More flexible API enforcement policy.

This CL adds the basics to set black, dark gray or light gray list
enforcement, rather than just black as before. It's not possible to
actually set the policy per-package yet.

PackageDexOptimizer still uses a single bit, for API checks on/off, rather
than the new enum. It assumes blacklist enforcement internally. This can
be improved in a follow up CL.

(cherry-picked from commit e52130ae4cf3b046b38a09fc7cc7712f5b7fb83d)

Test: m
Test: Boot device

BUG: 73337509
Change-Id: Ieb4bd9cc439c6a5b8fb9424d8902d8b46aec309f
Merged-In: Idd73c9938592c5c4d67cfb9efefdffed0dd5f262

4 files changed, 107 insertions, 15 deletions

diff --git a/core/java/android/content/pm/ApplicationInfo.java b/core/java/android/content/pm/ApplicationInfo.java
index 387a836e6961..e85058df8250 100644
--- a/core/java/android/content/pm/ApplicationInfo.java
+++ b/core/java/android/content/pm/ApplicationInfo.java
@@ -1101,6 +1101,58 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
     /** @hide */
     public String[] splitClassLoaderNames;
 
+    /**
+     * Represents the default policy. The actual policy used will depend on other properties of
+     * the application, e.g. the target SDK version.
+     * @hide
+     */
+    public static final int HIDDEN_API_ENFORCEMENT_DEFAULT = -1;
+    /**
+     * No API enforcement; the app can access the entire internal private API. Only for use by
+     * system apps.
+     * @hide
+     */
+    public static final int HIDDEN_API_ENFORCEMENT_NONE = 0;
+    /**
+     * Light grey list enforcement, the strictest option. Enforces the light grey, dark grey and
+     * black lists.
+     * @hide
+     * */
+    public static final int HIDDEN_API_ENFORCEMENT_ALL_LISTS = 1;
+    /**
+     * Dark grey list enforcement. Enforces the dark grey and black lists
+     * @hide
+     */
+    public static final int HIDDEN_API_ENFORCEMENT_DARK_GREY_AND_BLACK = 2;
+    /**
+     * Blacklist enforcement only.
+     * @hide
+     */
+    public static final int HIDDEN_API_ENFORCEMENT_BLACK = 3;
+
+    private static final int HIDDEN_API_ENFORCEMENT_MAX = HIDDEN_API_ENFORCEMENT_BLACK;
+
+    /**
+     * Values in this IntDef MUST be kept in sync with enum hiddenapi::EnforcementPolicy in
+     * art/runtime/hidden_api.h
+     * @hide
+     */
+    @IntDef(prefix = { "HIDDEN_API_ENFORCEMENT_" }, value = {
+            HIDDEN_API_ENFORCEMENT_DEFAULT,
+            HIDDEN_API_ENFORCEMENT_NONE,
+            HIDDEN_API_ENFORCEMENT_ALL_LISTS,
+            HIDDEN_API_ENFORCEMENT_DARK_GREY_AND_BLACK,
+            HIDDEN_API_ENFORCEMENT_BLACK,
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface HiddenApiEnforcementPolicy {}
+
+    private boolean isValidHiddenApiEnforcementPolicy(int policy) {
+        return policy >= HIDDEN_API_ENFORCEMENT_DEFAULT && policy <= HIDDEN_API_ENFORCEMENT_MAX;
+    }
+
+    private int mHiddenApiPolicy = HIDDEN_API_ENFORCEMENT_DEFAULT;
+
     public void dump(Printer pw, String prefix) {
         dump(pw, prefix, DUMP_FLAG_ALL);
     }
@@ -1188,7 +1240,7 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
             if (category != CATEGORY_UNDEFINED) {
                 pw.println(prefix + "category=" + category);
             }
-            pw.println(prefix + "isAllowedToUseHiddenApi=" + isAllowedToUseHiddenApi());
+            pw.println(prefix + "HiddenApiEnforcementPolicy=" + getHiddenApiEnforcementPolicy());
         }
         super.dumpBack(pw, prefix);
     }
@@ -1386,6 +1438,7 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
         appComponentFactory = orig.appComponentFactory;
         compileSdkVersion = orig.compileSdkVersion;
         compileSdkVersionCodename = orig.compileSdkVersionCodename;
+        mHiddenApiPolicy = orig.mHiddenApiPolicy;
     }
 
