linux/crypto/xts.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/* XTS: as defined in IEEE1619/D16
* http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
*
* Copyright (c) 2007 Rik Snel <rsnel@cube.dyndns.org>
*
* Based on ecb.c
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <crypto/xts.h>
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>
struct xts_tfm_ctx {
struct crypto_skcipher *child;
struct crypto_cipher *tweak;
};
struct xts_instance_ctx {
struct crypto_skcipher_spawn spawn;
char name[CRYPTO_MAX_ALG_NAME];
};
struct xts_request_ctx {
le128 t;
struct scatterlist *tail;
struct scatterlist sg[2];
struct skcipher_request subreq;
};
static int xts_setkey(struct crypto_skcipher *parent, const u8 *key,
unsigned int keylen)
{
struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child;
struct crypto_cipher *tweak;
int err;
err = xts_verify_key(parent, key, keylen);
if (err)
return err;
keylen /= 2;
/* we need two cipher instances: one to compute the initial 'tweak'
* by encrypting the IV (usually the 'plain' iv) and the other
* one to encrypt and decrypt the data */
/* tweak cipher, uses Key2 i.e. the second half of *key */
tweak = ctx->tweak;
crypto_cipher_clear_flags(tweak, CRYPTO_TFM_REQ_MASK);
crypto_cipher_set_flags(tweak, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_cipher_setkey(tweak, key + keylen, keylen);
if (err)
return err;
/* data cipher, uses Key1 i.e. the first half of *key */
child = ctx->child;
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
return crypto_skcipher_setkey(child, key, keylen);
}
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
/*
* We compute the tweak masks twice (both before and after the ECB encryption or
* decryption) to avoid having to allocate a temporary buffer and/or make
* mutliple calls to the 'ecb(..)' instance, which usually would be slower than
* just doing the gf128mul_x_ble() calls again.
*/
static int xts_xor_tweak(struct skcipher_request *req, bool second_pass,
bool enc)
{
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
const bool cts = (req->cryptlen % XTS_BLOCK_SIZE);
const int bs = XTS_BLOCK_SIZE;
struct skcipher_walk w;
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
le128 t = rctx->t;
int err;
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
if (second_pass) {
req = &rctx->subreq;
/* set to our TFM to enforce correct alignment: */
skcipher_request_set_tfm(req, tfm);
}
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
err = skcipher_walk_virt(&w, req, false);
while (w.nbytes) {
unsigned int avail = w.nbytes;
le128 *wsrc;
le128 *wdst;
wsrc = w.src.virt.addr;
wdst = w.dst.virt.addr;
do {
if (unlikely(cts) &&
w.total - w.nbytes + avail < 2 * XTS_BLOCK_SIZE) {
if (!enc) {
if (second_pass)
rctx->t = t;
gf128mul_x_ble(&t, &t);
}
le128_xor(wdst, &t, wsrc);
if (enc && second_pass)
gf128mul_x_ble(&rctx->t, &t);
skcipher_walk_done(&w, avail - bs);
return 0;
}
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
le128_xor(wdst++, &t, wsrc++);
gf128mul_x_ble(&t, &t);
} while ((avail -= bs) >= bs);
err = skcipher_walk_done(&w, avail);
}
return err;
}
static int xts_xor_tweak_pre(struct skcipher_request *req, bool enc)
{
return xts_xor_tweak(req, false, enc);
}
static int xts_xor_tweak_post(struct skcipher_request *req, bool enc)
{
return xts_xor_tweak(req, true, enc);
}
static void xts_cts_done(struct crypto_async_request *areq, int err)
{
struct skcipher_request *req = areq->data;
le128 b;
if (!err) {
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
le128_xor(&b, &rctx->t, &b);
scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 1);
}
skcipher_request_complete(req, err);
}
static int xts_cts_final(struct skcipher_request *req,
int (*crypt)(struct skcipher_request *req))
{
const struct xts_tfm_ctx *ctx =
crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
int offset = req->cryptlen & ~(XTS_BLOCK_SIZE - 1);
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
struct skcipher_request *subreq = &rctx->subreq;
int tail = req->cryptlen % XTS_BLOCK_SIZE;
le128 b[2];
int err;
rctx->tail = scatterwalk_ffwd(rctx->sg, req->dst,
offset - XTS_BLOCK_SIZE);
scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
b[1] = b[0];
scatterwalk_map_and_copy(b, req->src, offset, tail, 0);
le128_xor(b, &rctx->t, b);
scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE + tail, 1);
skcipher_request_set_tfm(subreq, ctx->child);
