str2key.c

Netscape公司提供的安全套接字层

/* str2key.c */
/* Copyright (C) 1993 Eric Young - see README for more details */
#include "des_locl.h"

extern int des_check_key;

int des_string_to_key(str,key)
char *str;
des_cblock *key;
    {
    des_key_schedule ks;
    int i,length;
    register unsigned char j;

    bzero(key,8);
    length=strlen(str);
#ifdef OLD_STR_TO_KEY
    for (i=0; i<length; i++)
        (*key)[i%8]^=(str[i]<<1);
#else /* MIT COMPATIBLE */
    for (i=0; i<length; i++)
        {
        j=str[i];
        if ((i%16) < 8)
            (*key)[i%8]^=(j<<1);
        else
            {
            /* Reverse the bit order 05/05/92 eay */
            j=((j<<4)&0xf0)|((j>>4)&0x0f);
            j=((j<<2)&0xcc)|((j>>2)&0x33);
            j=((j<<1)&0xaa)|((j>>1)&0x55);
            (*key)[7-(i%8)]^=j;
            }
        }
#endif
    des_set_odd_parity((des_cblock *)key);
    i=des_check_key;
    des_check_key=0;
    des_set_key((des_cblock *)key,ks);
    des_check_key=i;
    des_cbc_cksum((des_cblock *)str,(des_cblock *)key,(long)length,ks,
        (des_cblock *)key);
    bzero(ks,sizeof(ks));
    des_set_odd_parity((des_cblock *)key);
    return(0);
    }

int des_string_to_2keys(str,key1,key2)
char *str;
des_cblock *key1,*key2;
    {
    des_key_schedule ks;
    int i,length;
    register unsigned char j;

    bzero(key1,8);
    bzero(key2,8);
    length=strlen(str);
#ifdef OLD_STR_TO_KEY
    if (length <= 8)
        {
        for (i=0; i<length; i++)
            {
            (*key2)[i]=(*key1)[i]=(str[i]<<1);
            }
        }
    else
        {
        for (i=0; i<length; i++)
            {
            if ((i/8)&1)
                (*key2)[i%8]^=(str[i]<<1);
            else
                (*key1)[i%8]^=(str[i]<<1);
            }
        }
#else /* MIT COMPATIBLE */
    for (i=0; i<length; i++)
        {
        j=str[i];
        if ((i%32) < 16)
            {
            if ((i%16) < 8)
                (*key1)[i%8]^=(j<<1);
            else
                (*key2)[i%8]^=(j<<1);
            }
        else
            {
            j=((j<<4)&0xf0)|((j>>4)&0x0f);
            j=((j<<2)&0xcc)|((j>>2)&0x33);
            j=((j<<1)&0xaa)|((j>>1)&0x55);
            if ((i%16) < 8)
                (*key1)[7-(i%8)]^=j;
            else
                (*key2)[7-(i%8)]^=j;
            }
        }
    if (length <= 8) bcopy(key1,key2,8);
#endif
    des_set_odd_parity((des_cblock *)key1);
    des_set_odd_parity((des_cblock *)key2);
    i=des_check_key;
    des_check_key=0;
    des_set_key((des_cblock *)key1,ks);
    des_cbc_cksum((des_cblock *)str,(des_cblock *)key1,(long)length,ks,
        (des_cblock *)key1);
    des_set_key((des_cblock *)key2,ks);
    des_cbc_cksum((des_cblock *)str,(des_cblock *)key2,(long)length,ks,
        (des_cblock *)key2);
    des_check_key=i;
    bzero(ks,sizeof(ks));
    des_set_odd_parity(key1);
    des_set_odd_parity(key2);
    return(0);
    }