cristen.boston

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:ac:11:68:b7:e9:75:6b:6a:26:ce:ec:02:6e:ef:de:16:4f 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=cristen.boston

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:ac:11:68:b7:e9:75:6b:6a:26:ce:ec:02:6e:ef:de:16:4f
Serial Number (int): 319888565510661245784062671011635508680271
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: e8:f4:80:97:a9:2a:a1:48:51:b2:e5:c9:cf:8a:a3:58:76:f7:a7:93
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): c7:63:8c:11:e9:61:29:ba:77:da:27:d3:e4:4e:a5:1c:c3:15:47:4f
Fingerprint (sha256): 38:b7:39:75:ea:f9:c5:56:3c:55:5c:35:9f:12:55:cd:50:44:8a:68:06:be:96:3c:5e:c6:02:52:bf:03:0a:a6

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 cristen.boston

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for cristen.boston

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

cristen.boston

Other certificates including the domain name cristen.boston

(limited to 100 certificates)
www.cristen.boston
www.magdalen.boston
cristen.boston
www.cristen.boston
cristen.boston
www.cristen.boston
www.cristen.boston
kamiar.com
cristen.boston
cristen.boston
www.cristen.boston

Certificate

The complete raw certificate details for cristen.boston 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 319888565510661245784062671011635508680271
 . . . . . . . . [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 2019-11-08 12:27:16 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-02-06 12:27:16 +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 'cristen.boston'
 . . . . . . . . [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 917985687014314675691246724128923383442588100915233448876721430759979826331387531479810591334251217091458930417837835987001675439344513591913587934203514970261322779292030566145573799761583643488387436219234007423902475517601957560604226949031487316638072510742227704228501544410724279374627314298820849802423202111229737947386493703589543281913503337447983199279707694368442769437685584939266128993963942189909295054797265214951565052494713753791788181637172105214924983981344611465424949714496019938917996390980806080621507854166298962469842313987815410532103549135970504049237716326889332283861898707402524241934583651843138386386124078270999092025781036882085335321414401569691901562279441197940812794063575085308524224516359502886290733145739109703312282967744600088419957951620248038937430460238652196199614222758162224661559692388684941345499190436621533811110995840729636943381892997309046068368147109339241080723329798262027695770717500617850562071053708366651593982819935794947396746833162397602790981786645950683487095999562229068883337133465336742412602653525201507183396512850645784037232443866653899862172470492631156524035586536547335739797296886011086299181160673054977439144803395350292527471594495776076843405614959
 . . . . . . . . . . . . . . . . . . . . [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)
							e8f48097a92aa14851b2e5c9cf8aa35876f7a793
 . . . . . . . . . . . . . . . . [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 (18 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'cristen.boston'
 . . . . . . . . . . . . . . . . [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)
							00f0007600f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000016e4b329476000004030047304502202d6813ddf7731759cf67b0c4276c0a0e01e410572b5207568b53eda7ba97467f022100bd4c80c7ca71d96e6b5e2a7299959046c4b4f1079d7b37057e53c173f27b8eb300760007b75c1be57d68fff1b0c61d2315c7bae6577c5794b76aeebc613a1a69d3a21c0000016e4b32949b000004030047304502204cdc690a2be816e48c294a8c7ce3e08bc0106adea9d65ba44e72d540d6b2e430022100e3d47df9f6709b58e25f125d023ae6203b3253d7d4ae542f9981232a6985c1c6
 . . . . [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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