This one took me about 3 minutes to run on my machine. Depending on your network speed it shouldn't take much longer than that. I'd definitely suggest some debug output to ensure that your program is making progress recovering the cookie and not hanging somewhere.

I'm getting 404 when trying to request below

https://id0-rsa.pub/problem/crime-oracle/ https://id0-rsa.pub/problem/crime-oracle?Cookie:0123456789

Am I missing something ?

Note that the hint states:

The cookie is all lowercase letters

I think we set the oracle up so that the endpoint won't even compute the compressed size if there are digits in the last part of the url, it will simply 404. You should only have to use the characters a-z and =. In other words your query to the oracle should match the regex https://id0-rsa.pub/problem/crime-oracle/[a-z=]*.

Example valid URL - https://id0-rsa.pub/problem/crime-oracle/some=string

Got it @anton, & thanks for putting this together!

Well, the message I'm getting is 500 Server is FUBAR

Anton, do you still exist?

https://id0-rsa.pub/problem/crime-oracle/abcdefgh -> error 500
https://id0-rsa.pub/problem/crime-oracle/cookie=abcdefgh -> error 500
your example:
https://id0-rsa.pub/problem/crime-oracle/some=string -> error 500

????

Is this problem dead now? I also cannot seem to get anything other than 500 or 404 from using the oracle