/* Detects if a file is an EWF file
* Returns 1 if true, 0 otherwise
*/
uint8_t libewf_check_file_signature( const char *filename )
{
uint8_t signature[ 8 ];
int file_descriptor;
if( filename == NULL )
{
return( 0 );
}
file_descriptor = open( filename, O_RDONLY );
if( file_descriptor < 0 )
{
LIBEWF_FATAL_PRINT( "libewf_check_file_signature: unable to open file: %s: %m", filename );
}
if( read( file_descriptor, signature, 8 ) != 8 )
{
LIBEWF_FATAL_PRINT( "libewf_check_file_signature: unable to read signature from file: %s: %m", filename );
}
close( file_descriptor );
return( ewf_file_header_check_signature( signature ) );
}
/* Detects if a file is an EWF file (check for the EWF file signature)
* Returns 1 if true, 0 if not, or -1 on error
*/
int8_t libewf_check_file_signature( const wchar_t *filename )
{
uint8_t signature[ 8 ];
wchar_t *error_string = NULL;
ssize_t count = 0;
int file_descriptor = 0;
if( filename == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: invalid filename.\n" );
return( -1 );
}
file_descriptor = libewf_common_wide_open( filename, LIBEWF_OPEN_READ );
if( file_descriptor < 0 )
{
error_string = libewf_common_wide_strerror( errno );
if( error_string == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to open file: %ls.\n", filename );
}
else
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to open file: %ls with error: %ls.\n", filename, error_string );
libewf_common_free( error_string );
}
return( -1 );
}
count = libewf_common_read( file_descriptor, signature, 8 );
if( libewf_common_close( file_descriptor ) != 0 )
{
error_string = libewf_common_strerror( errno );
if( error_string == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to close file: %ls.\n", filename );
}
else
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to close file: %ls with error: %ls.\n", filename, error_string );
libewf_common_free( error_string );
}
return( -1 );
}
if( count <= -1 )
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: error reading signature from file: %ls.\n", filename );
return( -1 );
}
else if( count != 8 )
{
LIBEWF_WARNING_PRINT( "libewf_check_file_signature: unable to read signature from file: %ls.\n", filename );
return( -1 );
}
return( ewf_file_header_check_signature( signature ) );
}
/* Opens EWF file(s)
* For reading files should contain all filenames that make up an EWF image
* For writing files should contain the base of the filename, extentions like .e01 will be automatically added
* Returns a pointer to the new instance of handle, NULL on error
*/
LIBEWF_HANDLE *libewf_open( char * const filenames[], uint16_t file_amount, uint8_t flags )
{
EWF_FILE_HEADER file_header;
LIBEWF_INTERNAL_HANDLE *internal_handle = NULL;
char *error_string = NULL;
uint32_t iterator = 0;
uint16_t fields_segment = 0;
int file_descriptor = 0;
if( ( flags == LIBEWF_OPEN_READ ) || ( flags == LIBEWF_OPEN_READ_WRITE ) )
{
/* 1 additional entry required because
* entry [ 0 ] is not used for reading
*/
internal_handle = libewf_internal_handle_alloc( ( file_amount + 1 ), flags );
if( internal_handle == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to create handle.\n" );
return( NULL );
}
if( internal_handle->segment_table == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_open: invalid handle - missing segment table.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
for( iterator = 0; iterator < file_amount; iterator++ )
{
file_descriptor = libewf_common_open( filenames[ iterator ], flags );
if( file_descriptor == -1 )
{
error_string = libewf_common_strerror( errno );
if( error_string == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to open file: %s.\n", filenames[ iterator ] );
}
else
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to open file: %s with error: %s.\n", filenames[ iterator ], error_string );
libewf_common_free( error_string );
}
libewf_internal_handle_free( internal_handle );
return( NULL );
}
if( ewf_file_header_read( &file_header, file_descriptor ) <= -1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: invalid file header in: %s.\n", filenames[ iterator ] );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
if( ewf_file_header_check_signature( file_header.signature ) == 0 )
{
LIBEWF_WARNING_PRINT( "libewf_open: file signature does not match.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
if( libewf_endian_convert_16bit( &fields_segment, file_header.fields_segment ) != 1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to convert fields segment value.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
LIBEWF_VERBOSE_PRINT( "libewf_open: added segment file: %s with file descriptor: %d with segment number: %" PRIu16 ".\n",
filenames[ iterator ], file_descriptor, fields_segment );
if( libewf_segment_table_set_filename( internal_handle->segment_table, fields_segment, filenames[ iterator ], libewf_common_string_length( filenames[ iterator ] ) ) != 1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to set filename in segment table.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
if( libewf_segment_table_set_file_descriptor( internal_handle->segment_table, fields_segment, file_descriptor ) != 1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to set file descriptor in segment table.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
}
if( libewf_read_build_index( internal_handle ) != 1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to create index.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
}
else if( flags == LIBEWF_OPEN_WRITE )
{
/* Allocate 2 entries
* entry [ 0 ] is used for the base filename
*/
internal_handle = libewf_internal_handle_alloc( 1, flags );
if( internal_handle == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to create handle.\n" );
return( NULL );
}
if( internal_handle->segment_table == NULL )
{
LIBEWF_WARNING_PRINT( "libewf_open: invalid handle - missing segment table.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
if( libewf_segment_table_set_filename( internal_handle->segment_table, 0, filenames[ iterator ], libewf_common_string_length( filenames[ iterator ] ) ) != 1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to set filename in segment table.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
if( libewf_segment_table_set_file_descriptor( internal_handle->segment_table, 0, -1 ) != 1 )
{
LIBEWF_WARNING_PRINT( "libewf_open: unable to set file descriptor in segment table.\n" );
libewf_internal_handle_free( internal_handle );
return( NULL );
}
}
else
{
LIBEWF_WARNING_PRINT( "libewf_open: unsupported flags.\n" );
return( NULL );
}
LIBEWF_VERBOSE_PRINT( "libewf_open: open successful.\n" );
return( (LIBEWF_HANDLE *) internal_handle );
}
