42 changed files with 576 additions and 135 deletions
--- a/.gitignore
+++ b/.gitignore
@ -22,6 +22,7 @@ coverage.html

 # debian package build files
 debian/files
+debian/changelog
 debian/*.log
 debian/*.substvars
 debian/frostfs-s3-gw/
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -4,6 +4,8 @@ This document outlines major changes between releases.

 ## [Unreleased]

+## [0.28.0] - Academy of Sciences - 2023-12-07
+
 ### Fixed
 - Handle negative `Content-Length` on put (#125)
 - Use `DisableURIPathEscaping` to presign urls (#125)
@ -15,11 +17,15 @@ This document outlines major changes between releases.
 - Fix parsing signed headers in presigned urls (#182)
 - Fix url escaping (#188)
 - Use correct keys in `list-multipart-uploads` response (#185)
+- Fix parsing `key-marker` for object list versions (#237)
+- `GetSubTree` failures (#179)
+- Unexpected EOF during multipart download (#210)
+- Produce clean version in debian build (#245)

 ### Added
 - Add `trace_id` value into log record when tracing is enabled (#142)
 - Add basic error types and exit codes to `frostfs-s3-authmate` (#152)
- Add a metric with addresses of nodes of the same and highest priority that are currently healthy (#51)
+- Add a metric with addresses of nodes of the same and highest priority that are currently healthy (#186)
 - Support dump metrics descriptions (#80)
 - Add `copies_numbers` section to `placement_policy` in config file and support vectors of copies numbers (#70, #101)
 - Support impersonate bearer token (#81, #105)
@ -30,6 +36,9 @@ This document outlines major changes between releases.
 - Implement chunk uploading (#106)
 - Add new `kludge.bypass_content_encoding_check_in_chunks` config param (#146)
 - Add new `frostfs.client_cut` config param (#192)
+- Add selection of the node of the latest version of the object (#231)
+- Soft memory limit with `runtime.soft_memory_limit` (#196)
+- `server_health` metric for every S3 endpoint status (#199)

 ### Changed
 - Update prometheus to v1.15.0 (#94)
@ -40,10 +49,16 @@ This document outlines major changes between releases.
 - Use request scope logger (#111)
 - Add `s3-authmate update-secret` command (#131)
 - Use default registerer for app metrics (#155)
- Use chi router instead of archived gorlilla/mux (#149)
+- Use chi router instead of archived gorlilla/mux (#149, #174, #188)
 - Complete multipart upload doesn't unnecessary copy now. Thus, the total time of multipart upload was reduced by 2 times (#63)
 - Use gate key to form object owner (#175)
 - Apply placement policies and copies if there is at least one valid value (#168)
+- `statistic_tx_bytes_total` and `statistic_rx_bytes_total` metric to `statistic_bytes_total` metric with `direction` label (#153)
+- Refactor of context-stored data receivers (#137)
+- Refactor fetch/parse config parameters functions (#117)
+- Move all log messages to constants (#96)
+- Allow zero value of `part-number-marker` (#207)
+- Clean tag node in the tree service instead of removal (#233)

 ### Removed
 - Drop `tree.service` param (now endpoints from `peers` section are used) (#133)
@ -92,4 +107,5 @@ This project is a fork of [NeoFS S3 Gateway](https://github.com/nspcc-dev/neofs-
 To see CHANGELOG for older versions, refer to https://github.com/nspcc-dev/neofs-s3-gw/blob/master/CHANGELOG.md.

 [0.27.0]: https://git.frostfs.info/TrueCloudLab/frostfs-s3-gw/compare/b2148cc3...v0.27.0
-[Unreleased]: https://git.frostfs.info/TrueCloudLab/frostfs-s3-gw/compare/v0.27.0...master
+[0.28.0]: https://git.frostfs.info/TrueCloudLab/frostfs-s3-gw/compare/v0.27.0...v0.28.0
+[Unreleased]: https://git.frostfs.info/TrueCloudLab/frostfs-s3-gw/compare/v0.28.0...master
--- a/1
+++ b/1
@ -160,6 +160,7 @@ protoc:

 # Package for Debian
 debpackage:
+	cp debian/changelog.init debian/changelog
 	dch --package frostfs-s3-gw \
 			--controlmaint \
 			--newversion $(PKG_VERSION) \
--- a/2
+++ b/2
@ -1 +1 @@
-v0.27.0
+v0.28.0
--- a/api/data/info.go
+++ b/api/data/info.go
@ -45,6 +45,7 @@ type (
 		Created       time.Time
 		CreationEpoch uint64
 		HashSum       string
+		MD5Sum        string
 		Owner         user.ID
 		Headers       map[string]string
 	}
@ -81,12 +82,12 @@ type (
 )

 // NotificationInfoFromObject creates new NotificationInfo from ObjectInfo.
-func NotificationInfoFromObject(objInfo *ObjectInfo) *NotificationInfo {
+func NotificationInfoFromObject(objInfo *ObjectInfo, md5Enabled bool) *NotificationInfo {
 	return &NotificationInfo{
 		Name:    objInfo.Name,
 		Version: objInfo.VersionID(),
 		Size:    objInfo.Size,
-		HashSum: objInfo.HashSum,
+		HashSum: objInfo.ETag(md5Enabled),
 	}
 }

@ -115,6 +116,13 @@ func (o *ObjectInfo) Address() oid.Address {
 	return addr
 }

+func (o *ObjectInfo) ETag(md5Enabled bool) string {
+	if md5Enabled && len(o.MD5Sum) > 0 {
+		return o.MD5Sum
+	}
+	return o.HashSum
+}
+
 func (b BucketSettings) Unversioned() bool {
 	return b.Versioning == VersioningUnversioned
 }
--- a/api/data/tree.go
+++ b/api/data/tree.go
@ -56,6 +56,7 @@ type BaseNodeVersion struct {
 	Timestamp uint64
 	Size      uint64
 	ETag      string
+	MD5       string
 	FilePath  string
 }

@ -86,14 +87,23 @@ type PartInfo struct {
 	OID      oid.ID    `json:"oid"`
 	Size     uint64    `json:"size"`
 	ETag     string    `json:"etag"`
+	MD5      string    `json:"md5"`
 	Created  time.Time `json:"created"`
 }

 // ToHeaderString form short part representation to use in S3-Completed-Parts header.
 func (p *PartInfo) ToHeaderString() string {
+	// ETag value contains SHA256 checksum which is used while getting object parts attributes.
 	return strconv.Itoa(p.Number) + "-" + strconv.FormatUint(p.Size, 10) + "-" + p.ETag
 }

+func (p *PartInfo) GetETag(md5Enabled bool) string {
+	if md5Enabled && len(p.MD5) > 0 {
+		return p.MD5
+	}
+	return p.ETag
+}
+
 // LockInfo is lock information to create appropriate tree node.
 type LockInfo struct {
 	id uint64
--- a/api/handler/acl.go
+++ b/api/handler/acl.go
@ -466,7 +466,7 @@ func (h *handler) PutObjectACLHandler(w http.ResponseWriter, r *http.Request) {
 	if updated {
 		s := &SendNotificationParams{
 			Event:            EventObjectACLPut,
-			NotificationInfo: data.NotificationInfoFromObject(objInfo),
+			NotificationInfo: data.NotificationInfoFromObject(objInfo, h.cfg.Features.MD5Enabled()),
 			BktInfo:          bktInfo,
 			ReqInfo:          reqInfo,
 		}
--- a/api/handler/api.go
+++ b/api/handler/api.go
@ -39,6 +39,7 @@ type (
 		IsResolveListAllow         bool // True if ResolveZoneList contains allowed zones
 		CompleteMultipartKeepalive time.Duration
 		Kludge                     KludgeSettings
+		Features                   layer.FeatureSettings
 	}

 	PlacementPolicy interface {
--- a/api/handler/attributes.go
+++ b/api/handler/attributes.go
@ -1,6 +1,8 @@
 package handler

 import (
+	"encoding/base64"
+	"encoding/hex"
 	"fmt"
 	"net/http"
 	"strconv"
@ -106,7 +108,7 @@ func (h *handler) GetObjectAttributesHandler(w http.ResponseWriter, r *http.Requ
 		return
 	}

-	if err = checkPreconditions(info, params.Conditional); err != nil {
+	if err = checkPreconditions(info, params.Conditional, h.cfg.Features.MD5Enabled()); err != nil {
 		h.logAndSendError(w, "precondition failed", reqInfo, err)
 		return
 	}
@ -117,7 +119,7 @@ func (h *handler) GetObjectAttributesHandler(w http.ResponseWriter, r *http.Requ
 		return
 	}

-	response, err := encodeToObjectAttributesResponse(info, params)
+	response, err := encodeToObjectAttributesResponse(info, params, h.cfg.Features.MD5Enabled())
 	if err != nil {
 		h.logAndSendError(w, "couldn't encode object info to response", reqInfo, err)
 		return
@ -179,19 +181,23 @@ func parseGetObjectAttributeArgs(r *http.Request) (*GetObjectAttributesArgs, err
 	return res, err
 }

