Due to how this stack is being broken up into LDAP core, scanner
update, and exploit work, changes requested in #15972 actually
apply in this branch and get rebased to the remaining ones.
Address requests to clean up the textual messages, LDIF file read,
sourcing of LDAP methods from net-ldap, and YARD-related placement
of attr_* annotations.
In order to detect scan callbacks, serve payloads, and otherwise
interact with the LDAP protocol handler in JNDI, Metasploit needs
a native LDAP service properly exposed to various parts of the
Framework and users/consumers.
Implement Rex::Protocol::LDAP::Server with TCP and UDP socket
handlers abstracted to a common access pattern between L4 stacks.
Extend the socket clients to hold a state attibute for LDAP bind
authentication, and use the UDP client abstraction to implement
consistent callback semantics for data receipt from a client and
handling response on the other side. The server utilizes Rex'
native sockets, permitting full pivot and proxy support over the
Switchboard.
Implement the Msf::Exploit::Remote::LDAP::Server mixin to manage
service abstraction and shared methods exposed to Metasploit
modules.
Note: during implementation of this functionality, it was
discovered that the Scanner mixin's :replicant method resulted in
:dup calls to the Rex::ServiceManager service created by this new
mixin (and any others leveraging ServiceManager). As a result,
double-bind attempts created failures in service instantiation from
the duplicated MetasploitModules which also dropped the @service
instance variable reference to the actual running service; leaving
the socket inexorably bound until Framework was halted and Ruby
released the FDs. See https://github.com/rapid7/rex-core/pull/19
and the Issues/Pull Requests sections of R7's MSF GitHub.
Expose the new LDAP infrastructure to users by way of a basic LDAP
server MetasploitModule which consumes a tiny sample LDIF (provided)
and performs queries against it. This is intended to be a template
for future work such as LDAP authentication capture, protocol proxy
for MITM and intercept, and other more specific implementations for
exploits and auxiliary modules.
For feature completeness, provide a Rex::Socket override for
Net::LDAP::Connection until we have a proper, native to Rex, LDAP
client class implemented.
Testing:
Basic functionality only, this is an early effort which will be
extended for feature-completeness over time
Spencer McIntyre