[#12] services/session: Implement Sign/Verify service

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

pkg/services/session/sign.go

@@ -0,0 +1,33 @@
+package session
+
+import (
+	"context"
+	"crypto/ecdsa"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/session"
+	"github.com/nspcc-dev/neofs-node/pkg/services/util"
+)
+
+type signService struct {
+	unarySigService *util.UnarySignService
+}
+
+func NewSignService(key *ecdsa.PrivateKey, svc session.Service) session.Service {
+	return &signService{
+		unarySigService: util.NewUnarySignService(
+			key,
+			func(ctx context.Context, req interface{}) (interface{}, error) {
+				return svc.Create(ctx, req.(*session.CreateRequest))
+			},
+		),
+	}
+}
+
+func (s *signService) Create(ctx context.Context, req *session.CreateRequest) (*session.CreateResponse, error) {
+	resp, err := s.unarySigService.HandleUnaryRequest(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp.(*session.CreateResponse), nil
+}