Secure Shell (A.05.00.014) - Unable to connect with PuTTY

[Russell.Wood]

I have just installed the latest version of Secure Shell on 11.31 ia64 VM Guest and now I can no longer connect using PuTTY. The previous version work (A.05.00.014).

Strangely, connecting from other HP-UX servers (11.11 pa, 11.23 pa/ia64) using their ssh client works.

Has anyone experienced this before and know the solution?

Client Log:----------------
2008-05-22 14:01:50 Looking up host "devuv"
2008-05-22 14:01:50 Connecting to 172.16.5.20 port 22
2008-05-22 14:01:50 Server version: SSH-2.0-OpenSSH_5.0p1+sftpfilecontrol-v1.2-hpn13v1
2008-05-22 14:01:50 We claim version: SSH-2.0-PuTTY_Release_0.60
2008-05-22 14:01:50 Using SSH protocol version 2
2008-05-22 14:01:50 Doing Diffie-Hellman group exchange
2008-05-22 14:01:50 Doing Diffie-Hellman key exchange with hash SHA-256
2008-05-22 14:01:51 Host key fingerprint is:
2008-05-22 14:01:51 ssh-rsa 2048 65:96:19:b4:e0:c9:f1:12:50:70:8d:87:4f:82:49:b7
2008-05-22 14:01:51 Initialised AES-256 SDCTR client->server encryption
2008-05-22 14:01:51 Initialised HMAC-SHA1 client->server MAC algorithm
2008-05-22 14:01:51 Initialised AES-256 SDCTR server->client encryption
2008-05-22 14:01:51 Initialised HMAC-SHA1 server->client MAC algorithm
2008-05-22 14:01:52 Keyboard-interactive authentication refused
2008-05-22 14:01:54 Sent password
2008-05-22 14:01:54 Access granted
2008-05-22 14:01:54 Opened channel for session
2008-05-22 14:01:55 Allocated pty (ospeed 38400bps, ispeed 38400bps)
2008-05-22 14:01:55 Server unexpectedly closed network connection

