remove the unused code for decrypting io.Writer (#8277)

This commit removes unused code for decrypting
`io.Writer` since the actual implementation only
decrypts `io.Reader`

cmd/encryption-v1.go

@@ -32,7 +32,6 @@ import (
 	"github.com/minio/minio-go/v6/pkg/encrypt"
 	"github.com/minio/minio/cmd/crypto"
 	"github.com/minio/minio/cmd/logger"
-	"github.com/minio/minio/pkg/ioutil"
 	sha256 "github.com/minio/sha256-simd"
 	"github.com/minio/sio"
 )
@@ -64,17 +63,6 @@ const (
 
 )
 
-const (
-	// SSESealAlgorithmDareSha256 specifies DARE as authenticated en/decryption scheme and SHA256 as cryptographic
-	// hash function. The key derivation of DARE-SHA256 is not optimal and does not include the object path.
-	// It is considered legacy and should not be used anymore.
-	SSESealAlgorithmDareSha256 = "DARE-SHA256"
-
-	// SSESealAlgorithmDareV2HmacSha256 specifies DAREv2 as authenticated en/decryption scheme and SHA256 as cryptographic
-	// hash function for the HMAC PRF.
-	SSESealAlgorithmDareV2HmacSha256 = "DAREv2-HMAC-SHA256"
-)
-
 // hasServerSideEncryptionHeader returns true if the given HTTP header
 // contains server-side-encryption.
 func hasServerSideEncryptionHeader(header http.Header) bool {
@@ -597,236 +585,6 @@ func (d *DecryptBlocksReader) Read(p []byte) (int, error) {
 	return len(p), nil
 }
 
