container: implement SignedDataSource on PutRequest message

container/sign.go

@@ -0,0 +1,66 @@
+package container
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+var requestEndianness = binary.BigEndian
+
+// SignedData returns payload bytes of the request.
+func (m PutRequest) 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 PutRequest) SignedDataSize() (sz int) {
+	sz += m.GetMessageID().Size()
+
+	sz += 8
+
+	sz += m.GetOwnerID().Size()
+
+	rules := m.GetRules()
+	sz += rules.Size()
+
+	sz += 4
+
+	return
+}
+
+// ReadSignedData copies payload bytes to passed buffer.
+//
+// If the Request size is insufficient, io.ErrUnexpectedEOF returns.
+func (m PutRequest) ReadSignedData(p []byte) (int, error) {
+	if len(p) < m.SignedDataSize() {
+		return 0, io.ErrUnexpectedEOF
+	}
+
+	var off int
+
+	off += copy(p[off:], m.GetMessageID().Bytes())
+
+	requestEndianness.PutUint64(p[off:], m.GetCapacity())
+	off += 8
+
+	off += copy(p[off:], m.GetOwnerID().Bytes())
+
+	rules := m.GetRules()
+	// FIXME: implement and use stable functions
+	n, err := rules.MarshalTo(p[off:])
+	off += n
+	if err != nil {
+		return off, err
+	}
+
+	requestEndianness.PutUint32(p[off:], m.GetBasicACL())
+	off += 4
+
+	return off, nil
+}