Server Log:----------------
/sbin/init.d/secsh start
debug1: Config token is protocol
debug1: Config token is loglevel
debug1: Config token is permitrootlogin
debug1: Config token is passwordauthentication
debug1: Config token is usepam
debug1: Config token is x11forwarding
debug1: Config token is x11uselocalhost
debug1: Config token is hpndisabled
debug1: Config token is subsystem
debug1: sshd version OpenSSH_5.0p1+sftpfilecontrol-v1.2-hpn13v1 [ HP-UX Secure Shell-A.05.00.014 ]
debug1: read PEM private key done: type RSA
debug1: private host key: #0 type 1 RSA
debug1: read PEM private key done: type DSA
debug1: private host key: #1 type 2 DSA
debug1: rexec_argv[0]='/opt/ssh/sbin/sshd'
debug1: rexec_argv[1]='-d'
debug1: Bind to port 22 on ::.
debug1: Server TCP RWIN socket size: 32768
debug1: HPN Buffer Size: 131072
Server listening on :: port 22.
debug1: Bind to port 22 on 0.0.0.0.
debug1: Server TCP RWIN socket size: 32768
debug1: HPN Buffer Size: 131072
Server listening on 0.0.0.0 port 22.
debug1: Server will not fork when running in debugging mode.
debug1: rexec start in 6 out 6 newsock 6 pipe -1 sock 9
debug1: inetd sockets after dupping: 4, 4
debug1: audit connection from 172.16.6.98 port 4074 euid 0
Connection from 172.16.6.98 port 4074
debug1: Client protocol version 2.0; client software version PuTTY_Release_0.60
SSH: Server;Ltype: Version;Remote: 172.16.6.98-4074;Protocol: 2.0;Client: PuTTY_Release_0.60
debug1: no match: PuTTY_Release_0.60
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.0p1+sftpfilecontrol-v1.2-hpn13v1
debug1: permanently_set_uid: 105/105
debug1: MYFLAG IS 1
debug1: list_hostkey_types: ssh-rsa,ssh-dss
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: AUTH STATE IS 0
debug1: REQUESTED ENC.NAME is 'aes256-ctr'
debug1: kex: client->server aes256-ctr hmac-sha1 none
SSH: Server;Ltype: Kex;Remote: 172.16.6.98-4074;Enc: aes256-ctr;MAC: hmac-sha1;Comp: none
debug1: REQUESTED ENC.NAME is 'aes256-ctr'
debug1: kex: server->client aes256-ctr hmac-sha1 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST_OLD received
debug1: SSH2_MSG_KEX_DH_GEX_GROUP sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_INIT
debug1: SSH2_MSG_KEX_DH_GEX_REPLY sent
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: KEX done
debug1: userauth-request for user rjw service ssh-connection method none
SSH: Server;Ltype: Authname;Remote: 172.16.6.98-4074;Name: rjw
debug1: attempt 0 failures 0
debug1: Config token is protocol
debug1: Config token is loglevel
debug1: Config token is permitrootlogin
debug1: Config token is passwordauthentication
debug1: Config token is usepam
debug1: Config token is x11forwarding
debug1: Config token is x11uselocalhost
debug1: Config token is hpndisabled
debug1: Config token is subsystem
Failed none for rjw from 172.16.6.98 port 4074 ssh2
debug1: audit event euid 0 user rjw event 3 (AUTH_FAIL_NONE)
debug1: userauth-request for user rjw service ssh-connection method keyboard-interactive
debug1: attempt 1 failures 1
debug1: keyboard-interactive devs
debug1: auth2_challenge: user=rjw devs=
debug1: kbdint_alloc: devices ''
debug1: userauth-request for user rjw service ssh-connection method password
debug1: attempt 2 failures 2
Accepted password for rjw from 172.16.6.98 port 4074 ssh2
debug1: monitor_child_preauth: rjw has been authenticated by privileged process
debug1: audit event euid 0 user rjw event 2 (AUTH_SUCCESS)
debug1: permanently_set_uid: 3222/102
debug1: Entering interactive session for SSH2.
debug1: server_init_dispatch_20
debug1: server_input_channel_open: ctype session rchan 256 win 16384 max 16384
debug1: input_session_request
debug1: channel 0: new [server-session]
debug1: session_new: init
debug1: session_new: session 0
debug1: session_open: channel 0
debug1: session_open: session 0: link with channel 0
debug1: server_input_channel_open: confirm session
debug1: server_input_channel_req: channel 0 request pty-req reply 1
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req pty-req
debug1: Allocating pty.
debug1: session_new: init
debug1: session_new: session 0
debug1: session_pty_req: session 0 alloc /dev/pts/0
debug1: server_input_channel_req: channel 0 request shell reply 1
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 req shell
debug1: #### Writing pid 1325 tty /dev/pts/0 to priviledged process ###
debug1: #### Priviledged process: received pid 1325 tty /dev/pts/0 ###
debug1: audit session open euid 0 user rjw tty name /dev/pts/0
debug1: do_cleanup
debug1: session_pty_cleanup: session 0 release /dev/pts/0
debug1: audit event euid 0 user rjw event 12 (CONNECTION_ABANDON)
EXIT CODE: 255
-----------------------------------------------

[Russell.Wood]

Problem partly resolved. I played around with the ciphers and confirmed that when using any AES cipher the Secure Shell daemon closes the connection (tested with PuTTY and HP-UX SSH client).

I have installed latest OpenSSL depot also.

Any reason why this is happening? The previous version works well with AES.

[Steven E. Protter]

Shalom,

Suggestion:
Go back to secure shell version 4.4.x and let someone else beta test 5.0.x secure shell.

This appears to be a problem with the server software, assuming Putty works with 4.4.x secure shell.

SEP

[Unix System Engineers · Accepted solution]

In the putty configuration under SSH, try changing the order of the Encryption cypher policy by moving 3DES to the top (instead of (over AES) and save it. This worked for us.