OCSP

• OCSP

https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

Solar thermal - MicroCSP

1 MicroCSP references solar thermal technologies in which concentrating

solar power (CSP) collectors are based on the designs used in

traditional Concentrating Solar Power systems found in the Mojave Desert

but are smaller in collector size, lighter and operate at lower thermal temperatures usually below 315 °C

(600 °F)https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

Solar thermal - MicroCSP

1 MicroCSP is used for community-sized power plants (1MW to 50MW),

for industrial, agricultural and manufacturing 'process heat' applications, and when large

amounts of hot water are needed, such as resort swimming pools, water

parks, large laundry facilities, sterilization, distillation and other

such uses.https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

OCSP stapling

1 'OCSP stapling', formally known as the TLS 'Certificate Status Request'

extension, is an alternative approach to the Online Certificate Status Protocol (OCSP) for checking the revocation

status of X.509 digital certificates. It allows the presenter of a certificate to

bear the resource cost involved in providing OCSP responses, instead of the

issuing certificate authority (CA).


OCSP stapling - Motivation

1 When the certificate is issued to a legitimate high traffic web site, for

instance, this can result in enormous volumes of OCSP request traffic, all of which serves to indicate that the

certificate is valid and can be trusted.


OCSP stapling - Motivation

1 OCSP checking also creates a privacy impairment, since it requires the

client to contact a third party (the CA) to confirm certificate validity. A

way to verify validity without disclosing browsing behavior would

be desirable for some groups of users.


OCSP stapling - Solution

1 Also, an invalid stapled response (or no stapled response) will just cause

the client to ask the OCSP server directly



1 As a result, clients continue to have verifiable assurance from the certificate authority that the certificate is presently

valid (or was quite recently), but no longer need to individually contact the OCSP

server. This means that the brunt of the resource burden is now placed back on the certificate holder. It also means that the

client software no longer needs to disclose users' browsing habits to any third party.



1 Overall performance is also improved: When the client fetches the OCSP

response directly from the CA, it usually involves the lookup of the domain name

of the CA's OCSP server in the DNS as well as establishing a connection to the OCSP server. When OCSP stapling is used, the certificate status information is delivered

to the client through the established channel, which improves performance.


OCSP stapling - Specification

1 Hallam-Baker, [https://tools.ietf.org/html/draft-

hallambaker-muststaple-00 X.509v3 Extension: OCSP Stapling Required]

TLS developer Adam Langley discussed the extension in an April 2014 article following the repair of

the Heartbleed OpenSSL bug.A


OCSP stapling - Deployment

1 OCSP stapling has not seen broad deployment to date, however this is

changing. The OpenSSL project included support in their 0.9.8g

release with the assistance of a grant from the Mozilla Foundation.



1 Apache HTTP Server supports OCSP stapling since version

2.3.3,[https://httpd.apache.org/docs/trunk/mod/mod_ssl.html#sslusestapling Apache HTTP Server

mod_ssl documentation - SSLUseStapling directive] the nginx web server since version

1.3.7,[http://mailman.nginx.org/pipermail/nginx-announce/2012/000095.html nginx-announce

mailing list - nginx-1.3.7] LiteSpeed Web Server since version

4.2.4,[http://www.litespeedtech.com/products/litespeed-web-server/release-log Release Log - Litespeed

Tech]



1 On the browser side, OCSP stapling was implemented in Firefox

26[https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ OCSP Stapling in Firefox], retrieved 2013-07-

30mozillawiki:CA:ImprovingRevocation#OCSP_Stapling|Improving Revocation -

MozillaWiki, retrieved 2014-04-28 and in Internet Explorer since Windows Vista.


OCSP stapling - Limitations

1 However, OCSP stapling supports only one OCSP response at a time, which is

insufficient for sites which use several different certificates for a single page.

[https://bugzilla.mozilla.org/show_bug.cgi?id=360420#c10 Mozilla NSS Bug 360420],

Comment by Adam Langley[https://bugzilla.mozilla.org/show_bug.cgi?id=611836 Mozilla NSS Bug 611836 -

Implement multiple OCSP stapling extension]


For More Information, Visit:

• https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html

The Art of Servicehttps://store.theartofservice.com








Documents

OCSP