PhotoRec: recover Clip Studio Paint .clip files

src/Makefile.am

@@ -103,6 +103,7 @@ file_C			= filegen.c \
 			  file_che.c \
 			  file_chm.c \
 			  file_class.c \
+			  file_clip.c \
 			  file_cm.c \
 			  file_compress.c \
 			  file_cow.c \

src/file_clip.c

@@ -0,0 +1,113 @@
+/*
+
+    File: file_clip.c
+
+    Copyright (C) 2021 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.
+
+ */
+
+#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_clip)
+#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 "common.h"
+
+/*@ requires valid_register_header_check(file_stat); */
+static void register_header_check_clip(file_stat_t *file_stat);
+
+const file_hint_t file_hint_clip= {
+  .extension="clip",
+  .description="Clip Studio Paint",
+  .max_filesize=PHOTOREC_MAX_FILE_SIZE,
+  .recover=1,
+  .enable_by_default=1,
+  .register_header_check=&register_header_check_clip
+};
+
+struct clip_header
+{
+  char header[8];
+  uint64_t size;
+} __attribute__ ((gcc_struct, __packed__));
+
+struct clip_chunk
+{
+  char chunk[4];	/* CHNK */
+  char type[4];
+  uint64_t length;
+} __attribute__ ((gcc_struct, __packed__));
+
+/*@
+  @ requires file_recovery->data_check==&data_check_clip;
+  @ requires valid_data_check_param(buffer, buffer_size, file_recovery);
+  @ ensures  valid_data_check_result(\result, file_recovery);
+  @ assigns  file_recovery->calculated_file_size;
+  @*/
+static data_check_t data_check_clip(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
+{
+  /*@
+    @ loop assigns file_recovery->calculated_file_size;
+    @*/
+  while(file_recovery->calculated_file_size + buffer_size/2  >= file_recovery->file_size &&
+      file_recovery->calculated_file_size + 16 <= file_recovery->file_size + buffer_size/2)
+  {
+    const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
+    /*@ assert 0 <= i <= buffer_size - 16; */
+    const struct clip_chunk *chunk=(const struct clip_chunk *)&buffer[i];
+    const uint64_t length=be64(chunk->length);
+    if(length >= 0x100000000 ||
+	memcmp(&buffer[i], "CHNK", 4)!=0)
+      return DC_ERROR;
+    file_recovery->calculated_file_size+=(uint64_t)0x10 + length;
+    if(length==0)
+      return DC_STOP;
+  }
+  return DC_CONTINUE;
+}
+
+
+/*@
+  @ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
+  @ ensures  valid_header_check_result(\result, file_recovery_new);
+  @ assigns  *file_recovery_new;
+  @*/
+static int header_check_clip(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 clip_header *hdr=(const struct clip_header *)buffer;
+  const uint64_t size=be64(hdr->size);
+  if(size <= 0x18 || size > 0x100000000)
+    return 0;
+  reset_file_recovery(file_recovery_new);
+  file_recovery_new->extension=file_hint_clip.extension;
+  file_recovery_new->data_check=&data_check_clip;
+  file_recovery_new->file_check=&file_check_size;
+  file_recovery_new->calculated_file_size=0x18;
+  file_recovery_new->min_filesize=size;
+  return 1;
+}
+
+static void register_header_check_clip(file_stat_t *file_stat)
+{
+  register_header_check(0, "CSFCHUNK", 8, &header_check_clip, file_stat);
+}
+#endif

src/file_list.c

@@ -81,6 +81,7 @@ extern const file_hint_t file_hint_cdt;
 extern const file_hint_t file_hint_che;
 extern const file_hint_t file_hint_chm;
 extern const file_hint_t file_hint_class;
+extern const file_hint_t file_hint_clip;
 extern const file_hint_t file_hint_cm;
 extern const file_hint_t file_hint_compress;
 extern const file_hint_t file_hint_cow;
@@ -534,6 +535,9 @@ file_enable_t array_file_enable[]=
 #if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_class)
   { .enable=0, .file_hint=&file_hint_class },
 #endif
+#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_clip)
+  { .enable=0, .file_hint=&file_hint_clip  },
+#endif
 #if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_cm)
   { .enable=0, .file_hint=&file_hint_cm  },
 #endif