SSL Cert Fixes

src/server.js

@@ -121,6 +121,25 @@ function startRedirectServer() {
 
   http
     .createServer((req, res) => {
+      // DER for Apple tooling, PEM for everything else.
+      if (req.url === '/ca.cer' || req.url === '/ca.der') {
+        try {
+          const der = tls.caCertificateDer();
+          if (!der) {
+            res.writeHead(404, { 'Content-Type': 'text/plain' });
+            return res.end('No certificate authority has been generated yet.');
+          }
+          res.writeHead(200, {
+            'Content-Type': 'application/pkix-cert',
+            'Content-Disposition': 'attachment; filename="visitor-signin-ca.cer"',
+          });
+          return res.end(der);
+        } catch (err) {
+          res.writeHead(500, { 'Content-Type': 'text/plain' });
+          return res.end(`Could not convert the certificate: ${err.message}`);
+        }
+      }
+
       if (req.url === '/ca.crt' || req.url === '/ca.pem') {
         const ca = tls.caCertificate();
         if (!ca) {