Category: Web

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

Encrypting .NET Config Files in a Shared Development Environment

Jared Meredith

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:

Certificates, Web, Wordpress

Redirect All HTTP to HTTPS in WordPress with .htaccess

Jared Meredith

I recently had a request from a client to transfer all web traffic on some WordPress site (www or no www) to all be forced over HTTPS. And with all of the up and coming security issues that stem from HTTP-only traffic it is a must. Why you ask? Well, unless you are explicitly doing this already users may able to browse and intercept traffic from your site with no encryption. If you have a SSL certificate but have not done this to your WordPress site then please do so!

Edit your .htaccess file and append this somewhere at the bottom (and change your website URL to the URL that is associated with the SSL certificate):

RewriteCond %{HTTPS} !^on$
RewriteRule (.*) https://www.example.com/$1 [R,L]

After this you should see all browsing of HTTP to your site to be automatically redirected to HTTPS. Note: in some cases you will have to update all the links and content of your site to use links that are HTTPS also. There are useful plugins out there that can assist with doing a bulk conversion of this. Otherwise you users will not get the padlock icon on the page (or even cases where the page will not render entirely). Happy securing! Hope this helps, questions are always welcome.

HTML, JavaScript, Troubleshooting, Web

Check For Internet Explorer (IE) Compatibility Mode

Jared Meredith

Create a JavaScript file called iecheck.js and paste the following in the snippet:

function trueOrFalse() {
 return true;
}

function IeVersion() {
 // Set defaults
 var value = {
 IsIE: false,
 TrueVersion: 0,
 ActingVersion: 0,
 CompatibilityMode: false
 };

// Try to find the Trident version number
 var trident = navigator.userAgent.match(/Trident\/(\d+)/);
 if (trident) {
 value.IsIE = true;
 //Convert from the Trident version number to the IE version number
 value.TrueVersion = parseInt(trident[1], 10) + 4;
 }

// Try to find the MSIE number
 var msie = navigator.userAgent.match(/MSIE (\d+)/);
 if (msie) {
 value.IsIE = true;
 // Find the IE version number from the user agent string
 value.ActingVersion = parseInt(msie[1]);
 } else {
 // Must be IE 11 in "edge" mode
 value.ActingVersion = value.TrueVersion;
 }

// If we have both a Trident and MSIE version number, see if they're different
 if (value.IsIE &amp;&amp; value.TrueVersion &gt; 0 &amp;&amp; value.ActingVersion &gt; 0) {
 // In compatibility mode if the trident number doesn't match up with the MSIE number
 value.CompatibilityMode = value.TrueVersion != value.ActingVersion;
 }
 return value;
}

Once you have the JavaScript file then open your page where you are going to check for compatibility for and place a reference to the iecheck.js file in the head tag. 

<script src="iecheck.js" type="text/javascript"></script>

After that you have multiple options on how to use the script.

For example, if you would like to check for compatibility and redirect then paste the following snippet inside of the body of your html:

<script type="text/javascript">
// 0 = not in compatibility view, 1 = in compatibility view
var ie = IeVersion();
if ((ie.CompatibilityMode == "0") && (ie.IsIE == "1")) {
window.location = "redirecttosomewhere.html"
}
else {
// do nothing, is in compatibility view
}
</script>

Another example would be if you just want to see the results on the page; just place this snippet inside of the body of your html:


<script type="text/javascript">
// <![CDATA[
var ie = IeVersion();
document.write("IsIE: " + ie.IsIE + "</br>");
document.write("TrueVersion: " + ie.TrueVersion + "</br>");
document.write("ActingVersion: " + ie.ActingVersion + "</br>");
document.write("CompatibilityMode: " + ie.CompatibilityMode + "</br>");
// ]]>
</script>

Hope this helps. Questions are always welcome.

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

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

Jared Meredith

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.