fix(安全): 修复上游校验与 URL 清理问题

增加请求阶段 DNS 解析校验，阻断重绑定到私网补充默认透传 WWW-Authenticate 头，保留认证挑战前端相对 URL 过滤拒绝 // 协议相对路径测试: go test ./internal/repository -run TestGitHubReleaseServiceSuite 测试: go test ./internal/repository -run TestTurnstileServiceSuite 测试: go test ./internal/repository -run TestProxyProbeServiceSuite 测试: go test ./internal/repository -run TestClaudeUsageServiceSuite
2026-01-03 10:52:24 +08:00
parent bd4bf00856
commit 25e1632628
18 changed files with 168 additions and 58 deletions
--- a/backend/cmd/server/wire_gen.go
+++ b/backend/cmd/server/wire_gen.go
@@ -118,7 +118,7 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	adminSubscriptionHandler := admin.NewSubscriptionHandler(subscriptionService)
 	adminUsageHandler := admin.NewUsageHandler(usageService, apiKeyService, adminService)
 	adminHandlers := handler.ProvideAdminHandlers(dashboardHandler, adminUserHandler, groupHandler, accountHandler, oAuthHandler, openAIOAuthHandler, geminiOAuthHandler, antigravityOAuthHandler, proxyHandler, adminRedeemHandler, settingHandler, systemHandler, adminSubscriptionHandler, adminUsageHandler)
-	pricingRemoteClient := repository.NewPricingRemoteClient()
+	pricingRemoteClient := repository.NewPricingRemoteClient(configConfig)
 	pricingService, err := service.ProvidePricingService(configConfig, pricingRemoteClient)
 	if err != nil {
 		return nil, err
--- a/backend/internal/pkg/httpclient/pool.go
+++ b/backend/internal/pkg/httpclient/pool.go
@@ -26,6 +26,7 @@ import (
 	"sync"
 	"time"

+	"github.com/Wei-Shaw/sub2api/internal/util/urlvalidator"
 	"golang.org/x/net/proxy"
 )

@@ -43,6 +44,8 @@ type Options struct {
 	ResponseHeaderTimeout time.Duration // 等待响应头超时时间
 	InsecureSkipVerify    bool          // 是否跳过 TLS 证书验证
 	ProxyStrict           bool          // 严格代理模式：代理失败时返回错误而非回退
+	ValidateResolvedIP    bool          // 是否校验解析后的 IP（防止 DNS Rebinding）
+	AllowPrivateHosts     bool          // 允许私有地址解析（与 ValidateResolvedIP 一起使用）

 	// 可选的连接池参数（不设置则使用默认值）
 	MaxIdleConns        int // 最大空闲连接总数（默认 100）
@@ -86,8 +89,12 @@ func buildClient(opts Options) (*http.Client, error) {
 		return nil, err
 	}

+	var rt http.RoundTripper = transport
+	if opts.ValidateResolvedIP && !opts.AllowPrivateHosts {
+		rt = &validatedTransport{base: transport}
+	}
 	return &http.Client{
-		Transport: transport,
+		Transport: rt,
 		Timeout:   opts.Timeout,
 	}, nil
 }
@@ -144,14 +151,32 @@ func buildTransport(opts Options) (*http.Transport, error) {
 }

 func buildClientKey(opts Options) string {
-	return fmt.Sprintf("%s|%s|%s|%t|%t|%d|%d|%d",
+	return fmt.Sprintf("%s|%s|%s|%t|%t|%t|%t|%d|%d|%d",
 		strings.TrimSpace(opts.ProxyURL),
 		opts.Timeout.String(),
 		opts.ResponseHeaderTimeout.String(),
 		opts.InsecureSkipVerify,
 		opts.ProxyStrict,
+		opts.ValidateResolvedIP,
+		opts.AllowPrivateHosts,
 		opts.MaxIdleConns,
 		opts.MaxIdleConnsPerHost,
 		opts.MaxConnsPerHost,
 	)
 }
+
+type validatedTransport struct {
+	base http.RoundTripper
+}
+
+func (t *validatedTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	if req != nil && req.URL != nil {
+		host := strings.TrimSpace(req.URL.Hostname())
+		if host != "" {
+			if err := urlvalidator.ValidateResolvedIP(host); err != nil {
+				return nil, err
+			}
+		}
+	}
+	return t.base.RoundTrip(req)
+}
--- a/backend/internal/repository/claude_usage_service.go
+++ b/backend/internal/repository/claude_usage_service.go
@@ -15,7 +15,8 @@ import (
 const defaultClaudeUsageURL = "https://api.anthropic.com/api/oauth/usage"

