dentistrywebdesign.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:8a:dd:be:78:fc:7e:17:8d:19:d0:65:11:72:ac:f7:d7:92 was issued on by Let's Encrypt.

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:
  • Subscriber Certificate: commonName is deprecated. (BRs: 7.1.4.2.2)

Certificate Subject

CN=dentistrywebdesign.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:8a:dd:be:78:fc:7e:17:8d:19:d0:65:11:72:ac:f7:d7:92
Serial Number (int): 395702858739495755544258719666892216719250
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 84:78:a4:99:1e:d3:c4:cb:e6:27:96:ab:74:0b:d8:a4:58:22:62:bc
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): a4:70:17:d1:33:ce:98:80:4a:c4:49:01:4c:ee:13:6f:9d:2a:bc:76
Fingerprint (sha256): e0:68:af:d6:dd:64:44:68:83:b8:8a:49:88:45:15:d8:f8:55:2b:de:82:0d:b1:05:3f:1c:63:f4:4f:62:e2:72

Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/

Revocation information

OCSP Server: http://ocsp.int-x3.letsencrypt.org

Check the revocation status for certificate dentistrywebdesign.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for dentistrywebdesign.com

Public Key Algorithm

RSA

Key Size

4096

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

dentistrywebdesign.com

Other certificates including the domain name dentistrywebdesign.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for dentistrywebdesign.com in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----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-----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 395702858739495755544258719666892216719250
 . . . . . . . . [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 'Let's Encrypt Authority X3'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2018-12-17 03:00:54 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-03-17 03:00:54 +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 'dentistrywebdesign.com'
 . . . . . . . . [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 (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 682186725443031736375157719357855723486454786118229629707879977144603233712485547043327282621067150746584829703713929392034178083070432240699861902191663540748228936712133957136235856927806270934043566789684904875659251003930561310385388702733108498593198804712064097852418750736545381337234480580131577094433558719619841181975467968671737810884779711627925101585723796931838849584244200427489793719257014003345064377670258316374353034515856828669863407238798072719011777109921906107616799758996813590506792848293546643995676281323262293049540359626383111316288363796520257544913337115995025371747236584205149642840993210980060512195627031272542947257598075831724164146408258916566792267252332924686681290233964394947515622519815511723394698581589271336156676332634164151957617979709640762160764625247862104082260434067572374189102268203591543463616038019639764832944608010960208148578659208013917801779317769207195465167793762591554603697966036990956659688940051233605091743341959361631216859535494759098158962520344745782274271111280665583861141599465663430083528296334470076426584121871151645318113098516506011367189317059665533645091856058593849276203787374517036105099212002921345787418671518222583960396473304967708515535171329
 . . . . . . . . . . . . . . . . . . . . [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)
							8478a4991ed3c4cbe62796ab740bd8a4582262bc
 . . . . . . . . . . . . . . . . [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 a84a6a63047dddbae6d139b7a64565eff3a8eca1
 . . . . . . . . . . . . . . . . [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 (99 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://ocsp.int-x3.letsencrypt.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://cert.int-x3.letsencrypt.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 (26 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'dentistrywebdesign.com'
 . . . . . . . . . . . . . . . . [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 (69 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 1.3.6.1.4.1.44947.1.1.1
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.2.1 (cps)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:22|false] IA5String 'http://cps.letsencrypt.org'
 . . . . . . . . . . . . . . . . [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 (247 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (244 bytes)
							00f2007700747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc5600000167ba52e6f7000004030048304602210081fea9b8c1c3f0fe00ff6fb49dbe3416dcce446d667c11a4441bf7605dc1a547022100e5b51fb1def85a9a52d00f313b047d722f0459ea6aa4a684e7d433ae9fc54e0600770063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d00000167ba52e8f00000040300483046022100bca38530a908ce79f3ebef8f45cb029f04be4e929f639c201c8e0e0b067dd29c022100c45772d4f7e3c872971acca8fdec1e516d7f8bc2873172ea95a13d40756ade5c
 . . . . [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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