AES encryption of directory in cocoa

I can encrypt and decrypt files in Cocoa in AES standard thanks to the NSData category here. However, I do not know how I can do the same thing with directories and folders. Is it possible to encrypt a folder, because I have seen that other secu开发者_运维技巧rity software can do it. Is there another class I can use??

Thanks.

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First archive the directory, turning it into a file. There exist various Cocoa frameworks for this - many are listed here: http://www.cocoadev.com/index.pl?ZipArchiveLibraryForCocoa

And then encrypt the archive file.