 type claudeUsageService struct {
-	usageURL string
+	usageURL          string
+	allowPrivateHosts bool
 }

 func NewClaudeUsageFetcher() service.ClaudeUsageFetcher {
@@ -24,8 +25,10 @@ func NewClaudeUsageFetcher() service.ClaudeUsageFetcher {

 func (s *claudeUsageService) FetchUsage(ctx context.Context, accessToken, proxyURL string) (*service.ClaudeUsageResponse, error) {
 	client, err := httpclient.GetClient(httpclient.Options{
-		ProxyURL: proxyURL,
-		Timeout:  30 * time.Second,
+		ProxyURL:           proxyURL,
+		Timeout:            30 * time.Second,
+		ValidateResolvedIP: true,
+		AllowPrivateHosts:  s.allowPrivateHosts,
 	})
 	if err != nil {
 		client = &http.Client{Timeout: 30 * time.Second}
--- a/backend/internal/repository/claude_usage_service_test.go
+++ b/backend/internal/repository/claude_usage_service_test.go
@@ -45,7 +45,10 @@ func (s *ClaudeUsageServiceSuite) TestFetchUsage_Success() {
 }`)
 	}))

-	s.fetcher = &claudeUsageService{usageURL: s.srv.URL}
+	s.fetcher = &claudeUsageService{
+		usageURL:          s.srv.URL,
+		allowPrivateHosts: true,
+	}

 	resp, err := s.fetcher.FetchUsage(context.Background(), "at", "://bad-proxy-url")
 	require.NoError(s.T(), err, "FetchUsage")
@@ -64,7 +67,10 @@ func (s *ClaudeUsageServiceSuite) TestFetchUsage_NonOK() {
 		_, _ = io.WriteString(w, "nope")
 	}))

-	s.fetcher = &claudeUsageService{usageURL: s.srv.URL}
+	s.fetcher = &claudeUsageService{
+		usageURL:          s.srv.URL,
+		allowPrivateHosts: true,
+	}

 	_, err := s.fetcher.FetchUsage(context.Background(), "at", "")
 	require.Error(s.T(), err)
@@ -78,7 +84,10 @@ func (s *ClaudeUsageServiceSuite) TestFetchUsage_BadJSON() {
 		_, _ = io.WriteString(w, "not-json")
 	}))

-	s.fetcher = &claudeUsageService{usageURL: s.srv.URL}
+	s.fetcher = &claudeUsageService{
+		usageURL:          s.srv.URL,
+		allowPrivateHosts: true,
+	}

 	_, err := s.fetcher.FetchUsage(context.Background(), "at", "")
 	require.Error(s.T(), err)
@@ -91,7 +100,10 @@ func (s *ClaudeUsageServiceSuite) TestFetchUsage_ContextCancel() {
 		<-r.Context().Done()
 	}))

-	s.fetcher = &claudeUsageService{usageURL: s.srv.URL}
+	s.fetcher = &claudeUsageService{
+		usageURL:          s.srv.URL,
+		allowPrivateHosts: true,
+	}

 	ctx, cancel := context.WithCancel(context.Background())
 	cancel() // Cancel immediately
--- a/backend/internal/repository/github_release_service.go
+++ b/backend/internal/repository/github_release_service.go
@@ -14,18 +14,23 @@ import (
 )

 type githubReleaseClient struct {
-	httpClient *http.Client
+	httpClient        *http.Client
+	allowPrivateHosts bool
 }

 func NewGitHubReleaseClient() service.GitHubReleaseClient {
+	allowPrivate := false
 	sharedClient, err := httpclient.GetClient(httpclient.Options{
-		Timeout: 30 * time.Second,
+		Timeout:            30 * time.Second,
+		ValidateResolvedIP: true,
+		AllowPrivateHosts:  allowPrivate,
 	})
 	if err != nil {
 		sharedClient = &http.Client{Timeout: 30 * time.Second}
 	}
 	return &githubReleaseClient{
-		httpClient: sharedClient,
+		httpClient:        sharedClient,
+		allowPrivateHosts: allowPrivate,
 	}
 }

