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mirror of https://github.com/fafhrd91/actix-web synced 2024-11-28 18:02:39 +01:00
actix-web/src/middleware/session.rs
2018-04-18 20:41:03 -07:00

520 lines
16 KiB
Rust

//! User sessions.
//!
//! Actix provides a general solution for session management. The
//! [**SessionStorage**](struct.SessionStorage.html)
//! middleware can be used with different backend types to store session
//! data in different backends.
//!
//! By default, only cookie session backend is implemented. Other
//! backend implementations can be added.
//!
//! [**CookieSessionBackend**](struct.CookieSessionBackend.html)
//! uses cookies as session storage. `CookieSessionBackend` creates sessions
//! which are limited to storing fewer than 4000 bytes of data, as the payload
//! must fit into a single cookie. An internal server error is generated if a
//! session contains more than 4000 bytes.
//!
//! A cookie may have a security policy of *signed* or *private*. Each has
//! a respective `CookieSessionBackend` constructor.
//!
//! A *signed* cookie may be viewed but not modified by the client. A *private*
//! cookie may neither be viewed nor modified by the client.
//!
//! The constructors take a key as an argument. This is the private key
//! for cookie session - when this value is changed, all session data is lost.
//!
//! In general, you create a `SessionStorage` middleware and initialize it
//! with specific backend implementation, such as a `CookieSessionBackend`.
//! To access session data,
//! [*HttpRequest::session()*](trait.RequestSession.html#tymethod.session)
//! must be used. This method returns a
//! [*Session*](struct.Session.html) object, which allows us to get or set
//! session data.
//!
//! ```rust
//! # extern crate actix;
//! # extern crate actix_web;
//! use actix_web::{server, App, HttpRequest, Result};
//! use actix_web::middleware::{RequestSession, SessionStorage, CookieSessionBackend};
//!
//! fn index(mut req: HttpRequest) -> Result<&'static str> {
//! // access session data
//! if let Some(count) = req.session().get::<i32>("counter")? {
//! println!("SESSION value: {}", count);
//! req.session().set("counter", count+1)?;
//! } else {
//! req.session().set("counter", 1)?;
//! }
//!
//! Ok("Welcome!")
//! }
//!
//! fn main() {
//! let sys = actix::System::new("basic-example");
//! server::new(
//! || App::new().middleware(
//! SessionStorage::new( // <- create session middleware
//! CookieSessionBackend::signed(&[0; 32]) // <- create signed cookie session backend
//! .secure(false)
//! )))
//! .bind("127.0.0.1:59880").unwrap()
//! .start();
//! # actix::Arbiter::system().do_send(actix::msgs::SystemExit(0));
//! let _ = sys.run();
//! }
//! ```
use std::collections::HashMap;
use std::marker::PhantomData;
use std::rc::Rc;
use std::sync::Arc;
use cookie::{Cookie, CookieJar, Key};
use futures::Future;
use futures::future::{FutureResult, err as FutErr, ok as FutOk};
use http::header::{self, HeaderValue};
use serde::{Deserialize, Serialize};
use serde_json;
use serde_json::error::Error as JsonError;
use time::Duration;
use error::{Error, ResponseError, Result};
use httprequest::HttpRequest;
use httpresponse::HttpResponse;
use middleware::{Middleware, Response, Started};
/// The helper trait to obtain your session data from a request.
///
/// ```rust
/// use actix_web::*;
/// use actix_web::middleware::RequestSession;
///
/// fn index(mut req: HttpRequest) -> Result<&'static str> {
/// // access session data
/// if let Some(count) = req.session().get::<i32>("counter")? {
/// req.session().set("counter", count+1)?;
/// } else {
/// req.session().set("counter", 1)?;
/// }
///
/// Ok("Welcome!")
