Subchapter 7.20

Public Address

scripts/copy/public-address.mjs

JavaScript63 lines4 KB

1// Which source addresses import-media.mjs may download from. Only a GLOBAL UNICAST address
2// passes: this is an allowlist, not a list of known-private ranges, because a deny list misses
3// whatever it forgot (multicast, broadcast, benchmarking, documentation, newer IPv6 scopes). The
4// ranges are the IANA IPv4/IPv6 Special-Purpose Address Registries' entries that are not globally
5// reachable, plus multicast and reserved space; IPv6 must also lie in 2000::/3.
6//
7// The same rules live in wix-replatform's lib/document-url-guard.js. The two skills are published
8// separately and cannot import each other, so tests/target-wix/public-address-parity-test.js runs
9// one vector set against both to keep them identical.
10import net from 'node:net';
11
12// Generate File Upload URL is non-resumable and Wix sends files over 10 MB to the resumable

public-address.mjs on GitHub

// endpoint, so a download is capped below that.

export const MAX_UPLOAD_BYTES = 10 * 1000 * 1000;

const NON_GLOBAL = new net.BlockList();

for (const [address, prefix] of [

['0.0.0.0', 8], ['10.0.0.0', 8], ['100.64.0.0', 10], ['127.0.0.0', 8], ['169.254.0.0', 16],

['172.16.0.0', 12], ['192.0.0.0', 24], ['192.0.2.0', 24], ['192.88.99.0', 24], ['192.168.0.0', 16],

['198.18.0.0', 15], ['198.51.100.0', 24], ['203.0.113.0', 24], ['224.0.0.0', 4], ['240.0.0.0', 4],

]) NON_GLOBAL.addSubnet(address, prefix, 'ipv4');

// Inside 2000::/3: IETF protocol assignments (incl. Teredo), documentation, 6to4 (it can wrap any

// IPv4 address, private ones included), and the second documentation block.

for (const [address, prefix] of [['2001::', 23], ['2001:db8::', 32], ['2002::', 16], ['3fff::', 20]]) NON_GLOBAL.addSubnet(address, prefix, 'ipv6');

function ipv6Hextets(address) {

let text = address;

const dotted = text.match(/^(.*:)(\d{1,3}(?:\.\d{1,3}){3})$/);

if (dotted) {

const octets = dotted[2].split('.').map(Number);

text = `${dotted[1]}${((octets[0] << 8) | octets[1]).toString(16)}:${((octets[2] << 8) | octets[3]).toString(16)}`;

}

const [head, tail] = text.includes('::') ? text.split('::') : [text, null];

const left = head ? head.split(':') : [];

const right = tail ? tail.split(':') : [];

const fill = tail === null ? [] : new Array(8 - left.length - right.length).fill('0');

return [...left, ...fill, ...right].map((part) => parseInt(part, 16));

}

// True only for a literal IP address that is globally routable unicast.

export function isGlobalUnicastAddress(value) {

const address = String(value || '').toLowerCase().replace(/^\[|\]$/g, '');

const family = net.isIP(address);

if (family === 4) return !NON_GLOBAL.check(address, 'ipv4');

if (family !== 6) return false;

const hextets = ipv6Hextets(address);

// An IPv4-mapped address is the IPv4 destination in another notation: judge that address.

if (hextets.slice(0, 5).every((part) => part === 0) && hextets[5] === 0xffff) {

return isGlobalUnicastAddress([hextets[6] >> 8, hextets[6] & 0xff, hextets[7] >> 8, hextets[7] & 0xff].join('.'));

}

if ((hextets[0] & 0xe000) !== 0x2000) return false;

return !NON_GLOBAL.check(address, 'ipv6');

}

// Lexical check on a URL hostname: an IP literal must be global unicast; a name is refused only

// when it is local by definition, and is otherwise judged by the addresses it resolves to.

export function isPrivateHostname(hostname) {

// A trailing dot is the same name (`localhost.` resolves like `localhost`) and WHATWG URL keeps it on a name host.

const host = String(hostname || '').toLowerCase().replace(/^\[|\]$/g, '').replace(/\.+$/, '');

if (!host) return true;

if (net.isIP(host)) return !isGlobalUnicastAddress(host);

return host === 'localhost' || host.endsWith('.localhost') || host.endsWith('.local');

}