Merge pull request #299 from leookun/fix/issue-298-per-user-ca

Fix shared root CA by generating one per installation

cursor-proxy-debugger/proxy.go

@@ -28,6 +28,7 @@ type exchangeContext struct {
 type Server struct {
 	config      Config
 	certManager *certs.Manager
+	caCertPEM   []byte
 	store       *exchangeStore
 	counter     atomic.Uint64
 	proxyServer *http.Server
@@ -43,13 +44,14 @@ func New(config Config) (*Server, error) {
 	if err := validateLoopbackAddress(config.UIAddr); err != nil {
 		return nil, err
 	}
-	manager, err := certs.NewEmbeddedManager()
+	manager, caCertPEM, err := certs.NewGeneratedManager()
 	if err != nil {
 		return nil, fmt.Errorf("加载 MITM CA 失败：%w", err)
 	}
 	server := &Server{
 		config:      config,
 		certManager: manager,
+		caCertPEM:   caCertPEM,
 		store:       newExchangeStore(config.MaxExchanges),
 	}
 	proxyHandler, err := server.newProxyHandler()

cursor-proxy-debugger/web.go

@@ -8,8 +8,6 @@ import (
 	"net/http"
 	"strings"
 	"time"
-
-	"cursor/internal/certs"
 )
 
 //go:embed web/*
@@ -93,7 +91,7 @@ func (server *Server) handleEvents(writer http.ResponseWriter, request *http.Req
 func (server *Server) handleCACertificate(writer http.ResponseWriter, _ *http.Request) {
 	writer.Header().Set("Content-Type", "application/x-x509-ca-cert")
 	writer.Header().Set("Content-Disposition", `attachment; filename="cursor-local-proxy-ca.crt"`)
-	_, _ = writer.Write(certs.EmbeddedCACertPEM())
+	_, _ = writer.Write(server.caCertPEM)
 }
 
 func writeJSON(writer http.ResponseWriter, status int, payload any) {

internal/app/runner.go

@@ -70,20 +70,21 @@ func Run(resources EmbeddedResources) error {
 	logger.Init()
 	netproxy.InstallDefaultTransport()
 
-	embeddedCACertPEM := certs.EmbeddedCACertPEM()
-	logEmbeddedCAInfo(embeddedCACertPEM)
-
-	certManager, err := certs.NewEmbeddedManager()
+	if err := appdata.EnsureAssistantHome(); err != nil {
+		return err
+	}
+	certManager, caCertPEM, err := certs.LoadOrCreateManager(appdata.CACertFilePath(), appdata.CAKeyFilePath())
 	if err != nil {
 		return err
 	}
+	logCAInfo(caCertPEM)
 
 	defaultBackendBaseURL := "http://" + serverconfig.DefaultBackendListenAddr
 	proxyServer, err := mitm.NewProxyServer(serverconfig.DefaultProxyListenAddr, defaultBackendBaseURL, "", "", certManager)
 	if err != nil {
 		return err
 	}
-	proxyService := bridge.NewProxyService(proxyServer, certManager, embeddedCACertPEM)
+	proxyService := bridge.NewProxyService(proxyServer, certManager, caCertPEM)
 	adAssetBaseURL := defaultBackendBaseURL
 	if cfg, err := proxyService.LoadUserConfig(); err == nil {
 		adAssetBaseURL = browserReachableLoopbackBaseURL(cfg.BackendListenAddr)
@@ -442,20 +443,20 @@ func browserReachableLoopbackBaseURL(listenAddr string) string {
 	return "http://" + net.JoinHostPort(host, port)
 }
 
-// logEmbeddedCAInfo 用于处理与 logEmbeddedCAInfo 相关的逻辑。
-func logEmbeddedCAInfo(certPEM []byte) {
+// logCAInfo 记录当前安装专属 CA 的公开信息。
+func logCAInfo(certPEM []byte) {
 	if len(certPEM) == 0 {
-		logger.Errorf("embedded CA is empty")
+		logger.Errorf("installation CA is empty")
 		return
 	}
-	cert, err := parseEmbeddedCert(certPEM)
+	cert, err := parseCert(certPEM)
 	if err != nil {
-		logger.Errorf("parse embedded CA failed: %v", err)
+		logger.Errorf("parse installation CA failed: %v", err)
 		return
 	}
 	sum := sha256.Sum256(cert.Raw)
 	logger.Infof(
-		"embedded CA loaded: sha256=%s subject=%s valid=%s~%s",
+		"installation CA loaded: sha256=%s subject=%s valid=%s~%s",
 		strings.ToUpper(hex.EncodeToString(sum[:])),
 		cert.Subject.String(),
 		cert.NotBefore.Format(time.RFC3339),
@@ -463,8 +464,8 @@ func logEmbeddedCAInfo(certPEM []byte) {
 	)
 }
 
