comics: Use libarchive to unpack documents [CVE-2023-44452].

This commit eliminates the use of external commands for opening
comic documents, and uses libarchive instead.

Fixes:
CVE-2023-44452 - Linux Mint Xreader CBT File Parsing Argument
                 Injection Remote Code Execution Vulnerability.

Based on:
https://gitlab.gnome.org/GNOME/evince/-/commit/7b5ad18399b04cbfce02730d28baf30e9fc35b58

This vulnerability was discovered by:
Febin Mon Saji working with Trend Micro Zero Day Initiative

Author: mtwebster

backend/comics/comics-document.c

@@ -16,9 +16,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
-#ifndef __COMICS_DOCUMENT_H__
-#define __COMICS_DOCUMENT_H__
+#pragma once
 
+#include "ev-macros.h"
 #include "ev-document.h"
 
 G_BEGIN_DECLS
@@ -30,9 +30,6 @@ G_BEGIN_DECLS
 typedef struct _ComicsDocument ComicsDocument;
 
 GType                 comics_document_get_type (void) G_GNUC_CONST;
+GType                 register_evince_backend  (GTypeModule *module);
 
-G_MODULE_EXPORT GType register_xreader_backend  (GTypeModule *module);
-     
 G_END_DECLS
-
-#endif /* __COMICS_DOCUMENT_H__ */

backend/comics/comics-document.h

@@ -1,4 +1,4 @@
 [Xreader Backend]
 Module=comicsdocument
-_TypeDescription=Comic Books
-MimeType=application/x-cbr;application/x-cbz;application/x-cb7;application/x-cbt;application/vnd.comicbook+zip;
+TypeDescription=Comic Books
+MimeType=@COMICS_MIME_TYPES@;

