mono/mcs/class/referencesource/System.Data/System/Data/SqlClient/SqlConnectionString.cs

//------------------------------------------------------------------------------
// <copyright file="SqlConnectionString.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// <owner current="true" primary="true">[....]</owner>
// <owner current="true" primary="false">[....]</owner>
//------------------------------------------------------------------------------

namespace System.Data.SqlClient {

    using System;
    using System.Collections;
    using System.Data;
    using System.Data.Common;
    using System.Diagnostics;
    using System.Globalization;
    using System.IO;
    using System.Security;
    using System.Security.Permissions;
    using System.Text;
    using System.Runtime.Versioning;

    internal sealed class SqlConnectionString : DbConnectionOptions {
        // instances of this class are intended to be immutable, i.e readonly
        // used by pooling classes so it is much easier to verify correctness
        // when not worried about the class being modified during execution

        internal static class DEFAULT {
            internal const  ApplicationIntent ApplicationIntent = DbConnectionStringDefaults.ApplicationIntent;
            internal const  string Application_Name       = TdsEnums.SQL_PROVIDER_NAME;
            internal const  bool   Asynchronous           = false;
            internal const  string AttachDBFilename       = "";
            internal const  int    Connect_Timeout        = ADP.DefaultConnectionTimeout;
            internal const  bool   Connection_Reset       = true;
            internal const  bool   Context_Connection     = false;
            internal const  string Current_Language       = "";
            internal const  string Data_Source            = "";
            internal const  bool   Encrypt                = false;
            internal const  bool   Enlist                 = true;
            internal const  string FailoverPartner        = "";
            internal const  string Initial_Catalog        = "";
            internal const  bool   Integrated_Security    = false;
            internal const  int    Load_Balance_Timeout   = 0; // default of 0 means don't use
            internal const  bool   MARS                   = false;
            internal const  int    Max_Pool_Size          = 100;
            internal const  int    Min_Pool_Size          = 0;
            internal const  bool   MultiSubnetFailover    = DbConnectionStringDefaults.MultiSubnetFailover;
            internal const  string Network_Library        = "";
            internal const  int    Packet_Size            = 8000;
            internal const  string Password               = "";
            internal const  bool   Persist_Security_Info  = false;
            internal const  bool   Pooling                = true;
            internal const  bool   TrustServerCertificate = false;
            internal const  string Type_System_Version    = "";
            internal const  string User_ID                = "";
            internal const  bool   User_Instance          = false;
            internal const  bool   Replication            = false;
            internal const  int    Connect_Retry_Count    = 1;
            internal const  int    Connect_Retry_Interval = 10;
        }

        // SqlConnection ConnectionString Options
        // keys must be lowercase!
        internal static class KEY {
            internal const string ApplicationIntent      = "applicationintent";
            internal const string Application_Name       = "application name";
            internal const string AsynchronousProcessing = "asynchronous processing";
            internal const string AttachDBFilename       = "attachdbfilename";
            internal const string Connect_Timeout        = "connect timeout";
            internal const string Connection_Reset       = "connection reset";
            internal const string Context_Connection     = "context connection";
            internal const string Current_Language       = "current language";
            internal const string Data_Source            = "data source";
            internal const string Encrypt                = "encrypt";
            internal const string Enlist                 = "enlist";
            internal const string FailoverPartner        = "failover partner";
            internal const string Initial_Catalog        = "initial catalog";
            internal const string Integrated_Security    = "integrated security";
            internal const string Load_Balance_Timeout   = "load balance timeout";
            internal const string MARS                   = "multipleactiveresultsets";
            internal const string Max_Pool_Size          = "max pool size";
            internal const string Min_Pool_Size          = "min pool size";
            internal const string MultiSubnetFailover    = "multisubnetfailover";
            internal const string Network_Library        = "network library";
            internal const string Packet_Size            = "packet size";
            internal const string Password               = "password";
            internal const string Persist_Security_Info  = "persist security info";
            internal const string Pooling                = "pooling";
            internal const string TransactionBinding     = "transaction binding";
            internal const string TrustServerCertificate = "trustservercertificate";
            internal const string Type_System_Version    = "type system version";
            internal const string User_ID                = "user id";
            internal const string User_Instance          = "user instance";
            internal const string Workstation_Id         = "workstation id";
            internal const string Replication            = "replication";
            internal const string Connect_Retry_Count    = "connectretrycount";
            internal const string Connect_Retry_Interval = "connectretryinterval";
        }

