I am a former Lotus Notes/Domino developer, learning the Microsoft stack. I am building a web application with a SQL server back end. I want to build a basic CRUD application where users register, then login. They should be able to work with data they created or that has been shared with them. I am unsure how to achieve that result.
One of the cool features of the Domino database was the ability to add reader and or author fields to each record with user IDs, or roles and the server would automatically filter out those records when a user accesses the database. So if the user opened a View or Queried the database, the server would never let them see records they were not assigned access to.
Does SQL server have similar functionality? I've seen some information on row-level security, is that the best way to secure data? If not, what is the best practice to secure data so users can only see their data?
Thanks for any help you can offer.
Yes. SQL server has Row Level Security:
Row-Level Security enables you to use group membership or execution
context to control access to rows in a database table.
Row-Level Security (RLS) simplifies the design and coding of security
in your application. RLS helps you implement restrictions on data row
access. For example, you can ensure that workers access only those
data rows that are pertinent to their department. Another example is
to restrict customers' data access to only the data relevant to their
company.
The access restriction logic is located in the database tier rather
than away from the data in another application tier. The database
system applies the access restrictions every time that data access is
attempted from any tier. This makes your security system more reliable
and robust by reducing the surface area of your security system.
But it's more common to embed the authorization logic in a server-side application like a web server or web API. Row-Level Security is more common where users connect directly to the database, like in reporting and analytics, and client/server desktop applications.
Related
I am working on a JavaEE project with WildFly, Hibernate (JPA), C3P0 and a MS SQL Server database.
The database is a legacy database with more than a thousand Database Objects like Stored Procedures, Functions, Views, Triggers and so on. All these database Objects have fine grained Permissions set on User Role level.
Now I need to access this database with a JavaEE Web Application. My Problem is, that the usual JPA configuration let me set only one Username/Password for the Database in the configuration file. I can not find any way to configure the JPA layer so that will access the DB with the Enduser's Login.
I ended up to create one EntityManagerFactory per User by calling
EntityManagerFactory entityManagerFactory =
Persistence.createEntityManagerFactory(properties_with_credentials_here)
once per user.
The problem with this approach is, that this will basically instantiate the whole JPA layer per User and eat up way too much memory. I am not using any sort of Cache layer, of course. The memory is used just for the Entities meta information (which is a lot).
Now my original question: Is there any 'standard' way in JavaEE (JPA) to access the database layer with the Enduser's Login and Password?
I can not believe that I am the first person to encounter this situation. It seems to me, that 'impersonation' is quite normal in .net Web Applications. So there must be way to do this in Java, i guess.
Any comments or hints or new approaches are highly welcome.
The 'standard' way in JavaEE is to have an application user for accessing the database and achieve user-based access-rights through roles in your application.
If you need to rely on existing database user, your only chance is to establish a connection per user or per request. The entity manager would then indeed consume some memory as it's designed to be your application's persistence context (and thus some sort of cache).
Maybe you can have some trade-off here by accessing those parts which really have to be user-based by plain JDBC and potential execution of database procedures and others by some application user with extended rights which ensures the necessary user restrictions programmatically.
I have to use ASP.NET MVC 3 or above and SQL Server 2008. As per Multi-Tenant Data Architecture post, there are 3 ways to implement multi-tenancy
Separate Databases
Shared Database, Separate Schemas
Shared Database, Shared Schema
I have following details:
User should be able to backup and restore their data.
No of tenants : 1000 (approx)
Each tenant might belong to different domain(url).
It must support monitoring and management of tenants.
It must support user authentication and authorization for each tenant
It must support tenant customization(enable disable features set)
No of tables in each tenant: 100 (initial)
I would like to know what your experience says about which approach is more suitable for the project considering Economic and Security? Is there any good real time example(open source project) similar to this? I can use one dedicated server for the project.
Your requirement that users should be able to backup its data, can be achivable more easily with approachs 1 and 2... since it will be a native database task.
If you are in approach 3 (shared-shared), you will need to develop the logic to extract all the rows belonging to a single tenant and export it in a xml file or something like that. Then if you need to allow users to restore that backup file, you need to develop a restore logic.
I think this is the only requirement that could make you move away from #3.
Once you set your database using TenantID columns in your table... you can easily use one database for 1 tenant or a small group of tenants if your client is heavily concerned about security. For instance, you could have one database holding tenants that are not paying (free/demo accounts) and paying customers in another one. This way you are using approach #3, but being able to behave as #1 if you need it.
