steepup.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:60:79:ea:54:b2:4e:c4:da:88:0c:06:ce:7b:97:73:0d:4e was issued on by Let's Encrypt.

With 2 subject alternative names this certificate can be used to secure multiple fqdn's. 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=steepup.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:60:79:ea:54:b2:4e:c4:da:88:0c:06:ce:7b:97:73:0d:4e
Serial Number (int): 381278304254255348495757591266529750748494
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 3c:16:ef:59:ea:d0:1f:8b:e2:9c:13:11:0b:9e:7b:8b:59:27:89:c4
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 76:3f:1f:1d:ca:26:15:e0:3a:d2:7e:f6:28:8d:72:e8:79:7f:44:5d
Fingerprint (sha256): c6:c8:f2:36:40:21:b9:e7:ef:7e:d0:53:ff:2c:e4:11:95:51:15:4a:a5:08:39:4e:0d:88:d2:f0:f2:6e:14:35

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 steepup.com

2

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for steepup.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

steepup.com
www.steepup.com

Other certificates including the domain name steepup.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for steepup.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 381278304254255348495757591266529750748494
 . . . . . . . . [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 2019-09-12 07:29:09 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-12-11 07:29:09 +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 'steepup.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 886326648220345820543565155545245836426302936841393150164264918696902652480306277472879199301500755731088167944292438056140854855765302037777076061058182988924114584607013350641385567862547766783044490005513588017621275975377538737208692988697477727222869166522849148765708425462626695355878985927751707815766585804024533688919519185643950503120406293693988876330488758871381866355206721981492082148209565144451352782799712827192824995250074646182742415830998805738845260936417765918416810077117287089297279091618238657975225857581238452218092620179714602488482867102915333981266438456381431988385794167890804107632006575383590889803799700122927279988169788365018941512488244779530026736247016755514722052834665757395395221606399776320199468993717728520902709158621354087413324498056432286292894429672352959895696626089727958368517962422426410040989064118686172953233011401428406426218104893610440109788416453760227506136038001154654414521711146198129963633685760458321386783578204402149327193375132655819224750291832822415814596582204177554429431043590813919128962905223045009676170128091111132134902586801481529747125695205230567111107845001571693583533614311254985390325753682612626687062574821517715599288645924271341842944681119
 . . . . . . . . . . . . . . . . . . . . [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)
							3c16ef59ead01f8be29c13110b9e7b8b592789c4
 . . . . . . . . . . . . . . . . [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 (32 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'steepup.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.steepup.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)
							00f00076006f5376ac31f03119d89900a45115ff77151c11d902c10029068db2089a37d9130000016d2497298a00000403004730450220526cb00123f742fab9c10480bdad58354e7d3a9c81cf3e9a1f17633dad2f9177022100a55a8c62de9f04014b196b01a6a084c220d1325385776ced45b6792c8b7499f500760063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016d24972b54000004030047304502207bd09b041379ba188756b77f931ba45961f142ec26c3bc0b1b12f81eefa31ab2022100ee824b30990cd6cc1123f8a9e374de0d91ee24a211b17409c8d4f686bdd228a3
 . . . . [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)
		000575ff249d5979595992e2632f9dc2b8d19c6927cf5ea52c3a841430a968ae57f53215e9d9c2f521fb5356ff34a063f6dcf8c5c614ab398c8eab9f516f84d3be1fb3cbe6b01d50e6c55144ac779a601cf711afc670a2389ff18d659c08728ed2c0e9b4175b920bb7cc4d93298e3ef9e5bd46756c22deecee1dbc975a9940ed8861713891188be8253f7a39d657bffac81fb1b11577f368c7f9c8bbdc49f57667687d364d7aa8537d30bb786de70cddfc261fbf8851770cd9e4eb9017b38eee833a0659753069892e4a8ce7ab28134008d60ae3996e11f2274b82432e90f985ff2f1b318cdbe34e5d224f34f64926e0c6daef780b9c0276e0d35f6ae8c758289b