Is it possible to send LDAP "requests" via telnet?

Question

I am wondering whether is it possible or not to establish a connection to a LDAP server via telnet (or some other program) and start making requests and receiving responses as I would normally do with HTTP. In fact, the question is more generic and is related to my misunderstanding of network connections and communications protocols. Let me tell you the idea I have in my mind about this topic:

All application protocols define communication protocols (that is, messages that the server is going to understand and act upon its delivery). If I know how the application protocol works, I can establish a connection to the server (daemon controlling that protocol server-side) and start communicating with the server. For example with HTTP I can establish a connection to an HTTP SERVER via telnet and start talking with him with this requests for example:

GET /users/pepito HTTP/1.1
Host: stackoverflow
Content-Type: text/html

I am expecting this procedure to happen with ANY APPLICATION PROTOCOL. Is this concept right??

I have glimpsed the LDAP Protocol Specification RFC but I did not understand the format of the messages. I mean, I was expecting to read something like HTTP Protocol Specification; but it was like too generic. Can you give me an example of how LDAP search could be made?

Answer 1

The LDAP RFC specifies that LDAP messages are ASN1 encoded. This means the messages are binary data in a special format, instead of text, following a special format. This makes it very hard to write ladap-queries by hand with telnet.