[DO NOT MERGE] Backup account access grants (0dc4ff07) · Commits · e / os / android_frameworks_base

core/java/android/accounts/AccountManagerInternal.java

+14 −0

Original line number	Diff line number	Diff line
		@@ -73,4 +73,18 @@ public abstract class AccountManagerInternal {
		*/
		public abstract void addOnAppPermissionChangeListener(
		@NonNull OnAppPermissionChangeListener listener);

		/**
		* Backups the account access permissions.
		* @param userId The user for which to backup.
		* @return The backup data.
		*/
		public abstract byte[] backupAccountAccessPermissions(int userId);

		/**
		* Restores the account access permissions.
		* @param data The restore data.
		* @param userId The user for which to restore.
		*/
		public abstract void restoreAccountAccessPermissions(byte[] data, int userId);
		}

core/java/android/util/PackageUtils.java

0 → 100644

+96 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package android.util;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.content.pm.PackageInfo;
		import android.content.pm.PackageManager;
		import android.content.pm.Signature;

		import java.security.MessageDigest;
		import java.security.NoSuchAlgorithmException;

		/**
		* Helper functions applicable to packages.
		* @hide
		*/
		public final class PackageUtils {
		private final static char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();

		private PackageUtils() {
		/* hide constructor */
		}

		/**
		* Computes the SHA256 digest of the signing cert for a package.
		* @param packageManager The package manager.
		* @param packageName The package for which to generate the digest.
		* @param userId The user for which to generate the digest.
		* @return The digest or null if the package does not exist for this user.
		*/
		public static @Nullable String computePackageCertSha256Digest(
		@NonNull PackageManager packageManager,
		@NonNull String packageName, int userId) {
		final PackageInfo packageInfo;
		try {
		packageInfo = packageManager.getPackageInfoAsUser(packageName,
		PackageManager.GET_SIGNATURES, userId);
		} catch (PackageManager.NameNotFoundException e) {
		return null;
		}
		return computeCertSha256Digest(packageInfo.signatures[0]);
		}

		/**
		* Computes the SHA256 digest of a cert.
		* @param signature The signature.
		* @return The digest or null if an error occurs.
		*/
		public static @Nullable String computeCertSha256Digest(@NonNull Signature signature) {
		return computeSha256Digest(signature.toByteArray());
		}

		/**
		* Computes the SHA256 digest of some data.
		* @param data The data.
		* @return The digest or null if an error occurs.
		*/
		public static @Nullable String computeSha256Digest(@NonNull byte[] data) {
		MessageDigest messageDigest;
		try {
		messageDigest = MessageDigest.getInstance("SHA256");
		} catch (NoSuchAlgorithmException e) {
		/* can't happen */
		return null;
		}

		messageDigest.update(data);

		final byte[] digest = messageDigest.digest();
		final int digestLength = digest.length;
		final int charCount = 2 * digestLength;

		final char[] chars = new char[charCount];
		for (int i = 0; i < digestLength; i++) {
		final int byteHex = digest[i] & 0xFF;
		chars[i * 2] = HEX_ARRAY[byteHex >>> 4];
		chars[i * 2 + 1] = HEX_ARRAY[byteHex & 0x0F];
		}
		return new String(chars);
		}
		}

core/java/com/android/server/backup/AccountManagerBackupHelper.java

0 → 100644

+85 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.server.backup;

		import android.accounts.AccountManagerInternal;
		import android.app.backup.BlobBackupHelper;
		import android.os.UserHandle;
		import android.util.Slog;
		import com.android.server.LocalServices;

		/**
		* Helper for handling backup of account manager specific state.
		*/
		public class AccountManagerBackupHelper extends BlobBackupHelper {
		private static final String TAG = "AccountsBackup";
		private static final boolean DEBUG = false;

		// current schema of the backup state blob
		private static final int STATE_VERSION = 1;

		// key under which the account access grant state blob is committed to backup
		private static final String KEY_ACCOUNT_ACCESS_GRANTS = "account_access_grants";

		public AccountManagerBackupHelper() {
		super(STATE_VERSION, KEY_ACCOUNT_ACCESS_GRANTS);
		}

