Support SSE-C multipart source objects in CopyObject (#5603)

Current code didn't implement the logic to support
decrypting encrypted multiple parts, this PR fixes
by supporting copying encrypted multipart objects.

cmd/encryption-v1.go

@@ -28,6 +28,7 @@ import (
 	"io"
 	"net/http"
 
+	"github.com/minio/minio/pkg/ioutil"
 	sha256 "github.com/minio/sha256-simd"
 	"github.com/minio/sio"
 )
@@ -426,6 +427,7 @@ func newDecryptWriterWithObjectKey(client io.Writer, objectEncryptionKey []byte,
 	delete(metadata, ServerSideEncryptionIV)
 	delete(metadata, ServerSideEncryptionSealAlgorithm)
 	delete(metadata, ServerSideEncryptionSealedKey)
+	delete(metadata, ReservedMetadataPrefix+"Encrypted-Multipart")
 	return writer, nil
 }
 
@@ -463,6 +465,7 @@ type DecryptBlocksWriter struct {
 
 	partEncRelOffset int64
 
+	copySource bool
 	// Customer Key
 	customerKeyHeader string
 }
@@ -473,8 +476,15 @@ func (w *DecryptBlocksWriter) buildDecrypter(partID int) error {
 		m[k] = v
 	}
 	// Initialize the first decrypter, new decrypters will be initialized in Write() operation as needed.
-	w.req.Header.Set(SSECustomerKey, w.customerKeyHeader)
+	var key []byte
-	key, err := ParseSSECustomerRequest(w.req)
+	var err error
+	if w.copySource {
+		w.req.Header.Set(SSECopyCustomerKey, w.customerKeyHeader)
+		key, err = ParseSSECopyCustomerRequest(w.req)
+	} else {
+		w.req.Header.Set(SSECustomerKey, w.customerKeyHeader)
+		key, err = ParseSSECustomerRequest(w.req)
+	}
 	if err != nil {
 		return err
 	}
@@ -491,14 +501,24 @@ func (w *DecryptBlocksWriter) buildDecrypter(partID int) error {
 	mac.Write(partIDbin[:])
 	partEncryptionKey := mac.Sum(nil)
 
-	delete(m, SSECustomerKey) // make sure we do not save the key by accident
+	// make sure we do not save the key by accident
+	if w.copySource {
+		delete(m, SSECopyCustomerKey)
+	} else {
+		delete(m, SSECustomerKey)
+	}
 
-	decrypter, err := newDecryptWriterWithObjectKey(w.writer, partEncryptionKey, w.startSeqNum, m)
+	// make sure to provide a NopCloser such that a Close
+	// on sio.decryptWriter doesn't close the underlying writer's
+	// close which perhaps can close the stream prematurely.
+	decrypter, err := newDecryptWriterWithObjectKey(ioutil.NopCloser(w.writer), partEncryptionKey, w.startSeqNum, m)
 	if err != nil {
 		return err
 	}
 
 	if w.decrypter != nil {
+		// Pro-actively close the writer such that any pending buffers
+		// are flushed already before we allocate a new decrypter.
 		err = w.decrypter.Close()
 		if err != nil {
 			return err
@@ -561,9 +581,17 @@ func (w *DecryptBlocksWriter) Close() error {
 	return nil
 }
 
+// DecryptAllBlocksCopyRequest - setup a struct which can decrypt many concatenated encrypted data
+// parts information helps to know the boundaries of each encrypted data block, this function decrypts
+// all parts starting from part-1.
+func DecryptAllBlocksCopyRequest(client io.Writer, r *http.Request, objInfo ObjectInfo) (io.WriteCloser, int64, error) {
+	w, _, size, err := DecryptBlocksRequest(client, r, 0, objInfo.Size, objInfo, true)
+	return w, size, err
+}
+
 // DecryptBlocksRequest - setup a struct which can decrypt many concatenated encrypted data
 // parts information helps to know the boundaries of each encrypted data block.
-func DecryptBlocksRequest(client io.Writer, r *http.Request, startOffset, length int64, objInfo ObjectInfo) (io.WriteCloser, int64, int64, error) {
+func DecryptBlocksRequest(client io.Writer, r *http.Request, startOffset, length int64, objInfo ObjectInfo, copySource bool) (io.WriteCloser, int64, int64, error) {
 	seqNumber, encStartOffset, encLength := getEncryptedStartOffset(startOffset, length)
 
