This commit is contained in:
Pascal Engélibert 2025-04-06 16:20:05 +02:00
commit f5e4a421bb
7 changed files with 166 additions and 47 deletions

View file

@ -1,9 +1,9 @@
use crate::{MAC_LEN, SALT_LEN, SECRET_LEN};
use base64::Engine;
use sha3::Digest;
use subtle::ConstantTimeEq;
use crate::{CHALLENGE_TIMEOUT, MAC_LEN, SALT_LEN, SECRET_LEN};
pub fn check_challenge(seed: &[u8], proof: &[u8], target_zeros: u32) -> bool {
let mut hasher = sha2::Sha256::default();
hasher.update(proof);
@ -47,6 +47,7 @@ pub fn verify_challenge_cookie(
secret: &[u8; SECRET_LEN],
user_agent: &[u8],
ip: &[u8],
challenge_timeout: u64,
) -> bool {
let Ok(cookie_bytes) = base64::engine::general_purpose::URL_SAFE_NO_PAD.decode(cookie) else {
dbg!("invalid base64");
@ -58,7 +59,7 @@ pub fn verify_challenge_cookie(
}
let timestamp: [u8; 8] = cookie_bytes[SALT_LEN..SALT_LEN + 8].try_into().unwrap();
let timestamp_time = u64::from_be_bytes(timestamp);
if timestamp_time.wrapping_add(CHALLENGE_TIMEOUT)
if timestamp_time.wrapping_add(challenge_timeout)
< std::time::SystemTime::UNIX_EPOCH
.elapsed()
.unwrap()

10
src/cli.rs Normal file
View file

@ -0,0 +1,10 @@
/// PoW anti-crawler middle-proxy
///
/// https://git.txmn.tk/tuxmain/mesozoa/
/// Distributed under license GNU AGPL v3 without any warranty.
#[derive(argp::FromArgs)]
pub struct Cli {
/// Path to config file
#[argp(option, short = 'c')]
pub config: String,
}

73
src/config.rs Normal file
View file

@ -0,0 +1,73 @@
use crate::policy::{Action, Policy};
use std::{io::Read, net::SocketAddr, str::FromStr};
pub struct Config {
pub listen_addr: SocketAddr,
pub pass_addr: SocketAddr,
pub default_action: Action,
pub challenge_timeout: u64,
pub policy_groups: Vec<Vec<Policy>>,
}
impl Config {
pub fn from_file(path: &str) -> Self {
let mut config_file = std::fs::File::open(path).expect("Cannot open config file");
let mut config_str = String::new();
config_file
.read_to_string(&mut config_str)
.expect("Cannot read config file");
let config_yaml = saphyr::Yaml::load_from_str(&config_str).expect("Error parsing config");
let config_doc = &config_yaml[0];
Config {
listen_addr: config_doc["listen"]
.as_str()
.expect("Missing listen address in config")
.parse()
.expect("Invalid listen address"),
pass_addr: config_doc["pass"]
.as_str()
.expect("Missing pass address in config")
.parse()
.expect("Invalid pass address"),
challenge_timeout: config_doc["challenge-timeout"]
.as_i64()
.expect("Missing challenge timeout in config") as u64,
default_action: Action::from_str(
config_doc["default-action"]
.as_str()
.expect("Missing default action in config"),
)
.expect("Invalid default action"),
policy_groups: config_doc["policy-groups"]
.as_vec()
.expect("Missing policies in config")
.iter()
.map(|policy_group| {
policy_group
.as_vec()
.expect("Missing policies in config")
.iter()
.map(|policy| Policy {
name: policy["name"]
.as_str()
.expect("Expected policy name string")
.to_string(),
first_line_regex: policy["first-line"]
.as_str()
.expect("Expected policy first line regex string")
.to_string(),
action: Action::from_str(
policy["action"]
.as_str()
.expect("Expected policy action string"),
)
.expect("Invalid policy action"),
})
.collect()
})
.collect(),
}
}
}