		@Override
		protected byte[] getBackupPayload(String key) {
		AccountManagerInternal am = LocalServices.getService(AccountManagerInternal.class);
		if (DEBUG) {
		Slog.d(TAG, "Handling backup of " + key);
		}
		try {
		switch (key) {
		case KEY_ACCOUNT_ACCESS_GRANTS: {
		return am.backupAccountAccessPermissions(UserHandle.USER_SYSTEM);
		}

		default: {
		Slog.w(TAG, "Unexpected backup key " + key);
		}
		}
		} catch (Exception e) {
		Slog.e(TAG, "Unable to store payload " + key);
		}

		return new byte[0];
		}

		@Override
		protected void applyRestoredPayload(String key, byte[] payload) {
		AccountManagerInternal am = LocalServices.getService(AccountManagerInternal.class);
		if (DEBUG) {
		Slog.d(TAG, "Handling restore of " + key);
		}
		try {
		switch (key) {
		case KEY_ACCOUNT_ACCESS_GRANTS: {
		am.restoreAccountAccessPermissions(payload, UserHandle.USER_SYSTEM);
		} break;

		default: {
		Slog.w(TAG, "Unexpected restore key " + key);
		}
		}
		} catch (Exception e) {
		Slog.w(TAG, "Unable to restore key " + key);
		}
		}
		}

core/java/com/android/server/backup/SystemBackupAgent.java

+3 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@ public class SystemBackupAgent extends BackupAgentHelper {
		private static final String PERMISSION_HELPER = "permissions";
		private static final String USAGE_STATS_HELPER = "usage_stats";
		private static final String SHORTCUT_MANAGER_HELPER = "shortcut_manager";
		private static final String ACCOUNT_MANAGER_HELPER = "account_manager";

		// These paths must match what the WallpaperManagerService uses. The leaf *_FILENAME
		// are also used in the full-backup file format, so must not change unless steps are
		@@ -82,6 +83,7 @@ public class SystemBackupAgent extends BackupAgentHelper {
		addHelper(PERMISSION_HELPER, new PermissionBackupHelper());
		addHelper(USAGE_STATS_HELPER, new UsageStatsBackupHelper(this));
		addHelper(SHORTCUT_MANAGER_HELPER, new ShortcutBackupHelper());
		addHelper(ACCOUNT_MANAGER_HELPER, new AccountManagerBackupHelper());
		super.onBackup(oldState, data, newState);
		}

		@@ -111,6 +113,7 @@ public class SystemBackupAgent extends BackupAgentHelper {
		addHelper(PERMISSION_HELPER, new PermissionBackupHelper());
		addHelper(USAGE_STATS_HELPER, new UsageStatsBackupHelper(this));
		addHelper(SHORTCUT_MANAGER_HELPER, new ShortcutBackupHelper());
		addHelper(ACCOUNT_MANAGER_HELPER, new AccountManagerBackupHelper());

		try {
		super.onRestore(data, appVersionCode, newState);

services/core/java/com/android/server/accounts/AccountManagerBackupHelper.java

0 → 100644

+312 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.server.accounts;

		import android.accounts.Account;
		import android.accounts.AccountManager;
		import android.accounts.AccountManagerInternal;
		import android.annotation.IntRange;
		import android.annotation.NonNull;
		import android.content.pm.PackageInfo;
		import android.content.pm.PackageManager;
		import android.database.Cursor;
		import android.database.sqlite.SQLiteDatabase;
		import android.os.UserHandle;
		import android.text.TextUtils;
		import android.util.Log;
		import android.util.PackageUtils;
		import android.util.Xml;
		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.content.PackageMonitor;
		import com.android.internal.util.FastXmlSerializer;
		import com.android.internal.util.XmlUtils;
		import org.xmlpull.v1.XmlPullParser;
		import org.xmlpull.v1.XmlPullParserException;
		import org.xmlpull.v1.XmlSerializer;

		import java.io.ByteArrayInputStream;
		import java.io.ByteArrayOutputStream;
		import java.io.IOException;
		import java.nio.charset.StandardCharsets;
		import java.util.ArrayList;
		import java.util.List;

		/**
		* Helper class for backup and restore of account access grants.
		*/
		public final class AccountManagerBackupHelper {
		private static final String TAG = "AccountManagerBackupHelper";

		private static final long PENDING_RESTORE_TIMEOUT_MILLIS = 60 * 60 * 1000; // 1 hour

		private static final String TAG_PERMISSIONS = "permissions";
		private static final String TAG_PERMISSION = "permission";
		private static final String ATTR_ACCOUNT_SHA_256 = "account-sha-256";
		private static final String ATTR_PACKAGE = "package";
		private static final String ATTR_DIGEST = "digest";

		private static final String ACCOUNT_ACCESS_GRANTS = ""
		+ "SELECT " + AccountManagerService.ACCOUNTS_NAME + ", "
		+ AccountManagerService.GRANTS_GRANTEE_UID
		+ " FROM " + AccountManagerService.TABLE_ACCOUNTS
		+ ", " + AccountManagerService.TABLE_GRANTS
		+ " WHERE " + AccountManagerService.GRANTS_ACCOUNTS_ID
		+ "=" + AccountManagerService.ACCOUNTS_ID;

		private final Object mLock = new Object();

		private final AccountManagerService mAccountManagerService;
		private final AccountManagerInternal mAccountManagerInternal;

