archive/zip: handle mtime in NTFS/UNIX/ExtendedTS extra fields

Handle NTFS timestamp, UNIX timestamp, Extended extra timestamp.
Writer supports only Extended extra timestamp field, matching most
zip creators.

Fixes #10242.

Change-Id: Id665db274e63def98659231391fb77392267ac1e
Reviewed-on: https://go-review.googlesource.com/18274
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

6 files changed, 113 insertions, 12 deletions

diff --git a/src/archive/zip/reader.go b/src/archive/zip/reader.go
index f6c3ead3be..9bbc9a9745 100644
--- a/src/archive/zip/reader.go
+++ b/src/archive/zip/reader.go
@@ -13,6 +13,7 @@ import (
 	"hash/crc32"
 	"io"
 	"os"
+	"time"
 )
 
 var (
@@ -289,13 +290,16 @@ func readDirectoryHeader(f *File, r io.Reader) error {
 		// Other zip authors might not even follow the basic format,
 		// and we'll just ignore the Extra content in that case.
 		b := readBuf(f.Extra)
+
+	Extras:
 		for len(b) >= 4 { // need at least tag and size
 			tag := b.uint16()
 			size := b.uint16()
 			if int(size) > len(b) {
 				break
 			}
-			if tag == zip64ExtraId {
+			switch tag {
+			case zip64ExtraId:
 				// update directory values from the zip64 extra block.
 				// They should only be consulted if the sizes read earlier
 				// are maxed out.
@@ -323,7 +327,42 @@ func readDirectoryHeader(f *File, r io.Reader) error {
 					}
 					f.headerOffset = int64(eb.uint64())
 				}
-				break
+				break Extras
+
+			case ntfsExtraId:
+				if size == 32 {
+					eb := readBuf(b[:size])
+					eb.uint32() // reserved
+					eb.uint16() // tag1
+					size1 := eb.uint16()
+					if size1 == 24 {
+						sub := readBuf(eb[:size1])
+						lo := sub.uint32()
+						hi := sub.uint32()
+						tick := (uint64(uint64(lo)|uint64(hi)<<32) - 116444736000000000) / 10000000
+						f.SetModTime(time.Unix(int64(tick), 0))
+					}
+				}
+				break Extras
+
+			case unixExtraId:
+				if size >= 12 {
+					eb := readBuf(b[:size])
+					eb.uint32()          // AcTime
+					epoch := eb.uint32() // ModTime
+					f.SetModTime(time.Unix(int64(epoch), 0))
+					break Extras
+				}
+			case exttsExtraId:
+				if size >= 3 {
+					eb := readBuf(b[:size])
+					flags := eb.uint8()  // Flags
+					epoch := eb.uint32() // AcTime/ModTime/CrTime
+					if flags&1 != 0 {
+						f.SetModTime(time.Unix(int64(epoch), 0))
+					}
+					break Extras
+				}
 			}
 			b = b[size:]
 		}
@@ -508,6 +547,12 @@ func findSignatureInBlock(b []byte) int {
 
