OTG: Add support for persistent usb connection

No need to reinsert token on each operation

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/NfcTransport.java

@@ -28,4 +28,9 @@ public class NfcTransport implements Transport {
     public boolean isConnected() {
         return mIsoCard.isConnected();
     }
+
+    @Override
+    public boolean allowPersistentConnection() {
+        return false;
+    }
 }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/SmartcardDevice.java

@@ -32,7 +32,32 @@ public class SmartcardDevice {
     private boolean mPw3Validated;
     private boolean mTagHandlingEnabled;
 
-    public SmartcardDevice() {
+    protected SmartcardDevice() {
+    }
+
+    public static SmartcardDevice getInstance() {
+        return LazyHolder.mSmartcardDevice;
+    }
+
+    // METHOD UPDATED [OK]
+    private String getHolderName(String name) {
+        try {
+            String slength;
+            int ilength;
+            name = name.substring(6);
+            slength = name.substring(0, 2);
+            ilength = Integer.parseInt(slength, 16) * 2;
+            name = name.substring(2, ilength + 2);
+            name = (new String(Hex.decode(name))).replace('<', ' ');
+            return name;
+        } catch (IndexOutOfBoundsException e) {
+            // try-catch for https://github.com/FluffyKaon/OpenPGP-Card
+            // Note: This should not happen, but happens with
+            // https://github.com/FluffyKaon/OpenPGP-Card, thus return an empty string for now!
+
+            Log.e(Constants.TAG, "Couldn't get holder name, returning empty string!", e);
+            return "";
+        }
     }
 
     private static String getHex(byte[] raw) {
@@ -541,15 +566,8 @@ public class SmartcardDevice {
         return Hex.decode(signature);
     }
 
-    private String getHolderName(String name) {
+    public boolean isConnected() {
-        String slength;
+        return mTransport != null && mTransport.isConnected();
-        int ilength;
-        name = name.substring(6);
-        slength = name.substring(0, 2);
-        ilength = Integer.parseInt(slength, 16) * 2;
-        name = name.substring(2, ilength + 2);
-        name = (new String(Hex.decode(name))).replace('<', ' ');
-        return (name);
     }
 
     /**
@@ -560,8 +578,8 @@ public class SmartcardDevice {
         return getHex(mTransport.sendAndReceive(Hex.decode(apdu)));
     }
 
-    public boolean isConnected() {
+    public Transport getTransport() {
-        return mTransport.isConnected();
+        return mTransport;
     }
 
     // NEW METHOD [OK]
@@ -702,6 +720,13 @@ public class SmartcardDevice {
 
     public void setTransport(Transport mTransport) {
         this.mTransport = mTransport;
+    }
 
+    public boolean allowPersistentConnection() {
+        return mTransport != null && mTransport.allowPersistentConnection();
+    }
+
+    private static class LazyHolder {
+        private static final SmartcardDevice mSmartcardDevice = new SmartcardDevice();
     }
 }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/Transport.java

@@ -8,4 +8,6 @@ public interface Transport {
     void release();
 
     boolean isConnected();
+
+    boolean allowPersistentConnection();
 }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/UsbConnectionManager.java

@@ -51,4 +51,12 @@ public class UsbConnectionManager {
     public void onStop() {
         mActivity.unregisterReceiver(mUsbReceiver);
     }
+
+    public void rescanDevices() {
+        final SmartcardDevice smartcardDevice = SmartcardDevice.getInstance();
+        if (smartcardDevice.isConnected()
+                && (smartcardDevice.getTransport() instanceof UsbTransport)) {
+            mListener.usbDeviceDiscovered(((UsbTransport) smartcardDevice.getTransport()).getUsbDevice());
+        }
+    }
 }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/UsbTransport.java

@@ -12,6 +12,8 @@ import android.util.Pair;
 
 import org.bouncycastle.util.Arrays;
 import org.bouncycastle.util.encoders.Hex;
+import org.sufficientlysecure.keychain.Constants;
+import org.sufficientlysecure.keychain.util.Log;
 
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
@@ -45,33 +47,7 @@ public class UsbTransport implements Transport {
         // check result
 
         powerOn();
-
+        Log.d(Constants.TAG, "Usb transport connected");
-        setTimings();
-    }
-
-    private void setTimings()  throws TransportIoException {
-        byte[] data = {
-                0x6C,
-                0x00, 0x00, 0x00, 0x00,
-                0x00,
-                mCounter++,
-                0x00, 0x00, 0x00
-        };
-        sendRaw(data);
-        data = receive();
-
-        data[0] = 0x61;
-        data[1] = 0x04;
-        data[2] = data[3] = data[4] = 0x00;
-        data[5] = 0x00;
-        data[6] = mCounter++;
-        data[7] = 0x00;
-        data[8] = data[9] = 0x00;
-
-        data[13] = 1;
-
-        sendRaw(data);
-        receive();
     }
 
     private void powerOff() throws TransportIoException {
@@ -147,6 +123,11 @@ public class UsbTransport implements Transport {
         return mUsbManager.getDeviceList().containsValue(mUsbDevice);
     }
 