-// parseEmbeddedCert 用于处理与 parseEmbeddedCert 相关的逻辑。
-func parseEmbeddedCert(data []byte) (*x509.Certificate, error) {
+// parseCert 解析 DER 或 PEM 编码的证书。
+func parseCert(data []byte) (*x509.Certificate, error) {
 	if block, _ := pem.Decode(data); block != nil {
 		return x509.ParseCertificate(block.Bytes)
 	}

internal/appdata/paths.go

@@ -70,3 +70,8 @@ func LogsRootPath() string {
 func CACertFilePath() string {
 	return filepath.Join(DataRootPath(), "ca.crt")
 }
+
+// CAKeyFilePath 返回仅供本安装使用的 CA 私钥路径。
+func CAKeyFilePath() string {
+	return filepath.Join(DataRootPath(), "ca.key")
+}

internal/backend/README.md

@@ -97,6 +97,7 @@ internal/backend/
 
 - `~/.cursor-local-assistant-v2/config.yaml`
 - `~/.cursor-local-assistant-v2/data/ca.crt`
+- `~/.cursor-local-assistant-v2/data/ca.key`
 - `~/.cursor-local-assistant-v2/data/ads/`
 - `~/.cursor-local-assistant-v2/history/`
 - `~/.cursor-local-assistant-v2/logs/`
@@ -104,7 +105,8 @@ internal/backend/
 约定：
 
 - `config.yaml` 是用户配置
-- `data/ca.crt` 是注入给宿主的 CA 证书
+- `data/ca.crt` 是首次运行时为当前用户生成、注入给宿主的 CA 证书
+- `data/ca.key` 是与该证书配套的本地私钥，权限固定为 `0600`，不得打包或提交到仓库
 - `data/ads/` 是广告包与资源缓存目录
 - `history/` 是会话事实与全局 usage JSON 目录，不属于日志
 - `logs/` 只保留必要文本运行日志

internal/certs/ca.go

@@ -1,6 +1,7 @@
 package certs
 
 import (
+	"bytes"
 	"crypto"
 	"crypto/ecdsa"
 	"crypto/ed25519"
@@ -9,33 +10,24 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
-	_ "embed"
 	"encoding/pem"
 	"errors"
+	"fmt"
 	"math/big"
 	"net"
-	"os"
 	"strings"
 	"sync"
 	"time"
 )
 
-// embeddedCACertPEM 表示当前模块中的 embeddedCACertPEM 状态值。
-//
-//go:embed ca.crt
-var embeddedCACertPEM []byte
-
-// embeddedCAKeyPEM 表示当前模块中的 embeddedCAKeyPEM 状态值。
-//
-//go:embed ca.key
-var embeddedCAKeyPEM []byte
-
 // Manager 定义了当前模块中的 Manager 类型。
 type Manager struct {
 	// caCert 表示当前声明中的 caCert。
 	caCert *x509.Certificate
 	// caKey 表示当前声明中的 caKey。
 	caKey crypto.PrivateKey
+	// caCertPEM 保存可注入宿主信任存储的 CA 证书，不包含私钥。
+	caCertPEM []byte
 
 	// mu 表示当前声明中的 mu。
 	mu sync.Mutex
@@ -52,28 +44,26 @@ func NewManager(caCertPath, caKeyPath string) (*Manager, error) {
 	return NewManagerFromPEM(certPEM, keyPEM)
 }
 
