S3 Access Management
Explore multiple ways to manage access to an S3 bucket.
For data on the cloud, the number one priority of developers and enterprises is to secure it. The inherently public nature of the cloud poses challenges in preventing unauthorized access and handling potential security threats from malicious actors.
Fortunately, Amazon S3 offers a comprehensive suite of tools and mechanisms to effectively control and manage access to objects within a bucket, empowering users to implement security measures and protect their data in the cloud environment. Let’s dive in to learn more about these.
IAM user policies
IAM policies are JSON or YAML-based policies that help us control users' access to AWS services and resources. For example, the policy below allows fetching objects from the S3 bucket named my-bucket. If we attach it to a user, the user can have access to all objects in my-bucket.
{"Version": "2012-10-17","Statement": [{"Effect": "Allow","Action": "s3:GetObject","Resource": "arn:aws:s3:::my-bucket/*"}]}
These permissions can be attached to the users, groups, and roles allowed to access the bucket’s objects. Although IAM policies are simpler to manage when controlling access to multiple buckets, managing them for cross-account users can be difficult as we would need other IAM resources besides the policies.
Similarly, if we want to give access to external identities, we cannot attach any IAM permissions or roles to them.
To cater to these limitations and manage access permissions at the resource level, we have resource-based policies.
Resource-based policies
A resource-based policy defines the permission to access a resource in AWS. Multiple AWS services allow us to define and ...