SSH is a protocol for securely exchanging data between two computers over an untrusted network. SSH protects the privacy and integrity of the transferred identities, data, and files. It runs in most computers and in practically every server. It ships standard on UNIX, Linux, and macOS machines and it is used in over 90% of all data centers in the world.
ContentsHow Does SSH Server Work? Availability of SSH Servers Quality Equals Security Standardized Security
How Does SSH Server Work?
The SSH protocol works on the client/server-model. The SSH client always initiates the setup of the secure connection, and the SSH server listens for incoming connection requests (usually on TCP port 22 on the host system) and responds to them.
In the connection setup phase, the SSH server authenticates itself to the client by providing its public key. This allows the SSH client to verify that it is actually communicating with the correct SSH server (instead of an attacker that could be posing as the server).
After a successful authentication the server provides the client access to the host system. This access is governed with the user account permissions at the target host system.
The secure connection between the client and the server is used for remote system administration, remote command execution, file transfers, and securing the traffic of other applications. Automated SSH sessions are very often used as a part of many automated processes that perform tasks such as logfile collection, archiving, networked backups, and other critical system level tasks.
Availability of SSH Servers
Most server operating systems come with a native, preinstalled SSH server implementation. Those that are an exception to the rule are usually installed with an SSH server from a trusted security solution vendor, such as SSH Communications Security, Bitvise, or VanDyke Software. These companies sell SSH software and provide the technical support and maintenance services for it. The open source community maintains the OpenSSH project that provides a free to use, non-commercial SSH implementation.
Quality Equals Security
As security software, the SSH server has strict requirements for software quality. The SSH server process executes with wide system privileges, and acts as an access control "gatekeeper" to the host system. This makes the SSH server an attractive target for hackers and malware. The pivotal security role of the SSH server places stringent requirements for its code quality and reliability. Bugs and defects in the code can lead to serious security vulnerabilities.
The SSH protocol has been standardized by the Internet Engineering Task Force (IETF). The standards are open and were authored as a joint effort by many security specialists and companies. As the original inventor of the protocol, SSH Communications Security was a key contributor in the standardization effort.
SSH ni itifaki ya kubadilishana data salama kati ya kompyuta mbili juu ya mtandao untrusted. SSH inalinda faragha na uadilifu wa utambulisho uliohamishwa, data, na faili. Inaendesha katika kompyuta nyingi na katika karibu kila seva. Inapatikana kwa mashine za UNIX, Linux, na MacOS na hutumiwa katika zaidi ya 90% ya vituo vyote vya data ulimwenguni. Maudhui Jinsi gani SSH Server Kazi? Upatikanaji wa Seva za SSH Ubora ni sawa na Usalama Usalama wa kawaida Seva ya SSH inafanyaje kazi? SSH itifaki kazi juu ya mteja / server-mfano. Mteja wa SSH huanzisha kuanzisha uhusiano salama, na seva ya SSH husikiliza maombi ya kuunganisha yanayokuja (kwa kawaida kwenye bandari ya TCP 22 kwenye mfumo wa mwenyeji) na kujibu. Katika awamu ya kuanzisha uhusiano, seva ya SSH inajithibitisha kwa mteja kwa kutoa ufunguo wake wa umma. Hii inaruhusu mteja SSH kuthibitisha kwamba ni kweli kuwasiliana na server sahihi SSH (badala ya mshambuliaji ambayo inaweza kuwa posing kama server). Baada ya uthibitisho mafanikio server hutoa mteja upatikanaji wa mfumo mwenyeji. Upatikanaji huu unatawaliwa na ruhusa za akaunti ya mtumiaji kwenye mfumo wa mwenyeji wa lengo. Kuunganisha salama kati ya mteja na seva ni kutumika kwa ajili ya utawala wa mfumo wa mbali, utekelezaji wa amri ya mbali, uhamisho wa faili, na kupata trafiki ya maombi mengine. Sessions za SSH za kiotomatiki hutumiwa mara nyingi kama sehemu ya michakato mingi ya kiotomatiki ambayo hufanya kazi kama vile ukusanyaji wa faili za kumbukumbu, kuhifadhi, nakala rudufu za mtandao, na kazi zingine muhimu za kiwango cha mfumo. Upatikanaji wa Seva za SSH Mifumo mingi ya uendeshaji ya seva inakuja na asili, kutekelezwa kwa seva ya SSH iliyowekwa mapema. Kwa wale ambao ni tofauti na sheria, kawaida huwekwa na seva ya SSH kutoka kwa muuzaji wa suluhisho la usalama wa kuaminika, kama vile SSH Communications Security, Bitvise, au Programu ya VanDyke. Kampuni hizi kuuza programu SSH na kutoa msaada wa kiufundi na huduma za matengenezo kwa ajili yake. Open Source ni mradi wa OpenSSH ambao hutoa bure kwa kutumia, si kibiashara SSH utekelezaji. Ubora ni sawa na Usalama Kama programu ya usalama, seva ya SSH ina mahitaji kali kwa ubora wa programu. SSH server mchakato kutekelezwa na upendeleo wa mfumo pana, na vitendo kama upatikanaji wa kudhibiti "gatekeeper" kwa mfumo mwenyeji. Hii inafanya seva ya SSH kuwa shabaha ya kuvutia kwa wahasibu na programu hasidi. jukumu muhimu usalama wa seva SSH kuweka mahitaji kali kwa ajili ya ubora wake code na kuegemea. Bugs na kasoro katika kanuni inaweza kusababisha udhaifu mkubwa wa usalama. SSH itifaki imekuwa standardized na Internet Engineering Task Force (IETF). Viwango ni wazi na walikuwa mwandishi kama juhudi ya pamoja na wataalamu wengi wa usalama na makampuni. Kama mvumbuzi wa awali wa itifaki, SSH Communications Security ilikuwa mchangiaji muhimu katika juhudi za kiwango.