-// DecryptBlocksWriter - decrypts  multipart parts, while implementing
-// a io.Writer compatible interface.
-type DecryptBlocksWriter struct {
-	// Original writer where the plain data will be written
-	writer io.Writer
-	// Current decrypter for the current encrypted data block
-	decrypter io.WriteCloser
-	// Start sequence number
-	startSeqNum uint32
-	// Current part index
-	partIndex int
-	// Parts information
-	parts          []ObjectPartInfo
-	req            *http.Request
-	bucket, object string
-	metadata       map[string]string
-
-	partEncRelOffset int64
-
-	copySource bool
-	// Customer Key
-	customerKeyHeader string
-}
-
-func (w *DecryptBlocksWriter) buildDecrypter(partID int) error {
-	m := make(map[string]string)
-	for k, v := range w.metadata {
-		m[k] = v
-	}
-	// Initialize the first decrypter, new decrypters will be initialized in Write() operation as needed.
-	var key []byte
-	var err error
-	if w.copySource {
-		if crypto.SSEC.IsEncrypted(w.metadata) {
-			w.req.Header.Set(crypto.SSECopyKey, w.customerKeyHeader)
-			key, err = ParseSSECopyCustomerRequest(w.req.Header, w.metadata)
-		}
-	} else {
-		if crypto.SSEC.IsEncrypted(w.metadata) {
-			w.req.Header.Set(crypto.SSECKey, w.customerKeyHeader)
-			key, err = ParseSSECustomerRequest(w.req)
-		}
-	}
-	if err != nil {
-		return err
-	}
-
-	objectEncryptionKey, err := decryptObjectInfo(key, w.bucket, w.object, m)
-	if err != nil {
-		return err
-	}
-
-	var partIDbin [4]byte
-	binary.LittleEndian.PutUint32(partIDbin[:], uint32(partID)) // marshal part ID
-
-	mac := hmac.New(sha256.New, objectEncryptionKey) // derive part encryption key from part ID and object key
-	mac.Write(partIDbin[:])
-	partEncryptionKey := mac.Sum(nil)
-
-	// 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
-		}
-	}
-
-	w.decrypter = decrypter
-	return nil
-}
-
-func (w *DecryptBlocksWriter) Write(p []byte) (int, error) {
-	var err error
-	var n1 int
-	if int64(len(p)) < w.parts[w.partIndex].Size-w.partEncRelOffset {
-		n1, err = w.decrypter.Write(p)
-		if err != nil {
-			return 0, err
-		}
-		w.partEncRelOffset += int64(n1)
-	} else {
-		n1, err = w.decrypter.Write(p[:w.parts[w.partIndex].Size-w.partEncRelOffset])
-		if err != nil {
-			return 0, err
-		}
-
-		// We should now proceed to next part, reset all values appropriately.
-		w.partEncRelOffset = 0
-		w.startSeqNum = 0
-
-		w.partIndex++
-
-		err = w.buildDecrypter(w.partIndex + 1)
-		if err != nil {
-			return 0, err
-		}
-
-		n1, err = w.decrypter.Write(p[n1:])
-		if err != nil {
-			return 0, err
-		}
-
-		w.partEncRelOffset += int64(n1)
-	}
-
-	return len(p), nil
-}
-
-// Close closes the LimitWriter. It behaves like io.Closer.
-func (w *DecryptBlocksWriter) Close() error {
-	if w.decrypter != nil {
-		err := w.decrypter.Close()
-		if err != nil {
-			return err
-		}
-	}
-
-	if closer, ok := w.writer.(io.Closer); ok {
-		return closer.Close()
-	}
-	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, bucket, object string, objInfo ObjectInfo) (io.WriteCloser, int64, error) {
-	w, _, size, err := DecryptBlocksRequest(client, r, bucket, object, 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, bucket, object string, startOffset, length int64, objInfo ObjectInfo, copySource bool) (io.WriteCloser, int64, int64, error) {
-	var seqNumber uint32
-	var encStartOffset, encLength int64
-
-	if !isEncryptedMultipart(objInfo) {
-		seqNumber, encStartOffset, encLength = getEncryptedSinglePartOffsetLength(startOffset, length, objInfo)
-
-		var writer io.WriteCloser
-		var err error
-		if copySource {
-			writer, err = DecryptCopyRequest(client, r, bucket, object, objInfo.UserDefined)
-		} else {
-			writer, err = DecryptRequestWithSequenceNumber(client, r, bucket, object, seqNumber, objInfo.UserDefined)
-		}
-		if err != nil {
-			return nil, 0, 0, err
-		}
-		return writer, encStartOffset, encLength, nil
-	}
-
-	_, encStartOffset, encLength = getEncryptedMultipartsOffsetLength(startOffset, length, objInfo)
-
-	var partStartIndex int
-	var partStartOffset = startOffset
-	// Skip parts until final offset maps to a particular part offset.
-	for i, part := range objInfo.Parts {
-		decryptedSize, err := sio.DecryptedSize(uint64(part.Size))
-		if err != nil {
-			return nil, -1, -1, errObjectTampered
-		}
-
-		partStartIndex = i
-
-		// Offset is smaller than size we have reached the
-		// proper part offset, break out we start from
-		// this part index.
-		if partStartOffset < int64(decryptedSize) {
-			break
-		}
-
-		// Continue to look for next part.
-		partStartOffset -= int64(decryptedSize)
-	}
-
-	startSeqNum := partStartOffset / SSEDAREPackageBlockSize
-	partEncRelOffset := int64(startSeqNum) * (SSEDAREPackageBlockSize + SSEDAREPackageMetaSize)
-
-	w := &DecryptBlocksWriter{
-		writer:            client,
-		startSeqNum:       uint32(startSeqNum),
-		partEncRelOffset:  partEncRelOffset,
-		parts:             objInfo.Parts,
-		partIndex:         partStartIndex,
-		req:               r,
-		bucket:            bucket,
-		object:            object,
-		customerKeyHeader: r.Header.Get(crypto.SSECKey),
-		copySource:        copySource,
-	}
-
-	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, crypto.SSEIV)
-	delete(objInfo.UserDefined, crypto.SSESealAlgorithm)
-	delete(objInfo.UserDefined, crypto.SSECSealedKey)
-	delete(objInfo.UserDefined, crypto.SSEMultipart)
-
-	if crypto.S3.IsEncrypted(objInfo.UserDefined) {
-		delete(objInfo.UserDefined, crypto.S3SealedKey)
-		delete(objInfo.UserDefined, crypto.S3KMSKeyID)
-		delete(objInfo.UserDefined, crypto.S3KMSSealedKey)
-	}
-	if w.copySource {
-		w.customerKeyHeader = r.Header.Get(crypto.SSECopyKey)
-	}
-
-	if err := w.buildDecrypter(w.parts[w.partIndex].Number); err != nil {
-		return nil, 0, 0, err
-	}
-
-	return w, encStartOffset, encLength, nil
-}
-
 // getEncryptedMultipartsOffsetLength - fetch sequence number, encrypted start offset and encrypted length.
 func getEncryptedMultipartsOffsetLength(offset, length int64, obj ObjectInfo) (uint32, int64, int64) {
 	// Calculate encrypted offset of a multipart object

