androscalpel/androscalpel_serializer/src/file_reader.rs
2023-08-30 17:17:11 +02:00

276 lines
12 KiB
Rust

//! Parser for a .dex file.
use crate::{
CallSiteIdItem, ClassDefItem, EndianConstant, Error, FieldIdItem, HeaderItem, MapItemType,
MapList, MethodHandleItem, MethodIdItem, ProtoIdItem, Result, Serializable, StringIdItem,
TypeIdItem,
};
use std::io::{Cursor, Seek, SeekFrom};
pub struct DexFileReader<'a> {
data: &'a [u8],
header: HeaderItem,
string_ids: Vec<StringIdItem>,
type_ids: Vec<TypeIdItem>,
proto_ids: Vec<ProtoIdItem>,
field_ids: Vec<FieldIdItem>,
method_ids: Vec<MethodIdItem>,
class_defs: Vec<ClassDefItem>,
call_site_ids: Vec<CallSiteIdItem>,
method_handles: Vec<MethodHandleItem>,
map_list: MapList,
}
impl<'a> DexFileReader<'a> {
pub fn new(data: &'a [u8]) -> Result<Self> {
let mut buffer = Cursor::new(data);
let header = HeaderItem::deserialize(&mut buffer)?;
let mut tmp_file = Self {
data,
header,
// Default values before population
string_ids: vec![],
type_ids: vec![],
proto_ids: vec![],
field_ids: vec![],
method_ids: vec![],
class_defs: vec![],
call_site_ids: vec![],
method_handles: vec![],
map_list: MapList { list: vec![] },
};
tmp_file.map_list = tmp_file.get_struct_at_offset(tmp_file.header.map_off)?;
tmp_file.string_ids = tmp_file.get_item_list::<StringIdItem>(
tmp_file.header.string_ids_off,
tmp_file.header.string_ids_size,
)?;
tmp_file.type_ids = tmp_file.get_item_list::<TypeIdItem>(
tmp_file.header.type_ids_off,
tmp_file.header.type_ids_size,
)?;
tmp_file.proto_ids = tmp_file.get_item_list::<ProtoIdItem>(
tmp_file.header.proto_ids_off,
tmp_file.header.proto_ids_size,
)?;
tmp_file.field_ids = tmp_file.get_item_list::<FieldIdItem>(
tmp_file.header.field_ids_off,
tmp_file.header.field_ids_size,
)?;
tmp_file.method_ids = tmp_file.get_item_list::<MethodIdItem>(
tmp_file.header.method_ids_off,
tmp_file.header.method_ids_size,
)?;
tmp_file.class_defs = tmp_file.get_item_list::<ClassDefItem>(
tmp_file.header.class_defs_off,
tmp_file.header.class_defs_size,
)?;
if let Some(item) = tmp_file
.map_list
.list
.iter()
.find(|item| item.type_ == MapItemType::CallSiteIdItem)
{
tmp_file.call_site_ids =
tmp_file.get_item_list::<CallSiteIdItem>(item.offset, item.size)?
}
if let Some(item) = tmp_file
.map_list
.list
.iter()
.find(|item| item.type_ == MapItemType::CallSiteIdItem)
{
tmp_file.method_handles =
tmp_file.get_item_list::<MethodHandleItem>(item.offset, item.size)?
}
tmp_file.sanity_check()?;
Ok(tmp_file)
}
/// Return the file [`HeaderItem`].