-// NewEmbeddedManager 用于处理与 NewEmbeddedManager 相关的逻辑。
-func NewEmbeddedManager() (*Manager, error) {
-	return NewManagerFromPEM(embeddedCACertPEM, embeddedCAKeyPEM)
-}
-
-// EmbeddedCACertPEM 用于处理与 EmbeddedCACertPEM 相关的逻辑。
-func EmbeddedCACertPEM() []byte {
-	return cloneBytes(embeddedCACertPEM)
-}
-
-// EmbeddedCAKeyPEM 用于处理与 EmbeddedCAKeyPEM 相关的逻辑。
-func EmbeddedCAKeyPEM() []byte {
-	return cloneBytes(embeddedCAKeyPEM)
-}
-
 // NewManagerFromPEM 用于处理与 NewManagerFromPEM 相关的逻辑。
 func NewManagerFromPEM(caCertPEM, caKeyPEM []byte) (*Manager, error) {
 	caCert, caKey, err := loadCAFromPEM(caCertPEM, caKeyPEM)
 	if err != nil {
 		return nil, err
 	}
-	return &Manager{caCert: caCert, caKey: caKey, cache: make(map[string]*tls.Certificate)}, nil
+	return &Manager{
+		caCert:    caCert,
+		caKey:     caKey,
+		caCertPEM: cloneBytes(caCertPEM),
+		cache:     make(map[string]*tls.Certificate),
+	}, nil
+}
+
+// CACertPEM 返回当前 Manager 使用的 CA 证书。返回值不包含私钥。
+func (m *Manager) CACertPEM() []byte {
+	if m == nil {
+		return nil
+	}
+	return cloneBytes(m.caCertPEM)
 }
 
 // CATLSCertificate 用于处理与 CATLSCertificate 相关的逻辑。
@@ -185,19 +175,6 @@ func marshalPrivateKeyPEM(key any) ([]byte, error) {
 	}
 }
 
-// loadCAPEMFromFiles 用于处理与 loadCAPEMFromFiles 相关的逻辑。
-func loadCAPEMFromFiles(certPath, keyPath string) ([]byte, []byte, error) {
-	certPEM, err := os.ReadFile(certPath)
-	if err != nil {
-		return nil, nil, err
-	}
-	keyPEM, err := os.ReadFile(keyPath)
-	if err != nil {
-		return nil, nil, err
-	}
-	return certPEM, keyPEM, nil
-}
-
 // loadCAFromPEM 用于处理与 loadCAFromPEM 相关的逻辑。
 func loadCAFromPEM(certPEM, keyPEM []byte) (*x509.Certificate, crypto.PrivateKey, error) {
 	certBlock, _ := pem.Decode(certPEM)
@@ -214,28 +191,49 @@ func loadCAFromPEM(certPEM, keyPEM []byte) (*x509.Certificate, crypto.PrivateKey
 		return nil, nil, errors.New("invalid CA key PEM")
 	}
 
+	var caKey crypto.PrivateKey
 	switch keyBlock.Type {
 	case "RSA PRIVATE KEY":
 		key, err := x509.ParsePKCS1PrivateKey(keyBlock.Bytes)
 		if err != nil {
 			return nil, nil, err
 		}
-		return caCert, key, nil
+		caKey = key
 	case "EC PRIVATE KEY":
 		key, err := x509.ParseECPrivateKey(keyBlock.Bytes)
 		if err != nil {
 			return nil, nil, err
 		}
-		return caCert, key, nil
+		caKey = key
 	case "PRIVATE KEY":
 		key, err := x509.ParsePKCS8PrivateKey(keyBlock.Bytes)
 		if err != nil {
 			return nil, nil, err
 		}
-		return caCert, key, nil
+		caKey = key
 	default:
 		return nil, nil, errors.New("unsupported CA key format")
 	}
+
+	if !caCert.IsCA || !caCert.BasicConstraintsValid || caCert.KeyUsage&x509.KeyUsageCertSign == 0 {
+		return nil, nil, errors.New("certificate is not a valid signing CA")
+	}
+	signer, ok := caKey.(crypto.Signer)
+	if !ok {
+		return nil, nil, errors.New("CA private key cannot sign certificates")
+	}
+	certPublicKey, err := x509.MarshalPKIXPublicKey(caCert.PublicKey)
+	if err != nil {
+		return nil, nil, fmt.Errorf("marshal CA certificate public key: %w", err)
+	}
+	privatePublicKey, err := x509.MarshalPKIXPublicKey(signer.Public())
+	if err != nil {
+		return nil, nil, fmt.Errorf("marshal CA private key public key: %w", err)
+	}
+	if !bytes.Equal(certPublicKey, privatePublicKey) {
+		return nil, nil, errors.New("CA certificate and private key do not match")
+	}
+	return caCert, caKey, nil
 }
 
