www.hostelsfirenze.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:26:92:4b:40:b9:5f:58:2c:1c:d6:c2:5f:a2:dc:9c:27:c3 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.hostelsfirenze.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:26:92:4b:40:b9:5f:58:2c:1c:d6:c2:5f:a2:dc:9c:27:c3
Serial Number (int): 274462045760686321749563101781107687565251
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 53:e1:61:26:7b:6a:0e:97:43:1a:d6:41:28:0f:30:c0:32:3b:56:97
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 55:e7:86:db:46:f2:a6:47:0f:5e:4e:7a:99:28:5d:12:6e:14:d3:c4
Fingerprint (sha256): 21:2b:7b:0d:73:08:1b:61:fc:1c:cc:ff:21:b0:b5:e1:fb:89:5e:f9:43:3a:f8:a6:36:68:13:4c:c2:e8:7d:be

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.hostelsfirenze.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.hostelsfirenze.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.hostelsfirenze.com

Other certificates including the domain name hostelsfirenze.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.hostelsfirenze.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 274462045760686321749563101781107687565251
 . . . . . . . . [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 2019-08-28 03:01:43 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-11-26 03:01:43 +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.hostelsfirenze.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 769986753165219640518776792376924592347939476338839810784050629808348630847624968242661603258598026600764302921858889734251074895090859412803026379708048891736571083101663237680307095650058149662542267380983149144271251153732501142880807366609026580946281576714969972943743177738043081116802588111352216661952502065500216076853008929346593976150665471676252765398661764016585146189110886007055264164537361404527357206021575999839611678188844011109098380479277939478117144109127034007705581457840056349808314343930760755895236194339774300180693974007967949341901914695563608039253866870555837231214931786478064569608351381560148921550402960231881574197169073743176290477778967247795627949408574198267681585033210122997333217266844750667452373340922045382503422836223387798300154269446655575353600916945170894001166156293810734439554063968137439142104404915459009767411783493776828929576128071355670468422219731179822032710193586561880618396301486301886001534081423738660017605235911491624068085714318282528921821172526325121730275048294485115478190154475226918143690188884160614024991718539291857910930368619230174125814041593495627960338133472088781706684078722632924604790980455481890670685776904771352219906140630268998236871980741
 . . . . . . . . . . . . . . . . . . . . [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)
							53e161267b6a0e97431ad641280f30c0323b5697
 . . . . . . . . . . . . . . . . [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.hostelsfirenze.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)
							00ef007600747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc560000016cd662ef2e000004030047304502210081336981d388e7b3ec476e9df33cc092fba2e9419a7b9bec13aa647a6bf3fa0802205b57d2b3d2e7c97fc8d8b55cb66927dff202273654903cd39bb5e20c2ba32f7f007500293c519654c83965baaa50fc5807d4b76fbf587a2972dca4c30cf4e54547f4780000016cd662ef540000040300463044022100a7ae7a7bcf4c1cc14148b39f8356541d87cae132afdb3be487b3b26e262ed32c021f5b114d5d98b652d67beb43b9b710b6d33a06f6b0feea280268d6c62ba42048
 . . . . [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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