http-signature-normalization/http-signature-normalization-actix/src/digest/middleware.rs

204 lines
5.7 KiB
Rust

//! Types for setting up Digest middleware verification
use actix_web::{
dev::{Body, Payload, Service, ServiceRequest, ServiceResponse, Transform},
error::PayloadError,
http::{header::HeaderValue, StatusCode},
FromRequest, HttpMessage, HttpRequest, HttpResponse, ResponseError,
};
use bytes::{Bytes, BytesMut};
use futures::{
future::{err, ok, ready, Ready},
stream::once,
Stream, StreamExt,
};
use std::{
cell::RefCell,
future::Future,
pin::Pin,
rc::Rc,
task::{Context, Poll},
};
use super::{DigestPart, DigestVerify};
#[derive(Copy, Clone, Debug)]
/// A type implementing FromRequest that can be used in route handler to guard for verified
/// digests
///
/// This is only required when the [`VerifyDigest`] middleware is set to optional
pub struct DigestVerified;
/// The VerifyDigest middleware
///
/// ```rust,ignore
/// let middleware = VerifyDigest::new(MyVerify::new())
/// .optional();
///
/// HttpServer::new(move || {
/// App::new()
/// .wrap(middleware.clone())
/// .route("/protected", web::post().to(|_: DigestVerified| "Verified Digest Header"))
/// .route("/unprotected", web::post().to(|| "No verification required"))
/// })
/// ```
pub struct VerifyDigest<T>(bool, T);
#[doc(hidden)]
pub struct VerifyMiddleware<T, S>(Rc<RefCell<S>>, bool, T);
#[derive(Debug, thiserror::Error)]
#[error("Error verifying digest")]
#[doc(hidden)]
pub struct VerifyError;
impl<T> VerifyDigest<T>
where
T: DigestVerify + Clone,
{
/// Produce a new VerifyDigest with a user-provided [`Digestverify`] type
pub fn new(verify_digest: T) -> Self {
VerifyDigest(true, verify_digest)
}
/// Mark verifying the Digest as optional
///
/// If a digest is present in the request, it will be verified, but it is not required to be
/// present
pub fn optional(self) -> Self {
VerifyDigest(false, self.1)
}
}
impl FromRequest for DigestVerified {
type Error = VerifyError;
type Future = Ready<Result<Self, Self::Error>>;
type Config = ();
fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
ready(
req.extensions()
.get::<Self>()
.map(|s| *s)
.ok_or(VerifyError),
)
}
}
impl<T, S> Transform<S> for VerifyDigest<T>
where
T: DigestVerify + Clone + 'static,
S: Service<
Request = ServiceRequest,
Response = ServiceResponse<Body>,
Error = actix_web::Error,
> + 'static,
S::Error: 'static,
{
type Request = ServiceRequest;
type Response = ServiceResponse<Body>;
type Error = actix_web::Error;
type Transform = VerifyMiddleware<T, S>;
type InitError = ();
type Future = Ready<Result<Self::Transform, Self::InitError>>;
fn new_transform(&self, service: S) -> Self::Future {
ok(VerifyMiddleware(
Rc::new(RefCell::new(service)),
self.0,
self.1.clone(),
))
}
}
impl<T, S> Service for VerifyMiddleware<T, S>
where
T: DigestVerify + Clone + 'static,
S: Service<
Request = ServiceRequest,
Response = ServiceResponse<Body>,
Error = actix_web::Error,
> + 'static,
S::Error: 'static,
{
type Request = ServiceRequest;
type Response = ServiceResponse<Body>;
type Error = actix_web::Error;
type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
fn poll_ready(&mut self, cx: &mut Context) -> Poll<Result<(), Self::Error>> {
self.0.borrow_mut().poll_ready(cx)
}
fn call(&mut self, mut req: ServiceRequest) -> Self::Future {
if let Some(digest) = req.headers().get("Digest") {
let vec = match parse_digest(digest) {
Some(vec) => vec,
None => return Box::pin(err(VerifyError.into())),
};
let mut payload = req.take_payload();
let service = self.0.clone();
let mut verify_digest = self.2.clone();
Box::pin(async move {
let mut output_bytes = BytesMut::new();
while let Some(res) = payload.next().await {
let bytes = res?;
output_bytes.extend(bytes);
}
let bytes = output_bytes.freeze();
if verify_digest.verify(&vec, &bytes.as_ref()) {
req.set_payload(
(Box::pin(once(ok(bytes)))
as Pin<Box<dyn Stream<Item = Result<Bytes, PayloadError>> + 'static>>)
.into(),
);
req.extensions_mut().insert(DigestVerified);
service.borrow_mut().call(req).await
} else {
Err(VerifyError.into())
}
})
} else if self.1 {
Box::pin(err(VerifyError.into()))
} else {
Box::pin(self.0.borrow_mut().call(req))
}
}
}
fn parse_digest(h: &HeaderValue) -> Option<Vec<DigestPart>> {
let h = h.to_str().ok()?.split(";").next()?;
let v: Vec<_> = h
.split(",")
.filter_map(|p| {
let mut iter = p.splitn(2, "=");
iter.next()
.and_then(|alg| iter.next().map(|value| (alg, value)))
})
.map(|(alg, value)| DigestPart {
algorithm: alg.to_owned(),
digest: value.to_owned(),
})
.collect();
if v.is_empty() {
None
} else {
Some(v)
}
}
impl ResponseError for VerifyError {
fn status_code(&self) -> StatusCode {
StatusCode::BAD_REQUEST
}
fn error_response(&self) -> HttpResponse {
HttpResponse::BadRequest().finish()
}
}