Walkthrough of Krypton CTF Capture The Flag Craw security

1. Walkthrough of Krypton CTF (Capture The Flag) | Craw security The Flag) | Craw security Walkthrough of Krypton CTF (Capture Walkthrough of Krypton CTF (Capture Walkthrough of Krypton CTF (Capture The Flag) | Craw security through of Krypton CTF (Capture The Flag) | Craw through of Krypton CTF (Capture The Flag) | Craw Walkthrough of Krypton Walkthrough of Krypton SOURCE:- KRYPTON LEVEL1 We get base64 encrypted password for KRYPTON S1JZUFRPTklTR1JFQVQ= Lets decrypt it. Either we can decrypt it with cyberchef or we can decrypt it with termina Let se We get base64 encrypted password for KRYPTON2 Lets decrypt it. Either we can decrypt it with cyberchef or we can decrypt it with terminal

2. Above decryption is done by Cyberchef- Source:- https://gchg.github.io/cyberchef/ Here is done by Terminal Command:- echo “(ecrpted_text)” | base64 -d We got our password- KRYPTONISGREAT Now lets logged in with ssh and our port is 223 Command:- ssh krypton1@krypton.labs.overthewire.org ssh krypton1@krypton.labs.overthewire.org -p 2231 d Now lets logged in with ssh and our port is 2231

3. We got the shell Info for level2 The password for level 2 is in the file ‘krypton2’. It is ‘encrypted’ using a simple rotation. it is also in non when using alpha characters for cipher text it is normal to group the letters into 5 letter clusters, regardless o helps obfuscate any patterns. this file has kept the plain text boundaries and carried them to the cipher text. enjoy! helps obfuscate any patterns. this file has kept the plain text boundaries and carried them to the cipher text. enjoy! helps obfuscate any patterns. this file has kept the plain text boundaries and carried them to the cipher text. enjoy! The password for level 2 is in the file ‘krypton2’. It is ‘encrypted’ using a simple rotation. it is also in non- standard ciphertext format. when using alpha characters for cipher text it is normal to group the letters into 5 letter clusters, regardless of word boundaries. this standard ciphertext format. f word boundaries. this In instruction for level2 it is clear that have krypton 2 file in which there is encrypted password for krypton2 don’t find any text file of krypton2, so for finding we will run find command don’t find any text file of krypton2, so for finding we will run find command In instruction for level2 it is clear that have krypton 2 file in which there is encrypted password for krypton2 but if we navigate we but if we navigate we Command:- find/-name krypton2 2>/dev/null filter ther permission denied result name krypton2 2>/dev/null filter ther permission denied result We can see the Krypton2 file

4. Here is the ecrypted password “YRIRY GJB CNFFJBEQ EBGGRA Same decrypt it with with cyberchef or terminal Same decrypt it with with cyberchef or terminal Here is the ecrypted password “YRIRY GJB CNFFJBEQ EBGGRA” Both method are there in above pic Logged in krypton2 Then we got the encryption and key First, we need to check which type of encryption is used so we need to create a temp file as instruction is given In level3 w First, we need to check which type of encryption is used so we need to create a temp file as instruction is given In level3 w First, we need to check which type of encryption is used so we need to create a temp file as instruction is given In level3 web page.

5. krypton2@melinda:~$ mktemp -d /tmp/tmp.Wf2OnCpCDQ krypton2@melinda:~$ cd /tmp/tmp.Wf2OnCpCD krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ ln krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ l keyfile.dat krypton2@melinda:~$ cd /tmp/tmp.Wf2OnCpCDQ krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ ln -s /krypton/krypton2/keyfile.dat krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ ls krypton2@krypton: nano plain create a text file and encrypt it so that we can know tha create a text file and encrypt it so that we can know that which encryp krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ chmod 777 krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ /krypton/krypton2/encrypt /etc/issu krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ l ciphertext keyfile.dat know we will analyze the ciphertext file so that we know we will analyze the ciphertext file so that we can know which rot is used here krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ chmod 777 . krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ /krypton/krypton2/encrypt /etc/issue krypton2@melinda:/tmp/tmp.Wf2OnCpCDQ$ ls As we above image we created ptext as a plain text and than I encrypt it with the help of given encryption. As we above image we created ptext as a plain text and than I encrypt it with the help of given encryption. we found that A is converted into M so for this process, we are clear that encryption is used ROT12 we can decypt it from rea let’s decrypt it. we found that A is converted into M so for this process, we are clear that encryption is used ROT12 we can decypt it from rea we found that A is converted into M so for this process, we are clear that encryption is used ROT12 we can decypt it from real key. we got krypton3 password lets logged in:- ssh krypton3@krypton.labs.overthewire.org Password:- CAESARISEAS ssh krypton3@krypton.labs.overthewire.org -p 2231