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/*
* Copyright (c) 2000, 2002 Virtual Unlimited B.V.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/*!\file blockmode.c
* \brief Blockcipher operation modes.
* \todo Additional modes, such as CFB and OFB.
* \author Bob Deblier <bob.deblier@pandora.be>
* \ingroup BC_m
*/
#include "system.h"
#include "blockmode.h"
#include "mp.h"
#include "debug.h"
/*!\addtogroup BC_m
* \{
*/
int blockEncryptECB(const blockCipher* bc, blockCipherParam* bp, uint32_t* dst, const uint32_t* src, int nblocks)
{
register const int blockwords = bc->blocksize >> 2;
while (nblocks > 0)
{
bc->encrypt(bp, dst, src);
dst += blockwords;
src += blockwords;
nblocks--;
}
return 0;
}
int blockDecryptECB(const blockCipher* bc, blockCipherParam* bp, uint32_t* dst, const uint32_t* src, int nblocks)
{
register const int blockwords = bc->blocksize >> 2;
while (nblocks > 0)
{
bc->decrypt(bp, dst, src);
dst += blockwords;
src += blockwords;
nblocks--;
}
return 0;
}
int blockEncryptCBC(const blockCipher* bc, blockCipherParam* bp, uint32_t* dst, const uint32_t* src, int nblocks)
{
/* assumes that every blockcipher's blocksize is a multiple of 32 bits */
register int blockwords = bc->blocksize >> 2;
register uint32_t* fdback = bc->getfb(bp);
if (nblocks > 0)
{
register int i;
for (i = 0; i < blockwords; i++)
dst[i] = src[i] ^ fdback[i];
bc->encrypt(bp, dst, dst);
dst += blockwords;
src += blockwords;
nblocks--;
while (nblocks > 0)
{
for (i = 0; i < blockwords; i++)
dst[i] = src[i] ^ dst[i-blockwords];
bc->encrypt(bp, dst, dst);
dst += blockwords;
src += blockwords;
nblocks--;
}
for (i = 0; i < blockwords; i++)
fdback[i] = dst[i-blockwords];
}
return 0;
}
int blockDecryptCBC(const blockCipher* bc, blockCipherParam* bp, uint32_t* dst, const uint32_t* src, int nblocks)
{
/* assumes that every blockcipher's blocksize is a multiple of 32 bits */
register int blockwords = bc->blocksize >> 2;
register uint32_t* fdback = bc->getfb(bp);
register uint32_t* buf = (uint32_t*) malloc(blockwords * sizeof(uint32_t));
if (buf)
{
while (nblocks > 0)
{
register uint32_t tmp;
register int i;
bc->decrypt(bp, buf, src);
for (i = 0; i < blockwords; i++)
{
tmp = src[i];
dst[i] = buf[i] ^ fdback[i];
fdback[i] = tmp;
}
dst += blockwords;
src += blockwords;
nblocks--;
}
free(buf);
return 0;
}
return -1;
}
#ifdef DYING
int blockEncrypt(const blockCipher* bc, blockCipherParam* bp, cipherMode mode, int blocks, uint32* dst, const uint32* src)
{
if (bc->mode)
{
register const blockMode* bm = bc->mode+mode;
if (bm)
{
register const blockModeEncrypt be = bm->encrypt;
if (be)
return be(bp, blocks, dst, src);
}
}
return -1;
}
int blockDecrypt(const blockCipher* bc, blockCipherParam* bp, cipherMode mode, int blocks, uint32* dst, const uint32* src)
{
if (bc->mode)
{
register const blockMode* bm = bc->mode+mode;
if (bm)
{
register const blockModeEncrypt bd = bm->decrypt;
if (bd)
return bd(bp, blocks, dst, src);
}
}
return -1;
}
#endif
/*!\}
*/
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