PKIX Working Group A. Deacon
Internet Draft VeriSign
Category: Informational R. Hurst
Document: draft-ietf-pkix-lightweight-ocsp-profile-01.txt Microsoft
Expires: April 2005 October 2004
Lightweight OCSP Profile
for High Volume Environments
Status of this Memo
By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed,
or will be disclosed, and any of which I become aware will be
disclosed, in accordance with RFC 3668.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than a "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
Abstract
This specification defines a profile of the Online Certificate
Status Protocol (OCSP) that addresses the scalability issues
inherent when using OCSP in large scale (high volume) PKI
environments and/or PKI environments that require a lightweight
solution to minimize bandwidth and client side processing.
Table of Contents
Introduction......................................................2
1. OCSP Message Profile...........................................3
1.1 OCSP Request Profile......................................3
1.1.1 OCSPRequest Structure...................................3
1.1.2 Signed OCSPRequests.....................................4
1.2 OCSP Response Profile.....................................4
1.2.1 OCSPResponse Structure..................................4
1.2.2 Signed OCSPResponses....................................5
Deacon Expires - April 2005 [Page 1]
Lightweight OCSP Profile October 2004
1.2.3 OCSPResponseStatus Values...............................5
1.2.4 thisUpdate, nextUpdate and producedAt...................6
2. Client Behavior................................................6
2.1 OCSP Responder Discovery..................................6
2.2 Sending an OCSP Request...................................6
2.3 OCSP response status processing...........................7
3. Ensuring an OCSPResponse is Fresh..............................7
4. Transport Profile..............................................8
5. Caching Recommendations........................................9
5.1 Caching at the Client.....................................9
5.2 HTTP Proxies..............................................9
5.3 Caching at Servers.......................................11
6. Security Considerations.......................................11
6.1 Replay attacks...........................................11
6.2 Man-in-the-middle attacks................................12
6.3 Impersonation attacks....................................12
6.4 Denial of service attacks................................12
6.5 Modification of HTTP Headers.............................13
7. Acknowledgements..............................................13
8. References....................................................13
8.1 Normative................................................13
8.2 Informative..............................................14
9. Author's Addresses............................................14
Appendix A. Useful Response Extensions...........................14
Appendix A.1. nextPublish Response Extension.................14
Appendix B. Example OCSP Messages...............................15
Appendix B.1: OCSP Request...................................15
Appendix B.2: OCSP Response..................................15
Introduction
The Online Certificate Status Protocol [OCSP] specifies a mechanism
used to determine the status of digital certificates, without
requiring CRL's. Since its definition in 1999, it has been deployed
in a variety of environments and has proven to be a useful
certificate status checking mechanism.
To date, many OCSP deployments have been used to ensure timely and
secure certificate status information for high-value electronic
transactions or highly sensitive information, such as in the banking
and financial environments. As such, the requirement for an OCSP
responder to respond in "real time" (i.e. generating a new OCSP
response for each OCSP request) has been important. In addition,
these deployments have operated in environments where bandwidth
usage is not an issue, and have run on client and server systems
where processing power is not constrained.
As the use of PKI continues to grow and move into diverse
environments, so does the need for a scalable and cost effective
Deacon Expires - April 2005 [Page 2]
Lightweight OCSP Profile October 2004
certificate status mechanism. Although OCSP as currently defined
and deployed meets the need of small to medium sized PKI's which
operate on powerful systems on wired networks, there is a limit as
to how these OCSP deployments scale from both a performance and cost
perspective. Mobile environments, where network bandwidth is at a
premium and client side devices are constrained from a processing
point of view, require the careful use of OCSP to minimize bandwidth
usage and client side processing complexity.
Similarly, as PKI continues to be deployed into environments where
millions if not hundreds of millions of certificates have been
issued and an equal number of users (also known as relying parties)
have the need to ensure that the certificate they are relying upon
have not been revoked, it is important that OCSP is used in such a
way that ensures the load on OCSP responders and the network
infrastructure required to host those responders is kept to a
minimum.
