Use chunk-by-chunk encryption for SSE-S3 copy (consistent with SSE-C/SSE-KMS)

Instead of streaming encryption (which had IV mismatch issues for multi-chunk
files), SSE-S3 now uses the same chunk-by-chunk approach as SSE-C and SSE-KMS:

1. Extended copyMultipartCrossEncryption to handle SSE-S3:
   - Added SSE-S3 source decryption in copyCrossEncryptionChunk
   - Added SSE-S3 destination encryption with per-chunk IVs
   - Added object-level metadata generation for SSE-S3 destinations

2. Updated routing in executeEncryptCopy/executeDecryptCopy/executeReencryptCopy
   to use copyMultipartCrossEncryption for all SSE-S3 scenarios

3. Removed streaming copy functions (shouldUseStreamingCopy,
   executeStreamingReencryptCopy) as they're no longer used

4. Added large file (1MB) integration test to verify chunk-by-chunk copy works

This ensures consistent behavior across all SSE types and fixes data corruption
that occurred with large files in the streaming copy approach.

test/s3/sse/s3_sse_integration_test.go

@@ -2083,13 +2083,77 @@ func TestCopyToBucketDefaultEncryptedRegression(t *testing.T) {
 		assertDataEqual(t, testData, data, "Data mismatch")
 	})
 
-	// TODO: Large file SSE-S3 copy has a known issue with streaming encryption
-	// The streaming copy encrypts the entire stream with a single IV, but stores
-	// data in multiple chunks with calculated per-chunk IVs. This causes decryption
-	// to fail because each chunk tries to decrypt with its per-chunk IV, but the
-	// data was encrypted with the base IV. This needs architectural changes to fix:
-	// either use chunk-by-chunk encryption like SSE-C/SSE-KMS, or store a single IV.
-	// For now, small inline files work correctly (the original #7562 bug fix).
+	t.Run("LargeFileCopyEncrypted_ToTemp_ToEncrypted", func(t *testing.T) {
+		// Test with large file (1MB) to exercise chunk-by-chunk copy path
+		// This verifies consistent behavior with SSE-C and SSE-KMS
+		largeTestData := generateTestData(1024 * 1024) // 1MB
+		objectKey := "large-file-test.bin"
+
+		// Step 1: Upload large object to source bucket (will be automatically encrypted)
+		_, err = client.PutObject(ctx, &s3.PutObjectInput{
+			Bucket: aws.String(srcBucket),
+			Key:    aws.String(objectKey),
+			Body:   bytes.NewReader(largeTestData),
+		})
+		require.NoError(t, err, "Failed to upload large file to source bucket")
+
+		// Verify source object is encrypted
+		srcHead, err := client.HeadObject(ctx, &s3.HeadObjectInput{
+			Bucket: aws.String(srcBucket),
+			Key:    aws.String(objectKey),
+		})
+		require.NoError(t, err, "Failed to HEAD source object")
+		assert.Equal(t, types.ServerSideEncryptionAes256, srcHead.ServerSideEncryption,
+			"Source object should be SSE-S3 encrypted")
+
+		// Step 2: Copy to temp bucket (unencrypted) - exercises chunk-by-chunk decrypt
+		_, err = client.CopyObject(ctx, &s3.CopyObjectInput{
+			Bucket:     aws.String(tempBucket),
+			Key:        aws.String(objectKey),
+			CopySource: aws.String(fmt.Sprintf("%s/%s", srcBucket, objectKey)),
+		})
+		require.NoError(t, err, "Failed to copy large file to temp bucket")
+
+		// Verify temp object is unencrypted and data is correct
+		tempGet, err := client.GetObject(ctx, &s3.GetObjectInput{
+			Bucket: aws.String(tempBucket),
+			Key:    aws.String(objectKey),
+		})
+		require.NoError(t, err, "Failed to GET temp object")
+		tempData, err := io.ReadAll(tempGet.Body)
+		tempGet.Body.Close()
+		require.NoError(t, err, "Failed to read temp object")
+		assertDataEqual(t, largeTestData, tempData, "Temp object data mismatch after decrypt")
+
+		// Step 3: Copy from temp bucket to dest bucket (with default encryption)
+		// This exercises chunk-by-chunk encrypt copy
+		_, err = client.CopyObject(ctx, &s3.CopyObjectInput{
+			Bucket:     aws.String(dstBucket),
+			Key:        aws.String(objectKey),
+			CopySource: aws.String(fmt.Sprintf("%s/%s", tempBucket, objectKey)),
+		})
+		require.NoError(t, err, "Failed to copy large file to destination bucket")
+
+		// Verify destination object is encrypted
+		dstHead, err := client.HeadObject(ctx, &s3.HeadObjectInput{
+			Bucket: aws.String(dstBucket),
+			Key:    aws.String(objectKey),
+		})
+		require.NoError(t, err, "Failed to HEAD destination object")
+		assert.Equal(t, types.ServerSideEncryptionAes256, dstHead.ServerSideEncryption,
+			"Destination object should be SSE-S3 encrypted via bucket default")
+
+		// Verify destination object content is correct after re-encryption
+		dstGet, err := client.GetObject(ctx, &s3.GetObjectInput{
+			Bucket: aws.String(dstBucket),
+			Key:    aws.String(objectKey),
+		})
+		require.NoError(t, err, "Failed to GET destination object")
+		dstData, err := io.ReadAll(dstGet.Body)
+		dstGet.Body.Close()
+		require.NoError(t, err, "Failed to read destination object")
+		assertDataEqual(t, largeTestData, dstData, "Large file data mismatch after re-encryption")
+	})
 }
 