::: BONUS :::
AUTHENTICATION:
You will need to extend the SQL Membership and Role Providers used in your MVC3 app... so that a user login is valid only in the Tenant it belongs to.
MULTIPLE DOMAINS
Here you can see some approaches using ASP.NET MVC3 Routing:
MVC 3 Subdomain Routing
I would always use (3) Shared Database, Shared Schema.
If you want an example, how about Wordpress, Joomla, or any other popular open source web-based project?
Creating separate schemas or databases on a per-tenant basis will lead to massive management overhead. Not to mention increased complexity of analysing your data, costs, etc.
The only reason you'd go for (1) (or perhaps 2) is if you were to give your actual tenant direct access to some/all of the database. As you're using ASP.NET MVC 3, this isn't a consideration.
I have a rich client program installed on users PCs where I want to start storing some user created data on SQL Azure/SQL Server. The potential anonymous-to-me users would key in their name, email account and a password which would get stored on SQL Azure/SQL Server. Then they would start generating their own data. I'm anticipating volumes of maybe 1000 users.
There are times when those users would like to run their own queries against their own data but, obviously, I must ensure that they can never view other users data.
I'm thinking the best way to ensure security of data is for each user to be issued their own SQL Azure account and password. I will setup a SQL Azure user and long password, known only to me, which only has permissions to execute several stored procedures with appropriate parameters being passed to those SPs which will create the SQL Server accounts, logins and add the users to a role which I have created.
Obviously someone running debugging tools could figure out the user name and password but I'm thinking this isn't a big deal. If all that particular SQL Azure account can do is execute a few SPs so what if a malicious individual starts doing that. I will only allow a very limited amount of data to be uploaded before I require payment.
The users can only insert records using stored procedures which use the following:
SELECT #uName=SYSTEM_USER
and only select appropriate parent records. All stored procedures which users can execute would have the above as required to ensure they can only work with their own records.
All views will have embedded with them WHERE clauses such as
WHERE tbLoginName = SYSTEM_USER.
I'm new to SQL Server so I may be missing some fundamental concepts so I'd appreciate any and all comments.
The issue is, as pointed out on http://msdn.microsoft.com/en-us/library/ms189751.aspx:
In SQL Azure, only the server-level principal login (created by the provisioning process) or members of the loginmanager database role in the master database can create new logins.
Those accounts are also capable of alter and drop logins. So if you embed those accounts in the client application, you’re essentially granting every user permission to alter/drop other users accounts. While an average user won’t do that, a hacker will. So you cannot let a client application manage SQL Azure logins, unless only trusted users (such as your IT administrator) are permitted to use the app.
Best Regards,
Ming Xu.
I would like to point out a potential issue in the approach you mentioned: Your master SQL Azure account need to have privilege to create new accounts and grant them access to particular tables. This means your master account itself need to also have access to all those tables. If you store the master account on the client side, a clever user will get access to all users data.
From my experience, connecting to a database directly from a client side application will almost always make your solution less secure. You can do that for testing purposes, but in a real world solution, I would like to suggest you to use a service. You can host the service in Windows Azure. Then the service will access the database, and client application can only access the service. In this way, you can authenticate clients using any mechanisms you like, such as ASP.NET membership.
Best Regards,
Ming Xu.
You are essentially creating a physical two-tier database connection, allowing a client application to connect directly to the database. This is a problem in many ways, including security and performance. From a security standpoint, not controlling from where your customers will connect, you will need to keep your firewall rule wide open for anyone in the world to try to hack every customer uid/pwd. And instead of having only 1 user id to play with, hackers will have up to 1,000...
The second issue is performance. You applications will be unable to leverage connection pooling, creating undue stress on your database server and possibly hitting throttling issues at some point. Using a web service, with ASP.NET membership to manage logins, and using a service account (i.e. the same uid/pwd) to get data will ensure you will leverage connection pooling correctly if you keep the connection string the same for all your requests.
With a web service layer you also have a whole slew of new options at your fingertips that a two-tier architecture can't offer. This includes centralizing your business and data access logic, adding caching for improved performance, adding auditing in a centralized location, allowing to make updates to parts of your applications without redeploying anything at your customer locations and so much more...
In the cloud, you are much better off leveraging web services.
My 2 cents.
