bva-doxa.com
Issued by Let's Encrypt Authority X3
About this certificate
This digital certificate with serial number 04:77:b1:5a:10:8f:ad:8e:e9:65:7d:35:22:a3:c0:f8:1d:61 was issued on by Let's Encrypt.
With 6 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=bva-doxa.com
Let's Encrypt
Organization:
Let's Encrypt
Country:
US
This certificate has expire since
Certificate Details
Serial Number (hex): 04:77:b1:5a:10:8f:ad:8e:e9:65:7d:35:22:a3:c0:f8:1d:61Serial Number (int): 389178486388505756556943256737702536027489
Serial Number lenght: 139 bits, 18 octets
SubjectKeyId: ed:bf:db:0a:f5:f2:8c:6e:a6:18:18:47:d0:6a:e1:77:a7:8d:eb:26
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1
Fingerprint (sha1): c9:23:c0:1b:b5:35:8c:71:79:6c:b2:a5:e4:d5:5d:48:12:cc:2e:47
Fingerprint (sha256): d5:f8:56:06:1d:41:27:76:46:9d:0e:a6:b3:e8:98:7a:ff:99:a4:21:88:74:22:16:e4:c8:8b:e3:15:30:8d:0c
Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/
Revocation information
OCSP Server: http://ocsp.int-x3.letsencrypt.orgCheck the revocation status for certificate bva-doxa.com
6
DNS Names
0
Email Addresses
0
IP Addresses
Advanced Certificate Properties
Tehnical certificate details for bva-doxa.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
bva-doxa.com
doxa.it
duepuntozeroresearch.it
www.bva-doxa.com
www.doxa.it
www.duepuntozeroresearch.it
doxa.it
duepuntozeroresearch.it
www.bva-doxa.com
www.doxa.it
www.duepuntozeroresearch.it
Other certificates including the domain name bva-doxa.com
(limited to 100 certificates)
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
bva-doxa.com
Certificate
The complete raw certificate details for bva-doxa.com in PEM and ASN.1 format.
Certificate (PEM)
-----BEGIN CERTIFICATE----- MIIFsDCCBJigAwIBAgISBHexWhCPrY7pZX01IqPA+B1hMA0GCSqGSIb3DQEBCwUA MEoxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MSMwIQYDVQQD ExpMZXQncyBFbmNyeXB0IEF1dGhvcml0eSBYMzAeFw0xOTA3MDIxNzQxMTBaFw0x OTA5MzAxNzQxMTBaMBcxFTATBgNVBAMTDGJ2YS1kb3hhLmNvbTCCASIwDQYJKoZI hvcNAQEBBQADggEPADCCAQoCggEBALoawd1gN3EhKpS3pg7zLj+dQbe37cXWVW0y KimbRnkZzjun/6f5r0qI60PkhAmQxX8WFgkN5I0zOxMfsfT+Gpg41ATxETmFJNBK r2Q9eYh79ID9fx0nfezpKBTjdOiclJTsQzpebrnZZbSu7fO5rk8zT/qRaVvp+OcK LzIEUE/sHQdP3j3pak8GOjcTLyXFPephIudMCNRMYW4OXenrtakhmg76hUvndifC 98WvtyBNPr64xOHwxzp/QEu8EynBtSIWeY8ZCzPYOnMVFjE8WbklRuOsFyCZvrm0 7E12OxrbmmbPVJ68v6hybTu7djVpLdjID7QNfn/+QKwKsytg1acCAwEAAaOCAsEw ggK9MA4GA1UdDwEB/wQEAwIFoDAdBgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUH AwIwDAYDVR0TAQH/BAIwADAdBgNVHQ4EFgQU7b/bCvXyjG6mGBhH0Grhd6eN6yYw HwYDVR0jBBgwFoAUqEpqYwR93brm0Tm3pkVl7/Oo7KEwbwYIKwYBBQUHAQEEYzBh MC4GCCsGAQUFBzABhiJodHRwOi8vb2NzcC5pbnQteDMubGV0c2VuY3J5cHQub3Jn MC8GCCsGAQUFBzAChiNodHRwOi8vY2VydC5pbnQteDMubGV0c2VuY3J5cHQub3Jn LzB1BgNVHREEbjBsggxidmEtZG94YS5jb22CB2RveGEuaXSCF2R1ZXB1bnRvemVy b3Jlc2VhcmNoLml0ghB3d3cuYnZhLWRveGEuY29tggt3d3cuZG94YS5pdIIbd3d3 LmR1ZXB1bnRvemVyb3Jlc2VhcmNoLml0MEwGA1UdIARFMEMwCAYGZ4EMAQIBMDcG CysGAQQBgt8TAQEBMCgwJgYIKwYBBQUHAgEWGmh0dHA6Ly9jcHMubGV0c2VuY3J5 cHQub3JnMIIBBgYKKwYBBAHWeQIEAgSB9wSB9ADyAHcA4mlLribo6UAJ6IYbtjuD 1D7n/nSI+6SPKJMBnd3x2/4AAAFrs/2ZngAABAMASDBGAiEAwe88hk5SQLQbX7Yv 9IkvJgbh+1XrTC+FWOWlzpaded8CIQCfzQ6AxRBjs6MUtD59Va0UZ6l24Y/4RAjv 2dDhrkcfjAB3AGPy283oO8wszwtyhCdXazOkjWF3j711pjixx2hUS9iNAAABa7P9 