[MM-63421] add openID Authorization API-compliant PDP interface (#30462)

server/einterfaces/pdp.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package einterfaces
+
+import (
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/request"
+)
+
+// PolicyDecisionPointInterface is the service that evaluates access requests
+// using the OpenID Auth API spec. It determines whether a subject can perform
+// an action on a resource based on the resource policy.
+type PolicyDecisionPointInterface interface {
+	AccessEvaluation(rctx request.CTX, accessRequest model.AccessRequest) (*model.AccessDecision, *model.AppError)
+}