cercola.org

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:6b:fc:e5:7f:45:4e:c4:7d:08:d6:64:99:ef:a5:f8:55:db 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=cercola.org

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:6b:fc:e5:7f:45:4e:c4:7d:08:d6:64:99:ef:a5:f8:55:db
Serial Number (int): 298083228128096699053883399836753121007067
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 2e:74:98:78:5c:21:c9:0e:28:29:4c:01:01:ad:b7:d8:e2:96:b6:a6
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 44:bd:e2:19:2b:08:0c:6e:49:db:b5:e6:d0:19:19:68:11:2c:b7:c9
Fingerprint (sha256): 0b:54:9c:30:31:76:b7:31:a1:4f:26:c8:ed:47:81:b1:d3:0c:25:2a:99:c3:e7:27:a9:b1:6d:5c:f0:0b:52:db

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 cercola.org

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for cercola.org

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

cercola.org

Other certificates including the domain name cercola.org

(limited to 100 certificates)
cercola.org
cercola.org
cercola.org
www.cercola.org
www.cercola.org
www.cercola.org
www.ticket4444.com
cercola.org
cercola.org
cercola.org
cercola.org
www.cercola.org
www.cercola.org
948.me
insectrepellant.organic

Certificate

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

Certificate (PEM)

-----BEGIN CERTIFICATE-----
MIIGTTCCBTWgAwIBAgISA2v85X9FTsR9CNZkme+l+FXbMA0GCSqGSIb3DQEBCwUA
MEoxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MSMwIQYDVQQD
ExpMZXQncyBFbmNyeXB0IEF1dGhvcml0eSBYMzAeFw0xOTA1MjgwMTMxNDFaFw0x
OTA4MjYwMTMxNDFaMBYxFDASBgNVBAMTC2NlcmNvbGEub3JnMIICIjANBgkqhkiG
9w0BAQEFAAOCAg8AMIICCgKCAgEAy2CVWlRLiOcAZlGwhUMDLT1agMvFdY/ZFmPa
3IrwesH2z5MKkggV0YC6277X2oIf5fWC5cmVJXcUOtAxrOif0sZXYOMLBy+vxv1l
SFjz9ZVNqeS+/5E1sPZ+HzutFv4WPN0eOYg3jK4rqCLBHwTmihvyQNOZTwIMn/T5
edWr4ESsvjGS4DjuVayRnrkyhevO89k8gZq9LPnkXTqJh7znaWw4xWS4jeQZAk1n
VGpWX9kYQo/vTKP/B01HkJFsSoObOOcoELXVZ5fGfsnj+QQFDujXCwDc92PbWXTa
6vdg+OkKQYE7rtBSJ7Qg4mW+vToy7h/w8GtWk/f2f0xeBKn5CuBPoOrewTUDqGYc
1QPJYLuTQVbxg4jp0PoHogeYeCcdoLtdhXRBHocDlDtqmWxbhaJJu6l5VivviBLM
qNjjRzdoF+YRw9OdQjfslK/eQhVGEKU/HRwzScITSVULFwUJ9DQDWcvfxW7mTMYv
xuwbGSZdcpMkkmib//HMZ84i1/RT0+KrWsyreAKkWHMQv6no+l8MrBzhICvOoibK
oIadzvlycR27h/wIOKpf238pK+xc/Sr3FlIOoje0UC6+PWuS//WQ4KxGIL5fRddD
yYuIMPf9a1iLa6TViC3YcVQFQDXMQJ3J3cFpJjWuopg9wIvY3GcvaM7Hu3aXYEFo
YH9MihECAwEAAaOCAl8wggJbMA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggr
BgEFBQcDAQYIKwYBBQUHAwIwDAYDVR0TAQH/BAIwADAdBgNVHQ4EFgQULnSYeFwh
yQ4oKUwBAa232OKWtqYwHwYDVR0jBBgwFoAUqEpqYwR93brm0Tm3pkVl7/Oo7KEw
bwYIKwYBBQUHAQEEYzBhMC4GCCsGAQUFBzABhiJodHRwOi8vb2NzcC5pbnQteDMu
bGV0c2VuY3J5cHQub3JnMC8GCCsGAQUFBzAChiNodHRwOi8vY2VydC5pbnQteDMu
bGV0c2VuY3J5cHQub3JnLzAWBgNVHREEDzANggtjZXJjb2xhLm9yZzBMBgNVHSAE
RTBDMAgGBmeBDAECATA3BgsrBgEEAYLfEwEBATAoMCYGCCsGAQUFBwIBFhpodHRw
Oi8vY3BzLmxldHNlbmNyeXB0Lm9yZzCCAQMGCisGAQQB1nkCBAIEgfQEgfEA7wB2
AOJpS64m6OlACeiGG7Y7g9Q+5/50iPukjyiTAZ3d8dv+AAABavxHcbMAAAQDAEcw
RQIhALsTZIarL22I3FdXQp1mXYc7T2vzfpB+VQa8MXyMTiZGAiB/JcgvVMpuS3lr
GN0ewTR1N2zqKaVScGajafLXO/36rAB1AGPy283oO8wszwtyhCdXazOkjWF3j711
pjixx2hUS9iNAAABavxHcaUAAAQDAEYwRAIgXGbvmlcJT7nhquhxKF4ze4+cIAwl
