.Net, C#, HTML, MVC, Programming

.Net MVC – Display a user’s Full Name instead of User.Identity.Name (DOMAIN\USERNAME)

I had a request come in on a MVC web app to display a user’s full name instead of their domain network username. The app was using something like:

<p>Hello, @User.Identity.Name</p>

which displayed like:

Hello, MYDOMAIN\myusername!

So to update this on the MVC web app (and avoid a dedicated helper) here is what I did:

In your _ViewImports.cshtml include:

@using System.DirectoryServices.AccountManagement

Then, in your _Layouts.cshtml place this

@{ 
    var context = new PrincipalContext(ContextType.Domain);
    var principal = UserPrincipal.FindByIdentity(context, User.Identity.Name);
}

The above will render the user’s currently logged in claims and return their claim attributes as needed. You can use others as you have them also for other purposes, too.

Now, in your _Layouts.cshtml you can switch your original hello item to:

<p>Hello, @principal.GivenName @principal.Surname!</p>

You should get a friendlier format like:

Hello, Jared Meredith!

Hope that helps. Questions or comments are always welcome!

.Net, IIS, Programming, Troubleshooting, Visual Studio, Web, XML

Troubleshooting “Could not load file or assembly ‘DotNetOpenAuth.Core, Version=4.1.0.0, Culture=neutral, PublicKeyToken=2780ccd10d57b246’ or one of its dependencies”

The Issue:

After I had updated my .Net Core on my developer machine to a newer version I went to debug a web application I had and received this error:

Could not load file or assembly 'DotNetOpenAuth.Core, Version=4.1.0.0, Culture=neutral, PublicKeyToken=2780ccd10d57b246' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

The Problem:

Here is what I had in my config prior to the update install:

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="DotNetOpenAuth.Core" publicKeyToken="2780ccd10d57b246" />
        <bindingRedirect oldVersion="1.0.0.0-4.0.0.0" newVersion="4.1.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="DotNetOpenAuth.AspNet" publicKeyToken="2780ccd10d57b246" />
        <bindingRedirect oldVersion="1.0.0.0-4.0.0.0" newVersion="4.1.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" />
        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

I had outdated references in my config file.

The Solution:

Ensure your references get updated after you update your development environment.

Here is what I updated to:

  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="DotNetOpenAuth.AspNet" publicKeyToken="2780ccd10d57b246" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.3.0.0" newVersion="4.3.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="DotNetOpenAuth.Core" publicKeyToken="2780ccd10d57b246" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.3.0.0" newVersion="4.3.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" />
        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

Hope that helps. Questions are always welcome.

.Net, IIS, Security, Sitecore, Web, XML

Encrypting .NET Config Files in a Shared Development Environment

This page will attempt to describe how to encrypt sensitive information contained in .NET config files using the RSA Key Container, as well as how to export/import the key from that container so that other developers may use the same key to work on the same project.

Helpful Tips: The aspnet_regiis.exe utility must be run as a administrator, otherwise you may receive “duplicate object” errors. In addition, you will want to run Visual Studio as an administrator to ensure the program has access to the RSA Key Container store.

Creating a Custom RSA Key Container

In this part we will create an RSA key container by using aspnet_regiis.exe with the -pc option. This identifies the RSA key container as a user-level key container. RSA key containers must be identified as either user-level (by using the -pku option) or machine-level (by not using the -pku option). For more information about machine-level and user-level RSA key containers, see Understanding Machine-Level and User-Level RSA Key Containers.

In this example the following command will create an RSA key container named SampleKeys that is a machine-level key container and is exportable:

cd \WINDOWS\Microsoft.Net\Framework\v4.0.*
aspnet_regiis -pc "SampleKeys"–exp

Adding your provider to the web.config

The following example shows the configProtectedData section of a Web.config file. The section specifies an RsaProtectedConfigurationProvider that uses a machine-level RSA key container named SampleKeys.

<configProtectedData>
   <providers>
    <add keyContainerName="SampleKeys" useMachineContainer="true" description="RsaCryptoServiceProvider" name="SampleKeys" type="System.Configuration.RsaProtectedConfigurationProvider,System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
   </providers>
</configProtectedData>

Importing and Exporting the Key Container

In order for another developer to run your project (encrypted by your key) you will need to  export a key to be used by another developer:

aspnet_regiis -px "SampleKeys" "C:\keys.xml" -pri

Once you pass this along to another user to use then import with the following command:

aspnet_regiis -pi "SampleKeys" "C:\keys.xml"

If this is a machine level container, the code should now run without the need to assign permissions. However, if it’s a user container (i.e. your app pool is ran by a specific user or service account), additional permissions may need to be assigned:

aspnet_regiis -pa "SampleKeys" "NT AUTHORITY\NETWORK SERVICE"
aspnet_regiis -pa "SampleKeys" "[impersonation account]"

To use the default RsaProtectedConfigurationProvider specified in the machine configuration, you must first grant the application’s Windows identity access to the machine key container named NetFrameworkConfigurationKey, which is the key container specified for the default provider. For example, the following command grants the NETWORK SERVICE account access to the RSA key container used by the default RsaProtectedConfigurationProvider:

aspnet_regiis -pa "NetFrameworkConfigurationKey" "NT AUTHORITY\NETWORK SERVICE"

Encrypting and Decrypting Config Sections

.NET allows specific sections of a config file to be encrypted, so non-sensitive information can still be accessed. To encrypt a section:

aspnet_regiis -pef [section] [path] -prov [provider]

Where [section] is the name of the config section, relative to the configuration tag. [path] is the relative path to the directory containing the web.config file. For example, the following commands will encrypt the appSettings section as well as the impersonation credentials:

cd C:\SolutionFolder
aspnet_regiis -pef appSettings ProjectFolder -prov SampleKeys
aspnet_regiis -pef system.web/identity ProjectFolder -prov SampleKeys

To decrypt the appSettings section:

aspnet_regiis -pdf appSettings ProjectFolder

Partially Encrypting a Section

It may be necessary to only encrypt part of a section in a web.config file. For example, if the appSettings section contains multiple, non-sensitive keys and only a subset contain sensitive information. To encrypt only a few keys, a second appSettings section must be created and the new keys moved into it. The keys are accessed exactly the same way in the code, so no coding changes are needed.

