34935.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:05:bd:50:f4:7a:3f:f0:75:21:1f:55:e7:90:bf:50:cb:5d 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=34935.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:05:bd:50:f4:7a:3f:f0:75:21:1f:55:e7:90:bf:50:cb:5d
Serial Number (int): 263289914063431031512068837414307389033309
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: ae:4b:13:5b:d7:44:a1:a3:38:bc:ba:71:37:15:e4:49:d2:ae:4e:fd
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 27:02:6c:fe:db:f7:08:b1:09:18:01:ea:e5:32:d6:53:bb:85:d8:91
Fingerprint (sha256): bf:e1:c6:cd:7a:d3:87:56:00:90:d4:fe:99:ef:d3:8f:59:09:bc:ea:4e:e5:ce:af:a1:b1:0b:fd:fa:46:75:05

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 34935.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for 34935.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

34935.com

Other certificates including the domain name 34935.com

(limited to 100 certificates)
www.34935.com
mosquitorepellent.guide
34935.com
pbfc.ca
34935.com
34935.com
www.34935.com
www.34935.com
www.34935.com
734.me
www.34935.com
34896.com
34935.com
34935.com
epicman.org
www.45926.com
antonella.org
34975.com

Certificate

The complete raw certificate details for 34935.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 263289914063431031512068837414307389033309
 . . . . . . . . [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 2019-07-28 08:22:02 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-10-26 08:22:02 +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 '34935.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 898210177668227875249610812430804535297817721614384180497216975172871728715128315195286807392767531667026871783072985275400756423875031964441931984093934263821396092320959666814096406598828947170053722654669120754350015632619189562640246043838446209186270919872090713835562765490070060038396411994347401843901558900777280845089943538377854221218767642947170038316444629977620589577276228250317958725672070311551757967967771095414804159529057359612689321038690390192924947555075717912653060389945493510497799753656717329397458966699565728293850334261843031346876909940248785132084756258468695887677519782340864509306444637572325342280947087324176824080720549822131459296461238253418594644735798427187985909227013339620851304628751468955506629372683720453631088645464613078649718351883236926182252454681518661898833705724238108121369893391915150190530305964954138055266075764805533951730180081162117360365096924292583587694110603247511946309852061503213615168214047025519599140140830242349037074082696378564604516272492530829027741889519331343585231829880669629893716451456830393048056187135897599756939989634312669560389490566392225417371592726952784420707573086160774873712445965921136076287292184141178911138435948028704596348124129
 . . . . . . . . . . . . . . . . . . . . [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)
							ae4b135bd744a1a338bcba713715e449d2ae4efd
 . . . . . . . . . . . . . . . . [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 '34935.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 (244 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (241 bytes)
							00ef0075006f5376ac31f03119d89900a45115ff77151c11d902c10029068db2089a37d9130000016c37e30da1000004030046304402206262c88a683650c84f49d99c18e652302fa23e1752b6a2df477292eb9b065f7402203597664a04f14a52901e063892ec9bc7ba45ba9df8563d8d1b90b8bd532ec47c007600293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016c37e30b93000004030047304502205f7fab4fbeefeb110d73ff02ff1354c62e4c0c6747e99539a3bd7b1a86905b94022100db2fc6e5614e95a0ad8975047bff94324c68f3bae61da6fee4f0c44b8cd8c202
 . . . . [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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