1 files changed, 125 insertions, 0 deletions
diff --git a/executable-password/src/main.rs b/executable-password/src/main.rs
new file mode 100644
index 0000000..612cef5
--- /dev/null
+++ b/executable-password/src/main.rs
@@ -0,0 +1,125 @@
+use memmap2::Mmap;
+use sha2::{Digest, Sha256};
+use std::arch::asm;
+use std::fs::OpenOptions;
+
+#[derive(Debug)]
+#[repr(C)]
+struct SectionHeader {
+    name_offset: u32,
+    header_type: u32,
+    flags: u64,
+    virtual_addr: u64,
+    offset: u64,
+    size: u64,
+    link: u32,
+    info: u32,
+    addralign: u64,
+    entry_size: u64,
+}
+
+fn password_check() {
+    println!("Hello!");
+    unsafe {
+        asm!("jmp 0");
+    };
+}
+
+fn field(data: &Mmap, offset: usize, size: usize) -> Vec<u8> {
+    Vec::from(&data[offset..offset + size])
+}
+
+fn toi(data: Vec<u8>) -> u64 {
+    let mut res: u64 = 0;
+    for (i, byte) in data.iter().enumerate() {
+        res |= (*byte as u64) << (i * 8);
+    }
+    res
+}
+
+fn _compute_digest(
+    data: &Mmap,
+    skip_offset: usize,
+    skip_size: usize,
+) -> Vec<u8> {
+    let mut hasher = Sha256::new();
+    let mut offset = 0;
+    while offset != data.len() {
+        let end = std::cmp::min(offset + 1024, data.len());
+        let sz = end - offset;
+        let mut buf = [0; 1024];
+        buf[..sz].clone_from_slice(&data[offset..end]);
+
+        let skip_end = skip_offset + skip_size;
+        if skip_offset >= offset && skip_offset <= end {
+            for i in skip_offset..std::cmp::min(end, skip_end) {
+                buf[i - skip_offset] = 0;
+            }
+        }
+        if skip_end >= offset && skip_end <= end {
+            for i in offset..skip_end {
+                buf[i - offset] = 0;
+            }
+        }
+        hasher.update(buf);
+        offset = end;
+    }
+    Vec::from(&hasher.finalize()[..])
+}
+
+fn get_checksum_field(data: &Mmap) -> Option<(usize, usize)> {
+    // TODO: Учитывать битность бинарника
+    let shoff = toi(field(data, 0x28, 8)) as usize;
+    let section_header_num = toi(field(data, 0x3C, 2)) as usize;
+    let names_idx = toi(field(data, 0x3E, 2)) as usize;
+    let names_table_offset =
+        toi(field(data, shoff + 0x40 * names_idx + 0x18, 8)) as u32;
+
+    for i in 0..section_header_num {
+        let header: SectionHeader = unsafe {
+            const SIZE: usize = std::mem::size_of::<SectionHeader>();
+            let offset = shoff + SIZE * i;
+            let header_raw: [u8; SIZE] =
+                data[offset..offset + SIZE].try_into().unwrap();
+            std::mem::transmute(header_raw)
+        };
+        if header.header_type == 0 {
+            continue;
+        }
+        let mut name = Vec::new();
+        let mut name_idx = (names_table_offset + header.name_offset) as usize;
+        while data[name_idx] != 0 {
+            name.push(data[name_idx] as char);
+            name_idx += 1;
+        }
+        let name: String = name.into_iter().collect();
+        if name == ".text" {
+            println!(".text offset = {}", header.offset);
+        }
+    }
+    None
+}
+
+fn main() {
+    let exe_path = std::env::args().nth(1).unwrap();
+    println!("Запускается программа по следующему пути:");
+    println!("{exe_path}");
+
+    let file = OpenOptions::new()
+        .read(true)
+        .write(false)
+        .create(false)
+        .open(&exe_path)
+        .unwrap();
+    let mmap = unsafe { Mmap::map(&file).unwrap() };
+
+    let o = std::mem::size_of_val(&password_check);
+    println!("size of password_check(): {o}");
+
+    // let (checksum_offset, checksum_size) = get_checksum_field(&mmap).unwrap();
+    // let checksum = &mmap[checksum_offset..checksum_offset + checksum_size];
+    let entrypoint: [u8; 8] = mmap[0x18..0x18 + 8].try_into().unwrap();
+    let entrypoint: u64 = unsafe { std::mem::transmute(entrypoint) };
+    let _ = get_checksum_field(&mmap);
+    println!("{entrypoint}");
+}