using System;
using System.Collections;
using System.Globalization;
using System.IO;
using System.Text;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Asn1.Utilities;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.Collections;
using Org.BouncyCastle.Utilities.Encoders;
using Org.BouncyCastle.X509;

namespace Org.BouncyCastle.Pkcs
{
	public class Pkcs12Store
	{
		private readonly IgnoresCaseHashtable	keys = new IgnoresCaseHashtable();
		private readonly Hashtable				localIds = new Hashtable();
		private readonly IgnoresCaseHashtable	certs = new IgnoresCaseHashtable();
		private readonly Hashtable				chainCerts = new Hashtable();
		private readonly Hashtable				keyCerts = new Hashtable();

		private static readonly DerObjectIdentifier	keyAlgorithm = PkcsObjectIdentifiers.PbeWithShaAnd3KeyTripleDesCbc;
		private static readonly DerObjectIdentifier	CertAlgorithm = PkcsObjectIdentifiers.PbewithShaAnd40BitRC2Cbc;
		private int					MinIterations = 1024;
		private int					saltSize = 20;

		private static SubjectKeyIdentifier CreateSubjectKeyID(
			AsymmetricKeyParameter pubKey)
		{
			return new SubjectKeyIdentifier(
				SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(pubKey));
		}

		internal class CertId
		{
			private readonly byte[] id;

			internal CertId(
				AsymmetricKeyParameter pubKey)
			{
				this.id = CreateSubjectKeyID(pubKey).GetKeyIdentifier();
			}

			internal CertId(
				byte[] id)
			{
				this.id = id;
			}

			internal byte[] Id
			{
				get { return id; }
			}

			public override int GetHashCode()
			{
				return Arrays.GetHashCode(id);
			}

			public override bool Equals(
				object obj)
			{
				if (obj == this)
					return true;

				CertId other = obj as CertId;

				if (other == null)
					return false;

				return Arrays.AreEqual(id, other.id);
			}
		}

		public Pkcs12Store()
		{
		}

		public Pkcs12Store(
			Stream	input,
			char[]	password)
		{
			if (input == null)
				throw new ArgumentNullException("input");
			if (password == null)
				throw new ArgumentNullException("password");

			Asn1Sequence obj = (Asn1Sequence) Asn1Object.FromStream(input);
			Pfx bag = new Pfx(obj);
			ContentInfo info = bag.AuthSafe;
			bool unmarkedKey = false;
			bool wrongPkcs12Zero = false;

			if (bag.MacData != null) // check the mac code
			{
				MacData mData = bag.MacData;
				DigestInfo dInfo = mData.Mac;
				AlgorithmIdentifier algId = dInfo.AlgorithmID;
				byte[] salt = mData.GetSalt();
				int itCount = mData.IterationCount.IntValue;

				byte[] data = ((Asn1OctetString) info.Content).GetOctets();

				byte[] mac = CalculatePbeMac(algId.ObjectID, salt, itCount, password, false, data);
				byte[] dig = dInfo.GetDigest();

				if (!Arrays.AreEqual(mac, dig))
				{
					if (password.Length > 0)
						throw new IOException("PKCS12 key store MAC invalid - wrong password or corrupted file.");

					// Try with incorrect zero length password
					mac = CalculatePbeMac(algId.ObjectID, salt, itCount, password, true, data);

					if (!Arrays.AreEqual(mac, dig))
						throw new IOException("PKCS12 key store MAC invalid - wrong password or corrupted file.");

					wrongPkcs12Zero = true;
				}
			}

			ArrayList chain = new ArrayList();

			if (info.ContentType.Equals(PkcsObjectIdentifiers.Data))
			{
				byte[] octs = ((Asn1OctetString)info.Content).GetOctets();
				AuthenticatedSafe authSafe = new AuthenticatedSafe(
					(Asn1Sequence) Asn1OctetString.FromByteArray(octs));
				ContentInfo[] cis = authSafe.GetContentInfo();

				foreach (ContentInfo ci in cis)
				{
					DerObjectIdentifier oid = ci.ContentType;

