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2009-04-06Add a comment above PermitRootLogin in sshd_config pointing toColin Watson
README.Debian.
2008-07-22* New upstream release (closes: #474301). Important changes not previouslyColin Watson
backported to 4.7p1: - 4.9/4.9p1 (http://www.openssh.com/txt/release-4.9): + Added chroot(2) support for sshd(8), controlled by a new option "ChrootDirectory" (closes: #139047, LP: #24777). + Linked sftp-server(8) into sshd(8). The internal sftp server is used when the command "internal-sftp" is specified in a Subsystem or ForceCommand declaration. When used with ChrootDirectory, the internal sftp server requires no special configuration of files inside the chroot environment. + Added a protocol extension method "posix-rename@openssh.com" for sftp-server(8) to perform POSIX atomic rename() operations; sftp(1) prefers this if available (closes: #308561). + Removed the fixed limit of 100 file handles in sftp-server(8). + ssh(8) will now skip generation of SSH protocol 1 ephemeral server keys when in inetd mode and protocol 2 connections are negotiated. This speeds up protocol 2 connections to inetd-mode servers that also allow Protocol 1. + Accept the PermitRootLogin directive in a sshd_config(5) Match block. Allows for, e.g. permitting root only from the local network. + Reworked sftp(1) argument splitting and escaping to be more internally consistent (i.e. between sftp commands) and more consistent with sh(1). Please note that this will change the interpretation of some quoted strings, especially those with embedded backslash escape sequences. + Support "Banner=none" in sshd_config(5) to disable sending of a pre-login banner (e.g. in a Match block). + ssh(1) ProxyCommands are now executed with $SHELL rather than /bin/sh. + ssh(1)'s ConnectTimeout option is now applied to both the TCP connection and the SSH banner exchange (previously it just covered the TCP connection). This allows callers of ssh(1) to better detect and deal with stuck servers that accept a TCP connection but don't progress the protocol, and also makes ConnectTimeout useful for connections via a ProxyCommand. + scp(1) incorrectly reported "stalled" on slow copies (closes: #140828). + scp(1) date underflow for timestamps before epoch. + ssh(1) used the obsolete SIG DNS RRtype for host keys in DNS, instead of the current standard RRSIG. + Correctly drain ACKs when a sftp(1) upload write fails midway, avoids a fatal() exit from what should be a recoverable condition. + Fixed ssh-keygen(1) selective host key hashing (i.e. "ssh-keygen -HF hostname") to not include any IP address in the data to be hashed. + Make ssh(1) skip listening on the IPv6 wildcard address when a binding address of 0.0.0.0 is used against an old SSH server that does not support the RFC4254 syntax for wildcard bind addresses. + Enable IPV6_V6ONLY socket option on sshd(8) listen socket, as is already done for X11/TCP forwarding sockets (closes: #439661). + Fix FD leak that could hang a ssh(1) connection multiplexing master. + Make ssh(1) -q option documentation consistent with reality. + Fixed sshd(8) PAM support not calling pam_session_close(), or failing to call it with root privileges (closes: #372680). + Fix activation of OpenSSL engine support when requested in configure (LP: #119295). - 5.1/5.1p1 (http://www.openssh.com/txt/release-5.1): + Introduce experimental SSH Fingerprint ASCII Visualisation to ssh(1) and ssh-keygen(1). Visual fingerprint display is controlled by a new ssh_config(5) option "VisualHostKey". The intent is to render SSH host keys in a visual form that is amenable to easy recall and rejection of changed host keys. + sshd_config(5) now supports CIDR address/masklen matching in "Match address" blocks, with a fallback to classic wildcard matching. + sshd(8) now supports CIDR matching in ~/.ssh/authorized_keys from="..." restrictions, also with a fallback to classic wildcard matching. + Added an extended test mode (-T) to sshd(8) to request that it write its effective