Patch adds XTS support for serpent-sse2 by using xts_crypt(). Patch has been
tested with tcrypt and automated filesystem tests.
Tcrypt benchmarks results (serpent-sse2/serpent_generic speed ratios):
Intel Celeron T1600 (x86_64) (fam:6, model:15, step:13):
size xts-enc xts-dec
16B 0.98x 1.00x
64B 1.00x 1.01x
256B 2.78x 2.75x
1024B 3.30x 3.26x
8192B 3.39x 3.30x
AMD Phenom II 1055T (x86_64) (fam:16, model:10):
size xts-enc xts-dec
16B 1.05x 1.02x
64B 1.04x 1.03x
256B 2.10x 2.05x
1024B 2.34x 2.35x
8192B 2.34x 2.40x
Intel Atom N270 (i586):
size xts-enc xts-dec
16B 0.95x 0.96x
64B 1.53x 1.50x
256B 1.72x 1.75x
1024B 1.88x 1.87x
8192B 1.86x 1.83x
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@xxxxxxxx>
---
arch/x86/crypto/serpent_sse2_glue.c | 180 +++++++++++++++++++++++++++++++++++
1 files changed, 178 insertions(+), 2 deletions(-)
diff --git a/arch/x86/crypto/serpent_sse2_glue.c b/arch/x86/crypto/serpent_sse2_glue.c
index a6d8941..8e214db 100644
--- a/arch/x86/crypto/serpent_sse2_glue.c
+++ b/arch/x86/crypto/serpent_sse2_glue.c
@@ -40,6 +40,7 @@
#include <crypto/b128ops.h>
#include <crypto/ctr.h>
#include <crypto/lrw.h>
+#include <crypto/xts.h>
#include <asm/i387.h>
#include <asm/serpent.h>
#include <crypto/scatterwalk.h>
@@ -50,6 +51,10 @@
#define HAS_LRW
#endif
+#if defined(CONFIG_CRYPTO_XTS) || defined(CONFIG_CRYPTO_XTS_MODULE)
+#define HAS_XTS
+#endif
+
struct async_serpent_ctx {
struct cryptd_ablkcipher *cryptd_tfm;
};
@@ -465,7 +470,7 @@ static struct crypto_alg blk_ctr_alg = {
},
};
-#ifdef HAS_LRW
+#if defined(HAS_LRW) || defined(HAS_XTS)
struct crypt_priv {
struct serpent_ctx *ctx;
@@ -506,6 +511,10 @@ static void decrypt_callback(void *priv, u8 *srcdst, unsigned int nbytes)
__serpent_decrypt(ctx->ctx, srcdst, srcdst);
}
+#endif
+
+#ifdef HAS_LRW
+
struct serpent_lrw_ctx {
struct lrw_table_ctx lrw_table;
struct serpent_ctx serpent_ctx;
@@ -611,6 +620,114 @@ static struct crypto_alg blk_lrw_alg = {
#endif
+#ifdef HAS_XTS
+
+struct serpent_xts_ctx {
+ struct serpent_ctx tweak_ctx;
+ struct serpent_ctx crypt_ctx;
+};
+
+static int xts_serpent_setkey(struct crypto_tfm *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct serpent_xts_ctx *ctx = crypto_tfm_ctx(tfm);
+ u32 *flags = &tfm->crt_flags;
+ int err;
+
+ /* key consists of keys of equal size concatenated, therefore
+ * the length must be even
+ */
+ if (keylen % 2) {
+ *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+ return -EINVAL;
+ }
+
+ /* first half of xts-key is for crypt */
+ err = __serpent_setkey(&ctx->crypt_ctx, key, keylen / 2);
+ if (err)
+ return err;
+
+ /* second half of xts-key is for tweak */
+ return __serpent_setkey(&ctx->tweak_ctx, key + keylen / 2, keylen / 2);
+}
+
+static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct serpent_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ be128 buf[SERPENT_PARALLEL_BLOCKS];
+ struct crypt_priv crypt_ctx = {
+ .ctx = &ctx->crypt_ctx,
+ .fpu_enabled = false,
+ };
+ struct xts_crypt_req req = {
+ .tbuf = buf,
+ .tbuflen = sizeof(buf),
+
+ .tweak_ctx = &ctx->tweak_ctx,
+ .tweak_fn = XTS_TWEAK_CAST(__serpent_encrypt),
+ .crypt_ctx = &crypt_ctx,
+ .crypt_fn = encrypt_callback,
+ };
+ int ret;
+
+ ret = xts_crypt(desc, dst, src, nbytes, &req);
+ serpent_fpu_end(crypt_ctx.fpu_enabled);
+
+ return ret;
+}
+
+static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes)
+{
