We have around 50 applications currently configured with LDAP and we have around 20 Domain Controllers. As per the security best practice we have to migrate all these applications from LDAP to LDPAS.
Currently, all applications are connected using Domain's "NETBIOS" name so there no need to worry about high availability.
What is the best design approach to achieve high availability for LDAPS?
Prefer not to configure individual DC servers as LDAPS servers in the application.
Note: all the servers (DC and application servers) are enrolled in on-prem PKI.
In my enterprise environment, there is a load balancer with a virtual IP which distributes traffic accross multiple DCs. Clients access ad.example.com, and each DC behind ad.example.com has a cert valid both for hostname.example.com and ad.example.com (SAN, subject alternative name). This has the advantage of allowing the load balancer to manage which hosts are up -- if a target does not respond on port 636, it is automatically removed from the virtual IP. When the target begins responding, it is automatically added back. LDAP clients don't need to do anything unusual to use this high availability AD LDAPS solution. The down side is that the server admin has ongoing maintenance as DCs are replaced -- we build a new server and then remove the old one. In doing so, the old IP is retired. The new IP needs to be added to the load balancer virtual IP config.
Another approach would be to use DNS to find the domain controllers -- there are SRV records registered both for the Site domain controllers and all domain controllers. Something like _ldap.tcp.SiteName._sites.example.com will give you the DCs in example.com's SiteName site. For all DCs in the example.com domain, look up _ldap._tcp.example.com ... this approach, however, requires the LDAP client to be modified to perform the DNS lookups. The advantage of this approach is that the DCs manage their DNS entries. No one needs to remember to add a new DC to the DNS service records.
Related
I've been investigating the possibility of migrating to using Let's Encrypt to maintain the SSL certificates we have in place for the various resources we use for our operations. We have the following resources using SSL certificates:
Main website (www.example.com / example.com) - Hosted and maintained by a 3rd party who also maintains the SSL certificate
Client portal website (client.example.com) - IIS site hosted and maintained by us on a server located in a remote data center
FTP server (ftp.example.com) - WS_FTP Server hosted and maintained by us on a server located in a remote data center
Hardware firewall (firewall.example.com) - Local security appliance for our internal network
Remote Desktop Gateway (rd.example.com) - RDP server hosted and maintained by us on a server located locally
As indicated above, the SSL certificate for the main website (www) is maintained by the 3rd-party host, so I don't generally mess with that one. However, as you can tell, the DNS records for each of these endpoints point to a variety of different IP addresses. This is where my inexperience with the overall process of issuing and deploying SSL certificates has me a bit confused.
First of all, since I don't manage or maintain the main website, I'm currently manually generating the CSR's for each of the endpoints from the server/service that provides the endpoint - one from the IIS server, a different one from the RDP server, another from the WS_FTP server, and one from the hardware firewall. The manual process, while not excessively time-consuming, still requires me to go through several steps with different server systems requiring different processes.
I've considered using one of Let's Encrypt's free wildcard SSL certificates to cover all four of these endpoints (*.example.com), but I don't want to "interfere" with what our main website host is doing on that end. I realize the actual certificate itself is presented by the server to which the client is connecting, so it shouldn't matter (right?), but I'd probably still be more comfortable with individual SSL certificates for each of the subdomain endpoints.
So, I've been working on building an application using the Certes ACME client library in an attempt to automatically handle the entire SSL process from CSR to deployment. However, I've run into a few snags:
The firewall is secured against connections on port 80, so I wouldn't be able to serve up the HTTP-01 validation file for that subdomain (fw.example.com) on the device itself. The same is true for the FTP server's subdomain (ftp.example.com).
My DNS is hosted with a provider that does not currently offer an API (they say they're working on one), so I can't automate the process of the DNS-01 validation by writing the TXT record to the zone file.
I found the TLS-ALPN-01 validation method, but I'm not sure whether or not this is appropriate for the use case I'm trying to implement. According to the description of this method from Let's encrypt (emphasis mine):
This challenge is not suitable for most people. It is best suited to authors of TLS-terminating reverse proxies that want to perform host-based validation like HTTP-01, but want to do it entirely at the TLS layer in order to separate concerns. Right now that mainly means large hosting providers, but mainstream web servers like Apache and Nginx could someday implement this (and Caddy already does).
Pros:
It works if port 80 is unavailable to you.
It can be performed purely at the TLS layer.
Cons:
It’s not supported by Apache, Nginx, or Certbot, and probably won’t be soon.
Like HTTP-01, if you have multiple servers they need to all answer with the same content.
This method cannot be used to validate wildcard domains.
So, based on my research so far and my environment, my three biggest questions are these:
Would the TLS-ALPN-01 validation method be an effective - or even available - option for generating the individual SSL certificates for each subdomain? Since the firewall and FTP server cannot currently serve up the appropriate files on port 80, I don't see any way to use the HTTP-01 validation for these subdomains. Not being able to use an API to automate a DNS-01 validation would make that method generally more trouble than it's worth. While I could probably do the HTTP-01 validation for the client portal - and maybe the RDP server (I haven't gotten that far in my research yet) - I'd still be left with handling the other two subdomains manually.
