open-nomad/vendor/golang.org/x/crypto/internal/subtle/aliasing.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

33 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.
// +build !appengine
// 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)
}