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270 lines
5.9 KiB
JavaScript

5 years ago
/*eslint no-var:0, prefer-arrow-callback: 0, object-shorthand: 0 */
'use strict';
var Punycode = require('punycode');
var internals = {};
//
// Read rules from file.
//
internals.rules = require('./data/rules.json').map(function (rule) {
return {
rule: rule,
suffix: rule.replace(/^(\*\.|\!)/, ''),
punySuffix: -1,
wildcard: rule.charAt(0) === '*',
exception: rule.charAt(0) === '!'
};
});
//
// Check is given string ends with `suffix`.
//
internals.endsWith = function (str, suffix) {
return str.indexOf(suffix, str.length - suffix.length) !== -1;
};
//
// Find rule for a given domain.
//
internals.findRule = function (domain) {
var punyDomain = Punycode.toASCII(domain);
return internals.rules.reduce(function (memo, rule) {
if (rule.punySuffix === -1){
rule.punySuffix = Punycode.toASCII(rule.suffix);
}
if (!internals.endsWith(punyDomain, '.' + rule.punySuffix) && punyDomain !== rule.punySuffix) {
return memo;
}
// This has been commented out as it never seems to run. This is because
// sub tlds always appear after their parents and we never find a shorter
// match.
//if (memo) {
// var memoSuffix = Punycode.toASCII(memo.suffix);
// if (memoSuffix.length >= punySuffix.length) {
// return memo;
// }
//}
return rule;
}, null);
};
//
// Error codes and messages.
//
exports.errorCodes = {
DOMAIN_TOO_SHORT: 'Domain name too short.',
DOMAIN_TOO_LONG: 'Domain name too long. It should be no more than 255 chars.',
LABEL_STARTS_WITH_DASH: 'Domain name label can not start with a dash.',
LABEL_ENDS_WITH_DASH: 'Domain name label can not end with a dash.',
LABEL_TOO_LONG: 'Domain name label should be at most 63 chars long.',
LABEL_TOO_SHORT: 'Domain name label should be at least 1 character long.',
LABEL_INVALID_CHARS: 'Domain name label can only contain alphanumeric characters or dashes.'
};
//
// Validate domain name and throw if not valid.
//
// From wikipedia:
//
// Hostnames are composed of series of labels concatenated with dots, as are all
// domain names. Each label must be between 1 and 63 characters long, and the
// entire hostname (including the delimiting dots) has a maximum of 255 chars.
//
// Allowed chars:
//
// * `a-z`
// * `0-9`
// * `-` but not as a starting or ending character
// * `.` as a separator for the textual portions of a domain name
//
// * http://en.wikipedia.org/wiki/Domain_name
// * http://en.wikipedia.org/wiki/Hostname
//
internals.validate = function (input) {
// Before we can validate we need to take care of IDNs with unicode chars.
var ascii = Punycode.toASCII(input);
if (ascii.length < 1) {
return 'DOMAIN_TOO_SHORT';
}
if (ascii.length > 255) {
return 'DOMAIN_TOO_LONG';
}
// Check each part's length and allowed chars.
var labels = ascii.split('.');
var label;
for (var i = 0; i < labels.length; ++i) {
label = labels[i];
if (!label.length) {
return 'LABEL_TOO_SHORT';
}
if (label.length > 63) {
return 'LABEL_TOO_LONG';
}
if (label.charAt(0) === '-') {
return 'LABEL_STARTS_WITH_DASH';
}
if (label.charAt(label.length - 1) === '-') {
return 'LABEL_ENDS_WITH_DASH';
}
if (!/^[a-z0-9\-]+$/.test(label)) {
return 'LABEL_INVALID_CHARS';
}
}
};
//
// Public API
//
//
// Parse domain.
//
exports.parse = function (input) {
if (typeof input !== 'string') {
throw new TypeError('Domain name must be a string.');
}
// Force domain to lowercase.
var domain = input.slice(0).toLowerCase();
// Handle FQDN.
// TODO: Simply remove trailing dot?
if (domain.charAt(domain.length - 1) === '.') {
domain = domain.slice(0, domain.length - 1);
}
// Validate and sanitise input.
var error = internals.validate(domain);
if (error) {
return {
input: input,
error: {
message: exports.errorCodes[error],
code: error
}
};
}
var parsed = {
input: input,
tld: null,
sld: null,
domain: null,
subdomain: null,
listed: false
};
var domainParts = domain.split('.');
// Non-Internet TLD
if (domainParts[domainParts.length - 1] === 'local') {
return parsed;
}
var handlePunycode = function () {
if (!/xn--/.test(domain)) {
return parsed;
}
if (parsed.domain) {
parsed.domain = Punycode.toASCII(parsed.domain);
}
if (parsed.subdomain) {
parsed.subdomain = Punycode.toASCII(parsed.subdomain);
}
return parsed;
};
var rule = internals.findRule(domain);
// Unlisted tld.
if (!rule) {
if (domainParts.length < 2) {
return parsed;
}
parsed.tld = domainParts.pop();
parsed.sld = domainParts.pop();
parsed.domain = [parsed.sld, parsed.tld].join('.');
if (domainParts.length) {
parsed.subdomain = domainParts.pop();
}
return handlePunycode();
}
// At this point we know the public suffix is listed.
parsed.listed = true;
var tldParts = rule.suffix.split('.');
var privateParts = domainParts.slice(0, domainParts.length - tldParts.length);
if (rule.exception) {
privateParts.push(tldParts.shift());
}
parsed.tld = tldParts.join('.');
if (!privateParts.length) {
return handlePunycode();
}
if (rule.wildcard) {
tldParts.unshift(privateParts.pop());
parsed.tld = tldParts.join('.');
}
if (!privateParts.length) {
return handlePunycode();
}
parsed.sld = privateParts.pop();
parsed.domain = [parsed.sld, parsed.tld].join('.');
if (privateParts.length) {
parsed.subdomain = privateParts.join('.');
}
return handlePunycode();
};
//
// Get domain.
//
exports.get = function (domain) {
if (!domain) {
return null;
}
return exports.parse(domain).domain || null;
};
//
// Check whether domain belongs to a known public suffix.
//
exports.isValid = function (domain) {
var parsed = exports.parse(domain);
return Boolean(parsed.domain && parsed.listed);
};