I work on a vb.net winforms app where we currently are using simple roles for security. We enable/disable specific controls based on if the current user has the required role. We are to the point where this is no longer granular enough.
Our application is based on different physical locations we call sites. A user might have permission to do something (for example, edit a site's configuration) at one site but not another. Therefore, we now need to lookup permissions based on current user AND current site. Also, a certain user's permissions may be very specific to themselves ie. no other user's permissions are exactly the same as another user's. Therefore we need a security model that's more permissions based rather than role based.
What's the best way to design a new permissions model that can meet these requirements? I want to make sure that it's easy to implement the checking in the code (I don't want a million if statements sprinkled in our SetUIPermissions methods) and we don't want to have to update every user (400+ and counting) each time we add a new permission. Because of this last requirement I think we need to keep the idea of roles but possibly add/remove exceptions for particular permissions for specific users.
Any ideas?
You're on the right track with the roles and permissions. It's a relatively common solution to have a role refer to a set of "default" permissions; by having a user have a role and a set of permissions, you allow for the role to be overridden by the set of permissions specifically granted / revoked for that user. This gives reasonable flexibility and granularity, and supports your situation of adding new permissions (in the role) without needing to touch every user.
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I have developed a pretty standard and common authorization permission system for an internal business web application.
There are some roles with permission sets; system administrator can create new roles and assign permissions to them; every web controller method has an attribute to check for specific permission. So far so good.
But then I have the following conversation with the customer:
Customer: "Please, make it possible to hide specific form fields in specific forms for a specific role".
I: "Ok, so the users of this role shouldn't have permissions to modify these fields, right? I can also add a permission check to the method that saves the data."
Customer: "No, no, it's not a permission issue as such, it's just about convenience - this role doesn't need to work with these fields and we want to make the UI less cluttered. The users of this role shouldn't see these fields in this form only; however, there are other forms where it's totally OK to see these fields. Of course, we might later create new roles that will need to see these fields in this form, but by default the fields should be hidden."
And so the permission system gets cluttered with "pseudo-permissions", such as "See field X in form Y". They exist for UI convenience purposes only and have nothing to do with authorization for performing activities on data.
Is it a good practice to control UI through roles & permissions, even when the specific permission has nothing to do with data processing authorization? Is there a clean solution to avoid cluttering the permission system implementation with such UI-only pseudo-permissions and still provide the customer with granular control to achieve cleaner UI for specific roles?
I am working with a lot of MODX since 2010. From time to time i coudl need another user group with restricted permissions. Like "Can edit content, but not change settings". So the user can't break anything which is relevant for die CMS itself.
I added users, placed them into roles and groups, but somehow it never works the way I expect it to work. A role is not a "role" but a level of authority. A group is just a link to a set of permissions, which is already setup as a ruleset. Still, if I create and setup the group "content editor", I never get it running as expected.
Is there a guide (or even an extra?) to setup restricted user account without breaking ones brain?
There's a basic tutorial available in the official documentation: https://docs.modx.com/revolution/2.x/administering-your-site/security/security-tutorials/giving-a-user-manager-access
My personal recommendation would be to ignore roles altogether. Whenever you need to enter a role (when adding a policy to a user group, or when adding a user group to a user) just pick "Super User - 0". They're an added complexity to allow, essentially, different permissions within the same user group, that 99% of the people don't need.
The primary thing to do is to create a policy, based on the "Administrator" policy set, that contains the permissions you want the user to have in the manager. Those would include the relevant resource/document permissions, but not settings, for example.
Then you add that policy to the user group of your choice as a "mgr" context policy.
The usergroup will also need context permission to be able of interacting with specific contexts. So on the contexts tab in permissions, add the different contexts you want, with the contexts policy.
As #optimuscrime commented, ACLs can be a little complicated, but that's the general approach.
Currently I'm building a web app. So far I only have regular users. However, due to some requirements I need to have special admin accounts for the app administrators. I'm wondering now how these are usually implemented. The requirement is, that they use the same login mask as regular users and behave the same except for the additional capabilities. To differentiate I could put an admin flag into the users' profile or put the admins into a separate table in my DB. Maybe the the second option scales better for potential additional user groups. Also, how could these admins be signed up? I don't want to use predefined usernames I check against in the login handler. I know the question is rather general. I'm just looking for some directions.
Since you didn't give information about the platform(s) you are using, I can only give theoretical answer. While a simple "isadmin checkbox" will do the job for only separating normal users and admins, but if you will need another user type such as "power users" etc. you will keep adding new columns to your table, which is not ideal. Basically you can use a "Role Based" or a "Permission" based approach. In Role based, as the name implies, you assign each user a role and give access to specific resources depending on the role. In the "Permissions" approach you define for each user the permissions they have (resources to access, actions they can perform). Also you could combine these two approaches, where you assign each user his role and define permissions for each role.
I am trying to model some complex permission management system using apache shiro.
