This implementation introduces **public buckets**, which are accessible without signature-based authentication.
There are two ways to grant public access to a bucket:
* **Bucket ACLs**
* **Bucket Policies**
Only `Get` and `List` operations are permitted on public buckets. All **write operations** require authentication, regardless of whether public access is granted through an ACL or a policy.
The implementation includes an `AuthorizePublicBucketAccess` middleware, which checks if public access has been granted to the bucket. If so, authentication middlewares are skipped. For unauthenticated requests, appropriate errors are returned based on the specific S3 action.
---
**1. Bucket-Level Operations:**
```json
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": "*",
"Action": "s3:*",
"Resource": "arn:aws:s3:::test"
}
]
}
```
**2. Object-Level Operations:**
```json
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": "*",
"Action": "s3:*",
"Resource": "arn:aws:s3:::test/*"
}
]
}
```
**3. Both Bucket and Object-Level Operations:**
```json
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": "*",
"Action": "s3:*",
"Resource": "arn:aws:s3:::test"
},
{
"Effect": "Allow",
"Principal": "*",
"Action": "s3:*",
"Resource": "arn:aws:s3:::test/*"
}
]
}
```
---
```sh
aws s3api create-bucket --bucket test --object-ownership BucketOwnerPreferred
aws s3api put-bucket-acl --bucket test --acl public-read
```