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