fix(pipeline): validate CDN URLs against SSRF

HTTPS-only CDN URLs; блокировка private/loopback/metadata IP и DNS-resolve на fetch; проверка в httpapi при create/preview/patch CDN sources. Co-authored-by: Cursor <[email protected]>
2026-05-25 10:14:10 +07:00
parent 5a16a45922
commit 82382d90f2
6 changed files with 202 additions and 6 deletions
@@ -0,0 +1,116 @@
+package pipeline
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/netip"
+	"net/url"
+	"os"
+	"strings"
+	"time"
+)
+
+func isBlockedCDNIP(ip netip.Addr) bool {
+	if allowPrivateCDNURLs() {
+		return false
+	}
+	if !ip.IsValid() {
+		return true
+	}
+	return ip.IsLoopback() || ip.IsPrivate() || ip.IsLinkLocalUnicast() || ip.IsMulticast() ||
+		ip.IsUnspecified() || ip == netip.MustParseAddr("169.254.169.254")
+}
+
+func allowPrivateCDNURLs() bool {
+	v := strings.TrimSpace(os.Getenv("EVOBGP_CDN_ALLOW_PRIVATE"))
+	return v == "1" || strings.EqualFold(v, "true")
+}
+
+func isBlockedCDNHostname(host string) bool {
+	if allowPrivateCDNURLs() {
+		return false
+	}
+	h := strings.ToLower(strings.TrimSpace(host))
+	if h == "" || h == "localhost" {
+		return true
+	}
+	if strings.HasSuffix(h, ".local") || strings.HasSuffix(h, ".internal") || strings.HasSuffix(h, ".localhost") {
+		return true
+	}
+	return false
+}
+
+// ValidateCDNURL checks CDN source URLs for SSRF-safe HTTPS endpoints (hostname only; no DNS resolve).
+func ValidateCDNURL(raw string) (string, error) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return "", fmt.Errorf("pipeline: cdn url is required")
+	}
+	u, err := url.Parse(raw)
+	if err != nil {
+		return "", fmt.Errorf("pipeline: cdn url invalid: %w", err)
+	}
+	if u.Scheme != "https" {
+		return "", fmt.Errorf("pipeline: cdn url must use https")
+	}
+	if u.User != nil {
+		return "", fmt.Errorf("pipeline: cdn url must not include credentials")
+	}
+	host := strings.TrimSpace(u.Hostname())
+	if host == "" {
+		return "", fmt.Errorf("pipeline: cdn url missing host")
+	}
+	if isBlockedCDNHostname(host) {
+		return "", fmt.Errorf("pipeline: cdn url blocked host")
+	}
+	if ip, err := netip.ParseAddr(host); err == nil {
+		if isBlockedCDNIP(ip) {
+			return "", fmt.Errorf("pipeline: cdn url blocked host")
+		}
+	}
+	return u.String(), nil
+}
+
+// ResolveCDNURLHost resolves a CDN hostname and rejects private/link-local targets (SSRF at fetch time).
+func ResolveCDNURLHost(ctx context.Context, raw string) error {
+	u, err := url.Parse(strings.TrimSpace(raw))
+	if err != nil {
+		return err
+	}
+	host := strings.TrimSpace(u.Hostname())
+	if host == "" {
+		return fmt.Errorf("pipeline: cdn url missing host")
+	}
+	if ip, err := netip.ParseAddr(host); err == nil {
+		if isBlockedCDNIP(ip) {
+			return fmt.Errorf("pipeline: cdn url blocked host")
+		}
+		return nil
+	}
+	if isBlockedCDNHostname(host) {
+		return fmt.Errorf("pipeline: cdn url blocked host")
+	}
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	resolveCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+	ips, err := net.DefaultResolver.LookupIP(resolveCtx, "ip", host)
+	if err != nil {
+		return fmt.Errorf("pipeline: cdn url dns lookup: %w", err)
+	}
+	if len(ips) == 0 {
+		return fmt.Errorf("pipeline: cdn url dns lookup: no addresses")
+	}
+	for _, ip := range ips {
+		addr, ok := netip.AddrFromSlice(ip)
+		if !ok {
+			continue
+		}
+		if isBlockedCDNIP(addr) {
+			return fmt.Errorf("pipeline: cdn url resolves to blocked address")
+		}
+	}
+	return nil
+}