gistfile1.txt

/**
 * recover.c
 *
 * Computer Science 50
 * Problem Set 5
 *
 * Recovers JPEGs from a forensic image.
 *
 * edited by Patrick
 */
 
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
 
#include "bmp.h"
 
int main(void)
{
    // opens card.raw
    FILE* inptr = fopen("card.raw", "r");
    
    if (inptr == NULL)
    {
        printf("Could not open card.raw");
        return 1;
    }
    
    int counter = 1;
    
    char title[7];
    
    
    
    
    while (!feof(inptr)) // stop executing once EOF is reached
    {
    
        BYTE JPEG[512];
    
        // READ 512 BYTES INTO A BUFFER
        if (fread(&JPEG, sizeof(BYTE), 512, inptr) != 512)
        {
            break;
        }
          
          
        else if (JPEG[0] == 0xff && JPEG[1] == 0xd8 && JPEG[2] == 0xff)
        {
            if (JPEG[3] == 0xe0 || JPEG[3] == 0xe1)
            {
                
                // only do this once jpeg is found
                sprintf(title, "%d.jpg", counter);
                
                // update counter
                counter++;
                
                // only do this once jpeg is found
                FILE* img = fopen(title, "w");
                
                fwrite(&JPEG, sizeof(BYTE), 512, img);
                
                fclose(img);
                
                
            }    
        
        }
        
        
        // only executes once first jpeg is found
        else if (counter > 1)
        {
            // open existing file
            FILE* img = fopen(title, "a");
                    
            // write to existing jpeg till next jpeg found
            fwrite(&JPEG, sizeof(BYTE), 512, img);
                    
            fclose(img);
        }
     
    }
    
    // closes card.raw
    fclose(inptr);
    
    return 0;
}