fix: reject private callback and rate API URLs

src/util/security/url_guard_test.go

@@ -0,0 +1,77 @@
+package security
+
+import (
+	"context"
+	"errors"
+	"net"
+	"testing"
+)
+
+func withLookupIPAddr(t *testing.T, fn func(context.Context, string) ([]net.IPAddr, error)) {
+	t.Helper()
+	old := lookupIPAddr
+	lookupIPAddr = fn
+	t.Cleanup(func() {
+		lookupIPAddr = old
+	})
+}
+
+func TestValidatePublicHTTPURLAllowsPublicHTTPURL(t *testing.T) {
+	withLookupIPAddr(t, func(ctx context.Context, host string) ([]net.IPAddr, error) {
+		if host != "example.com" {
+			t.Fatalf("lookup host = %q, want example.com", host)
+		}
+		return []net.IPAddr{{IP: net.ParseIP("93.184.216.34")}}, nil
+	})
+
+	if err := ValidatePublicHTTPURL("https://example.com/api/"); err != nil {
+		t.Fatalf("ValidatePublicHTTPURL returned error: %v", err)
+	}
+}
+
+func TestValidatePublicHTTPURLRejectsUnsafeURLs(t *testing.T) {
+	tests := []string{
+		"",
+		"://bad",
+		"ftp://example.com/file",
+		"https:///missing-host",
+		"http://localhost/notify",
+		"http://localhost./notify",
+		"http://127.0.0.1/notify",
+		"http://[::1]/notify",
+		"http://10.0.0.1/notify",
+		"http://172.16.0.1/notify",
+		"http://172.31.255.255/notify",
+		"http://192.168.1.1/notify",
+		"http://169.254.1.1/notify",
+		"http://169.254.169.254/latest/meta-data/",
+	}
+
+	for _, raw := range tests {
+		t.Run(raw, func(t *testing.T) {
+			if err := ValidatePublicHTTPURL(raw); err == nil {
+				t.Fatalf("ValidatePublicHTTPURL(%q) returned nil, want error", raw)
+			}
+		})
+	}
+}
+
+func TestValidatePublicHTTPURLRejectsDomainResolvingToPrivateIP(t *testing.T) {
+	withLookupIPAddr(t, func(ctx context.Context, host string) ([]net.IPAddr, error) {
+		return []net.IPAddr{{IP: net.ParseIP("93.184.216.34")}, {IP: net.ParseIP("10.0.0.1")}}, nil
+	})
+
+	if err := ValidatePublicHTTPURL("https://example.com/api/"); err == nil {
+		t.Fatal("ValidatePublicHTTPURL returned nil, want error")
+	}
+}
+
+func TestValidatePublicHTTPURLRejectsUnresolvableDomain(t *testing.T) {
+	withLookupIPAddr(t, func(ctx context.Context, host string) ([]net.IPAddr, error) {
+		return nil, errors.New("lookup failed")
+	})
+
+	if err := ValidatePublicHTTPURL("https://example.com/api/"); err == nil {
+		t.Fatal("ValidatePublicHTTPURL returned nil, want error")
+	}
+}