ISO9660 is standard filesystem used on read-only optical discs (mostly CD-ROM). The standard was based on earlier High Sierra Format (HSF), proposed for CD-ROMs in 1985, and, after several revisions, it was accepted as ISO9960:1998.
The format emphasizes portability (thus having pretty minimal features and very conservative file names standards) and sequential access (which favors disc devices with relatively slow rotation speed).
This page hosts a formal specification of ISO9660 CD filesystem using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = Iso9660.from_file("path/to/local/file.iso")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = Iso9660(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.sector_size # => get sector size
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class Iso9660(KaitaiStruct):
"""ISO9660 is standard filesystem used on read-only optical discs
(mostly CD-ROM). The standard was based on earlier High Sierra
Format (HSF), proposed for CD-ROMs in 1985, and, after several
revisions, it was accepted as ISO9960:1998.
The format emphasizes portability (thus having pretty minimal
features and very conservative file names standards) and sequential
access (which favors disc devices with relatively slow rotation
speed).
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
pass
class VolDescPrimary(KaitaiStruct):
"""
.. seealso::
Source - https://wiki.osdev.org/ISO_9660#The_Primary_Volume_Descriptor
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.unused1 = self._io.read_bytes(1)
if not self.unused1 == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.unused1, self._io, u"/types/vol_desc_primary/seq/0")
self.system_id = (self._io.read_bytes(32)).decode(u"UTF-8")
self.volume_id = (self._io.read_bytes(32)).decode(u"UTF-8")
self.unused2 = self._io.read_bytes(8)
if not self.unused2 == b"\x00\x00\x00\x00\x00\x00\x00\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00\x00\x00\x00\x00\x00\x00\x00", self.unused2, self._io, u"/types/vol_desc_primary/seq/3")
self.vol_space_size = Iso9660.U4bi(self._io, self, self._root)
self.unused3 = self._io.read_bytes(32)
if not self.unused3 == b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", self.unused3, self._io, u"/types/vol_desc_primary/seq/5")
self.vol_set_size = Iso9660.U2bi(self._io, self, self._root)
self.vol_seq_num = Iso9660.U2bi(self._io, self, self._root)
self.logical_block_size = Iso9660.U2bi(self._io, self, self._root)
self.path_table_size = Iso9660.U4bi(self._io, self, self._root)
self.lba_path_table_le = self._io.read_u4le()
self.lba_opt_path_table_le = self._io.read_u4le()
self.lba_path_table_be = self._io.read_u4be()
self.lba_opt_path_table_be = self._io.read_u4be()
self._raw_root_dir = self._io.read_bytes(34)
_io__raw_root_dir = KaitaiStream(BytesIO(self._raw_root_dir))
self.root_dir = Iso9660.DirEntry(_io__raw_root_dir, self, self._root)
self.vol_set_id = (self._io.read_bytes(128)).decode(u"UTF-8")
self.publisher_id = (self._io.read_bytes(128)).decode(u"UTF-8")
self.data_preparer_id = (self._io.read_bytes(128)).decode(u"UTF-8")
self.application_id = (self._io.read_bytes(128)).decode(u"UTF-8")
self.copyright_file_id = (self._io.read_bytes(38)).decode(u"UTF-8")
self.abstract_file_id = (self._io.read_bytes(36)).decode(u"UTF-8")
self.bibliographic_file_id = (self._io.read_bytes(37)).decode(u"UTF-8")
self.vol_create_datetime = Iso9660.DecDatetime(self._io, self, self._root)
self.vol_mod_datetime = Iso9660.DecDatetime(self._io, self, self._root)
self.vol_expire_datetime = Iso9660.DecDatetime(self._io, self, self._root)
self.vol_effective_datetime = Iso9660.DecDatetime(self._io, self, self._root)
self.file_structure_version = self._io.read_u1()
self.unused4 = self._io.read_u1()
self.application_area = self._io.read_bytes(512)
@property
def path_table(self):
if hasattr(self, '_m_path_table'):
return self._m_path_table
_pos = self._io.pos()
self._io.seek((self.lba_path_table_le * self._root.sector_size))
self._raw__m_path_table = self._io.read_bytes(self.path_table_size.le)
_io__raw__m_path_table = KaitaiStream(BytesIO(self._raw__m_path_table))
self._m_path_table = Iso9660.PathTableLe(_io__raw__m_path_table, self, self._root)
self._io.seek(_pos)
return getattr(self, '_m_path_table', None)
class VolDescBootRecord(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.boot_system_id = (self._io.read_bytes(32)).decode(u"UTF-8")
self.boot_id = (self._io.read_bytes(32)).decode(u"UTF-8")
class Datetime(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.year = self._io.read_u1()
self.month = self._io.read_u1()
self.day = self._io.read_u1()
self.hour = self._io.read_u1()
