/*
 * Support functions
 *
 * Copyright (C) 2011-2018, Omar Choudary <choudary.omar@gmail.com>
 *                          Joachim Metz <joachim.metz@gmail.com>
 *
 * Refer to AUTHORS for acknowledgements.
 *
 * This software is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This software 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 Lesser General Public License
 * along with this software.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <common.h>
#include <narrow_string.h>
#include <types.h>
#include <wide_string.h>

#include "libfvde_definitions.h"
#include "libfvde_io_handle.h"
#include "libfvde_libbfio.h"
#include "libfvde_libcerror.h"
#include "libfvde_libclocale.h"
#include "libfvde_support.h"

#if !defined( HAVE_LOCAL_LIBFVDE )

/* Returns the library version
 */
const char *libfvde_get_version(
             void )
{
	return( (const char *) LIBFVDE_VERSION_STRING );
}

/* Returns the access flags for reading
 */
int libfvde_get_access_flags_read(
     void )
{
	return( (int) LIBFVDE_ACCESS_FLAG_READ );
}

/* Retrieves the narrow system string codepage
 * A value of 0 represents no codepage, UTF-8 encoding is used instead
 * Returns 1 if successful or -1 on error
 */
int libfvde_get_codepage(
     int *codepage,
     libcerror_error_t **error )
{
	static char *function = "libfvde_get_codepage";

	if( libclocale_codepage_get(
	     codepage,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_GET_FAILED,
		 "%s: unable to retrieve codepage.",
		 function );

		return( -1 );
	}
	return( 1 );
}

/* Sets the narrow system string codepage
 * A value of 0 represents no codepage, UTF-8 encoding is used instead
 * Returns 1 if successful or -1 on error
 */
int libfvde_set_codepage(
     int codepage,
     libcerror_error_t **error )
{
	static char *function = "libfvde_set_codepage";

	if( libclocale_codepage_set(
	     codepage,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_SET_FAILED,
		 "%s: unable to set codepage.",
		 function );

		return( -1 );
	}
	return( 1 );
}

#endif /* !defined( HAVE_LOCAL_LIBFVDE ) */

/* Determines if a file contains a FVDE volume signature
 * Returns 1 if true, 0 if not or -1 on error
 */
int libfvde_check_volume_signature(
     const char *filename,
     libcerror_error_t **error )
{
	libbfio_handle_t *file_io_handle = NULL;
	static char *function            = "libfvde_check_volume_signature";
	size_t filename_length           = 0;
	int result                       = 0;

	if( filename == NULL )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
		 LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
		 "%s: invalid filename.",
		 function );

		return( -1 );
	}
	filename_length = narrow_string_length(
	                   filename );

	if( filename_length == 0 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
		 LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
		 "%s: invalid filename.",
		 function );

		goto on_error;
	}
	if( libbfio_file_initialize(
	     &file_io_handle,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
		 "%s: unable to create file IO handle.",
		 function );

		goto on_error;
	}
	if( libbfio_file_set_name(
	     file_io_handle,
	     filename,
	     filename_length,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_SET_FAILED,
		 "%s: unable to set filename in file IO handle.",
		 function );

		goto on_error;
	}
	result = libfvde_check_volume_signature_file_io_handle(
	          file_io_handle,
	          error );

	if( result == -1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_GET_FAILED,
		 "%s: unable to check volume signature using a file handle.",
		 function );

		goto on_error;
	}
	if( libbfio_handle_free(
	     &file_io_handle,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
		 "%s: unable to free file IO handle.",
		 function );

		goto on_error;
	}
	return( result );

on_error:
	if( file_io_handle != NULL )
	{
		libbfio_handle_free(
		 &file_io_handle,
		 NULL );
	}
	return( -1 );
}

#if defined( HAVE_WIDE_CHARACTER_TYPE )

