Health Checks for target instances over mTls - amazon-web-services

I have a passthrough Network Load Balance forwarding TCP requests to a target group of backend servers on AWS. We require mutual TLS authentication so all requests require client certificates to be passed for encryption and authentication. However, I am struggling to figure out how I would do health checks to target group servers as the health checks would also require a client certificate in order to communicate to the backend servers.
Would it be possible to give the NLB a certificate via ACM and update my servers' truststores in order to then do healthchecks over TLS? I however have not been able to find how to import the AWS certificate chain into a truststore. If this would not work, what other methods would be appropriate for my scenario?

As far as the AWS documentation is considered we can't add client side certs in the LB and that too on the fly. TLS Listeners are supported but certificate support is limited there. Reference docs on the TLS LB Listeners: https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-tls-listener.html
Yes it's possible to use ACM cert with LBs Reference here: https://aws.amazon.com/premiumsupport/knowledge-center/associate-acm-certificate-alb-nlb/
but there's again no reference of exporting (public cert) anything out of ACM.

Related

Why does AWS's Application Load Balancer require a custom domain when using HTTPS?

If I create a new AWS Application Load Balancer (ALB) using HTTP, then AWS will create a load balancer with a randomly assigned domain name. Why can't AWS do the same thing when I create a new ALB using HTTPS? Instead, when creating a new ALB using HTTPS, AWS requires me to provide a custom domain name and custom certs.
The reason is that for valid public SSL certificate you require your own domain that you control. You can't register the certificate for the default domain provided by AWS for ALB because this is not your domain.
Having SSL certs is a lot of work, including managing its registration and renewals. I guess AWS does not want to do that, though they provide SSL for CloudFront AWS-provided default domains.
great question...
With many other aws tools like Amplify you will get a working https address on random aws domain, without the need to upload a certificate to a custom domain.
here They force me to use a certificate, which forces me to use aa custom domain and not the random autogenerated aws https address.
As per the docs - https://docs.aws.amazon.com/elasticloadbalancing/latest/application/create-https-listener.html
To use an HTTPS listener, you must deploy at least one SSL/TLS server
certificate on your load balancer. The load balancer uses a server
certificate to terminate the front-end connection and then decrypt
requests from clients before sending them to the targets.
The load balancer requires X.509 certificates (SSL/TLS server
certificates). Certificates are a digital form of identification
issued by a certificate authority (CA). A certificate contains
identification information, a validity period, a public key, a serial
number, and the digital signature of the issuer.
When you create a certificate for use with your load balancer, you must specify a domain name.
You could use Amazon's ACM to provision your certs. You will only be charged for the application as mentioned in the docs below - https://docs.aws.amazon.com/acm/latest/userguide/acm-billing.html

SSL Certificate with AWS Certificate Manager?

I am new on terms of every aspect of SSL certificate.
I have a architecture, where Route53 routes traffic to Load balance.
We are moving to production and we have to implement SSL certification to handle https traffic.
Where should i position the certificate in the architecture?
While searching i sow AWS Certificate Manager.
I am wondering how is it different ?
And when i buy a certificate can i use a single certificate with different account?
(Example: can i have same certificate set up for Staging and multiple production environment)
You can use the ACM to generate certifications for you.
It's totally free, if it's a public certificate, and will automatically renew when it expires.
But some security teams will require you to upload a more advanced certificate than ACM generates for you, in this case, you can buy the certificate and upload it in the ACM service. Keep in mind that it won't renew automatically and when it expires you will have to upload a new certificate.
Where should I position the certificate in the architecture?
It depends on your security requirements, but it's totally fine to create an HTTPS commutation between Client and Load Balancer, and an HTTP communication between Load Balancer and Server. In this case, you will only need a public certificate generated by ACM.
If your security requirements need to create a secure communication end-to-end (e.g. HTTPS communication between LoadBalancer and Server), you will need to install the same private certificate in all servers and upload your private certificate in ACM.
While searching I sow AWS Certificate Manager. I am wondering how is it different ?
The only difference is that you don't need no buy a certificate if you only use in Load Balancers / API Gateway, etc but if you want to download the certificate to install in your on-premise Load Balancer or in the servers, you will have to pay $400 for each certificate.
And when I buy a certificate can I use a single certificate with a different account? (Example: can I have the same certificate set up for Staging and multiple production environments)
Yes, you can. But keep in mind that you will need to create a wildcard certificate to support multiple DNS names.
The preferred service to use is AWS ACM.
You can either upload your own certificate (i.e. purchase it then upload) or have AWS generate and manage it for you.
If you let ACM manage and generate it will regenerate ahead of its expiry and handle the rotation on each attached resource.
It is important to note that an ACM certificate can only be bound to the following resources for HTTP traffic:
ELB
CloudFront
API Gateway
Once it is connected to these you can use SSL offloading (the TLS connection is terminated at the resource rather than the instance) to connecting to the backend resources over plain HTTP.
You should be aware that if you want to serve traffic directly from an EC2 you will not be able to use ACM public CA and instead would limited to one of the following:
Buy certificate and deploy to all servers
Use a service like certbot on each server
In addition you can use certificates that are hosted in IAM but this is considered legacy with less features than ACM.