self.minute = self._io.read_u1()
self.sec = self._io.read_u1()
self.timezone = self._io.read_u1()
class DirEntry(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.len = self._io.read_u1()
if self.len > 0:
self._raw_body = self._io.read_bytes((self.len - 1))
_io__raw_body = KaitaiStream(BytesIO(self._raw_body))
self.body = Iso9660.DirEntryBody(_io__raw_body, self, self._root)
class VolDesc(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.type = self._io.read_u1()
self.magic = self._io.read_bytes(5)
if not self.magic == b"\x43\x44\x30\x30\x31":
raise kaitaistruct.ValidationNotEqualError(b"\x43\x44\x30\x30\x31", self.magic, self._io, u"/types/vol_desc/seq/1")
self.version = self._io.read_u1()
if self.type == 0:
self.vol_desc_boot_record = Iso9660.VolDescBootRecord(self._io, self, self._root)
if self.type == 1:
self.vol_desc_primary = Iso9660.VolDescPrimary(self._io, self, self._root)
class PathTableEntryLe(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.len_dir_name = self._io.read_u1()
self.len_ext_attr_rec = self._io.read_u1()
self.lba_extent = self._io.read_u4le()
self.parent_dir_idx = self._io.read_u2le()
self.dir_name = (self._io.read_bytes(self.len_dir_name)).decode(u"UTF-8")
if (self.len_dir_name % 2) == 1:
self.padding = self._io.read_u1()
class DirEntries(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.entries = []
i = 0
while True:
_ = Iso9660.DirEntry(self._io, self, self._root)
self.entries.append(_)
if _.len == 0:
break
i += 1
class U4bi(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.le = self._io.read_u4le()
self.be = self._io.read_u4be()
class U2bi(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.le = self._io.read_u2le()
self.be = self._io.read_u2be()
class PathTableLe(KaitaiStruct):
"""
.. seealso::
Source - https://wiki.osdev.org/ISO_9660#The_Path_Table
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.entries = []
i = 0
while not self._io.is_eof():
self.entries.append(Iso9660.PathTableEntryLe(self._io, self, self._root))
i += 1
class DecDatetime(KaitaiStruct):
"""
.. seealso::
Source - https://wiki.osdev.org/ISO_9660#Date.2Ftime_format
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.year = (self._io.read_bytes(4)).decode(u"ASCII")
self.month = (self._io.read_bytes(2)).decode(u"ASCII")
self.day = (self._io.read_bytes(2)).decode(u"ASCII")
self.hour = (self._io.read_bytes(2)).decode(u"ASCII")
self.minute = (self._io.read_bytes(2)).decode(u"ASCII")
self.sec = (self._io.read_bytes(2)).decode(u"ASCII")
self.sec_hundreds = (self._io.read_bytes(2)).decode(u"ASCII")
self.timezone = self._io.read_u1()
class DirEntryBody(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.len_ext_attr_rec = self._io.read_u1()
self.lba_extent = Iso9660.U4bi(self._io, self, self._root)
self.size_extent = Iso9660.U4bi(self._io, self, self._root)
self.datetime = Iso9660.Datetime(self._io, self, self._root)
self.file_flags = self._io.read_u1()
self.file_unit_size = self._io.read_u1()
self.interleave_gap_size = self._io.read_u1()
self.vol_seq_num = Iso9660.U2bi(self._io, self, self._root)
self.len_file_name = self._io.read_u1()
self.file_name = (self._io.read_bytes(self.len_file_name)).decode(u"UTF-8")
if (self.len_file_name % 2) == 0:
self.padding = self._io.read_u1()
self.rest = self._io.read_bytes_full()
@property
def extent_as_dir(self):
if hasattr(self, '_m_extent_as_dir'):
return self._m_extent_as_dir
if (self.file_flags & 2) != 0:
io = self._root._io
_pos = io.pos()
io.seek((self.lba_extent.le * self._root.sector_size))
self._raw__m_extent_as_dir = io.read_bytes(self.size_extent.le)
_io__raw__m_extent_as_dir = KaitaiStream(BytesIO(self._raw__m_extent_as_dir))
self._m_extent_as_dir = Iso9660.DirEntries(_io__raw__m_extent_as_dir, self, self._root)
io.seek(_pos)
return getattr(self, '_m_extent_as_dir', None)
@property
def extent_as_file(self):
if hasattr(self, '_m_extent_as_file'):
return self._m_extent_as_file
if (self.file_flags & 2) == 0:
io = self._root._io
_pos = io.pos()
io.seek((self.lba_extent.le * self._root.sector_size))
self._m_extent_as_file = io.read_bytes(self.size_extent.le)
io.seek(_pos)
return getattr(self, '_m_extent_as_file', None)
@property
def sector_size(self):
if hasattr(self, '_m_sector_size'):
return self._m_sector_size
self._m_sector_size = 2048
return getattr(self, '_m_sector_size', None)
@property
def primary_vol_desc(self):
if hasattr(self, '_m_primary_vol_desc'):
return self._m_primary_vol_desc
_pos = self._io.pos()
self._io.seek((16 * self.sector_size))
self._m_primary_vol_desc = Iso9660.VolDesc(self._io, self, self._root)
self._io.seek(_pos)
return getattr(self, '_m_primary_vol_desc', None)