configuration to stdout and exit. Extended test mode also supports the specification of connection parameters (username, source address and hostname) to test the application of sshd_config(5) Match rules. + ssh(1) now prints the number of bytes transferred and the overall connection throughput for SSH protocol 2 sessions when in verbose mode (previously these statistics were displayed for protocol 1 connections only). + sftp-server(8) now supports extension methods statvfs@openssh.com and fstatvfs@openssh.com that implement statvfs(2)-like operations. + sftp(1) now has a "df" command to the sftp client that uses the statvfs@openssh.com to produce a df(1)-like display of filesystem space and inode utilisation (requires statvfs@openssh.com support on the server). + Added a MaxSessions option to sshd_config(5) to allow control of the number of multiplexed sessions supported over a single TCP connection. This allows increasing the number of allowed sessions above the previous default of 10, disabling connection multiplexing (MaxSessions=1) or disallowing login/shell/subsystem sessions entirely (MaxSessions=0). + Added a no-more-sessions@openssh.com global request extension that is sent from ssh(1) to sshd(8) when the client knows that it will never request another session (i.e. when session multiplexing is disabled). This allows a server to disallow further session requests and terminate the session in cases where the client has been hijacked. + ssh-keygen(1) now supports the use of the -l option in combination with -F to search for a host in ~/.ssh/known_hosts and display its fingerprint. + ssh-keyscan(1) now defaults to "rsa" (protocol 2) keys, instead of "rsa1". + Added an AllowAgentForwarding option to sshd_config(8) to control whether authentication agent forwarding is permitted. Note that this is a loose control, as a client may install their own unofficial forwarder. + ssh(1) and sshd(8): avoid unnecessary malloc/copy/free when receiving network data, resulting in a ~10% speedup. + ssh(1) and sshd(8) will now try additional addresses when connecting to a port forward destination whose DNS name resolves to more than one address. The previous behaviour was to try the only first address and give up if that failed. + ssh(1) and sshd(8) now support signalling that channels are half-closed for writing, through a channel protocol extension notification "eow@openssh.com". This allows propagation of closed file descriptors, so that commands such as "ssh -2 localhost od /bin/ls | true" do not send unnecessary data over the wire. + sshd(8): increased the default size of ssh protocol 1 ephemeral keys from 768 to 1024 bits. + When ssh(1) has been requested to fork after authentication ("ssh -f") with ExitOnForwardFailure enabled, delay the fork until after replies for any -R forwards have been seen. Allows for robust detection of -R forward failure when using -f. + "Match group" blocks in sshd_config(5) now support negation of groups. E.g. "Match group staff,!guests". + sftp(1) and sftp-server(8) now allow chmod-like operations to set set[ug]id/sticky bits. + The MaxAuthTries option is now permitted in sshd_config(5) match blocks. + Multiplexed ssh(1) sessions now support a subset of the ~ escapes that are available to a primary connection. + ssh(1) connection multiplexing will now fall back to creating a new connection in most error cases (closes: #352830). + Make ssh(1) deal more gracefully with channel requests that fail. Previously it would optimistically assume that requests would always succeed, which could cause hangs if they did not (e.g. when the server runs out of file descriptors). + ssh(1) now reports multiplexing errors via the multiplex slave's stderr where possible (subject to LogLevel in the mux master). + Prevent sshd(8) from erroneously applying public key restrictions leaned from ~/.ssh/authorized_keys to other authentication methods when public key authentication subsequently fails (LP: #161047). + Fixed an UMAC alignment problem that manifested on Itanium platforms.