 // normalizeHost 用于处理与 normalizeHost 相关的逻辑。

internal/certs/ca.key

@@ -1,27 +0,0 @@
------BEGIN RSA PRIVATE KEY-----
-MIIEpAIBAAKCAQEAyh3jND/aFusuRjGTmhQtX2hkF1qroNjEEKCxWPlfprvdl8Tx
-upxNv1TQcm+K9KsS7OxnKYP4Qtv068XLbaCCGuoA/xpor6enrT85KulBq0j8z/g1
-y0VWxjz3xN9F9ND13h9yxDZCn76egbRkhFxpXow67jLsIlrqWDSltERlTKh2cJ1g
-hTRuQNSr7jtKQgFAR3aQ6dTzOP4fCOtLYn63jL4+YcxdGoK66tx8eFHq8oBLYvsc
-LNjjkaAHilZFwA4Jr7zHBofTRBg04eZum2UTaRqmSyT65ifXm4vRdQa4k1FS1gnq
-hPMhIjST8b6RkxvbLNmFpkOfI9eCMRpFG7y+NQIDAQABAoIBAATU9ZVOcHmLSkop
-zcBJerM09O2dAIziGb/XA55fqdJ728aQ0gGW0oIANlKCCaWjQFrTJP04VzNL/F01
-l5EpnOqlTPxMRpPqc2cAI677sBL29fpH0gtnvzUSiI7Xkp3RcAtNH6qCrJGSlkn+
-BMgoSGmW+yKuK3h/yWnt6kc2umA8fN+bHKhS3pI56PMW8qVnny9n92RaCA7Uf/4j
-XDewIreiH5jRqRwrPbOpjDFmv+W18LWZQiTwwxfY6sRZiZpsfsHidzfFGUFZXMlq
-2P3FCqoF4oMM1rRgBlHhDR7JHmSkFpZG639HJTXLllpyDbj3H86nsjIj9WZYKn+h
-B9k9bcECgYEA1HDzRCqoRZh6cL46KiYjv+LwmEKMa3nPb4ljywgLbRkzTMyVs0MK
-fDsDoTLFY9PBhveypU5gjTbQqtyBsDtbU+dH9Eks1FdL9P8bJf0ZOJFRiEB7uB4a
-z3V9tcXHwH4l2bCWbWThQGFwRudDAoY0EH89oSA/WHayjOKe1Wi4ovUCgYEA848B
-cYi+Qbkk+fOv9gSJn8KS1LH/jE28S/e7E4YkTfYUuu+7wr8bdRKUNpPIsLX0Fo9R
-KpJX0Oyjjady9n/8ARZRmD8Upl+F7Sl7Ro6F8+nfqQUrxbVDiIL3b+aZF+cDfFrB
-/xL5kyZZqTtFfP360tfYnlS6Sssd4E2Jsj0fJkECgYEA0gG+WbqZkgMDtwQ114jQ
-elZLZRkUWwKVjzsQDZssQHNTBS6RJh619M0Z73aTLvYcL+IZFdT/GVoAuYc2JRLo
-W28c8F6OFHMfwVeWbN1g20y8fqbQJtiLxF3vIYwcxStvG123tvisu8oXBeCDm7Ez
-MsO2FtwcAsWECEXWojzdmSkCgYEA18GvPawtHnuszd+Z2Q5b/DKZb+Hex6N1Ura5
-+qmyL333D0Kfyf0RjbxPn6l690+4UuPSuyu4r1Nx72KO7N6jlzL2RTBcUqX8NgOx
-OOe4skJT5561EAdrM9sQ5wgYRpxW8ipUAGoGvNwUQV5ISFmVgIHFWz0jam5UoQcP
-G94ZYgECgYBN4PB8BuAwMRqhTCLL5RJKtcdC/Ls9xdWrmswtQQ4OSBUTLGdeMhEN
-E23F0d+NdtiTWDYRDJ7z6KAF8CcOwWMt2sNbrxgNRuDzyfLqbuVLOM8iY3xA50Nl
-clZWujKILWp47+gA6/AqJLv2lA2LK8gM8zYzzm/nCuLCBLYH/hOiCA==
------END RSA PRIVATE KEY-----

