Things learnt in zh3r0
Crypto
in order to uncipher , first, you need to identify them
| base16 | 0-9a-f | (blocksize 2) |
| base32 | A-Z2-7 | (blocksize 8) |
| base64 | 0-9a-zA-z+/ | (blocksize 4) |
| base85 | 0-9a-zA-Z!#$%&()*+-;<=>?@^_{|}~` | (blocksize 1) |
the padding for 32, 64 bases is ‘=’
In one the challenges, ‘Uncipher me’,
I came across this..
Are your rots strong.
<6Ji :"+:;v5@)\_96AGaH?u+~&D%(&\GeIJv(JB$2?0Afdrtl
w6C6VD 2?@E96C <6J 7@C E96 6?4CJAE:@?]
:7 J@F 2C6 2 8@@5 4CJAE@8C2A96C J@F 42? :56?E:7J E96 4@>>@? DJ>>6EC:4 6?4CJAE:@?]
Its rot47, just incase : how do i identify it without the hint??
The message uses ASCII characters. It contains common letters as 6 or t which are the ciphered values of E and e. –dcode.fr
given ciphertext:
b'gAAAAABe5zDHy1Vk74P8AspzQ4bqK9dzfI52djZeMbsXRk8G5ng1BtYmDj7v6SCbx7cvnUFu2fDh6XTVtQPQqlJcVVCxGoA0P4L_gtSIGHQPLZysxuoN1E7kP_5lZFbZLo6b6G-YqFxs'
In a writeup, it said it was a common symmentric encryption, fernet (I didnt even know it till I read it)
We can identify it by the gAAAAhead.
nice one– Double fish writeup
ciphers learnt : deadfish, blowfish
RSA attack learnt: Franklin reiter Related message attack
In a chall got saw some raw data:
UEsDBAoACQAAALq0vFDu3sG8JQAAABkAAAAIABwAZmxhZy50eHRVVAkAA+jvz179789edXgLAAEE
6AMAAAToAwAAt9tbOQhvceVTC9i83YoBgbIW5fmqoaO3mVwXSLOMqNulwvcwb1BLBwju3sG8JQAA
ABkAAABQSwECHgMKAAkAAAC6tLxQ7t7BvCUAAAAZAAAACAAYAAAAAAABAAAApIEAAAAAZmxhZy50
eHRVVAUAA+jvz151eAsAAQToAwAABOgDAABQSwUGAAAAAAEAAQBOAAAAdwAAAAAA
It’s base64 right?
but all i got is :
` ���P����flag.txtUT ���^���^ux
����[oq�S
ؼ݊���������\H���ۥ��0oP����%PK
���P����▒��flag.txtUT���^ux
��PKNw⏎ `
it looks like there is a flag.txt file …but where is it??? :(
Apparantly I learnt that zip files can be encoded to bas64 too..
Soo the above data when decoded , we get a zip file in which lies the flag.txt file :)