gotosocial/vendor/github.com/gorilla/websocket/mask.go
dependabot[bot] 2eb8b8eeb4
[chore]: Bump github.com/gorilla/websocket from 1.5.0 to 1.5.1 (#2335)
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: kim <grufwub@gmail.com>
2023-11-28 11:05:07 +00:00

60 lines
1.3 KiB
Go

// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved. Use of
// this source code is governed by a BSD-style license that can be found in the
// LICENSE file.
//go:build !appengine
// +build !appengine
package websocket
import "unsafe"
// #nosec G103 -- (CWE-242) Has been audited
const wordSize = int(unsafe.Sizeof(uintptr(0)))
func maskBytes(key [4]byte, pos int, b []byte) int {
// Mask one byte at a time for small buffers.
if len(b) < 2*wordSize {
for i := range b {
b[i] ^= key[pos&3]
pos++
}
return pos & 3
}
// Mask one byte at a time to word boundary.
//#nosec G103 -- (CWE-242) Has been audited
if n := int(uintptr(unsafe.Pointer(&b[0]))) % wordSize; n != 0 {
n = wordSize - n
for i := range b[:n] {
b[i] ^= key[pos&3]
pos++
}
b = b[n:]
}
// Create aligned word size key.
var k [wordSize]byte
for i := range k {
k[i] = key[(pos+i)&3]
}
//#nosec G103 -- (CWE-242) Has been audited
kw := *(*uintptr)(unsafe.Pointer(&k))
// Mask one word at a time.
n := (len(b) / wordSize) * wordSize
for i := 0; i < n; i += wordSize {
//#nosec G103 -- (CWE-242) Has been audited
*(*uintptr)(unsafe.Pointer(uintptr(unsafe.Pointer(&b[0])) + uintptr(i))) ^= kw
}
// Mask one byte at a time for remaining bytes.
b = b[n:]
for i := range b {
b[i] ^= key[pos&3]
pos++
}
return pos & 3
}