 type readBuf []byte
 
+func (b *readBuf) uint8() uint8 {
+	v := uint8((*b)[0])
+	*b = (*b)[1:]
+	return v
+}
+
 func (b *readBuf) uint16() uint16 {
 	v := binary.LittleEndian.Uint16(*b)
 	*b = (*b)[2:]
diff --git a/src/archive/zip/reader_test.go b/src/archive/zip/reader_test.go
index dfaae78436..576a1697a4 100644
--- a/src/archive/zip/reader_test.go
+++ b/src/archive/zip/reader_test.go
@@ -65,13 +65,13 @@ var tests = []ZipTest{
 			{
 				Name:    "test.txt",
 				Content: []byte("This is a test text file.\n"),
-				Mtime:   "09-05-10 12:12:02",
+				Mtime:   "09-05-10 02:12:00",
 				Mode:    0644,
 			},
 			{
 				Name:  "gophercolor16x16.png",
 				File:  "gophercolor16x16.png",
-				Mtime: "09-05-10 15:52:58",
+				Mtime: "09-05-10 05:52:58",
 				Mode:  0644,
 			},
 		},
@@ -83,13 +83,13 @@ var tests = []ZipTest{
 			{
 				Name:    "test.txt",
 				Content: []byte("This is a test text file.\n"),
-				Mtime:   "09-05-10 12:12:02",
+				Mtime:   "09-05-10 02:12:00",
 				Mode:    0644,
 			},
 			{
 				Name:  "gophercolor16x16.png",
 				File:  "gophercolor16x16.png",
-				Mtime: "09-05-10 15:52:58",
+				Mtime: "09-05-10 05:52:58",
 				Mode:  0644,
 			},
 		},
@@ -145,6 +145,17 @@ var tests = []ZipTest{
 		File: crossPlatform,
 	},
 	{
+		Name: "extra-timestamp.zip",
+		File: []ZipTestFile{
+			{
+				Name:    "hello.txt",
+				Content: []byte(""),
+				Mtime:   "01-06-16 12:25:56",
+				Mode:    0666,
+			},
+		},
+	},
+	{
 		// created by Go, before we wrote the "optional" data
 		// descriptor signatures (which are required by OS X)
 		Name: "go-no-datadesc-sig.zip",
@@ -152,13 +163,13 @@ var tests = []ZipTest{
 			{
 				Name:    "foo.txt",
 				Content: []byte("foo\n"),
-				Mtime:   "03-08-12 16:59:10",
+				Mtime:   "03-09-12 00:59:10",
 				Mode:    0644,
 			},
 			{
 				Name:    "bar.txt",
 				Content: []byte("bar\n"),
-				Mtime:   "03-08-12 16:59:12",
+				Mtime:   "03-09-12 00:59:12",
 				Mode:    0644,
 			},
 		},
@@ -205,13 +216,13 @@ var tests = []ZipTest{
 			{
 				Name:    "foo.txt",
 				Content: []byte("foo\n"),
-				Mtime:   "03-08-12 16:59:10",
+				Mtime:   "03-09-12 00:59:10",
 				Mode:    0644,
 			},
 			{
 				Name:    "bar.txt",
 				Content: []byte("bar\n"),
-				Mtime:   "03-08-12 16:59:12",
+				Mtime:   "03-09-12 00:59:12",
 				Mode:    0644,
 			},
 		},
@@ -225,14 +236,14 @@ var tests = []ZipTest{
 			{
 				Name:       "foo.txt",
 				Content:    []byte("foo\n"),
-				Mtime:      "03-08-12 16:59:10",
+				Mtime:      "03-09-12 00:59:10",
 				Mode:       0644,
 				ContentErr: ErrChecksum,
 			},
 			{
 				Name:    "bar.txt",
 				Content: []byte("bar\n"),
-				Mtime:   "03-08-12 16:59:12",
+				Mtime:   "03-09-12 00:59:12",
 				Mode:    0644,
 			},
 		},
diff --git a/src/archive/zip/struct.go b/src/archive/zip/struct.go
index e92d02f8a2..8e6eb840f9 100644
--- a/src/archive/zip/struct.go
+++ b/src/archive/zip/struct.go
@@ -63,6 +63,9 @@ const (
 
 	// extra header id's
 	zip64ExtraId = 0x0001 // zip64 Extended Information Extra Field
+	ntfsExtraId  = 0x000a // NTFS Extra Field
+	unixExtraId  = 0x000d // UNIX Extra Field
+	exttsExtraId = 0x5455 // Extra Timestamp Extra Field
 )
 
 // FileHeader describes a file within a zip file.
diff --git a/src/archive/zip/testdata/extra-timestamp.zip b/src/archive/zip/testdata/extra-timestamp.zip
new file mode 100644
index 0000000000..819e22cb68
--- /dev/null
+++ b/src/archive/zip/testdata/extra-timestamp.zip
diff --git a/src/archive/zip/writer.go b/src/archive/zip/writer.go
index 3a9292e380..2a747b8f37 100644
--- a/src/archive/zip/writer.go
+++ b/src/archive/zip/writer.go
@@ -98,6 +98,16 @@ func (w *Writer) Close() error {
 			b.uint32(h.CompressedSize)
 			b.uint32(h.UncompressedSize)
 		}
+
+		mt := uint32(h.FileHeader.ModTime().Unix())
+		var mbuf [9]byte // 2x uint16 + uint8 + uint32
+		eb := writeBuf(mbuf[:])
+		eb.uint16(exttsExtraId)
+		eb.uint16(5)  // size = uint8 + uint32
+		eb.uint8(1)   // flags = modtime
+		eb.uint32(mt) // ModTime
+		h.Extra = append(h.Extra, mbuf[:]...)
+
 		b.uint16(uint16(len(h.Name)))
 		b.uint16(uint16(len(h.Extra)))
 		b.uint16(uint16(len(h.Comment)))
@@ -376,6 +386,11 @@ func (w nopCloser) Close() error {
 
