From 00b99174f5f4c79eeadd4655edcfa3cfc812741f Mon Sep 17 00:00:00 2001
From: Anmol Sethi <hi@nhooyr.io>
Date: Sat, 30 Mar 2019 16:16:41 -0500
Subject: [PATCH] Add mask test
---
go.mod | 1 +
go.sum | 2 ++
mask.go | 3 ++-
mask_test.go | 24 ++++++++++++++++++++++++
4 files changed, 29 insertions(+), 1 deletion(-)
create mode 100644 mask_test.go
diff --git a/go.mod b/go.mod
index 60d1a3d..3bce5bd 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module nhooyr.io/websocket
go 1.12
require (
+ github.com/google/go-cmp v0.2.0
github.com/kr/pretty v0.1.0 // indirect
go.coder.com/go-tools v0.0.0-20190317003359-0c6a35b74a16
golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3
diff --git a/go.sum b/go.sum
index efb0130..9b7bf49 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
+github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
diff --git a/mask.go b/mask.go
index 6569bb2..6c67f1c 100644
--- a/mask.go
+++ b/mask.go
@@ -6,7 +6,8 @@ package websocket
// See https://tools.ietf.org/html/rfc6455#section-5.3
//
// The returned value is the position of the next byte
-// to be used for masking in the key.
+// to be used for masking in the key. This is so that
+// unmasking can be performed without the entire frame.
func mask(key [4]byte, pos int, p []byte) int {
for i := range p {
p[i] ^= key[pos&3]
diff --git a/mask_test.go b/mask_test.go
new file mode 100644
index 0000000..4a7b8c7
--- /dev/null
+++ b/mask_test.go
@@ -0,0 +1,24 @@
+package websocket
+
+import (
+ "testing"
+
+ "github.com/google/go-cmp/cmp"
+)
+
+func Test_mask(t *testing.T) {
+ t.Parallel()
+
+ key := [4]byte{0xa, 0xb, 0xc, 0xff}
+ p := []byte{0xa, 0xb, 0xc, 0xf2, 0xc}
+ pos := 0
+ pos = mask(key, pos, p)
+
+ if exp := []byte{0, 0, 0, 0x0d, 0x6}; !cmp.Equal(exp, p) {
+ t.Fatalf("unexpected mask: %v", cmp.Diff(exp, p))
+ }
+
+ if exp := 1; !cmp.Equal(exp, pos) {
+ t.Fatalf("unexpected mask pos: %v", cmp.Diff(exp, pos))
+ }
+}
--
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