From b9d30d613831de5f06bea5ef9a415c9ba719ce6d Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Mon, 11 May 2020 11:59:39 +0300
Subject: [PATCH] accounting: implement SignedDataSource on BalanceRequest
 message

---
 accounting/sign.go       | 33 ++++++++++++++++++++++++
 accounting/sign_test.go  | 54 ++++++++++++++++++++++++++++++++++++++++
 accounting/types.go      | 10 ++++++++
 accounting/types_test.go |  9 +++++++
 4 files changed, 106 insertions(+)
 create mode 100644 accounting/sign.go
 create mode 100644 accounting/sign_test.go

diff --git a/accounting/sign.go b/accounting/sign.go
new file mode 100644
index 0000000..a42375f
--- /dev/null
+++ b/accounting/sign.go
@@ -0,0 +1,33 @@
+package accounting
+
+import "io"
+
+// SignedData returns payload bytes of the request.
+func (m BalanceRequest) SignedData() ([]byte, error) {
+	data := make([]byte, m.SignedDataSize())
+
+	if _, err := m.ReadSignedData(data); err != nil {
+		return nil, err
+	}
+
+	return data, nil
+}
+
+// SignedDataSize returns payload size of the request.
+func (m BalanceRequest) SignedDataSize() int {
+	return m.GetOwnerID().Size()
+}
+
+// ReadSignedData copies payload bytes to passed buffer.
+//
+// If the buffer size is insufficient, io.ErrUnexpectedEOF returns.
+func (m BalanceRequest) ReadSignedData(p []byte) (int, error) {
+	sz := m.SignedDataSize()
+	if len(p) < sz {
+		return 0, io.ErrUnexpectedEOF
+	}
+
+	copy(p, m.GetOwnerID().Bytes())
+
+	return sz, nil
+}
diff --git a/accounting/sign_test.go b/accounting/sign_test.go
new file mode 100644
index 0000000..03eaf6c
--- /dev/null
+++ b/accounting/sign_test.go
@@ -0,0 +1,54 @@
+package accounting
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/service"
+	"github.com/nspcc-dev/neofs-crypto/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSignBalanceRequest(t *testing.T) {
+	// create test OwnerID
+	ownerID := OwnerID{1, 2, 3}
+
+	// create test BalanceRequest
+	req := new(BalanceRequest)
+	req.SetOwnerID(ownerID)
+
+	// create test private key
+	sk := test.DecodeKey(0)
+
+	items := []struct {
+		corrupt func()
+		restore func()
+	}{
+		{
+			corrupt: func() {
+				ownerID[0]++
+				req.SetOwnerID(ownerID)
+			},
+			restore: func() {
+				ownerID[0]--
+				req.SetOwnerID(ownerID)
+			},
+		},
+	}
+
+	for _, item := range items {
+		// sign with private key
+		require.NoError(t, service.AddSignatureWithKey(sk, req))
+
+		// ascertain that verification is passed
+		require.NoError(t, service.VerifyAccumulatedSignatures(req))
+
+		// corrupt the request
+		item.corrupt()
+
+		// ascertain that verification is failed
+		require.Error(t, service.VerifyAccumulatedSignatures(req))
+
+		// ascertain that request
+		item.restore()
+	}
+}
diff --git a/accounting/types.go b/accounting/types.go
index 6a3b2e2..3ac637d 100644
--- a/accounting/types.go
+++ b/accounting/types.go
@@ -351,3 +351,13 @@ func (m *Settlement) Equal(s *Settlement) bool {
 	}
 	return len(m.Transactions) == 0 || reflect.DeepEqual(m.Transactions, s.Transactions)
 }
+
+// GetOwnerID is an OwnerID field getter.
+func (m BalanceRequest) GetOwnerID() OwnerID {
+	return m.OwnerID
+}
+
+// SetOwnerID is an OwnerID field setter.
+func (m *BalanceRequest) SetOwnerID(owner OwnerID) {
+	m.OwnerID = owner
+}
diff --git a/accounting/types_test.go b/accounting/types_test.go
index df81b46..e89c08c 100644
--- a/accounting/types_test.go
+++ b/accounting/types_test.go
@@ -84,3 +84,12 @@ func TestCheque(t *testing.T) {
 		require.Equal(t, cheque.Amount, decimal.NewGAS(42))
 	})
 }
+
+func TestBalanceRequest_SetOwnerID(t *testing.T) {
+	ownerID := OwnerID{1, 2, 3}
+	m := new(BalanceRequest)
+
+	m.SetOwnerID(ownerID)
+
+	require.Equal(t, ownerID, m.GetOwnerID())
+}