+    @Override
+    public boolean allowPersistentConnection() {
+        return true;
+    }
+
     @Override
     public byte[] sendAndReceive(byte[] data) throws TransportIoException {
         send(data);
@@ -223,4 +204,8 @@ public class UsbTransport implements Transport {
     private boolean isXfrBlockNotReady(byte[] bytes) {
         return getStatus(bytes) == 2;
     }
+
+    public UsbDevice getUsbDevice() {
+        return mUsbDevice;
+    }
 }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateSecurityTokenImportResetFragment.java

@@ -249,9 +249,9 @@ public class CreateSecurityTokenImportResetFragment
     @Override
     public void doNfcInBackground() throws IOException {
 
-        mTokenFingerprints = mCreateKeyActivity.mSmartcardDevice.getFingerprints();
+        mTokenFingerprints = mCreateKeyActivity.getSmartcardDevice().getFingerprints();
-        mTokenAid = mCreateKeyActivity.mSmartcardDevice.getAid();
+        mTokenAid = mCreateKeyActivity.getSmartcardDevice().getAid();
-        mTokenUserId = mCreateKeyActivity.mSmartcardDevice.getUserId();
+        mTokenUserId = mCreateKeyActivity.getSmartcardDevice().getUserId();
 
         byte[] fp = new byte[20];
         ByteBuffer.wrap(fp).put(mTokenFingerprints, 0, 20);

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/SecurityTokenOperationActivity.java

@@ -140,6 +140,32 @@ public class SecurityTokenOperationActivity extends BaseSecurityTokenNfcActivity
         if (mRequiredInput.mType != RequiredInputParcel.RequiredInputType.NFC_MOVE_KEY_TO_CARD
                 && mRequiredInput.mType != RequiredInputParcel.RequiredInputType.NFC_RESET_CARD) {
             obtainSecurityTokenPin(mRequiredInput);
+            checkPinAvailability();
+        } else {
+            // No need for pin, rescan USB devices
+            mUsbDispatcher.rescanDevices();
+        }
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+        if (REQUEST_CODE_PIN == requestCode) {
+            checkPinAvailability();
+        }
+    }
+
+    private void checkPinAvailability() {
+        try {
+            Passphrase passphrase = PassphraseCacheService.getCachedPassphrase(this,
+                    mRequiredInput.getMasterKeyId(), mRequiredInput.getSubKeyId());
+            if (passphrase != null) {
+                // Rescan USB devices
+                mUsbDispatcher.rescanDevices();
+            }
+        } catch (PassphraseCacheService.KeyNotFoundException e) {
+            throw new AssertionError(
+                    "tried to find passphrase for non-existing key. this is a programming error!");
         }
     }
 
@@ -275,28 +301,33 @@ public class SecurityTokenOperationActivity extends BaseSecurityTokenNfcActivity
 
         nfcGuideView.setCurrentStatus(NfcGuideView.NfcGuideViewStatus.DONE);
 
-        new AsyncTask<Void, Void, Void>() {
+        if (mSmartcardDevice.allowPersistentConnection()) {
-            @Override
+            // Just close
-            protected Void doInBackground(Void... params) {
+            finish();
-                // check all 200ms if Security Token has been taken away
+        } else {
-                while (true) {
+            new AsyncTask<Void, Void, Void>() {
-                    if (isNfcConnected()) {
+                @Override
-                        try {
+                protected Void doInBackground(Void... params) {
-                            Thread.sleep(200);
+                    // check all 200ms if Security Token has been taken away
-                        } catch (InterruptedException ignored) {
+                    while (true) {
+                        if (isNfcConnected()) {
+                            try {
+                                Thread.sleep(200);
+                            } catch (InterruptedException ignored) {
+                            }
+                        } else {
+                            return null;
                         }
-                    } else {
-                        return null;
                     }
                 }
-            }
 
-            @Override
+                @Override
-            protected void onPostExecute(Void result) {
+                protected void onPostExecute(Void result) {
-                super.onPostExecute(result);
+                    super.onPostExecute(result);
-                finish();
+                    finish();
-            }
+                }
-        }.execute();
+            }.execute();
+        }
     }
 
     /**

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/base/BaseSecurityTokenNfcActivity.java

@@ -31,7 +31,6 @@ import android.nfc.TagLostException;
 import android.os.AsyncTask;
 import android.os.Bundle;
 
