2009-03-24 16:37:38 Loading Secure files
Tim Powell (UNITED STATES)
Message: 71467
Hello All,
I was just wondering if there was a way to load a file from within a program. For example,
suppose I have an encrypted file called "test.ece". I can decrypt this file to another file with
another program. The decrypted file is now present in the file system, which I don't want.
Right now I'm just searching for ideas to see if anyone has handled this before. Basically I
think I want to run one program that will decrypt and load another program to memory, and
immediately start executing the other program.
-Tim
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2009-03-24 18:09:46 Re: Loading Secure files
Mike Frysinger (UNITED STATES)
Message: 71470
reading/writing encrypted files as plain data is easy -- use an encryption library like openssl
if you want your executable to be encrypted, then use an encrypted filesystem. or decrypt the file to a RAM backed filesystem (like ramfs) and execute it from there.
in either case, if the encrypted data is placed into external memory, people can sniff the bus traffic and access the enencrypted data ...
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2009-03-24 18:50:22 Re: Loading Secure files
Robin Getz (UNITED STATES)
Message: 71472
Tim:
The answer to your question really depends on the level of attacker you want to keep out. You can do all kinds of crazy things - the part has internal memory - put the application there - if the application is too big - you can split it up with overlays (which makes it even more complex).
But if you are just trying to keep out some hackers - you will be better off as Mike said - just put everything in external memory, and bury the memory traces on inside layers - using BGAs - so no one can probe them.
-Robin