Add the malware scanner task

app/src/main/java/us/spotco/malwarescanner/DatabaseManager.java

@@ -54,7 +54,7 @@ public class DatabaseManager {
         new File(databasePath + "/" + name).delete();
     }
 
-    public void loadRemoteDatabases() {
+    public static void loadRemoteDatabases() {
         try {
             signatureDatabases.clear();
             String api = Utils.prefs.getString("database_repo", "https://spotco.us/MalwareScannerSignatures/api.php");
@@ -78,7 +78,7 @@ public class DatabaseManager {
         }
     }
 
-    public void updateDatabases() {
+    public static void updateDatabases() {
         loadRemoteDatabases();
         for (Signatures.SignatureDatabase db : signatureDatabases) {
             if (db.isAvailable()) {
@@ -88,7 +88,7 @@ public class DatabaseManager {
         loadAllAvailableDatabases(true);
     }
 
-    public void loadAllAvailableDatabases(boolean forceReload) {
+    public static void loadAllAvailableDatabases(boolean forceReload) {
         if (!Signatures.available() || forceReload) {
             Signatures.clear();
             for (Signatures.SignatureDatabase db : signatureDatabases) {
@@ -102,7 +102,7 @@ public class DatabaseManager {
         }
     }
 
-    private void loadDatabase(File database) {
+    private static void loadDatabase(File database) {
         try {
             if (database.exists()) {
                 BufferedReader reader;

app/src/main/java/us/spotco/malwarescanner/MalwareScanner.java

@@ -17,5 +17,128 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 package us.spotco.malwarescanner;
 
-public class MalwareScanner {
+import android.os.AsyncTask;
-}
+import android.os.Environment;
+import android.os.SystemClock;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+class MalwareScanner extends AsyncTask<Set<File>, Object, String> {
+
+    private boolean userFacing = false;
+    private long scanTime = 0;
+    private int hashMaxLength = 0;
+    private final HashMap<String, File> fileHashesMD5 = new HashMap<>();
+    private final HashMap<String, File> fileHashesSHA1 = new HashMap<>();
+    private final HashMap<String, File> fileHashesSHA256 = new HashMap<>();
+
+    public MalwareScanner(boolean userFacing) {
+        this.userFacing = userFacing;
+        hashMaxLength = Utils.prefs.getInt("database_hash_length", 12);
+    }
+
+    private void returnResult(String result, boolean userFacingOnly) {
+        //TODO HANDLE STATUS UPDATES
+    }
+
+    @Override
+    protected final void onPreExecute() {
+        scanTime = SystemClock.elapsedRealtime();
+        returnResult("Starting scan...", true);
+    }
+
+    @Override
+    protected final String doInBackground(Set<File>[] filesToScan) {
+        //Pre
+        fileHashesMD5.clear();
+        fileHashesSHA1.clear();
+        fileHashesSHA256.clear();
+
+        publishProgress(filesToScan[0].size() + " files pending scan\n", true);
+
+        DatabaseManager.loadAllAvailableDatabases(false);
+        if (Signatures.getSignatureCount() >= 0) {
+            publishProgress("Loaded database with " + Signatures.getSignatureCount() + " signatures\n", true);
+
+            //Get file hashes
+            publishProgress("Hashing files...", true);
+            for (File file : filesToScan[0]) {
+                getFileHashes(file);
+            }
+            publishProgress("Calculated MD5/SHA-1/SHA-256 hashes for all files\n", true);
+
+            //Check the hashes
+            checkSignature("MD5", fileHashesMD5, Signatures.MD5);
+            checkSignature("SHA-1", fileHashesSHA1, Signatures.SHA1);
+            checkSignature("SHA-256", fileHashesSHA256, Signatures.SHA256);
+
+            //Post
+            fileHashesMD5.clear();
+            fileHashesSHA1.clear();
+            fileHashesSHA256.clear();
+            System.gc();
+            Utils.amtFilesScanned += filesToScan[0].size();
+            publishProgress("Scan completed in " + ((SystemClock.elapsedRealtime() - scanTime) / 1000) + " seconds!\n\n\n\n", true);
+        } else {
+            publishProgress("No database available, not scanning...", true);
+        }
+        return null;
+    }
+
+    @Override
+    protected final void onProgressUpdate(Object... objects) {
+        returnResult((String) objects[0], (boolean) objects[1]);
+    }
+
+    private void checkSignature(String hashType, HashMap<String, File> signaturesToCheck, HashMap<String, String> signatureDatabase) {
+        if (signatureDatabase.size() > 0) {
+            for (Map.Entry<String, File> file : signaturesToCheck.entrySet()) {
+                if (signatureDatabase.containsKey(file.getKey())) {
+                    String result = signatureDatabase.get(file.getKey());
+                    publishProgress(result + " in " + file.getValue().toString().replaceAll(Environment.getExternalStorageDirectory().toString(), "~"), false);
+                }
+            }
+            publishProgress("Checked all " + hashType + " hashes against signature databases\n", true);
+        } else {
+            publishProgress("No " + hashType + " signatures available\n", true);
+        }
+    }
+
+    private void getFileHashes(File file) {
+        try {
+            InputStream fis = new FileInputStream(file);
+
+            byte[] buffer = new byte[4096];
+            int numRead;
+
+            MessageDigest digestMD5 = MessageDigest.getInstance("MD5");
+            MessageDigest digestSHA1 = MessageDigest.getInstance("SHA-1");
+            MessageDigest digestSHA256 = MessageDigest.getInstance("SHA-256");
+
+            do {
+                numRead = fis.read(buffer);
+                if (numRead > 0) {
+                    digestMD5.update(buffer, 0, numRead);
+                    digestSHA1.update(buffer, 0, numRead);
+                    digestSHA256.update(buffer, 0, numRead);
+                }
+            } while (numRead != -1);
+
+            fis.close();
+
+            fileHashesMD5.put(String.format("%032x", new BigInteger(1, digestMD5.digest())).substring(0, hashMaxLength), file);
+            fileHashesSHA1.put(String.format("%032x", new BigInteger(1, digestSHA1.digest())).substring(0, hashMaxLength), file);
+            fileHashesSHA256.put(String.format("%064x", new BigInteger(1, digestSHA256.digest())).substring(0, hashMaxLength), file);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+}

app/src/main/java/us/spotco/malwarescanner/Utils.java

@@ -36,6 +36,7 @@ import java.util.concurrent.ThreadPoolExecutor;
 
 public class Utils {
 
+    public static int amtFilesScanned = 0;
     public static SharedPreferences prefs = null;
 
     public Utils(Context context) {