bowlingverenigingtholen.nl

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:83:d0:0b:6b:1d:4d:27:56:11:6b:22:26:26:4b:2c:eb:f7 was issued on by Let's Encrypt.

With 4 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:
  • Subscriber Certificate: commonName is deprecated. (BRs: 7.1.4.2.2)

Certificate Subject

CN=bowlingverenigingtholen.nl

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:83:d0:0b:6b:1d:4d:27:56:11:6b:22:26:26:4b:2c:eb:f7
Serial Number (int): 306190386572851707242192119429255568092151
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 77:b1:eb:f7:8f:e3:69:5f:b7:c2:4a:96:36:56:4a:43:12:0f:f2:d3
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): bf:cb:63:ed:ab:f5:44:90:5c:71:16:10:25:13:b0:9e:f1:91:4d:55
Fingerprint (sha256): f8:6b:93:01:93:f8:02:08:ef:86:1b:47:3d:a7:8e:95:a5:ca:26:7f:7c:48:dd:cc:90:3f:1e:1b:1c:e5:7a:73

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 bowlingverenigingtholen.nl

4

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for bowlingverenigingtholen.nl

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

8 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

autoconfig.bowlingverenigingtholen.nl
autodiscover.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl

Other certificates including the domain name bowlingverenigingtholen.nl

(limited to 100 certificates)
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
www.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
server.bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl
bowlingverenigingtholen.nl

Certificate

The complete raw certificate details for bowlingverenigingtholen.nl in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqwA0CfPgWa4TYeo4IY3d
JtwVQsghfa21iJsV+3rNQ8V0xC54KZslQiJQh56CbvCrRVWUfVTVC1KTM528cT3g
3k8mPMH6rkQgo1lv28GojVSh8CLjEbOIXoMvmhvG6nLLp0Ue7L4DgWkQ9WeWNBRj
aIZW0dU1M/FPkkgSgHBEXrY/HYx2pxBuC7AM8Ku5V9GNn7BLVQtjbsG0SJ8P3B5e
7lL2ZyzmQdb0hF8vtmvsID+oOJMSCp7McU0V6R4gegf5WlkFlFHgB6AxWWuINJ8L
xRmKsf3pEGiNSbEweni1Tsk9Uw61HczRjuLfDmmF5qJl0RB2ktAaYxwd+fPWwF4T
wwIDAQAB
-----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 306190386572851707242192119429255568092151
 . . . . . . . . [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 2017-11-27 04:57:08 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2018-02-25 04:57:08 +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 'bowlingverenigingtholen.nl'
 . . . . . . . . [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 21586850388754266507032152815052642803982341692677706974263344425728496207227883007110017405978730100390241123895200170259521085831528683726137692317251650476322976747892999735235543897246391018878084987176231702957878430762907464559946603230074122569864373535680617077671177938979867678202973063939048326298862219404364576611186347559751606070771954339600119954985085300252033102696204977713625229122844148517602656687451834285669058777319519642196253105174545746232073528035015034439738903850946163395893992233960948890217518752632776425000811263559435323950403608447671241824919345058564595548847066603357271364547
 . . . . . . . . . . . . . . . . . . . . [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)
							77b1ebf78fe3695fb7c24a9636564a43120ff2d3
 . . . . . . . . . . . . . . . . [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 (143 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'autoconfig.bowlingverenigingtholen.nl'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'autodiscover.bowlingverenigingtholen.nl'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'bowlingverenigingtholen.nl'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.bowlingverenigingtholen.nl'
 . . . . . . . . . . . . . . . . [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 (246 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 1.3.6.1.5.5.7.2.2 (unotice)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:12|false] UTF8String 'This Certificate may only be relied upon by Relying Parties and only in accordance with the Certificate Policy found at https://letsencrypt.org/repository/'
 . . . . [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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