					if (oid.Equals(PkcsObjectIdentifiers.Data))
					{
						byte[] octets = ((Asn1OctetString)ci.Content).GetOctets();
						Asn1Sequence seq = (Asn1Sequence) Asn1Object.FromByteArray(octets);

						foreach (Asn1Sequence subSeq in seq)
						{
							SafeBag b = new SafeBag(subSeq);

							if (b.BagID.Equals(PkcsObjectIdentifiers.Pkcs8ShroudedKeyBag))
							{
								EncryptedPrivateKeyInfo eIn = EncryptedPrivateKeyInfo.GetInstance(b.BagValue);
								PrivateKeyInfo privInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(
									password, wrongPkcs12Zero, eIn);
								AsymmetricKeyParameter privKey = PrivateKeyFactory.CreateKey(privInfo);

								//
								// set the attributes on the key
								//
								Hashtable attributes = new Hashtable();
								AsymmetricKeyEntry pkcs12Key = new AsymmetricKeyEntry(privKey, attributes);
								string alias = null;
								Asn1OctetString localId = null;

								if (b.BagAttributes != null)
								{
									foreach (Asn1Sequence sq in b.BagAttributes)
									{
										DerObjectIdentifier aOid = (DerObjectIdentifier) sq[0];
										Asn1Set attrSet = (Asn1Set) sq[1];
										Asn1Encodable attr = null;

										if (attrSet.Count > 0)
										{
											// TODO We should be adding all attributes in the set
											attr = attrSet[0];

											// TODO We might want to "merge" attribute sets with
											// the same OID - currently, it is an error
											attributes.Add(aOid.Id, attr);

											if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName))
											{
												alias = ((DerBmpString)attr).GetString();
												// TODO Do these in a separate loop, just collect aliases here
												keys[alias] = pkcs12Key;
											}
											else if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtLocalKeyID))
											{
												localId = (Asn1OctetString)attr;
											}
										}
									}
								}

								if (localId != null)
								{
									byte[] hex = Hex.Encode(localId.GetOctets());
									string name = Encoding.ASCII.GetString(hex, 0, hex.Length);

									if (alias == null)
									{
										keys[name] = pkcs12Key;
									}
									else
									{
										// TODO There may have been more than one alias
										localIds[alias] = name;
									}
								}
								else
								{
									unmarkedKey = true;
									keys["unmarked"] = pkcs12Key;
								}
							}
							else if (b.BagID.Equals(PkcsObjectIdentifiers.CertBag))
							{
								chain.Add(b);
							}
							else
							{
								Console.WriteLine("extra " + b.BagID);
								Console.WriteLine("extra " + Asn1Dump.DumpAsString(b));
							}
						}
					}
					else if (oid.Equals(PkcsObjectIdentifiers.EncryptedData))
					{
						EncryptedData d = EncryptedData.GetInstance(ci.Content);
						byte[] octets = CryptPbeData(false, d.EncryptionAlgorithm,
							password, wrongPkcs12Zero, d.Content.GetOctets());
						Asn1Sequence seq = (Asn1Sequence) Asn1Object.FromByteArray(octets);

						foreach (Asn1Sequence subSeq in seq)
						{
							SafeBag b = new SafeBag(subSeq);

							if (b.BagID.Equals(PkcsObjectIdentifiers.CertBag))
							{
								chain.Add(b);
							}
							else if (b.BagID.Equals(PkcsObjectIdentifiers.Pkcs8ShroudedKeyBag))
							{
								EncryptedPrivateKeyInfo eIn = EncryptedPrivateKeyInfo.GetInstance(b.BagValue);
								PrivateKeyInfo privInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(
									password, wrongPkcs12Zero, eIn);
								AsymmetricKeyParameter privKey = PrivateKeyFactory.CreateKey(privInfo);

