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

/* set_key.c */ 
/* Copyright (C) 1993 Eric Young - see README for more details */ 
/* set_key.c v 1.4 eay 24/9/91 
 * 1.4 Speed up by 400% :-) 
 * 1.3 added register declarations. 
 * 1.2 unrolled make_key_sched a bit more 
 * 1.1 added norm_expand_bits 
 * 1.0 First working version 
 */ 
#include "des_locl.h" 
#include "podd.h" 
#include "sk.h" 
 
static int check_parity(); 
 
int des_check_key=0; 
 
void des_set_odd_parity(key) 
des_cblock *key; 
    { 
    int i; 
 
    for (i=0; i>(n))^(b))&(m)),\ 
 *  (b)^=(t),\ 
 *  (a)=((a)^((t)<<(n)))) 
 */ 
 
#define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\ 
    (a)=(a)^(t)^(t>>(16-(n)))) 
 
static char shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0}; 
 
/* return 0 if key parity is odd (correct), 
 * return -1 if key parity error, 
 * return -2 if illegal weak key. 
 */ 
int des_set_key(key,schedule) 
des_cblock *key; 
des_key_schedule schedule; 
    { 
    register unsigned long c,d,t,s; 
    register unsigned char *in; 
    register unsigned long *k; 
    register int i; 
 
    if (des_check_key) 
        { 
        if (!check_parity(key)) 
            return(-1); 
 
        if (des_is_weak_key(key)) 
            return(-2); 
        } 
 
    k=(unsigned long *)schedule; 
    in=(unsigned char *)key; 
 
    c2l(in,c); 
    c2l(in,d); 
 
    /* do PC1 in 60 simple operations */  
/*  PERM_OP(d,c,t,4,0x0f0f0f0f); 
    HPERM_OP(c,t,-2, 0xcccc0000); 
    HPERM_OP(c,t,-1, 0xaaaa0000); 
    HPERM_OP(c,t, 8, 0x00ff0000); 
    HPERM_OP(c,t,-1, 0xaaaa0000); 
    HPERM_OP(d,t,-8, 0xff000000); 
    HPERM_OP(d,t, 8, 0x00ff0000); 
    HPERM_OP(d,t, 2, 0x33330000); 
    d=((d&0x00aa00aa)<<7)|((d&0x55005500)>>7)|(d&0xaa55aa55); 
    d=(d>>8)|((c&0xf0000000)>>4); 
    c&=0x0fffffff; */ 
 
    /* I now do it in 47 simple operations :-) 
     * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov) 
     * for the inspiration. :-) */ 
    PERM_OP (d,c,t,4,0x0f0f0f0f); 
    HPERM_OP(c,t,-2,0xcccc0000); 
    HPERM_OP(d,t,-2,0xcccc0000); 
    PERM_OP (d,c,t,1,0x55555555); 
    PERM_OP (c,d,t,8,0x00ff00ff); 
    PERM_OP (d,c,t,1,0x55555555); 
    d=  (((d&0x000000ff)<<16)| (d&0x0000ff00)     | 
         ((d&0x00ff0000)>>16)|((c&0xf0000000)>>4)); 
    c&=0x0fffffff; 
 
    for (i=0; i>2)|(c<<26)); d=((d>>2)|(d<<26)); } 
        else 
            { c=((c>>1)|(c<<27)); d=((d>>1)|(d<<27)); } 
        c&=0x0fffffff; 
        d&=0x0fffffff; 
        /* could be a few less shifts but I am to lazy at this 
         * point in time to investigate */ 
        s=  des_skb[0][ (c    )&0x3f                ]| 
            des_skb[1][((c>> 6)&0x03)|((c>> 7)&0x3c)]| 
            des_skb[2][((c>>13)&0x0f)|((c>>14)&0x30)]| 
            des_skb[3][((c>>20)&0x01)|((c>>21)&0x06) | 
                          ((c>>22)&0x38)]; 
        t=  des_skb[4][ (d    )&0x3f                ]| 
            des_skb[5][((d>> 7)&0x03)|((d>> 8)&0x3c)]| 
            des_skb[6][ (d>>15)&0x3f                ]| 
            des_skb[7][((d>>21)&0x0f)|((d>>22)&0x30)]; 
 
        /* table contained 0213 4657 */ 
        *(k++)=((t<<16)|(s&0x0000ffff))&0xffffffff; 
        s=     ((s>>16)|(t&0xffff0000)); 
         
        s=(s<<4)|(s>>28); 
        *(k++)=s&0xffffffff; 
        } 
    return(0); 
    } 
 
int des_key_sched(key,schedule) 
des_cblock *key; 
des_key_schedule schedule; 
    { 
    return(des_set_key(key,schedule)); 
    }