www.helsinkihousut.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:48:86:ec:8d:0c:4e:28:d2:43:1d:7a:5c:33:f8:64:c4:79 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=www.helsinkihousut.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:48:86:ec:8d:0c:4e:28:d2:43:1d:7a:5c:33:f8:64:c4:79
Serial Number (int): 286016533007876783501314682281225613526137
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: d0:42:88:78:21:3f:55:24:46:80:4e:e0:e7:de:6e:60:2c:c1:07:29
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 83:8f:89:aa:5a:b9:0f:30:b9:66:ae:3d:22:47:59:c6:d9:0c:12:2a
Fingerprint (sha256): 22:9d:fa:8f:e5:f9:5f:0e:39:3c:ac:af:52:d0:b1:b4:b4:13:23:26:4d:ce:81:b2:46:ce:67:f1:59:db:9c:f5

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 www.helsinkihousut.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.helsinkihousut.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

www.helsinkihousut.com

Other certificates including the domain name helsinkihousut.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.helsinkihousut.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 286016533007876783501314682281225613526137
 . . . . . . . . [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 2020-01-25 08:30:22 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-04-24 08:30:22 +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 'www.helsinkihousut.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 686640924110590534000070247045489281229388558513318491726330570401600385859486369956197930552200328405625046662552405170704241446341362162614766839283889073014787658442692836916954940014441127150163406166191465379705094939249212637914868300075506876548516490867879949315051530984911980511499720445495775068242557671710546160292522288813255535566834841044932688555547049858373540486851932124073103978681119895876275411394560694074759030253778341877801551839010992722946006440395864791086484570280124928909432757993575005110761199791584378326886313435849768348548544554133650066276445899888608329540687904351617695853323588220024742646187872900607034507774839665621655956721590710425330803932506171407865319965196629355037190463918228755012179450862643387046214753108657001982957026400804417592771564457650390403402760694109057942704188620623825246600536866850716123243676458491360007707163721437510446802879557618243949609224626779472879278970694163508384955195992493756480898024204875366977369662427717887695276943916011517481589207696275324614422887252547474292866496475074665163963150515052464728466093441468973641460394893811839354717949861477016876329309277976620726232479887426664932516885987650571168609564329068784046494361353
 . . . . . . . . . . . . . . . . . . . . [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)
							d0428878213f552446804ee0e7de6e602cc10729
 . . . . . . . . . . . . . . . . [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 (26 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.helsinkihousut.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)
							00f0007600f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000016fdc09b99f000004030047304502206e07e51897ff777ab567f0f8603c87033d197735dd59de89202909a228b5f437022100f8c0cecfd5c8a78a0564722572c9d4bb307fcee645b40ff61758ebc75d594177007600b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000016fdc09b9bd0000040300473045022100afe1c0cafb093712c42f8b7a4ead46eaf74aa3f59e22609d12fcd1f167ab592b022034d3df42513fcc46c150216c44dd5dbd648568f2d48959832e2167e49f53f747
 . . . . [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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