Merge "Save KeyChainSnapshots to disk" into pi-dev (02c0bbdc) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/locksettings/recoverablekeystore/RecoverableKeyStoreManager.java

+1 −2

Original line number	Diff line number	Diff line
		@@ -31,7 +31,6 @@ import android.annotation.Nullable;
		import android.app.PendingIntent;
		import android.content.Context;
		import android.os.Binder;
		import android.os.Process;
		import android.os.RemoteException;
		import android.os.ServiceSpecificException;
		import android.os.UserHandle;
		@@ -128,7 +127,7 @@ public class RecoverableKeyStoreManager {
		db,
		new RecoverySessionStorage(),
		Executors.newSingleThreadExecutor(),
		new RecoverySnapshotStorage(),
		RecoverySnapshotStorage.newInstance(),
		new RecoverySnapshotListenersStorage(),
		platformKeyManager,
		applicationKeyStorage);

services/core/java/com/android/server/locksettings/recoverablekeystore/serialization/KeyChainSnapshotDeserializer.java

+8 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,9 @@ import static com.android.server.locksettings.recoverablekeystore.serialization.
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_ALIAS;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_APPLICATION_KEY;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_APPLICATION_KEYS;

		import static com.android.server.locksettings.recoverablekeystore.serialization
		.KeyChainSnapshotSchema.TAG_BACKEND_PUBLIC_KEY;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_COUNTER_ID;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_RECOVERY_KEY_MATERIAL;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_KEY_CHAIN_PROTECTION_PARAMS;
		@@ -128,6 +131,11 @@ public class KeyChainSnapshotDeserializer {
		}
		break;

		case TAG_BACKEND_PUBLIC_KEY:
		builder.setTrustedHardwarePublicKey(
		readBlobTag(parser, TAG_BACKEND_PUBLIC_KEY));
		break;

		case TAG_KEY_CHAIN_PROTECTION_PARAMS_LIST:
		builder.setKeyChainProtectionParams(readKeyChainProtectionParamsList(parser));
		break;

services/core/java/com/android/server/locksettings/recoverablekeystore/serialization/KeyChainSnapshotSchema.java

+1 −0

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@ class KeyChainSnapshotSchema {
		static final String TAG_RECOVERY_KEY_MATERIAL = "recoveryKeyMaterial";
		static final String TAG_SERVER_PARAMS = "serverParams";
		static final String TAG_TRUSTED_HARDWARE_CERT_PATH = "thmCertPath";
		static final String TAG_BACKEND_PUBLIC_KEY = "backendPublicKey";

		static final String TAG_KEY_CHAIN_PROTECTION_PARAMS_LIST =
		"keyChainProtectionParamsList";

services/core/java/com/android/server/locksettings/recoverablekeystore/serialization/KeyChainSnapshotSerializer.java

+7 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,9 @@ import static com.android.server.locksettings.recoverablekeystore.serialization.
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_ALIAS;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_APPLICATION_KEY;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_APPLICATION_KEYS;

		import static com.android.server.locksettings.recoverablekeystore.serialization
		.KeyChainSnapshotSchema.TAG_BACKEND_PUBLIC_KEY;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_COUNTER_ID;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_RECOVERY_KEY_MATERIAL;
		import static com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSchema.TAG_KEY_CHAIN_PROTECTION_PARAMS;
		@@ -159,6 +162,10 @@ public class KeyChainSnapshotSerializer {
		writePropertyTag(xmlSerializer, TAG_SERVER_PARAMS, keyChainSnapshot.getServerParams());
		writePropertyTag(xmlSerializer, TAG_TRUSTED_HARDWARE_CERT_PATH,
		keyChainSnapshot.getTrustedHardwareCertPath());
		if (keyChainSnapshot.getTrustedHardwarePublicKey() != null) {
		writePropertyTag(xmlSerializer, TAG_BACKEND_PUBLIC_KEY,
		keyChainSnapshot.getTrustedHardwarePublicKey());
		}
		}

		private static void writePropertyTag(

services/core/java/com/android/server/locksettings/recoverablekeystore/storage/RecoverySnapshotStorage.java

+120 −2

Original line number	Diff line number	Diff line
		@@ -17,13 +17,28 @@
		package com.android.server.locksettings.recoverablekeystore.storage;

		import android.annotation.Nullable;
		import android.os.Environment;
		import android.security.keystore.recovery.KeyChainSnapshot;
		import android.util.Log;
		import android.util.SparseArray;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.server.locksettings.recoverablekeystore.serialization
		.KeyChainSnapshotDeserializer;
		import com.android.server.locksettings.recoverablekeystore.serialization
		.KeyChainSnapshotParserException;
		import com.android.server.locksettings.recoverablekeystore.serialization.KeyChainSnapshotSerializer;

		import java.io.File;
		import java.io.FileInputStream;
		import java.io.FileOutputStream;
		import java.io.IOException;
		import java.security.cert.CertificateEncodingException;
		import java.util.Locale;

