Hi!

Im trying to set access from ServerA(SunOS) to ServerB(Some custom Linux with Keyboard Interactive login) with SSH Keys. As a proof of concept I was able to do it between 2 virtual machines. Now in my real life scenario it isnt working.

I created the keys in ServerA, copied them to ServerB, chmod'd .ssh folders to 700 on both ServerA,B.

For me *it seems* its working, but at the end it still falls back to Keyboard Interactive. Here is the log of what I get.

debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Rhosts Authentication disabled, originating port will not be trusted.
debug1: ssh_connect: needpriv 0
debug1: Connecting to xxx.xxx.xxx.xxx [xxx.xxx.xxx.xxx] port 22.
debug1: Connection established.
debug1: identity file /xxx/.ssh/identity type -1
debug1: identity file /xxx/.ssh/id_rsa type 1
debug1: identity file /xxx/.ssh/id_dsa type -1
debug1: Logging to host: xxx.xxx.xxx.xxx
debug1: Local user: xxx Remote user: xxx
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.2
debug1: match: OpenSSH_4.2 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-Sun_SSH_1.1.4
debug1: use_engine is 'yes'
debug1: pkcs11 engine initialized, now setting it as default for RSA, DSA, and symmetric ciphers
debug1: pkcs11 engine initialization complete
debug1: Failed to acquire GSS-API credentials for any mechanisms (No credentials were supplied, or the credentials were unavailable or inaccessible
Unknown code 0
)
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: Peer sent proposed langtags, ctos:
debug1: Peer sent proposed langtags, stoc:
debug1: We proposed langtags, ctos: en-US
debug1: We proposed langtags, stoc: en-US
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: dh_gen_key: priv key bits set: 125/256
debug1: bits set: 1039/2048
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'XXX.XXX.XXX.XXX' is known and matches the RSA host key.
debug1: Found key in /XXX/.ssh/known_hosts:1
debug1: bits set: 1061/2048
debug1: ssh_rsa_verify: signature correct
debug1: newkeys: mode 1
debug1: set_newkeys: setting new keys for 'out' mode
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: newkeys: mode 0
debug1: set_newkeys: setting new keys for 'in' mode
debug1: SSH2_MSG_NEWKEYS received
debug1: done: ssh_kex2.
debug1: send SSH2_MSG_SERVICE_REQUEST
debug1: got SSH2_MSG_SERVICE_ACCEPT
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Trying private key: /XXXX/.ssh/identity
debug1: Trying public key: /xxx/.ssh/id_rsa
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Trying private key: /xxx/.ssh/id_dsa
debug1: Next authentication method: keyboard-interactive
Password:

Are there any helpful messages in /var/log/secure (or another logfile where auth messages are written to) on the target system?

Are the permission bits of ~/.ssh on the target system equal to rwx------ (0700)?

If SELinux is active on the target system, is the label of the ~/.ssh directory equal to ssh_home_t (use "ls -Zd ~/.ssh" to find out)?

There are no helpfull messages, it doesnt even have a /secure folder. I tried cheking a few files around /log but it was useless...

The permissions are all Ok.

The target system is a propietary custom linux the -Zd command didnt work.

Hmm, some more ideas:

Is the public key in ~/.ssh/authorized_keys on the target system written as a single line? Because keys are long strings, sometimes they are pasted as multiple lines instead of a single one. Happened to me several times.

Is public key login disabled in /etc/ssh/sshd_config on the target system (look for PubkeyAuthentication )?

Try to connect using a higher debug level, like ssh -vv or even ssh -vvv . Maybe something useful comes up.

using -vv

 Next authentication method: publickey
debug1: Trying private key: /xxx/.ssh/identity
debug1: Trying public key: /xxx/.ssh/id_rsa
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Trying private key: /xxx/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug1: Next authentication method: keyboard-interactive

Doesn't look like much. You sent a RSA key to the target host, but it didn't like it. Try ssh -vvv too.

If that does not reveal anything useful, you have to make your sshd on the target machine write to syslog. Check SyslogFacility and LogLevel in /etc/ssh/sshd_config and verify, that the syslog messages are actually written somewhere (check /etc/syslog.conf). Can't say much more considering the fact you have some sort of custom linux.

First of all thanks a lot hergp for your help. I finally figured out what was happening.

Problem was that I didnt have the following keys enabled in the sshd_config file:

RSAAuthentication yes
PubKeyAuthentication yes
AuthorizedKeysFlle %h/.ssh/authorized_keys

ssh-copy-id