www.louisvillelimousines.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:c7:58:61:94:a1:dd:13:18:59:55:08:65:6f:c6:38:f8:fa 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.louisvillelimousines.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:c7:58:61:94:a1:dd:13:18:59:55:08:65:6f:c6:38:f8:fa
Serial Number (int): 416282813475352866067792201473652803827962
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 57:5b:42:21:22:73:8a:e3:5c:98:51:54:11:80:23:96:f8:8b:74:3b
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): cb:f9:9a:dc:99:98:36:65:84:57:75:42:29:f0:14:5f:3c:e4:05:bb
Fingerprint (sha256): fe:e5:8e:bf:5f:19:f8:54:ea:59:e0:31:17:45:d8:f8:d6:f3:52:52:ec:c2:d4:c4:84:b5:6e:b0:f8:12:16:f4

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.louisvillelimousines.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.louisvillelimousines.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.louisvillelimousines.com

Other certificates including the domain name louisvillelimousines.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.louisvillelimousines.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 416282813475352866067792201473652803827962
 . . . . . . . . [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 2019-11-14 21:47:12 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-02-12 21:47:12 +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.louisvillelimousines.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 657706384030475863419509100686184821791485675215781807148242913197812847003097774810784225964227172031196141003141178339159410941253821699612380618026092520207848035727914084731999996261821528124866474155240084546960779055778832756643432310862833250721903957318811093439089082443955697238247149756565294805330564864370934460348735044152886111001869600990598022842821026717830851317838855275432300044470324315112377117032699722348671217180269609226125831596776971455375598367914583197412014794948164702879740344515549072490110270156801711316332089579671835218767590372234661583121948028892051457749179115634398770796032749759378672629237113827611889703129177628372923191072971161351537472913287509640663400366412852290788109561576956790991579817197207439233565680845031948764666004955764505650695338368423661554294452177111586332650586283079382108998881329593782802309753912226371313118026054683542665694005033520279429766746924997297644083927647207558303901628968181656872523268434682378436623884009924825005732927447613590531117632648556404507509159147981097913823483741624953340247374005133601118379904684061103453608196019814831117212556193556751762170308145601523051800674819523283890992038368078216890948361613005418251433796751
 . . . . . . . . . . . . . . . . . . . . [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)
							575b422122738ae35c98515411802396f88b743b
 . . . . . . . . . . . . . . . . [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 (32 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.louisvillelimousines.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)
							00f0007700f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000016e6c1960720000040300483046022100dde6d55e824ae8af27c5c033f656e09aa831f101c419c49d7a3387a856e8d895022100d4465e646e7523244c0f7cc8fce6c869cd21c74958c5f6171f06165e78b37d92007500b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000016e6c196068000004030046304402203dd699c95d80ba8789f588cbeff5ae7354dbc8806c477cdd471aa3f5eaae5e8b02200207c67d607d20baa4da490eb486b7de7e7c724e32597fb16bdebcd733923b20
 . . . . [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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