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[Qemu-devel] [PATCH 5/6] crypto: convert xts_mult_x to use xts_uint128 t
From: |
Daniel P . Berrangé |
Subject: |
[Qemu-devel] [PATCH 5/6] crypto: convert xts_mult_x to use xts_uint128 type |
Date: |
Tue, 9 Oct 2018 13:55:40 +0100 |
Using 64-bit arithmetic increases the performance for xts-aes-128
when built with gcrypt:
Encrypt: 320 MB/s -> 460 MB/s
Decrypt: 325 MB/s -> 485 MB/s
Signed-off-by: Daniel P. Berrangé <address@hidden>
---
crypto/xts.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/crypto/xts.c b/crypto/xts.c
index f109c8a3ee..bba3280746 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -37,19 +37,17 @@ typedef struct {
(D)->b = (S1)->b ^ (S2)->b; \
} while (0)
-static void xts_mult_x(uint8_t *I)
+static void xts_mult_x(xts_uint128 *I)
{
- int x;
- uint8_t t, tt;
+ uint64_t tt;
- 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;
+ tt = I->a >> 63;
+ I->a = I->a << 1;
+
+ if (I->b >> 63) {
+ I->a ^= 0x87;
}
+ I->b = (I->b << 1) | tt;
}
@@ -77,7 +75,7 @@ static void xts_tweak_encdec(const void *ctx,
xts_uint128_xor(dst, dst, iv);
/* LFSR the tweak */
- xts_mult_x((uint8_t *)iv);
+ xts_mult_x(iv);
}
@@ -124,7 +122,7 @@ void xts_decrypt(const void *datactx,
if (mo > 0) {
xts_uint128 S, D;
memcpy(&CC, &T, XTS_BLOCK_SIZE);
- xts_mult_x((uint8_t *)&CC);
+ xts_mult_x(&CC);
/* PP = tweak decrypt block m-1 */
memcpy(&S, src, XTS_BLOCK_SIZE);
--
2.17.1
- Re: [Qemu-devel] [PATCH 1/6] crypto: expand algorithm coverage for cipher benchmark, (continued)
- [Qemu-devel] [PATCH 5/6] crypto: convert xts_mult_x to use xts_uint128 type,
Daniel P . Berrangé <=
[Qemu-devel] [PATCH 6/6] crypto: annotate xts_tweak_encdec as inlineable, Daniel P . Berrangé, 2018/10/09
[Qemu-devel] [PATCH 4/6] crypto: convert xts_tweak_encdec to use xts_uint128 type, Daniel P . Berrangé, 2018/10/09