futurebuild.io

Issued by Go Daddy Secure Certificate Authority - G2

About this certificate

This digital certificate with serial number 91:35:47:49:7f:0d:9e:ea was issued on by GoDaddy.com, Inc..

This certificate is currently not expired, we haven't checked the revocation status of this certificate but you can do this simply on revocationcheck.com. 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:
  • DV certificate contains a subject common name, this is not recommended. If certificate policy 2.23.140.1.2.1 (CA/B BR domain validated) is included, only country and/or common name is allowed in SubjectDN. (BRs: 7.1.2.7.2)
  • Subscriber certificates use of Subject Key Identifier is NOT RECOMMENDED (BRs v2: 7.1.2.7.6)
  • Subscriber Certificate: commonName is NOT RECOMMENDED. (BRs: 7.1.2.7.1)

Certificate Subject

CN=futurebuild.io

GoDaddy.com, Inc.

Organization: GoDaddy.com, Inc.
Organization unit: http://certs.godaddy.com/repository/
State / Province: Arizona
Locality: Scottsdale
Country: US

This certificate will expire on

Certificate Details

Serial Number (hex): 91:35:47:49:7f:0d:9e:ea
Serial Number (int): 10463347690254999274
Serial Number lenght: 64 bits, 8 octets

SubjectKeyId: 8b:51:5a:bb:d1:24:70:d4:25:8f:56:6a:5b:f8:ce:06:13:ff:41:a3
AuthorityKeyId: 40:c2:bd:27:8e:cc:34:83:30:a2:33:d7:fb:6c:b3:f0:b4:2c:80:ce

Fingerprint (sha1): 28:6a:b6:93:20:50:47:66:45:af:20:a8:93:78:97:08:34:f0:90:36
Fingerprint (sha256): ee:34:4b:c8:4f:73:94:81:7f:a6:25:90:7b:42:f2:44:ca:87:c4:e6:dd:b9:ca:58:99:07:df:9f:5c:c6:4c:fe

Issuing Certificate URL: http://certificates.godaddy.com/repository/gdig2.crt

Revocation information

OCSP Server: http://ocsp.godaddy.com/
CRL Distribution Point: http://crl.godaddy.com/gdig2s1-16270.crl

Check the revocation status for certificate futurebuild.io

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for futurebuild.io

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

10 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

futurebuild.io

Other certificates including the domain name futurebuild.io

(limited to 100 certificates)

Certificate

The complete raw certificate details for futurebuild.io in PEM and ASN.1 format.

Certificate (PEM)

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

Public Key (PEM)

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1o3bcFne8Rt6NMWaGET6
p1e/e+iOnU/pBbvd3u1SDJBhYyBIJV7KsZjumXr94wX/CT3vkqASnNq7IlPxnFWi
dGgQE3u9e3n4a4lKgF57vIdX1yQRvpqbqcfmiWQhTE/8c4mnNUYdzVTntO4hcB4o
T1N7MVkjJcTg+di08FXeoZGycc8HO6RGnftjb9CI79po5rk6DoeTrGyam3YnxhtZ
qQ3BZ4QIgiCgiZ6R+qGWvUHMOiFsfXJdNT7Lrv/VTeo/bLW99Uc1MyBntEN+KZf7
IbjYqw8a57uceS5pgEH7EwTd3B59bLBIWz/9hNO5D11xGBEVMBAfDm8N8ZC3JNvr
NQIDAQAB
-----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 10463347690254999274
 . . . . . . . . [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 2.5.4.8 (stateOrProvinceName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Arizona'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.7 (localityName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Scottsdale'
 . . . . . . . . . . . . [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 'GoDaddy.com, Inc.'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.11 (organizationalUnitName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'http://certs.godaddy.com/repository/'
 . . . . . . . . . . . . [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 'Go Daddy Secure Certificate Authority - G2'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2024-01-29 17:31:50 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2025-01-29 17:31:50 +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 'futurebuild.io'
 . . . . . . . . [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 27084949646879825636950219309954651730866218338334972719179018052049030330788016347789017026943638365669194771406798102610643205210701848126479598850224954164970412398720600405227810115242395747708158816152923511804226624948198616282820604139505108024912725070187561014415843603405114453539639466760104533255123283057206551321241857299333698377519806282218488854289044931164459610803439737930163423899959365102175504492789862501968298504371118599103110141193293226565343557369384744205889280090040341133305313533880405396158179835373106047027482762619382609974261307671366021782203775453145003899965801124937393236789
 . . . . . . . . . . . . . . . . . . . . [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 2.5.29.19 (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 2.5.29.37 (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 2.5.29.15 (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 2.5.29.31 (cRLDistributionPoints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (50 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://crl.godaddy.com/gdig2s1-16270.crl'
 . . . . . . . . . . . . . . . . [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 (86 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.16.840.1.114413.1.7.23.1
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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://certificates.godaddy.com/repository/'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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 1.3.6.1.5.5.7.1.1 (authorityInfoAccess)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (106 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.godaddy.com/'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [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://certificates.godaddy.com/repository/gdig2.crt'
 . . . . . . . . . . . . . . . . [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 40c2bd278ecc348330a233d7fb6cb3f0b42c80ce
 . . . . . . . . . . . . . . . . [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 (18 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'futurebuild.io'
 . . . . . . . . . . . . . . . . [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)
							8b515abbd12470d4258f566a5bf8ce0613ff41a3
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.11129.2.4.3 (CT Precertificate Poison)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . [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)
		00b014d7ad819912ee2a6ff8e2af91a83e36ca5e8faf9b18ee2b06ba7e8382cfa5aba8c17273eb432308da1da4307f131695d980404914ace57a515fb42023d96cf445c982c5f291ea8737cc280a9c32d074103d674dd10bd470f5f9f82d394a3e6e92e29258bddd42331a9a4cde7fc180224cd4d036d4f239d7f2f8e9070a4016d6d387bb4ab0aedc5a52eb9d3b29e4e8aa8ffa068a27c8dbd15ee9fbc69c046a2b8970938de491256bb7f0203322127f5123e2e13b9d1fffff563ebad5e8fdfdc38562f1169c78e641b13ece2dff4e5037e37761fc26c15f7b6cc83d0287082e29b6830f28ad45adf0e8ca36a2e0098bf232db77abaf3b2edc36c04c7d49502a