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authorChristophe Grenier <grenier@cgsecurity.org>2007-10-29 22:38:52 +0100
committerChristophe Grenier <grenier@cgsecurity.org>2007-10-29 22:38:52 +0100
commit9928d99936105b4653d2d1b8ca74dc3ffba5c71e (patch)
tree06aa4f5e9f0055027c6fb54dd47a8414cf2fba32 /src/file_ogg.c
First version in git
Diffstat (limited to 'src/file_ogg.c')
-rw-r--r--src/file_ogg.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/src/file_ogg.c b/src/file_ogg.c
new file mode 100644
index 0000000..7bf53d1
--- /dev/null
+++ b/src/file_ogg.c
@@ -0,0 +1,105 @@
+/*
+
+ File: file_ogg.c
+
+ Copyright (C) 1998-2005,2007 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
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write the Free Software Foundation, Inc., 51
+ Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#include <stdio.h>
+#include "types.h"
+#include "filegen.h"
+#include "log.h"
+
+static void register_header_check_ogg(file_stat_t *file_stat);
+static int header_check_ogg(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);
+static int data_check_ogg(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery);
+
+const file_hint_t file_hint_ogg= {
+ .extension="ogg",
+ .description="OGG audio",
+ .min_header_distance=0,
+ .max_filesize=PHOTOREC_MAX_FILE_SIZE,
+ .recover=1,
+ .header_check=&header_check_ogg,
+ .register_header_check=&register_header_check_ogg
+};
+
+static const unsigned char ogg_header[4]= {'O','g','g','S'};
+
+static void register_header_check_ogg(file_stat_t *file_stat)
+{
+ register_header_check(0, ogg_header,sizeof(ogg_header), &header_check_ogg, file_stat);
+}
+
+static int header_check_ogg(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(file_recovery!=NULL && file_recovery->file_stat!=NULL && file_recovery->file_stat->file_hint==&file_hint_ogg)
+ return 0;
+ if(memcmp(buffer,ogg_header,sizeof(ogg_header))==0)
+ {
+ reset_file_recovery(file_recovery_new);
+ file_recovery_new->calculated_file_size=0;
+ file_recovery_new->data_check=&data_check_ogg;
+ file_recovery_new->file_check=&file_check_size;
+ file_recovery_new->extension=file_hint_ogg.extension;
+ return 1;
+ }
+ return 0;
+}
+
+/* http://www.ietf.org/rfc/rfc3533.txt */
+static int data_check_ogg(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
+{
+ while(file_recovery->calculated_file_size + 27 + 255 < file_recovery->file_size + buffer_size/2)
+ {
+ unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
+ if(memcmp(&buffer[i],ogg_header,sizeof(ogg_header))==0)
+ {
+ unsigned int number_page_segments;
+ unsigned int header_size;
+ unsigned int page_size;
+ unsigned int j;
+ number_page_segments=buffer[i+26];
+ header_size = number_page_segments + 27;
+ page_size=header_size;
+ for(j=0;j<number_page_segments;j++)
+ page_size+=buffer[i+27+j];
+ if(page_size<27)
+ {
+ return 2;
+ }
+ /* By definition, page_size<=27+255+255*255=65307 */
+ file_recovery->calculated_file_size+=page_size;
+ /*
+ log_debug("+0x%x=0x%x\n",page_size,file_recovery->calculated_file_size);
+ */
+ }
+ else
+ {
+ return 2;
+ }
+ }
+ return 1;
+}
+