Edit File: ctr.js
var xor = require('buffer-xor') var Buffer = require('safe-buffer').Buffer var incr32 = require('../incr32') function getBlock (self) { var out = self._cipher.encryptBlockRaw(self._prev) incr32(self._prev) return out } var blockSize = 16 exports.encrypt = function (self, chunk) { var chunkNum = Math.ceil(chunk.length / blockSize) var start = self._cache.length self._cache = Buffer.concat([ self._cache, Buffer.allocUnsafe(chunkNum * blockSize) ]) for (var i = 0; i < chunkNum; i++) { var out = getBlock(self) var offset = start + i * blockSize self._cache.writeUInt32BE(out[0], offset + 0) self._cache.writeUInt32BE(out[1], offset + 4) self._cache.writeUInt32BE(out[2], offset + 8) self._cache.writeUInt32BE(out[3], offset + 12) } var pad = self._cache.slice(0, chunk.length) self._cache = self._cache.slice(chunk.length) return xor(chunk, pad) }
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