https://bz.apache.org/bugzilla/show_bug.cgi?id=59857
--- Comment #6 from Andreas Beeker <kiwiwi...@apache.org> --- Added encryption support for XOR/RC4/CryptoAPI via r1756964 Unfortunately I've realized, that the existing and modified XOR obfuscation is flawed. It works for very small files, but for files > ~4kb, the office file validation complaints and it doesn't get opened anymore ... Of course I've tried to generate un-/encrypted files via Office and check when the de-/encryption goes wrong. Interestingly the first encrypted records (even long ones) get de-/encrypted correctly, but starting with the FontRecords (with the xor-encryption-abc.xls) only one of the bytes differ. This also happens even when the whole record processing is bypassed and the plain/encrypted stream of the POIFS is processed. My guess is, that similar to RC4/CryptoAPI there's a block key somewhere, although libre office [1] hasn't got something like this. ... but probably, it's something completely different and I was just focusing to much on the wrong spots ... [1] http://docs.libreoffice.org/oox/html/binarycodec_8cxx_source.html -- You are receiving this mail because: You are the assignee for the bug. --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@poi.apache.org For additional commands, e-mail: dev-h...@poi.apache.org
