From 8c99d9d54c5ce9a64612091e11f992fc3f13f6aa Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Tue, 24 Nov 2020 13:22:07 +0300
Subject: [PATCH] [#207] sdk/client: Implement GetEACLWithSignature method

GetEACL method of Client receives eACL table with signature, verifies the
signature and return the table. In some cases we need to receive table and
signature regardless of their correctness. New method GetEACLWithSignature
provides such an opportunity.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 pkg/client/container.go | 71 +++++++++++++++++++++++++++++++----------
 1 file changed, 55 insertions(+), 16 deletions(-)

diff --git a/pkg/client/container.go b/pkg/client/container.go
index a09107e..3bd61e2 100644
--- a/pkg/client/container.go
+++ b/pkg/client/container.go
@@ -3,6 +3,7 @@ package client
 import (
 	"context"
 
+	"github.com/nspcc-dev/neofs-api-go/pkg"
 	"github.com/nspcc-dev/neofs-api-go/pkg/acl/eacl"
 	"github.com/nspcc-dev/neofs-api-go/pkg/container"
 	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
@@ -18,6 +19,13 @@ type delContainerSignWrapper struct {
 	body *v2container.DeleteRequestBody
 }
 
+// EACLWithSignature represents eACL table/signature pair.
+type EACLWithSignature struct {
+	table *eacl.Table
+
+	sig *pkg.Signature
+}
+
 var errNilReponseBody = errors.New("response body is nil")
 
 func (c delContainerSignWrapper) ReadSignedData(bytes []byte) ([]byte, error) {
@@ -28,6 +36,16 @@ func (c delContainerSignWrapper) SignedDataSize() int {
 	return len(c.body.GetContainerID().GetValue())
 }
 
+// EACL returns eACL table.
+func (e EACLWithSignature) EACL() *eacl.Table {
+	return e.table
+}
+
+// Signature returns table signature.
+func (e EACLWithSignature) Signature() *pkg.Signature {
+	return e.sig
+}
+
 func (c Client) PutContainer(ctx context.Context, cnr *container.Container, opts ...CallOption) (*container.ID, error) {
 	switch c.remoteNode.Version.Major() {
 	case 2:
@@ -77,9 +95,30 @@ func (c Client) DeleteContainer(ctx context.Context, id *container.ID, opts ...C
 }
 
 func (c Client) GetEACL(ctx context.Context, id *container.ID, opts ...CallOption) (*eacl.Table, error) {
+	v, err := c.getEACL(ctx, id, true, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return v.table, nil
+}
+
+func (c Client) GetEACLWithSignature(ctx context.Context, id *container.ID, opts ...CallOption) (*EACLWithSignature, error) {
+	return c.getEACL(ctx, id, false, opts...)
+}
+
+func (c Client) getEACL(ctx context.Context, id *container.ID, verify bool, opts ...CallOption) (*EACLWithSignature, error) {
 	switch c.remoteNode.Version.Major() {
 	case 2:
-		return c.getEACLV2(ctx, id, opts...)
+		resp, err := c.getEACLV2(ctx, id, verify, opts...)
+		if err != nil {
+			return nil, err
+		}
+
+		return &EACLWithSignature{
+			table: eacl.NewTableFromV2(resp.GetEACL()),
+			sig:   pkg.NewSignatureFromV2(resp.GetSignature()),
+		}, nil
 	default:
 		return nil, errUnsupportedProtocol
 	}
@@ -316,7 +355,7 @@ func (c Client) delContainerV2(ctx context.Context, id *container.ID, opts ...Ca
 	}
 }
 
-func (c Client) getEACLV2(ctx context.Context, id *container.ID, opts ...CallOption) (*eacl.Table, error) {
+func (c Client) getEACLV2(ctx context.Context, id *container.ID, verify bool, opts ...CallOption) (*v2container.GetExtendedACLResponseBody, error) {
 	// apply all available options
 	callOptions := c.defaultCallOptions()
 
@@ -358,23 +397,23 @@ func (c Client) getEACLV2(ctx context.Context, id *container.ID, opts ...CallOpt
 			return nil, errNilReponseBody
 		}
 
-		if err := signature.VerifyDataWithSource(
-			v2signature.StableMarshalerWrapper{
-				SM: body.GetEACL(),
-			},
-			func() (key, sig []byte) {
-				s := body.GetSignature()
+		if verify {
+			if err := signature.VerifyDataWithSource(
+				v2signature.StableMarshalerWrapper{
+					SM: body.GetEACL(),
+				},
+				func() (key, sig []byte) {
+					s := body.GetSignature()
 
-				return s.GetKey(), s.GetSign()
-			},
-			signature.SignWithRFC6979(),
-		); err != nil {
-			return nil, errors.Wrap(err, "incorrect signature")
+					return s.GetKey(), s.GetSign()
+				},
+				signature.SignWithRFC6979(),
+			); err != nil {
+				return nil, errors.Wrap(err, "incorrect signature")
+			}
 		}
 
-		result := eacl.NewTableFromV2(body.GetEACL())
-
-		return result, nil
+		return body, nil
 	default:
 		return nil, errUnsupportedProtocol
 	}