code: function(b) {
    var b2 = b.getByte();
    if(b2 === 0x80) {
      return undefined;
    }
  
    // see if the length is "short form" or "long form" (bit 8 set)
    var length;
    var longForm = b2 & 0x80;
    if(!longForm) {
      // length is just the first byte
      length = b2;
    } else {
      // the number of bytes the length is specified in bits 7 through 1
      // and each length byte is in big-endian base-256
      length = b.getInt((b2 & 0x7F) << 3);
    }
    return length;
  }
docs: Gets the length of an ASN.1 value.
  
  In case the length is not specified, undefined is returned.
  
  @param b the ASN.1 byte buffer.
  
  @return the length of the ASN.1 value.