Make listing metadata permissions stricter (#16974)

cmd/api-response.go

@@ -35,6 +35,7 @@ import (
 	"github.com/minio/minio/internal/hash"
 	xhttp "github.com/minio/minio/internal/http"
 	"github.com/minio/minio/internal/logger"
+	"github.com/minio/pkg/bucket/policy"
 	xxml "github.com/minio/xxml"
 )
 
@@ -493,7 +494,7 @@ func generateListBucketsResponse(buckets []BucketInfo) ListBucketsResponse {
 }
 
 // generates an ListBucketVersions response for the said bucket with other enumerated options.
-func generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delimiter, encodingType string, maxKeys int, resp ListObjectVersionsInfo, metadata bool) ListVersionsResponse {
+func generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delimiter, encodingType string, maxKeys int, resp ListObjectVersionsInfo, metadata metaCheckFn) ListVersionsResponse {
 	versions := make([]ObjectVersion, 0, len(resp.Objects))
 
 	owner := Owner{
@@ -501,11 +502,19 @@ func generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delim
 		DisplayName: "minio",
 	}
 	data := ListVersionsResponse{}
+	var lastObjMetaName string
+	var tagErr, metaErr APIErrorCode = -1, -1
 
 	for _, object := range resp.Objects {
 		if object.Name == "" {
 			continue
 		}
+		// Cache checks for the same object
+		if metadata != nil && lastObjMetaName != object.Name {
+			tagErr = metadata(object.Name, policy.GetObjectTaggingAction)
+			metaErr = metadata(object.Name, policy.GetObjectAction)
+			lastObjMetaName = object.Name
+		}
 		content := ObjectVersion{}
 		content.Key = s3EncodeName(object.Name, encodingType)
 		content.LastModified = amztime.ISO8601Format(object.ModTime.UTC())
@@ -518,8 +527,10 @@ func generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delim
 		} else {
 			content.StorageClass = globalMinioDefaultStorageClass
 		}
-		if metadata {
+		if tagErr == ErrNone {
 			content.UserTags = object.UserTags
+		}
+		if metaErr == ErrNone {
 			content.UserMetadata = &Metadata{}
 			switch kind, _ := crypto.IsEncrypted(object.UserDefined); kind {
 			case crypto.S3:
@@ -625,7 +636,7 @@ func generateListObjectsV1Response(bucket, prefix, marker, delimiter, encodingTy
 }
 
