2012-03-03 11:59:04

by Jussi Kivilinna

Subject: [PATCH] camellia: simplify key setup and CAMELLIA_ROUNDSM macro

camellia_setup_tail() applies 'inverse of the last half of P-function' to
subkeys, which is unneeded if keys are applied directly to yl/yr in
CAMELLIA_ROUNDSM.

Patch speeds up key setup and should speed up CAMELLIA_ROUNDSM as applying
key to yl/yr early has less register dependencies.

Quick tcrypt camellia results:
x86_64, AMD Phenom II, ~5% faster
x86_64, Intel Core 2, ~0.5% faster
i386, Intel Atom N270, ~1% faster

Signed-off-by: Jussi Kivilinna <[email protected]>
---
crypto/camellia.c | 24 +++---------------------
1 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/crypto/camellia.c b/crypto/camellia.c
index 64cff46..7ae4bcd 100644
--- a/crypto/camellia.c
+++ b/crypto/camellia.c
@@ -382,7 +382,6 @@ static void camellia_setup_tail(u32 *subkey, u32 *subL, u32 *subR, int max)
{
u32 dw, tl, tr;
u32 kw4l, kw4r;
- int i;

/* absorb kw2 to other subkeys */
/* round 2 */
@@ -557,24 +556,6 @@ static void camellia_setup_tail(u32 *subkey, u32 *subL, u32 *subR, int max)
SUBKEY_L(32) = subL[32] ^ subL[31]; /* kw3 */
SUBKEY_R(32) = subR[32] ^ subR[31];
}
-
- /* apply the inverse of the last half of P-function */
- i = 2;
- do {
- dw = SUBKEY_L(i + 0) ^ SUBKEY_R(i + 0); dw = rol32(dw, 8);/* round 1 */
- SUBKEY_R(i + 0) = SUBKEY_L(i + 0) ^ dw; SUBKEY_L(i + 0) = dw;
- dw = SUBKEY_L(i + 1) ^ SUBKEY_R(i + 1); dw = rol32(dw, 8);/* round 2 */
- SUBKEY_R(i + 1) = SUBKEY_L(i + 1) ^ dw; SUBKEY_L(i + 1) = dw;
- dw = SUBKEY_L(i + 2) ^ SUBKEY_R(i + 2); dw = rol32(dw, 8);/* round 3 */
- SUBKEY_R(i + 2) = SUBKEY_L(i + 2) ^ dw; SUBKEY_L(i + 2) = dw;
- dw = SUBKEY_L(i + 3) ^ SUBKEY_R(i + 3); dw = rol32(dw, 8);/* round 4 */
- SUBKEY_R(i + 3) = SUBKEY_L(i + 3) ^ dw; SUBKEY_L(i + 3) = dw;
- dw = SUBKEY_L(i + 4) ^ SUBKEY_R(i + 4); dw = rol32(dw, 8);/* round 5 */
- SUBKEY_R(i + 4) = SUBKEY_L(i + 4) ^ dw; SUBKEY_L(i + 4) = dw;
- dw = SUBKEY_L(i + 5) ^ SUBKEY_R(i + 5); dw = rol32(dw, 8);/* round 6 */
- SUBKEY_R(i + 5) = SUBKEY_L(i + 5) ^ dw; SUBKEY_L(i + 5) = dw;
- i += 8;
- } while (i < max);
}

static void camellia_setup128(const unsigned char *key, u32 *subkey)
@@ -869,6 +850,8 @@ static void camellia_setup192(const unsigned char *key, u32 *subkey)

#define CAMELLIA_ROUNDSM(xl, xr, kl, kr, yl, yr, il, ir) \
do { \
+ yl ^= kl; \
+ yr ^= kr; \
ir = camellia_sp1110[(u8)xr]; \
il = camellia_sp1110[ (xl >> 24)]; \
ir ^= camellia_sp0222[ (xr >> 24)]; \
@@ -877,8 +860,7 @@ static void camellia_setup192(const unsigned char *key, u32 *subkey)
il ^= camellia_sp3033[(u8)(xl >> 8)]; \
ir ^= camellia_sp4404[(u8)(xr >> 8)]; \
il ^= camellia_sp4404[(u8)xl]; \
- il ^= kl; \
- ir ^= il ^ kr; \
+ ir ^= il; \
yl ^= ir; \
yr ^= ror32(il, 8) ^ ir; \
} while (0)

2012-03-14 09:30:55

by Herbert Xu

Subject: Re: [PATCH] camellia: simplify key setup and CAMELLIA_ROUNDSM macro

On Sat, Mar 03, 2012 at 01:59:00PM +0200, Jussi Kivilinna wrote:
> camellia_setup_tail() applies 'inverse of the last half of P-function' to
> subkeys, which is unneeded if keys are applied directly to yl/yr in
> CAMELLIA_ROUNDSM.
>
> Patch speeds up key setup and should speed up CAMELLIA_ROUNDSM as applying
> key to yl/yr early has less register dependencies.
>
> Quick tcrypt camellia results:
> x86_64, AMD Phenom II, ~5% faster
> x86_64, Intel Core 2, ~0.5% faster
> i386, Intel Atom N270, ~1% faster
>
> Signed-off-by: Jussi Kivilinna <[email protected]>

Patch applied. Thanks!
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt