From 7dac0dd67426753646df0c23c819609b9e704f59 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 9 Oct 2018 10:55:14 +0100 Subject: [PATCH] crypto: convert xts_mult_x to use xts_uint128 type MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Using 64-bit arithmetic increases the performance for xts-aes-128 when built with gcrypt: Encrypt: 355 MB/s -> 545 MB/s Decrypt: 362 MB/s -> 568 MB/s Reviewed-by: Alberto Garcia Signed-off-by: Daniel P. Berrangé --- crypto/xts.c | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) diff --git a/crypto/xts.c b/crypto/xts.c index 0ad231f3e5..10ec83ff21 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -24,6 +24,7 @@ */ #include "qemu/osdep.h" +#include "qemu/bswap.h" #include "crypto/xts.h" typedef union { @@ -39,19 +40,34 @@ static inline void xts_uint128_xor(xts_uint128 *D, D->u[1] = S1->u[1] ^ S2->u[1]; } -static void xts_mult_x(uint8_t *I) +static inline void xts_uint128_cpu_to_les(xts_uint128 *v) { - int x; - uint8_t t, tt; + cpu_to_le64s(&v->u[0]); + cpu_to_le64s(&v->u[1]); +} - for (x = t = 0; x < 16; x++) { - tt = I[x] >> 7; - I[x] = ((I[x] << 1) | t) & 0xFF; - t = tt; - } - if (tt) { - I[0] ^= 0x87; +static inline void xts_uint128_le_to_cpus(xts_uint128 *v) +{ + le64_to_cpus(&v->u[0]); + le64_to_cpus(&v->u[1]); +} + +static void xts_mult_x(xts_uint128 *I) +{ + uint64_t tt; + + xts_uint128_le_to_cpus(I); + + tt = I->u[0] >> 63; + I->u[0] <<= 1; + + if (I->u[1] >> 63) { + I->u[0] ^= 0x87; } + I->u[1] <<= 1; + I->u[1] |= tt; + + xts_uint128_cpu_to_les(I); } @@ -79,7 +95,7 @@ static void xts_tweak_encdec(const void *ctx, xts_uint128_xor(dst, dst, iv); /* LFSR the tweak */ - xts_mult_x(iv->b); + xts_mult_x(iv); } @@ -134,7 +150,7 @@ void xts_decrypt(const void *datactx, if (mo > 0) { xts_uint128 S, D; memcpy(&CC, &T, XTS_BLOCK_SIZE); - xts_mult_x(CC.b); + xts_mult_x(&CC); /* PP = tweak decrypt block m-1 */ memcpy(&S, src, XTS_BLOCK_SIZE);