Add double encryption at S3 gateway. (#6423)

This PR adds pass-through, single encryption at gateway and double
encryption support (gateway encryption with pass through of SSE
headers to backend).

If KMS is set up (either with Vault as KMS or using
MINIO_SSE_MASTER_KEY),gateway will automatically perform
single encryption. If MINIO_GATEWAY_SSE is set up in addition to
Vault KMS, double encryption is performed.When neither KMS nor
MINIO_GATEWAY_SSE is set, do a pass through to backend.

When double encryption is specified, MINIO_GATEWAY_SSE can be set to
"C" for SSE-C encryption at gateway and backend, "S3" for SSE-S3
encryption at gateway/backend or both to support more than one option.

Fixes #6323, #6696

cmd/admin-heal-ops.go

@@ -133,7 +133,7 @@ func (ahs *allHealState) periodicHealSeqsClean() {
 				}
 			}
 			ahs.Unlock()
-		case <-globalServiceDoneCh:
+		case <-GlobalServiceDoneCh:
 			// server could be restarting - need
 			// to exit immediately
 			return

cmd/api-router.go

@@ -26,14 +26,19 @@ import (
 type objectAPIHandlers struct {
 	ObjectAPI func() ObjectLayer
 	CacheAPI  func() CacheObjectLayer
+	// Returns true of handlers should interpret encryption.
+	EncryptionEnabled func() bool
 }
 
 // registerAPIRouter - registers S3 compatible APIs.
-func registerAPIRouter(router *mux.Router) {
+func registerAPIRouter(router *mux.Router, encryptionEnabled bool) {
 	// Initialize API.
 	api := objectAPIHandlers{
 		ObjectAPI: newObjectLayerFn,
 		CacheAPI:  newCacheObjectsFn,
+		EncryptionEnabled: func() bool {
+			return encryptionEnabled
+		},
 	}
 
 	// API Router

cmd/bucket-handlers.go

@@ -486,7 +486,7 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -627,9 +627,17 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 	pReader := NewPutObjReader(rawReader, nil, nil)
 	var objectEncryptionKey []byte
 
+	// This request header needs to be set prior to setting ObjectOptions
 	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
 		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
 	}
+	// get gateway encryption options
+	var opts ObjectOptions
+	opts, err = putEncryptionOpts(ctx, r, bucket, object, nil)
+	if err != nil {
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
+		return
+	}
 	if objectAPI.IsEncryptionSupported() {
 		if hasServerSideEncryptionHeader(formValues) && !hasSuffix(object, slashSeparator) { // handle SSE-C and SSE-S3 requests
 			var reader io.Reader
@@ -656,7 +664,7 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		}
 	}
 
-	objInfo, err := objectAPI.PutObject(ctx, bucket, object, pReader, metadata, ObjectOptions{})
+	objInfo, err := objectAPI.PutObject(ctx, bucket, object, pReader, metadata, opts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return

cmd/crypto/metadata.go

@@ -40,6 +40,14 @@ func RemoveSensitiveEntries(metadata map[string]string) { // The functions is te
 	delete(metadata, SSECopyKey)
 }
 
+// RemoveSSEHeaders removes all crypto-specific SSE
+// header entries from the metadata map.
+func RemoveSSEHeaders(metadata map[string]string) {
+	delete(metadata, SSEHeader)
+	delete(metadata, SSECKeyMD5)
+	delete(metadata, SSECAlgorithm)
+}
+
 // RemoveInternalEntries removes all crypto-specific internal
 // metadata entries from the metadata map.
 func RemoveInternalEntries(metadata map[string]string) {

cmd/disk-cache-fs.go

@@ -91,7 +91,7 @@ func newCacheFSObjects(dir string, expiry int, maxDiskUsagePct int) (*cacheFSObj
 		appendFileMap: make(map[string]*fsAppendFile),
 	}
 
-	go fsObjects.cleanupStaleMultipartUploads(context.Background(), globalMultipartCleanupInterval, globalMultipartExpiry, globalServiceDoneCh)
+	go fsObjects.cleanupStaleMultipartUploads(context.Background(), GlobalMultipartCleanupInterval, GlobalMultipartExpiry, GlobalServiceDoneCh)
 
 	cacheFS := cacheFSObjects{
 		FSObjects:       fsObjects,
@@ -158,7 +158,7 @@ func (cfs *cacheFSObjects) purgeTrash() {
 
 	for {
 		select {
-		case <-globalServiceDoneCh:
+		case <-GlobalServiceDoneCh:
 			return
 		case <-ticker.C:
 			trashPath := path.Join(cfs.fsPath, minioMetaBucket, cacheTrashDir)

cmd/disk-cache_test.go

@@ -134,7 +134,7 @@ func TestCacheExclusion(t *testing.T) {
 		t.Fatal(err)
 	}
 	cobj := cobjects.(*cacheObjects)
-	globalServiceDoneCh <- struct{}{}
+	GlobalServiceDoneCh <- struct{}{}
 	testCases := []struct {
 		bucketName     string
 		objectName     string

cmd/dummy-object-layer_test.go

@@ -99,7 +99,7 @@ func (api *DummyObjectLayer) PutObjectPart(ctx context.Context, bucket, object,
 	return
 }
 
-func (api *DummyObjectLayer) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int) (result ListPartsInfo, err error) {
+func (api *DummyObjectLayer) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int, opts ObjectOptions) (result ListPartsInfo, err error) {
 	return
 }
 

cmd/encryption-v1.go

@@ -29,6 +29,7 @@ import (
 	"path"
 	"strconv"
 
+	"github.com/minio/minio-go/pkg/encrypt"
 	"github.com/minio/minio/cmd/crypto"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/ioutil"
@@ -55,11 +56,11 @@ const (
 	// SSEIVSize is the size of the IV data
 	SSEIVSize = 32 // 32 bytes
 
-	// SSE dare package block size.
+	// SSEDAREPackageBlockSize - SSE dare package block size.
-	sseDAREPackageBlockSize = 64 * 1024 // 64KiB bytes
+	SSEDAREPackageBlockSize = 64 * 1024 // 64KiB bytes
 
-	// SSE dare package meta padding bytes.
+	// SSEDAREPackageMetaSize - SSE dare package meta padding bytes.
-	sseDAREPackageMetaSize = 32 // 32 bytes
+	SSEDAREPackageMetaSize = 32 // 32 bytes
 
 )
 
@@ -158,14 +159,14 @@ func rotateKey(oldKey []byte, newKey []byte, bucket, object string, metadata map
 		crypto.SSEC.CreateMetadata(metadata, sealedKey)
 		return nil
 	case crypto.S3.IsEncrypted(metadata):
-		if globalKMS == nil {
+		if GlobalKMS == nil {
 			return errKMSNotConfigured
 		}
 		keyID, kmsKey, sealedKey, err := crypto.S3.ParseMetadata(metadata)
 		if err != nil {
 			return err
 		}
-		oldKey, err := globalKMS.UnsealKey(keyID, kmsKey, crypto.Context{bucket: path.Join(bucket, object)})
+		oldKey, err := GlobalKMS.UnsealKey(keyID, kmsKey, crypto.Context{bucket: path.Join(bucket, object)})
 		if err != nil {
 			return err
 		}
@@ -174,7 +175,7 @@ func rotateKey(oldKey []byte, newKey []byte, bucket, object string, metadata map
 			return err
 		}
 
-		newKey, encKey, err := globalKMS.GenerateKey(globalKMSKeyID, crypto.Context{bucket: path.Join(bucket, object)})
+		newKey, encKey, err := GlobalKMS.GenerateKey(globalKMSKeyID, crypto.Context{bucket: path.Join(bucket, object)})
 		if err != nil {
 			return err
 		}
@@ -187,10 +188,10 @@ func rotateKey(oldKey []byte, newKey []byte, bucket, object string, metadata map
 func newEncryptMetadata(key []byte, bucket, object string, metadata map[string]string, sseS3 bool) ([]byte, error) {
 	var sealedKey crypto.SealedKey
 	if sseS3 {
-		if globalKMS == nil {
+		if GlobalKMS == nil {
 			return nil, errKMSNotConfigured
 		}
-		key, encKey, err := globalKMS.GenerateKey(globalKMSKeyID, crypto.Context{bucket: path.Join(bucket, object)})
+		key, encKey, err := GlobalKMS.GenerateKey(globalKMSKeyID, crypto.Context{bucket: path.Join(bucket, object)})
 		if err != nil {
 			return nil, err
 		}
@@ -279,7 +280,7 @@ func decryptObjectInfo(key []byte, bucket, object string, metadata map[string]st
 	default:
 		return nil, errObjectTampered
 	case crypto.S3.IsEncrypted(metadata):
-		if globalKMS == nil {
+		if GlobalKMS == nil {
 			return nil, errKMSNotConfigured
 		}
 		keyID, kmsKey, sealedKey, err := crypto.S3.ParseMetadata(metadata)
@@ -287,7 +288,7 @@ func decryptObjectInfo(key []byte, bucket, object string, metadata map[string]st
 		if err != nil {
 			return nil, err
 		}
-		extKey, err := globalKMS.UnsealKey(keyID, kmsKey, crypto.Context{bucket: path.Join(bucket, object)})
+		extKey, err := GlobalKMS.UnsealKey(keyID, kmsKey, crypto.Context{bucket: path.Join(bucket, object)})
 		if err != nil {
 			return nil, err
 		}
@@ -395,7 +396,6 @@ func DecryptBlocksRequestR(inputReader io.Reader, h http.Header, offset,
 	io.Reader, error) {
 
 	bucket, object := oi.Bucket, oi.Name
-
 	// Single part case
 	if !isEncryptedMultipart(oi) {
 		var reader io.Reader
@@ -411,8 +411,8 @@ func DecryptBlocksRequestR(inputReader io.Reader, h http.Header, offset,
 		return reader, nil
 	}
 
-	partDecRelOffset := int64(seqNumber) * sseDAREPackageBlockSize
+	partDecRelOffset := int64(seqNumber) * SSEDAREPackageBlockSize
-	partEncRelOffset := int64(seqNumber) * (sseDAREPackageBlockSize + sseDAREPackageMetaSize)
+	partEncRelOffset := int64(seqNumber) * (SSEDAREPackageBlockSize + SSEDAREPackageMetaSize)
 
 	w := &DecryptBlocksReader{
 		reader:            inputReader,
@@ -477,7 +477,7 @@ type DecryptBlocksReader struct {
 	// Current part index
 	partIndex int
 	// Parts information
-	parts          []objectPartInfo
+	parts          []ObjectPartInfo
 	header         http.Header
 	bucket, object string
 	metadata       map[string]string
@@ -592,7 +592,7 @@ type DecryptBlocksWriter struct {
 	// Current part index
 	partIndex int
 	// Parts information
-	parts          []objectPartInfo
+	parts          []ObjectPartInfo
 	req            *http.Request
 	bucket, object string
 	metadata       map[string]string
@@ -743,6 +743,7 @@ func DecryptBlocksRequest(client io.Writer, r *http.Request, bucket, object stri
 	}
 
 	seqNumber, encStartOffset, encLength = getEncryptedMultipartsOffsetLength(startOffset, length, objInfo)
+
 	var partStartIndex int
 	var partStartOffset = startOffset
 	// Skip parts until final offset maps to a particular part offset.
@@ -765,8 +766,8 @@ func DecryptBlocksRequest(client io.Writer, r *http.Request, bucket, object stri
 		partStartOffset -= int64(decryptedSize)
 	}
 
-	startSeqNum := partStartOffset / sseDAREPackageBlockSize
+	startSeqNum := partStartOffset / SSEDAREPackageBlockSize
-	partEncRelOffset := int64(startSeqNum) * (sseDAREPackageBlockSize + sseDAREPackageMetaSize)
+	partEncRelOffset := int64(startSeqNum) * (SSEDAREPackageBlockSize + SSEDAREPackageMetaSize)
 
 	w := &DecryptBlocksWriter{
 		writer:            client,
@@ -857,9 +858,9 @@ func getEncryptedMultipartsOffsetLength(offset, length int64, obj ObjectInfo) (u
 
 // getEncryptedSinglePartOffsetLength - fetch sequence number, encrypted start offset and encrypted length.
 func getEncryptedSinglePartOffsetLength(offset, length int64, objInfo ObjectInfo) (seqNumber uint32, encOffset int64, encLength int64) {
-	onePkgSize := int64(sseDAREPackageBlockSize + sseDAREPackageMetaSize)
+	onePkgSize := int64(SSEDAREPackageBlockSize + SSEDAREPackageMetaSize)
 
-	seqNumber = uint32(offset / sseDAREPackageBlockSize)
+	seqNumber = uint32(offset / SSEDAREPackageBlockSize)
 	encOffset = int64(seqNumber) * onePkgSize
 	// The math to compute the encrypted length is always
 	// originalLength i.e (offset+length-1) to be divided under
@@ -867,10 +868,10 @@ func getEncryptedSinglePartOffsetLength(offset, length int64, objInfo ObjectInfo
 	// block. This is then multiplied by final package size which
 	// is basically 64KiB + 32. Finally negate the encrypted offset
 	// to get the final encrypted length on disk.
-	encLength = ((offset+length)/sseDAREPackageBlockSize)*onePkgSize - encOffset
+	encLength = ((offset+length)/SSEDAREPackageBlockSize)*onePkgSize - encOffset
 
 	// Check for the remainder, to figure if we need one extract package to read from.
-	if (offset+length)%sseDAREPackageBlockSize > 0 {
+	if (offset+length)%SSEDAREPackageBlockSize > 0 {
 		encLength += onePkgSize
 	}
 
@@ -1041,11 +1042,11 @@ func (o *ObjectInfo) GetDecryptedRange(rs *HTTPRangeSpec) (encOff, encLength, sk
 	// partStart is always found in the loop above,
 	// because off is validated.
 
-	sseDAREEncPackageBlockSize := int64(sseDAREPackageBlockSize + sseDAREPackageMetaSize)
+	sseDAREEncPackageBlockSize := int64(SSEDAREPackageBlockSize + SSEDAREPackageMetaSize)
-	startPkgNum := (off - cumulativeSum) / sseDAREPackageBlockSize
+	startPkgNum := (off - cumulativeSum) / SSEDAREPackageBlockSize
 
 	// Now we can calculate the number of bytes to skip
-	skipLen = (off - cumulativeSum) % sseDAREPackageBlockSize
+	skipLen = (off - cumulativeSum) % SSEDAREPackageBlockSize
 
 	encOff = encCumulativeSum + startPkgNum*sseDAREEncPackageBlockSize
 	// Locate the part containing the end of the required range
@@ -1062,7 +1063,7 @@ func (o *ObjectInfo) GetDecryptedRange(rs *HTTPRangeSpec) (encOff, encLength, sk
 	}
 	// partEnd is always found in the loop above, because off and
 	// length are validated.
-	endPkgNum := (endOffset - cumulativeSum) / sseDAREPackageBlockSize
+	endPkgNum := (endOffset - cumulativeSum) / SSEDAREPackageBlockSize
 	// Compute endEncOffset with one additional DARE package (so
 	// we read the package containing the last desired byte).
 	endEncOffset := encCumulativeSum + (endPkgNum+1)*sseDAREEncPackageBlockSize
@@ -1157,3 +1158,113 @@ func DecryptObjectInfo(info *ObjectInfo, headers http.Header) (encrypted bool, e
 	}
 	return
 }
+
+// The customer key in the header is used by the gateway for encryption in the case of
+// s3 gateway double encryption. A new client key is derived from the customer provided
+// key to be sent to the s3 backend for encryption at the backend.
+func deriveClientKey(clientKey [32]byte, bucket, object string) [32]byte {
+	var key [32]byte
+	mac := hmac.New(sha256.New, clientKey[:])
+	mac.Write([]byte(crypto.SSEC.String()))
+	mac.Write([]byte(path.Join(bucket, object)))
+	mac.Sum(key[:0])
+	return key
+}
+
+// extract encryption options for pass through to backend in the case of gateway
+func extractEncryptionOption(header http.Header, copySource bool, metadata map[string]string) (opts ObjectOptions, err error) {
+	var clientKey [32]byte
+	var sse encrypt.ServerSide
+
+	if copySource {
+		if crypto.SSECopy.IsRequested(header) {
+			clientKey, err = crypto.SSECopy.ParseHTTP(header)
+			if err != nil {
+				return
+			}
+			if sse, err = encrypt.NewSSEC(clientKey[:]); err != nil {
+				return
+			}
+			return ObjectOptions{ServerSideEncryption: encrypt.SSECopy(sse)}, nil
+		}
+		return
+	}
+
+	if crypto.SSEC.IsRequested(header) {
+		clientKey, err = crypto.SSEC.ParseHTTP(header)
+		if err != nil {
+			return
+		}
+		if sse, err = encrypt.NewSSEC(clientKey[:]); err != nil {
+			return
+		}
+		return ObjectOptions{ServerSideEncryption: sse}, nil
+	}
+	if crypto.S3.IsRequested(header) || (metadata != nil && crypto.S3.IsEncrypted(metadata)) {
+		return ObjectOptions{ServerSideEncryption: encrypt.NewSSE()}, nil
+	}
+	return opts, nil
+}
+
+// get ObjectOptions for GET calls from encryption headers
+func getEncryptionOpts(ctx context.Context, r *http.Request, bucket, object string) (ObjectOptions, error) {
+	var (
+		encryption encrypt.ServerSide
+		opts       ObjectOptions
+	)
+	if GlobalGatewaySSE.SSEC() && crypto.SSEC.IsRequested(r.Header) {
+		key, err := crypto.SSEC.ParseHTTP(r.Header)
+		if err != nil {
+			return opts, err
+		}
+		derivedKey := deriveClientKey(key, bucket, object)
+		encryption, err = encrypt.NewSSEC(derivedKey[:])
+		logger.CriticalIf(ctx, err)
+		return ObjectOptions{ServerSideEncryption: encryption}, nil
+	}
+	// default case of passing encryption headers to backend
+	return extractEncryptionOption(r.Header, false, nil)
+}
+
+// get ObjectOptions for PUT calls from encryption headers
+func putEncryptionOpts(ctx context.Context, r *http.Request, bucket, object string, metadata map[string]string) (opts ObjectOptions, err error) {
+	// In the case of multipart custom format, the metadata needs to be checked in addition to header to see if it
+	// is SSE-S3 encrypted, primarily because S3 protocol does not require SSE-S3 headers in PutObjectPart calls
+	if GlobalGatewaySSE.SSES3() && (crypto.S3.IsRequested(r.Header) || crypto.S3.IsEncrypted(metadata)) {
+		return ObjectOptions{ServerSideEncryption: encrypt.NewSSE()}, nil
+	}
+	if GlobalGatewaySSE.SSEC() && crypto.SSEC.IsRequested(r.Header) {
+		return getEncryptionOpts(ctx, r, bucket, object)
+	}
+	// default case of passing encryption headers to backend
+	return extractEncryptionOption(r.Header, false, metadata)
+}
+
+// get ObjectOptions for Copy calls for encryption headers provided on the target side
+func copyDstEncryptionOpts(ctx context.Context, r *http.Request, bucket, object string, metadata map[string]string) (opts ObjectOptions, err error) {
+	return putEncryptionOpts(ctx, r, bucket, object, metadata)
+}
+
+// get ObjectOptions for Copy calls for encryption headers provided on the source side
+func copySrcEncryptionOpts(ctx context.Context, r *http.Request, bucket, object string) (ObjectOptions, error) {
+	var (
+		ssec encrypt.ServerSide
+		opts ObjectOptions
+	)
+
+	if GlobalGatewaySSE.SSEC() && crypto.SSECopy.IsRequested(r.Header) {
+		key, err := crypto.SSECopy.ParseHTTP(r.Header)
+		if err != nil {
+			return opts, err
+		}
+		derivedKey := deriveClientKey(key, bucket, object)
+		ssec, err = encrypt.NewSSEC(derivedKey[:])
+		if err != nil {
+			return opts, err
+		}
+		return ObjectOptions{ServerSideEncryption: encrypt.SSECopy(ssec)}, nil
+	}
+
+	// default case of passing encryption headers to backend
+	return extractEncryptionOption(r.Header, true, nil)
+}

