cleanup auth code, verify CSRF prevention token

This commit is contained in:
Dietmar Maurer 2019-02-16 15:52:55 +01:00
parent c8fd2dd2b8
commit 5ddf8cb10a
2 changed files with 122 additions and 28 deletions

View File

@ -9,24 +9,79 @@ use openssl::sha;
use std::path::PathBuf;
fn compute_csrf_secret_digest(
timestamp: i64,
secret: &[u8],
username: &str,
) -> String {
let mut hasher = sha::Sha256::new();
let data = format!("{:08X}:{}:", timestamp, username);
hasher.update(data.as_bytes());
hasher.update(secret);
base64::encode_config(&hasher.finish(), base64::STANDARD_NO_PAD)
}
pub fn assemble_csrf_prevention_token(
secret: &[u8],
username: &str,
) -> String {
let epoch = std::time::SystemTime::now().duration_since(
std::time::SystemTime::UNIX_EPOCH).unwrap().as_secs();
std::time::SystemTime::UNIX_EPOCH).unwrap().as_secs() as i64;
let mut hasher = sha::Sha256::new();
let data = format!("{:08X}:{}:", epoch, username);
hasher.update(data.as_bytes());
hasher.update(secret);
let digest = base64::encode_config(&hasher.finish(), base64::STANDARD_NO_PAD);
let digest = compute_csrf_secret_digest(epoch, secret, username);
format!("{:08X}:{}", epoch, digest)
}
pub fn verify_csrf_prevention_token(
secret: &[u8],
username: &str,
token: &str,
min_age: i64,
max_age: i64,
) -> Result<i64, Error> {
use std::collections::VecDeque;
let mut parts: VecDeque<&str> = token.split(':').collect();
try_block!({
if parts.len() != 2 {
bail!("format error - wrong number of parts.");
}
let timestamp = parts.pop_front().unwrap();
let sig = parts.pop_front().unwrap();
let ttime = i64::from_str_radix(timestamp, 16).
map_err(|err| format_err!("timestamp format error - {}", err))?;
let digest = compute_csrf_secret_digest(ttime, secret, username);
if digest != sig {
bail!("invalid signature.");
}
let now = std::time::SystemTime::now().duration_since(
std::time::SystemTime::UNIX_EPOCH)?.as_secs() as i64;
let age = now - ttime;
if age < min_age {
bail!("timestamp newer than expected.");
}
if age > max_age {
bail!("timestamp too old.");
}
Ok(age)
}).map_err(|err| format_err!("invalid csrf token - {}", err))
}
pub fn generate_csrf_key() -> Result<(), Error> {
let path = PathBuf::from(configdir!("/csrf.key"));

View File

@ -422,6 +422,48 @@ fn handle_static_file_download(filename: PathBuf) -> BoxFut {
return Box::new(response);
}
fn extract_auth_data(headers: &http::HeaderMap) -> (Option<String>, Option<String>) {
let mut ticket = None;
if let Some(raw_cookie) = headers.get("COOKIE") {
if let Ok(cookie) = raw_cookie.to_str() {
ticket = tools::extract_auth_cookie(cookie, "PBSAuthCookie");
}
}
let token = match headers.get("CSRFPreventionToken").map(|v| v.to_str()) {
Some(Ok(v)) => Some(v.to_owned()),
_ => None,
};
(ticket, token)
}
fn check_auth(method: &hyper::Method, ticket: Option<String>, token: Option<String>) -> Result<String, Error> {
let ticket_lifetime = 3600*2; // 2 hours
let username = match ticket {
Some(ticket) => match tools::ticket::verify_rsa_ticket(public_auth_key(), "PBS", &ticket, None, -300, ticket_lifetime) {
Ok((_age, Some(username))) => username.to_owned(),
Ok((_, None)) => bail!("ticket without username."),
Err(err) => return Err(err),
}
None => bail!("missing ticket"),
};
if method != hyper::Method::GET {
if let Some(token) = token {
println!("CSRF prev token: {:?}", token);
verify_csrf_prevention_token(csrf_secret(), &username, &token, -300, ticket_lifetime)?;
} else {
bail!("");
}
}
Ok(username)
}
pub fn handle_request(api: Arc<ApiConfig>, req: Request<Body>) -> BoxFut {
let (parts, body) = req.into_parts();
@ -457,20 +499,9 @@ pub fn handle_request(api: Arc<ApiConfig>, req: Request<Body>) -> BoxFut {
let delay_unauth_time = std::time::Instant::now() + std::time::Duration::from_millis(3000);
if let Some(raw_cookie) = parts.headers.get("COOKIE") {
if let Ok(cookie) = raw_cookie.to_str() {
if let Some(ticket) = tools::extract_auth_cookie(cookie, "PBSAuthCookie") {
if let Ok((_, Some(username))) = tools::ticket::verify_rsa_ticket(
public_auth_key(), "PBS", &ticket, None, -300, 3600*2) {
rpcenv.set_user(Some(username));
}
}
}
}
if comp_len >= 1 && components[0] == "api2" {
println!("GOT API REQUEST");
if comp_len >= 2 {
let format = components[1];
let formatter = match format {
@ -486,16 +517,24 @@ pub fn handle_request(api: Arc<ApiConfig>, req: Request<Body>) -> BoxFut {
if comp_len == 4 && components[2] == "access" && components[3] == "ticket" {
// explicitly allow those calls without auth
} else {
if let Some(_username) = rpcenv.get_user() {
// fixme: check permissions
} else {
// always delay unauthorized calls by 3 seconds (from start of request)
let resp = (formatter.format_error)(http_err!(UNAUTHORIZED, "permission check failed.".into()));
let delayed_response = tokio::timer::Delay::new(delay_unauth_time)
.map_err(|err| http_err!(INTERNAL_SERVER_ERROR, format!("tokio timer delay error: {}", err)))
.and_then(|_| Ok(resp));
let (ticket, token) = extract_auth_data(&parts.headers);
match check_auth(&method, ticket, token) {
Ok(username) => {
return Box::new(delayed_response);
// fixme: check permissions
rpcenv.set_user(Some(username));
}
Err(err) => {
// always delay unauthorized calls by 3 seconds (from start of request)
let err = http_err!(UNAUTHORIZED, format!("permission check failed - {}", err));
let resp = (formatter.format_error)(err);
let delayed_response = tokio::timer::Delay::new(delay_unauth_time)
.map_err(|err| http_err!(INTERNAL_SERVER_ERROR, format!("tokio timer delay error: {}", err)))
.and_then(|_| Ok(resp));
return Box::new(delayed_response);
}
}
}