								//
								// set the attributes on the key
								//
								Hashtable attributes = new Hashtable();
								AsymmetricKeyEntry pkcs12Key = new AsymmetricKeyEntry(privKey, attributes);
								string alias = null;
								Asn1OctetString localId = null;

								foreach (Asn1Sequence sq in b.BagAttributes)
								{
									DerObjectIdentifier aOid = (DerObjectIdentifier) sq[0];
									Asn1Set attrSet = (Asn1Set) sq[1];
									Asn1Encodable attr = null;

									if (attrSet.Count > 0)
									{
										// TODO We should be adding all attributes in the set
										attr = attrSet[0];

										// TODO We might want to "merge" attribute sets with
										// the same OID - currently, it is an error
										attributes.Add(aOid.Id, attr);

										if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName))
										{
											alias = ((DerBmpString)attr).GetString();
											// TODO Do these in a separate loop, just collect aliases here
											keys[alias] = pkcs12Key;
										}
										else if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtLocalKeyID))
										{
											localId = (Asn1OctetString)attr;
										}
									}
								}

								// TODO Should we be checking localIds != null here
								// as for PkcsObjectIdentifiers.Data version above?

								byte[] hex = Hex.Encode(localId.GetOctets());
								string name = Encoding.ASCII.GetString(hex, 0, hex.Length);

								if (alias == null)
								{
									keys[name] = pkcs12Key;
								}
								else
								{
									// TODO There may have been more than one alias
									localIds[alias] = name;
								}
							}
							else if (b.BagID.Equals(PkcsObjectIdentifiers.KeyBag))
							{
								PrivateKeyInfo privKeyInfo = PrivateKeyInfo.GetInstance(b.BagValue);
								AsymmetricKeyParameter privKey = PrivateKeyFactory.CreateKey(privKeyInfo);

								//
								// set the attributes on the key
								//
								string alias = null;
								Asn1OctetString localId = null;
								Hashtable attributes = new Hashtable();
								AsymmetricKeyEntry pkcs12Key = new AsymmetricKeyEntry(privKey, attributes);

								foreach (Asn1Sequence sq in b.BagAttributes)
								{
									DerObjectIdentifier aOid = (DerObjectIdentifier) sq[0];
									Asn1Set attrSet = (Asn1Set) sq[1];
									Asn1Encodable attr = null;

									if (attrSet.Count > 0)
									{
										// TODO We should be adding all attributes in the set
										attr = attrSet[0];

										// TODO We might want to "merge" attribute sets with
										// the same OID - currently, it is an error
										attributes.Add(aOid.Id, attr);

										if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName))
										{
											alias = ((DerBmpString)attr).GetString();
											// TODO Do these in a separate loop, just collect aliases here
											keys[alias] = pkcs12Key;
										}
										else if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtLocalKeyID))
										{
											localId = (Asn1OctetString)attr;
										}
									}
								}

								// TODO Should we be checking localIds != null here
								// as for PkcsObjectIdentifiers.Data version above?

								byte[] hex = Hex.Encode(localId.GetOctets());
								string name = Encoding.ASCII.GetString(hex, 0, hex.Length);

								if (alias == null)
								{
									keys[name] = pkcs12Key;
								}
								else
								{
									// TODO There may have been more than one alias
									localIds[alias] = name;
								}
							}
							else
							{
								Console.WriteLine("extra " + b.BagID);
								Console.WriteLine("extra " + Asn1Dump.DumpAsString(b));
							}
						}
					}
					else
					{
						Console.WriteLine("extra " + oid);
						Console.WriteLine("extra " + Asn1Dump.DumpAsString(ci.Content));
					}
				}
			}

			certs = new IgnoresCaseHashtable();
			chainCerts = new Hashtable();
			keyCerts = new Hashtable();

			foreach (SafeBag b in chain)
			{
				CertBag cb = new CertBag((Asn1Sequence)b.BagValue);
				byte[] octets = ((Asn1OctetString) cb.CertValue).GetOctets();
				X509Certificate cert = new X509CertificateParser().ReadCertificate(octets);

