CRL & OCSP report for 0-apis.google.com.library.utulsa.edu - library.utulsa.edu (University of Tulsa)

library.utulsa.edu

Certificate details for library.utulsa.edu (At position 0 in certificate chain)
Serial number:
hex: 8134188ef6680c48f6e7715120f80ee
int: 10733806812336663876409143695753838830
Issued by: DigiCert SHA2 High Assurance Server CA
Public Key Algorithm: RSA
Not valid before:
Not valid after:
Organization: University of Tulsa
State / Province: Oklahoma
Locality: Tulsa
Country: US
  • This certificate does not contain any links to an LDAP server
  • This certificate does not contain any internal server links
  • This certificate does not contain any links with an unknown format

Check certificate compliance for 0-apis.google.com.library.utulsa.edu.

Certificate Revocation List (CRL)

This CRL was cached at
http://crl3.digicert.com/sha2-ha-server-g5.crl

CRL information

Source: CRL Distribution Points in Certificate
Location: http://crl3.digicert.com/sha2-ha-server-g5.crl
Size: 235699 bytes (DER data)
Response time: 578.761605ms
This update:
Next update:
Revoked: No
Revoked certificates in CRL: 6718

Relevant server response headers

Date:
Last Modified:
Expires:

Server and network information

Server Software: ECS (lga/1398)
Cache Information: HIT

Raw CRL response headers

Accept-Ranges: [bytes]
Cache-Control: [max-age=172800]
Content-Length: [235699]
Content-Type: [application/x-pkcs7-crl]
Date: [Tue, 27 Jun 2017 00:01:50 GMT]
Etag: ["2549515957"]
Expires: [Thu, 29 Jun 2017 00:01:50 GMT]
Last-Modified: [Mon, 26 Jun 2017 17:15:12 GMT]
Server: [ECS (lga/1398)]
X-Cache: [HIT]
  • Content-Type in response is set 'application/x-pkcs7-crl' and should be replaced with 'application/pkix-crl' (RFC 5280, section 4.2.1.13)
  • This CRL file is DER encoded
  • Issuer field is byte-for-byte equivalent with issuers subject
  • Response is already valid
  • Response is not expired
  • ThisUpdate is less than seven days old, CRLs must be updated and reissued at least every seven days (Mozilla Maintenance Policy section 3)
  • The NextUpdate field is not more than ten days beyond the value of the ThisUpdate field (Mozilla & Baseline Requirements)
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is after the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)
This CRL was cached at
http://crl4.digicert.com/sha2-ha-server-g5.crl

CRL information

Source: CRL Distribution Points in Certificate
Location: http://crl4.digicert.com/sha2-ha-server-g5.crl
Size: 235699 bytes (DER data)
Response time: 574.996019ms
This update:
Next update:
Revoked: No
Revoked certificates in CRL: 6718

Relevant server response headers

Date:
Last Modified:
Expires:

Server and network information

Server Software: CFS 0215

Raw CRL response headers

Accept-Ranges: [bytes]
Cache-Control: [max-age=172800]
Cf4age: [54]
Cf4ttl: [31536000.000]
Content-Length: [235699]
Content-Type: [application/x-pkcs7-crl]
Date: [Tue, 27 Jun 2017 00:01:50 GMT]
Expires: [Thu, 29 Jun 2017 00:01:50 GMT]
Last-Modified: [Mon, 26 Jun 2017 17:15:12 GMT]
Server: [CFS 0215]
X-Cf1: [13483:fC.ewr1:cf:cacheA.ewr1-01:H]
X-Cf2: [H]
X-Cf3: [H]
X-Cff: [B]
X-Cfhash: ["373b78b1c300909aaab4ae58e1a83ce0"]
  • Content-Type in response is set 'application/x-pkcs7-crl' and should be replaced with 'application/pkix-crl' (RFC 5280, section 4.2.1.13)
  • This CRL file is DER encoded
  • Issuer field is byte-for-byte equivalent with issuers subject
  • Response is already valid
  • Response is not expired
  • ThisUpdate is less than seven days old, CRLs must be updated and reissued at least every seven days (Mozilla Maintenance Policy section 3)
  • The NextUpdate field is not more than ten days beyond the value of the ThisUpdate field (Mozilla & Baseline Requirements)
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is after the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)

Online Certificate Status Protocol (OCSP)

This OCSP response was cached at
http://ocsp.digicert.com (POST)Good

OCSP response information

Source: Authority Information Access in Certificate
Location: http://ocsp.digicert.com (POST)
Size: 471 bytes (DER data)
Response time: 18.886908ms
Signature algorithm: SHA256WithRSA
Signature type: CA Signed
Reported statuses: 1
This update:
Next update:
Produced at:
Status: Good

