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- "use strict";
- const punycode = require("punycode");
- const regexes = require("./lib/regexes.js");
- const mappingTable = require("./lib/mappingTable.json");
- function containsNonASCII(str) {
- return /[^\x00-\x7F]/.test(str);
- }
- function findStatus(val, { useSTD3ASCIIRules }) {
- let start = 0;
- let end = mappingTable.length - 1;
- while (start <= end) {
- const mid = Math.floor((start + end) / 2);
- const target = mappingTable[mid];
- if (target[0][0] <= val && target[0][1] >= val) {
- if (target[1].startsWith("disallowed_STD3_")) {
- const newStatus = useSTD3ASCIIRules ? "disallowed" : target[1].slice(16);
- return [newStatus, ...target.slice(2)];
- }
- return target.slice(1);
- } else if (target[0][0] > val) {
- end = mid - 1;
- } else {
- start = mid + 1;
- }
- }
- return null;
- }
- function mapChars(domainName, { useSTD3ASCIIRules, processingOption }) {
- let hasError = false;
- let processed = "";
- for (const ch of domainName) {
- const [status, mapping] = findStatus(ch.codePointAt(0), { useSTD3ASCIIRules });
- switch (status) {
- case "disallowed":
- hasError = true;
- processed += ch;
- break;
- case "ignored":
- break;
- case "mapped":
- processed += mapping;
- break;
- case "deviation":
- if (processingOption === "transitional") {
- processed += mapping;
- } else {
- processed += ch;
- }
- break;
- case "valid":
- processed += ch;
- break;
- }
- }
- return {
- string: processed,
- error: hasError
- };
- }
- function validateLabel(label, { checkHyphens, checkBidi, checkJoiners, processingOption, useSTD3ASCIIRules }) {
- if (label.normalize("NFC") !== label) {
- return false;
- }
- const codePoints = Array.from(label);
- if (checkHyphens) {
- if ((codePoints[2] === "-" && codePoints[3] === "-") ||
- (label.startsWith("-") || label.endsWith("-"))) {
- return false;
- }
- }
- if (label.includes(".") ||
- (codePoints.length > 0 && regexes.combiningMarks.test(codePoints[0]))) {
- return false;
- }
- for (const ch of codePoints) {
- const [status] = findStatus(ch.codePointAt(0), { useSTD3ASCIIRules });
- if ((processingOption === "transitional" && status !== "valid") ||
- (processingOption === "nontransitional" &&
- status !== "valid" && status !== "deviation")) {
- return false;
- }
- }
- // https://tools.ietf.org/html/rfc5892#appendix-A
- if (checkJoiners) {
- let last = 0;
- for (const [i, ch] of codePoints.entries()) {
- if (ch === "\u200C" || ch === "\u200D") {
- if (i > 0) {
- if (regexes.combiningClassVirama.test(codePoints[i - 1])) {
- continue;
- }
- if (ch === "\u200C") {
- // TODO: make this more efficient
- const next = codePoints.indexOf("\u200C", i + 1);
- const test = next < 0 ? codePoints.slice(last) : codePoints.slice(last, next);
- if (regexes.validZWNJ.test(test.join(""))) {
- last = i + 1;
- continue;
- }
- }
- }
- return false;
- }
- }
- }
- // https://tools.ietf.org/html/rfc5893#section-2
- if (checkBidi) {
- let rtl;
- // 1
- if (regexes.bidiS1LTR.test(codePoints[0])) {
- rtl = false;
- } else if (regexes.bidiS1RTL.test(codePoints[0])) {
- rtl = true;
- } else {
- return false;
- }
- if (rtl) {
- // 2-4
- if (!regexes.bidiS2.test(label) ||
- !regexes.bidiS3.test(label) ||
- (regexes.bidiS4EN.test(label) && regexes.bidiS4AN.test(label))) {
- return false;
- }
- } else if (!regexes.bidiS5.test(label) ||
- !regexes.bidiS6.test(label)) { // 5-6
- return false;
- }
- }
- return true;
- }
- function isBidiDomain(labels) {
- const domain = labels.map(label => {
- if (label.startsWith("xn--")) {
- try {
- return punycode.decode(label.substring(4));
- } catch (err) {
- return "";
- }
- }
- return label;
- }).join(".");
- return regexes.bidiDomain.test(domain);
- }
- function processing(domainName, options) {
- const { processingOption } = options;
- // 1. Map.
- let { string, error } = mapChars(domainName, options);
- // 2. Normalize.
- string = string.normalize("NFC");
- // 3. Break.
- const labels = string.split(".");
- const isBidi = isBidiDomain(labels);
- // 4. Convert/Validate.
- for (const [i, origLabel] of labels.entries()) {
- let label = origLabel;
- let curProcessing = processingOption;
- if (label.startsWith("xn--")) {
- try {
- label = punycode.decode(label.substring(4));
- labels[i] = label;
- } catch (err) {
- error = true;
- continue;
- }
- curProcessing = "nontransitional";
- }
- // No need to validate if we already know there is an error.
- if (error) {
- continue;
- }
- const validation = validateLabel(label, Object.assign({}, options, {
- processingOption: curProcessing,
- checkBidi: options.checkBidi && isBidi
- }));
- if (!validation) {
- error = true;
- }
- }
- return {
- string: labels.join("."),
- error
- };
- }
- function toASCII(domainName, {
- checkHyphens = false,
- checkBidi = false,
- checkJoiners = false,
- useSTD3ASCIIRules = false,
- processingOption = "nontransitional",
- verifyDNSLength = false
- } = {}) {
- if (processingOption !== "transitional" && processingOption !== "nontransitional") {
- throw new RangeError("processingOption must be either transitional or nontransitional");
- }
- const result = processing(domainName, {
- processingOption,
- checkHyphens,
- checkBidi,
- checkJoiners,
- useSTD3ASCIIRules
- });
- let labels = result.string.split(".");
- labels = labels.map(l => {
- if (containsNonASCII(l)) {
- try {
- return "xn--" + punycode.encode(l);
- } catch (e) {
- result.error = true;
- }
- }
- return l;
- });
- if (verifyDNSLength) {
- const total = labels.join(".").length;
- if (total > 253 || total === 0) {
- result.error = true;
- }
- for (let i = 0; i < labels.length; ++i) {
- if (labels[i].length > 63 || labels[i].length === 0) {
- result.error = true;
- break;
- }
- }
- }
- if (result.error) {
- return null;
- }
- return labels.join(".");
- }
- function toUnicode(domainName, {
- checkHyphens = false,
- checkBidi = false,
- checkJoiners = false,
- useSTD3ASCIIRules = false
- } = {}) {
- const result = processing(domainName, {
- processingOption: "nontransitional",
- checkHyphens,
- checkBidi,
- checkJoiners,
- useSTD3ASCIIRules
- });
- return {
- domain: result.string,
- error: result.error
- };
- }
- module.exports = {
- toASCII,
- toUnicode
- };
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