b2b.eltrak.gr

- ELTRAK S.A. -

Issued by GeoTrust RSA CA 2018

About this certificate

This digital certificate with serial number 06:82:56:51:43:9f:34:d4:a2:69:87:f3:06:a4:2b:07 was issued on by DigiCert Inc.

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)

ELTRAK S.A.

Organization: ELTRAK S.A.
Locality: Kifisia
Country: GR

DigiCert Inc

Organization: DigiCert Inc
Organization unit: www.digicert.com
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 06:82:56:51:43:9f:34:d4:a2:69:87:f3:06:a4:2b:07
Serial Number (int): 8652117291954064877018344501023091463
Serial Number lenght: 123 bits, 16 octets

SubjectKeyId: 16:9e:68:de:f4:db:36:19:34:f3:0f:2c:2f:e0:46:35:0f:df:ec:2a
AuthorityKeyId: 90:58:ff:b0:9c:75:a8:51:54:77:b1:ed:f2:a3:43:16:38:9e:6c:c5

Fingerprint (sha1): ad:99:23:9f:9a:4a:d0:cc:6d:cf:e3:9f:86:ef:e0:3f:99:c8:fe:90
Fingerprint (sha256): 62:99:02:13:39:28:79:3e:cc:97:27:0a:87:83:6f:4d:57:df:d4:8e:33:88:52:73:8c:5a:7d:79:a2:00:93:bc

Issuing Certificate URL: http://cacerts.geotrust.com/GeoTrustRSACA2018.crt

Revocation information

OCSP Server: http://status.geotrust.com
CRL Distribution Point: http://cdp.geotrust.com/GeoTrustRSACA2018.crl

Check the revocation status for certificate b2b.eltrak.gr

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for b2b.eltrak.gr

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

10 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

b2b.eltrak.gr

Other certificates including the domain name eltrak.gr

(limited to 100 certificates)

Certificate

The complete raw certificate details for b2b.eltrak.gr in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArZZD5xnB5WZT4uJtZvPf
DKYXBLrdUPmaorAVhefOHNvEBOdYVloFJYThd1fylMRMXKFSIClrRPfTTJz2rqXl
lOzIZeSA2iCy3T18dLyf2nSK70XGPBIDyocO4U8X9a7LdvNUXKCYy41im2KvLc7s
wmvqkI5Mg+CQVt6ttMDnJ6cGtSiUpQLJ8Y607Rfq9uGMhcEXxhJ7NIqzpBJWV9my
19ok6Z3hng3WoFfHwTxUgsgmK619rZBgkgbjlDEBCKkj0XzdfBYw9k2ds303WRRc
G/VUAnCfnx6qZulVl1ObeDQj8vScjJ8xPUxKHNptPpB7Y/NavpTt2BO/kpaplzQu
FQIDAQAB
-----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 8652117291954064877018344501023091463
 . . . . . . . . [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 'DigiCert Inc'
 . . . . . . . . . . . . [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 'www.digicert.com'
 . . . . . . . . . . . . [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 'GeoTrust RSA CA 2018'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-09-23 00:00:00 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2021-10-22 12:00:00 +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 2.5.4.6 (countryName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'GR'
 . . . . . . . . . . . . [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 'Kifisia'
 . . . . . . . . . . . . [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 'ELTRAK S.A.'
 . . . . . . . . . . . . [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 'b2b.eltrak.gr'
 . . . . . . . . [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 21913325313160885718391671813563878876769582709756756021469358729292592859720678559257082326284630759854016854024131690969446062648509251736417715490704941074174778883023494302024081778198880669556842037559079382571460760797402975063294315110016679668325106971393507306309899234592850237025326096541147815592888078729724345149755528506781187076479286261400026182166559240705207496880171787676260010465930760042389516207643150752776692392496539231052399382275595168270607721024743970713219422239937712874274172733464656320539403312367568661560487245605630668228172716817312749405910307655563273863912063642520928923157
 . . . . . . . . . . . . . . . . . . . . [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 9058ffb09c75a8515477b1edf2a34316389e6cc5
 . . . . . . . . . . . . . . . . [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)
							169e68def4db361934f30f2c2fe046350fdfec2a
 . . . . . . . . . . . . . . . . [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 (17 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'b2b.eltrak.gr'
 . . . . . . . . . . . . . . . . [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 2.5.29.31 (cRLDistributionPoints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (55 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://cdp.geotrust.com/GeoTrustRSACA2018.crl'
 . . . . . . . . . . . . . . . . [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 2.16.840.1.114412.1.1 (digiCertOVCert)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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://www.digicert.com/CPS'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.23.140.1.2.2 (Organization Validation Certificates Policy)
 . . . . . . . . . . . . . . . . [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 (105 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://status.geotrust.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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://cacerts.geotrust.com/GeoTrustRSACA2018.crt'
 . . . . . . . . . . . . . . . . [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 1.3.6.1.4.1.11129.2.4.3 (CT Precertificate Poison)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . [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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