www.hificrypto.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:f0:ff:9b:96:5a:85:7f:43:0e:30:75:62:9f:ce:e8:52:89 was issued on by Let's Encrypt.

With 10 subject alternative names this certificate can be used to secure multiple fqdn's. 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.hificrypto.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:f0:ff:9b:96:5a:85:7f:43:0e:30:75:62:9f:ce:e8:52:89
Serial Number (int): 343344386850777488147534481820899875508873
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: 61:6f:a4:4e:25:24:0e:a0:1f:6f:37:c2:2c:eb:57:ff:6e:59:d9:3b
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 10:43:47:bb:97:5c:d4:a8:f1:3a:ab:53:56:81:2a:65:cb:29:c1:50
Fingerprint (sha256): 9b:5e:df:b9:8e:51:65:56:8f:a1:95:2d:ca:3d:96:35:66:f6:6a:56:8c:aa:03:2f:a5:43:c8:44:6d:bb:1a:ca

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.hificrypto.com

10

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.hificrypto.com

Public Key Algorithm

RSA

Key Size

2048

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

art-signs.com
canicattinibagni.net
whitecrossleafs.com
www.art-signs.com
www.canicattinibagni.net
www.cardiopower.net
www.healthygrains.net
www.hificrypto.com
www.parkcityseasons.com
www.whitecrossleafs.com

Other certificates including the domain name hificrypto.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.hificrypto.com in PEM and ASN.1 format.

Certificate (PEM)

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzDVInmuNLg6uKbOyQ6JK
u6TSRQ4q650n0wNuPIaak74rZ12FKRojJKUHufRfmqeYPmH3Jg5HsvnZZMq5fuzZ
0CnAb+ry31+ud9imRh53uurjOiW2Pm4P+HNh6RvD77+S37+W6Qf9YoOXylXYuNRw
7KVMbGglJcPSGWd+bgpjbrVCVE40Ngn8wapk7wAdIqwHhLBjbuNiGrwIPjRsuke1
8O0Z1dTjDoDcpJxLHeXTh2jeAwYP1elSe0V3VnvQM0KVYwJlcuYYyYkHD9ol4qXE
wSkWLd5lSUxEf1qPlzW4Wyd8a9jIvwplpWPVAf1bYrHBkQ37disvO/NxaVzY3Ysv
jwIDAQAB
-----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 343344386850777488147534481820899875508873
 . . . . . . . . [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 2019-03-24 01:51:38 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-06-22 01:51:38 +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.hificrypto.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 (2160 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 25778889368709675538888519845453461204250849148116488851106174866177625822613652011998873520011908810411421020374004730299957827941759634308701739135795100820676349951265093371249387439693757126427020373349869350139973996567879116371628608362752220854930292983821219645524605254092468998884631077947082523044965359706682511623075500551465871670814471480499130506675399217216582659580978566767435263898568320730058271985692135130270304224181921035209113695082597198098985179493148673829543662654956384037870742976528772208284709471623232226231686971459209510513495264689600191074854562444484110362348951256742809513871
 . . . . . . . . . . . . . . . . . . . . [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)
							616fa44e25240ea01f6f37c22ceb57ff6e59d93b
 . . . . . . . . . . . . . . . . [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 (220 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'art-signs.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'canicattinibagni.net'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'whitecrossleafs.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.art-signs.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.canicattinibagni.net'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.cardiopower.net'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.healthygrains.net'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.hificrypto.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.parkcityseasons.com'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.whitecrossleafs.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)
							00f2007700747eda8331ad331091219cce254f4270c2bffd5e422008c6373579e6107bcc5600000169ad9c57a40000040300483046022100da5740d009f3628d1b895835801b6e8cdfd1691b7ed1e2e1be4f029a3d4518e3022100e44fe2c7670dd2ca44b1ce2ef2a1438e5f11aad387ffed230a04981017793f7100770063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d00000169ad9c58020000040300483046022100d4486554875f3fa68d706be122b72f65dd29100818160b8ea095480ef335563d022100e7bedde852f246f3e802184f890d92f15386535cfdd8e7954f36290eefed48ee
 . . . . [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)
		005b54460cb6c2f129218a09ffe299fd1c3d5d8d60740ef782c1048ed7709b8a58f82c3f412d965591a132439e19d69638ce48e94142cbb51ac16bb11741bb3218829bb171a3bf26677d111dcb27678a6d9dfd34e99bcefc7090e4a84500fbce8fc4eb90f965d2c4a301e420433a29abf9fc2206883330f4f88b1ca56bd7905db86e6f8fa38f3365bcf250e2cddcc1c47f67624b42bae5b1af1061143641d2359e32c4ef5077b3510a86fb7e152c57313e20a4f237bd2e80b80162b9a73a04b26226dd8fd5f0de8d5a07380c0c32d694bcc597ecd8e0a8aee28b8284e4edcd18dd71dcd087ecec73db90585718c631f203213709ff0c88da2e4c1336368eb250c0