File: sum_amd64.go

package info (click to toggle)
golang-go.crypto 1%3A0.36.0-1~exp1
  • links: PTS, VCS
  • area: main
  • in suites: experimental
  • size: 7,352 kB
  • sloc: asm: 27,990; ansic: 258; sh: 25; makefile: 6
file content (47 lines) | stat: -rw-r--r-- 1,119 bytes parent folder | download | duplicates (20)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
// Copyright 2012 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.

//go:build gc && !purego

package poly1305

//go:noescape
func update(state *macState, msg []byte)

// mac is a wrapper for macGeneric that redirects calls that would have gone to
// updateGeneric to update.
//
// Its Write and Sum methods are otherwise identical to the macGeneric ones, but
// using function pointers would carry a major performance cost.
type mac struct{ macGeneric }

func (h *mac) Write(p []byte) (int, error) {
	nn := len(p)
	if h.offset > 0 {
		n := copy(h.buffer[h.offset:], p)
		if h.offset+n < TagSize {
			h.offset += n
			return nn, nil
		}
		p = p[n:]
		h.offset = 0
		update(&h.macState, h.buffer[:])
	}
	if n := len(p) - (len(p) % TagSize); n > 0 {
		update(&h.macState, p[:n])
		p = p[n:]
	}
	if len(p) > 0 {
		h.offset += copy(h.buffer[h.offset:], p)
	}
	return nn, nil
}

func (h *mac) Sum(out *[16]byte) {
	state := h.macState
	if h.offset > 0 {
		update(&state, h.buffer[:h.offset])
	}
	finalize(out, &state.h, &state.s)
}