-import org.bouncycastle.util.encoders.Hex;
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.pgp.exception.PgpKeyNotFoundException;
@@ -41,9 +40,9 @@ import org.sufficientlysecure.keychain.provider.ProviderHelper;
 import org.sufficientlysecure.keychain.service.PassphraseCacheService;
 import org.sufficientlysecure.keychain.service.input.CryptoInputParcel;
 import org.sufficientlysecure.keychain.service.input.RequiredInputParcel;
-import org.sufficientlysecure.keychain.smartcard.SmartcardDevice;
 import org.sufficientlysecure.keychain.smartcard.NfcTransport;
 import org.sufficientlysecure.keychain.smartcard.OnDiscoveredUsbDeviceListener;
+import org.sufficientlysecure.keychain.smartcard.SmartcardDevice;
 import org.sufficientlysecure.keychain.smartcard.UsbConnectionManager;
 import org.sufficientlysecure.keychain.smartcard.UsbTransport;
 import org.sufficientlysecure.keychain.ui.CreateKeyActivity;
@@ -72,7 +71,7 @@ public abstract class BaseSecurityTokenNfcActivity extends BaseActivity
 
     private static final String FIDESMO_APP_PACKAGE = "com.fidesmo.sec.android";
 
-    public SmartcardDevice mSmartcardDevice = new SmartcardDevice();
+    protected SmartcardDevice mSmartcardDevice = SmartcardDevice.getInstance();
     protected TagDispatcher mTagDispatcher;
     protected UsbConnectionManager mUsbDispatcher;
     private boolean mTagHandlingEnabled;
@@ -175,7 +174,7 @@ public abstract class BaseSecurityTokenNfcActivity extends BaseActivity
 
 
     public void usbDeviceDiscovered(final UsbDevice device) {
-        // Actual NFC operations are executed in doInBackground to not block the UI thread
+        // Actual USB operations are executed in doInBackground to not block the UI thread
         if (!mTagHandlingEnabled)
             return;
         new AsyncTask<Void, Void, IOException>() {
@@ -372,7 +371,6 @@ public abstract class BaseSecurityTokenNfcActivity extends BaseActivity
         Log.d(Constants.TAG, "BaseNfcActivity.onPause");
 
         mTagDispatcher.disableExclusiveNfc();
-//        mUsbDispatcher.stopListeningForDevices();
     }
 
     /**
@@ -453,10 +451,15 @@ public abstract class BaseSecurityTokenNfcActivity extends BaseActivity
     }
 
     protected void handleUsbDevice(UsbDevice device) throws IOException {
-        UsbManager usbManager = (UsbManager) getSystemService(USB_SERVICE);
+        // Don't reconnect if device was already connected
-        mSmartcardDevice.setTransport(new UsbTransport(device, usbManager));
+        if (!mSmartcardDevice.isConnected()
-        mSmartcardDevice.connectToDevice();
+                || !(mSmartcardDevice.getTransport() instanceof UsbTransport)
+                || !((UsbTransport) mSmartcardDevice.getTransport()).getUsbDevice().equals(device)) {
+            UsbManager usbManager = (UsbManager) getSystemService(USB_SERVICE);
 
+            mSmartcardDevice.setTransport(new UsbTransport(device, usbManager));
+            mSmartcardDevice.connectToDevice();
+        }
         doNfcInBackground();
     }
 
@@ -464,48 +467,6 @@ public abstract class BaseSecurityTokenNfcActivity extends BaseActivity
         return mSmartcardDevice.isConnected();
     }
 
-    /**
-     * Parses out the status word from a JavaCard response string.
-     *
-     * @param response A hex string with the response from the token
-     * @return A short indicating the SW1/SW2, or 0 if a status could not be determined.
-     */
-    short parseCardStatus(String response) {
-        if (response.length() < 4) {
-            return 0; // invalid input
-        }
-
-        try {
-            return Short.parseShort(response.substring(response.length() - 4), 16);
-        } catch (NumberFormatException e) {
-            return 0;
-        }
-    }
-
-    public String getHolderName(String name) {
-        try {
-            String slength;
-            int ilength;
-            name = name.substring(6);
-            slength = name.substring(0, 2);
-            ilength = Integer.parseInt(slength, 16) * 2;
-            name = name.substring(2, ilength + 2);
-            name = (new String(Hex.decode(name))).replace('<', ' ');
-            return name;
-        } catch (IndexOutOfBoundsException e) {
-            // try-catch for https://github.com/FluffyKaon/OpenPGP-Card
-            // Note: This should not happen, but happens with
-            // https://github.com/FluffyKaon/OpenPGP-Card, thus return an empty string for now!
-
-            Log.e(Constants.TAG, "Couldn't get holder name, returning empty string!", e);
-            return "";
-        }
-    }
-
-    public static String getHex(byte[] raw) {
-        return new String(Hex.encode(raw));
-    }
-
     public class IsoDepNotSupportedException extends IOException {
 
         public IsoDepNotSupportedException(String detailMessage) {
@@ -575,4 +536,8 @@ public abstract class BaseSecurityTokenNfcActivity extends BaseActivity
         super.onStart();
         mUsbDispatcher.onStart();
     }
+
+    public SmartcardDevice getSmartcardDevice() {
+        return mSmartcardDevice;
+    }
 }