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How I validate UNC Connection

Dani_S 3,786 Reputation points
2024-07-09T10:29:56.7866667+00:00

Hi,

When I supply bad domain i get success instead of failure ?, why ?

   public static bool IsUncConnectionValid(string directoryName, string uncDomain, string userName, string password)

   {   
   UncHelper uncHelper = null;

   try

   {  

       if(string.IsNullOrEmpty(directoryName) || string.IsNullOrEmpty(uncDomain) || string.IsNullOrEmpty(userName) || string.IsNullOrEmpty(password))

       {

           return false;

       }

       //if (!(Uri.CheckHostName(uncDomain) != UriHostNameType.Unknown))

       //{

       //    return false;

       //}

       uncHelper = new UncHelper(directoryName, userName, password, uncDomain);

       uint uncResult = uncHelper.Connect();

       if (!uncHelper.IsConnected)

       {

           return false;

       }

   }

   catch (Exception ex)

   {

       _logger.Error("UNC connection is not valid", ex);

   }

   finally

   {   

       if (uncHelper != null)

       { 

           uncHelper.Dispose();

       }


       

   }

   return true;
   }

public class UncHelper :  IDisposable

{

cpp
private static AppLogManager _logger = AppLogManager.GetLogger<UncHelper>();

public bool IsConnected { get; set;}

private string _userName = "";

private string _password = "";

private string _uncPath = "";

private string _domain = "";



[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]

internal struct USE_INFO_2

{

    internal LPWSTR ui2_local;

    internal LPWSTR ui2_remote;

    internal LPWSTR ui2_password;

    internal DWORD ui2_status;

    internal DWORD ui2_asg_type;

    internal DWORD ui2_refcount;

    internal DWORD ui2_usecount;

    internal LPWSTR ui2_username;

    internal LPWSTR ui2_domainname;

}

[DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]

internal static extern NET_API_STATUS NetUseAdd(LPWSTR UncServerName, DWORD Level, ref USE_INFO_2 Buf, out DWORD ParmError);

[DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]

internal static extern NET_API_STATUS NetUseDel(LPWSTR UncServerName, LPWSTR UseName, DWORD ForceCond);

[DllImport("advapi32.dll", SetLastError = true, BestFitMapping = false, ThrowOnUnmappableChar = true)]

[return: MarshalAs(UnmanagedType.Bool)]

public static extern bool LogonUser(

  [MarshalAs(UnmanagedType.LPStr)] string pszUserName,

  [MarshalAs(UnmanagedType.LPStr)] string pszDomain,

  [MarshalAs(UnmanagedType.LPStr)] string pszPassword,

  int dwLogonType,

  int dwLogonProvider,

  ref IntPtr phToken);

public UncHelper(string uncPath, string userName = "", string password = "", string domain = "")

{

    try

    {

        _uncPath = uncPath;

        _userName = userName;

        _password = password;

         _domain = domain;

    }

    catch (Exception ex)

    {

       _logger.Error("UncHelper has crashed: ", ex);

    }

}

/// <summary>

/// Connect to unc path by domain, user and pwaaword

/// </summary>

/// <returns>The function return the results of connection(succcess 0 or 1219) other vaue it false</returns>

public uint Connect()

{

    uint uiRes;

    try

    {

        USE_INFO_2 useinfo = new USE_INFO_2();

        useinfo.ui2_remote = _uncPath;

        useinfo.ui2_username = _userName;

        useinfo.ui2_domainname = _domain;

        useinfo.ui2_password = _password;

        useinfo.ui2_asg_type = 0;

        useinfo.ui2_usecount = 1;//100

        uint paramErrorIndex;

        uiRes = NetUseAdd(null, 2, ref useinfo, out paramErrorIndex);

         if (uiRes == (uint)0 )//|| uiRes == (uint)1219)

        {

            IsConnected = true;

        }

        else

        {

            IsConnected = false;

        }

    }

    catch (Exception ex)

    {

        _logger.Error("Unc helper has crashed: ", ex);

        uiRes = 1;

        IsConnected = false;

    }

    return uiRes;

}



// Delete the unc conection

private int NetUseDelete()

{

    int nRes;

    try

    {

        nRes = (int)NetUseDel(null, _uncPath, 2);

    }

    catch (Exception ex)

    {

        nRes = Marshal.GetLastWin32Error();

        _logger.Error($"UncHelper.NetUseDelete   Error: {nRes.ToString()} Error description:{UncErrorCode.GetSystemMessage(nRes)} has crashed: ", ex);

    }

    return nRes;

}



public void Dispose()

{

    try

    {

        Dispose(true);

     }

    catch (Exception ex)

    {

        _logger.Error("UncHelper.Dispose() has Crashed: ", ex);

    }

    finally

    {

        GC.SuppressFinalize(this);

    }

}

 public virtual void Dispose(bool disposing)

{

    try

    { 

            NetUseDelete();

            IsConnected = false;


       

     }

    catch (Exception ex)

    {

        _logger.Error("UncHelper.Dispose(bool disposing) has Crashed: ", ex);

