Linux

48157 readers

659 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
No misinformation
No NSFW content
No hate speech, bigotry, etc

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 5 years ago

MODERATORS

[email protected]

ssh won't ask for password unless i force PubkeyAuthentication=no (lemmy.ml)

submitted 1 month ago* (last edited 1 month ago) by [email protected] to c/[email protected]

16 comments fedilink hide all child comments

Lately I noticed that when I want to ssh to a server using a password I need to specify -o PubkeyAuthentication=no or I won't be asked for a password and the authentication will fail (well, for all I know, setting some other option may work too).

I use password authentication only once on freshly installed servers/vms, so it's not a huge deal, but... it still bothers me (mainly because I don't remember which option to set).

Do you guys have any idea what it may be?

client's ~/.ssh/config

Host 127.*.*.* 192.168.*.* 10.*.*.* 172.16.*.* 172.17.*.* 172.18.*.* 172.19.*.* 172.2?.*.* 172.30.*.* 172.31.*.*
  LogLevel quiet
  Stricthostkeychecking no
  Userknownhostsfile /dev/null

Host *
  ForwardAgent no
  AddKeysToAgent no
  Compression yes
  ServerAliveInterval 10
  ServerAliveCountMax 3
  HashKnownHosts no
  UserKnownHostsFile ~/.ssh/known_hosts
  ControlMaster no
  ControlPath ~/.ssh/master-%r@%n:%p
  ControlPersist no

server's /etc/ssh/sshd_config (it's from the nixos install iso)

AuthorizedPrincipalsFile none
Ciphers [email protected],[email protected],[email protected],aes256-ctr,aes192-ctr,aes128-ctr
GatewayPorts no
KbdInteractiveAuthentication yes
KexAlgorithms [email protected],curve25519-sha256,[email protected],diffie-hellman-group-exchange-sha256
LogLevel INFO
Macs [email protected],[email protected],[email protected]
PasswordAuthentication yes
PermitRootLogin yes
PrintMotd no
StrictModes yes
UseDns no
UsePAM yes
X11Forwarding no
Banner none
AddressFamily any
Port 22
Subsystem sftp /nix/store/78mv13w9mgh0s0rd7rnr6ff4d7a39bpd-openssh-9.7p1/libexec/sftp-server 
AuthorizedKeysFile %h/.ssh/authorized_keys /etc/ssh/authorized_keys.d/%u
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_ed25519_key

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 5 points 1 month ago

Yep, this is the reason. I have many different identity key files in my ~/.ssh folder, and for some reason ssh always tries all of those first, then exhausts the login tries and doesn't ask for a password.

I have the same problem when I specify a specific private key file with -i ./path/to/priv.key. If that key is different than the ones in my .ssh folder, it will use all those first before the specified one, and often exhausts login attempts giving a very hard to diagnose login failure. In that case I need -o IdentitiesOnly yes option to tell ssh to only use the one I specified.