[Pki-devel] [Freeipa-devel] Keytab for talking to PKI CA from IPA

[Rob Crittenden]

Adam Young wrote:
> When setting up replication, it should not be necessary to cache any
> passwords, anywhere, until the replication agreemsnts are set up, and
> then, all caching should be using known secure mechanisms.
>
> The two main repositories we care about are the Directory Server
> instances managed by IPA and the Certificate Authority. Currently, these
> are not in the same Dir Srv isntance (although they could be) due to the
> fact that we expect to replicate them seperately. Specifically, we
> expect to have more IPA instances than CA instances, and we will not
> have a CA instance without a co-located IPA instance.

Not really. I created two instances to provide logical separation and 
prevent us from having to deal with multiple naming contexts. There was 
some serious investigation over the summer to see if we could 
consolidate into a single instance. It was determined to be too much too 
late in the cycle.

> During normal operations, the IPA instance should not need to talk to
> the directory server instance of the CA. All communication between IPA
> and the CA should happen via the HTTPS secured via Certificates issued
> by the CA.

Right, this has never been in question AFAIK.

> Once the replication process starts, the file generated by ipa-prepare
> replicate should not need an passwords. Instead, when the replicated
> server is installed, the user performing the install should get a ticket
> as an administrative user. All authentication for the replication should
> be based on that ticket.
>
> The very first step is to install an new Directory server for IPA. For
> this, the replication process can generate a single use password and use
> it as the Directory server password for the local instance. Next, the
> ticket for the adminiustrative user should be used to download a keytab
> for the Directory Server to use when communicating back to the original
> IPA directory server.With these keytab in place, the replicated IPA DS
> should be able to talk to the original IPA DS and establish the
> replication agreement. At this point, the single use password should be
> disabled.

I think you mean the first step is to create a 389-ds instance for the 
CA, right?

Why not simply pre-create the keytab and ship it in the prepared file?

There is no need to disable the random DM password. Once the 
installation is complete it will be unknown so effectively disabled.

> Once the IPA Directory server has been replicated, we can either use the
> original keytab or download a second keytab to establish a replication
> agreement between the replicated CA directory server and the original CA
> directory server. The process would look the same as setting up the
> keytab for the IPA directory server.
>
> Why don't we do this now?

Because of permission issues writing the relevant entries to cn=config.

rob