				//
				// set the attributes
				//
				Hashtable attributes = new Hashtable();
				Asn1OctetString localId = null;
				string alias = null;

				if (b.BagAttributes != null)
				{
					foreach (Asn1Sequence sq in b.BagAttributes)
					{
						DerObjectIdentifier aOid = (DerObjectIdentifier) sq[0];
						Asn1Set attrSet = (Asn1Set) sq[1];

						if (attrSet.Count > 0)
						{
							// TODO We should be adding all attributes in the set
							Asn1Encodable attr = attrSet[0];

							// TODO We might want to "merge" attribute sets with
							// the same OID - currently, it is an error
							attributes.Add(aOid.Id, attr);

							if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName))
							{
								alias = ((DerBmpString)attr).GetString();
							}
							else if (aOid.Equals(PkcsObjectIdentifiers.Pkcs9AtLocalKeyID))
							{
								localId = (Asn1OctetString)attr;
							}
						}
					}
				}

				CertId certId = new CertId(cert.GetPublicKey());
				X509CertificateEntry pkcs12Cert = new X509CertificateEntry(cert, attributes);

				chainCerts[certId] = pkcs12Cert;

				if (unmarkedKey)
				{
					if (keyCerts.Count == 0)
					{
						byte[] hex = Hex.Encode(certId.Id);
						string name = Encoding.ASCII.GetString(hex, 0, hex.Length);

						keyCerts[name] = pkcs12Cert;

						object temp = keys["unmarked"];
						keys.Remove("unmarked");
						keys[name] = temp;
					}
				}
				else
				{
					if (localId != null)
					{
						byte[] hex = Hex.Encode(localId.GetOctets());
						string name = Encoding.ASCII.GetString(hex, 0, hex.Length);

						keyCerts[name] = pkcs12Cert;
					}

					if (alias != null)
					{
						// TODO There may have been more than one alias
						certs[alias] = pkcs12Cert;
					}
				}
			}
		}

		public AsymmetricKeyEntry GetKey(
			string alias)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");

			return (AsymmetricKeyEntry)keys[alias];
		}

		public bool IsCertificateEntry(
			string alias)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");

			return (certs[alias] != null && keys[alias] == null);
		}

		public bool IsKeyEntry(
			string alias)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");

			return (keys[alias] != null);
		}

		private Hashtable GetAliasesTable()
		{
			Hashtable tab = new Hashtable();

			foreach (string key in certs.Keys)
			{
				tab[key] = "cert";
			}

			foreach (string a in keys.Keys)
			{
				if (tab[a] == null)
				{
					tab[a] = "key";
				}
			}

			return tab;
		}

		public IEnumerable Aliases
		{
			get { return new EnumerableProxy(GetAliasesTable().Keys); }
		}

		public bool ContainsAlias(
			string alias)
		{
			return certs[alias] != null || keys[alias] != null;
		}

		/**
		 * simply return the cert entry for the private key
		 */
		public X509CertificateEntry GetCertificate(
			string alias)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");

			X509CertificateEntry c = (X509CertificateEntry) certs[alias];

			//
			// look up the key table - and try the local key id
			//
			if (c == null)
			{
				string id = (string)localIds[alias];
				if (id != null)
				{
					c = (X509CertificateEntry)keyCerts[id];
				}
				else
				{
					c = (X509CertificateEntry)keyCerts[alias];
				}
			}

			return c;
		}

		public string GetCertificateAlias(
			X509Certificate cert)
		{
			if (cert == null)
				throw new ArgumentNullException("cert");

			foreach (DictionaryEntry entry in certs)
			{
				X509CertificateEntry entryValue = (X509CertificateEntry) entry.Value;
				if (entryValue.Certificate.Equals(cert))
				{
					return (string) entry.Key;
				}
			}

			foreach (DictionaryEntry entry in keyCerts)
			{
				X509CertificateEntry entryValue = (X509CertificateEntry) entry.Value;
				if (entryValue.Certificate.Equals(cert))
				{
					return (string) entry.Key;
				}
			}

			return null;
		}

		public X509CertificateEntry[] GetCertificateChain(
			string alias)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");

			if (!IsKeyEntry(alias))
			{
				return null;
			}

			X509CertificateEntry c = GetCertificate(alias);

			if (c != null)
			{
				ArrayList cs = new ArrayList();

				while (c != null)
				{
					X509Certificate x509c = c.Certificate;
					X509CertificateEntry nextC = null;