cmd/encryption-v1_test.go

@@ -18,10 +18,12 @@ package cmd
 
 import (
 	"bytes"
+	"encoding/base64"
 	"net/http"
 	"testing"
 
 	humanize "github.com/dustin/go-humanize"
+	"github.com/minio/minio-go/pkg/encrypt"
 	"github.com/minio/minio/cmd/crypto"
 	"github.com/minio/sio"
 )
@@ -355,7 +357,7 @@ func TestGetDecryptedRange_Issue50(t *testing.T) {
 			"content-type":                         "application/octet-stream",
 			"etag":                                 "166b1545b4c1535294ee0686678bea8c-2",
 		},
-		Parts: []objectPartInfo{
+		Parts: []ObjectPartInfo{
 			{
 				Number:     1,
 				Name:       "part.1",
@@ -503,7 +505,7 @@ func TestGetDecryptedRange(t *testing.T) {
 	var (
 		// make a multipart object-info given part sizes
 		mkMPObj = func(sizes []int64) ObjectInfo {
-			r := make([]objectPartInfo, len(sizes))
+			r := make([]ObjectPartInfo, len(sizes))
 			sum := int64(0)
 			for i, s := range sizes {
 				r[i].Number = i
@@ -675,3 +677,84 @@ func TestGetDecryptedRange(t *testing.T) {
 
 	}
 }
+
+var extractEncryptionOptionTests = []struct {
+	headers        http.Header
+	copySource     bool
+	metadata       map[string]string
+	encryptionType encrypt.Type
+	err            error
+}{
+	{headers: http.Header{crypto.SSECAlgorithm: []string{"AES256"},
+		crypto.SSECKey:    []string{"MzJieXRlc2xvbmdzZWNyZXRrZXltdXN0cHJvdmlkZWQ="},
+		crypto.SSECKeyMD5: []string{"7PpPLAK26ONlVUGOWlusfg=="}},
+		copySource:     false,
+		metadata:       nil,
+		encryptionType: encrypt.SSEC,
+		err:            nil}, // 0
+	{headers: http.Header{crypto.SSECAlgorithm: []string{"AES256"},
+		crypto.SSECKey:    []string{"MzJieXRlc2xvbmdzZWNyZXRrZXltdXN0cHJvdmlkZWQ="},
+		crypto.SSECKeyMD5: []string{"7PpPLAK26ONlVUGOWlusfg=="}},
+		copySource:     true,
+		metadata:       nil,
+		encryptionType: "",
+		err:            nil}, // 1
+	{headers: http.Header{crypto.SSECAlgorithm: []string{"AES256"},
+		crypto.SSECKey:    []string{"Mz"},
+		crypto.SSECKeyMD5: []string{"7PpPLAK26ONlVUGOWlusfg=="}},
+		copySource:     false,
+		metadata:       nil,
+		encryptionType: "",
+		err:            crypto.ErrInvalidCustomerKey}, // 2
+	{headers: http.Header{crypto.SSEHeader: []string{"AES256"}},
+		copySource:     false,
+		metadata:       nil,
+		encryptionType: encrypt.S3,
+		err:            nil}, // 3
+	{headers: http.Header{},
+		copySource: false,
+		metadata: map[string]string{crypto.S3SealedKey: base64.StdEncoding.EncodeToString(make([]byte, 64)),
+			crypto.S3KMSKeyID:     "kms-key",
+			crypto.S3KMSSealedKey: "m-key"},
+		encryptionType: encrypt.S3,
+		err:            nil}, // 4
+	{headers: http.Header{},
+		copySource: true,
+		metadata: map[string]string{crypto.S3SealedKey: base64.StdEncoding.EncodeToString(make([]byte, 64)),
+			crypto.S3KMSKeyID:     "kms-key",
+			crypto.S3KMSSealedKey: "m-key"},
+		encryptionType: "",
+		err:            nil}, // 5
+	{headers: http.Header{crypto.SSECopyAlgorithm: []string{"AES256"},
+		crypto.SSECopyKey:    []string{"MzJieXRlc2xvbmdzZWNyZXRrZXltdXN0cHJvdmlkZWQ="},
+		crypto.SSECopyKeyMD5: []string{"7PpPLAK26ONlVUGOWlusfg=="}},
+		copySource:     true,
+		metadata:       nil,
+		encryptionType: encrypt.SSEC,
+		err:            nil}, // 6
+	{headers: http.Header{crypto.SSECopyAlgorithm: []string{"AES256"},
+		crypto.SSECopyKey:    []string{"MzJieXRlc2xvbmdzZWNyZXRrZXltdXN0cHJvdmlkZWQ="},
+		crypto.SSECopyKeyMD5: []string{"7PpPLAK26ONlVUGOWlusfg=="}},
+		copySource:     false,
+		metadata:       nil,
+		encryptionType: "",
+		err:            nil}, // 7
+}
+
+func TestExtractEncryptionOptions(t *testing.T) {
+	for i, test := range extractEncryptionOptionTests {
+		opts, err := extractEncryptionOption(test.headers, test.copySource, test.metadata)
+		if test.err != err {
+			t.Errorf("Case %d: expected err: %v , actual err: %v", i, test.err, err)
+		}
+		if err == nil {
+			if opts.ServerSideEncryption == nil && test.encryptionType != "" {
+				t.Errorf("Case %d: expected opts to be of %v encryption type", i, test.encryptionType)
+
+			}
+			if opts.ServerSideEncryption != nil && test.encryptionType != opts.ServerSideEncryption.Type() {
+				t.Errorf("Case %d: expected opts to have encryption type %v but was %v ", i, test.encryptionType, opts.ServerSideEncryption.Type())
+			}
+		}
+	}
+}

cmd/environment.go

@@ -136,13 +136,13 @@ func (env environment) LookupKMSConfig(config crypto.KMSConfig) (err error) {
 		if !config.Vault.IsEmpty() { // Vault and KMS master key provided
 			return errors.New("Ambiguous KMS configuration: vault configuration and a master key are provided at the same time")
 		}
-		globalKMSKeyID, globalKMS, err = parseKMSMasterKey(masterKey)
+		globalKMSKeyID, GlobalKMS, err = parseKMSMasterKey(masterKey)
 		if err != nil {
 			return err
 		}
 	}
 	if !config.Vault.IsEmpty() {
-		globalKMS, err = crypto.NewVault(config.Vault)
+		GlobalKMS, err = crypto.NewVault(config.Vault)
 		if err != nil {
 			return err
 		}
@@ -154,7 +154,7 @@ func (env environment) LookupKMSConfig(config crypto.KMSConfig) (err error) {
 		return err
 	}
 	globalAutoEncryption = bool(autoEncryption)
-	if globalAutoEncryption && globalKMS == nil { // auto-encryption enabled but no KMS
+	if globalAutoEncryption && GlobalKMS == nil { // auto-encryption enabled but no KMS
 		return errors.New("Invalid KMS configuration: auto-encryption is enabled but no valid KMS configuration is present")
 	}
 	return nil

cmd/fs-v1-metadata.go

@@ -113,7 +113,7 @@ type fsMetaV1 struct {
 	// Metadata map for current object.
 	Meta map[string]string `json:"meta,omitempty"`
 	// parts info for current object - used in encryption.
-	Parts []objectPartInfo `json:"parts,omitempty"`
+	Parts []ObjectPartInfo `json:"parts,omitempty"`
 }
 
 // IsValid - tells if the format is sane by validating the version
@@ -207,9 +207,9 @@ func parseFSMetaMap(fsMetaBuf []byte) map[string]string {
 	return metaMap
 }
 
-func parseFSPartsArray(fsMetaBuf []byte) []objectPartInfo {
+func parseFSPartsArray(fsMetaBuf []byte) []ObjectPartInfo {
 	// Get xlMetaV1.Parts array
-	var partsArray []objectPartInfo
+	var partsArray []ObjectPartInfo
 
 	partsArrayResult := gjson.GetBytes(fsMetaBuf, "parts")
 	partsArrayResult.ForEach(func(key, part gjson.Result) bool {
@@ -219,7 +219,7 @@ func parseFSPartsArray(fsMetaBuf []byte) []objectPartInfo {
 		etag := gjson.Get(partJSON, "etag").String()
 		size := gjson.Get(partJSON, "size").Int()
 		actualSize := gjson.Get(partJSON, "actualSize").Int()
-		partsArray = append(partsArray, objectPartInfo{
+		partsArray = append(partsArray, ObjectPartInfo{
 			Number:     int(number),
 			Name:       name,
 			ETag:       etag,

cmd/fs-v1-multipart.go

@@ -353,7 +353,7 @@ func (fs *FSObjects) PutObjectPart(ctx context.Context, bucket, object, uploadID
 // Implements S3 compatible ListObjectParts API. The resulting
 // ListPartsInfo structure is unmarshalled directly into XML and
 // replied back to the client.
-func (fs *FSObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker, maxParts int) (result ListPartsInfo, e error) {
+func (fs *FSObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker, maxParts int, opts ObjectOptions) (result ListPartsInfo, e error) {
 	if err := checkListPartsArgs(ctx, bucket, object, fs); err != nil {
 		return result, toObjectErr(err)
 	}
@@ -515,7 +515,7 @@ func (fs *FSObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 	fsMeta := fsMetaV1{}
 
 	// Allocate parts similar to incoming slice.
-	fsMeta.Parts = make([]objectPartInfo, len(parts))
+	fsMeta.Parts = make([]ObjectPartInfo, len(parts))
 
 	entries, err := readDir(uploadIDDir)
 	if err != nil {
@@ -560,7 +560,7 @@ func (fs *FSObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 			partSize = actualSize
 		}
 
-		fsMeta.Parts[i] = objectPartInfo{
+		fsMeta.Parts[i] = ObjectPartInfo{
 			Number:     part.PartNumber,
 			ETag:       part.ETag,
 			Size:       fi.Size(),

cmd/fs-v1-multipart_test.go

@@ -36,7 +36,7 @@ func TestFSCleanupMultipartUploadsInRoutine(t *testing.T) {
 
 	// Close the go-routine, we are going to
 	// manually start it and test in this test case.
-	globalServiceDoneCh <- struct{}{}
+	GlobalServiceDoneCh <- struct{}{}
 
 	bucketName := "bucket"
 	objectName := "object"
@@ -47,14 +47,14 @@ func TestFSCleanupMultipartUploadsInRoutine(t *testing.T) {
 		t.Fatal("Unexpected err: ", err)
 	}
 
-	go fs.cleanupStaleMultipartUploads(context.Background(), 20*time.Millisecond, 0, globalServiceDoneCh)
+	go fs.cleanupStaleMultipartUploads(context.Background(), 20*time.Millisecond, 0, GlobalServiceDoneCh)
 
 	// Wait for 40ms such that - we have given enough time for
 	// cleanup routine to kick in.
 	time.Sleep(40 * time.Millisecond)
 
 	// Close the routine we do not need it anymore.
-	globalServiceDoneCh <- struct{}{}
+	GlobalServiceDoneCh <- struct{}{}
 
 	// Check if upload id was already purged.
 	if err = obj.AbortMultipartUpload(context.Background(), bucketName, objectName, uploadID); err != nil {

cmd/fs-v1.go

@@ -152,10 +152,10 @@ func NewFSObjectLayer(fsPath string) (ObjectLayer, error) {
 	fs.fsFormatRlk = rlk
 
 	if !fs.diskMount {
-		go fs.diskUsage(globalServiceDoneCh)
+		go fs.diskUsage(GlobalServiceDoneCh)
 	}
 
-	go fs.cleanupStaleMultipartUploads(ctx, globalMultipartCleanupInterval, globalMultipartExpiry, globalServiceDoneCh)
+	go fs.cleanupStaleMultipartUploads(ctx, GlobalMultipartCleanupInterval, GlobalMultipartExpiry, GlobalServiceDoneCh)
 
 	// Return successfully initialized object layer.
 	return fs, nil
@@ -1317,7 +1317,7 @@ func (fs *FSObjects) IsListenBucketSupported() bool {
 	return true
 }
 
-// IsEncryptionSupported returns whether server side encryption is applicable for this layer.
+// IsEncryptionSupported returns whether server side encryption is implemented for this layer.
 func (fs *FSObjects) IsEncryptionSupported() bool {
 	return true
 }

cmd/fs-v1_test.go

@@ -354,7 +354,7 @@ func TestFSListBuckets(t *testing.T) {
 		t.Fatal("Unexpected error: ", err)
 	}
 
-	globalServiceDoneCh <- struct{}{}
+	GlobalServiceDoneCh <- struct{}{}
 
 	// Create a bucket with invalid name
 	if err := os.MkdirAll(pathJoin(fs.fsPath, "vo^"), 0777); err != nil {

cmd/gateway-common.go

@@ -18,7 +18,10 @@ package cmd
 
 import (
 	"net/http"
+	"os"
+	"strings"
 
+	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/hash"
 
 	minio "github.com/minio/minio-go"
@@ -30,8 +33,27 @@ var (
 
 	// MustGetUUID function alias.
 	MustGetUUID = mustGetUUID
+
+	// IsMinAllowedPartSize function alias.
+	IsMinAllowedPartSize = isMinAllowedPartSize
+
+	// GetCompleteMultipartMD5 functon alias.
+	GetCompleteMultipartMD5 = getCompleteMultipartMD5
+
+	// Contains function alias.
+	Contains = contains
+
+	// ExtractETag provides extractETag function alias.
+	ExtractETag = extractETag
+	// CleanMetadataKeys provides cleanMetadataKeys function alias.
+	CleanMetadataKeys = cleanMetadataKeys
 )
 
+// StatInfo -  alias for statInfo
+type StatInfo struct {
+	statInfo
+}
+
 // AnonErrToObjectErr - converts standard http codes into meaningful object layer errors.
 func AnonErrToObjectErr(statusCode int, params ...string) error {
 	bucket := ""
@@ -321,3 +343,30 @@ func ErrorRespToObjectError(err error, params ...string) error {
 
 	return err
 }
+
+// parse gateway sse env variable
+func parseGatewaySSE(s string) (gatewaySSE, error) {
+	l := strings.Split(s, ";")
+	var gwSlice = make([]string, 0)
+	for _, val := range l {
+		v := strings.ToUpper(val)
+		if v == gatewaySSES3 || v == gatewaySSEC {
+			gwSlice = append(gwSlice, v)
+			continue
+		}
+		return nil, uiErrInvalidGWSSEValue(nil).Msg("gateway SSE cannot be (%s) ", v)
+	}
+	return gatewaySSE(gwSlice), nil
+}
+
+// handle gateway env vars
+func handleGatewayEnvVars() {
+	gwsseVal, ok := os.LookupEnv("MINIO_GATEWAY_SSE")
+	if ok {
+		var err error
+		GlobalGatewaySSE, err = parseGatewaySSE(gwsseVal)
+		if err != nil {
+			logger.Fatal(err, "Unable to parse MINIO_GATEWAY_SSE value (`%s`)", gwsseVal)
+		}
+	}
+}

cmd/gateway-common_test.go

@@ -0,0 +1,52 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package cmd
+
+import (
+	"reflect"
+	"testing"
+)
+
+// Tests cache exclude parsing.
+func TestParseGatewaySSE(t *testing.T) {
+	testCases := []struct {
+		gwSSEStr string
+		expected gatewaySSE
+		success  bool
+	}{
+		// valid input
+		{"c;S3", []string{"C", "S3"}, true},
+		{"S3", []string{"S3"}, true},
+		{"c,S3", []string{}, false},
+		{"c;S3;KMS", []string{}, false},
+		{"C;s3", []string{"C", "S3"}, true},
+	}
+
+	for i, testCase := range testCases {
+		gwSSE, err := parseGatewaySSE(testCase.gwSSEStr)
+		if err != nil && testCase.success {
+			t.Errorf("Test %d: Expected success but failed instead %s", i+1, err)
+		}
+		if err == nil && !testCase.success {
+			t.Errorf("Test %d: Expected failure but passed instead", i+1)
+		}
+		if err == nil {
+			if !reflect.DeepEqual(gwSSE, testCase.expected) {
+				t.Errorf("Test %d: Expected %v, got %v", i+1, testCase.expected, gwSSE)
+			}
+		}
+	}
+}

cmd/gateway-env.go

@@ -0,0 +1,48 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+type gatewaySSE []string
+
+const (
+	// GatewaySSES3 is set when SSE-S3 encryption needed on both gateway and backend
+	gatewaySSES3 = "S3"
+	// GatewaySSEC is set when SSE-C encryption needed on both gateway and backend
+	gatewaySSEC = "C"
+)
+
+func (sse gatewaySSE) SSES3() bool {
+	for _, v := range sse {
+		if v == gatewaySSES3 {
+			return true
+		}
+	}
+	return false
+}
+
+func (sse gatewaySSE) SSEC() bool {
+	for _, v := range sse {
+		if v == gatewaySSEC {
+			return true
+		}
+	}
+	return false
+}
+
+func (sse gatewaySSE) IsSet() bool {
+	return sse.SSES3() || sse.SSEC()
+}

cmd/gateway-main.go

@@ -18,7 +18,6 @@ package cmd
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"net/url"
 	"os"
@@ -136,6 +135,9 @@ func StartGateway(ctx *cli.Context, gw Gateway) {
 	// Handle common env vars.
 	handleCommonEnvVars()
 
