private BasicOcspResp GenerateResponse(
			string					signatureName,
			AsymmetricKeyParameter	privateKey,
			X509Certificate[]		chain,
			DateTime				producedAt,
			SecureRandom			random)
        {
            DerObjectIdentifier signingAlgorithm;
            try
            {
                signingAlgorithm = OcspUtilities.GetAlgorithmOid(signatureName);
            }
            catch (Exception e)
            {
                throw new ArgumentException("unknown signing algorithm specified", e);
            }

            Asn1EncodableVector responses = new Asn1EncodableVector();

            foreach (ResponseObject respObj in list)
            {
                try
                {
                    responses.Add(respObj.ToResponse());
                }
                catch (Exception e)
                {
                    throw new OcspException("exception creating Request", e);
                }
            }

            ResponseData tbsResp = new ResponseData(responderID.ToAsn1Object(), new DerGeneralizedTime(producedAt), new DerSequence(responses), responseExtensions);

            ISigner sig = null;

            try
            {
                sig = SignerUtilities.GetSigner(signatureName);

                if (random != null)
                {
                    sig.Init(true, new ParametersWithRandom(privateKey, random));
                }
                else
                {
                    sig.Init(true, privateKey);
                }
            }
            catch (Exception e)
            {
                throw new OcspException("exception creating signature: " + e, e);
            }

            DerBitString bitSig = null;

            try
            {
                byte[] encoded = tbsResp.GetDerEncoded();
                sig.BlockUpdate(encoded, 0, encoded.Length);

                bitSig = new DerBitString(sig.GenerateSignature());
            }
            catch (Exception e)
            {
                throw new OcspException("exception processing TBSRequest: " + e, e);
            }

            AlgorithmIdentifier sigAlgId = OcspUtilities.GetSigAlgID(signingAlgorithm);

            if (chain != null && chain.Length > 0)
            {
                Asn1EncodableVector v = new Asn1EncodableVector();
                try
                {
                    for (int i = 0; i != chain.Length; i++)
                    {
                        v.Add(
                            X509CertificateStructure.GetInstance(
                                Asn1Object.FromByteArray(chain[i].GetEncoded())));
                    }
                }
                catch (IOException e)
                {
                    throw new OcspException("error processing certs", e);
                }
                catch (Security.Certificates.CertificateEncodingException e)
                {
                    throw new OcspException("error encoding certs", e);
                }

                return new BasicOcspResp(new BasicOcspResponse(tbsResp, sigAlgId, bitSig, new DerSequence(v)));
            }
            else
            {
                return new BasicOcspResp(new BasicOcspResponse(tbsResp, sigAlgId, bitSig, null));
            }
        }
		private BasicOcspResp GenerateResponse(
			ISignatureCalculator    signatureCalculator,
			X509Certificate[]		chain,
			DateTime				producedAt)
		{
            AlgorithmIdentifier signingAlgID = (AlgorithmIdentifier)signatureCalculator.AlgorithmDetails;
            DerObjectIdentifier signingAlgorithm = signingAlgID.Algorithm;

			Asn1EncodableVector responses = new Asn1EncodableVector();

			foreach (ResponseObject respObj in list)
			{
				try
				{
					responses.Add(respObj.ToResponse());
				}
				catch (Exception e)
				{
					throw new OcspException("exception creating Request", e);
				}
			}

			ResponseData tbsResp = new ResponseData(responderID.ToAsn1Object(), new DerGeneralizedTime(producedAt), new DerSequence(responses), responseExtensions);
			DerBitString bitSig = null;

			try
			{
                IStreamCalculator streamCalculator = signatureCalculator.CreateCalculator();

				byte[] encoded = tbsResp.GetDerEncoded();

                streamCalculator.Stream.Write(encoded, 0, encoded.Length);

                streamCalculator.Stream.Close();

                bitSig = new DerBitString(((IBlockResult)streamCalculator.GetResult()).DoFinal());
			}
			catch (Exception e)
			{
				throw new OcspException("exception processing TBSRequest: " + e, e);
			}

			AlgorithmIdentifier sigAlgId = OcspUtilities.GetSigAlgID(signingAlgorithm);

			DerSequence chainSeq = null;
			if (chain != null && chain.Length > 0)
			{
				Asn1EncodableVector v = new Asn1EncodableVector();
				try
				{
					for (int i = 0; i != chain.Length; i++)
					{
						v.Add(
							X509CertificateStructure.GetInstance(
								Asn1Object.FromByteArray(chain[i].GetEncoded())));
					}
				}
				catch (IOException e)
				{
					throw new OcspException("error processing certs", e);
				}
				catch (CertificateEncodingException e)
				{
					throw new OcspException("error encoding certs", e);
				}

				chainSeq = new DerSequence(v);
			}

			return new BasicOcspResp(new BasicOcspResponse(tbsResp, sigAlgId, bitSig, chainSeq));
		}