Android nanoapp header: Python parsing library

File extension


KS implementation details

License: Apache-2.0
Minimal Kaitai Struct required: 0.9

This page hosts a formal specification of Android nanoapp header using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.


Runtime 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 kaitaistruct


Parse a local file and get structure in memory:

data = AndroidNanoappHeader.from_file("path/to/local/file.napp_header")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = AndroidNanoappHeader(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.header_version # => get header version

Python source code to parse Android nanoapp header

# 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 AndroidNanoappHeader(KaitaiStruct):
    .. seealso::
       Source -
    def __init__(self, _io, _parent=None, _root=None):
        self._io = _io
        self._parent = _parent
        self._root = _root if _root else self

    def _read(self):
        self.header_version = self._io.read_u4le()
        if not self.header_version == 1:
            raise kaitaistruct.ValidationNotEqualError(1, self.header_version, self._io, u"/seq/0")
        self.magic = self._io.read_bytes(4)
        if not self.magic == b"\x4E\x41\x4E\x4F":
            raise kaitaistruct.ValidationNotEqualError(b"\x4E\x41\x4E\x4F", self.magic, self._io, u"/seq/1")
        self.app_id = self._io.read_u8le()
        self.app_version = self._io.read_u4le()
        self.flags = self._io.read_u4le()
        self.hub_type = self._io.read_u8le()
        self.chre_api_major_version = self._io.read_u1()
        self.chre_api_minor_version = self._io.read_u1()
        self.reserved = self._io.read_bytes(6)
        if not self.reserved == b"\x00\x00\x00\x00\x00\x00":
            raise kaitaistruct.ValidationNotEqualError(b"\x00\x00\x00\x00\x00\x00", self.reserved, self._io, u"/seq/8")

    def is_signed(self):
        if hasattr(self, '_m_is_signed'):
            return self._m_is_signed

        self._m_is_signed = (self.flags & 1) != 0
        return getattr(self, '_m_is_signed', None)

    def is_encrypted(self):
        if hasattr(self, '_m_is_encrypted'):
            return self._m_is_encrypted

        self._m_is_encrypted = (self.flags & 2) != 0
        return getattr(self, '_m_is_encrypted', None)

    def is_tcm_capable(self):
        if hasattr(self, '_m_is_tcm_capable'):
            return self._m_is_tcm_capable

        self._m_is_tcm_capable = (self.flags & 4) != 0
        return getattr(self, '_m_is_tcm_capable', None)