skcipher_request_set_callback(subreq, req->base.flags, xts_cts_done,
req);
skcipher_request_set_crypt(subreq, rctx->tail, rctx->tail,
XTS_BLOCK_SIZE, NULL);
err = crypt(subreq);
if (err)
return err;
scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
le128_xor(b, &rctx->t, b);
scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 1);
return 0;
}
static void xts_encrypt_done(struct crypto_async_request *areq, int err)
{
struct skcipher_request *req = areq->data;
if (!err) {
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
rctx->subreq.base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
err = xts_xor_tweak_post(req, true);
if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
err = xts_cts_final(req, crypto_skcipher_encrypt);
if (err == -EINPROGRESS)
return;
}
}
skcipher_request_complete(req, err);
}
static void xts_decrypt_done(struct crypto_async_request *areq, int err)
{
struct skcipher_request *req = areq->data;
if (!err) {
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
rctx->subreq.base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
err = xts_xor_tweak_post(req, false);
if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
err = xts_cts_final(req, crypto_skcipher_decrypt);
if (err == -EINPROGRESS)
return;
}
}
skcipher_request_complete(req, err);
}
static int xts_init_crypt(struct skcipher_request *req,
crypto_completion_t compl)
{
const struct xts_tfm_ctx *ctx =
crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
struct skcipher_request *subreq = &rctx->subreq;
if (req->cryptlen < XTS_BLOCK_SIZE)
return -EINVAL;
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
skcipher_request_set_tfm(subreq, ctx->child);
skcipher_request_set_callback(subreq, req->base.flags, compl, req);
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
skcipher_request_set_crypt(subreq, req->dst, req->dst,
req->cryptlen & ~(XTS_BLOCK_SIZE - 1), NULL);
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
/* calculate first value of T */
crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv);
return 0;
}
static int xts_encrypt(struct skcipher_request *req)
{
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
struct skcipher_request *subreq = &rctx->subreq;
int err;
err = xts_init_crypt(req, xts_encrypt_done) ?:
xts_xor_tweak_pre(req, true) ?:
crypto_skcipher_encrypt(subreq) ?:
xts_xor_tweak_post(req, true);
if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
return err;
return xts_cts_final(req, crypto_skcipher_encrypt);
}
static int xts_decrypt(struct skcipher_request *req)
{
struct xts_request_ctx *rctx = skcipher_request_ctx(req);
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
struct skcipher_request *subreq = &rctx->subreq;
int err;
err = xts_init_crypt(req, xts_decrypt_done) ?:
xts_xor_tweak_pre(req, false) ?:
crypto_skcipher_decrypt(subreq) ?:
xts_xor_tweak_post(req, false);
if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
return err;
crypto: xts - Drop use of auxiliary buffer Since commit acb9b159c784 ("crypto: gf128mul - define gf128mul_x_* in gf128mul.h"), the gf128mul_x_*() functions are very fast and therefore caching the computed XTS tweaks has only negligible advantage over computing them twice. In fact, since the current caching implementation limits the size of the calls to the child ecb(...) algorithm to PAGE_SIZE (usually 4096 B), it is often actually slower than the simple recomputing implementation. This patch simplifies the XTS template to recompute the XTS tweaks from scratch in the second pass and thus also removes the need to allocate a dynamic buffer using kmalloc(). As discussed at [1], the use of kmalloc causes deadlocks with dm-crypt. PERFORMANCE RESULTS I measured time to encrypt/decrypt a memory buffer of varying sizes with xts(ecb-aes-aesni) using a tool I wrote ([2]) and the results suggest that after this patch the performance is either better or comparable for both small and large buffers. Note that there is a lot of noise in the measurements, but the overall difference is easy to see. Old code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 331 328 xts(aes) 384 64 332 333 xts(aes) 512 64 338 348 xts(aes) 256 512 889 920 xts(aes) 384 512 1019 993 xts(aes) 512 512 1032 990 xts(aes) 256 4096 2152 2292 xts(aes) 384 4096 2453 2597 xts(aes) 512 4096 3041 2641 xts(aes) 256 16384 9443 8027 xts(aes) 384 16384 8536 8925 xts(aes) 512 16384 9232 9417 xts(aes) 256 32768 