rust-nex/prudpv1/src/prudp/secure.rs
2026-02-01 21:10:03 +01:00

136 lines
4 KiB
Rust

use crate::prudp::packet::PRUDPV1Packet;
use crate::prudp::socket::{CryptoHandler, CryptoHandlerConnectionInstance};
use hmac::digest::consts::U32;
use log::error;
use rc4::cipher::StreamCipherCoreWrapper;
use rc4::consts::U16;
use rc4::{KeyInit, Rc4, Rc4Core, StreamCipher};
use rnex_core::kerberos::{TicketInternalData, derive_key};
use rnex_core::nex::account::Account;
use rnex_core::prudp::encryption::EncryptionPair;
use rnex_core::prudp::ticket::read_secure_connection_data;
use rnex_core::rmc::structures::RmcSerialize;
use std::io::Cursor;
use typenum::U5;
use v_byte_helpers::{IS_BIG_ENDIAN, ReadExtensions};
type Rc4U32 = StreamCipherCoreWrapper<Rc4Core<U32>>;
pub fn generate_secure_encryption_pairs(
mut session_key: [u8; 32],
count: u8,
) -> Vec<EncryptionPair<Rc4<U32>>> {
let mut vec = Vec::with_capacity(count as usize);
vec.push(EncryptionPair {
send: Rc4U32::new_from_slice(&session_key).expect("unable to create rc4"),
recv: Rc4U32::new_from_slice(&session_key).expect("unable to create rc4"),
});
for _ in 1..=count {
let modifier = session_key.len() + 1;
let key_length = session_key.len();
for (position, val) in (&mut session_key[0..key_length / 2]).iter_mut().enumerate() {
*val = val.wrapping_add((modifier - position) as u8);
}
vec.push(EncryptionPair {
send: Rc4U32::new_from_slice(&session_key).expect("unable to create rc4"),
recv: Rc4U32::new_from_slice(&session_key).expect("unable to create rc4"),
});
}
vec
}
pub struct Secure(pub &'static str, pub Account);
pub struct SecureInstance {
access_key: &'static str,
session_key: [u8; 32],
streams: Vec<EncryptionPair<Rc4<U32>>>,
self_signature: [u8; 16],
remote_signature: [u8; 16],
pid: u32,
}
impl CryptoHandler for Secure {
type CryptoConnectionInstance = SecureInstance;
fn instantiate(
&self,
remote_signature: [u8; 16],
self_signature: [u8; 16],
payload: &[u8],
substream_count: u8,
) -> Option<(Vec<u8>, Self::CryptoConnectionInstance)> {
let (session_key, pid, check_value) = read_secure_connection_data(payload, &self.1)?;
let check_value_response = check_value + 1;
let data = bytemuck::bytes_of(&check_value_response);
let mut response = Vec::new();
data.serialize(&mut response).ok()?;
let encryption_pairs = generate_secure_encryption_pairs(session_key, substream_count);
Some((
response,
SecureInstance {
pid,
streams: encryption_pairs,
session_key,
access_key: self.0,
remote_signature,
self_signature,
},
))
}
fn sign_pre_handshake(&self, packet: &mut PRUDPV1Packet) {
packet.set_sizes();
packet.calculate_and_assign_signature(self.0, None, None);
}
}
impl CryptoHandlerConnectionInstance for SecureInstance {
type Encryption = Rc4<U5>;
fn decrypt_incoming(&mut self, substream: u8, data: &mut [u8]) {
if let Some(crypt_pair) = self.streams.get_mut(substream as usize) {
crypt_pair.recv.apply_keystream(data);
}
}
fn encrypt_outgoing(&mut self, substream: u8, data: &mut [u8]) {
if let Some(crypt_pair) = self.streams.get_mut(substream as usize) {
crypt_pair.send.apply_keystream(data);
}
}
fn get_user_id(&self) -> u32 {
self.pid
}
fn sign_connect(&self, packet: &mut PRUDPV1Packet) {
packet.set_sizes();
packet.calculate_and_assign_signature(self.access_key, None, Some(self.self_signature));
}
fn sign_packet(&self, packet: &mut PRUDPV1Packet) {
packet.set_sizes();
packet.calculate_and_assign_signature(
self.access_key,
Some(self.session_key),
Some(self.self_signature),
);
}
fn verify_packet(&self, _packet: &PRUDPV1Packet) -> bool {
true
}
}