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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
package org.mozilla.geckoview;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ProviderInfo;
import android.content.res.AssetFileDescriptor;
import android.net.Uri;
import android.os.Process;
import android.util.Log;
import androidx.annotation.AnyThread;
import androidx.annotation.NonNull;
import java.io.IOException;
import org.mozilla.gecko.GeckoAppShell;
import org.mozilla.gecko.annotation.WrapForJNI;
/**
* This class provides an {@link OutputStream} wrapper for a Gecko nsIOutputStream (or really,
* nsIRequest).
*/
/* package */ class ContentInputStream extends GeckoViewInputStream {
private static final String LOGTAG = "ContentInputStream";
private static final byte[][] HEADERS = {{'%', 'P', 'D', 'F', '-'}};
private AssetFileDescriptor mFd;
ContentInputStream(final @NonNull String aUri) {
final Uri uri = Uri.parse(aUri);
final Context context = GeckoAppShell.getApplicationContext();
final ContentResolver cr = context.getContentResolver();
try {
mFd = cr.openAssetFileDescriptor(uri, "r");
if (mFd == null) {
Log.e(LOGTAG, "Cannot open the uri: " + aUri + " (no file descriptor)");
close();
return;
}
setInputStream(mFd.createInputStream());
if (!checkHeaders(HEADERS)) {
Log.e(LOGTAG, "Cannot open the uri: " + aUri + " (invalid header)");
close();
}
} catch (final Exception e) {
Log.e(LOGTAG, "Cannot open the uri: " + aUri, e);
close();
}
}
@Override
public void close() {
if (mFd != null) {
try {
mFd.close();
} catch (final IOException e) {
Log.e(LOGTAG, "Cannot close the file descriptor", e);
} finally {
mFd = null;
}
}
super.close();
}
private static boolean isExported(final @NonNull Context aCtx, final @NonNull Uri aUri) {
// For reference:
final String authority = aUri.getAuthority();
final PackageManager packageManager = aCtx.getPackageManager();
if (authority == null || packageManager == null) {
return false;
}
final ProviderInfo info = packageManager.resolveContentProvider(authority, 0);
if (info == null) {
return false;
}
// We check that the provider is exported:
return info.exported;
}
private static boolean wasGrantedPermission(
final @NonNull Context aCtx, final @NonNull Uri aUri) {
// For reference:
final int pid = Process.myPid();
final int uid = Process.myUid();
return aCtx.checkUriPermission(aUri, pid, uid, Intent.FLAG_GRANT_READ_URI_PERMISSION)
== PackageManager.PERMISSION_GRANTED;
}
private static boolean belongsToCurrentApplication(
final @NonNull Context aCtx, final @NonNull Uri aUri) {
// For reference:
final String authority = aUri.getAuthority();
final PackageManager packageManager = aCtx.getPackageManager();
if (authority == null || packageManager == null) {
return false;
}
final ProviderInfo info = packageManager.resolveContentProvider(authority, 0);
if (info == null) {
return false;
}
// We check that the provider is GV itself (when testing GV, the provider is GV itself).
final String packageName = aCtx.getPackageName();
return packageName != null && packageName.equals(info.packageName);
}
@WrapForJNI
@AnyThread
private static boolean isReadable(final @NonNull String aUri) {
final Uri uri = Uri.parse(aUri);
final Context context = GeckoAppShell.getApplicationContext();
try {
// The check for this criteria is based on recommendations in
// The documentation recommends checking:
// 1. If URI targets our app (belongsToCurrentApplication)
// 2. OR if targeted provider is exported (isExported)
// 3. OR if granted explicit permission (wasGrantedPermission)
if (belongsToCurrentApplication(context, uri)
|| isExported(context, uri)
|| wasGrantedPermission(context, uri)) {
final ContentResolver cr = context.getContentResolver();
if (cr == null) {
Log.e(LOGTAG, "No content resolver");
return false;
}
final AssetFileDescriptor fd = cr.openAssetFileDescriptor(uri, "r");
if (fd == null) {
// The descriptor can be null because the provider crashed.
Log.e(LOGTAG, "No asset file descriptor");
return false;
}
fd.close();
Log.d(LOGTAG, "The uri is readable: " + uri);
return true;
}
} catch (final Exception e) {
// A SecurityException could happen if the uri is no more valid or if
// we're in an isolated process.
Log.e(LOGTAG, "Cannot read the uri: " + uri, e);
}
Log.d(LOGTAG, "The uri isn't readable: " + uri);
return false;
}
@WrapForJNI
@AnyThread
private static @NonNull GeckoViewInputStream getInstance(final @NonNull String aUri) {
return new ContentInputStream(aUri);
}
}