 	// Encryption length cannot be bigger than the file size, if it is
@@ -573,11 +601,16 @@ func DecryptBlocksRequest(client io.Writer, r *http.Request, startOffset, length
 	}
 
 	if len(objInfo.Parts) == 0 || !objInfo.IsEncryptedMultipart() {
-		writer, err := DecryptRequestWithSequenceNumber(client, r, seqNumber, objInfo.UserDefined)
+		var writer io.WriteCloser
+		var err error
+		if copySource {
+			writer, err = DecryptCopyRequest(client, r, objInfo.UserDefined)
+		} else {
+			writer, err = DecryptRequestWithSequenceNumber(client, r, seqNumber, objInfo.UserDefined)
+		}
 		if err != nil {
 			return nil, 0, 0, err
 		}
-
 		return writer, encStartOffset, encLength, nil
 	}
 
@@ -614,10 +647,28 @@ func DecryptBlocksRequest(client io.Writer, r *http.Request, startOffset, length
 		partIndex:         partStartIndex,
 		req:               r,
 		customerKeyHeader: r.Header.Get(SSECustomerKey),
-		metadata:          objInfo.UserDefined,
+		copySource:        copySource,
 	}
 
-	w.buildDecrypter(partStartIndex + 1)
+	w.metadata = map[string]string{}
+	// Copy encryption metadata for internal use.
+	for k, v := range objInfo.UserDefined {
+		w.metadata[k] = v
+	}
+
+	// Purge all the encryption headers.
+	delete(objInfo.UserDefined, ServerSideEncryptionIV)
+	delete(objInfo.UserDefined, ServerSideEncryptionSealAlgorithm)
+	delete(objInfo.UserDefined, ServerSideEncryptionSealedKey)
+	delete(objInfo.UserDefined, ReservedMetadataPrefix+"Encrypted-Multipart")
+
+	if w.copySource {
+		w.customerKeyHeader = r.Header.Get(SSECopyCustomerKey)
+	}
+
+	if err := w.buildDecrypter(partStartIndex + 1); err != nil {
+		return nil, 0, 0, err
+	}
 
 	return w, encStartOffset, encLength, nil
 }

cmd/fs-v1.go

@@ -398,6 +398,10 @@ func (fs *FSObjects) CopyObject(srcBucket, srcObject, dstBucket, dstObject strin
 
 		// Save objects' metadata in `fs.json`.
 		fsMeta := newFSMetaV1()
+		if _, err = fsMeta.ReadFrom(wlk); err != nil {
+			return oi, toObjectErr(err, srcBucket, srcObject)
+		}
+
 		fsMeta.Meta = srcInfo.UserDefined
 		if _, err = fsMeta.WriteTo(wlk); err != nil {
 			return oi, toObjectErr(err, srcBucket, srcObject)

cmd/object-handlers.go

@@ -152,7 +152,7 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 			// additionally also skipping mod(offset)64KiB boundaries.
 			writer = ioutil.LimitedWriter(writer, startOffset%(64*1024), length)
 
