yuzu/externals/libressl/crypto/des/cfb64ede.c
2020-12-28 15:15:37 +00:00

245 lines
6.5 KiB
C
Executable File

/* $OpenBSD: cfb64ede.c,v 1.9 2015/02/07 13:19:15 doug Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include "des_locl.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)
{
DES_LONG v0,v1;
long l=length;
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)
{
DES_LONG d0,d1,v0,v1;
unsigned long l=length,n=((unsigned int)numbits+7)/8;
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;
}