Pierangelo Masarati a écrit :
Guillaume Rousse wrote:
> I successfully setup the chain overlay, so as to push changes from a
> slave to a master, with something as:
> overlay chain
> chain-uri "ldap://ldap1.domain.tld"
> chain-idassert-bind bindmethod="simple"
> chain-idassert-authzFrom "*"
> chain-tls start
> chain-return-error TRUE
> I'm curious, tough, why the slave has to use a proxy identity to
> authenticate on the master, instead of reusing original query
> credentials. Is there something preventing it, or is just that all
> examples I found sofar were using it ?
First of all, in order to do that, slapd-ldap(5), which implements the
chain capability, should know about the details of syncrepl. Second,
the credentials used for syncrepl need to have broad *read* permissions,
while slapo-chain(5) credentials must have broad *authz* permissions.
One might want to use separate identities in order to craft their
permissions appropriately. The fact that slapo-chain(5) is very useful
in conjunction with sync replication is orthogonal to slapo-chain(5)
design. In fact, it was not designed for this purpose.
I guess you're
referring to syncrepl for multi-master replication
scenarios, right ? In my case, I'm using slapo-chain to allow my user to
change their password, whereas they only access the slave server.
Meaning I only push user-triggered changes to the master. Sorry if I was
not clear enough.
> I was also curious to know if the slapauth tool was usable to
> such kind of proxy setup. Reading the man page, it seems rather
> adapted to testing identity mapping through authz-regexp directives.
No. In fact, slapauth only tests authz-rgexp mapping, while what you
want is something similar to authz-regexp but specific to slapd-ldap(5),
and thus buried in its internals. Since it results in an RFC 4370
proxied authorization control, it could be interesting to have a
companion of the RFC 4532 who am I? operation that tells how a DSA is
going to authorize when chaining an operation, and what the who am I?
operation returned after chaining. However, I believe this would only
be useful for "maintenance" checking, as the whole purpose of
slapo-chain(5) is to hide the fact that operations are not handled locally.
thanks for the explanation.
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