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299 lines
7.2 KiB
JavaScript

"use strict";
const punycode = require("punycode");
const regexes = require("./lib/regexes.js");
const mappingTable = require("./lib/mappingTable.json");
const { STATUS_MAPPING } = require("./lib/statusMapping.js");
function containsNonASCII(str) {
return /[^\x00-\x7F]/u.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];
const min = Array.isArray(target[0]) ? target[0][0] : target[0];
const max = Array.isArray(target[0]) ? target[0][1] : target[0];
if (min <= val && max >= val) {
if (useSTD3ASCIIRules &&
(target[1] === STATUS_MAPPING.disallowed_STD3_valid || target[1] === STATUS_MAPPING.disallowed_STD3_mapped)) {
return [STATUS_MAPPING.disallowed, ...target.slice(2)];
} else if (target[1] === STATUS_MAPPING.disallowed_STD3_valid) {
return [STATUS_MAPPING.valid, ...target.slice(2)];
} else if (target[1] === STATUS_MAPPING.disallowed_STD3_mapped) {
return [STATUS_MAPPING.mapped, ...target.slice(2)];
}
return target.slice(1);
} else if (min > 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 STATUS_MAPPING.disallowed:
hasError = true;
processed += ch;
break;
case STATUS_MAPPING.ignored:
break;
case STATUS_MAPPING.mapped:
processed += mapping;
break;
case STATUS_MAPPING.deviation:
if (processingOption === "transitional") {
processed += mapping;
} else {
processed += ch;
}
break;
case STATUS_MAPPING.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 !== STATUS_MAPPING.valid) ||
(processingOption === "nontransitional" &&
status !== STATUS_MAPPING.valid && status !== STATUS_MAPPING.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, {
...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,
processingOption = "nontransitional"
} = {}) {
const result = processing(domainName, {
processingOption,
checkHyphens,
checkBidi,
checkJoiners,
useSTD3ASCIIRules
});
return {
domain: result.string,
error: result.error
};
}
module.exports = {
toASCII,
toUnicode
};