-			writer, startOffset, length, err = DecryptBlocksRequest(writer, r, startOffset, length, objInfo)
+			writer, startOffset, length, err = DecryptBlocksRequest(writer, r, startOffset, length, objInfo, false)
 			if err != nil {
 				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
 				return
@@ -382,19 +382,23 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 
 	var writer io.WriteCloser = pipeWriter
 	var reader io.Reader = pipeReader
+
+	srcInfo.Reader, err = hash.NewReader(reader, srcInfo.Size, "", "")
+	if err != nil {
+		pipeWriter.CloseWithError(err)
+		writeErrorResponse(w, toAPIErrorCode(err), r.URL)
+		return
+	}
+
+	// Save the original size for later use when we want to copy
+	// encrypted file into an unencrypted one.
+	size := srcInfo.Size
+
 	var encMetadata = make(map[string]string)
 	if objectAPI.IsEncryptionSupported() {
 		var oldKey, newKey []byte
 		sseCopyC := IsSSECopyCustomerRequest(r.Header)
 		sseC := IsSSECustomerRequest(r.Header)
-		if sseCopyC {
-			oldKey, err = ParseSSECopyCustomerRequest(r)
-			if err != nil {
-				pipeWriter.CloseWithError(err)
-				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
-				return
-			}
-		}
 		if sseC {
 			newKey, err = ParseSSECustomerRequest(r)
 			if err != nil {
@@ -406,7 +410,14 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		// AWS S3 implementation requires us to only rotate keys
 		// when/ both keys are provided and destination is same
 		// otherwise we proceed to encrypt/decrypt.
-		if len(oldKey) > 0 && len(newKey) > 0 && cpSrcDstSame {
+		if sseCopyC && sseC && cpSrcDstSame {
+			// Get the old key which needs to be rotated.
+			oldKey, err = ParseSSECopyCustomerRequest(r)
+			if err != nil {
+				pipeWriter.CloseWithError(err)
+				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
+				return
+			}
 			for k, v := range srcInfo.UserDefined {
 				encMetadata[k] = v
 			}
@@ -418,10 +429,8 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 		} else {
 			if sseCopyC {
 				// Source is encrypted make sure to save the encrypted size.
-				if srcInfo.IsEncrypted() {
+				writer = ioutil.LimitedWriter(writer, 0, srcInfo.Size)
-					srcInfo.Size = srcInfo.EncryptedSize()
+				writer, srcInfo.Size, err = DecryptAllBlocksCopyRequest(writer, r, srcInfo)
-				}
-				writer, err = newDecryptWriter(pipeWriter, oldKey, 0, srcInfo.UserDefined)
 				if err != nil {
 					pipeWriter.CloseWithError(err)
 					writeErrorResponse(w, toAPIErrorCode(err), r.URL)
@@ -431,11 +440,14 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 				// we are creating a new object at this point, even
 				// if source and destination are same objects.
 				srcInfo.metadataOnly = false
+				if sseC {
+					size = srcInfo.Size
+				}
 			}
 			if sseC {
 				reader, err = newEncryptReader(pipeReader, newKey, encMetadata)
 				if err != nil {
-					pipeReader.CloseWithError(err)
+					pipeWriter.CloseWithError(err)
 					writeErrorResponse(w, toAPIErrorCode(err), r.URL)
 					return
 				}
@@ -443,6 +455,15 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 				// we are creating a new object at this point, even
 				// if source and destination are same objects.
 				srcInfo.metadataOnly = false
+				if !sseCopyC {
+					size = srcInfo.EncryptedSize()
+				}
+			}
+			srcInfo.Reader, err = hash.NewReader(reader, size, "", "") // do not try to verify encrypted content
+			if err != nil {
+				pipeWriter.CloseWithError(err)
+				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
+				return
 			}
 		}
 	}
@@ -450,7 +471,7 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 
 	srcInfo.UserDefined, err = getCpObjMetadataFromHeader(r.Header, srcInfo.UserDefined)
 	if err != nil {
-		pipeReader.CloseWithError(err)
+		pipeWriter.CloseWithError(err)
 		errorIf(err, "found invalid http request header")
 		writeErrorResponse(w, ErrInternalError, r.URL)
 		return
@@ -469,21 +490,13 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 	// desination are same objects. Apply this restriction also when
 	// metadataOnly is true indicating that we are not overwriting the object.
 	if !isMetadataReplace(r.Header) && srcInfo.metadataOnly {
-		pipeReader.CloseWithError(fmt.Errorf("invalid copy dest"))
+		pipeWriter.CloseWithError(fmt.Errorf("invalid copy dest"))
 		// If x-amz-metadata-directive is not set to REPLACE then we need
 		// to error out if source and destination are same.
 		writeErrorResponse(w, ErrInvalidCopyDest, r.URL)
 		return
 	}
 
