udp: start work on HMAC connection ID generation and validation

This commit is contained in:
Joakim Frostegård 2022-04-13 21:24:43 +02:00
parent 26e2e87437
commit dc4523ede5
4 changed files with 124 additions and 13 deletions

37
Cargo.lock generated
View file

@ -209,8 +209,10 @@ dependencies = [
"aquatic_common",
"aquatic_toml_config",
"aquatic_udp_protocol",
"blake3",
"cfg-if",
"crossbeam-channel",
"getrandom",
"hex",
"log",
"mimalloc",
@ -350,6 +352,12 @@ version = "1.5.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c5d78ce20460b82d3fa150275ed9d55e21064fc7951177baacf86a145c4a4b1f"
[[package]]
name = "arrayref"
version = "0.3.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a4c527152e37cf757a3f78aae5a06fbeefdb07ccc535c980a3208ee3060dd544"
[[package]]
name = "arrayvec"
version = "0.4.12"
@ -359,6 +367,12 @@ dependencies = [
"nodrop",
]
[[package]]
name = "arrayvec"
version = "0.7.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8da52d66c7071e2e3fa2a1e5c6d088fec47b593032b254f5e980de8ea54454d6"
[[package]]
name = "async-trait"
version = "0.1.53"
@ -524,6 +538,20 @@ version = "3.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "303cec55cd9c5fde944b061b902f142b52a8bb5438cc822481ea1e3ebc96bbcb"
[[package]]
name = "blake3"
version = "1.3.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a08e53fc5a564bb15bfe6fae56bd71522205f1f91893f9c0116edad6496c183f"
dependencies = [
"arrayref",
"arrayvec 0.7.2",
"cc",
"cfg-if",
"constant_time_eq",
"digest 0.10.3",
]
[[package]]
name = "block-buffer"
version = "0.9.0"
@ -655,6 +683,12 @@ version = "0.6.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9d6f2aa4d0537bcc1c74df8755072bd31c1ef1a3a1b85a68e8404a8c353b7b8b"
[[package]]
name = "constant_time_eq"
version = "0.1.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
[[package]]
name = "cpufeatures"
version = "0.2.2"
@ -854,6 +888,7 @@ checksum = "f2fb860ca6fafa5552fb6d0e816a69c8e49f0908bf524e30a90d97c85892d506"
dependencies = [
"block-buffer 0.10.2",
"crypto-common",
"subtle",
]
[[package]]
@ -1756,7 +1791,7 @@ version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "bafe4179722c2894288ee77a9f044f02811c86af699344c498b0840c698a2465"
dependencies = [
"arrayvec",
"arrayvec 0.4.12",
"itoa 0.4.8",
]

View file

@ -24,8 +24,10 @@ aquatic_toml_config = { version = "0.2.0", path = "../aquatic_toml_config" }
aquatic_udp_protocol = { version = "0.2.0", path = "../aquatic_udp_protocol" }
anyhow = "1"
blake3 = { version = "1", features = ["traits-preview"] }
cfg-if = "1"
crossbeam-channel = "0.5"
getrandom = "0.2"
hex = "0.4"
log = "0.4"
mimalloc = { version = "0.1", default-features = false }

View file

@ -1,19 +1,94 @@
use std::collections::BTreeMap;
use std::hash::Hash;
use std::net::{Ipv4Addr, Ipv6Addr};
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
use std::sync::atomic::AtomicUsize;
use std::sync::Arc;
use std::time::{Duration, Instant};
use aquatic_common::CanonicalSocketAddr;
use crossbeam_channel::{Sender, TrySendError};
use getrandom::getrandom;
use aquatic_common::access_list::AccessListArcSwap;
use aquatic_common::CanonicalSocketAddr;
use aquatic_udp_protocol::*;
use crate::config::Config;
pub const MAX_PACKET_SIZE: usize = 8192;
pub struct ConnectionIdHandler {
start_time: Instant,
max_connection_age: Duration,
hmac: blake3::Hasher,
}
impl ConnectionIdHandler {
pub fn new(config: &Config) -> anyhow::Result<Self> {
let mut key = [0; 32];
getrandom(&mut key)?;
let hmac = blake3::Hasher::new_keyed(&key);
let start_time = Instant::now();
let max_connection_age = Duration::from_secs(config.cleaning.max_connection_age);
Ok(Self {
hmac,
start_time,
max_connection_age,
})
}
pub fn create_connection_id(&mut self, source_ip: IpAddr) -> ConnectionId {
// Seconds elapsed since server start, as bytes
let elapsed_time_bytes = (self.start_time.elapsed().as_secs() as u32).to_ne_bytes();
self.create_connection_id_inner(elapsed_time_bytes, source_ip)
}
pub fn connection_id_valid(&mut self, source_ip: IpAddr, connection_id: ConnectionId) -> bool {
let elapsed_time_bytes = connection_id.0.to_ne_bytes()[..4].try_into().unwrap();
// i64 comparison should be constant-time
let hmac_valid =
connection_id == self.create_connection_id_inner(elapsed_time_bytes, source_ip);
if !hmac_valid {
return false;
}
let connection_elapsed_since_start =
Duration::from_secs(u32::from_ne_bytes(elapsed_time_bytes) as u64);
connection_elapsed_since_start + self.max_connection_age > self.start_time.elapsed()
}
fn create_connection_id_inner(
&mut self,
elapsed_time_bytes: [u8; 4],
source_ip: IpAddr,
) -> ConnectionId {
// The first 4 bytes is the elapsed time since server start in seconds. The last 4 is a
// truncated message authentication code.
let mut connection_id_bytes = [0u8; 8];
(&mut connection_id_bytes[..4]).copy_from_slice(&elapsed_time_bytes);
self.hmac.update(&elapsed_time_bytes);
match source_ip {
IpAddr::V4(ip) => self.hmac.update(&ip.octets()),
IpAddr::V6(ip) => self.hmac.update(&ip.octets()),
};
self.hmac.finalize_xof().fill(&mut connection_id_bytes[4..]);
self.hmac.reset();
ConnectionId(i64::from_ne_bytes(connection_id_bytes))
}
}
#[derive(Debug)]
pub struct PendingScrapeRequest {
pub slab_key: usize,

View file

@ -2,25 +2,24 @@ pub mod common;
pub mod config;
pub mod workers;
use aquatic_common::PanicSentinelWatcher;
use config::Config;
use std::collections::BTreeMap;
use std::thread::Builder;
use anyhow::Context;
#[cfg(feature = "cpu-pinning")]
use aquatic_common::cpu_pinning::{pin_current_if_configured_to, WorkerIndex};
use aquatic_common::privileges::PrivilegeDropper;
use crossbeam_channel::{bounded, unbounded};
use aquatic_common::access_list::update_access_list;
use signal_hook::consts::{SIGTERM, SIGUSR1};
use signal_hook::iterator::Signals;
use common::{ConnectedRequestSender, ConnectedResponseSender, SocketWorkerIndex, State};
use aquatic_common::access_list::update_access_list;
#[cfg(feature = "cpu-pinning")]
use aquatic_common::cpu_pinning::{pin_current_if_configured_to, WorkerIndex};
use aquatic_common::privileges::PrivilegeDropper;
use aquatic_common::PanicSentinelWatcher;
use crate::common::RequestWorkerIndex;
use common::{
ConnectedRequestSender, ConnectedResponseSender, RequestWorkerIndex, SocketWorkerIndex, State,
};
use config::Config;
pub const APP_NAME: &str = "aquatic_udp: UDP BitTorrent tracker";
pub const APP_VERSION: &str = env!("CARGO_PKG_VERSION");