librespot/src/diffie_hellman.rs
2016-01-02 16:48:44 +01:00

50 lines
1.7 KiB
Rust

use num::{BigUint, FromPrimitive};
use rand::Rng;
use util;
lazy_static! {
pub static ref DH_GENERATOR: BigUint = BigUint::from_u64(0x2).unwrap();
pub static ref DH_PRIME: BigUint = BigUint::from_bytes_be(&[
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc9,
0x0f, 0xda, 0xa2, 0x21, 0x68, 0xc2, 0x34, 0xc4, 0xc6,
0x62, 0x8b, 0x80, 0xdc, 0x1c, 0xd1, 0x29, 0x02, 0x4e,
0x08, 0x8a, 0x67, 0xcc, 0x74, 0x02, 0x0b, 0xbe, 0xa6,
0x3b, 0x13, 0x9b, 0x22, 0x51, 0x4a, 0x08, 0x79, 0x8e,
0x34, 0x04, 0xdd, 0xef, 0x95, 0x19, 0xb3, 0xcd, 0x3a,
0x43, 0x1b, 0x30, 0x2b, 0x0a, 0x6d, 0xf2, 0x5f, 0x14,
0x37, 0x4f, 0xe1, 0x35, 0x6d, 0x6d, 0x51, 0xc2, 0x45,
0xe4, 0x85, 0xb5, 0x76, 0x62, 0x5e, 0x7e, 0xc6, 0xf4,
0x4c, 0x42, 0xe9, 0xa6, 0x3a, 0x36, 0x20, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff ]);
}
pub struct DHLocalKeys {
private_key: BigUint,
public_key: BigUint,
}
impl DHLocalKeys {
pub fn random<R: Rng>(rng: &mut R) -> DHLocalKeys {
let key_data = util::rand_vec(rng, 95);
let private_key = BigUint::from_bytes_be(&key_data);
let public_key = util::powm(&DH_GENERATOR, &private_key, &DH_PRIME);
DHLocalKeys {
private_key: private_key,
public_key: public_key,
}
}
pub fn public_key(&self) -> Vec<u8> {
self.public_key.to_bytes_be()
}
pub fn shared_secret(&self, remote_key: &[u8]) -> Vec<u8> {
let shared_key = util::powm(&BigUint::from_bytes_be(remote_key),
&self.private_key,
&DH_PRIME);
shared_key.to_bytes_be()
}
}