 // REGRESSION TESTS FOR CRITICAL BUGS FIXED

weed/s3api/s3api_object_handlers_copy.go

@@ -1524,7 +1524,7 @@ func (s3a *S3ApiServer) copyMultipartSSECChunk(chunk *filer_pb.FileChunk, copySo
 }
 
 // copyMultipartCrossEncryption handles all cross-encryption and decrypt-only copy scenarios
-// This unified function supports: SSE-C↔SSE-KMS, SSE-C→Plain, SSE-KMS→Plain
+// This unified function supports: SSE-C↔SSE-KMS↔SSE-S3, and any→Plain
 func (s3a *S3ApiServer) copyMultipartCrossEncryption(entry *filer_pb.Entry, r *http.Request, state *EncryptionState, dstBucket, dstPath string) ([]*filer_pb.FileChunk, map[string][]byte, error) {
 	var dstChunks []*filer_pb.FileChunk
 
@@ -1533,6 +1533,7 @@ func (s3a *S3ApiServer) copyMultipartCrossEncryption(entry *filer_pb.Entry, r *h
 	var destKMSKeyID string
 	var destKMSEncryptionContext map[string]string
 	var destKMSBucketKeyEnabled bool
+	var destSSES3Key *SSES3Key
 
 	if state.DstSSEC {
 		var err error
@@ -1546,7 +1547,13 @@ func (s3a *S3ApiServer) copyMultipartCrossEncryption(entry *filer_pb.Entry, r *h
 		if err != nil {
 			return nil, nil, fmt.Errorf("failed to parse destination SSE-KMS headers: %w", err)
 		}
-	} else {
+	} else if state.DstSSES3 {
+		// Generate SSE-S3 key for destination
+		var err error
+		destSSES3Key, err = GenerateSSES3Key()
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to generate SSE-S3 key: %w", err)
+		}
 	}
 
 	// Parse source encryption parameters
@@ -1565,12 +1572,18 @@ func (s3a *S3ApiServer) copyMultipartCrossEncryption(entry *filer_pb.Entry, r *h
 		var err error
 