2008-07-02 - djm@cvs.openbsd.org 2008/07/02 02:24:18Darren Tucker
[sshd_config sshd_config.5 sshd.8 servconf.c] increase default size of ssh protocol 1 ephemeral key from 768 to 1024 bits; prodded by & ok dtucker@ ok deraadt@
2008-05-19 - djm@cvs.openbsd.org 2008/05/08 12:21:16Damien Miller
[monitor.c monitor_wrap.c session.h servconf.c servconf.h session.c] [sshd_config sshd_config.5] Make the maximum number of sessions run-time controllable via a sshd_config MaxSessions knob. This is useful for disabling login/shell/subsystem access while leaving port-forwarding working (MaxSessions 0), disabling connection multiplexing (MaxSessions 1) or simply increasing the number of allows multiplexed sessions. Because some bozos are sure to configure MaxSessions in excess of the number of available file descriptors in sshd (which, at peak, might be as many as 9*MaxSessions), audit sshd to ensure that it doesn't leak fds on error paths, and make it fail gracefully on out-of-fd conditions - sending channel errors instead of than exiting with fatal(). bz#1090; MaxSessions config bits and manpage from junyer AT gmail.com ok markus@
2008-05-19 - pyr@cvs.openbsd.org 2008/05/07 06:43:35Damien Miller
[sshd_config] push the sshd_config bits in, spotted by ajacoutot@
2008-02-10 - djm@cvs.openbsd.org 2008/02/08 23:24:07Damien Miller
[servconf.c servconf.h session.c sftp-server.c sftp.h sshd_config] [sshd_config.5] add sshd_config ChrootDirectory option to chroot(2) users to a directory and tweak internal sftp server to work with it (no special files in chroot required). ok markus@
2007-12-24* New upstream release (closes: #453367).Colin Watson
- CVE-2007-4752: Prevent ssh(1) from using a trusted X11 cookie if creation of an untrusted cookie fails; found and fixed by Jan Pechanec (closes: #444738). - sshd(8) in new installations defaults to SSH Protocol 2 only. Existing installations are unchanged. - The SSH channel window size has been increased, and both ssh(1) sshd(8) now send window updates more aggressively. These improves performance on high-BDP (Bandwidth Delay Product) networks. - ssh(1) and sshd(8) now preserve MAC contexts between packets, which saves 2 hash calls per packet and results in 12-16% speedup for arcfour256/hmac-md5. - A new MAC algorithm has been added, UMAC-64 (RFC4418) as "umac-64@openssh.com". UMAC-64 has been measured to be approximately 20% faster than HMAC-MD5. - Failure to establish a ssh(1) TunnelForward is now treated as a fatal error when the ExitOnForwardFailure option is set. - ssh(1) returns a sensible exit status if the control master goes away without passing the full exit status. - When using a ProxyCommand in ssh(1), set the outgoing hostname with gethostname(2), allowing hostbased authentication to work. - Make scp(1) skip FIFOs rather than hanging (closes: #246774). - Encode non-printing characters in scp(1) filenames. These could cause copies to be aborted with a "protocol error". - Handle SIGINT in sshd(8) privilege separation child process to ensure that wtmp and lastlog records are correctly updated. - Report GSSAPI mechanism in errors, for libraries that support multiple mechanisms. - Improve documentation for ssh-add(1)'s -d option. - Rearrange and tidy GSSAPI code, removing server-only code being linked into the client. - Delay execution of ssh(1)'s LocalCommand until after all forwardings have been established. - In scp(1), do not truncate non-regular files. - Improve exit message from ControlMaster clients. - Prevent sftp-server(8) from reading until it runs out of buffer space, whereupon it would exit with a fatal error (closes: #365541). - pam_end() was not being called if authentication failed (closes: #405041). - Manual page datestamps updated (closes: #433181).
2007-09-17 - djm@cvs.openbsd.org 2007/08/23 03:22:16Damien Miller
[auth2-none.c sshd_config sshd_config.5] Support "Banner=none" to disable displaying of the pre-login banner; ok dtucker@ deraadt@
2007-06-12* New upstream release (closes: #395507, #397961, #420035). ImportantColin Watson
