(IDX0, IDX1, IDX2, IDX3): New macros, encapsualting the

structure of the idx table.

Rev: src/nettle/aes.c:1.11

diff --git a/aes.c b/aes.c
index b0c5a9495f1b71c6e71a1cca0d52eb856647b411..cf7ed32845ceaff29b12e5916ad73abe4adfd940 100644 (file)
--- a/aes.c
+++ b/aes.c
@@ -68,6 +68,11 @@ d2(const char *aname, uint32_t a, const char *bname,  uint32_t b)
 #define B2(x) (((x) >> 16) & 0xff)
 #define B3(x) (((x) >> 24) & 0xff)
 
+#define IDX0(j) (j)
+#define IDX1(j) (T->idx[0][j])
+#define IDX2(j) (T->idx[1][j])
+#define IDX3(j) (T->idx[2][j])
+
 void
 _aes_crypt(const struct aes_ctx *ctx,
           const struct aes_table *T,
@@ -105,15 +110,15 @@ _aes_crypt(const struct aes_ctx *ctx,
               * in the wrong direction, but I don't think so. */
 
 #if AES_SMALL
-             t[j] =         T->table[0][ B0(wtxt[j]) ] ^
-               ROTRBYTE(    T->table[0][ B1(wtxt[T->idx[0][j]]) ]^
-                 ROTRBYTE(  T->table[0][ B2(wtxt[T->idx[1][j]]) ] ^
-                   ROTRBYTE(T->table[0][ B3(wtxt[T->idx[2][j]]) ])));
+             t[j] =         T->table[0][ B0(wtxt[IDX0(j)]) ] ^
+               ROTRBYTE(    T->table[0][ B1(wtxt[IDX1(j)]) ]^
+                 ROTRBYTE(  T->table[0][ B2(wtxt[IDX2(j)]) ] ^
+                   ROTRBYTE(T->table[0][ B3(wtxt[IDX3(j)]) ])));
 #else /* !AES_SMALL */
-             t[j] = (  T->table[0][ B0(wtxt[j]) ]
-                     ^ T->table[1][ B1(wtxt[T->idx[0][j]]) ]
-                     ^ T->table[2][ B2(wtxt[T->idx[1][j]]) ]
-                     ^ T->table[3][ B3(wtxt[T->idx[2][j]]) ]);
+             t[j] = (  T->table[0][ B0(wtxt[IDX0(j)]) ]
+                     ^ T->table[1][ B1(wtxt[IDX1(j)]) ]
+                     ^ T->table[2][ B2(wtxt[IDX2(j)]) ]
+                     ^ T->table[3][ B3(wtxt[IDX3(j)]) ]);
 #endif /* !AES_SMALL */
            }
          D4(("t", round, t));
@@ -131,10 +136,10 @@ _aes_crypt(const struct aes_ctx *ctx,
             * It looks like this code shifts the rows in the wrong
             * direction, but it passes the testsuite. */
 
-           out = (   (uint32_t) T->sbox[ B0(wtxt[j]) ]
-                  | ((uint32_t) T->sbox[ B1(wtxt[T->idx[0][j]]) ] << 8)
-                  | ((uint32_t) T->sbox[ B2(wtxt[T->idx[1][j]]) ] << 16)
-                  | ((uint32_t) T->sbox[ B3(wtxt[T->idx[2][j]]) ] << 24));
+           out = (   (uint32_t) T->sbox[ B0(wtxt[IDX0(j)]) ]
+                  | ((uint32_t) T->sbox[ B1(wtxt[IDX1(j)]) ] << 8)
+                  | ((uint32_t) T->sbox[ B2(wtxt[IDX2(j)]) ] << 16)
+                  | ((uint32_t) T->sbox[ B3(wtxt[IDX3(j)]) ] << 24));
 
            D2(("t", out, "key", ctx->keys[4*round + j]));