I am doing a penetration test, and i would like to know if i can decrypt passwords stored in LDAP. i tried some sites decrypt MD5 , they give me error message tells that the input is not MD5. Could you please help thanks

This is an example

userPassword: {MD5}KdScezWFVZxY7rHb5C4X1w==
  • 7
    Hashing is not encryption. You cannot decrypt an MD5; you can only find a collision. Mar 16, 2012 at 15:45
  • 4
    And LDAP is not a storage location, it's a communications protocol. Mar 16, 2012 at 16:03
  • ok, i got the tree stored in LDAP and it contains passwords hashed using MD5, but when i am trying sites to get the original pass, the site gives error message tells "the input is not MD5". i wish it is more clear now.
    – user1028
    Mar 16, 2012 at 16:15
  • MD5 is not a difficult "format": it is 16 bytes of pure, raw data (or 32 ASCII-formatted hexadecimal numbers in the range of [0-9a-fA-F]). Anything else is not a valid MD5 signature. Mar 16, 2012 at 16:44
  • 1
    Other than references in WAHH, not familiar with burpsuite. It seems like burp is assuming some weird encoding for the b64 decode; rather than re-encoding in hexidecimal. A 24 char b64 encoding ending with == should be 16 bytes (each set of four-b64 chars corresponds to 3 bytes; except the last with has only one indicated by the two equals). As a byte is two hex chars, this works out right.
    – dr jimbob
    Mar 16, 2012 at 20:03

4 Answers 4


Your MD5 hash {MD5}KdScezWFVZxY7rHb5C4X1w== appears to be base64 encoded. MD5 hashes in the rainbow tables probably would be in hexidecimal, so you should convert the two.

In python you can do this with

>>> from base64 import b64decode, b16encode
>>> b16encode(b64decode('KdScezWFVZxY7rHb5C4X1w==')).lower()

Or you can use: http://tomeko.net/online_tools/base64.php?lang=en


In order to try and identify the password that gives you a particular hash, the only real way is to try all passwords and hash them to see what you get.

What those websites have done is already tried a huge number of passwords and stored the calculated hashes so when you input your hash they quickly look up their database and provide you with an answer. Have a look at this question on Rainbow Tables.

They do not cope with salted hashes, however (well, you can create a table for each salt, but that dramatically increases the size of the table space) - so the answer you have had back may just mean they have failed to look up that hash.


John The Ripper knows how to deal with the LDAP hashes. The option -format=nsldap should force it.

If it doesn't recognize your format, use base64.exe -d b64enc.hash | xxd -ps to convert your base64 encoded hashes into a hexdump.


dr jimbob right, it seems to be base64 encoded.

you can try http://md5pass.com to find your hash password. that site does not use a very own database but a Google Custom Search Engine (CSE).

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