infermi.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:10:54:ec:01:08:cd:2d:8f:f9:59:e5:fe:2b:48:0c:59:29 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=infermi.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:10:54:ec:01:08:cd:2d:8f:f9:59:e5:fe:2b:48:0c:59:29
Serial Number (int): 266894256220700036920269112926614399506729
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: ad:ba:ff:3e:00:40:93:04:08:66:2d:2b:ab:ff:7d:75:f9:25:c7:ff
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): e5:25:f9:32:ff:5e:dd:cd:7e:2b:fc:b7:d6:40:e2:95:1a:c2:72:7b
Fingerprint (sha256): b7:25:25:f4:d6:09:a9:d2:c2:c7:19:1b:50:39:77:32:d6:5e:94:62:7e:0a:9e:a8:a2:e0:b2:64:55:3e:2c:68

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 infermi.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for infermi.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

infermi.com

Other certificates including the domain name infermi.com

(limited to 100 certificates)
pc-memory.com
infermi.com
infermi.com
infermi.com
infermi.com
www.infermi.com
infermi.com
www.infermi.com
infermi.com
www.infermi.com
infermi.com
www.infermi.com
infermi.com
infermi.com
www.infermi.com
www.infermi.com

Certificate

The complete raw certificate details for infermi.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 266894256220700036920269112926614399506729
 . . . . . . . . [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 2019-11-09 07:01:17 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-02-07 07:01:17 +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 'infermi.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 730656590726209073634325863410157987156767300967045470980550415219353068022786381037777825698071780610087466935014948914277727541318369723756268195971057149268529651661560177982412107619052930801834954374307835468958922532664243962232428235237140917602982496522374594056805748697983363769214710510065244909858260889664064155191940332670074860041613512073688958690183204840043981217893910433761859486586317490757971413596930573495332343357974550098850058503039529259608485386077288741695782450081404451742727789349968999823473062346902664209154471092309250442241885008250243356143805851336111397599636048702421687895624586388598698286141318360212954329272166030837206308141631371905255503788572787736686522939539680458919491717490278152883452527281201641011283133966887650986833798246907130253403416741933834962692827066516877972804356422203852766209438679995493548864599490825163573523767964957005356808336403362555991267473413629659499234393282170963686073799461757309800036576294814550408163872628989558718532201909602986992404033971786356386357283645934273581302550976102853831183479727032712507708671504670437706222146699085317634748421839283975910074512135915964272733196576888359554460037385678207272326183078344660133572799881
 . . . . . . . . . . . . . . . . . . . . [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)
							adbaff3e0040930408662d2babff7d75f925c7ff
 . . . . . . . . . . . . . . . . [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 (15 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'infermi.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)
							00ef007500b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000016e4f2e7e4b000004030046304402205047153db1e98d863ea9af4922fe7ac2e485d405124702f7b3f82f2d1cf76f210220744e53cdc0284bd6f8128cefb18deed459cd9684bb8dfa21dc4f8457ac3f520c0076005ea773f9df56c0e7b536487dd049e0327a919a0c84a1121284187596817145580000016e4f2e802600000403004730450220421f1f57de1f2ef50b2c76f099cfd564e97a6cede95e13963b7445ee592f4710022100f5d748d1ae5933379dbb05b49aea9b9630de80a4d064cb031e9ab74266a834e8
 . . . . [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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