turn/auth/
mod.rs

1#[cfg(test)]
2mod auth_test;
3
4use std::net::SocketAddr;
5use std::time::{Duration, SystemTime, UNIX_EPOCH};
6
7use base64::prelude::BASE64_STANDARD;
8use base64::Engine;
9use md5::{Digest, Md5};
10use ring::hmac;
11
12use crate::error::*;
13
14pub trait AuthHandler {
15    fn auth_handle(&self, username: &str, realm: &str, src_addr: SocketAddr) -> Result<Vec<u8>>;
16}
17
18/// `generate_long_term_credentials()` can be used to create credentials valid for `duration` time/
19pub fn generate_long_term_credentials(
20    shared_secret: &str,
21    duration: Duration,
22) -> Result<(String, String)> {
23    let t = SystemTime::now().duration_since(UNIX_EPOCH)? + duration;
24    let username = format!("{}", t.as_secs());
25    let password = long_term_credentials(&username, shared_secret);
26    Ok((username, password))
27}
28
29fn long_term_credentials(username: &str, shared_secret: &str) -> String {
30    let mac = hmac::Key::new(
31        hmac::HMAC_SHA1_FOR_LEGACY_USE_ONLY,
32        shared_secret.as_bytes(),
33    );
34    let password = hmac::sign(&mac, username.as_bytes()).as_ref().to_vec();
35    BASE64_STANDARD.encode(password)
36}
37
38/// A convenience function to easily generate keys in the format used by [`AuthHandler`].
39pub fn generate_auth_key(username: &str, realm: &str, password: &str) -> Vec<u8> {
40    let s = format!("{username}:{realm}:{password}");
41
42    let mut h = Md5::new();
43    h.update(s.as_bytes());
44    h.finalize().as_slice().to_vec()
45}
46
47pub struct LongTermAuthHandler {
48    shared_secret: String,
49}
50
51impl AuthHandler for LongTermAuthHandler {
52    fn auth_handle(&self, username: &str, realm: &str, src_addr: SocketAddr) -> Result<Vec<u8>> {
53        log::trace!("Authentication username={username} realm={realm} src_addr={src_addr}");
54
55        let t = Duration::from_secs(username.parse::<u64>()?);
56        if t < SystemTime::now().duration_since(UNIX_EPOCH)? {
57            return Err(Error::Other(format!(
58                "Expired time-windowed username {username}"
59            )));
60        }
61
62        let password = long_term_credentials(username, &self.shared_secret);
63        Ok(generate_auth_key(username, realm, &password))
64    }
65}
66
67impl LongTermAuthHandler {
68    /// https://tools.ietf.org/search/rfc5389#section-10.2
69    pub fn new(shared_secret: String) -> Self {
70        LongTermAuthHandler { shared_secret }
71    }
72}
turn/auth/mod.rs

turn/auth/
mod.rs
