| 1 | package builtin |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "encoding/json" |
| 6 | "net" |
| 7 | "net/http" |
| 8 | "net/http/httptest" |
| 9 | "strings" |
| 10 | "testing" |
| 11 | ) |
| 12 | |
| 13 | func TestBlockedFetchIP(t *testing.T) { |
| 14 | blocked := []string{ |
| 15 | "169.254.169.254", // cloud metadata (link-local) |
| 16 | "10.1.2.3", // RFC1918 |
| 17 | "172.16.5.6", // RFC1918 |
| 18 | "192.168.1.1", // RFC1918 |
| 19 | "0.0.0.0", // unspecified |
| 20 | "fe80::1", // IPv6 link-local |
| 21 | "fc00::1", // IPv6 unique-local |
| 22 | "::ffff:10.0.0.1", // IPv4-mapped private |
| 23 | "100.100.100.200", // Alibaba Cloud metadata (CGNAT) |
| 24 | "100.64.0.1", // RFC 6598 shared space |
| 25 | "::ffff:100.100.100.1", // IPv4-mapped CGNAT |
| 26 | } |
| 27 | for _, s := range blocked { |
| 28 | if !blockedFetchIP(net.ParseIP(s)) { |
| 29 | t.Errorf("%s should be blocked", s) |
| 30 | } |
| 31 | } |
| 32 | allowed := []string{"8.8.8.8", "1.1.1.1", "127.0.0.1", "::1", "93.184.216.34"} |
| 33 | for _, s := range allowed { |
| 34 | if blockedFetchIP(net.ParseIP(s)) { |
| 35 | t.Errorf("%s should be allowed", s) |
| 36 | } |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | // TestWebFetchAllowsLoopback proves the guard doesn't break normal fetches: a |
| 41 | // loopback dev server (httptest binds 127.0.0.1) stays reachable. |
| 42 | func TestWebFetchAllowsLoopback(t *testing.T) { |
| 43 | srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 44 | _, _ = w.Write([]byte("hello from localhost")) |
| 45 | })) |
| 46 | defer srv.Close() |
| 47 | |
| 48 | args, _ := json.Marshal(map[string]any{"url": srv.URL}) |
| 49 | out, err := webFetch{}.Execute(context.Background(), args) |
| 50 | if err != nil { |
| 51 | t.Fatalf("loopback fetch should succeed, got %v", err) |
| 52 | } |
| 53 | if !strings.Contains(out, "hello from localhost") { |
| 54 | t.Fatalf("body missing: %q", out) |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | // TestWebFetchRefusesLinkLocal proves a fetch aimed at the cloud-metadata |
| 59 | // endpoint is refused at dial time (no packet leaves the host). |
| 60 | func TestWebFetchRefusesLinkLocal(t *testing.T) { |
| 61 | args, _ := json.Marshal(map[string]any{"url": "http://169.254.169.254/latest/meta-data/"}) |
| 62 | _, err := webFetch{}.Execute(context.Background(), args) |
| 63 | if err == nil { |
| 64 | t.Fatal("fetch to 169.254.169.254 should be refused") |
| 65 | } |
| 66 | if !strings.Contains(err.Error(), "169.254.169.254") { |
| 67 | t.Fatalf("error should name the refused address, got %v", err) |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | func stubFetchLookup(t *testing.T, addrs ...string) { |
| 72 | t.Helper() |
| 73 | prev := lookupFetchHost |
| 74 | t.Cleanup(func() { lookupFetchHost = prev }) |
| 75 | lookupFetchHost = func(context.Context, string) ([]net.IPAddr, error) { |
| 76 | out := make([]net.IPAddr, 0, len(addrs)) |
| 77 | for _, a := range addrs { |
| 78 | out = append(out, net.IPAddr{IP: net.ParseIP(a)}) |
| 79 | } |
| 80 | return out, nil |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | // A fake-ip resolver (Clash, mihomo) answers a public host with a unique-local |
| 85 | // AAAA beside a routable A. The blocked address is skipped, not fatal. |
| 86 | func TestWebFetchDialsAllowedAddressBesideBlockedOne(t *testing.T) { |
| 87 | srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 88 | _, _ = w.Write([]byte("reached through the allowed address")) |
| 89 | })) |
| 90 | defer srv.Close() |
| 91 | _, port, _ := net.SplitHostPort(strings.TrimPrefix(srv.URL, "http://")) |
| 92 | stubFetchLookup(t, "fdfe:dcba:9876::152", "127.0.0.1") |
| 93 | |
| 94 | args, _ := json.Marshal(map[string]any{"url": "http://api-docs.example:" + port + "/"}) |
| 95 | out, err := webFetch{}.Execute(context.Background(), args) |
| 96 | if err != nil { |
| 97 | t.Fatalf("fetch should use the allowed address, got %v", err) |
| 98 | } |
| 99 | if !strings.Contains(out, "reached through the allowed address") { |
| 100 | t.Fatalf("body missing: %q", out) |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | func TestWebFetchRefusesHostWithOnlyBlockedAddresses(t *testing.T) { |
| 105 | stubFetchLookup(t, "fdfe:dcba:9876::152", "10.0.0.7") |
| 106 | args, _ := json.Marshal(map[string]any{"url": "http://internal.example/"}) |
| 107 | _, err := webFetch{}.Execute(context.Background(), args) |
| 108 | if err == nil || !strings.Contains(err.Error(), "refusing to fetch internal address") { |
| 109 | t.Fatalf("want SSRF refusal, got %v", err) |
| 110 | } |
| 111 | } |
| 112 |