base/android/java/src/org/chromium/base/IntentUtils.java

// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.base;

import android.app.PendingIntent;
import android.content.ActivityNotFoundException;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.os.BadParcelableException;
import android.os.Binder;
import android.os.Build;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.TransactionTooLargeException;
import android.text.TextUtils;

import androidx.annotation.Nullable;

import org.chromium.base.compat.ApiHelperForM;
import org.chromium.base.compat.ApiHelperForS;

import java.io.Serializable;
import java.util.ArrayList;

/** Utilities dealing with extracting information from intents and creating common intents. */
public class IntentUtils {
    private static final String TAG = "IntentUtils";

    /** The scheme for referrer coming from an application. */
    public static final String ANDROID_APP_REFERRER_SCHEME = "android-app";

    /** Intent extra used to identify the sending application. */
    public static final String TRUSTED_APPLICATION_CODE_EXTRA = "trusted_application_code_extra";

    /** Fake ComponentName used in constructing TRUSTED_APPLICATION_CODE_EXTRA. */
    private static ComponentName sFakeComponentName;

    private static final Object COMPONENT_NAME_LOCK = new Object();

    private static boolean sForceTrustedIntentForTesting;

    /** Just like {@link Intent#hasExtra(String)} but doesn't throw exceptions. */
    public static boolean safeHasExtra(Intent intent, String name) {
        try {
            return intent.hasExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "hasExtra failed on intent " + intent);
            return false;
        }
    }

    /** Just like {@link Intent#removeExtra(String)} but doesn't throw exceptions. */
    public static void safeRemoveExtra(Intent intent, String name) {
        try {
            intent.removeExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "removeExtra failed on intent " + intent);
        }
    }

    /** Just like {@link Intent#getBooleanExtra(String, boolean)} but doesn't throw exceptions. */
    public static boolean safeGetBooleanExtra(Intent intent, String name, boolean defaultValue) {
        try {
            return intent.getBooleanExtra(name, defaultValue);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getBooleanExtra failed on intent " + intent);
            return defaultValue;
        }
    }

    /** Just like {@link Bundle#getBoolean(String, boolean)} but doesn't throw exceptions. */
    public static boolean safeGetBoolean(Bundle bundle, String name, boolean defaultValue) {
        try {
            return bundle.getBoolean(name, defaultValue);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getBoolean failed on bundle " + bundle);
            return defaultValue;
        }
    }

    /** Just like {@link Intent#getIntExtra(String, int)} but doesn't throw exceptions. */
    public static int safeGetIntExtra(Intent intent, String name, int defaultValue) {
        try {
            return intent.getIntExtra(name, defaultValue);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getIntExtra failed on intent " + intent);
            return defaultValue;
        }
    }

    /** Just like {@link Bundle#getInt(String, int)} but doesn't throw exceptions. */
    public static int safeGetInt(Bundle bundle, String name, int defaultValue) {
        try {
            return bundle.getInt(name, defaultValue);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getInt failed on bundle " + bundle);
            return defaultValue;
        }
    }

    /** Just like {@link Intent#getIntArrayExtra(String)} but doesn't throw exceptions. */
    public static int[] safeGetIntArrayExtra(Intent intent, String name) {
        try {
            return intent.getIntArrayExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getIntArrayExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just like {@link Bundle#getIntArray(String)} but doesn't throw exceptions. */
    public static int[] safeGetIntArray(Bundle bundle, String name) {
        try {
            return bundle.getIntArray(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getIntArray failed on bundle " + bundle);
            return null;
        }
    }

    /** Just like {@link Bundle#getFloatArray(String)} but doesn't throw exceptions. */
    public static float[] safeGetFloatArray(Bundle bundle, String name) {
        try {
            return bundle.getFloatArray(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getFloatArray failed on bundle " + bundle);
            return null;
        }
    }

    /** Just like {@link Intent#getLongExtra(String, long)} but doesn't throw exceptions. */
    public static long safeGetLongExtra(Intent intent, String name, long defaultValue) {
        try {
            return intent.getLongExtra(name, defaultValue);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getLongExtra failed on intent " + intent);
            return defaultValue;
        }
    }

