wip

.gitignore

@@ -1,2 +1,5 @@
 *.png
 *.out
+*.woo
+*.wow
+bin/

Makefile

@@ -0,0 +1,16 @@
+LIBRARIES = `pkg-config --libs zlib libsodium` -Iinclude
+SOURCES = ./src/* ./cmd/crc.c
+OUTPUT_DIR = ./bin
+OUTPUT = -o ${OUTPUT_DIR}/PROG
+
+build: output_dir
+	gcc -Wall ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=crc}
+
+debug: output_dir
+	gcc -Wall -g ${LIBRARIES} ${SOURCES} ${OUTPUT:PROG=crc}
+
+output_dir:
+	mkdir -p ${OUTPUT_DIR}
+
+clean:
+	rm -rf $(OUTPUT_DIR) **.h.gch

cmd/crc.c

@@ -1,7 +1,4 @@
 #include <stdio.h>
-#include <zlib.h>
-#include <assert.h>
-#include <errno.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
@@ -9,129 +6,11 @@
 #include "crc_util.h"
 #include "CRCLib.h"
 #include "crc.h"
+#include "compress_util.h"
 
-#define CHUNK 1024
 const long idat_signature = 1229209940;
 const long iend_signature = 1229278788;
 
-void zlib_decompress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
-	int ret;
-	unsigned int have;
-	z_stream strm;
-	unsigned char out[CHUNK];
-	unsigned char in[CHUNK];
-
-	errno=0;
-	FILE *data_stream = fmemopen(data_chunk, file_length, "r");
-	FILE *of = open_memstream((char**)buff, sz);
-	if(data_stream == NULL) {
-		perror("F MEM OPEN");
-	}
-
-	strm.zalloc = Z_NULL;
-	strm.zfree = Z_NULL;
-	strm.opaque = Z_NULL;
-	strm.avail_in = 0;
-	strm.next_in = Z_NULL;
-	ret = inflateInit(&strm);
-	if(ret != Z_OK) {
-		return;
-	}
-
-	do {
-		strm.avail_in = fread(in, 1, CHUNK, data_stream);
-		if(ferror(data_stream)) {
-			(void)inflateEnd(&strm);
-			return;
-		}
-		if(strm.avail_in == 0) {
-			break;
-		}
-		strm.next_in = in;
-	
-		do {
-			strm.avail_out = CHUNK;
-			strm.next_out = out;
-			ret = inflate(&strm, Z_NO_FLUSH);
-			assert(ret != Z_STREAM_ERROR);
-			switch(ret) {
-				case Z_NEED_DICT:
-					ret = Z_DATA_ERROR;
-				case Z_DATA_ERROR:
-				case Z_MEM_ERROR:
-					(void)inflateEnd(&strm);
-					printf("Error: %d\n", ret);
-					printf("MSG: %s\n", (char*)strm.msg);
-					return;
-			}
-			have = CHUNK - strm.avail_out;
-			fwrite(out, 1, have, of);
-		} while(strm.avail_out == 0);
-	} while(ret != Z_STREAM_END);
-
-	(void)inflateEnd(&strm);
-
-	fclose(data_stream);
-	fclose(of);
-}
-
-void zlib_compress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
-	int ret, flush;
-	unsigned int have;
-	z_stream strm;
-	unsigned char in[CHUNK];
-	unsigned char out[CHUNK];
-	int level = 9;
-	int method = Z_DEFLATED;
-	int windowBits = 10;
-	int memLevel = 9;
-	//int strategy = Z_DEFAULT_STRATEGY;
-	int strategy = Z_FILTERED;
-
-	FILE *data_stream = fmemopen(data_chunk, file_length, "r");
-	FILE *out_data_stream = NULL;
-	out_data_stream = open_memstream((char**)buff, sz);
-
-	strm.zalloc = Z_NULL;
-	strm.zfree = Z_NULL;
-	strm.opaque = Z_NULL;
-	ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
-	if (ret != Z_OK) {
-		return;
-	}
-
-	do {
-		strm.avail_in = fread(in, 1, CHUNK, data_stream);
-		if (ferror(data_stream)) {
-			(void)deflateEnd(&strm);
-			return;
-		}
-		flush = feof(data_stream) ? Z_FINISH : Z_NO_FLUSH;
-		strm.next_in = in;
-
-		do {
-			strm.avail_out = CHUNK;
-			strm.next_out = out;
-
-			ret = deflate(&strm, flush);
-			assert(ret != Z_STREAM_ERROR);
-			have = CHUNK - strm.avail_out;
-			if(fwrite(out, 1, have, out_data_stream) != have || ferror(out_data_stream)) {
-				(void)deflateEnd(&strm);
-				return;
-			}
-		} while(strm.avail_out == 0);
-		assert(strm.avail_in == 0);
-
-	} while(flush != Z_FINISH);
-	assert(ret == Z_STREAM_END);
-
-	fclose(data_stream);
-	fclose(out_data_stream);
-
-	(void)deflateEnd(&strm);
-}
-
 unsigned long first_idat(unsigned char *addr) {
 	int idat_found = 0;
 	unsigned long offset = 8;
@@ -177,6 +56,7 @@ int update_file_crc(unsigned char *addr, unsigned long offset , unsigned int crc
 		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) {
@@ -224,7 +104,7 @@ void random_data_change(unsigned char *color_data, int width, int length) {
 	} while(searching == 1);
 }
 
