82 lines
2.3 KiB
C
82 lines
2.3 KiB
C
|
/*
|
||
|
|
* Copyright 2008-2020 The OpenSSL Project Authors. All Rights Reserved.
|
||
|
|
*
|
||
|
|
* Licensed under the OpenSSL license (the "License"). You may not use
|
||
|
|
* this file except in compliance with the License. You can obtain a copy
|
||
|
|
* in the file LICENSE in the source distribution or at
|
||
|
|
* https://www.openssl.org/source/license.html
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <openssl/crypto.h>
|
||
|
|
#include "modes_local.h"
|
||
|
|
#include <string.h>
|
||
|
|
|
||
|
|
#if defined(__GNUC__) && !defined(STRICT_ALIGNMENT)
|
||
|
|
typedef size_t size_t_aX __attribute((__aligned__(1)));
|
||
|
|
#else
|
||
|
|
typedef size_t size_t_aX;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The input and output encrypted as though 128bit ofb mode is being used.
|
||
|
|
* The extra state information to record how much of the 128bit block we have
|
||
|
|
* used is contained in *num;
|
||
|
|
*/
|
||
|
|
void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out,
|
||
|
|
size_t len, const void *key,
|
||
|
|
unsigned char ivec[16], int *num, block128_f block)
|
||
|
|
{
|
||
|
|
unsigned int n;
|
||
|
|
size_t l = 0;
|
||
|
|
|
||
|
|
n = *num;
|
||
|
|
|
||
|
|
#if !defined(OPENSSL_SMALL_FOOTPRINT)
|
||
|
|
if (16 % sizeof(size_t) == 0) { /* always true actually */
|
||
|
|
do {
|
||
|
|
while (n && len) {
|
||
|
|
*(out++) = *(in++) ^ ivec[n];
|
||
|
|
--len;
|
||
|
|
n = (n + 1) % 16;
|
||
|
|
}
|
||
|
|
# if defined(STRICT_ALIGNMENT)
|
||
|
|
if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) !=
|
||
|
|
0)
|
||
|
|
break;
|
||
|
|
# endif
|
||
|
|
while (len >= 16) {
|
||
|
|
(*block) (ivec, ivec, key);
|
||
|
|
for (; n < 16; n += sizeof(size_t))
|
||
|
|
*(size_t_aX *)(out + n) =
|
||
|
|
*(size_t_aX *)(in + n)
|
||
|
|
^ *(size_t_aX *)(ivec + n);
|
||
|
|
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;
|
||
|
|
return;
|
||
|
|
} while (0);
|
||
|
|
}
|
||
|
|
/* the rest would be commonly eliminated by x86* compiler */
|
||
|
|
#endif
|
||
|
|
while (l < len) {
|
||
|
|
if (n == 0) {
|
||
|
|
(*block) (ivec, ivec, key);
|
||
|
|
}
|
||
|
|
out[l] = in[l] ^ ivec[n];
|
||
|
|
++l;
|
||
|
|
n = (n + 1) % 16;
|
||
|
|
}
|
||
|
|
|
||
|
|
*num = n;
|
||
|
|
}
|