[Samba] Printing via SMB-Kerberos no longer works

[Robert Schetterer]

Am 22.09.2018 um 09:49 schrieb Alex Persson via samba:
> Hello,
> 
> After upgrading from Ubuntu 16.04 to 18.04 printing via SMB-Kerberos no longer works (printing still works in 18.04 when I print via SMB but I don't want to have the password stored in clear text in /usr/lib/cups/backend/smb).
> 
> In 16.04 I can just type "lpr file.pdf", but when doing this in 18.04 I get "Password for [myuser] on localhost?" and it expects me to type my password instead of using my Kerberos ticket for sending the print job to the print queue.
> 
> I have the same Kerberos ticket available according to "klist" in 18.04 as I had in 16.04.
> I have "AuthInfoRequired negotiate" in /etc/cups/printers.conf
> The file /usr/lib/cups/backend/smb is a symbolic link pointing to /usr/lib/x86_64-linux-gnu/samba/smbspool_krb5_wrapper (in 16.04 it was pointing at /usr/bin/smbspool_krb5_wrapper).
> The permission is 700 on /usr/lib/x86_64-linux-gnu/samba/smbspool_krb5_wrapper.
> The version of cups is 2.2.7-1ubuntu2.1 in 18.04 while it was 2.1.3-4ubuntu0.5 in 16.04.
> The version of smbclient is 2:4.7.6+dfsg~ubuntu-0ubuntu2.2 in 18.04 while it was 2:4.3.11+dfsg-0ubuntu0.16.04.16 16.04.
> 
> Can you please help me figure out what the problem is? Maybe it is something wrong with smbspool_krb5_wrapper from the smbclient package?
> 
> Best regards, Alex
> 

this feature broke times before by varia reasons
"just a shot in the dark", if you use kerberos tickets in /tmp then
stuff changed in 18.04 this also broke our cifs automounter

see here

https://blog.nutmeg.at/2017/04/17/getting-pam-krb5-working-autofs-and-cifs/

i did

default_ccache_name = FILE:/tmp/krb5cc_%{uid}

in /etc/krb5.conf

to fix our problem

Best Regards
MfG Robert Schetterer

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