Unsigned handling of words and quads:

 - Words of importance are automatically made unsigned, as they are integer fields.
 - Quads of importance are made unsigned when used as such as they are still integer fields.

Author: notiska

src/main/java/software/coley/llzip/part/CentralDirectoryFileHeader.java

@@ -51,9 +51,9 @@ public void read(ByteData data, long offset) {
 		crc32 = ByteDataUtil.readQuad(data, offset + 16);
 		compressedSize = ByteDataUtil.readQuad(data, offset + 20);
 		uncompressedSize = ByteDataUtil.readQuad(data, offset + 24);
-		fileNameLength = ByteDataUtil.readWord(data, offset + 28);
-		extraFieldLength = ByteDataUtil.readWord(data, offset + 30);
-		fileCommentLength = ByteDataUtil.readWord(data, offset + 32);
+		setFileNameLength(ByteDataUtil.readWord(data, offset + 28));
+		setExtraFieldLength(ByteDataUtil.readWord(data, offset + 30));
+		setFileCommentLength(ByteDataUtil.readWord(data, offset + 32));
 		diskNumberStart = ByteDataUtil.readWord(data, offset + 34);
 		internalFileAttributes = ByteDataUtil.readWord(data, offset + 36);
 		externalFileAttributes = ByteDataUtil.readQuad(data, offset + 38);
@@ -254,7 +254,7 @@ public int getFileNameLength() {
 	 * 		Length of {@link #getFileName()}.
 	 */
 	public void setFileNameLength(int fileNameLength) {
-		this.fileNameLength = fileNameLength;
+		this.fileNameLength = fileNameLength & 0xffff;
 	}
 
 	/**
@@ -269,7 +269,7 @@ public int getExtraFieldLength() {
 	 * 		Length of {@link #getExtraField()}
 	 */
 	public void setExtraFieldLength(int extraFieldLength) {
-		this.extraFieldLength = extraFieldLength;
+		this.extraFieldLength = extraFieldLength & 0xffff;
 	}
 
 	/**
@@ -284,7 +284,7 @@ public int getFileCommentLength() {
 	 * 		Length of {@link #getFileComment()}.
 	 */
 	public void setFileCommentLength(int fileCommentLength) {
-		this.fileCommentLength = fileCommentLength;
+		this.fileCommentLength = fileCommentLength & 0xffff;
 	}
 
 	/**

src/main/java/software/coley/llzip/part/EndOfCentralDirectory.java

@@ -34,7 +34,7 @@ public void read(ByteData data, long offset) {
 		numEntries = ByteDataUtil.readWord(data, offset + 10);
 		centralDirectorySize = ByteDataUtil.readQuad(data, offset + 12);
 		centralDirectoryOffset = ByteDataUtil.readQuad(data, offset + 16);
-		zipCommentLength = ByteDataUtil.readWord(data, offset + 20);
+		setZipCommentLength(ByteDataUtil.readWord(data, offset + 20));
 		zipComment = data.sliceOf(offset + 22, zipCommentLength);
 	}
 
@@ -157,7 +157,7 @@ public int getZipCommentLength() {
 	 *        {@link #getZipComment() Comment} length.
 	 */
 	public void setZipCommentLength(int zipCommentLength) {
-		this.zipCommentLength = zipCommentLength;
+		this.zipCommentLength = zipCommentLength & 0xffff;
 	}
 