        // Constant for the number of duplicate options in the connnection string

        private static class SYNONYM {
            // application name
            internal const string APP                 = "app";
            internal const string Async               = "async";
            // attachDBFilename
            internal const string EXTENDED_PROPERTIES = "extended properties";
            internal const string INITIAL_FILE_NAME   = "initial file name";
            // connect timeout
            internal const string CONNECTION_TIMEOUT  = "connection timeout";
            internal const string TIMEOUT             = "timeout";
            // current language
            internal const string LANGUAGE            = "language";
            // data source
            internal const string ADDR                = "addr";
            internal const string ADDRESS             = "address";
            internal const string SERVER              = "server";
            internal const string NETWORK_ADDRESS     = "network address";
            // initial catalog
            internal const string DATABASE            = "database";
            // integrated security
            internal const string TRUSTED_CONNECTION  = "trusted_connection";
            // load balance timeout
            internal const string Connection_Lifetime = "connection lifetime";
            // network library
            internal const string NET                 = "net";
            internal const string NETWORK             = "network";
            // password
            internal const string Pwd                 = "pwd";
            // persist security info
            internal const string PERSISTSECURITYINFO = "persistsecurityinfo";
            // user id
            internal const string UID                 = "uid";
            internal const string User                = "user";
            // workstation id
            internal const string WSID                = "wsid";

            // make sure to update SynonymCount value below when adding or removing synonyms
        }

        internal const int SynonymCount = 21;

        // the following are all inserted as keys into the _netlibMapping hash
        internal static class NETLIB {
            internal const string AppleTalk     = "dbmsadsn";
            internal const string BanyanVines   = "dbmsvinn";
            internal const string IPXSPX        = "dbmsspxn";
            internal const string Multiprotocol = "dbmsrpcn";
            internal const string NamedPipes    = "dbnmpntw";
            internal const string SharedMemory  = "dbmslpcn";
            internal const string TCPIP         = "dbmssocn";
            internal const string VIA           = "dbmsgnet";
        }

        internal enum TypeSystem {
            Latest = 2008,
            SQLServer2000 = 2000,
            SQLServer2005 = 2005,
            SQLServer2008 = 2008,
            SQLServer2012 = 2012,
        }

        internal static class TYPESYSTEMVERSION {
            internal const string Latest          = "Latest";
            internal const string SQL_Server_2000 = "SQL Server 2000";
            internal const string SQL_Server_2005 = "SQL Server 2005";
            internal const string SQL_Server_2008 = "SQL Server 2008";
            internal const string SQL_Server_2012 = "SQL Server 2012";
        }

        internal enum TransactionBindingEnum {
            ImplicitUnbind,
            ExplicitUnbind
        }

        internal static class TRANSACIONBINDING {
            internal const string ImplicitUnbind = "Implicit Unbind";
            internal const string ExplicitUnbind = "Explicit Unbind";
        }

        static private Hashtable _sqlClientSynonyms;
        static private Hashtable _netlibMapping;

        private readonly bool _integratedSecurity;

        private readonly bool _connectionReset;
        private readonly bool _contextConnection;
        private readonly bool _encrypt;
        private readonly bool _trustServerCertificate;
        private readonly bool _enlist;
        private readonly bool _mars;
        private readonly bool _persistSecurityInfo;
        private readonly bool _pooling;
        private readonly bool _replication;
        private readonly bool _userInstance;
        private readonly bool _multiSubnetFailover;

        private readonly int _connectTimeout;
        private readonly int _loadBalanceTimeout;
        private readonly int _maxPoolSize;
        private readonly int _minPoolSize;
        private readonly int _packetSize;
        private readonly int _connectRetryCount;
        private readonly int _connectRetryInterval;

        private readonly ApplicationIntent _applicationIntent;
        private readonly string _applicationName;
        private readonly string _attachDBFileName;
        private readonly string _currentLanguage;
        private readonly string _dataSource;
        private readonly string _localDBInstance; // created based on datasource, set to NULL if datasource is not LocalDB 
        private readonly string _failoverPartner;
        private readonly string _initialCatalog;
        private readonly string _password;
        private readonly string _userID;

        private readonly string _networkLibrary;
        private readonly string _workstationId;

        private readonly TypeSystem _typeSystemVersion;
        private readonly Version _typeSystemAssemblyVersion;
        private static readonly Version constTypeSystemAsmVersion10 = new Version("10.0.0.0");
        private static readonly Version constTypeSystemAsmVersion11 = new Version("11.0.0.0");

        private readonly TransactionBindingEnum _transactionBinding;

        private readonly string _expandedAttachDBFilename; // expanded during construction so that CreatePermissionSet & Expand are consistent

        // SxS: reading Software\\Microsoft\\MSSQLServer\\Client\\SuperSocketNetLib\Encrypt value from registry
        [ResourceExposure(ResourceScope.None)]
        [ResourceConsumption(ResourceScope.Machine, ResourceScope.Machine)]
        internal SqlConnectionString(string connectionString) : base(connectionString, GetParseSynonyms(), false) {

            bool   runningInProc  = InOutOfProcHelper.InProc;
            