First, register a new section name called secureAppSettings by placing the following XML under the configuration node:

<configSections>
<section name="secureAppSettings" type="System.Configuration.NameValueSectionHandler, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
</configSections>

Next, create a new section called secureAppSettings and move the sensitive keys under it:

<secureAppSettings>
    <add key="Username" value="XXX" />
    <add key="Password" value="XXX" />
</secureAppSettings>
<appSettings>
    <add key="NotSensitive" value="XXX" />
</appSettings>

Finally, the new secure section can be encrypted and decrypted independently of the existing appSettings section:

aspnet_regiis -pef secureAppSettings ProjectFolder -prov ProviderName

App.config

This Microsoft utility was designed for web.config files. It will not find app.config files for other project types. To encrypt these config files, just rename them to web.config prior to encrypting, then rename back afterwards.

Other Helpful Links:

.Net, Troubleshooting, Visual Studio

How To Fix “no exports were found that match the constraint” In Visual Studio

So, you have that “no exports were found that match the constraint” message in Visual Studio, eh?

The first thing I would try doing on the affected version of visual studio is to go to programs and features, select the version and pick change: VSbugss3

When that loads let it repair. Once it does see if that resolves the issue.

VSbugss2

If it does not a more manual method that is to delete all of the contents of the ComponentModelCache folder from the following area (of which VS version is affected):

Put your username in the path:

VS 2012:

C:\Users\username\AppData\Local\Microsoft\VisualStudio\11.0\ComponentModelCache

VS 2013:

C:\Users\username\AppData\Local\Microsoft\VisualStudio\12.0\ComponentModelCache

VS 2015:

C:\Users\username\AppData\Local\Microsoft\VisualStudio\14.0\ComponentModelCache

It should look something like:

VSbugss1

If that fails there is also a patch that they released in response: https://www.microsoft.com/en-in/download/confirmation.aspx?id=36020#

.Net, C#, HTML, Office, Programming, VB, Web

Exporting asp:GridView Results To A Microsoft Excel Spreadsheet in VB/C#

I have received this requirement on more than one occasion so I thought it would benefit others if I posted these snippets. So here we go, let’s export a gridview as an excel file.

For starters let’s add a couple controls to the front-end aspx page:

 
<asp:Button ID="btnExport" runat="server" Text="Export Results To Excel" /> &amp;nbsp;&amp;nbsp;<br /><br />

<asp:GridView ID="grdSearch" runat="server" CellPadding="3" BackColor="White" BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px">
 <FooterStyle BackColor="White" ForeColor="#000066" />
 <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
 <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" />
 <RowStyle ForeColor="#000066" />
 <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
 <SortedAscendingCellStyle BackColor="#F1F1F1" />
 <SortedAscendingHeaderStyle BackColor="#007DBB" />
 <SortedDescendingCellStyle BackColor="#CAC9C9" />
 <SortedDescendingHeaderStyle BackColor="#00547E" />
 </asp:GridView>

I’m going to assume you know how to wire in your gridview to return results.

With that assumption in place here is the click event that performs the export (in VB):

You will need: Imports System.IO

Protected Sub btnExport_Click(sender As Object, e As EventArgs) Handles btnExport.Click
        Try
            Response.Clear()
            Response.Buffer = True
            Response.ClearContent()
            Response.ClearHeaders()
            Response.Charset = ""
            Dim FileName As String = "filename" + DateTime.Now + ".xls"
            Dim strwritter As New StringWriter()
            Dim htmltextwrtter As New HtmlTextWriter(strwritter)
            Response.Cache.SetCacheability(HttpCacheability.NoCache)
            Response.ContentType = "application/vnd.ms-excel"
            Response.AddHeader("Content-Disposition", Convert.ToString("attachment;filename=") &amp; FileName)
            grdSearch.GridLines = GridLines.Both
            grdSearch.HeaderStyle.Font.Bold = True
            grdSearch.RenderControl(htmltextwrtter)
            Response.Write(strwritter.ToString())
            Response.[End]()
        Catch ex As Exception
            ' Do something important here if you expect strange results
        End Try
    End Sub

Now in C#:

You will need: using System.IO;

try {
	Response.Clear();
	Response.Buffer = true;
	Response.ClearContent();
	Response.ClearHeaders();
	Response.Charset = "";
	string FileName = "filename" + DateTime.Now + ".xls";
	StringWriter strwritter = new StringWriter();
	HtmlTextWriter htmltextwrtter = new HtmlTextWriter(strwritter);
	Response.Cache.SetCacheability(HttpCacheability.NoCache);
	Response.ContentType = "application/vnd.ms-excel";
	Response.AddHeader("Content-Disposition", Convert.ToString("attachment;filename=") + FileName);
	grdSearch.GridLines = GridLines.Both;
	grdSearch.HeaderStyle.Font.Bold = true;
	grdSearch.RenderControl(htmltextwrtter);
	Response.Write(strwritter.ToString());
	Response.End();
} catch (Exception ex) {
	// Do something important here if you expect strange results
}

I realize you may not need some of the formatting that I used in this example so remove the Gridview related property assignments in the export snippet. Also, depending on how you format your gridview on the aspx page will dictate some of the formatting you have on the spreadsheet. Hope this helps, questions are welcome.