 	/**

src/main/java/software/coley/llzip/part/JvmLocalFileHeader.java

@@ -47,11 +47,11 @@ public void read(ByteData data, long offset) {
 	public void link(CentralDirectoryFileHeader directoryFileHeader) {
 		super.link(directoryFileHeader);
 		if (!foundPk) {
-			int fileDataLength;
+			long fileDataLength;
 			if (getCompressionMethod() == ZipCompressions.STORED) {
-				fileDataLength = directoryFileHeader.getUncompressedSize();
+				fileDataLength = directoryFileHeader.getUncompressedSize() & 0xffffffffL;
 			} else {
-				fileDataLength = directoryFileHeader.getCompressedSize();
+				fileDataLength = directoryFileHeader.getCompressedSize() & 0xffffffffL;
 			}
 			setFileData(data.sliceOf(offset, fileDataLength));
 			data = null;

src/main/java/software/coley/llzip/part/LocalFileHeader.java

@@ -46,15 +46,16 @@ public void read(ByteData data, long offset) {
 		crc32 = ByteDataUtil.readQuad(data, offset + 14);
 		compressedSize = ByteDataUtil.readQuad(data, offset + 18);
 		uncompressedSize = ByteDataUtil.readQuad(data, offset + 22);
-		fileNameLength = ByteDataUtil.readWord(data, offset + 26);
-		extraFieldLength = ByteDataUtil.readWord(data, offset + 28);
+		// Reading these to ints so ensure they act as unsigned shorts
+		setFileNameLength(ByteDataUtil.readWord(data, offset + 26));
+		setExtraFieldLength(ByteDataUtil.readWord(data, offset + 28));
 		fileName = data.sliceOf(offset + 30, fileNameLength);
 		extraField = data.sliceOf(offset + 30 + fileNameLength, extraFieldLength);
-		int fileDataLength;
+		long fileDataLength;
 		if (compressionMethod == STORED) {
-			fileDataLength = uncompressedSize;
+			fileDataLength = uncompressedSize & 0xffffffffL;
 		} else {
-			fileDataLength = compressedSize;
+			fileDataLength = compressedSize & 0xffffffffL;
 		}
 		fileData = data.sliceOf(offset + 30 + fileNameLength + extraFieldLength, fileDataLength);
 	}
@@ -241,7 +242,7 @@ public int getFileNameLength() {
 	 * 		Length of {@link #getFileName()}.
 	 */
 	public void setFileNameLength(int fileNameLength) {
-		this.fileNameLength = fileNameLength;
+		this.fileNameLength = fileNameLength & 0xffff;
 	}
 
 	/**
@@ -256,7 +257,7 @@ public int getExtraFieldLength() {
 	 * 		Length of {@link #getExtraField()}
 	 */
 	public void setExtraFieldLength(int extraFieldLength) {
-		this.extraFieldLength = extraFieldLength;
+		this.extraFieldLength = extraFieldLength & 0xffff;
 	}
 
 	/**

src/main/java/software/coley/llzip/strategy/DefaultZipReaderStrategy.java

@@ -35,11 +35,11 @@ public void read(ZipArchive zip, ByteData data) throws IOException {
 		zip.getParts().add(end);
 		// Read central directories
 		long len = data.length();
-		int centralDirectoryOffset = end.getCentralDirectoryOffset();
+		long centralDirectoryOffset = end.getCentralDirectoryOffset();
 		while (centralDirectoryOffset < len && ByteDataUtil.startsWith(data, centralDirectoryOffset, ZipPatterns.CENTRAL_DIRECTORY_FILE_HEADER)) {
 			CentralDirectoryFileHeader directory = new CentralDirectoryFileHeader();
 			directory.read(data, centralDirectoryOffset);
-			centralDirectoryOffset += directory.length();
+			centralDirectoryOffset += directory.length() & 0xffffffffL; // FIXME: Could still be a lossy cast
 			zip.getParts().add(directory);
 		}
 		// Read local files

src/test/java/software/coley/llzip/LargeStringTests.java

@@ -0,0 +1,21 @@
+package software.coley.llzip;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.nio.file.Paths;
+
+/**
+ * Tests that reading larger strings from zip files works correctly.
+ */
+public class LargeStringTests {
+	@Test
+	public void testLargeStrings() {
+		try {
+			ZipIO.readStandard(Paths.get("src/test/resources/large-strings.zip"));
+		} catch (IOException error) {
+			Assertions.fail(error);
+		}
+	}
+}