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 (at) 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 */ 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
