From: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/linux_domain_identity_authentication_and_policy_guide/migrating_from_a_directory_server_to_ipa

"Users cannot authenticate to the IdM domain or access IdM resources until they have Kerberos hashes."

To be sure I understand, without the kerberos keys SSH auth to an IPA system requiring for instance SSH key+password in sshd_config will fail, and 39.1.2.3 as described at link above won't generate the keys transparently? Just trying to be sure I understand the scope and what actions we need to take to make sure that logins will work, and that the necessary keys will get created for a user to not notice whether they are on an IPA or an LDAP system, or if this will require further action from us.

Also it sounds like we'll need to use ldapmodify to connect to the IPA system to write the password hash. It sounds like I can use the same user for this bind that does the migrate-ds currently. This user is currently set up with least privilege, has only a special group we have created. Is there anything I need to give it specially to be able to write hashes of an existing user, or I guess it already can do this if it can do a migrate-ds and create users (and their hash values)?

Andy

On Thu, Feb 4, 2021 at 12:38 PM Rob Crittenden <rcritten@redhat.com> wrote:

Alfred Victor via FreeIPA-users wrote:
> Hi Rob and IPA list -
>
> The alternative is if it is possible to use the sssd method similar to
> as described in 39.1.2.3 at the below link to update credentials at IPA
> as well when a user resets their password, but I expect that if this is
> possible to do with both systems in parallel (OpenLDAP remaining source
> of truth until IPA is given the reins), the configuration will be
> complex. Hence why I feel we are better off writing this value directly,
> or else our IPA systems are going to have a stale credential problem
> because migrate-ds will copy the user, or make sure any new user ends up
> in IPA, but eventually the user changes password and migrate-ds will
> only be concerned that the user already exists and will not update the
> credential. Can you please let us know what we'll need to change or do
> to write to the password hash directly? I do not plan to store any
> credential hashes during this process - nor do I plan to have them
> accessible by any means. They will be processed into IPA and that's it.
> We already sync public key, group changes to IPA.
>
> SSSD method:
> https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/linux_domain_identity_authentication_and_policy_guide/migrating_from_a_directory_server_to_ipa
>
> Another option is of course to drop all users and remigrate them, but
> this is incompatible with our use case, as we won't have this
> opportunity easily.

The problem with using a pre-hashed password is that IPA cannot generate
new keys so the user would always have to migrate their password using
either SSSD or an LDAP bind. How often that would be depends on how
often passwords are changing.

Syncing in a password change will also trigger an expired password. So
if you can grab the unhashed password and sync that then see
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/identity_management_guide/pass-sync
section 15.6.3 (ignore everything else, literally).

This will allow an unhashed password to be written without marking it as
expired.For DN you use the user that binds from your existing password
source to do the write.

rob

> Andy
>
> On Wed, Feb 3, 2021 at 3:10 PM Alfred Victor <alvic266@gmail.com
> <mailto:alvic266@gmail.com>> wrote:
>
>     Hi Rob,
>
>     We have our system in migration mode. Due to the number and
>     diversity of systems we have, we've found we really need to test
>     everything extensively before we can cut over and make our IPA
>     cluster our source of truth. Keeping a subset of systems on IPA
>     during this time allows us to be comfortable switching at some
>     future date, given that we know we've had no issues with each subset
>     x of all systems y with t duration of production utilization.
>
>     Andy
>
>     On Wed, Feb 3, 2021 at 2:08 PM Rob Crittenden <rcritten@redhat.com
>     <mailto:rcritten@redhat.com>> wrote:
>
>         Alfred Victor via FreeIPA-users wrote:
>         > Hi all,
>         >
>         > We have a need to set the password hash value directly, is this
>         > possible? It does not appear that ipa user-mod will support
>         this, and
>         > using the API or other methods looks like it will be fraught
>         with access
>         > control complications.
>
>         Why do you need to set the hash directly?
>
>         It is possible to do when adding a new user for migration
>         purposes, but
>         after that it is generally not allowed.
>
>         rob
>
>
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