contact.cdnsoilex.ca

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:1b:88:29:3d:7b:36:9c:6a:9a:53:2f:ce:e3:5b:42:81:15 was issued on by Let's Encrypt.

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=contact.cdnsoilex.ca

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:1b:88:29:3d:7b:36:9c:6a:9a:53:2f:ce:e3:5b:42:81:15
Serial Number (int): 270705470840732978038412762328092580675861
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 27:ef:8c:9b:65:14:17:37:5c:93:f5:c0:42:99:d0:47:aa:68:98:a9
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 5e:96:e3:23:ac:fa:d9:a2:54:df:ec:51:b2:17:d7:37:ed:3f:ef:8d
Fingerprint (sha256): 64:d6:0f:d9:be:8b:21:a8:98:07:28:65:3a:22:73:ef:5f:38:88:c5:91:fe:f1:ac:9b:24:70:b5:6b:5d:ab:46

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 contact.cdnsoilex.ca

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for contact.cdnsoilex.ca

Public Key Algorithm

RSA

Key Size

4096

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

contact.cdnsoilex.ca

Other certificates including the domain name cdnsoilex.ca

(limited to 100 certificates)

Certificate

The complete raw certificate details for contact.cdnsoilex.ca in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----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-----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 270705470840732978038412762328092580675861
 . . . . . . . . [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 2019-10-10 17:28:48 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-01-08 17:28:48 +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 'contact.cdnsoilex.ca'
 . . . . . . . . [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 (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 721943739906118010197491756263191437076716028359685903724763592475069041265269922863148114145373573568986442724110997267476866615630365160705572717710701311468268540142116059917610381817783738433594262952933571872276011999859769324955980309606086590199718588020988292944651439255001403483490101895381192599335498399557226779463777922747341605984255669565976785565822291200515120130204572366449388071067265539371206034516179373332433895612783527764519458256752944354717299689032980409913801753494957779944875901756054703564881021978782678219550956893882314831567156440810689527569512457491858744674865704548623748913305778700795287961314520698160142134476351394975378807934219360145753325308870909926084009183730941114948462003595516089009608598390323639232761115892355171946739829434858844408477408885360166663639045254704308836614288089675979867673213773191291795111305082069868386561575298113748791130562103353023304572239890012166647682328034912378820773455366520123695144910362574441781369818092031747315420020355806244412672430756839397827819797510566452313889703607284170521660415696367523512121897547854022150509445384384428649371943490893316404788606399101304172442179888297218532739774317121636945298537313563872986818509501
 . . . . . . . . . . . . . . . . . . . . [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)
							27ef8c9b651417375c93f5c04299d047aa6898a9
 . . . . . . . . . . . . . . . . [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 (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'contact.cdnsoilex.ca'
 . . . . . . . . . . . . . . . . [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)
							00ef007500293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016db6ee38a5000004030046304402200fa2ca794f18d27a0f200e075c0183ea73e95fb22f26b2138928ab689782ccd7022010b9ac9efb84a1e487cb82c1a4ded333da517e68a0dbda6108d48db411a727520076005ea773f9df56c0e7b536487dd049e0327a919a0c84a1121284187596817145580000016db6ee3aac0000040300473045022100cf25a3b2b6c4edb74ffcdb1906bebf8a2c0cbc168429b8de05a6692b61bea16902207b9fb79d0707798dfce7659b9aeb7f0de037e2343ee4d1837c66f2ac17af4063
 . . . . [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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