From 87a5437d85313b9c5a3d667be8901d5d4dfc6d1f Mon Sep 17 00:00:00 2001
From: Damian Debkowski <damian.debkowski@hashicorp.com>
Date: Thu, 8 Feb 2024 23:03:22 +0000
Subject: [PATCH] backport of commit ce96a600e0f7036c948486b472bc4f61abc7be53

---
 internal/bsr/internal/checksum/sha256sums.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/internal/bsr/internal/checksum/sha256sums.go b/internal/bsr/internal/checksum/sha256sums.go
index d8e2127dd6..cb0e4853c1 100644
--- a/internal/bsr/internal/checksum/sha256sums.go
+++ b/internal/bsr/internal/checksum/sha256sums.go
@@ -131,6 +131,8 @@ func (w *Sha256SumWriter) Write(b []byte) (int, error) {
 // WriteString will write the string to hash.
 func (w *Sha256SumWriter) WriteString(s string) (int, error) {
 	const op = "checksum.(Sha256SumWriter).WriteString"
+	w.l.Lock()
+	defer w.l.Unlock()
 	n, err := w.hash.Write([]byte(s))
 	if err != nil {
 		return n, fmt.Errorf("%s: %w", op, err)
@@ -168,6 +170,8 @@ func (w *Sha256SumWriter) WriteAndClose(b []byte) (int, error) {
 // and if so, then Close() is called; otherwise this is a noop
 func (w *Sha256SumWriter) Close() error {
 	const op = "checksum.(Sha256SumWriter).Close"
+	w.l.Lock()
+	defer w.l.Unlock()
 	var i interface{} = w.underlying
 	if v, ok := i.(io.Closer); ok {
 		if err := v.Close(); err != nil {