            _integratedSecurity = ConvertValueToIntegratedSecurity();

            ConvertValueToBoolean(KEY.AsynchronousProcessing, DEFAULT.Asynchronous); // while we don't use it anymore, we still need to verify it is true/false

            // SQLPT 41700: Ignore ResetConnection=False (still validate the keyword/value)
            _connectionReset     = ConvertValueToBoolean(KEY.Connection_Reset,      DEFAULT.Connection_Reset);
            _contextConnection   = ConvertValueToBoolean(KEY.Context_Connection,    DEFAULT.Context_Connection);
            _encrypt             = ConvertValueToBoolean(KEY.Encrypt,               DEFAULT.Encrypt);
            _enlist              = ConvertValueToBoolean(KEY.Enlist,                ADP.IsWindowsNT);
            _mars                = ConvertValueToBoolean(KEY.MARS,                  DEFAULT.MARS);
            _persistSecurityInfo = ConvertValueToBoolean(KEY.Persist_Security_Info, DEFAULT.Persist_Security_Info);
            _pooling             = ConvertValueToBoolean(KEY.Pooling,               DEFAULT.Pooling);
            _replication         = ConvertValueToBoolean(KEY.Replication,           DEFAULT.Replication);
            _userInstance        = ConvertValueToBoolean(KEY.User_Instance,         DEFAULT.User_Instance);
            _multiSubnetFailover = ConvertValueToBoolean(KEY.MultiSubnetFailover,   DEFAULT.MultiSubnetFailover);

            _connectTimeout     = ConvertValueToInt32(KEY.Connect_Timeout,       DEFAULT.Connect_Timeout);
            _loadBalanceTimeout = ConvertValueToInt32(KEY.Load_Balance_Timeout,  DEFAULT.Load_Balance_Timeout);
            _maxPoolSize        = ConvertValueToInt32(KEY.Max_Pool_Size,         DEFAULT.Max_Pool_Size);
            _minPoolSize        = ConvertValueToInt32(KEY.Min_Pool_Size,         DEFAULT.Min_Pool_Size);
            _packetSize         = ConvertValueToInt32(KEY.Packet_Size,           DEFAULT.Packet_Size);
            _connectRetryCount  = ConvertValueToInt32(KEY.Connect_Retry_Count,   DEFAULT.Connect_Retry_Count);
            _connectRetryInterval = ConvertValueToInt32(KEY.Connect_Retry_Interval, DEFAULT.Connect_Retry_Interval);

            _applicationIntent = ConvertValueToApplicationIntent();
            _applicationName  = ConvertValueToString(KEY.Application_Name, DEFAULT.Application_Name);
            _attachDBFileName = ConvertValueToString(KEY.AttachDBFilename, DEFAULT.AttachDBFilename);
            _currentLanguage  = ConvertValueToString(KEY.Current_Language, DEFAULT.Current_Language);
            _dataSource       = ConvertValueToString(KEY.Data_Source,      DEFAULT.Data_Source);
            _localDBInstance  = LocalDBAPI.GetLocalDbInstanceNameFromServerName(_dataSource);
            _failoverPartner  = ConvertValueToString(KEY.FailoverPartner,  DEFAULT.FailoverPartner);
            _initialCatalog   = ConvertValueToString(KEY.Initial_Catalog,  DEFAULT.Initial_Catalog);
            _networkLibrary   = ConvertValueToString(KEY.Network_Library,  null);
            _password         = ConvertValueToString(KEY.Password,         DEFAULT.Password);
            _trustServerCertificate  = ConvertValueToBoolean(KEY.TrustServerCertificate,  DEFAULT.TrustServerCertificate);

            // Temporary string - this value is stored internally as an enum.
            string typeSystemVersionString = ConvertValueToString(KEY.Type_System_Version, null);
            string transactionBindingString = ConvertValueToString(KEY.TransactionBinding, null);

            _userID           = ConvertValueToString(KEY.User_ID,          DEFAULT.User_ID);
            _workstationId    = ConvertValueToString(KEY.Workstation_Id,   null);

            if (_contextConnection) {
                // We have to be running in the engine for you to request a 
                // context connection.

                if (!runningInProc) {
                    throw SQL.ContextUnavailableOutOfProc();
                }

                // When using a context connection, we need to ensure that no 
                // other connection string keywords are specified.

                foreach (DictionaryEntry entry in Parsetable) {
                    if ((string) entry.Key != KEY.Context_Connection &&
                        (string) entry.Key != KEY.Type_System_Version) {
                        throw SQL.ContextAllowsLimitedKeywords();
                    }
                }
            }

            if (!_encrypt) {    // Support legacy registry encryption settings
                const string folder = "Software\\Microsoft\\MSSQLServer\\Client\\SuperSocketNetLib";
                const string value    = "Encrypt";