changes not previously backported to 4.3p2: - 4.4/4.4p1 (http://www.openssh.org/txt/release-4.4): + On portable OpenSSH, fix a GSSAPI authentication abort that could be used to determine the validity of usernames on some platforms. + Implemented conditional configuration in sshd_config(5) using the "Match" directive. This allows some configuration options to be selectively overridden if specific criteria (based on user, group, hostname and/or address) are met. So far a useful subset of post-authentication options are supported and more are expected to be added in future releases. + Add support for Diffie-Hellman group exchange key agreement with a final hash of SHA256. + Added a "ForceCommand" directive to sshd_config(5). Similar to the command="..." option accepted in ~/.ssh/authorized_keys, this forces the execution of the specified command regardless of what the user requested. This is very useful in conjunction with the new "Match" option. + Add a "PermitOpen" directive to sshd_config(5). This mirrors the permitopen="..." authorized_keys option, allowing fine-grained control over the port-forwardings that a user is allowed to establish. + Add optional logging of transactions to sftp-server(8). + ssh(1) will now record port numbers for hosts stored in ~/.ssh/known_hosts when a non-standard port has been requested (closes: #50612). + Add an "ExitOnForwardFailure" option to cause ssh(1) to exit (with a non-zero exit code) when requested port forwardings could not be established. + Extend sshd_config(5) "SubSystem" declarations to allow the specification of command-line arguments. + Replacement of all integer overflow susceptible invocations of malloc(3) and realloc(3) with overflow-checking equivalents. + Many manpage fixes and improvements. + Add optional support for OpenSSL hardware accelerators (engines), enabled using the --with-ssl-engine configure option. + Tokens in configuration files may be double-quoted in order to contain spaces (closes: #319639). + Move a debug() call out of a SIGCHLD handler, fixing a hang when the session exits very quickly (closes: #307890). + Fix some incorrect buffer allocation calculations (closes: #410599). + ssh-add doesn't ask for a passphrase if key file permissions are too liberal (closes: #103677). + Likewise, ssh doesn't ask either (closes: #99675). - 4.6/4.6p1 (http://www.openssh.org/txt/release-4.6): + sshd now allows the enabling and disabling of authentication methods on a per user, group, host and network basis via the Match directive in sshd_config. + Fixed an inconsistent check for a terminal when displaying scp progress meter (closes: #257524). + Fix "hang on exit" when background processes are running at the time of exit on a ttyful/login session (closes: #88337). * Update to current GSSAPI patch from http://www.sxw.org.uk/computing/patches/openssh-4.6p1-gsskex-20070312.patch; install ChangeLog.gssapi.
2007-03-21 - djm@cvs.openbsd.org 2007/03/19 01:01:29Darren Tucker
[sshd_config] Disable the legacy SSH protocol 1 for new installations via a configuration override. In the future, we will change the server's default itself so users who need the legacy protocol will need to turn it on explicitly
2006-07-24 - dtucker@cvs.openbsd.org 2006/07/19 13:07:10Damien Miller
[servconf.c servconf.h session.c sshd.8 sshd_config sshd_config.5] Add ForceCommand keyword to sshd_config, equivalent to the "command=" key option, man page entry and example in sshd_config. Feedback & ok djm@, man page corrections & ok jmc@
2006-02-23 - (dtucker) [sshd_config sshd_config.5] Update UsePAM to reflect currentDarren Tucker
reality. Pointed out by tryponraj at gmail.com.
2005-12-13 - reyk@cvs.openbsd.org 2005/12/06 22:38:28Damien Miller
[auth-options.c auth-options.h channels.c channels.h clientloop.c] [misc.c misc.h readconf.c readconf.h scp.c servconf.c servconf.h] [serverloop.c sftp.c ssh.1 ssh.c ssh_config ssh_config.5 sshconnect.c] [sshconnect.h sshd.8 sshd_config sshd_config.5] Add support for tun(4) forwarding over OpenSSH, based on an idea and initial channel code bits by markus@. This is a simple and easy way to use OpenSSH for ad hoc virtual private network connections, e.g. administrative tunnels or secure wireless access. It's based on a new ssh channel and works similar to the existing TCP forwarding support, except that it depends on the tun(4) network interface on both ends of the connection for layer 2 or layer 3 tunneling. This diff also adds support for LocalCommand in the ssh(1) client. ok djm@, markus@, jmc@ (manpages), tested and discussed with others
2005-07-26 - markus@cvs.openbsd.org 2005/07/25 11:59:40Damien Miller
