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authorJordan <me@jordan.im>2022-02-10 19:10:54 -0700
committerJordan <me@jordan.im>2022-02-10 19:10:54 -0700
commit2f0b35e3c25bc4394f3288e1baa77d250cb510ed (patch)
tree121612506bb8de7fc132a385b282f1d02922d65d /vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go
parent7d1248be0bd4a6412467301924fa99d037028b8d (diff)
downloadkeep-2f0b35e3c25bc4394f3288e1baa77d250cb510ed.tar.gz
keep-2f0b35e3c25bc4394f3288e1baa77d250cb510ed.zip
misc: go mod vendor
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.go35
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
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+++ 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)
+}