                Object obj = ADP.LocalMachineRegistryValue(folder, value);
                if ((obj is Int32) && (1 == (int)obj)) {         // If the registry key exists
                    _encrypt    = true;
                }
            }


            if (_loadBalanceTimeout < 0) {
                throw ADP.InvalidConnectionOptionValue(KEY.Load_Balance_Timeout);
            }

            if (_connectTimeout < 0) {
                throw ADP.InvalidConnectionOptionValue(KEY.Connect_Timeout);
            }

            if (_maxPoolSize < 1) {
                throw ADP.InvalidConnectionOptionValue(KEY.Max_Pool_Size);
            }

            if (_minPoolSize < 0) {
                throw ADP.InvalidConnectionOptionValue(KEY.Min_Pool_Size);
            }
            if (_maxPoolSize < _minPoolSize) {
                throw ADP.InvalidMinMaxPoolSizeValues();
            }

            if ((_packetSize < TdsEnums.MIN_PACKET_SIZE) || (TdsEnums.MAX_PACKET_SIZE < _packetSize)) {
                throw SQL.InvalidPacketSizeValue();
            }

            if (null != _networkLibrary) { // MDAC 83525
                string networkLibrary = _networkLibrary.Trim().ToLower(CultureInfo.InvariantCulture);
                Hashtable netlib = NetlibMapping();
                if (!netlib.ContainsKey(networkLibrary)) {
                    throw ADP.InvalidConnectionOptionValue(KEY.Network_Library);
                }
                _networkLibrary = (string) netlib[networkLibrary];
            }
            else {
                _networkLibrary = DEFAULT.Network_Library;
            }

            ValidateValueLength(_applicationName, TdsEnums.MAXLEN_APPNAME, KEY.Application_Name);
            ValidateValueLength(_currentLanguage , TdsEnums.MAXLEN_LANGUAGE, KEY.Current_Language);
            ValidateValueLength(_dataSource, TdsEnums.MAXLEN_SERVERNAME, KEY.Data_Source);
            ValidateValueLength(_failoverPartner, TdsEnums.MAXLEN_SERVERNAME, KEY.FailoverPartner);
            ValidateValueLength(_initialCatalog, TdsEnums.MAXLEN_DATABASE, KEY.Initial_Catalog);
            ValidateValueLength(_password, TdsEnums.MAXLEN_PASSWORD, KEY.Password);
            ValidateValueLength(_userID, TdsEnums.MAXLEN_USERNAME, KEY.User_ID);
            if (null != _workstationId) {
                ValidateValueLength(_workstationId, TdsEnums.MAXLEN_HOSTNAME, KEY.Workstation_Id);
            }

            if (!String.Equals(DEFAULT.FailoverPartner, _failoverPartner, StringComparison.OrdinalIgnoreCase)) {
                // fail-over partner is set

                if (_multiSubnetFailover) {
                    throw SQL.MultiSubnetFailoverWithFailoverPartner(serverProvidedFailoverPartner: false, internalConnection: null);
                }

                if (String.Equals(DEFAULT.Initial_Catalog, _initialCatalog, StringComparison.OrdinalIgnoreCase)) {
                    throw ADP.MissingConnectionOptionValue(KEY.FailoverPartner, KEY.Initial_Catalog);
                }
            }

            // expand during construction so that CreatePermissionSet and Expand are consistent
            string datadir = null;
            _expandedAttachDBFilename = ExpandDataDirectory(KEY.AttachDBFilename, _attachDBFileName, ref datadir);
            if (null != _expandedAttachDBFilename) {
                if (0 <= _expandedAttachDBFilename.IndexOf('|')) {
                    throw ADP.InvalidConnectionOptionValue(KEY.AttachDBFilename);
                }
                ValidateValueLength(_expandedAttachDBFilename, TdsEnums.MAXLEN_ATTACHDBFILE, KEY.AttachDBFilename);
                if (_localDBInstance == null)
                {
                    // fail fast to verify LocalHost when using |DataDirectory|
                    // still must check again at connect time
                    string host = _dataSource;
                    string protocol = _networkLibrary;
                    TdsParserStaticMethods.AliasRegistryLookup(ref host, ref protocol);
                    VerifyLocalHostAndFixup(ref host, true, false /*don't fix-up*/);
                }
            }
            else if (0 <= _attachDBFileName.IndexOf('|')) {
                throw ADP.InvalidConnectionOptionValue(KEY.AttachDBFilename);
            }
            else {
                ValidateValueLength(_attachDBFileName, TdsEnums.MAXLEN_ATTACHDBFILE, KEY.AttachDBFilename);
            }