		/**
		* In-memory storage for recovery snapshots.
		* Storage for recovery snapshots. Stores snapshots in memory, backed by disk storage.
		*
		* <p>Recovery snapshots are generated after a successful screen unlock. They are only generated if
		* the recoverable keystore has been mutated since the previous snapshot. This class stores only the
		@@ -33,14 +48,46 @@ import com.android.internal.annotations.GuardedBy;
		* {@link com.android.server.locksettings.recoverablekeystore.KeySyncTask} thread.
		*/
		public class RecoverySnapshotStorage {

		private static final String TAG = "RecoverySnapshotStorage";

		private static final String ROOT_PATH = "system";
		private static final String STORAGE_PATH = "recoverablekeystore/snapshots/";

		@GuardedBy("this")
		private final SparseArray<KeyChainSnapshot> mSnapshotByUid = new SparseArray<>();

		private final File rootDirectory;

		/**
		* A new instance, storing snapshots in /data/system/recoverablekeystore/snapshots.
		*
		* <p>NOTE: calling this multiple times DOES NOT return the same instance, so will NOT be backed
		* by the same in-memory store.
		*/
		public static RecoverySnapshotStorage newInstance() {
		return new RecoverySnapshotStorage(
		new File(Environment.getDataDirectory(), ROOT_PATH));
		}

		@VisibleForTesting
		public RecoverySnapshotStorage(File rootDirectory) {
		this.rootDirectory = rootDirectory;
		}

		/**
		* Sets the latest {@code snapshot} for the recovery agent {@code uid}.
		*/
		public synchronized void put(int uid, KeyChainSnapshot snapshot) {
		mSnapshotByUid.put(uid, snapshot);

		try {
		writeToDisk(uid, snapshot);
		} catch (IOException \| CertificateEncodingException e) {
		Log.e(TAG,
		String.format(Locale.US, "Error persisting snapshot for %d to disk", uid),
		e);
		}
		}

		/**
		@@ -48,7 +95,17 @@ public class RecoverySnapshotStorage {
		*/
		@Nullable
		public synchronized KeyChainSnapshot get(int uid) {
		return mSnapshotByUid.get(uid);
		KeyChainSnapshot snapshot = mSnapshotByUid.get(uid);
		if (snapshot != null) {
		return snapshot;
		}

		try {
		return readFromDisk(uid);
		} catch (IOException \| KeyChainSnapshotParserException e) {
		Log.e(TAG, String.format(Locale.US, "Error reading snapshot for %d from disk", uid), e);
		return null;
		}
		}

		/**
		@@ -56,5 +113,66 @@ public class RecoverySnapshotStorage {
		*/
		public synchronized void remove(int uid) {
		mSnapshotByUid.remove(uid);
		getSnapshotFile(uid).delete();
		}

		/**
		* Writes the snapshot for recovery agent {@code uid} to disk.
		*
		* @throws IOException if an IO error occurs writing to disk.
		*/
		private void writeToDisk(int uid, KeyChainSnapshot snapshot)
		throws IOException, CertificateEncodingException {
		File snapshotFile = getSnapshotFile(uid);

		try (
		FileOutputStream fileOutputStream = new FileOutputStream(snapshotFile)
		) {
		KeyChainSnapshotSerializer.serialize(snapshot, fileOutputStream);
		} catch (IOException \| CertificateEncodingException e) {
		// If we fail to write the latest snapshot, we should delete any older snapshot that
		// happens to be around. Otherwise snapshot syncs might end up going 'back in time'.
		snapshotFile.delete();
		throw e;
		}
		}

		/**
		* Reads the last snapshot for recovery agent {@code uid} from disk.
		*
		* @return The snapshot, or null if none existed.
		* @throws IOException if an IO error occurs reading from disk.
		*/
		@Nullable
		private KeyChainSnapshot readFromDisk(int uid)
		throws IOException, KeyChainSnapshotParserException {
		File snapshotFile = getSnapshotFile(uid);

		try (
		FileInputStream fileInputStream = new FileInputStream(snapshotFile)
		) {
		return KeyChainSnapshotDeserializer.deserialize(fileInputStream);
		} catch (IOException \| KeyChainSnapshotParserException e) {
		// If we fail to read the latest snapshot, we should delete it in case it is in some way
		// corrupted. We can regenerate snapshots anyway.
		snapshotFile.delete();
		throw e;
		}
		}

		private File getSnapshotFile(int uid) {
		File folder = getStorageFolder();
		String fileName = getSnapshotFileName(uid);
		return new File(folder, fileName);
		}

		private String getSnapshotFileName(int uid) {
		return String.format(Locale.US, "%d.xml", uid);
		}

		private File getStorageFolder() {
		File folder = new File(rootDirectory, STORAGE_PATH);
		folder.mkdirs();
		return folder;
		}
		}