my.vipnode.net

Issued by COMODO RSA Domain Validation Secure Server CA

About this certificate

This digital certificate with serial number c7:e3:da:2b:f0:b3:08:84:b6:e8:bf:8f:6e:98:0a:a1 was issued on by COMODO CA Limited.

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=my.vipnode.net,OU=Domain Control Validated+OU=EssentialSSL

COMODO CA Limited

Organization: COMODO CA Limited
State / Province: Greater Manchester
Locality: Salford
Country: GB

This certificate has expire since

Certificate Details

Serial Number (hex): c7:e3:da:2b:f0:b3:08:84:b6:e8:bf:8f:6e:98:0a:a1
Serial Number (int): 265699447594683089062968875420990573217
Serial Number lenght: 128 bits, 16 octets

SubjectKeyId: bb:74:94:a7:8d:f8:d9:4d:e4:20:f1:41:02:df:e7:51:c5:8e:50:49
AuthorityKeyId: 90:af:6a:3a:94:5a:0b:d8:90:ea:12:56:73:df:43:b4:3a:28:da:e7

Fingerprint (sha1): e4:6c:e1:12:cd:be:b1:4e:af:7d:78:1f:7c:f6:64:52:77:35:d2:43
Fingerprint (sha256): ce:5a:1f:25:7c:b9:d0:eb:d6:4d:18:e8:24:d5:0a:ba:b9:f2:0e:20:e3:ee:da:e1:64:a2:85:10:a1:5a:67:00

Issuing Certificate URL: http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt

Revocation information

OCSP Server: http://ocsp.comodoca.com
CRL Distribution Point: http://crl.comodoca.com/COMODORSADomainValidationSecureServerCA.crl

Check the revocation status for certificate my.vipnode.net

2

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for my.vipnode.net

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

my.vipnode.net
www.my.vipnode.net

Other certificates including the domain name vipnode.net

(limited to 100 certificates)

Certificate

The complete raw certificate details for my.vipnode.net in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAytnDpbrZw97zdPCnwWXb
8x9sKd8Xb6Ce+u2iMsKp+twf2GG++3hA7UGleb+xjwQioYC0YyQjcBStRcbalIgn
jlFiKJMfBJh7mLs2QK84CovXAxLcnssvrKlz+NzuQQS4QgoxNEAaAWw1BfPNIdbD
SZ0SnEwTVSNM6BUC65mcJqxsWacqk8tfeoNmi3csYHX4+LBcbUjWW+9WU+D1yyR2
sjLocr7gvkWBk6YHx5fYUdrXEWdc0G/w7QexxNE71uTa3tvOo0hkkrsUvI53HTJe
69b21H/CLbE5ktI+r2l46HQfbRXHpP9o/RqRnqLbjAM1uBSqk5HJjBdHa/9+JL8Q
CQIDAQAB
-----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 265699447594683089062968875420990573217
 . . . . . . . . [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 'GB'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.8 (stateOrProvinceName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Greater Manchester'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.7 (localityName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Salford'
 . . . . . . . . . . . . [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 'COMODO CA Limited'
 . . . . . . . . . . . . [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 'COMODO RSA Domain Validation Secure Server CA'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2015-09-07 00:00:00 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2016-09-06 23:59:59 +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 2.5.4.11 (organizationalUnitName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Domain Control Validated'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.11 (organizationalUnitName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'EssentialSSL'
 . . . . . . . . . . . . [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 'my.vipnode.net'
 . . . . . . . . [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 25607521155868988782233057542509718083538264941023179960376251611646677901920728784644384837764655291513951410302341342258085253604931382074642321354849617447754683077851501739839824750375368563694625962172585967079659448363424866422975811073475783252414099560081773378310603340836678951959109668130546251782878053438324863646800915553661505413102407269078279696533298366121364986277892056541982380827697184573635804058477241802019338496088834543863967082420832656473769779833689789933801454365041617949663567651356793424157811953661558162141714474888654505339820850118298652087789866719925280991933911472308049874953
 . . . . . . . . . . . . . . . . . . . . [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 2.5.29.35 (authorityKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName 90af6a3a945a0bd890ea125673df43b43a28dae7
 . . . . . . . . . . . . . . . . [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)
							bb7494a78df8d94de420f14102dfe751c58e5049
 . . . . . . . . . . . . . . . . [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 2.5.29.19 (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 2.5.29.37 (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 2.5.29.32 (certificatePolicies)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (72 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.6449.1.2.2.7
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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 'https://secure.comodo.com/CPS'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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 2.5.29.31 (cRLDistributionPoints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (77 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://crl.comodoca.com/COMODORSADomainValidationSecureServerCA.crl'
 . . . . . . . . . . . . . . . . [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 (121 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.2 (caIssuers)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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.comodoca.com'
 . . . . . . . . . . . . . . . . [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 (38 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'my.vipnode.net'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.my.vipnode.net'
 . . . . [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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