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#2123Fixes#2120Fixes#2116Fixes#2111Fixes#2108Fixes#2086Fixes#2085Fixes#2083Fixes#2081Fixes#2080Fixes#2073Fixes#2072Fixes#2071Fixes#2069Fixes#2044Fixes#2043Fixes#2042Fixes#2041Fixes#2040Fixes#2039Fixes#2036Fixes#2035Fixes#2034Fixes#2028Fixes#2020Fixes#1842Fixes#1810Fixes#1780Fixes#1775Fixes#1736Fixes#1705Fixes#1663Fixes#1645Fixes#1583Fixes#1526Fixes#1514Fixes#1493Fixes#1487Fixes#959Fixes#779Closes#823Closes#85
Refactor global S3 error handling around structured error types and centralized XML response generation.
All S3 errors now share the common APIError base for the fields every error has: Code, HTTP status code, and Message. Non-traditional errors that need AWS-compatible XML fields now have dedicated typed errors in the s3err package. Each typed error implements the shared S3Error behavior so controllers and middleware can handle errors consistently while still emitting error-specific XML fields.
Add a dedicated InvalidArgumentError type because InvalidArgument is used widely across request validation, auth, copy source handling, object lock validation, multipart validation, and header parsing. The new InvalidArgument path uses explicit InvalidArgErrorCode constants with predefined descriptions and ArgumentName values, keeping call sites readable while preserving the correct InvalidArgument XML shape and optional ArgumentValue.
New structured errors added in s3err:
- `AccessForbiddenError`: Method, ResourceType
- `BadDigestError`: CalculatedDigest, ExpectedDigest
- `BucketError`: BucketName
- `ContentSHA256MismatchError`: ClientComputedContentSHA256, S3ComputedContentSHA256
- `EntityTooLargeError`: ProposedSize, MaxSizeAllowed
- `EntityTooSmallError`: ProposedSize, MinSizeAllowed
- `ExpiredPresignedURLError`: ServerTime, XAmzExpires, Expires
- `InvalidAccessKeyIdError`: AWSAccessKeyId
- `InvalidArgumentError`: Description, ArgumentName, ArgumentValue
- `InvalidChunkSizeError`: Chunk, BadChunkSize
- `InvalidDigestError`: ContentMD5
- `InvalidLocationConstraintError`: LocationConstraint
- `InvalidPartError`: UploadId, PartNumber, ETag
- `InvalidRangeError`: RangeRequested, ActualObjectSize
- `InvalidTagError`: TagKey, TagValue
- `KeyTooLongError`: Size, MaxSizeAllowed
- `MetadataTooLargeError`: Size, MaxSizeAllowed
- `MethodNotAllowedError`: Method, ResourceType, AllowedMethods
- `NoSuchUploadError`: UploadId
- `NoSuchVersionError`: Key, VersionId
- `NotImplementedError`: Header, AdditionalMessage
- `PreconditionFailedError`: Condition
- `RequestTimeTooSkewedError`: RequestTime, ServerTime, MaxAllowedSkewMilliseconds
- `SignatureDoesNotMatchError`: AWSAccessKeyId, StringToSign, SignatureProvided, StringToSignBytes, CanonicalRequest, CanonicalRequestBytes
Fix CompleteMultipartUpload validation in the Azure backend so missing or empty `ETag` values return the appropriate S3 error instead of allowing a gateway panic.
Fix presigned authentication expiration validation to compare server time in `UTC`, matching the `UTC` timestamp used by presigned URL signing.
Add request ID and host ID support across S3 requests. Each request now receives AWS S3-like identifiers, returned in response headers as `x-amz-request-id` and `x-amz-id-2` and included in all XML error responses as RequestId and HostId. The generated ID structure is designed to resemble AWS S3 request IDs and host IDs.
The request signature calculation/validation for streaming uploads was previously delayed until the request body was fully read, both for Authorization header authentication and presigned URLs.
Now, the signature is validated immediately in the authorization middlewares without reading the request body, since the signature calculation itself does not depend on the request body. Instead, only the `x-amz-content-sha256` SHA-256 hash calculation is delayed.
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#1847
This PR introduces a global optional gateway CLI flag `--disable-acl` (`VGW_DISABLE_ACL`) to disable ACL handling. When this flag is enabled, the gateway ignores all ACL-related headers, particularly in `CreateBucket`, `PutObject`, `CopyObject`, and `CreateMultipartUpload`.
`GetBucketAcl` behavior is unchanged simply returning the bucket ACL config.
There's no change in object ACL actions(`PutObjectACL`, `GetObjectACL`). They return a`NotImplemented` error as before.
A new custom error is added for PutBucketAcl calls when ACLs are disabled at the gateway level. Its HTTP status code and error code match AWS S3’s behavior, with only a slightly different error message.
In the access-control checker, ACL evaluation is fully bypassed. If ACLs are disabled only the bucket owner gets access to the bucket and all grantee checks are ignored.
The PR also includes minor refactoring of the S3 API server and router. The growing list of parameters passed to the router’s Init method has been consolidated into fields within the router struct, initialized during router construction. Parameters not needed by the S3 server are no longer stored in the server configuration and are instead forwarded directly to the router.
Fixes#1765Fixes#1771
This PR addresses two issues:
1. CreateBucket was previously allowed when the gateway was running in read-only mode. It is now correctly blocked.
2. Write operations were permitted on public buckets in read-only mode because the public access checks in `auth.VerifyAccess` were evaluated before the read-only check. The read-only check now takes precedence, and all write operations on public buckets are blocked.
GetObject allows overriding response headers with the following
paramters:
response-cache-control
response-content-disposition
response-content-encoding
response-content-language
response-content-type
response-expires
This is only valid for signed (and pre-singed) requests. An error
is returned for anonymous requests if these are set.
More info on the GetObject overrides can be found in the GetObject
API reference.
This also clarifies the naming of the AccessOptions IsPublicBucket
to IsPublicRequest to indicate this is a public access request
and not just accessing a bucket that allows public access.
Fixes#1501
Fixes#1388Fixes#1389Fixes#1390Fixes#1401
Adds the `x-amz-copy-source` header validation for `CopyObject` and `UploadPartCopy` in front-end.
The error:
```
ErrInvalidCopySource: {
Code: "InvalidArgument",
Description: "Copy Source must mention the source bucket and key: sourcebucket/sourcekey.",
HTTPStatusCode: http.StatusBadRequest,
},
```
is now deprecated.
The conditional read/write headers validation in `CopyObject` should come with #821 and #822.
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
```
niksis02
alexgalie
Ben McClelland