openssl/crypto/seed/seed_cbc.c
2007-04-24 11:30:51 +00:00

129 lines
4.2 KiB
C

/* crypto/seed/seed_cbc.c -*- mode:C; c-file-style: "eay" -*- */
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
*/
#include "seed_locl.h"
#include <string.h>
void SEED_cbc_encrypt(const unsigned char *in, unsigned char *out,
size_t len, const SEED_KEY_SCHEDULE *ks,
unsigned char ivec[SEED_BLOCK_SIZE], int enc)
{
size_t n;
unsigned char tmp[SEED_BLOCK_SIZE];
const unsigned char *iv = ivec;
if (enc)
{
while (len >= SEED_BLOCK_SIZE)
{
for (n = 0; n < SEED_BLOCK_SIZE; ++n)
out[n] = in[n] ^ iv[n];
SEED_encrypt(out, out, ks);
iv = out;
len -= SEED_BLOCK_SIZE;
in += SEED_BLOCK_SIZE;
out += SEED_BLOCK_SIZE;
}
if (len)
{
for (n = 0; n < len; ++n)
out[n] = in[n] ^ iv[n];
for (n = len; n < SEED_BLOCK_SIZE; ++n)
out[n] = iv[n];
SEED_encrypt(out, out, ks);
iv = out;
}
memcpy(ivec, iv, SEED_BLOCK_SIZE);
}
else if (in != out) /* decrypt */
{
while (len >= SEED_BLOCK_SIZE)
{
SEED_decrypt(in, out, ks);
for (n = 0; n < SEED_BLOCK_SIZE; ++n)
out[n] ^= iv[n];
iv = in;
len -= SEED_BLOCK_SIZE;
in += SEED_BLOCK_SIZE;
out += SEED_BLOCK_SIZE;
}
if (len)
{
SEED_decrypt(in, tmp, ks);
for (n = 0; n < len; ++n)
out[n] = tmp[n] ^ iv[n];
iv = in;
}
memcpy(ivec, iv, SEED_BLOCK_SIZE);
}
else /* decrypt, overlap */
{
while (len >= SEED_BLOCK_SIZE)
{
memcpy(tmp, in, SEED_BLOCK_SIZE);
SEED_decrypt(in, out, ks);
for (n = 0; n < SEED_BLOCK_SIZE; ++n)
out[n] ^= ivec[n];
memcpy(ivec, tmp, SEED_BLOCK_SIZE);
len -= SEED_BLOCK_SIZE;
in += SEED_BLOCK_SIZE;
out += SEED_BLOCK_SIZE;
}
if (len)
{
memcpy(tmp, in, SEED_BLOCK_SIZE);
SEED_decrypt(tmp, tmp, ks);
for (n = 0; n < len; ++n)
out[n] = tmp[n] ^ ivec[n];
memcpy(ivec, tmp, SEED_BLOCK_SIZE);
}
}
}