+	// Handle gateway specific env
+	handleGatewayEnvVars()
+
 	// Validate if we have access, secret set through environment.
 	if !globalIsEnvCreds {
 		logger.Fatal(uiErrEnvCredentialsMissingGateway(nil), "Unable to start gateway")
@@ -168,8 +170,11 @@ func StartGateway(ctx *cli.Context, gw Gateway) {
 		logger.FatalIf(registerWebRouter(router), "Unable to configure web browser")
 	}
 
+	// Currently only NAS and S3 gateway support encryption headers.
+	encryptionEnabled := gatewayName == "s3" || gatewayName == "nas"
+
 	// Add API router.
-	registerAPIRouter(router)
+	registerAPIRouter(router, encryptionEnabled)
 
 	// Dummy endpoint representing gateway instance.
 	globalEndpoints = []Endpoint{{
@@ -226,6 +231,7 @@ func StartGateway(ctx *cli.Context, gw Gateway) {
 		// Load globalServerConfig from etcd
 		_ = globalConfigSys.Init(newObject)
 	}
+
 	// Load logger subsystem
 	loadLoggers()
 
@@ -262,8 +268,18 @@ func StartGateway(ctx *cli.Context, gw Gateway) {
 		_ = globalNotificationSys.Init(newObject)
 	}
 
-	if globalAutoEncryption && !newObject.IsEncryptionSupported() {
+	// Encryption support checks in gateway mode.
-		logger.Fatal(errors.New("Invalid KMS configuration"), "auto-encryption is enabled but gateway does not support encryption")
+	{
+
+		if (globalAutoEncryption || GlobalKMS != nil) && !newObject.IsEncryptionSupported() {
+			logger.Fatal(errInvalidArgument,
+				"Encryption support is requested but (%s) gateway does not support encryption", gw.Name())
+		}
+
+		if GlobalGatewaySSE.IsSet() && GlobalKMS == nil {
+			logger.Fatal(uiErrInvalidGWSSEEnvValue(nil).Msg("MINIO_GATEWAY_SSE set but KMS is not configured"),
+				"Unable to start gateway with SSE")
+		}
 	}
 
 	// Once endpoints are finalized, initialize the new object api.

cmd/gateway-unsupported.go

@@ -49,7 +49,7 @@ func (a GatewayUnsupported) PutObjectPart(ctx context.Context, bucket string, ob
 }
 
 // ListObjectParts returns all object parts for specified object in specified bucket
-func (a GatewayUnsupported) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int) (lpi ListPartsInfo, err error) {
+func (a GatewayUnsupported) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int, opts ObjectOptions) (lpi ListPartsInfo, err error) {
 	logger.LogIf(ctx, NotImplemented{})
 	return lpi, NotImplemented{}
 }
@@ -137,7 +137,7 @@ func (a GatewayUnsupported) IsListenBucketSupported() bool {
 	return false
 }
 
-// IsEncryptionSupported returns whether server side encryption is applicable for this layer.
+// IsEncryptionSupported returns whether server side encryption is implemented for this layer.
 func (a GatewayUnsupported) IsEncryptionSupported() bool {
 	return false
 }

cmd/gateway/azure/gateway-azure.go

@@ -981,7 +981,7 @@ func (a *azureObjects) PutObjectPart(ctx context.Context, bucket, object, upload
 }
 
 // ListObjectParts - Use Azure equivalent GetBlockList.
-func (a *azureObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int) (result minio.ListPartsInfo, err error) {
+func (a *azureObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int, opts minio.ObjectOptions) (result minio.ListPartsInfo, err error) {
 	if err = a.checkUploadIDExists(ctx, bucket, object, uploadID); err != nil {
 		return result, err
 	}

cmd/gateway/b2/gateway-b2.go

@@ -684,7 +684,7 @@ func (l *b2Objects) PutObjectPart(ctx context.Context, bucket string, object str
 }
 
 // ListObjectParts returns all object parts for specified object in specified bucket, uses B2's LargeFile upload API.
-func (l *b2Objects) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int) (lpi minio.ListPartsInfo, err error) {
+func (l *b2Objects) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int, opts minio.ObjectOptions) (lpi minio.ListPartsInfo, err error) {
 	bkt, err := l.Bucket(ctx, bucket)
 	if err != nil {
 		return lpi, err

cmd/gateway/gcs/gateway-gcs.go

@@ -1121,7 +1121,7 @@ func gcsGetPartInfo(ctx context.Context, attrs *storage.ObjectAttrs) (minio.Part
 }
 
 //  ListObjectParts returns all object parts for specified object in specified bucket
-func (l *gcsGateway) ListObjectParts(ctx context.Context, bucket string, key string, uploadID string, partNumberMarker int, maxParts int) (minio.ListPartsInfo, error) {
+func (l *gcsGateway) ListObjectParts(ctx context.Context, bucket string, key string, uploadID string, partNumberMarker int, maxParts int, opts minio.ObjectOptions) (minio.ListPartsInfo, error) {
 	it := l.client.Bucket(bucket).Objects(ctx, &storage.Query{
 		Prefix: path.Join(gcsMinioMultipartPathV1, uploadID),
 	})

cmd/gateway/oss/gateway-oss.go

@@ -886,7 +886,7 @@ func (l *ossObjects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, d
 }
 
 // ListObjectParts returns all object parts for specified object in specified bucket
-func (l *ossObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker, maxParts int) (lpi minio.ListPartsInfo, err error) {
+func (l *ossObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker, maxParts int, opts minio.ObjectOptions) (lpi minio.ListPartsInfo, err error) {
 	lupr, err := ossListObjectParts(l.Client, bucket, object, uploadID, partNumberMarker, maxParts)
 	if err != nil {
 		logger.LogIf(ctx, err)

cmd/gateway/s3/gateway-s3-metadata.go

@@ -0,0 +1,238 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"time"
+
+	minio "github.com/minio/minio/cmd"
+	"github.com/minio/minio/cmd/logger"
+	"github.com/minio/minio/pkg/hash"
+	"github.com/tidwall/gjson"
+)
+
+var (
+	errGWMetaNotFound      = errors.New("dare.meta file not found")
+	errGWMetaInvalidFormat = errors.New("dare.meta format is invalid")
+)
+
+// A gwMetaV1 represents `gw.json` metadata header.
+type gwMetaV1 struct {
+	Version string         `json:"version"` // Version of the current `gw.json`.
+	Format  string         `json:"format"`  // Format of the current `gw.json`.
+	Stat    minio.StatInfo `json:"stat"`    // Stat of the current object `gw.json`.
+	ETag    string         `json:"etag"`    // ETag of the current object
+
+	// Metadata map for current object `gw.json`.
+	Meta map[string]string `json:"meta,omitempty"`
+	// Captures all the individual object `gw.json`.
+	Parts []minio.ObjectPartInfo `json:"parts,omitempty"`
+}
+
+// Gateway metadata constants.
+const (
+	// Gateway meta version.
+	gwMetaVersion = "1.0.0"
+
+	// Gateway meta version.
+	gwMetaVersion100 = "1.0.0"
+
+	// Gateway meta format string.
+	gwMetaFormat = "gw"
+
+	// Add new constants here.
+)
+
+// newGWMetaV1 - initializes new gwMetaV1, adds version.
+func newGWMetaV1() (gwMeta gwMetaV1) {
+	gwMeta = gwMetaV1{}
+	gwMeta.Version = gwMetaVersion
+	gwMeta.Format = gwMetaFormat
+	return gwMeta
+}
+
+// IsValid - tells if the format is sane by validating the version
+// string, format fields.
+func (m gwMetaV1) IsValid() bool {
+	return ((m.Version == gwMetaVersion || m.Version == gwMetaVersion100) &&
+		m.Format == gwMetaFormat)
+}
+
+// Converts metadata to object info.
+func (m gwMetaV1) ToObjectInfo(bucket, object string) minio.ObjectInfo {
+	filterKeys := append([]string{
+		"ETag",
+		"Content-Length",
+		"Last-Modified",
+		"Content-Type",
+	}, defaultFilterKeys...)
+	objInfo := minio.ObjectInfo{
+		IsDir:           false,
+		Bucket:          bucket,
+		Name:            object,
+		Size:            m.Stat.Size,
+		ModTime:         m.Stat.ModTime,
+		ContentType:     m.Meta["content-type"],
+		ContentEncoding: m.Meta["content-encoding"],
+		ETag:            minio.CanonicalizeETag(m.ETag),
+		UserDefined:     minio.CleanMetadataKeys(m.Meta, filterKeys...),
+		Parts:           m.Parts,
+	}
+
+	if sc, ok := m.Meta["x-amz-storage-class"]; ok {
+		objInfo.StorageClass = sc
+	}
+	// Success.
+	return objInfo
+}
+
+// ObjectToPartOffset - translate offset of an object to offset of its individual part.
+func (m gwMetaV1) ObjectToPartOffset(ctx context.Context, offset int64) (partIndex int, partOffset int64, err error) {
+	if offset == 0 {
+		// Special case - if offset is 0, then partIndex and partOffset are always 0.
+		return 0, 0, nil
+	}
+	partOffset = offset
+	// Seek until object offset maps to a particular part offset.
+	for i, part := range m.Parts {
+		partIndex = i
+		// Offset is smaller than size we have reached the proper part offset.
+		if partOffset < part.Size {
+			return partIndex, partOffset, nil
+		}
+		// Continue to towards the next part.
+		partOffset -= part.Size
+	}
+	logger.LogIf(ctx, minio.InvalidRange{})
+	// Offset beyond the size of the object return InvalidRange.
+	return 0, 0, minio.InvalidRange{}
+}
+
+// parses gateway metadata stat info from metadata json
+func parseGWStat(gwMetaBuf []byte) (si minio.StatInfo, e error) {
+	// obtain stat info.
+	stat := minio.StatInfo{}
+	// fetching modTime.
+	modTime, err := time.Parse(time.RFC3339, gjson.GetBytes(gwMetaBuf, "stat.modTime").String())
+	if err != nil {
+		return si, err
+	}
+	stat.ModTime = modTime
+	// obtain Stat.Size .
+	stat.Size = gjson.GetBytes(gwMetaBuf, "stat.size").Int()
+	return stat, nil
+}
+
+// parses gateway metadata version from metadata json
+func parseGWVersion(gwMetaBuf []byte) string {
+	return gjson.GetBytes(gwMetaBuf, "version").String()
+}
+
+// parses gateway ETag from metadata json
+func parseGWETag(gwMetaBuf []byte) string {
+	return gjson.GetBytes(gwMetaBuf, "etag").String()
+}
+
+// parses gateway metadata format from metadata json
+func parseGWFormat(gwMetaBuf []byte) string {
+	return gjson.GetBytes(gwMetaBuf, "format").String()
+}
+
+// parses gateway metadata json to get list of ObjectPartInfo
+func parseGWParts(gwMetaBuf []byte) []minio.ObjectPartInfo {
+	// Parse the GW Parts.
+	partsResult := gjson.GetBytes(gwMetaBuf, "parts").Array()
+	partInfo := make([]minio.ObjectPartInfo, len(partsResult))
+	for i, p := range partsResult {
+		info := minio.ObjectPartInfo{}
+		info.Number = int(p.Get("number").Int())
+		info.Name = p.Get("name").String()
+		info.ETag = p.Get("etag").String()
+		info.Size = p.Get("size").Int()
+		partInfo[i] = info
+	}
+	return partInfo
+}
+
+// parses gateway metadata json to get the metadata map
+func parseGWMetaMap(gwMetaBuf []byte) map[string]string {
+	// Get gwMetaV1.Meta map.
+	metaMapResult := gjson.GetBytes(gwMetaBuf, "meta").Map()
+	metaMap := make(map[string]string)
+	for key, valResult := range metaMapResult {
+		metaMap[key] = valResult.String()
+	}
+	return metaMap
+}
+
+// Constructs GWMetaV1 using `gjson` lib to retrieve each field.
+func gwMetaUnmarshalJSON(ctx context.Context, gwMetaBuf []byte) (gwMeta gwMetaV1, e error) {
+	// obtain version.
+	gwMeta.Version = parseGWVersion(gwMetaBuf)
+	// obtain format.
+	gwMeta.Format = parseGWFormat(gwMetaBuf)
+	// Parse gwMetaV1.Stat .
+	stat, err := parseGWStat(gwMetaBuf)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		return gwMeta, err
+	}
+	gwMeta.ETag = parseGWETag(gwMetaBuf)
+	gwMeta.Stat = stat
+
+	// Parse the GW Parts.
+	gwMeta.Parts = parseGWParts(gwMetaBuf)
+	// parse gwMetaV1.
+	gwMeta.Meta = parseGWMetaMap(gwMetaBuf)
+
+	return gwMeta, nil
+}
+
+// readGWMeta reads `dare.meta` and returns back GW metadata structure.
+func readGWMetadata(ctx context.Context, buf bytes.Buffer) (gwMeta gwMetaV1, err error) {
+	if buf.Len() == 0 {
+		return gwMetaV1{}, errGWMetaNotFound
+	}
+	gwMeta, err = gwMetaUnmarshalJSON(ctx, buf.Bytes())
+	if err != nil {
+		return gwMetaV1{}, err
+	}
+	if !gwMeta.IsValid() {
+		return gwMetaV1{}, errGWMetaInvalidFormat
+	}
+	// Return structured `dare.meta`.
+	return gwMeta, nil
+}
+
+// getGWMetadata - unmarshals dare.meta into a *minio.PutObjReader
+func getGWMetadata(ctx context.Context, bucket, prefix string, gwMeta gwMetaV1) (*minio.PutObjReader, error) {
+	// Marshal json.
+	metadataBytes, err := json.Marshal(&gwMeta)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		return nil, err
+	}
+	hashReader, err := hash.NewReader(bytes.NewReader(metadataBytes), int64(len(metadataBytes)), "", "", int64(len(metadataBytes)))
+	if err != nil {
+		return nil, err
+	}
+	return minio.NewPutObjReader(hashReader, nil, nil), nil
+}

cmd/gateway/s3/gateway-s3-metadata_test.go

@@ -0,0 +1,74 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3
+
+import (
+	"bytes"
+	"context"
+	"testing"
+)
+
+// Tests for GW metadata format validity.
+func TestGWMetaFormatValid(t *testing.T) {
+	tests := []struct {
+		name    int
+		version string
+		format  string
+		want    bool
+	}{
+		{1, "123", "fs", false},
+		{2, "123", gwMetaFormat, false},
+		{3, gwMetaVersion, "test", false},
+		{4, gwMetaVersion100, "hello", false},
+		{5, gwMetaVersion, gwMetaFormat, true},
+		{6, gwMetaVersion100, gwMetaFormat, true},
+	}
+	for _, tt := range tests {
+		m := newGWMetaV1()
+		m.Version = tt.version
+		m.Format = tt.format
+		if got := m.IsValid(); got != tt.want {
+			t.Errorf("Test %d: Expected %v but received %v", tt.name, got, tt.want)
+		}
+	}
+}
+
+// Tests for reading GW metadata info.
+func TestReadGWMetadata(t *testing.T) {
+	tests := []struct {
+		metaStr string
+		pass    bool
+	}{
+		{`{"version": "` + gwMetaVersion + `", "format":"` + gwMetaFormat + `", {"stat": {"size": "132", "modTime": "2018-08-31T22:25:39.23626461Z" }}}`, true},
+		{`{"version": "` + gwMetaVersion + `", "format":"` + gwMetaFormat + `", {"stat": {"size": "132", "modTime": "0000-00-00T00:00:00.00000000Z" }}}`, false},
+		{`{"version": "` + gwMetaVersion + `", "format":"` + gwMetaFormat + `", {"stat": {"size": "5242880", "modTime": "2018-08-31T22:25:39.23626461Z" }},"meta":{"content-type":"application/octet-stream","etag":"57c743902b2fc8eea6ba3bb4fc58c8e8"},"parts":[{"number":1,"name":"part.1","etag":"","size":5242880}]}}`, true},
+		{`{"version": "` + gwMetaVersion + `", "format":"` + gwMetaFormat + `", {"stat": {"size": "68190720", "modTime": "2018-08-31T22:25:39.23626461Z" }},"meta":{"X-Minio-Internal-Encrypted-Multipart":"","X-Minio-Internal-Server-Side-Encryption-Iv":"kdbOcKdXD3Sew8tOiHe5eI9xkX1oQ2W9JURz0oslCZA=","X-Minio-Internal-Server-Side-Encryption-Seal-Algorithm":"DAREv2-HMAC-SHA256","X-Minio-Internal-Server-Side-Encryption-Sealed-Key":"IAAfAMfqKrxMXC9LuiI7ENP+p0xArepzAiIeB/MftFp7Xmq2OzDkKlmNbj5RKI89RrjiAbOVLSSEMvqQsrIrTQ==","content-type":"text/plain; charset=utf-8","etag":"2b137fa4ab80126af54623b010c98de6-2"},"parts":[{"number":1,"name":"part.1","etag":"c5cac075eefdab801a5198812f51b36e","size":67141632},{"number":2,"name":"part.2","etag":"ccdf4b774bc3be8eef9a8987309e8171","size":1049088}]}`, true},
+		{`{"version": "` + gwMetaVersion + `", "format":"` + gwMetaFormat + `", {"stat": {"size": "68190720", "modTime": "2018-08-31T22:25:39.23626461Z" }},"meta":{"X-Minio-Internal-Encrypted-Multipart":"","X-Minio-Internal-Server-Side-Encryption-Iv":"kdbOcKdXD3Sew8tOiHe5eI9xkX1oQ2W9JURz0oslCZA=","X-Minio-Internal-Server-Side-Encryption-Seal-Algorithm":"DAREv2-HMAC-SHA256","X-Minio-Internal-Server-Side-Encryption-Sealed-Key":"IAAfAMfqKrxMXC9LuiI7ENP+p0xArepzAiIeB/MftFp7Xmq2OzDkKlmNbj5RKI89RrjiAbOVLSSEMvqQsrIrTQ==","content-type":"text/plain; charset=utf-8","etag":"2b137fa4ab80126af54623b010c98de6-2"},"parts":"123"}`, true},
+	}
+
+	for i, tt := range tests {
+		buf := bytes.NewBufferString(tt.metaStr)
+		m, err := readGWMetadata(context.Background(), *buf)
+		t.Log(m)
+		if err != nil && tt.pass {
+			t.Errorf("Test %d: Expected parse gw metadata to succeed, but failed", i)
+		}
+		if err == nil && !tt.pass {
+			t.Errorf("Test %d: Expected parse gw metadata to succeed, but failed", i)
+		}
+	}
+}