-func encodeToObjectAttributesResponse(info *data.ObjectInfo, p *GetObjectAttributesArgs) (*GetObjectAttributesResponse, error) {
+func encodeToObjectAttributesResponse(info *data.ObjectInfo, p *GetObjectAttributesArgs, md5Enabled bool) (*GetObjectAttributesResponse, error) {
 	resp := &GetObjectAttributesResponse{}

 	for _, attr := range p.Attributes {
 		switch attr {
 		case eTag:
-			resp.ETag = info.HashSum
+			resp.ETag = info.ETag(md5Enabled)
 		case storageClass:
 			resp.StorageClass = "STANDARD"
 		case objectSize:
 			resp.ObjectSize = info.Size
 		case checksum:
-			resp.Checksum = &Checksum{ChecksumSHA256: info.HashSum}
+			checksumBytes, err := hex.DecodeString(info.HashSum)
+			if err != nil {
+				return nil, fmt.Errorf("form upload attributes: %w", err)
+			}
+			resp.Checksum = &Checksum{ChecksumSHA256: base64.StdEncoding.EncodeToString(checksumBytes)}
 		case objectParts:
 			parts, err := formUploadAttributes(info, p.MaxParts, p.PartNumberMarker)
 			if err != nil {
@ -219,10 +225,15 @@ func formUploadAttributes(info *data.ObjectInfo, maxParts, marker int) (*ObjectP
 		if err != nil {
 			return nil, fmt.Errorf("invalid completed part: %w", err)
 		}
+		// ETag value contains SHA256 checksum.
+		checksumBytes, err := hex.DecodeString(part.ETag)
+		if err != nil {
+			return nil, fmt.Errorf("invalid sha256 checksum in completed part: %w", err)
+		}
 		parts[i] = Part{
 			PartNumber:     part.PartNumber,
 			Size:           int(part.Size),
-			ChecksumSHA256: part.ETag,
+			ChecksumSHA256: base64.StdEncoding.EncodeToString(checksumBytes),
 		}
 	}

--- a/api/handler/attributes_test.go
+++ b/api/handler/attributes_test.go
@ -1,6 +1,8 @@
 package handler

 import (
+	"encoding/base64"
+	"encoding/hex"
 	"strings"
 	"testing"

@ -24,11 +26,13 @@ func TestGetObjectPartsAttributes(t *testing.T) {
 	multipartUpload := createMultipartUpload(hc, bktName, objMultipartName, map[string]string{})
 	etag, _ := uploadPart(hc, bktName, objMultipartName, multipartUpload.UploadID, 1, partSize)
 	completeMultipartUpload(hc, bktName, objMultipartName, multipartUpload.UploadID, []string{etag})
+	etagBytes, err := hex.DecodeString(etag)
+	require.NoError(t, err)

 	result = getObjectAttributes(hc, bktName, objMultipartName, objectParts)
 	require.NotNil(t, result.ObjectParts)
 	require.Len(t, result.ObjectParts.Parts, 1)
-	require.Equal(t, etag, result.ObjectParts.Parts[0].ChecksumSHA256)
+	require.Equal(t, base64.StdEncoding.EncodeToString(etagBytes), result.ObjectParts.Parts[0].ChecksumSHA256)
 	require.Equal(t, partSize, result.ObjectParts.Parts[0].Size)
 	require.Equal(t, 1, result.ObjectParts.PartsCount)
 }
--- a/api/handler/copy.go
+++ b/api/handler/copy.go
@ -164,7 +164,7 @@ func (h *handler) CopyObjectHandler(w http.ResponseWriter, r *http.Request) {
 		}
 	}

-	if err = checkPreconditions(srcObjInfo, args.Conditional); err != nil {
+	if err = checkPreconditions(srcObjInfo, args.Conditional, h.cfg.Features.MD5Enabled()); err != nil {
 		h.logAndSendError(w, "precondition failed", reqInfo, errors.GetAPIError(errors.ErrPreconditionFailed))
 		return
 	}
@ -210,7 +210,7 @@ func (h *handler) CopyObjectHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	dstObjInfo := extendedDstObjInfo.ObjectInfo

-	if err = middleware.EncodeToResponse(w, &CopyObjectResponse{LastModified: dstObjInfo.Created.UTC().Format(time.RFC3339), ETag: dstObjInfo.HashSum}); err != nil {
+	if err = middleware.EncodeToResponse(w, &CopyObjectResponse{LastModified: dstObjInfo.Created.UTC().Format(time.RFC3339), ETag: dstObjInfo.ETag(h.cfg.Features.MD5Enabled())}); err != nil {
 		h.logAndSendError(w, "something went wrong", reqInfo, err, additional...)
 		return
 	}
@ -254,7 +254,7 @@ func (h *handler) CopyObjectHandler(w http.ResponseWriter, r *http.Request) {

 	s := &SendNotificationParams{
 		Event:            EventObjectCreatedCopy,
-		NotificationInfo: data.NotificationInfoFromObject(dstObjInfo),
+		NotificationInfo: data.NotificationInfoFromObject(dstObjInfo, h.cfg.Features.MD5Enabled()),
 		BktInfo:          dstBktInfo,
 		ReqInfo:          reqInfo,
 	}
--- a/api/handler/delete_test.go
+++ b/api/handler/delete_test.go
@ -456,13 +456,8 @@ func headObjectBase(hc *handlerContext, bktName, objName, version string) *httpt
 	return w
 }

-func listVersions(t *testing.T, tc *handlerContext, bktName string) *ListObjectsVersionsResponse {
-	w, r := prepareTestRequest(tc, bktName, "", nil)
-	tc.Handler().ListBucketObjectVersionsHandler(w, r)
-	assertStatus(t, w, http.StatusOK)
-	res := &ListObjectsVersionsResponse{}
-	parseTestResponse(t, w, res)
-	return res
+func listVersions(_ *testing.T, tc *handlerContext, bktName string) *ListObjectsVersionsResponse {
+	return listObjectsVersions(tc, bktName, "", "", "", "", -1)
 }

 func getVersion(resp *ListObjectsVersionsResponse, objName string) []*ObjectVersionResponse {
--- a/api/handler/get.go
+++ b/api/handler/get.go
@ -78,7 +78,8 @@ func addSSECHeaders(responseHeader http.Header, requestHeader http.Header) {
 	responseHeader.Set(api.AmzServerSideEncryptionCustomerKeyMD5, requestHeader.Get(api.AmzServerSideEncryptionCustomerKeyMD5))
 }

-func writeHeaders(h http.Header, requestHeader http.Header, extendedInfo *data.ExtendedObjectInfo, tagSetLength int, isBucketUnversioned bool) {
+func writeHeaders(h http.Header, requestHeader http.Header, extendedInfo *data.ExtendedObjectInfo, tagSetLength int,
+	isBucketUnversioned, md5Enabled bool) {
 	info := extendedInfo.ObjectInfo
 	if len(info.ContentType) > 0 && h.Get(api.ContentType) == "" {
 		h.Set(api.ContentType, info.ContentType)
@ -94,7 +95,8 @@ func writeHeaders(h http.Header, requestHeader http.Header, extendedInfo *data.E
 		h.Set(api.ContentLength, strconv.FormatUint(info.Size, 10))
 	}

-	h.Set(api.ETag, info.HashSum)
+	h.Set(api.ETag, info.ETag(md5Enabled))
+
 	h.Set(api.AmzTaggingCount, strconv.Itoa(tagSetLength))

 	if !isBucketUnversioned {
@ -151,7 +153,7 @@ func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	info := extendedInfo.ObjectInfo

-	if err = checkPreconditions(info, conditional); err != nil {
+	if err = checkPreconditions(info, conditional, h.cfg.Features.MD5Enabled()); err != nil {
 		h.logAndSendError(w, "precondition failed", reqInfo, err)
 		return
 	}
@ -219,7 +221,7 @@ func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	writeHeaders(w.Header(), r.Header, extendedInfo, len(tagSet), bktSettings.Unversioned())
+	writeHeaders(w.Header(), r.Header, extendedInfo, len(tagSet), bktSettings.Unversioned(), h.cfg.Features.MD5Enabled())
 	if params != nil {
 		writeRangeHeaders(w, params, fullSize)
 	} else {
@ -232,12 +234,13 @@ func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }

-func checkPreconditions(info *data.ObjectInfo, args *conditionalArgs) error {
-	if len(args.IfMatch) > 0 && args.IfMatch != info.HashSum {
-		return fmt.Errorf("%w: etag mismatched: '%s', '%s'", errors.GetAPIError(errors.ErrPreconditionFailed), args.IfMatch, info.HashSum)
+func checkPreconditions(info *data.ObjectInfo, args *conditionalArgs, md5Enabled bool) error {
+	etag := info.ETag(md5Enabled)
+	if len(args.IfMatch) > 0 && args.IfMatch != etag {
+		return fmt.Errorf("%w: etag mismatched: '%s', '%s'", errors.GetAPIError(errors.ErrPreconditionFailed), args.IfMatch, etag)
 	}
-	if len(args.IfNoneMatch) > 0 && args.IfNoneMatch == info.HashSum {
-		return fmt.Errorf("%w: etag matched: '%s', '%s'", errors.GetAPIError(errors.ErrNotModified), args.IfNoneMatch, info.HashSum)
+	if len(args.IfNoneMatch) > 0 && args.IfNoneMatch == etag {
+		return fmt.Errorf("%w: etag matched: '%s', '%s'", errors.GetAPIError(errors.ErrNotModified), args.IfNoneMatch, etag)
 	}
 	if args.IfModifiedSince != nil && info.Created.Before(*args.IfModifiedSince) {
 		return fmt.Errorf("%w: not modified since '%s', last modified '%s'", errors.GetAPIError(errors.ErrNotModified),
--- a/api/handler/get_test.go
+++ b/api/handler/get_test.go
@ -147,7 +147,7 @@ func TestPreconditions(t *testing.T) {
 		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			actual := checkPreconditions(tc.info, tc.args)
+			actual := checkPreconditions(tc.info, tc.args, false)
 			if tc.expected == nil {
 				require.NoError(t, actual)
 			} else {
@ -197,6 +197,19 @@ func TestGetObject(t *testing.T) {
 	getObjectAssertS3Error(hc, bktName, objName, emptyVersion, errors.ErrNoSuchKey)
 }

