Share a derived cryp key between two instances of the same exe?

[Morthawt]

I am looking for a secure method of providing a single derived key to two copies of the same program. When you launch the program, the act of launching with no commandline params causes it to launch another exe with different purposes. If I generate the derived key on the first exe, is there a way I can securely pass this key on to the newly spawned process? I thought about including the password but that remains on the commandline of the running program that any good third-party task manager can see. So I need both processes to be able to encrypt and decrypt using the same key, without having to enter the password separately for each process.

Can you think of any way of achieving this?

[JohnOne]

There are many examples of inter-process communication.

Any sort of search will expose them.

Edited October 4, 2013 by JohnOne

[Morthawt]

I already am using inter-process communication. I could communicate the password if I wanted too but that is not secure because the password could be easily intercepted. I need a secure method to pass an encryption derived key from one copy of the running exe to a secondary copy of the same exe. Otherwise I would have to do without certain data being encrypted by the first and decrypted by the second program.

[JohnOne]

"intercepted" by what, these processes are running on the same machine?

[Morthawt]

Same machine yes. One has admin rights, the other has normal rights. I need to send an exe and parameter to the non-admin process so that it runs it. However right now the ini for that is plain text. It is not a big deal because if something malicious is running on your computer that can interact with a simple file, it would be capable of running things its self. But I would like to protect the data so that the only things it will execute come from the parent process that spawned it via encryption and decryption.

[BrewManNH]

IPC doesn't need a file to communicate, you could use something like WM_COPYDATA to send/receive information from another script, or use Trancexx's mailslot function.

[Morthawt]

I see nothing useful in the helpfile about WM_COPYDATA. Seems like it is some kind of message code what ever that is. Do you have any context or example of however WM_COPYDATA would be useful to send or receive information back and forth?

[BrewManNH]

This uses a function that sends data to the SciTE window, but should be adaptable to other programs. 

'?do=embed' frameborder='0' data-embedContent>>

This is another example of doing something similar.

'?do=embed' frameborder='0' data-embedContent>>

This Trancexx's mailslot function that does the same thing as well.

 

As long as the receiving program understands what you're sending it should work. Or

[Morthawt]

Thanks, I will have a look into this.