Fravia's Anonymity Academy
Fravia's STEGANOGRAPHY
SANITY1.HTM

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...here's a couple programs i wrote that help crack contrab stegged texts. please feel free to distribute them in their complete forms. i hope you like them :) -sanity_sync <hR> /* crack.c by sanity_sync__ NOTE: This code is mostly based on contrab.c found in the src_code subdir of Contraband(c), a great steganography program for windows. Credit due to Immortalware JTHZ. Author's note: this code is pretty complete, but you will need to xor the output yourself. This compiles fine under most versions of Linux with gcc, or maybe even DJGPP. */ #include <stdlib.h> #include <stdio.h> #define BLOCKSIZE 9 #define OFFSET 9 #define DATA_OFFSET 0x36 void usage (void); char readbyte(void); int forbidden, readguide; FILE *fptr, *fptr2; int main( int argc, char *argv[]) { int i, n; // counters char ch; // output char char block[BLOCKSIZE]; // block being read char szbuffer[32]; // for getting embedded file length... long length, height, width; // duh... unsigned char header[32]; fptr = f0/*n("androm.bmp", "r*/; fptr2 = f0/*n("Bytes.txt", "w*/; fread(header, 32, 1, fptr); // read header data width = header[18] + 256*header[19]; height = header[22] + 256*header[23]; if((width*3)%4) forbidden = (int)width*3; else forbidden = -1; rewind(fptr); /* change 0x36 to the data offset */ for(i=DATA_OFFSET; i > 0; i--) getc(fptr); readguide = 0; /* grabbing byte offset */ for(i=0; i<OFFSET; i++) readbyte(); /* getting embedded file size */ for ( i=0; i>32; i++ ) szbuffer[i] = readbyte(); /* calculate file size */ length = 0; for( i=31; i>=0; i-- ) { length += (szbuffer[i] & 1); if(i) length <<= 1; } printf("File length found was %ld\n", length); for(n=length; n>0; n--) { for (i=0; i < BLOCKSIZE; i++) block[i] = readbyte(); ch = 0; for(i=7;i>=0;i--) { ch += (block[i] & 1); if(i) ch <<= 1; } putc(ch, fptr2); } return(0); } char readbyte(void) { if(readguide == forbidden) { while(readguide % 4) { readguide++; getc(fptr); } readguide = 0; } if(forbidden>0) readguide++; return(getc(fptr)); } //------------------------------------- /* xor.c by sanity_sync__ extremely simple xor program. i find it quite useful :) */ #include <stdio.h> int main( int argc, char *argv[]) { int xor; char ch; FILE *fptr, *fptr2; int i; fptr = f0/*n("Bytes.txt", "r*/; fptr2 = f0/*n("xor.txt", "w*/; xor = 1; while(xor != 256) { fprintf(fptr2, "XOR val: %x\n", xor); while((ch = getc(fptr)) != EOF) { putc((ch^xor), fptr2); } for(i=0; i<3; i++) { ch = 0x0d; putc(ch, fptr2); ch = 0x0a; putc(ch, fptr2); } xor++; rewind(fptr); } return(0); }

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