Securing a password in source code?

Don't store you password in your source code, store it in a protected section within you App.Config (or Web.Config).

See Encrypting Configuration File Sections Using Protected Configuration section in this Microsoft Doc

This works by encrypting the encryption keys using built-in Windows stuff, locked to the MAC address and various other undocumented things.

This will even work if you are using more than one server:

... if you are planning to use the same encrypted configuration file on multiple servers, such as a Web farm, only the RsaProtectedConfigurationProvider enables you to export the encryption keys used to encrypt the data and import them on another server.

Using this, if someone wanted to get your password, they would have to first break the Windows security on your server (not impossible, but harder than looking into your IL for the password by far).

I actually consider using the "protected sections" feature in App.Config or Web.Config to be LESS secure than storing the password in your code.

Anyone with server access can decrypt that section of the config just as quick as you encrypted it by running the decrypt command described in the article everyone keeps quoting:

aspnet_regiis -pd "connectionStrings" -app "/SampleApplication"

https://msdn.microsoft.com/en-us/library/zhhddkxy.aspx#Anchor_1

So this feature of ASP.Net only adds security in the case that a hacker somehow had access to your web.config but not your entire server (happened in 2010 as @djteller mentioned in the oracle padding attack comment). But if they do have server access, you're exposed in one cmd call. They don't even have to install ildasm.exe.

However, storing actual passwords in your code is a maintenance nightmare. So one thing I've seen done is storing an encrypted password in your web.config and storing the encryption key in your code. This accomplishes the goal of hiding passwords from casual browsing while still being maintainable.

In this case a hacker has to at least decompile your code, find your key, and then figure out what encryption algorithm you're using. Not impossible, but certainly harder than running "aspnet_regiis -pd...".

Meanwhile I am also looking for better answers to this six year old question...