Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8763c625 authored by Hall Liu's avatar Hall Liu Committed by android-build-merger
Browse files

Add download request tokens and enforce destination clear

am: 2043f70a

Change-Id: I91e61d8f15815efc9f4d08d71d01944c096dc05f
parents 4a7e3de5 2043f70a
Loading
Loading
Loading
Loading
+54 −14
Original line number Diff line number Diff line
@@ -388,21 +388,10 @@ public class MbmsDownloadManager {
            tempRootDirectory.mkdirs();
            setTempFileRootDirectory(tempRootDirectory);
        }

        request.setAppName(mDownloadAppName);
        // Check if the request is a multipart download. If so, validate that the destination is
        // a directory that exists.
        // TODO: figure out what qualifies a request as a multipart download request.
        if (request.getSourceUri().getLastPathSegment() != null &&
                request.getSourceUri().getLastPathSegment().contains("*")) {
            File toFile = new File(request.getDestinationUri().getSchemeSpecificPart());
            if (!toFile.isDirectory()) {
                throw new IllegalArgumentException("Multipart download must specify valid " +
                        "destination directory.");
            }
        }
        // TODO: check to make sure destination is clear
        // TODO: write download request token

        checkValidDownloadDestination(request);
        writeDownloadRequestToken(request);
        try {
            downloadService.download(request, callback);
        } catch (RemoteException e) {
@@ -435,6 +424,7 @@ public class MbmsDownloadManager {
     * <li>ERROR_MSDC_UNKNOWN_REQUEST</li>
     */
    public int cancelDownload(DownloadRequest downloadRequest) {
        // TODO: don't forget to delete the token
        return 0;
    }

@@ -518,4 +508,54 @@ public class MbmsDownloadManager {
            Log.i(LOG_TAG, "Remote exception while disposing of service");
        }
    }

    private void writeDownloadRequestToken(DownloadRequest request) {
        // TODO: figure out when this token eventually gets deleted
        File tempFileLocation = MbmsUtils.getEmbmsTempFileDirForRequest(mContext, request);
        if (!tempFileLocation.exists()) {
            tempFileLocation.mkdirs();
        }
        String downloadTokenFileName = request.getHash()
                + MbmsDownloadReceiver.DOWNLOAD_TOKEN_SUFFIX;
        File token = new File(tempFileLocation, downloadTokenFileName);
        if (token.exists()) {
            Log.w(LOG_TAG, "Download token " + downloadTokenFileName + " already exists");
            return;
        }
        try {
            if (!token.createNewFile()) {
                throw new RuntimeException("Failed to create download token for request "
                        + request);
            }
        } catch (IOException e) {
            throw new RuntimeException("Failed to create download token for request " + request
                    + " due to IOException " + e);
        }
    }

    /**
     * Verifies the following:
     * If a request is multi-part,
     *     1. Destination Uri must exist and be a directory
     *     2. Directory specified must contain no files.
     * Otherwise
     *     1. The file specified by the destination Uri must not exist.
     */
    private void checkValidDownloadDestination(DownloadRequest request) {
        File toFile = new File(request.getDestinationUri().getSchemeSpecificPart());
        if (request.isMultipartDownload()) {
            if (!toFile.isDirectory()) {
                throw new IllegalArgumentException("Multipart download must specify valid " +
                        "destination directory.");
            }
            if (toFile.listFiles().length > 0) {
                throw new IllegalArgumentException("Destination directory must be clear of all " +
                        "files.");
            }
        } else {
            if (toFile.exists()) {
                throw new IllegalArgumentException("Destination file must not exist.");
            }
        }
    }
}
+55 −2
Original line number Diff line number Diff line
@@ -20,15 +20,22 @@ import android.content.Intent;
import android.net.Uri;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.Base64;

import java.lang.IllegalStateException;
import java.net.URISyntaxException;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * A Parcelable class describing a pending Cell-Broadcast download request
 * @hide
 */
public class DownloadRequest implements Parcelable {
    // Version code used to keep token calculation consistent.
    private static final int CURRENT_VERSION = 1;

    /** @hide */
    public static class Builder {
        private int id;
@@ -37,6 +44,7 @@ public class DownloadRequest implements Parcelable {
        private Uri dest;
        private int subscriptionId;
        private String appIntent;
        private int version = CURRENT_VERSION;

        public Builder setId(int id) {
            this.id = id;
@@ -68,9 +76,14 @@ public class DownloadRequest implements Parcelable {
            return this;
        }

        public Builder setVersion(int version) {
            this.version = version;
            return this;
        }

        public DownloadRequest build() {
            return new DownloadRequest(id, serviceInfo, source, dest,
                    subscriptionId, appIntent, null);
                    subscriptionId, appIntent, null, version);
        }
    }

