rust-nex/prudpv0/src/crypto/friends_secure.rs
2026-02-01 21:10:03 +01:00

96 lines
2.7 KiB
Rust

use hmac::Mac;
use md5::{Digest, Md5};
use rc4::{KeyInit, Rc4, StreamCipher};
use rnex_core::{
executables::common::SECURE_SERVER_ACCOUNT,
nex::account::Account,
prudp::{
encryption::EncryptionPair,
ticket::read_secure_connection_data,
types_flags::{TypesFlags, types::DATA},
},
rmc::structures::RmcSerialize,
};
use std::io::Write;
use typenum::U16;
use crate::crypto::{
Crypto, CryptoInstance,
common_crypto::common_checksum,
friends_common::{ACCESS_KEY, HmacMd5},
};
pub struct SecureInstance {
pair: EncryptionPair<Rc4<U16>>,
uid: u32,
self_signat: [u8; 4],
remote_signat: [u8; 4],
}
impl CryptoInstance for SecureInstance {
fn decrypt_incoming(&mut self, data: &mut [u8]) {
self.pair.recv.apply_keystream(data);
}
fn encrypt_outgoing(&mut self, data: &mut [u8]) {
self.pair.send.apply_keystream(data);
}
fn get_user_id(&self) -> u32 {
self.uid
}
fn generate_signature(&self, types_flags: TypesFlags, data: &[u8]) -> [u8; 4] {
if types_flags.get_types() == DATA {
if data.len() == 0 {
[0x78, 0x56, 0x34, 0x12]
} else {
let mut hash = Md5::new();
hash.write(ACCESS_KEY.as_bytes()).unwrap();
let mut hmac = <HmacMd5 as Mac>::new_from_slice(&hash.finalize().as_slice())
.expect("unable to create hmac md5");
hmac.update(data);
hmac.finalize().into_bytes()[0..4].try_into().unwrap()
}
} else {
self.self_signat
}
}
}
pub struct Secure(&'static Account);
impl Crypto for Secure {
type Instance = SecureInstance;
fn new() -> Self {
Self(&SECURE_SERVER_ACCOUNT)
}
fn calculate_checksum(&self, data: &[u8]) -> u8 {
common_checksum(ACCESS_KEY, data)
}
fn instantiate(
&self,
data: &[u8],
self_signat: [u8; 4],
remote_signat: [u8; 4],
) -> Option<(Self::Instance, Vec<u8>)> {
let (session_key, pid, check_value) = read_secure_connection_data(data, &self.0)?;
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()?;
Some((
SecureInstance {
pair: EncryptionPair::init_both(|| {
Rc4::new_from_slice(&session_key).expect("unable to initialize rc4 stream")
}),
self_signat,
remote_signat,
uid: pid,
},
response,
))
}
}