import dns from 'dns'; import { resolveAndValidate, BlockedHostError } from '../ssrf-guard'; jest.mock('dns', () => ({ promises: { resolve4: jest.fn(), resolve6: jest.fn(), }, })); const mockResolve4 = dns.promises.resolve4 as jest.MockedFunction; const mockResolve6 = dns.promises.resolve6 as jest.MockedFunction; beforeEach(() => { mockResolve4.mockReset(); mockResolve6.mockReset(); }); describe('resolveAndValidate', () => { describe('IP literals (no DNS round-trip)', () => { it('passes for public IPv4 literal', async () => { const result = await resolveAndValidate('8.8.8.8'); expect(result).toEqual({ ip: '8.8.8.8', family: 4, hostname: '8.8.8.8' }); expect(mockResolve4).not.toHaveBeenCalled(); expect(mockResolve6).not.toHaveBeenCalled(); }); it('passes for public IPv6 literal (with brackets)', async () => { const result = await resolveAndValidate('[2606:4700:4700::1111]'); expect(result.ip).toBe('2606:4700:4700::1111'); expect(result.family).toBe(6); expect(mockResolve4).not.toHaveBeenCalled(); }); it('rejects 127.0.0.1', async () => { await expect(resolveAndValidate('127.0.0.1')).rejects.toBeInstanceOf(BlockedHostError); }); it('rejects cloud metadata IP 169.254.169.254', async () => { await expect(resolveAndValidate('169.254.169.254')).rejects.toBeInstanceOf(BlockedHostError); }); it('rejects IPv6 loopback ::1', async () => { await expect(resolveAndValidate('::1')).rejects.toBeInstanceOf(BlockedHostError); }); it('allows RFC1918 IP when allowPrivate=true', async () => { // AUDIT-2 #2 (2026-05-24): switched from 127.0.0.1 to 10.0.0.5. // Loopback now needs its own allowLoopback flag (see tests // below); RFC1918 intranet ranges remain the canonical // allowPrivate target. const result = await resolveAndValidate('10.0.0.5', { allowPrivate: true }); expect(result.ip).toBe('10.0.0.5'); }); it('STILL rejects cloud metadata even with allowPrivate=true', async () => { // allowPrivate cannot unlock the always-blocked set — protects // cloud-hosted deployments from one-typo IAM-credential leaks. await expect( resolveAndValidate('169.254.169.254', { allowPrivate: true }) ).rejects.toBeInstanceOf(BlockedHostError); }); it('STILL rejects IPv6 link-local even with allowPrivate=true', async () => { await expect( resolveAndValidate('fe80::1', { allowPrivate: true }) ).rejects.toBeInstanceOf(BlockedHostError); }); // AUDIT-2 #2 (2026-05-24): on multi-container hosts, ALLOW_PRIVATE_NETWORK // was unlocking same-host private networks (loopback, ULA) the operator // probably did not intend to reach. Need a second-tier override // (ALLOW_LOOPBACK_PROBES / opts.allowLoopback) before these unlock. it('rejects IPv4 loopback 127.0.0.1 with allowPrivate=true but allowLoopback=false', async () => { await expect( resolveAndValidate('127.0.0.1', { allowPrivate: true, allowLoopback: false }) ).rejects.toBeInstanceOf(BlockedHostError); }); it('rejects IPv6 loopback ::1 with allowPrivate=true but allowLoopback=false', async () => { await expect( resolveAndValidate('::1', { allowPrivate: true, allowLoopback: false }) ).rejects.toBeInstanceOf(BlockedHostError); }); it('rejects ULA fc00::/7 with allowPrivate=true but allowLoopback=false', async () => { await expect( resolveAndValidate('fc00::1', { allowPrivate: true, allowLoopback: false }) ).rejects.toBeInstanceOf(BlockedHostError); }); it('allows loopback with allowPrivate=true AND allowLoopback=true (explicit opt-in)', async () => { const result = await resolveAndValidate('127.0.0.1', { allowPrivate: