PhotoRec: stricter check for .png

This commit is contained in:
Christophe Grenier 2014-07-26 19:17:12 +02:00
parent adb18ac16e
commit ecc15d0571

View file

@ -64,8 +64,16 @@ struct png_chunk
static int header_check_jng(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
if( !((isupper(buffer[8+4]) || islower(buffer[8+4])) &&
(isupper(buffer[8+5]) || islower(buffer[8+5])) &&
(isupper(buffer[8+6]) || islower(buffer[8+6])) &&
(isupper(buffer[8+7]) || islower(buffer[8+7]))))
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension="jng";
file_recovery_new->min_filesize=16;
if(file_recovery_new->blocksize < 8)
return 1;
file_recovery_new->calculated_file_size=8;
file_recovery_new->data_check=&data_check_png;
file_recovery_new->file_check=&file_check_size;
@ -74,8 +82,16 @@ static int header_check_jng(const unsigned char *buffer, const unsigned int buff
static int header_check_mng(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
if( !((isupper(buffer[8+4]) || islower(buffer[8+4])) &&
(isupper(buffer[8+5]) || islower(buffer[8+5])) &&
(isupper(buffer[8+6]) || islower(buffer[8+6])) &&
(isupper(buffer[8+7]) || islower(buffer[8+7]))))
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension="mng";
file_recovery_new->min_filesize=16;
if(file_recovery_new->blocksize < 8)
return 1;
file_recovery_new->calculated_file_size=8;
file_recovery_new->data_check=&data_check_mng;
file_recovery_new->file_check=&file_check_size;
@ -90,8 +106,16 @@ static int header_check_png(const unsigned char *buffer, const unsigned int buff
(strcmp(file_recovery->extension,"sld")==0 ||
strcmp(file_recovery->extension,"sldprt")==0))
return 0;
if( !((isupper(buffer[8+4]) || islower(buffer[8+4])) &&
(isupper(buffer[8+5]) || islower(buffer[8+5])) &&
(isupper(buffer[8+6]) || islower(buffer[8+6])) &&
(isupper(buffer[8+7]) || islower(buffer[8+7]))))
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_png.extension;
file_recovery_new->min_filesize=16;
if(file_recovery_new->blocksize < 8)
return 1;
file_recovery_new->calculated_file_size=8;
file_recovery_new->data_check=&data_check_png;
file_recovery_new->file_check=&file_check_size;
@ -106,9 +130,19 @@ static data_check_t data_check_mng(const unsigned char *buffer, const unsigned i
{
const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
const struct png_chunk *chunk=(const struct png_chunk *)&buffer[i];
file_recovery->calculated_file_size+=12 + be32(chunk->length);
if(memcmp(&buffer[i+4], mng_footer, sizeof(mng_footer))==0)
{
file_recovery->calculated_file_size+=12 + be32(chunk->length);
return DC_STOP;
}
if( !((isupper(buffer[i+4]) || islower(buffer[i+4])) &&
(isupper(buffer[i+5]) || islower(buffer[i+5])) &&
(isupper(buffer[i+6]) || islower(buffer[i+6])) &&
(isupper(buffer[i+7]) || islower(buffer[i+7]))))
{
return DC_ERROR;
}
file_recovery->calculated_file_size+=12 + be32(chunk->length);
}
return DC_CONTINUE;
}
@ -120,9 +154,11 @@ static data_check_t data_check_png(const unsigned char *buffer, const unsigned i
{
const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
const struct png_chunk *chunk=(const struct png_chunk *)&buffer[i];
file_recovery->calculated_file_size+=12 + be32(chunk->length);
if(memcmp(&buffer[i+4], "IEND", 4)==0)
{
file_recovery->calculated_file_size+=12 + be32(chunk->length);
return DC_STOP;
}
// PNG chunk code
// IDAT IHDR PLTE bKGD cHRM fRAc gAMA gIFg gIFt gIFx hIST iCCP
// iTXt oFFs pCAL pHYs sBIT sCAL sPLT sRGB sTER tEXt tRNS zTXt
@ -131,8 +167,9 @@ static data_check_t data_check_png(const unsigned char *buffer, const unsigned i
(isupper(buffer[i+6]) || islower(buffer[i+6])) &&
(isupper(buffer[i+7]) || islower(buffer[i+7]))))
{
return DC_STOP;
return DC_ERROR;
}
file_recovery->calculated_file_size+=12 + be32(chunk->length);
}
return DC_CONTINUE;
}
@ -142,7 +179,7 @@ static void register_header_check_png(file_stat_t *file_stat)
static const unsigned char png_header[8]= { 0x89, 'P', 'N','G', 0x0d, 0x0a, 0x1a, 0x0a};
static const unsigned char mng_header[8]= { 0x8a, 'M', 'N','G', 0x0d, 0x0a, 0x1a, 0x0a};
static const unsigned char jng_header[8]= { 0x8b, 'J', 'N','G', 0x0d, 0x0a, 0x1a, 0x0a};
register_header_check(0, png_header,sizeof(png_header), &header_check_png, file_stat);
register_header_check(0, mng_header,sizeof(mng_header), &header_check_mng, file_stat);
register_header_check(0, jng_header,sizeof(jng_header), &header_check_jng, file_stat);
register_header_check(0, png_header, sizeof(png_header), &header_check_png, file_stat);
register_header_check(0, mng_header, sizeof(mng_header), &header_check_mng, file_stat);
register_header_check(0, jng_header, sizeof(jng_header), &header_check_jng, file_stat);
}