Subgraph access control - neo4j

In the official Documentation (3.1: http://neo4j.com/docs/operations-manual/current/security/authentication-authorization/subgraph-access-control/)
It is said
"For example, a user can be allowed to read, but not write, nodes labelled with Employee and relationships of type REPORTS_TO"
But nowhere it's written in this page and others how to do it.
With the "call dbms.procedures()" we can see many more function in the enterprise edition but nothing about defining this Subgraph control
We think on changing the an enterprise edition, but if we are sure to be able to do that.
Can anyone explain me or gives me the address of the relevant documentation
Thanks

The documentation is all right there. Note the first sentence:
Through the use of user-defined procedures and custom roles, an
administrator may restrict a user’s access and subsequent actions to
specified portions of the graph.
The approach seems to be, for users without write permission, create roles for them as appropriate, then create (or use existing) user-defined procedures to do what operations they are allowed to do. Then configure the permissions of the procedures to the appropriate level, and associate the roles of the procedures (by modifying dbms.security.procedures.roles) with the roles you previously created. This allows the procedures you created to be executed by the roles you associated it with.
For example, given an HR user, who does not have write permissions, you could create a procedure to create or delete a :REPORTS_TO relationship between :Employee nodes. The procedure would need to be set to mode=WRITE since it needs write access. This would normally not be executable by this HR user, since they don't have write permissions.
But if you created a role, say 'hr', and added that role to this user, and set the procedure to be accessible by the hr role in dbms.security.procedures.roles, then the hr user could execute this procedure, and it would perform the necessary write operations.
In summary, Neo4j's subgraph access control isn't defined on the nodes or labels themselves, nor does it apply when executing write statements in Cypher. This access control is specific to user-defined procedures, and allows users with certain roles (where that role is associated with those procedures) to execute those procedures even if they normally would not be able to due to their access level.
EDIT
One final thing that could work for you...Neo4j has a means of registering transaction event handlers that can perform checking and logic on a transaction in progress, and reject if some criteria are not met. I would assume you could get a user's roles here, and probably check the transaction for writer operations on certain labels. Odd that this wasn't referenced in the securing the subgraph section of the documentation. I haven't tried this approach myself (I'll try my own testing later) so I'm not sure if it will fulfill what you need, but it's worth a look.
UPDATE:
It's been awhile, but we do have a more comprehensive means of access control coming to the upcoming Neo4j 4.0.
4.0 will include schema-based security, full ability to define, per user and role, the ability to grant or deny various levels of permissions (read, write, traverse, and more) for nodes and relationships of specific types. So for example you can have various roles that only have visibility on certain kinds of nodes, or are specifically denied visibility on others. You can also restrict whether certain nodes can be traversed through at all.
This should fulfill the needs of everyone who has been waiting for a more comprehensive security and access solution in Neo4j.
Here's the Neo4j 4.0 MR2 documentation, more to come as we approach the official 4.0 release!

Related

Can neo4j 3.* enterprise edition can control user data's access permission?

I'm using neo4j enterprise edition, and I found neo4j have no user data access control strategy, such as on user can grant some data's read/write permission to other user?
I found this: https://neo4j.com/docs/operations-manual/3.4-preview/security/authentication-authorization/subgraph-access-control/
The title is "Subgraph access control" but the content is control procedure's execution permission. It look likes have no relation with subgraph's access control...
I also found some people said that writing code to implement interface SecurityRole can resolve the problem, I can't found more information about this, is this right?
Thanks!
Subgraph access control is about restricting a user's ability to access the graph so that they can only go through the procedures granted to them. The code in the procedures should encapsulate the kind of queries you want them to be able to use, so either the procedures contain the queries in full, or it allows queries but performs filtering at some level.
While this can work, it may not have the right granularity for what you're trying to do, and it is a somewhat clunky approach.
Additional work is being done to fill in those gaps.
In the upcoming Neo4j 3.4, you will have the ability to restrict access to properties of nodes, though this is across all nodes, not just nodes of certain labels, and it will rely on a blacklist that is defined in the neo4j.conf file, so (at this point) requiring a restart to change which roles are blacklisted from accessing certain properties (though you should be able to grant roles to users through procs as usual, no restart needed).
There's more work to be done on this of course, it's just a matter of feature prioritization, so richer options are likely to be introduced in later releases.

