1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182
|
/*
* Copyright (C) 2001, 2002, and 2003 Roy Keene
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* email: dact@rkeene.org
*/
/*
Encrypt data.
*/
#include "cipher_sub.h"
#include "parse.h"
#include "dact.h"
#include "ui.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <fcntl.h>
#include <stdio.h>
#ifndef RANDOM_DEV
#ifdef TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif
#endif
#if defined(USE_MODULES) && defined(AS_MODULE)
#include "module.h"
uint32_t DC_NUM=1;
uint32_t DC_TYPE=DACT_MOD_TYPE_ENC;
void *DC_ALGO=cipher_sub;
char *DC_NAME="subst (MOD)";
#endif
int cipher_sub(const unsigned char *inblock, unsigned char *outblock, const int blksize, unsigned char *key, const int mode) {
switch (mode) {
case (DACT_MODE_CINIT+DACT_MODE_CDEC):
case (DACT_MODE_CINIT+DACT_MODE_CENC):
case DACT_MODE_CINIT:
return(cipher_sub_init(mode,key));
break;
case DACT_MODE_CDEC:
return(cipher_sub_decrypt(inblock, outblock, blksize, key));
break;
case DACT_MODE_CENC:
return(cipher_sub_encrypt(inblock, outblock, blksize, key));
break;
}
return(0);
}
int cipher_sub_init(const int mode, unsigned char *key) {
return(cipher_sub_init_getkey(mode-DACT_MODE_CINIT,key));
}
int cipher_sub_init_getkey(const int mode, unsigned char *key) {
char *fname;
char keybuf[1024], *ptrbuf;
int fd,x=257;
fname=dact_ui_getuserinput("Key file: ",128,0);
fd=open(fname, O_RDONLY);
if (fd>=0) {
x=read(fd, &keybuf, sizeof(keybuf));
if (x==257) {
memcpy(key,keybuf,257); /* For backward compatability with DACT 0.8.1*/
} else {
memcpy(key,ptrbuf=demime64((unsigned char *) keybuf),257);
free(ptrbuf);
}
close(fd);
return(257);
}
if (fd<0 && mode==DACT_MODE_CENC) {
fd=open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0600);
if (fd<0) { PERROR("open"); return(0); }
memcpy(key,generatekey(),257);
memcpy(keybuf, ptrbuf=mimes64(key,&x), 400);
write(fd, keybuf, x);
write(fd, "\n", 1);
close(fd);
free(ptrbuf);
return(257);
}
return(-1);
}
int cipher_sub_encrypt(const unsigned char *inblk, unsigned char *outblk, int blksize, unsigned char *key) {
int i,mod;
static int keyoffset=0;
mod=(int) key[0];
for (i=0;i<blksize;i++) {
if (!(i%mod)) {
keyoffset=((keyoffset+1)&0xff);
}
outblk[i]=key[((((int) inblk[i])+keyoffset)&0xff)+1];
}
return(blksize);
}
int cipher_sub_decrypt(const unsigned char *inblk, unsigned char *outblk, int blksize, unsigned char *key) {
int i,mod,x;
char reversekey[256];
static int keyoffset=0;
mod=(int) key[0];
for (i=1;i<257;i++) reversekey[(int) key[i]]=(i-1);
for (i=0;i<blksize;i++) {
if (!(i%mod)) {
keyoffset=((keyoffset+1)&0xff);
for (x=0;x<256;x++) reversekey[(int) key[((x+keyoffset)&0xff)+1]]=x;
}
outblk[i]=reversekey[(int) inblk[i]];
}
return(blksize);
}
char *generatekey(void) {
static char key[257];
char used[256];
int i,x;
#ifdef RANDOM_DEV
unsigned char buff[1];
int fd;
fd=open(RANDOM_DEV, O_RDONLY);
read(fd, buff, 1);
if (buff[0]==0) buff[0]=3;
key[0]=buff[0];
#else
srand(time(NULL)+rand());
key[0]=1+(int) (255.0*rand()/(RAND_MAX+1.0));
#endif
for (i=0;i<256;i++) used[i]=0;
for (i=1;i<257;i++) {
#ifdef RANDOM_DEV
read(fd, buff, 1);
x=buff[0];
#else
srand(time(NULL)+rand());
x=(int) (256.0*rand()/(RAND_MAX+1.0));
#endif
if (used[x]==0) { key[i]=x; used[x]=1; } else { i--; }
}
#ifdef RANDOM_DEV
close(fd);
#endif
return(key);
}
|