Object key validation allowed internal parent-directory segments such as `public/../private.txt`. Bucket policy and auth checks evaluated the raw key, so a policy allowing bucket/public/* could match the request while posix backend later resolved the key with `filepath.Join` and accessed `bucket/private.txt`.
Add backend-specific object key normalization to close that mismatch. The Backend interface now exposes `NormalizeObjectKey` so authorization can evaluate resources using the same key shape a backend will use for storage access.
Backends that do not collapse object paths, including Azure and the S3 proxy, inherit `BackendUnsupported.NormalizeObjectKey`. That implementation returns the input key unchanged, avoiding unnecessary normalization and keeping policy evaluation unpolluted for object stores where ../ is part of the key name.
posix/scoutfs normalize keys with filepath.Join so policy resources and request keys are compared after internal dot segments are collapsed.
Bucket policy evaluation now normalizes both the incoming object key and object resource patterns from the policy before matching. Object lock governance bypass policy checks use the same backend normalizer as well, so retention and legal hold authorization cannot diverge from backend path resolution.
Distinguish public bucket policy no-match from explicit deny during anonymous access checks. This preserves ACL fallback only for requests that are not allowed by policy, while ensuring a matching Deny statement short-circuits authorization and returns AccessDenied even when a public ACL would otherwise grant access.
Fixes#1986
When a client includes tagging, legal hold, or retention headers in a PutObject, CopyObject or CreateMultipartUpload request, the corresponding bucket policy permissions must be verified in addition to s3:PutObject:
`X-Amz-Tagging` - `s3:PutObjectTagging`
`X-Amz-Object-Lock-Legal-Hold` - `s3:PutObjectLegalHold`
`X-Amz-Object-Lock-Mode` - `s3:PutObjectRetention`
Previously, only s3:PutObject was checked, allowing users to set tagging, legal hold, and retention without having the required permissions. Now each action permission is check, if user tries to add them.
For CopyObject these permissions are checked on destination object.
Closes#1536
Adds bucket policy version support. Two versions are supported: **2008-10-17** and **2012-10-17**. If the `Version` field is omitted in the bucket policy document, it defaults to **2008-10-17**. However, if an empty string (`""`) is provided, it is considered invalid.
Fixes#1488
Adds full wildcard (`*`) and single-character (`?`) support for bucket policy actions, fixes resource detection with wildcards, and includes unit tests for `bucket_policy_actions`, `bucket_policy_effect`, and `bucket_policy_principals`.
Closes#1454
Adds the implementation of [S3 GetBucketPolicyStatus action](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetBucketPolicyStatus.html). The implementation goes to front-end. Front-End loads the bucket policy and checks if it grants public access to all users.
A bucket policy document `is public` only when `Principal` contains `*`(all users): only when it grants access to `ALL` users.
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
```
If `Statement` field is missing in the json document in `PutBucketPolicy` body, the gateway returns `Missing required field Statement` error description alongside with `MalformedPolicy` error code.
Fixes#965
Changes the returned error description to `Policies must be valid JSON and the first byte must be '{'` for invalid bucket policy json documents, which doesn't start with `{`.
The gateway returns `This policy contains invalid Json` error description, if the document starts with `{`, but still isn't valid json.
Implements the `policyErr` string type which implements the `error` interface, to handle the policy json document validation errors, by avoiding staticchecker warnings.
Bucket ACLs are now disabled by default the same as AWS.
By default the object ownership is BucketOwnerEnforced
which means that bucket ACLs are disabled. If one attempts
to set bucket ACL the following error is returned both in
the gateway and on AWS:
ErrAclNotSupported: {
Code: "AccessControlListNotSupported",
Description: "The bucket does not allow ACLs",
HTTPStatusCode: http.StatusBadRequest,
},
ACls can be enabled with PutBucketOwnershipControls
Changed bucket canned ACL translation
New backend interface methods:
PutBucketOwnershipControls
GetBucketOwnershipControls
DeleteBucketOwnershipControls
Added these to metrics
Added support to enable object lock on bucket creation in posix and azure
backends.
Implemented the logic to add object legal hold and retention on object creation
in azure and posix backends.
Added the functionality for HeadObject to return object lock related headers.
Added integration tests for these features.
niksis02
Ben McClelland
jonaustin09