cmd/encryption-v1_test.go

@@ -173,7 +173,7 @@ var decryptRequestTests = []struct {
 			crypto.SSECKeyMD5:    "7PpPLAK26ONlVUGOWlusfg==",
 		},
 		metadata: map[string]string{
-			crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256,
+			crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm,
 			crypto.SSEIV:            "7nQqotA8xgrPx6QK7Ap3GCfjKitqJSrGP7xzgErSJlw=",
 			crypto.SSECSealedKey:    "EAAfAAAAAAD7v1hQq3PFRUHsItalxmrJqrOq6FwnbXNarxOOpb8jTWONPPKyM3Gfjkjyj6NCf+aB/VpHCLCTBA==",
 		},
@@ -188,7 +188,7 @@ var decryptRequestTests = []struct {
 			crypto.SSECKeyMD5:    "7PpPLAK26ONlVUGOWlusfg==",
 		},
 		metadata: map[string]string{
-			crypto.SSESealAlgorithm: SSESealAlgorithmDareV2HmacSha256,
+			crypto.SSESealAlgorithm: crypto.SealAlgorithm,
 			crypto.SSEIV:            "qEqmsONcorqlcZXJxaw32H04eyXyXwUgjHzlhkaIYrU=",
 			crypto.SSECSealedKey:    "IAAfAIM14ugTGcM/dIrn4iQMrkl1sjKyeBQ8FBEvRebYj8vWvxG+0cJRpC6NXRU1wJN50JaUOATjO7kz0wZ2mA==",
 		},
@@ -218,7 +218,7 @@ var decryptRequestTests = []struct {
 			crypto.SSECKeyMD5:    "bY4wkxQejw9mUJfo72k53A==",
 		},
 		metadata: map[string]string{
-			crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256,
+			crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm,
 			crypto.SSEIV:            "RrJsEsyPb1UuFNezv1bl9hxuYsgUVC/MUctE2k=",
 			crypto.SSECSealedKey:    "SY5E9AvI2tI7/nUrUAssIGE32Hcs4rR9z/CUuPqu5N4=",
 		},
@@ -233,7 +233,7 @@ var decryptRequestTests = []struct {
 			crypto.SSECKeyMD5:    "bY4wkxQejw9mUJfo72k53A==",
 		},
 		metadata: map[string]string{
-			crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256,
+			crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm,
 			crypto.SSEIV:            "XAm0dRrJsEsyPb1UuFNezv1bl9ehxuYsgUVC/MUctE2k=",
 			crypto.SSECSealedKey:    "SY5E9AvI2tI7/nUrUAssIGE32Hds4rR9z/CUuPqu5N4=",
 		},
@@ -248,7 +248,7 @@ var decryptRequestTests = []struct {
 			crypto.SSECKeyMD5:    "7PpPLAK26ONlVUGOWlusfg==",
 		},
 		metadata: map[string]string{
-			crypto.SSESealAlgorithm: SSESealAlgorithmDareV2HmacSha256,
+			crypto.SSESealAlgorithm: crypto.SealAlgorithm,
 			crypto.SSEIV:            "qEqmsONcorqlcZXJxaw32H04eyXyXwUgjHzlhkaIYrU=",
 			crypto.SSECSealedKey:    "IAAfAIM14ugTGcM/dIrn4iQMrkl1sjKyeBQ8FBEvRebYj8vWvxG+0cJRpC6NXRU1wJN50JaUOATjO7kz0wZ2mA==",
 		},
@@ -298,12 +298,12 @@ var decryptObjectInfoTests = []struct {
 		expErr:  nil,
 	},
 	{
-		info:    ObjectInfo{Size: 100, UserDefined: map[string]string{crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256}},
+		info:    ObjectInfo{Size: 100, UserDefined: map[string]string{crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm}},
 		headers: http.Header{crypto.SSECAlgorithm: []string{crypto.SSEAlgorithmAES256}},
 		expErr:  nil,
 	},
 	{
-		info:    ObjectInfo{Size: 0, UserDefined: map[string]string{crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256}},
+		info:    ObjectInfo{Size: 0, UserDefined: map[string]string{crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm}},
 		headers: http.Header{crypto.SSECAlgorithm: []string{crypto.SSEAlgorithmAES256}},
 		expErr:  nil,
 	},
@@ -318,7 +318,7 @@ var decryptObjectInfoTests = []struct {
 		expErr:  errInvalidEncryptionParameters,
 	},
 	{
-		info:    ObjectInfo{Size: 31, UserDefined: map[string]string{crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256}},
+		info:    ObjectInfo{Size: 31, UserDefined: map[string]string{crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm}},
 		headers: http.Header{crypto.SSECAlgorithm: []string{crypto.SSEAlgorithmAES256}},
 		expErr:  errObjectTampered,
 	},
@@ -408,7 +408,7 @@ func TestGetDecryptedRange(t *testing.T) {
 		}
 		udMap = func(isMulti bool) map[string]string {
 			m := map[string]string{
-				crypto.SSESealAlgorithm: SSESealAlgorithmDareSha256,
+				crypto.SSESealAlgorithm: crypto.InsecureSealAlgorithm,
 				crypto.SSEMultipart:     "1",
 			}
 			if !isMulti {

cmd/generic-handlers_test.go

@@ -185,7 +185,7 @@ var containsReservedMetadataTests = []struct {
 		shouldFail: true,
 	},
 	{
-		header:     http.Header{crypto.SSESealAlgorithm: []string{SSESealAlgorithmDareSha256}},
+		header:     http.Header{crypto.SSESealAlgorithm: []string{crypto.InsecureSealAlgorithm}},
 		shouldFail: true,
 	},
 	{