appetizer.wwwhost.biz

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:ea:e0:e1:c9:c3:24:f9:2a:70:5f:a8:20:db:5e:7f:23:a3 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=appetizer.wwwhost.biz

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:ea:e0:e1:c9:c3:24:f9:2a:70:5f:a8:20:db:5e:7f:23:a3
Serial Number (int): 341261851084854596589610502711222606963619
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 92:ee:0c:75:2c:b5:a7:2b:f0:d4:28:00:01:38:3b:37:99:b4:ce:8f
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 33:33:4e:12:57:30:a9:c0:dc:40:6d:58:fd:b9:d2:a9:e8:55:f1:67
Fingerprint (sha256): 4f:9f:6d:7f:a1:83:e6:f9:bd:88:5d:e3:a6:82:cc:82:b1:a4:55:4a:c5:49:a0:8d:4f:56:2d:64:6c:2e:a0:35

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 appetizer.wwwhost.biz

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for appetizer.wwwhost.biz

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

appetizer.wwwhost.biz

Other certificates including the domain name wwwhost.biz

(limited to 100 certificates)

Certificate

The complete raw certificate details for appetizer.wwwhost.biz 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 341261851084854596589610502711222606963619
 . . . . . . . . [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 2019-07-24 08:10:38 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-10-22 08:10:38 +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 'appetizer.wwwhost.biz'
 . . . . . . . . [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 726283807967749496409937520254999529819818968149845997855288310750859599568548063700631231110856321335053295376008126109615012448232985075032288970563940989212224429356690602457062051339406090381461438600523891881915186349536627342834988150712240524154678787726263912839568793495095438611529399891169450275749490196656746576424998053835801994258794254424928184515668103310712111007546289844944667923701532397427811065994810585726511644862685972638828847232594747517335444581117299983028291506734865783317931159648266860566797123889287122180659375455259356017149044734677719676084305836314536100814690629437052786927628910019688355791116322647263800130523303141351408787048577642845747236764793039079383421847433124529205012993781618590949781898286565860146633520697279854195322068974543270965509347452490681033729671875159629361296495353746526365190122340956155300633539487840059322573974111552429380992589573871203808230448147619420138117137215283010709122042366690901449084282272948993430603666945386730505877335495506509870808129113145927958623813522157556487737237284674898162118350973695766654473833262832817122365202050050359482706937250222855233051796484396808232703686909852078329705533400400358375259113766179626244893089523
 . . . . . . . . . . . . . . . . . . . . [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)
							92ee0c752cb5a72bf0d4280001383b3799b4ce8f
 . . . . . . . . . . . . . . . . [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 (25 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'appetizer.wwwhost.biz'
 . . . . . . . . . . . . . . . . [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 (246 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (243 bytes)
							00f10076006f5376ac31f03119d89900a45115ff77151c11d902c10029068db2089a37d9130000016c233f2ca400000403004730450220387e5df300e5033382e88d63adbf7a8af575a723a10be7374b0c489d4838d182022100a77a62dd7128b3247494fa89e6b3235e7d9ccb43db2fbdcd7915d0846b501760007700293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016c233f2adb00000403004830460221008776c8edc5235feddeecd45874ba5021bc08d200bf1148b3d7e4c4396433e0e3022100f511b1256950d49589a325934b6d76aee5507fccb93a4f1647f08ccdfab7f8b0
 . . . . [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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