-	hashReader, err := hash.NewReader(reader, srcInfo.Size, "", "") // do not try to verify encrypted content
-	if err != nil {
-		pipeReader.CloseWithError(err)
-		writeErrorResponse(w, toAPIErrorCode(err), r.URL)
-		return
-	}
-	srcInfo.Reader = hashReader
-
 	// Copy source object to destination, if source and destination
 	// object is same then only metadata is updated.
 	objInfo, err := objectAPI.CopyObject(srcBucket, srcObject, dstBucket, dstObject, srcInfo)
@@ -876,6 +889,12 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 
 	var writer io.WriteCloser = pipeWriter
 	var reader io.Reader = pipeReader
+	srcInfo.Reader, err = hash.NewReader(reader, length, "", "")
+	if err != nil {
+		pipeWriter.CloseWithError(err)
+		writeErrorResponse(w, toAPIErrorCode(err), r.URL)
+		return
+	}
 	if objectAPI.IsEncryptionSupported() {
 		var li ListPartsInfo
 		li, err = objectAPI.ListObjectParts(dstBucket, dstObject, uploadID, 0, 1)
@@ -884,6 +903,18 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 			writeErrorResponse(w, toAPIErrorCode(err), r.URL)
 			return
 		}
+		sseCopyC := IsSSECopyCustomerRequest(r.Header)
+		if sseCopyC {
+			// Response writer should be limited early on for decryption upto required length,
+			// additionally also skipping mod(offset)64KiB boundaries.
+			writer = ioutil.LimitedWriter(writer, startOffset%(64*1024), length)
+			writer, startOffset, length, err = DecryptBlocksRequest(pipeWriter, r, startOffset, length, srcInfo, true)
+			if err != nil {
+				pipeWriter.CloseWithError(err)
+				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
+				return
+			}
+		}
 		if li.IsEncrypted() {
 			if !IsSSECustomerRequest(r.Header) {
 				writeErrorResponse(w, ErrSSEMultipartEncrypted, r.URL)
@@ -906,19 +937,20 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 				return
 			}
 
-			reader, err = sio.EncryptReader(reader, sio.Config{Key: objectEncryptionKey})
+			reader, err = sio.EncryptReader(pipeReader, sio.Config{Key: objectEncryptionKey})
 			if err != nil {
 				pipeWriter.CloseWithError(err)
 				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
 				return
 			}
-		}
-		if IsSSECopyCustomerRequest(r.Header) {
-			// Response writer should be limited early on for decryption upto required length,
-			// additionally also skipping mod(offset)64KiB boundaries.
-			writer = ioutil.LimitedWriter(writer, startOffset%(64*1024), length)
 
-			writer, startOffset, length, err = DecryptBlocksRequest(pipeWriter, r, startOffset, length, srcInfo)
+			size := length
+			if !sseCopyC {
+				info := ObjectInfo{Size: length}
+				size = info.EncryptedSize()
+			}
+
+			srcInfo.Reader, err = hash.NewReader(reader, size, "", "")
 			if err != nil {
 				pipeWriter.CloseWithError(err)
 				writeErrorResponse(w, toAPIErrorCode(err), r.URL)
@@ -926,14 +958,6 @@ func (api objectAPIHandlers) CopyObjectPartHandler(w http.ResponseWriter, r *htt
 			}
 		}
 	}
-
-	hashReader, err := hash.NewReader(reader, length, "", "") // do not try to verify encrypted content
-	if err != nil {
-		pipeWriter.CloseWithError(err)
-		writeErrorResponse(w, toAPIErrorCode(err), r.URL)
-		return
-	}
-	srcInfo.Reader = hashReader
 	srcInfo.Writer = writer
 
