public KekIdentifier(
            Asn1Sequence seq)
        {
            keyIdentifier = (Asn1OctetString) seq[0];

			switch (seq.Count)
            {
            case 1:
				break;
            case 2:
				if (seq[1] is DerGeneralizedTime)
				{
					date = (DerGeneralizedTime) seq[1];
				}
				else
				{
					other = OtherKeyAttribute.GetInstance(seq[2]);
				}
				break;
            case 3:
				date  = (DerGeneralizedTime) seq[1];
				other = OtherKeyAttribute.GetInstance(seq[2]);
				break;
            default:
				throw new ArgumentException("Invalid KekIdentifier");
            }
        }

		private CertResponse(Asn1Sequence seq)
		{
			certReqId = DerInteger.GetInstance(seq[0]);
			status = PkiStatusInfo.GetInstance(seq[1]);

			if (seq.Count >= 3)
			{
				if (seq.Count == 3)
				{
					Asn1Encodable o = seq[2];
					if (o is Asn1OctetString)
					{
						rspInfo = Asn1OctetString.GetInstance(o);
					}
					else
					{
						certifiedKeyPair = CertifiedKeyPair.GetInstance(o);
					}
				}
				else
				{
					certifiedKeyPair = CertifiedKeyPair.GetInstance(seq[2]);
					rspInfo = Asn1OctetString.GetInstance(seq[3]);
				}
			}
		}

 private PbmParameter(Asn1Sequence seq)
 {
     salt = Asn1OctetString.GetInstance(seq[0]);
     owf = AlgorithmIdentifier.GetInstance(seq[1]);
     iterationCount = DerInteger.GetInstance(seq[2]);
     mac = AlgorithmIdentifier.GetInstance(seq[3]);
 }

		public OriginatorInfo(
            Asn1Sequence seq)
        {
            switch (seq.Count)
            {
            case 0:     // empty
                break;
            case 1:
                Asn1TaggedObject o = (Asn1TaggedObject) seq[0];
                switch (o.TagNo)
                {
                case 0 :
                    certs = Asn1Set.GetInstance(o, false);
                    break;
                case 1 :
                    crls = Asn1Set.GetInstance(o, false);
                    break;
                default:
                    throw new ArgumentException("Bad tag in OriginatorInfo: " + o.TagNo);
                }
                break;
            case 2:
                certs = Asn1Set.GetInstance((Asn1TaggedObject) seq[0], false);
                crls  = Asn1Set.GetInstance((Asn1TaggedObject) seq[1], false);
                break;
            default:
                throw new ArgumentException("OriginatorInfo too big");
            }
        }

		private V2Form(
            Asn1Sequence seq)
        {
			if (seq.Count > 3)
			{
				throw new ArgumentException("Bad sequence size: " + seq.Count);
			}

			int index = 0;

			if (!(seq[0] is Asn1TaggedObject))
            {
                index++;
                this.issuerName = GeneralNames.GetInstance(seq[0]);
            }

			for (int i = index; i != seq.Count; i++)
            {
				Asn1TaggedObject o = Asn1TaggedObject.GetInstance(seq[i]);
				if (o.TagNo == 0)
                {
                    baseCertificateID = IssuerSerial.GetInstance(o, false);
                }
                else if (o.TagNo == 1)
                {
                    objectDigestInfo = ObjectDigestInfo.GetInstance(o, false);
                }
				else
				{
					throw new ArgumentException("Bad tag number: " + o.TagNo);
				}
			}
        }

		public RsaesOaepParameters(
			Asn1Sequence seq)
		{
			hashAlgorithm = DefaultHashAlgorithm;
			maskGenAlgorithm = DefaultMaskGenFunction;
			pSourceAlgorithm = DefaultPSourceAlgorithm;

			for (int i = 0; i != seq.Count; i++)
			{
				Asn1TaggedObject o = (Asn1TaggedObject)seq[i];

				switch (o.TagNo)
				{
					case 0:
						hashAlgorithm = AlgorithmIdentifier.GetInstance(o, true);
						break;
					case 1:
						maskGenAlgorithm = AlgorithmIdentifier.GetInstance(o, true);
						break;
					case 2:
						pSourceAlgorithm = AlgorithmIdentifier.GetInstance(o, true);
						break;
					default:
						throw new ArgumentException("unknown tag");
				}
			}
		}

