There is a static website on AWS S3 bucket.
This site has to be available only for one team. It could be authentication system, or access via AWS Client VPN Endpoint (only this team uses AWS VPN).
I have read about S3 Access Points, VPC Endpoints, Bucket Policy with VPC and IP-restriction, made some experiments. There was an idea to restrict access only for VPC with VPN. But I can not forward bucket traffic to VPN tunnel, because my bucket IP address changes all the time.
And this way doesn't look straight.
What service or service combination can I use to implement restriction with minimum efforts?
One approach I have done in the past is using an API Gateway as a proxy to static UI content hosted in a private S3 bucket. You can either use a public or private APIGW. With public you will need an APIGW resource policy to restrict access to the VPC-endpoint. You can also use a private APIGW-- the only downside is AWS doesn't support custom DNS for private api gateways (you will be accessing your site using a url similar to https://{rest-api-id}-{vpce-id}.execute-api.{region}.amazonaws.com/{stage}-- documentation). AWS also offers good documentation on creating an apigw as an s3 proxy.
In this example the flow of traffic would go: client-> vpn -> vpc endpoint -> apigw -> s3
Hopefully this helps!
Related
What is the difference between Private Link and VPC endpoint? As per the documentation it seems like VPC endpoint is a gateway to access AWS services without exposing the data to internet. But the definition about AWS private link also looks similar.
Reference Link:
https://docs.aws.amazon.com/vpc/latest/userguide/endpoint-services-overview.html
Does Private Link is the superset of VPC endpoint?
It would be really helpful if anyone provides the difference between these two with examples!
Thanks in Advance!
AWS defines them as:
VPC endpoint — The entry point in your VPC that enables you to connect privately to a service.
AWS PrivateLink — A technology that provides private connectivity between VPCs and services.
So PrivateLink is technology allowing you to privately (without Internet) access services in VPCs. These services can be your own, or provided by AWS.
Let's say that you've developed some application and you are hosting it in your VPC. You would like to enable access to this application to services in other VPCs and other AWS users/accounts. But you don't want to setup any VPC peering nor use Internet for that. This is where PrivateLink can be used. Using PrivateLink you can create your own VPC endpoint services which will enable other services to use your application.
In the above scenario, VPC interface endpoint is a resource that users of your application would have to create in their VPCs to connect to your application. This is same as when you create VPC interface endpoint to access AWS provided services privately (no Internet), such as Lambda, KMS or SMS.
There are also Gateway VPC endpoints which is older technology, replaced by PrivateLink. Gateways can only be used to access S3 and DynamoDB, nothing else.
To sum up, PrivateLink is general technology which can be used by you or AWS to allow private access to internal services. VPC interface endpoint is a resource that the users of such VPC services create in their own VPCs to interact with them.
Suppose there is a website xyz.com that I am hosting in a bunch of Ec2 instances, exposed to the outside world thru a Network load balancer.
Now, a client who has his/her own AWS account, wants to access this xyz.com from an Ec2 running in their aws account.
One approach is to go thru the Internet.
However the client wants to avoid the internet route.
He/she wants to use the AWS backbone to reach xyz.com.
The technology that enables that, is AWS Private link.
(note that if you search for Private Link in the AWS services, there will be none.
You will get "End point services" as the closest hit)
So, this is how to route traffic through the AWS backbone:
I, the owner of xyz.com, will create a VPC End Point Service (NOTE the keyword Service here)
The VPC End point service will point to my Network load balancer.
I will then give my VPC End point service name to the client.
The client will create a VPC End Point (NOTE.. this is different from #1).
While creating it, the client will specify the VPC End Point Service name (from #1) that he got from me.
I can choose to be prompted to accept the connection from the client to my VPC End point service.
As soon as I accept it, then the client can reach xyz.com from his/her EC2 instance.
There is no Internet, no direct connect or VPN.. this simply works; and its secure.
And which technology enabled it.. AWS Private link !!!
PRIVATE LINK IS THE ONLY TECHNOLOGY THAT ALLOWS 2 VPCS TO CONNECT THAT HAVE OVERLAPPING CIDR RANGES.
