How can I hide my password in my C# Connection string?

Question

I have the following connection string:

Data Source=Paul-HP\MYDB;Initial Catalog=MyMSDBSQL;Persist Security Info=True;User ID=sa;Password=password

(.net webservice) This can obviously be viewed simply by opening up the app.config file and looking at the configuration settings.

What I need is a way to make a hacker unable to see the password. But at the same time, leave it customisable so that it can be changed when deployed on another database.

Answer 1

You have a number of options - the ones that I am aware of (in order of preference):

1. Use integrated (SSPI) security where you don't need to include a password in the config file
2. Encrypt the connection string (see Encrypting Configuration Information Using Protected Configuration)
3. Store the username and password separately and use string formatting to construct the full connection string,

So for example the connection string might look like this:

Data Source=Paul-HP\MYDB;Initial Catalog=MyMSDBSQL;Persist Security Info=True;User ID={0};Password={1}

I'd go for option 1, if thats not possible then option 2. I've mentioned option 3 for completeness.

Have you read Protecting Connection Information (ADO.NET)?

Answer 2

First of all, don't use the "SA" account. It leaves your database wide open if someone gets the password. Use a custom account which only is allowed to do CRUD operations on a specific database.

The only way to get web.config is to hack your server. And if they have done that, you're screwed anyway.

Answer 3

Probably easiest to encrypt the connection strings within the web.config or app.config

See How To: Encrypt Configuration Sections in ASP.NET 2.0 Using DPAPI

Answer 4

You could encrypt the connection string - then when you access the connection string, decrypt it. This isn't fool proof though as you're then stuck with the problem of where to store the key to decrypt the connection string!

Answer 5

I Suggest en/decrypting the connection string. Therefore the connection string has to be set manually.

For encryption take a look at: http://dotnet-snippets.de/dns/encrypt-and-decrypt-strings-SID205.aspx

For Custom Settings take a look at: http://msdn.microsoft.com/en-us/library/8eyb2ct1.aspx

Replace the Encrypted with the correct one at runtime:

  public static void SetAppSettingValue(string Key, string Value)
   {

   System.Configuration.Configuration config == ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
// Add an Application Setting.

 config.AppSettings.Settings[Key].Value = Value;

  // Save the changes in App.config file.

   config.Save(ConfigurationSaveMode.Modified);

    ConfigurationManager.RefreshSection("appSettings");
  }