[Samba] Samba 4 / Kerberos / ssh

[steve]

On Sun, 2014-05-25 at 11:56 +0000, Vogel, Sven wrote:
> I try to get Samba 4 with ssh running.
> 
> I found in the Script from Matthieu Patou tot he sysvol sync the follwing intresting line.
> 
> ---
> 
> kinit -k -t /etc/krb5.keytab  `hostname -s | tr "[:lower:]" "[:upper:]"`\$
> 
> rsync  -X -u -a  $dc_account_name\$@${dc}.${domain}:$SYSVOL $STAGING
> ---
> 
> when i understand correct he uses the domain controller service principle to connect to the other domain controller. I know for  that i need a working /etc/krb5.keytab
> 
> e.g. i have two s4 dc's
> 
> bob
> alice
> 
> i have done the following. I want to connect from bob to alice with the service accounts
> 
> I added to  the following to both of the dcs
> 
> sshd_config
> GSSAPIAuthentication yes
> GSSAPICleanupCredentials yes
> GSSAPIStrictAcceptorCheck yes
> GSSAPIKeyExchange yes
> 
> ssh_config
> GSSAPIAuthentication yes
> GSSAPIDelegationCredentials yes
> GSSAPIKeyExchange yes
> GSSAPITrustDNS yes
> 
> After that i created the keytab i know i need an working ticket
> 
> Samba-tool domain exportkeytab /etc/krb5.keytab -principal=alice$
> 
> I get the ticket with on bob for alice
> 
> kinit -v -k -t /etc/krb5.keytab alice$
> 
> after that i tryed to get an ssh connection to alice with (force gssapi connection)
> 
> ssh -vvv -K alice\$@alice.example.local
> 
> when i look in the logs i see always on alice the follwing error messages by alice
> 
> "No principal in keytab matches the desired name"
> 
> And
> 
> May 25 13:43:44 alice sshd[29647]: debug1: userauth-request for user alice$ service ssh-connection method none [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: attempt 0 failures 0 [preauth]
> May 25 13:43:44 alice sshd[29647]: Invalid user alice$ from 192.168.24.3
> May 25 13:43:44 alice sshd[29647]: debug1: Unable to open the btmp file /var/log/btmp: No such file or directory
> May 25 13:43:44 alice sshd[29647]: input_userauth_request: invalid user alice$ [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: PAM: initializing for "alice$"
> May 25 13:43:44 alice sshd[29647]: debug1: PAM: setting PAM_RHOST to "bob.swi.local"
> May 25 13:43:44 alice sshd[29647]: debug1: PAM: setting PAM_TTY to "ssh"
> May 25 13:43:44 alice sshd[29647]: debug1: userauth-request for user alice$ service ssh-connection method gssapi-with-mic [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: attempt 1 failures 0 [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: userauth-request for user alice$ service ssh-connection method gssapi-with-mic [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: attempt 2 failures 1 [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: userauth-request for user alice$ service ssh-connection method gssapi-with-mic [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: attempt 3 failures 2 [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: userauth-request for user alice$ service ssh-connection method keyboard-interactive [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: attempt 4 failures 3 [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: keyboard-interactive devs  [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: auth2_challenge: user=alice$ devs= [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: kbdint_alloc: devices 'pam' [preauth]
> May 25 13:43:44 alice sshd[29647]: debug1: auth2_challenge_start: trying authentication method 'pam' [preauth]
> 
> 
> I am confused. Is there something what i forgotten? PAM? I read that i need maybe a "HOST/" principal for ssh. Is that the problem?
> 
> Anyone have an idea?
> 
> Sven

Extract the machine key:
samba-tool domain exportkeytab /etc/krb5.keytab --principal=ALICE$
if ssh needs host/ add that too.
HTH
Steve