97 lines
2.9 KiB
JavaScript
97 lines
2.9 KiB
JavaScript
(function() {
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var base64map
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= 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
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crypt = {
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// Bit-wise rotation left
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rotl: function(n, b) {
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return (n << b) | (n >>> (32 - b));
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},
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// Bit-wise rotation right
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rotr: function(n, b) {
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return (n << (32 - b)) | (n >>> b);
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},
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// Swap big-endian to little-endian and vice versa
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endian: function(n) {
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// If number given, swap endian
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if (n.constructor == Number) {
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return crypt.rotl(n, 8) & 0x00FF00FF | crypt.rotl(n, 24) & 0xFF00FF00;
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}
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// Else, assume array and swap all items
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for (var i = 0; i < n.length; i++)
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n[i] = crypt.endian(n[i]);
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return n;
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},
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// Generate an array of any length of random bytes
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randomBytes: function(n) {
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for (var bytes = []; n > 0; n--)
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bytes.push(Math.floor(Math.random() * 256));
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return bytes;
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},
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// Convert a byte array to big-endian 32-bit words
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bytesToWords: function(bytes) {
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for (var words = [], i = 0, b = 0; i < bytes.length; i++, b += 8)
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words[b >>> 5] |= bytes[i] << (24 - b % 32);
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return words;
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},
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// Convert big-endian 32-bit words to a byte array
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wordsToBytes: function(words) {
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for (var bytes = [], b = 0; b < words.length * 32; b += 8)
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bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF);
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return bytes;
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},
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// Convert a byte array to a hex string
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bytesToHex: function(bytes) {
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for (var hex = [], i = 0; i < bytes.length; i++) {
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hex.push((bytes[i] >>> 4).toString(16));
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hex.push((bytes[i] & 0xF).toString(16));
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}
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return hex.join('');
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},
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// Convert a hex string to a byte array
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hexToBytes: function(hex) {
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for (var bytes = [], c = 0; c < hex.length; c += 2)
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bytes.push(parseInt(hex.substr(c, 2), 16));
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return bytes;
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},
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// Convert a byte array to a base-64 string
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bytesToBase64: function(bytes) {
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for (var base64 = [], i = 0; i < bytes.length; i += 3) {
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var triplet = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];
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for (var j = 0; j < 4; j++)
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if (i * 8 + j * 6 <= bytes.length * 8)
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base64.push(base64map.charAt((triplet >>> 6 * (3 - j)) & 0x3F));
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else
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base64.push('=');
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}
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return base64.join('');
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},
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// Convert a base-64 string to a byte array
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base64ToBytes: function(base64) {
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// Remove non-base-64 characters
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base64 = base64.replace(/[^A-Z0-9+\/]/ig, '');
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for (var bytes = [], i = 0, imod4 = 0; i < base64.length;
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imod4 = ++i % 4) {
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if (imod4 == 0) continue;
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bytes.push(((base64map.indexOf(base64.charAt(i - 1))
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& (Math.pow(2, -2 * imod4 + 8) - 1)) << (imod4 * 2))
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| (base64map.indexOf(base64.charAt(i)) >>> (6 - imod4 * 2)));
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}
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return bytes;
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}
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};
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module.exports = crypt;
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})();
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