Kerberos service authentication - kerberos

I have installed Kerberos on my Cloudera manager server and I want to control which components each user can use through Kerberos. Currently, once you create a principal for the user, he immediately can use every service/component.
So is it possible to control which services (Impala, hive, etc.) a user can use through Kerberos? Or not?

Related

authentication server microservice, should I use different services for different user functionalities

I have an authentication server using oauth2.
I use it for :
Authentication from the other services, subscription, change and retrieve password etc.
As resource server to store and retrieve more users and groups informations. I have a ManyToMany relationship between users and groups.
Should I seperate the second part of functionalities of this app on another standalone service that will work as resource server only. And only keep the authentication part on the authorization server?
That way I could horizontally scale these two services separately.
Yes, the better idea would be to have the configuration as a separate standalone service running on cloud. With configuration server as a separate service you can add all the authorization and other sort of details like DB details, API details, messaging queue configuration etc, and get connected to N number of services.

SSO using Kerberos on Windows and Linux

We have a client/server based application that is developed internally. Clients and server communicate over a TCP/IP connection with an application-specific protocol. The clients run on Windows and the server runs on Linux. All machines are in the same Active Directory/Kerberos domain/realm.
Currently, the user enters a username and password when they start the application. The server checks the username and password (authentication). Based on the username, the server also determines access to resources (authorization).
We want to add Single Sign-On (SSO) capabilities to the application. That is, we do not want the user to enter a username and password but we want to automatically logon as the current Windows user.
Of course, determining the current Windows user has to be done securely.
I have come up with the following setup:
I use SSPI (Negotiate) on Windows and GSSAPI on Linux.
When the client connects to the server, it uses AcquireCredentialsHandle (Negotiate) to get the credentials of the current Windows user.
The client uses InitializeSecurityContext (Negotiate) to generate a token based on these credentials.
The client sends the token to the server.
The server uses gss_acquire_cred() to get the credentials of the service. These are stored in a .keytab file.
The server receives the token from the client.
The server uses gss_accept_sec_context() to process the token. This call also returns the "source name", that is the current Windows user of the client.
The server uses the "source name" as the username: the server performs no additional authentication. The server still performs authorization.
This works but I do have some questions:
Is this secure? It should not be possible for the client to specify any other username than the Windows user of the client process. If a user has the credentials to create a process as another user (either legally or illegally) than this is allowed.
Should I perform additional checks to verify the username?
Are there alternative ways to achieve SSO in this setup? What are their pros and cons?
What you've described here is the correct way to authenticate the user. You should not have to worry about the user specifying a different name; that's what Kerberos takes care of for you.
If the client is able to obtain a service ticket, then they must have been able to authenticate against the KDC (Active Directory). The KDC creates a service ticket that includes the user's name, and encrypts it with the service's secret key.
The client would not be able to create a ticket for the server with a fake name, because it doesn't have the necessary key to encrypt the ticket.
Of course, this all assumes that you've set everything up correctly; the client should not have access to the service's keytab file for example, and the service should not have any principals in its key tab except its own.
There's a pretty detailed explanation of how it works here.

How to use a ISO7816 smartcard to authenticate in Bluemix?

I have a smartcard that stores the user credentials and want to use this information to authenticate in Bluemix.
I suppose I could use the SSO service in bluemi but it seems that I need to program the federation routine. Any idea?

Application user validation with LDAP

My web application is currently configured to connect to LDAP for user validation without relying on application server settings. In other words, my applications utilizes naming params to connect to LDAP hence its agnostic to application server ie. JBoss or Websphere.
Naming params used are as follows:
ldapURL
ldapPrincipal (bind user)
ldapCredentials (bind user's password)
ldapAuthentication
ldapSearchBase
The requirement now is to allow encrypted password in the ldapCredentials naming param. I have a way out of this situation is using custom SecurityLoginModule to encrypt password and supply it to application using naming param. My application would then decrypt it and then proceed with LDAP user validation. However, this results into additional application installation step.
So I was wondering if there is a way to use application server security domain (or some other way) to store the user credentials in secured fashion on application server and later application would pick it up at the time of user validation with LDAP without writing server specific code in my application. I know that we can use security domain to perform data source connection without writing server specific code. But if I do this for LDAP then I make server talk to LDAP which is not what am looking. Basically may still continue to use Federated users instead of LDAP.
Any decent application server (including JBoss and WebSphere) have server provided LDAP registry, which you can configure and use without any application specific code, and I'd strongly suggest to utilize that instead of writing your own ldap connection code.
Regarding encryption:
for WebSphere traditional, you can plug in your own class into server infrastructure to encrypt passwords see - Plug point for custom password encryption
for WebSphere Liberty - you have out of the box support for aes and hash.
for JBoss first link in Google showed me this How do I encrypt the bindCredential password in Wildfly, but maybe JBoss experts will guide you to something different.

Kerberos - SPN and keytabs

I have a project that have embedded jetty with SPNEGO enabled. I would like to be able to run this project locally for development purposes (WITH SPNEGO enabled!)
My question is, is the SPN and keytab associated with a particular server at all or can I use the same set on multiple instances of my service?
Kerberos requires that both the client and server somehow figure the service principal to use without any prior contact. If you have control of both the client and server, you can use any principal you want provided you configure both sides to
use the same principal.
In the SPNEGO case, the client does the "standard" thing and builds a principal based on the hostname of the server. (i.e. I want to talk to www.foo.com, I'll try
requesting an HTTP/www.foo.com service ticket and see if the server accepts it. )
I don't know of any way to get the SPNEGO code in the browser to use a fixed service principal. So in this case you'll need a separate keytab for each server.