Allow custom HTTP headers to be set (#52)

crates/jmap/src/api/config.rs

@@ -21,7 +21,7 @@
  * for more details.
 */
 
-use std::time::Duration;
+use std::{str::FromStr, time::Duration};
 
 use store::{
     fts::Language,
@@ -140,6 +140,32 @@ impl crate::Config {
                 .unwrap_or(true),
             encrypt: settings.property_or_static("jmap.encryption.enable", "true")?,
             encrypt_append: settings.property_or_static("jmap.encryption.append", "false")?,
+            http_headers: settings
+                .values("jmap.http.headers")
+                .map(|(_, v)| {
+                    if let Some((k, v)) = v.split_once(':') {
+                        Ok((
+                            hyper::header::HeaderName::from_str(k.trim()).map_err(|err| {
+                                format!(
+                                    "Invalid header found in property \"jmap.http.headers\": {}",
+                                    err
+                                )
+                            })?,
+                            hyper::header::HeaderValue::from_str(v.trim()).map_err(|err| {
+                                format!(
+                                    "Invalid header found in property \"jmap.http.headers\": {}",
+                                    err
+                                )
+                            })?,
+                        ))
+                    } else {
+                        Err(format!(
+                            "Invalid header found in property \"jmap.http.headers\": {}",
+                            v
+                        ))
+                    }
+                })
+                .collect::<Result<Vec<_>, String>>()?,
         };
         config.add_capabilites(settings);
         Ok(config)

crates/jmap/src/api/http.rs

@@ -446,7 +446,18 @@ async fn handle_request<T: AsyncRead + AsyncWrite + Unpin + Send + 'static>(
                         uri = req.uri().to_string(),
                     );
 
-                    let response = parse_jmap_request(jmap, req, session.remote_ip, instance).await;
+                    // Parse JMAP request
+                    let mut response =
+                        parse_jmap_request(jmap.clone(), req, session.remote_ip, instance).await;
+
+                    // Add custom headers
+                    if !jmap.config.http_headers.is_empty() {
+                        let headers = response.headers_mut();
+
+                        for (header, value) in &jmap.config.http_headers {
+                            headers.insert(header.clone(), value.clone());
+                        }
+                    }
 
                     Ok::<_, hyper::Error>(response)
                 }

crates/jmap/src/lib.rs

@@ -150,6 +150,8 @@ pub struct Config {
     pub oauth_expiry_refresh_token_renew: u64,
     pub oauth_max_auth_attempts: u32,
 
+    pub http_headers: Vec<(hyper::header::HeaderName, hyper::header::HeaderValue)>,
+
     pub encrypt: bool,
     pub encrypt_append: bool,