added libtomcrypt-1.00

src/modes/ctr/ctr_setiv.c

@@ -0,0 +1,54 @@
+/* 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@iahu.ca, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file ctr_setiv.c
+  CTR implementation, set IV, Tom St Denis
+*/
+  
+#ifdef CTR
+
+/**
+   Set an initial vector
+   @param IV   The initial vector
+   @param len  The length of the vector (in octets)
+   @param ctr  The CTR state
+   @return CRYPT_OK if successful
+*/
+int ctr_setiv(const unsigned char *IV, unsigned long len, symmetric_CTR *ctr)
+{
+   int err;
+   
+   LTC_ARGCHK(IV  != NULL);
+   LTC_ARGCHK(ctr != NULL);
+
+   /* bad param? */
+   if ((err = cipher_is_valid(ctr->cipher)) != CRYPT_OK) {
+      return err;
+   }
+   
+   if (len != (unsigned long)ctr->blocklen) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   /* set IV */
+   XMEMCPY(ctr->ctr, IV, len);
+   
+   /* force next block */
+   ctr->padlen = 0;
+   cipher_descriptor[ctr->cipher].ecb_encrypt(IV, ctr->pad, &ctr->key);
+   
+   return CRYPT_OK;
+}
+
+#endif 
+