This document addresses the scalability issues inherent when using
OCSP in PKI environments described above by defining an message
profile and OCSP client and responder behavior that will permit:
1) OCSP response pre-production and distribution
2) Reduced OCSP message size to lower bandwidth usage
3) Response message caching both in the network and on the client
It is intended that the normative requirements defined in this
profile apply to OCSP clients and OCSP responders operating in very
large scale (high volume) PKI environments or PKI environments that
require a lightweight solution to minimize bandwidth and client side
processing power (or both), as described above.
1. OCSP Message Profile
This section defines a subset of OCSPRequest and OCSPResponse
functionality as defined in [OCSP].
1.1 OCSP Request Profile
1.1.1 OCSPRequest Structure
OCSPRequests conformant to this profile MUST include only one
Request in the OCSPRequest.RequestList structure.
Clients MUST use SHA1 as the hashing algorithm for the
CertID.issuerNameHash and the CertID.issuerKeyHash values.
Clients MUST NOT include the singleRequestExtensions structure.
Deacon Expires - April 2005 [Page 3]
Lightweight OCSP Profile October 2004
Clients SHOULD NOT include the requestExtensions structure. If a
requestExtensions structure is included, this profile RECOMMENDS
that it contain only the nonce extension (id-pkix-ocsp-nonce). See
Section 3 for issues concerning the use of a nonce in high volume
OCSP environments.
1.1.2 Signed OCSPRequests
Clients SHOULD NOT create or send signed OCSPRequests. Responders
MAY ignore the signature on OCSPRequests.
If the OCSPRequest is signed, the client SHALL specify its name in
the OCSPRequest.requestorName field, otherwise clients SHOULD NOT
include the requestorName field in the OCSPRequest. OCSP servers
MUST be prepared to receive unsigned OCSP requests that contains the
requestorName field, but must realize that the provided value is not
authenticated.
Note: The suggested use of unsigned requests in this environment
does not enable a responder to determine the authenticity of
incoming request. Thus, access to the responder is implicitly given
to any relying party.
1.2 OCSP Response Profile
1.2.1 OCSPResponse Structure
Responders MUST generate a BasicOCSPResponse as identified by the
id-pkix-ocsp-basic OID. Clients MUST be able to parse and accept a
BasicOCSPResponse. OCSPResponses conformant to this profile SHOULD
include only one SingleResponse in the ResponseData.responses
structure, but MAY include additional SingleResponse elements if
necessary to improve response pre-generation performance or cache
efficiency.
The responder SHOULD NOT include responseExtensions. Clients MUST
NOT fail if they encounter non-critical responseExtensions in the
response.
In the case a responder does not have the ability to respond to an
OCSP request containing a nonce, such as if it only has the ability
to use pre-produced responses, it SHOULD return a response that does
not include a nonce. Clients SHOULD attempt to accept a response
even if the response does not include a nonce. See Section 3 for
details on validating responses that do not contain a nonce. See
also Section 6 for relevant security considerations.
Responders that do not have the ability to respond to OCSP requests
that contain a nonce MAY forward the request to an OCSP responder
capable of doing so.
Deacon Expires - April 2005 [Page 4]
Lightweight OCSP Profile October 2004
The responder MAY include the singleResponse extensions structure.
1.2.2 Signed OCSPResponses
Responders MUST use the sha1WithRSAEncryption signature algorithm
when signing the OCSPResponse. Clients MUST validate the signature
on the returned OCSPResponse.
<<Editors Note: Need to determine best way to future-proof this
draft with the new sha*WithRSAEncryption signature algorithms.
Options are to either depend on the next version of OCSP and update
when available or simply define that clients and servers MAY use the
more modern algs.>>
If the response is signed by a delegate of the issuing CA the
responder certificate MUST be referenced in the
BasicOCSPResponse.certs structure.
The responder's certificate SHOULD have a validity window greater
than or equal to the validity window of the responses it issues.
