Keep secret key in separate file

secretKey.js

@@ -0,0 +1,25 @@
+const fs = require('fs');
+const path = require('path');
+const forge = require('node-forge');
+
+function readFile(file) {
+  return fs.readFileSync(path.resolve(__dirname, file), 'utf8');
+}
+
+let secretKey;
+if (process.env.NODE_ENV === 'production') {
+  secretKey = {
+    public: readFile('./secret_key.pub'),
+    private: readFile('./secret_key')
+  };
+} else {
+  // Generate a random keypair for dev/testing.
+  // See https://gist.github.com/sebadoom/2b70969e70db5da9a203bebd9cff099f
+  const keypair = forge.rsa.generateKeyPair({ bits: 2048 });
+  secretKey = {
+    public: forge.pki.publicKeyToPem(keypair.publicKey, 72),
+    private: forge.pki.privateKeyToPem(keypair.privateKey, 72)
+  };
+}
+
+module.exports = secretKey;