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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.gecko.util;
import android.content.Intent;
import android.net.Uri;
import java.net.URISyntaxException;
import java.util.Locale;
/** Utilities for Intents. */
public class IntentUtils {
private IntentUtils() {}
/**
* Return a Uri instance which is equivalent to uri, but with a guaranteed-lowercase scheme as if
* the API level 16 method Uri.normalizeScheme had been called.
*
* @param uri The URI string to normalize.
* @return The corresponding normalized Uri.
*/
private static Uri normalizeUriScheme(final Uri uri) {
final String scheme = uri.getScheme();
if (scheme == null) {
return uri;
}
final String lower = scheme.toLowerCase(Locale.ROOT);
if (lower.equals(scheme)) {
return uri;
}
// Otherwise, return a new URI with a normalized scheme.
return uri.buildUpon().scheme(lower).build();
}
/**
* Return a normalized Uri instance that corresponds to the given URI string with cross-API-level
* compatibility.
*
* @param aUri The URI string to normalize.
* @return The corresponding normalized Uri.
*/
public static Uri normalizeUri(final String aUri) {
return normalizeUriScheme(
aUri.indexOf(':') >= 0 ? Uri.parse(aUri) : new Uri.Builder().scheme(aUri).build());
}
public static boolean isUriSafeForScheme(final String aUri) {
return isUriSafeForScheme(normalizeUri(aUri));
}
/**
* Verify whether the given URI is considered safe to load in respect to its scheme. Unsafe URIs
* should be blocked from further handling.
*
* @param aUri The URI instance to test.
* @return Whether the provided URI is considered safe in respect to its scheme.
*/
public static boolean isUriSafeForScheme(final Uri aUri) {
final String scheme = aUri.getScheme();
if ("tel".equals(scheme) || "sms".equals(scheme)) {
// dialer, and ensure the Uri class doesn't parse a URI
// containing a fragment ('#')
final String number = aUri.getSchemeSpecificPart();
if (number.contains("#") || number.contains("*") || aUri.getFragment() != null) {
return false;
}
}
if (("intent".equals(scheme) || "android-app".equals(scheme))) {
return getSafeIntent(aUri) != null;
}
return true;
}
/**
* Create a safe intent for the given URI. Intents with file data schemes are considered unsafe.
*
* @param aUri The URI for the intent.
* @return A safe intent for the given URI or null if URI is considered unsafe.
*/
public static Intent getSafeIntent(final Uri aUri) {
final Intent intent;
try {
intent = Intent.parseUri(aUri.toString(), 0);
} catch (final URISyntaxException e) {
return null;
}
final Uri data = intent.getData();
if (data != null && "file".equals(normalizeUriScheme(data).getScheme())) {
return null;
}
// Only open applications which can accept arbitrary data from a browser.
intent.addCategory(Intent.CATEGORY_BROWSABLE);
// Prevent site from explicitly opening our internal activities,
// which can leak data.
intent.setComponent(null);
nullIntentSelector(intent);
return intent;
}
// We create a separate method to better encapsulate the @TargetApi use.
private static void nullIntentSelector(final Intent intent) {
intent.setSelector(null);
}
}