www.pudn.com > sslref30.zip > cbc_cksm.c

/* cbc_cksm.c */ 
/* Copyright (C) 1993 Eric Young - see README for more details */ 
#include "des_locl.h" 
 
unsigned long des_cbc_cksum(input,output,length,schedule,ivec) 
des_cblock *input; 
des_cblock *output; 
long length; 
des_key_schedule schedule; 
des_cblock *ivec; 
    { 
    register unsigned long tout0,tout1,tin0,tin1; 
    register long l=length; 
    unsigned long tin[2],tout[2]; 
    unsigned char *in,*out,*iv; 
 
    in=(unsigned char *)input; 
    out=(unsigned char *)output; 
    iv=(unsigned char *)ivec; 
 
    c2l(iv,tout0); 
    c2l(iv,tout1); 
    for (; l>0; l-=8) 
        { 
        if (l >= 8) 
            { 
            c2l(in,tin0); 
            c2l(in,tin1); 
            } 
        else 
            c2ln(in,tin0,tin1,l); 
             
        tin0^=tout0; 
        tin1^=tout1; 
        tin[0]=tin0; 
        tin[1]=tin1; 
        des_encrypt((unsigned long *)tin,(unsigned long *)tout, 
            schedule,DES_ENCRYPT); 
        /* fix 15/10/91 eay - thanks to keithr@sco.COM */ 
        tout0=tout[0]; 
        tout1=tout[1]; 
        } 
    if (out != NULL) 
        { 
        l2c(tout0,out); 
        l2c(tout1,out); 
        } 
    tout0=tin0=tin1=tin[0]=tin[1]=tout[0]=tout[1]=0; 
    return(tout1); 
    }