Update

Signed-off-by: Pin <wf6DJd8a3xSSCZbn@protonmail.com>

README.md

@@ -0,0 +1,37 @@
+# PSPNG
+
+Sample program to embed messages into PNG images
+
+## Install
+
+**NOTE:** Set the core_count variable to one value lower than maximum cores on the host in cmd/pspng.c
+
+Requires zlib, pthread, and sodium header files to compile (These will be distro specific packages)
+
+Build:
+
+```bash
+make
+```
+
+System Wide:
+
+```bash
+make
+make install
+```
+
+## Usage
+
+Embed Message:
+
+pspng --compress -f {input file name} -o {output file name} -m "{input message}"
+
+Extract Message:
+
+pspng --uncompress -f {input file name}
+
+Help Message:
+
+pspng --help
+

cmd/crc.c

@@ -1,304 +0,0 @@
-#pragma GCC optimize("Ofast")
-
-#include <endian.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
-#include <sodium.h>
-#include <getopt.h>
-#include "crc_util.h"
-#include "CRCLib.h"
-#include "crc.h"
-#include "compress_util.h"
-
-const long idat_signature = 1229209940;
-const long iend_signature = 1229278788;
-
-unsigned long first_idat(unsigned char *addr) {
-	int idat_found = 0;
-	unsigned long offset = 8;
-	int jump_offset = 0;
-	int header_type = 0;
-	while(idat_found == 0) {
-		jump_offset = check_header_length(addr, offset);
-		header_type = check_header_length(addr, offset+4);
-		if(header_type == idat_signature) {
-			idat_found = 1;
-		} else {
-			offset = offset + jump_offset + 12;
-		}
-	}
-	return offset;
-}
-
-int total_idat(unsigned char *addr) {
-	int iend_found = 0;
-	int found_idat = 0;
-	unsigned long offset = 8;
-	int jump_offset = 0;
-	int header_type = 0;
-	while(iend_found == 0) {
-		jump_offset = check_header_length(addr, offset);
-		header_type = check_header_length(addr, offset+4);
-		if(header_type == iend_signature) {
-			iend_found = 1;
-		} else {
-			if(header_type == idat_signature) {
-				found_idat++;
-			}
-			offset = offset + jump_offset + 12;
-		}
-	}
-	return found_idat;
-}
-
-int update_file_crc(unsigned char *addr, unsigned long offset , unsigned int crc_num) {
-	int startCRC = 8 + offset + check_header_length(addr, offset);
-	unsigned char new_crc;
-	for(int i = 0; i < 4; i++) {
-		new_crc = crc_num >> (8*(3-i)) & 0xFF;
-		addr[startCRC+i] = new_crc;
-	}
-	return 0;
-}
-
-void random_data_change(unsigned char *color_data, int width, int length) {
-	int searching = 1;
-	size_t rounds = 0;
-	width = 16;
-	int color_range = 3;	
-	unsigned char temp_color_data[length];
-
-	do {
-		rounds++;
-		// Creating temporary data set
-		memcpy(temp_color_data, color_data, length);
-		// Generating random byte to change
-		int random_num = randombytes_uniform(length);
-		// Checking for index break
-		if(random_num % ((width * color_range) + 1)) {
-			if(color_data[random_num] == 255) {
-				temp_color_data[random_num]--;
-			} else {
-				temp_color_data[random_num]++;
-			}
-			unsigned char *check_data_buff = NULL;
-			size_t check_data_length = 0;
-			zlib_compress_data(temp_color_data, length, &check_data_buff, &check_data_length);
-
-			unsigned char full_data[check_data_length+4];
-			full_data[0] = 0x49;
-			full_data[1] = 0x44;
-			full_data[2] = 0x41;
-			full_data[3] = 0x54;
-			for(int i = 0; i < check_data_length; i++) {
-				full_data[i+4] = check_data_buff[i];
-			}
-			unsigned int temp_crc = crc(full_data, check_data_length);
-			if ((temp_crc >> (8*3)) == 10 ) {
-				printf("Found in %zu rounds!\n", rounds);
-				memcpy(color_data, temp_color_data, length);
-				searching = 0;
-			}
-			free(check_data_buff);
-		}
-	
-	} while(searching == 1);
-}
-
-void build_png_file(struct PNG_FILE_STRUCT *png_file, char *out_file_name) {
-	FILE *fp;
-
-	fp = fopen(out_file_name, "w");
-
-	union{
-		unsigned char data[sizeof(struct PNG_START_FILE_STRUCT)];
-		struct PNG_START_FILE_STRUCT png_data;
-	}start_data;
-
-	start_data.png_data = png_file->png_start_data;
-
-	// IHDR Data
-	for(int i = 0; i < sizeof(start_data.data); i++) {
-		fputc(start_data.data[i], fp);
-	}
-	// IDAT Data
-	for(int i = 0; i < 4; i++) {
-		fputc(png_file->png_idat_data.idat_length[i], fp);
-	}
-	for(int i = 0; i < 4; i++) {
-		fputc(png_file->png_idat_data.idat_header[i], fp);
-	}
-	for(int i = 0; i < be32toh(png_file->png_idat_data.idat_data_length); i++) {
-		fputc(png_file->png_idat_data.idat_data[i], fp);
-	}
-	// Generating CRC
-	unsigned char full_data[be32toh(png_file->png_idat_data.idat_data_length)+4];
-	for(int i = 0; i < 4; i++) {
