Definition of OpenSSH Version
OpenSSH is a networking-related shell-based security utility that also acts as a secured protocol for unsecured networks. OpenSSH is a kind of networking protocol that often makes the client-server architecture secured with its secure shell software utility present for all security aspects. Open SSH was started with a fork of free SSH programs developed by Tatu Yiolen but in later versions of OpenSSH, it was difficult to make it free as many more features and protocol improvisation was introduced due to which the latter version holds proprietory rights for the software invented by SSH Communications Security.
There are many versions of OpenSSH where every Release of version has some or the other addition or deprecation on the software. Thus it helps to identify and track on Release. Thus there are the following versions used for release:
– OpenSSH 1.2.2p1: This version of OpenSSH was released on March 5 2000 and contains many more changes in terms of features and deprecations in this initial release as a proprietary release.
– OpenSSH 2.5.1p1: This version of OpenSSH got released in February 19, 2001, with deprecation of SkeyAuthentication, use, and introduction of ChallengeAcceptanceResponse.
– OpenSSH 2.9.9: This version of OpenSSH got released somewhat at the same time as the previous version with some of the important changes where OpenSSH might have introduced upgrade issues removing the file structure, checkmail sshd_config is deprecated.
– OpenSSH 3.0: This version of OpenSSH improved Kerberos support in protocol v1 (KerbIV) and (KerbV).
– OpenSSH 3.4: This version of OpenSSH got introduced on June 26 2002 which supports some of the features for rekeying in protocol version 2.
– OpenSSH 3.5: This version of OpenSSH got introduced on October 14 2002 which supports some of the features like clearAllForwardings in ssh(1), smartcard support for this feature service.
– OpenSSH 3.6: This version of OpenSSH got introduced on March 31, 2003, which supports some of the features like March 31, 2003, with some of the releases changes likeability to pass environment variables in between the variables and keys.
– OpenSSH3.6.1: This version of OpenSSH got introduced on April 1 2003 with some more changes similar to the earlier changes.
– OpenSSH3.7: This version of OpenSSH got introduced in September 16 2003 with some changes like rhosts authentication has been removed in sshd (1) and sshd (8).
– OpenSSH3.7.1: This version of OpenSSH got introduced on September 16 2003 same as the previous version.
– OpenSSH3.8: This version of OpenSSH got introduced on February 24 2004 with no major changes.
– OpenSSH3.9: This version of OpenSSH got introduced on August 18 2004 with many major changes like Implement session multiplexing, Control Master option, Re-introduce support for PAM password authentication.
– OpenSSH4.0: This version of OpenSSH got introduced in March 2009 and simultaneous changes in the next version.
– OpenSSH4.1: This version of OpenSSH got introduced on May 26, 2005, with changes in the next version.
– OpenSSH4.2: This version of OpenSSH got introduced on September 1, 2005, with no major changes.
– OpenSSH4.3: This version of OpenSSH involves changes on February 1 2006 Added OSI layer 2/3 tun-based VPN.
– OpenSSH4.9: This version of OpenSSH involves changes in other versions ranging from 4.4 to 4.9 with major changes in the 4.9 version which says for chroot support for sshd(8), create an internal SFTP server for easier use.
– OpenSSH5.0: This version of OpenSSH involves changes on April 3, 2008.
– OpenSSH5.1: This version of OpenSSH involves changes on July 21 2008 where a major change has been added related to MaxSessions option to sshd_config.
– OpenSSH5.2 – OpenSSH5.4: These versions don’t have major changes in them. But in version 5.4 there are certain changes regarding disabled SSH protocol 1 default support, Added certificate-based authentication.
– OpenSSH5.5.-OpenSSH6.1: These versions don’t have major changes in them. But in version 6.1 has a primary bug fix, pre-auth sandboxing of a separated child.
– OpenSSH6.2: This version release date is GCM mode for AES cipher similar to RFC 5674.
– OpenSSH 6.3: This version release date is September 13 2013 and is predominantly a bug fix.
– OpenSSH 6.4: This version release date is November 8, 2013.
– OpenSSH6.5: This version release date is January 30, 2014, which added new ssh ed-25519 and public key changes, the addition of transport cipher.
– OpenSSH6.6: This version release date is March 16 2014 which is a primary bugfix release.
– OpenSSH6.7: This version release date is October 6 2014 which has a feature implementation with a default set of transfers of ciphers and MACs, compile-time option to not depend on OpenSSL, ability to transfer the socket forwarding in the UNIX domain.
– OpenSSH6.8: This version release date is March 18 2015 added a new firstname.lastname@example.org extension to solve problems related to the hosts for authentication using two different keys.
– OpenSSH6.9: This version is related to bugfix and is released on July 1, 2015.
– OpenSSH7.0: This version is released on August 11 2015 whose focus is to primarily deprecate the weak and legacy cryptography which is unsafe.
– OpenSSH7.1: This version is released on August 20 2015 which is a bugfix release.
– OpenSSH7.3: This version got released on August 01 2016 and the features added include the Proxy Jump option and an include directive for ssh_cconfig files.
– OpenSSH7.4: In this version, the template and Release date with a range having a disabled forwarding option will be configured.
– OpenSSH7.5: In this version of the release which is released in March 2017 a bugfix release happened.
– OpenSSH7.6: In this version of the release which got released in October 2017 with add remote command Option, Add SSHLOGFacility to match equivalent option in sshd.
– OpenSSH7.7: This version of OpenSSH got released in February 2018 with the addition of expire time in sshd_authorization to allow for key generation.
– OpenSSH7.8: This version of OpenSSH got released in August 2018 which has some incompatible changes ssh-keygen with write OpenSSH format private key by default instead of using OpenSSL PEM format.
– OpenSSH7.9: This version of OpenSSH got released in October 2018 which allows key revocation key lists to revoke keys specified by SHA256.
– OpenSSH8.0: This version of OpenSSH got released in April 2019 with security CVE -2019-6111 related to SCP tool or protocol allowing to write arbitrary files in the SCP.
– OpenSSH8.1: This version of OpenSSH was released in October 2019 having ssh and sshd agents and all.
– OpenSSH8.2: This version of OpenSSH was released with an added feature of FIDO /U2F support.
OpenSSH has a lot of advantages in terms of security as entire security suites and relevant utilities are present in this. It helps in many ways for the networks to safeguard from the intruders and maintain the entire client-server architecture for lots of information to be safe and proper authentication facilities are also available which makes it quite useful.
This is a guide to OpenSSH version. Here we discuss the definition, various versions of OpenSSH version respectively. You may also have a look at the following articles to learn more –