Would I be better off trying to do a wildcard certificate for the subdomains? Other than "simplifying" the process by reducing the number of SSL certificates that need to be issued, is there any inherent benefit to going this route versus using individual certificates for each subdomain? Since the main site is hosted/managed by a 3rd-party and (again) I can't currently use an API to automate a DNS-01 validation, I suppose I would need to use an HTTP-01 validation. Based on my understanding, that means that I would need to get access/permission to create the response file, along with the appropriate directories on that server.
Just to be certain, is there any chance of causing some sort of "conflict" if I were to generate/deploy a wildcard certificate to the subdomains while the main website still used its own SSL certificate for the www? Again, I wouldn't think that to be the case, but I want to do my best to avoid introducing more complexity and/or problems into the situation.
I've responded to your related question on https://community.certifytheweb.com/t/tls-alpn-01-validation/1444/2 but the answer is to use DNS validation and my suggestion is to use Certify DNS (https://docs.certifytheweb.com/docs/dns/providers/certifydns), which is an alternative managed alternative cloud implementation of acme-dns (CNAME delegation of DNS challenge responses.
Certify DNS is compatible with most existing acme-dns clients so it can be used with acme-dns compatible clients as well as with Certify The Web (https://certifytheweb.com)
Updated the question:
Assume that i run several web applications in one windows server under IIS. As you know, for the several web applications to co-exist in IIS, i need to differentiate them using a hostname, ip address or port combinations. Assuming that i go with defining a hostname binding unique for each of the web applications, do i need to create a DNS entry for the hostnames to be resolved?
There are three different sites i host in IIS in the same windows server. I can not allocate different ip address to each of my dev sites so i chose to use unique host names for each of the sites thus
api-orders.dev
api-catalog.dev
api-products.dev
etc..
api - indicates it is a web api.
orders | catalog | products - indicate it is an application serving a business department.
dev - indicates it is my development site.
My organization has several domains such as usdev.org.com, us.org.com, uk.dtt.org.com and more like.
Assuming that my Dev servers are hosted in the usdev.org.com domain. I should be able to request my hypothetical sites from within and also outside of the usdev.org.com domain
right now, when i use the below urls, i am not able to hit the site within or outside the domain. Not even from the web server where the sites are hosted. I ask this question to several people and could not get a clear response.
DO i need to create DNS entries corresponding to the hostname IIS binding of each site in order to solve this issue?
api-orders.dev.computer-name.domain.com
api-catalog.dev.computer-name.domain.com
api-products.dev.computer-name.domain.com
What kind of setup i need to acheive this?
If you just want to access the website via your Active directory. I think you shouldn't include servername in your domain name.
Because in common AD DNS Forward Lookup Zone.
You should have a primary zone called domain.com. Your web server will displayed as a HOST(A) Servername and its FQDN will be servername.domain.com.
Then you could create a CNAME api-orders.dev and map it to your servername.domain.com. The FQDN should be api-orders.dev.domain.com.
Finally you have to set the domain into IIS binding so that IIS can share 80 port for mutiple sites.
Since your cname api-orders.dev will not be considered as a seperate website, you have to input FQDN instead of CNAME.
If you want to access the website from internet, then you may need to purchase public domain from domain provider and map it to your server's public IP address.
I recently signed up for CloudFlare to take advantage of the security feautres the service provides. Specifically, I'm interested in its use against DDOS attacks (which are a problem I'm facing).
My web application employs nginx as a reverse proxy (with gunicorn as the application server). The Ubuntu-based virtual machine - procured via Azure - has a static/reserved IP (used as a VIP). I've read that after connecting to CloudFlare, it's best practice to change server IP so that malicious actors can't directly DDOS the said server.
Being a newbie, I'm unsure whether this guideline was applicable to the public VIP (virtual IP) or to the internal IP (which is entirely different). Can someone please conceptually and functionally clarify this for me? Can really use some help in setting this up!
What services like CloudFlare do is acting like a CDN for your website. They become front-end of your content delivery to clients while they have vast network for doing so (resources i.e. bandwidth which are consumed by DDoS). Then your IP is just known by the anti-DDoS service provider to fetch the content and deliver on your behalf.
You see if the IP is leaked by any mean the whole defense mechanism become useless since attackers can directly point to your machine while dynamic DNS of CloudFlare would distribute requests to its network and serve clients via them.
Since your website was up for a while before you migrate to CloudFlare your current public IP is known to attackers and hiding behind CloudFlare is useless since they don't ask CloudFlare DNS service and directly attack your server. This is the reason you need a new IP and the new one should not be revealed by any mean. Just set it in your CloudFlare panel and don't use it for other purposes.
I faced attacks too and used CloudFlare to prevent them, however, I have learned how to perform those attacks by myself and also how to bypass CloudFlare and take down the protected website. The best practice is to secure your server by yourself. Using nginx as a reverse proxy is a good option.
