How to decompress an AES-256 Encrypted zip files?

Question

I am developing an android application which requires to decompress an AES-256 encrypted zip files, is there any libraries out there that I can use to accomplish that?

I am greatly appreciative of any guidance or help.

Answer 1

zip4j, java library to handle Zip files (Open source, Apache License v2.0).

http://www.lingala.net/zip4j/

• Create, Add, Extract, Update, Remove files from a Zip file
• Read/Write password protected Zip files
• Supports AES 128/256 Encryption
• Supports Standard Zip Encryption

You can download binary, sources and examples.

Answer 2

I ended up using an external library at http://code.google.com/p/winzipaes/

it's limited to compression/decompression Zip files encrypted with AES-256 ONLY

but at least it fits my need.

Answer 3

It depends on you encoding of encrypted zip files. Be more specific please. If its compress then encrypt then you decompress then decrypt the file using java.util.zip.GZIPInputStream

Answer 4

As far as I remember AES encrypted ZIP files were introduced some years the first time by WinZip. On the WinZip home page there is a detailed explanation how the AES encrypted ZIP files differs from a standard ZIP file:

http://www.winzip.com/aes_info.htm

Answer 5

I am working on a normal JRE. Using http://www.lingala.net/zip4j/ the following code works to decrypt a zip file:

ZipFile zipFile = new ZipFile(zipFile);
zipFile.setPassword(password);
for (Object fileHeaderObj : zipFile.getFileHeaders()) {
  FileHeader fileHeader = (FileHeader) fileHeaderObj;
  String fileName = fileHeader.getFileName();
  ZipInputStream zipIn = zipFile.getInputStream(fileHeader);
  // do whatever with the input stream
}

Answer 6

I don't have tested it yet, but some time ago I found this.

I hope it can help you