            _typeSystemAssemblyVersion = constTypeSystemAsmVersion10;

            if (true == _userInstance && !ADP.IsEmpty(_failoverPartner)) {
                throw SQL.UserInstanceFailoverNotCompatible();
            }

            if (ADP.IsEmpty(typeSystemVersionString)) {
                typeSystemVersionString = DbConnectionStringDefaults.TypeSystemVersion;
            }

            if (typeSystemVersionString.Equals(TYPESYSTEMVERSION.Latest, StringComparison.OrdinalIgnoreCase)) {
                _typeSystemVersion = TypeSystem.Latest;
            }
            else if (typeSystemVersionString.Equals(TYPESYSTEMVERSION.SQL_Server_2000, StringComparison.OrdinalIgnoreCase)) {
                if (_contextConnection) {
                    throw SQL.ContextAllowsOnlyTypeSystem2005();
                }
                _typeSystemVersion = TypeSystem.SQLServer2000;
            }
            else if (typeSystemVersionString.Equals(TYPESYSTEMVERSION.SQL_Server_2005, StringComparison.OrdinalIgnoreCase)) {
                _typeSystemVersion = TypeSystem.SQLServer2005;
            }
            else if (typeSystemVersionString.Equals(TYPESYSTEMVERSION.SQL_Server_2008, StringComparison.OrdinalIgnoreCase)) {
                _typeSystemVersion = TypeSystem.SQLServer2008;
            }
            else if (typeSystemVersionString.Equals(TYPESYSTEMVERSION.SQL_Server_2012, StringComparison.OrdinalIgnoreCase)) {
                _typeSystemVersion = TypeSystem.SQLServer2012;
                _typeSystemAssemblyVersion = constTypeSystemAsmVersion11;
            }
            else {
                throw ADP.InvalidConnectionOptionValue(KEY.Type_System_Version);
            }

            if (ADP.IsEmpty(transactionBindingString)) {
                transactionBindingString = DbConnectionStringDefaults.TransactionBinding;
            }

            if (transactionBindingString.Equals(TRANSACIONBINDING.ImplicitUnbind, StringComparison.OrdinalIgnoreCase)) {
                _transactionBinding = TransactionBindingEnum.ImplicitUnbind;
            }
            else if (transactionBindingString.Equals(TRANSACIONBINDING.ExplicitUnbind, StringComparison.OrdinalIgnoreCase)) {
                _transactionBinding = TransactionBindingEnum.ExplicitUnbind;
            }
            else {
                throw ADP.InvalidConnectionOptionValue(KEY.TransactionBinding);
            }

            if (_applicationIntent == ApplicationIntent.ReadOnly && !String.IsNullOrEmpty(_failoverPartner))
                throw SQL.ROR_FailoverNotSupportedConnString();

            if ((_connectRetryCount<0) || (_connectRetryCount>255)) {
                throw ADP.InvalidConnectRetryCountValue();
            }

            if ((_connectRetryInterval < 1) || (_connectRetryInterval > 60)) {
                throw ADP.InvalidConnectRetryIntervalValue();
            }
        }

        // This c-tor is used to create SSE and user instance connection strings when user instance is set to true
        // 
        internal SqlConnectionString(SqlConnectionString connectionOptions, string dataSource, bool userInstance, bool? setEnlistValue) : base(connectionOptions) {
            _integratedSecurity       = connectionOptions._integratedSecurity;
            _connectionReset          = connectionOptions._connectionReset;
            _contextConnection        = connectionOptions._contextConnection;
            _encrypt                  = connectionOptions._encrypt;

            if (setEnlistValue.HasValue) {
                _enlist = setEnlistValue.Value;
            }
            else {
                _enlist = connectionOptions._enlist;
            }
            
            _mars                     = connectionOptions._mars;
            _persistSecurityInfo      = connectionOptions._persistSecurityInfo;
            _pooling                  = connectionOptions._pooling;
            _replication              = connectionOptions._replication;
            _userInstance             = userInstance;
            _connectTimeout           = connectionOptions._connectTimeout;
            _loadBalanceTimeout       = connectionOptions._loadBalanceTimeout;
            _maxPoolSize              = connectionOptions._maxPoolSize;
            _minPoolSize              = connectionOptions._minPoolSize;
            _multiSubnetFailover      = connectionOptions._multiSubnetFailover;
            _packetSize               = connectionOptions._packetSize;
            _applicationName          = connectionOptions._applicationName;
            _attachDBFileName         = connectionOptions._attachDBFileName;
            _currentLanguage          = connectionOptions._currentLanguage;
            _dataSource               = dataSource;
            _localDBInstance          = LocalDBAPI.GetLocalDbInstanceNameFromServerName(_dataSource);
            _failoverPartner          = connectionOptions._failoverPartner;
            _initialCatalog           = connectionOptions._initialCatalog;
            _password                 = connectionOptions._password;
            _userID                   = connectionOptions._userID;
            _networkLibrary           = connectionOptions._networkLibrary;
            _workstationId            = connectionOptions._workstationId;
            _expandedAttachDBFilename = connectionOptions._expandedAttachDBFilename;
            _typeSystemVersion        = connectionOptions._typeSystemVersion;
            _typeSystemAssemblyVersion =connectionOptions._typeSystemAssemblyVersion;
            _transactionBinding       = connectionOptions._transactionBinding;
            _applicationIntent        = connectionOptions._applicationIntent;
            _connectRetryCount        = connectionOptions._connectRetryCount;
            _connectRetryInterval     = connectionOptions._connectRetryInterval;

