2018 juni examen

Theorie 

 8 multiple choice vragen 

 DNS 

 Waarom wordt er bij SSL/TCL zowel symmetrische als asymmetrische encryptie gebruikt? Leg uit met een schema van SSL en zeg waar welke gebruikt wordt. 

 Praktijk 

 Praktijkexamen 23/05/2018 

 1. A simulated phone is running at  http://darthvader.uclllabs.be/nw2/phone/ . Create a oneliner to bruteforce the pincode. Tip: pincode range: 1200-1300. 

 for i in {1200..1300}; do if wget -q http://darthvader.uclllabs.be/nw2/phone/ --http-user=admin --http-password=$i; then echo $i; break; fi;done; 

 

 2. Ontcijfer de volgende boodschap: RGUgcHVudGVuIG9wIGRlemUgdnJhYWcgemlqbiBhbCBiaW5uZW4uCg== (deze boodschap staat in het bestand /home/logs/secret | base64 -d 

 cat /home/logs/secret | base64 -d 

 

 3. Show the file /etc/debconf.conf on screen without comment lines (i.e. lines starting with a #). 

 cat /etc/debconf.conf | grep -Ev "^#" 

 

 4. Use Netcat to download an image from " http://darthvader.uclllabs.be/nw2/images/ ". You can use a browser to choose an image. check the echo -ne options or use printf. If needed, slow down netcat with option -i. The image part in the HTTP stream starts after a blank line. 

 echo -ne "GET /nw2/images/image1.jpg HTTP/1.0\r\n\r\n" | nc darthvader.uclllabs.be 80 > image1.jpg; cat image1.jpg | tail -n +13 > imagetester.jpg 

 

 5. Perform a zone transfer of the cnw2.uclllabs.be zone to see which hostnames you need to use. Use "dig axfr cnw2.uclllabs.be @ns2.uclllabs.be". Sort the output and format it as follows: 

 

 *.1.cnw2.uclllabs.be. 3600 IN A 193.191.176.1 

 *.2.cnw2.uclllabs.be. 3600 IN A 193.191.176.2 

 *.3.cnw2.uclllabs.be. 3600 IN A 193.191.176.3 

 *.4.cnw2.uclllabs.be. 3600 IN A 193.191.176.4 

 *.5.cnw2.uclllabs.be. 3600 IN A 193.191.176.5 

 *.6.cnw2.uclllabs.be. 3600 IN A 193.191.176.6 

 *.7.cnw2.uclllabs.be. 3600 IN A 193.191.176.7 

 *.8.cnw2.uclllabs.be. 3600 IN A 193.191.176.8 

 *.9.cnw2.uclllabs.be. 3600 IN A 193.191.176.9 

 *.10.cnw2.uclllabs.be. 3600 IN A 193.191.176.10 

 

 dig axfr cnw2.uclllabs.be @ns2.uclllabs.be | awk '{print $1,$2,$3,$4,$5}' | grep "IN A" | sort -V 

 

 Praktijkexamen 22/05/2018 

 1) A simulated phone is running at  http://darthvader.uclllabs.be/nw2/phone/ . Create a oneliner to bruteforce the pincode. Tip: pincode range: 1200-1300 

 for pin in {1200..1300}; do if wget -q --http-user='admin' --http-password=$pin http://darthvader.uclllabs.be/nw2/phone; then echo $pin; break; fi; done 

 

 Give a list of words with 5 letters that are also palindromes. 

 grep -P '^(.)(.).\2\1$' dutch 

 

 Show the file /etc/debconf.conf on screen without comment lines (i.e. lines starting with a #). 

 grep -vP '^#' /etc/debconf.conf 

 

 Give a list of the usernames tried in ftp_bruteforce.pcap. You can only use tshark and sort (Step by step solution:  https://wiki.uclllabs.be/index.php/TShark_Tutorial#Exercises ) 

 tshark -r ftp_bruteforce.pcap -Y 'ftp.request.command == USER' -T fields -e ‘ftp.request.arg’ | sort -u 

 

 Write a oneliner to display the fingerprint, serial and public key of wiki.uclllabs.be 

 echo | openssl s_client -connect wiki.uclllabs.be:443 2>/dev/null | openssl x509 -fingerprint -serial -pubkey