ssh clients, file
.ssh/knwon_hosts may use plain text (this happens, for example, in FreeBSD 12.0):
<ip_address> ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEIlD8R6Kxj9CdToar+3ay4B0yE65dP0EYoRJjEEgLjmvCTIv59DBp+0j2z0+NM0hxxJew79i1bYuN02lEvT2/E=
or it may be hashed (as in Ubuntu 18.04):
|1|3Et6QShrP2OrD4tWdOGP3jy3YC4=|f2FrJ5tOjjmFSrGWyen1DokJyLc= ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBIyZLGNvIADWL5SSkohBmDCVpLUzAHNejqQAXP3SSY300YIdNKCn3jqGmFAJiKB1CY0HnVirgFjdAKpyw3+6yzo=
Is it possible to obtain the plain text lines from an hashed
Ubuntu sshd manpage states that:
Only one hashed hostname may appear on a single line and none of the above negation or wildcard operators may be applied.
I am not sure about what it's meant here.
Does that mean that addresses like
192.168.*.* can never be accepted in the hashed form of
known_hosts, even when they are created as plain text and then manually hashed?
As in a previous question, I am using these clients:
OpenSSH_7.8p1, OpenSSL 1.1.1a-freebsd 20 Nov 2018 and
OpenSSH_7.6p1 Ubuntu-4ubuntu0.3, OpenSSL 1.0.2n 7 Dec 2017.