            ValidateValueLength(_dataSource, TdsEnums.MAXLEN_SERVERNAME, KEY.Data_Source);
        }

        internal bool IntegratedSecurity { get { return _integratedSecurity; } }

        // We always initialize in Async mode so that both synchronous and asynchronous methods
        // will work.  In the future we can deprecate the keyword entirely.
        internal bool Asynchronous { get { return true; } }

        // SQLPT 41700: Ignore ResetConnection=False, always reset the connection for security
        internal bool ConnectionReset { get { return true; } }
        internal bool ContextConnection { get { return _contextConnection; } }
//        internal bool EnableUdtDownload { get { return _enableUdtDownload;} }
        internal bool Encrypt { get { return _encrypt; } }
        internal bool TrustServerCertificate { get { return _trustServerCertificate; } }
        internal bool Enlist { get { return _enlist; } }
        internal bool MARS { get { return _mars; } }
        internal bool MultiSubnetFailover { get { return _multiSubnetFailover; } }

        internal bool PersistSecurityInfo { get { return _persistSecurityInfo; } }
        internal bool Pooling { get { return _pooling; } }
        internal bool Replication { get { return _replication; } }
        internal bool UserInstance { get { return _userInstance; } }

        internal int ConnectTimeout { get { return _connectTimeout; } }
        internal int LoadBalanceTimeout { get { return _loadBalanceTimeout; } }
        internal int MaxPoolSize { get { return _maxPoolSize; } }
        internal int MinPoolSize { get { return _minPoolSize; } }
        internal int PacketSize { get { return _packetSize; } }
        internal int ConnectRetryCount { get { return _connectRetryCount; } }
        internal int ConnectRetryInterval { get { return _connectRetryInterval; } }

        internal ApplicationIntent ApplicationIntent { get { return _applicationIntent; } }
        internal string ApplicationName { get { return _applicationName; } }
        internal string AttachDBFilename { get { return _attachDBFileName; } }
        internal string CurrentLanguage { get { return _currentLanguage; } }
        internal string DataSource { get { return _dataSource; } }
        internal string LocalDBInstance { get { return _localDBInstance; } }
        internal string FailoverPartner { get { return _failoverPartner; } }
        internal string InitialCatalog { get { return _initialCatalog; } }
        internal string NetworkLibrary { get { return _networkLibrary; } }
        internal string Password { get { return _password; } }
        internal string UserID { get { return _userID; } }
        internal string WorkstationId { get { return _workstationId; } }

        internal TypeSystem TypeSystemVersion { get { return _typeSystemVersion; } }
        internal Version    TypeSystemAssemblyVersion { get { return _typeSystemAssemblyVersion; } }
        internal TransactionBindingEnum TransactionBinding { get { return _transactionBinding; } }

        internal bool EnforceLocalHost {
            get {
                // so tdsparser.connect can determine if SqlConnection.UserConnectionOptions
                // needs to enfoce local host after datasource alias lookup
                return (null != _expandedAttachDBFilename) && (null == _localDBInstance);
            }
        }

        protected internal override System.Security.PermissionSet CreatePermissionSet() {
            System.Security.PermissionSet permissionSet = new System.Security.PermissionSet(System.Security.Permissions.PermissionState.None);
            permissionSet.AddPermission(new SqlClientPermission(this));
            return permissionSet;
        }

        protected internal override string Expand() {
            if (null != _expandedAttachDBFilename) {
                return ExpandKeyword(KEY.AttachDBFilename, _expandedAttachDBFilename);
            }
            else {
                return base.Expand();
            }
        }

        private static bool CompareHostName(ref string host, string name, bool fixup) {
            // same computer name or same computer name + "\named instance"
            bool equal = false;

            if (host.Equals(name, StringComparison.OrdinalIgnoreCase)) {
                if (fixup) {
                    host = ".";
                }
                equal = true;
            }
            else if (host.StartsWith(name+@"\", StringComparison.OrdinalIgnoreCase)) {
                if (fixup) {
                    host = "." + host.Substring(name.Length);
                }
                equal = true;
            }
            return equal;
        }
            
