diff options
Diffstat (limited to 'wgcfg/key.go')
| -rw-r--r-- | wgcfg/key.go | 182 |
1 files changed, 0 insertions, 182 deletions
diff --git a/wgcfg/key.go b/wgcfg/key.go deleted file mode 100644 index d75f0d9..0000000 --- a/wgcfg/key.go +++ /dev/null @@ -1,182 +0,0 @@ -package wgcfg - -import ( - "bytes" - cryptorand "crypto/rand" - "crypto/subtle" - "encoding/base64" - "encoding/hex" - "errors" - "fmt" - "strings" - - "golang.org/x/crypto/chacha20poly1305" - "golang.org/x/crypto/curve25519" -) - -const KeySize = 32 - -// PublicKey is curve25519 key. -// It is used by WireGuard to represent public and preshared keys. -type PublicKey [KeySize]byte - -func ParseKey(b64 string) (*PublicKey, error) { return parseKeyBase64(base64.StdEncoding, b64) } - -func ParseHexKey(s string) (PublicKey, error) { - b, err := hex.DecodeString(s) - if err != nil { - return PublicKey{}, &ParseError{"invalid hex key: " + err.Error(), s} - } - if len(b) != KeySize { - return PublicKey{}, &ParseError{fmt.Sprintf("invalid hex key length: %d", len(b)), s} - } - - var key PublicKey - copy(key[:], b) - return key, nil -} - -func ParsePrivateHexKey(v string) (PrivateKey, error) { - k, err := ParseHexKey(v) - if err != nil { - return PrivateKey{}, err - } - pk := PrivateKey(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 PublicKey) Base64() string { return base64.StdEncoding.EncodeToString(k[:]) } -func (k PublicKey) String() string { return k.ShortString() } -func (k PublicKey) HexString() string { return hex.EncodeToString(k[:]) } -func (k PublicKey) Equal(k2 PublicKey) bool { return subtle.ConstantTimeCompare(k[:], k2[:]) == 1 } - -func (k *PublicKey) ShortString() string { - long := k.Base64() - return "[" + long[0:5] + "]" -} - -func (k PublicKey) IsZero() bool { - var zeros PublicKey - return subtle.ConstantTimeCompare(zeros[:], k[:]) == 1 -} - -// PrivateKey is curve25519 key. -// It is used by WireGuard to represent private keys. -type PrivateKey [KeySize]byte - -// NewPrivateKey generates a new curve25519 secret key. -// It conforms to the format described on https://cr.yp.to/ecdh.html. -func NewPrivateKey() (pk PrivateKey, err error) { - _, err = cryptorand.Read(pk[:]) - if err != nil { - return PrivateKey{}, err - } - pk.clamp() - return pk, nil -} - -func ParsePrivateKey(b64 string) (*PrivateKey, error) { - k, err := parseKeyBase64(base64.StdEncoding, b64) - return (*PrivateKey)(k), err -} - -func (k *PrivateKey) String() string { return base64.StdEncoding.EncodeToString(k[:]) } -func (k *PrivateKey) HexString() string { return hex.EncodeToString(k[:]) } -func (k *PrivateKey) Equal(k2 PrivateKey) bool { return subtle.ConstantTimeCompare(k[:], k2[:]) == 1 } - -func (k PrivateKey) IsZero() bool { - var zeros PrivateKey - return subtle.ConstantTimeCompare(zeros[:], k[:]) == 1 -} - -func (k *PrivateKey) clamp() { - k[0] &= 248 - k[31] = (k[31] & 127) | 64 -} - -// Public computes the public key matching this curve25519 secret key. -func (k PrivateKey) Public() PublicKey { - if k.IsZero() { - panic("wgcfg: tried to generate public key for a zero key") - } - var p [KeySize]byte - curve25519.ScalarBaseMult(&p, (*[KeySize]byte)(&k)) - return (PublicKey)(p) -} - -func (k PrivateKey) MarshalText() ([]byte, error) { - buf := new(bytes.Buffer) - fmt.Fprintf(buf, `privkey:%x`, k[:]) - return buf.Bytes(), nil -} - -func (k *PrivateKey) UnmarshalText(b []byte) error { - s := string(b) - if !strings.HasPrefix(s, `privkey:`) { - return errors.New("wgcfg.PrivateKey: UnmarshalText not given a private-key string") - } - s = strings.TrimPrefix(s, `privkey:`) - key, err := ParseHexKey(s) - if err != nil { - return fmt.Errorf("wgcfg.PrivateKey: UnmarshalText: %v", err) - } - copy(k[:], key[:]) - return nil -} - -func (k PrivateKey) SharedSecret(pub PublicKey) (ss [KeySize]byte) { - apk := (*[KeySize]byte)(&pub) - ask := (*[KeySize]byte)(&k) - curve25519.ScalarMult(&ss, ask, apk) - return ss -} - -func parseKeyBase64(enc *base64.Encoding, s string) (*PublicKey, error) { - k, err := enc.DecodeString(s) - if err != nil { - return nil, &ParseError{"Invalid key: " + err.Error(), s} - } - if len(k) != KeySize { - return nil, &ParseError{"Keys must decode to exactly 32 bytes", s} - } - var key PublicKey - copy(key[:], k) - return &key, nil -} - -func ParseSymmetricKey(b64 string) (SymmetricKey, error) { - k, err := parseKeyBase64(base64.StdEncoding, b64) - if err != nil { - return SymmetricKey{}, err - } - return SymmetricKey(*k), nil -} - -func ParseSymmetricHexKey(s string) (SymmetricKey, error) { - b, err := hex.DecodeString(s) - if err != nil { - return SymmetricKey{}, &ParseError{"invalid symmetric hex key: " + err.Error(), s} - } - if len(b) != chacha20poly1305.KeySize { - return SymmetricKey{}, &ParseError{fmt.Sprintf("invalid symmetric hex key length: %d", len(b)), s} - } - var key SymmetricKey - copy(key[:], b) - return key, nil -} - -// SymmetricKey is a 32-byte value used as a pre-shared key. -type SymmetricKey [chacha20poly1305.KeySize]byte - -func (k SymmetricKey) Base64() string { return base64.StdEncoding.EncodeToString(k[:]) } -func (k SymmetricKey) String() string { return "sym:" + k.Base64()[:8] } -func (k SymmetricKey) HexString() string { return hex.EncodeToString(k[:]) } -func (k SymmetricKey) IsZero() bool { return k.Equal(SymmetricKey{}) } -func (k SymmetricKey) Equal(k2 SymmetricKey) bool { return subtle.ConstantTimeCompare(k[:], k2[:]) == 1 } |