View file

@ -1,19 +1,16 @@
mod challenge;
mod cli;
mod config;
mod http;
mod policy;
use http::HeaderLineIterator;
use policy::{CompiledPolicies, Policy};
use policy::CompiledPolicies;
use rand::Rng;
use realm_syscall::socket2::TcpKeepalive;
use regex::bytes::Regex;
use std::{
io::{Read, Write},
net::SocketAddr,
str::FromStr,
time::Duration,
};
use std::{io::Write, net::SocketAddr, time::Duration};
use tokio::{
io::{AsyncWriteExt, ReadBuf},
net::{TcpSocket, TcpStream},
@ -23,7 +20,6 @@ use tokio::{
const SALT_LEN: usize = 16;
const SECRET_LEN: usize = 32;
const MAC_LEN: usize = 32;
const CHALLENGE_TIMEOUT: u64 = 3600;
const TARGET_ZEROS: u32 = 15;
static CHALLENGE_BODY: &str = include_str!("challenge.html");
@ -39,35 +35,9 @@ macro_rules! mk_static {
#[tokio::main]
async fn main() {
let mut config_file =
std::fs::File::open("example-config.yaml").expect("Cannot open config file");
let mut config_str = String::new();
config_file
.read_to_string(&mut config_str)
.expect("Cannot read config file");
let config_yaml = saphyr::Yaml::load_from_str(&config_str).expect("Error parsing config");
let config_doc = &config_yaml[0];
let listen_addr: SocketAddr = config_doc["listen"]
.as_str()
.expect("Missing listen address in config")
.parse()
.expect("Invalid listen address");
let pass_addr: SocketAddr = config_doc["pass"]
.as_str()
.expect("Missing pass address in config")
.parse()
.expect("Invalid pass address");
let default_action = policy::Action::from_str(
config_doc["default-action"]
.as_str()
.expect("Missing default action in config"),
)
.expect("Invalid default action");
let policy_groups: Vec<Vec<Policy>> = config_doc["policy-groups"].as_vec().expect("Missing policies in config").into_iter().map(|policy_group| policy_group.as_vec().expect("Missing policies in config").into_iter().map(|policy| Policy {
name: policy["name"].as_str().expect("Expected policy name string").to_string(),
first_line_regex: policy["first-line"].as_str().expect("Expected policy first line regex string").to_string(),
action: policy::Action::from_str(policy["action"].as_str().expect("Expected policy action string")).expect("Invalid policy action"),
}).collect()).collect();
let cli: cli::Cli = argp::parse_args_or_exit(argp::DEFAULT);
let config = config::Config::from_file(&cli.config);
let mut rng = rand::thread_rng();
@ -75,17 +45,18 @@ async fn main() {
let policy_groups = &*mk_static!(
Vec<CompiledPolicies>,
policy_groups
config
.policy_groups
.into_iter()
.map(CompiledPolicies::new)
.collect()
);
let socket = realm_syscall::new_tcp_socket(&listen_addr).unwrap();
let socket = realm_syscall::new_tcp_socket(&config.listen_addr).unwrap();
socket.set_reuse_address(true).ok();
socket.bind(&listen_addr.into()).unwrap();
socket.bind(&config.listen_addr.into()).unwrap();
socket.listen(1024).unwrap();
let listener = tokio::net::TcpListener::from_std(socket.into()).unwrap();
@ -144,7 +115,7 @@ async fn main() {
return;
};
let mut action = default_action;
let mut action = config.default_action;
for policy_group in policy_groups.iter() {
if let Some(policy) = policy_group.evaluate(first_line) {
println!("Applying policy {}", policy.name);
@ -156,7 +127,7 @@ async fn main() {
match action {
policy::Action::Drop => {}
policy::Action::Allow => {
do_proxy(pass_addr, client_stream).await;
do_proxy(config.pass_addr, client_stream).await;
}
policy::Action::Challenge => {
let mut req_challenge = None;
@ -187,6 +158,7 @@ async fn main() {
&secret,
req_user_agent,
req_ip,
config.challenge_timeout,
);
allow = dbg!(valid_challenge)
&& dbg!(challenge::check_challenge(
@ -197,7 +169,7 @@ async fn main() {
}
if allow {
do_proxy(pass_addr, client_stream).await;
do_proxy(config.pass_addr, client_stream).await;
} else {
let salt: [u8; SALT_LEN] = rand::thread_rng().r#gen();