I am trying to use the AWS application load balancer in my application with WAF support in it. At the same time, I also need support for reverse proxy. Does the AWS application load balancer handle reverse proxy?
Not sure if we talk about the same thing, but in my understanding, AWS ALB's are reverse proxy servers.
You add your actual application server(s) in a targetgroup to an ALB listener, and then, external clients connecting to the ALB over http/https will see your application as if it was served by the ALB.
You can add HTTP request filtering to the ALB listener, so you can configure which requests go to which targetgroup, both by domain name and http paths.
ALB's also do SSL offloading, i.e. it handles https handshakes with a server certificate registered in the ALB, so your own application server doesn't need to do that anymore.
No, it can't.
To do reverse proxy in AWS, you can set a NAT Gateway in your VPC. This way, all connections from your servers to a specific IP (or the public internet) will be a single IP.
Related
i created an architecture for my WebApplication. In Front of my Application which runs on ECS i use an Application Load Balancer configured with an SSL Certificate from Certificate Manager and a Route53 Domain. To secure my ALB i use a WAF associated with my ALB. In my ALB i configured a listener for https and a listener for http, which redirects the traffic to https.
Everything works fine. But i saw that the DNS Name of my Application Load Balancer in the Browser is still available over http and i reach my app over this way through http. How can i deny this connection over the ALB DNS Name or hown can i make it secure? My goal is that all inbound https connections end at the ALB. Then the ALB directs the traffic over http to the Application.
Best regards,
L.J.
You can redirect HTTP to HTTPS as explained in AWS docs:
How can I redirect HTTP requests to HTTPS using an Application Load Balancer?
I have the cert applied on the load balancer, and https works fine, but i am wondering if I need to add the certs to nginx itself, which seems overkill but i am not sure.
No, one of the benefit of using a Load Balancer is you can hide your EC2 from public internet, making it less open and more secured.
Therefore, it is normal practice to use HTTP between your EC2 and load balancers, since they are in the same AWS Region (a safe and trusted internal environment).
By doing this you will also increase performance, because the https network overhead is only executed once in the load balancer, not twice. Your EC2 will focus the CPU resources on running the application logic instead.
Load Balancer is also Highly Available and can be configured to work with CloudFront and WAF for security and anti-DDoS controls.
No, you don't have to do this. The reason is that your load balancer (LB) is going to termiante the https connection, decrypt it using a SSL certificate you've deployed on it, and then forward HTTP connection to your ec2 instance(s).
Therefore, typical connections for LB with HTTPS have the following form:
client ---(HTTPS)---->LB---(HTTP)--->EC2 instance
This configuration is suited for most use-cases as HTTP traffic is happening withing AWS private network, not over the internet.
I was reading about backend authentication option in AWS ELB.
What it mentions is there is a instance public key (.pem encoded) to be configured in ELB.
What I could not understand is what is this key or certificate?
Since it is optional will the traffic will still be encrypted between ELB and EC2 instances if port 443 is used.
There is no details mentioned on how to actually do this.
Basically I want end to end encryption from user to elb and elb to ec2.
Basically what this is saying is that if you what encryption in transit for the entire journey you will need to install an SSL certificate on your EC2 instance. The journey will look like the below.
client ---(HTTPS)--> load balancer ---(HTTPS)--> EC2 host
You will need to either purchase an SSL, or use a free option such as certbot on your server.
Then once you have this you will need to configure for the web server software you are running. Below are some instructions for common web servers:
Apache
Nginx
IIS
Tomcat
Ensure that your target group is configured for HTTPS port 443 traffic, to have the load balancer forward requests to HTTPS on your backend.
If the load balancer to EC2 host is not encrypted (plain HTTP) the clients traffic to load balancer will still be encrypted, but after this will be forward in HTTP.
I have an ec2 instance behind Application ELB in AWS. I want to apply SSL to both ec2 instance as well as loadbalancer. For ec2 instance i have purchased ssl and installed it and it is working fine. For load balancer i will be using the free AWS ACM certificate and installing it on load balancer. Will this have any issues? i.e. installing SSL on both places ec2 and elb.
It will not have any issues but it does come with a caveat. The traffic in to the Application Load Balancer (ALB) will be encrypted and the ACM cert will be validated by the client. The traffic to the host from the ALB will also be encrypted but the certificate on the host will not be validated.
It looks like ALB Backend Authentication is on AWS's roadmap per the reference below. The reason given for it not being a priority is summarized in this quote from the AWS Engineer who wrote the first reference:
The role that server certificates play in TLS is to authenticate the server, so that it can’t be impersonated or MITM. ALBs run exclusively on our Amazon VPC network, a Software Defined Network where we encapsulate and authenticate traffic at the packet level.
The upside of this is you can use self-signed certs on your hosts to save money when using an ALB or ELB in front of them.
If you need to ensure the certificate on the host is valid you can use a Classic Elastic Load Balancer (ELB). See the reference for more details.
References
AWS ALB Validation TLS Reply
AWS ELB Configure Backend Authentication
If you use SSl/TSL at ELB, it will handle the encryption/decryption of the HTTPS connections (freeing your EC2 instance's CPU to do other work).
If you use an HTTPS/SSL connection for your back end, you can enable authentication on the back-end instance. This authentication can be used to ensure that back-end instances accept only encrypted communication, and to ensure that the back-end instance has the correct certificates.
Using SSL/TLS on both ELB and Backend can create problems since ELB HTTPS listener does not support Client-Side SSL certificates.
I have considered that you are using a 2-way SSL (Mutual or Client Authentication)
If I would like to expose a web-app to external internet what steps I need to follow in aws?
Create cloudfront or static ip or route 53? Not sure what needs to
be exposed
Create WAF?
Create ELB?AWS ELB or nginx
Enforce https through webserver?
Any other requirements please point me through?
Route53 is not a requirement at all. You can use Route53 for DNS, or you can use a third-party DNS service, or you can just use a static ip (AWS Elastic IP).
WAF is not needed just for exposing an API.
ELB is only needed if you are running this on multiple servers.
You could enforce HTTPS at the web server, or you could just leave port 80 closed and only open port 443.
At an absolute minimum you just need to deploy your application to an EC2 server, open the appropriate port(s) in the Security Group, and assign the server an Elastic IP.