Home | History | Annotate | Download | only in ofb
      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 ofb_setiv.c
     15    OFB implementation, set IV, Tom St Denis
     16 */
     17 
     18 #ifdef LTC_OFB_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 ofb  The OFB state
     25    @return CRYPT_OK if successful
     26 */
     27 int ofb_setiv(const unsigned char *IV, unsigned long len, symmetric_OFB *ofb)
     28 {
     29    int err;
     30 
     31    LTC_ARGCHK(IV  != NULL);
     32    LTC_ARGCHK(ofb != NULL);
     33 
     34    if ((err = cipher_is_valid(ofb->cipher)) != CRYPT_OK) {
     35        return err;
     36    }
     37 
     38    if (len != (unsigned long)ofb->blocklen) {
     39       return CRYPT_INVALID_ARG;
     40    }
     41 
     42    /* force next block */
     43    ofb->padlen = 0;
     44    return cipher_descriptor[ofb->cipher].ecb_encrypt(IV, ofb->IV, &ofb->key);
     45 }
     46 
     47 #endif
     48 
     49 
     50 /* $Source: /cvs/libtom/libtomcrypt/src/modes/ofb/ofb_setiv.c,v $ */
     51 /* $Revision: 1.6 $ */
     52 /* $Date: 2006/06/29 01:51:34 $ */
     53