[Bug 1961833] Re: openssh 8.8 breaks login to canonical servers

[Julian Andres Klode]

It says

Incompatibility is more likely when connecting to older SSH
implementations that have not been upgraded or have not closely tracked
improvements in the SSH protocol. For these cases, it may be necessary
to selectively re-enable RSA/SHA1 to allow connection and/or user
authentication via the HostkeyAlgorithms and PubkeyAcceptedAlgorithms
options. For example, the following stanza in ~/.ssh/config will enable
RSA/SHA1 for host and user authentication for a single destination host:

    Host old-host
        HostkeyAlgorithms +ssh-rsa
    PubkeyAcceptedAlgorithms +ssh-rsa

So this may be a server too old issue; and we can fix this in internal
tooling.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to openssh in Ubuntu.
https://bugs.launchpad.net/bugs/1961833

Title:
  openssh 8.8 breaks login to Canonical servers

Status in openssh package in Ubuntu:
  New

Bug description:
  With 8.7p1-4 connecting to wendigo

  debug1: Next authentication method: publickey
  debug1: Offering public key: /home/jak/.ssh/id_rsa RSA SHA256:Dj1/l9g5RH00/wO7puC1WVxgpvmhmaQg3wEETwmOFPk agent
  debug1: Server accepts key: /home/jak/.ssh/id_rsa RSA SHA256:Dj1/l9g5RH00/wO7puC1WVxgpvmhmaQg3wEETwmOFPk agent

  With 8.8p1-1

  debug1: Offering public key: /home/jak/.ssh/id_rsa RSA SHA256:Dj1/l9g5RH00/wO7puC1WVxgpvmhmaQg3wEETwmOFPk agent                                                                                                                                                                             
  debug1: send_pubkey_test: no mutual signature algorithm   

  
  Needs further investigation, but blocks people a bit right now

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1961833/+subscriptions