On Thu, 27 Jan 2000, Mark Adamson wrote: > Hello all. > > I am working on getting OpenLDAP 2.0 working for the CMU campus > here. I CVS downloaded the source in early December and have it > compiled and running on my desktop machine. > > I am working on getting Kerberos authentication working, and ran > into what I'd have to call a bug. It has to do with a client such as > ldapsearch uses ldap_kerberos_bind_s() and how the server binds your > DN using do_bind(). > > When a client uses ldap_kerberos_bind_s() it first binds with an > authmethod LDAP_AUTH_KRBV41 (the "ldapserver" ticket), and then again > with LDAP_AUTH_KRBV42 (the "x500dsa" ticket). On the server, in the > function > > servers/slapd/back-ldbm/bind.c > ldbm_back_bind() > > the first bind does all of the leg work of checking the krbName and > returns 0 to the calling function > > servers/slapd/bind.c > do_bind() > > The second bind on the server simply sends a SUCCESS message back to > the client and returns a non-zero code back to do_bind(), with the > comment "stop front end from sending result". > > When do_bind() was called, it first cleared any previous bindings and > then if the backend bind returns 0 it will store the requested DN in > the connection. > > The bug is that the second (LDAP_AUTH_KRBV42) binding in > ldbm_back_bind() always returns a non-zero code to do_bind(), so the > DN binding from the first binding was erased and not stored the second > time. The result is a connection that has NO binding: you are > unauthenticated. > > > I am curious as to why the second binding wants to send the SUCCESS > message itself and return !0, instead of returning 0 and letting > do_bind() return SUCCESS (and set the DN binding). - The whole double-bind thing is a hack from the Umich code when ldap was more integrated into the whole X500 environment. If you are running slapd, there is really no point to doing anything besides LDAP_AUTH_KRBV41. It's my understanding that the original idea was to authenticate to both the ldap server and the X500 DSA. I have no idea why this was done, but since X500 DSA's have gone the way of the dodo, there is really no point in doing it now. - Booker C. Bense
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