     public String toString() {
@@ -1459,6 +1512,7 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
         dest.writeInt(compileSdkVersion);
         dest.writeString(compileSdkVersionCodename);
         dest.writeString(appComponentFactory);
+        dest.writeInt(mHiddenApiPolicy);
     }
 
     public static final Parcelable.Creator<ApplicationInfo> CREATOR
@@ -1529,6 +1583,7 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
         compileSdkVersion = source.readInt();
         compileSdkVersionCodename = source.readString();
         appComponentFactory = source.readString();
+        mHiddenApiPolicy = source.readInt();
     }
 
     /**
@@ -1599,13 +1654,31 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
         }
     }
 
+    private boolean isPackageWhitelistedForHiddenApis() {
+        return SystemConfig.getInstance().getHiddenApiWhitelistedApps().contains(packageName);
+    }
+
     /**
      * @hide
      */
-    public boolean isAllowedToUseHiddenApi() {
-        boolean whitelisted =
-                SystemConfig.getInstance().getHiddenApiWhitelistedApps().contains(packageName);
-        return whitelisted && (isSystemApp() || isUpdatedSystemApp());
+    public @HiddenApiEnforcementPolicy int getHiddenApiEnforcementPolicy() {
+        if (mHiddenApiPolicy != HIDDEN_API_ENFORCEMENT_DEFAULT) {
+            return mHiddenApiPolicy;
+        }
+        if (isPackageWhitelistedForHiddenApis() && (isSystemApp() || isUpdatedSystemApp())) {
+            return HIDDEN_API_ENFORCEMENT_NONE;
+        }
+        return HIDDEN_API_ENFORCEMENT_BLACK;
+    }
+
+    /**
+     * @hide
+     */
+    public void setHiddenApiEnforcementPolicy(@HiddenApiEnforcementPolicy int policy) {
+        if (!isValidHiddenApiEnforcementPolicy(policy)) {
+            throw new IllegalArgumentException("Invalid API enforcement policy: " + policy);
+        }
+        mHiddenApiPolicy = policy;
     }
 
     /**
diff --git a/core/java/com/android/internal/os/Zygote.java b/core/java/com/android/internal/os/Zygote.java
index 28a7c1204071..cbd3ad5980f5 100644
--- a/core/java/com/android/internal/os/Zygote.java
+++ b/core/java/com/android/internal/os/Zygote.java
@@ -53,10 +53,21 @@ public final class Zygote {
     public static final int DISABLE_VERIFIER = 1 << 9;
     /** Only use oat files located in /system. Otherwise use dex/jar/apk . */
     public static final int ONLY_USE_SYSTEM_OAT_FILES = 1 << 10;
-    /** Do enfore hidden API access restrictions. */
-    public static final int ENABLE_HIDDEN_API_CHECKS = 1 << 11;
     /** Force generation of native debugging information for backtraces. */
-    public static final int DEBUG_GENERATE_MINI_DEBUG_INFO = 1 << 12;
+    public static final int DEBUG_GENERATE_MINI_DEBUG_INFO = 1 << 11;
+    /**
+     * Hidden API access restrictions. This is a mask for bits representing the API enforcement
+     * policy, defined by {@code @ApplicationInfo.HiddenApiEnforcementPolicy}.
+     */
+    public static final int API_ENFORCEMENT_POLICY_MASK = (1 << 12) | (1 << 13);
+    /**
+     * Bit shift for use with {@link #API_ENFORCEMENT_POLICY_MASK}.
+     *
+     * (flags & API_ENFORCEMENT_POLICY_MASK) >> API_ENFORCEMENT_POLICY_SHIFT gives
+     * @ApplicationInfo.ApiEnforcementPolicy values.
+     */
+    public static final int API_ENFORCEMENT_POLICY_SHIFT =
+            Integer.numberOfTrailingZeros(API_ENFORCEMENT_POLICY_MASK);
 
