Separate out key scheduling.

diff --git a/rijndael.c b/rijndael.c
index c2bb8f3..981e79c 100644 (file)
--- a/rijndael.c
+++ b/rijndael.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: rijndael.c,v 1.3 2001/05/07 15:44:46 mdw Exp $
+ * $Id: rijndael.c,v 1.4 2001/05/07 17:31:53 mdw Exp $
  *
  * The Rijndael block cipher
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: rijndael.c,v $
+ * Revision 1.4  2001/05/07 17:31:53  mdw
+ * Separate out key scheduling.
+ *
  * Revision 1.3  2001/05/07 15:44:46  mdw
  * Fix unusual numbers of rounds.  Simplify implementation.
  *
@@ -51,29 +54,10 @@
 #include "blkc.h"
 #include "gcipher.h"
 #include "rijndael.h"
-#include "rijndael-tab.h"
-
-/*----- Global variables --------------------------------------------------*/
-
-const octet rijndael_keysz[] = { KSZ_RANGE, RIJNDAEL_KEYSZ, 4, 32, 4 };
-
-/*----- Constant tables ---------------------------------------------------*/
-
-static const octet S[256] = RIJNDAEL_S, SI[256] = RIJNDAEL_SI;
-static const uint32 T[4][256] = RIJNDAEL_T, TI[4][256] = RIJNDAEL_TI;
-static const uint32 U[4][256] = RIJNDAEL_U;
-static const octet rcon[] = RIJNDAEL_RCON;
+#include "rijndael-base.h"
 
 /*----- Main code ---------------------------------------------------------*/
 
-#define SUB(s, a, b, c, d)                                             \
-  (s[U8((a) >>  0)] <<  0 | s[U8((b) >>  8)] <<  8 |                   \
-   s[U8((c) >> 16)] << 16 | s[U8((d) >> 24)] << 24)
-
-#define MIX(t, a, b, c, d)                                             \
-  (t[0][U8((a) >>  0)] ^ t[1][U8((b) >>  8)] ^                         \
-   t[2][U8((c) >> 16)] ^ t[3][U8((d) >> 24)])
-
 /* --- @rijndael_init@ --- *
  *
  * Arguments:  @rijndael_ctx *k@ = pointer to context to initialize
@@ -90,67 +74,7 @@ static const octet rcon[] = RIJNDAEL_RCON;
 
 void rijndael_init(rijndael_ctx *k, const void *buf, size_t sz)
 {
-  unsigned nk, nr, nw;
-  unsigned i, j, jj;
-  const octet *p;
-  uint32 ww;
-
-  /* --- Sort out the key size --- */
-
-  KSZ_ASSERT(rijndael, sz);
-  nk = sz / 4;
-
-  /* --- Select the number of rounds --- */
-
-  nr = nk + 6;
-  if (nr < 10)
-    nr = 10;
-  k->nr = nr;
-
-  /* --- Fetch the first key words out --- */
-
-  p = buf;
-  for (i = 0; i < nk; i++) {
-    k->w[i] = LOAD32_L(p);
-    p += 4;
-  }
-
-  /* --- Expand this material to fill the rest of the table --- */
-
-  nw = (nr + 1) * (RIJNDAEL_BLKSZ / 4);
-  ww = k->w[i - 1];
-  p = rcon;
-  for (; i < nw; i++) {
-    uint32 w = k->w[i - nk];
-    if (i % nk == 0) {
-      ww = ROR32(ww, 8);
-      w ^= SUB(S, ww, ww, ww, ww) ^ *p++;
-    } else if (nk > 6 && i % nk == 4)
-      w ^= SUB(S, ww, ww, ww, ww);
-    else
-      w ^= ww;
-    k->w[i] = ww = w;
-  }
-
-  /* --- Make the decryption keys --- */
-
-  j = nw;
-
-  j -= RIJNDAEL_BLKSZ / 4; jj = 0;
-  for (i = 0; i < RIJNDAEL_BLKSZ / 4; i++)
-    k->wi[i] = k->w[j + jj++];
-
-  for (; i < nw - RIJNDAEL_BLKSZ / 4; i += RIJNDAEL_BLKSZ / 4) {
-    j -= RIJNDAEL_BLKSZ / 4;
-    for (jj = 0; jj < RIJNDAEL_BLKSZ / 4; jj++) {
-      uint32 w = k->w[j + jj];
-      k->wi[i + jj] = MIX(U, w, w, w, w);
-    }
-  }
-
-  j -= RIJNDAEL_BLKSZ / 4; jj = 0;
-  for (; i < nw; i++)
-    k->wi[i] = k->w[j + jj++];
+  rijndael_setup(k, RIJNDAEL_BLKSZ / 4, buf, sz);
 }
 
 /* --- @rijndael_eblk@, @rijndael_dblk@ --- *

diff --git a/rijndael.h b/rijndael.h
index 88463b7..282cef8 100644 (file)
--- a/rijndael.h
+++ b/rijndael.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: rijndael.h,v 1.2 2000/10/08 15:48:58 mdw Exp $
+ * $Id: rijndael.h,v 1.3 2001/05/07 17:31:53 mdw Exp $
  *
  * The Rijndael block cipher
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: rijndael.h,v $
+ * Revision 1.3  2001/05/07 17:31:53  mdw
+ * Separate out key scheduling.
+ *
  * Revision 1.2  2000/10/08 15:48:58  mdw
  * Update comments now that AES has been chosen.
  *
@@ -71,8 +74,8 @@ extern const octet rijndael_keysz[];
 
 /*----- Data structures ---------------------------------------------------*/
 
-#define RIJNDAEL_MAXROUNDS 32
-#define RIJNDAEL_KWORDS ((RIJNDAEL_MAXROUNDS + 1) * (RIJNDAEL_BLKSZ / 4))
+#define RIJNDAEL_MAXROUNDS 16
+#define RIJNDAEL_KWORDS ((RIJNDAEL_MAXROUNDS + 1) * 8)
 
 typedef struct rijndael_ctx {
   unsigned nr;
@@ -82,6 +85,21 @@ typedef struct rijndael_ctx {
 
 /*----- Functions provided ------------------------------------------------*/
 
+/* --- @rijndael_setup@ --- *
+ *
+ * Arguments:  @rijndael_ctx *k@ = pointer to context to initialize
+ *             @unsigned nb@ = number of words in the block
+ *             @const void *buf@ = pointer to buffer of key material
+ *             @size_t sz@ = size of the key material
+ *
+ * Returns:    ---
+ *
+ * Use:                Low-level key-scheduling.  Don't call this directly.
+ */
+
+extern void rijndael_setup(rijndael_ctx */*k*/, unsigned /*nb*/,
+                          const void */*buf*/, size_t /*sz*/);
+
 /* --- @rijndael_init@ --- *
  *
  * Arguments:  @rijndael_ctx *k@ = pointer to context to initialize