openssl/crypto/rc2/rc2_cbc.c

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2023-05-09 22:08:48 +00:00
/*
* 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/rc2.h>
#include "rc2_local.h"
void RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
RC2_KEY *ks, unsigned char *iv, int encrypt)
{
register unsigned long tin0, tin1;
register unsigned long tout0, tout1, xor0, xor1;
register long l = length;
unsigned long tin[2];
if (encrypt) {
c2l(iv, tout0);
c2l(iv, tout1);
iv -= 8;
for (l -= 8; l >= 0; l -= 8) {
c2l(in, tin0);
c2l(in, tin1);
tin0 ^= tout0;
tin1 ^= tout1;
tin[0] = tin0;
tin[1] = tin1;
RC2_encrypt(tin, ks);
tout0 = tin[0];
l2c(tout0, out);
tout1 = tin[1];
l2c(tout1, out);
}
if (l != -8) {
c2ln(in, tin0, tin1, l + 8);
tin0 ^= tout0;
tin1 ^= tout1;
tin[0] = tin0;
tin[1] = tin1;
RC2_encrypt(tin, ks);
tout0 = tin[0];
l2c(tout0, out);
tout1 = tin[1];
l2c(tout1, out);
}
l2c(tout0, iv);
l2c(tout1, iv);
} else {
c2l(iv, xor0);
c2l(iv, xor1);
iv -= 8;
for (l -= 8; l >= 0; l -= 8) {
c2l(in, tin0);
tin[0] = tin0;
c2l(in, tin1);
tin[1] = tin1;
RC2_decrypt(tin, ks);
tout0 = tin[0] ^ xor0;
tout1 = tin[1] ^ xor1;
l2c(tout0, out);
l2c(tout1, out);
xor0 = tin0;
xor1 = tin1;
}
if (l != -8) {
c2l(in, tin0);
tin[0] = tin0;
c2l(in, tin1);
tin[1] = tin1;
RC2_decrypt(tin, ks);
tout0 = tin[0] ^ xor0;
tout1 = tin[1] ^ xor1;
l2cn(tout0, tout1, out, l + 8);
xor0 = tin0;
xor1 = tin1;
}
l2c(xor0, iv);
l2c(xor1, iv);
}
tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
tin[0] = tin[1] = 0;
}
void RC2_encrypt(unsigned long *d, RC2_KEY *key)
{
int i, n;
register RC2_INT *p0, *p1;
register RC2_INT x0, x1, x2, x3, t;
unsigned long l;
l = d[0];
x0 = (RC2_INT) l & 0xffff;
x1 = (RC2_INT) (l >> 16L);
l = d[1];
x2 = (RC2_INT) l & 0xffff;
x3 = (RC2_INT) (l >> 16L);
n = 3;
i = 5;
p0 = p1 = &(key->data[0]);
for (;;) {
t = (x0 + (x1 & ~x3) + (x2 & x3) + *(p0++)) & 0xffff;
x0 = (t << 1) | (t >> 15);
t = (x1 + (x2 & ~x0) + (x3 & x0) + *(p0++)) & 0xffff;
x1 = (t << 2) | (t >> 14);
t = (x2 + (x3 & ~x1) + (x0 & x1) + *(p0++)) & 0xffff;
x2 = (t << 3) | (t >> 13);
t = (x3 + (x0 & ~x2) + (x1 & x2) + *(p0++)) & 0xffff;
x3 = (t << 5) | (t >> 11);
if (--i == 0) {
if (--n == 0)
break;
i = (n == 2) ? 6 : 5;
x0 += p1[x3 & 0x3f];
x1 += p1[x0 & 0x3f];
x2 += p1[x1 & 0x3f];
x3 += p1[x2 & 0x3f];
}
}
d[0] =
(unsigned long)(x0 & 0xffff) | ((unsigned long)(x1 & 0xffff) << 16L);
d[1] =
(unsigned long)(x2 & 0xffff) | ((unsigned long)(x3 & 0xffff) << 16L);
}
void RC2_decrypt(unsigned long *d, RC2_KEY *key)
{
int i, n;
register RC2_INT *p0, *p1;
register RC2_INT x0, x1, x2, x3, t;
unsigned long l;
l = d[0];
x0 = (RC2_INT) l & 0xffff;
x1 = (RC2_INT) (l >> 16L);
l = d[1];
x2 = (RC2_INT) l & 0xffff;
x3 = (RC2_INT) (l >> 16L);
n = 3;
i = 5;
p0 = &(key->data[63]);
p1 = &(key->data[0]);
for (;;) {
t = ((x3 << 11) | (x3 >> 5)) & 0xffff;
x3 = (t - (x0 & ~x2) - (x1 & x2) - *(p0--)) & 0xffff;
t = ((x2 << 13) | (x2 >> 3)) & 0xffff;
x2 = (t - (x3 & ~x1) - (x0 & x1) - *(p0--)) & 0xffff;
t = ((x1 << 14) | (x1 >> 2)) & 0xffff;
x1 = (t - (x2 & ~x0) - (x3 & x0) - *(p0--)) & 0xffff;
t = ((x0 << 15) | (x0 >> 1)) & 0xffff;
x0 = (t - (x1 & ~x3) - (x2 & x3) - *(p0--)) & 0xffff;
if (--i == 0) {
if (--n == 0)
break;
i = (n == 2) ? 6 : 5;
x3 = (x3 - p1[x2 & 0x3f]) & 0xffff;
x2 = (x2 - p1[x1 & 0x3f]) & 0xffff;
x1 = (x1 - p1[x0 & 0x3f]) & 0xffff;
x0 = (x0 - p1[x3 & 0x3f]) & 0xffff;
}
}
d[0] =
(unsigned long)(x0 & 0xffff) | ((unsigned long)(x1 & 0xffff) << 16L);
d[1] =
(unsigned long)(x2 & 0xffff) | ((unsigned long)(x3 & 0xffff) << 16L);
}