add support for truncated appended data

gildas-lormeau · Nov 16, 2023 · 5890f47 · 5890f47
1 parent 2a10dda
commit 5890f47
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/lib/core/zip-reader.js b/lib/core/zip-reader.js
@@ -207,10 +207,14 @@ class ZipReader {
 			}
 			directoryDataOffset -= directoryDataLength;
 		}
+		if (directoryDataOffset >= reader.size) {
+			prependedDataLength = reader.size - directoryDataOffset - directoryDataLength - END_OF_CENTRAL_DIR_LENGTH;
+			directoryDataOffset = reader.size - directoryDataLength - END_OF_CENTRAL_DIR_LENGTH;	
+		}
 		if (expectedLastDiskNumber != lastDiskNumber) {
 			throw new Error(ERR_SPLIT_ZIP_FILE);
 		}
-		if (directoryDataOffset < 0 || directoryDataOffset >= reader.size) {
+		if (directoryDataOffset < 0) {
 			throw new Error(ERR_BAD_FORMAT);
 		}
 		let offset = 0;
@@ -221,7 +225,7 @@ class ZipReader {
 			if (getUint32(directoryView, offset) != CENTRAL_FILE_HEADER_SIGNATURE && directoryDataOffset != expectedDirectoryDataOffset) {
 				const originalDirectoryDataOffset = directoryDataOffset;
 				directoryDataOffset = expectedDirectoryDataOffset;
-				prependedDataLength = directoryDataOffset - originalDirectoryDataOffset;
+				prependedDataLength += directoryDataOffset - originalDirectoryDataOffset;
 				directoryArray = await readUint8Array(reader, directoryDataOffset, directoryDataLength, diskNumber);
 				directoryView = getDataView(directoryArray);
 			}