-		full_data[i] = png_file->png_idat_data.idat_header[i];
-	}
-	for(int i = 0; i < be32toh(png_file->png_idat_data.idat_data_length); i++) {
-		full_data[i+4] = png_file->png_idat_data.idat_data[i];
-	}
-
-	unsigned int int_crc = crc(full_data, be32toh(png_file->png_idat_data.idat_data_length));
-	unsigned char new_crc[4];
-
-	for(int i = 0; i < 4; i++) {
-		new_crc[i] = int_crc >> (8*(3-i)) & 0xFF;
-		fputc(new_crc[i], fp);
-	}
-	// IEND Data
-	unsigned char IEND_DATA[12] = { 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82};
-	for(int i = 0; i < 12; i++) {
-		fputc(IEND_DATA[i], fp);
-	}
-	fclose(fp);
-}
-
-int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, char *message, int accuracy, unsigned long offset, char *out_file_name) {
-	if(accuracy > 4) {
-		printf("Warning, accuracy cannot be larger than 4");
-		return EXIT_FAILURE;
-	}
-	if(accuracy > 2) {
-		printf("Notice, this could take a long time...");
-	}
-	if(total_idat(addr) < strlen((char*)message)) {
-		printf("Warning, message exceeds IDAT amount\n");
-		exit(EXIT_FAILURE);
-	}
-
-	int idat_length = check_header_length(addr, offset);
-	printf("IDAT Length: %d\n", idat_length);
-
-	long size = 1;
-	size_t idat_byte_length = 0;
-	unsigned char* idat_data = calloc(size, sizeof(unsigned char));
-	for(size_t i = 0; i <= idat_length; i++) {
-		if(i == size) {
-			size *= 2;
-			idat_data = reallocarray(idat_data, size, sizeof(unsigned char));
-		}
-		idat_data[i] = addr[i+offset+8];
-		idat_byte_length = i;
-	}
-	unsigned char temp_idat_data[idat_byte_length];
-	for(int i = 0; i <= idat_length; i++) {
-		temp_idat_data[i] = idat_data[i];
-	}
-	// Decompressing Data
-	unsigned char *uncom_data_buff = NULL;
-	size_t uncom_data_size = 0;
-	zlib_decompress_data(temp_idat_data, idat_byte_length, &uncom_data_buff, &uncom_data_size);
-
-	random_data_change(uncom_data_buff, 16, uncom_data_size);
-	
-	// Compress Data
-	unsigned char *com_data_buff;
-	size_t com_data_size = 0;
-	zlib_compress_data(uncom_data_buff, uncom_data_size, &com_data_buff, &com_data_size);
-
-	png_file->png_idat_data.idat_data = calloc(com_data_size, sizeof(unsigned char));
-
-	png_file->png_idat_data.idat_data_length = be32toh(com_data_size);
-
-	for(size_t i = 0; i < com_data_size; i++) {
-		png_file->png_idat_data.idat_data[i] = com_data_buff[i];
-	}
-
-	// Build PNG File
-	build_png_file(png_file, out_file_name);
-
-	free(uncom_data_buff);
-	free(com_data_buff);
-	free(idat_data);
-	free(png_file->png_idat_data.idat_data);
-
-	return 0;
-}
-
-// This is where it all starts
-int main(int argc, char **argv) {
-	FILE *fp;
-	size_t i = 0;
-	unsigned long offset = 0;
-	struct PNG_FILE_STRUCT png_file_data;
-	char *in_file_name = NULL;
-	char *out_file_name = NULL;
-	char *message = NULL;
-
-	static const struct option long_options[] = {
-		{"help", no_argument, NULL, 'h'},
-		{"file", required_argument, NULL, 'f'},
-		{"outfile", required_argument, NULL, 'o'},
-		{"message", required_argument, NULL, 'm'},
-		{0, 0, 0, 0}
-	};
-
-	const char* usage =
-		"Usage: crc [options]\n"
-		"  -h, --help		Shows help message\n"
-		"  -f, --file		Denotes input file\n"
-		"  -o, --outfile	Denotes output file\n"
-		"  -m, --message	Encoded message\n"
-		"\n";
-
-	int c;
-	while (1) {
-		int option_index = 0;
-		c = getopt_long(argc, argv, "hf:o:m:", long_options ,&option_index);
-		if(c == -1) {
-			break;
-		}
-		switch(c) {
-			case 'h':
-				printf("%s", usage);
-				exit(EXIT_SUCCESS);
-			case 'f':
-				in_file_name = optarg;
-				break;
-			case 'o':
-				out_file_name = optarg;
-				break;
-			case 'm':
-				message = optarg;
-				break;
-		}
-	}
-
-	if(in_file_name == NULL) {
-		printf("Input file required!\n");
-		exit(EXIT_FAILURE);
-	} else if(out_file_name == NULL) {
-		printf("Output file required!\n");
-		exit(EXIT_FAILURE);
-	} else if(message == NULL) {
-		printf("Message required!\n");
-		exit(EXIT_FAILURE);
-	}
-
-	if(sodium_init() == -1) {
-		return EXIT_FAILURE;
-	}
-
-	fp = fopen(in_file_name, "rt");
-	if (fp == NULL) {
-		printf("File error\n");
-		exit(EXIT_FAILURE);
-	}
-
-	unsigned char *file_data = file_to_char_array(fp, &i);
-	fclose(fp);
-
-	populate_start_png(file_data, &png_file_data.png_start_data);
-
-	offset = first_idat(file_data);
-
-	populate_idat_png(file_data, &png_file_data.png_idat_data, offset);
-
-	change_idat_content(file_data, &png_file_data, message, 1, offset, out_file_name);
-
-	free(file_data);
-}