 // generates an ListObjectsV2 response for the said bucket with other enumerated options.
-func generateListObjectsV2Response(bucket, prefix, token, nextToken, startAfter, delimiter, encodingType string, fetchOwner, isTruncated bool, maxKeys int, objects []ObjectInfo, prefixes []string, metadata bool) ListObjectsV2Response {
+func generateListObjectsV2Response(bucket, prefix, token, nextToken, startAfter, delimiter, encodingType string, fetchOwner, isTruncated bool, maxKeys int, objects []ObjectInfo, prefixes []string, metadata metaCheckFn) ListObjectsV2Response {
 	contents := make([]Object, 0, len(objects))
 	owner := Owner{
 		ID:          globalMinioDefaultOwnerID,
@@ -650,28 +661,32 @@ func generateListObjectsV2Response(bucket, prefix, token, nextToken, startAfter,
 			content.StorageClass = globalMinioDefaultStorageClass
 		}
 		content.Owner = owner
-		if metadata {
+		if metadata != nil {
-			content.UserTags = object.UserTags
+			if metadata(object.Name, policy.GetObjectTaggingAction) == ErrNone {
-			content.UserMetadata = &Metadata{}
+				content.UserTags = object.UserTags
-			switch kind, _ := crypto.IsEncrypted(object.UserDefined); kind {
-			case crypto.S3:
-				content.UserMetadata.Set(xhttp.AmzServerSideEncryption, xhttp.AmzEncryptionAES)
-			case crypto.S3KMS:
-				content.UserMetadata.Set(xhttp.AmzServerSideEncryption, xhttp.AmzEncryptionKMS)
-			case crypto.SSEC:
-				content.UserMetadata.Set(xhttp.AmzServerSideEncryptionCustomerAlgorithm, xhttp.AmzEncryptionAES)
 			}
-			for k, v := range cleanMinioInternalMetadataKeys(object.UserDefined) {
+			if metadata(object.Name, policy.GetObjectAction) == ErrNone {
-				if strings.HasPrefix(strings.ToLower(k), ReservedMetadataPrefixLower) {
+				content.UserMetadata = &Metadata{}
-					// Do not need to send any internal metadata
+				switch kind, _ := crypto.IsEncrypted(object.UserDefined); kind {
-					// values to client.
+				case crypto.S3:
-					continue
+					content.UserMetadata.Set(xhttp.AmzServerSideEncryption, xhttp.AmzEncryptionAES)
+				case crypto.S3KMS:
+					content.UserMetadata.Set(xhttp.AmzServerSideEncryption, xhttp.AmzEncryptionKMS)
+				case crypto.SSEC:
+					content.UserMetadata.Set(xhttp.AmzServerSideEncryptionCustomerAlgorithm, xhttp.AmzEncryptionAES)
 				}
-				// https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+				for k, v := range cleanMinioInternalMetadataKeys(object.UserDefined) {
-				if equals(k, xhttp.AmzMetaUnencryptedContentLength, xhttp.AmzMetaUnencryptedContentMD5) {
+					if strings.HasPrefix(strings.ToLower(k), ReservedMetadataPrefixLower) {
-					continue
+						// Do not need to send any internal metadata
+						// values to client.
+						continue
+					}
+					// https://github.com/google/security-research/security/advisories/GHSA-76wf-9vgp-pj7w
+					if equals(k, xhttp.AmzMetaUnencryptedContentLength, xhttp.AmzMetaUnencryptedContentMD5) {
+						continue
+					}
+					content.UserMetadata.Set(k, v)
 				}
-				content.UserMetadata.Set(k, v)
 			}
 		}
 		contents = append(contents, content)
@@ -699,6 +714,8 @@ func generateListObjectsV2Response(bucket, prefix, token, nextToken, startAfter,
 	return data
 }
 
+type metaCheckFn = func(name string, action policy.Action) (s3Err APIErrorCode)
+
 // generates CopyObjectResponse from etag and lastModified time.
 func generateCopyObjectResponse(etag string, lastModified time.Time) CopyObjectResponse {
 	return CopyObjectResponse{

cmd/bucket-listobjects-handlers.go

@@ -88,7 +88,12 @@ func (api objectAPIHandlers) listObjectVersionsHandler(w http.ResponseWriter, r
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
 		return
 	}
-
+	var checkObjMeta metaCheckFn
+	if metadata {
+		checkObjMeta = func(name string, action policy.Action) (s3Err APIErrorCode) {
+			return checkRequestAuthType(ctx, r, action, bucket, name)
+		}
+	}
 	urlValues := r.Form
 
 	// Extract all the listBucketVersions query params to their native values.
@@ -119,7 +124,7 @@ func (api objectAPIHandlers) listObjectVersionsHandler(w http.ResponseWriter, r
 		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
 		return
 	}
-	response := generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delimiter, encodingType, maxkeys, listObjectVersionsInfo, metadata)
+	response := generateListVersionsResponse(bucket, prefix, marker, versionIDMarker, delimiter, encodingType, maxkeys, listObjectVersionsInfo, checkObjMeta)
 
