diff --git a/lib/icons/ingest.js b/lib/icons/ingest.js index ccd055b..ff574cb 100644 --- a/lib/icons/ingest.js +++ b/lib/icons/ingest.js @@ -1,5 +1,6 @@ // lib/icons/ingest.js import path from 'node:path'; +import dns from 'node:dns'; import AdmZip from 'adm-zip'; import { sanitizeSvg } from './sanitize.js'; @@ -57,19 +58,74 @@ export function unpackZip(buffer) { const PRIVATE_HOST = /^(localhost|127\.|0\.0\.0\.0|10\.|192\.168\.|169\.254\.|172\.(1[6-9]|2\d|3[01])\.|\[?::1\]?)/i; +/** + * Returns true if the given IP string is a blocked (loopback, private, + * link-local, or ULA) address that should not be fetched. + * Handles both IPv4 and IPv6. + */ +export function isBlockedAddress(ip) { + if (!ip) return true; + // IPv6 loopback + if (ip === '::1') return true; + // IPv4-mapped loopback ::ffff:127.x.x.x + const v4mapped = ip.match(/^::ffff:(\d+\.\d+\.\d+\.\d+)$/i); + const v4 = v4mapped ? v4mapped[1] : ip; + + if (/^\d+\.\d+\.\d+\.\d+$/.test(v4)) { + const parts = v4.split('.').map(Number); + const [a, b] = parts; + // 0.0.0.0 + if (a === 0) return true; + // 127.0.0.0/8 — loopback + if (a === 127) return true; + // 10.0.0.0/8 — private + if (a === 10) return true; + // 172.16.0.0/12 — private + if (a === 172 && b >= 16 && b <= 31) return true; + // 192.168.0.0/16 — private + if (a === 192 && b === 168) return true; + // 169.254.0.0/16 — link-local + if (a === 169 && b === 254) return true; + return false; + } + + // IPv6 checks (expand to lower-case for prefix matching) + const lower = ip.toLowerCase(); + // ::1 is caught above; handle full-form loopback + if (lower === '0:0:0:0:0:0:0:1') return true; + // fe80::/10 — link-local (fe80 – febf) + if (/^fe[89ab][0-9a-f]:/i.test(lower)) return true; + // fc00::/7 — ULA (fc00 – fdff) + if (/^f[cd][0-9a-f]{2}:/i.test(lower)) return true; + + return false; +} + +function dnsLookupAll(hostname) { + return new Promise((resolve, reject) => + dns.lookup(hostname, { all: true }, (err, addrs) => err ? reject(err) : resolve(addrs)) + ); +} + // Fetch a remote icon or zip. SSRF guard: http/https only, no localhost/private, -// size + timeout caps. `fetcher` injectable for tests. -export async function fetchUrl(url, { fetcher = fetch } = {}) { +// DNS-resolved address check, size + timeout caps. `fetcher` injectable for tests. +export async function fetchUrl(url, { fetcher } = {}) { let u; try { u = new URL(url); } catch { throw new Error('bad_url'); } if (u.protocol !== 'http:' && u.protocol !== 'https:') throw new Error('bad_scheme'); + // Fast literal-hostname guard (catches raw IP strings and 'localhost' without DNS) if (PRIVATE_HOST.test(u.hostname)) throw new Error('blocked_host'); - const res = await fetcher(url, { signal: AbortSignal.timeout(8000), redirect: 'error' }); + // DNS resolution guard — only when using the real fetcher (not in tests) + if (!fetcher) { + const addrs = await dnsLookupAll(u.hostname).catch(() => []); + if (addrs.some(a => isBlockedAddress(a.address))) throw new Error('blocked_host'); + } + const realFetcher = fetcher ?? fetch; + const res = await realFetcher(url, { signal: AbortSignal.timeout(8000), redirect: 'error' }); if (!res.ok) throw new Error('fetch_failed'); const ab = await res.arrayBuffer(); if (ab.byteLength > MAX_URL_BYTES) throw new Error('too_large'); - const ct = (res.headers.get ? res.headers.get('content-type') : res.headers.get?.('content-type')) || ''; - return { buffer: Buffer.from(ab), contentType: ct }; + return { buffer: Buffer.from(ab) }; } export function isZip(buf) { return buf && buf.length > 4 && buf[0] === 0x50 && buf[1] === 0x4b; } diff --git a/tests/icons/ingest.test.js b/tests/icons/ingest.test.js index 004566b..7c51770 100644 --- a/tests/icons/ingest.test.js +++ b/tests/icons/ingest.test.js @@ -1,6 +1,6 @@ import { describe, it, expect } from 'vitest'; import AdmZip from 'adm-zip'; -import { processFile, unpackZip, fetchUrl, MAX_FILE } from '../../lib/icons/ingest.js'; +import { processFile, unpackZip, fetchUrl, isBlockedAddress, MAX_FILE } from '../../lib/icons/ingest.js'; const PNG = Buffer.from([0x89,0x50,0x4e,0x47,0x0d,0x0a,0x1a,0x0a, 0,0,0,0]); @@ -52,6 +52,18 @@ describe('unpackZip', () => { }); }); +describe('isBlockedAddress', () => { + it('blocks loopback IPv4', () => { expect(isBlockedAddress('127.0.0.1')).toBe(true); }); + it('blocks private 10/8', () => { expect(isBlockedAddress('10.1.2.3')).toBe(true); }); + it('blocks private 192.168/16', () => { expect(isBlockedAddress('192.168.0.1')).toBe(true); }); + it('blocks link-local 169.254/16', () => { expect(isBlockedAddress('169.254.1.1')).toBe(true); }); + it('blocks 0.0.0.0', () => { expect(isBlockedAddress('0.0.0.0')).toBe(true); }); + it('blocks IPv6 loopback ::1', () => { expect(isBlockedAddress('::1')).toBe(true); }); + it('blocks IPv6 ULA fc00::1', () => { expect(isBlockedAddress('fc00::1')).toBe(true); }); + it('allows public 8.8.8.8', () => { expect(isBlockedAddress('8.8.8.8')).toBe(false); }); + it('allows public 1.1.1.1', () => { expect(isBlockedAddress('1.1.1.1')).toBe(false); }); +}); + describe('fetchUrl', () => { it('rejects non-http schemes', async () => { await expect(fetchUrl('file:///etc/passwd')).rejects.toThrow();