Clash.Meta/component/generater/types.go
2025-02-04 00:44:18 +08:00

98 lines
2.4 KiB
Go

// Copy from https://github.com/WireGuard/wgctrl-go/blob/a9ab2273dd1075ea74b88c76f8757f8b4003fcbf/wgtypes/types.go#L71-L155
package generater
import (
"crypto/rand"
"encoding/base64"
"fmt"
"golang.org/x/crypto/curve25519"
)
// KeyLen is the expected key length for a WireGuard key.
const KeyLen = 32 // wgh.KeyLen
// A Key is a public, private, or pre-shared secret key. The Key constructor
// functions in this package can be used to create Keys suitable for each of
// these applications.
type Key [KeyLen]byte
// GenerateKey generates a Key suitable for use as a pre-shared secret key from
// a cryptographically safe source.
//
// The output Key should not be used as a private key; use GeneratePrivateKey
// instead.
func GenerateKey() (Key, error) {
b := make([]byte, KeyLen)
if _, err := rand.Read(b); err != nil {
return Key{}, fmt.Errorf("wgtypes: failed to read random bytes: %v", err)
}
return NewKey(b)
}
// GeneratePrivateKey generates a Key suitable for use as a private key from a
// cryptographically safe source.
func GeneratePrivateKey() (Key, error) {
key, err := GenerateKey()
if err != nil {
return Key{}, err
}
// Modify random bytes using algorithm described at:
// https://cr.yp.to/ecdh.html.
key[0] &= 248
key[31] &= 127
key[31] |= 64
return key, nil
}
// NewKey creates a Key from an existing byte slice. The byte slice must be
// exactly 32 bytes in length.
func NewKey(b []byte) (Key, error) {
if len(b) != KeyLen {
return Key{}, fmt.Errorf("wgtypes: incorrect key size: %d", len(b))
}
var k Key
copy(k[:], b)
return k, nil
}
// ParseKey parses a Key from a base64-encoded string, as produced by the
// Key.String method.
func ParseKey(s string) (Key, error) {
b, err := base64.StdEncoding.DecodeString(s)
if err != nil {
return Key{}, fmt.Errorf("wgtypes: failed to parse base64-encoded key: %v", err)
}
return NewKey(b)
}
// PublicKey computes a public key from the private key k.
//
// PublicKey should only be called when k is a private key.
func (k Key) PublicKey() Key {
var (
pub [KeyLen]byte
priv = [KeyLen]byte(k)
)
// ScalarBaseMult uses the correct base value per https://cr.yp.to/ecdh.html,
// so no need to specify it.
curve25519.ScalarBaseMult(&pub, &priv)
return Key(pub)
}
// String returns the base64-encoded string representation of a Key.
//
// ParseKey can be used to produce a new Key from this string.
func (k Key) String() string {
return base64.StdEncoding.EncodeToString(k[:])
}