[kex.c kex.h myproposal.h packet.c packet.h servconf.c session.c] [sshconnect2.c sshd.c sshd_config sshd_config.5] add a new compression method that delays compression until the user has been authenticated successfully and set compression to 'delayed' for sshd. this breaks older openssh clients (< 3.5) if they insist on compression, so you have to re-enable compression in sshd_config. ok djm@
2005-05-26 - djm@cvs.openbsd.org 2005/05/19 02:40:52Damien Miller
[sshd_config] whitespace nit, from grunk AT pestilenz.org
2005-01-20 - djm@cvs.openbsd.org 2004/12/23 23:11:00Darren Tucker
[servconf.c servconf.h sshd.c sshd_config sshd_config.5] bz #898: support AddressFamily in sshd_config. from peak@argo.troja.mff.cuni.cz; ok deraadt@
2004-05-24 - dtucker@cvs.openbsd.org 2004/05/23 23:59:53Darren Tucker
[auth.c auth.h auth1.c auth2.c servconf.c servconf.h sshd_config sshd_config.5] Add MaxAuthTries sshd config option; ok markus@
2004-05-23 - (djm) Explain consequences of UsePAM=yes a little better in sshd_config;Damien Miller
ok dtucker@
2003-12-31 - millert@cvs.openbsd.org 2003/12/29 16:39:50Darren Tucker
[sshd_config] KeepAlive has been obsoleted, use TCPKeepAlive instead; markus@ OK
2003-12-31 - jakob@cvs.openbsd.org 2003/12/23 16:12:10Darren Tucker
[servconf.c servconf.h session.c sshd_config] implement KerberosGetAFSToken server option. ok markus@, beck@
2003-11-06 - (djm) Clarify UsePAM consequences a little moreDamien Miller
2003-10-02 - markus@cvs.openbsd.org 2003/09/29 20:19:57Darren Tucker
[servconf.c sshd_config] GSSAPICleanupCreds -> GSSAPICleanupCredentials
2003-09-25[sshd_config] UsePAM defaults to no.Tim Rice
2003-09-02 - markus@cvs.openbsd.org 2003/08/28 12:54:34Damien Miller
[auth-krb5.c auth.h auth1.c monitor.c monitor.h monitor_wrap.c] [monitor_wrap.h readconf.c servconf.c session.c ssh_config.5] [sshconnect1.c sshd.c sshd_config sshd_config.5] remove kerberos support from ssh1, since it has been replaced with GSSAPI; but keep kerberos passwd auth for ssh1 and 2; ok djm, hin, henning, ...
2003-08-26 - markus@cvs.openbsd.org 2003/08/22 10:56:09Darren Tucker
[auth2.c auth2-gss.c auth.h compat.c compat.h gss-genr.c gss-serv-krb5.c gss-serv.c monitor.c monitor.h monitor_wrap.c monitor_wrap.h readconf.c readconf.h servconf.c servconf.h session.c session.h ssh-gss.h ssh_config.5 sshconnect2.c sshd_config sshd_config.5] support GSS API user authentication; patches from Simon Wilkinson, stripped down and tested by Jakob and myself.
2003-08-13 - markus@cvs.openbsd.org 2003/08/13 08:46:31Darren Tucker
[auth1.c readconf.c readconf.h servconf.c servconf.h ssh.c ssh_config ssh_config.5 sshconnect1.c sshd.8 sshd.c sshd_config sshd_config.5] remove RhostsAuthentication; suggested by djm@ before; ok djm@, deraadt@, fgsch@, miod@, henning@, jakob@ and others
2003-08-02 - markus@cvs.openbsd.org 2003/07/23 07:42:43Darren Tucker
[sshd_config] remove AFS; itojun@
2003-06-2220030622Darren Tucker
- (dtucker) OpenBSD CVS Sync - djm@cvs.openbsd.org 2003/06/20 05:48:21 [sshd_config] sync some implemented options; ok markus@
2003-06-03 - (djm) OpenBSD CVS SyncDamien Miller
- markus@cvs.openbsd.org 2003/06/02 09:17:34 [auth2-hostbased.c auth.c auth-options.c auth-rhosts.c auth-rh-rsa.c] [canohost.c monitor.c servconf.c servconf.h session.c sshd_config] [sshd_config.5] deprecate VerifyReverseMapping since it's dangerous if combined with IP based access control as noted by Mike Harding; replace with a UseDNS option, UseDNS is on by default and includes the VerifyReverseMapping check; with itojun@, provos@, jakob@ and deraadt@ ok deraadt@, djm@ - (djm) Fix portable-specific uses of verify_reverse_mapping too
2003-05-16clarifyDamien Miller
2003-05-15 - jakob@cvs.openbsd.org 2003/05/15 01:48:10Damien Miller
[readconf.c readconf.h servconf.c servconf.h] always parse kerberos options. ok djm@ markus@ - (djm) Always parse UsePAM
2002-09-27 - (djm) OpenBSD CVS SyncDamien Miller
- markus@cvs.openbsd.org 2002/09/25 11:17:16 [sshd_config] sync LoginGraceTime with default
2002-09-04 - stevesk@cvs.openbsd.org 2002/08/21 19:38:06Damien Miller
[servconf.c sshd.8 sshd_config sshd_config.5] change LoginGraceTime default to 1 minute; ok mouring@ markus@
2002-08-01 - markus@cvs.openbsd.org 2002/07/30 17:03:55Ben Lindstrom
[auth-options.c servconf.c servconf.h session.c sshd_config sshd_config.5] add PermitUserEnvironment (off by default!); from dot@dotat.at; ok provos, deraadt
2002-06-2720020628Kevin Steves
- (stevesk) [sshd_config] PAMAuthenticationViaKbdInt no; commented options should contain default value. from solar.
