[systemd-devel] Systemd and kernel keyring

[Sietse van Zanen]

Hi Dinesh,

Did you do a 'keyctl link @us @s' after logging in?

And could you tell me how you aceive 2. Because according to documentation it is not possible to have systemd-ask-password insert a key into a users keylist:
 --keyname=
           Configure a kernel keyring key name to use as cache for the password. If set, then the tool will try to push any collected passwords into the
           kernel keyring of the root user

-Sietse
________________________________________
From: systemd-devel <systemd-devel-bounces at lists.freedesktop.org> on behalf of Dinesh Prasanth Moluguwan Krishnamoorthy <dmoluguw at redhat.com>
Sent: Thursday, December 6, 2018 04:11
To: systemd-devel at lists.freedesktop.org
Subject: [systemd-devel] Systemd and kernel keyring

Hi team,

I'm working on accessing kernel keyring in my application started using
systemd.

The list of steps I'm doing:

1. Starting a systemd service with `KeyringMode=shared` as a SPECIFIC
USER
2. In the `ExecStartPre`, I'm launching a subprocess that invokes
`systemd-ask-password` to accept the input and store it in the USER's
kernel keyring
3. In the main program started using `ExecStart`, I'm accessing the
value stored in the keyring

I'm able to access the values from my main program -- everything works
as expected! When I try to login as that specific user and do a `keyctl
show @u`, I find the entry.

However, when I try to do `keyctl print <keyID>`, it throws "Permission
Denied" error. IIUC, this protects the keys in the keyring from
accessing outside the systemd service. Is it the desired behaviour?

I have the sample systemd unit file available in [1].

[1]
https://github.com/SilleBille/keyctl-java-test/blob/master/pki-tomcatd-nuxwdog%40pki-tomcat.service

Thanks,
Dinesh

_______________________________________________
systemd-devel mailing list
systemd-devel at lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/systemd-devel