kati.org

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:00:5a:7a:ff:5a:28:33:bb:d7:08:54:00:ab:ec:08:31:00 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=kati.org

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:00:5a:7a:ff:5a:28:33:bb:d7:08:54:00:ab:ec:08:31:00
Serial Number (int): 261457126954275549117522306880240272027904
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 8b:92:8d:e1:23:3c:c9:19:6f:97:ab:67:66:d7:0d:f0:19:10:51:7c
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): c3:c9:c5:37:65:e8:46:cc:a5:57:fa:63:85:e1:08:0c:01:23:23:2e
Fingerprint (sha256): 32:9e:c4:14:b2:ef:ed:ae:29:9a:d8:de:64:98:10:f8:54:73:08:a8:8c:f1:9f:d0:d1:fd:85:7a:94:4d:bf:f2

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 kati.org

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for kati.org

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

kati.org

Other certificates including the domain name kati.org

(limited to 100 certificates)
potatoplastic.com
kati.org
kati.org
kati.org
www.kati.org
kati.org
www.kati.org
ourfamilycontinues.life
kati.org
tatertots.world
kati.org
www.sallie.com
magicalmusicforlife.com
www.kati.org
kati.org
www.kati.org
www.kati.org
kati.org

Certificate

The complete raw certificate details for kati.org 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 261457126954275549117522306880240272027904
 . . . . . . . . [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 2019-12-09 12:59:03 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-03-08 12:59:03 +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 'kati.org'
 . . . . . . . . [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 883980388398430860236723663929117640712856327921302820917319675928727322960804489149789087001458316757206777853225025479863486061245679736428642028249015287012581391638187383847684433704626682922696250881492250198559897391489513956861806337273842372723565795334977857815664362911038838631658333899845301090929735737763422537734037290193361774517577796835232665439015811291461540476511951651817821043501976882080101199345138057468303836359387224696866987225673643866828417283331582616137249421123880925621536887095269957144740912485256876202027295899352913296767303310421395354811843259021790191946807270170469072097999375741581013704587719260684124010126299522868299785281879185271683635493825057659341933100932761078657784936250420865194827241252385750075242781512916228204588940019602359536516540408417464802403320768579076532529236277272641144975161631858274615857563011776605670465942828237852166592647772400327302289232609645763889184460636929204456249498857740302808241341691251374261549476197634738284445261723074116863570077171423432885842334513814748724906132596221407316915036372327342955802483054152536388306491851510963780376467641389792000098474887873293419410185792966346323771726363766042897569862230156949008172308731
 . . . . . . . . . . . . . . . . . . . . [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)
							8b928de1233cc9196f97ab6766d70df01910517c
 . . . . . . . . . . . . . . . . [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 (12 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'kati.org'
 . . . . . . . . . . . . . . . . [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)
							00ef00760007b75c1be57d68fff1b0c61d2315c7bae6577c5794b76aeebc613a1a69d3a21c0000016eeaf4d38c0000040300473045022100f7602539daa75e01528346adb929e8ebad05675bc7d2a2c0af0c611491463b7d022017906c68fb5769b76fdc77152d437e845395a2678935ef791e577ebc12a2328a0075005ea773f9df56c0e7b536487dd049e0327a919a0c84a1121284187596817145580000016eeaf4d3c70000040300463044022029e04e9a4440ffe8512762fcf6c9e68ebd2a87c747acc19732d6deec52acba0c02206fba2d52057fa4e818b7311a2743fc52b4f67800e8491db781d8a8c375fea1a3
 . . . . [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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