| // 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 cipher | |
| // xorBytes xors the bytes in a and b. The destination should have enough | |
| // space, otherwise xorBytes will panic. Returns the number of bytes xor'd. | |
| func xorBytes(dst, a, b []byte) int { | |
| n := len(a) | |
| if len(b) < n { | |
| n = len(b) | |
| } | |
| if n == 0 { | |
| return 0 | |
| } | |
| _ = dst[n-1] | |
| xorBytesSSE2(&dst[0], &a[0], &b[0], n) // amd64 must have SSE2 | |
| return n | |
| } | |
| func xorWords(dst, a, b []byte) { | |
| xorBytes(dst, a, b) | |
| } | |
| //go:noescape | |
| func xorBytesSSE2(dst, a, b *byte, n int) |