-int change_idat_content(unsigned char *addr, char *message, int accuracy, unsigned long offset) {
+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");
@@ -282,6 +162,7 @@ int change_idat_content(unsigned char *addr, char *message, int accuracy, unsign
 	return 0;
 }
 
+// This is where it all starts
 int main() {
 	FILE *fp;
 	size_t i = 0;
@@ -294,6 +175,9 @@ int main() {
 	}
 
 	fp = fopen("./1.png", "rt");
+    if (fp == NULL) {
+        return EXIT_FAILURE;
+    }
 	unsigned char *file_data = file_to_char_array(fp, &i);
 	fclose(fp);
 

include/compress_util.h

@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <zlib.h>
+#include <stddef.h>
+#include <assert.h>
+#include <errno.h>
+
+void zlib_decompress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz);
+void zlib_compress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz);

include/crc.h

@@ -3,4 +3,4 @@ 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);
-int change_idat_content(unsigned char *addr, char *message, int accuracy, unsigned long offset);
+int change_idat_content(unsigned char *addr, unsigned char *message, int accuracy, unsigned long offset);

src/compress_util.c

@@ -0,0 +1,126 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include "compress_util.h"
+
+#define CHUNK 1024 
+
+void zlib_decompress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
+        int ret;
+        unsigned int have;
+        z_stream strm;
+        // Adding one to zero here
+        unsigned char out[CHUNK];
+        unsigned char in[CHUNK];
+
+        errno=0;
+        FILE *data_stream = fmemopen(data_chunk, file_length, "r");
+        FILE *of = open_memstream((char**)buff, sz);
+        if(data_stream == NULL) {
+                perror("F MEM OPEN");
+        }
+
+        strm.zalloc = Z_NULL;
+        strm.zfree = Z_NULL;
+        strm.opaque = Z_NULL;
+        strm.avail_in = 0;
+        strm.next_in = Z_NULL;
+        ret = inflateInit(&strm);
+        if(ret != Z_OK) {
+                return;
+        }
+
+        do {
+                strm.avail_in = fread(in, 1, CHUNK, data_stream);
+                if(ferror(data_stream)) {
+                        (void)inflateEnd(&strm);
+                        return;
+                }
+                if(strm.avail_in == 0) {
+                        break;
+                }
+                strm.next_in = in;
+        
+                do {
+                        strm.avail_out = CHUNK;
+                        strm.next_out = out;
+                        ret = inflate(&strm, Z_NO_FLUSH);
+                        assert(ret != Z_STREAM_ERROR);
+                        switch(ret) {
+                                case Z_NEED_DICT:
+                                        ret = Z_DATA_ERROR;
+                                case Z_DATA_ERROR:
+                                case Z_MEM_ERROR:
+                                        (void)inflateEnd(&strm);
+                                        printf("Error: %d\n", ret);
+                                        printf("MSG: %s\n", (char*)strm.msg);
+                                        return;
+                        }
+                        have = CHUNK - strm.avail_out;
+                        fwrite(out, 1, have, of);
+                } while(strm.avail_out == 0);
+        } while(ret != Z_STREAM_END);
+
+        (void)inflateEnd(&strm);
+
+        fclose(data_stream);
+        fclose(of);
+}
+
+void zlib_compress_data(unsigned char *data_chunk, size_t file_length, unsigned char **buff, size_t *sz) {
+        int ret, flush;
+        unsigned int have;
+        z_stream strm;
+        unsigned char in[CHUNK];
+        unsigned char out[CHUNK];
+        int level = 9;
+        int method = Z_DEFLATED;
+        int windowBits = 10;
+        int memLevel = 9;
+        //int strategy = Z_DEFAULT_STRATEGY;
+        int strategy = Z_FILTERED;
+
+        FILE *data_stream = fmemopen(data_chunk, file_length, "r");
+        FILE *out_data_stream = NULL;
+        out_data_stream = open_memstream((char**)buff, sz);
+
+        strm.zalloc = Z_NULL;
+        strm.zfree = Z_NULL;
+        strm.opaque = Z_NULL;
+        ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
+        if (ret != Z_OK) {
+                return;
+        }
+
+        do {
+                strm.avail_in = fread(in, 1, CHUNK, data_stream);
+                if (ferror(data_stream)) {
+                        (void)deflateEnd(&strm);
+                        return;
+                }
+                flush = feof(data_stream) ? Z_FINISH : Z_NO_FLUSH;
+                strm.next_in = in;
+
+                do {
+                        strm.avail_out = CHUNK;
+                        strm.next_out = out;
+
+                        ret = deflate(&strm, flush);
+                        assert(ret != Z_STREAM_ERROR);
+                        have = CHUNK - strm.avail_out;
+                        if(fwrite(out, 1, have, out_data_stream) != have || ferror(out_data_stream)) {
+                                (void)deflateEnd(&strm);
+                                return;
+                        }
+                } while(strm.avail_out == 0);
+                assert(strm.avail_in == 0);
+
+        } while(flush != Z_FINISH);
+        assert(ret == Z_STREAM_END);
+
+        fclose(data_stream);
+        fclose(out_data_stream);
+
+        (void)deflateEnd(&strm);
+}

src/crc_util.c

@@ -39,6 +39,7 @@ int create_cc_file(unsigned char *addr, unsigned long file_length) {
                 fputc(addr[i], fp);
         }
         fclose(fp);
+	return 0;
 }
 
 unsigned char* file_to_char_array(FILE *in_file, size_t* size) {