Does AWS NLB pass through SNI values when terminating TLS? (Routing via SNI)

AWS Network Load Balancers support TLS termination. This means a certificate can be created in AWS Certificate Manager and installed onto a NLB and then TCP connections using TLS encryption will be decrypted at the NLB and then either re-encrypted or passed through to a non-encrypted listener. Details are here: https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-tls-listener.html.
The benefits of using AWS Certificate Manager are that the certificate will be managed and rotated automatically by AWS. No need to put public-facing certificates on private instances.
I'd like to route TCP connections to the NLB based on the SNI, i.e. connections to the same port and IP can be routed to different targets based on the server name that was requested by the client. Whilst I can see that multiple TLS certificates for a given listener are supported using SNI to determine which certificate to serve up, I don't see how to configure listeners based on SNI.
I have therefore put HAProxy behind a NLB and want to route to different backends using SNI. I terminate TLS with the client at the NLB, reencrypt the traffic between NLB and HAProxy using a self-signed certificate on HAProxy, then route to the backends using unencyrpted TCP.
(client) --TLS/TCP--> (NLB on port 443) --TLS/TCP--> (AWS target group on port 5000, running HAProxy) --TCP--> backends on different IPs/ports
Does AWS NLB pass through the SNI details to the target groups?
If I connect directly to HAProxy (not via NLB) then I can route to the backend of choice by using SNI, but I can't get the SNI routing to work if I connect via the NLB.
According to this SO answer and to the istio docs, if you terminate TLS on the load balancer it won't carry SNI to the target group. I had the exact same issue and I ended up solving it by setting the host as '*' on the ingress Gateway and then specifying the hosts on the different VirtualServices (as recommended here).
I think that this solution could also work but didn't tried it. You would have to set the certificate on istio Gateway secret and do a TLS pass through on the NLB, but then you can't use the AWS ACM SSL certificates as pointed out on the previous link.

AWS - Load balancer with TLS termination but using self-signed certs to back-ends?

Question
Is it possible to have a load balancer in AWS handle TLS termination for a real certificate, while also having it use a self-signed certificate on the back-end? If so, how?
Conext
This way, I could pay for the certificate once for one server (the LB) and then still have TLS between the LB and the large number of back-end servers. The front-end user would be happy as they would get a real cert and no warnings, and the back-end app would be secure via the self-signed cert.
Thats possible, You can use trusted cert on ELB and self signed cert on backend. once you configure listener (for frontend on port 443 and valid cert) and Target group on port 443 for backend, the entire traffic should be encrypted. Client would see cert used on ELB/ALB and you can also restrict backend to allow connects only from ELB/ALB.
You can use ACM cert on ELB/ALB which is free.

AWS, steps for enabling HTTPS on a Windows EC2 instance?

I'm very new to AWS, so if any of the info I give you is not correct, I would appreciate a correction.
I have a single EC2 instance, running Windows, and using Internet Information Services (IIS). That instance has an elastic IP address set, so anytime I want to access my web, I do it through "http://xx.xxx.xxx.xxx/myWeb/controller/view.
I have a mobile app that opens a webview through an address like the one before, to register a credit card, and the API i'm using for that is requesting to make the connection secure. Doing research, I found about AWS Certificate Manager. It's of my uderstanding that you can only deploy a Certificate generated from the certificate manager to an ELB or CloudFront, but I don't have any of those.
All the documentation I read is fairly advanced for my understanding at this point or is focused on Linux servers, so I would like to know, how would you guys solve this? should I put ELB in front of my EC2 to be able to use Certificate Manager? or is there a better way to enable a HTTPS connection?
I also read about having to enable port 443 (HTTPS), is this an extra step I have to take, besides getting the SSL certificate?
Sorry if I'm all over the place. Any help would be greatly appreciated :)
There are 2 options, host the SSL within the Instance, or use ELB/ALB to terminate SSL (and change port) and forward the connection to the Instance. In either case you would need a domain name registered (the trust relationship is against the domain name, not the IP address).
If you choose the AWS route:
(Optional) Register the domain in Route 53, or transfer it in
Register the certificate in ACM, or upload your own
Create an ELB / ALB. Set it to use the custom domain and enable SSL.
Create a 'listener' on the ELB / ALB listening on port 443 (IIRC the SSL is actually attached to this listener). Set the listener to forward all incoming connections to the Instance on a port of your choosing (e.g. 80 now that it is HTTP).
If you are using websockets you would need to use an ALB (not ELB)
Beware there is a monetary cost for using ELB / ALB.