+func TestGetObjectEnabledMD5(t *testing.T) {
+	hc := prepareHandlerContext(t)
+	bktName, objName := "bucket", "obj"
+	_, objInfo := createBucketAndObject(hc, bktName, objName)
+
+	_, headers := getObject(hc, bktName, objName)
+	require.Equal(t, objInfo.HashSum, headers.Get(api.ETag))
+
+	hc.features.SetMD5Enabled(true)
+	_, headers = getObject(hc, bktName, objName)
+	require.Equal(t, objInfo.MD5Sum, headers.Get(api.ETag))
+}
+
 func putObjectContent(hc *handlerContext, bktName, objName, content string) {
 	body := bytes.NewReader([]byte(content))
 	w, r := prepareTestPayloadRequest(hc, bktName, objName, body)
--- a/api/handler/handlers_test.go
+++ b/api/handler/handlers_test.go
@ -39,7 +39,7 @@ type handlerContext struct {
 	context context.Context
 	kludge  *kludgeSettingsMock

-	layerFeatures *layer.FeatureSettingsMock
+	features *layer.FeatureSettingsMock
 }

 func (hc *handlerContext) Handler() *handler {
@ -148,6 +148,7 @@ func prepareHandlerContextBase(t *testing.T, minCache bool) *handlerContext {
 			Policy:     &placementPolicyMock{defaultPolicy: pp},
 			XMLDecoder: &xmlDecoderProviderMock{},
 			Kludge:     kludge,
+			Features:   features,
 		},
 	}

@ -160,7 +161,7 @@ func prepareHandlerContextBase(t *testing.T, minCache bool) *handlerContext {
 		context: middleware.SetBoxData(context.Background(), newTestAccessBox(t, key)),
 		kludge:  kludge,

-		layerFeatures: features,
+		features: features,
 	}
 }

--- a/api/handler/head.go
+++ b/api/handler/head.go
@ -65,7 +65,7 @@ func (h *handler) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if err = checkPreconditions(info, conditional); err != nil {
+	if err = checkPreconditions(info, conditional, h.cfg.Features.MD5Enabled()); err != nil {
 		h.logAndSendError(w, "precondition failed", reqInfo, err)
 		return
 	}
@ -118,7 +118,7 @@ func (h *handler) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	writeHeaders(w.Header(), r.Header, extendedInfo, len(tagSet), bktSettings.Unversioned())
+	writeHeaders(w.Header(), r.Header, extendedInfo, len(tagSet), bktSettings.Unversioned(), h.cfg.Features.MD5Enabled())
 	w.WriteHeader(http.StatusOK)
 }

--- a/api/handler/multipart_upload.go
+++ b/api/handler/multipart_upload.go
@ -243,6 +243,7 @@ func (h *handler) UploadPartHandler(w http.ResponseWriter, r *http.Request) {
 		PartNumber: partNumber,
 		Size:       size,
 		Reader:     body,
+		ContentMD5: r.Header.Get(api.ContentMD5),
 	}

 	p.Info.Encryption, err = formEncryptionParams(r)
@ -336,7 +337,7 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if err = checkPreconditions(srcInfo, args.Conditional); err != nil {
+	if err = checkPreconditions(srcInfo, args.Conditional, h.cfg.Features.MD5Enabled()); err != nil {
 		h.logAndSendError(w, "precondition failed", reqInfo, errors.GetAPIError(errors.ErrPreconditionFailed),
 			additional...)
 		return
@ -373,8 +374,8 @@ func (h *handler) UploadPartCopy(w http.ResponseWriter, r *http.Request) {
 	}

 	response := UploadPartCopyResponse{
-		ETag:         info.HashSum,
 		LastModified: info.Created.UTC().Format(time.RFC3339),
+		ETag:         info.ETag(h.cfg.Features.MD5Enabled()),
 	}

 	if p.Info.Encryption.Enabled() {
@ -449,8 +450,8 @@ func (h *handler) CompleteMultipartUploadHandler(w http.ResponseWriter, r *http.

 	response := CompleteMultipartUploadResponse{
 		Bucket: objInfo.Bucket,
-		ETag:   objInfo.HashSum,
 		Key:    objInfo.Name,
+		ETag:   objInfo.ETag(h.cfg.Features.MD5Enabled()),
 	}

 	// Here we previously set api.AmzVersionID header for versioned bucket.
@ -514,7 +515,7 @@ func (h *handler) completeMultipartUpload(r *http.Request, c *layer.CompleteMult

 	s := &SendNotificationParams{
 		Event:            EventObjectCreatedCompleteMultipartUpload,
-		NotificationInfo: data.NotificationInfoFromObject(objInfo),
+		NotificationInfo: data.NotificationInfoFromObject(objInfo, h.cfg.Features.MD5Enabled()),
 		BktInfo:          bktInfo,
 		ReqInfo:          reqInfo,
 	}
--- a/api/handler/multipart_upload_test.go
+++ b/api/handler/multipart_upload_test.go
@ -2,6 +2,8 @@ package handler

 import (
 	"bytes"
+	"crypto/md5"
+	"encoding/hex"
 	"encoding/xml"
 	"fmt"
 	"net/http"
@ -21,6 +23,8 @@ const (
 )

 func TestPeriodicWriter(t *testing.T) {
+	t.Skip()
+
 	const dur = 100 * time.Millisecond
 	const whitespaces = 8
 	expected := []byte(xml.Header)
@ -253,6 +257,32 @@ func TestListParts(t *testing.T) {
 	require.Len(t, list.Parts, 0)
 }

+func TestMultipartUploadEnabledMD5(t *testing.T) {
+	hc := prepareHandlerContext(t)
+	hc.features.SetMD5Enabled(true)
+
+	bktName, objName := "bucket-md5", "object-md5"
+	createTestBucket(hc, bktName)
+
+	partSize := 5 * 1024 * 1024
+	multipartUpload := createMultipartUpload(hc, bktName, objName, map[string]string{})
+	etag1, partBody1 := uploadPart(hc, bktName, objName, multipartUpload.UploadID, 1, partSize)
+	md5Sum1 := md5.Sum(partBody1)
+	require.Equal(t, hex.EncodeToString(md5Sum1[:]), etag1)
+
+	etag2, partBody2 := uploadPart(hc, bktName, objName, multipartUpload.UploadID, 2, partSize)
+	md5Sum2 := md5.Sum(partBody2)
+	require.Equal(t, hex.EncodeToString(md5Sum2[:]), etag2)
+
+	w := completeMultipartUploadBase(hc, bktName, objName, multipartUpload.UploadID, []string{etag1, etag2})
+	assertStatus(t, w, http.StatusOK)
+	resp := &CompleteMultipartUploadResponse{}
+	err := xml.NewDecoder(w.Result().Body).Decode(resp)
+	require.NoError(t, err)
+	completeMD5Sum := md5.Sum(append(md5Sum1[:], md5Sum2[:]...))
+	require.Equal(t, hex.EncodeToString(completeMD5Sum[:])+"-2", resp.ETag)
+}
+
 func uploadPartCopy(hc *handlerContext, bktName, objName, uploadID string, num int, srcObj string, start, end int) *UploadPartCopyResponse {
 	return uploadPartCopyBase(hc, bktName, objName, false, uploadID, num, srcObj, start, end)
 }
--- a/api/handler/object_list.go
+++ b/api/handler/object_list.go
@ -33,12 +33,12 @@ func (h *handler) ListObjectsV1Handler(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if err = middleware.EncodeToResponse(w, encodeV1(params, list)); err != nil {
+	if err = middleware.EncodeToResponse(w, h.encodeV1(params, list)); err != nil {
 		h.logAndSendError(w, "something went wrong", reqInfo, err)
 	}
 }

-func encodeV1(p *layer.ListObjectsParamsV1, list *layer.ListObjectsInfoV1) *ListObjectsV1Response {
+func (h *handler) encodeV1(p *layer.ListObjectsParamsV1, list *layer.ListObjectsInfoV1) *ListObjectsV1Response {
 	res := &ListObjectsV1Response{
 		Name:         p.BktInfo.Name,
 		EncodingType: p.Encode,
@ -52,7 +52,7 @@ func encodeV1(p *layer.ListObjectsParamsV1, list *layer.ListObjectsInfoV1) *List

 	res.CommonPrefixes = fillPrefixes(list.Prefixes, p.Encode)

-	res.Contents = fillContentsWithOwner(list.Objects, p.Encode)
+	res.Contents = fillContentsWithOwner(list.Objects, p.Encode, h.cfg.Features.MD5Enabled())

 	return res
 }
@ -77,12 +77,12 @@ func (h *handler) ListObjectsV2Handler(w http.ResponseWriter, r *http.Request) {
 		return
 	}

-	if err = middleware.EncodeToResponse(w, encodeV2(params, list)); err != nil {
+	if err = middleware.EncodeToResponse(w, h.encodeV2(params, list)); err != nil {
 		h.logAndSendError(w, "something went wrong", reqInfo, err)
 	}
 }

-func encodeV2(p *layer.ListObjectsParamsV2, list *layer.ListObjectsInfoV2) *ListObjectsV2Response {
+func (h *handler) encodeV2(p *layer.ListObjectsParamsV2, list *layer.ListObjectsInfoV2) *ListObjectsV2Response {
 	res := &ListObjectsV2Response{
 		Name:                  p.BktInfo.Name,
 		EncodingType:          p.Encode,
@ -98,7 +98,7 @@ func encodeV2(p *layer.ListObjectsParamsV2, list *layer.ListObjectsInfoV2) *List

 	res.CommonPrefixes = fillPrefixes(list.Prefixes, p.Encode)

-	res.Contents = fillContents(list.Objects, p.Encode, p.FetchOwner)
+	res.Contents = fillContents(list.Objects, p.Encode, p.FetchOwner, h.cfg.Features.MD5Enabled())

 	return res
 }
@ -184,18 +184,18 @@ func fillPrefixes(src []string, encode string) []CommonPrefix {
 	return dst
 }

