OpenSSH（Open Secure Shell）是使用SSH透过计算机网络加密通讯的实现。它是取代由SSH Communications Security所提供的商用版本的开放源代码方案。目前OpenSSH是OpenBSD的子计划。
2012-08-29发布6.1正式版。上一个版本是2012-04-21的6.0
发布声明及改进：
Changes since OpenSSH 6.0
=========================
This is primarily a bugfix release.
Features:
* sshd(8): This release turns on pre-auth sandboxing sshd by default for
new installs, by setting UsePrivilegeSeparation=sandbox in sshd_config.
* ssh-keygen(1): Add options to specify starting line number and number of
lines to process when screening moduli candidates, allowing processing
of different parts of a candidate moduli file in parallel
* sshd(8): The Match directive now supports matching on the local (listen)
address and port upon which the incoming connection was received via
LocalAddress and LocalPort clauses.
* sshd(8): Extend sshd_config Match directive to allow setting AcceptEnv
and {Allow,Deny}{Users,Groups}
* Add support for RFC6594 SSHFP DNS records for ECDSA key types. bz#1978
* ssh-keygen(1): Allow conversion of RSA1 keys to public PEM and PKCS8
* sshd(8): Allow the sshd_config PermitOpen directive to accept "none" as
an argument to refuse all port-forwarding requests.
* sshd(8): Support "none" as an argument for AuthorizedPrincipalsFile
* ssh-keyscan(1): Look for ECDSA keys by default. bz#1971
* sshd(8): Add "VersionAddendum" to sshd_config to allow server operators
to append some arbitrary text to the server SSH protocol banner.
Bugfixes:
* ssh(1)/sshd(8): Don't spin in accept() in situations of file
descriptor exhaustion. Instead back off for a while.
* ssh(1)/sshd(8): Remove hmac-sha2-256-96 and hmac-sha2-512-96 MACs as
they were removed from the specification. bz#2023,
* sshd(8): Handle long comments in config files better. bz#2025
* ssh(1): Delay setting tty_flag so RequestTTY options are correctly
picked up. bz#1995
* sshd(8): Fix handling of /etc/nologin incorrectly being applied to root
on platforms that use login_cap.
Portable OpenSSH:
* sshd(8): Allow sshd pre-auth sandboxing to fall-back to the rlimit
sandbox from the Linux SECCOMP filter sandbox when the latter is
not available in the kernel.
* ssh(1): Fix NULL dereference when built with LDNS and using DNSSEC to
retrieve a CNAME SSHFP record.
* Fix cross-compilation problems related to pkg-config. bz#1996
主页：http://www.openssh.com/
下载：ftp://ftp.openbsd.com/pub/OpenBSD/OpenSSH/portable/openssh-6.1p1.tar.gz
来自:开源中国社区
