sellerfy.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:0b:ea:fa:0f:03:8c:58:79:4e:21:79:0e:e5:15:fc:63:1a 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=sellerfy.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:0b:ea:fa:0f:03:8c:58:79:4e:21:79:0e:e5:15:fc:63:1a
Serial Number (int): 265392301561156630461148008874942515667738
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: fc:39:21:2c:53:83:b2:ce:c1:55:54:28:42:ea:b8:61:cb:64:7f:10
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 69:7e:31:4b:04:ee:02:a0:0b:ab:c4:0e:ec:8c:39:15:a6:04:6d:4f
Fingerprint (sha256): 5c:f4:7a:81:96:43:0b:00:17:fd:b6:ab:56:6b:b5:c6:9c:ad:c3:52:8e:b3:2e:6c:f0:5f:3c:7d:3d:18:42:1e

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 sellerfy.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for sellerfy.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

sellerfy.com

Other certificates including the domain name sellerfy.com

(limited to 100 certificates)
www.sellerfy.com
www.sellerfy.com
sellerfy.com
sellerfy.com
www.sellerfy.com
www.sellerfy.com
www.resert.com
sellerfy.com

Certificate

The complete raw certificate details for sellerfy.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 265392301561156630461148008874942515667738
 . . . . . . . . [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 2019-05-17 07:08:39 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-08-15 07:08:39 +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 'sellerfy.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 806290371102332036824125628419313285851309682622324724467758310097168177461956724390836226229321216714418563606296611382167872100999286358967619143792979021749173923300576528067055454097703665171584859136524312041547516812035298193431028846042005990429404773806367983848948553340095169018237309320529618841945554856698225463450003884534170117545785365463796230096516608110949042007696162227461856549762611327213606666492305972207007823762147106398705679931280489911780918524666870998941471693907195959552904517441007693578227300681842246537060730167587132450563744405410648828968241350332190614722973255690940155391537590382717309195615520165561083587079267116542239545332145491613235293928447886709262343154870257309227224495096934305115164530058832310691401323213371013208661370233174081259231684510881955198444894251719703324718316940622342643239693590844541636605374614623782111498036829998507884528726195830373029459235385057968565907867283225820904450044160818266663112905803400433072030369775313374667661195198454020246316545453232738781510698246750985515800546986185498247429382313693884418616470000897449860426500740114012412882546019221172888728708039639495328546433126968123463517586122091733137270441952054720565381673741
 . . . . . . . . . . . . . . . . . . . . [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)
							fc39212c5383b2cec155542842eab861cb647f10
 . . . . . . . . . . . . . . . . [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 (16 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'sellerfy.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 (247 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (244 bytes)
							00f200770063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016ac4d5fd64000004030048304602210089487efb6ae20dd63bcf019651497283b4718675edd225707e323231aa7a8559022100fb475c0a57c7b385cdad7c2e1e2eaebef2f1be2cf6f5abd08258db246b3cc1710077006f5376ac31f03119d89900a45115ff77151c11d902c10029068db2089a37d9130000016ac4d5fef30000040300483046022100917270a5930ce920818ebea99a2a3103186e4f4b2c4fcdfb6448dc0dbe2a3b37022100d2dd3ac6ff8bb627ac890f450f97a9c7059c73f14b14c02ab2d075bac93f5c90
 . . . . [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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