					Asn1OctetString ext = x509c.GetExtensionValue(X509Extensions.AuthorityKeyIdentifier);
					if (ext != null)
					{
						AuthorityKeyIdentifier id = AuthorityKeyIdentifier.GetInstance(
							Asn1Object.FromByteArray(ext.GetOctets()));

						if (id.GetKeyIdentifier() != null)
						{
							nextC = (X509CertificateEntry) chainCerts[new CertId(id.GetKeyIdentifier())];
						}
					}

					if (nextC == null)
					{
						//
						// no authority key id, try the Issuer DN
						//
						X509Name i = x509c.IssuerDN;
						X509Name s = x509c.SubjectDN;

						if (!i.Equivalent(s))
						{
							foreach (CertId certId in chainCerts.Keys)
							{
								X509CertificateEntry x509CertEntry = (X509CertificateEntry) chainCerts[certId];

								X509Certificate crt = x509CertEntry.Certificate;

								X509Name sub = crt.SubjectDN;
								if (sub.Equivalent(i))
								{
									try
									{
										x509c.Verify(crt.GetPublicKey());

										nextC = x509CertEntry;
										break;
									}
									catch (InvalidKeyException)
									{
										// TODO What if it doesn't verify?
									}
								}
							}
						}
					}

					cs.Add(c);
					if (nextC != c) // self signed - end of the chain
					{
						c = nextC;
					}
					else
					{
						c = null;
					}
				}

				return (X509CertificateEntry[]) cs.ToArray(typeof(X509CertificateEntry));
			}

			return null;
		}

		public void SetCertificateEntry(
			string					alias,
			X509CertificateEntry	certEntry)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");
			if (certEntry == null)
				throw new ArgumentNullException("certEntry");
			if (keys[alias] != null)
				throw new ArgumentException("There is a key entry with the name " + alias + ".");

			certs[alias] = certEntry;
			chainCerts[new CertId(certEntry.Certificate.GetPublicKey())] = certEntry;
		}

		public void SetKeyEntry(
			string					alias,
			AsymmetricKeyEntry		keyEntry,
			X509CertificateEntry[]	chain)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");
			if (keyEntry == null)
				throw new ArgumentNullException("keyEntry");
			if (keyEntry.Key.IsPrivate && (chain == null))
				throw new ArgumentException("No certificate chain for private key");

			if (keys[alias] != null)
			{
				DeleteEntry(alias);
			}

			keys[alias] = keyEntry;
			certs[alias] = chain[0];

			for (int i = 0; i != chain.Length; i++)
			{
				chainCerts[new CertId(chain[i].Certificate.GetPublicKey())] = chain[i];
			}
		}

		public void DeleteEntry(
			string alias)
		{
			if (alias == null)
				throw new ArgumentNullException("alias");

			AsymmetricKeyEntry k = (AsymmetricKeyEntry)keys[alias];
			if (k != null)
			{
				keys.Remove(alias);
			}

			X509CertificateEntry c = (X509CertificateEntry)certs[alias];

			if (c != null)
			{
				certs.Remove(alias);
				chainCerts.Remove(new CertId(c.Certificate.GetPublicKey()));
			}

			if (k != null)
			{
				string id = (string)localIds[alias];
				if (id != null)
				{
					localIds.Remove(alias);
					c = (X509CertificateEntry)keyCerts[id];
				}
				if (c != null)
				{
					keyCerts.Remove(id);
					chainCerts.Remove(new CertId(c.Certificate.GetPublicKey()));
				}
			}

			if (c == null && k == null)
			{
				throw new ArgumentException("no such entry as " + alias);
			}
		}