        // this hashtable is meant to be read-only translation of parsed string
        // keywords/synonyms to a known keyword string
        internal static Hashtable GetParseSynonyms() {            

            Hashtable hash = _sqlClientSynonyms;
            if (null == hash) {
                hash = new Hashtable(SqlConnectionStringBuilder.KeywordsCount + SynonymCount);
                hash.Add(KEY.ApplicationIntent,      KEY.ApplicationIntent);
                hash.Add(KEY.Application_Name,       KEY.Application_Name);
                hash.Add(KEY.AsynchronousProcessing, KEY.AsynchronousProcessing);
                hash.Add(KEY.AttachDBFilename,       KEY.AttachDBFilename);
                hash.Add(KEY.Connect_Timeout,        KEY.Connect_Timeout);
                hash.Add(KEY.Connection_Reset,       KEY.Connection_Reset);
                hash.Add(KEY.Context_Connection,     KEY.Context_Connection);
                hash.Add(KEY.Current_Language,       KEY.Current_Language);
                hash.Add(KEY.Data_Source,            KEY.Data_Source);
                hash.Add(KEY.Encrypt,                KEY.Encrypt);
                hash.Add(KEY.Enlist,                 KEY.Enlist);
                hash.Add(KEY.FailoverPartner,        KEY.FailoverPartner);
                hash.Add(KEY.Initial_Catalog,        KEY.Initial_Catalog);
                hash.Add(KEY.Integrated_Security,    KEY.Integrated_Security);
                hash.Add(KEY.Load_Balance_Timeout,   KEY.Load_Balance_Timeout);
                hash.Add(KEY.MARS,                   KEY.MARS);
                hash.Add(KEY.Max_Pool_Size,          KEY.Max_Pool_Size);
                hash.Add(KEY.Min_Pool_Size,          KEY.Min_Pool_Size);
                hash.Add(KEY.MultiSubnetFailover,    KEY.MultiSubnetFailover);
                hash.Add(KEY.Network_Library,        KEY.Network_Library);
                hash.Add(KEY.Packet_Size,            KEY.Packet_Size);
                hash.Add(KEY.Password,               KEY.Password);
                hash.Add(KEY.Persist_Security_Info,  KEY.Persist_Security_Info);
                hash.Add(KEY.Pooling,                KEY.Pooling);
                hash.Add(KEY.Replication,            KEY.Replication);
                hash.Add(KEY.TrustServerCertificate, KEY.TrustServerCertificate);
                hash.Add(KEY.TransactionBinding,     KEY.TransactionBinding);
                hash.Add(KEY.Type_System_Version,    KEY.Type_System_Version);
                hash.Add(KEY.User_ID,                KEY.User_ID);
                hash.Add(KEY.User_Instance,          KEY.User_Instance);
                hash.Add(KEY.Workstation_Id,         KEY.Workstation_Id);
                hash.Add(KEY.Connect_Retry_Count,    KEY.Connect_Retry_Count);
                hash.Add(KEY.Connect_Retry_Interval, KEY.Connect_Retry_Interval);

                hash.Add(SYNONYM.APP,                 KEY.Application_Name);
                hash.Add(SYNONYM.Async,               KEY.AsynchronousProcessing);
                hash.Add(SYNONYM.EXTENDED_PROPERTIES, KEY.AttachDBFilename);
                hash.Add(SYNONYM.INITIAL_FILE_NAME,   KEY.AttachDBFilename);
                hash.Add(SYNONYM.CONNECTION_TIMEOUT,  KEY.Connect_Timeout);
                hash.Add(SYNONYM.TIMEOUT,             KEY.Connect_Timeout);
                hash.Add(SYNONYM.LANGUAGE,            KEY.Current_Language);
                hash.Add(SYNONYM.ADDR,                KEY.Data_Source);
                hash.Add(SYNONYM.ADDRESS,             KEY.Data_Source);
                hash.Add(SYNONYM.NETWORK_ADDRESS,     KEY.Data_Source);
                hash.Add(SYNONYM.SERVER,              KEY.Data_Source);
                hash.Add(SYNONYM.DATABASE,            KEY.Initial_Catalog);
                hash.Add(SYNONYM.TRUSTED_CONNECTION,  KEY.Integrated_Security);
                hash.Add(SYNONYM.Connection_Lifetime, KEY.Load_Balance_Timeout);
                hash.Add(SYNONYM.NET,                 KEY.Network_Library);
                hash.Add(SYNONYM.NETWORK,             KEY.Network_Library);
                hash.Add(SYNONYM.Pwd,                 KEY.Password);
                hash.Add(SYNONYM.PERSISTSECURITYINFO, KEY.Persist_Security_Info);
                hash.Add(SYNONYM.UID,                 KEY.User_ID);
                hash.Add(SYNONYM.User,                KEY.User_ID);
                hash.Add(SYNONYM.WSID,                KEY.Workstation_Id);
                Debug.Assert(SqlConnectionStringBuilder.KeywordsCount + SynonymCount == hash.Count, "incorrect initial ParseSynonyms size");
                _sqlClientSynonyms = hash;
            }
            return hash;
        }

