From da113638122dc1d9e8b3b621ca1c7740b3752d1c Mon Sep 17 00:00:00 2001
From: Adrian Roos <roosa@google.com>
Date: Wed, 4 Jun 2014 15:53:14 +0200
Subject: [PATCH] Ensure trust agents are only provided by platform packages

Ensures that Settings only shows TrustAgentServices from
platform packages.

Bug: 15287044
Change-Id: I62c131d99c7266f8617ec32a50a4f5549a07b4b7
---
 .../settings/AdvancedSecuritySettings.java     |  1 +
 src/com/android/settings/SecuritySettings.java |  1 +
 src/com/android/settings/TrustAgentUtils.java  | 18 ++++++++++++++++++
 3 files changed, 20 insertions(+)

diff --git a/src/com/android/settings/AdvancedSecuritySettings.java b/src/com/android/settings/AdvancedSecuritySettings.java
index c497ac44e11..2a8c623e83e 100644
--- a/src/com/android/settings/AdvancedSecuritySettings.java
+++ b/src/com/android/settings/AdvancedSecuritySettings.java
@@ -109,6 +109,7 @@ public class AdvancedSecuritySettings extends ListFragment implements View.OnCli
 
         for (ResolveInfo resolveInfo : resolveInfos) {
             if (resolveInfo.serviceInfo == null) continue;
+            if (!TrustAgentUtils.checkProvidePermission(resolveInfo, pm)) continue;
             ComponentName name = TrustAgentUtils.getComponentName(resolveInfo);
             if (!mAvailableAgents.containsKey(name)) {
                 AgentInfo agentInfo = new AgentInfo();
diff --git a/src/com/android/settings/SecuritySettings.java b/src/com/android/settings/SecuritySettings.java
index ab03853711a..b35a362d8c8 100644
--- a/src/com/android/settings/SecuritySettings.java
+++ b/src/com/android/settings/SecuritySettings.java
@@ -317,6 +317,7 @@ public class SecuritySettings extends RestrictedSettingsFragment
                     PackageManager.GET_META_DATA);
             for (ResolveInfo resolveInfo : resolveInfos) {
                 if (resolveInfo.serviceInfo == null) continue;
+                if (!TrustAgentUtils.checkProvidePermission(resolveInfo, pm)) continue;
                 TrustAgentUtils.TrustAgentComponentInfo trustAgentComponentInfo =
                         TrustAgentUtils.getSettingsComponent(pm, resolveInfo);
                 if (trustAgentComponentInfo.componentName == null ||
diff --git a/src/com/android/settings/TrustAgentUtils.java b/src/com/android/settings/TrustAgentUtils.java
index 64829a20074..f1713abfe6b 100644
--- a/src/com/android/settings/TrustAgentUtils.java
+++ b/src/com/android/settings/TrustAgentUtils.java
@@ -16,6 +16,8 @@
 
 package com.android.settings;
 
+import com.android.internal.Manifest;
+
 import android.content.ComponentName;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
@@ -24,6 +26,7 @@ import android.content.res.TypedArray;
 import android.content.res.XmlResourceParser;
 import android.service.trust.TrustAgentService;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.util.Slog;
 import android.util.Xml;
 
@@ -36,6 +39,21 @@ public class TrustAgentUtils {
     static final String TAG = "TrustAgentUtils";
 
     private static final String TRUST_AGENT_META_DATA = TrustAgentService.TRUST_AGENT_META_DATA;
+    private static final String PERMISSION_PROVIDE_AGENT = Manifest.permission.PROVIDE_TRUST_AGENT;
+
+    /**
+     * @return true, if the service in resolveInfo has the permission to provide a trust agent.
+     */
+    public static boolean checkProvidePermission(ResolveInfo resolveInfo, PackageManager pm) {
+        String packageName = resolveInfo.serviceInfo.packageName;
+        if (pm.checkPermission(PERMISSION_PROVIDE_AGENT, packageName)
+                != PackageManager.PERMISSION_GRANTED) {
+            Log.w(TAG, "Skipping agent because package " + packageName
+                    + " does not have permission " + PERMISSION_PROVIDE_AGENT + ".");
+            return false;
+        }
+        return true;
+    }
 
     public static class TrustAgentComponentInfo {
         ComponentName componentName;