initial: ZeroTier-like P2P mesh VPN server with multi-tenant Web UI

2026-06-17 03:50:23 +08:00
commit ee5f036325
74 changed files with 9517 additions and 0 deletions
--- a/internal/identity/identity.go
+++ b/internal/identity/identity.go
@@ -0,0 +1,142 @@
+package identity
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+)
+
+type Identity struct {
+	PublicKey  ed25519.PublicKey  `json:"public_key"`
+	PrivateKey ed25519.PrivateKey `json:"private_key"`
+	Address    Address            `json:"address"`
+}
+
+type Address [5]byte
+
+func (a Address) String() string {
+	return hex.EncodeToString(a[:])
+}
+
+func (a Address) MarshalText() ([]byte, error) {
+	return []byte(a.String()), nil
+}
+
+func (a *Address) UnmarshalText(text []byte) error {
+	decoded, err := hex.DecodeString(string(text))
+	if err != nil {
+		return err
+	}
+	if len(decoded) != 5 {
+		return fmt.Errorf("address must be 5 bytes")
+	}
+	copy(a[:], decoded)
+	return nil
+}
+
+func AddressFromPublicKey(pubKey []byte) Address {
+	var addr Address
+	h := hashBytes(pubKey)
+	copy(addr[:], h[:5])
+	return addr
+}
+
+func Generate() *Identity {
+	pub, priv, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		panic(err)
+	}
+	return &Identity{
+		PublicKey:  pub,
+		PrivateKey: priv,
+		Address:    AddressFromPublicKey(pub),
+	}
+}
+
+func (id *Identity) PublicKeyHex() string {
+	return hex.EncodeToString(id.PublicKey)
+}
+
+func (id *Identity) PrivateKeyHex() string {
+	return hex.EncodeToString(id.PrivateKey)
+}
+
+func (id *Identity) Sign(data []byte) []byte {
+	return ed25519.Sign(id.PrivateKey, data)
+}
+
+func (id *Identity) Verify(data, sig []byte) bool {
+	return ed25519.Verify(id.PublicKey, data, sig)
+}
+
+func LoadOrGenerate(path string) (*Identity, error) {
+	data, err := os.ReadFile(path)
+	if err == nil {
+		return Parse(strings.TrimSpace(string(data)))
+	}
+	if !os.IsNotExist(err) {
+		return nil, err
+	}
+	id := Generate()
+	encoded, err := id.Serialize()
+	if err != nil {
+		return nil, err
+	}
+	if err := os.MkdirAll(dir(path), 0755); err != nil {
+		return nil, err
+	}
+	if err := os.WriteFile(path, []byte(encoded), 0600); err != nil {
+		return nil, err
+	}
+	return id, nil
+}
+
+func (id *Identity) Serialize() (string, error) {
+	data, err := json.Marshal(id)
+	if err != nil {
+		return "", err
+	}
+	return string(data), nil
+}
+
+func Parse(data string) (*Identity, error) {
+	var id Identity
+	if err := json.Unmarshal([]byte(data), &id); err != nil {
+		return nil, fmt.Errorf("parse identity: %w", err)
+	}
+	if len(id.PrivateKey) == 0 {
+		return nil, fmt.Errorf("invalid identity: no private key")
+	}
+	id.Address = AddressFromPublicKey(id.PublicKey)
+	return &id, nil
+}
+
+func dir(path string) string {
+	idx := strings.LastIndex(path, "/")
+	if idx == -1 {
+		idx = strings.LastIndex(path, "\\")
+	}
+	if idx == -1 {
+		return "."
+	}
+	return path[:idx]
+}
+
+func hashBytes(data []byte) []byte {
+	h := make([]byte, 32)
+	for i, b := range data {
+		h[i%32] ^= b
+	}
+	// simple hash expansion
+	for round := 0; round < 3; round++ {
+		for i := 0; i < 32; i++ {
+			h[i] = h[i] ^ h[(i+1)%32] ^ h[(i+7)%32]
+			h[i] = (h[i] << 3) | (h[i] >> 5)
+		}
+	}
+	return h
+}