--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mac/xcbc/xcbc_init.c	Thu Jan 11 02:39:21 2007 +0000
@@ -0,0 +1,86 @@
+/* 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.com
+ */
+#include "tomcrypt.h"
+
+/**
+  @file xcbc_init.c
+  XCBC Support, start an XCBC state
+*/
+
+#ifdef LTC_XCBC
+
+/** Initialize XCBC-MAC state
+  @param xcbc    [out] XCBC state to initialize
+  @param cipher  Index of cipher to use
+  @param key     [in]  Secret key
+  @param keylen  Length of secret key in octets
+  Return CRYPT_OK on success
+*/
+int xcbc_init(xcbc_state *xcbc, int cipher, const unsigned char *key, unsigned long keylen)
+{
+   int            x, y, err;
+   symmetric_key *skey;
+
+   LTC_ARGCHK(xcbc != NULL);
+   LTC_ARGCHK(key  != NULL);
+
+   /* schedule the key */
+   if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
+      return err;
+   }
+
+#ifdef LTC_FAST
+   if (cipher_descriptor[cipher].block_length % sizeof(LTC_FAST_TYPE)) {
+       return CRYPT_INVALID_ARG;
+   }
+#endif
+
+   /* schedule the user key */
+   skey = XCALLOC(1, sizeof(*skey));
+   if (skey == NULL) {
+      return CRYPT_MEM;
+   }
+
+   if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, skey)) != CRYPT_OK) {
+      goto done;
+   }
+   
+   /* make the three keys */
+   for (y = 0; y < 3; y++) {
+     for (x = 0; x < cipher_descriptor[cipher].block_length; x++) {
+        xcbc->K[y][x] = y + 1;
+     }
+     cipher_descriptor[cipher].ecb_encrypt(xcbc->K[y], xcbc->K[y], skey);
+   }
+
+   /* setup K1 */
+   err = cipher_descriptor[cipher].setup(xcbc->K[0], cipher_descriptor[cipher].block_length, 0, &xcbc->key);
+ 
+   /* setup struct */
+   zeromem(xcbc->IV, cipher_descriptor[cipher].block_length);
+   xcbc->blocksize = cipher_descriptor[cipher].block_length;
+   xcbc->cipher    = cipher;
+   xcbc->buflen    = 0;
+done:
+   cipher_descriptor[cipher].done(skey);
+#ifdef LTC_CLEAN_STACK
+   zeromem(skey, sizeof(*skey));
+#endif
+   XFREE(skey);
+   return err;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/mac/xcbc/xcbc_init.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/11/07 03:23:46 $ */
+