85915.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:17:95:a1:b6:c4:08:b9:99:bc:b2:f5:16:97:28:47:96:1c 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=85915.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:17:95:a1:b6:c4:08:b9:99:bc:b2:f5:16:97:28:47:96:1c
Serial Number (int): 269362246872558469146598156936960528586268
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 52:59:12:d9:ce:97:28:9e:bf:5b:e3:0b:5d:93:36:e6:3f:ae:ef:b1
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 28:84:fe:5c:25:0e:8f:14:20:b5:2f:42:b6:82:1b:0a:45:03:ff:39
Fingerprint (sha256): d5:25:89:f7:26:93:2d:c9:25:55:87:44:b0:69:12:37:39:da:8b:73:49:6a:f9:b1:c9:d7:55:80:41:9c:f4:02

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 85915.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for 85915.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

85915.com

Other certificates including the domain name 85915.com

(limited to 100 certificates)
www.85915.com
www.85915.com
83275.com
85915.com
85915.com
85915.com
www.85915.com
www.85915.com
71782.com
85915.com
www.83275.com
www.85915.com
www.85915.com
85915.com
85915.com
85915.com

Certificate

The complete raw certificate details for 85915.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 269362246872558469146598156936960528586268
 . . . . . . . . [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 2019-03-24 07:30:09 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-06-22 07:30:09 +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 '85915.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 732564160186596590939574118198006117359568438102792028602381389298379750996621965412432277252560507463092049339624380423009355574310037068495322544071638939314812480122092908743538671972261802846246944385542610564817787876998623019889556753275770781595835195061159029880533107420262770161094257865716399643477801962844019125478367722441409722936423240684978658325255877216242876488363198836127252054219603639770056526329305365562680597788020935516040961017022537560370729388550613886107955251839358295752211445436207210626866296822946064936193646765591311700222946897246075577518901664819879572712740730175124184232907414694096366072901961747034898797427909286136163559181359415742585542034476542398781133174530284604100733988506049636613221127683824767168657112452804972261479038329231291779172032318127780523241064806939992720613002037240254986747468183056847791724430754240563543822083272465464053394118661679026229116729260050951474688136712406351959150177221269039186125907388940599051987948018166313888956232652045810472128473811745456692460593628644019394205422019718082102916636502293761611640701210647350499311523061509997362143671007627490590242627501191424813487238523908820250588312871086421953529054324685415097817820697
 . . . . . . . . . . . . . . . . . . . . [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)
							525912d9ce97289ebf5be30b5d9336e63faeefb1
 . . . . . . . . . . . . . . . . [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 '85915.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)
							00f2007700747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc5600000169aed24553000004030048304602210080cbc4e585cf733f9d446e2d32b58ec4feafb3ab4ce693084a272456122120e6022100c59b4ad8938ba0bc0e107fff80d680c81b0fd4cd882bade70c6ace848cd63fba00770063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d00000169aed245690000040300483046022100d93ca2cf1c2fa78ee9fc728d4b4ee4f4b3a52ca3eec5fa4447c55b913dbaf1f1022100f7b4b89ca86fc36fb0200624b727b579f70d7612cf37facd92ac003b5e4e0581
 . . . . [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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