true, allowLoopback: true }); expect(result.ip).toBe('127.0.0.1'); }); it('rejects ULA with allowPrivate=false (also covered by private-range check)', async () => { await expect( resolveAndValidate('fc00::1') ).rejects.toBeInstanceOf(BlockedHostError); }); }); describe('hostnames (DNS resolution)', () => { it('passes when DNS returns only public IPv4', async () => { mockResolve4.mockResolvedValue(['8.8.8.8']); mockResolve6.mockRejectedValue(new Error('ENOTFOUND')); const result = await resolveAndValidate('dns.google'); expect(result.ip).toBe('8.8.8.8'); expect(result.family).toBe(4); }); it('passes when only AAAA available (IPv6 fallback)', async () => { mockResolve4.mockRejectedValue(new Error('ENODATA')); mockResolve6.mockResolvedValue(['2606:4700:4700::1111']); const result = await resolveAndValidate('one.one.one.one'); expect(result.ip).toBe('2606:4700:4700::1111'); expect(result.family).toBe(6); }); it('prefers IPv4 when both families resolve to public IPs', async () => { mockResolve4.mockResolvedValue(['8.8.8.8']); mockResolve6.mockResolvedValue(['2001:4860:4860::8888']); const result = await resolveAndValidate('dns.google'); expect(result.ip).toBe('8.8.8.8'); }); it('rejects when DNS returns a private IPv4', async () => { mockResolve4.mockResolvedValue(['127.0.0.1']); mockResolve6.mockRejectedValue(new Error('ENODATA')); await expect(resolveAndValidate('attacker.example.com')).rejects.toBeInstanceOf(BlockedHostError); }); it('rejects on mixed public + private response (DNS rebinding defence)', async () => { mockResolve4.mockResolvedValue(['8.8.8.8', '10.0.0.1']); mockResolve6.mockRejectedValue(new Error('ENODATA')); const err = await resolveAndValidate('mixed.example.com').catch(e => e); expect(err).toBeInstanceOf(BlockedHostError); expect(err.ip).toBe('10.0.0.1'); }); it('rejects when only AAAA resolves to a private IPv6', async () => { mockResolve4.mockRejectedValue(new Error('ENODATA')); mockResolve6.mockResolvedValue(['::1']); await expect(resolveAndValidate('lo.example.com')).rejects.toBeInstanceOf(BlockedHostError); }); it('rejects when neither family resolves (unresolvable host)', async () => { mockResolve4.mockRejectedValue(new Error('ENOTFOUND')); mockResolve6.mockRejectedValue(new Error('ENOTFOUND')); await expect(resolveAndValidate('does-not-exist.invalid')).rejects.toBeInstanceOf(BlockedHostError); }); it('bypasses the check when allowPrivate=true', async () => { mockResolve4.mockResolvedValue(['10.0.0.5']); mockResolve6.mockRejectedValue(new Error('ENODATA')); const result = await resolveAndValidate('internal.intranet', { allowPrivate: true }); expect(result.ip).toBe('10.0.0.5'); }); it('STILL rejects DNS-resolved cloud metadata even with allowPrivate=true', async () => { mockResolve4.mockResolvedValue(['169.254.169.254']); mockResolve6.mockRejectedValue(new Error('ENODATA')); await expect( resolveAndValidate('aws-metadata.evil.example', { allowPrivate: true }) ).rejects.toBeInstanceOf(BlockedHostError); }); }); describe('BlockedHostError shape', () => { it('carries hostname and offending ip', async () => { mockResolve4.mockResolvedValue(['10.0.0.5']); mockResolve6.mockRejectedValue(new Error('ENODATA')); const err = await resolveAndValidate('evil.example').catch(e => e); expect(err).toBeInstanceOf(BlockedHostError); expect(err.hostname).toBe('evil.example'); expect(err.ip).toBe('10.0.0.5'); expect(err.status).toBe(400); expect(err.message).toMatch(/Blocked/); }); }); });