Initial skeletal implementation of the PrincipalService. Also, use the Login()/GetUserBlessing()

services/vanadium/security/principal_service.go

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package main
+
+import (
+        "log"
+
+        "golang.org/x/mobile/app"
+
+        "mojo/public/go/application"
+        "mojo/public/go/bindings"
+        "mojo/public/go/system"
+        "mojo/services/vanadium/security/public/interfaces/principal"
+)
+
+//#include "mojo/public/c/system/types.h"
+import "C"
+
+type PrincipalServiceImpl struct {
+     defaultBlessing *principal.Blessing
+}
+
+func (p *PrincipalServiceImpl) Login() (b *principal.Blessing, err error) {
+     return p.defaultBlessing, nil
+}
+
+func (p *PrincipalServiceImpl) Logout() (err error) {
+     return nil
+}
+
+func (p *PrincipalServiceImpl) Sign(msg []byte) (s *principal.Signature, err error) {
+     return nil, nil
+}
+
+func (p *PrincipalServiceImpl) GetUserBlessing(app principal.AppInstanceName) (b *principal.Blessing, err error) {
+     return p.defaultBlessing, nil
+}
+
+type PrincipalServiceDelegate struct {
+        psImpl *PrincipalServiceImpl
+        stubs  []*bindings.Stub   
+}
+
+func (d *PrincipalServiceDelegate) Initialize(context application.Context) {
+     defaultCertChain := []principal.Certificate{principal.Certificate{Extension:"default"}} 
+     d.psImpl = &PrincipalServiceImpl{&principal.Blessing{defaultCertChain}}
+}
+
+func (d *PrincipalServiceDelegate) Create(r principal.PrincipalService_Request) {
+        stub := principal.NewPrincipalServiceStub(r, d.psImpl, bindings.GetAsyncWaiter())
+        d.stubs = append(d.stubs, stub)
+        go func() {
+                for {
+                        if err := stub.ServeRequest(); err != nil {
+                                connectionError, ok := err.(*bindings.ConnectionError)
+                                if !ok || !connectionError.Closed() {
+                                        log.Println(err)
+                                }
+                                break
+                        }
+                }
+        }()
+}
+
+func (d *PrincipalServiceDelegate) AcceptConnection(connection *application.Connection) {
+        connection.ProvideServices(&principal.PrincipalService_ServiceFactory{d})
+}
+
+func (d *PrincipalServiceDelegate) Quit() {
+        for _, stub := range d.stubs {
+                stub.Close()
+        }
+}
+
+//export MojoMain
+func MojoMain(handle C.MojoHandle) C.MojoResult {
+        application.Run(&PrincipalServiceDelegate{}, system.MojoHandle(handle))
+        return C.MOJO_RESULT_OK
+}
+
+func main() {
+        app.Run(app.Callbacks{})
+}