@@ -64,7 +69,9 @@ func (c *githubReleaseClient) DownloadFile(ctx context.Context, url, dest string
 	}

 	downloadClient, err := httpclient.GetClient(httpclient.Options{
-		Timeout: 10 * time.Minute,
+		Timeout:            10 * time.Minute,
+		ValidateResolvedIP: true,
+		AllowPrivateHosts:  c.allowPrivateHosts,
 	})
 	if err != nil {
 		downloadClient = &http.Client{Timeout: 10 * time.Minute}
--- a/backend/internal/repository/github_release_service_test.go
+++ b/backend/internal/repository/github_release_service_test.go
@@ -37,6 +37,13 @@ func (t *testTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 	return http.DefaultTransport.RoundTrip(newReq)
 }

+func newTestGitHubReleaseClient() *githubReleaseClient {
+	return &githubReleaseClient{
+		httpClient:        &http.Client{},
+		allowPrivateHosts: true,
+	}
+}
+
 func (s *GitHubReleaseServiceSuite) SetupTest() {
 	s.tempDir = s.T().TempDir()
 }
@@ -55,9 +62,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_EnforcesMaxSize_ContentLeng
 		_, _ = w.Write(bytes.Repeat([]byte("a"), 100))
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	dest := filepath.Join(s.tempDir, "file1.bin")
 	err := s.client.DownloadFile(context.Background(), s.srv.URL, dest, 10)
@@ -82,9 +87,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_EnforcesMaxSize_Chunked() {
 		}
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	dest := filepath.Join(s.tempDir, "file2.bin")
 	err := s.client.DownloadFile(context.Background(), s.srv.URL, dest, 10)
@@ -108,9 +111,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_Success() {
 		}
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	dest := filepath.Join(s.tempDir, "file3.bin")
 	err := s.client.DownloadFile(context.Background(), s.srv.URL, dest, 200)
@@ -127,9 +128,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_404() {
 		w.WriteHeader(http.StatusNotFound)
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	dest := filepath.Join(s.tempDir, "notfound.bin")
 	err := s.client.DownloadFile(context.Background(), s.srv.URL, dest, 100)
@@ -145,9 +144,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchChecksumFile_Success() {
 		_, _ = w.Write([]byte("sum"))
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	body, err := s.client.FetchChecksumFile(context.Background(), s.srv.URL)
 	require.NoError(s.T(), err, "FetchChecksumFile")
@@ -159,9 +156,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchChecksumFile_Non200() {
 		w.WriteHeader(http.StatusInternalServerError)
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	_, err := s.client.FetchChecksumFile(context.Background(), s.srv.URL)
 	require.Error(s.T(), err, "expected error for non-200")
@@ -172,9 +167,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_ContextCancel() {
 		<-r.Context().Done()
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
@@ -185,9 +178,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_ContextCancel() {
 }

 func (s *GitHubReleaseServiceSuite) TestDownloadFile_InvalidURL() {
-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	dest := filepath.Join(s.tempDir, "invalid.bin")
 	err := s.client.DownloadFile(context.Background(), "://invalid-url", dest, 100)
@@ -200,9 +191,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_InvalidDestPath() {
 		_, _ = w.Write([]byte("content"))
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	// Use a path that cannot be created (directory doesn't exist)
 	dest := filepath.Join(s.tempDir, "nonexistent", "subdir", "file.bin")
@@ -211,9 +200,7 @@ func (s *GitHubReleaseServiceSuite) TestDownloadFile_InvalidDestPath() {
 }

 func (s *GitHubReleaseServiceSuite) TestFetchChecksumFile_InvalidURL() {
-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	_, err := s.client.FetchChecksumFile(context.Background(), "://invalid-url")
 	require.Error(s.T(), err, "expected error for invalid URL")
@@ -247,6 +234,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchLatestRelease_Success() {
 		httpClient: &http.Client{
 			Transport: &testTransport{testServerURL: s.srv.URL},
 		},
+		allowPrivateHosts: true,
 	}

 	release, err := s.client.FetchLatestRelease(context.Background(), "test/repo")
@@ -266,6 +254,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchLatestRelease_Non200() {
 		httpClient: &http.Client{
 			Transport: &testTransport{testServerURL: s.srv.URL},
 		},
+		allowPrivateHosts: true,
 	}

