Files
2025-07-11 14:49:28 +08:00

325 lines
10 KiB
JavaScript

/**********************************************************\
| |
| xxtea.js |
| |
| XXTEA encryption algorithm library for Node.js. |
| |
| Encryption Algorithm Authors: |
| David J. Wheeler |
| Roger M. Needham |
| |
| Code Author: Ma Bingyao <mabingyao@gmail.com> |
| LastModified: Dec 27, 2019 |
| |
\**********************************************************/
/*jshint node:true, eqeqeq:true */
'use strict';
var delta = 0x9E3779B9;
function toUint8Array(v, includeLength) {
var length = v.length;
var n = length << 2;
if (includeLength) {
var m = v[length - 1];
n -= 4;
if ((m < n - 3) || (m > n)) {
return null;
}
n = m;
}
var bytes = new Uint8Array(n);
for (var i = 0; i < n; ++i) {
bytes[i] = v[i >> 2] >> ((i & 3) << 3);
}
return bytes;
}
function toUint32Array(bytes, includeLength) {
var length = bytes.length;
var n = length >> 2;
if ((length & 3) !== 0) {
++n;
}
var v;
if (includeLength) {
v = new Uint32Array(n + 1);
v[n] = length;
}
else {
v = new Uint32Array(n);
}
for (var i = 0; i < length; ++i) {
v[i >> 2] |= bytes[i] << ((i & 3) << 3);
}
return v;
}
function mx(sum, y, z, p, e, k) {
return ((z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4)) ^ ((sum ^ y) + (k[p & 3 ^ e] ^ z));
}
function fixk(k) {
if (k.length < 16) {
var key = new Uint8Array(16);
key.set(k);
k = key;
}
return k;
}
function encryptUint32Array(v, k) {
var length = v.length;
var n = length - 1;
var y, z, sum, e, p, q;
z = v[n];
sum = 0;
for (q = Math.floor(6 + 52 / length) | 0; q > 0; --q) {
sum += delta;
e = sum >>> 2 & 3;
for (p = 0; p < n; ++p) {
y = v[p + 1];
z = v[p] += mx(sum, y, z, p, e, k);
}
y = v[0];
z = v[n] += mx(sum, y, z, p, e, k);
}
return v;
}
function decryptUint32Array(v, k) {
var length = v.length;
var n = length - 1;
var y, z, sum, e, p, q;
y = v[0];
q = Math.floor(6 + 52 / length);
for (sum = q * delta; sum !== 0; sum -= delta) {
e = sum >>> 2 & 3;
for (p = n; p > 0; --p) {
z = v[p - 1];
y = v[p] -= mx(sum, y, z, p, e, k);
}
z = v[n];
y = v[0] -= mx(sum, y, z, p, e, k);
}
return v;
}
function toBytes(str) {
var n = str.length;
// A single code unit uses at most 3 bytes.
// Two code units at most 4.
var bytes = new Uint8Array(n * 3);
var length = 0;
for (var i = 0; i < n; i++) {
var codeUnit = str.charCodeAt(i);
if (codeUnit < 0x80) {
bytes[length++] = codeUnit;
}
else if (codeUnit < 0x800) {
bytes[length++] = 0xC0 | (codeUnit >> 6);
bytes[length++] = 0x80 | (codeUnit & 0x3F);
}
else if (codeUnit < 0xD800 || codeUnit > 0xDFFF) {
bytes[length++] = 0xE0 | (codeUnit >> 12);
bytes[length++] = 0x80 | ((codeUnit >> 6) & 0x3F);
bytes[length++] = 0x80 | (codeUnit & 0x3F);
}
else {
if (i + 1 < n) {
var nextCodeUnit = str.charCodeAt(i + 1);
if (codeUnit < 0xDC00 && 0xDC00 <= nextCodeUnit && nextCodeUnit <= 0xDFFF) {
var rune = (((codeUnit & 0x03FF) << 10) | (nextCodeUnit & 0x03FF)) + 0x010000;
bytes[length++] = 0xF0 | (rune >> 18);
bytes[length++] = 0x80 | ((rune >> 12) & 0x3F);
bytes[length++] = 0x80 | ((rune >> 6) & 0x3F);
bytes[length++] = 0x80 | (rune & 0x3F);
i++;
continue;
}
}
throw new Error('Malformed string');
}
}
return bytes.subarray(0, length);
}
function toShortString(bytes, n) {
var charCodes = new Uint16Array(n);
var i = 0, off = 0;
for (var len = bytes.length; i < n && off < len; i++) {
var unit = bytes[off++];
switch (unit >> 4) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
charCodes[i] = unit;
break;
case 12:
case 13:
if (off < len) {
charCodes[i] = ((unit & 0x1F) << 6) |
(bytes[off++] & 0x3F);
}
else {