     /** No external storage should be mounted. */
     public static final int MOUNT_EXTERNAL_NONE = IVold.REMOUNT_MODE_NONE;
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index fb8f7491e726..e96a17d45644 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -283,6 +283,7 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.pm.ActivityInfo;
 import android.content.pm.ApplicationInfo;
+import android.content.pm.ApplicationInfo.HiddenApiEnforcementPolicy;
 import android.content.pm.ConfigurationInfo;
 import android.content.pm.IPackageDataObserver;
 import android.content.pm.IPackageManager;
@@ -4184,12 +4185,14 @@ public class ActivityManagerService extends IActivityManager.Stub
                 runtimeFlags |= Zygote.ONLY_USE_SYSTEM_OAT_FILES;
             }
 
-            if (!app.info.isAllowedToUseHiddenApi() &&
-                    !disableHiddenApiChecks &&
-                    !mHiddenApiBlacklist.isDisabled()) {
-                // This app is not allowed to use undocumented and private APIs, or blacklisting is
-                // enabled. Set up its runtime with the appropriate flag.
-                runtimeFlags |= Zygote.ENABLE_HIDDEN_API_CHECKS;
+            if (!disableHiddenApiChecks && !mHiddenApiBlacklist.isDisabled()) {
+                @HiddenApiEnforcementPolicy int policy =
+                        app.info.getHiddenApiEnforcementPolicy();
+                int policyBits = (policy << Zygote.API_ENFORCEMENT_POLICY_SHIFT);
+                if ((policyBits & Zygote.API_ENFORCEMENT_POLICY_MASK) != policyBits) {
+                    throw new IllegalStateException("Invalid API policy: " + policy);
+                }
+                runtimeFlags |= policyBits;
             }
 
             String invokeWith = null;
diff --git a/services/core/java/com/android/server/pm/PackageDexOptimizer.java b/services/core/java/com/android/server/pm/PackageDexOptimizer.java
index 9e7ad47deab9..61c6be7c84e1 100644
--- a/services/core/java/com/android/server/pm/PackageDexOptimizer.java
+++ b/services/core/java/com/android/server/pm/PackageDexOptimizer.java
@@ -47,6 +47,8 @@ import java.util.Map;
 
 import dalvik.system.DexFile;
 
+import static android.content.pm.ApplicationInfo.HIDDEN_API_ENFORCEMENT_NONE;
+
 import static com.android.server.pm.Installer.DEXOPT_BOOTCOMPLETE;
 import static com.android.server.pm.Installer.DEXOPT_DEBUGGABLE;
 import static com.android.server.pm.Installer.DEXOPT_PROFILE_GUIDED;
@@ -532,7 +534,10 @@ public class PackageDexOptimizer {
         int profileFlag = isProfileGuidedFilter ? DEXOPT_PROFILE_GUIDED : 0;
         // Some apps are executed with restrictions on hidden API usage. If this app is one
         // of them, pass a flag to dexopt to enable the same restrictions during compilation.
-        int hiddenApiFlag = info.isAllowedToUseHiddenApi() ? 0 : DEXOPT_ENABLE_HIDDEN_API_CHECKS;
+        // TODO we should pass the actual flag value to dexopt, rather than assuming blacklist
+        int hiddenApiFlag = info.getHiddenApiEnforcementPolicy() == HIDDEN_API_ENFORCEMENT_NONE
+                ? 0
+                : DEXOPT_ENABLE_HIDDEN_API_CHECKS;
         // Avoid generating CompactDex for modes that are latency critical.
         final int compilationReason = options.getCompilationReason();
         boolean generateCompactDex = true;