#NEWLINE# def validate_key( self , activation_key ) : #NEWLINE# #INDENT# '\n        Verify that the activation key is valid and within the\n        permitted activation time window, returning the username if\n        valid or ``None`` if not.\n\n        ' #NEWLINE# try : #NEWLINE# #INDENT# username = signing . loads ( activation_key , salt = REGISTRATION_SALT , max_age = ( settings . ACCOUNT_ACTIVATION_DAYS * 86400 ) ) #NEWLINE# return activation_key #NEWLINE# #UNINDENT# except signing . BadSignature : #NEWLINE# #INDENT# return None