Friendly Disclaimer: I am new to working with Keycloak and IdP in general. So it's likely that I use incorrect terminology and/or am more confused than I think I am. Corrections are gratefully accepted.
My question is conceptual.
I have a TLS certificate that is terminated on my host machine by my host company. My reverse proxy (Traefik) is picking up that certificate.
Which of the following proxy modes should I use now to be able to deploy Keycloak to production: edge, reencrypt or passthrough? (see here for relevant documentation)
I can pretty much rule out passthrough, because as I wrote, the TLS certificate is terminated on the server. But I am unsure if I have to bring my own certificate and reencrypt or if it is considered safe to go along with edge?
I have done my best to keep this question short and general. However, I am happy to share configurations or further details if needed.
As far as I know, most organizations consider a request to be safe when the proxy validated and terminated the TLS. It also removes the performance overhead (depends on your load). Unless your organization is going for Zero Trust for its internal network, using the edge should be totally acceptable.
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)
I am quite new to ssl stuffs but I am afraid I can guess the final answer of the following problem/question:
We are building hardware (let's call them servers) that WILL have IP address modifications along there lifetime. Each Server must be reachable in a secured manner. We are planning to use a TLS 1.3 secured connection to perform some actions on the servers (update firmware, change configuration and so on). As a consequence we need to provide the server's with one certificate (each) so that they can state their identity. PKI issue is out of the scope of this question (we suppose) and we can take for granted that the clients and the servers will share a common trusted CA to ensure the SSL handshake goes ok. The server's will serve http connection on there configured (changeable) IP addresses only. There is no DNS involved on the loop.
We are wondering how to set the servers' certificates appropriately.
As IP will change, it cannot be used as the common name in the server's certificate.
Therefore, we are considering using something more persistent such as a serial number or a MAC address.
The problem is, as there is no DNS in the loop, the client can not issue http request to www.serialNumberOfServer.com and must connect to http://x.y.z.t (which will change frequently (at least frequently enough so that we don't issue a new server's certificate at each time))
If we get it right, ssl handshake requires to have the hostname (that's in the URL we are connecting to) matching either the commonName of the server's Certificate or one of its Subject's Alternative Name (SAN). Right? Here, it would be x.y.z.t.
So we think we are stucked in a situation in which the server cannot use it's IP to prove its identity and the client wants to use it exclusively to connect to the server.
Is there any work around?
Are we missing something?
Any help would be very (VERY) appreciated. Do not hesitated in cas you should need more detailed explanation!
For what it's worth, the development environment will be Qt using the QNetworkAccessManager/QSSlstuffs framework.
If you're not having the client use DNS at all, then you do have a problem. The right solution is to use DNS or static hostname lists (/etc/hosts, eg, on unix* or hosts.txt on windows eg.). That will let you set names appropriately.
If you can only use IP addresses, another option is to put all of your IP addresses into the certificate that the server might use. This is only doable if you have a reasonable small number of addresses that they might get assigned to.
Or you could keep a cache of certificates on the server with one address for each, and have part of the webserver start process to select the right certificate. Requires a bit more complex startup.
Edit: Finally, some SSL stacks (e.g. openssl) let you decide whether or not each particular verification error should be accepted as an error or that it can be ignored. This would let you override the errors on the client side. However, this is hard to implement properly and very prone to security issues if you don't bind the remote certificate properly it means you're subjecting yourself to man-in-the-middle or other attacks by blindly accepting any old certificate. I don't remember if Qt's SSL library gives you this level of flexibility or not (I don't believe so but didn't go pull up the documentation).
Went back on the subject 9 mont later!
Turns out there is an easy solution (at least with Qt framework)
Qt's QNetworkRequest::setPeerVerifyName does the job for us. It allows to connect to an host using its IP and verify a given CN during SSL handshake
See Qt's documentation extract below:
void QNetworkRequest::setPeerVerifyName(const QString &peerName)
Sets peerName as host name for the certificate validation, instead of the one used for the TCP connection.
This function was introduced in Qt 5.13.
See also peerVerifyName.
Just tested it positively right now
I'm doing a network security course and trying to wrap my head around all the concepts. One of which is:
What technology other than firewall can be used to allow only a specific customers while block some other customers? Why is firewall not suitable?
During the course, I've been learning about all the security tools such as: firewall (static, dynamic, DPI), Proxy, VPN, Tunnel, all sorts of IDS (signature, anomaly, darknet/greynet and honeypot) then mod_security to secure apache but still puzzled by this question.