2002-06-21 - markus@cvs.openbsd.org 2002/06/20 23:37:12Ben Lindstrom
[sshd_config] add Compression
2002-06-21 - stevesk@cvs.openbsd.org 2002/06/20 20:03:34Ben Lindstrom
[ssh_config sshd_config] refer to config file man page
2002-06-06 - markus@cvs.openbsd.org 2002/05/15 21:56:38Ben Lindstrom
[servconf.c sshd.8 sshd_config] re-enable privsep and disable setuid for post-3.2.2
2002-05-15 - markus@cvs.openbsd.org 2002/05/15 21:02:53Ben Lindstrom
[servconf.c sshd.8 sshd_config] disable privsep and enable setuid for the 3.2.2 release
2002-05-15 - deraadt@cvs.openbsd.org 2002/05/04 02:39:35Ben Lindstrom
[servconf.c sshd.8 sshd_config] enable privsep by default; provos ok (historical)
2002-04-23 - markus@cvs.openbsd.org 2002/04/22 16:16:53Damien Miller
[servconf.c sshd.8 sshd_config] do not auto-enable KerberosAuthentication; ok djm@, provos@, deraadt@
2002-04-23 - stevesk@cvs.openbsd.org 2002/04/21 16:19:27Damien Miller
[sshd.8 sshd_config] document default AFSTokenPassing no; ok deraadt@
2002-03-22 - markus@cvs.openbsd.org 2002/03/21 20:51:12Ben Lindstrom
[sshd_config] add privsep (off)
2002-02-26 - (bal) Update sshd_config CVSIDBen Lindstrom
2002-02-19 - deraadt@cvs.openbsd.org 2002/02/19 02:50:59Damien Miller
[sshd_config] stategy is not an english word
2002-02-10 - (djm) OpenBSD CVS SyncDamien Miller
- deraadt@cvs.openbsd.org 2002/02/09 17:37:34 [pathnames.h session.c ssh.1 sshd.8 sshd_config ssh-keyscan.1] move ssh config files to /etc/ssh - (djm) Adjust portable Makefile.in tnd ssh-rand-helper.c o match
2002-02-05 - markus@cvs.openbsd.org 2002/01/29 14:32:03Damien Miller
[auth2.c auth.c auth-options.c auth-rhosts.c auth-rh-rsa.c canohost.c servconf.c servconf.h session.c sshd.8 sshd_config] s/ReverseMappingCheck/VerifyReverseMapping/ and avoid confusion; ok stevesk@
2002-02-05 - stevesk@cvs.openbsd.org 2002/01/27 14:57:46Damien Miller
[channels.c servconf.c servconf.h session.c sshd.8 sshd_config] add X11UseLocalhost; ok markus@
2002-01-30[configure.ac] fix logic on when ssh-rand-helper is installed.Tim Rice
[sshd_config] put back in line that tells what PATH was compiled into sshd.
2002-01-22 - stevesk@cvs.openbsd.org 2002/01/16 17:40:23Damien Miller
[sshd_config] The stategy now used for options in the default sshd_config shipped with OpenSSH is to specify options with their default value where possible, but leave them commented. Uncommented options change a default value. Subsystem is currently the only default option changed. ok markus@