 		if chunk.GetSseType() == filer_pb.SSEType_SSE_C {
-			copiedChunk, err = s3a.copyCrossEncryptionChunk(chunk, sourceSSECKey, destSSECKey, destKMSKeyID, destKMSEncryptionContext, destKMSBucketKeyEnabled, dstPath, dstBucket, state)
+			copiedChunk, err = s3a.copyCrossEncryptionChunk(chunk, sourceSSECKey, destSSECKey, destKMSKeyID, destKMSEncryptionContext, destKMSBucketKeyEnabled, destSSES3Key, dstPath, dstBucket, state)
 		} else if chunk.GetSseType() == filer_pb.SSEType_SSE_KMS {
-			copiedChunk, err = s3a.copyCrossEncryptionChunk(chunk, nil, destSSECKey, destKMSKeyID, destKMSEncryptionContext, destKMSBucketKeyEnabled, dstPath, dstBucket, state)
+			copiedChunk, err = s3a.copyCrossEncryptionChunk(chunk, nil, destSSECKey, destKMSKeyID, destKMSEncryptionContext, destKMSBucketKeyEnabled, destSSES3Key, dstPath, dstBucket, state)
+		} else if chunk.GetSseType() == filer_pb.SSEType_SSE_S3 {
+			copiedChunk, err = s3a.copyCrossEncryptionChunk(chunk, nil, destSSECKey, destKMSKeyID, destKMSEncryptionContext, destKMSBucketKeyEnabled, destSSES3Key, dstPath, dstBucket, state)
 		} else {
-			// Unencrypted chunk, copy directly
-			copiedChunk, err = s3a.copySingleChunk(chunk, dstPath)
+			// Unencrypted chunk - may need encryption if destination requires it
+			if state.DstSSEC || state.DstSSEKMS || state.DstSSES3 {
+				copiedChunk, err = s3a.copyCrossEncryptionChunk(chunk, nil, destSSECKey, destKMSKeyID, destKMSEncryptionContext, destKMSBucketKeyEnabled, destSSES3Key, dstPath, dstBucket, state)
+			} else {
+				copiedChunk, err = s3a.copySingleChunk(chunk, dstPath)
+			}
 		}
 
 		if err != nil {
@@ -1621,6 +1634,20 @@ func (s3a *S3ApiServer) copyMultipartCrossEncryption(entry *filer_pb.Entry, r *h
 		} else {
 			glog.Errorf("Failed to serialize SSE-KMS metadata: %v", serErr)
 		}
+	} else if state.DstSSES3 && destSSES3Key != nil {
+		// For SSE-S3 destination, create object-level metadata using first chunk's IV
+		if len(dstChunks) > 0 && dstChunks[0].GetSseType() == filer_pb.SSEType_SSE_S3 && len(dstChunks[0].GetSseMetadata()) > 0 {
+			keyManager := GetSSES3KeyManager()
+			if sses3Metadata, err := DeserializeSSES3Metadata(dstChunks[0].GetSseMetadata(), keyManager); err == nil {
+				// Use the first chunk's key with its IV for object-level metadata
+				keyData, serErr := SerializeSSES3Metadata(sses3Metadata)
+				if serErr != nil {
+					return nil, nil, fmt.Errorf("failed to serialize SSE-S3 metadata: %w", serErr)
+				}
+				dstMetadata[s3_constants.SeaweedFSSSES3Key] = keyData
+				dstMetadata[s3_constants.AmzServerSideEncryption] = []byte("AES256")
+			}
+		}
 	}
 	// For unencrypted destination, no metadata needed (dstMetadata remains empty)
 
@@ -1628,7 +1655,7 @@ func (s3a *S3ApiServer) copyMultipartCrossEncryption(entry *filer_pb.Entry, r *h
 }
 
 // copyCrossEncryptionChunk handles copying a single chunk with cross-encryption support
-func (s3a *S3ApiServer) copyCrossEncryptionChunk(chunk *filer_pb.FileChunk, sourceSSECKey *SSECustomerKey, destSSECKey *SSECustomerKey, destKMSKeyID string, destKMSEncryptionContext map[string]string, destKMSBucketKeyEnabled bool, dstPath, dstBucket string, state *EncryptionState) (*filer_pb.FileChunk, error) {
+func (s3a *S3ApiServer) copyCrossEncryptionChunk(chunk *filer_pb.FileChunk, sourceSSECKey *SSECustomerKey, destSSECKey *SSECustomerKey, destKMSKeyID string, destKMSEncryptionContext map[string]string, destKMSBucketKeyEnabled bool, destSSES3Key *SSES3Key, dstPath, dstBucket string, state *EncryptionState) (*filer_pb.FileChunk, error) {
 	// Create destination chunk
 	dstChunk := s3a.createDestinationChunk(chunk, chunk.Offset, chunk.Size)
 