cmd/pspng.c

@@ -8,6 +8,7 @@
 #include <sodium.h>
 #include <getopt.h>
 #include <pthread.h>
+#include <math.h>
 #include "crc_util.h"
 #include "CRCLib.h"
 #include "pspng.h"
@@ -70,11 +71,74 @@ int update_file_crc(unsigned char *addr, unsigned long offset , unsigned int crc
 	return 0;
 }
 
-static void random_window_bit_change(unsigned char *data, int width, int rounds, int color_range, size_t length, size_t offset) {
+static unsigned char* create_raw_pixel_values(unsigned char *data, int width, int color_range, size_t length) {
+	// Generating twice the size we migth need
+	length = length * 4;
+	//length = 500000;
+	unsigned char* raw_data = calloc(length, sizeof(unsigned char*));
+	size_t filter_chunk_byte = 0;
+
+	for(size_t i = 0; i < length; i++) {
+		filter_chunk_byte = i  - (i % ((width * color_range) + 1));
+		// Grabbing raw pixel data
+		if(data[filter_chunk_byte] == 0) {
+			// Filter: None
+			raw_data[i] = data[i];
+		} else if(data[filter_chunk_byte] == 1) {
+			// Filter: Sub
+			if ((i % ((width * color_range) + 1)) == 0) {
+				// Setting filter type
+				raw_data[i] = data[i];
+			} else if ((i - filter_chunk_byte) <= color_range) {
+				// Setting initial color_range byte
+				raw_data[i] = data[i];
+			} else {
+				// Setting remaining bytes
+				raw_data[i] = data[i] + raw_data[i - color_range];
+			}
+		
+		} else if(data[filter_chunk_byte] == 3) {
+			// Filter: Average
+			if((i % ((width * color_range) + 1)) == 0) {
+				// Setting filter type
+				raw_data[i] = data[i];
+			} else {
+				// Setting remaining bytes
+				if(filter_chunk_byte == 0) {
+					// If no scanline is present before current
+					if((i - filter_chunk_byte) <= color_range) {
+						// If no pixel present before current
+						raw_data[i] = data[i] + floor((0 + 0) / 2);
+					} else {
+						// If pixel present before current
+						raw_data[i] = data[i] + floor((data[i - color_range] + 0) / 2);
+					}
+				
+				} else {
+					// Scanline is present before current
+					if((i - filter_chunk_byte) <= color_range) {
+						// If no pixel present before current
+						raw_data[i] = data[i] + floor((0 + raw_data[i - ((width * color_range) + 1)]) / 2);
+					} else {
+						// If pixel present before current
+						raw_data[i] = data[i] + floor((raw_data[i - color_range] + raw_data[i - ((width * color_range) + 1)]) / 2);
+					}
+				}
+			}
+		
+		} else {
+			// Filter: Error Unsupported
+			printf("Exiting due to unsupported filter type\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	return raw_data;
+}
+
+static void random_window_bit_change(unsigned char *data, unsigned char *raw_data, int width, int rounds, int color_range, size_t length, size_t offset) {
 	size_t random_num = 0;
 	size_t filter_chunk_byte = 0;
-	size_t change_num = 0;
-	long prior_chuck_check = 0;
 	for (int i = 0; i < rounds; i++) {
 		random_num = 0;
 		do {
@@ -86,24 +150,30 @@ static void random_window_bit_change(unsigned char *data, int width, int rounds,
 			// None Filter Type Change
 			if(data[random_num] == 255) {
 				data[random_num]--;
+				raw_data[random_num]--;
 			} else {
 				data[random_num]++;
+				raw_data[random_num]++;
 			}