Neo4J Multi Tenancy and Role Based Access to Nodes

I am trying to define a user management and permissions model for Neo4j. I have a web application (Angular 2) that connects to Neo4j via an API (KOANEO4J). Neo4j is the only database or persistent storage that the application uses. Through the application a user can add/edit/delete content which uses the API to carry out these instructions in Neo4j by running Cypher Statements. Up to now I have not worried about supporting multiple users but as a next step I am starting to think about this.
The product will be used by multiple different companies and each company will have multiple users so I need some way to support this. The model I am considering in Neo4J is as follows:
An "Orgaization" is represented by a node and it can have 1 or more "Organization Catalogs". All of the nodes belonging to that catalog will be children of one of the "Organization Catalogs".
Each user will also be represented by a node in the database. They will belong to an Organisation. They will have certain access permissions on an Organization Catalog identified by a an edge.
I am looking for some advice on whether or not this is an appropriate model to follow or if there are any examples or documents that describe how to achieve this in Neo4j.
If I do implement this model then would it be better to model the permissions as seperate nodes so a user is connected to a permission node (e.g. Read Only Access) that is then connected to the Organization Catalog.
Any suggestions on how I would actually get the API to work with this type of model. I'm sure I can pass the User Id to Neo4j as part of each query and then filter the results to show only nodes the user has access to but this doesn't seem like a very elegant solution - it also means that all of the security would be dependant on carefully written Cypher queries that don't leak data that a user isnt supposed to access.
Thanks a lot
I am looking for some advice on whether or not this is an appropriate
model to follow or if there are any examples or documents that
describe how to achieve this in Neo4j.
The answer for this question is: it depends. Remember that when modelling a graph database you should consider the queries that are asked to the database. If this model fits the queries that you are asking to the database then this model is appropriated, otherwise, not. Take a look in the Chapter 5 (Graphs in the Real World) of the book Graph Databases (by Ian Robison, Jim Webber and Emil Eifrem. Available for download here). This chapter shows the modelling process of an Authorization and Access Control system in Neo4j. Can be enlightening and helpful to you.
If I do implement this model then would it be better to model the
permissions as seperate nodes so a user is connected to a permission
node (e.g. Read Only Access) that is then connected to the
Organization Catalog.
Again, it depends. Do it if the Permission entity has connection to others entities of your application besides an User and an Organization Catalog. Otherwise I believe that your permission can be modeled as a relationship between an user and an organization catalog.
Any suggestions on how I would actually get the API to work with this
type of model. I'm sure I can pass the User Id to Neo4j as part of
each query and then filter the results to show only nodes the user has
access to but this doesn't seem like a very elegant solution - it also
means that all of the security would be dependant on carefully written
Cypher queries that don't leak data that a user isnt supposed to
access.
Maybe is a good idea add another layer of software between your AngularJS client app and the Neo4j database. This way in this new layer of software (a Node.js application, for example) you can implement a access control system, then verifiy if the authenticated user can access the resource that is being requested.

What are the permissions required in desire2learn (D2L) Valence PUT call for .../courses?

I continue to get a "HTTP/1.1 403 Forbidden" response from a PUT request to /d2l/api/lp/1.2/courses/7917 . This may be a permission problem with the user/role that I'm using, but I can't figure out what specific permissions may be required. Can anyone point me to a list or matrix of valence routes and required permissions? Or, answer for this specific one?
The same appid/userid/username works for the GETs associated with the same path.
confused...
cwt
The permissions associated with API calls should mirror the permissions you'd have to have if you were to perform the relevant function through the Learning Envrionment's web UI. You can think about this problem in two ways:
Frame the question in terms of a user role: identify the class of users you'd reserve this ability for in your existing configuration, and ensure that a user of that role can make the call through the API as you'd expect.
Frame the question in terms of an abstract single user: start with a role that has no privileges and add permissions until you arrive at only the ones required for the API call. This is not a trivial exercise, and the first way is far more useful in the long run.
In this particular case, because the API requires you provide a complete course offering set of properties when you want to update it, you have to have permission to alter all the properties in the set (under the Manage Courses tool). You also need to be able to see the course info in the first place, so you need to have Course Management Console > See Course Info as well.
You're probably safest to look at the permissions array in the Manage Courses and Course Management Console tools for the user roles that would do this thing in the web UI and make sure that the users employing your app also have a similar permissions array specified in those tools.