internal/certs/local_ca.go

@@ -0,0 +1,191 @@
+package certs
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/hex"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"math/big"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+const legacySharedCASHA256 = "836E6BB84F6C3E63316DBB4EC257223AF09F7490E7AAE09030B8515ED61EE9FF"
+
+// LoadOrCreateManager loads the installation-specific CA, generating it on
+// first run. The private key is persisted only in the supplied local path.
+func LoadOrCreateManager(certPath, keyPath string) (*Manager, []byte, error) {
+	certPEM, certErr := os.ReadFile(certPath)
+	keyPEM, keyErr := os.ReadFile(keyPath)
+
+	if certErr == nil && isLegacySharedCA(certPEM) {
+		return generateAndPersistManager(certPath, keyPath)
+	}
+	if certErr == nil && keyErr == nil {
+		manager, err := NewManagerFromPEM(certPEM, keyPEM)
+		if err != nil {
+			return nil, nil, fmt.Errorf("load installation CA: %w", err)
+		}
+		if err := os.Chmod(keyPath, 0o600); err != nil {
+			return nil, nil, fmt.Errorf("restrict installation CA private key permissions: %w", err)
+		}
+		return manager, manager.CACertPEM(), nil
+	}
+	if errors.Is(certErr, os.ErrNotExist) && errors.Is(keyErr, os.ErrNotExist) {
+		return generateAndPersistManager(certPath, keyPath)
+	}
+	// A key without a certificate cannot have been installed as a trusted root.
+	// This is safe to recover if the first-run write was interrupted.
+	if errors.Is(certErr, os.ErrNotExist) && keyErr == nil {
+		return generateAndPersistManager(certPath, keyPath)
+	}
+	if certErr != nil && !errors.Is(certErr, os.ErrNotExist) {
+		return nil, nil, fmt.Errorf("read installation CA certificate: %w", certErr)
+	}
+	if keyErr != nil && !errors.Is(keyErr, os.ErrNotExist) {
+		return nil, nil, fmt.Errorf("read installation CA private key: %w", keyErr)
+	}
+	return nil, nil, errors.New("installation CA is incomplete; both certificate and private key are required")
+}
+
+// NewGeneratedManager creates an in-memory CA suitable for short-lived tools.
+func NewGeneratedManager() (*Manager, []byte, error) {
+	certPEM, keyPEM, err := generateCA()
+	if err != nil {
+		return nil, nil, err
+	}
+	manager, err := NewManagerFromPEM(certPEM, keyPEM)
+	if err != nil {
+		return nil, nil, err
+	}
+	return manager, manager.CACertPEM(), nil
+}
+
+func generateAndPersistManager(certPath, keyPath string) (*Manager, []byte, error) {
+	if filepath.Dir(certPath) != filepath.Dir(keyPath) {
+		return nil, nil, errors.New("installation CA certificate and key must share a directory")
+	}
+	certPEM, keyPEM, err := generateCA()
+	if err != nil {
+		return nil, nil, err
+	}
+	if err := os.MkdirAll(filepath.Dir(certPath), 0o700); err != nil {
+		return nil, nil, fmt.Errorf("create installation CA directory: %w", err)
+	}
+	// Write the private key first so a crash cannot leave a new certificate
+	// without the signing key needed by the proxy.
+	if err := writeLocalCAFile(keyPath, keyPEM, 0o600); err != nil {
+		return nil, nil, fmt.Errorf("persist installation CA private key: %w", err)
+	}
+	if err := writeLocalCAFile(certPath, certPEM, 0o644); err != nil {
+		return nil, nil, fmt.Errorf("persist installation CA certificate: %w", err)
+	}
+	manager, err := NewManagerFromPEM(certPEM, keyPEM)
+	if err != nil {
+		return nil, nil, err
+	}
+	return manager, manager.CACertPEM(), nil
+}
+
+func generateCA() ([]byte, []byte, error) {
+	privateKey, err := rsa.GenerateKey(rand.Reader, 3072)
+	if err != nil {
+		return nil, nil, fmt.Errorf("generate installation CA private key: %w", err)
+	}
+	serial, err := rand.Int(rand.Reader, new(big.Int).Lsh(big.NewInt(1), 128))
+	if err != nil {
+		return nil, nil, fmt.Errorf("generate installation CA serial: %w", err)
+	}
+	publicKeyDER, err := x509.MarshalPKIXPublicKey(&privateKey.PublicKey)
+	if err != nil {
+		return nil, nil, fmt.Errorf("marshal installation CA public key: %w", err)
+	}
+	subjectKeyID := sha256.Sum256(publicKeyDER)
+	now := time.Now()
+	template := &x509.Certificate{
+		SerialNumber: serial,
+		Subject: pkix.Name{
+			CommonName:   "Cursor BYOK Local CA",
+			Organization: []string{"Cursor BYOK"},
+		},
+		NotBefore:             now.Add(-5 * time.Minute),
+		NotAfter:              now.AddDate(10, 0, 0),
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign | x509.KeyUsageCRLSign,
+		BasicConstraintsValid: true,
+		IsCA:                  true,
+		MaxPathLen:            0,
+		MaxPathLenZero:        true,
+		SubjectKeyId:          append([]byte(nil), subjectKeyID[:20]...),
+	}
+	der, err := x509.CreateCertificate(rand.Reader, template, template, &privateKey.PublicKey, privateKey)
+	if err != nil {
+		return nil, nil, fmt.Errorf("create installation CA certificate: %w", err)
+	}
+	certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der})
+	keyPEM := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)})
+	return certPEM, keyPEM, nil
+}
+
+func writeLocalCAFile(path string, data []byte, mode os.FileMode) error {
+	temp, err := os.CreateTemp(filepath.Dir(path), ".ca-*")
+	if err != nil {
+		return err
+	}
+	tempPath := temp.Name()
+	defer os.Remove(tempPath)
+	if err := temp.Chmod(mode); err != nil {
+		_ = temp.Close()
+		return err
+	}
+	if _, err := temp.Write(data); err != nil {
+		_ = temp.Close()
+		return err
+	}
+	if err := temp.Sync(); err != nil {
+		_ = temp.Close()
+		return err
+	}
+	if err := temp.Close(); err != nil {
+		return err
+	}
+	if err := os.Remove(path); err != nil && !errors.Is(err, os.ErrNotExist) {
+		return err
+	}
+	if err := os.Rename(tempPath, path); err != nil {
+		return err
+	}
+	return os.Chmod(path, mode)
+}
+
+func isLegacySharedCA(certPEM []byte) bool {
+	block, _ := pem.Decode(certPEM)
+	if block == nil {
+		return false
+	}
+	cert, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		return false
+	}
+	sum := sha256.Sum256(cert.Raw)
+	return strings.EqualFold(hex.EncodeToString(sum[:]), legacySharedCASHA256)
+}
+
+// loadCAPEMFromFiles reads an explicitly supplied CA pair.
+func loadCAPEMFromFiles(certPath, keyPath string) ([]byte, []byte, error) {
+	certPEM, err := os.ReadFile(certPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	keyPEM, err := os.ReadFile(keyPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	return certPEM, keyPEM, nil
+}

