www.hotelsisarenas.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:81:c7:e1:98:b8:a9:a2:96:d2:6c:82:4f:d6:3a:5e:36:2f 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.hotelsisarenas.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:81:c7:e1:98:b8:a9:a2:96:d2:6c:82:4f:d6:3a:5e:36:2f
Serial Number (int): 392611256795353158150752934364844060980783
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 8f:53:5e:c1:9e:a5:6e:53:2b:2a:8c:e3:c2:b6:7d:f2:8a:c4:32:7a
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 01:86:1b:22:9c:0f:9d:46:95:6f:6f:45:ca:50:a4:9f:51:bc:59:cc
Fingerprint (sha256): 25:19:e1:2f:66:f8:cf:a9:c6:87:50:69:14:b7:2a:2d:e2:41:10:78:78:34:e8:53:45:e2:98:18:12:da:0d:eb

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.hotelsisarenas.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.hotelsisarenas.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.hotelsisarenas.com

Other certificates including the domain name hotelsisarenas.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.hotelsisarenas.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 392611256795353158150752934364844060980783
 . . . . . . . . [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 2020-02-24 15:08:31 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-05-24 15:08:31 +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.hotelsisarenas.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 726619107297630865834458687486430410549683497931924648843227802403430204259925415524777082745703921268107999727982494439055786011160262838992876567266454040366779657272778068828220841660329561391902288130559136665492287673110578262994760700886279538622993631494654781306203316627619202166569335728350721572462238196738981997777366868576725298572227657749093266679526375676109989900671911469892906223045698928559535816519140095247184880745841505328566866276970954665377893587785134830769867383928091038686949250428904078730950822340500815071771672749149278533558994345976059149910755974317605435094554458375994670364493568248186760964976272553049460633481966712263016662404349000071180184279650065512731322556173190084015367180559142901062854778718794340544733467358121031700788206626777403859721917972279179049438154000232759509491329844003587709534336289193388742143731095096528029849520876076958955854056206833538063852547147072745029065355440668892142888269188794808980047513966747454106679879954282381219096152780405980176960657829156736732520338948036665098985105972391941304999891565248392908920091440344504366950829099292917971669669470280677608757615843683829167778914155043123098276562826519120374147722650637043786372349357
 . . . . . . . . . . . . . . . . . . . . [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)
							8f535ec19ea56e532b2a8ce3c2b67df28ac4327a
 . . . . . . . . . . . . . . . . [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.hotelsisarenas.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)
							00f2007700f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000017077f5060b000004030048304602210087c8bd2c47a864f2803dfb85f37dacb227857efd518883d2b4946f55bb4f4f93022100ec44056463914138fbb23a8a32354bf27d6a4223e4b3a713b6d0fc1b862a8227007700b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000017077f505fe000004030048304602210099ec0f4c29cb6514a26e63c3240f4f0391ea0d5218e8d54672e28442a9db0f2a0221008c5753c31fd3dae76e4036bf620e0e7e226daf02f08544c4133c3e60a6622a6c
 . . . . [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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