/* Determines if a file contains a FVDE volume signature
 * Returns 1 if true, 0 if not or -1 on error
 */
int libfvde_check_volume_signature_wide(
     const wchar_t *filename,
     libcerror_error_t **error )
{
	libbfio_handle_t *file_io_handle = NULL;
	static char *function            = "libfvde_check_volume_signature_wide";
	size_t filename_length           = 0;
	int result                       = 0;

	if( filename == NULL )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
		 LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
		 "%s: invalid filename.",
		 function );

		return( -1 );
	}
	filename_length = wide_string_length(
	                   filename );

	if( filename_length == 0 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
		 LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
		 "%s: invalid filename.",
		 function );

		goto on_error;
	}
	if( libbfio_file_initialize(
	     &file_io_handle,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
		 "%s: unable to create file IO handle.",
		 function );

		goto on_error;
	}
	if( libbfio_file_set_name_wide(
	     file_io_handle,
	     filename,
	     filename_length,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_SET_FAILED,
		 "%s: unable to set filename in file IO handle.",
		 function );

		goto on_error;
	}
	result = libfvde_check_volume_signature_file_io_handle(
	          file_io_handle,
	          error );

	if( result == -1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_GET_FAILED,
		 "%s: unable to check volume signature using a file handle.",
		 function );

		goto on_error;
	}
	if( libbfio_handle_free(
	     &file_io_handle,
	     error ) != 1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_RUNTIME,
		 LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,
		 "%s: unable to free file IO handle.",
		 function );

		goto on_error;
	}
	return( result );

on_error:
	if( file_io_handle != NULL )
	{
		libbfio_handle_free(
		 &file_io_handle,
		 NULL );
	}
	return( -1 );
}

#endif /* defined( HAVE_WIDE_CHARACTER_TYPE ) */

/* Determines if a file contains a FVDE volume signature using a Basic File IO (bfio) handle
 * Returns 1 if true, 0 if not or -1 on error
 */
int libfvde_check_volume_signature_file_io_handle(
     libbfio_handle_t *file_io_handle,
     libcerror_error_t **error )
{
	uint8_t signature[ 2 ];

	static char *function      = "libfvde_check_volume_signature_file_io_handle";
	ssize_t read_count         = 0;
	int file_io_handle_is_open = 0;
	int result                 = 0;

	if( file_io_handle == NULL )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_ARGUMENTS,
		 LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,
		 "%s: invalid file IO handle.",
		 function );

		return( -1 );
	}
	file_io_handle_is_open = libbfio_handle_is_open(
	                          file_io_handle,
	                          error );

	if( file_io_handle_is_open == -1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_IO,
		 LIBCERROR_IO_ERROR_OPEN_FAILED,
		 "%s: unable to open file.",
		 function );

		goto on_error;
	}
	else if( file_io_handle_is_open == 0 )
	{
		if( libbfio_handle_open(
		     file_io_handle,
		     LIBBFIO_OPEN_READ,
		     error ) != 1 )
		{
			libcerror_error_set(
			 error,
			 LIBCERROR_ERROR_DOMAIN_IO,
			 LIBCERROR_IO_ERROR_OPEN_FAILED,
			 "%s: unable to open file.",
			 function );

			goto on_error;
		}
	}
	if( libbfio_handle_seek_offset(
	     file_io_handle,
	     88,
	     SEEK_SET,
	     error ) == -1 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_IO,
		 LIBCERROR_IO_ERROR_SEEK_FAILED,
		 "%s: unable to seek file header offset: 88.",
		 function );

		goto on_error;
	}
	read_count = libbfio_handle_read_buffer(
	              file_io_handle,
	              signature,
	              2,
	              error );

	if( read_count != 2 )
	{
		libcerror_error_set(
		 error,
		 LIBCERROR_ERROR_DOMAIN_IO,
		 LIBCERROR_IO_ERROR_READ_FAILED,
		 "%s: unable to read signature.",
		 function );

		goto on_error;
	}
	if( file_io_handle_is_open == 0 )
	{
		if( libbfio_handle_close(
		     file_io_handle,
		     error ) != 0 )
		{
			libcerror_error_set(
			 error,
			 LIBCERROR_ERROR_DOMAIN_IO,
			 LIBCERROR_IO_ERROR_CLOSE_FAILED,
			 "%s: unable to close file.",
			 function );

			goto on_error;
		}
	}
	else if( memory_compare(
	          signature,
	          libfvde_core_storage_signature,
	          2 ) == 0 )
	{
        	result = 1;
	}
        return( result );

on_error:
	if( file_io_handle_is_open == 0 )
	{
		libbfio_handle_close(
		 file_io_handle,
		 NULL );
	}
	return( -1 );
}