16383 14897 xts(aes) 384 32768 17527 16102 xts(aes) 512 32768 18483 17322 New code: ALGORITHM KEY (b) DATA (B) TIME ENC (ns) TIME DEC (ns) xts(aes) 256 64 328 324 xts(aes) 384 64 324 319 xts(aes) 512 64 320 322 xts(aes) 256 512 476 473 xts(aes) 384 512 509 492 xts(aes) 512 512 531 514 xts(aes) 256 4096 2132 1829 xts(aes) 384 4096 2357 2055 xts(aes) 512 4096 2178 2027 xts(aes) 256 16384 6920 6983 xts(aes) 384 16384 8597 7505 xts(aes) 512 16384 7841 8164 xts(aes) 256 32768 13468 12307 xts(aes) 384 32768 14808 13402 xts(aes) 512 32768 15753 14636 [1] https://lkml.org/lkml/2018/8/23/1315 [2] https://gitlab.com/omos/linux-crypto-bench Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-11 15:40:08 +08:00
return xts_cts_final(req, crypto_skcipher_decrypt);
}
static int xts_init_tfm(struct crypto_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child;
struct crypto_cipher *tweak;
child = crypto_spawn_skcipher(&ictx->spawn);
if (IS_ERR(child))
return PTR_ERR(child);
ctx->child = child;
tweak = crypto_alloc_cipher(ictx->name, 0, 0);
if (IS_ERR(tweak)) {
crypto_free_skcipher(ctx->child);
return PTR_ERR(tweak);
}
ctx->tweak = tweak;
crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) +
sizeof(struct xts_request_ctx));
return 0;
}
static void xts_exit_tfm(struct crypto_skcipher *tfm)
{
struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_free_skcipher(ctx->child);
crypto_free_cipher(ctx->tweak);
}
static void xts_free_instance(struct skcipher_instance *inst)
{
struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
crypto_drop_skcipher(&ictx->spawn);
kfree(inst);
}
static int xts_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct xts_instance_ctx *ctx;
struct skcipher_alg *alg;
const char *cipher_name;
u32 mask;
int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
if (err)
return err;
cipher_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(cipher_name))
return PTR_ERR(cipher_name);
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
return -ENOMEM;
ctx = skcipher_instance_ctx(inst);
err = crypto_grab_skcipher(&ctx->spawn, skcipher_crypto_instance(inst),
cipher_name, 0, mask);
if (err == -ENOENT) {
err = -ENAMETOOLONG;
if (snprintf(ctx->name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
cipher_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
err = crypto_grab_skcipher(&ctx->spawn,
skcipher_crypto_instance(inst),
ctx->name, 0, mask);
}
if (err)
goto err_free_inst;
alg = crypto_skcipher_spawn_alg(&ctx->spawn);
err = -EINVAL;
if (alg->base.cra_blocksize != XTS_BLOCK_SIZE)
goto err_free_inst;
if (crypto_skcipher_alg_ivsize(alg))
goto err_free_inst;
err = crypto_inst_setname(skcipher_crypto_instance(inst), "xts",
&alg->base);
if (err)
goto err_free_inst;
err = -EINVAL;
cipher_name = alg->base.cra_name;
/* Alas we screwed up the naming so we have to mangle the
* cipher name.
*/
if (!strncmp(cipher_name, "ecb(", 4)) {
unsigned len;
len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
if (len < 2 || len >= sizeof(ctx->name))
goto err_free_inst;
if (ctx->name[len - 1] != ')')
goto err_free_inst;
ctx->name[len - 1] = 0;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"xts(%s)", ctx->name) >= CRYPTO_MAX_ALG_NAME) {
err = -ENAMETOOLONG;
goto err_free_inst;
}
} else
goto err_free_inst;
inst->alg.base.cra_priority = alg->base.cra_priority;
inst->alg.base.cra_blocksize = XTS_BLOCK_SIZE;
inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
(__alignof__(u64) - 1);
inst->alg.ivsize = XTS_BLOCK_SIZE;
inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) * 2;
inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) * 2;
inst->alg.base.cra_ctxsize = sizeof(struct xts_tfm_ctx);
inst->alg.init = xts_init_tfm;
inst->alg.exit = xts_exit_tfm;
inst->alg.setkey = xts_setkey;
inst->alg.encrypt = xts_encrypt;
inst->alg.decrypt = xts_decrypt;
inst->free = xts_free_instance;
err = skcipher_register_instance(tmpl, inst);
if (err) {
err_free_inst:
xts_free_instance(inst);
}
return err;
}
static struct crypto_template xts_tmpl = {
.name = "xts",
.create = xts_create,
.module = THIS_MODULE,
};
static int __init xts_module_init(void)
{
return crypto_register_template(&xts_tmpl);
}
static void __exit xts_module_exit(void)
{
crypto_unregister_template(&xts_tmpl);
}
subsys_initcall(xts_module_init);
module_exit(xts_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("XTS block cipher mode");
MODULE_ALIAS_CRYPTO("xts");