--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pmac_init.c	Mon May 31 18:25:41 2004 +0000
@@ -0,0 +1,114 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, [email protected], http://libtomcrypt.org
+ */
+
+/* PMAC implementation by Tom St Denis */
+#include "mycrypt.h"
+
+#ifdef PMAC
+
+static const struct {
+    int           len;
+    unsigned char poly_div[MAXBLOCKSIZE], 
+                  poly_mul[MAXBLOCKSIZE];
+} polys[] = {
+{
+    8,
+    { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0D },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1B }
+}, {
+    16, 
+    { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x43 },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87 }
+}
+};
+
+int pmac_init(pmac_state *pmac, int cipher, const unsigned char *key, unsigned long keylen)
+{
+   int poly, x, y, m, err;
+   unsigned char L[MAXBLOCKSIZE];
+
+   _ARGCHK(pmac  != NULL);
+   _ARGCHK(key   != NULL);
+
+   /* valid cipher? */
+   if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* determine which polys to use */
+   pmac->block_len = cipher_descriptor[cipher].block_length;
+   for (poly = 0; poly < (int)(sizeof(polys)/sizeof(polys[0])); poly++) {
+       if (polys[poly].len == pmac->block_len) { 
+          break;
+       }
+   }
+   if (polys[poly].len != pmac->block_len) {
+      return CRYPT_INVALID_ARG;
+   }   
+
+   /* schedule the key */
+   if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, &pmac->key)) != CRYPT_OK) {
+      return err;
+   }
+ 
+   /* find L = E[0] */
+   zeromem(L, pmac->block_len);
+   cipher_descriptor[cipher].ecb_encrypt(L, L, &pmac->key);
+
+   /* find Ls[i] = L << i for i == 0..31 */
+   memcpy(pmac->Ls[0], L, pmac->block_len);
+   for (x = 1; x < 32; x++) {
+       m = pmac->Ls[x-1][0] >> 7;
+       for (y = 0; y < pmac->block_len-1; y++) {
+           pmac->Ls[x][y] = ((pmac->Ls[x-1][y] << 1) | (pmac->Ls[x-1][y+1] >> 7)) & 255;
+       }
+       pmac->Ls[x][pmac->block_len-1] = (pmac->Ls[x-1][pmac->block_len-1] << 1) & 255;
+
+       if (m == 1) {
+          for (y = 0; y < pmac->block_len; y++) {
+              pmac->Ls[x][y] ^= polys[poly].poly_mul[y];
+          }
+       }
+    }
+
+    /* find Lr = L / x */
+    m = L[pmac->block_len-1] & 1;
+
+    /* shift right */
+    for (x = pmac->block_len - 1; x > 0; x--) {
+        pmac->Lr[x] = ((L[x] >> 1) | (L[x-1] << 7)) & 255;
+    }
+    pmac->Lr[0] = L[0] >> 1;
+
+    if (m == 1) {
+       for (x = 0; x < pmac->block_len; x++) {
+           pmac->Lr[x] ^= polys[poly].poly_div[x];
+       }
+    }
+
+    /* zero buffer, counters, etc... */
+    pmac->block_index = 1;
+    pmac->cipher_idx  = cipher;
+    pmac->buflen      = 0;
+    zeromem(pmac->block,    sizeof(pmac->block));
+    zeromem(pmac->Li,       sizeof(pmac->Li));
+    zeromem(pmac->checksum, sizeof(pmac->checksum));
+
+#ifdef CLEAN_STACK
+    zeromem(L, sizeof(L));
+#endif
+
+    return CRYPT_OK;
+}
+
+#endif