[tests] fix zip Slip

It was possible to create a directory outside the extraction directory.
https://github.com/eclipse-jdt/eclipse.jdt.core/security/code-scanning/38

Also simplified the code for extraction.

Tested by FullSourceWorkspaceASTTests

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/util/Util.java

@@ -18,6 +18,7 @@
 import java.io.*;
 import java.net.ServerSocket;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.*;
 import java.util.zip.*;
 
@@ -1218,68 +1219,31 @@ public static String toString(String[] strings, boolean addExtraNewLine) {
  }
  return buffer.toString();
 }
-private static String getZipEntryFileName(File destDir, ZipEntry e, String canonicalDestDirPath) throws IOException {
- String result = e.getName();
- File destfile = new File(destDir, result);
- String canonicalDestFile = destfile.getCanonicalPath();
- if (!canonicalDestFile.startsWith(canonicalDestDirPath + File.separator)) {
- throw new ZipEntryStorageException("Entry is outside of the target dir: " + e.getName());
- }
- return result;
-}
 /**
  * Unzip the contents of the given zip in the given directory (create it if it doesn't exist)
  */
 public static void unzip(String zipPath, String destDirPath) throws IOException {
-
- InputStream zipIn = new FileInputStream(zipPath);
- byte[] buf = new byte[8192];
- File destDir = new File(destDirPath);
- String canonicalDestDirPath = destDir.getCanonicalPath();
- ZipInputStream zis = new ZipInputStream(zipIn);
- FileOutputStream fos = null;
- try {
- ZipEntry zEntry;
- while ((zEntry = zis.getNextEntry()) != null) {
- // if it is empty directory, create it
- if (zEntry.isDirectory()) {
- new File(destDir, zEntry.getName()).mkdirs();
- continue;
- }
- // if it is a file, extract it
- String filePath = getZipEntryFileName(destDir, zEntry, canonicalDestDirPath);
- int lastSeparator = filePath.lastIndexOf("/"); //$NON-NLS-1$
- String fileDir = ""; //$NON-NLS-1$
- if (lastSeparator >= 0) {
- fileDir = filePath.substring(0, lastSeparator);
- }
- //create directory for a file
- new File(destDir, fileDir).mkdirs();
- //write file
- File outFile = new File(destDir, filePath);
- fos = new FileOutputStream(outFile);
- int n = 0;
- while ((n = zis.read(buf)) >= 0) {
- fos.write(buf, 0, n);
- }
- fos.close();
- }
- } catch (IOException ioe) {
- if (fos != null) {
- try {
- fos.close();
- } catch (IOException ioe2) {
- }
- }
- } finally {
- try {
- zipIn.close();
- if (zis != null)
- zis.close();
- } catch (IOException ioe) {
- }
- }
+ File destDir = new File(destDirPath);
+ try (ZipInputStream zis = new ZipInputStream(new FileInputStream(zipPath))) {
+ ZipEntry zEntry;
+ while ((zEntry = zis.getNextEntry()) != null) {
+ // if it is empty directory, create it
+ String filePath = org.eclipse.jdt.internal.core.util.Util.getEntryName(destDirPath, zEntry);
+ File outFile = new File(destDir, filePath);
+ if (zEntry.isDirectory()) {
+ outFile.mkdirs();
+ continue;
+ }
+ // if it is a file, extract it
+ Path entryTarget = outFile.toPath();
+ // create directory for a file
+ Files.createDirectories(entryTarget.getParent());
+ // write file
+ Files.copy(zis, entryTarget);
+ }
+ }
 }
+
 public static void waitAtLeast(int time) {
  long start = System.currentTimeMillis();
  do {