public AttributeCertificateInfo GenerateAttributeCertificateInfo()
        {
            if ((serialNumber == null) || (signature == null)
                || (issuer == null) || (startDate == null) || (endDate == null)
                || (holder == null) || (attributes == null))
            {
                throw new InvalidOperationException("not all mandatory fields set in V2 AttributeCertificateInfo generator");
            }

            Asn1EncodableVector v = new Asn1EncodableVector(
                version, holder, issuer, signature, serialNumber);

            //
            // before and after dates => AttCertValidityPeriod
            //
            v.Add(new AttCertValidityPeriod(startDate, endDate));

            // Attributes
            v.Add(new DerSequence(attributes));

            if (issuerUniqueID != null)
            {
                v.Add(issuerUniqueID);
            }

            if (extensions != null)
            {
                v.Add(extensions);
            }

            return AttributeCertificateInfo.GetInstance(new DerSequence(v));
        }

		/**
		 * Constructor for elliptic curves over binary fields
		 * <code>F<sub>2<sup>m</sup></sub></code>.
		 * @param m  The exponent <code>m</code> of
		 * <code>F<sub>2<sup>m</sup></sub></code>.
		 * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
		 * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
		 * represents the reduction polynomial <code>f(z)</code>.
		 * @param k2 The integer <code>k2</code> where <code>x<sup>m</sup> +
		 * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
		 * represents the reduction polynomial <code>f(z)</code>.
		 * @param k3 The integer <code>k3</code> where <code>x<sup>m</sup> +
		 * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
		 * represents the reduction polynomial <code>f(z)</code>..
		 */
		public X9FieldID(
			int m,
			int k1,
			int k2,
			int k3)
		{
			this.id = X9ObjectIdentifiers.CharacteristicTwoField;

			Asn1EncodableVector fieldIdParams = new Asn1EncodableVector(new DerInteger(m));

			if (k2 == 0)
			{
				fieldIdParams.Add(
					X9ObjectIdentifiers.TPBasis,
					new DerInteger(k1));
			}
			else
			{
				fieldIdParams.Add(
					X9ObjectIdentifiers.PPBasis,
					new DerSequence(
						new DerInteger(k1),
						new DerInteger(k2),
						new DerInteger(k3)));
			}

			this.parameters = new DerSequence(fieldIdParams);
		}

		/**
         * Constructor for elliptic curves over binary fields
         * <code>F<sub>2<sup>m</sup></sub></code>.
         * @param m  The exponent <code>m</code> of
         * <code>F<sub>2<sup>m</sup></sub></code>.
         * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
         * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
         * represents the reduction polynomial <code>f(z)</code>.
         * @param k2 The integer <code>k2</code> where <code>x<sup>m</sup> +
         * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
         * represents the reduction polynomial <code>f(z)</code>.
         * @param k3 The integer <code>k3</code> where <code>x<sup>m</sup> +
         * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
         * represents the reduction polynomial <code>f(z)</code>..
         */
		public X9FieldID(
			int m,
			int k1,
			int k2,
			int k3)
		{
			this.id = X9ObjectIdentifiers.CharacteristicTwoField;

			Asn1EncodableVector fieldIdParams = new Asn1EncodableVector(new DerInteger(m));

			if(k2 == 0)
			{
				if(k3 != 0)
					throw new ArgumentException("inconsistent k values");

				fieldIdParams.Add(
					X9ObjectIdentifiers.TPBasis,
					new DerInteger(k1));
			}
			else
			{
				if(k2 <= k1 || k3 <= k2)
					throw new ArgumentException("inconsistent k values");

				fieldIdParams.Add(
					X9ObjectIdentifiers.PPBasis,
					new DerSequence(
						new DerInteger(k1),
						new DerInteger(k2),
						new DerInteger(k3)));
			}