cmd/gateway/s3/gateway-s3-sse.go

@@ -0,0 +1,778 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net/http"
+	"path"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/minio/minio-go/pkg/encrypt"
+	minio "github.com/minio/minio/cmd"
+
+	"github.com/minio/minio/cmd/logger"
+)
+
+const (
+	// name of custom multipart metadata file for s3 backend.
+	gwdareMetaJSON string = "dare.meta"
+
+	// name of temporary per part metadata file
+	gwpartMetaJSON string = "part.meta"
+	// custom multipart files are stored under the defaultMinioGWPrefix
+	defaultMinioGWPrefix     = ".minio"
+	defaultGWContentFileName = "data"
+	slashSeparator           = "/"
+)
+
+// s3EncObjects is a wrapper around s3Objects and implements gateway calls for
+// custom large objects encrypted at the gateway
+type s3EncObjects struct {
+	s3Objects
+}
+
+/*
+ NOTE:
+ Custom gateway encrypted objects are stored on backend as follows:
+	 obj/.minio/data   <= encrypted content
+	 obj/.minio/dare.meta  <= metadata
+
+ When a multipart upload operation is in progress, the metadata set during
+ NewMultipartUpload is stored in obj/.minio/uploadID/dare.meta and each
+ UploadPart operation saves additional state of the part's encrypted ETag and
+ encrypted size in obj/.minio/uploadID/part1/part.meta
+
+ All the part metadata and temp dare.meta are cleaned up when upload completes
+*/
+
+// ListObjects lists all blobs in S3 bucket filtered by prefix
+func (l *s3EncObjects) ListObjects(ctx context.Context, bucket string, prefix string, marker string, delimiter string, maxKeys int) (loi minio.ListObjectsInfo, e error) {
+	var continuationToken, startAfter string
+	res, err := l.ListObjectsV2(ctx, bucket, prefix, continuationToken, delimiter, maxKeys, false, startAfter)
+	if err != nil {
+		return loi, err
+	}
+	loi.IsTruncated = res.IsTruncated
+	loi.NextMarker = res.NextContinuationToken
+	loi.Objects = res.Objects
+	loi.Prefixes = res.Prefixes
+	return loi, nil
+
+}
+
+// ListObjectsV2 lists all blobs in S3 bucket filtered by prefix
+func (l *s3EncObjects) ListObjectsV2(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (loi minio.ListObjectsV2Info, e error) {
+
+	var objects []minio.ObjectInfo
+	var prefixes []string
+	var isTruncated bool
+
+	// filter out objects that contain a .minio prefix, but is not a dare.meta metadata file.
+	for {
+		loi, e = l.s3Objects.ListObjectsV2(ctx, bucket, prefix, continuationToken, delimiter, 1000, fetchOwner, startAfter)
+		if e != nil {
+			return loi, minio.ErrorRespToObjectError(e, bucket)
+		}
+		for _, obj := range loi.Objects {
+			startAfter = obj.Name
+			continuationToken = loi.NextContinuationToken
+			isTruncated = loi.IsTruncated
+
+			if !isGWObject(obj.Name) {
+				continue
+			}
+			// get objectname and ObjectInfo from the custom metadata file
+			if strings.HasSuffix(obj.Name, gwdareMetaJSON) {
+				objSlice := strings.Split(obj.Name, slashSeparator+defaultMinioGWPrefix)
+				gwMeta, e := l.getGWMetadata(ctx, bucket, getDareMetaPath(objSlice[0]))
+				if e != nil {
+					continue
+				}
+				oInfo := gwMeta.ToObjectInfo(bucket, objSlice[0])
+				objects = append(objects, oInfo)
+			} else {
+				objects = append(objects, obj)
+			}
+			if len(objects) > maxKeys {
+				break
+			}
+		}
+		for _, p := range loi.Prefixes {
+			objName := strings.TrimSuffix(p, slashSeparator)
+			gm, err := l.getGWMetadata(ctx, bucket, getDareMetaPath(objName))
+			// if prefix is actually a custom multi-part object, append it to objects
+			if err == nil {
+				objects = append(objects, gm.ToObjectInfo(bucket, objName))
+				continue
+			}
+			isPrefix := l.isPrefix(ctx, bucket, p, fetchOwner, startAfter)
+			if isPrefix {
+				prefixes = append(prefixes, p)
+			}
+		}
+		if (len(objects) > maxKeys) || !loi.IsTruncated {
+			break
+		}
+	}
+
+	loi.IsTruncated = isTruncated
+	loi.ContinuationToken = continuationToken
+	loi.Objects = make([]minio.ObjectInfo, 0)
+	loi.Prefixes = make([]string, 0)
+
+	for _, obj := range objects {
+		loi.NextContinuationToken = obj.Name
+		loi.Objects = append(loi.Objects, obj)
+	}
+	for _, pfx := range prefixes {
+		if pfx != prefix {
+			loi.Prefixes = append(loi.Prefixes, pfx)
+		}
+	}
+	return loi, nil
+}
+
+// isGWObject returns true if it is a custom object
+func isGWObject(objName string) bool {
+	isEncrypted := strings.Contains(objName, defaultMinioGWPrefix)
+	if !isEncrypted {
+		return true
+	}
+	// ignore temp part.meta files
+	if strings.Contains(objName, gwpartMetaJSON) {
+		return false
+	}
+
+	pfxSlice := strings.Split(objName, slashSeparator)
+	var i1, i2 int
+	for i := len(pfxSlice) - 1; i >= 0; i-- {
+		p := pfxSlice[i]
+		if p == defaultMinioGWPrefix {
+			i1 = i
+		}
+		if p == gwdareMetaJSON {
+			i2 = i
+		}
+		if i1 > 0 && i2 > 0 {
+			break
+		}
+	}
+	// incomplete uploads would have a uploadID between defaultMinioGWPrefix and gwdareMetaJSON
+	return i2 > 0 && i1 > 0 && i2-i1 == 1
+}
+
+// isPrefix returns true if prefix exists and is not an incomplete multipart upload entry
+func (l *s3EncObjects) isPrefix(ctx context.Context, bucket, prefix string, fetchOwner bool, startAfter string) bool {
+	var continuationToken, delimiter string
+
+	for {
+		loi, e := l.s3Objects.ListObjectsV2(ctx, bucket, prefix, continuationToken, delimiter, 1000, fetchOwner, startAfter)
+		if e != nil {
+			return false
+		}
+		for _, obj := range loi.Objects {
+			if isGWObject(obj.Name) {
+				return true
+			}
+		}
+
+		continuationToken = loi.NextContinuationToken
+		if !loi.IsTruncated {
+			break
+		}
+	}
+	return false
+}
+
+// GetObject reads an object from S3. Supports additional
+// parameters like offset and length which are synonymous with
+// HTTP Range requests.
+func (l *s3EncObjects) GetObject(ctx context.Context, bucket string, key string, startOffset int64, length int64, writer io.Writer, etag string, opts minio.ObjectOptions) error {
+	return l.getObject(ctx, bucket, key, startOffset, length, writer, etag, opts)
+}
+
+func (l *s3EncObjects) isGWEncrypted(ctx context.Context, bucket, object string) bool {
+	_, err := l.s3Objects.GetObjectInfo(ctx, bucket, getDareMetaPath(object), minio.ObjectOptions{})
+	return err == nil
+}
+
+// getDaremetadata fetches dare.meta from s3 backend and marshals into a structured format.
+func (l *s3EncObjects) getGWMetadata(ctx context.Context, bucket, metaFileName string) (m gwMetaV1, err error) {
+	oi, err1 := l.s3Objects.GetObjectInfo(ctx, bucket, metaFileName, minio.ObjectOptions{})
+	if err1 != nil {
+		return m, err1
+	}
+	var buffer bytes.Buffer
+	err = l.s3Objects.GetObject(ctx, bucket, metaFileName, 0, oi.Size, &buffer, oi.ETag, minio.ObjectOptions{})
+	if err != nil {
+		return m, err
+	}
+	return readGWMetadata(ctx, buffer)
+}
+
+// writes dare metadata to the s3 backend
+func (l *s3EncObjects) writeGWMetadata(ctx context.Context, bucket, metaFileName string, m gwMetaV1, o minio.ObjectOptions) error {
+	reader, err := getGWMetadata(ctx, bucket, metaFileName, m)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		return err
+	}
+	_, err = l.s3Objects.PutObject(ctx, bucket, metaFileName, reader, map[string]string{}, o)
+	return err
+}
+
+// returns path of temporary metadata json file for the upload
+func getTmpDareMetaPath(object, uploadID string) string {
+	return path.Join(getGWMetaPath(object), uploadID, gwdareMetaJSON)
+}
+
+// returns path of metadata json file for encrypted objects
+func getDareMetaPath(object string) string {
+	return path.Join(getGWMetaPath(object), gwdareMetaJSON)
+}
+
+// returns path of temporary part metadata file for multipart uploads
+func getPartMetaPath(object, uploadID string, partID int) string {
+	return path.Join(object, defaultMinioGWPrefix, uploadID, strconv.Itoa(partID), gwpartMetaJSON)
+}
+
+// deletes the custom dare metadata file saved at the backend
+func (l *s3EncObjects) deleteGWMetadata(ctx context.Context, bucket, metaFileName string) error {
+	return l.s3Objects.DeleteObject(ctx, bucket, metaFileName)
+}
+
+func (l *s3EncObjects) getObject(ctx context.Context, bucket string, key string, startOffset int64, length int64, writer io.Writer, etag string, opts minio.ObjectOptions) error {
+	var o minio.ObjectOptions
+	if minio.GlobalGatewaySSE.SSEC() {
+		o = opts
+	}
+	dmeta, err := l.getGWMetadata(ctx, bucket, getDareMetaPath(key))
+	if err != nil {
+		// unencrypted content
+		return l.s3Objects.GetObject(ctx, bucket, key, startOffset, length, writer, etag, o)
+	}
+	if startOffset < 0 {
+		logger.LogIf(ctx, minio.InvalidRange{})
+	}
+
+	// For negative length read everything.
+	if length < 0 {
+		length = dmeta.Stat.Size - startOffset
+	}
+	// Reply back invalid range if the input offset and length fall out of range.
+	if startOffset > dmeta.Stat.Size || startOffset+length > dmeta.Stat.Size {
+		logger.LogIf(ctx, minio.InvalidRange{OffsetBegin: startOffset, OffsetEnd: length, ResourceSize: dmeta.Stat.Size})
+		return minio.InvalidRange{OffsetBegin: startOffset, OffsetEnd: length, ResourceSize: dmeta.Stat.Size}
+	}
+	// Get start part index and offset.
+	_, partOffset, err := dmeta.ObjectToPartOffset(ctx, startOffset)
+	if err != nil {
+		return minio.InvalidRange{OffsetBegin: startOffset, OffsetEnd: length, ResourceSize: dmeta.Stat.Size}
+	}
+
+	// Calculate endOffset according to length
+	endOffset := startOffset
+	if length > 0 {
+		endOffset += length - 1
+	}
+
+	// Get last part index to read given length.
+	if _, _, err := dmeta.ObjectToPartOffset(ctx, endOffset); err != nil {
+		return minio.InvalidRange{OffsetBegin: startOffset, OffsetEnd: length, ResourceSize: dmeta.Stat.Size}
+	}
+	return l.s3Objects.GetObject(ctx, bucket, key, partOffset, endOffset, writer, dmeta.ETag, o)
+}
+
+// GetObjectNInfo - returns object info and locked object ReadCloser
+func (l *s3EncObjects) GetObjectNInfo(ctx context.Context, bucket, object string, rs *minio.HTTPRangeSpec, h http.Header, lockType minio.LockType, o minio.ObjectOptions) (gr *minio.GetObjectReader, err error) {
+	var opts minio.ObjectOptions
+	if minio.GlobalGatewaySSE.SSEC() {
+		opts = o
+	}
+	objInfo, err := l.GetObjectInfo(ctx, bucket, object, opts)
+	if err != nil {
+		return l.s3Objects.GetObjectNInfo(ctx, bucket, object, rs, h, lockType, opts)
+	}
+	objInfo.UserDefined = minio.CleanMinioInternalMetadataKeys(objInfo.UserDefined)
+	fn, off, length, err := minio.NewGetObjectReader(rs, objInfo)
+	if err != nil {
+		return nil, minio.ErrorRespToObjectError(err)
+	}
+	if l.isGWEncrypted(ctx, bucket, object) {
+		object = getGWContentPath(object)
+	}
+	pr, pw := io.Pipe()
+	go func() {
+		err := l.getObject(ctx, bucket, object, off, length, pw, objInfo.ETag, opts)
+		pw.CloseWithError(err)
+	}()
+
+	// Setup cleanup function to cause the above go-routine to
+	// exit in case of partial read
+	pipeCloser := func() { pr.Close() }
+	return fn(pr, h, pipeCloser)
+}
+
+// GetObjectInfo reads object info and replies back ObjectInfo
+// For custom gateway encrypted large objects, the ObjectInfo is retrieved from the dare.meta file.
+func (l *s3EncObjects) GetObjectInfo(ctx context.Context, bucket string, object string, o minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) {
+	var opts minio.ObjectOptions
+	if minio.GlobalGatewaySSE.SSEC() {
+		opts = o
+	}
+
+	gwMeta, err := l.getGWMetadata(ctx, bucket, getDareMetaPath(object))
+	if err != nil {
+		return l.s3Objects.GetObjectInfo(ctx, bucket, object, opts)
+	}
+	return gwMeta.ToObjectInfo(bucket, object), nil
+}
+
+// CopyObject copies an object from source bucket to a destination bucket.
+func (l *s3EncObjects) CopyObject(ctx context.Context, srcBucket string, srcObject string, dstBucket string, dstObject string, srcInfo minio.ObjectInfo, s, d minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) {
+	cpSrcDstSame := strings.EqualFold(path.Join(srcBucket, srcObject), path.Join(dstBucket, dstObject))
+	if cpSrcDstSame {
+		var gwMeta gwMetaV1
+		if s.ServerSideEncryption != nil && d.ServerSideEncryption != nil &&
+			((s.ServerSideEncryption.Type() == encrypt.SSEC && d.ServerSideEncryption.Type() == encrypt.SSEC) ||
+				(s.ServerSideEncryption.Type() == encrypt.S3 && d.ServerSideEncryption.Type() == encrypt.S3)) {
+			gwMeta, err = l.getGWMetadata(ctx, srcBucket, getDareMetaPath(srcObject))
+			if err != nil {
+				return
+			}
+			header := make(http.Header)
+			if d.ServerSideEncryption != nil {
+				d.ServerSideEncryption.Marshal(header)
+			}
+			for k, v := range header {
+				srcInfo.UserDefined[k] = v[0]
+			}
+			gwMeta.Meta = srcInfo.UserDefined
+			if err = l.writeGWMetadata(ctx, dstBucket, getDareMetaPath(dstObject), gwMeta, minio.ObjectOptions{}); err != nil {
+				return objInfo, minio.ErrorRespToObjectError(err)
+			}
+			return gwMeta.ToObjectInfo(dstBucket, dstObject), nil
+		}
+	}
+	return l.PutObject(ctx, dstBucket, dstObject, srcInfo.PutObjReader, srcInfo.UserDefined, d)
+}
+
+// DeleteObject deletes a blob in bucket
+// For custom gateway encrypted large objects, cleans up encrypted content and metadata files
+// from the backend.
+func (l *s3EncObjects) DeleteObject(ctx context.Context, bucket string, object string) error {
+
+	// Get dare meta json
+	if _, err := l.getGWMetadata(ctx, bucket, getDareMetaPath(object)); err != nil {
+		return l.s3Objects.DeleteObject(ctx, bucket, object)
+	}
+	// delete encrypted object
+	l.s3Objects.DeleteObject(ctx, bucket, getGWContentPath(object))
+	return l.deleteGWMetadata(ctx, bucket, getDareMetaPath(object))
+}
+
+// ListMultipartUploads lists all multipart uploads.
+func (l *s3EncObjects) ListMultipartUploads(ctx context.Context, bucket string, prefix string, keyMarker string, uploadIDMarker string, delimiter string, maxUploads int) (lmi minio.ListMultipartsInfo, e error) {
+
+	lmi, e = l.s3Objects.ListMultipartUploads(ctx, bucket, prefix, keyMarker, uploadIDMarker, delimiter, maxUploads)
+	if e != nil {
+		return
+	}
+	lmi.KeyMarker = strings.TrimSuffix(lmi.KeyMarker, getGWContentPath("/"))
+	lmi.NextKeyMarker = strings.TrimSuffix(lmi.NextKeyMarker, getGWContentPath("/"))
+	for i := range lmi.Uploads {
+		lmi.Uploads[i].Object = strings.TrimSuffix(lmi.Uploads[i].Object, getGWContentPath("/"))
+	}
+	return
+}
+
+// NewMultipartUpload uploads object in multiple parts
+func (l *s3EncObjects) NewMultipartUpload(ctx context.Context, bucket string, object string, metadata map[string]string, o minio.ObjectOptions) (uploadID string, err error) {
+	var opts minio.ObjectOptions
+	if o.ServerSideEncryption != nil &&
+		((minio.GlobalGatewaySSE.SSEC() && o.ServerSideEncryption.Type() == encrypt.SSEC) ||
+			(minio.GlobalGatewaySSE.SSES3() && o.ServerSideEncryption.Type() == encrypt.S3)) {
+		opts = o
+	}
+	if o.ServerSideEncryption == nil {
+		return l.s3Objects.NewMultipartUpload(ctx, bucket, object, metadata, opts)
+	}
+	uploadID, err = l.s3Objects.NewMultipartUpload(ctx, bucket, getGWContentPath(object), map[string]string{}, opts)
+	if err != nil {
+		return
+	}
+	// Create uploadID and write a temporary dare.meta object under object/uploadID prefix
+	gwmeta := newGWMetaV1()
+	gwmeta.Meta = metadata
+	gwmeta.Stat.ModTime = time.Now().UTC()
+	err = l.writeGWMetadata(ctx, bucket, getTmpDareMetaPath(object, uploadID), gwmeta, minio.ObjectOptions{})
+	if err != nil {
+		return uploadID, minio.ErrorRespToObjectError(err)
+	}
+	return uploadID, nil
+}
+
+// PutObject creates a new object with the incoming data,
+func (l *s3EncObjects) PutObject(ctx context.Context, bucket string, object string, data *minio.PutObjReader, metadata map[string]string, opts minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) {
+	var s3Opts minio.ObjectOptions
+	if opts.ServerSideEncryption != nil &&
+		((minio.GlobalGatewaySSE.SSEC() && opts.ServerSideEncryption.Type() == encrypt.SSEC) ||
+			(minio.GlobalGatewaySSE.SSES3() && opts.ServerSideEncryption.Type() == encrypt.S3)) {
+		s3Opts = opts
+	}
+	if opts.ServerSideEncryption == nil {
+		defer l.deleteGWMetadata(ctx, bucket, getDareMetaPath(object))
+		defer l.DeleteObject(ctx, bucket, getGWContentPath(object))
+		return l.s3Objects.PutObject(ctx, bucket, object, data, metadata, s3Opts)
+	}
+
+	oi, err := l.s3Objects.PutObject(ctx, bucket, getGWContentPath(object), data, map[string]string{}, s3Opts)
+	if err != nil {
+		return objInfo, minio.ErrorRespToObjectError(err)
+	}
+
+	gwMeta := newGWMetaV1()
+	gwMeta.Meta = make(map[string]string)
+	for k, v := range oi.UserDefined {
+		gwMeta.Meta[k] = v
+	}
+	for k, v := range metadata {
+		gwMeta.Meta[k] = v
+	}
+	encMD5 := data.MD5CurrentHexString()
+
+	gwMeta.ETag = encMD5
+	gwMeta.Stat.Size = oi.Size
+	gwMeta.Stat.ModTime = time.Now().UTC()
+	if err = l.writeGWMetadata(ctx, bucket, getDareMetaPath(object), gwMeta, minio.ObjectOptions{}); err != nil {
+		return objInfo, minio.ErrorRespToObjectError(err)
+	}
+	objInfo = gwMeta.ToObjectInfo(bucket, object)
+	// delete any unencrypted content of the same name created previously
+	l.s3Objects.DeleteObject(ctx, bucket, object)
+	return objInfo, nil
+}
+
+// PutObjectPart puts a part of object in bucket
+func (l *s3EncObjects) PutObjectPart(ctx context.Context, bucket string, object string, uploadID string, partID int, data *minio.PutObjReader, opts minio.ObjectOptions) (pi minio.PartInfo, e error) {
+
+	if opts.ServerSideEncryption == nil {
+		return l.s3Objects.PutObjectPart(ctx, bucket, object, uploadID, partID, data, opts)
+	}
+
+	var s3Opts minio.ObjectOptions
+	// for sse-s3 encryption options should not be passed to backend
+	if opts.ServerSideEncryption != nil && opts.ServerSideEncryption.Type() == encrypt.SSEC && minio.GlobalGatewaySSE.SSEC() {
+		s3Opts = opts
+	}
+
+	uploadPath := getTmpGWMetaPath(object, uploadID)
+	tmpDareMeta := path.Join(uploadPath, gwdareMetaJSON)
+	_, err := l.s3Objects.GetObjectInfo(ctx, bucket, tmpDareMeta, minio.ObjectOptions{})
+	if err != nil {
+		return pi, minio.InvalidUploadID{UploadID: uploadID}
+	}
+
+	pi, e = l.s3Objects.PutObjectPart(ctx, bucket, getGWContentPath(object), uploadID, partID, data, s3Opts)
+	if e != nil {
+		return
+	}
+	gwMeta := newGWMetaV1()
+	gwMeta.Parts = make([]minio.ObjectPartInfo, 1)
+	// Add incoming part.
+	gwMeta.Parts[0] = minio.ObjectPartInfo{
+		Number: partID,
+		ETag:   pi.ETag,
+		Size:   pi.Size,
+		Name:   strconv.Itoa(partID),
+	}
+	gwMeta.ETag = data.MD5CurrentHexString() // encrypted ETag
+	gwMeta.Stat.Size = pi.Size
+	gwMeta.Stat.ModTime = pi.LastModified
+
+	if err = l.writeGWMetadata(ctx, bucket, getPartMetaPath(object, uploadID, partID), gwMeta, minio.ObjectOptions{}); err != nil {
+		return pi, minio.ErrorRespToObjectError(err)
+	}
+	return minio.PartInfo{
+		Size:         gwMeta.Stat.Size,
+		ETag:         minio.CanonicalizeETag(gwMeta.ETag),
+		LastModified: gwMeta.Stat.ModTime,
+		PartNumber:   partID,
+	}, nil
+}
+
+// CopyObjectPart creates a part in a multipart upload by copying
+// existing object or a part of it.
+func (l *s3EncObjects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, destBucket, destObject, uploadID string,
+	partID int, startOffset, length int64, srcInfo minio.ObjectInfo, srcOpts, dstOpts minio.ObjectOptions) (p minio.PartInfo, err error) {
+	return l.PutObjectPart(ctx, destBucket, destObject, uploadID, partID, srcInfo.PutObjReader, dstOpts)
+}
+
+// ListObjectParts returns all object parts for specified object in specified bucket
+func (l *s3EncObjects) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int, opts minio.ObjectOptions) (lpi minio.ListPartsInfo, e error) {
+	// We do not store parts uploaded so far in the dare.meta. Only CompleteMultipartUpload finalizes the parts under upload prefix.Otherwise,
+	// there could be situations of dare.meta getting corrupted by competing upload parts.
+	dm, err := l.getGWMetadata(ctx, bucket, getTmpDareMetaPath(object, uploadID))
+	if err != nil {
+		return l.s3Objects.ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts, opts)
+	}
+
+	lpi, err = l.s3Objects.ListObjectParts(ctx, bucket, getGWContentPath(object), uploadID, partNumberMarker, maxParts, opts)
+	if err != nil {
+		return lpi, err
+	}
+	for i, part := range lpi.Parts {
+		partMeta, err := l.getGWMetadata(ctx, bucket, getPartMetaPath(object, uploadID, part.PartNumber))
+		if err != nil || len(partMeta.Parts) == 0 {
+			return lpi, minio.InvalidPart{}
+		}
+		lpi.Parts[i].ETag = partMeta.ETag
+	}
+	lpi.UserDefined = dm.Meta
+	lpi.Object = object
+	return lpi, nil
+}
+
+// AbortMultipartUpload aborts a ongoing multipart upload
+func (l *s3EncObjects) AbortMultipartUpload(ctx context.Context, bucket string, object string, uploadID string) error {
+	if _, err := l.getGWMetadata(ctx, bucket, getTmpDareMetaPath(object, uploadID)); err != nil {
+		return l.s3Objects.AbortMultipartUpload(ctx, bucket, object, uploadID)
+	}
+
+	if err := l.s3Objects.AbortMultipartUpload(ctx, bucket, getGWContentPath(object), uploadID); err != nil {
+		return err
+	}
+
+	uploadPrefix := getTmpGWMetaPath(object, uploadID)
+	var continuationToken, startAfter, delimiter string
+	for {
+		loi, err := l.s3Objects.ListObjectsV2(ctx, bucket, uploadPrefix, continuationToken, delimiter, 1000, false, startAfter)
+		if err != nil {
+			return minio.InvalidUploadID{UploadID: uploadID}
+		}
+		for _, obj := range loi.Objects {
+			if err := l.s3Objects.DeleteObject(ctx, bucket, obj.Name); err != nil {
+				return minio.ErrorRespToObjectError(err)
+			}
+			startAfter = obj.Name
+		}
+		continuationToken = loi.NextContinuationToken
+		if !loi.IsTruncated {
+			break
+		}
+	}
+	return nil
+}
+
+// CompleteMultipartUpload completes ongoing multipart upload and finalizes object
+func (l *s3EncObjects) CompleteMultipartUpload(ctx context.Context, bucket, object, uploadID string, uploadedParts []minio.CompletePart, opts minio.ObjectOptions) (oi minio.ObjectInfo, e error) {
+
+	tmpMeta, err := l.getGWMetadata(ctx, bucket, getTmpDareMetaPath(object, uploadID))
+	if err != nil {
+		oi, e = l.s3Objects.CompleteMultipartUpload(ctx, bucket, object, uploadID, uploadedParts, opts)
+		if e == nil {
+			// delete any encrypted version of object that might exist
+			defer l.deleteGWMetadata(ctx, bucket, getDareMetaPath(object))
+			defer l.DeleteObject(ctx, bucket, getGWContentPath(object))
+		}
+		return oi, e
+	}
+	gwMeta := newGWMetaV1()
+	gwMeta.Meta = make(map[string]string)
+	for k, v := range tmpMeta.Meta {
+		gwMeta.Meta[k] = v
+	}
+	// Allocate parts similar to incoming slice.
+	gwMeta.Parts = make([]minio.ObjectPartInfo, len(uploadedParts))
+
+	bkUploadedParts := make([]minio.CompletePart, len(uploadedParts))
+	// Calculate full object size.
+	var objectSize int64
+
+	// Validate each part and then commit to disk.
+	for i, part := range uploadedParts {
+		partMeta, err := l.getGWMetadata(ctx, bucket, getPartMetaPath(object, uploadID, part.PartNumber))
+		if err != nil || len(partMeta.Parts) == 0 {
+			return oi, minio.InvalidPart{}
+		}
+		bkUploadedParts[i] = minio.CompletePart{PartNumber: part.PartNumber, ETag: partMeta.Parts[0].ETag}
+		gwMeta.Parts[i] = partMeta.Parts[0]
+		objectSize += partMeta.Parts[0].Size
+	}
+	oi, e = l.s3Objects.CompleteMultipartUpload(ctx, bucket, getGWContentPath(object), uploadID, bkUploadedParts, opts)
+	if e != nil {
+		return oi, e
+	}
+
+	//delete any unencrypted version of object that might be on the backend
+	defer l.s3Objects.DeleteObject(ctx, bucket, object)
+
+	// Save the final object size and modtime.
+	gwMeta.Stat.Size = objectSize
+	gwMeta.Stat.ModTime = time.Now().UTC()
+	gwMeta.ETag = oi.ETag
+
+	if err = l.writeGWMetadata(ctx, bucket, getDareMetaPath(object), gwMeta, minio.ObjectOptions{}); err != nil {
+		return oi, minio.ErrorRespToObjectError(err)
+	}
+	// Clean up any uploaded parts that are not being committed by this CompleteMultipart operation
+	var continuationToken, startAfter, delimiter string
+	uploadPrefix := getTmpGWMetaPath(object, uploadID)
+	done := false
+	for {
+		loi, lerr := l.s3Objects.ListObjectsV2(ctx, bucket, uploadPrefix, continuationToken, delimiter, 1000, false, startAfter)
+		if lerr != nil {
+			done = true
+			break
+		}
+		for _, obj := range loi.Objects {
+			if !strings.HasPrefix(obj.Name, uploadPrefix) {
+				done = true
+				break
+			}
+			startAfter = obj.Name
+			l.s3Objects.DeleteObject(ctx, bucket, obj.Name)
+		}
+		continuationToken = loi.NextContinuationToken
+		if !loi.IsTruncated || done {
+			break
+		}
+	}
+
+	return gwMeta.ToObjectInfo(bucket, object), nil
+}
+
+// getTmpGWMetaPath returns the prefix under which uploads in progress are stored on backend
+func getTmpGWMetaPath(object, uploadID string) string {
+	return path.Join(object, defaultMinioGWPrefix, uploadID)
+}
+
+// getGWMetaPath returns the prefix under which custom object metadata and object are stored on backend after upload completes
+func getGWMetaPath(object string) string {
+	return path.Join(object, defaultMinioGWPrefix)
+}
+
+// getGWContentPath returns the prefix under which custom object is stored on backend after upload completes
+func getGWContentPath(object string) string {
+	return path.Join(object, defaultMinioGWPrefix, defaultGWContentFileName)
+}
+
+// Clean-up the stale incomplete encrypted multipart uploads. Should be run in a Go routine.
+func (l *s3EncObjects) cleanupStaleEncMultipartUploads(ctx context.Context, cleanupInterval, expiry time.Duration, doneCh chan struct{}) {
+	ticker := time.NewTicker(cleanupInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-doneCh:
+			return
+		case <-ticker.C:
+			l.cleanupStaleEncMultipartUploadsOnGW(ctx, expiry)
+		}
+	}
+}
+
+// cleanupStaleMultipartUploads removes old custom encryption multipart uploads on backend
+func (l *s3EncObjects) cleanupStaleEncMultipartUploadsOnGW(ctx context.Context, expiry time.Duration) {
+	for {
+		buckets, err := l.s3Objects.ListBuckets(ctx)
+		if err != nil {
+			break
+		}
+		for _, b := range buckets {
+			expParts := l.getStalePartsForBucket(ctx, b.Name, expiry)
+			for k := range expParts {
+				l.s3Objects.DeleteObject(ctx, b.Name, k)
+			}
+		}
+	}
+}
+
+func (l *s3EncObjects) getStalePartsForBucket(ctx context.Context, bucket string, expiry time.Duration) (expParts map[string]string) {
+	var prefix, continuationToken, delimiter, startAfter string
+	expParts = make(map[string]string)
+	now := time.Now()
+	for {
+		loi, err := l.s3Objects.ListObjectsV2(ctx, bucket, prefix, continuationToken, delimiter, 1000, false, startAfter)
+		if err != nil {
+			break
+		}
+		for _, obj := range loi.Objects {
+			startAfter = obj.Name
+			if !strings.Contains(obj.Name, defaultMinioGWPrefix) {
+				continue
+			}
+
+			if isGWObject(obj.Name) {
+				continue
+			}
+
+			// delete temporary part.meta or dare.meta files for incomplete uploads that are past expiry
+			if (strings.HasSuffix(obj.Name, gwpartMetaJSON) || strings.HasSuffix(obj.Name, gwdareMetaJSON)) &&
+				now.Sub(obj.ModTime) > expiry {
+				expParts[obj.Name] = ""
+			}
+		}
+		continuationToken = loi.NextContinuationToken
+		if !loi.IsTruncated {
+			break
+		}
+	}
+	return
+}
+
+func (l *s3EncObjects) DeleteBucket(ctx context.Context, bucket string) error {
+	var prefix, continuationToken, delimiter, startAfter string
+	expParts := make(map[string]string)
+
+	for {
+		loi, err := l.s3Objects.ListObjectsV2(ctx, bucket, prefix, continuationToken, delimiter, 1000, false, startAfter)
+		if err != nil {
+			break
+		}
+		for _, obj := range loi.Objects {
+			startAfter = obj.Name
+			if !strings.Contains(obj.Name, defaultMinioGWPrefix) {
+				return minio.BucketNotEmpty{}
+			}
+			if isGWObject(obj.Name) {
+				return minio.BucketNotEmpty{}
+			}
+			// delete temporary part.meta or dare.meta files for incomplete uploads
+			if strings.HasSuffix(obj.Name, gwpartMetaJSON) || strings.HasSuffix(obj.Name, gwdareMetaJSON) {
+				expParts[obj.Name] = ""
+			}
+		}
+		continuationToken = loi.NextContinuationToken
+		if !loi.IsTruncated {
+			break
+		}
+	}
+	for k := range expParts {
+		l.s3Objects.DeleteObject(ctx, bucket, k)
+	}
+	err := l.Client.RemoveBucket(bucket)
+	if err != nil {
+		return minio.ErrorRespToObjectError(err, bucket)
+	}
+	return nil
+}