@@ -1728,6 +1755,30 @@ func (s3a *S3ApiServer) copyCrossEncryptionChunk(chunk *filer_pb.FileChunk, sour
 			previewLen = len(finalData)
 		}
 
+	} else if chunk.GetSseType() == filer_pb.SSEType_SSE_S3 {
+		// Decrypt SSE-S3 source
+		if len(chunk.GetSseMetadata()) == 0 {
+			return nil, fmt.Errorf("SSE-S3 chunk missing per-chunk metadata")
+		}
+
+		keyManager := GetSSES3KeyManager()
+		sourceSSEKey, err := DeserializeSSES3Metadata(chunk.GetSseMetadata(), keyManager)
+		if err != nil {
+			return nil, fmt.Errorf("failed to deserialize SSE-S3 metadata: %w", err)
+		}
+
+		decryptedReader, decErr := CreateSSES3DecryptedReader(bytes.NewReader(encryptedData), sourceSSEKey, sourceSSEKey.IV)
+		if decErr != nil {
+			return nil, fmt.Errorf("create SSE-S3 decrypted reader: %w", decErr)
+		}
+
+		decryptedData, readErr := io.ReadAll(decryptedReader)
+		if readErr != nil {
+			return nil, fmt.Errorf("decrypt SSE-S3 chunk data: %w", readErr)
+		}
+		finalData = decryptedData
+		glog.V(4).Infof("Decrypted SSE-S3 chunk, size: %d", len(finalData))
+
 	} else {
 		// Source is unencrypted
 		finalData = encryptedData
@@ -1789,6 +1840,36 @@ func (s3a *S3ApiServer) copyCrossEncryptionChunk(chunk *filer_pb.FileChunk, sour
 		dstChunk.SseMetadata = kmsMetadata
 
 		glog.V(4).Infof("Re-encrypted chunk with SSE-KMS")
+
+	} else if state.DstSSES3 && destSSES3Key != nil {
+		// Encrypt with SSE-S3
+		encryptedReader, iv, encErr := CreateSSES3EncryptedReader(bytes.NewReader(finalData), destSSES3Key)
+		if encErr != nil {
+			return nil, fmt.Errorf("create SSE-S3 encrypted reader: %w", encErr)
+		}
+
+		reencryptedData, readErr := io.ReadAll(encryptedReader)
+		if readErr != nil {
+			return nil, fmt.Errorf("re-encrypt with SSE-S3: %w", readErr)
+		}
+		finalData = reencryptedData
+
+		// Create per-chunk SSE-S3 metadata with chunk-specific IV
+		chunkSSEKey := &SSES3Key{
+			Key:       destSSES3Key.Key,
+			KeyID:     destSSES3Key.KeyID,
+			Algorithm: destSSES3Key.Algorithm,
+			IV:        iv,
+		}
+		sses3Metadata, err := SerializeSSES3Metadata(chunkSSEKey)
+		if err != nil {
+			return nil, fmt.Errorf("serialize SSE-S3 metadata: %w", err)
+		}
+
+		dstChunk.SseType = filer_pb.SSEType_SSE_S3
+		dstChunk.SseMetadata = sses3Metadata
+
+		glog.V(4).Infof("Re-encrypted chunk with SSE-S3")
 	}
 	// For unencrypted destination, finalData remains as decrypted plaintext
 

weed/s3api/s3api_object_handlers_copy_unified.go

@@ -1,14 +1,12 @@
 package s3api
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"net/http"
 
