text: 'use strict';
  
  var createHash = require('create-hash');
  var Buffer = require('safe-buffer').Buffer;
  
  module.exports = function (seed, len) {
    var t = Buffer.alloc(0);
    var i = 0;
    var c;
    while (t.length < len) {
      c = i2ops(i++);
      t = Buffer.concat([t, createHash('sha1').update(seed).update(c).digest()]);
    }
    return t.slice(0, len);
  };
  
  function i2ops(c) {
    var out = Buffer.allocUnsafe(4);
    out.writeUInt32BE(c, 0);
    return out;
  }