Decoding 64-bit encoded Cookies in logs

[ArtemisFowl]

I swear it's like they do this to make my life more difficult.

Marketing: Can you log cookies?
Me: yep
Marketing: the contents?
Me: yep
Marketing: Great...

What they didn't tell me is that the content is encoded and now they want my log file analyser to decode the cookie contents and report the result.

Sigh...

Little help?

[hakre]

maybe the server is able to modify it while logging. if you're using apache try logformat or such.