We have an ldap entry with an encryption key and an identifying name, then an entry with an encrypted password that can be retrieved when needed. (This is used for storing service account passwords and the like). It is fronted by a couple jsp web sites that use javabeans, so everything is compiled and the source is no where to be found.


I was wondering if there is a way to tell what encryption method is used if you have the encryption key, the ciphertext, and also the plaintext. I'm pretty sure it is private key encryption, as there is only one key listed in LDAP.

The only sure way is to try each algorithm if you have all data. But there may be a problem if the software uses random IV's or salts. Run "strings" on the binaries and maybe you'll find a clue in the function names. The developers may be kind to provide this information, so try asking them first.