adztogo.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:08:4b:b2:60:3d:32:92:16:19:d8:00:7d:cc:a7:ce:14:0d 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=adztogo.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:08:4b:b2:60:3d:32:92:16:19:d8:00:7d:cc:a7:ce:14:0d
Serial Number (int): 264159735011132826259324371409962877719565
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 1c:f9:54:3c:7e:d2:93:0b:42:27:d9:d5:d9:ba:6a:eb:5e:6a:34:01
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 31:5d:45:ab:02:31:ce:70:a3:31:84:e8:fd:57:18:ad:e0:e6:8f:50
Fingerprint (sha256): 9f:8e:4d:2f:e8:e3:ca:b9:a7:54:1e:a5:d3:c5:1e:56:f9:d4:32:c1:18:37:46:b5:58:65:b6:91:ff:80:0d:ad

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 adztogo.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for adztogo.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

adztogo.com

Other certificates including the domain name adztogo.com

(limited to 100 certificates)
www.adztogo.com
adztogo.com
www.adztogo.com
adztogo.com
adztogo.com
adztogo.com
adztogo.com
www.adztogo.com
adztogo.com

Certificate

The complete raw certificate details for adztogo.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 264159735011132826259324371409962877719565
 . . . . . . . . [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 2019-08-03 19:48:26 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-11-01 19:48:26 +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 'adztogo.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 793027981666496498893931541825024637868959817906938904367285476927874175706214370003423815515760378622377193427089045459144723574322060767525240633839494072482452952619967649313054346625197599726435993930166725208498935100573035564511911292818374357400779263486746366896274778680537357062090984549440268288861466481503214628090068469330278469910302487544170668185347295190615470434530940906890107614283264171209642853515532746443296696079028837112796279695463879036057480537267206669441086836515804334033724627692967184098786502853899951283809274683181453241492610550829602294649323825823497896586672554558858123437930901486237912796413083263158437541312816247181583745740195474307126016511880844862646651036097392985355450720166571414215143224323456316984696573168507187370733764854134388984228347123697864967624256417132688389223116344903919111651213682356238976178604588514820580013152032774403198611543080661843776189216362050703007142075400349616990769532494546059785120737793090496780766517165750499725931618553670179869463599468672981102726012323839152544928774556935085122250059860475437387645631087422544933784161100082382189066004599924344028779205142785290858605205240980103939898260188817602457971883586687884352918990401
 . . . . . . . . . . . . . . . . . . . . [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)
							1cf9543c7ed2930b4227d9d5d9ba6aeb5e6a3401
 . . . . . . . . . . . . . . . . [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 (15 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'adztogo.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)
							00f2007700747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc560000016c593da11f0000040300483046022100b9040c8930b9862e730ea0d7183bfa21785404aaa5ba76e767e7862d17f90028022100b5a28e12e83e8b885d5c9414980a79e56fe6a7f4825c50c2069a7b1eebed6b32007700293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016c593da3300000040300483046022100842587ba5a524f676a8244ddb984e6dbe8215b1fdb795ff022ab86369a6e2195022100feb0dbe1fa954be495edf24ab590b3f21083765438cd56a353ec482e6d6c90c8
 . . . . [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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