You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
34 lines
1.2 KiB
Go
34 lines
1.2 KiB
Go
// Copyright 2018 The Go 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 !purego
|
|
// +build !purego
|
|
|
|
// Package subtle implements functions that are often useful in cryptographic
|
|
// code but require careful thought to use correctly.
|
|
package subtle // import "golang.org/x/crypto/internal/subtle"
|
|
|
|
import "unsafe"
|
|
|
|
// AnyOverlap reports whether x and y share memory at any (not necessarily
|
|
// corresponding) index. The memory beyond the slice length is ignored.
|
|
func AnyOverlap(x, y []byte) bool {
|
|
return len(x) > 0 && len(y) > 0 &&
|
|
uintptr(unsafe.Pointer(&x[0])) <= uintptr(unsafe.Pointer(&y[len(y)-1])) &&
|
|
uintptr(unsafe.Pointer(&y[0])) <= uintptr(unsafe.Pointer(&x[len(x)-1]))
|
|
}
|
|
|
|
// InexactOverlap reports whether x and y share memory at any non-corresponding
|
|
// index. The memory beyond the slice length is ignored. Note that x and y can
|
|
// have different lengths and still not have any inexact overlap.
|
|
//
|
|
// InexactOverlap can be used to implement the requirements of the crypto/cipher
|
|
// AEAD, Block, BlockMode and Stream interfaces.
|
|
func InexactOverlap(x, y []byte) bool {
|
|
if len(x) == 0 || len(y) == 0 || &x[0] == &y[0] {
|
|
return false
|
|
}
|
|
return AnyOverlap(x, y)
|
|
}
|