 	_, err := s.client.FetchLatestRelease(context.Background(), "test/repo")
@@ -283,6 +272,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchLatestRelease_InvalidJSON() {
 		httpClient: &http.Client{
 			Transport: &testTransport{testServerURL: s.srv.URL},
 		},
+		allowPrivateHosts: true,
 	}

 	_, err := s.client.FetchLatestRelease(context.Background(), "test/repo")
@@ -298,6 +288,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchLatestRelease_ContextCancel() {
 		httpClient: &http.Client{
 			Transport: &testTransport{testServerURL: s.srv.URL},
 		},
+		allowPrivateHosts: true,
 	}

 	ctx, cancel := context.WithCancel(context.Background())
@@ -312,9 +303,7 @@ func (s *GitHubReleaseServiceSuite) TestFetchChecksumFile_ContextCancel() {
 		<-r.Context().Done()
 	}))

-	client, ok := NewGitHubReleaseClient().(*githubReleaseClient)
-	require.True(s.T(), ok, "type assertion failed")
-	s.client = client
+	s.client = newTestGitHubReleaseClient()

 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
--- a/backend/internal/repository/http_upstream.go
+++ b/backend/internal/repository/http_upstream.go
@@ -14,6 +14,7 @@ import (

 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/Wei-Shaw/sub2api/internal/util/urlvalidator"
 )

 // 默认配置常量
@@ -119,6 +120,10 @@ func NewHTTPUpstream(cfg *config.Config) service.HTTPUpstream {
 //   - 调用方必须关闭 resp.Body，否则会导致 inFlight 计数泄漏
 //   - inFlight > 0 的客户端不会被淘汰，确保活跃请求不被中断
 func (s *httpUpstreamService) Do(req *http.Request, proxyURL string, accountID int64, accountConcurrency int) (*http.Response, error) {
+	if err := s.validateRequestHost(req); err != nil {
+		return nil, err
+	}
+
 	// 获取或创建对应的客户端，并标记请求占用
 	entry, err := s.acquireClient(proxyURL, accountID, accountConcurrency)
 	if err != nil {
@@ -144,6 +149,37 @@ func (s *httpUpstreamService) Do(req *http.Request, proxyURL string, accountID i
 	return resp, nil
 }

+func (s *httpUpstreamService) shouldValidateResolvedIP() bool {
+	if s.cfg == nil {
+		return false
+	}
+	return !s.cfg.Security.URLAllowlist.AllowPrivateHosts
+}
+
+func (s *httpUpstreamService) validateRequestHost(req *http.Request) error {
+	if !s.shouldValidateResolvedIP() {
+		return nil
+	}
+	if req == nil || req.URL == nil {
+		return errors.New("request url is nil")
+	}
+	host := strings.TrimSpace(req.URL.Hostname())
+	if host == "" {
+		return errors.New("request host is empty")
+	}
+	if err := urlvalidator.ValidateResolvedIP(host); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *httpUpstreamService) redirectChecker(req *http.Request, via []*http.Request) error {
+	if len(via) >= 10 {
+		return errors.New("stopped after 10 redirects")
+	}
+	return s.validateRequestHost(req)
+}
+
 // acquireClient 获取或创建客户端，并标记为进行中请求
 // 用于请求路径，避免在获取后被淘汰
 func (s *httpUpstreamService) acquireClient(proxyURL string, accountID int64, accountConcurrency int) (*upstreamClientEntry, error) {
@@ -226,6 +262,9 @@ func (s *httpUpstreamService) getClientEntry(proxyURL string, accountID int64, a
 	// 缓存未命中或需要重建，创建新客户端
 	settings := s.resolvePoolSettings(isolation, accountConcurrency)
 	client := &http.Client{Transport: buildUpstreamTransport(settings, parsedProxy)}
+	if s.shouldValidateResolvedIP() {
+		client.CheckRedirect = s.redirectChecker
+	}
 	entry := &upstreamClientEntry{
 		client:   client,
 		proxyKey: proxyKey,
--- a/backend/internal/repository/http_upstream_test.go
+++ b/backend/internal/repository/http_upstream_test.go
@@ -23,7 +23,13 @@ type HTTPUpstreamSuite struct {
 // SetupTest 每个测试用例执行前的初始化
 // 创建空配置，各测试用例可按需覆盖
 func (s *HTTPUpstreamSuite) SetupTest() {
-	s.cfg = &config.Config{}
+	s.cfg = &config.Config{
+		Security: config.SecurityConfig{
+			URLAllowlist: config.URLAllowlistConfig{
+				AllowPrivateHosts: true,
+			},
+		},
+	}
 }

