crashtest-r0ket/tools/crypto/main.c

257 lines
5.6 KiB
C

/* simple XXTEA en/decrypt utility
*
* BSD Licence
*
* btea function is from
* <https://secure.wikimedia.org/wikipedia/en/wiki/XXTEA#Reference_code>
*
* (c) by Sec <sec@42.org> 6/2011
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <getopt.h>
#include "xxtea.h"
// default block size
void hexkey(char *string, uint32_t k[4]);
int main(int argc, char *argv[]) {
FILE *fp;
FILE *ofp;
char *prog;
char c; /* for getopt */
uint32_t k[4]; /* key */
uint8_t *buf;
/* Default values */
char verbose=0; // be silent
k[0]=0; k[1]=0; k[2]=0; k[3]=0;
char *outfile=NULL; // outfile == infile
int decrypt=0;
int encrypt=0;
int sign=0;
/* init section */
prog=argv[0];
if(!prog)prog="xxtea";
if(strrchr(prog,'/')){
prog=strrchr(argv[0],'/');
prog++;
}
/* The big getopt loop */
while ((c = getopt(argc, argv, "vhesdk:o:")) != EOF)
switch (c) {
case 'v':
verbose++;
break;
case 'd':
decrypt=1;
break;
case 'e':
encrypt=1;
break;
case 's':
sign=1;
break;
case 'k':
hexkey(optarg, k);
break;
case 'o':
outfile=optarg;
break;
case 'h':
default:
fprintf(stderr, "Usage: %s [options] filename\n\n"
"This program en/decrypts a file with the XXTEA algorithm\n"
"\n\n"
"-v Be verbose (-v -v = even more)\n"
"-d Decrypt file\n"
"-e Encrypt file\n"
"-s Sign file\n\n"
"-o file Output to <file>. (Default: overwrite input file)\n"
"-k key 128bit hex key.\n"
"-h This help\n\n"
"\n",prog);
exit(255);
}
argc -= optind; argv += optind;
if (argc !=1){
fprintf(stderr,"Error: No filename given!\n");
exit(254);
};
if( !(decrypt||encrypt||sign) ){
fprintf(stderr, "No operation specified!\n");
exit(254);
}
if( decrypt && (encrypt || sign) ){
fprintf(stderr, "Can not decrypt and sign or decrypt and encrypt!\n");
exit(254);
}
if(outfile){
if ((fp = fopen(argv[0],"rb")) == NULL){
fprintf(stderr,"Error: Can't open file %s\n",argv[0]);
exit(253);
}
if ((ofp = fopen(outfile,"wb")) == NULL){
fprintf(stderr,"Error: Can't open file %s\n",argv[0]);
exit(253);
}
}else{
if ((fp = fopen(argv[0],"r+b")) == NULL){
fprintf(stderr,"Error: Can't open file %s\n",argv[0]);
exit(253);
}
ofp=fp;
};
fseek(fp, 0L, SEEK_END);
int filesize = ftell(fp);
fseek(fp, 0L, SEEK_SET);
if (verbose)
fprintf(stderr,"file size=%d\n", filesize);
int words = (((filesize+3)/sizeof(uint32_t)+3)/4)*4;
int bytes = sizeof(uint32_t)*words;
if (verbose)
fprintf(stderr,"byte count=%d word count=%d\n", bytes, words);
buf=malloc(bytes);
if(!buf){
fprintf(stderr,"Error: malloc() failed.\n");
exit(253);
};
if (verbose)
fprintf(stderr,"Key: %08x %08x %08x %08x\n",k[0],k[1],k[2],k[3]);
if( sign ){
if (verbose)
fprintf(stderr,"Signing: ");
memset(buf, 0, bytes);
int cnt = fread(buf,sizeof(*buf),filesize,fp);
cnt = 0;
uint32_t mac[4];
xxtea_cbcmac(mac, (uint32_t*)buf, words, k);
if (verbose)
fprintf(stderr,"MAC: %08x %08x %08x %08x\n",mac[0],mac[1],mac[2],mac[3]);
if(!outfile) // in-place crypting...
if( fseek(fp, 0L, SEEK_SET) != 0){
fprintf(stderr, "Error: Seek failed\n");
exit(253);
}
if (fwrite(buf,sizeof(*buf),bytes,ofp) != bytes){
fprintf(stderr, "Error: file write failed\n");
exit(253);
}
if (fwrite(mac,sizeof(*mac),4,ofp) != 4){
fprintf(stderr, "Error: mac write failed\n");
exit(253);
}
if(verbose) fprintf(stderr,".\n");
}
if( encrypt ){
int cnt, block=0;
if (verbose)
fprintf(stderr,"Encrypting: ");
do{
cnt=fread(buf,sizeof(*buf),block,fp); // XXX: deal with non-block-sized?
if(cnt<0){
fprintf(stderr, "Error: read failed\n");
exit(253);
};
if(verbose)
fprintf(stderr,"cnt=%d:",cnt);
/* if(cnt%sizeof(*buf)!=0){
fprintf(stderr,"Whoops. needs padding: cnt=%d, mod=%d\n",cnt,cnt%sizeof(*buf));
}; */
//btea(buf, decrypt?-cnt:cnt, k);
if(!outfile) // in-place crypting...
if (fseek(fp,-cnt*sizeof(*buf),SEEK_CUR) != 0){
fprintf(stderr, "Error: Seek failed\n");
exit(253);
}
if (fwrite(buf,sizeof(*buf),cnt,ofp) != cnt){
fprintf(stderr, "Error: CRC write failed\n");
exit(253);
}
if(verbose) fprintf(stderr,".\n");
}while(cnt==block);
}
if(verbose)
fprintf(stderr,"done\n");
fclose(fp);
if(outfile)
fclose(ofp);
return 0;
}
void hexkey(char *string, uint32_t k[4]){
int idx=0;
int kidx=0;
int kctr=0;
int value;
char ch;
while ((ch=string[idx++])!=0){
if(ch == ' ')
continue;
if(ch == '\t')
continue;
if (ch >= '0' && ch <= '9')
value = (ch - '0');
else if (ch >= 'A' && ch <= 'F')
value = (ch - 'A' + 10);
else if (ch >= 'a' && ch <= 'f')
value = (ch - 'a' + 10);
else
continue;
k[kidx]=(k[kidx]<<4)+value;
kctr++;
if(kctr>=8){
kctr=0;
kidx++;
if(kidx>4)
return;
};
};
}