public CertificationRequest(
            CertificationRequestInfo	requestInfo,
            AlgorithmIdentifier			algorithm,
            DerBitString				signature)
        {
            this.reqInfo = requestInfo;
            this.sigAlgId = algorithm;
            this.sigBits = signature;
        }
		public CertificationRequest(
            Asn1Sequence seq)
        {
			if (seq.Count != 3)
				throw new ArgumentException("Wrong number of elements in sequence", "seq");

			reqInfo = CertificationRequestInfo.GetInstance(seq[0]);
            sigAlgId = AlgorithmIdentifier.GetInstance(seq[1]);
            sigBits = DerBitString.GetInstance(seq[2]);
        }