			this.parameters = new DerSequence(fieldIdParams);
		}

		private void AddOptional(Asn1EncodableVector v, int tagNo, Asn1Encodable obj)
		{
			if (obj != null)
			{
				v.Add(new DerTaggedObject(true, tagNo, obj));
			}
		}

        private static Asn1EncodableVector ConvertVector(IList numbers)
        {
            Asn1EncodableVector av = new Asn1EncodableVector();

            foreach (object o in numbers)
            {
                DerInteger di;

                if (o is BigInteger)
                {
                    di = new DerInteger((BigInteger)o);
                }
                else if (o is int)
                {
                    di = new DerInteger((int)o);
                }
                else
                {
                    throw new ArgumentException();
                }

                av.Add(di);
            }
            return av;
        }

		/**
		 * <pre>
		 * Challenge ::= SEQUENCE {
		 *                 owf                 AlgorithmIdentifier  OPTIONAL,
		 *
		 *                 -- MUST be present in the first Challenge; MAY be omitted in
		 *                 -- any subsequent Challenge in POPODecKeyChallContent (if
		 *                 -- omitted, then the owf used in the immediately preceding
		 *                 -- Challenge is to be used).
		 *
		 *                 witness             OCTET STRING,
		 *                 -- the result of applying the one-way function (owf) to a
		 *                 -- randomly-generated INTEGER, A.  [Note that a different
		 *                 -- INTEGER MUST be used for each Challenge.]
		 *                 challenge           OCTET STRING
		 *                 -- the encryption (under the public key for which the cert.
		 *                 -- request is being made) of Rand, where Rand is specified as
		 *                 --   Rand ::= SEQUENCE {
		 *                 --      int      INTEGER,
		 *                 --       - the randomly-generated INTEGER A (above)
		 *                 --      sender   GeneralName
		 *                 --       - the sender's name (as included in PKIHeader)
		 *                 --   }
		 *      }
		 * </pre>
		 * @return a basic ASN.1 object representation.
		 */
		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector();
			v.AddOptional(owf);
			v.Add(witness);
			v.Add(challenge);
			return new DerSequence(v);
		}

		/**
		 * <pre>
		 * OobCertHash ::= SEQUENCE {
		 *                      hashAlg     [0] AlgorithmIdentifier     OPTIONAL,
		 *                      certId      [1] CertId                  OPTIONAL,
		 *                      hashVal         BIT STRING
		 *                      -- hashVal is calculated over the Der encoding of the
		 *                      -- self-signed certificate with the identifier certID.
		 *       }
		 * </pre>
		 * @return a basic ASN.1 object representation.
		 */
		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector();
			AddOptional(v, 0, hashAlg);
			AddOptional(v, 1, certId);
			v.Add(hashVal);
			return new DerSequence(v);
		}

        /**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * ContentInfo ::= Sequence {
         *          contentType ContentType,
         *          content
         *          [0] EXPLICIT ANY DEFINED BY contentType OPTIONAL }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(contentType);

            if (content != null)
            {
                v.Add(new BerTaggedObject(0, content));
            }

            return new BerSequence(v);
        }

		/**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * RevokedInfo ::= Sequence {
         *      revocationTime              GeneralizedTime,
         *      revocationReason    [0]     EXPLICIT CRLReason OPTIONAL }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
			Asn1EncodableVector v = new Asn1EncodableVector(revocationTime);

			if (revocationReason != null)
            {
                v.Add(new DerTaggedObject(true, 0, revocationReason));
            }

			return new DerSequence(v);
        }

		/**
		* <pre>
		*       EncryptedData ::= SEQUENCE {
		*                     version CMSVersion,
		*                     encryptedContentInfo EncryptedContentInfo,
		*                     unprotectedAttrs [1] IMPLICIT UnprotectedAttributes OPTIONAL }
		* </pre>
		* @return a basic ASN.1 object representation.
		*/
		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector(version, encryptedContentInfo);

			if (unprotectedAttrs != null)
			{
				v.Add(new BerTaggedObject(false, 1, unprotectedAttrs));
			}

			return new BerSequence(v);
		}

        public AttributeTable(Asn1EncodableVector v)
        {
            _attributes = Platform.CreateHashtable(v.Count);

            for (int i = 0; i != v.Count; i++)
            {
                AttributeX509 a = AttributeX509.GetInstance(v[i]);