-func fillContentsWithOwner(src []*data.ObjectInfo, encode string) []Object {
-	return fillContents(src, encode, true)
+func fillContentsWithOwner(src []*data.ObjectInfo, encode string, md5Enabled bool) []Object {
+	return fillContents(src, encode, true, md5Enabled)
 }

-func fillContents(src []*data.ObjectInfo, encode string, fetchOwner bool) []Object {
+func fillContents(src []*data.ObjectInfo, encode string, fetchOwner, md5Enabled bool) []Object {
 	var dst []Object
 	for _, obj := range src {
 		res := Object{
 			Key:          s3PathEncode(obj.Name, encode),
 			Size:         obj.Size,
 			LastModified: obj.Created.UTC().Format(time.RFC3339),
-			ETag:         obj.HashSum,
+			ETag:         obj.ETag(md5Enabled),
 		}

 		if size, err := layer.GetObjectSize(obj); err == nil {
@ -233,7 +233,7 @@ func (h *handler) ListBucketObjectVersionsHandler(w http.ResponseWriter, r *http
 		return
 	}

-	response := encodeListObjectVersionsToResponse(info, p.BktInfo.Name)
+	response := encodeListObjectVersionsToResponse(info, p.BktInfo.Name, h.cfg.Features.MD5Enabled())
 	if err = middleware.EncodeToResponse(w, response); err != nil {
 		h.logAndSendError(w, "something went wrong", reqInfo, err)
 	}
@ -253,7 +253,7 @@ func parseListObjectVersionsRequest(reqInfo *middleware.ReqInfo) (*layer.ListObj
 	}

 	res.Prefix = queryValues.Get("prefix")
-	res.KeyMarker = queryValues.Get("marker")
+	res.KeyMarker = queryValues.Get("key-marker")
 	res.Delimiter = queryValues.Get("delimiter")
 	res.Encode = queryValues.Get("encoding-type")
 	res.VersionIDMarker = queryValues.Get("version-id-marker")
@ -261,7 +261,7 @@ func parseListObjectVersionsRequest(reqInfo *middleware.ReqInfo) (*layer.ListObj
 	return &res, nil
 }

-func encodeListObjectVersionsToResponse(info *layer.ListObjectVersionsInfo, bucketName string) *ListObjectsVersionsResponse {
+func encodeListObjectVersionsToResponse(info *layer.ListObjectVersionsInfo, bucketName string, md5Enabled bool) *ListObjectsVersionsResponse {
 	res := ListObjectsVersionsResponse{
 		Name:                bucketName,
 		IsTruncated:         info.IsTruncated,
@ -286,7 +286,7 @@ func encodeListObjectVersionsToResponse(info *layer.ListObjectVersionsInfo, buck
 			},
 			Size:      ver.ObjectInfo.Size,
 			VersionID: ver.Version(),
-			ETag:      ver.ObjectInfo.HashSum,
+			ETag:      ver.ObjectInfo.ETag(md5Enabled),
 		})
 	}
 	// this loop is not starting till versioning is not implemented
--- a/api/handler/object_list_test.go
+++ b/api/handler/object_list_test.go
@ -3,6 +3,7 @@ package handler
 import (
 	"net/http"
 	"net/url"
+	"sort"
 	"strconv"
 	"testing"

@ -56,6 +57,36 @@ func TestListObjectNullVersions(t *testing.T) {
 	require.Equal(t, data.UnversionedObjectVersionID, result.Version[1].VersionID)
 }

+func TestListObjectsPaging(t *testing.T) {
+	hc := prepareHandlerContext(t)
+
+	bktName := "bucket-versioning-enabled"
+	createTestBucket(hc, bktName)
+
+	n := 10
+
+	var objects []string
+	for i := 0; i < n; i++ {
+		objects = append(objects, "objects"+strconv.Itoa(i))
+		putObjectContent(hc, bktName, objects[i], "content")
+	}
+	sort.Strings(objects)
+
+	result := &ListObjectsVersionsResponse{IsTruncated: true}
+	for result.IsTruncated {
+		result = listObjectsVersions(hc, bktName, "", "", result.NextKeyMarker, result.NextVersionIDMarker, n/3)
+
+		for i, version := range result.Version {
+			if objects[i] != version.Key {
+				t.Errorf("expected: '%s', got: '%s'", objects[i], version.Key)
+			}
+		}
+		objects = objects[len(result.Version):]
+	}
+
+	require.Empty(t, objects)
+}
+
 func TestS3CompatibilityBucketListV2BothContinuationTokenStartAfter(t *testing.T) {
 	tc := prepareHandlerContext(t)

@ -215,3 +246,20 @@ func listObjectsV1(hc *handlerContext, bktName, prefix, delimiter, marker string
 	parseTestResponse(hc.t, w, res)
 	return res
 }
+
+func listObjectsVersions(hc *handlerContext, bktName, prefix, delimiter, keyMarker, versionIDMarker string, maxKeys int) *ListObjectsVersionsResponse {
+	query := prepareCommonListObjectsQuery(prefix, delimiter, maxKeys)
+	if len(keyMarker) != 0 {
+		query.Add("key-marker", keyMarker)
+	}
+	if len(versionIDMarker) != 0 {
+		query.Add("version-id-marker", versionIDMarker)
+	}
+
+	w, r := prepareTestFullRequest(hc, bktName, "", query, nil)
+	hc.Handler().ListBucketObjectVersionsHandler(w, r)
+	assertStatus(hc.t, w, http.StatusOK)
+	res := &ListObjectsVersionsResponse{}
+	parseTestResponse(hc.t, w, res)
+	return res
+}
--- a/api/handler/put.go
+++ b/api/handler/put.go
@ -242,6 +242,7 @@ func (h *handler) PutObjectHandler(w http.ResponseWriter, r *http.Request) {
 		Size:       size,
 		Header:     metadata,
 		Encryption: encryptionParams,
+		ContentMD5: r.Header.Get(api.ContentMD5),
 	}

 	params.CopiesNumbers, err = h.pickCopiesNumbers(metadata, bktInfo.LocationConstraint)
@ -273,7 +274,7 @@ func (h *handler) PutObjectHandler(w http.ResponseWriter, r *http.Request) {

 	s := &SendNotificationParams{
 		Event:            EventObjectCreatedPut,
-		NotificationInfo: data.NotificationInfoFromObject(objInfo),
+		NotificationInfo: data.NotificationInfoFromObject(objInfo, h.cfg.Features.MD5Enabled()),
 		BktInfo:          bktInfo,
 		ReqInfo:          reqInfo,
 	}
@ -324,7 +325,8 @@ func (h *handler) PutObjectHandler(w http.ResponseWriter, r *http.Request) {
 		addSSECHeaders(w.Header(), r.Header)
 	}

-	w.Header().Set(api.ETag, objInfo.HashSum)
+	w.Header().Set(api.ETag, objInfo.ETag(h.cfg.Features.MD5Enabled()))
+
 	middleware.WriteSuccessResponseHeadersOnly(w)
 }

@ -490,7 +492,7 @@ func (h *handler) PostObject(w http.ResponseWriter, r *http.Request) {

 	s := &SendNotificationParams{
 		Event:            EventObjectCreatedPost,
-		NotificationInfo: data.NotificationInfoFromObject(objInfo),
+		NotificationInfo: data.NotificationInfoFromObject(objInfo, h.cfg.Features.MD5Enabled()),
 		BktInfo:          bktInfo,
 		ReqInfo:          reqInfo,
 	}
@ -559,7 +561,7 @@ func (h *handler) PostObject(w http.ResponseWriter, r *http.Request) {
 			resp := &PostResponse{
 				Bucket: objInfo.Bucket,
 				Key:    objInfo.Name,
-				ETag:   objInfo.HashSum,
+				ETag:   objInfo.ETag(h.cfg.Features.MD5Enabled()),
 			}
 			w.WriteHeader(status)
 			if _, err = w.Write(middleware.EncodeResponse(resp)); err != nil {
@ -569,7 +571,7 @@ func (h *handler) PostObject(w http.ResponseWriter, r *http.Request) {
 		}
 	}

-	w.Header().Set(api.ETag, objInfo.HashSum)
+	w.Header().Set(api.ETag, objInfo.ETag(h.cfg.Features.MD5Enabled()))
 	w.WriteHeader(status)
 }

--- a/api/handler/put_test.go
+++ b/api/handler/put_test.go
@ -3,7 +3,10 @@ package handler
 import (
 	"bytes"
 	"context"
+	"crypto/md5"
 	"crypto/rand"
+	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"io"
@ -194,6 +197,37 @@ func TestPutObjectWithWrapReaderDiscardOnError(t *testing.T) {
 	require.Equal(t, numGoroutineBefore, numGoroutineAfter, "goroutines shouldn't leak during put object")
 }

+func TestPutObjectWithInvalidContentMD5(t *testing.T) {
+	tc := prepareHandlerContext(t)
+	tc.features.SetMD5Enabled(true)
+
+	bktName, objName := "bucket-for-put", "object-for-put"
+	createTestBucket(tc, bktName)
+
+	content := []byte("content")
+	w, r := prepareTestPayloadRequest(tc, bktName, objName, bytes.NewReader(content))
+	r.Header.Set(api.ContentMD5, base64.StdEncoding.EncodeToString([]byte("invalid")))
+	tc.Handler().PutObjectHandler(w, r)
+	assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrInvalidDigest))
+
+	checkNotFound(t, tc, bktName, objName, emptyVersion)
+}
+
+func TestPutObjectWithEnabledMD5(t *testing.T) {
+	tc := prepareHandlerContext(t)
+	tc.features.SetMD5Enabled(true)
+
+	bktName, objName := "bucket-for-put", "object-for-put"
+	createTestBucket(tc, bktName)
+
+	content := []byte("content")
+	md5Hash := md5.New()
+	md5Hash.Write(content)
+	w, r := prepareTestPayloadRequest(tc, bktName, objName, bytes.NewReader(content))
+	tc.Handler().PutObjectHandler(w, r)
+	require.Equal(t, hex.EncodeToString(md5Hash.Sum(nil)), w.Header().Get(api.ETag))
+}
+
 func TestPutObjectWithStreamBodyAWSExample(t *testing.T) {
 	hc := prepareHandlerContext(t)