internal/certs/local_ca_test.go

@@ -0,0 +1,125 @@
+package certs
+
+import (
+	"bytes"
+	"crypto/x509"
+	"encoding/pem"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+func TestLoadOrCreateManagerPersistsAndReusesInstallationCA(t *testing.T) {
+	dir := t.TempDir()
+	certPath := filepath.Join(dir, "ca.crt")
+	keyPath := filepath.Join(dir, "ca.key")
+
+	manager, certPEM, err := LoadOrCreateManager(certPath, keyPath)
+	if err != nil {
+		t.Fatalf("LoadOrCreateManager() error = %v", err)
+	}
+	if isLegacySharedCA(certPEM) {
+		t.Fatal("generated CA reused the legacy shared certificate")
+	}
+	keyInfo, err := os.Stat(keyPath)
+	if err != nil {
+		t.Fatalf("stat private key: %v", err)
+	}
+	if runtime.GOOS != "windows" && keyInfo.Mode().Perm() != 0o600 {
+		t.Fatalf("private key mode = %o, want 600", keyInfo.Mode().Perm())
+	}
+
+	leaf, err := manager.CertificateForServerName("api2.cursor.sh")
+	if err != nil {
+		t.Fatalf("CertificateForServerName() error = %v", err)
+	}
+	ca := parseCertificatePEM(t, certPEM)
+	roots := x509.NewCertPool()
+	roots.AddCert(ca)
+	if _, err := leaf.Leaf.Verify(x509.VerifyOptions{DNSName: "api2.cursor.sh", Roots: roots}); err != nil {
+		t.Fatalf("verify generated leaf: %v", err)
+	}
+
+	_, reusedCertPEM, err := LoadOrCreateManager(certPath, keyPath)
+	if err != nil {
+		t.Fatalf("second LoadOrCreateManager() error = %v", err)
+	}
+	if !bytes.Equal(certPEM, reusedCertPEM) {
+		t.Fatal("installation CA changed between loads")
+	}
+}
+
+func TestLoadOrCreateManagerCreatesUniqueCAsPerInstallation(t *testing.T) {
+	firstDir := t.TempDir()
+	secondDir := t.TempDir()
+	_, firstCert, err := LoadOrCreateManager(filepath.Join(firstDir, "ca.crt"), filepath.Join(firstDir, "ca.key"))
+	if err != nil {
+		t.Fatalf("create first CA: %v", err)
+	}
+	_, secondCert, err := LoadOrCreateManager(filepath.Join(secondDir, "ca.crt"), filepath.Join(secondDir, "ca.key"))
+	if err != nil {
+		t.Fatalf("create second CA: %v", err)
+	}
+	if bytes.Equal(firstCert, secondCert) {
+		t.Fatal("separate installations received the same CA certificate")
+	}
+}
+
+func TestLoadOrCreateManagerReplacesLegacySharedCertificate(t *testing.T) {
+	dir := t.TempDir()
+	certPath := filepath.Join(dir, "ca.crt")
+	keyPath := filepath.Join(dir, "ca.key")
+	legacyCert, err := os.ReadFile(filepath.Join("testdata", "legacy_shared_ca.crt"))
+	if err != nil {
+		t.Fatalf("read legacy certificate fixture: %v", err)
+	}
+	if !isLegacySharedCA(legacyCert) {
+		t.Fatal("legacy certificate fixture fingerprint changed")
+	}
+	if err := os.WriteFile(certPath, legacyCert, 0o644); err != nil {
+		t.Fatalf("write legacy certificate: %v", err)
+	}
+
+	_, generatedCert, err := LoadOrCreateManager(certPath, keyPath)
+	if err != nil {
