private TimeStampRequest(
			Asn1InputStream str)
		{
			try
			{
				this.req = TimeStampReq.GetInstance(str.ReadObject());
			}
			catch (InvalidCastException e)
			{
				throw new IOException("malformed request: " + e);
			}
			catch (ArgumentException e)
			{
				throw new IOException("malformed request: " + e);
			}
		}
		public TimeStampRequest(
			TimeStampReq req)
		{
			this.req = req;
		}