CouchDB Authorization Logic?

Question

I did read http://guide.couchdb.org/draft/security.html and

and the previous question CouchDB Authorization on a Per-Database Basis and http://wiki.apache.org/couchdb/Security_Features_Overview

I am currently using Apache CouchDB 1.2.0 and via futon the adding an admin result in adding a user at _users for example

_id
org.couchdb.user:stackoverflow
 _rev 
1-b9f223532b662d4ac52d14082d81e6a5

name
stackoverflow

password
null

roles
[ ]

type
user

So the first question is why the admin is added as type user and not admin is puzzling. This users are admin as they can do anything in any database and the role is empty BUT I did protect the _users document with

["admin"]

roles as the only members and only admins can access this (even if their role in the _users document is empty).

This protection does not allow new "normal" users to be created so the futon "signup" command will return Signup error: You are not authorized to access this db.

I think this setup is the only logical one. Why would you want anyone to be able to create a user on your database ??

Even if you specify read access in a db to be only for one admin every admin can access it

(

 " admins" : {
   "names" : ["guru"],
   "roles" : ["boss"]
  },
  "readers" : {
    "names" : ["guru"],
   "roles" : ["boss"]
  }
}

the above case has no impact on the newly created stackoverflow admin as per above example.

So my assumption is that admins created via futon can do everything and anything regardless. The only confusing logical part is the _users documents where they have no special type (they are users) nor a special role.

So back to the concrete question: - when adding an admin via futon why is it not marked as admin inside the _users document and how does CouchDB from that document determine that it is a wide system admin? - if you want to create a normal user WITHOUT allowing them to signup (via futon or direct HTTP Request) you have to protect the _users document. Yet how would you go to create yourself a user to read/write on his own database ? - As the user (per CouchDB Docs) will have the read/write rights on a DB but not the possibility to create design documents how can he really use it efficiently as views will be needed for anyone developing using the DB?

It should be possible to have a normal, simply multi hosting without jeopardizing security as there is a shared CouchDB offering at http://www.iriscouch.com/ so I just don't understand how logically you would structure a simple service where a user has his own database and can do anything but just on this database. As the admin role is anyway "user" how would you distinguish them from a non admin in the _users table ?

Answer 1

Why is the admin added as a normal user and not an admin?

CouchDB is similar to Windows's Active Directory, or Unix NIS and LDAP: most users have "normal" accounts, however the admin account (e.g. Windows "Administrator", or Unix "root") does not use the normal accounting system, but rather a much simpler system (the local.ini config file).

If the account and authentication system ever has a problem, you can still log in as the admin and fix it.

Do I need to add the "_admin" role to a user?

No, the admin role (the role "_admin") does not come from the user's document, but only from the configuration, in the "admins" section.

How come all admins can read the database?

By creating an admin in the global configuration (either editing the local.ini file, or using Futon's "Configuration" tab, or clicking the "Fix this" link in Admin Party), you created a system admin. System admins have access to all data, always (similar to Windows Administrator and Unix root).

CouchDB supports database admins which are normal users. Those users have admin access only to a database, not to anything else, such as other databases, or the server config. Database admins are set in the "Security" section, by adding a user's name or role to the "Admins" lists.

The concrete question: - when adding an admin via futon why is it not marked as admin inside the _users document and how does CouchDB from that document determine that it is a wide system admin?

When adding an admin via Futon, two things happen

1. A normal user is created (with no valid password in fact)
2. The same user name is added to the system configuration "admins" section. GET /_config/admins/the_username to see it. (That's what Futon's configuration tab does.)

In other words, CouchDB does not know it is a wide system admin from the document but rather from the config. If you delete that config entry, the user is "demoted" back to a normal user.

Side note about Iris Couch

It can be a little confusing at first, but the CouchDB user and security system is pretty simple and powerful once you learn it. But each Iris Couch users have entire CouchDB servers. If you sign up, you have an account at Iris Couch, but you have an entire CouchDB server to use. Inside that server, you can create multiple users for your own applications.