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author | Frédéric Guillot <fred@miniflux.net> | 2018-07-06 21:18:14 -0700 |
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committer | Frédéric Guillot <fred@miniflux.net> | 2018-07-06 21:18:14 -0700 |
commit | 459bb4531f92f8663afb6f36aa9be5b789bd591f (patch) | |
tree | f14e6c06b8e5c63612d1ff36f8cab40ae8a99d20 /vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go | |
parent | 34a3fe426b33a63f2d8e02d4a70c88f137fa5410 (diff) |
Update vendor dependencies
Diffstat (limited to 'vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go')
-rw-r--r-- | vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go b/vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go new file mode 100644 index 0000000..0cc4a8a --- /dev/null +++ b/vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go @@ -0,0 +1,35 @@ +// 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" + +// This is the Google App Engine standard variant based on reflect +// because the unsafe package and cgo are disallowed. + +import "reflect" + +// 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 && + reflect.ValueOf(&x[0]).Pointer() <= reflect.ValueOf(&y[len(y)-1]).Pointer() && + reflect.ValueOf(&y[0]).Pointer() <= reflect.ValueOf(&x[len(x)-1]).Pointer() +} + +// 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) +} |