Relevant server response headers

Date:
Last Modified:
Expires:
Cache Control Max-age: 48h0m0s

Server and network information

Server Software: ECS (dca/24E0)
Cache Information: HIT

Raw OCSP request (PEM encoded)

-----BEGIN OCSP REQUEST-----
MFEwTzBNMEswSTAJBgUrDgMCGgUABBTPJvUY+sl+j4yzQuAcL2oQno5fCgQUUWj/
kK8CB3U8zNllZGKiErhZcjsCEAgTQYjvZoDEj253FRIPgO4=
-----END OCSP REQUEST-----

Raw OCSP response (PEM encoded)

-----BEGIN OCSP RESPONSE-----
MIIB0woBAKCCAcwwggHIBgkrBgEFBQcwAQEEggG5MIIBtTCBnqIWBBRRaP+QrwIH
dTzM2WVkYqISuFlyOxgPMjAxNzA2MjMxNTEzMDBaMHMwcTBJMAkGBSsOAwIaBQAE
FM8m9Rj6yX6PjLNC4BwvahCejl8KBBRRaP+QrwIHdTzM2WVkYqISuFlyOwIQCBNB
iO9mgMSPbncVEg+A7oAAGA8yMDE3MDYyMzE1MTMwMFqgERgPMjAxNzA2MzAxNDI4
MDBaMA0GCSqGSIb3DQEBCwUAA4IBAQCn6Yed4XaJPrbEWl5venPimcyRrwgv1riV
R36Q3oNTUJPk2aKFv4SfGTO0m/j42nrXiy6WPMO71cW/Am6FLYiAIs9ztaXvbfyt
3WlDI91u/IU36R804VedN1UR7eAgnLe0iR/6iB0hgW0WX6/DJm7YcTOVUujLlvQo
qdoAkHQGBy2YM2eevhWFrvouNfpoUmyrvx5zixEf6lac298uswp0KMoN2g+zfqit
RUUk6MxWTqY2APXkJOLxD8FWSi+nwA9IpuAhjVGQfwd2XmBKzGiYytuRfoqiyRZd
JlDw4yfiB9nE/et8PIcFfh5oOuV9/D4EOJ6LozC30Dr00DL1sJSP
-----END OCSP RESPONSE-----

Raw OCSP Signing Certificate (PEM encoded)


Raw OCSP response headers

Accept-Ranges: [bytes]
Cache-Control: [public, max-age=172800]
Content-Length: [471]
Content-Type: [application/ocsp-response]
Date: [Sat, 24 Jun 2017 00:14:06 GMT]
Etag: ["594d365f-1d7"]
Expires: [Fri, 30 Jun 2017 12:14:06 GMT]
Last-Modified: [Fri, 23 Jun 2017 15:40:15 GMT]
Server: [ECS (dca/24E0)]
X-Cache: [HIT]
  • OCSP response is valid for at least 8 hours (Microsoft)
  • OCSP response is available at least 8 hours before the current period expires or at ½ the validity if valid for more than 16 hours (Microsoft)
  • Content-Type in response is set to 'application/ocsp-response'
  • Response is already valid
  • Response is not expired
  • ThisUpdate is less than four days old, OCSP information must be updated at least every four days (Mozilla & Baseline Requirements)
  • The NextUpdate field is not more than ten days beyond the value of the ThisUpdate field (Mozilla & Baseline Requirements)
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is after the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)
This OCSP response was cached at
http://ocsp.digicert.com (GET)Good

OCSP response information

Source: Authority Information Access in Certificate
Location: http://ocsp.digicert.com (GET)
Size: 471 bytes (DER data)
Response time: 33.990899ms
Signature algorithm: SHA256WithRSA
Signature type: CA Signed
Reported statuses: 1
This update:
Next update:
Produced at:
Status: Good

Relevant server response headers

Date:
Last Modified:
Expires:
Cache Control Max-age: 48h0m0s

Server and network information

Server Software: ECS (lga/13A3)
Cache Information: HIT

URL used for GET request

http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBTPJvUY%2Bsl%2Bj4yzQuAcL2oQno5fCgQUUWj%2FkK8CB3U8zNllZGKiErhZcjsCEAgTQYjvZoDEj253FRIPgO4%3D

Raw OCSP request (PEM encoded)

-----BEGIN OCSP REQUEST-----
MFEwTzBNMEswSTAJBgUrDgMCGgUABBTPJvUY+sl+j4yzQuAcL2oQno5fCgQUUWj/
kK8CB3U8zNllZGKiErhZcjsCEAgTQYjvZoDEj253FRIPgO4=
-----END OCSP REQUEST-----

Raw OCSP response (PEM encoded)

-----BEGIN OCSP RESPONSE-----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-----END OCSP RESPONSE-----

Raw OCSP Signing Certificate (PEM encoded)


