42 lines
1 KiB
JavaScript
42 lines
1 KiB
JavaScript
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/*jshint node:true */
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'use strict';
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var Buffer = require('buffer').Buffer; // browserify
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var SlowBuffer = require('buffer').SlowBuffer;
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module.exports = bufferEq;
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function bufferEq(a, b) {
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// shortcutting on type is necessary for correctness
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if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
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return false;
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}
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// buffer sizes should be well-known information, so despite this
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// shortcutting, it doesn't leak any information about the *contents* of the
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// buffers.
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if (a.length !== b.length) {
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return false;
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}
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var c = 0;
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for (var i = 0; i < a.length; i++) {
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/*jshint bitwise:false */
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c |= a[i] ^ b[i]; // XOR
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}
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return c === 0;
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}
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bufferEq.install = function() {
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Buffer.prototype.equal = SlowBuffer.prototype.equal = function equal(that) {
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return bufferEq(this, that);
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};
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};
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var origBufEqual = Buffer.prototype.equal;
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var origSlowBufEqual = SlowBuffer.prototype.equal;
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bufferEq.restore = function() {
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Buffer.prototype.equal = origBufEqual;
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SlowBuffer.prototype.equal = origSlowBufEqual;
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};
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