1 files changed, 52 insertions, 0 deletions
diff --git a/vendor/mellium.im/sasl/xor_unaligned.go b/vendor/mellium.im/sasl/xor_unaligned.go
new file mode 100644
index 000000000..a6b6bebcc
--- /dev/null
+++ b/vendor/mellium.im/sasl/xor_unaligned.go
@@ -0,0 +1,52 @@
+// Copyright 2013 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.
+
+// This file was split out from Go's crypto/cipher/xor.go
+
+// +build 386 amd64 ppc64 ppc64le s390x appengine
+
+package sasl
+
+import (
+	"unsafe"
+)
+
+const wordSize = int(unsafe.Sizeof(uintptr(0)))
+
+// xorBytes xors in bulk. It only works on architectures that support unaligned
+// read/writes.
+func xorBytes(dst, a, b []byte) int {
+	n := len(a)
+	if len(b) < n {
+		n = len(b)
+	}
+
+	w := n / wordSize
+	if w > 0 {
+		dw := *(*[]uintptr)(unsafe.Pointer(&dst))
+		aw := *(*[]uintptr)(unsafe.Pointer(&a))
+		bw := *(*[]uintptr)(unsafe.Pointer(&b))
+		for i := 0; i < w; i++ {
+			dw[i] = aw[i] ^ bw[i]
+		}
+	}
+
+	for i := (n - n%wordSize); i < n; i++ {
+		dst[i] = a[i] ^ b[i]
+	}
+
+	return n
+}
+
+// xorWords XORs multiples of 4 or 8 bytes (depending on architecture.) The
+// arguments are assumed to be of equal length.
+func xorWords(dst, a, b []byte) {
+	dw := *(*[]uintptr)(unsafe.Pointer(&dst))
+	aw := *(*[]uintptr)(unsafe.Pointer(&a))
+	bw := *(*[]uintptr)(unsafe.Pointer(&b))
+	n := len(b) / wordSize
+	for i := 0; i < n; i++ {
+		dw[i] = aw[i] ^ bw[i]
+	}
+}