		public bool IsEntryOfType(
			string	alias,
			Type	entryType)
		{
			if (entryType == typeof(X509CertificateEntry))
				return IsCertificateEntry(alias);

			if (entryType == typeof(AsymmetricKeyEntry))
				return IsKeyEntry(alias) && GetCertificate(alias) != null;

			return false;
		}

		[Obsolete("Use 'Count' property instead")]
		public int Size()
		{
			return Count;
		}

		public int Count
		{
			// TODO Seems a little inefficient
			get { return GetAliasesTable().Count; }
		}

		public void Save(
			Stream			stream,
			char[]			password,
			SecureRandom	random)
		{
			if (stream == null)
				throw new ArgumentNullException("stream");
			if (password == null)
				throw new ArgumentNullException("password");
			if (random == null)
				throw new ArgumentNullException("random");

			//
			// handle the key
			//
			Asn1EncodableVector keyS = new Asn1EncodableVector();
			foreach (string name in keys.Keys)
			{
				byte[] kSalt = new byte[saltSize];
				random.NextBytes(kSalt);

				AsymmetricKeyEntry privKey = (AsymmetricKeyEntry) keys[name];
				EncryptedPrivateKeyInfo kInfo =
					EncryptedPrivateKeyInfoFactory.CreateEncryptedPrivateKeyInfo(
					keyAlgorithm, password, kSalt, MinIterations, privKey.Key);

				Asn1EncodableVector kName = new Asn1EncodableVector();

				foreach (string oid in privKey.BagAttributeKeys)
				{
					Asn1Encodable entry = privKey[oid];

					// NB: Ignore any existing FriendlyName
					if (oid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName.Id))
						continue;

					kName.Add(
						new DerSequence(
							new DerObjectIdentifier(oid),
							new DerSet(entry)));
				}

				//
				// make sure we are using the local alias on store
				//
				// NB: We always set the FriendlyName based on 'name'
				//if (privKey[PkcsObjectIdentifiers.Pkcs9AtFriendlyName] == null)
				{
					kName.Add(
						new DerSequence(
							PkcsObjectIdentifiers.Pkcs9AtFriendlyName,
							new DerSet(new DerBmpString(name))));
				}

				//
				// make sure we have a local key-id
				//
				if (privKey[PkcsObjectIdentifiers.Pkcs9AtLocalKeyID] == null)
				{
					X509CertificateEntry ct = GetCertificate(name);
					AsymmetricKeyParameter pubKey = ct.Certificate.GetPublicKey();
					SubjectKeyIdentifier subjectKeyID = CreateSubjectKeyID(pubKey);

					kName.Add(
						new DerSequence(
							PkcsObjectIdentifiers.Pkcs9AtLocalKeyID,
							new DerSet(subjectKeyID)));
				}

				SafeBag kBag = new SafeBag(PkcsObjectIdentifiers.Pkcs8ShroudedKeyBag, kInfo.ToAsn1Object(), new DerSet(kName));
				keyS.Add(kBag);
			}

			byte[] derEncodedBytes = new DerSequence(keyS).GetDerEncoded();

			BerOctetString keyString = new BerOctetString(derEncodedBytes);

			//
			// certificate processing
			//
			byte[] cSalt = new byte[saltSize];

			random.NextBytes(cSalt);

			Asn1EncodableVector	certSeq = new Asn1EncodableVector();
			Pkcs12PbeParams		cParams = new Pkcs12PbeParams(cSalt, MinIterations);
			AlgorithmIdentifier	cAlgId = new AlgorithmIdentifier(CertAlgorithm, cParams.ToAsn1Object());
			ISet				doneCerts = new HashSet();

			foreach (string name in keys.Keys)
			{
				X509CertificateEntry certEntry = GetCertificate(name);
				CertBag cBag = new CertBag(
					PkcsObjectIdentifiers.X509Certificate,
					new DerOctetString(certEntry.Certificate.GetEncoded()));

				Asn1EncodableVector fName = new Asn1EncodableVector();

				foreach (string oid in certEntry.BagAttributeKeys)
				{
					Asn1Encodable entry = certEntry[oid];

