diff options
Diffstat (limited to 'src/main.c')
| -rw-r--r-- | src/main.c | 64 |
1 files changed, 61 insertions, 3 deletions
@@ -12,10 +12,12 @@ #include <stdint.h> #include <errno.h> -//SWAPPED + +//Magic values #define _MAGIC_JPG 0xD8FF //JPG Magic Value -#define _MAGIC_PNG 0xFFFA //PNG Magic Value -#define _MAGIC_TFF 0xFFFF //TIFF Magic Value +#define _MAGIC_PNG 0x5089 +#define _MAGIC_PNG_FULL 0x0A1A0A0D474E5089 //89 50 4E 47 0D 0A 1A 0A +#define _MAGIC_TFF 0x2A00 //TIFF Magic Value //JPG #define _JPG_EXIF 0xE1 //EXIF @@ -25,6 +27,13 @@ #define _JPG_SOS 0xDA //Start of image data #define _JPG_EOI 0xD9 //End of image +//PNG +#define _PNG_IHDR 0x52444849 +#define _PNG_IDAT 0x54414449 +#define _PNG_IEND 0x444E4549 +#define _PNG_PLTE 0x45544C50 + + int strip_jpg(char *_filename); int strip_png(char *_filename); @@ -167,6 +176,53 @@ int strip_png(char *_filename) printf("Unable to open for writing %s: %i\n", f__outfile, errno); return 1; } + + uint64_t magic_num = _MAGIC_PNG_FULL; + fwrite(&magic_num, 1, 8, out); + + uint32_t read_buff = 0; + uint32_t chunk_len = 0; + while(1) + { + //Heavy shifting + //Chunk header is 4B + chunk_len = ((chunk_len << 8) & 0xFFFFFF00) + ( read_buff & 0x000000FF ); + + unsigned char c = fgetc(in); + read_buff = ((read_buff >> 8) & 0x00FFFFFF) + (((uint32_t)c << 24) & 0xFF000000); + + //Whitelist only important PNG chunks + if( read_buff == _PNG_IHDR || + read_buff == _PNG_IDAT || + read_buff == _PNG_PLTE || + read_buff == _PNG_IEND ) + { + char *f__buffer = malloc( chunk_len ); + uint32_t crc; + //*Ghetto music plays* + uint64_t chunk_str = 0; + chunk_str += read_buff; + + printf("CHUNK %s SIZE %uB\n", &chunk_str, chunk_len); + + fread(f__buffer, 1, chunk_len, in); + fread(&crc, 1, 4, in); + + fwrite(&chunk_len, 1, sizeof(chunk_len), out); + fwrite(&read_buff, 1, sizeof(read_buff), out); + fwrite(f__buffer, 1, chunk_len, out); + fwrite(&crc, 1, 4, out); + + free(f__buffer); + + if(read_buff == _PNG_IEND) + break; + } + + if(feof(in)) + break; + } + fclose(in); fclose(out); @@ -197,6 +253,8 @@ int strip_tiff(char *_filename) return 1; } + printf("Unimplemented\n"); + fclose(in); fclose(out); free(f__outfile); |