45842.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:03:a8:d0:c9:11:20:c2:38:71:78:41:7c:5a:d9:cf:8e:62 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=45842.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:03:a8:d0:c9:11:20:c2:38:71:78:41:7c:5a:d9:cf:8e:62
Serial Number (int): 262582099275203343856253603956920700341858
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 82:55:78:c8:9d:87:49:eb:f2:6c:cd:19:5e:10:64:03:61:38:1f:37
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): f3:4c:c6:e8:c1:6f:40:32:65:b7:fd:43:83:41:ff:a0:c3:ad:dd:98
Fingerprint (sha256): c7:94:fe:34:f6:ee:14:c8:ba:70:66:71:a3:bc:7c:47:35:a1:14:28:af:61:a6:3e:e3:5d:d0:47:6f:45:08:b1

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 45842.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for 45842.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

45842.com

Other certificates including the domain name 45842.com

(limited to 100 certificates)
45842.com
www.45842.com
lumbu.bible
45842.com
33941.com
www.45842.com
45842.com
www.45842.com
45842.com
45842.com
www.45842.com
bonanza.world
45924.com
www.45842.com
monserrato.org
www.clotilde.boston

Certificate

The complete raw certificate details for 45842.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 262582099275203343856253603956920700341858
 . . . . . . . . [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 2019-05-27 23:40:41 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-08-25 23:40:41 +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 '45842.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 710842854903562209745515517293549526559235024271942736866226586888737589850324701763905982325939265885873526332522915872175695923436030693655042543270367699474787814905254791209123069779791447119206880097947598264839887698971687164201209911162169460942229625592655053990597314229681538106483961401586738707436836589319468939989708422294005319080629003468167767266277633633806466097269708900072586327193854095521774476292551786503957037035533641538513134901271561218609636198635514934115356704812090704501570209547000318974828880739459436853266432086465713218929695822202169284920899504406198178536170186695939508737967242713685690951974618147114020018858697537747559034972122745384398428722000311975619674610721163602652762851835398251555186293232176202228950898689568394023746535996090764745013575082235610993101271668347000018014037782444217312705530893643602267303895065416483997821739119916862663624307161726543226560725856934065663829956793552566372836721540639003402447728025459601249535938025058436177295129818962809100066840630597596114550689045833865948392781924678784615459656083486182081697984331451713103497432744328689647225317055664631138643001785671904046243635085433208841921659150033803405629232651605514007091661999
 . . . . . . . . . . . . . . . . . . . . [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)
							825578c89d8749ebf26ccd195e10640361381f37
 . . . . . . . . . . . . . . . . [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 (13 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String '45842.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 (245 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (242 bytes)
							00f0007500747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc560000016afbe1d1e50000040300463044022066315942584872ea8b1cd4e0c53fda723e49627a8e96ea17179e9024efe3edbe022012de98fc414d5dbe97568ac7e16b9aa89ac1365471d2f127ce1e60681f5ce381007700293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016afbe1d00f00000403004830460221009dd50529c8f27446bd034befa274c5b2a01bbe4b9a3eee28608fa869e08f0ab3022100bf8c2de7947ff3a35684df66bc05088e0e91fb9f90466c57dae8057c79ac8b79
 . . . . [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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