/// }
/// # fn main() {}
/// ```
pub trait RequestSession {
fn session(&mut self) -> Session;
}
impl<S> RequestSession for HttpRequest<S> {
fn session(&mut self) -> Session {
if let Some(s_impl) = self.extensions().get_mut::<Arc<SessionImplBox>>() {
if let Some(s) = Arc::get_mut(s_impl) {
return Session(s.0.as_mut());
}
}
Session(unsafe { &mut DUMMY })
}
}
/// The high-level interface you use to modify session data.
///
/// Session object could be obtained with
/// [`RequestSession::session`](trait.RequestSession.html#tymethod.session)
/// method. `RequestSession` trait is implemented for `HttpRequest`.
///
/// ```rust
/// use actix_web::*;
/// use actix_web::middleware::RequestSession;
///
/// fn index(mut req: HttpRequest) -> Result<&'static str> {
/// // access session data
/// if let Some(count) = req.session().get::<i32>("counter")? {
/// req.session().set("counter", count+1)?;
/// } else {
/// req.session().set("counter", 1)?;
/// }
///
/// Ok("Welcome!")
/// }
/// # fn main() {}
/// ```
pub struct Session<'a>(&'a mut SessionImpl);
impl<'a> Session<'a> {
/// Get a `value` from the session.
pub fn get<T: Deserialize<'a>>(&'a self, key: &str) -> Result<Option<T>> {
if let Some(s) = self.0.get(key) {
Ok(Some(serde_json::from_str(s)?))
} else {
Ok(None)
}
}
/// Set a `value` from the session.
pub fn set<T: Serialize>(&mut self, key: &str, value: T) -> Result<()> {
self.0.set(key, serde_json::to_string(&value)?);
Ok(())
}
/// Remove value from the session.
pub fn remove(&'a mut self, key: &str) {
self.0.remove(key)
}
/// Clear the session.
pub fn clear(&'a mut self) {
self.0.clear()
}
}
struct SessionImplBox(Box<SessionImpl>);
#[doc(hidden)]
unsafe impl Send for SessionImplBox {}
#[doc(hidden)]
unsafe impl Sync for SessionImplBox {}
/// Session storage middleware
///
/// ```rust
/// # extern crate actix;
/// # extern crate actix_web;
/// use actix_web::App;
/// use actix_web::middleware::{SessionStorage, CookieSessionBackend};
///
/// fn main() {
/// let app = App::new().middleware(
/// SessionStorage::new( // <- create session middleware
/// CookieSessionBackend::signed(&[0; 32]) // <- create cookie session backend
/// .secure(false))
/// );
/// }
/// ```
pub struct SessionStorage<T, S>(T, PhantomData<S>);
impl<S, T: SessionBackend<S>> SessionStorage<T, S> {
/// Create session storage
pub fn new(backend: T) -> SessionStorage<T, S> {
SessionStorage(backend, PhantomData)
}
}
impl<S: 'static, T: SessionBackend<S>> Middleware<S> for SessionStorage<T, S> {
fn start(&self, req: &mut HttpRequest<S>) -> Result<Started> {
let mut req = req.clone();
let fut = self.0
.from_request(&mut req)
.then(move |res| match res {
Ok(sess) => {
req.extensions()
.insert(Arc::new(SessionImplBox(Box::new(sess))));
FutOk(None)
}
Err(err) => FutErr(err),
});
Ok(Started::Future(Box::new(fut)))
}
fn response(
&self, req: &mut HttpRequest<S>, resp: HttpResponse
) -> Result<Response> {
if let Some(s_box) = req.extensions().remove::<Arc<SessionImplBox>>() {
s_box.0.write(resp)
} else {
Ok(Response::Done(resp))
}
}
}
/// A simple key-value storage interface that is internally used by `Session`.
#[doc(hidden)]
pub trait SessionImpl: 'static {
fn get(&self, key: &str) -> Option<&str>;
fn set(&mut self, key: &str, value: String);
fn remove(&mut self, key: &str);
fn clear(&mut self);
/// Write session to storage backend.
fn write(&self, resp: HttpResponse) -> Result<Response>;
}
/// Session's storage backend trait definition.