    /** Just like {@link Intent#getStringExtra(String)} but doesn't throw exceptions. */
    public static String safeGetStringExtra(Intent intent, String name) {
        try {
            return intent.getStringExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getStringExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just like {@link Bundle#getString(String)} but doesn't throw exceptions. */
    public static String safeGetString(Bundle bundle, String name) {
        try {
            return bundle.getString(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getString failed on bundle " + bundle);
            return null;
        }
    }

    /** Just like {@link Intent#getBundleExtra(String)} but doesn't throw exceptions. */
    public static Bundle safeGetBundleExtra(Intent intent, String name) {
        try {
            return intent.getBundleExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getBundleExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just like {@link Bundle#getBundle(String)} but doesn't throw exceptions. */
    public static Bundle safeGetBundle(Bundle bundle, String name) {
        try {
            return bundle.getBundle(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getBundle failed on bundle " + bundle);
            return null;
        }
    }

    /** Just like {@link Bundle#getParcelable(String)} but doesn't throw exceptions. */
    public static <T extends Parcelable> T safeGetParcelable(Bundle bundle, String name) {
        try {
            return bundle.getParcelable(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getParcelable failed on bundle " + bundle);
            return null;
        }
    }

    /** Just like {@link Intent#getParcelableExtra(String)} but doesn't throw exceptions. */
    public static <T extends Parcelable> T safeGetParcelableExtra(Intent intent, String name) {
        try {
            return intent.getParcelableExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getParcelableExtra failed on intent " + intent);
            return null;
        }
    }

    /**
     * Just link {@link Intent#getParcelableArrayListExtra(String)} but doesn't throw exceptions.
     */
    public static <T extends Parcelable> ArrayList<T> getParcelableArrayListExtra(
            Intent intent, String name) {
        try {
            return intent.getParcelableArrayListExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getParcelableArrayListExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just link {@link Bundle#getParcelableArrayList(String)} but doesn't throw exceptions. */
    public static <T extends Parcelable> ArrayList<T> safeGetParcelableArrayList(
            Bundle bundle, String name) {
        try {
            return bundle.getParcelableArrayList(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getParcelableArrayList failed on bundle " + bundle);
            return null;
        }
    }

    /** Just like {@link Intent#getParcelableArrayExtra(String)} but doesn't throw exceptions. */
    public static Parcelable[] safeGetParcelableArrayExtra(Intent intent, String name) {
        try {
            return intent.getParcelableArrayExtra(name);
        } catch (Throwable t) {
            Log.e(TAG, "getParcelableArrayExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just like {@link Intent#getStringArrayListExtra(String)} but doesn't throw exceptions. */
    public static ArrayList<String> safeGetStringArrayListExtra(Intent intent, String name) {
        try {
            return intent.getStringArrayListExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getStringArrayListExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just like {@link Intent#getByteArrayExtra(String)} but doesn't throw exceptions. */
    public static byte[] safeGetByteArrayExtra(Intent intent, String name) {
        try {
            return intent.getByteArrayExtra(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getByteArrayExtra failed on intent " + intent);
            return null;
        }
    }

    /** Just like {@link Intent#getSerializableExtra(String)} but doesn't throw exceptions. */
    @SuppressWarnings("unchecked")
    public static <T extends Serializable> T safeGetSerializableExtra(Intent intent, String name) {
        try {
            return (T) intent.getSerializableExtra(name);
        } catch (ClassCastException ex) {
            Log.e(TAG, "Invalide class for Serializable: " + name, ex);
            return null;
        } catch (Throwable t) {
            // Catches un-serializable exceptions.
            Log.e(TAG, "getSerializableExtra failed on intent " + intent);
            return null;
        }
    }

    /**
     * Returns the value associated with the given name, or null if no mapping of the desired type
     * exists for the given name or a null value is explicitly associated with the name.
     *
     * @param name a key string
     * @return an IBinder value, or null
     */
    public static IBinder safeGetBinder(Bundle bundle, String name) {
        if (bundle == null) return null;
        try {
            return bundle.getBinder(name);
        } catch (Throwable t) {
            // Catches un-parceling exceptions.
            Log.e(TAG, "getBinder failed on bundle " + bundle);
            return null;
        }
    }