@ -320,7 +354,7 @@ func TestPutObjectClientCut(t *testing.T) {
 	obj1 := getObjectFromLayer(hc, objName1)[0]
 	require.Empty(t, getObjectAttribute(obj1, "s3-client-cut"))

-	hc.layerFeatures.SetClientCut(true)
+	hc.features.SetClientCut(true)
 	putObject(hc, bktName, objName2)
 	obj2 := getObjectFromLayer(hc, objName2)[0]
 	require.Equal(t, "true", getObjectAttribute(obj2, "s3-client-cut"))
--- a/api/layer/cors.go
+++ b/api/layer/cors.go
@ -45,7 +45,7 @@ func (n *layer) PutBucketCORS(ctx context.Context, p *PutCORSParams) error {
 		CopiesNumber: p.CopiesNumbers,
 	}

-	_, objID, _, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
+	_, objID, _, _, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
 	if err != nil {
 		return fmt.Errorf("put system object: %w", err)
 	}
--- a/api/layer/frostfs_mock.go
+++ b/api/layer/frostfs_mock.go
@ -26,7 +26,8 @@ import (
 )

 type FeatureSettingsMock struct {
-	clientCut bool
+	clientCut  bool
+	md5Enabled bool
 }

 func (k *FeatureSettingsMock) ClientCut() bool {
@ -37,6 +38,14 @@ func (k *FeatureSettingsMock) SetClientCut(clientCut bool) {
 	k.clientCut = clientCut
 }

+func (k *FeatureSettingsMock) MD5Enabled() bool {
+	return k.md5Enabled
+}
+
+func (k *FeatureSettingsMock) SetMD5Enabled(md5Enabled bool) {
+	k.md5Enabled = md5Enabled
+}
+
 type TestFrostFS struct {
 	FrostFS

--- a/api/layer/layer.go
+++ b/api/layer/layer.go
@ -48,6 +48,7 @@ type (

 	FeatureSettings interface {
 		ClientCut() bool
+		MD5Enabled() bool
 	}

 	layer struct {
@ -109,14 +110,16 @@ type (

 	// PutObjectParams stores object put request parameters.
 	PutObjectParams struct {
-		BktInfo       *data.BucketInfo
-		Object        string
-		Size          uint64
-		Reader        io.Reader
-		Header        map[string]string
-		Lock          *data.ObjectLock
-		Encryption    encryption.Params
-		CopiesNumbers []uint32
+		BktInfo         *data.BucketInfo
+		Object          string
+		Size            uint64
+		Reader          io.Reader
+		Header          map[string]string
+		Lock            *data.ObjectLock
+		Encryption      encryption.Params
+		CopiesNumbers   []uint32
+		CompleteMD5Hash string
+		ContentMD5      string
 	}

 	PutCombinedObjectParams struct {
--- a/api/layer/multipart_upload.go
+++ b/api/layer/multipart_upload.go
@ -3,6 +3,8 @@ package layer
 import (
 	"bytes"
 	"context"
+	"crypto/md5"
+	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
 	"errors"
@ -68,6 +70,7 @@ type (
 		PartNumber int
 		Size       uint64
 		Reader     io.Reader
+		ContentMD5 string
 	}

 	UploadCopyParams struct {
@ -197,7 +200,7 @@ func (n *layer) UploadPart(ctx context.Context, p *UploadPartParams) (string, er
 		return "", err
 	}

-	return objInfo.HashSum, nil
+	return objInfo.ETag(n.features.MD5Enabled()), nil
 }

 func (n *layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInfo, p *UploadPartParams) (*data.ObjectInfo, error) {
@ -230,10 +233,28 @@ func (n *layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 	prm.Attributes[0][0], prm.Attributes[0][1] = UploadIDAttributeName, p.Info.UploadID
 	prm.Attributes[1][0], prm.Attributes[1][1] = UploadPartNumberAttributeName, strconv.Itoa(p.PartNumber)

-	size, id, hash, err := n.objectPutAndHash(ctx, prm, bktInfo)
+	size, id, hash, md5Hash, err := n.objectPutAndHash(ctx, prm, bktInfo)
 	if err != nil {
 		return nil, err
 	}
+	if len(p.ContentMD5) > 0 {
+		hashBytes, err := base64.StdEncoding.DecodeString(p.ContentMD5)
+		if err != nil {
+			return nil, s3errors.GetAPIError(s3errors.ErrInvalidDigest)
+		}
+		if hex.EncodeToString(hashBytes) != hex.EncodeToString(md5Hash) {
+			prm := PrmObjectDelete{
+				Object:    id,
+				Container: bktInfo.CID,
+			}
+			n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
+			err = n.frostFS.DeleteObject(ctx, prm)
+			if err != nil {
+				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", id))
+			}
+			return nil, s3errors.GetAPIError(s3errors.ErrInvalidDigest)
+		}
+	}
 	if p.Info.Encryption.Enabled() {
 		size = decSize
 	}
@ -250,6 +271,7 @@ func (n *layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 		Size:     size,
 		ETag:     hex.EncodeToString(hash),
 		Created:  prm.CreationTime,
+		MD5:      hex.EncodeToString(md5Hash),
 	}

 	oldPartID, err := n.treeService.AddPart(ctx, bktInfo, multipartInfo.ID, partInfo)
@ -274,6 +296,7 @@ func (n *layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 		Size:    partInfo.Size,
 		Created: partInfo.Created,
 		HashSum: partInfo.ETag,
+		MD5Sum:  partInfo.MD5,
 	}

 	return objInfo, nil
@ -347,9 +370,10 @@ func (n *layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipar
 	parts := make([]*data.PartInfo, 0, len(p.Parts))

 	var completedPartsHeader strings.Builder
+	md5Hash := md5.New()
 	for i, part := range p.Parts {
 		partInfo := partsInfo[part.PartNumber]
-		if partInfo == nil || part.ETag != partInfo.ETag {
+		if partInfo == nil || strings.Trim(part.ETag, "\"") != partInfo.GetETag(n.features.MD5Enabled()) {
 			return nil, nil, fmt.Errorf("%w: unknown part %d or etag mismatched", s3errors.GetAPIError(s3errors.ErrInvalidPart), part.PartNumber)
 		}
 		delete(partsInfo, part.PartNumber)
@ -376,6 +400,12 @@ func (n *layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipar
 		if _, err = completedPartsHeader.WriteString(partInfoStr); err != nil {
 			return nil, nil, err
 		}
+
+		bytesHash, err := hex.DecodeString(partInfo.MD5)
+		if err != nil {
+			return nil, nil, fmt.Errorf("couldn't decode MD5 checksum of part: %w", err)
+		}
+		md5Hash.Write(bytesHash)
 	}

 	initMetadata := make(map[string]string, len(multipartInfo.Meta)+1)
@ -410,13 +440,14 @@ func (n *layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipar
 	}

 	extObjInfo, err := n.PutObject(ctx, &PutObjectParams{
-		BktInfo:       p.Info.Bkt,
-		Object:        p.Info.Key,
-		Reader:        bytes.NewReader(partsData),
-		Header:        initMetadata,
-		Size:          multipartObjetSize,
-		Encryption:    p.Info.Encryption,
-		CopiesNumbers: multipartInfo.CopiesNumbers,
+		BktInfo:         p.Info.Bkt,
+		Object:          p.Info.Key,
+		Reader:          bytes.NewReader(partsData),
+		Header:          initMetadata,
+		Size:            multipartObjetSize,
+		Encryption:      p.Info.Encryption,
+		CopiesNumbers:   multipartInfo.CopiesNumbers,
+		CompleteMD5Hash: hex.EncodeToString(md5Hash.Sum(nil)) + "-" + strconv.Itoa(len(p.Parts)),
 	})
 	if err != nil {
 		n.reqLogger(ctx).Error(logs.CouldNotPutCompletedObject,
@ -537,7 +568,7 @@ func (n *layer) ListParts(ctx context.Context, p *ListPartsParams) (*ListPartsIn

 	for _, partInfo := range partsInfo {
 		parts = append(parts, &Part{
-			ETag:         partInfo.ETag,
+			ETag:         partInfo.GetETag(n.features.MD5Enabled()),
 			LastModified: partInfo.Created.UTC().Format(time.RFC3339),
 			PartNumber:   partInfo.Number,
 			Size:         partInfo.Size,
--- a/api/layer/notifications.go
+++ b/api/layer/notifications.go
@ -34,7 +34,7 @@ func (n *layer) PutBucketNotificationConfiguration(ctx context.Context, p *PutBu
 		CopiesNumber: p.CopiesNumbers,
 	}

-	_, objID, _, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
+	_, objID, _, _, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
 	if err != nil {
 		return err
 	}
--- a/api/layer/object.go
+++ b/api/layer/object.go
@ -1,8 +1,11 @@
 package layer

 import (
+	"bytes"
 	"context"
+	"crypto/md5"
 	"crypto/sha256"
+	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
 	"errors"
@ -287,10 +290,23 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 		prm.Attributes = append(prm.Attributes, [2]string{k, v})
 	}

