Monthly Archives: September 2010

Raw binary protocol analysis with Wireshark

I’m currently trying to analyze a binary protocol between 2 devices, but their communication does not occur over the network, neither can it be sniffed easily. Since this involves communication between 2 parties, I think the most apt software for analyzing such “conversations” would be Wireshark.

Wireshark allows for custom protocol dissectors. Writing such a dissector is usually done in C for speed, but I didn’t really want to setup the whole compilation environment to compile Wireshark. Fortunately, the Wireshark (Windows) binaries are compiled with Lua scripting support, which can also be used to write dissectors (although they run slower than C implementations).

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Copying files between users in Windows 7

I’ve recently installed Windows 7 on my desktop and I’m trying to migrate files from the laptop’s hard disk.

Whenever I try to copy files from a folder that I do not have permissions to, it asks me if I want to gain “permanent access” to the folder and its contents, which means to alter the folder permissions to take ownership of the folder & files. Why would I want to do that? After the folder is copied to the new user, I would still need to alter the permissions for that user again anyway, which means the permissions are altered twice. Altering permissions on a directory tree is no fast operation either. This problem is also detailed here by sbalfour.

After following some links, the solution is to use the real Administrator account, which needs to be activated first using the following command line. You need to launch the Command Prompt using “run as administrator”.

net user Administrator /active

After the command completes, simply logout and login using the newly activated Administrator account and you can move the files around without being forced to take ownership of the folder & files.