[knot-dns-users] More fine-grained ACLs

Network renumbering requires that A and AAAA RRs are directly or indirectly (DHCP) updated. This in turn requires dynamic DNS updates (RFC 2136). Although Knot DNS allows dynamic updates, it is not really prepared to securely handle this scenario. Knot DNS can either allow an address or key to update RRs in a zone via ACLs which is not fine-grained enough to useful for this purpose because it is questionable from a security perspective (under a certain threat model etc.). Assume that example.com uses dynamic DNS updates to update A and AAAA RRs to be prepared to renumber its network. If example.com uses a DHCP server to update the RRs, it suffices to take over the DHCP server of example.com to update any RRs in the zone of example.com, including NS, MX, TLSA and SSHFP RRs. If every host of example.com updates its own A and AAAA RRs directly and indirectly via a DHCP server, the problem is still the same, even if you move every hostname in a separate zone, for example it suffices to take over the webserver that serves example.com to change the MX RRs of example.com. With more fine-grained ACLs the problem would not exist. Currently ACLs consist of a subject (address and key), operation (transfer, notify, update, control) and object (zone). I think it would suffice to extend the object of an ACL to a triple (zone, name, type) similar to dynamic update policies in BIND. Perhaps it would also be useful to be able to use wildcards and negation. Are there any plans to extend the ACL mechanism in this way? Regards, Matthias-Christian