entrecloud.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:bd:e1:5d:55:53:5f:8d:d7:d0:88:ba:d7:29:97:40:cf:b7 was issued on by Let's Encrypt.

With 3 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=entrecloud.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:bd:e1:5d:55:53:5f:8d:d7:d0:88:ba:d7:29:97:40:cf:b7
Serial Number (int): 413062071988368132344151297247493295755191
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 0a:77:7f:7f:08:a2:73:77:f5:7d:0c:85:70:62:83:6e:39:cc:00:ec
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 99:3d:33:df:8f:c6:1a:52:8f:77:0e:fb:45:49:f4:33:4c:80:4a:82
Fingerprint (sha256): a0:90:ee:09:df:2e:7e:8c:e6:0a:9c:4a:2a:f7:10:02:34:43:49:09:c0:6a:20:68:38:ce:c8:4a:a1:dc:6d:3a

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 entrecloud.com

3

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for entrecloud.com

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

8 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

dev.entrecloud.com
entrecloud.com
www.entrecloud.com

Other certificates including the domain name entrecloud.com

(limited to 100 certificates)
entrecloud.com
controlsystems.newcenturyresources.com
www.viveportstatus.com
*.entrecloud.com
go.entrecloud.com
entrecloud.com
www.viveportstatus.com
entrecloud.com
www.viveportstatus.com
www.viveportstatus.com
www.entrecloud.com
app.entrecloud.com
go.entrecloud.com
app.entrecloud.com
entrecloud.com
www.viveportstatus.com
go.entrecloud.com
entrecloud.com
www.entrecloud.com
entrecloud.com
www.viveportstatus.com
www.viveportstatus.com
sni.cloudflaressl.com
entrecloud.com
www.viveportstatus.com
www.viveportstatus.com
www.viveportstatus.com
links.emails.entrecloud.com
go.entrecloud.com
app.entrecloud.com
*.entrecloud.com
www.viveportstatus.com
status.fire.com
entrecloud.com
www.viveportstatus.com
portal.entrecloud.com
app.entrecloud.com
app.entrecloud.com
www.viveportstatus.com
status.entrecloud.com
go.entrecloud.com
www.entrecloud.com
entrecloud.com
go.entrecloud.com
entrecloud.com
status.us.deptagency.com
status.sentrygroup.com.au
entrecloud.com
sni.cloudflaressl.com
entrecloud.com
monitoring.i-beheer.nl
entrecloud.com
go.entrecloud.com
www.viveportstatus.com
www.entrecloud.com
app.entrecloud.com
entrecloud.com
entrecloud.com
go.entrecloud.com
go.entrecloud.com
portal.entrecloud.com
www.viveportstatus.com
go.entrecloud.com
go.entrecloud.com
app.entrecloud.com
www.entrecloud.com
entrecloud.com
www.viveportstatus.com
app.entrecloud.com
www.viveportstatus.com
entrecloud.com
go.entrecloud.com
portal.entrecloud.com
go.entrecloud.com
*.entrecloud.com
entrecloud.com
entrecloud.com
entrecloud.com
go.entrecloud.com
www.viveportstatus.com
status.cedrsystems.org
status.sentrygroup.com.au
monitoring.i-beheer.nl
status.fire.com
www.viveportstatus.com
www.viveportstatus.com
go.entrecloud.com
entrecloud.com
www.viveportstatus.com
support.hertech.com.ar
app.entrecloud.com
www.viveportstatus.com
status.myopenpay.co.uk
entrecloud.com
www.viveportstatus.com
go.entrecloud.com
www.viveportstatus.com
entrecloud.com
www.viveportstatus.com
status.appetizeapp.com

Certificate

The complete raw certificate details for entrecloud.com in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAssJpE0oEVDpjV5UqQI+F
1zpPkJYYBdacbWTZem1YhdHpg28ysDhDq/e+/obWQcyRqXxODOXDPgHkOimcwlKF
7rEvmbUlPB96/K814r+mnwfyramU2THM3UN1hj1UBBSC9HMXCehGh6FxHwpZM/WA
p885BD/AfO7JhaxgT7VdJOYTkMTxL+SAB772i7k8nbE8XZ++lGT+aYa3VtpxI9cR
ukdLhVXgGZMvXKkL6CRD84lCmplxKXluktmbuMwpCiQRJBLayH1mxSicx95u7P9C
WEwYTJSF5jD9xhOp6hSOckg977s7C+m2rGmYC7xz2i70Do7yHDKuCUH0bGH/pRtp
6QIDAQAB
-----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 413062071988368132344151297247493295755191
 . . . . . . . . [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 2017-08-14 19:06:00 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2017-11-12 19:06:00 +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 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'entrecloud.com'
 . . . . . . . . [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 22566285650164482933286069707816628058466096032563358115643155048604914839671198948647550431455990219502579834129549067072161858638296483052732899987839784147284132558730884607428153719810841105636948191259940217043702861736416748191688973131485373477459220539816903841529427946366803809425717095000320149412537154791294760957395344135108755654241032485705000767432951306902953464902729639345569445319642532314883372556962825716378264248700671070902139827860180439056710625791292574318146758353584389797854354572603142329013285730620130320379586890349609475474797776455537801249815978077155589292500350519589488781801
 . . . . . . . . . . . . . . . . . . . . [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)
							0a777f7f08a27377f57d0c857062836e39cc00ec
 . . . . . . . . . . . . . . . . [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 (58 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'dev.entrecloud.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'entrecloud.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.entrecloud.com'
 . . . . . . . . . . . . . . . . [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 (246 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 1.3.6.1.5.5.7.2.2 (unotice)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:12|false] UTF8String 'This Certificate may only be relied upon by Relying Parties and only in accordance with the Certificate Policy found at https://letsencrypt.org/repository/'
 . . . . [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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