    /**
     * @return a Binder from an Intent, or null.
     *
     * Creates a temporary copy of the extra Bundle, which is required as
     * Intent#getBinderExtra() doesn't exist, but Bundle.getBinder() does.
     */
    public static IBinder safeGetBinderExtra(Intent intent, String name) {
        if (!intent.hasExtra(name)) return null;
        Bundle extras = intent.getExtras();
        return safeGetBinder(extras, name);
    }

    /**
     * Inserts a {@link Binder} value into an Intent as an extra.
     *
     * @param intent Intent to put the binder into.
     * @param name Key.
     * @param binder Binder object.
     */
    public static void safePutBinderExtra(Intent intent, String name, IBinder binder) {
        if (intent == null) return;
        Bundle bundle = new Bundle();
        try {
            bundle.putBinder(name, binder);
        } catch (Throwable t) {
            // Catches parceling exceptions.
            Log.e(TAG, "putBinder failed on bundle " + bundle);
        }
        intent.putExtras(bundle);
    }

    /** See {@link #safeStartActivity(Context, Intent, Bundle)}. */
    public static boolean safeStartActivity(Context context, Intent intent) {
        return safeStartActivity(context, intent, null);
    }

    /**
     * Catches any failures to start an Activity.
     * @param context Context to use when starting the Activity.
     * @param intent  Intent to fire.
     * @param bundle  Bundle of launch options.
     * @return Whether or not Android accepted the Intent.
     */
    public static boolean safeStartActivity(
            Context context, Intent intent, @Nullable Bundle bundle) {
        try {
            context.startActivity(intent, bundle);
            return true;
        } catch (ActivityNotFoundException e) {
            return false;
        }
    }

    /** Returns whether the intent starts an activity in a new task or a new document. */
    public static boolean isIntentForNewTaskOrNewDocument(Intent intent) {
        int testFlags = Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_NEW_DOCUMENT;
        return (intent.getFlags() & testFlags) != 0;
    }

    /**
     * Returns how large the Intent will be in Parcel form, which is helpful for gauging whether
     * Android will deliver the Intent instead of throwing a TransactionTooLargeException.
     *
     * @param intent Intent to get the size of.
     * @return Number of bytes required to parcel the Intent.
     */
    public static int getParceledIntentSize(Intent intent) {
        Parcel parcel = Parcel.obtain();
        intent.writeToParcel(parcel, 0);
        return parcel.dataSize();
    }

    /**
     * Given an exception, check whether it wrapped a {@link TransactionTooLargeException}.  If it
     * does, then log the underlying error.  If not, throw the original exception again.
     *
     * @param e      The caught RuntimeException.
     * @param intent The intent that triggered the RuntimeException to be thrown.
     */
    public static void logTransactionTooLargeOrRethrow(RuntimeException e, Intent intent) {
        // See http://crbug.com/369574.
        if (e.getCause() instanceof TransactionTooLargeException) {
            Log.e(TAG, "Could not resolve Activity for intent " + intent.toString(), e);
        } else {
            throw e;
        }
    }

    private static Intent logInvalidIntent(Intent intent, Exception e) {
        Log.e(TAG, "Invalid incoming intent.", e);
        return intent.replaceExtras((Bundle) null);
    }

    /**
     * Sanitizes an intent. In case the intent cannot be unparcelled, all extras will be removed to
     * make it safe to use.
     * @return A safe to use version of this intent.
     */
    public static Intent sanitizeIntent(final Intent incomingIntent) {
        // On Android T+, items are only deserialized when the items themselves are queried, so the
        // code below is a no-op.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) return incomingIntent;
        if (incomingIntent == null) return null;
        try {
            incomingIntent.getBooleanExtra("TriggerUnparcel", false);
            return incomingIntent;
        } catch (BadParcelableException e) {
            return logInvalidIntent(incomingIntent, e);
        } catch (RuntimeException e) {
            if (e.getCause() instanceof ClassNotFoundException) {
                return logInvalidIntent(incomingIntent, e);
            }
            throw e;
        }
    }

    /**
     * @return True if the intent is a MAIN intent a launcher would send.
     */
    public static boolean isMainIntentFromLauncher(Intent intent) {
        return intent != null
                && TextUtils.equals(intent.getAction(), Intent.ACTION_MAIN)
                && intent.hasCategory(Intent.CATEGORY_LAUNCHER)
                && 0 == (intent.getFlags() & Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY);
    }

