diff --git a/crc.c b/crc.c index 9771842..30a0747 100644 --- a/crc.c +++ b/crc.c @@ -14,18 +14,16 @@ const long idat_signature = 1229209940; const long iend_signature = 1229278788; -int zlib_compress_data(unsigned char *data_chunk, size_t file_length) { +FILE *zlib_decompress_data(unsigned char *data_chunk, size_t file_length) { int ret; unsigned int have; z_stream strm; unsigned char out[CHUNK]; unsigned char in[CHUNK]; - printf("Len: %zu\n", file_length); - errno=0; - FILE *data_stream = fmemopen(data_chunk, file_length-1, "r"); - FILE *of = fopen("wow.wow", "w"); + FILE *data_stream = fmemopen(data_chunk, file_length, "r"); + FILE *of = open_memstream(NULL, NULL); if(data_stream == NULL) { perror("F MEM OPEN"); } @@ -37,20 +35,20 @@ int zlib_compress_data(unsigned char *data_chunk, size_t file_length) { strm.next_in = Z_NULL; ret = inflateInit(&strm); if(ret != Z_OK) { - return ret; + return NULL; } do { strm.avail_in = fread(in, 1, CHUNK, data_stream); if(ferror(data_stream)) { (void)inflateEnd(&strm); - return Z_ERRNO; + return NULL; } if(strm.avail_in == 0) { break; } strm.next_in = in; - + do { strm.avail_out = CHUNK; strm.next_out = out; @@ -64,7 +62,7 @@ int zlib_compress_data(unsigned char *data_chunk, size_t file_length) { (void)inflateEnd(&strm); printf("Error: %d\n", ret); printf("MSG: %s\n", (char*)strm.msg); - return ret; + return NULL; } have = CHUNK - strm.avail_out; fwrite(out, 1, have, of); @@ -73,9 +71,8 @@ int zlib_compress_data(unsigned char *data_chunk, size_t file_length) { (void)inflateEnd(&strm); - printf("String: %s\n", out); - return 1; + return of; } unsigned long first_idat(unsigned char *addr) { @@ -125,6 +122,31 @@ int update_file_crc(unsigned char *addr, unsigned long offset , unsigned int crc } } +void random_data_change(unsigned char *color_data, int width, int length) { + int searching = 1; + width = 16; + int color_range = 3; + unsigned char temp_color_data[length]; + + memcpy(temp_color_data, color_data, length); + + do { + // 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]++; + } + } + + } while(searching == 1); +} + int change_idat_content(unsigned char *addr, char *message, int accuracy, unsigned long offset) { //printf("Starting IDAT Tranform\n"); if(accuracy > 4) { @@ -160,33 +182,41 @@ int change_idat_content(unsigned char *addr, char *message, int accuracy, unsign for(int i = 0; i <= idat_length; i++) { temp_idat_data[i] = idat_data[i]; } - int r = randombytes_uniform(5) + 1; - int j = randombytes_uniform(idat_length); + //int r = randombytes_uniform(5) + 1; + //int j = randombytes_uniform(idat_length); - temp_idat_data[j] = (temp_idat_data[j] + r) % 255; - unsigned char crc_check[size+4]; - unsigned int idat_header[] = { 0x49, 0x44, 0x41, 0x54 }; - for(int i = 0; i < 4; i++) { - crc_check[i] = idat_header[i]; - } - for(int i = 0; i < idat_byte_length; i++) { - crc_check[i] = temp_idat_data[i+4]; - } - unsigned int crcnum = crc(crc_check, idat_length); - //printf("New CRC: %08X\n", crcnum); - //printf("Test: %X\n", crcnum >> (8*3)); - unsigned int checked_crc = crcnum >> (8*3); - rounds++; - if(checked_crc == 61) { - zlib_compress_data(temp_idat_data, idat_byte_length); - printf("Found %d in %d rounds\n", checked_crc ,rounds); + //temp_idat_data[j] = (temp_idat_data[j] + r) % 255; + //unsigned char crc_check[size+4]; + //unsigned int idat_header[] = { 0x49, 0x44, 0x41, 0x54 }; + //for(int i = 0; i < 4; i++) { + // crc_check[i] = idat_header[i]; + //} + //for(int i = 0; i < idat_byte_length; i++) { + // crc_check[i] = temp_idat_data[i+4]; + //} + //unsigned int crcnum = crc(crc_check, idat_length); + //unsigned int checked_crc = crcnum >> (8*3); + //rounds++; + //if(checked_crc == 61) { + // Setting TEMP IDAT DATA BACK TO ORIGINAL + // TO STOP DECOMPRESSION CORRUPTION + //temp_idat_data[j] = addr[offset+8+j]; + // Decompressing Data + FILE *uncom_data = zlib_decompress_data(temp_idat_data, idat_byte_length); + size_t uncom_data_size = 0; + + unsigned char *uncom_data_array = file_to_char_array(uncom_data, &uncom_data_size); + printf("UnCom: %zu\n", uncom_data_size); + random_data_change(uncom_data_array, 16, uncom_data_size); + + //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); + //addr[offset+8+j] = temp_idat_data[j]; + //update_file_crc(addr, offset, crcnum); prop_found = 1; - } + //} } return 0; @@ -194,28 +224,18 @@ int change_idat_content(unsigned char *addr, char *message, int accuracy, unsign int main() { FILE *fp; - unsigned int c; - unsigned long file_data_cap = 8; - unsigned char* file_data = calloc(file_data_cap, sizeof(unsigned char)); size_t i = 0; unsigned long offset = 0; char message[1]; + if(sodium_init() == -1) { return EXIT_FAILURE; } + fp = fopen("./1.png", "rt"); - for(size_t i = 0;(c = fgetc(fp)) != EOF; i++) { - if(i == file_data_cap) { - file_data_cap *= 2; - file_data = reallocarray(file_data, file_data_cap, sizeof(unsigned char)); - if(file_data == NULL) { - perror("FAILED ARRAY RESIZE"); - return EXIT_FAILURE; - } - } - file_data[i] = c; - } + unsigned char *file_data = file_to_char_array(fp, &i); fclose(fp); + offset = first_idat(file_data); change_idat_content(file_data, message, 1, offset); //create_cc_file(file_data, i); diff --git a/crc_util.c b/crc_util.c index 0f18bf3..91fc57a 100644 --- a/crc_util.c +++ b/crc_util.c @@ -41,3 +41,23 @@ int create_cc_file(unsigned char *addr, unsigned long file_length) { } fclose(fp); } + +unsigned char* file_to_char_array(FILE *in_file, size_t* size) { + unsigned int c; + unsigned long file_data_cap = 8; + unsigned char* file_data = calloc(file_data_cap, sizeof(unsigned char)); + + for(size_t i = 0;(c = fgetc(in_file)) != EOF; i++) { + if(i == file_data_cap) { + file_data_cap *= 2; + file_data = reallocarray(file_data, file_data_cap, sizeof(unsigned char)); + if(file_data == NULL) { + perror("FAILED ARRAY RESIZE"); + return NULL; + } + } + file_data[i] = c; + *size += 1; + } + return file_data; +} diff --git a/crc_util.h b/crc_util.h index 9edfc34..03f2ae9 100644 --- a/crc_util.h +++ b/crc_util.h @@ -4,3 +4,4 @@ extern const long png_signature[8]; 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);