[CDM Transport] Exchange platform info to decide which Transport to (66495b58) · Commits · e / os / android_frameworks_base

services/companion/java/com/android/server/companion/datatransfer/SystemDataTransferProcessor.java

+3 −1

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@ import static android.companion.CompanionDeviceManager.COMPANION_DEVICE_DISCOVER
		import static android.content.ComponentName.createRelative;

		import static com.android.server.companion.Utils.prepareForIpc;
		import static com.android.server.companion.transport.Transport.MESSAGE_REQUEST_PERMISSION_RESTORE;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		@@ -91,7 +92,8 @@ public class SystemDataTransferProcessor {
		mAssociationStore = associationStore;
		mSystemDataTransferRequestStore = systemDataTransferRequestStore;
		mTransportManager = transportManager;
		mTransportManager.setListener(this::onReceivePermissionRestore);
		mTransportManager.addListener(MESSAGE_REQUEST_PERMISSION_RESTORE,
		this::onReceivePermissionRestore);
		mPermissionControllerManager = mContext.getSystemService(PermissionControllerManager.class);
		mExecutor = Executors.newSingleThreadExecutor();
		}

services/companion/java/com/android/server/companion/securechannel/AttestationVerifier.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -35,7 +35,7 @@ import java.util.function.BiConsumer;
		/**
		* Helper class to perform attestation verification synchronously.
		*/
		class AttestationVerifier {
		public class AttestationVerifier {
		private static final long ATTESTATION_VERIFICATION_TIMEOUT_SECONDS = 10; // 10 seconds
		private static final String PARAM_OWNED_BY_SYSTEM = "android.key_owned_by_system";

services/companion/java/com/android/server/companion/securechannel/SecureChannel.java

+4 −3

Original line number	Diff line number	Diff line
		@@ -110,7 +110,7 @@ public class SecureChannel {
		this(in, out, callback, null, new AttestationVerifier(context));
		}

		private SecureChannel(
		public SecureChannel(
		final InputStream in,
		final OutputStream out,
		Callback callback,
		@@ -381,9 +381,10 @@ public class SecureChannel {

		private void exchangeAuthentication()
		throws IOException, GeneralSecurityException, BadHandleException, CryptoException {
		if (mVerifier == null) {
		if (mPreSharedKey != null) {
		exchangePreSharedKey();
		} else {
		}
		if (mVerifier != null) {
		exchangeAttestation();
		}
		}

services/companion/java/com/android/server/companion/transport/CompanionTransportManager.java

+96 −21

Original line number	Diff line number	Diff line
		@@ -19,9 +19,9 @@ package com.android.server.companion.transport;
		import static android.Manifest.permission.DELIVER_COMPANION_MESSAGES;

		import static com.android.server.companion.transport.Transport.MESSAGE_REQUEST_PERMISSION_RESTORE;
		import static com.android.server.companion.transport.Transport.MESSAGE_REQUEST_PLATFORM_INFO;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.annotation.SuppressLint;
		import android.app.ActivityManagerInternal;
		import android.content.Context;
		@@ -30,12 +30,17 @@ import android.content.pm.PackageManager.NameNotFoundException;
		import android.os.Binder;
		import android.os.Build;
		import android.os.ParcelFileDescriptor;
		import android.util.Slog;
		import android.util.SparseArray;

		import com.android.internal.annotations.GuardedBy;
		import com.android.server.LocalServices;
		import com.android.server.companion.transport.Transport.Listener;

		import java.io.IOException;
		import java.nio.ByteBuffer;
		import java.util.HashMap;
		import java.util.Map;
		import java.util.concurrent.CompletableFuture;
		import java.util.concurrent.Future;

		@@ -44,6 +49,8 @@ public class CompanionTransportManager {
		private static final String TAG = "CDM_CompanionTransportManager";
		private static final boolean DEBUG = false;

		private static final int NON_ANDROID = -1;

		private boolean mSecureTransportEnabled = true;

		private static boolean isRequest(int message) {
		@@ -54,24 +61,29 @@ public class CompanionTransportManager {
		return (message & 0xFF000000) == 0x33000000;
		}

		public interface Listener {
		void onRequestPermissionRestore(byte[] data);
		}

		private final Context mContext;