Raw OCSP response headers

Accept-Ranges: [bytes]
Cache-Control: [public, max-age=172800]
Content-Length: [471]
Content-Type: [application/ocsp-response]
Date: [Sat, 24 Jun 2017 00:14:06 GMT]
Etag: ["59499641-1d7"]
Expires: [Fri, 30 Jun 2017 12:14:06 GMT]
Last-Modified: [Tue, 20 Jun 2017 21:40:17 GMT]
Server: [ECS (lga/13A3)]
X-Cache: [HIT]
  • OCSP requests is smaller than 255 bytes
  • OCSP response is valid for at least 8 hours (Microsoft)
  • OCSP response is available at least 8 hours before the current period expires or at ½ the validity if valid for more than 16 hours (Microsoft)
  • Content-Type in response is set to 'application/ocsp-response'
  • Response is already valid
  • Response is not expired
  • ThisUpdate is less than four days old, OCSP information must be updated at least every four days (Mozilla & Baseline Requirements)
  • The NextUpdate field is not more than ten days beyond the value of the ThisUpdate field (Mozilla & Baseline Requirements)
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is 63h46m6s before the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)

DigiCert SHA2 High Assurance Server CA (CA Certificate)

Certificate details for DigiCert SHA2 High Assurance Server CA (At position 1 in certificate chain)
Serial number:
hex: 4e1e7a4dc5cf2f36dc02b42b85d159f
int: 6489877074546166222510380951761917343
Issued by: DigiCert High Assurance EV Root CA
Public Key Algorithm: RSA
Not valid before:
Not valid after:
Organization: DigiCert Inc
Organization unit: www.digicert.com
Country: US
  • This certificate does not contain any links to an LDAP server
  • This certificate does not contain any internal server links
  • This certificate does not contain any links with an unknown format

Certificate Revocation List (CRL)

This CRL was cached at
http://crl4.digicert.com/DigiCertHighAssuranceEVRootCA.crl

CRL information

Source: CRL Distribution Points in Certificate
Location: http://crl4.digicert.com/DigiCertHighAssuranceEVRootCA.crl
Size: 543 bytes (DER data)
Response time: 19.463671ms
This update:
Next update:
Revoked: No
Revoked certificates in CRL: 1

Relevant server response headers

Date:
Last Modified:
Expires:

Server and network information

Server Software: CFS 0215

Raw CRL response headers

Accept-Ranges: [bytes]
Cache-Control: [max-age=172800]
Cf4age: [0]
Cf4ttl: [31536000.000]
Content-Length: [543]
Content-Type: [application/x-pkcs7-crl]
Date: [Tue, 27 Jun 2017 00:08:37 GMT]
Expires: [Thu, 29 Jun 2017 00:08:37 GMT]
Last-Modified: [Wed, 21 Jun 2017 18:15:04 GMT]
Server: [CFS 0215]
X-Cf1: [13483:fD.ewr1:cf:cacheB.ewr1-01:H]
X-Cf2: [H]
X-Cf3: [M]
X-Cff: [B]
X-Cfhash: ["ac0a00808eb29f705a902c55d1fa900d"]
  • Content-Type in response is set 'application/x-pkcs7-crl' and should be replaced with 'application/pkix-crl' (RFC 5280, section 4.2.1.13)
  • This CRL file is DER encoded
  • Issuer field is byte-for-byte equivalent with issuers subject
  • Response is already valid
  • Response is not expired
  • Revocation information is updated at least once every twelve months
  • The value of the NextUpdate field is not more than twelve months beyond the value of the ThisUpdate field
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is after the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)

Online Certificate Status Protocol (OCSP)

This OCSP response was cached at
http://ocsp.digicert.com (GET)Good

OCSP response information

Source: Authority Information Access in Certificate
Location: http://ocsp.digicert.com (GET)
Size: 471 bytes (DER data)
Response time: 287.443963ms
Signature algorithm: SHA256WithRSA
Signature type: CA Signed
Reported statuses: 1
This update:
Next update:
Produced at:
Status: Good

Relevant server response headers

Date:
Last Modified:
Expires:
Cache Control Max-age: 48h0m0s

Server and network information

Server Software: ECS (lga/135E)
Cache Information: HIT

URL used for GET request

http://ocsp.digicert.com/MFEwTzBNMEswSTAJBgUrDgMCGgUABBTfqhLjKLEJQZPin0KCzkdAQpVYowQUsT7DaQP4v0cB1JgmGggC72NkK8MCEATh56TcXPLzbcArQrhdFZ8%3D

Raw OCSP request (PEM encoded)

-----BEGIN OCSP REQUEST-----
MFEwTzBNMEswSTAJBgUrDgMCGgUABBTfqhLjKLEJQZPin0KCzkdAQpVYowQUsT7D
aQP4v0cB1JgmGggC72NkK8MCEATh56TcXPLzbcArQrhdFZ8=
-----END OCSP REQUEST-----

