今天進度 : 鳥哥私房菜 - 第十九章、主機名稱控制者： DNS 伺服器

今天使用 whois 指令嘗試查詢 it home 收集詳盡的 DNS 主機資訊
發現居然歸在 PCHOME 底下註冊 XD，而且是從 1993 年就購買，到現在有 22 年了，真厲害!
但，過期時間怎麼怪怪的，2021-04，不就代表在幾個月就過期?
看網上的前輩說，最好要三個月前就續訂，否則會被搶走

test@test:~$ whois ithelp.ithome.com.tw

Domain Name: ithome.com.tw
   Domain Status: clientTransferProhibited
   Registrant:
      iThome Weekly
      DomainAdministrator  domain@staff.pchome.com.tw
      +886.0227000898
      
      12F No.105, Sec.2 Tun-Hwa South Road. Taipei,Taiwan, R.O.C Taipei,106,TW 
      Taipei, TW
      TW

   Administrative Contact:
      DomainAdministrator  domain@staff.pchome.com.tw
      +886.0227000898
      

   Technical Contact:
      DomainAdministrator  domain@staff.pchome.com.tw
      +886.0227000898
      

   Record expires on 2021-04-12 (YYYY-MM-DD)
   Record created on 1999-12-31 (YYYY-MM-DD)

   Domain servers in listed order:
      ns1.ithome.com.tw     220.130.119.129 
      ns2.ithome.com.tw     210.59.230.252 

Registration Service Provider: PCHOME
Registration Service URL: http://myname.pchome.com.tw

使用 openssl 查詢憑證資料
發現憑證時間在 12 月也要過期了...

test@test:~$ echo | openssl s_client -showcerts -servername ithome.com.tw -connect ithome.com.tw:443 2>/dev/null | openssl x509 -inform pem -noout -text
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            67:88:95:f4:42:7e:92:c7:c5:5d:6e:46
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C = BE, O = GlobalSign nv-sa, CN = GlobalSign Organization Validation CA - SHA256 - G2
        Validity
            Not Before: Nov  1 09:32:34 2018 GMT
            Not After : Dec 19 09:14:42 2020 GMT
        Subject: C = TW, ST = Taipei, L = Taipei, OU = IT Dept., O = \E9\9B\BB\E9\80\B1\E6\96\87\E5\8C\96\E4\BA\8B\E6\A5\AD\E8\82\A1\E4\BB\BD\E6\9C\89\E9\99\90\E5\85\AC\E5\8F\B8, CN = *.ithome.com.tw
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:b3:46:49:87:fe:9f:c1:9e:66:63:fd:05:3d:e5:
                    38:41
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Key Usage: critical
                Digital Signature, Key Encipherment
            Authority Information Access: 
                CA Issuers - URI:http://secure.globalsign.com/cacert/gsorganizationvalsha2g2r1.crt
                OCSP - URI:http://ocsp2.globalsign.com/gsorganizationvalsha2g2

            X509v3 Certificate Policies: 
                Policy: 1.3.6.1.4.1.4146.1.20
                  CPS: https://www.globalsign.com/repository/
                Policy: 2.23.140.1.2.2

            X509v3 Basic Constraints: 
                CA:FALSE
            X509v3 CRL Distribution Points: 

                Full Name:
                  URI:http://crl.globalsign.com/gs/gsorganizationvalsha2g2.crl

            X509v3 Subject Alternative Name: 
                DNS:*.ithome.com.tw, DNS:owa.ithome.com.tw, DNS:mail.ithome.com.tw, DNS:autodiscover.ithome.com.tw, DNS:www.ithome.com.tw, DNS:ithome.com.tw
            X509v3 Extended Key Usage: 
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Subject Key Identifier: 
            X509v3 Authority Key Identifier: 
            CT Precertificate SCTs: 
                Signed Certificate Timestamp:
                    Version   : v1 (0x0)
                    Log ID    : 
                    Timestamp : Nov  1 09:32:36.635 2018 GMT
                    Extensions: none
                    Signature : ecdsa-with-SHA256
                Signed Certificate Timestamp:
                    Version   : v1 (0x0)
                    Log ID    : 
                    Timestamp : Nov  1 09:32:36.630 2018 GMT
                    Extensions: none
                    Signature : ecdsa-with-SHA256
                Signed Certificate Timestamp:
                    Version   : v1 (0x0)
                    Log ID    : 
                    Timestamp : Nov  1 09:32:37.000 2018 GMT
                    Extensions: none
                    Signature : ecdsa-with-SHA256
    Signature Algorithm: sha256WithRSAEncryption

查詢it邦主機的資訊

test@test:~$ nslookup ithome.com.tw
Server:		127.0.0.53
Address:	127.0.0.53#53

Non-authoritative answer:
Name:	ithome.com.tw
Address: 220.130.119.130

host 查詢 IP 地址

test@test:~$ host ithome.com.tw
ithome.com.tw has address 220.130.119.130

dig 查詢 詳細的主機資訊

test@test:~$ dig ithome.com.tw

; <<>> DiG 9.16.1-Ubuntu <<>> ithome.com.tw
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9020
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;ithome.com.tw.			IN	A

;; ANSWER SECTION:
ithome.com.tw.		0	IN	A	220.130.119.130

;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Fri Oct 16 00:46:06 UTC 2020
;; MSG SIZE  rcvd: 58