Fixes#1327Fixes#1567Closes#2264
Wires the S3 gateway up to the standalone IAM service so identity policies, not just bucket policies and ACLs, are enforced on the S3 data plane. The gateway authenticates SigV4 requests by calling new private derive-signing-key and resolve-identity endpoints on the IAM service instead of holding secrets itself, and evaluates identity policy through the same PolicyEvaluator path added to auth.VerifyAccess, combined with the bucket policy using explicit-deny-wins precedence. The private endpoints are served over their own mTLS listener (new iamapi/private package, genmtlscerts.sh to generate test material, and client-cert support in internal/netutil), separate from the public IAM API. As part of this the vendored aws/signer/v4 package is deleted and replaced by a pure-Go SigV4 implementation in internal/sigv4auth, which now reads canonical request data directly off the fiber.Ctx instead of reconstructing an http.Request, and is shared by both the S3 request-signing verification and the new private-endpoint signing.
DeleteObjects moves from an all-or-nothing authorization check to true partial success: VerifyObjectsAccess evaluates every object in a batch independently against both the identity policy and any object lock, so a denial or a locked object only removes that key from the batch instead of failing the whole request. It also batches the identity-policy round trip and the bucket-policy fetch once per request rather than once per object, and separates plain deletes from versioned ones since a versioned delete needs s3:DeleteObjectVersion rather than s3:DeleteObject. Object lock handling got a few correctness fixes alongside this: a bypass is now modeled as BypassNone/BypassRequested/BypassOverwrite rather than a single bool, because root's blanket ability to override a GOVERNANCE retention should only apply when the client actually asked to bypass it (DeleteObject/DeleteObjects/PutObjectRetention), not when the gateway is silently replacing a locked object via an overwrite, which needs the permission from everyone including root. Retention changes are now correctly classified as an extension (allowed under plain s3:PutObjectRetention) versus a weakening (date or mode change, which needs the bypass permission), and a COMPLIANCE lock can never be weakened by anyone regardless of permissions, matching AWS. Separately, VerifyObjectCopyAccess had a readonly-mode gap: it returned early for root/admin before ever calling VerifyAccess, so the readonly check inside VerifyAccess never ran for them on CopyObject; access checks are now ordered so the readonly gate always applies before any root/admin bypass, for copy as well as every other write path.
Bucket policies also gained Condition block support, via a new shared internal/condition package moved out of the IAM policy package since both bucket and identity policies share the same evaluation semantics. It implements the full AWS operator set — String{Equals,NotEquals,EqualsIgnoreCase,NotEqualsIgnoreCase,Like,NotLike}, Numeric{Equals,NotEquals,LessThan,LessThanEquals,GreaterThan,GreaterThanEquals}, Date{Equals,NotEquals,LessThan,LessThanEquals,GreaterThan,GreaterThanEquals}, Bool, BinaryEquals, Arn{Equals,Like,NotEquals,NotLike}, IpAddress/NotIpAddress, and Null — along with the ForAllValues/ForAnyValue set qualifiers and the IfExists modifier. A new requestConditionContext builds the per-request keys a bucket policy's Condition block can reference — aws:SourceIp, aws:SecureTransport, aws:CurrentTime, aws:EpochTime, aws:UserAgent, aws:Referer, s3:prefix, s3:delimiter, s3:max-keys, s3:x-amz-acl, s3:VersionId — following AWS's own per-action rules for which keys a given S3 operation actually populates. Identity-derived keys such as aws:PrincipalArn and aws:username are deliberately left unwired here, since the gateway has no way to know them; the standalone IAM service fills those in itself when it evaluates an identity policy.
Also added new integration test suites for S3-side IAM: s3_iam_access_control.go and s3_iam_session_access_control.go cover identity-policy enforcement and session-credential requests against real S3 operations, alongside expanded OIDC/web-identity coverage and a new runoidctests.sh runner wired into the OIDC GitHub Actions workflow.
Fix the gateway panic when validating malformed bucket ownership controls bodies with no rules. The handler now checks the rules count before indexing the first rule.
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.
