manual-serializer

Serialization tools for manual buffer processing

Overview

This crate is useful when you need to quickly and manually extract data structures from u8 buffers. This can be useful when parsing 3rd-party custom binary data files that have complex data layout making it hard to use existing serializers or structs with #[repr(packed)] (as those can be difficult to deal with due to alignment issues).

Beside the basic functions for loading and storing u8,u16,u32,u64 primitives, this serializer provides the following helpers:

• Functions for handling u16le arrays
• Functions for extracting u16 zero terminated strings (such as PCWSTR - used in Windows data structures)
• Alignment functions to position the cursor on N-byte boundaries (such as align_u32())

NOTE: This crate currently supports only little-endian encoded primitives.

Example

#[derive(Debug)]
pub struct Header {
    pub magic : usize,
    pub version : u16,
    pub payload : Vec<u8>,
}

impl TrySerialize for Header {
    type Error = Error;
    fn try_serialize(&self, dest: &mut Serializer) -> Result<()> {
        dest.try_align_u32()?;
        dest.try_store_u16le(self.magic as u16)?;
        dest.try_store_u16le(self.version)?;
        dest.try_store_u32le(self.payload.len() as u32)?;
        dest.try_store_u8_slice(&self.payload)?;
        Ok(())
    }
}

fn store() {
    let mut dest = Serializer::new(4096);
    let header = Header::default();
    dest.try_store(&header)?;
}

impl TryDeserialize for Header {
    type Error = Error;

    fn try_deserialize(src: &mut Deserializer) -> Result<Header> {
        src.try_align_u32()?;

        let magic = src.try_load_u16le()? as usize;
        let version = src.try_load_u16le()?;
        let payload_length = src.try_load_u32le()? as usize;
        let payload = src.try_load_u8_vec(payload_length)?.to_vec()?;

        Ok(Header{magic, version, payload})
    }
}

fn load(data: &[u8], offset: usize) -> Result<(u32,Header)>{
    let mut src = Deserializer::new(data);
    src.offset(offset)?;
    let signature = src.try_load_u32le()?;
    let header: Header = src.try_load()?;
    Ok((signature,header))
}