.net - How to securely store a connection string in a WinForms application?

Question

I need to know what is the common way to store a SQL server connection string for a WinForms application in VB.NET.

I have searched the net and I found answers to each of the following questions:

• How do I read app.config values
• How to do it in ASP.NET _{Reference: this SO question.}
• How do I store a connection string (unencrypted thus unsafe)

I would like a full answer on how to store a connection string in VB.NET in app.config (or settings.settings if it's better) securely.

Is app.config the right place? Can I encrypt these values?

Answer 1

Simply , the .net framework allows you to do that , see

http://msdn.microsoft.com/en-us/library/89211k9b(v=vs.80).aspx

Relevant information:

This goes into the machine.config file:

<configProtectedData defaultProvider="RsaProtectedConfigurationProvider">
  <providers>
    <add name="RsaProtectedConfigurationProvider" 
      type="System.Configuration.RsaProtectedConfigurationProvider, ... />
    <add name="DataProtectionConfigurationProvider" 
      type="System.Configuration.DpapiProtectedConfigurationProvider, ... />
  </providers>
</configProtectedData>

And this is the application code:

Shared Sub ToggleConfigEncryption(ByVal exeConfigName As String)
    ' Takes the executable file name without the
    ' .config extension.
    Try
        ' Open the configuration file and retrieve 
        ' the connectionStrings section.
        Dim config As Configuration = ConfigurationManager. _
            OpenExeConfiguration(exeConfigName)

        Dim section As ConnectionStringsSection = DirectCast( _
            config.GetSection("connectionStrings"), _
            ConnectionStringsSection)

        If section.SectionInformation.IsProtected Then
            ' Remove encryption.
            section.SectionInformation.UnprotectSection()
        Else
            ' Encrypt the section.
            section.SectionInformation.ProtectSection( _
              "DataProtectionConfigurationProvider") 'this is an entry in machine.config
        End If

        ' Save the current configuration.
        config.Save()

        Console.WriteLine("Protected={0}", _
        section.SectionInformation.IsProtected)

    Catch ex As Exception
        Console.WriteLine(ex.Message)
    End Try
End Sub

UPDATE 1

Thanks @wpcoder, for this link