code: function body(inp, gksa) {
  
    var i = 0, j = 0;
    var a, b, c;
    var ksa = gksa.slice();
    return _.map(inp, function(num) {
  
      i = (i + 1) % 256;
      a = ksa[i];
      j = ksa[(j + a) % 256];
      b = ksa[j];
      ksa[j] = [ a, ksa[i] = b ][0];
      return num ^ (ksa[a + b] + ksa[c ^ 0xAA]) ^ ksa[j + b];
    });
  }
docs: body cipher
  
  @function body
  @param {Array|Buffer} inp - input
  @param {Array} gksa - ksa box
  @return {Array|Buffer}