 // newService 创建测试用的 httpUpstreamService 实例
--- a/backend/internal/repository/pricing_service.go
+++ b/backend/internal/repository/pricing_service.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 	"time"

+	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/httpclient"
 	"github.com/Wei-Shaw/sub2api/internal/service"
 )
@@ -16,9 +17,15 @@ type pricingRemoteClient struct {
 	httpClient *http.Client
 }

-func NewPricingRemoteClient() service.PricingRemoteClient {
+func NewPricingRemoteClient(cfg *config.Config) service.PricingRemoteClient {
+	allowPrivate := false
+	if cfg != nil {
+		allowPrivate = cfg.Security.URLAllowlist.AllowPrivateHosts
+	}
 	sharedClient, err := httpclient.GetClient(httpclient.Options{
-		Timeout: 30 * time.Second,
+		Timeout:            30 * time.Second,
+		ValidateResolvedIP: true,
+		AllowPrivateHosts:  allowPrivate,
 	})
 	if err != nil {
 		sharedClient = &http.Client{Timeout: 30 * time.Second}
--- a/backend/internal/repository/pricing_service_test.go
+++ b/backend/internal/repository/pricing_service_test.go
@@ -6,6 +6,7 @@ import (
 	"net/http/httptest"
 	"testing"

+	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 )
@@ -19,7 +20,13 @@ type PricingServiceSuite struct {

 func (s *PricingServiceSuite) SetupTest() {
 	s.ctx = context.Background()
-	client, ok := NewPricingRemoteClient().(*pricingRemoteClient)
+	client, ok := NewPricingRemoteClient(&config.Config{
+		Security: config.SecurityConfig{
+			URLAllowlist: config.URLAllowlistConfig{
+				AllowPrivateHosts: true,
+			},
+		},
+	}).(*pricingRemoteClient)
 	require.True(s.T(), ok, "type assertion failed")
 	s.client = client
 }
--- a/backend/internal/repository/proxy_probe_service.go
+++ b/backend/internal/repository/proxy_probe_service.go
@@ -5,19 +5,21 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"time"

 	"github.com/Wei-Shaw/sub2api/internal/config"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/httpclient"
 	"github.com/Wei-Shaw/sub2api/internal/service"
-	"log"
 )

 func NewProxyExitInfoProber(cfg *config.Config) service.ProxyExitInfoProber {
 	insecure := false
+	allowPrivate := false
 	if cfg != nil {
 		insecure = cfg.Security.ProxyProbe.InsecureSkipVerify
+		allowPrivate = cfg.Security.URLAllowlist.AllowPrivateHosts
 	}
 	if insecure {
 		log.Printf("[ProxyProbe] Warning: TLS verification is disabled for proxy probing.")
@@ -25,6 +27,7 @@ func NewProxyExitInfoProber(cfg *config.Config) service.ProxyExitInfoProber {
 	return &proxyProbeService{
 		ipInfoURL:          defaultIPInfoURL,
 		insecureSkipVerify: insecure,
+		allowPrivateHosts:  allowPrivate,
 	}
 }

@@ -33,6 +36,7 @@ const defaultIPInfoURL = "https://ipinfo.io/json"
 type proxyProbeService struct {
 	ipInfoURL          string
 	insecureSkipVerify bool
+	allowPrivateHosts  bool
 }

 func (s *proxyProbeService) ProbeProxy(ctx context.Context, proxyURL string) (*service.ProxyExitInfo, int64, error) {
@@ -41,6 +45,8 @@ func (s *proxyProbeService) ProbeProxy(ctx context.Context, proxyURL string) (*s
 		Timeout:            15 * time.Second,
 		InsecureSkipVerify: s.insecureSkipVerify,
 		ProxyStrict:        true,
+		ValidateResolvedIP: true,
+		AllowPrivateHosts:  s.allowPrivateHosts,
 	})
 	if err != nil {
 		return nil, 0, fmt.Errorf("failed to create proxy client: %w", err)
--- a/backend/internal/repository/proxy_probe_service_test.go
+++ b/backend/internal/repository/proxy_probe_service_test.go
@@ -20,7 +20,10 @@ type ProxyProbeServiceSuite struct {