maEAAAQDAEgwRgIhAIgrwZfItOyx1RMo+KQTrD/ccLYwFTN8VuLEYONBjRiiAiEA 7LTt9gm2kNN22OcRKEeY5rkrpjSwOmYiYfQgTAKFCA8wDQYJKoZIhvcNAQELBQAD ggEBACN/s86Eupbsv1wdLLMg78mlAwKBzZ06rt4kaDv4utbnJedjp+uBj6Q8POd4 EBjJkxHXhmZtGzl7n7/Dv+kjHJJdHuVOx72EUNEqfyKbtVJG/YIW9CiwCFLLuS3o Mg8hbqFsh3hIa7Qb0q/CalHg/gTH71QTIwU0jY8eiBkQXWCZITKiCXcXAEruftK6 10woCmFKEHtdSrv+8ljRsHky25W+aEU1FY7sCu7LqPiCm3DNfU1uf0Z8wV7aN1ei z+xuLW6yxTFRrrgqtjBcDtGiioYq/neR/ZKvwecJRrVZcEKkkssbC/3yvfQ1wnUq Uk2ra13KxvCdBALAh9aiKrFSUcM= -----END CERTIFICATE-----
Public Key (PEM)
-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuhrB3WA3cSEqlLemDvMu P51Bt7ftxdZVbTIqKZtGeRnOO6f/p/mvSojrQ+SECZDFfxYWCQ3kjTM7Ex+x9P4a mDjUBPEROYUk0EqvZD15iHv0gP1/HSd97OkoFON06JyUlOxDOl5uudlltK7t87mu TzNP+pFpW+n45wovMgRQT+wdB0/ePelqTwY6NxMvJcU96mEi50wI1Exhbg5d6eu1 qSGaDvqFS+d2J8L3xa+3IE0+vrjE4fDHOn9AS7wTKcG1IhZ5jxkLM9g6cxUWMTxZ uSVG46wXIJm+ubTsTXY7GtuaZs9Unry/qHJtO7t2NWkt2MgPtA1+f/5ArAqzK2DV pwIDAQAB -----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 389178486388505756556943256737702536027489 . . . . . . . . [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 2019-07-02 17:41:10 +0000 UTC . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-09-30 17:41:10 +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 'bva-doxa.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 23493519232280818583502651315376079839298374690107312742994984093228785590142338455566141081657888379441514874565967169039385622139381232203177450011494755385426684947414398123638009239757306592049342124321193908994300446643227251048622263087375500626750918734593383957483485992235975434639473028382382838987452022728339246869081796431225966580124903853577629895296896998577698273235034036208725958677993294425730779717142822944434405264662207511782402098408987566232239354780777735731632762010183233376798888972504344486463752285470291818341902186012890265761913521040689372979009830523794052363570599804366732973479 . . . . . . . . . . . . . . . . . . . . [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) edbfdb0af5f28c6ea6181847d06ae177a78deb26 . . . . . . . . . . . . . . . . [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 (110 bytes) . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'bva-doxa.com' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'doxa.it' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'duepuntozeroresearch.it' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.bva-doxa.com' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.doxa.it' . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.duepuntozeroresearch.it' . . . . . . . . . . . . . . . . [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) 00f2007700e2694bae26e8e94009e8861bb63b83d43ee7fe7488fba48f2893019dddf1dbfe0000016bb3fd999e0000040300483046022100c1ef3c864e5240b41b5fb62ff4892f2606e1fb55eb4c2f8558e5a5ce969d79df0221009fcd0e80c51063b3a314b43e7d55ad1467a976e18ff84408efd9d0e1ae471f8c00770063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016bb3fd99a10000040300483046022100882bc197c8b4ecb1d51328f8a413ac3fdc70b63015337c56e2c460e3418d18a2022100ecb4edf609b690d376d8e711284798e6b92ba634b03a662261f4204c0285080f . . . . [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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