 		} else if(data[filter_chunk_byte] == 1) {
 			// Sub Filter Type Change
 			if(data[random_num] == 255) {
 				data[random_num]--;
-				change_num = 1;
+				raw_data[random_num]--;
 			} else {
 				data[random_num]++;
-				change_num = -1;
+				raw_data[random_num]++;
 			}
-			// Starting after random change
+			// Fixing Next Pixel in Scanline
-			for(int j = 1; j < 2; j++) {
+			if(!(random_num+3 > (filter_chunk_byte + (width * color_range) + 1))){
-				data[random_num+(color_range * j)] = (data[random_num+(color_range * j)] + change_num) % 256;
+				data[random_num+color_range] = raw_data[random_num+color_range] - raw_data[random_num];
+			}
+			// Checking Next Scanline type
+			if(data[filter_chunk_byte+((width * color_range) + 1)] == 3){
+				data[random_num+((width * color_range)+1)] = raw_data[random_num+((width * color_range)+1)] - floor((raw_data[random_num+((width * color_range)+1)-color_range] + raw_data[random_num]) / 2);
 			}
 		} else if(data[filter_chunk_byte] == 2) {
-			printf("2\n");
+			// Add Support
 			if(data[random_num] == 255) {
 				data[random_num]--;
 			} else {
@@ -111,21 +181,26 @@ static void random_window_bit_change(unsigned char *data, int width, int rounds,
 			}
 		} else if(data[filter_chunk_byte] == 3) {
 			// Average Filter Type Change
-			//printf("HEE: %d\n", data[(filter_chunk_byte - (width * color_range))-1]);
+			if(raw_data[random_num] == 255) {
-			prior_chuck_check = filter_chunk_byte;
+				raw_data[random_num]--;
-			do {
-				//printf("C: %d\n", data[prior_chuck_check]);
-				prior_chuck_check = (prior_chuck_check - (width * color_range)-1);
-				//printf("CH: %ld\n", prior_chuck_check);
-			} while(prior_chuck_check >= 0);
-
-			if(data[random_num] == 255) {
-				data[random_num]--;
 			} else {
-				data[random_num]++;
+				raw_data[random_num]++;
+			}
+			// Update Current Pixel
+			data[random_num] = raw_data[random_num] - floor((raw_data[random_num-color_range] + 
+						raw_data[random_num-((width * color_range) + 1)]) / 2);
+			// Fixing Next Pixel in Scanline
+			if(!(random_num+color_range > (filter_chunk_byte + (width * color_range) + 1))){
+				data[random_num+color_range] = raw_data[random_num+color_range] - 
+					floor((raw_data[random_num] + raw_data[random_num-((width * color_range)+ 1)+color_range]) / 2);
+			}
+			// Checking Next Scanline type
+			if(data[filter_chunk_byte+((width * color_range) + 1)] == 3){
+				data[random_num+((width * color_range)+1)] = raw_data[random_num+((width * color_range)+1)] - 
+					floor((raw_data[random_num+((width * color_range)+1)-color_range] + raw_data[random_num]) / 2);
 			}
 		} else if(data[filter_chunk_byte] == 4) {
-			printf("4\n");
+			// Add Support
 			if(data[random_num] == 255) {
 				data[random_num]--;
 			} else {
@@ -166,7 +241,7 @@ static int verify_crc_chunks(unsigned char *data, size_t data_length, int crc_de
 		}
 		crc_check_length = test_data_length+4;
 		crc_check = crc(testing_chunk, crc_check_length);
-		
+
 		if ((crc_check >> (8*3)) != message ) {
 			free(testing_chunk);
 			return 1;
@@ -180,23 +255,39 @@ static int verify_crc_chunks(unsigned char *data, size_t data_length, int crc_de
 	return 0;
 }
 