Any insights here will be greatly appreciated.
A firewall implied that you block based on the customer IP address. This may work if the customer has his own range of addresses and all requests from him are legitimate.
It gets complicated when he is with a large cloud provider who who provide a wide range of possible IPs, including IPs from other people.
For an application one good solution would be to use client-side certificates. In that case, during the TLS handshake (the process of putting in place a TLS (was: SSL) tunnel), the server will request the client to provide a certificate he (the server) trusts. Failure to providing one will break the connection.
This way, you can distribute the certificate to the clients you want to be able to reach your service and others will be rejected. This solution is better as it uses technologies which were developed exactly to solve this problem. The drawback is that you have to maintain and distribute the certificates (and usually run a PKI).
I am using the Let's Encrypt IIS client from https://github.com/Lone-Coder/letsencrypt-win-simple to generate a certificate for a server. Since the certificate is only valid for three months, I want it to auto-renew.
But the server for which I need that auto-renewing certificate is only bound to https:||mysubdomain.mydomain.com:443 and smtp:||mysubdomain.mydomain.com:25.
Both http:||mysubdomain.mydomain.com:80 and ftp:||mysubdomain.mydomain.com:21 point to a different server.
As you may have guessed, the error that is now thrown during the process is "The ACME server was probably unable to reach http:||mysubdomain.mydomain.com:80/.well-known/acme-challenge/abcdefgh...xyz".
It is completely clear to me why, but I can't fix it, because http:||mysubdomain.mydomain.com has to point to the other server. If the ACME server would try https:||mysubdomain.mydomain.com:443/.well-known/acme-challenge/abcdefgh...xyz, but ignore any certificate issue, he would successfully find the challenge.
Is there anything I can do, any feature I have overlooked, that would help me to get automated renewal working?
There are multiple options:
http-01
Redirect http://example.com/.well-known/acme-challenge/* to https://example.com/.well-known/acme-challenge/*, Boulder will happily follow any such redirect and ignore the provided certificate. That's the most simple way if you have access to the other server and can configure that redirect. It's a permanent redirect that you don't have to adjust, it'll be just fine every three months.
The option to use HTTPS directly has been removed due to security issues with some popular server software that uses the first host defined if some other virtual host doesn't define any HTTP host, which might lead to wrong issuances in multi-user environments aka shared hosting.
tls-sni-01
If you want to use just port 443, you can use another challenge type called tls-sni-01. But I think there's no client for Windows available yet that supports that challenge type.
dns-01
If you have control over the DNS via a simple API, you could also use the DNS challenge, it's completely independent of the port you can use.
I've created WCF Service and I share it via ssl. I have little knowledge about security, but I'm curious why can I see whole communication as a plain text in httpAnalyzer, even though POSTs are sending via https?
When my client application invokes wcf service, then I can see it in sniffer - passwords etc.
Does it mean that SSL works only on the lower layer - while transporting data? So every evil application can sniff communication on client's side and an encryption only secures us against man-in-the-middle?
SSL works indeed on a "lower layer" than HTTP. According to the OSI Model, SSL works on the Session Layer, while HTTP is on the Application Layer.
Most of these clientside HTTP Analyzers work from within the browser, analyzing the HTTP traffic on the application layer, before it is processed by the SSL logic. So it is completely normal to see the plain HTTP request.
Concerning security, an evil application installed within the browser can indeed read upon the traffic. But once it is processed by the SSL layer, it becomes way harder for an evil application to read the traffic.
SSL works by firstly authenticating the server to you as a client. (Do I talk to the one I really want to talk to). As you can't know all of the servers and their certificates before hand, you use some well known root certificates, which are pre-installed on your OS. These are used to check if some server is perhaps known by an already well known service. (I don't know you, but some really important server tells me that you indeed are who you say you are).
This authentication step works independent from the encryption of the traffic. No program can decrypt an arbitrary SSL stream by "installing a root certificate". (As said these root certificates are already on your machine from the first moment you install an OS on it =)
But if a evil programs is able to let you believe that you are talking to a legitimate server, using a forged root certificate for example, instead of actually talking to malware, it is able to see what the contents of the SSL traffic is. But then again, you are talking to the evil program itself, not the server you were intended to talk to. This is however not the case with HTTP Analyzer
This is in short terms how SSL works and hopefully answers your question.
Most likely HTTP analyzer install it's own root certificate, and intercepts SSL traffic, working as man-in-the-middle.