136 lines
4.8 KiB
C
136 lines
4.8 KiB
C
/*
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File: file_flv.c
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Copyright (C) 2007,2014 Christophe GRENIER <grenier@cgsecurity.org>
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This software is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write the Free Software Foundation, Inc., 51
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Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_flv)
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#ifdef HAVE_STRING_H
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#include <string.h>
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#endif
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#include <stdio.h>
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#include "types.h"
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#include "filegen.h"
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#include "common.h"
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#include "log.h"
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/*@ requires valid_register_header_check(file_stat); */
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static void register_header_check_flv(file_stat_t *file_stat);
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const file_hint_t file_hint_flv= {
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.extension="flv",
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.description="Macromedia",
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.max_filesize=PHOTOREC_MAX_FILE_SIZE,
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.recover=1,
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.enable_by_default=1,
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.register_header_check=®ister_header_check_flv
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};
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struct flv_header
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{
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char signature[3];
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uint8_t version;
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uint8_t type_flags;
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uint32_t data_offset;
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} __attribute__ ((gcc_struct, __packed__));
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struct flv_tag
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{
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uint32_t prev_tag_size;
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uint8_t info;
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uint8_t data_size[3];
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uint8_t timestamp[3];
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uint8_t timestamp_ext;
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uint8_t streamID[3];
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} __attribute__ ((gcc_struct, __packed__));
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/*@
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@ requires file_recovery->data_check==&data_check_flv;
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@ requires valid_data_check_param(buffer, buffer_size, file_recovery);
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@ ensures valid_data_check_result(\result, file_recovery);
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@ assigns file_recovery->calculated_file_size, file_recovery->data_check_tmp;
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@*/
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static data_check_t data_check_flv(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
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{
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/*@
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@ loop assigns file_recovery->calculated_file_size, file_recovery->data_check_tmp;
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@*/
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while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
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file_recovery->calculated_file_size + 15 < file_recovery->file_size + buffer_size/2)
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{
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const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
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/*@ assert 0 <= i < buffer_size - 15; */
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const struct flv_tag *tag=(const struct flv_tag *)&buffer[i];
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/*@ assert \valid_read(tag); */
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#ifdef DEBUG_FLV
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log_info("cfs=0x%llx file_recovery->data_check_tmp=%u\n", (long long unsigned)file_recovery->calculated_file_size, file_recovery->data_check_tmp);
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#endif
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if((be32(tag->prev_tag_size)==0 && file_recovery->calculated_file_size < buffer_size/2) ||
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be32(tag->prev_tag_size)==11+file_recovery->data_check_tmp)
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{
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file_recovery->data_check_tmp=(tag->data_size[0]<<16) | (tag->data_size[1]<<8) | tag->data_size[2];
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if((tag->info&0xc0)!=0 || file_recovery->data_check_tmp==0
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|| tag->streamID[0]!=0 || tag->streamID[1]!=0 || tag->streamID[2]!=0 )
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{
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file_recovery->calculated_file_size+=4;
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return DC_STOP;
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}
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/* 4+11=15*/
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file_recovery->calculated_file_size+=(uint64_t)15+file_recovery->data_check_tmp;
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}
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else
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return DC_ERROR;
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}
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return DC_CONTINUE;
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}
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/*@
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@ requires buffer_size >= sizeof(struct flv_header);
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@ requires separation: \separated(&file_hint_flv, buffer+(..), file_recovery, file_recovery_new);
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@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
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@ ensures valid_header_check_result(\result, file_recovery_new);
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@ assigns *file_recovery_new;
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@*/
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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)
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{
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const struct flv_header *flv=(const struct flv_header *)buffer;
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const unsigned int data_offset=be32(flv->data_offset);
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if((flv->type_flags & 0xfa)==0 && data_offset>=9)
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{
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reset_file_recovery(file_recovery_new);
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file_recovery_new->extension=file_hint_flv.extension;
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if(file_recovery_new->blocksize < 15)
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return 1;
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file_recovery_new->calculated_file_size=data_offset;
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file_recovery_new->data_check=&data_check_flv;
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file_recovery_new->file_check=&file_check_size;
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return 1;
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}
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return 0;
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}
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static void register_header_check_flv(file_stat_t *file_stat)
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{
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static const unsigned char flv_header[4]= {'F', 'L', 'V', 0x01};
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register_header_check(0, flv_header,sizeof(flv_header), &header_check_flv, file_stat);
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}
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#endif
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