- If you receive the error, `Permission denied (publickey)`, increase ssh verbosity with the `-v` flag and ensure the public key from the card is being offered: `Offering public key: RSA SHA256:abcdefg... cardno:00060123456`. If it is, ensure you are connecting as the right user on the target system, rather than as the user on the local system. Otherwise, be sure `IdentitiesOnly` is not [enabled](https://github.com/FiloSottile/whosthere#how-do-i-stop-it) for this host.
- If SSH authentication stil fails - add up to 3 `-v` flags to increase verbosity.
- If SSH authentication still fails - add up to 3 `-v` flags to the `ssh` client to increase verbosity.
- If it still fails, it may be useful to stop the background `sshd` daemon process service on the server (e.g. using `sudo systemctl stop sshd`) and instead start it in the foreground with extensive debugging output, using `sshd -eddd`. Note that (quote `man sshd`) _The server also will not fork and will only process one connection._, and therefore has to be re-started after every `ssh` test.
Michael Vorburger ⛑️
5 years ago
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