		@GuardedBy("mLock")
		private List<PendingAppPermission> mRestorePendingAppPermissions;

		@GuardedBy("mLock")
		private RestorePackageMonitor mRestorePackageMonitor;

		@GuardedBy("mLock")
		private Runnable mRestoreCancelCommand;

		public AccountManagerBackupHelper(AccountManagerService accountManagerService,
		AccountManagerInternal accountManagerInternal) {
		mAccountManagerService = accountManagerService;
		mAccountManagerInternal = accountManagerInternal;
		}

		private final class PendingAppPermission {
		private final @NonNull String accountDigest;
		private final @NonNull String packageName;
		private final @NonNull String certDigest;
		private final @IntRange(from = 0) int userId;

		public PendingAppPermission(String accountDigest, String packageName,
		String certDigest, int userId) {
		this.accountDigest = accountDigest;
		this.packageName = packageName;
		this.certDigest = certDigest;
		this.userId = userId;
		}

		public boolean apply(PackageManager packageManager) {
		Account account = null;
		AccountManagerService.UserAccounts accounts = mAccountManagerService
		.getUserAccounts(userId);
		synchronized (accounts.cacheLock) {
		for (Account[] accountsPerType : accounts.accountCache.values()) {
		for (Account accountPerType : accountsPerType) {
		if (accountDigest.equals(PackageUtils.computeSha256Digest(
		accountPerType.name.getBytes()))) {
		account = accountPerType;
		break;
		}
		}
		if (account != null) {
		break;
		}
		}
		}
		if (account == null) {
		return false;
		}
		final PackageInfo packageInfo;
		try {
		packageInfo = packageManager.getPackageInfoAsUser(packageName,
		PackageManager.GET_SIGNATURES, userId);
		} catch (PackageManager.NameNotFoundException e) {
		return false;
		}
		String currentCertDigest = PackageUtils.computeCertSha256Digest(
		packageInfo.signatures[0]);
		if (!certDigest.equals(currentCertDigest)) {
		return false;
		}
		final int uid = packageInfo.applicationInfo.uid;
		if (!mAccountManagerInternal.hasAccountAccess(account, uid)) {
		mAccountManagerService.grantAppPermission(account,
		AccountManager.ACCOUNT_ACCESS_TOKEN_TYPE, uid);
		}
		return true;
		}
		}

		public byte[] backupAccountAccessPermissions(int userId) {
		final AccountManagerService.UserAccounts accounts = mAccountManagerService
		.getUserAccounts(userId);
		synchronized (accounts.cacheLock) {
		SQLiteDatabase db = accounts.openHelper.getReadableDatabase();
		try (
		Cursor cursor = db.rawQuery(ACCOUNT_ACCESS_GRANTS, null);
		) {
		if (cursor == null \|\| !cursor.moveToFirst()) {
		return null;
		}

		final int nameColumnIdx = cursor.getColumnIndex(
		AccountManagerService.ACCOUNTS_NAME);
		final int uidColumnIdx = cursor.getColumnIndex(
		AccountManagerService.GRANTS_GRANTEE_UID);

		ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
		try {
		final XmlSerializer serializer = new FastXmlSerializer();
		serializer.setOutput(dataStream, StandardCharsets.UTF_8.name());
		serializer.startDocument(null, true);
		serializer.startTag(null, TAG_PERMISSIONS);

		PackageManager packageManager = mAccountManagerService.mContext
		.getPackageManager();

		do {
		final String accountName = cursor.getString(nameColumnIdx);
		final int uid = cursor.getInt(uidColumnIdx);

		final String[] packageNames = packageManager.getPackagesForUid(uid);
		if (packageNames == null) {
		continue;
		}

		for (String packageName : packageNames) {
		String digest = PackageUtils.computePackageCertSha256Digest(
		packageManager, packageName, userId);
		if (digest != null) {
		serializer.startTag(null, TAG_PERMISSION);
		serializer.attribute(null, ATTR_ACCOUNT_SHA_256,
		PackageUtils.computeSha256Digest(accountName.getBytes()));
		serializer.attribute(null, ATTR_PACKAGE, packageName);
		serializer.attribute(null, ATTR_DIGEST, digest);
		serializer.endTag(null, TAG_PERMISSION);
		}
		}
		} while (cursor.moveToNext());

