[#13] services: Define signing Object service and implement Search

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/services/object/sign.go

@@ -0,0 +1,84 @@
+package object
+
+import (
+	"context"
+	"crypto/ecdsa"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/object"
+	"github.com/nspcc-dev/neofs-api-go/v2/signature"
+	"github.com/nspcc-dev/neofs-node/pkg/services/util"
+	"github.com/pkg/errors"
+)
+
+type signService struct {
+	key *ecdsa.PrivateKey
+
+	searchSigService *util.UnarySignService
+}
+
+type searchStreamSigner struct {
+	key *ecdsa.PrivateKey
+
+	stream object.SearchObjectStreamer
+}
+
+func NewSignService(key *ecdsa.PrivateKey, svc object.Service) object.Service {
+	return &signService{
+		key: key,
+		searchSigService: util.NewUnarySignService(
+			nil, // private key is not needed because service returns stream
+			func(ctx context.Context, req interface{}) (interface{}, error) {
+				return svc.Search(ctx, req.(*object.SearchRequest))
+			},
+		),
+	}
+}
+
+func (s *signService) Get(context.Context, *object.GetRequest) (object.GetObjectStreamer, error) {
+	panic("implement me")
+}
+
+func (s *signService) Put(context.Context) (object.PutObjectStreamer, error) {
+	panic("implement me")
+}
+
+func (s *signService) Head(context.Context, *object.HeadRequest) (*object.HeadResponse, error) {
+	panic("implement me")
+}
+
+func (s *searchStreamSigner) Recv() (*object.SearchResponse, error) {
+	r, err := s.stream.Recv()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not receive response")
+	}
+
+	if err := signature.SignServiceMessage(s.key, r); err != nil {
+		return nil, errors.Wrap(err, "could not sign response")
+	}
+
+	return r, nil
+}
+
+func (s *signService) Search(ctx context.Context, req *object.SearchRequest) (object.SearchObjectStreamer, error) {
+	resp, err := s.searchSigService.HandleServerStreamRequest(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	return &searchStreamSigner{
+		key:    s.key,
+		stream: resp.(object.SearchObjectStreamer),
+	}, nil
+}
+
+func (s *signService) Delete(context.Context, *object.DeleteRequest) (*object.DeleteResponse, error) {
+	panic("implement me")
+}
+
+func (s *signService) GetRange(context.Context, *object.GetRangeRequest) (object.GetRangeObjectStreamer, error) {
+	panic("implement me")
+}
+
+func (s *signService) GetRangeHash(context.Context, *object.GetRangeHashRequest) (*object.GetRangeHashResponse, error) {
+	panic("implement me")
+}