pub fn get_header(&self) -> &HeaderItem {
&self.header
}
fn sanity_check(&self) -> Result<()> {
if self.header.magic.version != [0x30, 0x33, 0x39] {
println!(
"DEX 039 is the only verion currently supported, found {}",
std::str::from_utf8(self.header.magic.version.as_slice())
.unwrap_or(&format!("{:x?}", self.header.magic.version))
); // TODO: use proper logging
}
// TODO: check checksum
// TODO: check signature
if self.header.file_size as usize != self.data.len() {
println!(
"Unexpected file size found: {}, expected {}",
self.header.file_size,
self.data.len()
); // TODO: use proper logging
}
if self.header.header_size != 0x70 {
println!(
"Unexpected header size found: 0x{:x}",
self.header.header_size
); // TODO: use proper logging
}
if self.header.endian_tag != EndianConstant::EndianConstant {
println!("Wrong endian_tag found: {:x?}", self.header.endian_tag); // TODO: use proper logging
}
if self.header.link_off != 0 || self.header.link_size != 0 {
println!("Found non empty link section"); // TODO: use proper logging
}
for item in &self.map_list.list {
match item.type_ {
MapItemType::HeaderItem if item.offset != 0 || item.size != 1 => {
return Err(Error::InconsistantStruct(format!(
"Inconsistant Header Mapping info found in map_list: {item:x?}"
)))
}
MapItemType::StringIdItem
if item.offset != self.header.string_ids_off
|| item.size != self.header.string_ids_size =>
{
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.string_ids_off: 0x{:x}, header.string_ids_size: {}",
self.header.string_ids_off, self.header.string_ids_size
)))
}
MapItemType::TypeIdItem
if item.offset != self.header.type_ids_off
|| item.size != self.header.type_ids_size =>
{
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.type_ids_off: 0x{:x}, header.type_ids_size: {}",
self.header.type_ids_off, self.header.type_ids_size
)))
}
MapItemType::ProtoIdItem
if item.offset != self.header.proto_ids_off
|| item.size != self.header.proto_ids_size =>
{
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.proto_ids_off: 0x{:x}, header.proto_ids_size: {}",
self.header.proto_ids_off, self.header.proto_ids_size
)))
}
MapItemType::FieldIdItem
if item.offset != self.header.field_ids_off
|| item.size != self.header.field_ids_size =>
{
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.field_ids_off: 0x{:x}, header.field_ids_size: {}",
self.header.field_ids_off, self.header.field_ids_size
)))
}
MapItemType::MethodIdItem
if item.offset != self.header.method_ids_off
|| item.size != self.header.method_ids_size =>
{
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.method_ids_off: 0x{:x}, header.method_ids_size: {}",
self.header.method_ids_off, self.header.method_ids_size
)))
}
MapItemType::ClassDefItem
if item.offset != self.header.class_defs_off
|| item.size != self.header.class_defs_size =>
{
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.class_defs_off: 0x{:x}, header.class_defs_size: {}",
self.header.class_defs_off, self.header.class_defs_size
)))
}
MapItemType::CallSiteIdItem => todo!(),
MapItemType::MethodHandleItem => todo!(),
MapItemType::MapList if item.offset != self.header.map_off || item.size != 0 => {
return Err(Error::InconsistantStruct(format!(
"Inconsistant MapList Mapping info found in map_list: {item:x?}, \
header.map_list_off: 0x{:x}",
self.header.map_off
)))
}
/*
MapItemType::TypeList => todo!(),
MapItemType::AnnotationSetRefList => todo!(),
MapItemType::AnnotationSetItem => todo!(),
MapItemType::ClassDataItem => todo!(),
MapItemType::CodeItem => todo!(),
MapItemType::StringDataItem => todo!(),
MapItemType::DebugInfoItem => todo!(),
MapItemType::AnnotationItem => todo!(),
MapItemType::EncodedArrayItem => todo!(),
MapItemType::AnnotationsDirectoryItem => todo!(),
MapItemType::HiddenapiClassDataItem => todo!(),
*/
MapItemType::UnkownType(ty) => {
println!("Unknown Type found in map_list: 0x{ty:04x}"); // TODO: use proper
// loggin
}
_ => (),
}
let mut occurences = std::collections::HashMap::new();
for ty in self.map_list.list.iter().map(|val| val.type_) {
*occurences.entry(ty).or_insert(0) += 1;
}
let mut duplicate = false;
for (ty, val) in occurences {
if val > 1 {
println!("Found multiple {} occurence of {:?} in map_list", val, ty);
// TODO: use proper loggin
duplicate = true;
}
}
if duplicate {
return Err(Error::InconsistantStruct(
"Found multiple occurence of the same item type in map_list".into(),
));
}
}
Ok(())
}
fn get_item_list<T: Serializable>(&self, offset: u32, size: u32) -> Result<Vec<T>> {
let mut buffer = Cursor::new(self.data);
buffer.seek(SeekFrom::Start(offset as u64)).map_err(|err| {
Error::DeserializationError(format!("Failed to seek 0x{offset:x} position: {err}"))
})?;
let mut list = vec![];
for _ in 0..size {
let pos = buffer.stream_position().map_err(|err| {
Error::DeserializationError(format!("Failled to read buffer position: {err}"))
})?;
list.push(T::deserialize(&mut buffer).map_err(|err| {
Error::DeserializationError(format!(
"Failed to deserialize {} at 0x{:x}: {err}",
std::any::type_name::<T>(),
pos
))
})?);
}
Ok(list)
}
/// Return the structure `T` located at `offset` in the file.
///
/// # Warning
///
/// If the offset is invalid, UB.
pub fn get_struct_at_offset<T: Serializable>(&self, offset: u32) -> Result<T> {
let mut buffer = Cursor::new(self.data);
buffer.seek(SeekFrom::Start(offset as u64)).unwrap();
T::deserialize(&mut buffer).map_err(|err| {
Error::DeserializationError(format!(
"Failed to deserialize {} at 0x{:x}: {err}",
std::any::type_name::<T>(),
offset
))
})
}
}