-static int crc_embed_data(unsigned char *data, unsigned int data_length, int bit_width, int color_range, unsigned int sliding_window, char message, size_t offset , size_t iteration) {
+static int crc_embed_data(unsigned char *data, unsigned int data_length, int bit_width, int color_range, unsigned int sliding_window, char message, size_t offset , size_t iteration, size_t prior_offset) {
 	unsigned char *check_data;
+	unsigned char *raw_data;
+	unsigned char *new_data = calloc(1, sizeof(unsigned char));
 	size_t check_data_length = 0;
+	int match_crc = 1;
+	
+	raw_data = create_raw_pixel_values(data, bit_width, color_range, sliding_window);
+	random_window_bit_change(data, raw_data, bit_width, 2, color_range, sliding_window, offset);
 
-	random_window_bit_change(data, bit_width, 2, color_range, sliding_window, offset);
+	//if(offset > 500000) {
-
+	if(offset == -1) {
-	// Compressing data for test
+		new_data = calloc(300000, sizeof(unsigned char));
-	zlib_compress_data(data, data_length, &check_data, &check_data_length);
+		for(int k = 0; k < 300000; k++) {
-
+			new_data[k] = data[offset-(offset-prior_offset-1)+k];
-	int match_crc = verify_crc_chunks(check_data, check_data_length, 1, MAX_IDAT_SIZE, message, iteration);
+		}
+		zlib_compress_data(new_data, 100000, &check_data, &check_data_length);
+		match_crc = verify_crc_chunks(check_data, check_data_length, 1, MAX_IDAT_SIZE, message, 1);
+	} else {
+		zlib_compress_data(data, data_length, &check_data, &check_data_length);
+		match_crc = verify_crc_chunks(check_data, check_data_length, 1, MAX_IDAT_SIZE, message, iteration);
+	}
 
 	if(match_crc == 0) {
 		printf("COM SIZE: %zu\n", check_data_length);
+		free(new_data);
 		free(check_data);
+		free(raw_data);
 		return 0;
 	}
+	free(new_data);
 	free(check_data);
+	free(raw_data);
 	return 1;
 }
 
@@ -209,21 +300,21 @@ void *random_data_change_thread_call(void *w) {
 		// Creating temporary data set
 		memcpy(temp_color_data, data->data, data->uncom_data_len);
 
