code: function bnToByteArray(encode_sign_bit) {
    var i = this.t, r = new Array();
    r[0] = this.s;
    var p = this.DB-(i*this.DB)%8, d, k = 0;
    if(i-- > 0) {
      if(p < this.DB && (d = this[i]>>p) != (this.s&this.DM)>>p)
        r[k++] = d|(this.s<<(this.DB-p));
      while(i >= 0) {
        if(p < 8) {
          d = (this[i]&((1<<p)-1))<<(8-p);
          d |= this[--i]>>(p+=this.DB-8);
        }
        else {
          d = (this[i]>>(p-=8))&0xff;
          if(p <= 0) { p += this.DB; --i; }
        }
        if (encode_sign_bit) {
          if((d&0x80) != 0) d |= -256;
          if(k == 0 && (this.s&0x80) != (d&0x80)) ++k;
        }
        if(k > 0 || d != this.s) r[k++] = d;
      }
    }
    return r;
  }
docs: (public) convert to bigendian byte array