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[CRYPTO] twofish: Use rol32/ror32 where appropriate
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Convert open coded rotations to rol32/ror32.

Signed-off-by: Herbert Xu <[email protected]>
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Denis Vlasenko authored and herbertx committed Mar 21, 2006
1 parent c4a1745 commit a5f8c47
Showing 1 changed file with 11 additions and 10 deletions.
21 changes: 11 additions & 10 deletions crypto/twofish.c
Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,7 @@
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/crypto.h>
#include <linux/bitops.h>


/* The large precomputed tables for the Twofish cipher (twofish.c)
Expand Down Expand Up @@ -542,9 +543,9 @@ static const u8 calc_sb_tbl[512] = {
#define CALC_K(a, j, k, l, m, n) \
x = CALC_K_2 (k, l, k, l, 0); \
y = CALC_K_2 (m, n, m, n, 4); \
y = (y << 8) + (y >> 24); \
y = rol32(y, 8); \
x += y; y += x; ctx->a[j] = x; \
ctx->a[(j) + 1] = (y << 9) + (y >> 23)
ctx->a[(j) + 1] = rol32(y, 9)

#define CALC_K192_2(a, b, c, d, j) \
CALC_K_2 (q0[a ^ key[(j) + 16]], \
Expand All @@ -555,9 +556,9 @@ static const u8 calc_sb_tbl[512] = {
#define CALC_K192(a, j, k, l, m, n) \
x = CALC_K192_2 (l, l, k, k, 0); \
y = CALC_K192_2 (n, n, m, m, 4); \
y = (y << 8) + (y >> 24); \
y = rol32(y, 8); \
x += y; y += x; ctx->a[j] = x; \
ctx->a[(j) + 1] = (y << 9) + (y >> 23)
ctx->a[(j) + 1] = rol32(y, 9)

#define CALC_K256_2(a, b, j) \
CALC_K192_2 (q1[b ^ key[(j) + 24]], \
Expand All @@ -568,9 +569,9 @@ static const u8 calc_sb_tbl[512] = {
#define CALC_K256(a, j, k, l, m, n) \
x = CALC_K256_2 (k, l, 0); \
y = CALC_K256_2 (m, n, 4); \
y = (y << 8) + (y >> 24); \
y = rol32(y, 8); \
x += y; y += x; ctx->a[j] = x; \
ctx->a[(j) + 1] = (y << 9) + (y >> 23)
ctx->a[(j) + 1] = rol32(y, 9)


/* Macros to compute the g() function in the encryption and decryption
Expand All @@ -594,15 +595,15 @@ static const u8 calc_sb_tbl[512] = {
x = G1 (a); y = G2 (b); \
x += y; y += x + ctx->k[2 * (n) + 1]; \
(c) ^= x + ctx->k[2 * (n)]; \
(c) = ((c) >> 1) + ((c) << 31); \
(d) = (((d) << 1)+((d) >> 31)) ^ y
(c) = ror32((c), 1); \
(d) = rol32((d), 1) ^ y

#define DECROUND(n, a, b, c, d) \
x = G1 (a); y = G2 (b); \
x += y; y += x; \
(d) ^= y + ctx->k[2 * (n) + 1]; \
(d) = ((d) >> 1) + ((d) << 31); \
(c) = (((c) << 1)+((c) >> 31)); \
(d) = ror32((d), 1); \
(c) = rol32((c), 1); \
(c) ^= (x + ctx->k[2 * (n)])

/* Encryption and decryption cycles; each one is simply two Feistel rounds
Expand Down

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