[SOLVED] SSH chaining (tunnelling) problem with public keys

[lmendes1979]

Hello,

I've been searching for a while in forums about the issue I'm facing but couldn't find anything clear, or at least my net search skills are pretty lame.
I'm facing a problem with prompted user password in a SSH chain connection when using authorized_keys.

I have:

(1) Client - (2) Server - (3) Testing machine (testing machine is connect to Server via usb network)

I've created keys for Client and Server, and updated authorized_keys in host machines with the key values:

Testing machine has Server public key, and Server has Client public key.

Until now everything is fine, if I try to connect via ssh the user password prompt is not shown since public key is found in authorized_keys.

For example:

from Client:

ssh server

Works fine, no password prompt.

from Server:

ssh testing_machine

Works fine, no password prompt.

But if try to do that from Client only:

from Client:

client:$ ssh server

Works fine, no password prompt.

from Client:

server:$ ssh testing_machine

Asks for password.

Bellow the verbose output from previous ssh command:

ssh -v root(at)192.168.100.2
OpenSSH_5.3p1 Debian-3ubuntu4, OpenSSL 0.9.8k 25 Mar 2009
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 192.168.100.2 [192.168.100.2] port 22.
debug1: Connection established.
debug1: identity file /home/hudson/.ssh/identity type -1
debug1: identity file /home/hudson/.ssh/id_rsa type -1
debug1: identity file /home/hudson/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3p1 Debian-3ubuntu4
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: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host '192.168.100.2' is known and matches the RSA host key.
debug1: Found key in /home/hudson/.ssh/known_hosts:1
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Trying private key: /home/hudson/.ssh/identity
debug1: Trying private key: /home/hudson/.ssh/id_rsa
debug1: Trying private key: /home/hudson/.ssh/id_dsa
debug1: Next authentication method: password
root(at)192.168.100.2's password:

I feel like I'm missing something pretty basic, but could not find solution for this in the last couple of days...

Anyone ever faced the same issue ?

[lmendes1979]

From verbose output it seems it was looking for id_dsa key, I had renamed it to something else to be more human 'readable', tried to rename it back but same problem persisted.

Tried a clean start.

1. Deleted all authorized_keys
2. Deleted all known_hosts
3. Deleted all public/private keys
4. Created again all keys "ssh-keygen -t dsa" and left default name
5. Copied public keys to right locations "ssh-copy-id"

And now it works!
Guess I've messed up trying to rename private/public keys or something