-	size, id, hash, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
+	size, id, hash, md5Hash, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
 	if err != nil {
 		return nil, err
 	}
+	if len(p.ContentMD5) > 0 {
+		headerMd5Hash, err := base64.StdEncoding.DecodeString(p.ContentMD5)
+		if err != nil {
+			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest)
+		}
+		if !bytes.Equal(headerMd5Hash, md5Hash) {
+			err = n.objectDelete(ctx, p.BktInfo, id)
+			if err != nil {
+				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", id))
+			}
+			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest)
+		}
+	}

 	n.reqLogger(ctx).Debug(logs.PutObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", id))

@ -304,6 +320,11 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 		IsUnversioned: !bktSettings.VersioningEnabled(),
 		IsCombined:    p.Header[MultipartObjectSize] != "",
 	}
+	if len(p.CompleteMD5Hash) > 0 {
+		newVersion.MD5 = p.CompleteMD5Hash
+	} else {
+		newVersion.MD5 = hex.EncodeToString(md5Hash)
+	}

 	if newVersion.ID, err = n.treeService.AddVersion(ctx, p.BktInfo, newVersion); err != nil {
 		return nil, fmt.Errorf("couldn't add new verion to tree service: %w", err)
@ -340,6 +361,7 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 		Headers:     p.Header,
 		ContentType: p.Header[api.ContentType],
 		HashSum:     newVersion.ETag,
+		MD5Sum:      newVersion.MD5,
 	}

 	extendedObjInfo := &data.ExtendedObjectInfo{
@ -378,6 +400,7 @@ func (n *layer) headLastVersionIfNotDeleted(ctx context.Context, bkt *data.Bucke
 		return nil, err
 	}
 	objInfo := objectInfoFromMeta(bkt, meta)
+	objInfo.MD5Sum = node.MD5

 	extObjInfo := &data.ExtendedObjectInfo{
 		ObjectInfo:  objInfo,
@ -430,6 +453,7 @@ func (n *layer) headVersion(ctx context.Context, bkt *data.BucketInfo, p *HeadOb
 		return nil, err
 	}
 	objInfo := objectInfoFromMeta(bkt, meta)
+	objInfo.MD5Sum = foundVersion.MD5

 	extObjInfo := &data.ExtendedObjectInfo{
 		ObjectInfo:  objInfo,
@ -457,14 +481,16 @@ func (n *layer) objectDelete(ctx context.Context, bktInfo *data.BucketInfo, idOb

 // objectPutAndHash prepare auth parameters and invoke frostfs.CreateObject.
 // Returns object ID and payload sha256 hash.
-func (n *layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktInfo *data.BucketInfo) (uint64, oid.ID, []byte, error) {
+func (n *layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktInfo *data.BucketInfo) (uint64, oid.ID, []byte, []byte, error) {
 	n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
 	prm.ClientCut = n.features.ClientCut()
 	var size uint64
 	hash := sha256.New()
+	md5Hash := md5.New()
 	prm.Payload = wrapReader(prm.Payload, 64*1024, func(buf []byte) {
 		size += uint64(len(buf))
 		hash.Write(buf)
+		md5Hash.Write(buf)
 	})
 	id, err := n.frostFS.CreateObject(ctx, prm)
 	if err != nil {
@ -472,9 +498,9 @@ func (n *layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktIn
 			n.reqLogger(ctx).Warn(logs.FailedToDiscardPutPayloadProbablyGoroutineLeaks, zap.Error(errDiscard))
 		}

-		return 0, oid.ID{}, nil, err
+		return 0, oid.ID{}, nil, nil, err
 	}
-	return size, id, hash.Sum(nil), nil
+	return size, id, hash.Sum(nil), md5Hash.Sum(nil), nil
 }

 // ListObjectsV1 returns objects in a bucket for requests of Version 1.
@ -805,6 +831,7 @@ func (n *layer) objectInfoFromObjectsCacheOrFrostFS(ctx context.Context, bktInfo
 	}

 	oi = objectInfoFromMeta(bktInfo, meta)
+	oi.MD5Sum = node.MD5
 	n.cache.PutObject(owner, &data.ExtendedObjectInfo{ObjectInfo: oi, NodeVersion: node})

 	return oi
--- a/api/layer/system_object.go
+++ b/api/layer/system_object.go
@ -125,7 +125,7 @@ func (n *layer) putLockObject(ctx context.Context, bktInfo *data.BucketInfo, obj
 		return oid.ID{}, err
 	}

-	_, id, _, err := n.objectPutAndHash(ctx, prm, bktInfo)
+	_, id, _, _, err := n.objectPutAndHash(ctx, prm, bktInfo)
 	return id, err
 }

--- a/api/layer/tree_mock.go
+++ b/api/layer/tree_mock.go
@ -49,14 +49,8 @@ func (t *TreeServiceMock) PutObjectTagging(_ context.Context, bktInfo *data.Buck
 	return nil
 }

-func (t *TreeServiceMock) DeleteObjectTagging(_ context.Context, bktInfo *data.BucketInfo, objVersion *data.NodeVersion) error {
-	cnrTagsMap, ok := t.tags[bktInfo.CID.EncodeToString()]
-	if !ok {
-		return nil
-	}
-
-	delete(cnrTagsMap, objVersion.ID)
-	return nil
+func (t *TreeServiceMock) DeleteObjectTagging(ctx context.Context, bktInfo *data.BucketInfo, objVersion *data.NodeVersion) error {
+	return t.PutObjectTagging(ctx, bktInfo, objVersion, nil)
 }

 func (t *TreeServiceMock) GetBucketTagging(context.Context, *data.BucketInfo) (map[string]string, error) {
--- a/api/middleware/reqinfo.go
+++ b/api/middleware/reqinfo.go
@ -10,6 +10,7 @@ import (
 	"sync"

 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
+	treepool "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree"
 	"github.com/go-chi/chi/v5"
 	"github.com/google/uuid"
 	"go.uber.org/zap"
@ -206,6 +207,8 @@ func Request(log *zap.Logger) Func {
 				r.Context(), HdrAmzRequestID, reqInfo.RequestID,
 			))

+			r = r.WithContext(treepool.SetRequestID(r.Context(), reqInfo.RequestID))
+
 			reqLogger := log.With(zap.String("request_id", reqInfo.RequestID))
 			r = r.WithContext(SetReqLogger(r.Context(), reqLogger))

--- a/cmd/s3-gw/app.go
+++ b/cmd/s3-gw/app.go
@ -73,6 +73,7 @@ type (
 		maxClient                     maxClientsConfig
 		bypassContentEncodingInChunks atomic.Bool
 		clientCut                     atomic.Bool
+		md5Enabled                    atomic.Bool
 	}

 	maxClientsConfig struct {
@ -176,6 +177,7 @@ func newAppSettings(log *Logger, v *viper.Viper) *appSettings {

 	settings.setBypassContentEncodingInChunks(v.GetBool(cfgKludgeBypassContentEncodingCheckInChunks))
 	settings.setClientCut(v.GetBool(cfgClientCut))
+	settings.setMD5Enabled(v.GetBool(cfgMD5Enabled))

 	return settings
 }
@ -196,6 +198,14 @@ func (s *appSettings) setClientCut(clientCut bool) {
 	s.clientCut.Store(clientCut)
 }

+func (s *appSettings) MD5Enabled() bool {
+	return s.md5Enabled.Load()
+}
+
+func (s *appSettings) setMD5Enabled(md5Enabled bool) {
+	s.md5Enabled.Store(md5Enabled)
+}
+
 func (a *App) initAPI(ctx context.Context) {
 	a.initLayer(ctx)
 	a.initHandler()
@ -315,6 +325,8 @@ func getPools(ctx context.Context, logger *zap.Logger, cfg *viper.Viper) (*pool.
 	prm.SetLogger(logger)
 	prmTree.SetLogger(logger)

+	prmTree.SetMaxRequestAttempts(cfg.GetInt(cfgTreePoolMaxAttempts))
+
 	var apiGRPCDialOpts []grpc.DialOption
 	var treeGRPCDialOpts []grpc.DialOption
 	if cfg.GetBool(cfgTracingEnabled) {
@ -536,6 +548,7 @@ func (a *App) updateSettings() {
 	a.settings.xmlDecoder.UseDefaultNamespaceForCompleteMultipart(a.cfg.GetBool(cfgKludgeUseDefaultXMLNSForCompleteMultipartUpload))
 	a.settings.setBypassContentEncodingInChunks(a.cfg.GetBool(cfgKludgeBypassContentEncodingCheckInChunks))
 	a.settings.setClientCut(a.cfg.GetBool(cfgClientCut))
+	a.settings.setMD5Enabled(a.cfg.GetBool(cfgMD5Enabled))
 }

 func (a *App) startServices() {
@ -679,6 +692,7 @@ func (a *App) initHandler() {

 	cfg.CompleteMultipartKeepalive = a.cfg.GetDuration(cfgKludgeCompleteMultipartUploadKeepalive)
 	cfg.Kludge = a.settings
+	cfg.Features = a.settings

 	var err error
 	a.api, err = handler.New(a.log, a.obj, a.nc, cfg)
--- a/cmd/s3-gw/app_settings.go
+++ b/cmd/s3-gw/app_settings.go
@ -149,6 +149,8 @@ const ( // Settings.
 	cfgSetCopiesNumber = "frostfs.set_copies_number"
 	// Enabling client side object preparing for PUT operations.
 	cfgClientCut = "frostfs.client_cut"
+	// Sets max attempt to make successful tree request.
+	cfgTreePoolMaxAttempts = "frostfs.tree_pool_max_attempts"

 	// List of allowed AccessKeyID prefixes.
 	cfgAllowedAccessKeyIDPrefixes = "allowed_access_key_id_prefixes"
@ -160,6 +162,9 @@ const ( // Settings.
 	// Runtime.
 	cfgSoftMemoryLimit = "runtime.soft_memory_limit"

