How to Obtain Domain User Name when connecting via SQL Authentication - tsql

I have an application which connects to SQL Server 2000 (using a generic SQL Login and SQL Authentication). I would like to implement some logging via triggers to track data changes. I can't use USER_NAME() because that returns the generic account.
I've poked through master..sysprocesses and it doesn't seem to record the username (although it does record the machine name).
Any ideas how, within SQL, to gain access to the username?
(Note: yes, I could pass it in as a variable via the application ... but that would mean I'd have to roll out a new version of the app; I'm trying to do this from within SQL, so I can avoid that, if possible.)

You can't. Simple. SQL Server has no knowledge of the end user with a SQL login at all
The same applies if you use a proxy (web server etc) too: you don't know the end user. We use parameters/stored procs to pass in the username from the web server.
I would suggest that you set CONTEXT_INFO in the client which persists for that connection.

Have you tried SYSTEM_USER?
SELECT SYSTEM_USER

Related

How to setup row level access in Postgres without creating a user

I have an existing API connected to an AWS PostgreSQL database that uses AWS Cognito for User authentication.
The goal is for users to insert data via the API with some field mapped to their Cognito id, and retrieve the same data. The idea would be for each user to only have access to the data 'owned' by them. Similarly to the way row level access works.
But I do not want to create a role for each user which seems to be necessary.
The idea would be that I need to somehow setup a connection to the PostgreSQL DB with the user_id without creating a user and handle the accessible data via a policy, or somehow pass the data to the policy directly.
What would be an ideal way to do this, or is creating a PG user for each user a necessity for this setup?
Thanks in advance
EDIT: I am currently querying the database through my backend with custom code. But I would rather have a system where instead of writing the code myself, the PostgreSQL system handles the security itself using policies(or something similar). I fully understand how PostgreSQL row-level-access works with roles and policies and I would prefer a system where PostgreSQL does the major work without me implementing custom back-end logic and preferably not creating thousands of PostgreSQL roles for the users.
You should not allow users to make a direct connection to the database.
Instead, they should make requests to your back-end, where you have business logic that determines what each user is permitted to access. Your back-end then makes the appropriate calls to the database and returns the response to the user.
This is a much 'safer' response because it prevents users having direct access to your database and it is also a better architecture because it allows you to swap-out the database engine for another one without impacting your service.
The database is for your application, not for your users.

MeteorJS Removing insecure Security Flaw?

i know this is a question that has been asked many time. but im still concerned about best practice when trying to develop secure code in meteor.
i know you can prevent the client from being able to access the database with the command:
meteor remove insecure
my code currently adds, retrieves records by using Meteor.methods() so although the client is not able to insert data into a collection, it can use the Meteor.method() function. im concerned about holding the login details in the database because would this not mean that the client can use the Meteor.method() function to add/get/remove data from the database.
the client being able to call the Meteor.methods() function seems to still keep the same risk doesn't it? or have i coded me work wrong?
if it help, here is a run down of what my work is doing:
application loads
client calls to get username and password from database
client sends login details to external server (over https) to initiate socket.io connection.
step 2 is the risk because it seems to allow the client to get the login details. once it has this, it uses the socket.io.js library and the api to my webservice to login. so meteor remove insecure doesnt seem to have secured it because get methods are still available in the Meteor.methods()?
being able to use these functions are quite crucial to retrieving data from the database, is there a way around this? what would be best practice for communicating to the database without exposing private data to the client?
Meteor's insecure package is just a tool provided by MDG to quickly prototype apps. It is not meant to be runned in a production app and some people think is a best practise to remove it all together from the start.
After you remove this package, if you want to interact with the database on the client using mini-mongo you must create the appropiate allow and deny rules on the collection. Here is the link for the Meteor documentation on this topic. The other way to interact with the database, is as you said, using Meteor.methods().
Meteor methods calls don't trigger allow or deny rules, since they are runned on the server. You must hardwire all the security measures you need on the Meteor Call by yourself. So it can be a security problem if you don't take the time to secure the call.
Regarding authenticating your clients I would suggest you take a look at Meteor's Accounts package. For example you can add this two packages for basic username/password authentication:
meteor add accounts-base accounts-passwords
Then you can just use the methods detailed on the Meteor Documentation.
I hope this helps.
Login
If you are using accounts-password, you can check the source here to see details of how it works. But here's a rough overview of it. When you call Meteor.loginWithPassword, the password is hashed client-side. Then a method is called with the parameters. The password is then salted and checked against the database server-side. If it matches, the client gets logged in. The client then subscribes to their own user data (Meteor.user()). The server only publishes their data. So everyone else's data is save.
Methods
A method executes code server-side. So they are generally secure. But you can of course write insecure methods. Just know, that you can't trust the parameters passed by the user.

