Steganografia

/*	This program shadows a message in an image (i prefer jpeg)
 *	If you have problems with an image, try with another one
 *	
 *	shadow-ass.c
 *	Coded by:
 *		TheAlchemist -> http://thealchemist-geek.tk
 *		I.M.G. Member -> http://www.inside-me.org
 *	
 *	Usage:
 *	o) 2 code: shadow-ass -c message.txt image.jpeg
 *	o) 2 decode: shadow-ass -d image.jpeg
 *
 *	See you :)
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int lunghezza_mess(char *filem);
long lunghezza_ima(char *filei);
int preleva_dim(int *imm, int *st);
int code(int carattere, int state, int *imm, char *chiam, char *text, char *ack);
int decode(int *imm, int *st);
void usage(char *argom);

main(int argn, char **argv)
{
	FILE *ima,*mes;
	int a,stato,j,lenm,decchar;
	long len;
	char azione[2];
	int *mess_bis, *imm_bis, car;

	if(argn<3)
	{
		usage(argv[0]);
		exit(-1);
	}
	
	strncpy(azione, argv[1], 3);
	if(strstr(azione,"-c"))
	{
		lenm = lunghezza_mess(argv[2]);
		len = lunghezza_ima(argv[3]);
		if(len<(lenm*8 + 300))
		{
			printf("\nImage is too little!");
			printf("\nTheAlchemist\n");
		}
		printf("\nImage lenght: %d",len);
		printf("\nMessage lenght: %d",lenm);
		stato=300;
		
		if(argn<4)
			usage(argv[0]);
		
		imm_bis = malloc( (len * sizeof(int)) + 1 );
		ima = fopen(argv[3], "r");
		printf("\nImage %s opened in read mode",argv[3]);
		for(j=0;j<len;j++)
		{
			imm_bis[j] = fgetc(ima);
			if(imm_bis[j]==EOF)
				break;
		}
		fclose(ima);
		
		mess_bis = malloc( (lenm * sizeof(int)) + 2 );
		mess_bis[0]=lenm;
		mes = fopen(argv[2], "r");
		for(j=1;j<len;j++)
		{
			mess_bis[j] = fgetc(mes);
			if(mess_bis[j]==EOF)
				break;
		}
		fclose(mes);
		printf("\nMessage 2code: ");
		for(j=1;j<=lenm;j++)
			printf("%c",mess_bis[j]);
		printf("\nI'm coding:");
		for(a=0;a<lenm+1;a++)
		{
			car=mess_bis[a];
			stato=code(car, stato, imm_bis, argv[0], argv[2], argv[3]);
		}
		printf("Coded!\nTheAlchemist\n");
		
	}
	else if(strstr(azione,"-d"))
	{
		stato=300;
		len = lunghezza_ima(argv[2]);
		imm_bis = malloc( (len * sizeof(int)) + 1 );
		ima = fopen(argv[2], "r");
		printf("\nImage %s opened in read mode",argv[2]);
		for(j=0;j<len;j++)
		{
			imm_bis[j] = fgetc(ima);
		        if(imm_bis[j]==EOF)
		        	break;
		}
		fclose(ima);
		lenm = preleva_dim(imm_bis, &stato);
		printf("\nMessage lenght: %d",lenm);
		printf("\nIm going to decode: %s",argv[2]);
		printf("\nMessage decoded:\n\n");
		for(j=0;j<lenm;j++)
		{
			decchar=decode(imm_bis, &stato);
			printf("%c",decchar);
		}
		printf("\n\nTheAlchemist\n");
	}
	else if(strstr(azione,"-h"))
        {
                usage(argv[0]);
        }
	else
	{
		printf("\nScelta non valida!\n");
		usage(argv[0]);
	}
}

int code(int carattere, int state, int *imm, char *chiam, char *text, char *ack)
{  
	FILE *fw;
	char *afterfile, temp;
	int namelen=strlen(ack),j,t;
	long imagelen;
	unsigned char mask;
	afterfile = malloc( (namelen * sizeof(char)) + 6 );
	strcpy(afterfile,"coded-");
	strncat(afterfile, ack, namelen);
	
	fw = fopen(afterfile, "w");
	imagelen = lunghezza_ima(ack);
	for(j=0;j<imagelen;j++)
	{
		fputc(imm[j],fw);
	}

	fseek(fw,(state * sizeof(int)),SEEK_SET);

	//heart
	mask=128;
	t=0;
	temp=0;
	for(j=0;j<8;j++)
	{
		printf(".");
		temp = carattere & mask;
		temp = temp>>(7-t);
		mask = mask>>1;
		if(mask==0)
			mask=80;
		t++;
		if(t==8)
			t=0;
		imm[state] = imm[state] & 254;
		imm[state] = imm[state] | temp;
		fputc(imm[state],fw);
		state++;
	}
	
	fclose(fw);

	return state;
}

int decode(int *imm, int *st)
{
	int m, k, t, sum, temp, car;
        unsigned char mask;

        mask=01;
        temp=0;
        sum=0;
        t=8;
        for(m=0;m<8;m++)
        {
		temp = imm[(*st)] & mask;
		t--;
		temp = temp<<t;
		if(t==0)
		t=7;
		sum = sum | temp;
		(*st)++;
	 }
	 return sum;
}

void usage(char *argom)
{
        printf("Usage: %s [option] <file> {image}", argom);
	printf("\n\nOptions are:");
	printf("\n\t-c\t: code a message => file is a textfile, image is the image where will be inserted the message");
	printf("\n\t-d\t: decode a message => file is an image");
	printf("\n\t-h\t: print this help");
	printf("\n\nExample:");
	printf("\ncoding a message: %s -c message.txt image",argom);
	printf("\ndecoding a message: %s -d image",argom);
	printf("\n\nTheAlchemist\n");
	exit(-1);
}

int lunghezza_mess(char *filem)
{
	FILE *mes;
	int lenm;
	
	mes = fopen(filem, "r");
	if (fseek (mes,0L,SEEK_END) == 0)
	{
		lenm = ftell (mes);
		rewind (mes);
	}
	fclose(mes);

	return lenm;			
}

long lunghezza_ima(char *filei)
{
	FILE *ima;
	long len;
	
	ima = fopen(filei, "r");
        if (fseek (ima,0L,SEEK_END) == 0)
	{
		len = ftell (ima);
		rewind (ima);
	}
        fclose(ima);

	return len;
}

int preleva_dim(int *imm, int *st)
{
	int m, k, t, sum, temp, car;
	unsigned char mask;
	
	mask=01;
	temp=0;
	sum=0;
	t=8;
	for(m=0;m<8;m++)
	{
		temp = imm[(*st)] & mask; 
		t--;
		temp = temp<<t;
		if(t==0)
			t=7;
		sum = sum | temp;
		(*st)++;
	}
	return sum;
}