c_enc.c
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/*
* Copyright 1995-2016 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/cast.h>
#include "cast_lcl.h"
void CAST_encrypt(CAST_LONG *data, const CAST_KEY *key)
{
CAST_LONG l, r, t;
const CAST_LONG *k;
k = &(key->data[0]);
l = data[0];
r = data[1];
E_CAST(0, k, l, r, +, ^, -);
E_CAST(1, k, r, l, ^, -, +);
E_CAST(2, k, l, r, -, +, ^);
E_CAST(3, k, r, l, +, ^, -);
E_CAST(4, k, l, r, ^, -, +);
E_CAST(5, k, r, l, -, +, ^);
E_CAST(6, k, l, r, +, ^, -);
E_CAST(7, k, r, l, ^, -, +);
E_CAST(8, k, l, r, -, +, ^);
E_CAST(9, k, r, l, +, ^, -);
E_CAST(10, k, l, r, ^, -, +);
E_CAST(11, k, r, l, -, +, ^);
if (!key->short_key) {
E_CAST(12, k, l, r, +, ^, -);
E_CAST(13, k, r, l, ^, -, +);
E_CAST(14, k, l, r, -, +, ^);
E_CAST(15, k, r, l, +, ^, -);
}
data[1] = l & 0xffffffffL;
data[0] = r & 0xffffffffL;
}
void CAST_decrypt(CAST_LONG *data, const CAST_KEY *key)
{
CAST_LONG l, r, t;
const CAST_LONG *k;
k = &(key->data[0]);
l = data[0];
r = data[1];
if (!key->short_key) {
E_CAST(15, k, l, r, +, ^, -);
E_CAST(14, k, r, l, -, +, ^);
E_CAST(13, k, l, r, ^, -, +);
E_CAST(12, k, r, l, +, ^, -);
}
E_CAST(11, k, l, r, -, +, ^);
E_CAST(10, k, r, l, ^, -, +);
E_CAST(9, k, l, r, +, ^, -);
E_CAST(8, k, r, l, -, +, ^);
E_CAST(7, k, l, r, ^, -, +);
E_CAST(6, k, r, l, +, ^, -);
E_CAST(5, k, l, r, -, +, ^);
E_CAST(4, k, r, l, ^, -, +);
E_CAST(3, k, l, r, +, ^, -);
E_CAST(2, k, r, l, -, +, ^);
E_CAST(1, k, l, r, ^, -, +);
E_CAST(0, k, r, l, +, ^, -);
data[1] = l & 0xffffffffL;
data[0] = r & 0xffffffffL;
}
void CAST_cbc_encrypt(const unsigned char *in, unsigned char *out,
long length, const CAST_KEY *ks, unsigned char *iv,
int enc)
{
register CAST_LONG tin0, tin1;
register CAST_LONG tout0, tout1, xor0, xor1;
register long l = length;
CAST_LONG tin[2];
if (enc) {
n2l(iv, tout0);
n2l(iv, tout1);
iv -= 8;
for (l -= 8; l >= 0; l -= 8) {
n2l(in, tin0);
n2l(in, tin1);
tin0 ^= tout0;
tin1 ^= tout1;
tin[0] = tin0;
tin[1] = tin1;
CAST_encrypt(tin, ks);
tout0 = tin[0];
tout1 = tin[1];
l2n(tout0, out);
l2n(tout1, out);
}
if (l != -8) {
n2ln(in, tin0, tin1, l + 8);
tin0 ^= tout0;
tin1 ^= tout1;
tin[0] = tin0;
tin[1] = tin1;
CAST_encrypt(tin, ks);
tout0 = tin[0];
tout1 = tin[1];
l2n(tout0, out);
l2n(tout1, out);
}
l2n(tout0, iv);
l2n(tout1, iv);
} else {
n2l(iv, xor0);
n2l(iv, xor1);
iv -= 8;
for (l -= 8; l >= 0; l -= 8) {
n2l(in, tin0);
n2l(in, tin1);
tin[0] = tin0;
tin[1] = tin1;
CAST_decrypt(tin, ks);
tout0 = tin[0] ^ xor0;
tout1 = tin[1] ^ xor1;
l2n(tout0, out);
l2n(tout1, out);
xor0 = tin0;
xor1 = tin1;
}
if (l != -8) {
n2l(in, tin0);
n2l(in, tin1);
tin[0] = tin0;
tin[1] = tin1;
CAST_decrypt(tin, ks);
tout0 = tin[0] ^ xor0;
tout1 = tin[1] ^ xor1;
l2nn(tout0, tout1, out, l + 8);
xor0 = tin0;
xor1 = tin1;
}
l2n(xor0, iv);
l2n(xor1, iv);
}
tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
tin[0] = tin[1] = 0;
}