        IsConnected = false;

    }

}


 

~UncHelper()

{

    Dispose(false);

}
}

Thanks,

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1 answer

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  1. Jiale Xue - MSFT 46,556 Reputation points Microsoft Vendor
    2024-07-10T04:25:43.8466667+00:00

    Hi @Dani_S , Welcome to Microsoft Q&A, Proper Exception Handling: Ensure exception handling provides detailed information. Logging Enhancements: Improve logging for better traceability. Resource Management: Ensure resources are properly managed and disposed.

    public static bool IsUncConnectionValid(string directoryName, string uncDomain, string userName, string password)
{   
    UncHelper uncHelper = null;

    try
    {  
        if (string.IsNullOrEmpty(directoryName) || string.IsNullOrEmpty(uncDomain) || string.IsNullOrEmpty(userName) || string.IsNullOrEmpty(password))
        {
            return false;
        }

        uncHelper = new UncHelper(directoryName, userName, password, uncDomain);

        uint uncResult = uncHelper.Connect();
        if (!uncHelper.IsConnected)
        {
            return false;
        }
    }
    catch (Exception ex)
    {
        _logger.Error("UNC connection is not valid", ex);
        return false;
    }
    finally
    {   
        uncHelper?.Dispose();
    }

    return true;
}

public class UncHelper : IDisposable
{
    private static AppLogManager _logger = AppLogManager.GetLogger<UncHelper>();

    public bool IsConnected { get; private set; }

    private readonly string _userName;
    private readonly string _password;
    private readonly string _uncPath;
    private readonly string _domain;

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    internal struct USE_INFO_2
    {
        internal LPWSTR ui2_local;
        internal LPWSTR ui2_remote;
        internal LPWSTR ui2_password;
        internal DWORD ui2_status;
        internal DWORD ui2_asg_type;
        internal DWORD ui2_refcount;
        internal DWORD ui2_usecount;
        internal LPWSTR ui2_username;
        internal LPWSTR ui2_domainname;
    }

    [DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern NET_API_STATUS NetUseAdd(LPWSTR UncServerName, DWORD Level, ref USE_INFO_2 Buf, out DWORD ParmError);

    [DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern NET_API_STATUS NetUseDel(LPWSTR UncServerName, LPWSTR UseName, DWORD ForceCond);

    [DllImport("advapi32.dll", SetLastError = true, BestFitMapping = false, ThrowOnUnmappableChar = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool LogonUser(
        [MarshalAs(UnmanagedType.LPStr)] string pszUserName,
        [MarshalAs(UnmanagedType.LPStr)] string pszDomain,
        [MarshalAs(UnmanagedType.LPStr)] string pszPassword,
        int dwLogonType,
        int dwLogonProvider,
        ref IntPtr phToken);

    public UncHelper(string uncPath, string userName = "", string password = "", string domain = "")
    {
        _uncPath = uncPath;
        _userName = userName;
        _password = password;
        _domain = domain;
    }

    /// <summary>
    /// Connect to UNC path by domain, user, and password
    /// </summary>
    /// <returns>The function returns the result of the connection (success 0 or 1219), otherwise it returns false</returns>
    public uint Connect()
    {
        uint uiRes;
        try
        {
            USE_INFO_2 useinfo = new USE_INFO_2
            {
                ui2_remote = _uncPath,
                ui2_username = _userName,
                ui2_domainname = _domain,
                ui2_password = _password,
                ui2_asg_type = 0,
                ui2_usecount = 1
            };
            uint paramErrorIndex;
            uiRes = NetUseAdd(null, 2, ref useinfo, out paramErrorIndex);
            IsConnected = uiRes == 0;
        }
        catch (Exception ex)
        {
            _logger.Error("UncHelper has crashed: ", ex);
            uiRes = 1;
            IsConnected = false;
        }
        return uiRes;
    }

    /// <summary>
    /// Delete the UNC connection
    /// </summary>
    private int NetUseDelete()
    {
        int nRes;
        try
        {
            nRes = (int)NetUseDel(null, _uncPath, 2);
        }
        catch (Exception ex)
        {
            nRes = Marshal.GetLastWin32Error();
            _logger.Error($"UncHelper.NetUseDelete Error: {nRes} Error description: {UncErrorCode.GetSystemMessage(nRes)} has crashed: ", ex);
        }
        return nRes;
    }

    public void Dispose()
    {
        try
        {
            Dispose(true);
        }
        catch (Exception ex)
        {
            _logger.Error("UncHelper.Dispose() has Crashed: ", ex);
        }
        finally
        {
            GC.SuppressFinalize(this);
        }
    }

    protected virtual void Dispose(bool disposing)
    {
        try
        {
            NetUseDelete();
            IsConnected = false;
        }
        catch (Exception ex)
        {
            _logger.Error("UncHelper.Dispose(bool disposing) has Crashed: ", ex);
            IsConnected = false;
        }
    }

    ~UncHelper()
    {
        Dispose(false);
    }
}

    Best Regards,

    Jiale

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