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authorChristophe Grenier <grenier@cgsecurity.org>2009-01-18 15:09:35 +0100
committerChristophe Grenier <grenier@cgsecurity.org>2009-01-18 15:09:35 +0100
commite91fc1e8a7fffb826aaf5ec3c5df39429668a4dd (patch)
tree4c56f26faaefc631c94a2b5051089bbfc183af1c /src/file_ttf.c
parent64dd89ad436af24f87894a41aa4b5f8a29343c66 (diff)
PhotoRec: recover TrueType Font .ttf files
Diffstat (limited to 'src/file_ttf.c')
-rw-r--r--src/file_ttf.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/src/file_ttf.c b/src/file_ttf.c
new file mode 100644
index 0000000..ffc475a
--- /dev/null
+++ b/src/file_ttf.c
@@ -0,0 +1,127 @@
+/*
+
+ File: file_ttf.c
+
+ Copyright (C) 2009 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_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#ifdef HAVE_TIME_H
+#include <time.h>
+#endif
+#include <stdio.h>
+#include "types.h"
+#include "common.h"
+#include "filegen.h"
+#include "log.h"
+
+static void register_header_check_ttf(file_stat_t *file_stat);
+static int header_check_ttf(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_ttf= {
+ .extension="ttf",
+ .description="TrueType Font",
+ .min_header_distance=0,
+ .max_filesize=PHOTOREC_MAX_FILE_SIZE,
+ .recover=1,
+ .enable_by_default=1,
+ .register_header_check=&register_header_check_ttf
+};
+
+static const unsigned char header_ttf[5]= {0x00 , 0x01, 0x00, 0x00, 0x00};
+
+static void register_header_check_ttf(file_stat_t *file_stat)
+{
+ register_header_check(0, header_ttf, sizeof(header_ttf), &header_check_ttf, file_stat);
+}
+
+/*
+ * http://www.microsoft.com/typography/otspec/otff.htm
+ */
+
+struct ttf_offset_table
+{
+ int32_t sfnt_version;
+ uint16_t numTables;
+ uint16_t searchRange;
+ uint16_t entrySelector;
+ uint16_t rangeShift;
+};
+
+struct ttf_table_directory
+{
+ uint32_t tag;
+ uint32_t checkSum;
+ uint32_t offset; /* Offset from beginning of TrueType font file. */
+ uint32_t length; /* Length of this table. */
+};
+
+static unsigned int td_ilog2(unsigned int v)
+{
+ unsigned int l = 0;
+ while(v >>= 1)
+ l++;
+ return l;
+}
+
+static int header_check_ttf(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 struct ttf_offset_table *ttf=(const struct ttf_offset_table *)buffer;
+ unsigned int numTables;
+ if(memcmp(buffer, header_ttf, sizeof(header_ttf))!=0)
+ return 0;
+ numTables=be16(ttf->numTables);
+ /* searchRange (Maximum power of 2 <= numTables) x 16.
+ * entrySelector Log2(maximum power of 2 <= numTables).
+ * rangeShift NumTables x 16-searchRange.
+ * */
+ if(td_ilog2(numTables) != be16(ttf->entrySelector))
+ return 0;
+ if((16<<be16(ttf->entrySelector)) != be16(ttf->searchRange))
+ return 0;
+ if(numTables * 16 != (unsigned int)be16(ttf->rangeShift)+be16(ttf->searchRange))
+ return 0;
+ reset_file_recovery(file_recovery_new);
+ file_recovery_new->extension=file_hint_ttf.extension;
+ if(sizeof(struct ttf_offset_table) + numTables * sizeof(struct ttf_table_directory)
+ <= buffer_size)
+ {
+ const struct ttf_table_directory*ttf_dir=(const struct ttf_table_directory*)(ttf+1);
+ uint64_t max_offset=0;
+ int i;
+ for(i=0; i<numTables; i++,ttf_dir++)
+ {
+ /* | 0x3: align the end of the table */
+ const uint64_t new_offset=(be32(ttf_dir->offset) + be32(ttf_dir->length))|0x3;
+ if(max_offset < new_offset)
+ max_offset=new_offset;
+ }
+ file_recovery_new->calculated_file_size=max_offset;
+ file_recovery_new->data_check=&data_check_size;
+ file_recovery_new->file_check=&file_check_size;
+ }
+ return 1;
+}