		@GuardedBy("mTransports")
		private final SparseArray<Transport> mTransports = new SparseArray<>();

		@Nullable
		private Listener mListener;
		@NonNull
		private final Map<Integer, Listener> mListeners = new HashMap<>();

		private Transport mTempTransport;

		public CompanionTransportManager(Context context) {
		mContext = context;
		}

		public void setListener(@NonNull Listener listener) {
		mListener = listener;
		/**
		* Add a message listener when a message is received for the message type
		*/
		@GuardedBy("mTransports")
		public void addListener(int message, @NonNull Listener listener) {
		mListeners.put(message, listener);
		for (int i = 0; i < mTransports.size(); i++) {
		mTransports.valueAt(i).addListener(message, listener);
		}
		}

		/**
		@@ -105,15 +117,7 @@ public class CompanionTransportManager {
		detachSystemDataTransport(packageName, userId, associationId);
		}

		final Transport transport;
		if (isSecureTransportEnabled(associationId)) {
		transport = new SecureTransport(associationId, fd, mContext, mListener);
		} else {
		transport = new RawTransport(associationId, fd, mContext, mListener);
		}

		transport.start();
		mTransports.put(associationId, transport);
		initializeTransport(associationId, fd);
		}
		}

		@@ -128,13 +132,85 @@ public class CompanionTransportManager {
		}
		}

		@GuardedBy("mTransports")
		private void initializeTransport(int associationId, ParcelFileDescriptor fd) {
		if (!isSecureTransportEnabled()) {
		Transport transport = new RawTransport(associationId, fd, mContext);
		for (Map.Entry<Integer, Listener> entry : mListeners.entrySet()) {
		transport.addListener(entry.getKey(), entry.getValue());
		}
		transport.start();
		mTransports.put(associationId, transport);
		Slog.i(TAG, "RawTransport is created");
		return;
		}

		// Exchange platform info to decide which transport should be created
		mTempTransport = new RawTransport(associationId, fd, mContext);
		for (Map.Entry<Integer, Listener> entry : mListeners.entrySet()) {
		mTempTransport.addListener(entry.getKey(), entry.getValue());
		}
		mTempTransport.addListener(MESSAGE_REQUEST_PLATFORM_INFO, this::onPlatformInfoReceived);
		mTempTransport.start();

		int sdk = Build.VERSION.SDK_INT;
		String release = Build.VERSION.RELEASE;
		// data format: \| SDK_INT (int) \| release length (int) \| release \|
		final ByteBuffer data = ByteBuffer.allocate(4 + 4 + release.getBytes().length)
		.putInt(sdk)
		.putInt(release.getBytes().length)
		.put(release.getBytes());

		// TODO: it should check if preSharedKey is given
		mTempTransport.requestForResponse(MESSAGE_REQUEST_PLATFORM_INFO, data.array());
		}

		/**
		* Depending on the remote platform info to decide which transport should be created
		*/
		@GuardedBy("mTransports")
		private void onPlatformInfoReceived(byte[] data) {
		// TODO: it should check if preSharedKey is given

		ByteBuffer buffer = ByteBuffer.wrap(data);
		int remoteSdk = buffer.getInt();
		byte[] remoteRelease = new byte[buffer.getInt()];
		buffer.get(remoteRelease);

		Slog.i(TAG, "Remote device SDK: " + remoteSdk + ", release:" + new String(remoteRelease));

		Transport transport = mTempTransport;
		mTempTransport = null;

		int sdk = Build.VERSION.SDK_INT;
		String release = Build.VERSION.RELEASE;
		if (remoteSdk == NON_ANDROID) {
		// TODO: pass in a real preSharedKey
		transport = new SecureTransport(transport.getAssociationId(), transport.getFd(),
		mContext, null, null);
		} else if (sdk < Build.VERSION_CODES.UPSIDE_DOWN_CAKE
		\|\| remoteSdk < Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
		// TODO: depending on the release version, either
		// 1) using a RawTransport for old T versions
		// 2) or an Ukey2 handshaked transport for UKey2 backported T versions
		} else {
		Slog.i(TAG, "Creating a secure channel");
		transport = new SecureTransport(transport.getAssociationId(), transport.getFd(),
		mContext);
		for (Map.Entry<Integer, Listener> entry : mListeners.entrySet()) {
		transport.addListener(entry.getKey(), entry.getValue());
		}
		transport.start();
		}
		mTransports.put(transport.getAssociationId(), transport);
		}