    /**
     * Gets the PendingIntent flag for the specified mutability.
     * PendingIntent.FLAG_IMMUTABLE was added in API level 23 (M), and FLAG_MUTABLE was added in
     * Android S.
     *
     * Unless mutability is required, PendingIntents should always be marked as Immutable as this
     * is the more secure default.
     */
    public static int getPendingIntentMutabilityFlag(boolean mutable) {
        if (!mutable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            return ApiHelperForM.getPendingIntentImmutableFlag();
        } else if (mutable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            return ApiHelperForS.getPendingIntentMutableFlag();
        }
        return 0;
    }

    /**
     * Determines whether this app is the only possible handler for this Intent.
     *
     * @param context Any context for this app.
     * @param intent The intent to check.
     * @return True if the intent targets this app.
     */
    public static boolean intentTargetsSelf(Context context, Intent intent) {
        boolean hasPackage = !TextUtils.isEmpty(intent.getPackage());
        boolean matchesPackage = hasPackage && context.getPackageName().equals(intent.getPackage());
        boolean hasComponent = intent.getComponent() != null;
        boolean matchesComponent =
                hasComponent
                        && context.getPackageName().equals(intent.getComponent().getPackageName());

        // Component takes precedence over PackageName when routing Intents if both are set, but to
        // be on the safe side, ensure that if we have both package and component set, that they
        // agree.
        if (matchesComponent) {
            if (hasPackage) {
                // We should not create intents that disagree on package/component, but for security
                // purposes we should handle this case.
                assert matchesPackage;
                return matchesPackage;
            }
            return true;
        }
        if (matchesPackage) {
            assert !hasComponent;
            return !hasComponent;
        }
        return false;
    }

    private static ComponentName getFakeComponentName(String packageName) {
        synchronized (COMPONENT_NAME_LOCK) {
            if (sFakeComponentName == null) {
                sFakeComponentName = new ComponentName(packageName, "FakeClass");
            }
        }

        return sFakeComponentName;
    }

    private static PendingIntent getAuthenticationToken() {
        Intent fakeIntent = new Intent();
        Context appContext = ContextUtils.getApplicationContext();
        fakeIntent.setComponent(getFakeComponentName(appContext.getPackageName()));
        return PendingIntent.getActivity(
                appContext, 0, fakeIntent, getPendingIntentMutabilityFlag(false));
    }

    /**
     * Sets TRUSTED_APPLICATION_CODE_EXTRA on the provided intent to identify it as coming from
     * a trusted source.
     *
     * @param intent An Intent that targets either current package, or explicitly targets a
     *         component of the current package.
     */
    public static void addTrustedIntentExtras(Intent intent) {
        // It is crucial that we never leak the authentication token to other packages, because
        // then the other package could be used to impersonate us/do things as us.
        boolean toSelf =
                IntentUtils.intentTargetsSelf(ContextUtils.getApplicationContext(), intent);
        assert toSelf;
        // For security reasons we have to check the asserted condition anyways.
        if (!toSelf) return;

        // The PendingIntent functions as an authentication token --- it could only have come
        // from us. Stash it in the real Intent as an extra we can validate upon receiving it.
        intent.putExtra(TRUSTED_APPLICATION_CODE_EXTRA, getAuthenticationToken());
    }

    /**
     * @param intent An Intent to be checked.
     * @return Whether an intent originates from the current app.
     */
    public static boolean isTrustedIntentFromSelf(@Nullable Intent intent) {
        if (intent == null) return false;

        if (sForceTrustedIntentForTesting) return true;

        // Fetch the authentication token (a PendingIntent) created by
        // addTrustedIntentExtras, if any. If anything goes wrong trying to retrieve the
        // token (examples include BadParcelableException or ClassNotFoundException), fail closed.
        PendingIntent token =
                IntentUtils.safeGetParcelableExtra(intent, TRUSTED_APPLICATION_CODE_EXTRA);
        if (token == null) return false;

        // Fetch what should be a matching token. If the PendingIntents are equal, we know that the
        // sender was us.
        PendingIntent pending = getAuthenticationToken();
        return pending.equals(token);
    }

    public static void setForceIsTrustedIntentForTesting(boolean isTrusted) {
        sForceTrustedIntentForTesting = isTrusted;
        ResettersForTesting.register(() -> sForceTrustedIntentForTesting = false);
    }
}