countone.co.zw

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:8c:f7:37:cf:15:9c:ac:ee:a3:e9:8a:83:30:53:2b:e4:c9 was issued on by Let's Encrypt.

With 7 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=countone.co.zw

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:8c:f7:37:cf:15:9c:ac:ee:a3:e9:8a:83:30:53:2b:e4:c9
Serial Number (int): 309304998255669286553286256076908860794057
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 5a:0d:11:4b:ac:0a:e0:07:28:40:0b:0c:08:63:94:7f:3f:49:fd:de
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): dc:05:55:5e:af:64:14:40:9f:31:b8:2f:c0:17:9e:23:b5:20:42:c9
Fingerprint (sha256): 37:07:75:65:a2:91:d7:13:78:b1:2c:c1:0b:66:56:8c:ad:53:2a:b2:8f:c9:60:0b:fd:9d:cd:1d:2d:cf:a4:a0

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 countone.co.zw

7

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for countone.co.zw

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

autodiscover.countone.co.zw
countone.co.zw
cpanel.countone.co.zw
mail.countone.co.zw
webdisk.countone.co.zw
webmail.countone.co.zw
www.countone.co.zw

Other certificates including the domain name countone.co.zw

(limited to 100 certificates)
countone.co.zw
meeting.mig.business
people.countone.co.zw
countone.co.zw
countone.co.zw
rh.h8agencia.com.br
rh.younit.com.br
eoffice.daikin.com.vn
myhr.rangercollege.edu
myhr.rangercollege.edu
countone.co.zw
hrms.soluzytech.com
employeehub.southcbo.com
countone.co.zw
countone.co.zw
myhr.rangercollege.edu
countone.co.zw
meeting.telecommunicologue.fr
hr.chiquispr.com
hrms.soluzytech.com
meeting.h2immigration.com
countone.co.zw
countone.co.zw
meeting.pingdeveloper.com
countone.co.zw
meeting.telecommunicologue.fr
hrms.soluzytech.com
countone.co.zw
countone.co.zw

Certificate

The complete raw certificate details for countone.co.zw in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1vuIhrOekZlTozK9JOru
sWArsQtIKxK+j0LKC6AVfNG/GtzErW6IAQhJrQGYMoBf+Me4oqNs+BCxl2xUUpGZ
0TX/d/M8wv6tZx8I7WsgPzkU3ccW3jqQTaRgunJdlBahYUmvgtmzwRRQvFMfbGVs
GhCD0obL7h0Phd2B2OFaVPiDS3DIsa+5LlbuahACgN1ZklBCenLtkeIVkrNIKxE1
K7HZb0TElwe7yLBMIa3i5QUqi/U61l1PvxTzl052Q7S2ZV7LL6eywUy4k1OpAkDC
e2LlU7rdhEHWOkakg6V23A8cyI2gsbuZ58sigw3xLoUL0BcqxaKISbC3j8zs2Ad8
WwIDAQAB
-----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 309304998255669286553286256076908860794057
 . . . . . . . . [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 2020-04-10 14:24:33 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-07-09 14:24:33 +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 'countone.co.zw'
 . . . . . . . . [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 27139032958495028317646197619563866320451025133629022342307607915601408737228068261515349088304204562861006946371727095557856400690274969280809342994495131721483183767889922708008900391880751930604170318898602554908755007179596383896604552280766957855389420529505616262886253204311076004710038466505592029519955697113853094456111378073133533906425983980913780187919362193626630172739399916405782262305261284189023342434472685255113781550025062206972003968796324272894129269925830693289310996419302347408908237034776827216635185703733382330253801968992102542834007785448563880996135184233642305947934561439029934914651
 . . . . . . . . . . . . . . . . . . . . [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)
							5a0d114bac0ae00728400b0c0863947f3f49fdde
 . . . . . . . . . . . . . . . . [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 (160 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'autodiscover.countone.co.zw'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'countone.co.zw'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'cpanel.countone.co.zw'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'mail.countone.co.zw'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'webdisk.countone.co.zw'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'webmail.countone.co.zw'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.countone.co.zw'
 . . . . . . . . . . . . . . . . [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 (245 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (242 bytes)
							00f0007600f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000017164b14ed8000004030047304502200979d6ded95231f526232c9a2e2e74d273da5797d56b5621737b7a0936f60629022100ac8672c8eb4fcdb9aa775ba632443d3160858b5d6c0206aa254efa7c842118d8007600b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000017164b14ed00000040300473045022100841855b614ec913591a0bf5b13d2f3a095213accbfb6eefb6c5e371a97ee98bf02202dc6d3451189bf23dce961da08b4a55a23e404b93baf4f1fc0424caf615988c4
 . . . . [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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