RRbgDwAzaRZ7i/ICIHPV25OhtRFqjaLF2xtnf0NZFwS1kVxniCegfi3VfBqFMA0G
CSqGSIb3DQEBCwUAA4IBAQCDf2HEm2rD4LrdIZrr6t1zr1jHAGbcsUpyyojvsoBJ
aO/VZCbVmiWmkE9rxMwb2RApW4KLp2rUzEIxHzJh2YWIjP+u8g+9+3/bCIhi189z
7kVs8r4kdd7rRnKr51iVf2PU1p8hqCX7nTGDjUK35qy1ITeI8a85TgpeJfkgqBCA
3OTmLRqP/1I8y0DyC0FMHnMlWPVDaOlsn1okww06ALixewuuJdnq/DPrXvCEjuaN
s4LCSncGvqhOgiMSZRQti+2a+OfMg6+DzhBT6vksDsQUr4tR3L5IPuGr7QUgBMwP
W0m8XaM8WGoMH7naZHyPQYjnrxRdlC7VtiNUJhc1cnQb
-----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 298083228128096699053883399836753121007067
 . . . . . . . . [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 2019-05-28 01:31:41 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-08-26 01:31:41 +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 'cercola.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 (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 829706909612392856072555155544615839741388860387252798070448155055154346850842576446605005236484397058612049221887832529691629472334599534512220530216793526073508889758158635089480739532337290101739181257632745244847091056869652591517432866887368981313833408759688471168955135708410752832544887674276283249906272234405558452232648338072855496551934330159545847224409670543345320161208272728093553261306585858074093139538083655390502720682317619193683476420075562279284906858269371599213674955620302150929847498358105134647000111778641680428635872231129300608925371621204014194545407955104360832444912589836897637452955993959834920675956619699564905200972488911161915242715285362517912137882713387683124882309251810683746676125780871525469511123666243422140936293910708719375522973857602137266272536224896082680393584089060335831809297536084688981907106484706672358467641906598660041006027951459193599951957844811712914978187579679099618230533782804179969722010903969684986244581126705655382852438269739439601807092990131357669295992250701348371466890374470940095518538481300805776586120107321532599116013500478941722050686112918596874372690289818847073078303642656617988320023991644656147357354199685162770896658267188305758201350673
 . . . . . . . . . . . . . . . . . . . . [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)
							2e7498785c21c90e28294c0101adb7d8e296b6a6
 . . . . . . . . . . . . . . . . [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 'cercola.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 (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 (244 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (241 bytes)
							00ef007600e2694bae26e8e94009e8861bb63b83d43ee7fe7488fba48f2893019dddf1dbfe0000016afc4771b30000040300473045022100bb136486ab2f6d88dc5757429d665d873b4f6bf37e907e5506bc317c8c4e264602207f25c82f54ca6e4b796b18dd1ec13475376cea29a5527066a369f2d73bfdfaac00750063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016afc4771a5000004030046304402205c66ef9a57094fb9e1aae871285e337b8f9c200c254516e00f003369167b8bf2022073d5db93a1b5116a8da2c5db1b677f43591704b5915c678827a07e2dd57c1a85
 . . . . [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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