+	// Enable return MD5 checksum in ETag.
+	cfgMD5Enabled = "features.md5.enabled"
+
 	// envPrefix is an environment variables prefix used for configuration.
 	envPrefix = "S3_GW"
 )
--- a/config/config.env
+++ b/config/config.env
@ -127,6 +127,9 @@ S3_GW_CORS_DEFAULT_MAX_AGE=600
 S3_GW_FROSTFS_SET_COPIES_NUMBER=0
 # This flag enables client side object preparing.
 S3_GW_FROSTFS_CLIENT_CUT=false
+# max attempt to make successful tree request.
+# default value is 0 that means the number of attempts equals to number of nodes in pool.
+S3_GW_FROSTFS_TREE_POOL_MAX_ATTEMPTS=0

 # List of allowed AccessKeyID prefixes
 # If not set, S3 GW will accept all AccessKeyIDs
@ -147,4 +150,6 @@ S3_GW_TRACING_ENABLED=false
 S3_GW_TRACING_ENDPOINT="localhost:4318"
 S3_GW_TRACING_EXPORTER="otlp_grpc"

-S3_GW_RUNTIME_SOFT_MEMORY_LIMIT=1073741824
+S3_GW_RUNTIME_SOFT_MEMORY_LIMIT=1073741824
+
+S3_GW_FEATURES_MD5_ENABLED=false
--- a/config/config.yaml
+++ b/config/config.yaml
@ -152,6 +152,9 @@ frostfs:
  set_copies_number: [0]
  # This flag enables client side object preparing.
  client_cut: false
+  # max attempt to make successful tree request.
+  # default value is 0 that means the number of attempts equals to number of nodes in pool.
+  tree_pool_max_attempts: 0

 # List of allowed AccessKeyID prefixes
 # If the parameter is omitted, S3 GW will accept all AccessKeyIDs
@ -173,4 +176,8 @@ kludge:
  bypass_content_encoding_check_in_chunks: false

 runtime:
-  soft_memory_limit: 1gb
+  soft_memory_limit: 1gb
+
+features:
+  md5:
+    enabled: false
--- a/debian/changelog.init
+++ b/debian/changelog.init
--- a/docs/configuration.md
+++ b/docs/configuration.md
@ -186,6 +186,7 @@ There are some custom types used for brevity:
 | `resolve_bucket`   | [Bucket name resolving configuration](#resolve_bucket-section) |
 | `kludge`           | [Different kludge configuration](#kludge-section)              |
 | `runtime`          | [Runtime configuration](#runtime-section)                      |
+| `features`         | [Features configuration](#features-section)                    |

