vivesconnect9.be
Issued by Let's Encrypt Authority X3
About this certificate
This digital certificate with serial number 03:c5:55:9e:1a:8f:73:97:c1:e1:b2:62:c2:45:be:b8:bd:2b was issued on by Let's Encrypt.
With 2 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=vivesconnect9.be
Let's Encrypt
Organization:
Let's Encrypt
Country:
US
This certificate has expire since
Certificate Details
Serial Number (hex): 03:c5:55:9e:1a:8f:73:97:c1:e1:b2:62:c2:45:be:b8:bd:2bSerial Number (int): 328486289379959034768110178040931671391531
Serial Number lenght: 138 bits, 18 octets
SubjectKeyId: 2c:c8:43:b0:42:bd:89:28:9c:e1:9b:df:d0:30:30:5e:46:a5:b5:e2
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1
Fingerprint (sha1): af:ab:3d:c5:50:17:df:29:24:ea:63:c0:34:fd:48:93:f6:3a:80:b9
Fingerprint (sha256): 4c:78:a3:60:a7:84:7f:7a:bf:6e:ab:bb:c5:08:74:99:f6:03:6a:d8:5b:88:f3:85:74:65:ee:91:33:6e:e7:21
Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/
Revocation information
OCSP Server: http://ocsp.int-x3.letsencrypt.orgCheck the revocation status for certificate vivesconnect9.be
2
DNS Names
0
Email Addresses
0
IP Addresses
Advanced Certificate Properties
Tehnical certificate details for vivesconnect9.be
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
9 extensions
No
unhandled critical extensions
CA Certificate
This is not a CA certificate
Subject Alternative Names
vivesconnect9.be
www.vivesconnect9.be
www.vivesconnect9.be
Other certificates including the domain name vivesconnect9.be
(limited to 100 certificates)
vivesalumni.be
m.vivesconnect9.be
graduway.co.uk
m.vivesconnect9.be
graduway.co.uk
graduway.co.uk
vivesconnect9.be
vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
vivesconnect9.be
graduway.co.uk
m.vivesconnect9.be
graduway.co.uk
www.vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
vivesconnect9.be
graduway.co.uk
m.vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
graduway.co.uk
vivesconnect9.be
vivesalumni.be
vivesalumni.be
www.vivesconnect9.be
vaughanconnected.com
vivesconnect9.be
graduway.co.uk
graduway.co.uk
graduway.co.uk
vivesalumni.be
graduway.co.uk
graduway.co.uk
graduway.co.uk
www.vivesconnect9.be
vivesconnect9.be
vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
vivesconnect9.be
graduway.co.uk
vaughanconnected.com
vivesconnect9.be
vivesalumni.be
vaughanconnected.com
vivesalumni.be
graduway.co.uk
graduway.co.uk
graduway.co.uk
vivesalumni.be
vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
m.vivesconnect9.be
graduway.co.uk
graduway.co.uk
vivesconnect9.be
vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
vivesconnect9.be
graduway.co.uk
m.vivesconnect9.be
graduway.co.uk
www.vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
vivesconnect9.be
graduway.co.uk
m.vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
graduway.co.uk
vivesconnect9.be
vivesalumni.be
vivesalumni.be
www.vivesconnect9.be
vaughanconnected.com
vivesconnect9.be
graduway.co.uk
graduway.co.uk
graduway.co.uk
vivesalumni.be
graduway.co.uk
graduway.co.uk
graduway.co.uk
www.vivesconnect9.be
vivesconnect9.be
vivesconnect9.be
m.vivesconnect9.be
graduway.co.uk
vivesconnect9.be
graduway.co.uk
vaughanconnected.com
vivesconnect9.be
vivesalumni.be
vaughanconnected.com
vivesalumni.be
graduway.co.uk
graduway.co.uk
graduway.co.uk
vivesalumni.be
vivesconnect9.be
Certificate
The complete raw certificate details for vivesconnect9.be in PEM and ASN.1 format.
