Bug 3235

Summary: pubkey auth with dns name in from= filter in authorized keys not working on ip6-only hosts from dual-stack hosts
Product: Portable OpenSSH Reporter: Max Langbein <m_langbe>
Component: sshdAssignee: Assigned to nobody <unassigned-bugs>
Status: CLOSED INVALID    
Severity: minor CC: djm
Priority: P5    
Version: 8.0p1   
Hardware: amd64   
OS: Linux   
Attachments:
Description Flags
example settings none

Description Max Langbein 2020-11-21 01:00:24 AEDT
Created attachment 3456 [details]
example settings

In case the host is ip6 only, and the originating host has ip6+ip4, with the dns entry containing the ip4 address before the ip6 address, no match is recognized, and public-key authentication fails.

I may be a general problem with multi-address dns entries, where only the first one is used to compare with the connecting ip.
Comment 1 Damien Miller 2020-11-23 10:10:48 AEDT
Does the ssh server in this case have UseDNS enabled? It's not on by default.
Comment 2 Max Langbein 2020-11-24 04:37:09 AEDT
You are right. Sorry for wasting your time, however, you helped me finding my bug , so thank you very much :-)
Comment 3 Damien Miller 2021-03-04 09:52:22 AEDT
close bugs that were resolved in OpenSSH 8.5 release cycle