cmd/gateway/s3/gateway-s3-utils.go

@@ -0,0 +1,47 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package s3
+
+import minio "github.com/minio/minio/cmd"
+
+// List of header keys to be filtered, usually
+// from all S3 API http responses.
+var defaultFilterKeys = []string{
+	"Connection",
+	"Transfer-Encoding",
+	"Accept-Ranges",
+	"Date",
+	"Server",
+	"Vary",
+	"x-amz-bucket-region",
+	"x-amz-request-id",
+	"x-amz-id-2",
+	"Content-Security-Policy",
+	"X-Xss-Protection",
+
+	// Add new headers to be ignored.
+}
+
+// FromGatewayObjectPart converts ObjectInfo for custom part stored as object to PartInfo
+func FromGatewayObjectPart(partID int, oi minio.ObjectInfo) (pi minio.PartInfo) {
+	return minio.PartInfo{
+		Size:         oi.Size,
+		ETag:         minio.CanonicalizeETag(oi.ETag),
+		LastModified: oi.ModTime,
+		PartNumber:   partID,
+	}
+}

cmd/gateway/s3/gateway-s3.go

@@ -28,12 +28,13 @@ import (
 	"github.com/minio/cli"
 	miniogo "github.com/minio/minio-go"
 	"github.com/minio/minio-go/pkg/credentials"
+	minio "github.com/minio/minio/cmd"
+
+	"github.com/minio/minio-go/pkg/encrypt"
 	"github.com/minio/minio-go/pkg/s3utils"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/auth"
 	"github.com/minio/minio/pkg/policy"
-
-	minio "github.com/minio/minio/cmd"
 )
 
 const (
@@ -223,9 +224,20 @@ func (g *S3) NewGatewayLayer(creds auth.Credentials) (minio.ObjectLayer, error)
 		return nil, err
 	}
 
-	return &s3Objects{
+	s := s3Objects{
 		Client: clnt,
-	}, nil
+	}
+	// Enables single encyption of KMS is configured.
+	if minio.GlobalKMS != nil {
+		encS := s3EncObjects{s}
+
+		// Start stale enc multipart uploads cleanup routine.
+		go encS.cleanupStaleEncMultipartUploads(context.Background(),
+			minio.GlobalMultipartCleanupInterval, minio.GlobalMultipartExpiry, minio.GlobalServiceDoneCh)
+
+		return &encS, nil
+	}
+	return &s, nil
 }
 
 // Production - s3 gateway is production ready.
@@ -330,6 +342,7 @@ func (l *s3Objects) ListObjects(ctx context.Context, bucket string, prefix strin
 
 // ListObjectsV2 lists all blobs in S3 bucket filtered by prefix
 func (l *s3Objects) ListObjectsV2(ctx context.Context, bucket, prefix, continuationToken, delimiter string, maxKeys int, fetchOwner bool, startAfter string) (loi minio.ListObjectsV2Info, e error) {
+
 	result, err := l.Client.ListObjectsV2(bucket, prefix, continuationToken, fetchOwner, delimiter, maxKeys, startAfter)
 	if err != nil {
 		return loi, minio.ErrorRespToObjectError(err, bucket)
@@ -387,7 +400,6 @@ func (l *s3Objects) GetObject(ctx context.Context, bucket string, key string, st
 		return minio.ErrorRespToObjectError(err, bucket, key)
 	}
 	defer object.Close()
-
 	if _, err := io.Copy(writer, object); err != nil {
 		return minio.ErrorRespToObjectError(err, bucket, key)
 	}
@@ -396,7 +408,11 @@ func (l *s3Objects) GetObject(ctx context.Context, bucket string, key string, st
 
