openssl/crypto/des/xcbc_enc.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 "des_local.h"
/* RSA's DESX */
void DES_xcbc_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *schedule,
DES_cblock *ivec, const_DES_cblock *inw,
const_DES_cblock *outw, int enc)
{
register DES_LONG tin0, tin1;
register DES_LONG tout0, tout1, xor0, xor1;
register DES_LONG inW0, inW1, outW0, outW1;
register const unsigned char *in2;
register long l = length;
DES_LONG tin[2];
unsigned char *iv;
in2 = &(*inw)[0];
c2l(in2, inW0);
c2l(in2, inW1);
in2 = &(*outw)[0];
c2l(in2, outW0);
c2l(in2, outW1);
iv = &(*ivec)[0];
if (enc) {
c2l(iv, tout0);
c2l(iv, tout1);
for (l -= 8; l >= 0; l -= 8) {
c2l(in, tin0);
c2l(in, tin1);
tin0 ^= tout0 ^ inW0;
tin[0] = tin0;
tin1 ^= tout1 ^ inW1;
tin[1] = tin1;
DES_encrypt1(tin, schedule, DES_ENCRYPT);
tout0 = tin[0] ^ outW0;
l2c(tout0, out);
tout1 = tin[1] ^ outW1;
l2c(tout1, out);
}
if (l != -8) {
c2ln(in, tin0, tin1, l + 8);
tin0 ^= tout0 ^ inW0;
tin[0] = tin0;
tin1 ^= tout1 ^ inW1;
tin[1] = tin1;
DES_encrypt1(tin, schedule, DES_ENCRYPT);
tout0 = tin[0] ^ outW0;
l2c(tout0, out);
tout1 = tin[1] ^ outW1;
l2c(tout1, out);
}
iv = &(*ivec)[0];
l2c(tout0, iv);
l2c(tout1, iv);
} else {
c2l(iv, xor0);
c2l(iv, xor1);
for (l -= 8; l > 0; l -= 8) {
c2l(in, tin0);
tin[0] = tin0 ^ outW0;
c2l(in, tin1);
tin[1] = tin1 ^ outW1;
DES_encrypt1(tin, schedule, DES_DECRYPT);
tout0 = tin[0] ^ xor0 ^ inW0;
tout1 = tin[1] ^ xor1 ^ inW1;
l2c(tout0, out);
l2c(tout1, out);
xor0 = tin0;
xor1 = tin1;
}
if (l != -8) {
c2l(in, tin0);
tin[0] = tin0 ^ outW0;
c2l(in, tin1);
tin[1] = tin1 ^ outW1;
DES_encrypt1(tin, schedule, DES_DECRYPT);
tout0 = tin[0] ^ xor0 ^ inW0;
tout1 = tin[1] ^ xor1 ^ inW1;
l2cn(tout0, tout1, out, l + 8);
xor0 = tin0;
xor1 = tin1;
}
iv = &(*ivec)[0];
l2c(xor0, iv);
l2c(xor1, iv);
}
tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
inW0 = inW1 = outW0 = outW1 = 0;
tin[0] = tin[1] = 0;
}