OpenSSH used to show host key fingerprints using MD5, so we did the same when showing them in ThinLinc. However OpenSSH 6.8 changed this to SHA-256 instead. In order to show something familiar to users we should follow upstream's change and also switch algorithm.
Tested the client on Fedora 34 and the host key fingerprint shown when connecting to a new, unknown, host is now identical to what is shown by OpenSSH. Ideally, this bug is to be tested along with bug 7756 on both Windows and macOS. We want to make sure the correct SHA256 fingerprint is shown in the following scenarios: - When connecting to a host for the first time - When connecting to a known host, but the hosts public key has changed since last time - With the client configured to allow connecting if the key has changed - With the client configured to disallow connecting if the key has changed
Tested on Fedora 34 against Ubuntu 20.04. > - Host key fingerprints use the same format as in SSH > - In the GUI Yup. Checked: * New host key * Changed host key * Changed host key, and not allowed to continue > - In the logs Yup. * Logged received host key * Logged known host keys * Logged acceptable host keys * Logged new keys via hostkeys-00 extension > - The change should not require users to re-accept host keys that were accepted before the change Works fine.
