rc5_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 <stdio.h>
#include <openssl/rc5.h>
#include "rc5_locl.h"
void RC5_32_cbc_encrypt(const unsigned char *in, unsigned char *out,
long length, RC5_32_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;
RC5_32_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;
RC5_32_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;
RC5_32_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;
RC5_32_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 RC5_32_encrypt(unsigned long *d, RC5_32_KEY *key)
{
RC5_32_INT a, b, *s;
s = key->data;
a = d[0] + s[0];
b = d[1] + s[1];
E_RC5_32(a, b, s, 2);
E_RC5_32(a, b, s, 4);
E_RC5_32(a, b, s, 6);
E_RC5_32(a, b, s, 8);
E_RC5_32(a, b, s, 10);
E_RC5_32(a, b, s, 12);
E_RC5_32(a, b, s, 14);
E_RC5_32(a, b, s, 16);
if (key->rounds == 12) {
E_RC5_32(a, b, s, 18);
E_RC5_32(a, b, s, 20);
E_RC5_32(a, b, s, 22);
E_RC5_32(a, b, s, 24);
} else if (key->rounds == 16) {
/* Do a full expansion to avoid a jump */
E_RC5_32(a, b, s, 18);
E_RC5_32(a, b, s, 20);
E_RC5_32(a, b, s, 22);
E_RC5_32(a, b, s, 24);
E_RC5_32(a, b, s, 26);
E_RC5_32(a, b, s, 28);
E_RC5_32(a, b, s, 30);
E_RC5_32(a, b, s, 32);
}
d[0] = a;
d[1] = b;
}
void RC5_32_decrypt(unsigned long *d, RC5_32_KEY *key)
{
RC5_32_INT a, b, *s;
s = key->data;
a = d[0];
b = d[1];
if (key->rounds == 16) {
D_RC5_32(a, b, s, 32);
D_RC5_32(a, b, s, 30);
D_RC5_32(a, b, s, 28);
D_RC5_32(a, b, s, 26);
/* Do a full expansion to avoid a jump */
D_RC5_32(a, b, s, 24);
D_RC5_32(a, b, s, 22);
D_RC5_32(a, b, s, 20);
D_RC5_32(a, b, s, 18);
} else if (key->rounds == 12) {
D_RC5_32(a, b, s, 24);
D_RC5_32(a, b, s, 22);
D_RC5_32(a, b, s, 20);
D_RC5_32(a, b, s, 18);
}
D_RC5_32(a, b, s, 16);
D_RC5_32(a, b, s, 14);
D_RC5_32(a, b, s, 12);
D_RC5_32(a, b, s, 10);
D_RC5_32(a, b, s, 8);
D_RC5_32(a, b, s, 6);
D_RC5_32(a, b, s, 4);
D_RC5_32(a, b, s, 2);
d[0] = a - s[0];
d[1] = b - s[1];
}