I'm orientating around FreeIPA. I have a test setup with a couple of hosts and am experimenting with LDAP. Once thing I noticed is that the hosts are able to query the entirety of the LDAP directory in FreeIPA:
kinit -kt /etc/krb5.keytab
ldapsearch -x
This will dump all users, groups, hosts and other items in the database. For a production environment, this is bad and could potentially expose this information on a host that has been compromised.
I'm having trouble finding a way to limit the access a host has to this information. How have others fixed this issue?
Related
So I'm looking for a solution for ssh key authorisation access to numerous servers, and have been pointed towards using LDAP. I wanted to present the use case and see if LDAP would be applicable and any suggestions or help would be appropriated.
Would it be possible to use LDAP to restrict access to specific servers per user/group using ssh keys. So a user tries to access a box which would bounce out to the LDAP server with the server and user details. This would then check if that person has access to that server and potentially return the correlating key to grant access.
After some research it seems possible to do the above, but I couldn't find anywhere where its for specific servers.
Also is openLDAP the best to use, I've tried setting this up and run into several issues like checksum on config files etc.
First, I feel very silly.
For fun/slight profit, I rent a vps which hosts an email and web server and which I use largely as a study aid. Recently, I was in the middle of working on something, and managed to lose connection to the box directly after having accidentally changed the ownership of my home folder to an arbitrary non-root, incorrect user. As ssh denies root, and anything but pubkey authentication, I'm in a bad way. Though the machine is up, I can't access it!
Assuming this is the only issue, a single chown should fix the problem, but I haven't been able to convince my provider's support team to do this.
So my question is this: have I officially goofed, or is there some novel way I can fix my setup?
I have all the passwords and reasonable knowledge of how all the following public facing services are configured:
Roundcube mail
Dovecot and postfix running imaps, smtps and smtp
Apache (but my websites are all located in that same home folder, and
so aren't accessible - At least I now get why this was a very bad idea...)
Baikal calendar setup in a very basic fashion
phpMyAdmin but with MySql's file creation locked to a folder which apache isn't serving
I've investigated some very simple ways to 'abuse' some of the other services in a way that might allow me either shell access, or some kind of chown primitive, but this isn't really my area.
Thanks!!
None of these will help you, at least of the services you listed none have the ability to restore the permissions.
All the VPS providers I've used give "console" access through the web interface. This is equivalent to sitting down at the machine, including the ability to login or reboot in recovery mode. Your hosting provider probably offers some similar functionality (for situations just like this, or for installing the operating system, etc), and it is going to be your easiest and most effective means of recovery. Log in there as root and restore your user's permissions.
One thing struck me as odd,
I haven't been able to convince my provider's support team to do this.
Is that because they don't want to do anything on your server which you aren't paying them to manage, or because they don't understand what you're asking? The latter would be quite odd to me, but the former scenario would be very typical of an unmanaged VPS setup (you have root, console access, and anything more than that is your problem).
I read this recommendation in the installation guidelines from Symfony:
1. Use the same user for the CLI and the web server
In development environments, it is a common practice to use the same UNIX user for the CLI and the web server because it avoids any of these permissions issues when setting up new projects. This can be done by editing your web server configuration (e.g. commonly httpd.conf or apache2.conf for Apache) and setting its user to be the same as your CLI user (e.g. for Apache, update the User and Group values).
This is only good practice for local development environments or should I do this on my public test & prod server as well? To me this doesn't seem as a very secure configuration?
Questions Can I safely follow this recommendation on a prod server? What are the risks, if there are any?
This recommendation give an easy alternative to avoid the common permissions problem.
I would prefer setup the web server permissions correctly once and keep the default webserver group/user.
The documentation has a good guide to achieve this.
EDIT
You shouldn't make your CLI user as your webserver user, especially in production because it opens you up to all kinds of potential abuse.
The whole point of the www-data user is that it is an unprivileged user, by default not able to write to any file .
Your CLI user is most often root, also keep the www-data user as the web server owner protect you from bad manipulations that can involves a lot of problems and potential security issues.
Plus, if your webserver is under an attack, other services which depends on the same user can be also compromised.
Server daemons accessible from the outside network (such as the web server) typically run as an unprivileged user so that in the event that they are hacked due to a vulnerability, the possible things the attacker can do is minimal.
We currently use the auth_ldap with apache for authentication and due to security compliance we have to change the auth for SVN.
The requirement is pretty simple. Users cannot save password unencrypted locally on clients. Ofcourse, the password can be set to encrypt by individual users by editing the ''servers'' but due to size of the firm, we cannot monitor this and be sure that they are doing it.
What are the available authentication mechanisms?
1) SASL + GSSAPI: I have been struggling to implement this for a while. Looks like it no longer works. See here
2) [RULED OUT] SSH Keys: There is a quite some overhead in adding and removing keys. But this is doable. Ruled out as we have some services that access over https.
3) Passwords: There must be some way to be sure that password are stored encrypted on user home dir.
PS: Not interested in deploying the repo on Widows server.
I'd appreciate if someone can add some insight into possible authentication mechanisms per my requirement.
SYSTEMS: SVN 1.6.11 on apache & RHEL6.2, Windows Server 2008 R2 Active Directory.
So I'm setting up a dedicated server using Debian 5 Lenny. I will be using some Atlassian Tools (JIRA, Confluence, Bamboo, and Fisheye). I want to use a local LDAP server to store information for the users that will be accessing these software titles, so that they can use one set of credentials to log in.
I also want webmail users to be configured using LDAP.
However, this is a small operation. Three people. That's why all of the software, including the ldap server, will all be on the same machine.
That said, is it safe to use LDAP to store user credentials (including passwords) in LDAP without using Kerberos? I'm confused as to when Kerberos should be used.
Hypothetically, let's say I had two servers on a subnet. Server A received requests from the outside world, for atlassian tools. Server a communicates to ldap server (internally) on server b. In that case, would I use kerberos?
When do I use Kerberos? When do I not?
I am not setting anything like "Active Directory" up. No Samba either. Users do not need to login to a domain (with access to files on the domain), they just need to login to webapps. But if I was doing LDAP on it's own dedicated machine, then I might want Kerberos?
:confuzzled: :(
-Sam
The simplest possible answer is yes, it is possible to store user names, user ids, and passwords without using Kerberos, and in fact directory services accessed via LDAP are an excellent tool for storing this sort of authentication and authorization information.
Update:
In my opinion, if you do choose an open source server, you will find OpenDS to be superior to OpenLDAP or Apache.
Basically, if you have Kerberos, you do not need any directory server. If you aren't in a corporate environment and are looking for an identity management store, you should definitively go for a directory server like OpenLDAP or Apache Directory. Kerberos require running a correctly set up DNS and NTP server. This might be way to much. Even if you do, those lazy morons from Atlassian still did not implement Kerberos support into their products. You can't even go with that.
I just noticed that there are only three of you, maybe a simple database setup with MySQL would suffice instead of running a full-blown directory server?