From 1c448eaab91a48abe4868828446c4e81bbda1656 Mon Sep 17 00:00:00 2001
From: Christopher Tate <ctate@google.com>
Date: Tue, 17 Dec 2019 11:21:02 -0800
Subject: [PATCH] Revoke 'always' web handler status when not autoverifying

If an app has previously used autoVerify to make claims about its status
re handling web navigation intents, but is updated such that it no
longer makes those claims, step down its "official handler" status as
though it had never invoked autoVerify in the first place.

Bug: 146204120
Test: manual: as described in bug; observe policy before/after via
      'adb shell dumpsys package d'
Test: atest CtsOsHostTestCases
Change-Id: I58502d1b32d793aba9aa772fa2ad5ac38acca48a
---
 .../server/pm/PackageManagerService.java      | 46 +++++++++++++------
 .../java/com/android/server/pm/Settings.java  |  1 +
 2 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index cb362b0f0a23a..7205c328e503c 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -249,7 +249,6 @@ import android.os.storage.VolumeInfo;
 import android.os.storage.VolumeRecord;
 import android.permission.IPermissionManager;
 import android.provider.DeviceConfig;
-import android.provider.MediaStore;
 import android.provider.Settings.Global;
 import android.provider.Settings.Secure;
 import android.security.KeyStore;
@@ -16629,37 +16628,48 @@ public class PackageManagerService extends IPackageManager.Stub
                 + " Activities needs verification ...");
 
         int count = 0;
-
+        boolean handlesWebUris = false;
+        final boolean alreadyVerified;
         synchronized (mLock) {
             // If this is a new install and we see that we've already run verification for this
             // package, we have nothing to do: it means the state was restored from backup.
-            if (!replacing) {
-                IntentFilterVerificationInfo ivi =
-                        mSettings.getIntentFilterVerificationLPr(packageName);
-                if (ivi != null) {
-                    if (DEBUG_DOMAIN_VERIFICATION) {
-                        Slog.i(TAG, "Package " + packageName+ " already verified: status="
-                                + ivi.getStatusString());
-                    }
-                    return;
+            final IntentFilterVerificationInfo ivi =
+                    mSettings.getIntentFilterVerificationLPr(packageName);
+            alreadyVerified = (ivi != null);
+            if (!replacing && alreadyVerified) {
+                if (DEBUG_DOMAIN_VERIFICATION) {
+                    Slog.i(TAG, "Package " + packageName + " already verified: status="
+                            + ivi.getStatusString());
                 }
+                return;
             }
 
-            // If any filters need to be verified, then all need to be.
+            // If any filters need to be verified, then all need to be.  In addition, we need to
+            // know whether an updating app has any web navigation intent filters, to re-
+            // examine handling policy even if not re-verifying.
             boolean needToVerify = false;
             for (ParsedActivity a : activities) {
                 for (ParsedActivityIntentInfo filter : a.intents) {
+                    if (filter.handlesWebUris(true)) {
+                        handlesWebUris = true;
+                    }
                     if (filter.needsVerification() && needsNetworkVerificationLPr(filter)) {
                         if (DEBUG_DOMAIN_VERIFICATION) {
                             Slog.d(TAG,
                                     "Intent filter needs verification, so processing all filters");
                         }
                         needToVerify = true;
+                        // It's safe to break out here because filter.needsVerification()
+                        // can only be true if filter.handlesWebUris(true) returns true, so
+                        // we've already noted that.
                         break;
                     }
                 }
             }
 
+            // Note whether this app publishes any web navigation handling support at all,
+            // and whether there are any web-nav filters that fit the profile for running
+            // a verification pass now.
             if (needToVerify) {
                 final int verificationId = mIntentFilterVerificationToken++;
                 for (ParsedActivity a : activities) {
@@ -16677,13 +16687,23 @@ public class PackageManagerService extends IPackageManager.Stub
         }
 
         if (count > 0) {
+            // count > 0 means that we're running a full verification pass
             if (DEBUG_DOMAIN_VERIFICATION) Slog.d(TAG, "Starting " + count
                     + " IntentFilter verification" + (count > 1 ? "s" : "")
                     +  " for userId:" + userId);
             mIntentFilterVerifier.startVerifications(userId);
+        } else if (alreadyVerified && handlesWebUris) {
+            // App used autoVerify in the past, no longer does, but still handles web
+            // navigation starts.
+            if (DEBUG_DOMAIN_VERIFICATION) {
+                Slog.d(TAG, "App changed web filters but no longer verifying - resetting policy");
+            }
+            synchronized (mLock) {
+                clearIntentFilterVerificationsLPw(packageName, userId);
+            }
         } else {
             if (DEBUG_DOMAIN_VERIFICATION) {
-                Slog.d(TAG, "No filters or not all autoVerify for " + packageName);
+                Slog.d(TAG, "No web filters or no prior verify policy for " + packageName);
             }
         }
     }
diff --git a/services/core/java/com/android/server/pm/Settings.java b/services/core/java/com/android/server/pm/Settings.java
index 6653011b8b222..9642a1a21cf30 100644
--- a/services/core/java/com/android/server/pm/Settings.java
+++ b/services/core/java/com/android/server/pm/Settings.java
@@ -1249,6 +1249,7 @@ public final class Settings {
             return false;
         }
         ps.clearDomainVerificationStatusForUser(userId);
+        ps.setIntentFilterVerificationInfo(null);
         return true;
     }