Give challenge plugins the ability to specify the response message (#351)

CTFd/challenges.py

@@ -287,15 +287,16 @@ def chal(chalid):
                 })
 
             chal_class = get_chal_class(chal.type)
-            if chal_class.solve(chal, provided_key):
+            status, message = chal_class.solve(chal, provided_key)
+            if status:  # The challenge plugin says the input is right
                 if utils.ctftime():
                     solve = Solves(teamid=session['id'], chalid=chalid, ip=utils.get_ip(), flag=provided_key)
                     db.session.add(solve)
                     db.session.commit()
                     db.session.close()
                 logger.info("[{0}] {1} submitted {2} with kpm {3} [CORRECT]".format(*data))
-                return jsonify({'status': 1, 'message': 'Correct'})
-
+                return jsonify({'status': 1, 'message': message})
+            else:  # The challenge plugin says the input is wrong
                 if utils.ctftime():
                     wrong = WrongKeys(teamid=session['id'], chalid=chalid, ip=utils.get_ip(), flag=provided_key)
                     db.session.add(wrong)
@@ -308,9 +309,11 @@ def chal(chalid):
                     tries_str = 'tries'
                     if attempts_left == 1:
                         tries_str = 'try'
-                return jsonify({'status': 0, 'message': 'Incorrect. You have {} {} remaining.'.format(attempts_left, tries_str)})
+                    if message[-1] not in '!().;?[]\{\}':  # Add a punctuation mark if there isn't one
+                        message = message + '.'
+                    return jsonify({'status': 0, 'message': '{} You have {} {} remaining.'.format(message, attempts_left, tries_str)})
                 else:
-                return jsonify({'status': 0, 'message': 'Incorrect'})
+                    return jsonify({'status': 0, 'message': message})
 
         # Challenge already solved
         else:

CTFd/plugins/challenges/__init__.py

@@ -16,8 +16,8 @@ class CTFdStandardChallenge(BaseChallenge):
         chal_keys = Keys.query.filter_by(chal=chal.id).all()
         for chal_key in chal_keys:
             if get_key_class(chal_key.key_type).compare(chal_key.flag, provided_key):
-                return True
-        return False
+                return True, 'Correct'
+        return False, 'Incorrect'
 
 
 CHALLENGE_CLASSES = {