Securing a password in source code?

Question

I have a password in my code which is needed to connect to a sftp server. Whats the best way to \"obfuscate\" or hide it in the code?

Thanks

Answer 1

Best way is don't!

Failing that:

Encrypting Configuration File Sections Using Protected Configuration

Answer 2

There's not much you can do against someone who really wants your password. However, if this isn't a public app (intranet? in-house app or something) you could simply encrypt it using a symmetric encryption algorithm, or do something like base 64 encoding it. You could also run an obfuscator over your code to make it less obvious that there is a password in there somewhere.

Do you have another option? Raw SFTP access is kinda dangerous, maybe you can create some sort of proxy service in between, which only allows the specific actions your app requires. Storing the password for that service in your code is a not as risky as storing your SFTP password in your code.

Answer 3

You could use something like SLP Code Protector to block reverse engineering of your assemblies. Still, I agree with everyone else, it's not the best idea.

Answer 4

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).

Answer 5

Don't bother.
Anything you can do, your attacker can trivially undo.

If it only needs to run on a single machine, however, you can use the ProtectedData class, which will protect it securely against anyone not on that machine and/or user.

In general, the only remotely secure way to do this is to store the key in a separate, secure, location.
For example, you can encrypt it using a (non-MD5) hash of a password, then require the user to enter the password so that you can get the hash. (The hash and password themselves would not be stored anywhere; you should make a separate hash to verify the password)

Answer 6

Encrypt it with something strong like AES, but as implied by SLaks, your attacker can reverse engineer your code and work out the encryption method and key. All you are doing is adding a layer which keeps script kiddies and a certain level of attacker out. Someone who really wants to work it out, can do. They could also run your program and watch what password is sent.