Service with one login credential

I am developing a Rest service with Web API. The service only requires one login credential as it is used by an application developed by a third party. If I use the project template with "Individual User Accounts", I have to have a SQL server running(?), which is an overkill to support a single username and password. How about the LocalDB comes with VS 2013 ?
"Windows Authentication" cannot be used because the service is accessed from the Internet.
What is the proper way to authenticate ?. Are there any "in memory" or config file providers that come with Web API ? I know there is Asp.net Identity package, but It uses entity framework as a provider. Can anyone please suggest ?
You can create a custom store for ASP.NET Identity and it could be memory or a config file. Here is a tutorial on creating a custom store in ASP.NET Identity. I would not put it in memory because you will most likely want to change the password and that would require a recompile and redeploy. Personally I would just use SQL Express or SQL Compact as they take minimal resources and rewriting the data store seems like a lot of work for little benefit in this scenario.
No matter how do you want to authorize the call, the users has to be present in a database or cache to check the validity of the provided user. Microsoft will offer you out of the box a solution based on SQL server or some of their own products.
If you want to implement you own user check, you will probably have to take care of the authentication by yourself. This means that you will have to check the HTTP header by yourself and reject or accept the request by yourself.
My question is, why do you want to use some "in memory" provider? The users has to be somewhere. Why not a SQL express?

How can I create an XMPP account?

I have a web application using XMPP for chatting. The only real problem is that users have to create their own XMPP account on the right server. I'd like to automate this process.
How do I automatically create a new XMPP account for a new user ? How do I know what address can be used or not for the account ?
There are a few different approaches:
Have the client register in-band. They can then choose their username themselves.
Connect to an existing user database, or interface with it directly.
The server might have some CLI or Web-based management tool that can be used.
As ggozad wrote, use the Add user command defined by Service Administration.
You need to implement (and your server to support) XEP-0133 Service Administration and in particular the add user command. You can create random user ids or generate them with some logic and store them somehow to check for uniqueness. The get-registered-users command might also be of help.

How to keep the username and password in WCF Rest Service

I am working on the WCF REST Service project. The WCF REST will be set on the IIS. The service is to update the database in SQL server. The updated store procedure will get the login username and look for the id on the user table as a parameter. Therefore, the connection to SQL server must use the client’s username and password; I am not able to modify anything on SQL. The client may use website or Cell Phone to consume this Service. I shouldn’t ask the user for providing their username and password on every request in the same season. Does anyone give me an idea or example or link how to deal with this issue?
Thanks.
It sounds like you need some authentication mechanism between the client and the server. How to best accomplish this will depend on the client technology. If you use ASP.NET you could consider one of the ASP.NET authentication mechanisms (e.g. forms authentication). Please check out something like: http://msdn.microsoft.com/en-us/library/eeyk640h.aspx. This handles session state in e.g. a cookie or by appending url info. An other and perhaps more cool solution is to use OpenAuth which makes it possible for users to authenticate with their existing e.g. google/twitter accounts or similar. Please check out http://www.dotnetopenauth.net/. I would not recommend writing your own authentication mechanism, but encourage you to use one of the existing frameworks.
You could save the information in session state.
Here is some info on using session state http://msdn.microsoft.com/en-us/library/ms972429.aspx
Or you could store it in the cookie http://msdn.microsoft.com/en-us/library/ms178194.aspx