初版功能完成

internal/bootstrap/token.go

@@ -0,0 +1,107 @@
+package bootstrap
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/base64"
+	"fmt"
+	"sync"
+
+	"remlink/internal/database"
+)
+
+const joinTokenSetting = "join_token"
+
+// JoinTokens maintains the single rotatable enrollment secret in settings.
+type JoinTokens struct {
+	mu sync.Mutex
+	db databaseSettings
+}
+
+type databaseSettings interface {
+	Get(context.Context, string) (string, bool, error)
+	Set(context.Context, string, string) error
+}
+
+type settingsAdapter struct{ store *database.Store }
+
+func (a settingsAdapter) Get(ctx context.Context, key string) (string, bool, error) {
+	return database.GetSetting(ctx, a.store.DB(), key)
+}
+
+func (a settingsAdapter) Set(ctx context.Context, key, value string) error {
+	return database.SetSetting(ctx, a.store.DB(), key, value)
+}
+
+// NewJoinTokens binds token management to Server settings.
+func NewJoinTokens(store *database.Store) *JoinTokens {
+	return &JoinTokens{db: settingsAdapter{store: store}}
+}
+
+// Ensure returns the current Join Token, generating it on first startup.
+func (m *JoinTokens) Ensure(ctx context.Context) (string, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	value, found, err := m.db.Get(ctx, joinTokenSetting)
+	if err != nil {
+		return "", err
+	}
+	if found {
+		return value, nil
+	}
+	return m.rotateLocked(ctx)
+}
+
+// Rotate revokes the previous Join Token and returns a new one.
+func (m *JoinTokens) Rotate(ctx context.Context) (string, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.rotateLocked(ctx)
+}
+
+// Verify compares a submitted token without data-dependent early exit.
+func (m *JoinTokens) Verify(ctx context.Context, submitted string) (bool, error) {
+	current, err := m.Ensure(ctx)
+	if err != nil {
+		return false, err
+	}
+	return subtle.ConstantTimeCompare([]byte(current), []byte(submitted)) == 1, nil
+}
+
+func (m *JoinTokens) rotateLocked(ctx context.Context) (string, error) {
+	value, err := randomToken()
+	if err != nil {
+		return "", err
+	}
+	if err := m.db.Set(ctx, joinTokenSetting, value); err != nil {
+		return "", err
+	}
+	return value, nil
+}
+
+func randomToken() (string, error) {
+	bytes := make([]byte, 32)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", fmt.Errorf("generate random token: %w", err)
+	}
+	return base64.RawURLEncoding.EncodeToString(bytes), nil
+}
+
+func newNodeToken() (plain string, hash []byte, err error) {
+	plain, err = randomToken()
+	if err != nil {
+		return "", nil, err
+	}
+	digest := sha256.Sum256([]byte(plain))
+	return plain, digest[:], nil
+}
+
+func nodeTokenMatches(storedHash []byte, submitted string) bool {
+	if len(storedHash) != sha256.Size || submitted == "" {
+		return false
+	}
+	digest := sha256.Sum256([]byte(submitted))
+	return subtle.ConstantTimeCompare(storedHash, digest[:]) == 1
+}