                _attributes.Add(a.AttrType, a);
            }
        }

		/**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * OcspRequest     ::=     Sequence {
         *     tbsRequest                  TBSRequest,
         *     optionalSignature   [0]     EXPLICIT Signature OPTIONAL }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(tbsRequest);

			if (optionalSignature != null)
            {
                v.Add(new DerTaggedObject(true, 0, optionalSignature));
            }

			return new DerSequence(v);
        }

		/**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * OcspResponse ::= Sequence {
         *     responseStatus         OcspResponseStatus,
         *     responseBytes          [0] EXPLICIT ResponseBytes OPTIONAL }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(responseStatus);

			if (responseBytes != null)
            {
                v.Add(new DerTaggedObject(true, 0, responseBytes));
            }

			return new DerSequence(v);
        }

		public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector seq = new Asn1EncodableVector(qcStatementId);

			if (qcStatementInfo != null)
            {
                seq.Add(qcStatementInfo);
            }

			return new DerSequence(seq);
        }

		/**
        * <pre>
        * CommitmentTypeIndication ::= SEQUENCE {
        *      commitmentTypeId   CommitmentTypeIdentifier,
        *      commitmentTypeQualifier   SEQUENCE SIZE (1..MAX) OF
        *              CommitmentTypeQualifier OPTIONAL }
        * </pre>
        */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(commitmentTypeId);

			if (commitmentTypeQualifier != null)
            {
                v.Add(commitmentTypeQualifier);
            }

			return new DerSequence(v);
        }

		/**
		 * <pre>
		 * MacData ::= SEQUENCE {
		 *     mac      DigestInfo,
		 *     macSalt  OCTET STRING,
		 *     iterations INTEGER DEFAULT 1
		 *     -- Note: The default is for historic reasons and its use is deprecated. A
		 *     -- higher value, like 1024 is recommended.
		 * </pre>
		 * @return the basic DERObject construction.
		 */
		public override Asn1Object ToAsn1Object()
        {
			Asn1EncodableVector v = new Asn1EncodableVector(digInfo, new DerOctetString(salt));

			if (!iterationCount.Equals(BigInteger.One))
			{
				v.Add(new DerInteger(iterationCount));
			}

			return new DerSequence(v);
        }

		/**
		 * <pre>
		 * EssCertID ::= SEQUENCE {
		 *     certHash Hash,
		 *     issuerSerial IssuerSerial OPTIONAL }
		 * </pre>
		 */
		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector(certHash);

			if (issuerSerial != null)
			{
				v.Add(issuerSerial);
			}

			return new DerSequence(v);
		}

        /*
         * PolicyInformation ::= Sequence {
         *      policyIdentifier   CertPolicyId,
         *      policyQualifiers   Sequence SIZE (1..MAX) OF
         *              PolicyQualifierInfo OPTIONAL }
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(policyIdentifier);

            if (policyQualifiers != null)
            {
                v.Add(policyQualifiers);
            }

            return new DerSequence(v);
        }

		/**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * ServiceLocator ::= Sequence {
         *     issuer    Name,
         *     locator   AuthorityInfoAccessSyntax OPTIONAL }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(issuer);

			if (locator != null)
            {
                v.Add(locator);
            }

			return new DerSequence(v);
        }

        /**
         * <pre>
         * TimeStampResp ::= SEQUENCE  {
         *   status                  PkiStatusInfo,
         *   timeStampToken          TimeStampToken     OPTIONAL  }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector(pkiStatusInfo);

            if (timeStampToken != null)
            {
                v.Add(timeStampToken);
            }

            return new DerSequence(v);
        }