sector) |
| rbp = &(*rbp)->rb_left; |
| else |
| rbp = &(*rbp)->rb_right; |
| } |
| rb_link_node(&io->rb_node, parent, rbp); |
| rb_insert_color(&io->rb_node, &cc->write_tree); |
| |
| wake_up_locked(&cc->write_thread_wait); |
| spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags); |
| } |
| |
| static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) |
| { |
| struct crypt_config *cc = io->cc; |
| struct bio *clone; |
| int crypt_finished; |
| 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); |
| |
| clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); |
| if (unlikely(!clone)) { |
| io->error = -EIO; |
| goto dec; |
| } |
| |
| io->ctx.bio_out = clone; |
| io->ctx.iter_out = clone->bi_iter; |
| |
| sector += bio_sectors(clone); |
| |
| crypt_inc_pending(io); |
| r = crypt_convert(cc, &io->ctx); |
| if (r) |
| 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); |
| io->sector = sector; |
| } |
| |
| dec: |
| 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->write_thread) |
| kthread_stop(cc->write_thread); |
| |
| 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->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; |
| size_t iv_size_padding; |
| struct dm_arg_set as; |
| const char *opt_string; |
| char dummy; |
| |
| static struct dm_arg _args[] = { |
| {0, 3, "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; |
| |
| cc->dmreq_start = sizeof(struct ablkcipher_request); |
| cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc)); |
| cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); |
| |
| if (crypto_ablkcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) { |
| /* Allocate the padding exactly */ |
| iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) |
| & crypto_ablkcipher_alignmask(any_tfm(cc)); |
| } else { |
| /* |
| * If the cipher requires greater alignment than kmalloc |
| * alignment, we don't know the exact position of the |
| * initialization vector. We must assume worst case. |
| */ |
| iv_size_padding = crypto_ablkcipher_alignmask(any_tfm(cc)); |
| } |
| |
| ret = -ENOMEM; |
| cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + |
| sizeof(struct dm_crypt_request) + iv_size_padding + 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 = |
| ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + |
| sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size, |
| ARCH_KMALLOC_MINALIGN); |
| |
| cc->page_pool = mempool_create_page_pool(BIO_MAX_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; |
| } |
| |
| mutex_init(&cc->bio_alloc_lock); |
| |
| 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; |
| |
| ret = -EINVAL; |
| while (opt_params--) { |
| opt_string = dm_shift_arg(&as); |
| if (!opt_string) { |
| ti->error = "Not enough feature arguments"; |
| goto bad; |
| } |
| |
| if (!strcasecmp(opt_string, "allow_discards")) |
| ti->num_discard_bios = 1; |
| |
| else if (!strcasecmp(opt_string, "same_cpu_crypt")) |
| set_bit(DM_CRYPT_SAME_CPU, &cc->flags); |
| |
| else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) |
| set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); |
| |
| else { |
| 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; |
| } |
| |
| if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) |
| cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); |
| else |
| cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, |
| num_online_cpus()); |
| if (!cc->crypt_queue) { |
| ti->error = "Couldn't create kcryptd queue"; |
| goto bad; |
| } |
| |
| init_waitqueue_head(&cc->write_thread_wait); |
| cc->write_tree = RB_ROOT; |
| |
| cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); |
| if (IS_ERR(cc->write_thread)) { |
| ret = PTR_ERR(cc->write_thread); |
| cc->write_thread = NULL; |
| ti->error = "Couldn't spawn write thread"; |
| goto bad; |
| } |
| wake_up_process(cc->write_thread); |
| |
| 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_read(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; |
| int num_feature_args = 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); |
| |
| num_feature_args += !!ti->num_discard_bios; |
| num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); |
| num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); |
| if (num_feature_args) { |
| DMEMIT(" %d", num_feature_args); |
| if (ti->num_discard_bios) |
| DMEMIT(" allow_discards"); |
| if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) |
| DMEMIT(" same_cpu_crypt"); |
| if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) |
| DMEMIT(" submit_from_crypt_cpus"); |
| } |
| |
| 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 void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) |
| { |
| /* |
| * Unfortunate constraint that is required to avoid the potential |
| * for exceeding underlying device's max_segments limits -- due to |
| * crypt_alloc_buffer() possibly allocating pages for the encryption |
| * bio that are not as physically contiguous as the original bio. |
| */ |
| limits->max_segment_size = PAGE_SIZE; |
| } |
| |
| static struct target_type crypt_target = { |
| .name = "crypt", |
| .version = {1, 14, 1}, |
| .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, |
| .io_hints = crypt_io_hints, |
| }; |
| |
| static int __init dm_crypt_init(void) |
| { |
| int r; |
| |
| r = dm_register_target(&crypt_target); |
| if (r < 0) |
| DMERR("register failed %d", r); |
| |
| return r; |
| } |
| |
| static void __exit dm_crypt_exit(void) |
| { |
| dm_unregister_target(&crypt_target); |
| } |
| |
| 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"); |