+ struct serpent_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+ be128 buf[SERPENT_PARALLEL_BLOCKS];
+ struct crypt_priv crypt_ctx = {
+ .ctx = &ctx->crypt_ctx,
+ .fpu_enabled = false,
+ };
+ struct xts_crypt_req req = {
+ .tbuf = buf,
+ .tbuflen = sizeof(buf),
+
+ .tweak_ctx = &ctx->tweak_ctx,
+ .tweak_fn = XTS_TWEAK_CAST(__serpent_encrypt),
+ .crypt_ctx = &crypt_ctx,
+ .crypt_fn = decrypt_callback,
+ };
+ int ret;
+
+ ret = xts_crypt(desc, dst, src, nbytes, &req);
+ serpent_fpu_end(crypt_ctx.fpu_enabled);
+
+ return ret;
+}
+
+static struct crypto_alg blk_xts_alg = {
+ .cra_name = "__xts-serpent-sse2",
+ .cra_driver_name = "__driver-xts-serpent-sse2",
+ .cra_priority = 0,
+ .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .cra_blocksize = SERPENT_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct serpent_xts_ctx),
+ .cra_alignmask = 0,
+ .cra_type = &crypto_blkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(blk_xts_alg.cra_list),
+ .cra_u = {
+ .blkcipher = {
+ .min_keysize = SERPENT_MIN_KEY_SIZE * 2,
+ .max_keysize = SERPENT_MAX_KEY_SIZE * 2,
+ .ivsize = SERPENT_BLOCK_SIZE,
+ .setkey = xts_serpent_setkey,
+ .encrypt = xts_encrypt,
+ .decrypt = xts_decrypt,
+ },
+ },
+};
+
+#endif
+
static int ablk_set_key(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int key_len)
{
@@ -851,6 +968,46 @@ static struct crypto_alg ablk_lrw_alg = {
#endif
+#ifdef HAS_XTS
+
+static int ablk_xts_init(struct crypto_tfm *tfm)
+{
+ struct cryptd_ablkcipher *cryptd_tfm;
+
+ cryptd_tfm = cryptd_alloc_ablkcipher("__driver-xts-serpent-sse2", 0, 0);
+ if (IS_ERR(cryptd_tfm))
+ return PTR_ERR(cryptd_tfm);
+ ablk_init_common(tfm, cryptd_tfm);
+ return 0;
+}
+
+static struct crypto_alg ablk_xts_alg = {
+ .cra_name = "xts(serpent)",
+ .cra_driver_name = "xts-serpent-sse2",
+ .cra_priority = 400,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+ .cra_blocksize = SERPENT_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(struct async_serpent_ctx),
+ .cra_alignmask = 0,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(ablk_xts_alg.cra_list),
+ .cra_init = ablk_xts_init,
+ .cra_exit = ablk_exit,
+ .cra_u = {
+ .ablkcipher = {
+ .min_keysize = SERPENT_MIN_KEY_SIZE * 2,
+ .max_keysize = SERPENT_MAX_KEY_SIZE * 2,
+ .ivsize = SERPENT_BLOCK_SIZE,
+ .setkey = ablk_set_key,
+ .encrypt = ablk_encrypt,
+ .decrypt = ablk_decrypt,
+ },
+ },
+};
+
+#endif
+
static int __init serpent_sse2_init(void)
{
int err;
@@ -886,14 +1043,29 @@ static int __init serpent_sse2_init(void)
if (err)
goto ablk_lrw_err;
#endif
+#ifdef HAS_XTS
+ err = crypto_register_alg(&blk_xts_alg);
+ if (err)
+ goto blk_xts_err;
+ err = crypto_register_alg(&ablk_xts_alg);
+ if (err)
+ goto ablk_xts_err;
+#endif
return err;
+#ifdef HAS_XTS
+ crypto_unregister_alg(&ablk_xts_alg);
+ablk_xts_err:
+ crypto_unregister_alg(&blk_xts_alg);
+blk_xts_err:
+#endif
#ifdef HAS_LRW
+ crypto_unregister_alg(&ablk_lrw_alg);
ablk_lrw_err:
crypto_unregister_alg(&blk_lrw_alg);
blk_lrw_err:
- crypto_unregister_alg(&ablk_ctr_alg);
#endif
+ crypto_unregister_alg(&ablk_ctr_alg);
ablk_ctr_err:
crypto_unregister_alg(&ablk_cbc_alg);
ablk_cbc_err:
@@ -910,6 +1082,10 @@ blk_ecb_err:
static void __exit serpent_sse2_exit(void)
{
+#ifdef HAS_XTS
+ crypto_unregister_alg(&ablk_xts_alg);
+ crypto_unregister_alg(&blk_xts_alg);
+#endif
#ifdef HAS_LRW
crypto_unregister_alg(&ablk_lrw_alg);
crypto_unregister_alg(&blk_lrw_alg);
--
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