Add auth-token class

lib/auth_token.rb

@@ -0,0 +1,26 @@
+class AuthToken
+  def initialize; end
+
+  def generate_token(user, secret = Rails.application.config.secret_key_base)
+    cipher = OpenSSL::Cipher::AES.new(256, :CBC)
+    expires_at = (Time.now.utc + 2.hours).strftime("%F %T %Z")
+
+    data = {
+      username: user.username,
+      expires_at: expires_at
+    }
+
+    hashable = data.to_json
+
+    cipher.encrypt
+    cipher.key = secret
+    encrypted = cipher.update(hashable) + cipher.final
+    base64_encoded = Base64.encode64(encrypted)
+
+    {
+      access_token: base64_encoded,
+      expires_at: expires_at,
+      type: "Bearer"
+    }
+  end
+end