English not being my native tongue I am afraid I might be missing some of the subtleties of terms such as "Roles", "Permissions", "Rights" & "privileges".
For example lets say I want to create a system that manages resources such as printers located inside buildings.
A DB holds the information of which printer is located in what building.
Users of that system should be able to reset a printer or print to it.
Its clear to me that some users will be "Super Admins" and be able to reset and print to any printer ('printer:*:*')- I guess that we could say that those people have a "Super Admin Role".
But what if someone should be allowed to reset the printers in a specific building ('building:A:*') ? Is "Building Admin" a (prarametric) role? or is this just a permission on a specific building? How would you model this using apache Shiro?
n.b.
When tagging this Q I added the user-roles tag and it says:"A user role is a group of users that share the same privileges or permissions on a system. Use this tag for questions about how user roles work in a particular security framework, or questions about the implementation of user roles in your program."
Would I be correct to assume that based on this definition there is not such role as a "Building Admin" because being an Admin of Building A does not give you the same permissions as does being an Admin of building B?
and if so, what would be the correct terminology to describe a "Building admin"?
Have you considered using more than three tokens within the WildCardPermission format?
There is no limit to the number of tokens that can be used, so it is up to your imagination in terms of ways that this could be used in your application.
— WildCardPermission Javadoc
Instead of the domain:action:instance syntax commonly used in Apache Shiro examples and documentation, you could add another token to represent the building, e.g. printer:print,reset:*:buildingA.
The downside of this scheme is that whenever you are checking if an action is permitted on a particular printer, you'd now also have to specify the location, even though the token representing the printer instance might already uniquely identify that printer:
// let's say the role for buildingA-admin has permission of "printer:*:*:buildingA"
subject.isPermitted("printer:print:epson123:buildingA"); // returns true
subject.isPermitted("printer:print:epson123"); // returns false
Depending on your application domain, maybe a structure like buildingA:printer:print,reset:epson123 might even be more appropriate or useful.
To answer your other question regarding user roles, you'd be correct to assume that if you have both buildingA-admin and buildingB-admin roles, they are different user roles, if the permissions assigned to them are not the same.
You might conceive a general user role of Building Admin for permissions that all admins for the different buildings might have in common, to avoid duplicating those permissions across the different building-specific admin roles.
Does anyone have any tips as we develop an application that will require each user to be assigned a permission level. The permission level will determine what functionality is available to the user.
Any advice?
How would you (do you) employ such functionality in your application?
First you need to figure out what functionality you want to cover by your permission system, and in what detail:
Access to tables (List, CRUD)
Functions/Modules
Access on record level (=ACL)
Positive (grant) or Negative (revoke) semantics
What is the "admin" role allowed to do
If you want to restrict access to tables, you can easily set up an additional table containing all the table names, and grant select-list/select-record/insert/update/delete access to the roles/groups, as sketched by JV.
If you want to grant access to functions or modules, have a table of modules and grant execute to roles/groups.
Both functionality is equivalent to grants in SQL.
Access restriction on record level is much more complicated, as you need to model access rights on the status of a record (e.g. "public", "private", "released" in CMS apps), or have explicit permissions on each record.
If you want to implement a permission scheme equivalent to NTFS, you calculate the permission per record based on the group the user is assigned to, and have user-specific permissions that may override the group permissions, and revokes overriding grants.
My applications typically work on table+function / group level, which may be good enough, depending on your requirements.
This is the partial ER diagram for identity module in Turbogears, Python. It implements what you are looking forward to. Users are associated with groups and groups have associated permissions.
The two ways restricted feature availability can be implemented are:
(I prefer)In your controllers check the group to which the user belongs to and moderate your response to the View according to that. Thus View is just a renderer - no business logic.
The View gets the user details like groups and permissions and it decides what to display and what not to (MVC violated).
Read more about MVC (and Turbogears may be).
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It depends a lot of the language you use and the architecture of your application (web service ? client software ?).
For a server toy project, I though about assigning a minimum permission level to each command, and check it directly when a command network packet is received, triggering a permission error when the user hasn't a high enough level. I might not be suitable for another architecture.
It may be a bit of a dead end to pursue the concept of 'levels'. It may suit your current application, however a data model that consists of a mapping of roles to privileges is more general and suits most purposes.
Assign roles to users. A user may have more than one role, and their role(s) define the privileges they have. The concept is similar to groups, however 'role' is usually easily mapped directly to business logic (think of roles such as 'administrator', 'user', 'clerk', 'account manager', 'regional manager', etc). Privileges also map fairly directly to functions and data objects. You may also be able to map to implementations that use underlying platform access control (e.g. Java privileges).
In the controller code, you check (via their roles) that the user holds the required privilege to perform a function. It is also good practice to modify your views to hide functions that the user does not have the privileges to perform.
In your design you can visualise / document the access control system as a matrix (roles to privileges).