Close stream in finally block, increase buffer size, detect crx via m…

…agic number

src/android/Zip.java

@@ -2,8 +2,8 @@
 
 import java.io.BufferedInputStream;
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.FileOutputStream;
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.FileNotFoundException;
 import java.util.zip.ZipEntry;
@@ -20,7 +20,7 @@
 public class Zip extends CordovaPlugin {
 
     private static final String LOG_TAG = "Zip";
-    
+
     @Override
     public boolean execute(String action, CordovaArgs args, final CallbackContext callbackContext) throws JSONException {
         if ("unzip".equals(action)) {
@@ -38,7 +38,17 @@ public void run() {
         });
     }
 
+    // Can't use DataInputStream because it has the wrong endian-ness.
+    private static int readInt(InputStream is) throws IOException {
+        int a = is.read();
+        int b = is.read();
+        int c = is.read();
+        int d = is.read();
+        return a | b << 8 | c << 16 | d << 24;
+    }
+
     private void unzipSync(CordovaArgs args, CallbackContext callbackContext) {
+        InputStream inputStream = null;
         try {
             String zipFileName = args.getString(0);
             String outputDirectory = args.getString(1);
@@ -64,9 +74,12 @@ private void unzipSync(CordovaArgs args, CallbackContext callbackContext) {
                 throw new FileNotFoundException("File: \"" + outputDirectory + "\" not found");
             }
 
-            InputStream is = resourceApi.openForRead(zipUri).inputStream;
-
-            if (zipFileName.endsWith("crx")) {
+            inputStream = new BufferedInputStream(resourceApi.openForRead(zipUri).inputStream);
+            inputStream.mark(10);
+            int magic = readInt(inputStream);
+            if (magic != 875721283) { // CRX identifier
+                inputStream.reset();
+            } else {
                 // CRX files contain a header. This header consists of:
                 //  * 4 bytes of magic number
                 //  * 4 bytes of CRX format version,
@@ -75,28 +88,22 @@ private void unzipSync(CordovaArgs args, CallbackContext callbackContext) {
                 //  * the public key
                 //  * the signature
                 // and then the ordinary zip data follows. We skip over the header before creating the ZipInputStream.
+                readInt(inputStream); // version == 2.
+                int pubkeyLength = readInt(inputStream);
+                int signatureLength = readInt(inputStream);
 
-                is.skip(8); // 4 bytes for the magic number, 4 for the version.
-                int pubkeyLength = is.read();
-                pubkeyLength += is.read() << 8;
-                is.skip(2);
-
-                int signatureLength = is.read();
-                signatureLength += is.read() << 8;
-                is.skip(2);
-
-                is.skip(pubkeyLength + signatureLength);
+                inputStream.skip(pubkeyLength + signatureLength);
             }
 
             // The inputstream is now pointing at the start of the actual zip file content.
-            ZipInputStream zis = new ZipInputStream(new BufferedInputStream(is));
+            ZipInputStream zis = new ZipInputStream(inputStream);
+            inputStream = zis;
 
             ZipEntry ze;
-
-            byte[] buffer = new byte[1024];
+            byte[] buffer = new byte[32 * 1024];
             boolean anyEntries = false;
 
-            while ((ze = zis.getNextEntry()) != null) 
+            while ((ze = zis.getNextEntry()) != null)
             {
                 anyEntries = true;
                 String compressedName = ze.getName();
@@ -108,6 +115,7 @@ private void unzipSync(CordovaArgs args, CallbackContext callbackContext) {
                     File file = new File(outputDirectory + compressedName);
                     file.getParentFile().mkdirs();
                     if(file.exists() || file.createNewFile()){
+                        Log.w("Zip", "extracting: " + file.getPath());
                         FileOutputStream fout = new FileOutputStream(file);
                         int count;
                         while ((count = zis.read(buffer)) != -1)
@@ -120,7 +128,6 @@ private void unzipSync(CordovaArgs args, CallbackContext callbackContext) {
                 }
                 zis.closeEntry();
             }
-            zis.close();
             if (anyEntries)
                 callbackContext.success();
             else
@@ -129,6 +136,13 @@ private void unzipSync(CordovaArgs args, CallbackContext callbackContext) {
             String errorMessage = "An error occurred while unzipping.";
             callbackContext.error(errorMessage);
             Log.e(LOG_TAG, errorMessage, e);
+        } finally {
+            if (inputStream != null) {
+                try {
+                    inputStream.close();
+                } catch (IOException e) {
+                }
+            }
         }
     }