1 #[cfg(test)] 2 mod auth_test; 3 4 use crate::error::*; 5 6 use std::net::SocketAddr; 7 use std::time::{Duration, SystemTime, UNIX_EPOCH}; 8 9 use md5::{Digest, Md5}; 10 use ring::hmac; 11 12 pub trait AuthHandler { 13 fn auth_handle(&self, username: &str, realm: &str, src_addr: SocketAddr) -> Result<Vec<u8>>; 14 } 15 16 // generate_long_term_credentials can be used to create credentials valid for [duration] time 17 pub fn generate_long_term_credentials( 18 shared_secret: &str, 19 duration: Duration, 20 ) -> Result<(String, String)> { 21 let t = SystemTime::now().duration_since(UNIX_EPOCH)? + duration; 22 let username = format!("{}", t.as_secs()); 23 let password = long_term_credentials(&username, shared_secret); 24 Ok((username, password)) 25 } 26 27 fn long_term_credentials(username: &str, shared_secret: &str) -> String { 28 let mac = hmac::Key::new( 29 hmac::HMAC_SHA1_FOR_LEGACY_USE_ONLY, 30 shared_secret.as_bytes(), 31 ); 32 let password = hmac::sign(&mac, username.as_bytes()).as_ref().to_vec(); 33 base64::encode(&password) 34 } 35 36 // generate_auth_key is a convenience function to easily generate keys in the format used by AuthHandler 37 pub fn generate_auth_key(username: &str, realm: &str, password: &str) -> Vec<u8> { 38 let s = format!("{}:{}:{}", username, realm, password); 39 40 let mut h = Md5::new(); 41 h.update(s.as_bytes()); 42 h.finalize().as_slice().to_vec() 43 } 44 45 pub struct LongTermAuthHandler { 46 shared_secret: String, 47 } 48 49 impl AuthHandler for LongTermAuthHandler { 50 fn auth_handle(&self, username: &str, realm: &str, src_addr: SocketAddr) -> Result<Vec<u8>> { 51 log::trace!( 52 "Authentication username={} realm={} src_addr={}", 53 username, 54 realm, 55 src_addr 56 ); 57 58 let t = Duration::from_secs(username.parse::<u64>()?); 59 if t < SystemTime::now().duration_since(UNIX_EPOCH)? { 60 return Err(Error::Other(format!( 61 "Expired time-windowed username {}", 62 username 63 ))); 64 } 65 66 let password = long_term_credentials(username, &self.shared_secret); 67 Ok(generate_auth_key(username, realm, &password)) 68 } 69 } 70 71 impl LongTermAuthHandler { 72 // https://tools.ietf.org/search/rfc5389#section-10.2 73 pub fn new(shared_secret: String) -> Self { 74 LongTermAuthHandler { shared_secret } 75 } 76 } 77