Certificate (PEM)
-----BEGIN CERTIFICATE----- MIIFbTCCBFWgAwIBAgISA8VVnhqPc5fB4bJiwkW+uL0rMA0GCSqGSIb3DQEBCwUA MEoxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MSMwIQYDVQQD ExpMZXQncyBFbmNyeXB0IEF1dGhvcml0eSBYMzAeFw0xOTExMDcyMTE0NDJaFw0y MDAyMDUyMTE0NDJaMBsxGTAXBgNVBAMTEHZpdmVzY29ubmVjdDkuYmUwggEiMA0G CSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCV2PUoonDUgmF5ffEBqNV8TGysJQ+V H/Cd/0IVComsOrSd9qXev4GjUOxP0qzov6iHrMQHSeEoaj+ZClByZkorTnZJBu23 ItzKaEmYf4oE6K7mmEKikIXgHmTMaY0ESAKluXOZ1su4NRHlTqKMjA9fo0Eu7cjx Yx+klNmyfVB3RB2hjzH9opk5PUe9h7Cm4YAla2Bc5RafRWCJqGKUb4F8erU+/EB7 CoR1EhzbYTUJmakEo2GwdywQB7CJCUssg3Wt1Wb7ZHgz+bzyLx2yp+V0WOK7VLG2 dGtCzrzhpeq/f9NW15TMoEgIEtb4LJayCUYt1OKbPEYYN9l769Xw76WjAgMBAAGj ggJ6MIICdjAOBgNVHQ8BAf8EBAMCBaAwHQYDVR0lBBYwFAYIKwYBBQUHAwEGCCsG AQUFBwMCMAwGA1UdEwEB/wQCMAAwHQYDVR0OBBYEFCzIQ7BCvYkonOGb39AwMF5G pbXiMB8GA1UdIwQYMBaAFKhKamMEfd265tE5t6ZFZe/zqOyhMG8GCCsGAQUFBwEB BGMwYTAuBggrBgEFBQcwAYYiaHR0cDovL29jc3AuaW50LXgzLmxldHNlbmNyeXB0 Lm9yZzAvBggrBgEFBQcwAoYjaHR0cDovL2NlcnQuaW50LXgzLmxldHNlbmNyeXB0 Lm9yZy8wMQYDVR0RBCowKIIQdml2ZXNjb25uZWN0OS5iZYIUd3d3LnZpdmVzY29u bmVjdDkuYmUwTAYDVR0gBEUwQzAIBgZngQwBAgEwNwYLKwYBBAGC3xMBAQEwKDAm BggrBgEFBQcCARYaaHR0cDovL2Nwcy5sZXRzZW5jcnlwdC5vcmcwggEDBgorBgEE AdZ5AgQCBIH0BIHxAO8AdgBep3P531bA57U2SH3QSeAyepGaDIShEhKEGHWWgXFF WAAAAW5H7xsiAAAEAwBHMEUCIBmIVAePT0kgS603S+UBTryILMKU+1IkeFqia77n dCE9AiEArzpnLfO2w9p/c9IuzrPxZ9Sbf8uccqA385geAO1J8OIAdQCyHgXMi6LN iiBOh2b5K7mKJSBna9r6cOeySVMt74uQXgAAAW5H7xsQAAAEAwBGMEQCIGKhqnkl 7weT9KpypIXcTL4pzBqLEl4tAphUtF2xO1t0AiB+antNCPCe88E/dsjzeD2xGSHT 8pcHdd2vTLY0mMA5PzANBgkqhkiG9w0BAQsFAAOCAQEAYSU3HrxIFldxYuDDn10A TQQelcNCHl2f4dweXQjHXBDeipgmnRSL96lqVYa/2tTmxCfID5bi3H8JRMJAwRpS IYhIXvvIEEpMEJYwjCpa/3f2zyqy3VstFP0NROzrM9keCozzL3Did7xzz84hl+Fi y53fN33ipfbnTzF32PGVj5zSfp++TsCIxyMoHyDjqCg7g0vZrKUqHEz5TOPqEN14 5XtwsD5PqGhXIZuSi1sxYcxbtbf9iD8sYLH2FeJ7Xj7W9AHRETm8c3MoQJ/6KZSI i9jW79EfQ2IocG/49HC+kzucU5aIkKAhM0dV/HEqJiO4kglC8+5StRgSK7xVrbEI vw== -----END CERTIFICATE-----
Public Key (PEM)
-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAldj1KKJw1IJheX3xAajV fExsrCUPlR/wnf9CFQqJrDq0nfal3r+Bo1DsT9Ks6L+oh6zEB0nhKGo/mQpQcmZK K052SQbttyLcymhJmH+KBOiu5phCopCF4B5kzGmNBEgCpblzmdbLuDUR5U6ijIwP X6NBLu3I8WMfpJTZsn1Qd0QdoY8x/aKZOT1HvYewpuGAJWtgXOUWn0VgiahilG+B fHq1PvxAewqEdRIc22E1CZmpBKNhsHcsEAewiQlLLIN1rdVm+2R4M/m88i8dsqfl dFjiu1SxtnRrQs684aXqv3/TVteUzKBICBLW+CyWsglGLdTimzxGGDfZe+vV8O+l owIDAQAB -----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 328486289379959034768110178040931671391531 . . . . . . . . [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 2019-11-07 21:14:42 +0000 UTC . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-02-05 21:14:42 +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 'vivesconnect9.be' . . . . . . . . [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 18916493245206337389235278020637669941823780826799429976261790686480070002676465565430595834311678485968688376806386633208192552371060661126985221601934373164658668156265819039320913631604577477884138266331159665330615721695214082939832672211923730478846596326973196682492907192134417215450879052977190828018178468285985406432517168366590092640537452002216781525339902499676734686750536090641639279822498757678996733549107466827431068061999689120371863042123503192216183053351592110894830056606004202612684132412192029582152263432028616571042736794806992544906264642032226581279940303274379973071101221654866611381667 . . . . . . . . . . . . . . . . . . . . [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) 2cc843b042bd89289ce19bdfd030305e46a5b5e2 . . . . . . . . . . . . . . . . [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 (42 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'vivesconnect9.be' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.vivesconnect9.be' . . . . . . . . . . . . . . . . [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) 00ef0076005ea773f9df56c0e7b536487dd049e0327a919a0c84a1121284187596817145580000016e47ef1b2200000403004730450220198854078f4f49204bad374be5014ebc882cc294fb5224785aa26bbee774213d022100af3a672df3b6c3da7f73d22eceb3f167d49b7fcb9c72a037f3981e00ed49f0e2007500b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000016e47ef1b100000040300463044022062a1aa7925ef0793f4aa72a485dc4cbe29cc1a8b125e2d029854b45db13b5b7402207e6a7b4d08f09ef3c13f76c8f3783db11921d3f2970775ddaf4cb63498c0393f . . . . [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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