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.
-- This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
--
-- This file is compatible with Lua 5.3
local class = require("class")
require("kaitaistruct")
--
-- See also: Source (https://android.googlesource.com/platform/system/chre/+/a7ff61b9/build/build_template.mk#130)
AndroidNanoappHeader = class.class(KaitaiStruct)
function AndroidNanoappHeader:_init(io, parent, root)
KaitaiStruct._init(self, io)
self._parent = parent
self._root = root or self
self:_read()
end
function AndroidNanoappHeader:_read()
self.header_version = self._io:read_u4le()
if not(self.header_version == 1) then
error("not equal, expected " .. 1 .. ", but got " .. self.header_version)
end
self.magic = self._io:read_bytes(4)
if not(self.magic == "\078\065\078\079") then
error("not equal, expected " .. "\078\065\078\079" .. ", but got " .. self.magic)
end
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 == "\000\000\000\000\000\000") then
error("not equal, expected " .. "\000\000\000\000\000\000" .. ", but got " .. self.reserved)
end
end
AndroidNanoappHeader.property.is_signed = {}
function AndroidNanoappHeader.property.is_signed:get()
if self._m_is_signed ~= nil then
return self._m_is_signed
end
self._m_is_signed = (self.flags & 1) ~= 0
return self._m_is_signed
end
AndroidNanoappHeader.property.is_encrypted = {}
function AndroidNanoappHeader.property.is_encrypted:get()
if self._m_is_encrypted ~= nil then
return self._m_is_encrypted
end
self._m_is_encrypted = (self.flags & 2) ~= 0
return self._m_is_encrypted
end
AndroidNanoappHeader.property.is_tcm_capable = {}
function AndroidNanoappHeader.property.is_tcm_capable:get()
if self._m_is_tcm_capable ~= nil then
return self._m_is_tcm_capable
end
self._m_is_tcm_capable = (self.flags & 4) ~= 0
return self._m_is_tcm_capable
end