mirror of
https://github.com/tailscale/tailscale.git
synced 2024-12-04 23:45:34 +00:00
4037fc25c5
Pointer receivers used with MarshalJSON are code rakes. https://github.com/golang/go/issues/22967 https://github.com/dominikh/go-tools/issues/911 I just stepped on one, and it hurt. Turn it over. While we're here, optimize the code a bit. name old time/op new time/op delta MarshalJSON-8 184ns ± 0% 44ns ± 0% -76.03% (p=0.000 n=20+19) name old alloc/op new alloc/op delta MarshalJSON-8 184B ± 0% 80B ± 0% -56.52% (p=0.000 n=20+20) name old allocs/op new allocs/op delta MarshalJSON-8 4.00 ± 0% 1.00 ± 0% -75.00% (p=0.000 n=20+20) Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
240 lines
6.1 KiB
Go
240 lines
6.1 KiB
Go
// Copyright (c) 2020 Tailscale Inc & 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 wgkey contains types and helpers for WireGuard keys.
|
|
// It is very similar to package tailscale.com/types/key,
|
|
// which is also used for curve25519 keys.
|
|
// These keys are used for WireGuard clients;
|
|
// those keys are used in other curve25519 clients.
|
|
package wgkey
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/rand"
|
|
"crypto/subtle"
|
|
"encoding/base64"
|
|
"encoding/hex"
|
|
"errors"
|
|
"fmt"
|
|
"strings"
|
|
|
|
"golang.org/x/crypto/chacha20poly1305"
|
|
"golang.org/x/crypto/curve25519"
|
|
)
|
|
|
|
// Size is the number of bytes in a curve25519 key.
|
|
const Size = 32
|
|
|
|
// A Key is a curve25519 key.
|
|
// It is used by WireGuard to represent public and preshared keys.
|
|
type Key [Size]byte
|
|
|
|
// NewPreshared generates a new random Key.
|
|
func NewPreshared() (*Key, error) {
|
|
var k [Size]byte
|
|
_, err := rand.Read(k[:])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return (*Key)(&k), nil
|
|
}
|
|
|
|
func Parse(b64 string) (*Key, error) { return parseBase64(base64.StdEncoding, b64) }
|
|
|
|
func ParseHex(s string) (Key, error) {
|
|
b, err := hex.DecodeString(s)
|
|
if err != nil {
|
|
return Key{}, fmt.Errorf("invalid hex key (%q): %w", s, err)
|
|
}
|
|
if len(b) != Size {
|
|
return Key{}, fmt.Errorf("invalid hex key (%q): length=%d, want %d", s, len(b), Size)
|
|
}
|
|
|
|
var key Key
|
|
copy(key[:], b)
|
|
return key, nil
|
|
}
|
|
|
|
func ParsePrivateHex(v string) (Private, error) {
|
|
k, err := ParseHex(v)
|
|
if err != nil {
|
|
return Private{}, err
|
|
}
|
|
pk := Private(k)
|
|
if pk.IsZero() {
|
|
// Do not clamp a zero key, pass the zero through
|
|
// (much like NaN propagation) so that IsZero reports
|
|
// a useful result.
|
|
return pk, nil
|
|
}
|
|
pk.clamp()
|
|
return pk, nil
|
|
}
|
|
|
|
func (k Key) Base64() string { return base64.StdEncoding.EncodeToString(k[:]) }
|
|
func (k Key) String() string { return k.ShortString() }
|
|
func (k Key) HexString() string { return hex.EncodeToString(k[:]) }
|
|
func (k Key) Equal(k2 Key) bool { return subtle.ConstantTimeCompare(k[:], k2[:]) == 1 }
|
|
|
|
func (k *Key) ShortString() string {
|
|
long := k.Base64()
|
|
return "[" + long[0:5] + "]"
|
|
}
|
|
|
|
func (k *Key) IsZero() bool {
|
|
if k == nil {
|
|
return true
|
|
}
|
|
var zeros Key
|
|
return subtle.ConstantTimeCompare(zeros[:], k[:]) == 1
|
|
}
|
|
|
|
func (k Key) MarshalJSON() ([]byte, error) {
|
|
buf := make([]byte, 2+len(k)*2)
|
|
buf[0] = '"'
|
|
hex.Encode(buf[1:], k[:])
|
|
buf[len(buf)-1] = '"'
|
|
return buf, nil
|
|
}
|
|
|
|
func (k *Key) UnmarshalJSON(b []byte) error {
|
|
if k == nil {
|
|
return errors.New("wgkey.Key: UnmarshalJSON on nil pointer")
|
|
}
|
|
if len(b) < 3 || b[0] != '"' || b[len(b)-1] != '"' {
|
|
return errors.New("wgkey.Key: UnmarshalJSON not given a string")
|
|
}
|
|
b = b[1 : len(b)-1]
|
|
key, err := ParseHex(string(b))
|
|
if err != nil {
|
|
return fmt.Errorf("wgkey.Key: UnmarshalJSON: %v", err)
|
|
}
|
|
copy(k[:], key[:])
|
|
return nil
|
|
}
|
|
|
|
func (a *Key) LessThan(b *Key) bool {
|
|
for i := range a {
|
|
if a[i] < b[i] {
|
|
return true
|
|
} else if a[i] > b[i] {
|
|
return false
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
// A Private is a curve25519 key.
