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 */
ctr_setiv(const unsigned char * IV,unsigned long len,symmetric_CTR * ctr)27 int 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