imba/polyfills/crypto/esm/lib/browserify-aes/modes/ctr.js

Intuitive and powerful language for building webapps that fly

import xor from "../../buffer-xor";
import incr32 from "../incr32";
function getBlock(self) {
    var out = self._cipher.encryptBlockRaw(self._prev);
    incr32(self._prev);
    return out;
}
var blockSize = 16;
export const 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);
};