www.lightningtorch.world

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:fc:cc:de:9f:56:7c:d6:8d:3d:b1:b4:b8:fe:73:57:cf:8c 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.lightningtorch.world

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:fc:cc:de:9f:56:7c:d6:8d:3d:b1:b4:b8:fe:73:57:cf:8c
Serial Number (int): 434472618623915581424249214789401284431756
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: c4:49:bc:11:dc:25:00:04:fb:ef:cb:b0:b7:35:15:47:74:ba:62:4f
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 5c:f2:8d:61:70:ce:9c:f7:5e:22:17:e3:eb:9b:b1:c6:6f:32:38:d8
Fingerprint (sha256): de:31:30:46:66:b3:f5:4d:b5:cc:83:c9:5f:f8:ef:57:3e:17:fe:18:ae:49:26:44:1d:fd:88:33:fb:fa:96:86

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.lightningtorch.world

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.lightningtorch.world

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.lightningtorch.world

Other certificates including the domain name lightningtorch.world

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.lightningtorch.world 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 434472618623915581424249214789401284431756
 . . . . . . . . [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 2020-03-13 08:17:37 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-06-11 08:17:37 +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.lightningtorch.world'
 . . . . . . . . [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 845228488963217670815393308252335913577368410340987491835858237523129480692454725421792826296140301203195826900672186648826306623231981618645193522169238709951706788805277231271286542569231930962307692283387168278260182609174628622228021374810532802456529810348842286975738449709016543800935784671104154100501863002661676588585286957822756237002560625540958047872341050233161016885457688942666289885641894712369905837303223698741043254104409295583125366571092910262935079220417267005589129608771485140739097091415189965312840953369966493784528093825943220790882344046447444353794363076414069953267500172981385578437448163664431466212702912261410878792547469083578699924466349578229756777410747592476191653089053837545824384852401414976132943871257001337417089519069960787940719334899931097942667499811910104066795199048913545195579550960885556096881835826427995748626010361136123239398478995320447067313222725734964582170150441633290766645290288840780171219371232903879044299061121896164680344203427407630676612984200021830162003348403340486873716796992889987018521888009512515252733409021209873158263314312171980196015653249482812568562895498532130622794773915731789062878128720729700798607676284681875530305153800098678681020300563
 . . . . . . . . . . . . . . . . . . . . [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)
							c449bc11dc250004fbefcbb0b735154774ba624f
 . . . . . . . . . . . . . . . . [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 (28 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.lightningtorch.world'
 . . . . . . . . . . . . . . . . [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)
							00f1007700e712f2b0377e1a62fb8ec90c6184f1ea7b37cb561d11265bf3e0f34bf241546e00000170d32f4bb800000403004830460221008d06afee842bc9966ec0786e8130ad589301cc404949fa1481efc0df7eb0873f022100c693ba70aeaa0f48f11cf8e0811a159aee460ac58e153133f75eb437026e96e200760007b75c1be57d68fff1b0c61d2315c7bae6577c5794b76aeebc613a1a69d3a21c00000170d32f4bea0000040300473045022100d747d6a50e87d19ed822c02eef614821376d4417cc453de74862b17e7461cbb302204fe00a7b8b6faf578bc2a1431177fb998f522f3b582fecba333a081a9375ed04
 . . . . [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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