#sshfp

[anitakumarigrewal]

According to study, “Global DNS Service Market Size study, by Type (Primary, Secondary), by Vertical (Banking, Financial Services and Insurance, Telecom & Information Technology, Media & Entertainment, Retail & E-commerce, Healthcare, Government, Education, Others) and Regional Forecasts 2018-2025” some of the major companies that are currently working in the global DNS service market are AWS route, Oracle Corp., Cloud flare Inc., Akamai Technologies Inc., Google LLC, Dynu Systems Inc., DNS Made Easy, Infoblox Inc., Verisign Inc., Amazon Web Services Inc., Cotendo Advanced DNS, Symantec Corp., GoDaddy Operating Company LLC, Microsoft Corp., Verizon, Ultra DNS, Namecheap Inc., Rackspace US Inc., Nsone Inc., Cdnetworks Inc., IBM Corp., AdGuard Software Ltd., Cisco Systems Inc., Easy DNS, Neustar Inc.

Domain Name System (DNS) is a way in which province names of internet are sited & are converted into internet protocol addresses. It is a distributed, reliable, coherent, autonomous and hierarchical database. It also has a directory of key information on domain names of email servers (MX records) and sending of verification (SPF, DKIM, DMARC), TXT record confirmation of domain possession, and even SSH fingerprints (SSHFP). The process of DNS resolution occupies converting a hostname into a computer friendly IP address. It offers various benefits such as no requirement of memorizing the IP addresses, security enhancement, as it can browse the internet worldwide, and DNS servers that have faster internet connections.

Based on type, global DNS service market is segmented into recursive DNS and authoritative DNS. Based on DNS server, market is segmented into primary DNS server & secondary DNS server. Based on service provider, market is segmented into enterprise service provider and self-service provider. Based on operation, market is segmented into client lookup, reverse lookup, DNS resolver, record caching, address resolution mechanism, circular dependencies & glue records and other applications. Based on industry vertical, market is segmented into financial services & insurance, retail & e-commerce, government, telecom & information technology, banking, media & entertainment, healthcare, education and others.

The global DNS service market is primarily driven by growing number of internet user, followed by increase in DNS communications in the organization to progress the streamline management & performance, emphasis on safeguarding websites from Ddos attacks, and increase in awareness to safeguard websites from various attacks, rising E-business and low cost associated with DNS service. In addition to major restraining factors such as high cost of installation, DNS server outages followed by the availability of free DNS providers. Additionally, some of opportunities include the growing era of Ipv6, growing ubiquity of the internet usage with the increase in online presence of businesses on the web world etc.

North American region is a major of high use of technology infrastructure & adoption followed by the Asia-Pacific region which is predictable to expect a higher growth rate over the projected period 2018-2025 due to increase in adoption of 4G with the production of internet usage & mobile devices. It is expected that the global DNS service market to reach at US $600 million, by 2025.

To know more, click on the link below:-

 Global DNS Service Market

Related Report:-

https://www.kenresearch.com/technology-and-telecom/it-and-ites/global-dns-services-market/178615-105.html

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Ken Research

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[gslin]

SSH 的 SSHFP record

SSH 的 SSHFP record

很久前看過 SSHFPT record，當時支援度不高就忘記了… 剛剛在 Cloudflare 的這篇「Additional Record Types Available with Cloudflare DNS」看到發現 OpenSSH 很久前就有支援了…

用法是 VerifyHostKeyDNS 這個 option，像是 ssh -o "VerifyHostKeyDNS=yes" -o "StrictHostKeyChecking=yes" hostname 這樣的指令，對於 ~/.ssh/known_hosts 裡沒有的機器，在第一次連線的時候會去查 DNS record，如果沒有查到的話就會中斷。

產生 SSHFP record 的方式則是可以參考「How do I generate SSHFP records?」這篇，也就是直接用 sshkey-gen -r [hostname]

[gslin]

OpenSSH 的三個進階用法：CA 架構、透過 Jump Server 連線、2FA

在「How to SSH Properly」這篇裡面講了三個 OpenSSH 的進階用法：CA 架構、透過 Jump Server 連線，以及 2FA 的設定。

之前蠻常看到使用 -o StrictHostKeyChecking=off 關閉檢查，但 OpenSSH 有支援 CA 架構，可以先產生出 Root CA，然後對 Host 的 Public Key 簽名，在連線的時候就可以確保連線沒有被調包 (通常是 MITM)，但得設計一套機制，自動化機器生出來後的步驟。

另外一個可能的方式是 SSHFP，搭配 DNSSEC 也可以確認連線沒有被調包，不過這又牽扯到 DNS 的部份…

第二個提到的是 Jump Server (Bastion host)，之前的作法是用 -A把 authentication agent 帶過去再連進去，這邊則是教你怎麼下指令直接連線，而不需要先連到 Jump…

[gslin]

Ptt 公告使用安全連線

Ptt 官方公告，建議使用安全連線：「[公告] 請使用安全的連線方式連線本站」。

目前 Ptt 有三種方式可以連線，第一種是 Telnet，這是最古老，支援度最廣泛，但沒有加密的協定。

第二種是 SSH，算是蠻早就支援的安全協定 (至少是 2006，依照「[問題] SSH連接是否變換方式了﹖」這篇)，屬於 Trust on first use 的方式，不過在有 DNSSEC 的情況下可以搭配 SSHFP record 避免第一次連線的信任問題。

最後一種登入方式也是安全協定，透過 2011 年定義出來的 WebSocket 連線，這個方法在 Let’s Encrypt 盛行後可以透過瀏覽器內的 CA 驗證連線的安全性。

可以理解 SSH 吃的資源比較多，不過在 Linux command line 下好像還沒有什麼比較堪用的 WebSocket 指令可以連線… 而且我記得 Ptt 的…