freebsd-dev/eBones/des/pcbc_enc.c

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/* pcbc_enc.c */
/* Copyright (C) 1993 Eric Young - see README for more details */
/*-
* $Id: pcbc_enc.c,v 1.2 1994/07/19 19:22:01 g89r4222 Exp $
*/
#include "des_locl.h"
int des_pcbc_encrypt(input,output,length,schedule,ivec,encrypt)
des_cblock *input;
des_cblock *output;
register long length;
des_key_schedule schedule;
des_cblock *ivec;
int encrypt;
{
register unsigned long sin0,sin1,xor0,xor1,tout0,tout1;
unsigned long tin[2],tout[2];
unsigned char *in,*out,*iv;
in=(unsigned char *)input;
out=(unsigned char *)output;
iv=(unsigned char *)ivec;
if (encrypt)
{
c2l(iv,xor0);
c2l(iv,xor1);
for (; length>0; length-=8)
{
if (length >= 8)
{
c2l(in,sin0);
c2l(in,sin1);
}
else
c2ln(in,sin0,sin1,length);
tin[0]=sin0^xor0;
tin[1]=sin1^xor1;
des_encrypt((unsigned long *)tin,(unsigned long *)tout,
schedule,encrypt);
tout0=tout[0];
tout1=tout[1];
xor0=sin0^tout[0];
xor1=sin1^tout[1];
l2c(tout0,out);
l2c(tout1,out);
}
}
else
{
c2l(iv,xor0); c2l(iv,xor1);
for (; length>0; length-=8)
{
c2l(in,sin0);
c2l(in,sin1);
tin[0]=sin0;
tin[1]=sin1;
des_encrypt((unsigned long *)tin,(unsigned long *)tout,
schedule,encrypt);
tout0=tout[0]^xor0;
tout1=tout[1]^xor1;
if (length >= 8)
{
l2c(tout0,out);
l2c(tout1,out);
}
else
l2cn(tout0,tout1,out,length);
xor0=tout0^sin0;
xor1=tout1^sin1;
}
}
tin[0]=tin[1]=tout[0]=tout[1]=0;
sin0=sin1=xor0=xor1=tout0=tout1=0;
return(0);
}