/* 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@gmail.com, http://libtomcrypt.com */#include "tomcrypt.h"/**   @file lrw_setiv.c   LRW_MODE implementation, Set the current IV, Tom St Denis*/#ifdef LTC_LRW_MODE/**  Set the IV for LRW  @param IV      The IV, must be 16 octets  @param len     Length ... must be 16 :-)  @param lrw     The LRW state to update  @return CRYPT_OK if successful*/int lrw_setiv(const unsigned char *IV, unsigned long len, symmetric_LRW *lrw){   int           err;#ifdef LRW_TABLES   unsigned char T[16];   int           x, y;#endif   LTC_ARGCHK(IV != NULL);   LTC_ARGCHK(lrw != NULL);   if (len != 16) {      return CRYPT_INVALID_ARG;   }   if ((err = cipher_is_valid(lrw->cipher)) != CRYPT_OK) {      return err;   }   /* copy the IV */   XMEMCPY(lrw->IV, IV, 16);   /* check if we have to actually do work */   if (cipher_descriptor[lrw->cipher].accel_lrw_encrypt != NULL && cipher_descriptor[lrw->cipher].accel_lrw_decrypt != NULL) {       /* we have accelerators, let's bail since they don't use lrw->pad anyways */       return CRYPT_OK;   }#ifdef LRW_TABLES   XMEMCPY(T, &lrw->PC[0][IV[0]][0], 16);   for (x = 1; x < 16; x++) {#ifdef LTC_FAST       for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {           *((LTC_FAST_TYPE *)(T + y)) ^= *((LTC_FAST_TYPE *)(&lrw->PC[x][IV[x]][y]));       }#else       for (y = 0; y < 16; y++) {           T[y] ^= lrw->PC[x][IV[x]][y];       }#endif   }   XMEMCPY(lrw->pad, T, 16);#else        gcm_gf_mult(lrw->tweak, IV, lrw->pad); #endif   return CRYPT_OK;}#endif/* $Source: /cvs/libtom/libtomcrypt/src/modes/lrw/lrw_setiv.c,v $ *//* $Revision: 1.12 $ *//* $Date: 2006/06/29 01:53:13 $ */