TUN-3403: Unit test for origin/proxy to test serving HTTP and Websocket

vendor/github.com/gobwas/ws/cipher.go

@@ -0,0 +1,61 @@
+package ws
+
+import (
+	"encoding/binary"
+)
+
+// Cipher applies XOR cipher to the payload using mask.
+// Offset is used to cipher chunked data (e.g. in io.Reader implementations).
+//
+// To convert masked data into unmasked data, or vice versa, the following
+// algorithm is applied.  The same algorithm applies regardless of the
+// direction of the translation, e.g., the same steps are applied to
+// mask the data as to unmask the data.
+func Cipher(payload []byte, mask [4]byte, offset int) {
+	n := len(payload)
+	if n < 8 {
+		for i := 0; i < n; i++ {
+			payload[i] ^= mask[(offset+i)%4]
+		}
+		return
+	}
+
+	// Calculate position in mask due to previously processed bytes number.
+	mpos := offset % 4
+	// Count number of bytes will processed one by one from the beginning of payload.
+	ln := remain[mpos]
+	// Count number of bytes will processed one by one from the end of payload.
+	// This is done to process payload by 8 bytes in each iteration of main loop.
+	rn := (n - ln) % 8
+
+	for i := 0; i < ln; i++ {
+		payload[i] ^= mask[(mpos+i)%4]
+	}
+	for i := n - rn; i < n; i++ {
+		payload[i] ^= mask[(mpos+i)%4]
+	}
+
+	// NOTE: we use here binary.LittleEndian regardless of what is real
+	// endianess on machine is. To do so, we have to use binary.LittleEndian in
+	// the masking loop below as well.
+	var (
+		m  = binary.LittleEndian.Uint32(mask[:])
+		m2 = uint64(m)<<32 | uint64(m)
+	)
+	// Skip already processed right part.
+	// Get number of uint64 parts remaining to process.
+	n = (n - ln - rn) >> 3
+	for i := 0; i < n; i++ {
+		var (
+			j     = ln + (i << 3)
+			chunk = payload[j : j+8]
+		)
+		p := binary.LittleEndian.Uint64(chunk)
+		p = p ^ m2
+		binary.LittleEndian.PutUint64(chunk, p)
+	}
+}
+
+// remain maps position in masking key [0,4) to number
+// of bytes that need to be processed manually inside Cipher().
+var remain = [4]int{0, 3, 2, 1}