DroidFS/app/libgocryptfs/gocryptfs_internal/jacobsa_crypto/common/xor.go
2020-07-17 22:12:20 +02:00

34 lines
1.1 KiB
Go

// Copyright 2012 Aaron Jacobs. All Rights Reserved.
// Author: aaronjjacobs@gmail.com (Aaron Jacobs)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package common
import "log"
// Xor computes `a XOR b`, as defined by RFC 4493. dst, a, and b must all have
// the same length.
func Xor(dst []byte, a []byte, b []byte) {
// TODO(jacobsa): Consider making this a helper function with known sizes
// where it is most hot, then even trying to inline it entirely.
if len(dst) != len(a) || len(a) != len(b) {
log.Panicf("Bad buffer lengths: %d, %d, %d", len(dst), len(a), len(b))
}
for i, _ := range a {
dst[i] = a[i] ^ b[i]
}
}