		public Future<?> requestPermissionRestore(int associationId, byte[] data) {
		synchronized (mTransports) {
		final Transport transport = mTransports.get(associationId);
		if (transport == null) {
		return CompletableFuture.failedFuture(new IOException("Missing transport"));
		}

		return transport.requestForResponse(MESSAGE_REQUEST_PERMISSION_RESTORE, data);
		}
		}
		@@ -146,10 +222,9 @@ public class CompanionTransportManager {
		this.mSecureTransportEnabled = enabled;
		}

		private boolean isSecureTransportEnabled(int associationId) {
		private boolean isSecureTransportEnabled() {
		boolean enabled = !Build.IS_DEBUGGABLE \|\| mSecureTransportEnabled;

		// TODO: version comparison logic
		return enabled;
		}
		}

services/companion/java/com/android/server/companion/transport/CryptoManager.java

+38 −65

Original line number	Diff line number	Diff line
		@@ -16,51 +16,51 @@

		package com.android.server.companion.transport;

		import android.security.keystore.KeyGenParameterSpec;
		import android.security.keystore.KeyProperties;
		import android.util.Slog;

		import java.io.IOException;
		import java.nio.ByteBuffer;
		import java.security.InvalidAlgorithmParameterException;
		import java.security.InvalidKeyException;
		import java.security.KeyStore;
		import java.security.KeyStoreException;
		import java.security.NoSuchAlgorithmException;
		import java.security.UnrecoverableEntryException;
		import java.security.cert.CertificateException;
		import java.util.Arrays;

		import javax.crypto.BadPaddingException;
		import javax.crypto.Cipher;
		import javax.crypto.IllegalBlockSizeException;
		import javax.crypto.KeyGenerator;
		import javax.crypto.NoSuchPaddingException;
		import javax.crypto.SecretKey;
		import javax.crypto.spec.IvParameterSpec;
		import javax.crypto.spec.SecretKeySpec;

		/**
		* This class can be used to encrypt and decrypt bytes using Android Cryptography
		* This class uses Java Cryptography to encrypt and decrypt messages
		*/
		public class CryptoManager {

		private static final String TAG = "CDM_CryptoManager";
		private static final int SECRET_KEY_LENGTH = 32;
		private static final String ALGORITHM = "AES";
		private static final String TRANSFORMATION = "AES/CBC/PKCS7Padding";

		private static final String KEY_STORE_ALIAS = "cdm_secret";
		private static final String ALGORITHM = KeyProperties.KEY_ALGORITHM_AES;
		private static final String BLOCK_MODE = KeyProperties.BLOCK_MODE_CBC;
		private static final String PADDING = KeyProperties.ENCRYPTION_PADDING_PKCS7;
		private static final String TRANSFORMATION = ALGORITHM + "/" + BLOCK_MODE + "/" + PADDING;
		private final byte[] mPreSharedKey;
		private Cipher mEncryptCipher;
		private Cipher mDecryptCipher;

		private final KeyStore mKeyStore;
		private SecretKey mSecretKey;

		public CryptoManager() {
		// Initialize KeyStore
		public CryptoManager(byte[] preSharedKey) {
		if (preSharedKey == null) {
		mPreSharedKey = Arrays.copyOf(new byte[0], SECRET_KEY_LENGTH);
		} else {
		mPreSharedKey = Arrays.copyOf(preSharedKey, SECRET_KEY_LENGTH);
		}
		mSecretKey = new SecretKeySpec(mPreSharedKey, ALGORITHM);
		try {
		mKeyStore = KeyStore.getInstance("AndroidKeyStore");
		mKeyStore.load(null);
		} catch (KeyStoreException \| IOException \| NoSuchAlgorithmException
		\| CertificateException e) {
		throw new RuntimeException(e);
		mEncryptCipher = Cipher.getInstance(TRANSFORMATION);
		mEncryptCipher.init(Cipher.ENCRYPT_MODE, mSecretKey);
		mDecryptCipher = Cipher.getInstance(TRANSFORMATION);
		} catch (NoSuchPaddingException \| NoSuchAlgorithmException \| InvalidKeyException e) {
		Slog.e(TAG, e.getMessage());
		}
		}