|
|
// It is used by WireGuard to represent private keys.
|
|
type Private [Size]byte
|
|
|
|
// NewPrivate generates a new curve25519 secret key.
|
|
// It conforms to the format described on https://cr.yp.to/ecdh.html.
|
|
func NewPrivate() (Private, error) {
|
|
k, err := NewPreshared()
|
|
if err != nil {
|
|
return Private{}, err
|
|
}
|
|
k[0] &= 248
|
|
k[31] = (k[31] & 127) | 64
|
|
return (Private)(*k), nil
|
|
}
|
|
|
|
func ParsePrivate(b64 string) (*Private, error) {
|
|
k, err := parseBase64(base64.StdEncoding, b64)
|
|
return (*Private)(k), err
|
|
}
|
|
|
|
func (k *Private) String() string { return base64.StdEncoding.EncodeToString(k[:]) }
|
|
func (k *Private) HexString() string { return hex.EncodeToString(k[:]) }
|
|
func (k *Private) Equal(k2 Private) bool { return subtle.ConstantTimeCompare(k[:], k2[:]) == 1 }
|
|
|
|
func (k *Private) IsZero() bool {
|
|
pk := Key(*k)
|
|
return pk.IsZero()
|
|
}
|
|
|
|
func (k *Private) clamp() {
|
|
k[0] &= 248
|
|
k[31] = (k[31] & 127) | 64
|
|
}
|
|
|
|
// Public computes the public key matching this curve25519 secret key.
|
|
func (k *Private) Public() Key {
|
|
pk := Key(*k)
|
|
if pk.IsZero() {
|
|
panic("Tried to generate emptyPrivate.Public()")
|
|
}
|
|
var p [Size]byte
|
|
curve25519.ScalarBaseMult(&p, (*[Size]byte)(k))
|
|
return (Key)(p)
|
|
}
|
|
|
|
func (k Private) MarshalText() ([]byte, error) {
|
|
// TODO(josharian): use encoding/hex instead?
|
|
buf := new(bytes.Buffer)
|
|
fmt.Fprintf(buf, `privkey:%x`, k[:])
|
|
return buf.Bytes(), nil
|
|
}
|
|
|
|
func (k *Private) UnmarshalText(b []byte) error {
|
|
s := string(b)
|
|
if !strings.HasPrefix(s, `privkey:`) {
|
|
return errors.New("wgkey.Private: UnmarshalText not given a private-key string")
|
|
}
|
|
s = strings.TrimPrefix(s, `privkey:`)
|
|
key, err := ParseHex(s)
|
|
if err != nil {
|
|
return fmt.Errorf("wgkey.Private: UnmarshalText: %v", err)
|
|
}
|
|
copy(k[:], key[:])
|
|
return nil
|
|
}
|
|
|
|
func parseBase64(enc *base64.Encoding, s string) (*Key, error) {
|
|
k, err := enc.DecodeString(s)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("invalid key (%q): %w", s, err)
|
|
}
|
|
if len(k) != Size {
|
|
return nil, fmt.Errorf("invalid key (%q): length=%d, want %d", s, len(k), Size)
|
|
}
|
|
var key Key
|
|
copy(key[:], k)
|
|
return &key, nil
|
|
}
|
|
|
|
func ParseSymmetric(b64 string) (Symmetric, error) {
|
|
k, err := parseBase64(base64.StdEncoding, b64)
|
|
if err != nil {
|
|
return Symmetric{}, err
|
|
}
|
|
return Symmetric(*k), nil
|
|
}
|
|
|
|
func ParseSymmetricHex(s string) (Symmetric, error) {
|
|
b, err := hex.DecodeString(s)
|
|
if err != nil {
|
|
return Symmetric{}, fmt.Errorf("invalid symmetric hex key (%q): %w", s, err)
|
|
}
|
|
if len(b) != chacha20poly1305.KeySize {
|
|
return Symmetric{}, fmt.Errorf("invalid symmetric hex key length (%q): length=%d, want %d", s, len(b), chacha20poly1305.KeySize)
|
|
}
|
|
var key Symmetric
|
|
copy(key[:], b)
|
|
return key, nil
|
|
}
|
|
|
|
// Symmetric is a chacha20poly1305 key.
|
|
// It is used by WireGuard to represent pre-shared symmetric keys.
|
|
type Symmetric [chacha20poly1305.KeySize]byte
|
|
|
|
func (k Symmetric) Base64() string { return base64.StdEncoding.EncodeToString(k[:]) }
|
|
func (k Symmetric) String() string { return "sym:" + k.Base64()[:8] }
|
|
func (k Symmetric) HexString() string { return hex.EncodeToString(k[:]) }
|
|
func (k Symmetric) IsZero() bool { return k.Equal(Symmetric{}) }
|
|
func (k Symmetric) Equal(k2 Symmetric) bool {
|
|
return subtle.ConstantTimeCompare(k[:], k2[:]) == 1
|
|
}
|