A useful way in understanding differences is in how they technically connect private resources to public services.
Gateway Endpoints route traffic by adding prefix lists within a VPC route table which targets the Gateway endpoint. It is a logical gateway object similar to a Internet Gateway.
In contrast, an Interface Endpoint uses Privatelink to inject into a VPC at the subnet level, via an Elastic Network Interface (ENI), giving network interface functionality, and therefore, DNS and private IP addressing as a means to connect to AWS public services, rather than simply being routed to it.
The differences in connections offer differing advantages and disadvantages (availability, resiliency, access, scalability, and etc), which then dictates how best to connect private resources to public services.
Privatelink is simply a very much abstracted technology to allow a more simplified connection by using DNS. The following AWS re:Invent offers a great overview of Privatelink: https://www.youtube.com/watch?v=abOFqytVqBU
As you correctly mentioned in the question that both VPC endpoint and AWS private link do not expose to internet. On AWS console under VPC, there is a clear option available to create an endpoint. But there is no option/label to create AWS private link. Actually, there is one more option/label called endpoint service. Creating endpoint service is one way to establish AWS private link. At one side of this AWS private link is your endpoint service and at the other side is your endpoint itself. And interestingly we create both these sides in two different VPCs. In other words, you are connecting two VPCs with this private link (instead of using internet or VPC peering).
understand like,
VPC1 got endpoint service ----> private link -----> VPC2 got endpoint
Here endpoint service side is service provider while endpoint is service consumer. So when you have some service (may be some application or s/w) that you think other VPC endpoints can consume you create endpoint service at your end and consumers will create endpoints at there end. When consumers create endpoints at their end they have to give/select your service name and thus private link will be established with your service.
Ultimately you can have multiple consumers of your service just like one to many relationship.
Go easy on me as I'm new to software development, but I've been tasked with creating an application that is hosted in an s3 bucket and is authenticated using cognito. When a user signs in they should redirected to a homepage which contains the users previous login times, these times are stored in a dynamodb database.
What I do understand about vpcs is that it gives you a private piece of the aws cloud for your resources, and subnets divide that piece into public (accessible by the internet) and private subnets (not accessible by the internet).
Now whats not clear to me is which AWS resources fall under a vpc and what resources should you put under a private subnet and which should you put under a public subnet. I've attached an image of a architecural solution to my application and would like some feedback on it if possible.
You might want to start with a few AWS tutorials such as:
Serverless Web Application with Cognito, API Gateway, S3, and Lambda
Build a Serverless Web Application with Amplify
In your situation, there's no need to deploy into VPC. You're not currently using any private resources (such as a MySQL database) that would need to be in VPC.
S3, API Gateway, Cognito, and DynamoDB are all AWS services. They don't run in your VPC (if you had a VPC). A VPC-hosted application could create private VPC endpoints to these services (except Cognito) but that's a relatively sophisticated use case that's not needed here, given the information available in your question.
I have a docker image which is just an Java application. The java application reads data from DynamoDB and S3 buckets and outputs something (its a test app). I have hosted the docker images onto public docker-hub repo.
In AWS, i have created private subnet which is hosting an EC2 via AWS ECS. Now to have security high; i am using VPC Endpoints for DynamoDB and S3 bucket operations for the containers.
And i have used NAT Gateway to allow EC2 to pull docker images from docker-hub.
Problem:
When i remove VPC Endpoint, the application is able to read DynamoDB and S3 via NAT. Which means the traffic is going through public network.
Thoughts:
Can not whitelist the Ip addresses of Dockerhub as it can change.
Since AWS ECS handles all the docker pull etc tasks, i do not have control to customize.
I do not want to use AWS container registry. I prefer dockerhub.
DynamoDB/S3 private addresses are not known
Question:
How to make sure that traffic for docker hub should only be allowed via NAT?
How to make sure that the DynamoDB and S3 access should be via Endpoints only?