#[doc(hidden)]
pub trait SessionBackend<S>: Sized + 'static {
type Session: SessionImpl;
type ReadFuture: Future<Item = Self::Session, Error = Error>;
/// Parse the session from request and load data from a storage backend.
fn from_request(&self, request: &mut HttpRequest<S>) -> Self::ReadFuture;
}
/// Dummy session impl, does not do anything
struct DummySessionImpl;
static mut DUMMY: DummySessionImpl = DummySessionImpl;
impl SessionImpl for DummySessionImpl {
fn get(&self, _: &str) -> Option<&str> {
None
}
fn set(&mut self, _: &str, _: String) {}
fn remove(&mut self, _: &str) {}
fn clear(&mut self) {}
fn write(&self, resp: HttpResponse) -> Result<Response> {
Ok(Response::Done(resp))
}
}
/// Session that uses signed cookies as session storage
pub struct CookieSession {
changed: bool,
state: HashMap<String, String>,
inner: Rc<CookieSessionInner>,
}
/// Errors that can occur during handling cookie session
#[derive(Fail, Debug)]
pub enum CookieSessionError {
/// Size of the serialized session is greater than 4000 bytes.
#[fail(display = "Size of the serialized session is greater than 4000 bytes.")]
Overflow,
/// Fail to serialize session.
#[fail(display = "Fail to serialize session")]
Serialize(JsonError),
}
impl ResponseError for CookieSessionError {}
impl SessionImpl for CookieSession {
fn get(&self, key: &str) -> Option<&str> {
if let Some(s) = self.state.get(key) {
Some(s)
} else {
None
}
}
fn set(&mut self, key: &str, value: String) {
self.changed = true;
self.state.insert(key.to_owned(), value);
}
fn remove(&mut self, key: &str) {
self.changed = true;
self.state.remove(key);
}
fn clear(&mut self) {
self.changed = true;
self.state.clear()
}
fn write(&self, mut resp: HttpResponse) -> Result<Response> {
if self.changed {
let _ = self.inner.set_cookie(&mut resp, &self.state);
}
Ok(Response::Done(resp))
}
}
enum CookieSecurity {
Signed,
Private,
}
struct CookieSessionInner {
key: Key,
security: CookieSecurity,
name: String,
path: String,
domain: Option<String>,
secure: bool,
max_age: Option<Duration>,
}
impl CookieSessionInner {
fn new(key: &[u8], security: CookieSecurity) -> CookieSessionInner {
CookieSessionInner {
security,
key: Key::from_master(key),
name: "actix-session".to_owned(),
path: "/".to_owned(),
domain: None,
secure: true,
max_age: None,
}
}
fn set_cookie(
&self, resp: &mut HttpResponse, state: &HashMap<String, String>
) -> Result<()> {
let value =
serde_json::to_string(&state).map_err(CookieSessionError::Serialize)?;
if value.len() > 4064 {
return Err(CookieSessionError::Overflow.into());
}
let mut cookie = Cookie::new(self.name.clone(), value);
cookie.set_path(self.path.clone());
cookie.set_secure(self.secure);
cookie.set_http_only(true);
if let Some(ref domain) = self.domain {
cookie.set_domain(domain.clone());
}
if let Some(max_age) = self.max_age {
cookie.set_max_age(max_age);
}
let mut jar = CookieJar::new();
match self.security {
CookieSecurity::Signed => jar.signed(&self.key).add(cookie),
CookieSecurity::Private => jar.private(&self.key).add(cookie),
}
for cookie in jar.delta() {
let val = HeaderValue::from_str(&cookie.to_string())?;
resp.headers_mut().append(header::SET_COOKIE, val);
}
Ok(())
}
fn load<S>(&self, req: &mut HttpRequest<S>) -> HashMap<String, String> {
if let Ok(cookies) = req.cookies() {
for cookie in cookies {
if cookie.name() == self.name {
let mut jar = CookieJar::new();
jar.add_original(cookie.clone());
let cookie_opt = match self.security {
CookieSecurity::Signed => jar.signed(&self.key).get(&self.name),
CookieSecurity::Private => {
jar.private(&self.key).get(&self.name)
}
};
if let Some(cookie) = cookie_opt {
if let Ok(val) = serde_json::from_str(cookie.value()) {
return val;
}
}
}
}
}
HashMap::new()
}
}
/// Use cookies for session storage.
