Regression ACL & namespace prefix

[Aki Tuomi]

Sorry, we have not yet been able to look into this..

It's now in our internal system as DOP-966

Aki

> On 7 March 2019 17:31 Michal Hlavinka via dovecot <dovecot at dovecot.org> wrote:
> 
>  
> Hi,
> any progress with this issue? Do you need more information to debug and 
> fix this?
> 
> Cheers
> Michal Hlavinka
> 
> On 9/18/18 4:10 PM, Michal Hlavinka wrote:
> > Hi
> > 
> > tl;dr:
> > Seems that for Global ACL directory, namespace prefix is not part of the 
> > path, when looking for acl file.
> > 
> > Long version:
> > 
> > We're planning to update dovecot in next os update to 2.2.36 and while 
> > going through regression testing, we found a problem with ACL 
> > configuration combined with namespace.
> > 
> > Test uses "Global ACL directory" configuration.
> > 
> > Relevant configuration part:
> > mail_location = maildir:~/Maildir
> > 
> > namespace inbox {
> >    hidden = no
> >    inbox = yes
> >    list = yes
> >    location =
> >    prefix =
> >    separator = /
> > }
> > namespace {
> >    hidden = no
> >    list = yes
> >    location = maildir:/var/mail/pub
> >    prefix = pub/
> >    separator = /
> >    type = public
> > }
> > 
> > mail_plugins = acl
> > 
> > protocol imap {
> >    mail_plugins = $mail_plugins acl imap_acl
> > }
> > plugin {
> >    acl = vfile:/etc/dovecot/global-acls
> > }
> > 
> > ACL config file is stored at:
> > /etc/dovecot/global-acls/pub/.DEFAULT
> > 
> > when trying to examine "pub", it is denied:
> > fetchmail: IMAP> A0005 EXAMINE "pub"
> > fetchmail: IMAP< A0005 NO Mailbox doesn't exist: pub (0.001 + 0.000 secs).
> > 
> > # doveadm acl debug -u d2 pub
> > doveadm(d2): Info: Mailbox '' is in namespace 'pub/'
> > doveadm(d2): Info: Mailbox path: /var/mail/pub
> > doveadm(d2): Info: All message flags are shared across users in mailbox
> > doveadm(d2): Info: User d2 has no rights for mailbox
> > doveadm(d2): Error: User d2 is missing 'lookup' right
> > doveadm(d2): Info: Mailbox pub is NOT visible in LIST
> > 
> > because it did not find acl file:
> > imap(d2): Debug: Namespace : type=public, prefix=pub/, sep=/, inbox=no, 
> > hidden=no, list=yes, subscriptions=yes location=maildir:/var/mail/pub
> > imap(d2): Debug: maildir++: root=/var/mail/pub, index=, indexpvt=, 
> > control=, inbox=, alt=
> > imap(d2): Debug: acl: initializing backend with data: 
> > vfile:/etc/dovecot/global-acls
> > imap(d2): Debug: acl: acl username = d2
> > imap(d2): Debug: acl: owner = 0
> > imap(d2): Debug: acl vfile: Global ACL legacy directory: 
> > /etc/dovecot/global-acls
> > imap(d2): Debug: pub: Mailbox opened because: EXAMINE
> > imap(d2): Debug: acl vfile: file /etc/dovecot/global-acls//.DEFAULT not 
> > found
> > imap(d2): Debug: acl vfile: file /var/mail/pub/dovecot-acl not found
> > 
> > 
> > see it's looking for:
> > /etc/dovecot/global-acls//.DEFAULT
> > instead of
> > /etc/dovecot/global-acls/pub/.DEFAULT
> > 
> > Checking with documentation
> > https://wiki.dovecot.org/ACL
> > it seems that prefix should still be part of the path, as it was before:
> > """The filenames must start with namespace prefix (if it has one). For 
> > example with namespace prefix=INBOX/ containing mailbox "foo" use 
> > /etc/dovecot/acls/INBOX/foo."""
> > 
> > 
> > Just for comparison, previous version (2.2.10) would work fine:
> > imap(d2): Debug: Namespace : type=public, prefix=pub/, sep=/, inbox=no, 
> > hidden=no, list=yes, subscriptions=yes location=maildir:/var/mail/pub
> > imap(d2): Debug: maildir++: root=/var/mail/pub, index=, indexpvt=, 
> > control=, inbox=, alt=
> > imap(d2): Debug: acl: initializing backend with data: 
> > vfile:/etc/dovecot/global-acls
> > imap(d2): Debug: acl: acl username = d2
> > imap(d2): Debug: acl: owner = 0
> > imap(d2): Debug: acl vfile: Global ACL directory: /etc/dovecot/global-acls
> > imap(d2): Debug: acl vfile: reading file 
> > /etc/dovecot/global-acls/pub/.DEFAULT
> > imap(d2): Debug: acl vfile: file /var/mail/pub/dovecot-acl not found
> > 
> > 
> > I've localized problem to:
> > src/plugins/acl/acl-backend-vfile.c: acl_backend_vfile_object_init(...)
> > and change from:
> > 
> > vname = mailbox_list_get_vname(_backend->list, name);
> > 
> > to:
> > 
> > vname = *name == '\0' ? "" :
> >      mailbox_list_get_vname(_backend->list, name);
> > 
> > that happened quite time ago during bigger acl changes and I don't know 
> > why exactly this line was changed previously. Anyway, reverting this 
> > line alone fixes the problem and while testing both per-mailbox ACL 
> > vfile and Global ACL file, reverting this did not affect them.