Function main

src/main.rs:8–58

()

use std::io::BufWriter;

fn main() -> Result<()> {
    let src_path = "shellcode\\target\\x86_64-pc-windows-msvc\\release\\shellcode.exe";
    let mut file = File::open(src_path)?;
    let mut buffer = Vec::new();
    file.read_to_end(&mut buffer)?;
    let pe = PE::parse(&mut buffer)?;
    let standard_fileds = pe.header.optional_header.unwrap().standard_fields;
    let entry_offset = standard_fileds.address_of_entry_point - standard_fileds.base_of_code;
    for section in pe.sections {
        let name = String::from_utf8(section.name.to_vec())?;
        if !name.starts_with(".text") {
            continue;
        }
        let start = section.pointer_to_raw_data as usize;
        let size = section.size_of_raw_data as usize;
        let dst_path = "shellcode\\target\\x86_64-pc-windows-msvc\\release\\shellcode.bin";
        let shellcode = File::create(dst_path)?;
        let mut buf_writer = BufWriter::new(shellcode);
        println!("[*] section text addr: 0x{:x}, size: 0x{:x}", start, size);
        println!("[*] entry offset: 0x{:x}", entry_offset);
        println!("== before patch ==");
        show_disassemble(&buffer[start..start + size], 5);
        if entry_offset >= 0x100 {
            buffer[0 + start] = 0xe9;
            let hi = (entry_offset - 2) / 0x100;
            let li = (entry_offset - 2) % 0x100;
            dbg!(hi, li);
            buffer[1 + start] = li as _;
            buffer[2 + start] = hi as _;
            buffer[3 + start] = 0 as _;
            buffer[4 + start] = 0 as _;
        } else if entry_offset >= 0x80 {
            buffer[0 + start] = 0xe9;
            buffer[1 + start] = (entry_offset - 5) as _;
            buffer[2 + start] = 0 as _;
            buffer[3 + start] = 0 as _;
            buffer[4 + start] = 0 as _;
        } else {
            buffer[0 + start] = 0xeb;
            buffer[1 + start] = (entry_offset - 2) as _;
        }
        println!("== after patch ==");
        show_disassemble(&buffer[start..start + size], 5);
        for i in start..start + size {
            buf_writer.write(&[buffer[i]])?;
        }
        buf_writer.flush().unwrap();
        println!("done! shellcode saved in {}", dst_path);
    }
    Ok(())
}
pub fn show_disassemble(bytes: &[u8], max_line: u32) {
    let mut decoder = Decoder::new(EXAMPLE_CODE_BITNESS, bytes, DecoderOptions::NONE);
    decoder.set_ip(EXAMPLE_CODE_RIP);