		serializer.endTag(null, TAG_PERMISSIONS);
		serializer.endDocument();
		serializer.flush();
		} catch (IOException e) {
		Log.e(TAG, "Error backing up account access grants", e);
		return null;
		}

		return dataStream.toByteArray();
		}
		}
		}

		public void restoreAccountAccessPermissions(byte[] data, int userId) {
		try {
		ByteArrayInputStream dataStream = new ByteArrayInputStream(data);
		XmlPullParser parser = Xml.newPullParser();
		parser.setInput(dataStream, StandardCharsets.UTF_8.name());
		PackageManager packageManager = mAccountManagerService.mContext.getPackageManager();

		final int permissionsOuterDepth = parser.getDepth();
		while (XmlUtils.nextElementWithin(parser, permissionsOuterDepth)) {
		if (!TAG_PERMISSIONS.equals(parser.getName())) {
		continue;
		}
		final int permissionOuterDepth = parser.getDepth();
		while (XmlUtils.nextElementWithin(parser, permissionOuterDepth)) {
		if (!TAG_PERMISSION.equals(parser.getName())) {
		continue;
		}
		String accountDigest = parser.getAttributeValue(null, ATTR_ACCOUNT_SHA_256);
		if (TextUtils.isEmpty(accountDigest)) {
		XmlUtils.skipCurrentTag(parser);
		}
		String packageName = parser.getAttributeValue(null, ATTR_PACKAGE);
		if (TextUtils.isEmpty(packageName)) {
		XmlUtils.skipCurrentTag(parser);
		}
		String digest = parser.getAttributeValue(null, ATTR_DIGEST);
		if (TextUtils.isEmpty(digest)) {
		XmlUtils.skipCurrentTag(parser);
		}

		PendingAppPermission pendingAppPermission = new PendingAppPermission(
		accountDigest, packageName, digest, userId);

		if (!pendingAppPermission.apply(packageManager)) {
		synchronized (mLock) {
		// Start watching before add pending to avoid a missed signal
		if (mRestorePackageMonitor == null) {
		mRestorePackageMonitor = new RestorePackageMonitor();
		mRestorePackageMonitor.register(mAccountManagerService.mContext,
		mAccountManagerService.mMessageHandler.getLooper(), true);
		}
		if (mRestorePendingAppPermissions == null) {
		mRestorePendingAppPermissions = new ArrayList<>();
		}
		mRestorePendingAppPermissions.add(pendingAppPermission);
		}
		}
		}
		}

		// Make sure we eventually prune the in-memory pending restores
		mRestoreCancelCommand = new CancelRestoreCommand();
		mAccountManagerService.mMessageHandler.postDelayed(mRestoreCancelCommand,
		PENDING_RESTORE_TIMEOUT_MILLIS);
		} catch (XmlPullParserException \| IOException e) {
		Log.e(TAG, "Error restoring app permissions", e);
		}
		}

		private final class RestorePackageMonitor extends PackageMonitor {
		@Override
		public void onPackageAdded(String packageName, int uid) {
		synchronized (mLock) {
		if (mRestorePendingAppPermissions == null) {
		return;
		}
		if (UserHandle.getUserId(uid) != UserHandle.USER_SYSTEM) {
		return;
		}
		final int count = mRestorePendingAppPermissions.size();
		for (int i = count - 1; i >= 0; i--) {
		PendingAppPermission pendingAppPermission =
		mRestorePendingAppPermissions.get(i);
		if (!pendingAppPermission.packageName.equals(packageName)) {
		continue;
		}
		if (pendingAppPermission.apply(
		mAccountManagerService.mContext.getPackageManager())) {
		mRestorePendingAppPermissions.remove(i);
		}
		}
		if (mRestorePendingAppPermissions.isEmpty()
		&& mRestoreCancelCommand != null) {
		mAccountManagerService.mMessageHandler.removeCallbacks(mRestoreCancelCommand);
		mRestoreCancelCommand.run();
		mRestoreCancelCommand = null;
		}
		}
		}
		}

		private final class CancelRestoreCommand implements Runnable {
		@Override
		public void run() {
		synchronized (mLock) {
		mRestorePendingAppPermissions = null;
		if (mRestorePackageMonitor != null) {
		mRestorePackageMonitor.unregister();
		mRestorePackageMonitor = null;
		}
		}
		}
		}
		}