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
-	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
 	"github.com/seaweedfs/seaweedfs/weed/s3api/s3err"
 	weed_server "github.com/seaweedfs/seaweedfs/weed/server"
 )
@@ -134,30 +132,9 @@ func (s3a *S3ApiServer) executeEncryptCopy(entry *filer_pb.Entry, r *http.Reques
 	}
 
 	if state.DstSSES3 {
-		// Use streaming copy for SSE-S3 encryption
-		chunks, encSpec, err := s3a.executeStreamingReencryptCopy(entry, r, state, dstPath)
-		if err != nil {
-			return nil, nil, err
-		}
-
-		// Generate SSE-S3 destination metadata from the encryption spec
-		dstMetadata := make(map[string][]byte)
-		if encSpec != nil && encSpec.DestinationKey != nil {
-			if sseKey, ok := encSpec.DestinationKey.(*SSES3Key); ok {
-				// Store the IV on the key before serialization
-				if len(encSpec.DestinationIV) > 0 {
-					sseKey.IV = encSpec.DestinationIV
-				}
-				keyData, serErr := SerializeSSES3Metadata(sseKey)
-				if serErr != nil {
-					return nil, nil, fmt.Errorf("failed to serialize SSE-S3 metadata: %w", serErr)
-				}
-				dstMetadata[s3_constants.SeaweedFSSSES3Key] = keyData
-				dstMetadata[s3_constants.AmzServerSideEncryption] = []byte("AES256")
-				glog.V(3).Infof("Generated SSE-S3 metadata for streaming encrypt copy: %s", dstPath)
-			}
-		}
-		return chunks, dstMetadata, nil
+		// Use chunk-by-chunk copy for SSE-S3 encryption (consistent with SSE-C and SSE-KMS)
+		glog.V(2).Infof("Plain→SSE-S3 copy: using unified multipart encrypt copy")
+		return s3a.copyMultipartCrossEncryption(entry, r, state, dstBucket, dstPath)
 	}
 
 	return nil, nil, fmt.Errorf("unknown target encryption type")
@@ -165,30 +142,18 @@ func (s3a *S3ApiServer) executeEncryptCopy(entry *filer_pb.Entry, r *http.Reques
 
 // executeDecryptCopy handles encrypted → plain copies
 func (s3a *S3ApiServer) executeDecryptCopy(entry *filer_pb.Entry, r *http.Request, state *EncryptionState, dstPath string) ([]*filer_pb.FileChunk, map[string][]byte, error) {
-	// Use unified multipart-aware decrypt copy for all encryption types
-	if state.SrcSSEC || state.SrcSSEKMS {
+	// Use unified multipart-aware decrypt copy for all encryption types (consistent chunk-by-chunk)
+	if state.SrcSSEC || state.SrcSSEKMS || state.SrcSSES3 {
 		glog.V(2).Infof("Encrypted→Plain copy: using unified multipart decrypt copy")
 		return s3a.copyMultipartCrossEncryption(entry, r, state, "", dstPath)
 	}
 
-	if state.SrcSSES3 {
-		// Use streaming copy for SSE-S3 decryption
-		chunks, _, err := s3a.executeStreamingReencryptCopy(entry, r, state, dstPath)
-		return chunks, nil, err
-	}
-
 	return nil, nil, fmt.Errorf("unknown source encryption type")
 }
 
 // executeReencryptCopy handles encrypted → encrypted copies with different keys/methods
 func (s3a *S3ApiServer) executeReencryptCopy(entry *filer_pb.Entry, r *http.Request, state *EncryptionState, dstBucket, dstPath string) ([]*filer_pb.FileChunk, map[string][]byte, error) {
-	// Check if we should use streaming copy for better performance
-	if s3a.shouldUseStreamingCopy(entry, state) {
-		chunks, _, err := s3a.executeStreamingReencryptCopy(entry, r, state, dstPath)
-		return chunks, nil, err
-	}
-
-	// Fallback to chunk-by-chunk approach for compatibility
+	// Use chunk-by-chunk approach for all cross-encryption scenarios (consistent behavior)
 	if state.SrcSSEC && state.DstSSEC {
 		return s3a.copyChunksWithSSEC(entry, r)
 	}
@@ -199,84 +164,9 @@ func (s3a *S3ApiServer) executeReencryptCopy(entry *filer_pb.Entry, r *http.Requ
 		return chunks, dstMetadata, err
 	}
 
