fix: generate a per-installation root CA

2026-08-18 12:07:02 +08:00 · 2026-08-12 20:04:29 +08:00
parent 7a67e76617
commit 2b8d1c9e3d
14 changed files with 454 additions and 89 deletions
@@ -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
+}