 type writeBuf []byte
 
+func (b *writeBuf) uint8(v uint8) {
+	(*b)[0] = v
+	*b = (*b)[1:]
+}
+
 func (b *writeBuf) uint16(v uint16) {
 	binary.LittleEndian.PutUint16(*b, v)
 	*b = (*b)[2:]
diff --git a/src/archive/zip/writer_test.go b/src/archive/zip/writer_test.go
index 86841c755f..f20daa0e3d 100644
--- a/src/archive/zip/writer_test.go
+++ b/src/archive/zip/writer_test.go
@@ -11,6 +11,7 @@ import (
 	"math/rand"
 	"os"
 	"testing"
+	"time"
 )
 
 // TODO(adg): a more sophisticated test suite
@@ -20,6 +21,7 @@ type WriteTest struct {
 	Data   []byte
 	Method uint16
 	Mode   os.FileMode
+	Mtime  string
 }
 
 var writeTests = []WriteTest{
@@ -28,30 +30,35 @@ var writeTests = []WriteTest{
 		Data:   []byte("Rabbits, guinea pigs, gophers, marsupial rats, and quolls."),
 		Method: Store,
 		Mode:   0666,
+		Mtime:  "02-01-08 00:01:02",
 	},
 	{
 		Name:   "bar",
 		Data:   nil, // large data set in the test
 		Method: Deflate,
 		Mode:   0644,
+		Mtime:  "03-02-08 01:02:03",
 	},
 	{
 		Name:   "setuid",
 		Data:   []byte("setuid file"),
 		Method: Deflate,
 		Mode:   0755 | os.ModeSetuid,
+		Mtime:  "04-03-08 02:03:04",
 	},
 	{
 		Name:   "setgid",
 		Data:   []byte("setgid file"),
 		Method: Deflate,
 		Mode:   0755 | os.ModeSetgid,
+		Mtime:  "05-04-08 03:04:04",
 	},
 	{
 		Name:   "symlink",
 		Data:   []byte("../link/target"),
 		Method: Deflate,
 		Mode:   0755 | os.ModeSymlink,
+		Mtime:  "03-02-08 11:22:33",
 	},
 }
 
@@ -148,6 +155,11 @@ func testCreate(t *testing.T, w *Writer, wt *WriteTest) {
 	if wt.Mode != 0 {
 		header.SetMode(wt.Mode)
 	}
+	mtime, err := time.Parse("01-02-06 15:04:05", wt.Mtime)
+	if err != nil {
+		t.Fatal("time.Parse:", err)
+	}
+	header.SetModTime(mtime)
 	f, err := w.CreateHeader(header)
 	if err != nil {
 		t.Fatal(err)
@@ -178,6 +190,21 @@ func testReadFile(t *testing.T, f *File, wt *WriteTest) {
 	if !bytes.Equal(b, wt.Data) {
 		t.Errorf("File contents %q, want %q", b, wt.Data)
 	}
+
+	mtime, err := time.Parse("01-02-06 15:04:05", wt.Mtime)
+	if err != nil {
+		t.Fatal("time.Parse:", err)
+	}
+
+	diff := mtime.Sub(f.ModTime())
+	if diff < 0 {
+		diff = -diff
+	}
+
+	// allow several time span
+	if diff > 5*time.Second {
+		t.Errorf("File modtime %v, want %v", mtime, f.ModTime())
+	}
 }
 
 func BenchmarkCompressedZipGarbage(b *testing.B) {