fix(rustproxy): use SNI-based certificate resolution for QUIC TLS connections

rust/crates/rustproxy/src/lib.rs

@@ -1003,44 +1003,25 @@ impl RustProxy {
     fn build_quic_tls_config(
         tls_configs: &HashMap<String, TlsCertConfig>,
     ) -> Option<Arc<rustls::ServerConfig>> {
-        // Find the first available cert (prefer wildcard, then any)
-        let cert_config = tls_configs.get("*")
-            .or_else(|| tls_configs.values().next());
-
-        let cert_config = match cert_config {
-            Some(c) => c,
-            None => return None,
-        };
-
-        // Parse cert chain from PEM
-        let mut cert_reader = std::io::BufReader::new(cert_config.cert_pem.as_bytes());
-        let certs: Vec<rustls::pki_types::CertificateDer<'static>> =
-            rustls_pemfile::certs(&mut cert_reader)
-                .filter_map(|r| r.ok())
-                .collect();
-
-        if certs.is_empty() {
+        if tls_configs.is_empty() {
             return None;
         }
 
-        // Parse private key from PEM
-        let mut key_reader = std::io::BufReader::new(cert_config.key_pem.as_bytes());
-        let key = match rustls_pemfile::private_key(&mut key_reader) {
-            Ok(Some(key)) => key,
-            _ => return None,
-        };
-
-        let mut tls_config = match rustls::ServerConfig::builder()
-            .with_no_client_auth()
-            .with_single_cert(certs, key)
-        {
-            Ok(c) => c,
+        // Reuse CertResolver for SNI-based cert selection (same as TCP/TLS path).
+        // This ensures QUIC connections get the correct certificate for each domain
+        // instead of a single static cert.
+        let resolver = match rustproxy_passthrough::tls_handler::CertResolver::new(tls_configs) {
+            Ok(r) => r,
             Err(e) => {
-                warn!("Failed to build QUIC TLS config: {}", e);
+                warn!("Failed to build QUIC cert resolver: {}", e);
                 return None;
             }
         };
 
+        let mut tls_config = rustls::ServerConfig::builder()
+            .with_no_client_auth()
+            .with_cert_resolver(Arc::new(resolver));
+
         // QUIC requires h3 ALPN
         tls_config.alpn_protocols = vec![b"h3".to_vec()];