wip

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

.gitignore

@@ -2,6 +2,4 @@
 *.out
 *.woo
 *.wow
-*.gch
-vgcore.*
 bin/

Makefile

@@ -14,6 +14,3 @@ output_dir:
 
 clean:
 	rm -rf $(OUTPUT_DIR) **.h.gch
-
-memcheck: debug
-	valgrind --tool=memcheck --leak-check=yes --show-reachable=yes --num-callers=20 --track-fds=yes -s ${OUTPUT_DIR}/crc

cmd/crc.c

@@ -1,12 +1,8 @@
-#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"
@@ -70,6 +66,8 @@ void random_data_change(unsigned char *color_data, int width, int length) {
 	int color_range = 3;	
 	unsigned char temp_color_data[length];
 
+	memcpy(temp_color_data, color_data, length);
+
 	do {
 		rounds++;
 		// Creating temporary data set
@@ -98,7 +96,6 @@ void random_data_change(unsigned char *color_data, int width, int length) {
 			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);
@@ -107,57 +104,8 @@ void random_data_change(unsigned char *color_data, int width, int length) {
 	} 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) {
+int change_idat_content(unsigned char *addr, unsigned char *message, int accuracy, unsigned long offset) {
+	//printf("Starting IDAT Tranform\n");
 	if(accuracy > 4) {
 		printf("Warning, accuracy cannot be larger than 4");
 		return EXIT_FAILURE;
@@ -165,15 +113,17 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 	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);
+	if(total_idat(addr) < strlen(message)) {
+		printf("Warning, message exceeds IDAT amount");
+		return EXIT_FAILURE;
 	}
 
 	int idat_length = check_header_length(addr, offset);
 	printf("IDAT Length: %d\n", idat_length);
 
+	int prop_found = 0;
 	long size = 1;
+	long rounds = 0;
 	size_t idat_byte_length = 0;
 	unsigned char* idat_data = calloc(size, sizeof(unsigned char));
 	for(size_t i = 0; i <= idat_length; i++) {
@@ -185,120 +135,55 @@ int change_idat_content(unsigned char *addr, struct PNG_FILE_STRUCT *png_file, c
 		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);
+	while(prop_found == 0) {
+		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);
+		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);
+		free(uncom_data_buff);
 
-	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];
+		//printf("Found %d in %d rounds\n", checked_crc ,rounds);
+		//printf("Full CRC: %08X\n", crcnum);
+		//printf("Original: %02X\n", idat_data[j]);
+		//printf("Change offset: %d to hex: %02X\n", j, temp_idat_data[j]);
+		//addr[offset+8+j] = temp_idat_data[j];
+		//update_file_crc(addr, offset, crcnum);
+		prop_found = 1;
 	}
 
-	// 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) {
+int main() {
 	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);
-	}
+	unsigned char *message = malloc(sizeof(char));
+	message[0] = '\0';
 
 	if(sodium_init() == -1) {
 		return EXIT_FAILURE;
 	}
 
-	fp = fopen(in_file_name, "rt");
-	if (fp == NULL) {
-		printf("File error\n");
-		exit(EXIT_FAILURE);
-	}
-
+	fp = fopen("./1.png", "rt");
+    if (fp == NULL) {
+        return 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);
-
+	change_idat_content(file_data, message, 1, offset);
 	free(file_data);
+	free(message);
+	//create_cc_file(file_data, i);
 }

include/CRCLib.h

@@ -1,7 +1,3 @@
-/*
- * Code Implemented From: https://www.w3.org/TR/PNG/#D-CRCAppendix
-*/
-
 /* Table of CRCs of all 8-bit messages. */
 unsigned long crc_table[256];
    

include/crc.h

@@ -1,8 +1,6 @@
-#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);
+int change_idat_content(unsigned char *addr, unsigned char *message, int accuracy, unsigned long offset);

include/crc_util.h

@@ -1,37 +1,4 @@
 #include <stdio.h>
-#include <stdint.h>
-
-#pragma once
-
-// PNG File Struct
-struct PNG_START_FILE_STRUCT {
-	unsigned char file_sig[8];
-	unsigned char ihdr_length[4];
-	unsigned char ihdr_header[4];
-	unsigned char file_width[4];
-	unsigned char file_height[4];
-	unsigned char bit_depth[1];
-	unsigned char color_type[1];
-	unsigned char compression_method[1];
-	unsigned char filter_method[1];
-	unsigned char interlace_method[1];
-	unsigned char ihdr_crc[4];
-};
-
-struct PNG_IDAT_FILE_STRUCT {
-	union{
-		unsigned char idat_length[4];
-		uint32_t idat_data_length;
-	};
-	unsigned char idat_header[4];
-	unsigned char idat_crc[4];
-	unsigned char *idat_data;
-};
-
-struct PNG_FILE_STRUCT {
-	struct PNG_START_FILE_STRUCT png_start_data;
-	struct PNG_IDAT_FILE_STRUCT png_idat_data;
-};
 
 extern const long png_signature[8];
 
@@ -39,5 +6,3 @@ int check_header_length(unsigned char *addr, long offset);
 int check_file_header(char *addr);
 int create_cc_file(unsigned char *addr, unsigned long file_length);
 unsigned char* file_to_char_array(FILE *in_file, size_t* size);
-void populate_start_png(unsigned char *addr, struct PNG_START_FILE_STRUCT *png_data);
-void populate_idat_png(unsigned char *addr, struct PNG_IDAT_FILE_STRUCT *png_data, unsigned long offset);

src/compress_util.c

@@ -6,9 +6,6 @@
 
 #define CHUNK 1024 
 
-/*
- * Built from exmaple provided in: https://zlib.net/zlib_how.html
-*/
 void zlib_decompress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
         int ret;
         unsigned int have;
@@ -71,9 +68,6 @@ void zlib_decompress_data(unsigned char *data_chunk, size_t file_length, unsigne
         fclose(of);
 }
 
-/*
- * Built from exmaple provided in: https://zlib.net/zlib_how.html
-*/
 void zlib_compress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
         int ret, flush;
         unsigned int have;

src/crc_util.c

@@ -27,34 +27,6 @@ int check_file_header(char *addr) {
 
 }
 
-void populate_idat_png(unsigned char *addr, struct PNG_IDAT_FILE_STRUCT *png_data, unsigned long offset) {
-	unsigned long cur_idat_length = 0;
-	for(int i = 0; i < 4; i++){
-		png_data->idat_length[i] = addr[i+offset];
-	}
-
-	for(int i = 0; i < 4; i++){
-		cur_idat_length += (png_data->idat_length[i] << (24-(8*i)));
-	}
-
-	for(int i = 0; i < 4; i++){
-		png_data->idat_header[i] = addr[i+offset+4];
-	}
-}
-
-void populate_start_png(unsigned char *addr, struct PNG_START_FILE_STRUCT *png_data) {
-	union{
-		unsigned char *data;
-		struct PNG_START_FILE_STRUCT *png_data;
-	}png;
-
-	png.png_data = png_data;
-
-	for(int i = 0; i < sizeof(struct PNG_START_FILE_STRUCT); i++) {
-		png.data[i] = addr[i];
-	}
-}
-
 int create_cc_file(unsigned char *addr, unsigned long file_length) {
         FILE *fp;
         fp = fopen("png2.png", "w");