open-keychain/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/service/remote/RemoteService.java
2014-03-06 14:02:21 +01:00

230 lines
8.6 KiB
Java

/*
* Copyright (C) 2013-2014 Dominik Schürmann <dominik@dominikschuermann.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.sufficientlysecure.keychain.service.remote;
import java.util.ArrayList;
import java.util.Arrays;
import org.openintents.openpgp.OpenPgpError;
import org.openintents.openpgp.util.OpenPgpApi;
import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.provider.KeychainContract;
import org.sufficientlysecure.keychain.provider.ProviderHelper;
import org.sufficientlysecure.keychain.util.Log;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.Signature;
import android.net.Uri;
import android.os.Binder;
/**
* Abstract service class for remote APIs that handle app registration and user input.
*/
public abstract class RemoteService extends Service {
Context mContext;
private static final int PRIVATE_REQUEST_CODE_REGISTER = 651;
private static final int PRIVATE_REQUEST_CODE_ERROR = 652;
public Context getContext() {
return mContext;
}
protected Intent isAllowed(Intent data) {
try {
if (isCallerAllowed(false)) {
return null;
} else {
String[] callingPackages = getPackageManager().getPackagesForUid(
Binder.getCallingUid());
// TODO: currently simply uses first entry
String packageName = callingPackages[0];
byte[] packageSignature;
try {
packageSignature = getPackageSignature(packageName);
} catch (NameNotFoundException e) {
Log.e(Constants.TAG, "Should not happen, returning!", e);
// return error
Intent result = new Intent();
result.putExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR);
result.putExtra(OpenPgpApi.RESULT_ERROR,
new OpenPgpError(OpenPgpError.GENERIC_ERROR, e.getMessage()));
return result;
}
Log.e(Constants.TAG, "Not allowed to use service! return PendingIntent for registration!");
Intent intent = new Intent(getBaseContext(), RemoteServiceActivity.class);
intent.setAction(RemoteServiceActivity.ACTION_REGISTER);
intent.putExtra(RemoteServiceActivity.EXTRA_PACKAGE_NAME, packageName);
intent.putExtra(RemoteServiceActivity.EXTRA_PACKAGE_SIGNATURE, packageSignature);
intent.putExtra(RemoteServiceActivity.EXTRA_DATA, data);
PendingIntent pi = PendingIntent.getActivity(getBaseContext(), PRIVATE_REQUEST_CODE_REGISTER, intent, 0);
// return PendingIntent to be executed by client
Intent result = new Intent();
result.putExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED);
result.putExtra(OpenPgpApi.RESULT_INTENT, pi);
return result;
}
} catch (WrongPackageSignatureException e) {
Log.e(Constants.TAG, "wrong signature!", e);
Intent intent = new Intent(getBaseContext(), RemoteServiceActivity.class);
intent.setAction(RemoteServiceActivity.ACTION_ERROR_MESSAGE);
intent.putExtra(RemoteServiceActivity.EXTRA_ERROR_MESSAGE, getString(R.string.api_error_wrong_signature));
intent.putExtra(RemoteServiceActivity.EXTRA_DATA, data);
PendingIntent pi = PendingIntent.getActivity(getBaseContext(), PRIVATE_REQUEST_CODE_ERROR, intent, 0);
// return PendingIntent to be executed by client
Intent result = new Intent();
result.putExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED);
result.putExtra(OpenPgpApi.RESULT_INTENT, pi);
return result;
}
}
private byte[] getPackageSignature(String packageName) throws NameNotFoundException {
PackageInfo pkgInfo = getPackageManager().getPackageInfo(packageName,
PackageManager.GET_SIGNATURES);
Signature[] signatures = pkgInfo.signatures;
// TODO: Only first signature?!
byte[] packageSignature = signatures[0].toByteArray();
return packageSignature;
}
/**
* Retrieves AppSettings from database for the application calling this remote service
*
* @return
*/
protected AppSettings getAppSettings() {
String[] callingPackages = getPackageManager().getPackagesForUid(Binder.getCallingUid());
// get app settings for this package
for (int i = 0; i < callingPackages.length; i++) {
String currentPkg = callingPackages[i];
Uri uri = KeychainContract.ApiApps.buildByPackageNameUri(currentPkg);
AppSettings settings = ProviderHelper.getApiAppSettings(this, uri);
if (settings != null)
return settings;
}
return null;
}
/**
* Checks if process that binds to this service (i.e. the package name corresponding to the
* process) is in the list of allowed package names.
*
* @param allowOnlySelf allow only Keychain app itself
* @return true if process is allowed to use this service
* @throws WrongPackageSignatureException
*/
private boolean isCallerAllowed(boolean allowOnlySelf) throws WrongPackageSignatureException {
return isUidAllowed(Binder.getCallingUid(), allowOnlySelf);
}
private boolean isUidAllowed(int uid, boolean allowOnlySelf)
throws WrongPackageSignatureException {
if (android.os.Process.myUid() == uid) {
return true;
}
if (allowOnlySelf) { // barrier
return false;
}
String[] callingPackages = getPackageManager().getPackagesForUid(uid);
// is calling package allowed to use this service?
for (int i = 0; i < callingPackages.length; i++) {
String currentPkg = callingPackages[i];
if (isPackageAllowed(currentPkg)) {
return true;
}
}
Log.d(Constants.TAG, "Caller is NOT allowed!");
return false;
}
/**
* Checks if packageName is a registered app for the API. Does not return true for own package!
*
* @param packageName
* @return
* @throws WrongPackageSignatureException
*/
private boolean isPackageAllowed(String packageName) throws WrongPackageSignatureException {
Log.d(Constants.TAG, "packageName: " + packageName);
ArrayList<String> allowedPkgs = ProviderHelper.getRegisteredApiApps(this);
Log.d(Constants.TAG, "allowed: " + allowedPkgs);
// check if package is allowed to use our service
if (allowedPkgs.contains(packageName)) {
Log.d(Constants.TAG, "Package is allowed! packageName: " + packageName);
// check package signature
byte[] currentSig;
try {
currentSig = getPackageSignature(packageName);
} catch (NameNotFoundException e) {
throw new WrongPackageSignatureException(e.getMessage());
}
byte[] storedSig = ProviderHelper.getApiAppSignature(this, packageName);
if (Arrays.equals(currentSig, storedSig)) {
Log.d(Constants.TAG,
"Package signature is correct! (equals signature from database)");
return true;
} else {
throw new WrongPackageSignatureException(
"PACKAGE NOT ALLOWED! Signature wrong! (Signature not equals signature from database)");
}
}
return false;
}
@Override
public void onCreate() {
super.onCreate();
mContext = this;
}
}