backend/comics/comicsdocument.xreader-backend.in

@@ -0,0 +1,323 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; c-indent-level: 8 -*- */
+/*
+ * Copyright (C) 2017, Bastien Nocera <[email protected]>
+ *
+ * This program 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, 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 to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "config.h"
+#include "ev-archive.h"
+
+#include <archive.h>
+#include <archive_entry.h>
+#include <gio/gio.h>
+
+#define BUFFER_SIZE (64 * 1024)
+
+struct _EvArchive {
+	GObject parent_instance;
+	EvArchiveType type;
+
+	/* libarchive */
+	struct archive *libar;
+	struct archive_entry *libar_entry;
+};
+
+G_DEFINE_TYPE(EvArchive, ev_archive, G_TYPE_OBJECT);
+
+static void
+ev_archive_finalize (GObject *object)
+{
+	EvArchive *archive = EV_ARCHIVE (object);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		g_clear_pointer (&archive->libar, archive_free);
+		break;
+	default:
+		break;
+	}
+
+	G_OBJECT_CLASS (ev_archive_parent_class)->finalize (object);
+}
+
+static void
+ev_archive_class_init (EvArchiveClass *klass)
+{
+        GObjectClass *object_class = (GObjectClass *) klass;
+
+        object_class->finalize = ev_archive_finalize;
+}
+
+EvArchive *
+ev_archive_new (void)
+{
+	return g_object_new (EV_TYPE_ARCHIVE, NULL);
+}
+
+static void
+libarchive_set_archive_type (EvArchive *archive,
+			     EvArchiveType archive_type)
+{
+	archive->type = archive_type;
+	archive->libar = archive_read_new ();
+
+	if (archive_type == EV_ARCHIVE_TYPE_ZIP)
+		archive_read_support_format_zip (archive->libar);
+	else if (archive_type == EV_ARCHIVE_TYPE_7Z)
+		archive_read_support_format_7zip (archive->libar);
+	else if (archive_type == EV_ARCHIVE_TYPE_TAR)
+		archive_read_support_format_tar (archive->libar);
+	else if (archive_type == EV_ARCHIVE_TYPE_RAR) {
+		archive_read_support_format_rar (archive->libar);
+		archive_read_support_format_rar5 (archive->libar);
+	} else
+		g_assert_not_reached ();
+}
+
+EvArchiveType
+ev_archive_get_archive_type (EvArchive *archive)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), EV_ARCHIVE_TYPE_NONE);
+
+	return archive->type;
+}
+
+gboolean
+ev_archive_set_archive_type (EvArchive *archive,
+			     EvArchiveType archive_type)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
+	g_return_val_if_fail (archive->type == EV_ARCHIVE_TYPE_NONE, FALSE);
+
+	switch (archive_type) {
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		libarchive_set_archive_type (archive, archive_type);
+		break;
+	default:
+		g_assert_not_reached ();
+	}
+
+	return TRUE;
+}
+
+gboolean
+ev_archive_open_filename (EvArchive   *archive,
+			  const char  *path,
+			  GError     **error)
+{
+	int r;
+
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);
+	g_return_val_if_fail (path != NULL, FALSE);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_NONE:
+		g_assert_not_reached ();
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		r = archive_read_open_filename (archive->libar, path, BUFFER_SIZE);
+		if (r != ARCHIVE_OK) {
+			g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+				     "Error opening archive: %s", archive_error_string (archive->libar));
+			return FALSE;
+		}
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+static gboolean
+libarchive_read_next_header (EvArchive *archive,
+			     GError   **error)
+{
+	while (1) {
+		int r;
+
+		r = archive_read_next_header (archive->libar, &archive->libar_entry);
+		if (r != ARCHIVE_OK) {
+			if (r != ARCHIVE_EOF)
+				g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+					     "Error reading archive: %s", archive_error_string (archive->libar));
+			return FALSE;
+		}
+
+		if (archive_entry_filetype (archive->libar_entry) != AE_IFREG) {
+			g_debug ("Skipping '%s' as it's not a regular file",
+				 archive_entry_pathname (archive->libar_entry));
+			continue;
+		}
+
+		g_debug ("At header for file '%s'", archive_entry_pathname (archive->libar_entry));
+
+		break;
+	}
+
+	return TRUE;
+}
+
+gboolean
+ev_archive_read_next_header (EvArchive *archive,
+			     GError   **error)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_NONE:
+		g_assert_not_reached ();
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		return libarchive_read_next_header (archive, error);
+	}
+
+	return FALSE;
+}
+
+gboolean
+ev_archive_at_entry (EvArchive *archive)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);
+
+	return (archive->libar_entry != NULL);
+}
+
+const char *
+ev_archive_get_entry_pathname (EvArchive *archive)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), NULL);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, NULL);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_NONE:
+		g_assert_not_reached ();
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		g_return_val_if_fail (archive->libar_entry != NULL, NULL);
+		return archive_entry_pathname (archive->libar_entry);
+	}
+
+	return NULL;
+}
+
+gint64
+ev_archive_get_entry_size (EvArchive *archive)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), -1);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, -1);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_NONE:
+		g_assert_not_reached ();
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		g_return_val_if_fail (archive->libar_entry != NULL, -1);
+		return archive_entry_size (archive->libar_entry);
+	}
+
+	return -1;
+}
+
+gboolean
+ev_archive_get_entry_is_encrypted (EvArchive *archive)
+{
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), FALSE);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, FALSE);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_NONE:
+		g_assert_not_reached ();
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		g_return_val_if_fail (archive->libar_entry != NULL, -1);
+		return archive_entry_is_encrypted (archive->libar_entry);
+	}
+
+	return FALSE;
+}
+
+gssize
+ev_archive_read_data (EvArchive *archive,
+		      void      *buf,
+		      gsize      count,
+		      GError   **error)
+{
+	gssize r = -1;
+
+	g_return_val_if_fail (EV_IS_ARCHIVE (archive), -1);
+	g_return_val_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE, -1);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_NONE:
+		g_assert_not_reached ();
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		g_return_val_if_fail (archive->libar_entry != NULL, -1);
+		r = archive_read_data (archive->libar, buf, count);
+		if (r < 0) {
+			g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+				     "Failed to decompress data: %s", archive_error_string (archive->libar));
+		}
+		break;
+	}
+
+	return r;
+}
+
+void
+ev_archive_reset (EvArchive *archive)
+{
+	g_return_if_fail (EV_IS_ARCHIVE (archive));
+	g_return_if_fail (archive->type != EV_ARCHIVE_TYPE_NONE);
+
+	switch (archive->type) {
+	case EV_ARCHIVE_TYPE_RAR:
+	case EV_ARCHIVE_TYPE_ZIP:
+	case EV_ARCHIVE_TYPE_7Z:
+	case EV_ARCHIVE_TYPE_TAR:
+		g_clear_pointer (&archive->libar, archive_free);
+		libarchive_set_archive_type (archive, archive->type);
+		archive->libar_entry = NULL;
+		break;
+	default:
+		g_assert_not_reached ();
+	}
+}
+
+static void
+ev_archive_init (EvArchive *archive)
+{
+}