Thanks for your help
IF you want to restrict outbound traffic over your NAT (by DNS hostname) to DockerHub only you will need a third party solution that can allow or deny outbound traffic before it traverses the internet.
You would install this appliance in a separate subnet which has NAT Gateway access. Then in your existing subnet(s) for ECS you would update the route table to have the 0.0.0.0/0 route speak to this appliance (by specifying its ENI). If you check the AWS marketplace there may be a solution already in place to fulfil the domain filter.
Alternatively you could automate a tool that is able scrape the whitelisted IP addresses for DockerHub, and then have it add these as allow all traffic rules with a NACL. This NACL would only be applied to the subnets that the NAT Gateway resides in.
Regarding your second question, from the VPC point of view by adding the prefix list of the S3 and DynamoDB endpoints to the route table it will forward any requests that hit these API endpoints through the private route.
At this time DynamoDB does not have the ability to prevent public routed interaction, however S3 does. By adding a condition of the VPCE to its bucket policy you can deny any access that tries to interact outside of the listed VPC Endpoint. Be careful not to block yourself access from the console however, by blocking only the specific verbs that you don't want allowed.
We have a hybrid model with on-premise connected to AWS via a site-to-site VPN. There is a need to download data from s3 to on-premise in a way that the traffic will go from on-premise to AWS and back without going to the open Internet for security considerations. I.e. similar to this:
on-prem --VPN--> AWS private subnet --> s3 endpoint --> s3
This schema works with interface endpoints since they generate private DNS names which can be used to call from on-premise, but the s3 endpoint is a gateway endpoint, not an interface endpoint, so it doesn't generate private DNS names.
How can this be achieved?
In February 2021, AWS released S3 PrivateLink Interface Endpoints which are different to the S3 Gateway Endpoints.
The difference is that S3 Interface Endpoints resolve to private VPC IP addresses and are routeable from outside the VPC (e.g via VPN, Direct Connect, Transit Gateway etc). S3 Gateway Endpoints use public IP ranges and are only routeable from resources within the VPC.
Interface Endpoints mean you can route to S3 buckets from your on-premise network via your VPN and one or more subnets without needing a proxy in the VPC, and without traversing the public Internet.
Refer to the blog announcement and the S3 privatelink user guide for more details.
According to the VPC endpoints documentation S3 doesn't provide direct access through a VPN:
Endpoint connections cannot be extended out of a VPC. Resources on the other side of a VPN connection, a VPC peering connection, an AWS Direct Connect connection, or a ClassicLink connection in your VPC cannot use the endpoint to communicate with resources in the endpoint service.
However, you could route the Amazon S3 IP address ranges through your VPN connection to the VPC and explicitly allow access to the S3 buckets for your VPN's public IP addresses in the bucket policy and deny everything else.
Please note that the Amazon S3 IP address ranges are subject to change.
my web servers needs to access S3. When I place them in the public subnets, or place them in the private subnets and use NAT gateways, everything works fine:
IAmazonS3 client = new AmazonS3Client("myaccesskey", "mysecretkey", enRegion);
PutObjectRequest putReq = new PutObjectRequest();
putReq.FilePath = "c:\temp\myphoto.jpg";
putReq.BucketName = "MyBucket";
putReq.Key = "myphoto.jpg";
PutObjectResponse putResp = client.PutObject(putReq);
Now I tried to place the web servers in the private subnet with S3 endpoints, my code can no longer access S3. Do I need to change the code?
Just a FYI VPC's are truly private. Only traffic that you explicitly allow can transit the borders of the VPC.
So, inside a VPC, instances needing access to external resources either need to be assigned an EIP (in which case they can access external resources using AWS's infrastructure), or you need to provide a NAT host (in which case all of the traffic egresses the VPC via your own NAT).
As of May 11th, 2015, AWS has released a "VPC Endpoint" for S3, which allows access to S3 directly from a VPC without having to go through a proxy host or NAT instance
You Can Create Endpoint, choose the desired VPC, and customize the access policy (if you want):
Please Refer AWS Blog Post For Details.
Hope this helps.