 // GetObjectInfo reads object info and replies back ObjectInfo
 func (l *s3Objects) GetObjectInfo(ctx context.Context, bucket string, object string, opts minio.ObjectOptions) (objInfo minio.ObjectInfo, err error) {
-	oi, err := l.Client.StatObject(bucket, object, miniogo.StatObjectOptions{GetObjectOptions: miniogo.GetObjectOptions{ServerSideEncryption: opts.ServerSideEncryption}})
+	oi, err := l.Client.StatObject(bucket, object, miniogo.StatObjectOptions{
+		GetObjectOptions: miniogo.GetObjectOptions{
+			ServerSideEncryption: opts.ServerSideEncryption,
+		},
+	})
 	if err != nil {
 		return minio.ObjectInfo{}, minio.ErrorRespToObjectError(err, bucket, object)
 	}
@@ -426,6 +442,18 @@ func (l *s3Objects) CopyObject(ctx context.Context, srcBucket string, srcObject
 	// So preserve it by adding "REPLACE" directive to save all the metadata set by CopyObject API.
 	srcInfo.UserDefined["x-amz-metadata-directive"] = "REPLACE"
 	srcInfo.UserDefined["x-amz-copy-source-if-match"] = srcInfo.ETag
+	header := make(http.Header)
+	if srcOpts.ServerSideEncryption != nil {
+		encrypt.SSECopy(srcOpts.ServerSideEncryption).Marshal(header)
+	}
+
+	if dstOpts.ServerSideEncryption != nil {
+		dstOpts.ServerSideEncryption.Marshal(header)
+	}
+	for k, v := range header {
+		srcInfo.UserDefined[k] = v[0]
+	}
+
 	if _, err = l.Client.CopyObject(srcBucket, srcObject, dstBucket, dstObject, srcInfo.UserDefined); err != nil {
 		return objInfo, minio.ErrorRespToObjectError(err, srcBucket, srcObject)
 	}
@@ -478,10 +506,21 @@ func (l *s3Objects) PutObjectPart(ctx context.Context, bucket string, object str
 // existing object or a part of it.
 func (l *s3Objects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, destBucket, destObject, uploadID string,
 	partID int, startOffset, length int64, srcInfo minio.ObjectInfo, srcOpts, dstOpts minio.ObjectOptions) (p minio.PartInfo, err error) {
-
 	srcInfo.UserDefined = map[string]string{
 		"x-amz-copy-source-if-match": srcInfo.ETag,
 	}
+	header := make(http.Header)
+	if srcOpts.ServerSideEncryption != nil {
+		encrypt.SSECopy(srcOpts.ServerSideEncryption).Marshal(header)
+	}
+
+	if dstOpts.ServerSideEncryption != nil {
+		dstOpts.ServerSideEncryption.Marshal(header)
+	}
+	for k, v := range header {
+		srcInfo.UserDefined[k] = v[0]
+	}
+
 	completePart, err := l.Client.CopyObjectPart(srcBucket, srcObject, destBucket, destObject,
 		uploadID, partID, startOffset, length, srcInfo.UserDefined)
 	if err != nil {
@@ -493,7 +532,7 @@ func (l *s3Objects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, de
 }
 
 // ListObjectParts returns all object parts for specified object in specified bucket
-func (l *s3Objects) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int) (lpi minio.ListPartsInfo, e error) {
+func (l *s3Objects) ListObjectParts(ctx context.Context, bucket string, object string, uploadID string, partNumberMarker int, maxParts int, opts minio.ObjectOptions) (lpi minio.ListPartsInfo, e error) {
 	result, err := l.Client.ListObjectParts(bucket, object, uploadID, partNumberMarker, maxParts)
 	if err != nil {
 		return lpi, minio.ErrorRespToObjectError(err, bucket, object)
@@ -557,3 +596,8 @@ func (l *s3Objects) DeleteBucketPolicy(ctx context.Context, bucket string) error
 func (l *s3Objects) IsCompressionSupported() bool {
 	return false
 }
+
+// IsEncryptionSupported returns whether server side encryption is implemented for this layer.
+func (l *s3Objects) IsEncryptionSupported() bool {
+	return minio.GlobalKMS != nil || len(minio.GlobalGatewaySSE) > 0
+}

cmd/gateway/s3/gateway-s3_test.go

@@ -110,8 +110,8 @@ func TestS3ToObjectError(t *testing.T) {
 		// Special test case for error that is not of type
 		// miniogo.ErrorResponse
 		{
-			inputErr:    fmt.Errorf("not a minio.ErrorResponse"),
+			inputErr:    fmt.Errorf("not a ErrorResponse"),
-			expectedErr: fmt.Errorf("not a minio.ErrorResponse"),
+			expectedErr: fmt.Errorf("not a ErrorResponse"),
 		},
 	}
 

cmd/globals.go

@@ -79,10 +79,11 @@ const (
 	// date and server date during signature verification.
 	globalMaxSkewTime = 15 * time.Minute // 15 minutes skew allowed.
 
-	// Expiry duration after which the multipart uploads are deemed stale.
+	// GlobalMultipartExpiry - Expiry duration after which the multipart uploads are deemed stale.
-	globalMultipartExpiry = time.Hour * 24 * 14 // 2 weeks.
+	GlobalMultipartExpiry = time.Hour * 24 * 14 // 2 weeks.
-	// Cleanup interval when the stale multipart cleanup is initiated.
+	// GlobalMultipartCleanupInterval - Cleanup interval when the stale multipart cleanup is initiated.
-	globalMultipartCleanupInterval = time.Hour * 24 // 24 hrs.
+	GlobalMultipartCleanupInterval = time.Hour * 24 // 24 hrs.
+
 	// Refresh interval to update in-memory bucket policy cache.
 	globalRefreshBucketPolicyInterval = 5 * time.Minute
 	// Refresh interval to update in-memory iam config cache.
@@ -236,8 +237,9 @@ var (
 
 	// KMS key id
 	globalKMSKeyID string
-	// Allocated KMS
+
-	globalKMS crypto.KMS
+	// GlobalKMS initialized KMS configuration
+	GlobalKMS crypto.KMS
 
 	// Auto-Encryption, if enabled, turns any non-SSE-C request
 	// into an SSE-S3 request. If enabled a valid, non-empty KMS
@@ -269,6 +271,9 @@ var (
 	// Deployment ID - unique per deployment
 	globalDeploymentID string
 
+	// GlobalGatewaySSE sse options
+	GlobalGatewaySSE gatewaySSE
+
 	// Add new variable global values here.
 )
 

cmd/iam.go

@@ -78,7 +78,7 @@ func (sys *IAMSys) Init(objAPI ObjectLayer) error {
 			defer ticker.Stop()
 			for {
 				select {
-				case <-globalServiceDoneCh:
+				case <-GlobalServiceDoneCh:
 					return
 				case <-ticker.C:
 					sys.refresh(objAPI)

cmd/lock-rpc-server.go

@@ -166,7 +166,7 @@ func startLockMaintenance(lkSrv *lockRPCReceiver) {
 	for {
 		// Verifies every minute for locks held more than 2minutes.
 		select {
-		case <-globalServiceDoneCh:
+		case <-GlobalServiceDoneCh:
 			return
 		case <-ticker.C:
 			lkSrv.lockMaintenance(lockValidityCheckInterval)

cmd/object-api-datatypes.go

@@ -103,7 +103,7 @@ type ObjectInfo struct {
 	UserDefined map[string]string
 
 	// List of individual parts, maximum size of upto 10,000
-	Parts []objectPartInfo `json:"-"`
+	Parts []ObjectPartInfo `json:"-"`
 
 	// Implements writer and reader used by CopyObject API
 	Writer       io.WriteCloser `json:"-"`

cmd/object-api-interface.go

@@ -75,7 +75,7 @@ type ObjectLayer interface {
 	CopyObjectPart(ctx context.Context, srcBucket, srcObject, destBucket, destObject string, uploadID string, partID int,
 		startOffset int64, length int64, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (info PartInfo, err error)
 	PutObjectPart(ctx context.Context, bucket, object, uploadID string, partID int, data *PutObjReader, opts ObjectOptions) (info PartInfo, err error)
-	ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int) (result ListPartsInfo, err error)
+	ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int, opts ObjectOptions) (result ListPartsInfo, err error)
 	AbortMultipartUpload(ctx context.Context, bucket, object, uploadID string) error
 	CompleteMultipartUpload(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart, opts ObjectOptions) (objInfo ObjectInfo, err error)
 

cmd/object-api-multipart_test.go

@@ -1429,7 +1429,7 @@ func testListObjectPartsDiskNotFound(obj ObjectLayer, instanceType string, disks
 	}
 
 	for i, testCase := range testCases {
-		actualResult, actualErr := obj.ListObjectParts(context.Background(), testCase.bucket, testCase.object, testCase.uploadID, testCase.partNumberMarker, testCase.maxParts)
+		actualResult, actualErr := obj.ListObjectParts(context.Background(), testCase.bucket, testCase.object, testCase.uploadID, testCase.partNumberMarker, testCase.maxParts, ObjectOptions{})
 		if actualErr != nil && testCase.shouldPass {
 			t.Errorf("Test %d: %s: Expected to pass, but failed with: <ERROR> %s", i+1, instanceType, actualErr.Error())
 		}
@@ -1667,7 +1667,7 @@ func testListObjectParts(obj ObjectLayer, instanceType string, t TestErrHandler)
 	}
 
 	for i, testCase := range testCases {
-		actualResult, actualErr := obj.ListObjectParts(context.Background(), testCase.bucket, testCase.object, testCase.uploadID, testCase.partNumberMarker, testCase.maxParts)
+		actualResult, actualErr := obj.ListObjectParts(context.Background(), testCase.bucket, testCase.object, testCase.uploadID, testCase.partNumberMarker, testCase.maxParts, ObjectOptions{})
 		if actualErr != nil && testCase.shouldPass {
 			t.Errorf("Test %d: %s: Expected to pass, but failed with: <ERROR> %s", i+1, instanceType, actualErr.Error())
 		}

cmd/object-api-utils.go

@@ -487,7 +487,6 @@ func NewGetObjectReader(rs *HTTPRangeSpec, oi ObjectInfo, cleanUpFns ...func())
 		// encrypted bytes. The header parameter is used to
 		// provide encryption parameters.
 		fn = func(inputReader io.Reader, h http.Header, cFns ...func()) (r *GetObjectReader, err error) {
-
 			copySource := h.Get(crypto.SSECopyAlgorithm) != ""
 
 			cFns = append(cleanUpFns, cFns...)
@@ -577,7 +576,6 @@ func NewGetObjectReader(rs *HTTPRangeSpec, oi ObjectInfo, cleanUpFns ...func())
 			return r, nil
 		}
 	}
-
 	return fn, off, length, nil
 }
 
@@ -663,3 +661,17 @@ func sealETagFn(key crypto.ObjectKey) SealMD5CurrFn {
 	}
 	return fn
 }
+
+// CleanMinioInternalMetadataKeys removes X-Amz-Meta- prefix from minio internal
+// encryption metadata that was sent by minio gateway
+func CleanMinioInternalMetadataKeys(metadata map[string]string) map[string]string {
+	var newMeta = make(map[string]string, len(metadata))
+	for k, v := range metadata {
+		if strings.HasPrefix(k, "X-Amz-Meta-X-Minio-Internal-") {
+			newMeta[strings.TrimPrefix(k, "X-Amz-Meta-")] = v
+		} else {
+			newMeta[k] = v
+		}
+	}
+	return newMeta
+}

cmd/object-api-utils_test.go

@@ -431,7 +431,7 @@ func TestGetActualSize(t *testing.T) {
 					"X-Minio-Internal-actual-size": "100000001",
 					"content-type":                 "application/octet-stream",
 					"etag":                         "b3ff3ef3789147152fbfbc50efba4bfd-2"},
-				Parts: []objectPartInfo{
+				Parts: []ObjectPartInfo{
 					{
 						Size:       39235668,
 						ActualSize: 67108864,
@@ -450,7 +450,7 @@ func TestGetActualSize(t *testing.T) {
 					"X-Minio-Internal-actual-size": "841",
 					"content-type":                 "application/octet-stream",
 					"etag":                         "b3ff3ef3789147152fbfbc50efba4bfd-2"},
-				Parts: []objectPartInfo{},
+				Parts: []ObjectPartInfo{},
 			},
 			result: 841,
 		},
@@ -459,7 +459,7 @@ func TestGetActualSize(t *testing.T) {
 				UserDefined: map[string]string{"X-Minio-Internal-compression": "golang/snappy/LZ77",
 					"content-type": "application/octet-stream",
 					"etag":         "b3ff3ef3789147152fbfbc50efba4bfd-2"},
-				Parts: []objectPartInfo{},
+				Parts: []ObjectPartInfo{},
 			},
 			result: -1,
 		},
@@ -482,7 +482,7 @@ func TestGetCompressedOffsets(t *testing.T) {
 	}{
 		{
 			objInfo: ObjectInfo{
-				Parts: []objectPartInfo{
+				Parts: []ObjectPartInfo{
 					{
 						Size:       39235668,
 						ActualSize: 67108864,
@@ -499,7 +499,7 @@ func TestGetCompressedOffsets(t *testing.T) {
 		},
 		{
 			objInfo: ObjectInfo{
-				Parts: []objectPartInfo{
+				Parts: []ObjectPartInfo{
 					{
 						Size:       39235668,
 						ActualSize: 67108864,
@@ -516,7 +516,7 @@ func TestGetCompressedOffsets(t *testing.T) {
 		},
 		{
 			objInfo: ObjectInfo{
-				Parts: []objectPartInfo{
+				Parts: []ObjectPartInfo{
 					{
 						Size:       39235668,
 						ActualSize: 67108864,

cmd/object-handlers.go

@@ -35,6 +35,7 @@ import (
 	"github.com/gorilla/mux"
 	"github.com/klauspost/readahead"
 	miniogo "github.com/minio/minio-go"
+	"github.com/minio/minio-go/pkg/encrypt"
 	"github.com/minio/minio/cmd/crypto"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/dns"
@@ -91,7 +92,7 @@ func (api objectAPIHandlers) SelectObjectContentHandler(w http.ResponseWriter, r
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrBadRequest, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -99,6 +100,12 @@ func (api objectAPIHandlers) SelectObjectContentHandler(w http.ResponseWriter, r
 	bucket := vars["bucket"]
 	object := vars["object"]
 
+	// get gateway encryption options
+	opts, err := getEncryptionOpts(ctx, r, bucket, object)
+	if err != nil {
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
+		return
+	}
 	// Check for auth type to return S3 compatible error.
 	// type to return the correct error (NoSuchKey vs AccessDenied)
 	if s3Error := checkRequestAuthType(ctx, r, policy.GetObjectAction, bucket, object); s3Error != ErrNone {
@@ -127,7 +134,7 @@ func (api objectAPIHandlers) SelectObjectContentHandler(w http.ResponseWriter, r
 					getObjectInfo = api.CacheAPI().GetObjectInfo
 				}
 
-				_, err := getObjectInfo(ctx, bucket, object, ObjectOptions{})
+				_, err = getObjectInfo(ctx, bucket, object, opts)
 				if toAPIErrorCode(ctx, err) == ErrNoSuchKey {
 					s3Error = ErrNoSuchKey
 				}
@@ -148,6 +155,7 @@ func (api objectAPIHandlers) SelectObjectContentHandler(w http.ResponseWriter, r
 		writeErrorResponse(w, ErrEmptyRequestBody, r.URL, guessIsBrowserReq(r))
 		return
 	}
+
 	var selectReq s3select.ObjectSelectRequest
 	if err := xmlDecoder(r.Body, &selectReq, r.ContentLength); err != nil {
 		writeErrorResponse(w, ErrMalformedXML, r.URL, guessIsBrowserReq(r))
@@ -168,7 +176,6 @@ func (api objectAPIHandlers) SelectObjectContentHandler(w http.ResponseWriter, r
 		getObjectNInfo = api.CacheAPI().GetObjectNInfo
 	}
 
-	var opts ObjectOptions
 	gr, err := getObjectNInfo(ctx, bucket, object, nil, r.Header, readLock, opts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
@@ -246,6 +253,7 @@ func (api objectAPIHandlers) SelectObjectContentHandler(w http.ResponseWriter, r
 
 	// Set encryption response headers
 	if objectAPI.IsEncryptionSupported() {
+		objInfo.UserDefined = CleanMinioInternalMetadataKeys(objInfo.UserDefined)
 		if crypto.IsEncrypted(objInfo.UserDefined) {
 			switch {
 			case crypto.S3.IsEncrypted(objInfo.UserDefined):
@@ -322,7 +330,7 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 		writeErrorResponse(w, ErrBadRequest, r.URL, guessIsBrowserReq(r))
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrBadRequest, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -335,10 +343,13 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 		return
 	}
 
-	var (
+	// get gateway encryption options
-		opts ObjectOptions
+	opts, err := getEncryptionOpts(ctx, r, bucket, object)
-		err  error
+	if err != nil {
-	)
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
+		return
+	}
+
 	// Check for auth type to return S3 compatible error.
 	// type to return the correct error (NoSuchKey vs AccessDenied)
 	if s3Error := checkRequestAuthType(ctx, r, policy.GetObjectAction, bucket, object); s3Error != ErrNone {
@@ -409,6 +420,7 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 	objInfo := gr.ObjInfo
 
 	if objectAPI.IsEncryptionSupported() {
+		objInfo.UserDefined = CleanMinioInternalMetadataKeys(objInfo.UserDefined)
 		if _, err = DecryptObjectInfo(&objInfo, r.Header); err != nil {
 			writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 			return
@@ -498,7 +510,7 @@ func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Re
 		writeErrorResponseHeadersOnly(w, ErrBadRequest)
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrBadRequest, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -516,10 +528,11 @@ func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Re
 		getObjectInfo = api.CacheAPI().GetObjectInfo
 	}
 
-	var (
+	opts, err := getEncryptionOpts(ctx, r, bucket, object)
-		opts ObjectOptions
+	if err != nil {
-		err  error
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
-	)
+		return
+	}
 
 	if s3Error := checkRequestAuthType(ctx, r, policy.GetObjectAction, bucket, object); s3Error != ErrNone {
 		if getRequestAuthType(r) == authTypeAnonymous {
@@ -574,12 +587,12 @@ func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Re
 		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
 		return
 	}
-
 	if objectAPI.IsEncryptionSupported() {
 		if _, err = DecryptObjectInfo(&objInfo, r.Header); err != nil {
 			writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
 			return
 		}
+		objInfo.UserDefined = CleanMinioInternalMetadataKeys(objInfo.UserDefined)
 	}
 
