openssl/crypto/des/cfb64ede.c

190 lines
5.4 KiB
C

/*
* Copyright 1995-2017 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"
/*
* The input and output encrypted as though 64bit cfb mode is being used.
* The extra state information to record how much of the 64bit block we have
* used is contained in *num;
*/
void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_key_schedule *ks3,
DES_cblock *ivec, int *num, int enc)
{
register DES_LONG v0, v1;
register long l = length;
register int n = *num;
DES_LONG ti[2];
unsigned char *iv, c, cc;
iv = &(*ivec)[0];
if (enc) {
while (l--) {
if (n == 0) {
c2l(iv, v0);
c2l(iv, v1);
ti[0] = v0;
ti[1] = v1;
DES_encrypt3(ti, ks1, ks2, ks3);
v0 = ti[0];
v1 = ti[1];
iv = &(*ivec)[0];
l2c(v0, iv);
l2c(v1, iv);
iv = &(*ivec)[0];
}
c = *(in++) ^ iv[n];
*(out++) = c;
iv[n] = c;
n = (n + 1) & 0x07;
}
} else {
while (l--) {
if (n == 0) {
c2l(iv, v0);
c2l(iv, v1);
ti[0] = v0;
ti[1] = v1;
DES_encrypt3(ti, ks1, ks2, ks3);
v0 = ti[0];
v1 = ti[1];
iv = &(*ivec)[0];
l2c(v0, iv);
l2c(v1, iv);
iv = &(*ivec)[0];
}
cc = *(in++);
c = iv[n];
iv[n] = cc;
*(out++) = c ^ cc;
n = (n + 1) & 0x07;
}
}
v0 = v1 = ti[0] = ti[1] = c = cc = 0;
*num = n;
}
/*
* This is compatible with the single key CFB-r for DES, even thought that's
* not what EVP needs.
*/
void DES_ede3_cfb_encrypt(const unsigned char *in, unsigned char *out,
int numbits, long length, DES_key_schedule *ks1,
DES_key_schedule *ks2, DES_key_schedule *ks3,
DES_cblock *ivec, int enc)
{
register DES_LONG d0, d1, v0, v1;
register unsigned long l = length, n = ((unsigned int)numbits + 7) / 8;
register int num = numbits, i;
DES_LONG ti[2];
unsigned char *iv;
unsigned char ovec[16];
if (num > 64)
return;
iv = &(*ivec)[0];
c2l(iv, v0);
c2l(iv, v1);
if (enc) {
while (l >= n) {
l -= n;
ti[0] = v0;
ti[1] = v1;
DES_encrypt3(ti, ks1, ks2, ks3);
c2ln(in, d0, d1, n);
in += n;
d0 ^= ti[0];
d1 ^= ti[1];
l2cn(d0, d1, out, n);
out += n;
/*
* 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
* gcc :-(
*/
if (num == 32) {
v0 = v1;
v1 = d0;
} else if (num == 64) {
v0 = d0;
v1 = d1;
} else {
iv = &ovec[0];
l2c(v0, iv);
l2c(v1, iv);
l2c(d0, iv);
l2c(d1, iv);
/* shift ovec left most of the bits... */
memmove(ovec, ovec + num / 8, 8 + (num % 8 ? 1 : 0));
/* now the remaining bits */
if (num % 8 != 0)
for (i = 0; i < 8; ++i) {
ovec[i] <<= num % 8;
ovec[i] |= ovec[i + 1] >> (8 - num % 8);
}
iv = &ovec[0];
c2l(iv, v0);
c2l(iv, v1);
}
}
} else {
while (l >= n) {
l -= n;
ti[0] = v0;
ti[1] = v1;
DES_encrypt3(ti, ks1, ks2, ks3);
c2ln(in, d0, d1, n);
in += n;
/*
* 30-08-94 - eay - changed because l>>32 and l<<32 are bad under
* gcc :-(
*/
if (num == 32) {
v0 = v1;
v1 = d0;
} else if (num == 64) {
v0 = d0;
v1 = d1;
} else {
iv = &ovec[0];
l2c(v0, iv);
l2c(v1, iv);
l2c(d0, iv);
l2c(d1, iv);
/* shift ovec left most of the bits... */
memmove(ovec, ovec + num / 8, 8 + (num % 8 ? 1 : 0));
/* now the remaining bits */
if (num % 8 != 0)
for (i = 0; i < 8; ++i) {
ovec[i] <<= num % 8;
ovec[i] |= ovec[i + 1] >> (8 - num % 8);
}
iv = &ovec[0];
c2l(iv, v0);
c2l(iv, v1);
}
d0 ^= ti[0];
d1 ^= ti[1];
l2cn(d0, d1, out, n);
out += n;
}
}
iv = &(*ivec)[0];
l2c(v0, iv);
l2c(v1, iv);
v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0;
}