 ### General section

@ -509,12 +510,14 @@ header for `PutObject`, `CopyObject`, `CreateMultipartUpload`.
 frostfs:
  set_copies_number: [0]
  client_cut: false
+  tree_pool_max_attempts: 0
 ```

-| Parameter           | Type       | SIGHUP reload | Default value | Description                                                                                                                                                                                                     |
-|---------------------|------------|---------------|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `set_copies_number` | `[]uint32` | yes           | `[0]`         | Numbers of the object copies (for each replica) to consider PUT to FrostFS successful. <br/>Default value `[0]` or empty list means that object will be processed according to the container's placement policy |
-| `client_cut`        | `bool`     | yes           | `false`       | This flag enables client side object preparing.                                                                                                                                                                 |
+| Parameter                 | Type       | SIGHUP reload | Default value | Description                                                                                                                                                                                                     |
+|---------------------------|------------|---------------|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `set_copies_number`       | `[]uint32` | yes           | `[0]`         | Numbers of the object copies (for each replica) to consider PUT to FrostFS successful. <br/>Default value `[0]` or empty list means that object will be processed according to the container's placement policy |
+| `client_cut`              | `bool`     | yes           | `false`       | This flag enables client side object preparing.                                                                                                                                                                 |
+| `tree_pool_max_attempts`  | `uint32`   | no            | `0`           | Sets max attempt to make successful tree request. Value 0 means the number of attempts equals to number of nodes in pool.                                                                                       |

 # `resolve_bucket` section

@ -559,4 +562,17 @@ runtime:

 | Parameter           | Type   | SIGHUP reload | Default value | Description                                                                                                                                                                  |
 |---------------------|--------|---------------|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `soft_memory_limit` | `size` | yes           | maxint64      | Soft memory limit for the runtime. Zero or no value stands for no limit. If `GOMEMLIMIT` environment variable is set, the value from the configuration file will be ignored. |
+| `soft_memory_limit` | `size` | yes           | maxint64      | Soft memory limit for the runtime. Zero or no value stands for no limit. If `GOMEMLIMIT` environment variable is set, the value from the configuration file will be ignored. |
+
+# `features` section
+Contains parameters for enabling features.
+
+```yaml
+features:
+   md5:
+      enabled: false
+```
+
+| Parameter     | Type   | SIGHUP reload | Default value | Description                                                    |
+|---------------|--------|---------------|---------------|----------------------------------------------------------------|
+| `md5.enabled` | `bool` | yes           | false         | Flag to enable return MD5 checksum in ETag headers and fields. |
--- a/go.mod
+++ b/go.mod
@ -3,9 +3,9 @@ module git.frostfs.info/TrueCloudLab/frostfs-s3-gw
 go 1.20

 require (
-	git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.15.1-0.20230802075510-964c3edb3f44
+	git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.16.1-0.20231121085847-241a9f1ad0a4
 	git.frostfs.info/TrueCloudLab/frostfs-observability v0.0.0-20230531082742-c97d21411eb6
-	git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20230821090303-202412230a05
+	git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20231107114540-ab75edd70939
 	github.com/aws/aws-sdk-go v1.44.6
 	github.com/bluele/gcache v0.0.2
 	github.com/go-chi/chi/v5 v5.0.8
--- a/go.sum
+++ b/go.sum
@ -36,16 +36,16 @@ cloud.google.com/go/storage v1.8.0/go.mod h1:Wv1Oy7z6Yz3DshWRJFhqM/UCfaWIRTdp0RX
 cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9ullr3+Kg0=
 cloud.google.com/go/storage v1.14.0/go.mod h1:GrKmX003DSIwi9o29oFT7YDnHYwZoctc3fOKtUw0Xmo=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
-git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.15.1-0.20230802075510-964c3edb3f44 h1:v6JqBD/VzZx3QSxbaXnUwnnJ1KEYheU4LzLGr3IhsAE=
-git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.15.1-0.20230802075510-964c3edb3f44/go.mod h1:pKJJRLOChW4zDQsAt1e8k/snWKljJtpkiPfxV53ngjI=
+git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.16.1-0.20231121085847-241a9f1ad0a4 h1:wjLfZ3WCt7qNGsQv+Jl0TXnmtg0uVk/jToKPFTBc/jo=
+git.frostfs.info/TrueCloudLab/frostfs-api-go/v2 v2.16.1-0.20231121085847-241a9f1ad0a4/go.mod h1:uY0AYmCznjZdghDnAk7THFIe1Vlg531IxUcus7ZfUJI=
 git.frostfs.info/TrueCloudLab/frostfs-contract v0.0.0-20230307110621-19a8ef2d02fb h1:S/TrbOOu9qEXZRZ9/Ddw7crnxbBUQLo68PSzQWYrc9M=
 git.frostfs.info/TrueCloudLab/frostfs-contract v0.0.0-20230307110621-19a8ef2d02fb/go.mod h1:nkR5gaGeez3Zv2SE7aceP0YwxG2FzIB5cGKpQO2vV2o=
 git.frostfs.info/TrueCloudLab/frostfs-crypto v0.6.0 h1:FxqFDhQYYgpe41qsIHVOcdzSVCB8JNSfPG7Uk4r2oSk=
 git.frostfs.info/TrueCloudLab/frostfs-crypto v0.6.0/go.mod h1:RUIKZATQLJ+TaYQa60X2fTDwfuhMfm8Ar60bQ5fr+vU=
 git.frostfs.info/TrueCloudLab/frostfs-observability v0.0.0-20230531082742-c97d21411eb6 h1:aGQ6QaAnTerQ5Dq5b2/f9DUQtSqPkZZ/bkMx/HKuLCo=
 git.frostfs.info/TrueCloudLab/frostfs-observability v0.0.0-20230531082742-c97d21411eb6/go.mod h1:W8Nn08/l6aQ7UlIbpF7FsQou7TVpcRD1ZT1KG4TrFhE=
-git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20230821090303-202412230a05 h1:OuViMF54N87FXmaBEpYw3jhzaLrJ/EWOlPL1wUkimE0=
-git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20230821090303-202412230a05/go.mod h1:t1akKcUH7iBrFHX8rSXScYMP17k2kYQXMbZooiL5Juw=
+git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20231107114540-ab75edd70939 h1:jZEepi9yWmqrWgLRQcHQu4YPJaudmd7d2AEhpmM3m4U=
+git.frostfs.info/TrueCloudLab/frostfs-sdk-go v0.0.0-20231107114540-ab75edd70939/go.mod h1:t1akKcUH7iBrFHX8rSXScYMP17k2kYQXMbZooiL5Juw=
 git.frostfs.info/TrueCloudLab/hrw v1.2.1 h1:ccBRK21rFvY5R1WotI6LNoPlizk7qSvdfD8lNIRudVc=
 git.frostfs.info/TrueCloudLab/hrw v1.2.1/go.mod h1:C1Ygde2n843yTZEQ0FP69jYiuaYV0kriLvP4zm8JuvM=
 git.frostfs.info/TrueCloudLab/rfc6979 v0.4.0 h1:M2KR3iBj7WpY3hP10IevfIB9MURr4O9mwVfJ+SjT3HA=
--- a/internal/logs/logs.go
+++ b/internal/logs/logs.go
@ -75,6 +75,7 @@ const (
 	ResolveBucket                                        = "resolve bucket"                                                                                    // Info in ../../api/layer/layer.go
 	CouldntDeleteCorsObject                              = "couldn't delete cors object"                                                                       // Error in ../../api/layer/cors.go
 	PutObject                                            = "put object"                                                                                        // Debug in ../../api/layer/object.go
+	FailedToDeleteObject                                 = "failed to delete object"                                                                           // Debug in ../../api/layer/object.go
 	FailedToDiscardPutPayloadProbablyGoroutineLeaks      = "failed to discard put payload, probably goroutine leaks"                                           // Warn in ../../api/layer/object.go
 	FailedToSubmitTaskToPool                             = "failed to submit task to pool"                                                                     // Warn in ../../api/layer/object.go
 	CouldNotFetchObjectMeta                              = "could not fetch object meta"                                                                       // Warn in ../../api/layer/object.go
--- a/pkg/service/tree/tree.go
+++ b/pkg/service/tree/tree.go
@ -81,6 +81,7 @@ const (
 	partNumberKV    = "Number"
 	sizeKV          = "Size"
 	etagKV          = "ETag"
+	md5KV           = "MD5"

 	// keys for lock.
 	isLockKV       = "IsLock"
@ -185,6 +186,7 @@ func newNodeVersionFromTreeNode(filePath string, treeNode *treeNode) *data.NodeV
 	_, isDeleteMarker := treeNode.Get(isDeleteMarkerKV)
 	_, isCombined := treeNode.Get(isCombinedKV)
 	eTag, _ := treeNode.Get(etagKV)
+	md5, _ := treeNode.Get(md5KV)

 	version := &data.NodeVersion{
 		BaseNodeVersion: data.BaseNodeVersion{
@ -193,6 +195,7 @@ func newNodeVersionFromTreeNode(filePath string, treeNode *treeNode) *data.NodeV
 			OID:       treeNode.ObjID,
 			Timestamp: treeNode.TimeStamp,
 			ETag:      eTag,
+			MD5:       md5,
 			Size:      treeNode.Size,
 			FilePath:  filePath,
 		},
@ -302,6 +305,8 @@ func newPartInfo(node NodeResponse) (*data.PartInfo, error) {
 				return nil, fmt.Errorf("invalid created timestamp: %w", err)
 			}
 			partInfo.Created = time.UnixMilli(utcMilli)
+		case md5KV:
+			partInfo.MD5 = value
 		}
 	}

@ -471,16 +476,7 @@ func (c *Tree) PutObjectTagging(ctx context.Context, bktInfo *data.BucketInfo, o
 }

 func (c *Tree) DeleteObjectTagging(ctx context.Context, bktInfo *data.BucketInfo, objVersion *data.NodeVersion) error {
-	tagNode, err := c.getTreeNode(ctx, bktInfo, objVersion.ID, isTagKV)
-	if err != nil {
-		return err
-	}
-
-	if tagNode == nil {
-		return nil
-	}
-
-	return c.service.RemoveNode(ctx, bktInfo, versionTree, tagNode.ID)
+	return c.PutObjectTagging(ctx, bktInfo, objVersion, nil)
 }

 func (c *Tree) GetBucketTagging(ctx context.Context, bktInfo *data.BucketInfo) (map[string]string, error) {
@ -524,16 +520,7 @@ func (c *Tree) PutBucketTagging(ctx context.Context, bktInfo *data.BucketInfo, t
 }

 func (c *Tree) DeleteBucketTagging(ctx context.Context, bktInfo *data.BucketInfo) error {
-	node, err := c.getSystemNode(ctx, bktInfo, []string{bucketTaggingFilename}, nil)
-	if err != nil && !errors.Is(err, layer.ErrNodeNotFound) {
-		return err
-	}
-
-	if node != nil {
-		return c.service.RemoveNode(ctx, bktInfo, systemTree, node.ID)
-	}
-
-	return nil
+	return c.PutBucketTagging(ctx, bktInfo, nil)
 }

 func (c *Tree) getTreeNode(ctx context.Context, bktInfo *data.BucketInfo, nodeID uint64, key string) (*treeNode, error) {
@ -578,7 +565,7 @@ func (c *Tree) GetVersions(ctx context.Context, bktInfo *data.BucketInfo, filepa
 }

 func (c *Tree) GetLatestVersion(ctx context.Context, bktInfo *data.BucketInfo, objectName string) (*data.NodeVersion, error) {
-	meta := []string{oidKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV}
+	meta := []string{oidKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV, md5KV}
 	path := pathFromName(objectName)

 	p := &GetNodesParams{
@ -586,7 +573,7 @@ func (c *Tree) GetLatestVersion(ctx context.Context, bktInfo *data.BucketInfo, o
 		TreeID:     versionTree,
 		Path:       path,
 		Meta:       meta,
-		LatestOnly: true,
+		LatestOnly: false,
 		AllAttrs:   false,
 	}
 	nodes, err := c.service.GetNodes(ctx, p)
@ -594,11 +581,43 @@ func (c *Tree) GetLatestVersion(ctx context.Context, bktInfo *data.BucketInfo, o
 		return nil, err
 	}

-	if len(nodes) == 0 {
+	latestNode, err := getLatestNode(nodes)
+	if err != nil {
+		return nil, err
+	}
+
+	return newNodeVersion(objectName, latestNode)
+}
+
+func getLatestNode(nodes []NodeResponse) (NodeResponse, error) {
+	var (
+		maxCreationTime uint64
+		targetIndexNode = -1
+	)
+
+	for i, node := range nodes {
+		currentCreationTime := node.GetTimestamp()
+		if checkExistOID(node.GetMeta()) && currentCreationTime > maxCreationTime {
+			maxCreationTime = currentCreationTime
+			targetIndexNode = i
+		}
+	}
+
+	if targetIndexNode == -1 {
 		return nil, layer.ErrNodeNotFound
 	}

-	return newNodeVersion(objectName, nodes[0])
+	return nodes[targetIndexNode], nil
+}
+
+func checkExistOID(meta []Meta) bool {
+	for _, kv := range meta {
+		if kv.GetKey() == "OID" {
+			return true
+		}
+	}
+
+	return false
 }

 // pathFromName splits name by '/'.
@ -992,6 +1011,7 @@ func (c *Tree) AddPart(ctx context.Context, bktInfo *data.BucketInfo, multipartN
 		sizeKV:       strconv.FormatUint(info.Size, 10),
 		createdKV:    strconv.FormatInt(info.Created.UTC().UnixMilli(), 10),
 		etagKV:       info.ETag,
+		md5KV:        info.MD5,
 	}

 	for _, part := range parts {
@ -1124,6 +1144,9 @@ func (c *Tree) addVersion(ctx context.Context, bktInfo *data.BucketInfo, treeID
 	if len(version.ETag) > 0 {
 		meta[etagKV] = version.ETag
 	}
+	if len(version.MD5) > 0 {
+		meta[md5KV] = version.MD5
+	}

 	if version.IsDeleteMarker() {
 		meta[isDeleteMarkerKV] = "true"
@ -1168,7 +1191,7 @@ func (c *Tree) clearOutdatedVersionInfo(ctx context.Context, bktInfo *data.Bucke
 }

 func (c *Tree) getVersions(ctx context.Context, bktInfo *data.BucketInfo, treeID, filepath string, onlyUnversioned bool) ([]*data.NodeVersion, error) {
-	keysToReturn := []string{oidKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV}
+	keysToReturn := []string{oidKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV, md5KV}
 	path := pathFromName(filepath)
 	p := &GetNodesParams{
 		BktInfo:    bktInfo,
--- a/pkg/service/tree/tree_test.go
+++ b/pkg/service/tree/tree_test.go
@ -168,3 +168,127 @@ func TestTreeServiceAddVersion(t *testing.T) {
 	require.Len(t, versions, 1)
 	require.Equal(t, storedNode, versions[0])
 }
+
+func TestGetLatestNode(t *testing.T) {
+	for _, tc := range []struct {
+		name           string
+		nodes          []NodeResponse
+		exceptedNodeID uint64
+		error          bool
+	}{
+		{
+			name:  "empty",
+			nodes: []NodeResponse{},
+			error: true,
+		},
+		{
+			name: "one node of the object version",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    1,
+					parentID:  0,
+					timestamp: 1,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+			},
+			exceptedNodeID: 1,
+		},
+		{
+			name: "one node of the object version and one node of the secondary object",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    2,
+					parentID:  0,
+					timestamp: 3,
+					meta:      []nodeMeta{},
+				},
+				nodeResponse{
+					nodeID:    1,
+					parentID:  0,
+					timestamp: 1,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+			},
+			exceptedNodeID: 1,
+		},
+		{
+			name: "all nodes represent a secondary object",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    2,
+					parentID:  0,
+					timestamp: 3,
+					meta:      []nodeMeta{},
+				},
+				nodeResponse{
+					nodeID:    4,
+					parentID:  0,
+					timestamp: 5,
+					meta:      []nodeMeta{},
+				},
+			},
+			error: true,
+		},
+		{
+			name: "several nodes of different types and with different timestamp",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    1,
+					parentID:  0,
+					timestamp: 1,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+				nodeResponse{
+					nodeID:    3,
+					parentID:  0,
+					timestamp: 3,
+					meta:      []nodeMeta{},
+				},
+				nodeResponse{
+					nodeID:    4,
+					parentID:  0,
+					timestamp: 4,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+				nodeResponse{
+					nodeID:    6,
+					parentID:  0,
+					timestamp: 6,
+					meta:      []nodeMeta{},
+				},
+			},
+			exceptedNodeID: 4,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			actualNode, err := getLatestNode(tc.nodes)
+			if tc.error {
+				require.Error(t, err)
+				return
+			}
+
+			require.NoError(t, err)
+			require.Equal(t, tc.exceptedNodeID, actualNode.GetNodeID())
+		})
+	}
+}