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PhotoRec: parse .flv files to get the correct filesize

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This commit is contained in:
Christophe Grenier 2014-04-13 19:26:24 +02:00
parent 7aaa9b6bfa
commit dd25874e79
1 changed files with 57 additions and 7 deletions
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64
src/file_flv.c
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@ -2,7 +2,7 @@
File: file_flv.c
Copyright (C) 2007 Christophe GRENIER <grenier@cgsecurity.org>
Copyright (C) 2007,2014 Christophe GRENIER <grenier@cgsecurity.org>
This software is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@ -30,9 +30,9 @@
#include "types.h"
#include "filegen.h"
#include "common.h"
#include "log.h"
static void register_header_check_flv(file_stat_t *file_stat);
static int header_check_flv(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);
const file_hint_t file_hint_flv= {
.extension="flv",
@ -44,20 +44,70 @@ const file_hint_t file_hint_flv= {
.register_header_check=&register_header_check_flv
};
static const unsigned char flv_header[4]= {'F', 'L', 'V', 0x01};
static void register_header_check_flv(file_stat_t *file_stat)
struct flv_header
{
register_header_check(0, flv_header,sizeof(flv_header), &header_check_flv, file_stat);
char signature[3];
uint8_t version;
uint8_t type_flags;
uint32_t data_offset;
} __attribute__ ((__packed__));
struct flv_tag
{
uint32_t prev_tag_size;
uint8_t info;
uint8_t data_size[3];
uint8_t timestamp[3];
uint8_t timestamp_ext;
uint8_t streamID[3];
} __attribute__ ((__packed__));
static data_check_t data_check_flv(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
static uint32_t datasize=0;
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 15 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
const struct flv_tag *tag=(const struct flv_tag *)&buffer[i];
#ifdef DEBUG_FLV
log_info("cfs=0x%llx datasize=%u\n", (long long unsigned)file_recovery->calculated_file_size, datasize);
#endif
if((be32(tag->prev_tag_size)==0 && file_recovery->calculated_file_size < buffer_size/2) ||
be32(tag->prev_tag_size)==11+datasize)
{
datasize=(tag->data_size[0]<<16) | (tag->data_size[1]<<8) | tag->data_size[2];
if((tag->info&0xc0)!=0 || datasize==0
|| tag->streamID[0]!=0 || tag->streamID[1]!=0 || tag->streamID[2]!=0 )
{
file_recovery->calculated_file_size+=4;
return DC_STOP;
}
file_recovery->calculated_file_size+=4+11+datasize;
}
else
return DC_ERROR;
}
return DC_CONTINUE;
}
static int header_check_flv(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(memcmp(buffer, flv_header, sizeof(flv_header))==0 && (buffer[4]==1 || buffer[4]==5))
const struct flv_header *flv=(const struct flv_header *)buffer;
if((flv->type_flags & 0xfa)==0 && be32(flv->data_offset)>=9)
{
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_flv.extension;
file_recovery_new->calculated_file_size=be32(flv->data_offset);
file_recovery_new->data_check=&data_check_flv;
file_recovery_new->file_check=&file_check_size;
return 1;
}
return 0;
}
static void register_header_check_flv(file_stat_t *file_stat)
{
static const unsigned char flv_header[4]= {'F', 'L', 'V', 0x01};
register_header_check(0, flv_header,sizeof(flv_header), &header_check_flv, file_stat);
}