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