We have some corporate intranet users using a WinForms app to work on a system with SQL server behind. Integrated Security is setup, allowing all users update and delete permissions, where application security limits how and where table updates take place.
However, some users are power users with SQL query tools at their disposal, and access the DB directly for building reports. However, with integrated security, they have default update rights on tables where they should not have, as the application apply rules to the updates.
Is this an example of where it's more appropriate providing the app with a central SQL authenticated login, whilst users get read only rights for integrated security?
As Jon mentioned stored procedures would give you the protection over direct table modifications. There are other options too. You can use SQL Server's "Application Role" (via sp_setapprole proc). This enables you to continue to use a separate ID for everyone but only at application connection time (through the front-end) are the user's rights elevated.
A major downside to using a shared ID is you lose track of who is submitting SQL to the server though if they're all internal you can get to the machine name.
Something else is concerning though. It sounds as if your users can connect to the database and run queries at will. You run a major risk of downtime in the application due to user behavior in the directly connected SQL sessions. If you can pull it off you may want to try to have a reporting database created that is updated at intervals that your business can tolerate, i.e., daily. HTH
I presume from the way that you've worded your question that your app executes sql statements directly. If you could refactor it so that it executes stored procedures, you could grant exec rights on the procedures and deny direct updating of the tables. This might not be possible though, depending on what your app does.
sql authentication is one option. Stored procedures are another. However, building more granular roles for assigning just the appropriate permissions to just the appropriate user types is where you should really be looking.
Additionally, I would really avoid giving these users direct access to the DB at all. Security reasons aside, it doesn't take much for a user who isn't proficient in SQL to accidentally execute a query that will swamp your database server and create an effective denial of service. Even pros can do this accidentally from time to time.
Instead, give them access to a reporting services or analysis services type solution, or use replication to give them access to a clone of the data. This way your production system is protected.
Personally I would do all application data access through stored procedures. I would set Integrated security to only allow users to run the SP's and not manipulate the data directly.
Advanced access can be given to DB admins to manipulate the data directly when needed.
Group based permissions will provide you with much more flexibility for access rights, and less administrative burden when controlling these with integrated security.
What is the best option for a windows application that uses SQL server authentication? Should I create a single SQL account and manage the users inside the application (using a users table). Or should I create a SQL server account for each user. What is your experience? Thank you!
Depends on whether the username/password for the SQL server would be exposed to the user, and whether that would be a problem. Generally for internal apps (in smaller organisations), one would trust the users not too log in directly to the sql server. If you have a middleware layer (ie webservices) the password can be hidden from user.
I prefer to use a general login for the DB and manage users in the application. Even if you do create a login to sql for each application user, they could still connect directly, so why not just use a generic sql login that is easier to manage. This is of course assuming all users have the same accesses.
One good practice, if the users potentially can get direct access to the db, would be to grant access only through Stored Procedures and not directly to tables, so that only certain actions can be performed. Steer away from writing business logic or security checks (except basic ones) within the stored procs.
One way I would solve your problem is to write some webservices that check security and does your CRUD (via datasets, etc), but again it depends on the app and environment.
In summary if you have a middle layer or all users have the same access manage the user within the application and use a single user login. Otherwise use a login per user or role.
One option that I have used in the past is to use the ASP.NET Membership Provider. It makes authentication a breeze to use. The only drawback that I saw was that it added a bunch of tables to your database.
The code for using it is very straight-forward.
Here's a blog post about using this in a Windows app. http://msmvps.com/blogs/theproblemsolver/archive/2006/01/12/80905.aspx Here's another article with more details. http://www.c-sharpcorner.com/UploadFile/jmcfet/Provider-basedASP.NET10162006104542AM/Provider-basedASP.NET.aspx
Here's another article that talks about using it with Windows applications: http://www.theproblemsolver.nl/usingthemembershipproviderinwinforms.htm
Google for "ASP.NET 2.0 Membership Provider", and you will get plenty of hits.
What about having SQL accounts based on the level of permissions needed for the task. For example you could have a read only account just used for reporting if your system has a lot of reporting. You would also need an account what has write access for people to change their passwords and other user admin tasks.
If you have situations where certain users are only going to have access to certain data I would have separate accounts for that data. The problem with using 1 account is you are saying that there is no SQL injection anywhere in your application. That is something everyone would strive for but sometimes perfect security is not possible, hence the multi-pronged approach.