Connection problem

We have two test servers in our lan which we use for testing the SSH connection and file transfer.

We've successfully tested the connection the other day, but somehow today it won't work.

Here's the info:
I've created two keys with Putty keygen.
I've copied public key to server 2 and saved the private key to server 1.
I've installed freeSSHd on server 2 and also created a user.
Everything is setup as it should but I can't connect anymore..

Here's the log about this connection:

. 2008-01-31 14:42:11.513 --------------------------------------------------------------------------
. 2008-01-31 14:42:11.513 WinSCP Version 4.0.6 (Build 358) (OS 6.0.6000)
. 2008-01-31 14:42:11.514 Login time: 31. siječanj 2008 14:42:11
. 2008-01-31 14:42:11.514 --------------------------------------------------------------------------
. 2008-01-31 14:42:11.514 Session name: cafmtest
. 2008-01-31 14:42:11.514 Host name: xx.xxx.xxx.164 (Port: 22)
. 2008-01-31 14:42:11.515 User name: testinguser (Password: No, Key file: Yes)
. 2008-01-31 14:42:11.515 Tunnel: No
. 2008-01-31 14:42:11.515 Transfer Protocol: SFTP (SCP)
. 2008-01-31 14:42:11.515 Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
. 2008-01-31 14:42:11.515 Proxy: none
. 2008-01-31 14:42:11.515 SSH protocol version: 2; Compression: No
. 2008-01-31 14:42:11.515 Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
. 2008-01-31 14:42:11.515 Ciphers: aes,blowfish,3des,WARN,des; Ssh2DES: No
. 2008-01-31 14:42:11.515 SSH Bugs: -,-,-,-,-,-,-,-
. 2008-01-31 14:42:11.515 SFTP Bugs: -,-,-
. 2008-01-31 14:42:11.515 Return code variable: Autodetect; Lookup user groups: Yes
. 2008-01-31 14:42:11.515 Shell: default, EOL: 0
. 2008-01-31 14:42:11.515 Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
. 2008-01-31 14:42:11.515 Alias LS: No, Ign LS warn: Yes, Scp1 Comp: No
. 2008-01-31 14:42:11.515 Local directory: default, Remote directory: home, Update: No, Cache: Yes
. 2008-01-31 14:42:11.515 Cache directory changes: Yes, Permanent: Yes
. 2008-01-31 14:42:11.516 DST mode: 1
. 2008-01-31 14:42:11.516 --------------------------------------------------------------------------
. 2008-01-31 14:42:11.627 Looking up host "xx.xx.xx.164"
. 2008-01-31 14:42:11.628 Connecting to xx.xx.xx.164 port 22
. 2008-01-31 14:42:11.631 Selecting events 63 for socket 588
. 2008-01-31 14:42:11.640 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:11.640 Looking for incoming data
. 2008-01-31 14:42:11.640 Looking for network events
. 2008-01-31 14:42:11.640 Detected network event
. 2008-01-31 14:42:11.640 Enumerating network events for socket 588
. 2008-01-31 14:42:11.640 Enumerated 19 network events making 19 cumulative events for socket 588
. 2008-01-31 14:42:11.641 Handling network read event on socket 588 with error 0
. 2008-01-31 14:42:11.641 Server version: SSH-2.0-WeOnlyDo 2.0.0
. 2008-01-31 14:42:11.641 We claim version: SSH-2.0-WinSCP_release_4.0.6
. 2008-01-31 14:42:11.641 Using SSH protocol version 2
. 2008-01-31 14:42:11.641 Handling network write event on socket 588 with error 0
. 2008-01-31 14:42:11.641 Handling network connect event on socket 588 with error 0
. 2008-01-31 14:42:11.642 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:11.642 Looking for incoming data
. 2008-01-31 14:42:11.642 Looking for network events
. 2008-01-31 14:42:11.642 Detected network event
. 2008-01-31 14:42:11.642 Enumerating network events for socket 588
. 2008-01-31 14:42:11.642 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:11.643 Handling network read event on socket 588 with error 0
. 2008-01-31 14:42:11.643 Using Diffie-Hellman with standard group "group14"
. 2008-01-31 14:42:11.643 Doing Diffie-Hellman key exchange
. 2008-01-31 14:42:11.774 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:11.774 Looking for incoming data
. 2008-01-31 14:42:11.774 Looking for network events
. 2008-01-31 14:42:12.060 Detected network event
. 2008-01-31 14:42:12.060 Enumerating network events for socket 588
. 2008-01-31 14:42:12.061 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:12.061 Handling network read event on socket 588 with error 0
. 2008-01-31 14:42:12.265 Selecting events 63 for socket 588
. 2008-01-31 14:42:12.265 Host key fingerprint is:
. 2008-01-31 14:42:12.265 ssh-rsa 1024 68:c1:ea:c3:98:18:55:b2:b0:1c:90:2c:c7:06:85:b2
. 2008-01-31 14:42:12.265 Initialised AES-256 client->server encryption
. 2008-01-31 14:42:12.266 Initialised HMAC-SHA1 client->server MAC algorithm
. 2008-01-31 14:42:12.266 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:12.266 Looking for incoming data
. 2008-01-31 14:42:12.266 Looking for network events
. 2008-01-31 14:42:12.266 Detected network event
. 2008-01-31 14:42:12.266 Enumerating network events for socket 588
. 2008-01-31 14:42:12.266 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:12.266 Handling network read event on socket 588 with error 0
. 2008-01-31 14:42:12.266 Initialised AES-256 server->client encryption
. 2008-01-31 14:42:12.266 Initialised HMAC-SHA1 server->client MAC algorithm
. 2008-01-31 14:42:12.266 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:12.266 Looking for incoming data
. 2008-01-31 14:42:12.267 Looking for network events
. 2008-01-31 14:42:12.267 Detected network event
. 2008-01-31 14:42:12.267 Enumerating network events for socket 588
. 2008-01-31 14:42:12.267 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:12.267 Handling network read event on socket 588 with error 0
! 2008-01-31 14:42:12.267 Using username "testinguser".
. 2008-01-31 14:42:12.280 Reading private key file "C:\pathtothekey\private.ppk"
. 2008-01-31 14:42:12.281 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:12.281 Looking for incoming data
. 2008-01-31 14:42:12.281 Looking for network events
. 2008-01-31 14:42:12.281 Detected network event
. 2008-01-31 14:42:12.281 Enumerating network events for socket 588
. 2008-01-31 14:42:12.281 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:12.281 Handling network read event on socket 588 with error 0
. 2008-01-31 14:42:12.282 Offered public key
. 2008-01-31 14:42:12.282 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:12.282 Looking for incoming data
. 2008-01-31 14:42:12.282 Looking for network events
. 2008-01-31 14:42:12.282 Detected network event
. 2008-01-31 14:42:12.282 Enumerating network events for socket 588
. 2008-01-31 14:42:12.282 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:12.282 Handling network read event on socket 588 with error 0
. 2008-01-31 14:42:12.282 Offer of public key accepted
! 2008-01-31 14:42:12.283 Authenticating with public key "rsa-key-20080131"
. 2008-01-31 14:42:12.436 Waiting for the server to continue with the initialisation
. 2008-01-31 14:42:12.436 Looking for incoming data
. 2008-01-31 14:42:12.436 Looking for network events
. 2008-01-31 14:42:12.437 Detected network event
. 2008-01-31 14:42:12.437 Enumerating network events for socket 588
. 2008-01-31 14:42:12.437 Enumerated 1 network events making 1 cumulative events for socket 588
. 2008-01-31 14:42:12.437 Handling network read event on socket 588 with error 0
! 2008-01-31 14:42:12.437 Access denied
. 2008-01-31 14:42:12.441 Access denied
! 2008-01-31 14:42:12.441 No supported authentication methods left to try!
. 2008-01-31 14:42:12.445 No supported authentications offered. Disconnecting
. 2008-01-31 14:42:12.445 Selecting events 0 for socket 588
. 2008-01-31 14:42:12.445 Server closed network connection
* 2008-01-31 14:42:12.478 (ESshFatal) Connection has been unexpectedly closed. Server sent command exit status 0.
* 2008-01-31 14:42:12.478 Authentication log (see session log for details):
* 2008-01-31 14:42:12.478 Using username "testinguser".
* 2008-01-31 14:42:12.478 Authenticating with public key "rsa-key-20080131".
* 2008-01-31 14:42:12.478 Access denied.
* 2008-01-31 14:42:12.478 No supported authentication methods left to try!
* 2008-01-31 14:42:12.478
* 2008-01-31 14:42:12.478 Authentication failed.