No result returned using Valence API desire2learn

I'm working on migrating from SOAP to valence API. I'm having some problems with a few calls like getting users (All users, based on role, by userID, etc) and grades (All variations).
I see an empty list returned with no items. There's no error of any kind. When I try to get the data using SOAP, I get the desired data.
I've checked the permissions for "Search for Students", so technically, I should be getting something when I try to get all users or by role id of students. What else am I missing here...
The D2LWS service's authentication mechanism puts the API caller in the position of being a privileged caller. The Valence Learning Framework APIs use a different auth model: the user ID/Key tokens that identify a user get employed by the back-end to restrict the functionality of calls. That is: the authenticated user should have access to the same functionality and data as the user would get through the web UI, and no more.
In this particular case, the calls succeed: they send back all the elements in the result set that your calling user has privileges to see -- none of them.
This is almost certainly an issue with the role privileges afforded to your calling user, and debugging the permissions around calls can be challenging. The Valence project's documentation provides a walkthrough topic on investigating role permissions that might shed let on a possible approach here, especially with respect to the calls to gain access to user records (or properties that appear in user records).
As the walkthrough discusses, there are various aspects to making the general call to /d2l/api/lp/{version}/users/ that bring permissions into play:
If you're trying to filter with a query parameter, does the calling user context have permissions to use the data on which you want to filter
Does the calling user context have permission to see properties affected by User Information Privacy settings
Does the calling user have permission to search for all the user roles they need to, in order find users in the result set
The users call operates on the root organization unit, so the permissions the calling user requires must be set on the organization org unit type.
By contrast, the Grades-related API calls operate not on the root organization unit, but typically on course offerings, sections, or groups. The permissions surrounding the calls there will get checked in the associated org unit types, so the calling user will need the right permissions against those types. Additionally, many of the calls related to course offerings (also sections and groups) require that the calling user be enrolled in the org unit in question (and in some cases, explicitly enrolled, not merely enrolled by cascading enrollment).
If you're sure that your calling user context does give you access to these things (and allows you access to this data through the web UI), and you still see a mismatch like this when you're calling through the API, then you may have uncovered a defect of some kind and you should please ask your organization's support contact, or your account manager, to open a support ticket to report that through Desire2Learn's support desk.

Rights for running system procedures?

Can a non-adssys user run the system procedures?
I am developing a BizTalk WCF Adapter for Advantage that can be used and I need to browse and resolve the metadata. This is an add-in for Visual Studio, supporting .Net 2.0 or higher, that generates schemas and a binding file (wsdl). It can also generate classes that can be used in a WCF Service.
Our database has over 1000 tables, 50 views, and 50 procedures. We want to assign objects to a User ID and just return the objects belonging to the user.
Thanks,
Howard
Yes, non-adssys user can run the system procedures and use select to retrieve information from the system tables. Advantage uses a permission, and user/role based system to determine the user's access to the objects in the database. The user's permission will determine whether the procedure can be executed successfully or how much information are returned from the system tables.
This link provides the comprehensive information on the permission system in the Advantage data dictionary.
With regards to tables and views, to see the name of a table or view, the user must have at least the SELECT permission on the table a view. To modify table property such as constraint and index of a table the user must have ALTER permission to the table. For users who do not have ALTER permission to the table, those constrain objects and index objects are hidden from the them.
For stored procedures, the user must have EXECUTE permission on the procedure in order to see the name of the procedure.
The favored method for managing the permissions is to assign users to groups (roles), and grant permissions to the groups. User belonging to a group will inherit the permission from the group.
Conceptually, you might want to look at storing/retrieving the metadata from a descriptive table, then using THAT result to return your objects. You have a single point of access for all users using the ability to filter by SQL clause. Once you have the object data you can use a higher level permissioned "user" to return the objects without actually giving access to individual users. Just an idea.

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