up vote 16 down vote favorite
2

How to unpack a packed chrome theme(*.crx)? Their FAQ states how to pack, but not how to unpack.

share|improve this question
up vote 12 down vote

I got the solution: apparently, a .crx file is just a renamed .zip file. Additionally, when you install it, the theme is decompressed into the chrome install directory...

share|improve this answer
2  
Not quite; it’s not just a renamed ZIP. Open one in a hex-editor and see that there is clearly a proprietary header. That said, yes, it is basically a ZIP, and can be opened in most ZIP-capable programs. I prefer 7-Zip. – Synetech Jul 13 '11 at 3:25
2  
@Synetech is correct, the file header contains a public key and signature. Google's .crx Package Format page explains this. In practice, you should be able to extract a .crx file with unzip, and it will ignore the extra bytes. If you do end up needing to chop off the header first, running unzip -l will show you how many (N+1 bytes with tail). For example: If unzip -l complains with warning [file.crx]: **306 extra bytes at beginning or within zipfile**, then run: tail -c +307 file.crx > /tmp/file.crx; unzip -l /tmp/file.crx – TrinitronX Dec 13 '12 at 22:45
up vote 4 down vote

Actually it's more than a zip. When you unzip -l you'll see a message:

warning [extension.crx]: 306 extra bytes at beginning or within zipfile

So the crx file is 306 bytes of something plus a zip archive.

share|improve this answer
up vote 3 down vote

This video explains everything about what a .crx is. In addition to a .zip holding all the extension's resources, it includes a public key and a signature, to ensure integrity and authenticity of the file: Antony Sargent explains .crx files Hosted by: youtube.com

The details of the .crx package format are published here.

share|improve this answer
up vote 3 down vote

On Mac OS X, you can use unzip to decompress the .crx file:

unzip extension.crx

Here's the result:

unzip result

share|improve this answer
up vote 1 down vote

Chrome extension install directory:

Mac:

/Users/username/Library/Application Support/Google/Chrome/Default/Extensions

Windows 7:

C:\Users\username\AppData\Local\Google\Chrome\User Data\Default\Extensions

Windows XP:

C:\Documents and Settings\YourUserName\Local Settings\Application Data\Google\Chrome\User Data\Default
share|improve this answer
    
Best solution out of them all. This worked for me, none of the others did. – daviesgeek Jan 27 '12 at 17:20
up vote 0 down vote

Yep aviraldg is right. rename it to a .zip and use your favorite extraction tool. XPIs for firefox, etc, are the same process.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.