Restricting AWS S3 bucket to only certain instances for /GET requests - amazon-web-services

Folks,
We have (sensitive) images and video stored in an S3 bucket. Would like to only allow our web server instances to be able to access the data in these buckets via http calls. What are our options?
Thanks

Create a policy that will restrict access:
http://docs.aws.amazon.com/AmazonS3/latest/dev/AccessPolicyLanguage_UseCases_s3_a.html
http://awspolicygen.s3.amazonaws.com/policygen.html

Related

How to handle bucket limits on AWS

We create an s3 bucket for each client to keep their data separated. The buckets are accessed by clients via Amazon's SFTP service.
I'm reading that there is a 1000 bucket limit per account. What are the work arounds for this?

Should my bucket be public for my usecase and how should I avoid bad practice?

I'm new to AWS tools and although I have tried to search thoroughly for an answer I wasn't able to fixate on a solution.
My usecase is this:
I have a bucket where I need to store images, upload them via my server however I need to display them on my website.
Should my bucket be public?
If not, what should I do to allow everyone to read those images but not be able to mass upload on it from origins who are not my server?
If you want the images to be publicly accessible for your website, then the objects need to be public.
This can be done by creating a Bucket Policy that makes the whole bucket, or part of the bucket, publicly accessible.
Alternatively, when uploading the images, you can use ACL='public-read', which makes the individual objects public even if the bucket isn't public. This way, you can have more fine-grained control over what content in the bucket is public.
Both of these options require you to turn off portions of S3 Block Public Access to allow the Bucket Policy or ACLs.
When your server uploads to S3, it should be using Amazon S3 API calls using a set of AWS credentials (Access Key, Secret Key) from an IAM User. Grant the IAM User permission to put objects in the bucket. This way, that software can upload to the bucket totally independently to whether the bucket is public. (Never make a bucket publicly writable/uploadable, otherwise people can store anything in there without your control.)
upload them via my server however I need to display them on my website.
In that case only your server can upload the images. So if you are hosting your web app on EC2 or ECS, then you use instance role and task role to provide S3 write access.
Should my bucket be public?
It does not have to. Often CloudFront is used to host images or files from S3 using OAI. This way your bucket remains fully private.

How to block public access on S3 bucket while allowing my rest API and mobile apps to access the files

Use Case:
I want to be able to:
Upload images and audio files from my backend to S3 bucket
List and view/play content on my backend
Return the objects URLs in API responses
Mobile apps can view/play the URLs with or without? authentication from the mobile side
Is that possible without making the S3 bucket public ?
Is that possible without making the S3 bucket public ?
Yes, it should be possible. Since you are using EC2 instance for backend, you, you can setup instance role to enable private and secure access of your backed application to S3. In the role, you would allow S3 read/write. This way, if your application is using AWS SDK, you can seamlessly access S3 without making S3 public.
Regarding the links to the object, the general way is to return S3 pre-signed links. This allows for temporary access to your objects without the need for public access. The alternative is to share your objects through CloudFront as explained in Amazon S3 + Amazon CloudFront: A Match Made in the Cloud. In either case, bucket can be private.

How to access objects in S3 bucket, without making the object's folder public

I have provided AmazonS3FullAccess policy for both the IAM user and group. Also the buket that I am trying to access says "Objects can be public". I have explicitly made the folder inside the bucket public. Despite all this I am getting access denied error when I tried to access it through its url. Any idea on this?
Objects in Amazon S3 are private by default. This means that objects are not accessible by anonymous users.
You have granted permission for your IAM User to be able to access S3. Therefore, you have access to the objects but you must identify yourself to S3 so that it can verify your identity.
You should be able to access S3 content:
Via the Amazon S3 management console
Using the AWS CLI (eg aws s3 ls s3://bucketname)
Via authenticated requests in a web browser
I suspect that you have been accessing your bucket via an unauthenticated request (eg bucketname.s3.amazonaws.com/foo.txt. Unfortunately, this does not tell Amazon S3 who you are, so it will deny the request.
To access content with this type of URL, you can generate an Amazon S3 pre-signed URLs, which appends some authentication information to the URL to prove your identity. An easy way to generate the URL is with the AWS CLI:
aws s3 presign s3://bucketname/foo.txt
It will return a URL that looks like this:
https://bucketname.s3.amazonaws.com/foo.txt?AWSAccessKeyId=AKIAxxx&Signature=xxx&Expires=1608175109
The URL will be valid for one hour by default, up to 7 days.
There are two ways I will recommend.
go to s3 dashboard, and download the object you need, one by one manually, the bucket can be kept private at the same time.
build a gateway/a small service, to handle authentication for you, set a policy and give the permission to the service container/lambda to visit the private bucket, and restrict only specific users to download the objects.
References
download from aws s3
aws policy, permission and roles

Limit aws to just s3

Is there a way to disable access to all aws services, but s3? I have an account that will only use s3 and I am worried about unexpected charges from running ec2.
Alternatively, is there a way to create a api keys for s3 access only?
You could easily create an IAM user and allow (maybe) full permissions to S3 and all other services just read only access. In that way even using api keys, he can only use s3 and cant create any other resources in any other services.