1 files changed, 65 insertions, 0 deletions
diff --git a/src/internal/obscuretestdata/obscuretestdata.go b/src/internal/obscuretestdata/obscuretestdata.go
new file mode 100644
index 0000000..d54d3f6
--- /dev/null
+++ b/src/internal/obscuretestdata/obscuretestdata.go
@@ -0,0 +1,65 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package obscuretestdata contains functionality used by tests to more easily
+// work with testdata that must be obscured primarily due to
+// golang.org/issue/34986.
+package obscuretestdata
+
+import (
+	"encoding/base64"
+	"io"
+	"os"
+)
+
+// Rot13 returns the rot13 encoding or decoding of its input.
+func Rot13(data []byte) []byte {
+	out := make([]byte, len(data))
+	copy(out, data)
+	for i, c := range out {
+		switch {
+		case 'A' <= c && c <= 'M' || 'a' <= c && c <= 'm':
+			out[i] = c + 13
+		case 'N' <= c && c <= 'Z' || 'n' <= c && c <= 'z':
+			out[i] = c - 13
+		}
+	}
+	return out
+}
+
+// DecodeToTempFile decodes the named file to a temporary location.
+// If successful, it returns the path of the decoded file.
+// The caller is responsible for ensuring that the temporary file is removed.
+func DecodeToTempFile(name string) (path string, err error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	tmp, err := os.CreateTemp("", "obscuretestdata-decoded-")
+	if err != nil {
+		return "", err
+	}
+	if _, err := io.Copy(tmp, base64.NewDecoder(base64.StdEncoding, f)); err != nil {
+		tmp.Close()
+		os.Remove(tmp.Name())
+		return "", err
+	}
+	if err := tmp.Close(); err != nil {
+		os.Remove(tmp.Name())
+		return "", err
+	}
+	return tmp.Name(), nil
+}
+
+// ReadFile reads the named file and returns its decoded contents.
+func ReadFile(name string) ([]byte, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return io.ReadAll(base64.NewDecoder(base64.StdEncoding, f))
+}