Add key rotation.

Change certificate checks to also consider the possibility of
signing certificate rotation by checking the
SigningDetails#pastSigningCertificates field.  In particular, add a
SigningDetails#checkCapability method which reports whether or not
the older SigningDetails is an ancestor of the current one, and
queries whether or not the old one has been granted capabilities,
such as being a sharedUser.

Bug: 64686581
Test: Builds, boots, browser and camera work, all with v3 signing.

Change-Id: I4199ff3f2d9ae959325b117b28e666ae31889800
diff --git a/services/core/java/com/android/server/pm/permission/PermissionManagerService.java b/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
index cb3b107..08f8bbd 100644
--- a/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
+++ b/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
@@ -1022,12 +1022,24 @@
                 PackageManagerInternal.PACKAGE_SYSTEM, UserHandle.USER_SYSTEM);
         final PackageParser.Package systemPackage =
                 mPackageManagerInt.getPackage(systemPackageName);
-        boolean allowed = (PackageManagerServiceUtils.compareSignatures(
-                                bp.getSourceSignatures(), pkg.mSigningDetails.signatures)
-                        == PackageManager.SIGNATURE_MATCH)
-                || (PackageManagerServiceUtils.compareSignatures(
-                systemPackage.mSigningDetails.signatures, pkg.mSigningDetails.signatures)
-                        == PackageManager.SIGNATURE_MATCH);
+
+        // check if the package is allow to use this signature permission.  A package is allowed to
+        // use a signature permission if:
+        //     - it has the same set of signing certificates as the source package
+        //     - or its signing certificate was rotated from the source package's certificate
+        //     - or its signing certificate is a previous signing certificate of the defining
+        //       package, and the defining package still trusts the old certificate for permissions
+        //     - or it shares the above relationships with the system package
+        boolean allowed =
+                pkg.mSigningDetails.hasAncestorOrSelf(
+                        bp.getSourcePackageSetting().getSigningDetails())
+                || bp.getSourcePackageSetting().getSigningDetails().checkCapability(
+                        pkg.mSigningDetails,
+                        PackageParser.SigningDetails.CertCapabilities.PERMISSION)
+                || pkg.mSigningDetails.hasAncestorOrSelf(systemPackage.mSigningDetails)
+                || systemPackage.mSigningDetails.checkCapability(
+                        pkg.mSigningDetails,
+                        PackageParser.SigningDetails.CertCapabilities.PERMISSION);
         if (!allowed && (privilegedPermission || oemPermission)) {
             if (pkg.isSystem()) {
                 // For updated system applications, a privileged/oem permission