Implement signed data calculating function from SignedDataReader

service/utils.go

@@ -0,0 +1,18 @@
+package service
+
+// SignedDataFromReader allocates buffer and reads bytes from passed reader to it.
+//
+// If passed SignedDataReader is nil, ErrNilSignedDataReader returns.
+func SignedDataFromReader(r SignedDataReader) ([]byte, error) {
+	if r == nil {
+		return nil, ErrNilSignedDataReader
+	}
+
+	data := make([]byte, r.SignedDataSize())
+
+	if _, err := r.ReadSignedData(data); err != nil {
+		return nil, err
+	}
+
+	return data, nil
+}