experimenting with some refactoring

lib/framework/SecurityManager.h

@@ -0,0 +1,110 @@
+#ifndef SecurityManager_h
+#define SecurityManager_h
+
+#include <list>
+#include <ArduinoJsonJWT.h>
+#include <ESPAsyncWebServer.h>
+
+#define DEFAULT_JWT_SECRET "esp8266-react"
+
+#define AUTHORIZATION_HEADER "Authorization"
+#define AUTHORIZATION_HEADER_PREFIX "Bearer "
+#define AUTHORIZATION_HEADER_PREFIX_LEN 7
+
+#define MAX_JWT_SIZE 128
+
+class User {
+  private:
+    String _username;
+    String _password;
+    bool _admin;
+  public:
+    User(String username, String password, bool admin): _username(username), _password(password), _admin(admin) {}
+    String getUsername() {
+      return _username;
+    }
+    String getPassword() {
+      return _password;
+    }    
+    bool isAdmin() {
+      return _admin;
+    }
+};
+
+class Authentication {
+  private:
+    User *_user;
+    boolean _authenticated;
+  public:
+    Authentication(User& user): _user(new User(user)), _authenticated(true) {}
+    Authentication() : _user(nullptr), _authenticated(false) {}  
+    ~Authentication() {
+      delete(_user);   
+    }
+    User* getUser() {
+      return _user;
+    }
+    bool isAuthenticated() {
+      return _authenticated;
+    }
+};
+
+typedef std::function<boolean(Authentication &authentication)> AuthenticationPredicate;
+
+class AuthenticationPredicates {
+  public:
+    static bool NONE_REQUIRED(Authentication &authentication) {
+      return true;
+    };
+    static bool IS_AUTHENTICATED(Authentication &authentication) {
+      return authentication.isAuthenticated();
+    };    
+    static bool IS_ADMIN(Authentication &authentication) {
+      return authentication.isAuthenticated() && authentication.getUser()->isAdmin();
+    };
+};
+
+class SecurityManager {
+
+  public:
+
+    /*
+    * Authenticate, returning the user if found
+    */
+    Authentication authenticate(String username, String password);
+
+    /*
+    * Check the request header for the Authorization token
+    */
+    Authentication authenticateRequest(AsyncWebServerRequest *request);
+    
+    /*
+    * Generate a JWT for the user provided
+    */
+    String generateJWT(User *user);
+
+    /**
+     * Wrap the provided request to provide validation against an AuthenticationPredicate.
+     */
+    ArRequestHandlerFunction wrapRequest(ArRequestHandlerFunction onRequest, AuthenticationPredicate predicate); 
+
+  protected:
+
+    ArduinoJsonJWT _jwtHandler = ArduinoJsonJWT(DEFAULT_JWT_SECRET);
+    std::list<User> _users;
+
+  private:
+
+    /*
+    * Lookup the user by JWT
+    */
+    Authentication authenticateJWT(String jwt);
+
+    /*
+    * Verify the payload is correct
+    */
+    boolean validatePayload(JsonObject &parsedPayload, User *user);
+
+};
+
+#endif // end SecurityManager_h