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 X-MimeOLE: Produced By Microsoft Exchange V6.0.4417.0 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Subject: RE: openSSH 'privilege separation feature Date: Mon, 24 Jun 2002 10:51:57 -0400 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: From: "Harig, Mark A." To: "Tony Arnold" , Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id g5OErho29915 Corinna Vinschen made it pretty clear at the start of the announcement of the availability of OpenSSH 3.3p1-1 that the Cygwin version would NOT support privilege separation: > This release introduces privilege separation (see official release > message below) as default setting. Since privilege separation requires > the OS to be able to transmit file descriptors via sendmsg(2)/recvmsg(2), > this doesn't work in current Cygwin releases. However, in Cygwin the > /etc/sshd_config file must contain the following line to let sshd work: > > UsePrivilegeSeparation no > -----Original Message----- > From: Tony Arnold [mailto:tony DOT arnold AT man DOT ac DOT uk] > Sent: Monday, June 24, 2002 10:32 AM > To: cygwin AT cygwin DOT com > Subject: openSSH 'privilege separation feature > > > 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/ > > -- 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/