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/*
* Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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 <string.h>
#include <openssl/crypto.h>
#include "internal/modes_int.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;
if (len == 0)
return;
#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;
if (len == 0)
return;
#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;
}
}
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