RTCP - That's Some Interesting Tea(rs)
Posted on sam. 25 janvier 2020 in CTF
solves : 177
Point : 175
You know, the tears of one's enemies works lovely in tea. Turns out, there's tons of different bases for tea. In fact, I think I heard Delphine talk about this chef website she used for her tea base combinations...
Oh! Speaking of which, GIANt wants Delphine to make him tea... all he has is the tea leaves and the cup though. Maybe you can help Delphine, since she's really busy with cooking other things?
O53GG4CSJRHEWQT2GJ5HC4CGOM4VKY3SOZGECZ2YNJTXO6LROV3DIR3CK4ZEMWCDHFMTOWSXGRSHU23DLJVTS5BXOQZXMU3ONJSFKRCVO5BEGVSELJSGUNSYLI2XQ32UOI3FKWDYMJQWOMKQOJ4XIU2WN5KTKWT2INUW44SZONGUUN2BMFRTQQJYKM3WGSSUNVXGEU3THFIFUSDHIVWVEQ3LJVUXEMSXK5MXSZ3TG5JXORKTMZRFIVQ=
The description gives us some clues : we are looking for the "chef" website and using combinations. A well know website CyberChef allow to perform directly online a bunch of encode/decode and encrypt/decrypt texts and files.
Ok, we got the website! Now, we have to figure out which encoding was used. We input the text and CyberChef offers to already add some "recipes" from this input : base32 and base58. Hum, it seems to only use base encoding and chain it. We can add the other base encoding present on the website :
| Text | Base used | Result |
|---|---|---|
O53GG4CSJRHEWQT2[...]XORKTMZRFIVQ= |
base32 | wvcpRLNKBz2zqpFs[...]Yygs7SwESfbTV |
wvcpRLNKBz2zqpFs[...]Yygs7SwESfbTV |
base58 | BGJz4dCH0UuQZ2Q9[...]iOvz2DYGDb9dh |
BGJz4dCH0UuQZ2Q9[...]iOvz2DYGDb9dh |
base62 | RWNiZjFIWldwWEY+[...]kV0Y+R2FvRisi |
RWNiZjFIWldwWEY+[...]kV0Y+R2FvRisi |
base64 | Ecbf1HZWpXF>[D_0[...]0QT$WF>GaoF+" |
Ecbf1HZWpXF>[D_0[...]0QT$WF>GaoF+" |
base85 | rtcp{th4t5_50m3_54lty_t34_1_bl4m3_4ll_th0s3_t34rs} |
If you didn't know about this website, I recommend you to bookmark it. The automatic tool may help you with some case to find what was used.