 	// Set encryption response headers
@@ -626,7 +639,6 @@ func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Re
 	if err != nil {
 		host, port = "", ""
 	}
-
 	// Notify object accessed via a HEAD request.
 	sendEvent(eventArgs{
 		EventName:    event.ObjectAccessedHead,
@@ -650,6 +662,9 @@ func getCpObjMetadataFromHeader(ctx context.Context, r *http.Request, userMeta m
 		defaultMeta[k] = v
 	}
 
+	// remove SSE Headers from source info
+	crypto.RemoveSSEHeaders(defaultMeta)
+
 	// if x-amz-metadata-directive says REPLACE then
 	// we extract metadata from the input headers.
 	if isMetadataReplace(r.Header) {
@@ -712,7 +727,7 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r)) // SSE-KMS is not supported
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && (hasServerSideEncryptionHeader(r.Header) || crypto.SSECopy.IsRequested(r.Header)) {
+	if !api.EncryptionEnabled() && (hasServerSideEncryptionHeader(r.Header) || crypto.SSECopy.IsRequested(r.Header)) {
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -767,8 +782,30 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		writeErrorResponse(w, ErrInvalidMetadataDirective, r.URL, guessIsBrowserReq(r))
 		return
 	}
+	// This request header needs to be set prior to setting ObjectOptions
+	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
+		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
+	}
 
 	var srcOpts, dstOpts ObjectOptions
+	srcOpts, err = copySrcEncryptionOpts(ctx, r, srcBucket, srcObject)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+		return
+	}
+	// convert copy src encryption options for GET calls
+	var getOpts = ObjectOptions{}
+	getSSE := encrypt.SSE(srcOpts.ServerSideEncryption)
+	if getSSE != srcOpts.ServerSideEncryption {
+		getOpts.ServerSideEncryption = getSSE
+	}
+	dstOpts, err = copyDstEncryptionOpts(ctx, r, dstBucket, dstObject, nil)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+		return
+	}
 
 	// Deny if WORM is enabled
 	if globalWORMEnabled {
@@ -791,7 +828,7 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 	}
 
 	var rs *HTTPRangeSpec
-	gr, err := getObjectNInfo(ctx, srcBucket, srcObject, rs, r.Header, lock, srcOpts)
+	gr, err := getObjectNInfo(ctx, srcBucket, srcObject, rs, r.Header, lock, getOpts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
@@ -890,9 +927,6 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 	rawReader := srcInfo.Reader
 	pReader := NewPutObjReader(srcInfo.Reader, nil, nil)
 
-	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
-		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
-	}
 	var encMetadata = make(map[string]string)
 	if objectAPI.IsEncryptionSupported() && !isCompressed {
 		// Encryption parameters not applicable for this object.
@@ -927,6 +961,7 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		// - the object is encrypted using SSE-C and two different SSE-C keys are present
 		// - the object is encrypted using SSE-S3 and the SSE-S3 header is present
 		// than execute a key rotation.
+		var keyRotation bool
 		if cpSrcDstSame && ((sseCopyC && sseC) || (sseS3 && sseCopyS3)) {
 			if sseCopyC && sseC {
 				oldKey, err = ParseSSECopyCustomerRequest(r.Header, srcInfo.UserDefined)
@@ -950,12 +985,15 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 
 			// Since we are rotating the keys, make sure to update the metadata.
 			srcInfo.metadataOnly = true
+			keyRotation = true
 		} else {
 			if isSourceEncrypted || isTargetEncrypted {
 				// We are not only copying just metadata instead
 				// we are creating a new object at this point, even
 				// if source and destination are same objects.
-				srcInfo.metadataOnly = false
+				if !keyRotation {
+					srcInfo.metadataOnly = false
+				}
 			}
 
 			// Calculate the size of the target object
@@ -1017,7 +1055,6 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 
 	// Ensure that metadata does not contain sensitive information
 	crypto.RemoveSensitiveEntries(srcInfo.UserDefined)
-
 	// Check if x-amz-metadata-directive was not set to REPLACE and source,
 	// desination are same objects. Apply this restriction also when
 	// metadataOnly is true indicating that we are not overwriting the object.
@@ -1115,7 +1152,7 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r)) // SSE-KMS is not supported
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -1276,7 +1313,17 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 	rawReader := hashReader
 	pReader := NewPutObjReader(rawReader, nil, nil)
 
+	// This request header needs to be set prior to setting ObjectOptions
+	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
+		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
+	}
+	// get gateway encryption options
 	var opts ObjectOptions
+	opts, err = putEncryptionOpts(ctx, r, bucket, object, nil)
+	if err != nil {
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
+		return
+	}
 
 	// Deny if WORM is enabled
 	if globalWORMEnabled {
@@ -1285,9 +1332,7 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 			return
 		}
 	}
-	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
+
-		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
-	}
 	var objectEncryptionKey []byte
 	if objectAPI.IsEncryptionSupported() {
 		if hasServerSideEncryptionHeader(r.Header) && !hasSuffix(object, slashSeparator) { // handle SSE requests
@@ -1384,7 +1429,7 @@ func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r)) // SSE-KMS is not supported
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -1392,10 +1437,21 @@ func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r
 	bucket := vars["bucket"]
 	object := vars["object"]
 
-	var (
+	// This request header needs to be set prior to setting ObjectOptions
-		opts ObjectOptions
+	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
-		err  error
+		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
-	)
+	}
+
+	// get gateway encryption options
+	var opts ObjectOptions
+	var err error
+
+	opts, err = putEncryptionOpts(ctx, r, bucket, object, nil)
+	if err != nil {
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
+		return
+	}
+
 	if s3Error := checkRequestAuthType(ctx, r, policy.PutObjectAction, bucket, object); s3Error != ErrNone {
 		writeErrorResponse(w, s3Error, r.URL, guessIsBrowserReq(r))
 		return
@@ -1419,9 +1475,6 @@ func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r
 
 	var encMetadata = map[string]string{}
 
-	if globalAutoEncryption && !crypto.SSEC.IsRequested(r.Header) {
-		r.Header.Add(crypto.SSEHeader, crypto.SSEAlgorithmAES256)
-	}
 	if objectAPI.IsEncryptionSupported() {
 		if hasServerSideEncryptionHeader(r.Header) {
 			if err = setEncryptionMetadata(r, bucket, object, encMetadata); err != nil {
@@ -1487,7 +1540,7 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r)) // SSE-KMS is not supported
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && (hasServerSideEncryptionHeader(r.Header) || crypto.SSECopy.IsRequested(r.Header)) {
+	if !api.EncryptionEnabled() && (hasServerSideEncryptionHeader(r.Header) || crypto.SSECopy.IsRequested(r.Header)) {
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -1552,6 +1605,21 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 	}
 
 	var srcOpts, dstOpts ObjectOptions
+	srcOpts, err = copySrcEncryptionOpts(ctx, r, srcBucket, srcObject)
+	if err != nil {
+		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+		return
+	}
+	// convert copy src and dst encryption options for GET/PUT calls
+	var getOpts = ObjectOptions{}
+	if srcOpts.ServerSideEncryption != nil {
+		getOpts.ServerSideEncryption = encrypt.SSE(srcOpts.ServerSideEncryption)
+	}
+	dstOpts, err = copyDstEncryptionOpts(ctx, r, dstBucket, dstObject, nil)
+	if err != nil {
+		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+		return
+	}
 
 	// Deny if WORM is enabled
 	if globalWORMEnabled {
@@ -1582,7 +1650,7 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 		}
 	}
 
-	gr, err := getObjectNInfo(ctx, srcBucket, srcObject, rs, r.Header, readLock, srcOpts)
+	gr, err := getObjectNInfo(ctx, srcBucket, srcObject, rs, r.Header, readLock, getOpts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
@@ -1627,7 +1695,7 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 	var reader io.Reader
 
 	var li ListPartsInfo
-	li, err = objectAPI.ListObjectParts(ctx, dstBucket, dstObject, uploadID, 0, 1)
+	li, err = objectAPI.ListObjectParts(ctx, dstBucket, dstObject, uploadID, 0, 1, dstOpts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
@@ -1669,7 +1737,19 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 	isEncrypted := false
 	var objectEncryptionKey []byte
 	if objectAPI.IsEncryptionSupported() && !isCompressed {
+		li, lerr := objectAPI.ListObjectParts(ctx, dstBucket, dstObject, uploadID, 0, 1, dstOpts)
+		if lerr != nil {
+			writeErrorResponse(w, toAPIErrorCode(ctx, lerr), r.URL, guessIsBrowserReq(r))
+			return
+		}
+		li.UserDefined = CleanMinioInternalMetadataKeys(li.UserDefined)
+		dstOpts, err = copyDstEncryptionOpts(ctx, r, dstBucket, dstObject, li.UserDefined)
+		if err != nil {
+			writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+			return
+		}
 		if crypto.IsEncrypted(li.UserDefined) {
+			isEncrypted = true
 			if !crypto.SSEC.IsRequested(r.Header) && crypto.SSEC.IsEncrypted(li.UserDefined) {
 				writeErrorResponse(w, ErrSSEMultipartEncrypted, r.URL, guessIsBrowserReq(r))
 				return
@@ -1714,7 +1794,6 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 			pReader = NewPutObjReader(rawReader, srcInfo.Reader, objectEncryptionKey)
 		}
 	}
-
 	srcInfo.PutObjReader = pReader
 	// Copy source object to destination, if source and destination
 	// object is same then only metadata is updated.
@@ -1724,6 +1803,9 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
 	}
+	if isEncrypted {
+		partInfo.ETag = tryDecryptETag(objectEncryptionKey, partInfo.ETag, crypto.SSEC.IsRequested(r.Header))
+	}
 
 	if isEncrypted {
 		partInfo.ETag = tryDecryptETag(objectEncryptionKey, partInfo.ETag, crypto.SSEC.IsRequested(r.Header))
@@ -1751,7 +1833,7 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r)) // SSE-KMS is not supported
 		return
 	}
-	if !objectAPI.IsEncryptionSupported() && hasServerSideEncryptionHeader(r.Header) {
+	if !api.EncryptionEnabled() && hasServerSideEncryptionHeader(r.Header) {
 		writeErrorResponse(w, ErrNotImplemented, r.URL, guessIsBrowserReq(r))
 		return
 	}
@@ -1856,8 +1938,17 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 	var pipeReader *io.PipeReader
 	var pipeWriter *io.PipeWriter
 
+	// get encryption options
+	var opts ObjectOptions
+	if crypto.SSEC.IsRequested(r.Header) {
+		opts, err = putEncryptionOpts(ctx, r, bucket, object, nil)
+		if err != nil {
+			writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+			return
+		}
+	}
 	var li ListPartsInfo
-	li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1)
+	li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1, opts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
@@ -1897,10 +1988,8 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
 	}
-
 	rawReader := hashReader
 	pReader := NewPutObjReader(rawReader, nil, nil)
-	var opts ObjectOptions
 
 	// Deny if WORM is enabled
 	if globalWORMEnabled {
@@ -1914,17 +2003,25 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 	var objectEncryptionKey []byte
 	if objectAPI.IsEncryptionSupported() && !isCompressed {
 		var li ListPartsInfo
-		li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1)
+		li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1, ObjectOptions{})
 		if err != nil {
 			writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 			return
 		}
+		li.UserDefined = CleanMinioInternalMetadataKeys(li.UserDefined)
 		if crypto.IsEncrypted(li.UserDefined) {
 			if !crypto.SSEC.IsRequested(r.Header) && crypto.SSEC.IsEncrypted(li.UserDefined) {
 				writeErrorResponse(w, ErrSSEMultipartEncrypted, r.URL, guessIsBrowserReq(r))
 				return
 			}
+
 			isEncrypted = true // to detect SSE-S3 encryption
+			opts, err = putEncryptionOpts(ctx, r, bucket, object, li.UserDefined)
+			if err != nil {
+				writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
+				return
+			}
+
 			var key []byte
 			if crypto.SSEC.IsRequested(r.Header) {
 				key, err = ParseSSECustomerRequest(r)
@@ -1940,7 +2037,6 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 				writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 				return
 			}
-
 			var partIDbin [4]byte
 			binary.LittleEndian.PutUint32(partIDbin[:], uint32(partID)) // marshal part ID
 
@@ -2067,16 +2163,16 @@ func (api objectAPIHandlers) ListObjectPartsHandler(w http.ResponseWriter, r *ht
 		writeErrorResponse(w, ErrInvalidMaxParts, r.URL, guessIsBrowserReq(r))
 		return
 	}
-	listPartsInfo, err := objectAPI.ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts)
+	var opts ObjectOptions
+	listPartsInfo, err := objectAPI.ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts, opts)
 	if err != nil {
 		writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 		return
 	}
-
 	var ssec bool
 	if objectAPI.IsEncryptionSupported() {
 		var li ListPartsInfo
-		li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1)
+		li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1, opts)
 		if err != nil {
 			writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 			return
@@ -2169,10 +2265,9 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 	var objectEncryptionKey []byte
 	var opts ObjectOptions
 	var isEncrypted, ssec bool
-
 	if objectAPI.IsEncryptionSupported() {
 		var li ListPartsInfo
-		li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1)
+		li, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, 0, 1, opts)
 		if err != nil {
 			writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 			return
@@ -2181,6 +2276,8 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 			isEncrypted = true
 			ssec = crypto.SSEC.IsEncrypted(li.UserDefined)
 			var key []byte
+			isEncrypted = true
+			ssec = crypto.SSEC.IsEncrypted(li.UserDefined)
 			if crypto.S3.IsEncrypted(li.UserDefined) {
 				// Calculating object encryption key
 				objectEncryptionKey, err = decryptObjectInfo(key, bucket, object, li.UserDefined)
@@ -2193,13 +2290,11 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 	}
 
 	partsMap := make(map[string]PartInfo)
-	var listPartsInfo ListPartsInfo
-
 	if isEncrypted {
 		var partNumberMarker int
 		maxParts := 1000
 		for {
-			listPartsInfo, err = objectAPI.ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts)
+			listPartsInfo, err := objectAPI.ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts, opts)
 			if err != nil {
 				writeErrorResponse(w, toAPIErrorCode(ctx, err), r.URL, guessIsBrowserReq(r))
 				return
@@ -2213,6 +2308,7 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 			}
 		}
 	}
+
 	// Complete parts.
 	var completeParts []CompletePart
 	for _, part := range complMultipartUpload.Parts {

cmd/object-handlers_test.go

@@ -1731,7 +1731,7 @@ func testAPICopyObjectPartHandler(obj ObjectLayer, instanceType, bucketName stri
 			// See if the new part has been uploaded.
 			// testing whether the copy was successful.
 			var results ListPartsInfo
-			results, err = obj.ListObjectParts(context.Background(), testCase.bucketName, testObject, testCase.uploadID, 0, 1)
+			results, err = obj.ListObjectParts(context.Background(), testCase.bucketName, testObject, testCase.uploadID, 0, 1, ObjectOptions{})
 			if err != nil {
 				t.Fatalf("Test %d: %s: Failed to look for copied object part: <ERROR> %s", i+1, instanceType, err)
 			}
@@ -2245,7 +2245,7 @@ func testAPINewMultipartHandler(obj ObjectLayer, instanceType, bucketName string
 		t.Fatalf("Error decoding the recorded response Body")
 	}
 	// verify the uploadID my making an attempt to list parts.
-	_, err = obj.ListObjectParts(context.Background(), bucketName, objectName, multipartResponse.UploadID, 0, 1)
+	_, err = obj.ListObjectParts(context.Background(), bucketName, objectName, multipartResponse.UploadID, 0, 1, ObjectOptions{})
 	if err != nil {
 		t.Fatalf("Invalid UploadID: <ERROR> %s", err)
 	}
@@ -2297,7 +2297,7 @@ func testAPINewMultipartHandler(obj ObjectLayer, instanceType, bucketName string
 		t.Fatalf("Error decoding the recorded response Body")
 	}
 	// verify the uploadID my making an attempt to list parts.
-	_, err = obj.ListObjectParts(context.Background(), bucketName, objectName, multipartResponse.UploadID, 0, 1)
+	_, err = obj.ListObjectParts(context.Background(), bucketName, objectName, multipartResponse.UploadID, 0, 1, ObjectOptions{})
 	if err != nil {
 		t.Fatalf("Invalid UploadID: <ERROR> %s", err)
 	}
@@ -2412,7 +2412,7 @@ func testAPINewMultipartHandlerParallel(obj ObjectLayer, instanceType, bucketNam
 	wg.Wait()
 	// Validate the upload ID by an attempt to list parts using it.
 	for _, uploadID := range testUploads.uploads {
-		_, err := obj.ListObjectParts(context.Background(), bucketName, objectName, uploadID, 0, 1)
+		_, err := obj.ListObjectParts(context.Background(), bucketName, objectName, uploadID, 0, 1, ObjectOptions{})
 		if err != nil {
 			t.Fatalf("Invalid UploadID: <ERROR> %s", err)
 		}

cmd/policy.go

@@ -141,7 +141,7 @@ func (sys *PolicySys) Init(objAPI ObjectLayer) error {
 			defer ticker.Stop()
 			for {
 				select {
-				case <-globalServiceDoneCh:
+				case <-GlobalServiceDoneCh:
 					return
 				case <-ticker.C:
 					sys.refresh(objAPI)

cmd/posix.go

@@ -202,7 +202,7 @@ func newPosix(path string) (*posix, error) {
 	}
 
 	if !p.diskMount {
-		go p.diskUsage(globalServiceDoneCh)
+		go p.diskUsage(GlobalServiceDoneCh)
 	}
 
 	// Success.

cmd/routers.go

@@ -123,8 +123,8 @@ func configureServerHandler(endpoints EndpointList) (http.Handler, error) {
 		}
 	}
 
-	// Add API router.
+	// Add API router, additionally all server mode support encryption.
-	registerAPIRouter(router)
+	registerAPIRouter(router, true)
 
 	// Register rest of the handlers.
 	return registerHandlers(router, globalHandlers...), nil

cmd/service.go

@@ -34,12 +34,12 @@ const (
 // Global service signal channel.
 var globalServiceSignalCh chan serviceSignal
 
-// Global service done channel.
+// GlobalServiceDoneCh - Global service done channel.
-var globalServiceDoneCh chan struct{}
+var GlobalServiceDoneCh chan struct{}
 
