vendor: update all dependencies

vendor/golang.org/x/crypto/internal/chacha20/chacha_generic.go

@@ -9,6 +9,8 @@ package chacha20
 import (
 	"crypto/cipher"
 	"encoding/binary"
+
+	"golang.org/x/crypto/internal/subtle"
 )
 
 // assert that *Cipher implements cipher.Stream
@@ -41,6 +43,13 @@ func New(key [8]uint32, nonce [3]uint32) *Cipher {
 // the src buffers was passed in a single run. That is, Cipher
 // maintains state and does not reset at each XORKeyStream call.
 func (s *Cipher) XORKeyStream(dst, src []byte) {
+	if len(dst) < len(src) {
+		panic("chacha20: output smaller than input")
+	}
+	if subtle.InexactOverlap(dst[:len(src)], src) {
+		panic("chacha20: invalid buffer overlap")
+	}
+
 	// xor src with buffered keystream first
 	if s.len != 0 {
 		buf := s.buf[len(s.buf)-s.len:]

vendor/golang.org/x/crypto/internal/subtle/aliasing.go

@@ -0,0 +1,30 @@
+// 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 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)
+}

vendor/golang.org/x/crypto/internal/subtle/aliasing_test.go

@@ -0,0 +1,48 @@
+// 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"
+
+	"golang.org/x/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},
+}
+
+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)
+	}
+}