I need to inject a custom, unique, static string into my .NET based EXE. For all intents and purposes, assume that this is my Private key of a PKI.
I have a few ideas on how I'll approach protecting the Private key within the C# source code, my question is how do I take my .CS files and create an executable based off it?
The simplest thing to do would be to call csc, the C# compiler.
For example: (from the msdn page linked above)
csc /out:My.exe File.cs
Would produce an executable called My.exe from an input file called File.cs.
If the executable you want to compile is fairly complex, it might prove simpler to keep that pre-compiled and only compile a DLL that it calls a method in at runtime to obtain the private key, as that would be a simpler command line to pass to csc.
Take a look at CSharpCodeProvider, which can essentially be used take a string containing source code and compile it to an assembly (EXE or DLL), or if you require, an in memory assembly.
You can also use the codeDOM for the code generation side of things. Take a look at 'Generating Source Code and Compiling a Program from a CodeDOM Graph' as a starting point.