58 lines
1.3 KiB
JavaScript
58 lines
1.3 KiB
JavaScript
'use strict';
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function Random() {
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}
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/* secure random bytes that sometimes throws an error due to lack of entropy */
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Random.getRandomBuffer = function(size) {
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if (process.browser)
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return Random.getRandomBufferBrowser(size);
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else
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return Random.getRandomBufferNode(size);
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};
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Random.getRandomBufferNode = function(size) {
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var crypto = require('crypto');
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return crypto.randomBytes(size);
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};
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Random.getRandomBufferBrowser = function(size) {
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if (!window.crypto && !window.msCrypto)
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throw new Error('window.crypto not available');
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if (window.crypto && window.crypto.getRandomValues)
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var crypto = window.crypto;
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else if (window.msCrypto && window.msCrypto.getRandomValues) //internet explorer
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var crypto = window.msCrypto;
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else
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throw new Error('window.crypto.getRandomValues not available');
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var bbuf = new Uint8Array(size);
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crypto.getRandomValues(bbuf);
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var buf = new Buffer(bbuf);
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return buf;
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};
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/* insecure random bytes, but it never fails */
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Random.getPseudoRandomBuffer = function(size) {
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var b32 = 0x100000000;
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var b = new Buffer(size);
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var r;
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for (var i = 0; i <= size; i++) {
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var j = Math.floor(i / 4);
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var k = i - j * 4;
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if (k === 0) {
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r = Math.random() * b32;
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b[i] = r & 0xff;
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} else {
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b[i] = (r = r >>> 8) & 0xff;
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}
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}
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return b;
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};
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module.exports = Random;
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