CouchDB read/write restrictions on _users database - couchdb

I would like to restrict the user permissions so that a normal user is only able to read/write its own user document.
I managed to set the write permissions such that a user can only edit their own document (via the validate_doc_update function in the design document).
Now I only have to limit a user from viewing the user list or other user documents. If I set the database read permissions to the '_admin' role, then the user will not be able to view their own document, which it's not what I intend.
Can this be done in a more general way? I.e. to set read permissions such that a user is able to read only some specific documents in the database?

Unfortunately, per-document read control is not possible.
However, if you use a list function you can perform a "post-query filter" that limits the results of a view query based on the current session user. (via the userCtx parameter)

In CouchDB creating a new database is cheap and it was designed to keep the data as close as possible to the user who needs it.
So the suggested approach is to have one database for each user.

Related

Setting PermissionModes in Azure CosmosDB

Hi I working on a simple application using Azure CosmosDB. Now I want to use resource tokens to provide specific access to documents and collection in the DB. In the permission modes there are PermissionMode.Read and PermisssionMode.All. So I am assuming that PermissionMode.All allows the users to read, write, delete and post. If what I am assuming is correct, I specifically do not want my users to delete or post in a certain collection. How do I achieve this?
For better understanding, my database contains a container called users, which contains user information along with their posts and likes per post and stuff. Now I allow all my users to read (view posts of other users) and write (give a like or increment the like field), but I want to allow Post and Delete to a document to only the user of the document.
The finest granularity for assigning permissions is a partition key value so the only way to grant per document permissions is if your document id is also the partition key. If your partition key is userId and the user profile and posts, etc. all share that same partition key then that should work for you. Here is a sample that creates a permission on a partition key for a user.

How do I manage authorization (not authentication) with node and a postgresql db?

This question is regarding authorization, not authentication which i will be managing with passportjs. How do i restrict access for data that's bound to specific users without spreading user_id's all over every table in the database?
Should i create a new database user for each new user of my app and restrict access that way? Or is the "user id in every table" approach actually a good way to go?
I'm working on a project right now where someone else wrote the authorization logic and it works using a kind of authorization path in the code so it can find which user a resource belongs to using some breadcrumb logic.
But I'm really at a loss here and I'm having a hard time finding any information regarding this since almost all articles that I find are about authentication rather than authorization. And I do not mean access to a resource, but rather the filtration of data returned from a resource that the user has access to.
If you want to restrict access of users to certain objects, you either have to store that information with the user or with the object.
The latter is the preferred way because it makes permissions disappear with the object. That's the way PostgreSQL does it – it stores an access control list (ACL) with every object.
So you can either use PostgreSQL to implement privileges (then every application user or at least every group with equal privileges has to have a database user, and you can use permissions on tables and columns and row level security), or you implement it in your application and have some sort of ACL with every row in the database.

How to only show documents to specific users in a shared database?

I'm managing a multiuser app using Ionic 3.x, PouchDB, CouchDB and a node.js server running Superlogin. The app is steadily growing and I want to introduce a new feature.
My app has normal users and superusers. Each normal and superuser in my application gets it's own user database. There is also a shared database, let's call it the generaldb.
And here's my problem: Both users can create documents. These documents are synced to the userdb as well as to the general db. These documents have, amongst other things, a keyword (e.g. "colour": "green"). Superusers have access to a specific key. (In the above example that would mean that there are for example 5 superusers who can access the key green.)
Now, no normal user should be able to read, update or write other user's documents on the generaldb. Superusers should be able to read, update or write documents in the generaldb depending on which key they have access to. But they should not be allowed to change documents that don't match their key.
How can I restrict access for normal users in the generaldb, so that only documents created by themselves are synced to their devices and so that they couldn't change other users documents?
How can I ensure, superusers can change normal users documents, as long as they have access to the correct key?
How can I ensure superusers cannot change their own key, so that when number 2 is accomplished, they cannot manually work around the system?
One of the ideas of mine is to only let the users access their own db and have the shared db only accessible by superusers and then do a filtered replication of the userdb to the shared db. But this only solves 1 and seems very inefficient.

CouchDB add user without predefined admin

I'm just want to create a standalone application with CouchDB back-end, but I don't know if I can add a new (ordinary) user without using admin credentials.
In the documentation I just got information about creating an admin user and existing user's permissions:
Only administrators may browse list of all documents (GET
/_users/_all_docs) Only administrators may listen to changes feed
(GET /_users/_changes)
Only administrators may execute design functions like views, shows and
others
There is a special design document _auth that cannot be modified
Every document except the design documents represent registered
CouchDB users and belong to them
Users may only access (GET /_users/org.couchdb.user:Jan) or modify
(PUT /_users/org.couchdb.user:Jan) documents that they own
Here is the relevant part of documentation.
Short answer:
YES, you can
Makes no sense in a registration if you have to use admin credentials to create your account. Anyway, here is an example:
https://serverfault.com/questions/742184/couchdb-user-creation-without-authentication-standard-behavior
In this topic also can be useful this articol:
http://www.staticshin.com/programming/easy-user-accounts-management-with-couchdb
One more tip:
Creating regular users in CouchDB

Place to store user settings in Sharepoint besides profiles

Is user profiles an appropriate place to store things like number of items per page in a custom grid user selected? (I you can store it in the view, but it won't be per user this way).
My first though was to store these settings in user profiles, but there are problems with access permissions for programmatically creating user profile properties boiling down to you either have to give every user 'Manager User Profiles' permission in SSP or you have to run the application pool under a domain user, not NETWORK SERVICE. Both scenarios are unrealistic for me, so I'm now looking for another way to store such 'per user' settings.
Thanks!
Edit: I'm now considering ASP.NET profile mechanism with an additional DB to store user properties.
Given that the information is not sensitive a simple database with values stored against AD login should suffice.
And as you have the ASP.Net user database already, storing the information there would be the best option.
Maybe a Global List, that is only accessible for the SHAREPOINT\SYSTEM User and that you can then Query in a SPSecurity.RunWithElevatedPrivileges Function.
Disadvantage: You require Custom code to read/write to that list.
Cookie?
Sure they have limitations, but it is fairly easy to create the control to run javascript to add/edit the value

Resources