🦺 Support <auth> elements

src/config.rs

@@ -1,4 +1,4 @@
-use std::path::PathBuf;
+use std::{collections::HashSet, path::PathBuf};
 
 use anyhow::{Error, Result};
 use quick_xml::{events::Event, Reader};
@@ -27,6 +27,14 @@ pub struct BusConfig {
     // TODO: consider finding a way to make this `bool` instead of `Option<()>`
     pub allow_anonymous: Option<()>,
 
+    /// Lists permitted authorization mechanisms.
+    /// If this element doesn't exist, then all known mechanisms are allowed.
+    /// If there are multiple <auth> elements, all the listed mechanisms are allowed.
+    #[query(r#".auth.[].["$value"]"#)]
+    #[serde(default)]
+    // TODO: if there is a fixed set of possible values, consider using an `enum`
+    pub auth: HashSet<String>,
+
     /// If `Some`, the bus daemon becomes a real daemon (forks into the background, etc.).
     #[query(".fork")]
     // TODO: consider finding a way to make this `bool` instead of `Option<()>`
@@ -199,6 +207,23 @@ mod tests {
         );
     }
 
+    #[test]
+    fn bus_config_parse_with_auth_ok() {
+        let input = r#"<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-Bus Bus Configuration 1.0//EN"
+        "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+        <busconfig>
+            <auth>ANONYMOUS</auth>
+            <auth>EXTERNAL</auth>
+        </busconfig>
+        "#;
+
+        let busconfig = BusConfig::parse(input).expect("should parse XML input");
+        let want = HashSet::from_iter([String::from("ANONYMOUS"), String::from("EXTERNAL")]);
+        let diff = busconfig.auth.symmetric_difference(&want);
+
+        assert_eq!(diff.count(), 0);
+    }
+
     #[test]
     fn bus_config_parse_with_listen_ok() {
         let input = r#"<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-Bus Bus Configuration 1.0//EN"