					// NB: Ignore any existing FriendlyName
					if (oid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName.Id))
						continue;

					fName.Add(
						new DerSequence(
							new DerObjectIdentifier(oid),
							new DerSet(entry)));
				}

				//
				// make sure we are using the local alias on store
				//
				// NB: We always set the FriendlyName based on 'name'
				//if (certEntry[PkcsObjectIdentifiers.Pkcs9AtFriendlyName] == null)
				{
					fName.Add(
						new DerSequence(
							PkcsObjectIdentifiers.Pkcs9AtFriendlyName,
							new DerSet(new DerBmpString(name))));
				}

				//
				// make sure we have a local key-id
				//
				if (certEntry[PkcsObjectIdentifiers.Pkcs9AtLocalKeyID] == null)
				{
					AsymmetricKeyParameter pubKey = certEntry.Certificate.GetPublicKey();
					SubjectKeyIdentifier subjectKeyID = CreateSubjectKeyID(pubKey);

					fName.Add(
						new DerSequence(
							PkcsObjectIdentifiers.Pkcs9AtLocalKeyID,
							new DerSet(subjectKeyID)));
				}

				SafeBag sBag = new SafeBag(
					PkcsObjectIdentifiers.CertBag, cBag.ToAsn1Object(), new DerSet(fName));

				certSeq.Add(sBag);

				doneCerts.Add(certEntry.Certificate);
			}

			foreach (string certId in certs.Keys)
			{
				X509CertificateEntry cert = (X509CertificateEntry)certs[certId];

				if (keys[certId] != null)
					continue;

				CertBag cBag = new CertBag(
					PkcsObjectIdentifiers.X509Certificate,
					new DerOctetString(cert.Certificate.GetEncoded()));

				Asn1EncodableVector fName = new Asn1EncodableVector();

				foreach (string oid in cert.BagAttributeKeys)
				{
					Asn1Encodable entry = cert[oid];

					// NB: Ignore any existing FriendlyName
					if (oid.Equals(PkcsObjectIdentifiers.Pkcs9AtFriendlyName.Id))
						continue;

					fName.Add(
						new DerSequence(
							new DerObjectIdentifier(oid),
							new DerSet(entry)));
				}

				//
				// make sure we are using the local alias on store
				//
				// NB: We always set the FriendlyName based on 'certId'
				//if (cert[PkcsObjectIdentifiers.Pkcs9AtFriendlyName] == null)
				{
					fName.Add(
						new DerSequence(
							PkcsObjectIdentifiers.Pkcs9AtFriendlyName,
							new DerSet(new DerBmpString(certId))));
				}

				SafeBag sBag = new SafeBag(PkcsObjectIdentifiers.CertBag,
					cBag.ToAsn1Object(), new DerSet(fName));

				certSeq.Add(sBag);

				doneCerts.Add(cert.Certificate);
			}

			foreach (CertId certId in chainCerts.Keys)
			{
				X509CertificateEntry cert = (X509CertificateEntry)chainCerts[certId];

				if (doneCerts.Contains(cert.Certificate))
					continue;

				CertBag cBag = new CertBag(
					PkcsObjectIdentifiers.X509Certificate,
					new DerOctetString(cert.Certificate.GetEncoded()));

				Asn1EncodableVector fName = new Asn1EncodableVector();

				foreach (string oid in cert.BagAttributeKeys)
				{
					fName.Add(
						new DerSequence(
							new DerObjectIdentifier(oid),
							new DerSet(cert[oid])));
				}

				SafeBag sBag = new SafeBag(PkcsObjectIdentifiers.CertBag, cBag.ToAsn1Object(), new DerSet(fName));

				certSeq.Add(sBag);
			}

			derEncodedBytes = new DerSequence(certSeq).GetDerEncoded();

			byte[] certBytes = CryptPbeData(true, cAlgId, password, false, derEncodedBytes);

			EncryptedData cInfo = new EncryptedData(PkcsObjectIdentifiers.Data, cAlgId, new BerOctetString(certBytes));