 	// Copy source object to destination, if source and destination

cmd/xl-v1-object.go

@@ -83,7 +83,9 @@ func (xl xlObjects) CopyObject(srcBucket, srcObject, dstBucket, dstObject string
 	cpSrcDstSame := isStringEqual(pathJoin(srcBucket, srcObject), pathJoin(dstBucket, dstObject))
 
 	// Read metadata associated with the object from all disks.
-	metaArr, errs := readAllXLMetadata(xl.getDisks(), srcBucket, srcObject)
+	storageDisks := xl.getDisks()
+
+	metaArr, errs := readAllXLMetadata(storageDisks, srcBucket, srcObject)
 
 	// get Quorum for this object
 	readQuorum, writeQuorum, err := objectQuorumFromMeta(xl, metaArr, errs)
@@ -96,7 +98,7 @@ func (xl xlObjects) CopyObject(srcBucket, srcObject, dstBucket, dstObject string
 	}
 
 	// List all online disks.
-	onlineDisks, modTime := listOnlineDisks(xl.getDisks(), metaArr, errs)
+	_, modTime := listOnlineDisks(storageDisks, metaArr, errs)
 
 	// Pick latest valid metadata.
 	xlMeta, err := pickValidXLMeta(metaArr, modTime)
@@ -104,25 +106,22 @@ func (xl xlObjects) CopyObject(srcBucket, srcObject, dstBucket, dstObject string
 		return oi, toObjectErr(err, srcBucket, srcObject)
 	}
 
-	// Reorder online disks based on erasure distribution order.
-	onlineDisks = shuffleDisks(onlineDisks, xlMeta.Erasure.Distribution)
-
 	// Length of the file to read.
 	length := xlMeta.Stat.Size
 
 	// Check if this request is only metadata update.
 	if cpSrcDstSame {
-		xlMeta.Meta = srcInfo.UserDefined
-		partsMetadata := make([]xlMetaV1, len(xl.getDisks()))
 		// Update `xl.json` content on each disks.
-		for index := range partsMetadata {
+		for index := range metaArr {
-			partsMetadata[index] = xlMeta
+			metaArr[index].Meta = srcInfo.UserDefined
 		}
 
+		var onlineDisks []StorageAPI
+
 		tempObj := mustGetUUID()
 
 		// Write unique `xl.json` for each disk.
-		if onlineDisks, err = writeUniqueXLMetadata(onlineDisks, minioMetaTmpBucket, tempObj, partsMetadata, writeQuorum); err != nil {
+		if onlineDisks, err = writeUniqueXLMetadata(storageDisks, minioMetaTmpBucket, tempObj, metaArr, writeQuorum); err != nil {
 			return oi, toObjectErr(err, srcBucket, srcObject)
 		}
 		// Rename atomically `xl.json` from tmp location to destination for each disk.

pkg/ioutil/ioutil.go

@@ -114,3 +114,15 @@ func (w *LimitWriter) Close() error {
 func LimitedWriter(w io.Writer, skipBytes int64, limit int64) *LimitWriter {
 	return &LimitWriter{w, skipBytes, limit}
 }
+
+type nopCloser struct {
+	io.Writer
+}
+
+func (nopCloser) Close() error { return nil }
+
+// NopCloser returns a WriteCloser with a no-op Close method wrapping
+// the provided Writer w.
+func NopCloser(w io.Writer) io.WriteCloser {
+	return nopCloser{w}
+}