Re: [COMPRESS] pkware header id for crypto extensions

2015-12-03 Thread Stefan Bodewig
On 2015-09-04, Bear Giles wrote: > I just came across a press release that suggests that it is possible to > support AES encryption for zip files: > http://www.prnewswire.com/news-releases/pkware-announces-free-licensing-program-for-secure-ziptm-and-pkzip-reader-technologies-72382192.html I

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-21 Thread Bear Giles
I have a moment to explain why the PKWARE crypto is stronger than the WinZip crypto. 1. The key has validation data, the VData and VCRC32 values. There are a couple different ways to compute a message integrity check that allows you to verify the encryption key and that the message contents have

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-20 Thread Bear Giles
I took out some debugging scaffolding so you can check it out. One of the unit tests fails but it should since it's trying to read an archive with an encrypted CD. (I haven't gotten around to wrapping it with an exception handler that fails if an exception isn't thrown.) Theoretically you can do

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-15 Thread Stefan Bodewig
On 2015-09-14, Bear Giles wrote: > I want to capture as much information as possible but the documentation is > a weird mixture of details and hand-waving. Some is detailed, some is > "compatible with the format used by the Microsoft CRYPTOAPI". How is > anyone supposed to use that if all they

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-14 Thread Bear Giles
No problem, I've also been preempted. I want to capture as much information as possible but the documentation is a weird mixture of details and hand-waving. Some is detailed, some is "compatible with the format used by the Microsoft CRYPTOAPI". How is anyone supposed to use that if all they have

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-14 Thread Stefan Bodewig
Hi Bear sorry for the late reply. My spare time is currently severly limited but this should be getting better by the end of the month. On 2015-09-05, Bear Giles wrote: > I was just reminded of the risks of making assumptions. There's two > separate implementations of AES strong encryption -

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-05 Thread Bear Giles
I was just reminded of the risks of making assumptions. There's two separate implementations of AES strong encryption - WinZip AES and PKWare. I've been focused on the latter but we should recognize both types of headers. I've pushed a bit more code that partially parses the PKWare headers. It's

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-04 Thread Bear Giles
I just came across a press release that suggests that it is possible to support AES encryption for zip files: http://www.prnewswire.com/news-releases/pkware-announces-free-licensing-program-for-secure-ziptm-and-pkzip-reader-technologies-72382192.html (We might have discussed this several years

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-03 Thread Bear Giles
I've forked at github.com/beargiles/commons-compress and committed some initial work - five new ExtraHeader classes, their registration, two test files and four unit tests. One test file uses certificate encryption and signature but does not encrypt filenames. The second test file uses

Re: [COMPRESS] pkware header id for crypto extensions

2015-09-02 Thread Stefan Bodewig
On 2015-09-02, Bear Giles wrote: > Hi, I know that the implementation of the PKWARE AES crypto is subject to > license restrictions but is it possible to recognize the extension fields > so anyone scanning an unfamiliar file will at least know what the extra > field headers contain? I don't

[COMPRESS] pkware header id for crypto extensions

2015-09-02 Thread Bear Giles
Hi, I know that the implementation of the PKWARE AES crypto is subject to license restrictions but is it possible to recognize the extension fields so anyone scanning an unfamiliar file will at least know what the extra field headers contain? I don't know if code to parse the contents (solely