I'm specifically trying to do this with Apache Storm (1.0.2), but it's relevant to any service that is secured with Kerberos. I'm trying to run a secured Storm cluster in Docker. There are a number of out-of-the-box docker images out there for Storm, and they work great unsecured. I'm using https://github.com/Baqend/docker-storm. I also have Storm running securely on RHEL VM's.
However, my understanding is that Kerberos ties hostnames to principals, so if I'm making service foobar available to clients, I need to create a principal of foobar/hostname#REALM. Then a client service might connect to hostname with principal foobar, Kerberos will look up foobar/hostname#REALM in its database, find that it's there (because we created a principal with exactly that name), and everything will work.
In my case, it's described here: https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.3.0/bk_installing_manually_book/content/configure_kerberos_for_storm.html. The nimbus authenticates as storm/<nimbus host>#REALM, and the supervisors and outside clients authenticate as storm/REALM. Everything works.
But here in 2017, we have containers and hostnames are no longer static. So how would I Kerberize a service that runs in Docker Data Center (or Kubernetes, etc)? I have to attach an unknown hostname to the server authentication. I imagine I could create a principal for all possible hostnames and dynamically pick the right one at startup based on where the container lives, but that's kludgy.
Am I misunderstanding how Kerberos works? Is there a solution here that I don't see? I see multiple examples online of people running Storm in Docker, but I can't imagine that nobody's clusters are secure.
I don't know Apache Storm or Docker, but based on previous workings with JBOSS in a cluster in which an inbound client could be connecting to any one of a possible number of different hosts, then you would simply assign a virtual name to the entire pool at the load balancer and kerberize the service according to the virtual name instead of individual host name at the host level. So if you're making service foobar available to clients, you need to create a service principal (SPN) of foobar/virtualhostname#REALM in your Directory to kerberize the service with. You assign that SPN to a user account (not a computer account) to give it the flexibility to work with any Kerberized service which uses that SPN. If you are using Active Directory, you must create a keytab with the SPN inside of it, and place the keytab on each host running the kerberized service instance foobar/virtualhostname#REALM.
Context
I developed an application deployed in a Glassfish 3.1. This application is accessed only by https and sometimes it must connect to third-party webservices located out the customers networks. The customer have other applications inside his network; mine is only a new one "service".
Topology approximation
Big-ip F5 is the ssl end point. The customer have in this device the valid certificate
IIS redirects by domain to the respective service
glassfish is the machine with the application (over, of course, a glassfish 3.1)
How it works
When a user try to connect to _https://somedomain the request arrives to the F5 where the SSL encryption ends; now we have a request to _http://somedomain. In the next step F5 redirects this request to the IIS and this, finally, redirects to glassfish. This petitions are successfully processed.
Points of interest
I've full control over glassfish server and S.O. of the vm where it is located. Not other applications are or will be deployed on this server; it's a dedicated server for the app and some services it needs. The Glassfish runs on a VM with a Debian distribution as S.O. This VM is provided by a VM Server but I don't know the brand, model, etc. The glassfish have the default http listeners configuration.
I don't have any more information about network and other devices and i can't access to
any configuration file of any other device. I can't modify any part of the network for my own but maybe ask, suggest or advice for a change. Network's behavior should not change.
Actually users reach the application without problem.
The used certificate is a simple domain certificate trusted by Verysign
The customer have no idea of how to solve this.
The problem
All the third party WS the application must access have an unique https access and, in some cases, the authentication required is mutual (two-way) and here we find the problem. When the application wants to connect to WS with mutual ssl authentication it sends the glassfish local keystore configuration targeted certificate. Customer wants, if possible, use the same cert for incoming and outcoming secure connections. This cert is in the F5 and i can't add to the glassfish keystore because if I do this I would be breaking Verysign contract requirements. I've been looking for a solution at google, here(stackoverflow), jita,... but only incoming traffic solutions I've found. I understand that maybe a SSL proxy is required but I haven't found any example or alternative solution for the outcoming ssl connections.
What I'm asking for
I'm not english speaker (isn't obvious?) and maybe i doesn't use the correct terms in my search terms. I can understand that this context can be a nightmare and hard to solve but I will stand... The first think I need is to know if exists a solution (or solutions) for this problem and if it (or they!) exist where or how can I find it/them. I've prepared different alternatives to negotiate with the customer but I need to known the true. I've spent tones of hours on this.
There are a couple of solutions.
1)pay verisign more money for a second "license/cert". They will be happy to take your money for the "privilege". :)
2)Create a different virtual server listening on 443 which points to a pool that has your client's server address as the pool member. Then on the virtual server, attach a serverssl profile that is configured to use the same cert you are using for the incoming connections. Then the F5 would authenticate with the same cert along with your app server would not need a client cert installed. Also, if they need to initiate a session to you, you would have to setup a virtual server with a clientssl profile that uses the same cert and requires a client cert to connect.
If your destinations may not be static addresses, then an irule(s) would have to be created to deal with that. Can be handled in 10 or later code with a DNS call in the irule and setting a node for the session to go.