Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com From: "Tony Arnold" To: Subject: openSSH 'privilege separation feature Date: Mon, 24 Jun 2002 15:31:35 +0100 Organization: University of Manchester Message-ID: <31CB870AD5AA384BB5419025DD9F7A841042B3@dailymail.cfs.ac.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Importance: Normal Dear Cygwinners! I've just upgraded to the latest OpenSSH cygwin package, viz., 3.3p1-1 and it seems the new 'privilege separation' feature is causing problems. The first problem was that after upgrading, the sshd service would not start. /var/log/sshd.log indicated the username sshd did not exist so 'privilelge separation' did not work. I then followed some instructiosn on the Openssh WEB pages which said I had to create a user called sshd and also a group sshd and also create a directory /var/empty which I chown'd to SYSTEM.SYSTEM. The sshd service would then start without error. However, when trying to ssh to my PC, debug output from sshd shows the following: ----------- sshd output starts here ------------------- C:\cygwin\usr\sbin>sshd -d > sshd.log debug1: sshd version OpenSSH_3.3 debug1: private host key: #0 type 0 RSA1 debug1: read PEM private key done: type RSA debug1: private host key: #1 type 1 RSA debug1: read PEM private key done: type DSA debug1: private host key: #2 type 2 DSA debug1: Bind to port 22 on 0.0.0.0. Server listening on 0.0.0.0 port 22. Generating 768 bit RSA key. RSA key generation complete. debug1: Server will not fork when running in debugging mode. Connection from 130.88.201.150 port 2608 debug1: Client protocol version 2.0; client software version OpenSSH_3.3 debug1: match: OpenSSH_3.3 pat OpenSSH* Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-1.99-OpenSSH_3.3 debug1: list_hostkey_types: ssh-rsa,ssh-dss debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: client->server aes128-cbc hmac-md5 none debug1: kex: server->client aes128-cbc hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST received debug1: SSH2_MSG_KEX_DH_GEX_GROUP sent debug1: dh_gen_key: priv key bits set: 122/256 debug1: bits set: 1615/3191 debug1: expecting SSH2_MSG_KEX_DH_GEX_INIT debug1: bits set: 1616/3191 debug1: SSH2_MSG_KEX_DH_GEX_REPLY sent debug1: kex_derive_keys debug1: newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: waiting for SSH2_MSG_NEWKEYS debug1: newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: KEX done debug1: userauth-request for user zzalsaca service ssh-connection method none debug1: attempt 0 failures 0 Failed none for zzalsaca from 130.88.201.150 port 2608 ssh2 Failed none for zzalsaca from 130.88.201.150 port 2608 ssh2 debug1: userauth-request for user zzalsaca service ssh-connection method publick ey debug1: attempt 1 failures 1 debug1: test whether pkalg/pkblob are acceptable debug1: temporarily_use_uid: 1000/513 (e=18) debug1: trying public key file /home/zzalsaca/.ssh/authorized_keys debug1: matching key found: file /home/zzalsaca/.ssh/authorized_keys, line 1 Found matching DSA key: 84:41:80:86:3c:50:aa:c6:92:c0:c0:1a:3e:ab:46:ab debug1: restore_uid Postponed publickey for zzalsaca from 130.88.201.150 port 2608 ssh2 debug1: userauth-request for user zzalsaca service ssh-connection method publick ey debug1: attempt 2 failures 1 debug1: temporarily_use_uid: 1000/513 (e=18) debug1: trying public key file /home/zzalsaca/.ssh/authorized_keys debug1: matching key found: file /home/zzalsaca/.ssh/authorized_keys, line 1 Found matching DSA key: 84:41:80:86:3c:50:aa:c6:92:c0:c0:1a:3e:ab:46:ab debug1: restore_uid debug1: ssh_dss_verify: signature correct Accepted hostbased for zzalsaca from 130.88.201.150 port 2608 ssh2 debug1: monitor_child_preauth: zzalsaca has been authenticated by privileged pro cess Accepted publickey for zzalsaca from 130.88.201.150 port 2608 ssh2 debug1: newkeys: mode 0 debug1: newkeys: mode 1 debug1: Entering interactive session for SSH2. debug1: fd 7 setting O_NONBLOCK debug1: fd 8 setting O_NONBLOCK debug1: server_init_dispatch_20 debug1: server_input_channel_open: ctype session rchan 0 win 65536 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 0 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 mm_send_fd: sendmsg(3): Bad address debug1: Calling cleanup 0x415acc(0x446474) debug1: session_pty_cleanup: session 0 release /dev/tty2 syslogin_perform_logout: logout() returned an error debug1: Calling cleanup 0x41c724(0x0) mm_receive_fd: recvmsg: expected received 1 got 0 debug1: Calling cleanup 0x427064(0x0) debug1: channel_free: channel 0: server-session, nchannels 1 debug1: Calling cleanup 0x41c724(0x0) C:\cygwin\usr\sbin> -------------- sshd output ends here ------------------ It looks to me like the line starting mm_send_fd is where the problem lies, but I don't know what it means. Can anyone help? Regards, Tony. -- Tony Arnold, Deputy to the Head of COS Division, Manchester Computing, University of Manchester, Oxford Road, Manchester M13 9PL. T: +44 (0)161 275 6093, F: +44 (0)870 136 1004, M: +44 (0)773 330 0039 E-mail: tony DOT arnold AT man DOT ac DOT uk, Home: http://www.man.ac.uk/Tony.Arnold -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/