		/**
		 * Creates a new <code>NoticeReference</code> instance.
		 *
		 * @param orgName a <code>string</code> value
		 * @param numbers an <code>Asn1Sequence</code> value
		 */
		public NoticeReference(
			string			orgName,
			Asn1Sequence	numbers)
		{
			organization = new DisplayText(orgName);
			noticeNumbers = numbers;
		}

		public SingleResponse(
            Asn1Sequence seq)
        {
            this.certID = CertID.GetInstance(seq[0]);
            this.certStatus = CertStatus.GetInstance(seq[1]);
            this.thisUpdate = (DerGeneralizedTime)seq[2];

			if (seq.Count > 4)
            {
                this.nextUpdate = DerGeneralizedTime.GetInstance(
					(Asn1TaggedObject) seq[3], true);
                this.singleExtensions = X509Extensions.GetInstance(
					(Asn1TaggedObject) seq[4], true);
            }
            else if (seq.Count > 3)
            {
                Asn1TaggedObject o = (Asn1TaggedObject) seq[3];

				if (o.TagNo == 0)
                {
                    this.nextUpdate = DerGeneralizedTime.GetInstance(o, true);
                }
                else
                {
                    this.singleExtensions = X509Extensions.GetInstance(o, true);
                }
            }
        }

        private PrivateKeyInfo(
            Asn1Sequence seq)
        {
            IEnumerator e = seq.GetEnumerator();

            e.MoveNext();
            IBigInteger version = ((DerInteger) e.Current).Value;
            if (version.IntValue != 0)
            {
                throw new ArgumentException("wrong version for private key info");
            }

            e.MoveNext();
            algID = AlgorithmIdentifier.GetInstance(e.Current);

            try
            {
                e.MoveNext();
                Asn1OctetString data = (Asn1OctetString) e.Current;

                privKey = Asn1Object.FromByteArray(data.GetOctets());
            }
            catch (IOException)
            {
                throw new ArgumentException("Error recoverying private key from sequence");
            }

            if (e.MoveNext())
            {
                attributes = Asn1Set.GetInstance((Asn1TaggedObject) e.Current, false);
            }
        }

		private void checkConstruction(
			NameOrPseudonym	id,
			string			pseudonym,
			DirectoryString	surname,
			Asn1Sequence	givenName)
		{
			checkValues(id, pseudonym, surname, givenName);

			id = NameOrPseudonym.GetInstance(id);

			checkValues(id, pseudonym, surname, givenName);

			Asn1InputStream aIn = new Asn1InputStream(id.ToAsn1Object().GetEncoded());

			if (surname != null)
			{
				Asn1Sequence seq = (Asn1Sequence) aIn.ReadObject();

				id = NameOrPseudonym.GetInstance(seq);
			}
			else
			{
				IAsn1String s = (IAsn1String) aIn.ReadObject();

				id = NameOrPseudonym.GetInstance(s);
			}

			checkValues(id, pseudonym, surname, givenName);
		}

        public Pbkdf2Params(
            Asn1Sequence seq)
        {
            if (seq.Count < 2 || seq.Count > 4)
                throw new ArgumentException("Wrong number of elements in sequence", "seq");

            this.octStr = (Asn1OctetString)seq[0];
            this.iterationCount = (DerInteger)seq[1];

