1/* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
10 */
11#include "tomcrypt.h"
12
13/**
14  @file ctr_setiv.c
15  CTR implementation, set IV, Tom St Denis
16*/
17
18#ifdef LTC_CTR_MODE
19
20/**
21   Set an initial vector
22   @param IV   The initial vector
23   @param len  The length of the vector (in octets)
24   @param ctr  The CTR state
25   @return CRYPT_OK if successful
26*/
27int ctr_setiv(const unsigned char *IV, unsigned long len, symmetric_CTR *ctr)
28{
29   int err;
30
31   LTC_ARGCHK(IV  != NULL);
32   LTC_ARGCHK(ctr != NULL);
33
34   /* bad param? */
35   if ((err = cipher_is_valid(ctr->cipher)) != CRYPT_OK) {
36      return err;
37   }
38
39   if (len != (unsigned long)ctr->blocklen) {
40      return CRYPT_INVALID_ARG;
41   }
42
43   /* set IV */
44   XMEMCPY(ctr->ctr, IV, len);
45
46   /* force next block */
47   ctr->padlen = 0;
48   return cipher_descriptor[ctr->cipher].ecb_encrypt(IV, ctr->pad, &ctr->key);
49}
50
51#endif
52
53
54/* $Source: /cvs/libtom/libtomcrypt/src/modes/ctr/ctr_setiv.c,v $ */
55/* $Revision: 1.6 $ */
56/* $Date: 2006/06/29 01:46:46 $ */
57