-	if state.SrcSSEC && state.DstSSEKMS {
-		// SSE-C → SSE-KMS: use unified multipart-aware cross-encryption copy
-		glog.V(2).Infof("SSE-C→SSE-KMS cross-encryption copy: using unified multipart copy")
-		return s3a.copyMultipartCrossEncryption(entry, r, state, dstBucket, dstPath)
-	}
-
-	if state.SrcSSEKMS && state.DstSSEC {
-		// SSE-KMS → SSE-C: use unified multipart-aware cross-encryption copy
-		glog.V(2).Infof("SSE-KMS→SSE-C cross-encryption copy: using unified multipart copy")
-		return s3a.copyMultipartCrossEncryption(entry, r, state, dstBucket, dstPath)
-	}
-
-	// Handle SSE-S3 cross-encryption scenarios
-	if state.SrcSSES3 || state.DstSSES3 {
-		// Any scenario involving SSE-S3 uses streaming copy
-		chunks, _, err := s3a.executeStreamingReencryptCopy(entry, r, state, dstPath)
-		return chunks, nil, err
-	}
-
-	return nil, nil, fmt.Errorf("unsupported cross-encryption scenario")
+	// All other cross-encryption scenarios use unified multipart copy
+	// This includes: SSE-C↔SSE-KMS, SSE-C↔SSE-S3, SSE-KMS↔SSE-S3, SSE-S3↔SSE-S3
+	glog.V(2).Infof("Cross-encryption copy: using unified multipart copy")
+	return s3a.copyMultipartCrossEncryption(entry, r, state, dstBucket, dstPath)
 }
 
-// shouldUseStreamingCopy determines if streaming copy should be used
-func (s3a *S3ApiServer) shouldUseStreamingCopy(entry *filer_pb.Entry, state *EncryptionState) bool {
-	// Use streaming copy for large files or when beneficial
-	fileSize := entry.Attributes.FileSize
-
-	// Use streaming for files larger than 10MB
-	if fileSize > 10*1024*1024 {
-		return true
-	}
-
-	// Check if this is a multipart encrypted object
-	isMultipartEncrypted := false
-	if state.IsSourceEncrypted() {
-		encryptedChunks := 0
-		for _, chunk := range entry.GetChunks() {
-			if chunk.GetSseType() != filer_pb.SSEType_NONE {
-				encryptedChunks++
-			}
-		}
-		isMultipartEncrypted = encryptedChunks > 1
-	}
-
-	// For multipart encrypted objects, avoid streaming copy to use per-chunk metadata approach
-	if isMultipartEncrypted {
-		glog.V(3).Infof("Multipart encrypted object detected, using chunk-by-chunk approach")
-		return false
-	}
-
-	// Use streaming for cross-encryption scenarios (for single-part objects only)
-	if state.IsSourceEncrypted() && state.IsTargetEncrypted() {
-		srcType := s3a.getEncryptionTypeString(state.SrcSSEC, state.SrcSSEKMS, state.SrcSSES3)
-		dstType := s3a.getEncryptionTypeString(state.DstSSEC, state.DstSSEKMS, state.DstSSES3)
-		if srcType != dstType {
-			return true
-		}
-	}
-
-	// Use streaming for compressed files
-	if isCompressedEntry(entry) {
-		return true
-	}
-
-	// Use streaming for SSE-S3 scenarios (always)
-	if state.SrcSSES3 || state.DstSSES3 {
-		return true
-	}
-
-	return false
-}
-
-// executeStreamingReencryptCopy performs streaming re-encryption copy and returns encryption spec
-// The encryption spec is needed for SSE-S3 to properly set destination metadata (fixes GitHub #7562)
-func (s3a *S3ApiServer) executeStreamingReencryptCopy(entry *filer_pb.Entry, r *http.Request, state *EncryptionState, dstPath string) ([]*filer_pb.FileChunk, *EncryptionSpec, error) {
-	// Create streaming copy manager
-	streamingManager := NewStreamingCopyManager(s3a)
-
-	// Execute streaming copy
-	return streamingManager.ExecuteStreamingCopy(context.Background(), entry, r, dstPath, state)
-}