+		t.Fatalf("migrate legacy certificate: %v", err)
+	}
+	if bytes.Equal(legacyCert, generatedCert) || isLegacySharedCA(generatedCert) {
+		t.Fatal("legacy shared certificate was not replaced")
+	}
+	if _, err := os.Stat(keyPath); err != nil {
+		t.Fatalf("generated private key missing: %v", err)
+	}
+}
+
+func TestNewManagerFromPEMRejectsMismatchedKey(t *testing.T) {
+	firstDir := t.TempDir()
+	secondDir := t.TempDir()
+	_, _, err := LoadOrCreateManager(filepath.Join(firstDir, "ca.crt"), filepath.Join(firstDir, "ca.key"))
+	if err != nil {
+		t.Fatalf("create first CA: %v", err)
+	}
+	_, _, err = LoadOrCreateManager(filepath.Join(secondDir, "ca.crt"), filepath.Join(secondDir, "ca.key"))
+	if err != nil {
+		t.Fatalf("create second CA: %v", err)
+	}
+	certPEM, _ := os.ReadFile(filepath.Join(firstDir, "ca.crt"))
+	keyPEM, _ := os.ReadFile(filepath.Join(secondDir, "ca.key"))
+	if _, err := NewManagerFromPEM(certPEM, keyPEM); err == nil {
+		t.Fatal("NewManagerFromPEM() accepted a mismatched private key")
+	}
+}
+
+func parseCertificatePEM(t *testing.T, certPEM []byte) *x509.Certificate {
+	t.Helper()
+	block, _ := pem.Decode(certPEM)
+	if block == nil {
+		t.Fatal("certificate PEM is invalid")
+	}
+	cert, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		t.Fatalf("parse certificate: %v", err)
+	}
+	return cert
+}

internal/client/cursor.go

@@ -5,6 +5,7 @@ import (
 	goruntime "runtime"
 
 	"cursor/internal/cursor"
+	"cursor/internal/logger"
 )
 
 // ApplyCursorSettings 用于处理与 ApplyCursorSettings 相关的逻辑。
@@ -21,6 +22,9 @@ func (s *ProxyService) ApplyCursorSettings() error {
 	if err != nil {
 		return fmt.Errorf("ensure ca cert file: %w", err)
 	}
+	if err := cursor.EnsureLegacySharedCACertRemoved(); err != nil {
+		logger.Errorf("remove legacy shared ca cert failed, continuing with installation CA: %v", err)
+	}
 
 	switch goruntime.GOOS {
 	case "windows":

internal/cursor/darwin_cert.go

@@ -16,6 +16,7 @@ import (
 const (
 	darwinSecurityExe       = "security"
 	darwinLoginKeychainName = "login.keychain-db"
+	legacySharedCASHA1      = "C14B7488C5AB83F098BEB2603F1135595A381FC0"
 )
 
 func getCertSHA1Fingerprint(certPEM []byte) (string, error) {
@@ -36,7 +37,10 @@ func isCACertInstalled(certPEM []byte) (bool, error) {
 	if err != nil {
 		return false, fmt.Errorf("获取证书指纹失败: %w", err)
 	}
+	return isCACertFingerprintInstalled(fingerprint)
+}
 
+func isCACertFingerprintInstalled(fingerprint string) (bool, error) {
 	out, err := exec.Command(darwinSecurityExe, "find-certificate", "-a", "-Z", darwinLoginKeychainName).CombinedOutput()
 	if err != nil {
 		return false, fmt.Errorf("检查 macOS 登录钥匙串失败: %w: %s", err, strings.TrimSpace(string(out)))
@@ -50,6 +54,36 @@ func isCACertInstalled(certPEM []byte) (bool, error) {
 	return installed, nil
 }
 
