External services security
From MoodleDocs
Moodle 2.0
Descriptions of security framework for web services, also used for RSS feeds, embedded application and similar parts that can not use normal HTTP cookies.
Current solutions
- user keys for gradebook import and export - see require_user_key_login() and db table user_private_key
- open RSS feeds - no security at all
- chat_sid tokens - generated separately for each user in each chat
- calendar hash from user name, password and salt
Types of token
We need several types of tokens
- token sharing/linked to active session, should time out or be destroyed at the same time as session (ex.: chat) - shared $SESSION and $USER
- permanent token, revokeable by user (ex.: RSS feeds, web services) - emulated $SESSION and $USER
In the second case we need to deal with performance problems if many repeated request expected. This can be dealt with alter.