		@@ -69,21 +69,19 @@ public class CryptoManager {
		*/
		public byte[] encrypt(byte[] input) {
		try {
		// Encrypt using Cipher
		Cipher encryptCipher = Cipher.getInstance(TRANSFORMATION);
		encryptCipher.init(Cipher.ENCRYPT_MODE, getKey());
		byte[] encryptedBytes = encryptCipher.doFinal(input);
		if (mEncryptCipher == null) {
		return null;
		}

		// Write to bytes
		byte[] encryptedBytes = mEncryptCipher.doFinal(input);
		ByteBuffer buffer = ByteBuffer.allocate(
		4 + encryptCipher.getIV().length + 4 + encryptedBytes.length)
		.putInt(encryptCipher.getIV().length)
		.put(encryptCipher.getIV())
		4 + mEncryptCipher.getIV().length + 4 + encryptedBytes.length)
		.putInt(mEncryptCipher.getIV().length)
		.put(mEncryptCipher.getIV())
		.putInt(encryptedBytes.length)
		.put(encryptedBytes);
		return buffer.array();
		} catch (NoSuchAlgorithmException \| NoSuchPaddingException \| InvalidKeyException
		\| IllegalBlockSizeException \| BadPaddingException e) {
		} catch (IllegalBlockSizeException \| BadPaddingException e) {
		Slog.e(TAG, e.getMessage());
		return null;
		}
		@@ -99,45 +97,20 @@ public class CryptoManager {
		byte[] encryptedBytes = new byte[buffer.getInt()];
		buffer.get(encryptedBytes);
		try {
		Cipher decryptCipher = Cipher.getInstance(TRANSFORMATION);
		decryptCipher.init(Cipher.DECRYPT_MODE, getKey(), new IvParameterSpec(iv));
		return decryptCipher.doFinal(encryptedBytes);
		} catch (NoSuchAlgorithmException \| NoSuchPaddingException \| InvalidKeyException
		\| InvalidAlgorithmParameterException \| IllegalBlockSizeException
		\| BadPaddingException e) {
		mDecryptCipher.init(Cipher.DECRYPT_MODE, getKey(), new IvParameterSpec(iv));
		return mDecryptCipher.doFinal(encryptedBytes);
		} catch (InvalidKeyException \| InvalidAlgorithmParameterException
		\| IllegalBlockSizeException \| BadPaddingException e) {
		Slog.e(TAG, e.getMessage());
		return null;
		}
		}

		private SecretKey getKey() {
		try {
		KeyStore.Entry keyEntry = mKeyStore.getEntry(KEY_STORE_ALIAS, null);
		if (keyEntry instanceof KeyStore.SecretKeyEntry
		&& ((KeyStore.SecretKeyEntry) keyEntry).getSecretKey() != null) {
		return ((KeyStore.SecretKeyEntry) keyEntry).getSecretKey();
		} else {
		return createKey();
		}
		} catch (NoSuchAlgorithmException \| UnrecoverableEntryException \| KeyStoreException e) {
		throw new RuntimeException(e);
		}
		}

		private SecretKey createKey() {
		try {
		KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM);
		keyGenerator.init(
		new KeyGenParameterSpec.Builder(KEY_STORE_ALIAS,
		KeyProperties.PURPOSE_ENCRYPT \| KeyProperties.PURPOSE_DECRYPT)
		.setBlockModes(BLOCK_MODE)
		.setEncryptionPaddings(PADDING)
		.setUserAuthenticationRequired(false)
		.setRandomizedEncryptionRequired(true)
		.build());
		return keyGenerator.generateKey();
		} catch (NoSuchAlgorithmException \| InvalidAlgorithmParameterException e) {
		throw new RuntimeException(e);
		if (mSecretKey != null) {
		return mSecretKey;
		}
		mSecretKey = new SecretKeySpec(mPreSharedKey, ALGORITHM);
		return mSecretKey;
		}
		}