Add top level phone number validation.

apps/cic-ussd/.config/app.ini

@@ -6,6 +6,9 @@ MAX_BODY_LENGTH=1024
 PASSWORD_PEPPER=QYbzKff6NhiQzY3ygl2BkiKOpER8RE/Upqs/5aZWW+I=
 SERVICE_CODE=*483*46#
 
+[phone_number]
+REGION=KE
+
 [ussd]
 MENU_FILE=/usr/src/data/ussd_menu.json
 

apps/cic-ussd/cic_ussd/runnable/server.py

@@ -27,6 +27,7 @@ from cic_ussd.metadata.user import UserMetadata
 from cic_ussd.operations import (define_response_with_content,
                                  process_menu_interaction_requests,
                                  define_multilingual_responses)
+from cic_ussd.phone_number import process_phone_number
 from cic_ussd.redis import InMemoryStore
 from cic_ussd.requests import (get_request_endpoint,
                                get_request_method,
@@ -151,6 +152,10 @@ def application(env, start_response):
         external_session_id = post_data.get('sessionId')
         user_input = post_data.get('text')
 
+        # add validation for phone number
+        if phone_number:
+            phone_number = process_phone_number(phone_number=phone_number, region=config.get('PHONE_NUMBER_REGION'))
+
         # validate ip address
         if not check_ip(config=config, env=env):
             start_response('403 Sneaky, sneaky', errors_headers)