///
/// `CookieSessionBackend` creates sessions which are limited to storing
/// fewer than 4000 bytes of data (as the payload must fit into a single
/// cookie). An Internal Server Error is generated if the session contains more
/// than 4000 bytes.
///
/// A cookie may have a security policy of *signed* or *private*. Each has a
/// respective `CookieSessionBackend` constructor.
///
/// A *signed* cookie is stored on the client as plaintext alongside
/// a signature such that the cookie may be viewed but not modified by the
/// client.
///
/// A *private* cookie is stored on the client as encrypted text
/// such that it may neither be viewed nor modified by the client.
///
/// The constructors take a key as an argument.
/// This is the private key for cookie session - when this value is changed,
/// all session data is lost. The constructors will panic if the key is less
/// than 32 bytes in length.
///
///
/// # Example
///
/// ```rust
/// # extern crate actix_web;
/// use actix_web::middleware::CookieSessionBackend;
///
/// # fn main() {
/// let backend: CookieSessionBackend = CookieSessionBackend::signed(&[0; 32])
/// .domain("www.rust-lang.org")
/// .name("actix_session")
/// .path("/")
/// .secure(true);
/// # }
/// ```
pub struct CookieSessionBackend(Rc<CookieSessionInner>);
impl CookieSessionBackend {
/// Construct new *signed* `CookieSessionBackend` instance.
///
/// Panics if key length is less than 32 bytes.
pub fn signed(key: &[u8]) -> CookieSessionBackend {
CookieSessionBackend(Rc::new(CookieSessionInner::new(
key,
CookieSecurity::Signed,
)))
}
/// Construct new *private* `CookieSessionBackend` instance.
///
/// Panics if key length is less than 32 bytes.
pub fn private(key: &[u8]) -> CookieSessionBackend {
CookieSessionBackend(Rc::new(CookieSessionInner::new(
key,
CookieSecurity::Private,
)))
}
/// Sets the `path` field in the session cookie being built.
pub fn path<S: Into<String>>(mut self, value: S) -> CookieSessionBackend {
Rc::get_mut(&mut self.0).unwrap().path = value.into();
self
}
/// Sets the `name` field in the session cookie being built.
pub fn name<S: Into<String>>(mut self, value: S) -> CookieSessionBackend {
Rc::get_mut(&mut self.0).unwrap().name = value.into();
self
}
/// Sets the `domain` field in the session cookie being built.
pub fn domain<S: Into<String>>(mut self, value: S) -> CookieSessionBackend {
Rc::get_mut(&mut self.0).unwrap().domain = Some(value.into());
self
}
/// Sets the `secure` field in the session cookie being built.
///
/// If the `secure` field is set, a cookie will only be transmitted when the
/// connection is secure - i.e. `https`
pub fn secure(mut self, value: bool) -> CookieSessionBackend {
Rc::get_mut(&mut self.0).unwrap().secure = value;
self
}
/// Sets the `max-age` field in the session cookie being built.
pub fn max_age(mut self, value: Duration) -> CookieSessionBackend {
Rc::get_mut(&mut self.0).unwrap().max_age = Some(value);
self
}
}
impl<S> SessionBackend<S> for CookieSessionBackend {
type Session = CookieSession;
type ReadFuture = FutureResult<CookieSession, Error>;
fn from_request(&self, req: &mut HttpRequest<S>) -> Self::ReadFuture {
let state = self.0.load(req);
FutOk(CookieSession {
changed: false,
inner: Rc::clone(&self.0),
state,
})
}
}