Closes#1648Fixes#1980Fixes#1981
This PR implements browser-based POST object uploads for S3-compatible form uploads. It adds support for handling `multipart/form-data` object uploads submitted from browsers, including streaming multipart parsing so file content is not buffered in memory, POST policy decoding and evaluation, SigV4-based form authorization, and integration with the existing `PutObject` backend flow. The implementation covers the full browser POST upload path, including validation of required form fields, credential scope and request date checks, signature verification, metadata extraction from `x-amz-meta-*` fields, checksum field parsing, object tagging conversion from XML into the query-string format expected by `PutObject`, and browser-compatible success handling through `success_action_status` and `success_action_redirect`. It also wires the new flow into the router and metrics layer and adds POST-specific error handling and debug logging across policy parsing, multipart parsing, and POST authorization. AWS S3 also accepts the `redirect` form field alongside `success_action_redirect`, but since AWS has marked `redirect` as deprecated and is planning to remove it, this gateway intentionally does not support it.
Fixes#1870Fixes#1863
A validation has been added to **PutBucketCors** for `CORSRule.AllowedOrigins`. The `AllowedOrigins` list can no longer be empty—otherwise a **MalformedXML** error is returned. Additionally, each origin is now validated to ensure it does not contain more than one wildcard.
A similar validation has been added for `AllowedMethods`. The list must not be empty, or a **MalformedXML** error is returned. Previously, empty method values (e.g., `[]string{""}`) were incorrectly treated as valid. This has been fixed, and an **UnsupportedCORSMethod** error is now returned.
Fixes#1654Fixes#1644
CreateBucket `LocationConstraint` rejects empty values with an `InvalidLocationConstraint` error.
The `us-east-1` `LocationConstraint` is considered invalid because it is the default value and must not be present in the `CreateBucketConfiguration` request body.
This PR fixes both issues by returning `InvalidLocationConstraint` in both cases.
Fixes#1712
A successful `PutBucketPolicy` call returns `204`(No Content) http status. This PR fixes the response status code, by sending correct `204`, insted of `200`.
Fixes#1379
Adds validation for bucket canned ACLs in `CreateBucket` and `PutBucketAcl`. The gateway supports three values: `private`, `public-read`, and `public-read-write`. All other values (including `authenticated-read`, which is not supported) are considered invalid and result in an `InvalidArgument` error with an empty error message.
Closes#1595
This implementation diverges from AWS S3 behavior. The `CreateBucket` request body is no longer ignored. Based on the S3 request body schema, the gateway parses only the `LocationConstraint` and `Tags` fields. If the `LocationConstraint` does not match the gateway’s region, it returns an `InvalidLocationConstraint` error.
In AWS S3, tagging during bucket creation is supported only for directory buckets. The gateway extends this support to general-purpose buckets.
If the request body is malformed, the gateway returns a `MalformedXML` error.
Closes#1549Fixes#1593Fixes#1521Fixes#1427Fixes#1311Fixes#1301Fixes#1040
This PR primarily focuses on checksum calculation within the gateway, but it also includes several related fixes and improvements.
It introduces a middleware responsible for handling and calculating checksums for the `x-amz-checksum-*` headers and `Content-MD5`. The middleware is applied only to actions that expect a request body or checksum headers. It also enforces validation for actions that require a non-empty request body, returning an error if the body is missing. Similarly, it returns an error for actions where at least one checksum header (`Content-MD5` or `x-amz-checksum-*`) is required but none is provided.
The implementation is based on [https://gist.github.com/niksis02/eec3198f03e561a0998d67af75c648d7](the reference table), tested directly against S3:
It also fixes the error case where the `x-amz-sdk-checksum-algorithm` header is present but no corresponding `x-amz-checksum-*` or `x-amz-trailer` header is included.
Additionally, the PR improves validation for the `x-amz-content-sha256` header. For actions that require this header, an error is now returned when it’s missing. For actions that don’t require it, the middleware no longer enforces its presence. Following the common S3 pattern, the header remains mandatory for admin routes.
Finally, the `x-amz-content-sha256` header is now optional for anonymous requests, as it is not required in that case.
Closes#1003
**Changes Introduced:**
1. **S3 Bucket CORS Actions**
* Implemented the following S3 bucket CORS APIs:
* `PutBucketCors` – Configure CORS rules for a bucket.
* `GetBucketCors` – Retrieve the current CORS configuration for a bucket.
* `DeleteBucketCors` – Remove CORS configuration from a bucket.
2. **CORS Preflight Handling**
* Added an `OPTIONS` endpoint to handle browser preflight requests.
* The endpoint evaluates incoming requests against bucket CORS rules and returns the appropriate `Access-Control-*` headers.
3. **CORS Middleware**
* Implemented middleware that:
* Checks if a bucket has CORS configured.
* Detects the `Origin` header in the request.
* Adds the necessary `Access-Control-*` headers to the response when the request matches the bucket CORS configuration.
Michał "DualFroz" FoxandGitHub
niksis02