 func (s *ProxyProbeServiceSuite) SetupTest() {
 	s.ctx = context.Background()
-	s.prober = &proxyProbeService{ipInfoURL: "http://ipinfo.test/json"}
+	s.prober = &proxyProbeService{
+		ipInfoURL:         "http://ipinfo.test/json",
+		allowPrivateHosts: true,
+	}
 }

 func (s *ProxyProbeServiceSuite) TearDownTest() {
--- a/backend/internal/repository/turnstile_service.go
+++ b/backend/internal/repository/turnstile_service.go
@@ -22,7 +22,8 @@ type turnstileVerifier struct {

 func NewTurnstileVerifier() service.TurnstileVerifier {
 	sharedClient, err := httpclient.GetClient(httpclient.Options{
-		Timeout: 10 * time.Second,
+		Timeout:            10 * time.Second,
+		ValidateResolvedIP: true,
 	})
 	if err != nil {
 		sharedClient = &http.Client{Timeout: 10 * time.Second}
--- a/backend/internal/repository/turnstile_service_test.go
+++ b/backend/internal/repository/turnstile_service_test.go
@@ -41,6 +41,7 @@ func (s *TurnstileServiceSuite) TearDownTest() {
 func (s *TurnstileServiceSuite) setupServer(handler http.HandlerFunc) {
 	s.srv = httptest.NewServer(handler)
 	s.verifier.verifyURL = s.srv.URL
+	s.verifier.httpClient = s.srv.Client()
 }

 func (s *TurnstileServiceSuite) TestVerifyToken_SendsFormAndDecodesJSON() {
--- a/backend/internal/service/crs_sync_service.go
+++ b/backend/internal/service/crs_sync_service.go
@@ -203,7 +203,9 @@ func (s *CRSSyncService) SyncFromCRS(ctx context.Context, input SyncFromCRSInput
 	}

 	client, err := httpclient.GetClient(httpclient.Options{
-		Timeout: 20 * time.Second,
+		Timeout:            20 * time.Second,
+		ValidateResolvedIP: true,
+		AllowPrivateHosts:  s.cfg.Security.URLAllowlist.AllowPrivateHosts,
 	})
 	if err != nil {
 		client = &http.Client{Timeout: 20 * time.Second}
--- a/backend/internal/service/gemini_oauth_service.go
+++ b/backend/internal/service/gemini_oauth_service.go
@@ -498,8 +498,9 @@ func fetchProjectIDFromResourceManager(ctx context.Context, accessToken, proxyUR
 	req.Header.Set("User-Agent", geminicli.GeminiCLIUserAgent)

 	client, err := httpclient.GetClient(httpclient.Options{
-		ProxyURL: strings.TrimSpace(proxyURL),
-		Timeout:  30 * time.Second,
+		ProxyURL:           strings.TrimSpace(proxyURL),
+		Timeout:            30 * time.Second,
+		ValidateResolvedIP: true,
 	})
 	if err != nil {
 		client = &http.Client{Timeout: 30 * time.Second}
--- a/backend/internal/util/responseheaders/responseheaders.go
+++ b/backend/internal/util/responseheaders/responseheaders.go
@@ -31,6 +31,7 @@ var defaultAllowed = map[string]struct{}{
 	"x-ratelimit-reset-tokens":       {},
 	"retry-after":                    {},
 	"location":                       {},
+	"www-authenticate":               {},
 }

 // hopByHopHeaders 是跳过的 hop-by-hop 头部，这些头部由 HTTP 库自动处理
--- a/frontend/src/utils/url.ts
+++ b/frontend/src/utils/url.ts
@@ -14,7 +14,7 @@ export function sanitizeUrl(value: string, options: SanitizeOptions = {}): strin
    return ''
  }

-  if (options.allowRelative && trimmed.startsWith('/')) {
+  if (options.allowRelative && trimmed.startsWith('/') && !trimmed.startsWith('//')) {
    return trimmed
  }