International Domain Names (IDN) support (closes #207)

crates/common/src/cache/principals.rs

@@ -41,9 +41,14 @@ use store::{
 };
 use trc::{AddContext, StoreEvent};
 use types::id::Id;
+use utils::DomainPart;
 
 impl Server {
     pub async fn domain(&self, domain: &str) -> trc::Result<Option<Arc<DomainCache>>> {
+        let Some(domain) = domain.to_ascii_domain() else {
+            return Ok(None);
+        };
+        let domain = domain.as_ref();
         let domain_names = &self.inner.cache.domain_names;
 
         if let Some(domain_id) = domain_names.get(domain) {

crates/common/src/config/server/tls.rs

@@ -189,6 +189,17 @@ pub(crate) fn build_certified_key(
 pub(crate) fn build_self_signed_cert(
     domains: impl Into<Vec<String>>,
 ) -> Result<CertifiedKey, String> {
+    let domains = domains
+        .into()
+        .into_iter()
+        .map(|domain| {
+            if domain.is_ascii() {
+                domain
+            } else {
+                idna::domain_to_ascii(&domain).unwrap_or(domain)
+            }
+        })
+        .collect::<Vec<_>>();
     let rcgen::CertifiedKey { cert, signing_key } = generate_simple_self_signed(domains)
         .map_err(|err| format!("Failed to generate self-signed certificate: {err}",))?;
     build_certified_key(