@@ -80,11 +93,12 @@ public class DownloadRequest implements Parcelable {
    private final Uri destinationUri;
    private final int subscriptionId;
    private final String serializedResultIntentForApp;
    private final int version;
    private String appName; // not the Android app Name, the embms app name

    private DownloadRequest(int id, FileServiceInfo serviceInfo,
            Uri source, Uri dest,
            int sub, String appIntent, String name) {
            int sub, String appIntent, String name, int version) {
        downloadId = id;
        fileServiceInfo = serviceInfo;
        sourceUri = source;
@@ -92,6 +106,7 @@ public class DownloadRequest implements Parcelable {
        subscriptionId = sub;
        serializedResultIntentForApp = appIntent;
        appName = name;
        this.version = version;
    }

    public static DownloadRequest copy(DownloadRequest other) {
@@ -106,6 +121,7 @@ public class DownloadRequest implements Parcelable {
        subscriptionId = dr.subscriptionId;
        serializedResultIntentForApp = dr.serializedResultIntentForApp;
        appName = dr.appName;
        version = dr.version;
    }

    private DownloadRequest(Parcel in) {
@@ -116,6 +132,7 @@ public class DownloadRequest implements Parcelable {
        subscriptionId = in.readInt();
        serializedResultIntentForApp = in.readString();
        appName = in.readString();
        version = in.readInt();
    }

    public int describeContents() {
@@ -130,6 +147,7 @@ public class DownloadRequest implements Parcelable {
        out.writeInt(subscriptionId);
        out.writeString(serializedResultIntentForApp);
        out.writeString(appName);
        out.writeInt(version);
    }

    public int getDownloadId() {
@@ -172,6 +190,10 @@ public class DownloadRequest implements Parcelable {
        return appName;
    }

    public int getVersion() {
        return version;
    }

    public static final Parcelable.Creator<DownloadRequest> CREATOR =
            new Parcelable.Creator<DownloadRequest>() {
        public DownloadRequest createFromParcel(Parcel in) {
@@ -181,4 +203,35 @@ public class DownloadRequest implements Parcelable {
            return new DownloadRequest[size];
        }
    };

    /**
     * @hide
     */
    public boolean isMultipartDownload() {
        // TODO: figure out what qualifies a request as a multipart download request.
        return getSourceUri().getLastPathSegment() != null &&
                getSourceUri().getLastPathSegment().contains("*");
    }

    /**
     * Retrieves the hash string that should be used as the filename when storing a token for
     * this DownloadRequest.
     * @hide
     */
    public String getHash() {
        MessageDigest digest;
        try {
            digest = MessageDigest.getInstance("SHA-256");
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("Could not get sha256 hash object");
        }
        if (version >= 1) {
            // Hash the source URI, destination URI, and the app intent
            digest.update(sourceUri.toString().getBytes(StandardCharsets.UTF_8));
            digest.update(destinationUri.toString().getBytes(StandardCharsets.UTF_8));
            digest.update(serializedResultIntentForApp.getBytes(StandardCharsets.UTF_8));
        }
        // Add updates for future versions here
        return Base64.encodeToString(digest.digest(), Base64.URL_SAFE | Base64.NO_WRAP);
    }
}
+17 −17
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ import java.util.UUID;
public class MbmsDownloadReceiver extends BroadcastReceiver {
    private static final String LOG_TAG = "MbmsDownloadReceiver";
    private static final String TEMP_FILE_SUFFIX = ".embms.temp";
    public static final String DOWNLOAD_TOKEN_SUFFIX = ".download_token";
    private static final int MAX_TEMP_FILE_RETRIES = 5;

    public static final String MBMS_FILE_PROVIDER_META_DATA_KEY = "mbms-file-provider-authority";
@@ -50,7 +51,7 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (!verifyIntentContents(intent)) {
        if (!verifyIntentContents(context, intent)) {
            setResultCode(1 /* TODO: define error constants */);
            return;
        }
@@ -69,7 +70,7 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {
        // TODO: Add handling for ACTION_CLEANUP
    }

