1 files changed, 226 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/UsbTransport.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/UsbTransport.java
new file mode 100644
index 000000000..08f296c25
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/smartcard/UsbTransport.java
@@ -0,0 +1,226 @@
+package org.sufficientlysecure.keychain.smartcard;
+
+import android.hardware.usb.UsbConstants;
+import android.hardware.usb.UsbDevice;
+import android.hardware.usb.UsbDeviceConnection;
+import android.hardware.usb.UsbEndpoint;
+import android.hardware.usb.UsbInterface;
+import android.hardware.usb.UsbManager;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.util.Pair;
+
+import org.bouncycastle.util.Arrays;
+import org.bouncycastle.util.encoders.Hex;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+public class UsbTransport implements Transport {
+    private static final int CLASS_SMARTCARD = 11;
+    private static final int TIMEOUT = 20 * 1000; // 2 s
+
+    private final UsbManager mUsbManager;
+    private final UsbDevice mUsbDevice;
+    private final UsbInterface mUsbInterface;
+    private final UsbEndpoint mBulkIn;
+    private final UsbEndpoint mBulkOut;
+    private final UsbDeviceConnection mConnection;
+    private byte mCounter = 0;
+
+    public UsbTransport(final UsbDevice usbDevice, final UsbManager usbManager) throws TransportIoException {
+        mUsbDevice = usbDevice;
+        mUsbManager = usbManager;
+
+        mUsbInterface = getSmartCardInterface(mUsbDevice);
+        // throw if mUsbInterface == null
+        final Pair<UsbEndpoint, UsbEndpoint> ioEndpoints = getIoEndpoints(mUsbInterface);
+        mBulkIn = ioEndpoints.first;
+        mBulkOut = ioEndpoints.second;
+        // throw if any endpoint is null
+
+        mConnection = mUsbManager.openDevice(mUsbDevice);
+        // throw if connection is null
+        mConnection.claimInterface(mUsbInterface, true);
+        // check result
+
+        powerOn();
+
+        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 {
+        final byte[] iccPowerOff = {
+                0x63,
+                0x00, 0x00, 0x00, 0x00,
+                0x00,
+                mCounter++,
+                0x00,
+                0x00, 0x00
+        };
+        sendRaw(iccPowerOff);
+        receive();
+    }
+
+    void powerOn() throws TransportIoException {
+        final byte[] iccPowerOn = {
+                0x62,
+                0x00, 0x00, 0x00, 0x00,
+                0x00,
+                mCounter++,
+                0x00,
+                0x00, 0x00
+        };
+        sendRaw(iccPowerOn);
+        receive();
+    }
+
+    /**
+     * Get first class 11 (Chip/Smartcard) interface for the device
+     *
+     * @param device {@link UsbDevice} which will be searched
+     * @return {@link UsbInterface} of smartcard or null if it doesn't exist
+     */
+    @Nullable
+    private static UsbInterface getSmartCardInterface(final UsbDevice device) {
+        for (int i = 0; i < device.getInterfaceCount(); i++) {
+            final UsbInterface anInterface = device.getInterface(i);
+            if (anInterface.getInterfaceClass() == CLASS_SMARTCARD) {
+                return anInterface;
+            }
+        }
+        return null;
+    }
+
+    @NonNull
+    private static Pair<UsbEndpoint, UsbEndpoint> getIoEndpoints(final UsbInterface usbInterface) {
+        UsbEndpoint bulkIn = null, bulkOut = null;
+        for (int i = 0; i < usbInterface.getEndpointCount(); i++) {
+            final UsbEndpoint endpoint = usbInterface.getEndpoint(i);
+            if (endpoint.getType() != UsbConstants.USB_ENDPOINT_XFER_BULK) {
+                continue;
+            }
+
+            if (endpoint.getDirection() == UsbConstants.USB_DIR_IN) {
+                bulkIn = endpoint;
+            } else if (endpoint.getDirection() == UsbConstants.USB_DIR_OUT) {
+                bulkOut = endpoint;
+            }
+        }
+        return new Pair<>(bulkIn, bulkOut);
+    }
+
+    @Override
+    public void release() {
+        mConnection.releaseInterface(mUsbInterface);
+        mConnection.close();
+    }
+
+    @Override
+    public boolean isConnected() {
+        // TODO: redo
+        return mUsbManager.getDeviceList().containsValue(mUsbDevice);
+    }
+
+    @Override
+    public byte[] sendAndReceive(byte[] data) throws TransportIoException {
+        send(data);
+        byte[] bytes;
+        do {
+            bytes = receive();
+        } while (isXfrBlockNotReady(bytes));
+
+        checkXfrBlockResult(bytes);
+        return Arrays.copyOfRange(bytes, 10, bytes.length);
+    }
+
+    public void send(byte[] d) throws TransportIoException {
+        int l = d.length;
+        byte[] data = Arrays.concatenate(new byte[]{
+                        0x6f,
+                        (byte) l, (byte) (l >> 8), (byte) (l >> 16), (byte) (l >> 24),
+                        0x00,
+                        mCounter++,
+                        0x00,
+                        0x00, 0x00},
+                d);
+
+        int send = 0;
+        while (send < data.length) {
+            final int len = Math.min(mBulkIn.getMaxPacketSize(), data.length - send);
+            sendRaw(Arrays.copyOfRange(data, send, send + len));
+            send += len;
+        }
+    }
+
+    public byte[] receive() throws TransportIoException {
+        byte[] buffer = new byte[mBulkIn.getMaxPacketSize()];
+        byte[] result = null;
+        int readBytes = 0, totalBytes = 0;
+
+        do {
+            int res = mConnection.bulkTransfer(mBulkIn, buffer, buffer.length, TIMEOUT);
+            if (res < 0) {
+                throw new TransportIoException("USB error, failed to receive response " + res);
+            }
+            if (result == null) {
+                if (res < 10) {
+                    throw new TransportIoException("USB error, failed to receive ccid header");
+                }
+                totalBytes = ByteBuffer.wrap(buffer, 1, 4).order(ByteOrder.LITTLE_ENDIAN).asIntBuffer().get() + 10;
+                result = new byte[totalBytes];
+            }
+            System.arraycopy(buffer, 0, result, readBytes, res);
+            readBytes += res;
+        } while (readBytes < totalBytes);
+
+        return result;
+    }
+
+    private void sendRaw(final byte[] data) throws TransportIoException {
+        final int tr1 = mConnection.bulkTransfer(mBulkOut, data, data.length, TIMEOUT);
+        if (tr1 != data.length) {
+            throw new TransportIoException("USB error, failed to send data " + tr1);
+        }
+    }
+
+    private byte getStatus(byte[] bytes) {
+        return (byte) ((bytes[7] >> 6) & 0x03);
+    }
+
+    private void checkXfrBlockResult(byte[] bytes) throws TransportIoException {
+        final byte status = getStatus(bytes);
+        if (status != 0) {
+            throw new TransportIoException("CCID error, status " + status + " error code: " + Hex.toHexString(bytes, 8, 1));
+        }
+    }
+
+    private boolean isXfrBlockNotReady(byte[] bytes) {
+        return getStatus(bytes) == 2;
+    }
+}