-		// Look into testing these values more
+		// Look into testing these values more for speed
 		if(data->uncom_data_len > 800000) {
 			data->data_len = 90000 + (90000 * data->cur_iteration);
 		} else {
 			data->data_len = data->uncom_data_len;
 		}
-		if(data->uncom_data_len > 16000) {
+		if(data->uncom_data_len > 36000) {
-			data->win_size = 9000 + (9000 * data->cur_iteration);
+			data->win_size = 36000 + (36000 * data->cur_iteration);
 		} else {
 			data->win_size = data->uncom_data_len;
 		}
 
 		cur_message = data->message[data->cur_iteration];
 
-		searching = crc_embed_data(temp_color_data, data->data_len, data->width, data->color_range, data->win_size, cur_message, data->cur_offset, data->cur_iteration);
+		searching = crc_embed_data(temp_color_data, data->data_len, data->width, data->color_range, data->win_size, cur_message, data->cur_offset, data->cur_iteration, data->offset[data->cur_iteration-1]);
 
 		pthread_mutex_lock(&data->mutex_lock);
 		if (searching == 0 && *data->searching == 1) {
@@ -247,6 +338,7 @@ size_t generate_offset(unsigned char *data, size_t data_len, size_t iteration) {
 	size_t uncom_data_size = 0;
 
 	printf("Gen Offset\n");
+	// See if we can make this call faster
 	zlib_compress_data(data, data_len, &com_data_buff, &com_data_size);
 
 	zlib_decompress_data(com_data_buff, (MAX_WINDOW_SIZE * (iteration+1)), &uncom_data_buff, &uncom_data_size);
@@ -260,7 +352,7 @@ size_t generate_offset(unsigned char *data, size_t data_len, size_t iteration) {
 
 void random_data_change(unsigned char *color_data, unsigned char *width, size_t length, char *message) {
 	int searching = 1;
-	int core_count = 24;
+	int core_count = 28;
 	unsigned int sliding_window = 0;
 	unsigned int compress_data_length = 0;
 	// Needs to be turned into a variable
@@ -279,11 +371,13 @@ void random_data_change(unsigned char *color_data, unsigned char *width, size_t
 		printf("Mutex Lock Error\n");
 		return;
 	}
+	// Building Struct Data
 	t_data->searching = &searching;
 	t_data->message = message;
 	t_data->data = color_data;
 	t_data->data_len = compress_data_length;
 	t_data->uncom_data_len = length;
+	// Original Offset set to 0
 	t_data->cur_offset = 0;
 	t_data->width = be32toh(w.width_int);
 	t_data->color_range = color_range;
@@ -307,7 +401,10 @@ void random_data_change(unsigned char *color_data, unsigned char *width, size_t
 
 		// Only generate new offset if not last char in message
 		if(j != (strlen(message) - 1)) {
-			t_data->cur_offset = generate_offset(color_data, t_data->uncom_data_len, j);
+			// Changing offset check size to not be full length of picture to speed up generation
+			//t_data->cur_offset = generate_offset(color_data, t_data->uncom_data_len, j);
+			t_data->cur_offset = generate_offset(color_data, (200000 * (j+1)), j);
+			t_data->offset[j] = t_data->cur_offset;
 		}
 	}
 	return;
@@ -417,13 +514,14 @@ unsigned char* populate_idat_array(unsigned char *addr, unsigned long offset, si
 
 int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, char *message, int accuracy, unsigned long offset, char *out_file_name) {
 	if(accuracy > 4) {
+		// Accuracy is currently unused
 		printf("Warning, accuracy cannot be larger than 4");
 		return EXIT_FAILURE;
-	}
+	} else if (accuracy > 2) {
-	if(accuracy > 2) {
 		printf("Notice, this could take a long time...");
 	}
-	if(total_idat(addr) < strlen(message)) {
+	// Checking if total IDAT / 4 (Since Sliding Window is assumed to be 32k)
+	if((total_idat(addr) / 4) < strlen(message)) {
 		printf("Warning, message exceeds IDAT amount\n");
 		exit(EXIT_FAILURE);
 	}
@@ -431,20 +529,16 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 	size_t idat_byte_length = 0;
 	unsigned char *idat_data = populate_idat_array(addr, offset, &idat_byte_length);
 