    private boolean verifyIntentContents(Intent intent) {
    private boolean verifyIntentContents(Context context, Intent intent) {
        if (MbmsDownloadManager.ACTION_DOWNLOAD_RESULT_INTERNAL.equals(intent.getAction())) {
            if (!intent.hasExtra(MbmsDownloadManager.EXTRA_RESULT)) {
                Log.w(LOG_TAG, "Download result did not include a result code. Ignoring.");
@@ -93,8 +94,19 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {
                        "temp file. Ignoring.");
                return false;
            }
            DownloadRequest request = intent.getParcelableExtra(MbmsDownloadManager.EXTRA_REQUEST);
            String expectedTokenFileName = request.getHash() + DOWNLOAD_TOKEN_SUFFIX;
            File expectedTokenFile = new File(
                    MbmsUtils.getEmbmsTempFileDirForRequest(context, request),
                    expectedTokenFileName);
            if (!expectedTokenFile.exists()) {
                Log.w(LOG_TAG, "Supplied download request does not match a token that we have. " +
                        "Expected " + expectedTokenFile);
                return false;
            }
            return true;
        } else if (MbmsDownloadManager.ACTION_FILE_DESCRIPTOR_REQUEST.equals(intent.getAction())) {
            // TODO: get rid of the request argument for a file descriptor request.
            if (!intent.hasExtra(MbmsDownloadManager.EXTRA_REQUEST)) {
                Log.w(LOG_TAG, "Temp file request not include the associated request. Ignoring.");
                return false;
@@ -112,7 +124,6 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {

    private void moveDownloadedFile(Context context, Intent intent) {
        DownloadRequest request = intent.getParcelableExtra(MbmsDownloadManager.EXTRA_REQUEST);
        // TODO: check request against token
        Intent intentForApp = request.getIntentForApp();

        int result = intent.getIntExtra(MbmsDownloadManager.EXTRA_RESULT,
@@ -149,7 +160,6 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {
    }

    private void cleanupPostMove(Context context, Intent intent) {
        // TODO: account for in-use temp files
        DownloadRequest request = intent.getParcelableExtra(MbmsDownloadManager.EXTRA_REQUEST);
        if (request == null) {
            Log.w(LOG_TAG, "Intent does not include a DownloadRequest. Ignoring.");
@@ -199,7 +209,7 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {

    private ArrayList<UriPathPair> generateFreshTempFiles(Context context, DownloadRequest request,
            int freshFdCount) {
        File tempFileDir = getEmbmsTempFileDirForRequest(context, request);
        File tempFileDir = MbmsUtils.getEmbmsTempFileDirForRequest(context, request);
        if (!tempFileDir.exists()) {
            tempFileDir.mkdirs();
        }
@@ -345,24 +355,14 @@ public class MbmsDownloadReceiver extends BroadcastReceiver {
            return false;
        }

        if (!MbmsUtils.isContainedIn(getEmbmsTempFileDirForRequest(context, request), tempFile)) {
        if (!MbmsUtils.isContainedIn(
                MbmsUtils.getEmbmsTempFileDirForRequest(context, request), tempFile)) {
            return false;
        }

        return true;
    }

    /**
     * Returns a File linked to the directory used to store temp files for this request
     */
    private static File getEmbmsTempFileDirForRequest(Context context, DownloadRequest request) {
        File embmsTempFileDir = MbmsTempFileProvider.getEmbmsTempFileDir(context);

        // TODO: better naming scheme for temp file dirs
        String tempFileDirName = String.valueOf(request.getFileServiceInfo().getServiceId());
        return new File(embmsTempFileDir, tempFileDirName);
    }

    private String getFileProviderAuthorityCached(Context context) {
        if (mFileProviderAuthorityCache != null) {
            return mFileProviderAuthorityCache;
+10 −0
Original line number Diff line number Diff line
@@ -85,4 +85,14 @@ public class MbmsUtils {

        context.bindService(bindIntent, serviceConnection, Context.BIND_AUTO_CREATE);
    }

    /**
     * Returns a File linked to the directory used to store temp files for this request
     */
    public static File getEmbmsTempFileDirForRequest(Context context, DownloadRequest request) {
        File embmsTempFileDir = MbmsTempFileProvider.getEmbmsTempFileDir(context);

        String tempFileDirName = String.valueOf(request.getFileServiceInfo().getServiceId());
        return new File(embmsTempFileDir, tempFileDirName);
    }
}