在24位真彩色位图中插入文件并隐藏文件

程序中限制了文件大小，大小是 (data_size = bih.biHeight*bih.biWidth*3) / 4 ;

 

/////////////////////////////////////////////// // File Inside Bitmap (inserttobitmap.exe) // 'Melts' a file into a bitmap file // That way, files can be hidden inside bitmaps // The algorithm uses a modulation technique // Written by WolfCoder (2007) /////////////////////////////////////////////// ///////////////////////////////////////////// // ****** Sample Command Line Usages ****** ///////////////////////////////////////////// // Puts a file INTO a bitmap image // -m file.xyz image.bmp ///////////////////////////////////////////// // Removes a file from the image // NOTE: extracts garbage if the image // did not have any coded files to begin with // -e image.bmp outfile.xyz ///////////////////////////////////////////// ///////////////////////////////////////////// // BATCH FILE HELP // Copy the following lines into the batch file: // -m file.xyz image.bmp // -e image.bmp outfile.xyz // Use notepad and save the lines as .bat // Simply copy the -m line in order to melt something // and the -e line to extract something // Then double click on the .bat file to execute ///////////////////////////////////////////// // Program Headers #include <iostream> // On my compiler, the .h is not allowed here, but it might in yours using namespace std; // Keep in mind you might not need this namespace line #include <windows.h> // Uses windows methods of file handling, bitmap reading, ect... // Global Variables BITMAPFILEHEADER bfh; // Contains file size information (and format tag) BITMAPINFOHEADER bih; // Contains dimensions, color depth, ect... unsigned char *data; // Pointer to bitmap image data in memory unsigned char *source; // Pointer to source data in memory HANDLE hfile; // Handle to file on disk DWORD written,read; // Byte written/read result DWORD data_size; DWORD file_size; // Insert a file into a bitmap void insert_into_bitmap(char *bitmap,char *filename) { // Gather information on the bitmap image specified // Open a channel to the file hfile = CreateFile(bitmap,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,NULL,NULL); // Read file information ReadFile(hfile,&bfh,sizeof(bfh),&read,NULL); // Read file image format ReadFile(hfile,&bih,sizeof(bih),&read,NULL); // Allocate necessary data for image data = new unsigned char[bih.biHeight*bih.biWidth*3]; // Read image data ReadFile(hfile,data,bih.biHeight*bih.biWidth*3,&read,NULL); // Close the channel, image has been completly read CloseHandle(hfile); // Is this a valid bitmap file? if(bih.biBitCount != 24) { cout<<"Only 24-bit RGB true-color bitmap images are allowed./n"; return; } // Measure the size of the file and it's dimensions cout<<"Image data is "<<(bih.biHeight*bih.biWidth*3)<<" bytes long./n"; cout<<"It has a height of "<<bih.biHeight<<" and a width of "<<bih.biWidth<<"./n"; data_size = bih.biHeight*bih.biWidth*3; // Measure the capacity of the bitmap file cout<<"A file of up to "<<(data_size/4)<<" bytes can be hidden inside./n"; // Prepare the image for insertion for(DWORD i = 0;i < data_size;i++) { data[i] /= 4; // Reduce precision for extra data data[i] *= 4; } // Read the source data // Open a channel to data hfile = CreateFile(filename,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,NULL,NULL); // Get file size file_size = GetFileSize(hfile,NULL); // Report that size cout<<"Input file has a size of "<<file_size<<" bytes./n"; // Allocate and read data source = new unsigned char[file_size]; ReadFile(hfile,source,file_size,&read,NULL); // Close the channel since the data was retrived from disk CloseHandle(hfile); // Now check for size errors if(file_size > data_size/4) { cout<<"File to be inserted doesn't fit in this bitmap!./n"; return; } // Apply the data to the image for(DWORD i = 0;i < file_size;i++) { // Get the base index DWORD index = i*4; // Start adding data data[index] += source[i]&3; // 1+2 = 3 00000011 data[index+1] += (source[i]&12)>>2; // 4+8 = 12 00001100 data[index+2] += (source[i]&48)>>4; // 16+32 = 48 00110000 data[index+3] += (source[i]&192)>>6; // 64+128 = 192 11000000 } // Write the file size into Xpelspermeter bih.biXPelsPerMeter = file_size; // Output final result // Open a channel to output image hfile = CreateFile("output.bmp",GENERIC_WRITE,NULL,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL); // Write back information and image format data WriteFile(hfile,&bfh,sizeof(bfh),&written,NULL); WriteFile(hfile,&bih,sizeof(bih),&written,NULL); // Write back the edited image data WriteFile(hfile,data,data_size,&written,NULL); // Close the channel, operation complete CloseHandle(hfile); } // Extracts a file from a bitmap image void extract_from_image(char *bitmap,char *filename) { // Gather information about the file inside the bitmap // Open a channel to the file hfile = CreateFile(bitmap,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,NULL,NULL); // Read file information ReadFile(hfile,&bfh,sizeof(bfh),&read,NULL); // Read file image format ReadFile(hfile,&bih,sizeof(bih),&read,NULL); // Allocate necessary data for image data = new unsigned char[bih.biHeight*bih.biWidth*3]; // Read image data ReadFile(hfile,data,bih.biHeight*bih.biWidth*3,&read,NULL); // Close the channel, image has been completly read CloseHandle(hfile); // Check to see if the bitmap could possibly hold data if(bih.biBitCount != 24) { cout<<"This image is not a 24-bit true color RGB image. This program doesn't work with them./n"; return; } // Measure the size of the file and it's dimensions cout<<"Image host data is "<<(bih.biHeight*bih.biWidth*3)<<" bytes long./n"; cout<<"It has a height of "<<bih.biHeight<<" and a width of "<<bih.biWidth<<"./n"; data_size = bih.biHeight*bih.biWidth*3; // Find out how big the file inside is cout<<"The file inside is "<<bih.biXPelsPerMeter<<" bytes long./n"; file_size = bih.biXPelsPerMeter; // Allocate data for inside file source = new unsigned char[file_size]; // Begin re-constructing data for(DWORD i = 0;i < file_size;i++) { // Get base index DWORD index = i*4; // Begin data reconstruction source[i] = data[index]%4; source[i] += (data[index+1]%4)<<2; source[i] += (data[index+2]%4)<<4; source[i] += (data[index+3]%4)<<6; } // Write out extracted data // Open a channel hfile = CreateFile(filename,GENERIC_WRITE,NULL,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL); // Write the data WriteFile(hfile,source,file_size,&written,NULL); // Close channel CloseHandle(hfile); } // Program Entry void main(int argn,char *argv[]) { // Determine the number of arguments if(argn <= 1) { // No command given, assume the user wants help cout<<"Usage:/n-m file.xyz image.bmp (Inserts file inside a bitmap)./n-e image.bmp outfile.xyz (Extracts file from inside a bitmap)./n"; return; } if(argn == 2) { // A command was given, but there was no parameters issued cout<<"Error: no input or output files defined./n"; return; } if(argn == 3) { // Only some parameters were given, but not enough cout<<"Error: not enough input/output files given./n"; return; } // All the parameters are here, start the action // Check what action needs to be taken if(argv[1][1] == 'm' || argv[1][1] == 'M') insert_into_bitmap(&argv[3][0],&argv[2][0]); // User wants to inset a file into a bitmap else extract_from_image(&argv[2][0],&argv[3][0]); // User wants to take a file out of the bitmap // Clean up after operation delete data; delete source; }