client.aerialcanvas.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:9e:76:f4:37:cb:3c:ba:e3:0a:3b:9d:5c:aa:2d:eb:31:2d 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=client.aerialcanvas.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:9e:76:f4:37:cb:3c:ba:e3:0a:3b:9d:5c:aa:2d:eb:31:2d
Serial Number (int): 315259588724359759962224114773425123963181
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 6c:84:5e:08:c0:0c:b2:7f:d2:91:74:3a:2d:e4:b2:2c:1c:55:3f:b6
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): a6:8e:65:2f:f5:ee:6f:46:e9:cb:e9:b8:33:cd:93:02:a7:f0:46:45
Fingerprint (sha256): a1:52:c8:99:a4:03:dd:2a:6e:58:ab:0c:d1:0a:09:91:8e:43:ed:37:54:2b:0e:47:a5:e4:f0:b5:a0:e0:10:47

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 client.aerialcanvas.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for client.aerialcanvas.com

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

client.aerialcanvas.com

Other certificates including the domain name aerialcanvas.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for client.aerialcanvas.com 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 315259588724359759962224114773425123963181
 . . . . . . . . [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 2019-11-11 23:15:16 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-02-09 23:15:16 +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 'client.aerialcanvas.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 (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 944081390047993660072264573812466029682781131749499660182783670660698776232443622318568519484370451560127298833894157090702916147569733528311075650257195821775264094103932841908070597503542269042692997004049214348310814282481511257082631668919324833685796413818859726642410592526530575817688450331651947130434661620114200045774944500684279338432493607080465528223485111726638685100045699785604048750852341848916151010832339075720038206666789159773969870103994843596760828097811435844322017544990735839938589739374399937007292770974023518347102264964682322716297073797979041395768112635966613797657164214825663853760738321274990907351665956558364941714254016705981550409610428488364689835505460671896001995888404989302964631207299105357720333407789665204022606745025509370589843823032962025314413067388430756091591177004682643991046153896658517493694124812168617735752488841161241382336355736601274665810547330814027457648038687061014735790821631727476348448816669276071554673034748580194385070966812365959822763603810630632999943196822568703545422126959597293893464114622825376852321757143265578074031928930152520505810421822290061890554931307676500739770268948795619726495602928085898370328557467826756919349413698430125685926985449
 . . . . . . . . . . . . . . . . . . . . [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)
							6c845e08c00cb27fd291743a2de4b22c1c553fb6
 . . . . . . . . . . . . . . . . [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 (27 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'client.aerialcanvas.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 (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 (246 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (243 bytes)
							00f1007600f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000016e5cf6ee13000004030047304502203f47144f9df80c922ddb7a8b2842732b4970095dd17fbebd8e569913c09e553a022100ed6b49a4ad5ff2c9780d6fcc156e55baf6b8e51bb2f2ec67c2cd291f12c39e66007700b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000016e5cf6ee060000040300483046022100ee722df1820901f1ba338a31033de3103596e1768c25cc8d7eeb74a70b531b49022100ea7a441913015ad273be8f5f37e9bcca391f0160389b1e24c414548c8f46c38b
 . . . . [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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