Generating AES encrypted zip files for winzip
794117Apr 21 2005 — edited Feb 11 2010Subject says it pretty much. My current task is to produce as output from a java process, a zip file which can be opened with Winzip 9.
Winzip 9 provides a password, and does the encryption using AES 128 or 256 bit encryption.
I know I can use the java.util.zip classes to generate a zip archive.
I can use the java.security and javax.crypto classes to do AES encryption.
But combining the two is proving troublesome. I'm not even sure it is possible.
There is some info on winzips encryption here: http://www.winzip.com/aes_info.htm
It specifies what has to be put into the "extra data" bits, and also the format of some extra data to store at the beginning of the file. The main thing I'm not sure of right now is how to generate the key to use for the encoding, and encode it as part of the zip entry, so that the combination of password and "salt" value gets the key used to encrypt.
I am just starting on this, and am continuing research, but just putting out a feeler to see if anyone else has accomplished this, or if there are any java tools out there that do this already
Cheers,
evnafets