ssh-keygen
ssh-copy-id -i /root/.ssh/id_rsa.pub oracle@192.168.6.226

ssh-keygen -lf /root/.ssh/id_rsa.pub -E md5
MD5:9a:3d:f7:c9:38:91:41:c7:8e:ca:a0:75:a2:51:b5:fm
ssh-keygen -lf /root/.ssh/id_rsa.pub -E sha256
2048 SHA256:9V6hDnLdq7heMYT2S54AHamAo9Bi8eQVa5oNa1dyHuo

type=CRYPTO_KEY_USER msg=audit(19/02/2019 12:35:42.590:1145) : pid=12444 uid=root auid=unset ses=unset subj=system_u:system_r:sshd_t:s0-s0:c0.c1023 msg='op=destroy kind=server fp=SHA256:8a:99:38:f8:db:fd:02:52:76:ce:f8:c5:9a:ef:ef:47:98:23:fb:49:bf:c6:4b:de:e3:76:08:9c:f7:33:01:16 direction=? spid=12444 suid=root  exe=/usr/sbin/sshd hostname=? addr=? terminal=? res=success'