How do I into md5?

Question: how exactly are 4chan's pictures hashed?

I figured it's md5 since in clearly says so in the motherfucking tag, but if I try to actually hash a picture with md5 I always get a different code.
Now, I admit it, I don't know shit about hashing.

So then I tried comparing the results to see some pattern
what 4chan had: 4XgNLCurJpsOWCRH/Vlicg==
what I got: e1780d2c2bab269b0e582447fd596272

It looks like 4chan does some additional shit to the hash string, but I have no clues as to what exactly it does.
Hell, it's 22 characters against 32. How the fuck am I even supposed to deal with that.

So... help? I'm out of ideas to be honest.

4chan
We dont care.

Nobody seems to care, but nonetheless:
By skimming through Yotsuba sources I figured it's base64.
Fine, I now get ZTE3ODBkMmMyYmFiMjY5YjBlNTgyNDQ3ZmQ1OTYyNzI=
which is considerably closer but still not quite there.

>>2
Ok, use your imagination for a second and pretend it's not there.
What kind of encoding turns a 32 character hex string into something that's 22 characters long, has numbers, letters and some other characters, is case sensitive and ends with a == ?

Is it base 85?

>>3
Now run it through base64 again. Problem solved.

If it ends with '=' it's almost always base64.

>>5
<~AMH,'0OuqK11F[$1,_.%0P*+$1,LgHAn3bZ2DR3H~>

>>6
WlRFM09EQmtNbU15WW1GaU1qWTVZakJsTlRneU5EUTNabVExT1RZeU56ST0=



Anyhow, I wrote my own base64 decoding method, according to... well... wikipedia... and it suddenly works.
Apparently the one I had was corrupt?
Oh well, thank you for your attention.

>>1
┌[hax@myanus] [~]
└─> echo 4XgNLCurJpsOWCRH/Vlicg== | base64 -d | hexdump -ve'/1 "%02x"'; echo
e1780d2c2bab269b0e582447fd596272
┌[hax@myanus] [~]
└─>

Why are they still using MD5? I remember md5coll could generate collisions in a few seconds on average PC hardware 5 years ago.

>>10
So what? The hash is solely used for checking duplicate images on the server.

This thread sucks. I hate you all.

>>11
Enjoy your Collisions, Patrick.

>>1
How did you even find /prog/ if you're so retarded?

>>10
How feasible would it be to make a valid image that would collide with a specific hash?

>>13
How feasible would it be to make a valid image that would collide with a specific hash?

And what would the purpose be?  So that you could not post an image that is different to the first!

>>14
I have my reasons.

Use sha256, or md6...

>>1
/facepalm

Its a base64 representation of the md5 has instead of in hex... if you undid the base64 you'd see its the same hex