This greatly shrinks the IP() and FP() macros.
---
crypto/des_generic.c | 103 +++++++++++++++-----------------------------------
1 files changed, 31 insertions(+), 72 deletions(-)
diff --git a/crypto/des_generic.c b/crypto/des_generic.c
index 5bd3ee3..afde5b4 100644
--- a/crypto/des_generic.c
+++ b/crypto/des_generic.c
@@ -22,9 +22,6 @@
#include <crypto/des.h>
-#define ROL(x, r) ((x) = rol32((x), (r)))
-#define ROR(x, r) ((x) = ror32((x), (r)))
-
struct des_ctx {
u32 expkey[DES_EXPKEY_WORDS];
};
@@ -521,70 +518,38 @@ static const u32 S8[64] = {
/* Encryption components: IP, FP, and round function */
-#define IP(L, R, T) \
- ROL(R, 4); \
- T = L; \
- L ^= R; \
- L &= 0xf0f0f0f0; \
- R ^= L; \
- L ^= T; \
- ROL(R, 12); \
- T = L; \
- L ^= R; \
- L &= 0xffff0000; \
- R ^= L; \
- L ^= T; \
- ROR(R, 14); \
- T = L; \
- L ^= R; \
- L &= 0xcccccccc; \
- R ^= L; \
- L ^= T; \
- ROL(R, 6); \
- T = L; \
- L ^= R; \
- L &= 0xff00ff00; \
- R ^= L; \
- L ^= T; \
- ROR(R, 7); \
- T = L; \
- L ^= R; \
- L &= 0xaaaaaaaa; \
- R ^= L; \
+#define ROL(x, r) ((x) = rol32((x), (r)))
+#define ROR(x, r) ((x) = ror32((x), (r)))
+/* Swap the bits set in "mask" between L and R */
+#define MASKSWAP(L, R, T, mask) \
+ T = (L ^ R) & (mask); \
L ^= T; \
+ R ^= T; \
+
+#define IP(L, R, T) \
+ ROL(R, 4); \
+ MASKSWAP(L, R, T, 0xf0f0f0f0); \
+ ROL(R, 12); \
+ MASKSWAP(L, R, T, 0xffff0000); \
+ ROR(R, 14); \
+ MASKSWAP(L, R, T, 0xcccccccc); \
+ ROL(R, 6); \
+ MASKSWAP(L, R, T, 0xff00ff00); \
+ ROR(R, 7); \
+ MASKSWAP(L, R, T, 0xaaaaaaaa); \
ROL(L, 1);
-#define FP(L, R, T) \
- ROR(L, 1); \
- T = L; \
- L ^= R; \
- L &= 0xaaaaaaaa; \
- R ^= L; \
- L ^= T; \
- ROL(R, 7); \
- T = L; \
- L ^= R; \
- L &= 0xff00ff00; \
- R ^= L; \
- L ^= T; \
- ROR(R, 6); \
- T = L; \
- L ^= R; \
- L &= 0xcccccccc; \
- R ^= L; \
- L ^= T; \
- ROL(R, 14); \
- T = L; \
- L ^= R; \
- L &= 0xffff0000; \
- R ^= L; \
- L ^= T; \
- ROR(R, 12); \
- T = L; \
- L ^= R; \
- L &= 0xf0f0f0f0; \
- R ^= L; \
- L ^= T; \
+#define FP(L, R, T) \
+ ROR(L, 1); \
+ MASKSWAP(L, R, T, 0xaaaaaaaa); \
+ ROL(R, 7); \
+ MASKSWAP(L, R, T, 0xff00ff00); \
+ ROR(R, 6); \
+ MASKSWAP(L, R, T, 0xcccccccc); \
+ ROL(R, 14); \
+ MASKSWAP(L, R, T, 0xffff0000); \
+ ROR(R, 12); \
+ MASKSWAP(L, R, T, 0xf0f0f0f0); \
ROR(R, 4);
#define ROUND(L, R, A, B, K, d) \
@@ -691,10 +656,7 @@ unsigned long des_ekey(u32 *pe, const u8 *k)
for (d = 0; d < 16; ++d) {
a = pe[2 * d];
b = pe[2 * d + 1];
- c = a ^ b;
- c &= 0xffff0000;
- a ^= c;
- b ^= c;
+ MASKSWAP(a, b, c, 0xffff0000);
ROL(b, 18);
pe[2 * d] = a;
pe[2 * d + 1] = b;
@@ -768,10 +730,7 @@ static void dkey(u32 *pe, const u8 *k)
for (d = 0; d < 16; ++d) {
a = pe[2 * d];
b = pe[2 * d + 1];
- c = a ^ b;
- c &= 0xffff0000;
- a ^= c;
- b ^= c;
+ MASKSWAP(a, b, c, 0xffff0000);
ROL(b, 18);
pe[2 * d] = a;
pe[2 * d + 1] = b;
--
1.6.0.6