Add a profile field to the authz.Rotate RPC.

authz/authz.proto

@@ -148,6 +148,22 @@ message RotateAuthzRequest {
   // version` is already in use (is not unique).
   // It is a no-op for the `finalize_rotation` request.
   bool force_overwrite = 3;
+
+  // The profile for which the authz policy is being rotated. In the case that
+  // this field is not specified, the default authz policy which applies to all
+  // gRPC endpoints run by the target is assumed. Where non-default policies
+  // are to supported by an endpoint, the value of the profile determines which
+  // set of policies are to be rotated.
+  //
+  // It is not permitted to rotate multiple profiles' policies at the same time
+  // - if a `Rotate` RPC is in progress for profile "foo" (i.e.,
+  // `upload_request` has been supplied, but the rotation has not been
+  // finalised), and a second `RotateAuthzRequest` with `upload_request` is sent
+  // from the client for profile "bar" this is considered an error.
+  //
+  // Note that the authz profile is considered independent from a SSL profile
+  // ID (as referenced by gnsi.Certz).
+  string authz_profile_id = 4;
 }
 
 // Response messages from the target.