throw new Error('Unfinished UTF-8 octet sequence');
}
break;
case 14:
if (off + 1 < len) {
charCodes[i] = ((unit & 0x0F) << 12) |
((bytes[off++] & 0x3F) << 6) |
(bytes[off++] & 0x3F);
}
else {
throw new Error('Unfinished UTF-8 octet sequence');
}
break;
case 15:
if (off + 2 < len) {
var rune = (((unit & 0x07) << 18) |
((bytes[off++] & 0x3F) << 12) |
((bytes[off++] & 0x3F) << 6) |
(bytes[off++] & 0x3F)) - 0x10000;
if (0 <= rune && rune <= 0xFFFFF) {
charCodes[i++] = (((rune >> 10) & 0x03FF) | 0xD800);
charCodes[i] = ((rune & 0x03FF) | 0xDC00);
}
else {
throw new Error('Character outside valid Unicode range: 0x' + rune.toString(16));
}
}
else {
throw new Error('Unfinished UTF-8 octet sequence');
}
break;
default:
throw new Error('Bad UTF-8 encoding 0x' + unit.toString(16));
}
}
if (i < n) {
charCodes = charCodes.subarray(0, i);
}
return String.fromCharCode.apply(String, charCodes);
}
function toLongString(bytes, n) {
var buf = [];
var charCodes = new Uint16Array(0x8000);
var i = 0, off = 0;
for (var len = bytes.length; i < n && off < len; i++) {
var unit = bytes[off++];
switch (unit >> 4) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
charCodes[i] = unit;
break;
case 12:
case 13:
if (off < len) {
charCodes[i] = ((unit & 0x1F) << 6) |
(bytes[off++] & 0x3F);
}
else {
throw new Error('Unfinished UTF-8 octet sequence');
}
break;
case 14:
if (off + 1 < len) {
charCodes[i] = ((unit & 0x0F) << 12) |
((bytes[off++] & 0x3F) << 6) |
(bytes[off++] & 0x3F);
}
else {
throw new Error('Unfinished UTF-8 octet sequence');
}
break;
case 15:
if (off + 2 < len) {
var rune = (((unit & 0x07) << 18) |
((bytes[off++] & 0x3F) << 12) |
((bytes[off++] & 0x3F) << 6) |
(bytes[off++] & 0x3F)) - 0x10000;
if (0 <= rune && rune <= 0xFFFFF) {
charCodes[i++] = (((rune >> 10) & 0x03FF) | 0xD800);
charCodes[i] = ((rune & 0x03FF) | 0xDC00);
}
else {
throw new Error('Character outside valid Unicode range: 0x' + rune.toString(16));
}
}
else {
throw new Error('Unfinished UTF-8 octet sequence');
}
break;
default:
throw new Error('Bad UTF-8 encoding 0x' + unit.toString(16));
}
if (i >= 0x7FFF - 1) {
var size = i + 1;
buf.push(String.fromCharCode.apply(String, charCodes.subarray(0, size)));
n -= size;
i = -1;
}
}
if (i > 0) {
buf.push(String.fromCharCode.apply(String, charCodes.subarray(0, i)));
}
return buf.join('');
}
function toString(bytes) {
var n = bytes.length;
if (n === 0) return '';
return ((n < 0x7FFF) ?
toShortString(bytes, n) :
toLongString(bytes, n));
}
function encrypt(data, key) {
if (typeof data === 'string') data = toBytes(data);
if (typeof key === 'string') key = toBytes(key);
if (data === undefined || data === null || data.length === 0) {
return data;
}
return toUint8Array(encryptUint32Array(toUint32Array(data, true), toUint32Array(fixk(key), false)), false);
}
function encryptToString(data, key) {
return new Buffer(encrypt(data, key)).toString('base64');
}
function decrypt(data, key) {
if (typeof data === 'string') data = new Buffer(data, 'base64');
if (typeof key === 'string') key = toBytes(key);
if (data === undefined || data === null || data.length === 0) {
return data;
}
return toUint8Array(decryptUint32Array(toUint32Array(data, false), toUint32Array(fixk(key), false)), true);
}
function decryptToString(data, key) {
return toString(decrypt(data, key));
}
module.exports = Object.create(null, {
toBytes: { value: toBytes },
toString: { value: toString },
encrypt: { value: encrypt },
encryptToString: { value: encryptToString },
decrypt: { value: decrypt },
decryptToString: { value: decryptToString }
});