/* ====================================================================
* 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,
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ==================================================================== */
#include <openssl/type_check.h>
#include <assert.h>
#include <string.h>
#include "internal.h"
OPENSSL_STATIC_ASSERT(16 % sizeof(size_t) == 0,
"block cannot be divided into size_t");
void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
const AES_KEY *key, uint8_t ivec[16], unsigned *num,
block128_f block) {
assert(in && out && key && ivec && num);
unsigned n = *num;
while (n && len) {
*(out++) = *(in++) ^ ivec[n];
--len;
n = (n + 1) % 16;
}
while (len >= 16) {
(*block)(ivec, ivec, key);
for (; n < 16; n += sizeof(size_t)) {
size_t a, b;
OPENSSL_memcpy(&a, in + n, sizeof(size_t));
OPENSSL_memcpy(&b, ivec + n, sizeof(size_t));
const size_t c = a ^ b;
OPENSSL_memcpy(out + n, &c, sizeof(size_t));
}
len -= 16;
out += 16;
in += 16;
n = 0;
}
if (len) {
(*block)(ivec, ivec, key);
while (len--) {
out[n] = in[n] ^ ivec[n];
++n;
}
}
*num = n;
}