openssl1.0/crypto/modes/cbc128.c

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2019-08-09 10:00:55 +02:00
/* ====================================================================
* Copyright (c) 2008 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 <openssl/crypto.h>
#include "modes_lcl.h"
#include <string.h>
#ifndef MODES_DEBUG
# ifndef NDEBUG
# define NDEBUG
# endif
#endif
#include <assert.h>
#if !defined(STRICT_ALIGNMENT) && !defined(PEDANTIC)
# define STRICT_ALIGNMENT 0
#endif
void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
size_t len, const void *key,
unsigned char ivec[16], block128_f block)
{
size_t n;
const unsigned char *iv = ivec;
assert(in && out && key && ivec);
#if !defined(OPENSSL_SMALL_FOOTPRINT)
if (STRICT_ALIGNMENT &&
((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
while (len >= 16) {
for (n = 0; n < 16; ++n)
out[n] = in[n] ^ iv[n];
(*block) (out, out, key);
iv = out;
len -= 16;
in += 16;
out += 16;
}
} else {
while (len >= 16) {
for (n = 0; n < 16; n += sizeof(size_t))
*(size_t *)(out + n) =
*(size_t *)(in + n) ^ *(size_t *)(iv + n);
(*block) (out, out, key);
iv = out;
len -= 16;
in += 16;
out += 16;
}
}
#endif
while (len) {
for (n = 0; n < 16 && n < len; ++n)
out[n] = in[n] ^ iv[n];
for (; n < 16; ++n)
out[n] = iv[n];
(*block) (out, out, key);
iv = out;
if (len <= 16)
break;
len -= 16;
in += 16;
out += 16;
}
memcpy(ivec, iv, 16);
}
void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
size_t len, const void *key,
unsigned char ivec[16], block128_f block)
{
size_t n;
union {
size_t t[16 / sizeof(size_t)];
unsigned char c[16];
} tmp;
assert(in && out && key && ivec);
#if !defined(OPENSSL_SMALL_FOOTPRINT)
if (in != out) {
const unsigned char *iv = ivec;
if (STRICT_ALIGNMENT &&
((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
while (len >= 16) {
(*block) (in, out, key);
for (n = 0; n < 16; ++n)
out[n] ^= iv[n];
iv = in;
len -= 16;
in += 16;
out += 16;
}
} else if (16 % sizeof(size_t) == 0) { /* always true */
while (len >= 16) {
size_t *out_t = (size_t *)out, *iv_t = (size_t *)iv;
(*block) (in, out, key);
for (n = 0; n < 16 / sizeof(size_t); n++)
out_t[n] ^= iv_t[n];
iv = in;
len -= 16;
in += 16;
out += 16;
}
}
memcpy(ivec, iv, 16);
} else {
if (STRICT_ALIGNMENT &&
((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
unsigned char c;
while (len >= 16) {
(*block) (in, tmp.c, key);
for (n = 0; n < 16; ++n) {
c = in[n];
out[n] = tmp.c[n] ^ ivec[n];
ivec[n] = c;
}
len -= 16;
in += 16;
out += 16;
}
} else if (16 % sizeof(size_t) == 0) { /* always true */
while (len >= 16) {
size_t c, *out_t = (size_t *)out, *ivec_t = (size_t *)ivec;
const size_t *in_t = (const size_t *)in;
(*block) (in, tmp.c, key);
for (n = 0; n < 16 / sizeof(size_t); n++) {
c = in_t[n];
out_t[n] = tmp.t[n] ^ ivec_t[n];
ivec_t[n] = c;
}
len -= 16;
in += 16;
out += 16;
}
}
}
#endif
while (len) {
unsigned char c;
(*block) (in, tmp.c, key);
for (n = 0; n < 16 && n < len; ++n) {
c = in[n];
out[n] = tmp.c[n] ^ ivec[n];
ivec[n] = c;
}
if (len <= 16) {
for (; n < 16; ++n)
ivec[n] = in[n];
break;
}
len -= 16;
in += 16;
out += 16;
}
}