        internal string ObtainWorkstationId() {
            // If not supplied by the user, the default value is the MachineName
            // Note: In Longhorn you'll be able to rename a machine without
            // rebooting.  Therefore, don't cache this machine name.
            string result = WorkstationId;
            if (null == result) {
                // permission to obtain Environment.MachineName is Asserted
                // since permission to open the connection has been granted
                // the information is shared with the server, but not directly with the user
                result = ADP.MachineName();
                ValidateValueLength(result, TdsEnums.MAXLEN_HOSTNAME, KEY.Workstation_Id);
            }
            return result;
        }

        static internal Hashtable NetlibMapping() {
            const int NetLibCount = 8;

            Hashtable hash = _netlibMapping;
            if (null == hash) {
                hash = new Hashtable(NetLibCount);
                hash.Add(NETLIB.TCPIP,         TdsEnums.TCP);
                hash.Add(NETLIB.NamedPipes,    TdsEnums.NP);
                hash.Add(NETLIB.Multiprotocol, TdsEnums.RPC);
                hash.Add(NETLIB.BanyanVines,   TdsEnums.BV);
                hash.Add(NETLIB.AppleTalk,     TdsEnums.ADSP);
                hash.Add(NETLIB.IPXSPX,        TdsEnums.SPX);
                hash.Add(NETLIB.VIA,           TdsEnums.VIA);
                hash.Add(NETLIB.SharedMemory,  TdsEnums.LPC);
                Debug.Assert(NetLibCount == hash.Count, "incorrect initial NetlibMapping size");
                _netlibMapping = hash;
            }
            return hash;
        }

        static internal bool ValidProtocal (string protocal) {
            switch (protocal) {
                case TdsEnums.TCP  :
                case TdsEnums.NP   :
                case TdsEnums.VIA  :
                case TdsEnums.LPC  :
                    return true;

//              case TdsEnums.RPC  :  Invalid Protocals
//              case TdsEnums.BV   :
//              case TdsEnums.ADSP :
//              case TdsEnums.SPX  :
                default :
                    return false;
            }
        }

        private void ValidateValueLength (string value, int limit, string key) {
            if (limit < value.Length) {
                throw ADP.InvalidConnectionOptionValueLength(key, limit);
            }
        }

        internal static void VerifyLocalHostAndFixup(ref string host, bool enforceLocalHost, bool fixup) {
            if (ADP.IsEmpty(host)) {
                if (fixup) {
                    host = ".";
                }
            }
            else if (!CompareHostName(ref host, @".", fixup) &&
                     !CompareHostName(ref host, @"(local)", fixup)) {
                // Fix-up completed in CompareHostName if return value true.
                string name = ADP.GetComputerNameDnsFullyQualified(); // i.e, machine.location.corp.company.com
                if (!CompareHostName(ref host, name, fixup)) {
                    int separatorPos = name.IndexOf('.'); // to compare just 'machine' part
                    if ((separatorPos <= 0) || !CompareHostName(ref host, name.Substring(0, separatorPos), fixup)) {
                        if (enforceLocalHost) {
                            throw ADP.InvalidConnectionOptionValue(KEY.AttachDBFilename);
                        }
                    }
                }
            }
        }
        
        internal System.Data.SqlClient.ApplicationIntent ConvertValueToApplicationIntent() {
            object value = base.Parsetable[KEY.ApplicationIntent];
            if (value == null) {
                return DEFAULT.ApplicationIntent;
            }

            // when wrong value is used in the connection string provided to SqlConnection.ConnectionString or c-tor,
            // wrap Format and Overflow exceptions with Argument one, to be consistent with rest of the keyword types (like int and bool)
            try {
                return DbConnectionStringBuilderUtil.ConvertToApplicationIntent(KEY.ApplicationIntent, value);
            }
            catch (FormatException e) {
                throw ADP.InvalidConnectionOptionValue(KEY.ApplicationIntent, e);
            }
            catch (OverflowException e) {
                throw ADP.InvalidConnectionOptionValue(KEY.ApplicationIntent, e);
            }
            // ArgumentException and other types are raised as is (no wrapping)
        }
    }
}