. 2008-01-31 14:40:46.644 Handling network read event on socket 576 with error 0
! 2008-01-31 14:40:46.644 Access denied
. 2008-01-31 14:40:46.648 Access denied
. 2008-01-31 14:40:46.648 Session password prompt (testing user@xx.xxx.xx.xxx's password: )
. 2008-01-31 14:40:49.323 Unable to authenticate
. 2008-01-31 14:40:49.323 Attempt to close connection due to fatal exception:
* 2008-01-31 14:40:49.324 Unable to authenticate
. 2008-01-31 14:40:49.324 Closing connection.
. 2008-01-31 14:40:49.324 Selecting events 0 for socket 576
* 2008-01-31 14:40:49.387 (ESshFatal) Unable to authenticate
* 2008-01-31 14:40:49.387 Authentication log (see session log for details):
* 2008-01-31 14:40:49.387 Using username "testinguser".
* 2008-01-31 14:40:49.387 Authenticating with public key "rsa-key-20080131".
* 2008-01-31 14:40:49.387 Access denied.
* 2008-01-31 14:40:49.387
* 2008-01-31 14:40:49.387 Authentication failed.

To which server are you tring to connect? 1 or 2?

martin wrote:

To which server are you tring to connect? 1 or 2?

I'm trying to connect to server 2 and I've found the solution..

I've created two 512bit keys and everything is working now...When I create 1024bit keys or above it won't work with FreeSSHd client, at least not every time, sometimes I'm able to connect.

Any ideas why it won't work with 1024bit keys?