--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/omac_done.c	Mon May 31 18:21:40 2004 +0000
@@ -0,0 +1,66 @@
+/* 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_done(omac_state *state, unsigned char *out, unsigned long *outlen)
+{
+   int err, mode, x;
+
+   _ARGCHK(state != NULL);
+   _ARGCHK(out   != 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;
+   }
+
+   /* figure out mode */
+   if (state->buflen != state->blklen) {
+      /* add the 0x80 byte */
+      state->block[state->buflen++] = 0x80;
+
+      /* pad with 0x00 */
+      while (state->buflen < state->blklen) {
+         state->block[state->buflen++] = 0x00;
+      }
+      mode = 1;
+   } else {
+      mode = 0;
+   }
+
+   /* now xor prev + Lu[mode] */
+   for (x = 0; x < state->blklen; x++) {
+       state->block[x] ^= state->prev[x] ^ state->Lu[mode][x];
+   }
+
+   /* encrypt it */
+   cipher_descriptor[state->cipher_idx].ecb_encrypt(state->block, state->block, &state->key);
+ 
+   /* output it */
+   for (x = 0; x < state->blklen && (unsigned long)x < *outlen; x++) {
+       out[x] = state->block[x];
+   }
+   *outlen = x;
+
+#ifdef CLEAN_STACK
+   zeromem(state, sizeof(*state));
+#endif
+   return CRYPT_OK;
+}
+
+#endif
+