 // Initialize service mutex once.
 func init() {
-	globalServiceDoneCh = make(chan struct{}, 1)
+	GlobalServiceDoneCh = make(chan struct{}, 1)
 	globalServiceSignalCh = make(chan serviceSignal)
 }
 

cmd/test-utils_test.go

@@ -2115,7 +2115,7 @@ func registerBucketLevelFunc(bucket *mux.Router, api objectAPIHandlers, apiFunct
 func registerAPIFunctions(muxRouter *mux.Router, objLayer ObjectLayer, apiFunctions ...string) {
 	if len(apiFunctions) == 0 {
 		// Register all api endpoints by default.
-		registerAPIRouter(muxRouter)
+		registerAPIRouter(muxRouter, true)
 		return
 	}
 	// API Router.
@@ -2133,8 +2133,9 @@ func registerAPIFunctions(muxRouter *mux.Router, objLayer ObjectLayer, apiFuncti
 	// to underlying cache layer to manage object layer operation and disk caching
 	// operation
 	api := objectAPIHandlers{
-		ObjectAPI: newObjectLayerFn,
+		ObjectAPI:         newObjectLayerFn,
-		CacheAPI:  newCacheObjectsFn,
+		CacheAPI:          newCacheObjectsFn,
+		EncryptionEnabled: func() bool { return true },
 	}
 
 	// Register ListBuckets	handler.
@@ -2155,7 +2156,7 @@ func initTestAPIEndPoints(objLayer ObjectLayer, apiFunctions []string) http.Hand
 		registerAPIFunctions(muxRouter, objLayer, apiFunctions...)
 		return muxRouter
 	}
-	registerAPIRouter(muxRouter)
+	registerAPIRouter(muxRouter, true)
 	return muxRouter
 }
 

cmd/ui-errors.go

@@ -203,4 +203,16 @@ Example 1:
 		"Please check the passed value",
 		"Compress extensions/mime-types are delimited by `,`. For eg, MINIO_COMPRESS_ATTR=\"A,B,C\"",
 	)
+
+	uiErrInvalidGWSSEValue = newUIErrFn(
+		"Invalid gateway SSE value",
+		"Please check the passed value",
+		"MINIO_GATEWAY_SSE: Gateway SSE accepts only C and S3 as valid values. Delimit by `;` to set more than one value",
+	)
+
+	uiErrInvalidGWSSEEnvValue = newUIErrFn(
+		"Invalid gateway SSE configuration",
+		"",
+		"Refer to https://docs.minio.io/docs/minio-kms-quickstart-guide.html for setting up SSE",
+	)
 )

cmd/web-handlers.go

@@ -931,7 +931,13 @@ func (web *webAPIHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 	pReader = NewPutObjReader(hashReader, nil, nil)
-
+	// get gateway encryption options
+	var opts ObjectOptions
+	opts, err = putEncryptionOpts(ctx, r, bucket, object, nil)
+	if err != nil {
+		writeErrorResponseHeadersOnly(w, toAPIErrorCode(ctx, err))
+		return
+	}
 	if objectAPI.IsEncryptionSupported() {
 		if hasServerSideEncryptionHeader(r.Header) && !hasSuffix(object, slashSeparator) { // handle SSE requests
 			rawReader := hashReader
@@ -954,7 +960,6 @@ func (web *webAPIHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 	// Ensure that metadata does not contain sensitive information
 	crypto.RemoveSensitiveEntries(metadata)
 
-	var opts ObjectOptions
 	// Deny if WORM is enabled
 	if globalWORMEnabled {
 		if _, err = objectAPI.GetObjectInfo(ctx, bucket, object, opts); err == nil {

cmd/xl-sets.go

@@ -234,7 +234,7 @@ func (s *xlSets) monitorAndConnectEndpoints(monitorInterval time.Duration) {
 
 	for {
 		select {
-		case <-globalServiceDoneCh:
+		case <-GlobalServiceDoneCh:
 			return
 		case <-s.disksConnectDoneCh:
 			return
@@ -288,7 +288,7 @@ func newXLSets(endpoints EndpointList, format *formatXLV3, setCount int, drivesP
 			nsMutex:  mutex,
 			bp:       bp,
 		}
-		go s.sets[i].cleanupStaleMultipartUploads(context.Background(), globalMultipartCleanupInterval, globalMultipartExpiry, globalServiceDoneCh)
+		go s.sets[i].cleanupStaleMultipartUploads(context.Background(), GlobalMultipartCleanupInterval, GlobalMultipartExpiry, GlobalServiceDoneCh)
 	}
 
 	// Connect disks right away, but wait until we have `format.json` quorum.
@@ -521,7 +521,7 @@ func (s *xlSets) IsListenBucketSupported() bool {
 	return true
 }
 
-// IsEncryptionSupported returns whether server side encryption is applicable for this layer.
+// IsEncryptionSupported returns whether server side encryption is implemented for this layer.
 func (s *xlSets) IsEncryptionSupported() bool {
 	return s.getHashedSet("").IsEncryptionSupported()
 }
@@ -840,8 +840,8 @@ func (s *xlSets) PutObjectPart(ctx context.Context, bucket, object, uploadID str
 }
 
 // ListObjectParts - lists all uploaded parts to an object in hashedSet.
-func (s *xlSets) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int) (result ListPartsInfo, err error) {
+func (s *xlSets) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker int, maxParts int, opts ObjectOptions) (result ListPartsInfo, err error) {
-	return s.getHashedSet(object).ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts)
+	return s.getHashedSet(object).ListObjectParts(ctx, bucket, object, uploadID, partNumberMarker, maxParts, opts)
 }
 
 // Aborts an in-progress multipart operation on hashedSet based on the object name.

cmd/xl-v1-bucket.go

@@ -299,7 +299,7 @@ func (xl xlObjects) IsListenBucketSupported() bool {
 	return true
 }
 
-// IsEncryptionSupported returns whether server side encryption is applicable for this layer.
+// IsEncryptionSupported returns whether server side encryption is implemented for this layer.
 func (xl xlObjects) IsEncryptionSupported() bool {
 	return true
 }

cmd/xl-v1-healing-common_test.go

@@ -97,7 +97,7 @@ func partsMetaFromModTimes(modTimes []time.Time, algorithm BitrotAlgorithm, chec
 			Stat: statInfo{
 				ModTime: modTime,
 			},
-			Parts: []objectPartInfo{
+			Parts: []ObjectPartInfo{
 				{
 					Name: "part.1",
 				},

cmd/xl-v1-metadata.go

@@ -31,9 +31,9 @@ import (
 
 const erasureAlgorithmKlauspost = "klauspost/reedsolomon/vandermonde"
 
-// objectPartInfo Info of each part kept in the multipart metadata
+// ObjectPartInfo Info of each part kept in the multipart metadata
 // file after CompleteMultipartUpload() is called.
-type objectPartInfo struct {
+type ObjectPartInfo struct {
 	Number     int    `json:"number"`
 	Name       string `json:"name"`
 	ETag       string `json:"etag"`
@@ -42,7 +42,7 @@ type objectPartInfo struct {
 }
 
 // byObjectPartNumber is a collection satisfying sort.Interface.
-type byObjectPartNumber []objectPartInfo
+type byObjectPartNumber []ObjectPartInfo
 
 func (t byObjectPartNumber) Len() int           { return len(t) }
 func (t byObjectPartNumber) Swap(i, j int)      { t[i], t[j] = t[j], t[i] }
@@ -153,7 +153,7 @@ type xlMetaV1 struct {
 	// Metadata map for current object `xl.json`.
 	Meta map[string]string `json:"meta,omitempty"`
 	// Captures all the individual object `xl.json`.
-	Parts []objectPartInfo `json:"parts,omitempty"`
+	Parts []ObjectPartInfo `json:"parts,omitempty"`
 }
 
 // XL metadata constants.
@@ -243,7 +243,7 @@ func (m xlMetaV1) ToObjectInfo(bucket, object string) ObjectInfo {
 }
 
 // objectPartIndex - returns the index of matching object part number.
-func objectPartIndex(parts []objectPartInfo, partNumber int) int {
+func objectPartIndex(parts []ObjectPartInfo, partNumber int) int {
 	for i, part := range parts {
 		if partNumber == part.Number {
 			return i
@@ -254,7 +254,7 @@ func objectPartIndex(parts []objectPartInfo, partNumber int) int {
 
 // AddObjectPart - add a new object part in order.
 func (m *xlMetaV1) AddObjectPart(partNumber int, partName string, partETag string, partSize int64, actualSize int64) {
-	partInfo := objectPartInfo{
+	partInfo := ObjectPartInfo{
 		Number:     partNumber,
 		Name:       partName,
 		ETag:       partETag,
@@ -351,7 +351,7 @@ func pickValidXLMeta(ctx context.Context, metaArr []xlMetaV1, modTime time.Time,
 var objMetadataOpIgnoredErrs = append(baseIgnoredErrs, errDiskAccessDenied, errVolumeNotFound, errFileNotFound, errFileAccessDenied, errCorruptedFormat)
 
 // readXLMetaParts - returns the XL Metadata Parts from xl.json of one of the disks picked at random.
-func (xl xlObjects) readXLMetaParts(ctx context.Context, bucket, object string) (xlMetaParts []objectPartInfo, xlMeta map[string]string, err error) {
+func (xl xlObjects) readXLMetaParts(ctx context.Context, bucket, object string) (xlMetaParts []ObjectPartInfo, xlMeta map[string]string, err error) {
 	var ignoredErrs []error
 	for _, disk := range xl.getLoadBalancedDisks() {
 		if disk == nil {

cmd/xl-v1-multipart.go

@@ -493,7 +493,7 @@ func (xl xlObjects) PutObjectPart(ctx context.Context, bucket, object, uploadID
 // Implements S3 compatible ListObjectParts API. The resulting
 // ListPartsInfo structure is marshaled directly into XML and
 // replied back to the client.
-func (xl xlObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker, maxParts int) (result ListPartsInfo, e error) {
+func (xl xlObjects) ListObjectParts(ctx context.Context, bucket, object, uploadID string, partNumberMarker, maxParts int, opts ObjectOptions) (result ListPartsInfo, e error) {
 	if err := checkListPartsArgs(ctx, bucket, object, xl); err != nil {
 		return result, err
 	}
@@ -656,7 +656,7 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 	var currentXLMeta = xlMeta
 
 	// Allocate parts similar to incoming slice.
-	xlMeta.Parts = make([]objectPartInfo, len(parts))
+	xlMeta.Parts = make([]ObjectPartInfo, len(parts))
 
 	// Validate each part and then commit to disk.
 	for i, part := range parts {
@@ -695,7 +695,7 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 		objectActualSize += currentXLMeta.Parts[partIdx].ActualSize
 
 		// Add incoming parts.
-		xlMeta.Parts[i] = objectPartInfo{
+		xlMeta.Parts[i] = ObjectPartInfo{
 			Number:     part.PartNumber,
 			ETag:       part.ETag,
 			Size:       currentXLMeta.Parts[partIdx].Size,

cmd/xl-v1-multipart_test.go

@@ -36,7 +36,7 @@ func TestXLCleanupStaleMultipartUploads(t *testing.T) {
 
 	// Close the go-routine, we are going to
 	// manually start it and test in this test case.
-	globalServiceDoneCh <- struct{}{}
+	GlobalServiceDoneCh <- struct{}{}
 
 	bucketName := "bucket"
 	objectName := "object"
@@ -48,14 +48,14 @@ func TestXLCleanupStaleMultipartUploads(t *testing.T) {
 		t.Fatal("Unexpected err: ", err)
 	}
 
-	go xl.cleanupStaleMultipartUploads(context.Background(), 20*time.Millisecond, 0, globalServiceDoneCh)
+	go xl.cleanupStaleMultipartUploads(context.Background(), 20*time.Millisecond, 0, GlobalServiceDoneCh)
 
 	// Wait for 40ms such that - we have given enough time for
 	// cleanup routine to kick in.
 	time.Sleep(40 * time.Millisecond)
 
 	// Close the routine we do not need it anymore.
-	globalServiceDoneCh <- struct{}{}
+	GlobalServiceDoneCh <- struct{}{}
 
 	// Check if upload id was already purged.
 	if err = obj.AbortMultipartUpload(context.Background(), bucketName, objectName, uploadID); err != nil {

cmd/xl-v1-object.go

@@ -526,7 +526,7 @@ func (xl xlObjects) renameCorruptedObject(ctx context.Context, bucket, object st
 			},
 		}
 
-		validMeta.Parts = []objectPartInfo{
+		validMeta.Parts = []ObjectPartInfo{
 			{
 				Number: 1,
 				Name:   "part.1",

cmd/xl-v1-utils.go

@@ -192,12 +192,12 @@ func parseXLErasureInfo(ctx context.Context, xlMetaBuf []byte) (ErasureInfo, err
 	return erasure, nil
 }
 
-func parseXLParts(xlMetaBuf []byte) []objectPartInfo {
+func parseXLParts(xlMetaBuf []byte) []ObjectPartInfo {
 	// Parse the XL Parts.
 	partsResult := gjson.GetBytes(xlMetaBuf, "parts").Array()
-	partInfo := make([]objectPartInfo, len(partsResult))
+	partInfo := make([]ObjectPartInfo, len(partsResult))
 	for i, p := range partsResult {
-		info := objectPartInfo{}
+		info := ObjectPartInfo{}
 		info.Number = int(p.Get("number").Int())
 		info.Name = p.Get("name").String()
 		info.ETag = p.Get("etag").String()
@@ -249,7 +249,7 @@ func xlMetaV1UnmarshalJSON(ctx context.Context, xlMetaBuf []byte) (xlMeta xlMeta
 }
 
 // read xl.json from the given disk, parse and return xlV1MetaV1.Parts.
-func readXLMetaParts(ctx context.Context, disk StorageAPI, bucket string, object string) ([]objectPartInfo, map[string]string, error) {
+func readXLMetaParts(ctx context.Context, disk StorageAPI, bucket string, object string) ([]ObjectPartInfo, map[string]string, error) {
 	// Reads entire `xl.json`.
 	xlMetaBuf, err := disk.ReadAll(bucket, path.Join(object, xlMetaJSONFile))
 	if err != nil {

cmd/xl-v1-utils_test.go

@@ -174,7 +174,7 @@ func (m *xlMetaV1) AddTestObjectCheckSum(checkSumNum int, name string, algorithm
 
 // AddTestObjectPart - add a new object part in order.
 func (m *xlMetaV1) AddTestObjectPart(partNumber int, partName string, partETag string, partSize int64) {
-	partInfo := objectPartInfo{
+	partInfo := ObjectPartInfo{
 		Number: partNumber,
 		Name:   partName,
 		ETag:   partETag,
@@ -201,7 +201,7 @@ func getSampleXLMeta(totalParts int) xlMetaV1 {
 	// Number of checksum info == total parts.
 	xlMeta.Erasure.Checksums = make([]ChecksumInfo, totalParts)
 	// total number of parts.
-	xlMeta.Parts = make([]objectPartInfo, totalParts)
+	xlMeta.Parts = make([]ObjectPartInfo, totalParts)
 	for i := 0; i < totalParts; i++ {
 		partName := "part." + strconv.Itoa(i+1)
 		// hard coding hash and algo value for the checksum, Since we are benchmarking the parsing of xl.json the magnitude doesn't affect the test,

docs/kms/README.md

@@ -108,7 +108,22 @@ export MINIO_SSE_VAULT_NAMESPACE=ns1
 
 Note: If [Vault Namespaces](https://learn.hashicorp.com/vault/operations/namespaces) are in use, MINIO_SSE_VAULT_NAMESPACE variable needs to be set before setting approle and transit secrets engine.
 
+Minio gateway to S3 supports encryption. Three encryption modes are possible - encryption can be set to ``pass-through`` to backend, ``single encryption`` (at the gateway) or ``double encryption`` (single encryption at gateway and pass through to backend). This can be specified by setting MINIO_GATEWAY_SSE and KMS environment variables set in Step 2.1.2.
 
+If MINIO_GATEWAY_SSE and KMS are not setup, all encryption headers are passed through to the backend. If KMS environment variables are set up, ``single encryption`` is automatically performed at the gateway and encrypted object is saved at the backend.
+
+To specify ``double encryption``, MINIO_GATEWAY_SSE environment variable needs to be set to "s3" for sse-s3
+and "c" for sse-c encryption. More than one encryption option can be set, delimited by ";". Objects are encrypted at the gateway and the gateway also does a pass-through to backend. Note that in the case of SSE-C encryption, gateway derives a unique SSE-C key for pass through from the SSE-C client key using a KDF.
+
+```sh
+export MINIO_GATEWAY_SSE="s3;c"
+export MINIO_SSE_VAULT_APPROLE_ID=9b56cc08-8258-45d5-24a3-679876769126
+export MINIO_SSE_VAULT_APPROLE_SECRET=4e30c52f-13e4-a6f5-0763-d50e8cb4321f
+export MINIO_SSE_VAULT_ENDPOINT=https://vault-endpoint-ip:8200
+export MINIO_SSE_VAULT_KEY_NAME=my-minio-key
+export MINIO_SSE_VAULT_AUTH_TYPE=approle
+minio gateway s3
+```
 
 #### 2.2 Specify a master key
 
@@ -126,7 +141,6 @@ head -c 32 /dev/urandom | xxd -c 32 -ps
 ```
 
 ### 3. Test your setup
-
 To test this setup, start minio server with environment variables set in Step 3, and server is ready to handle SSE-S3 requests.
 
 ### Auto-Encryption

docs/zh_CN/backend/fs/README.md

@@ -1,9 +1,9 @@
 ### Backend format `fs.json`
 
 ```go
-// objectPartInfo Info of each part kept in the multipart metadata
+// ObjectPartInfo Info of each part kept in the multipart metadata
 // file after CompleteMultipartUpload() is called.
-type objectPartInfo struct {
+type ObjectPartInfo struct {
 	Number int    `json:"number"`
 	Name   string `json:"name"`
 	ETag   string `json:"etag"`
@@ -19,6 +19,6 @@ type fsMetaV1 struct {
 	} `json:"minio"`
 	// Metadata map for current object `fs.json`.
 	Meta  map[string]string `json:"meta,omitempty"`
-	Parts []objectPartInfo  `json:"parts,omitempty"`
+	Parts []ObjectPartInfo  `json:"parts,omitempty"`
 }
 ```

docs/zh_CN/backend/xl/README.md

@@ -1,9 +1,9 @@
 ### Backend format `xl.json`
 
 ```go
-// objectPartInfo Info of each part kept in the multipart metadata
+// ObjectPartInfo Info of each part kept in the multipart metadata
 // file after CompleteMultipartUpload() is called.
-type objectPartInfo struct {
+type ObjectPartInfo struct {
 	Number int    `json:"number"`
 	Name   string `json:"name"`
 	ETag   string `json:"etag"`
@@ -49,6 +49,6 @@ type xlMetaV1 struct {
 	// Metadata map for current object `xl.json`.
 	Meta map[string]string `json:"meta,omitempty"`
 	// Captures all the individual object `xl.json`.
-	Parts []objectPartInfo `json:"parts,omitempty"`
+	Parts []ObjectPartInfo `json:"parts,omitempty"`
 }
 ```