From 8cd00a5262e7e2af213066ffa1ac9a7dcafcbaed Mon Sep 17 00:00:00 2001
From: Diogo Pinela <diogoid7400@gmail.com>
Date: Sat, 21 Apr 2018 09:55:50 +0100
Subject: [PATCH] archive/zip: prevent writing data for a directory
When creating a directory, Writer.Create now returns a dummy
io.Writer that always returns an error on Write.
Fixes #24043
Change-Id: I7792f54440d45d22d0aa174cba5015ed5fab1c5c
Reviewed-on: https://go-review.googlesource.com/108615
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---
src/archive/zip/writer.go | 55 +++++++++++++++++++++-------------
src/archive/zip/writer_test.go | 11 +++++++
2 files changed, 46 insertions(+), 20 deletions(-)
diff --git a/src/archive/zip/writer.go b/src/archive/zip/writer.go
index 12675d60a0..f3abe8770c 100644
--- a/src/archive/zip/writer.go
+++ b/src/archive/zip/writer.go
@@ -11,6 +11,7 @@ import (
"hash"
"hash/crc32"
"io"
+ "strings"
"unicode/utf8"
)
@@ -320,35 +321,43 @@ func (w *Writer) CreateHeader(fh *FileHeader) (io.Writer, error) {
fh.Extra = append(fh.Extra, mbuf[:]...)
}
- fw := &fileWriter{
- zipw: w.cw,
- compCount: &countWriter{w: w.cw},
- crc32: crc32.NewIEEE(),
- }
- comp := w.compressor(fh.Method)
- if comp == nil {
- return nil, ErrAlgorithm
- }
- var err error
- fw.comp, err = comp(fw.compCount)
- if err != nil {
- return nil, err
- }
- fw.rawCount = &countWriter{w: fw.comp}
-
+ var (
+ ow io.Writer
+ fw *fileWriter
+ )
h := &header{
FileHeader: fh,
offset: uint64(w.cw.count),
}
- w.dir = append(w.dir, h)
- fw.header = h
+ if strings.HasSuffix(fh.Name, "/") {
+ ow = dirWriter{}
+ } else {
+ fw = &fileWriter{
+ zipw: w.cw,
+ compCount: &countWriter{w: w.cw},
+ crc32: crc32.NewIEEE(),
+ }
+ comp := w.compressor(fh.Method)
+ if comp == nil {
+ return nil, ErrAlgorithm
+ }
+ var err error
+ fw.comp, err = comp(fw.compCount)
+ if err != nil {
+ return nil, err
+ }
+ fw.rawCount = &countWriter{w: fw.comp}
+ fw.header = h
+ ow = fw
+ }
+ w.dir = append(w.dir, h)
if err := writeHeader(w.cw, fh); err != nil {
return nil, err
}
-
+ // If we're creating a directory, fw is nil.
w.last = fw
- return fw, nil
+ return ow, nil
}
func writeHeader(w io.Writer, h *FileHeader) error {
@@ -401,6 +410,12 @@ func (w *Writer) compressor(method uint16) Compressor {
return comp
}
+type dirWriter struct{}
+
+func (dirWriter) Write([]byte) (int, error) {
+ return 0, errors.New("zip: write to directory")
+}
+
type fileWriter struct {
*header
zipw io.Writer
diff --git a/src/archive/zip/writer_test.go b/src/archive/zip/writer_test.go
index 38f32296fa..271a36729c 100644
--- a/src/archive/zip/writer_test.go
+++ b/src/archive/zip/writer_test.go
@@ -299,6 +299,17 @@ func TestWriterFlush(t *testing.T) {
}
}
+func TestWriterDir(t *testing.T) {
+ w := NewWriter(ioutil.Discard)
+ dw, err := w.Create("dir/")
+ if err != nil {
+ t.Fatal(err)
+ }
+ if _, err := dw.Write([]byte("hello")); err == nil {
+ t.Error("Write to directory: got nil error, want non-nil")
+ }
+}
+
func testCreate(t *testing.T, w *Writer, wt *WriteTest) {
header := &FileHeader{
Name: wt.Name,
--
2.30.9