+// EnsureLegacySharedCACertRemoved removes the compromised CA shipped by older versions.
+func EnsureLegacySharedCACertRemoved() error {
+	installed, err := isCACertFingerprintInstalled(legacySharedCASHA1)
+	if err != nil {
+		return fmt.Errorf("检查旧版共享 CA 失败: %w", err)
+	}
+	if !installed {
+		return nil
+	}
+	out, err := exec.Command(
+		darwinSecurityExe,
+		"delete-certificate",
+		"-Z", legacySharedCASHA1,
+		"-t",
+		darwinLoginKeychainName,
+	).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("从 macOS 登录钥匙串删除旧版共享 CA 失败: %w: %s", err, strings.TrimSpace(string(out)))
+	}
+	installed, err = isCACertFingerprintInstalled(legacySharedCASHA1)
+	if err != nil {
+		return fmt.Errorf("验证旧版共享 CA 删除状态失败: %w", err)
+	}
+	if installed {
+		return fmt.Errorf("删除命令已执行，但 macOS 登录钥匙串中仍存在旧版共享 CA")
+	}
+	logger.Infof("ensureLegacySharedCACertRemoved: legacy shared CA removed from macOS login keychain")
+	return nil
+}
+
 func installCACertToDarwinKeychain(certPEM []byte, certPath string) error {
 	fingerprint, err := getCertSHA1Fingerprint(certPEM)
 	if err != nil {

internal/cursor/windows_cert.go

@@ -20,6 +20,7 @@ const (
 	windowsCertutilExe    = "certutil.exe"
 	windowsPowerShellExe  = "powershell.exe"
 	windowsUserCancelCode = 1223
+	legacySharedCASHA1    = "C14B7488C5AB83F098BEB2603F1135595A381FC0"
 )
 
 // getCertThumbprint 获取证书的SHA1指纹，用于唯一标识证书
@@ -51,7 +52,10 @@ func isCACertInstalled(certPEM []byte) (bool, error) {
 	if err != nil {
 		return false, fmt.Errorf("获取证书指纹失败: %w", err)
 	}
+	return isCACertThumbprintInstalled(thumbprint)
+}
 
+func isCACertThumbprintInstalled(thumbprint string) (bool, error) {
 	cmd := exec.Command(windowsCertutilExe, "-verifystore", windowsRootStoreName, thumbprint)
 	cmd.SysProcAttr = hideWindow()
 	output, err := cmd.CombinedOutput()
@@ -76,6 +80,29 @@ func isCACertInstalled(certPEM []byte) (bool, error) {
 	return false, nil
 }
 
+// EnsureLegacySharedCACertRemoved removes the compromised CA shipped by older versions.
+func EnsureLegacySharedCACertRemoved() error {
+	installed, err := isCACertThumbprintInstalled(legacySharedCASHA1)
+	if err != nil {
+		return fmt.Errorf("检查旧版共享 CA 失败: %w", err)
+	}
+	if !installed {
+		return nil
+	}
+	if err := runElevatedCertutil("-delstore", windowsRootStoreName, legacySharedCASHA1); err != nil {
+		return fmt.Errorf("从 Windows 系统信任存储删除旧版共享 CA 失败: %w", err)
+	}
+	installed, err = isCACertThumbprintInstalled(legacySharedCASHA1)
+	if err != nil {
+		return fmt.Errorf("验证旧版共享 CA 删除状态失败: %w", err)
+	}
+	if installed {
+		return fmt.Errorf("删除命令已执行，但 Windows 系统信任存储中仍存在旧版共享 CA")
+	}
+	logger.Infof("ensureLegacySharedCACertRemoved: legacy shared CA removed from Windows system store")
+	return nil
+}
+
 func quotePowerShellLiteral(value string) string {
 	return "'" + strings.ReplaceAll(value, "'", "''") + "'"
 }

internal/cursor/windows_cert_stub.go

@@ -8,3 +8,8 @@ import "fmt"
 func EnsureCACertInstalled(_ []byte, certPath string) error {
 	return fmt.Errorf("ensureCACertInstalled: 当前平台暂不支持，certPath=%s", certPath)
 }
+
+// EnsureLegacySharedCACertRemoved is a no-op on unsupported platforms.
+func EnsureLegacySharedCACertRemoved() error {
+	return nil
+}