D:/opendownloadmanager/ODM-1.x/FDMCustomized/FDMCustomized_lib/libdes/pcbc_enc.c

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/* pcbc_enc.c */
/* Copyright (C) 1995 Eric Young (eay@mincom.oz.au).
 * All rights reserved.
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * See the COPYRIGHT file in the libdes distribution for more details.
 */

#ifdef _MSC_VER
  #include "des_locl.h"
#else
  #include "libdes/des_locl.h"
#endif /* _MSC_VER */

int des_pcbc_encrypt(input,output,length,schedule,ivec,encrypt)
des_cblock *input;
des_cblock *output;
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);
        }

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