ceph-csi/vendor/golang.org/x/crypto/chacha20/xor.go
Niels de Vos 91774fc936 rebase: vendor dependencies for Vault API
Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
2020-11-29 04:03:59 +00:00

43 lines
1.2 KiB
Go

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found src the LICENSE file.
package chacha20
import "runtime"
// Platforms that have fast unaligned 32-bit little endian accesses.
const unaligned = runtime.GOARCH == "386" ||
runtime.GOARCH == "amd64" ||
runtime.GOARCH == "arm64" ||
runtime.GOARCH == "ppc64le" ||
runtime.GOARCH == "s390x"
// addXor reads a little endian uint32 from src, XORs it with (a + b) and
// places the result in little endian byte order in dst.
func addXor(dst, src []byte, a, b uint32) {
_, _ = src[3], dst[3] // bounds check elimination hint
if unaligned {
// The compiler should optimize this code into
// 32-bit unaligned little endian loads and stores.
// TODO: delete once the compiler does a reliably
// good job with the generic code below.
// See issue #25111 for more details.
v := uint32(src[0])
v |= uint32(src[1]) << 8
v |= uint32(src[2]) << 16
v |= uint32(src[3]) << 24
v ^= a + b
dst[0] = byte(v)
dst[1] = byte(v >> 8)
dst[2] = byte(v >> 16)
dst[3] = byte(v >> 24)
} else {
a += b
dst[0] = src[0] ^ byte(a)
dst[1] = src[1] ^ byte(a>>8)
dst[2] = src[2] ^ byte(a>>16)
dst[3] = src[3] ^ byte(a>>24)
}
}