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v/vlib/crypto/cipher/xor_generic.v
2019-08-07 08:59:00 +02:00

37 lines
949 B
Go

// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module cipher
// NOTE: Implement other versions (joe-c)
// xor_bytes xors the bytes in a and b. The destination should have enough
// space, otherwise xor_bytes will panic. Returns the number of bytes xor'd.
pub fn xor_bytes(dst mut []byte, a, b []byte) int {
mut n := a.len
if b.len < n {
n = b.len
}
if n == 0 {
return 0
}
safe_xor_bytes(mut dst, a, b, n)
return n
}
// n needs to be smaller or equal than the length of a and b.
pub fn safe_xor_bytes(dst mut []byte, a, b []byte, n int) {
for i := 0; i < n; i++ {
dst[i] = a[i] ^ b[i]
}
}
// fast_xor_words XORs multiples of 4 or 8 bytes (depending on architecture.)
// The slice arguments a and b are assumed to be of equal length.
pub fn xor_words(dst, a, b []byte) {
safe_xor_bytes(mut dst, a, b, b.len)
}