www.duqlawbookclub.org

Issued by R3

About this certificate

This digital certificate with serial number 04:3d:8e:0b:e2:31:cd:9e:dd:98:8d:51:bf:d5:ae:a9:ea:b0 was issued on by Let's Encrypt.

With 11 subject alternative names this certificate can be used to secure multiple fqdn's. This certificate has already expired and will cause a warning or error message in the browser it's still listed on this site to allow you to look back on previously issued certificates. If we have found any compliance issues with this certificate they will be shown below. I hope this certificate review is providing you the detailed information in a simple form you where looking for.


We have idenified some issues with this certificate:
  • DV certificate contains a subject common name, this is not recommended. If certificate policy 2.23.140.1.2.1 (CA/B BR domain validated) is included, only country and/or common name is allowed in SubjectDN. (BRs: 7.1.2.7.2)
  • Subscriber certificates use of Subject Key Identifier is NOT RECOMMENDED (BRs v2: 7.1.2.7.6)
  • Subscriber Certificate: commonName is NOT RECOMMENDED. (BRs: 7.1.2.7.1)

Certificate Subject

CN=www.duqlawbookclub.org

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:3d:8e:0b:e2:31:cd:9e:dd:98:8d:51:bf:d5:ae:a9:ea:b0
Serial Number (int): 369395180187655521667044127650700952464048
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 63:3d:3f:8d:74:3f:94:73:bb:73:68:f7:3c:09:d5:53:61:ab:2a:24
AuthorityKeyId: 14:2e:b3:17:b7:58:56:cb:ae:50:09:40:e6:1f:af:9d:8b:14:c2:c6

Fingerprint (sha1): 78:f5:53:c4:6a:a2:c2:e3:30:2d:92:c6:d2:f8:85:7c:a9:37:95:02
Fingerprint (sha256): 6c:8d:4d:d1:1f:c5:91:5f:fc:71:e4:4f:1b:25:06:95:9e:3d:e3:37:ef:6c:d2:64:c9:1f:ad:b2:b1:cb:58:2f

Issuing Certificate URL: http://r3.i.lencr.org/

Revocation information

OCSP Server: http://r3.o.lencr.org

Check the revocation status for certificate www.duqlawbookclub.org

11

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.duqlawbookclub.org

Public Key Algorithm

RSA

Key Size

2048

Signature Algorithm

SHA256 with RSA

Key Usage

Digital Signature
Key Encipherment

Extended Key Usages

Server Authentication
Client Authentication

Extensions

9 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

autodiscover.duqlawbookclub.org
cpanel.duqlawbookclub.org
cpcalendars.duqlawbookclub.org
cpcontacts.duqlawbookclub.org
duqlawbookclub-org.duqlawblogs.org
duqlawbookclub.org
mail.duqlawbookclub.org
webdisk.duqlawbookclub.org
webmail.duqlawbookclub.org
www.duqlawbookclub-org.duqlawblogs.org
www.duqlawbookclub.org

Other certificates including the domain name duqlawbookclub.org

(limited to 100 certificates)
webdisk.duqlawbookclub.org
duqlawbookclub-org.duqlawblogs.org
www.duqlawbookclub.org
autodiscover.duqlawbookclub.org

Certificate

The complete raw certificate details for www.duqlawbookclub.org in PEM and ASN.1 format.

Certificate (PEM)

-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA6hy1RGWAIuaaVTC8eLjF
X227JtuseZkKPtVL8f1K7zaQkkFoYXzhN/Aooze9MLJ0iNZJrUQf65szVOe0ZD/Y
evPVTpOuqVp424KkNUkfIl6ByZBrLxijGL2Ho9LjYIvIN5p2xgC4pQ87545hoKTf
P5vwo/HP0goUR5iYLbSaUpW2dyyUtPppypkETlMTa8iyDKERNKKVbySvDo2s+49T
LwtM7HuaZPLptGWr275Z+CaBJS5vfz1SDkEogNwg+m0ljEFXWLy91LOqhU55EaUO
J4K3/5ATEkkwcoec+D49iYYTAvyiAtY0NQOpa9KoXoYaemOWX7ZycCaqvZ9+/HBj
tQIDAQAB
-----END PUBLIC KEY-----

ASN.1 decoded

 [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . [c:0|t:2|false] INTEGER 2
 . . . . . . . . [c:0|t:2|false] INTEGER 369395180187655521667044127650700952464048
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption)
 . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.6 (countryName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'US'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.10 (organizationName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'R3'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2023-10-19 16:26:19 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2024-01-17 16:26:18 +0000 UTC
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'www.duqlawbookclub.org'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.1 (rsaEncryption)
 . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (2160 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 29553919841408915112070711978767154926510325980900465145007826830679258318630340647242827762961253120581820584569330880844128690677723038916115121442413153340006145548130026860441988478302320066241974809368749341793217563064794974421501895291147222621619365780542193081597131059561662415296392400493792873349040024958782133171513337585334607595034877940643321027324935882043631259441991776434562453752309296706488404774201565812108546724207103907781335812410563289222871567037556952974082484370807601975347825057918270011483055019979907960415193383888074994452381845148216440129395012161775773183099890292910415963061
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 65537

 . . . . . . . . [c:2|t:3|true] ORAddress 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.15 (keyUsage)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (4 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (3 bits)
							05a0
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.37 (extKeyUsage)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.1 (serverAuth)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.2 (clientAuth)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.19 (basicConstraints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.14 (subjectKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (20 bytes)
							633d3f8d743f9473bb7368f73c09d55361ab2a24
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.35 (authorityKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName 142eb317b75856cbae500940e61faf9d8b14c2c6
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.1.1 (authorityInfoAccess)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (73 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.1 (ocsp)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://r3.o.lencr.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.2 (caIssuers)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://r3.i.lencr.org/'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.17 (subjectAltName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (328 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'autodiscover.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'cpanel.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'cpcalendars.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'cpcontacts.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'duqlawbookclub-org.duqlawblogs.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'mail.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'webdisk.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'webmail.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.duqlawbookclub-org.duqlawblogs.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.duqlawbookclub.org'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.32 (certificatePolicies)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (12 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.23.140.1.2.1 (Domain Validation Certificates Policy)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.11129.2.4.2
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (245 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (242 bytes)
							00f00076003b5377753e2db9804e8b305b06fe403b67d84fc3f4c7bd000d2d726fe1fad4170000018b48f94dc40000040300473045022100c4b5fcf02cd1dadc0ae4cc3ebe16b4e21521870e3afce686adcf919f975f881202200d2b9e760539c742a60ca7e3034f4d64234463f7e9d33101159e192d645ee9e0007600eecdd064d5db1acec55cb79db4cd13a23287467cbcecdec351485946711fb59b0000018b48f94dcd0000040300473045022017972f99a7a489c2a28c63bbb83a768c80bfb854bce02a0f624e451b5b92a3e5022100c4d2939f1036587a89e4a52388ff76f3297a86b8a6b4da47b6113b0d0bdd4efc
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption)
 . . . . . . . . [c:0|t:5|false] NULL 
 . . . . [c:0|t:3|false] BIT STRING (2048 bits)
		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