-	unsigned char* temp_idat_data = calloc(idat_byte_length, sizeof(unsigned char));
-	memcpy(temp_idat_data, idat_data, idat_byte_length);
-
 	// Decompressing Data
 	unsigned char *uncom_data_buff = NULL;
 	size_t uncom_data_size = 0;
-	zlib_decompress_data(temp_idat_data, idat_byte_length, &uncom_data_buff, &uncom_data_size);
+	zlib_decompress_data(idat_data, idat_byte_length, &uncom_data_buff, &uncom_data_size);
 
 	printf("ORIG UNCOM LEN: %zu\n", uncom_data_size);
 
 	// Start data testing
 	random_data_change(uncom_data_buff, png_file->png_start_data.file_width, uncom_data_size, message);
 	
-	//return 0;
 	// Compress Data
 	unsigned char *com_data_buff;
 	size_t com_data_size = 0;
@@ -467,7 +561,6 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 	free(uncom_data_buff);
 	free(com_data_buff);
 	free(idat_data);
-	free(temp_idat_data);
 	free(png_file->png_idat_data.idat_data);
 
 	return 0;
@@ -570,35 +663,29 @@ int main(int argc, char **argv) {
 	if(uncompress_call == 1) {
 		size_t idat_byte_length = 0;
 		unsigned long cur_idat_len = 0;
-		//unsigned char message_data[8192];
 		unsigned char* idat_data = populate_idat_array(file_data, offset, &idat_byte_length);
 
-		//for(int i = 0; i < idat_byte_length; i++) {
+		printf("Decompressed Data:\n");
-			//printf("%02X ", idat_data[i]);
-		//}
-		printf("\nDecompressed Data:\n\n");
-		// Decompressing data
-		//unsigned char *uncom_data_buff = NULL;
-		//size_t uncom_data_size = 0;
-		//zlib_decompress_data(idat_data, idat_byte_length, &uncom_data_buff, &uncom_data_size);
-		//for(int i = 0; i < uncom_data_size; i++) {
-		//	printf("%02X ", uncom_data_buff[i]);
-		//}
-		//printf("\n");
 
 		do {
-			for(int j = 0; j < 64; j++) {
+			for(int j = 0; j < 1020; j++) {
 				cur_idat_len = 0;
 				for(int i = 0; i < 4; i++) {
 					cur_idat_len += (file_data[offset+i] << (24-(8*i)));
 				}
 					//printf("%c", file_data[offset+cur_idat_len+8]);
 				if((j % 4) == 0) {
-					printf("%c", file_data[offset+cur_idat_len+8]);
+					if(31 < file_data[offset+cur_idat_len+8] && file_data[offset+cur_idat_len+8] < 128) {
+						printf("%c", file_data[offset+cur_idat_len+8]);
+					} else {
+						offset = idat_byte_length;
+						break;
+					}
 				}
 				// Offset Plus idat length + 3 bytes
 				offset += cur_idat_len + 12;
 			}
+			printf("\n");
 		} while(offset < idat_byte_length);
 
 		free(idat_data);

include/crc.h

@@ -1,8 +0,0 @@
-#pragma once
-
-int check_file_header(char *addr);
-int check_header_length(unsigned char *addr, long offset);
-unsigned long first_idat(unsigned char *addr);
-int total_idat(unsigned char *addr);
-void build_png_file(struct PNG_FILE_STRUCT *png_file, char *out_file_name);
-int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, char *message, int accuracy, unsigned long offset, char *out_file_name);

include/crc_util.h

@@ -41,6 +41,7 @@ struct EMBED_THREAD_STRUCT {
 	unsigned int data_len;
 	size_t uncom_data_len;
 	size_t cur_offset;
+	size_t offset[8096];
 	size_t cur_iteration;
 	int width;
 	int color_range;

src/compress_util.c

@@ -82,6 +82,7 @@ void zlib_compress_data(unsigned char *data_chunk, size_t file_length, unsigned
         unsigned char out[CHUNK];
         int level = 9;
         int method = Z_DEFLATED;
+        //int windowBits = 15;
         int windowBits = 10;
         int memLevel = 9;
         //int strategy = Z_DEFAULT_STRATEGY;