Raw OCSP response (PEM encoded)

-----BEGIN OCSP RESPONSE-----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-----END OCSP RESPONSE-----

Raw OCSP Signing Certificate (PEM encoded)


Raw OCSP response headers

Accept-Ranges: [bytes]
Cache-Control: [public, max-age=172800]
Content-Length: [471]
Content-Type: [application/ocsp-response]
Date: [Tue, 27 Jun 2017 00:01:50 GMT]
Etag: ["59513a15-1d7"]
Expires: [Mon, 03 Jul 2017 12:01:50 GMT]
Last-Modified: [Mon, 26 Jun 2017 16:45:09 GMT]
Server: [ECS (lga/135E)]
X-Cache: [HIT]
  • OCSP requests is smaller than 255 bytes
  • OCSP response is valid for at least 8 hours (Microsoft)
  • OCSP response is available at least 8 hours before the current period expires or at ½ the validity if valid for more than 16 hours (Microsoft)
  • Content-Type in response is set to 'application/ocsp-response'
  • Response is already valid
  • Response is not expired
  • Revocation information is updated at least once every twelve months
  • The value of the NextUpdate field is not more than twelve months beyond the value of the ThisUpdate field
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is 14h1m50s before the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)
This OCSP response was cached at
http://ocsp.digicert.com (POST)Good

OCSP response information

Source: Authority Information Access in Certificate
Location: http://ocsp.digicert.com (POST)
Size: 471 bytes (DER data)
Response time: 596.568716ms
Signature algorithm: SHA256WithRSA
Signature type: CA Signed
Reported statuses: 1
This update:
Next update:
Produced at:
Status: Good

Relevant server response headers

Date:
Last Modified:
Expires:
Cache Control Max-age: 48h0m0s

Server and network information

Server Software: ECS (lga/13A2)
Cache Information: HIT

Raw OCSP request (PEM encoded)

-----BEGIN OCSP REQUEST-----
MFEwTzBNMEswSTAJBgUrDgMCGgUABBTfqhLjKLEJQZPin0KCzkdAQpVYowQUsT7D
aQP4v0cB1JgmGggC72NkK8MCEATh56TcXPLzbcArQrhdFZ8=
-----END OCSP REQUEST-----

Raw OCSP response (PEM encoded)

-----BEGIN OCSP RESPONSE-----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-----END OCSP RESPONSE-----

Raw OCSP Signing Certificate (PEM encoded)


Raw OCSP response headers

Accept-Ranges: [bytes]
Cache-Control: [public, max-age=172800]
Content-Length: [471]
Content-Type: [application/ocsp-response]
Date: [Tue, 27 Jun 2017 00:01:49 GMT]
Etag: ["59513a15-1d7"]
Expires: [Mon, 03 Jul 2017 12:01:49 GMT]
Last-Modified: [Mon, 26 Jun 2017 16:45:09 GMT]
Server: [ECS (lga/13A2)]
X-Cache: [HIT]
  • OCSP response is valid for at least 8 hours (Microsoft)
  • OCSP response is available at least 8 hours before the current period expires or at ½ the validity if valid for more than 16 hours (Microsoft)
  • Content-Type in response is set to 'application/ocsp-response'
  • Response is already valid
  • Response is not expired
  • Revocation information is updated at least once every twelve months
  • The value of the NextUpdate field is not more than twelve months beyond the value of the ThisUpdate field
  • Last-Modified header is not the same as ThisUpdate (RFC 5019, section 6.2)
  • NextUpdate is 14h1m49s before the date in the Expires cache header
  • The Cache-Control max-age header does not outlive NextUpdate
  • ThisUpdate has a date before NextUpdate
  • Expires cache header is not the same as the NextUpdate field (RFC 5019 section 6.2)

DigiCert High Assurance EV Root CA (CA Certificate)

Certificate details for DigiCert High Assurance EV Root CA (At position 2 in certificate chain)
Serial number:
hex: 2ac5c266a0b409b8f0b79f2ae462577
int: 3553400076410547919724730734378100087
Issued by: DigiCert High Assurance EV Root CA
Public Key Algorithm: RSA
Not valid before:
Not valid after:
Organization: DigiCert Inc
Organization unit: www.digicert.com
Country: US
  • This certificate does not contain any links to an LDAP server
  • This certificate does not contain any internal server links
  • This certificate does not contain any links with an unknown format

This is a self signed certificate

Check the revocation status for another website

Created by Paul van Brouwershaven
© 2015 - 2017 Digitorus B.V.
Revoked certificates can't and should not be trusted, these certificate will cause errors like "NET::ERR_CERT_REVOKED" in browsers.