			ContentInfo[] info = new ContentInfo[]
			{
				new ContentInfo(PkcsObjectIdentifiers.Data, keyString),
				new ContentInfo(PkcsObjectIdentifiers.EncryptedData, cInfo.ToAsn1Object())
			};

			byte[] data = new AuthenticatedSafe(info).GetEncoded();

			ContentInfo mainInfo = new ContentInfo(PkcsObjectIdentifiers.Data, new BerOctetString(data));

			//
			// create the mac
			//
			byte[] mSalt = new byte[20];
			random.NextBytes(mSalt);

			byte[] mac = CalculatePbeMac(OiwObjectIdentifiers.IdSha1,
				mSalt, MinIterations, password, false, data);

			AlgorithmIdentifier algId = new AlgorithmIdentifier(
				OiwObjectIdentifiers.IdSha1, DerNull.Instance);
			DigestInfo dInfo = new DigestInfo(algId, mac);

			MacData mData = new MacData(dInfo, mSalt, MinIterations);

			//
			// output the Pfx
			//
			Pfx pfx = new Pfx(mainInfo, mData);

			BerOutputStream berOut = new BerOutputStream(stream);
			berOut.WriteObject(pfx);
		}

		private static byte[] CalculatePbeMac(
			DerObjectIdentifier	oid,
			byte[]				salt,
			int					itCount,
			char[]				password,
			bool				wrongPkcs12Zero,
			byte[]				data)
		{
			Asn1Encodable asn1Params = PbeUtilities.GenerateAlgorithmParameters(
				oid, salt, itCount);
			ICipherParameters cipherParams = PbeUtilities.GenerateCipherParameters(
				oid, password, wrongPkcs12Zero, asn1Params);

			IMac mac = (IMac) PbeUtilities.CreateEngine(oid);
			mac.Init(cipherParams);
			mac.BlockUpdate(data, 0, data.Length);
			return MacUtilities.DoFinal(mac);
		}

		private static byte[] CryptPbeData(
			bool				forEncryption,
			AlgorithmIdentifier	algId,
			char[]				password,
			bool				wrongPkcs12Zero,
			byte[]				data)
		{
			Pkcs12PbeParams pbeParams = Pkcs12PbeParams.GetInstance(algId.Parameters);
			ICipherParameters cipherParams = PbeUtilities.GenerateCipherParameters(
				algId.ObjectID, password, wrongPkcs12Zero, pbeParams);

			IBufferedCipher cipher = PbeUtilities.CreateEngine(algId.ObjectID) as IBufferedCipher;

			if (cipher == null)
				throw new Exception("Unknown encryption algorithm: " + algId.ObjectID);

			cipher.Init(forEncryption, cipherParams);

			return cipher.DoFinal(data);
		}

		private class IgnoresCaseHashtable
			: IEnumerable
		{
			private readonly Hashtable orig = new Hashtable();
			private readonly Hashtable keys = new Hashtable();

			public IEnumerator GetEnumerator()
			{
				return orig.GetEnumerator();
			}

			public ICollection Keys
			{
				get { return orig.Keys; }
			}

			public object Remove(
				string alias)
			{
				string lower = alias.ToLower(CultureInfo.InvariantCulture);
				string k = (string) keys[lower];

				if (k == null)
					return null;

				keys.Remove(lower);

				object o = orig[k];
				orig.Remove(k);
				return o;
			}

			public object this[
				string alias]
			{
				get
				{
					string lower = alias.ToLower(CultureInfo.InvariantCulture);
					string k = (string) keys[lower];

					if (k == null)
						return null;

					return orig[k];
				}
				set
				{
					string lower = alias.ToLower(CultureInfo.InvariantCulture);
					string k = (string) keys[lower];
					if (k != null)
					{
						orig.Remove(k);
					}
					keys[lower] = alias;
					orig[alias] = value;
				}
			}

			public ICollection Values
			{
				get { return orig.Values; }
			}
		}
	}
}