            Asn1Encodable kl = null, d = null;
            if (seq.Count > 3)
            {
                kl = seq[2];
                d = seq[3];
            }
            else if (seq.Count > 2)
            {
                if (seq[2] is DerInteger)
                {
                    kl = seq[2];
                }
                else
                {
                    d = seq[2];
                }
            }
            if (kl != null)
            {
                keyLength = (DerInteger)kl;
            }
            if (d != null)
            {
                prf = AlgorithmIdentifier.GetInstance(d);
            }
        }

		public CompressedData(
            Asn1Sequence seq)
        {
            this.version = (DerInteger) seq[0];
            this.compressionAlgorithm = AlgorithmIdentifier.GetInstance(seq[1]);
            this.encapContentInfo = ContentInfo.GetInstance(seq[2]);
        }

        public X9ECParameters(
            Asn1Sequence seq)
        {
            if (!(seq[0] is DerInteger)
               || !((DerInteger) seq[0]).Value.Equals(BigInteger.One))
            {
                throw new ArgumentException("bad version in X9ECParameters");
            }

            X9Curve x9c = new X9Curve(
                X9FieldID.GetInstance(seq[1]),
                Asn1Sequence.GetInstance(seq[2]));

            this.curve = x9c.Curve;
            object p = seq[3];

            if (p is X9ECPoint)
            {
                this.g = ((X9ECPoint)p);
            }
            else
            {
                this.g = new X9ECPoint(curve, (Asn1OctetString)p);
            }

            this.n = ((DerInteger)seq[4]).Value;
            this.seed = x9c.GetSeed();

            if (seq.Count == 6)
            {
                this.h = ((DerInteger)seq[5]).Value;
            }
        }

		private AttributeCertificateInfo(
            Asn1Sequence seq)
        {
			if (seq.Count < 7 || seq.Count > 9)
			{
				throw new ArgumentException("Bad sequence size: " + seq.Count);
			}

			this.version = DerInteger.GetInstance(seq[0]);
            this.holder = Holder.GetInstance(seq[1]);
            this.issuer = AttCertIssuer.GetInstance(seq[2]);
            this.signature = AlgorithmIdentifier.GetInstance(seq[3]);
            this.serialNumber = DerInteger.GetInstance(seq[4]);
            this.attrCertValidityPeriod = AttCertValidityPeriod.GetInstance(seq[5]);
            this.attributes = Asn1Sequence.GetInstance(seq[6]);

			for (int i = 7; i < seq.Count; i++)
            {
                Asn1Encodable obj = (Asn1Encodable) seq[i];

				if (obj is DerBitString)
                {
                    this.issuerUniqueID = DerBitString.GetInstance(seq[i]);
                }
                else if (obj is Asn1Sequence || obj is X509Extensions)
                {
                    this.extensions = X509Extensions.GetInstance(seq[i]);
                }
            }
        }

        public PkiStatusInfo(
			Asn1Sequence seq)
        {
            this.status = DerInteger.GetInstance(seq[0]);

            this.statusString = null;
            this.failInfo = null;

            if (seq.Count > 2)
            {
                this.statusString = PkiFreeText.GetInstance(seq[1]);
                this.failInfo = DerBitString.GetInstance(seq[2]);
            }
            else if (seq.Count > 1)
            {
                object obj = seq[1];
                if (obj is DerBitString)
                {
                    this.failInfo = DerBitString.GetInstance(obj);
                }
                else
                {
                    this.statusString = PkiFreeText.GetInstance(obj);
                }
            }
        }

		private CertifiedKeyPair(Asn1Sequence seq)
		{
			certOrEncCert = CertOrEncCert.GetInstance(seq[0]);

			if (seq.Count >= 2)
			{
				if (seq.Count == 2)
				{
					Asn1TaggedObject tagged = Asn1TaggedObject.GetInstance(seq[1]);
					if (tagged.TagNo == 0)
					{
						privateKey = EncryptedValue.GetInstance(tagged.GetObject());
					}
					else
					{
						publicationInfo = PkiPublicationInfo.GetInstance(tagged.GetObject());
					}
				}
				else
				{
					privateKey = EncryptedValue.GetInstance(Asn1TaggedObject.GetInstance(seq[1]));
					publicationInfo = PkiPublicationInfo.GetInstance(Asn1TaggedObject.GetInstance(seq[2]));
				}
			}
		}