 	// Write success response.
 	writeSuccessResponseXML(w, encodeResponseList(response))
@@ -135,64 +140,7 @@ func (api objectAPIHandlers) listObjectVersionsHandler(w http.ResponseWriter, r
 // MinIO continues to support ListObjectsV1 and V2 for supporting legacy tools.
 func (api objectAPIHandlers) ListObjectsV2MHandler(w http.ResponseWriter, r *http.Request) {
 	ctx := newContext(r, w, "ListObjectsV2M")
-
+	api.listObjectsV2Handler(ctx, w, r, true)
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
-
-	vars := mux.Vars(r)
-	bucket := vars["bucket"]
-
-	objectAPI := api.ObjectAPI()
-	if objectAPI == nil {
-		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL)
-		return
-	}
-
-	if s3Error := checkRequestAuthType(ctx, r, policy.ListBucketAction, bucket, ""); s3Error != ErrNone {
-		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
-		return
-	}
-
-	urlValues := r.Form
-
-	// Extract all the listObjectsV2 query params to their native values.
-	prefix, token, startAfter, delimiter, fetchOwner, maxKeys, encodingType, errCode := getListObjectsV2Args(urlValues)
-	if errCode != ErrNone {
-		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(errCode), r.URL)
-		return
-	}
-
-	// Validate the query params before beginning to serve the request.
-	// fetch-owner is not validated since it is a boolean
-	if s3Error := validateListObjectsArgs(prefix, token, delimiter, encodingType, maxKeys); s3Error != ErrNone {
-		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
-		return
-	}
-
-	listObjectsV2 := objectAPI.ListObjectsV2
-
-	// Inititate a list objects operation based on the input params.
-	// On success would return back ListObjectsInfo object to be
-	// marshaled into S3 compatible XML header.
-	listObjectsV2Info, err := listObjectsV2(ctx, bucket, prefix, token, delimiter, maxKeys, fetchOwner, startAfter)
-	if err != nil {
-		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
-		return
-	}
-
-	if err = DecryptETags(ctx, GlobalKMS, listObjectsV2Info.Objects); err != nil {
-		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
-		return
-	}
-
-	// The next continuation token has id@node_index format to optimize paginated listing
-	nextContinuationToken := listObjectsV2Info.NextContinuationToken
-
-	response := generateListObjectsV2Response(bucket, prefix, token, nextContinuationToken, startAfter,
-		delimiter, encodingType, fetchOwner, listObjectsV2Info.IsTruncated,
-		maxKeys, listObjectsV2Info.Objects, listObjectsV2Info.Prefixes, true)
-
-	// Write success response.
-	writeSuccessResponseXML(w, encodeResponseList(response))
 }
 
 // ListObjectsV2Handler - GET Bucket (List Objects) Version 2.
@@ -205,7 +153,11 @@ func (api objectAPIHandlers) ListObjectsV2MHandler(w http.ResponseWriter, r *htt
 // MinIO continues to support ListObjectsV1 for supporting legacy tools.
 func (api objectAPIHandlers) ListObjectsV2Handler(w http.ResponseWriter, r *http.Request) {
 	ctx := newContext(r, w, "ListObjectsV2")
+	api.listObjectsV2Handler(ctx, w, r, false)
+}
 
+// listObjectsV2Handler performs listing either with or without extra metadata.
+func (api objectAPIHandlers) listObjectsV2Handler(ctx context.Context, w http.ResponseWriter, r *http.Request, metadata bool) {
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
 	vars := mux.Vars(r)
@@ -222,6 +174,12 @@ func (api objectAPIHandlers) ListObjectsV2Handler(w http.ResponseWriter, r *http
 		return
 	}
 
+	var checkObjMeta metaCheckFn
+	if metadata {
+		checkObjMeta = func(name string, action policy.Action) (s3Err APIErrorCode) {
+			return checkRequestAuthType(ctx, r, action, bucket, name)
+		}
+	}
 	urlValues := r.Form
 
 	// Extract all the listObjectsV2 query params to their native values.
@@ -264,7 +222,7 @@ func (api objectAPIHandlers) ListObjectsV2Handler(w http.ResponseWriter, r *http
 
 	response := generateListObjectsV2Response(bucket, prefix, token, listObjectsV2Info.NextContinuationToken, startAfter,
 		delimiter, encodingType, fetchOwner, listObjectsV2Info.IsTruncated,
-		maxKeys, listObjectsV2Info.Objects, listObjectsV2Info.Prefixes, false)
+		maxKeys, listObjectsV2Info.Objects, listObjectsV2Info.Prefixes, checkObjMeta)
 
 	// Write success response.
 	writeSuccessResponseXML(w, encodeResponseList(response))