Adding upstream version 1.17.13.upstream/1.17.13upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 161 insertions, 0 deletions

diff --git a/src/crypto/internal/randutil/randutil.go b/src/crypto/internal/randutil/randutil.go
new file mode 100644
index 0000000..84b1295
--- /dev/null
+++ b/src/crypto/internal/randutil/randutil.go
@@ -0,0 +1,38 @@
+// 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.
+
+// Package randutil contains internal randomness utilities for various
+// crypto packages.
+package randutil
+
+import (
+	"io"
+	"sync"
+)
+
+var (
+	closedChanOnce sync.Once
+	closedChan     chan struct{}
+)
+
+// MaybeReadByte reads a single byte from r with ~50% probability. This is used
+// to ensure that callers do not depend on non-guaranteed behaviour, e.g.
+// assuming that rsa.GenerateKey is deterministic w.r.t. a given random stream.
+//
+// This does not affect tests that pass a stream of fixed bytes as the random
+// source (e.g. a zeroReader).
+func MaybeReadByte(r io.Reader) {
+	closedChanOnce.Do(func() {
+		closedChan = make(chan struct{})
+		close(closedChan)
+	})
+
+	select {
+	case <-closedChan:
+		return
+	case <-closedChan:
+		var buf [1]byte
+		r.Read(buf[:])
+	}
+}
diff --git a/src/crypto/internal/subtle/aliasing.go b/src/crypto/internal/subtle/aliasing.go
new file mode 100644
index 0000000..86e0f3c
--- /dev/null
+++ b/src/crypto/internal/subtle/aliasing.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.
+
+//go:build !appengine
+// +build !appengine
+
+// Package subtle implements functions that are often useful in cryptographic
+// code but require careful thought to use correctly.
+//
+// This is a mirror of golang.org/x/crypto/internal/subtle.
+package subtle // import "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)
+}
diff --git a/src/crypto/internal/subtle/aliasing_appengine.go b/src/crypto/internal/subtle/aliasing_appengine.go
new file mode 100644
index 0000000..35b442f
--- /dev/null
+++ b/src/crypto/internal/subtle/aliasing_appengine.go
@@ -0,0 +1,38 @@
+// 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 appengine
+// +build appengine
+
+// Package subtle implements functions that are often useful in cryptographic
+// code but require careful thought to use correctly.
+//
+// This is a mirror of golang.org/x/crypto/internal/subtle.
+package subtle // import "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)
+}
diff --git a/src/crypto/internal/subtle/aliasing_test.go b/src/crypto/internal/subtle/aliasing_test.go
new file mode 100644
index 0000000..f1e7238
--- /dev/null
+++ b/src/crypto/internal/subtle/aliasing_test.go
@@ -0,0 +1,50 @@
+// 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.
+
+package subtle_test
+
+import (
+	"testing"
+
+	"crypto/internal/subtle"
+)
+
+var a, b [100]byte
+
+var aliasingTests = []struct {
+	x, y                       []byte
+	anyOverlap, inexactOverlap bool
+}{
+	{a[:], b[:], false, false},
+	{a[:], b[:0], false, false},
+	{a[:], b[:50], false, false},
+	{a[40:50], a[50:60], false, false},
+	{a[40:50], a[60:70], false, false},
+	{a[:51], a[50:], true, true},
+	{a[:], a[:], true, false},
+	{a[:50], a[:60], true, false},
+	{a[:], nil, false, false},
+	{nil, nil, false, false},
+	{a[:], a[:0], false, false},
+	{a[:10], a[:10:20], true, false},
+	{a[:10], a[5:10:20], true, true},
+}
+
+func testAliasing(t *testing.T, i int, x, y []byte, anyOverlap, inexactOverlap bool) {
+	any := subtle.AnyOverlap(x, y)
+	if any != anyOverlap {
+		t.Errorf("%d: wrong AnyOverlap result, expected %v, got %v", i, anyOverlap, any)
+	}
+	inexact := subtle.InexactOverlap(x, y)
+	if inexact != inexactOverlap {
+		t.Errorf("%d: wrong InexactOverlap result, expected %v, got %v", i, inexactOverlap, any)
+	}
+}
+
+func TestAliasing(t *testing.T) {
+	for i, tt := range aliasingTests {
+		testAliasing(t, i, tt.x, tt.y, tt.anyOverlap, tt.inexactOverlap)
+		testAliasing(t, i, tt.y, tt.x, tt.anyOverlap, tt.inexactOverlap)
+	}
+}