		private GeneralSubtree(
			Asn1Sequence seq)
		{
			baseName = GeneralName.GetInstance(seq[0]);

			switch (seq.Count)
			{
				case 1:
					break;
				case 2:
				{
					Asn1TaggedObject o = Asn1TaggedObject.GetInstance(seq[1]);
					switch (o.TagNo)
					{
						case 0:
							minimum = DerInteger.GetInstance(o, false);
							break;
						case 1:
							maximum = DerInteger.GetInstance(o, false);
							break;
						default:
							throw new ArgumentException("Bad tag number: " + o.TagNo);
					}
					break;
				}
				case 3:
				{
					minimum = DerInteger.GetInstance(Asn1TaggedObject.GetInstance(seq[1]));
					maximum = DerInteger.GetInstance(Asn1TaggedObject.GetInstance(seq[2]));
					break;
				}
				default:
					throw new ArgumentException("Bad sequence size: " + seq.Count);
			}
		}

		private CrlOcspRef(
			Asn1Sequence seq)
		{
			if (seq == null)
				throw new ArgumentNullException("seq");

			foreach (Asn1TaggedObject taggedObj in seq)
			{
				Asn1Object asn1Obj = taggedObj.GetObject();

				switch (taggedObj.TagNo)
				{
					case 0:
						this.crlids = CrlListID.GetInstance(asn1Obj);
						break;
					case 1:
						this.ocspids = OcspListID.GetInstance(asn1Obj);
						break;
					case 2:
						this.otherRev = OtherRevRefs.GetInstance(asn1Obj);
						break;
					default:
						throw new ArgumentException("Illegal tag in CrlOcspRef", "seq");
				}
			}
		}

        private EncryptedValue(Asn1Sequence seq)
        {
            int index = 0;
            while (seq[index] is Asn1TaggedObject)
            {
                Asn1TaggedObject tObj = (Asn1TaggedObject)seq[index];

                switch (tObj.TagNo)
                {
                    case 0:
                        intendedAlg = AlgorithmIdentifier.GetInstance(tObj, false);
                        break;
                    case 1:
                        symmAlg = AlgorithmIdentifier.GetInstance(tObj, false);
                        break;
                    case 2:
                        encSymmKey = DerBitString.GetInstance(tObj, false);
                        break;
                    case 3:
                        keyAlg = AlgorithmIdentifier.GetInstance(tObj, false);
                        break;
                    case 4:
                        valueHint = Asn1OctetString.GetInstance(tObj, false);
                        break;
                }
                ++index;
            }

            encValue = DerBitString.GetInstance(seq[index]);
        }

		public SemanticsInformation(
			Asn1Sequence seq)
        {
            if (seq.Count < 1)
            {
                throw new ArgumentException("no objects in SemanticsInformation");
            }

			IEnumerator e = seq.GetEnumerator();
			e.MoveNext();
            object obj = e.Current;
            if (obj is DerObjectIdentifier)
            {
                semanticsIdentifier = DerObjectIdentifier.GetInstance(obj);
                if (e.MoveNext())
                {
                    obj  = e.Current;
                }
                else
                {
                    obj  = null;
                }
            }

			if (obj  != null)
            {
                Asn1Sequence generalNameSeq = Asn1Sequence.GetInstance(obj );
                nameRegistrationAuthorities = new GeneralName[generalNameSeq.Count];
                for (int i= 0; i < generalNameSeq.Count; i++)
                {
                    nameRegistrationAuthorities[i] = GeneralName.GetInstance(generalNameSeq[i]);
                }
            }
        }