--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/omac_process.c	Mon May 31 18:21:40 2004 +0000
@@ -0,0 +1,53 @@
+/* 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
+ */
+/* OMAC1 Support by Tom St Denis (for 64 and 128 bit block ciphers only) */
+#include "mycrypt.h"
+
+#ifdef OMAC
+
+int omac_process(omac_state *state, const unsigned char *buf, unsigned long len)
+{
+   int err, n, x;
+
+   _ARGCHK(state != NULL);
+   _ARGCHK(buf   != NULL);
+   if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
+       (state->blklen > (int)sizeof(state->block)) || (state->buflen > state->blklen)) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   while (len != 0) { 
+       /* ok if the block is full we xor in prev, encrypt and replace prev */
+       if (state->buflen == state->blklen) {
+          for (x = 0; x < state->blklen; x++) {
+              state->block[x] ^= state->prev[x];
+          }
+          cipher_descriptor[state->cipher_idx].ecb_encrypt(state->block, state->prev, &state->key);
+          state->buflen = 0;
+       }
+
+       /* add bytes */
+       n = MIN(len, (unsigned long)(state->blklen - state->buflen));
+       memcpy(state->block + state->buflen, buf, n);
+       state->buflen += n;
+       len           -= n;
+       buf           += n;
+   }
+
+   return CRYPT_OK;
+}
+
+#endif
+