www.681.me

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:b5:8e:8f:a9:5c:65:5d:75:7c:3a:2a:1a:d6:cb:49:77:a7 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=www.681.me

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:b5:8e:8f:a9:5c:65:5d:75:7c:3a:2a:1a:d6:cb:49:77:a7
Serial Number (int): 410229748448630661947015889089763075520423
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 2e:f7:0a:ea:82:f1:9d:42:d7:c8:96:53:44:56:0f:49:9b:a4:dd:71
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): e6:c0:b4:6d:e0:5f:71:24:00:36:2c:7d:9c:e1:6f:ae:27:78:5f:cb
Fingerprint (sha256): d1:92:c3:5a:a5:0b:55:ac:31:c9:bb:b4:15:6f:b5:d4:db:09:16:ab:51:70:5c:e0:17:66:c3:69:30:56:76:0f

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 www.681.me

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.681.me

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

www.681.me

Other certificates including the domain name 681.me

(limited to 100 certificates)
kamiwear.be
681.me
681.me
681.me
681.me
www.681.me
681.me
681.me
www.681.me
681.me
bacon.world
681.me
681.me
681.me
www.681.me
www.681.me
www.681.me
www.681.me

Certificate

The complete raw certificate details for www.681.me 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 410229748448630661947015889089763075520423
 . . . . . . . . [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 2020-02-02 18:22:43 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-05-02 18:22:43 +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 'www.681.me'
 . . . . . . . . [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 784287302730154181524325788529337239556505958939434285085875370266622953417625969434741030457700346479699079425388526101257874264667564342197084683053037685268411241561287269505676095191728830113967974118048116449195704944003706525853832283252716405687376361120447075244692673326860915064836640000686604805807243421486479514870653551331805607542340904612290974009701385894522565180143153727790363698714537392003325780010820416314089809848928863033520124576956512994431799213479998034934052169627542694606845342642135920104798380534770623965831782162535847702662697797154635630158421121659477216069653535509007554817311379206050539767552802357536151381056116855232264769451629556260881249194090814385020322923135119726600755024742914656202831694817587939403211402766984184906187989209993466000057904170543461131993624052314022421643463319830133454693103200653520463624690046081043743669600539816931353106667738074499455882529313656695272200092875863077425740976483012181134330147657296095752588817353193697693673324092630511876927340684248307249953016735638105187475520178323489849492541606912200352494960782826366927085380760670306039044908644974811334879286257784974340302352142308274975414911110028696402263039202323537247180611031
 . . . . . . . . . . . . . . . . . . . . [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)
							2ef70aea82f19d42d7c8965344560f499ba4dd71
 . . . . . . . . . . . . . . . . [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 (14 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.681.me'
 . . . . . . . . . . . . . . . . [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)
							00f10077005ea773f9df56c0e7b536487dd049e0327a919a0c84a11212841875968171455800000170075aeaea0000040300483046022100f7625203527d506d7bf9fc387272a8ad3f016b78851aaf5f06e9b8e09608af1f022100c49e66ddb2595f1d32839aa5c77fdb928fb95ade9ff2d92abe25dba819d6d7b5007600b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e00000170075aeada0000040300473045022100bd9ad099061cef41b63c584c250d4aa52be008f43c89a15f7265fd7c8338ab3d02202cb94e0689bb9c4e7e116ee832e77fb0d28f011c39bb780de8856b154c6d6588
 . . . . [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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