1 files changed, 67 insertions, 0 deletions
diff --git a/libtomcrypt/src/modes/cfb/cfb_start.c b/libtomcrypt/src/modes/cfb/cfb_start.c
new file mode 100644
index 0000000..755e173
--- /dev/null
+++ b/libtomcrypt/src/modes/cfb/cfb_start.c
@@ -0,0 +1,67 @@
+/* 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, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+   @file cfb_start.c
+   CFB implementation, start chain, Tom St Denis
+*/
+
+
+#ifdef CFB
+
+/**
+   Initialize a CFB context
+   @param cipher      The index of the cipher desired
+   @param IV          The initial vector
+   @param key         The secret key 
+   @param keylen      The length of the secret key (octets)
+   @param num_rounds  Number of rounds in the cipher desired (0 for default)
+   @param cfb         The CFB state to initialize
+   @return CRYPT_OK if successful
+*/
+int cfb_start(int cipher, const unsigned char *IV, const unsigned char *key, 
+              int keylen, int num_rounds, symmetric_CFB *cfb)
+{
+   int x, err;
+
+   LTC_ARGCHK(IV != NULL);
+   LTC_ARGCHK(key != NULL);
+   LTC_ARGCHK(cfb != NULL);
+
+   if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
+      return err;
+   }
+   
+
+   /* copy data */
+   cfb->cipher = cipher;
+   cfb->blocklen = cipher_descriptor[cipher].block_length;
+   for (x = 0; x < cfb->blocklen; x++)
+       cfb->IV[x] = IV[x];
+
+   /* init the cipher */
+   if ((err = cipher_descriptor[cipher].setup(key, keylen, num_rounds, &cfb->key)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* encrypt the IV */
+   cipher_descriptor[cfb->cipher].ecb_encrypt(cfb->IV, cfb->IV, &cfb->key);
+   cfb->padlen = 0;
+
+   return CRYPT_OK;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/modes/cfb/cfb_start.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2005/05/05 14:35:59 $ */