1 files changed, 70 insertions, 0 deletions
diff --git a/aero-proto/src/dav/middleware.rs b/aero-proto/src/dav/middleware.rs
new file mode 100644
index 0000000..8964699
--- /dev/null
+++ b/aero-proto/src/dav/middleware.rs
@@ -0,0 +1,70 @@
+use anyhow::{anyhow, Result};
+use base64::Engine;
+use hyper::body::Incoming;
+use hyper::{Request, Response};
+
+use aero_collections::user::User;
+use aero_user::login::ArcLoginProvider;
+
+use super::codec::text_body;
+use super::controller::HttpResponse;
+
+type ArcUser = std::sync::Arc<User>;
+
+pub(super) async fn auth<'a>(
+    login: ArcLoginProvider,
+    req: Request<Incoming>,
+    next: impl Fn(ArcUser, Request<Incoming>) -> futures::future::BoxFuture<'a, Result<HttpResponse>>,
+) -> Result<HttpResponse> {
+    let auth_val = match req.headers().get(hyper::header::AUTHORIZATION) {
+        Some(hv) => hv.to_str()?,
+        None => {
+            tracing::info!("Missing authorization field");
+            return Ok(Response::builder()
+                .status(401)
+                .header("WWW-Authenticate", "Basic realm=\"Aerogramme\"")
+                .body(text_body("Missing Authorization field"))?);
+        }
+    };
+
+    let b64_creds_maybe_padded = match auth_val.split_once(" ") {
+        Some(("Basic", b64)) => b64,
+        _ => {
+            tracing::info!("Unsupported authorization field");
+            return Ok(Response::builder()
+                .status(400)
+                .body(text_body("Unsupported Authorization field"))?);
+        }
+    };
+
+    // base64urlencoded may have trailing equals, base64urlsafe has not
+    // theoretically authorization is padded but "be liberal in what you accept"
+    let b64_creds_clean = b64_creds_maybe_padded.trim_end_matches('=');
+
+    // Decode base64
+    let creds = base64::engine::general_purpose::STANDARD_NO_PAD.decode(b64_creds_clean)?;
+    let str_creds = std::str::from_utf8(&creds)?;
+
+    // Split username and password
+    let (username, password) = str_creds.split_once(':').ok_or(anyhow!(
+        "Missing colon in Authorization, can't split decoded value into a username/password pair"
+    ))?;
+
+    // Call login provider
+    let creds = match login.login(username, password).await {
+        Ok(c) => c,
+        Err(_) => {
+            tracing::info!(user = username, "Wrong credentials");
+            return Ok(Response::builder()
+                .status(401)
+                .header("WWW-Authenticate", "Basic realm=\"Aerogramme\"")
+                .body(text_body("Wrong credentials"))?);
+        }
+    };
+
+    // Build a user
+    let user = User::new(username.into(), creds).await?;
+
+    // Call router with user
+    next(user, req).await
+}