It is RECOMMENDED that the OCSP responder's certificate contain the
id-ocsp-nocheck EKU OID to indicate to the client that it need not
check its status. In addition, it is RECOMMENDED that neither an
OCSP authorityInfoAccess (AIA) extension nor CDP extension be
included in the the OCSP responder's certificate. Accordingly, the
responder's signing certificate SHOULD be relatively short-lived and
rolled over regularly.
Clients MUST be able to identify OCSP responder certificates using
both the byName and byKey ResponseData.ResponderID choices.
Responders MAY use byKey to further reduce the size of the response
in scenarios where reducing bandwidth is an issue.
1.2.3 OCSPResponseStatus Values
As long as the responder has records for a particular certificate,
an OCSPResponseStatus of "successful" will be returned.
In order to ensure the database of revocation information does not
grow unbounded over time, the responder MAY remove the status
records of expired certificates.
OCSP responders that pre-produce and distribute OCSP responses in
advance do not have the ability to properly respond with a signed
"sucessful" yet "unknown" response as it is impossible to
pre-produce and sign a response for the set of all possible
"unknown" CertID's in advance. Because of this, the responder will
return an OCSPResponseStatus of "unauthorized" when processing
Deacon Expires - April 2005 [Page 5]
Lightweight OCSP Profile October 2004
requests for which it is not capable of responding authoritatively.
This includes the scenario where a responder has removed the records
of expired certificates from its database.
1.2.4 thisUpdate, nextUpdate and producedAt
When pre-producing OCSPResponse messages, the responder MUST set the
thisUpdate, nextUpdate and producedAt times as follows:
thisUpdate The time at which the status being indicated is
known to be correct.
nextUpdate The time at or before which newer information
will be available about the status of the
certificate. Responders MUST always include
this value to aid in response caching. See
Section 5 for additional information on
caching.
producedAt The time at which the OCSP response is signed.
Note: In many cases the value of thisUpdate and producedAt will be
the same.
For the purposes of this profile, GeneralizedTime values such as
thisUpdate, nextUpdate and producedAt MUST be expressed Greenwich
Mean Time (Zulu) and MUST include seconds (i.e.,times are
YYYYMMDDHHMMSSZ), even where the number of seconds is zero.
GeneralizedTime values MUST NOT include fractional seconds.
2. Client Behavior
2.1 OCSP Responder Discovery
Clients MUST support the authorityInfoAccess extension as defined in
[PKIX] and MUST recognize the id-ad-ocsp access method. This
enables CAs to inform clients how they can contact the OCSP service.
In the case where a client is checking the status of a certificate
that contains both an authorityInformationAccess (AIA) extension
pointing to a OCSP responder and a cRLDistributionPoints extension
pointing to a CRL, the client MUST contact the OCSP responder first.
Clients MAY attempt to retrieve the CRL if and only if no
OCSPResponse is received from the responder.
2.2 Sending an OCSP Request
To avoid needless network traffic, applications MUST verify the
signature of signed data before asking an OCSP client to check the
status of certificates used to verify the data. If the signature is
Deacon Expires - April 2005 [Page 6]
Lightweight OCSP Profile October 2004
invalid or the application is not able to verify it, an OCSP check
MUST NOT be requested.
Similarly, applications MUST validate the signature on certificates
and its chain, before asking an OCSP client to check the status of
the certificate. If the certificate signature is invalid or the
application is not able to verify it, an OCSP check MUST NOT be
requested. Clients SHOULD NOT request the status of expired
certificates.
2.3 OCSP response status processing
OCSP response status 'good': The client MUST inform the calling
application that the certificate has not been revoked.
The client SHOULD NOT accept an OCSP response that indicates (in the
nextUpdate field) that a newer response is available. See Section
5.1 for details on client caching behavior
OCSP response status 'revoked': The client MUST inform the calling
application that the signature is untrusted and abort any further
processing of the signed data.
OCSP response status 'unknown': The client MUST inform the calling
application about the unknown certificate status. This profile
RECOMMENDS calling applications to warn the user about the unknown
certificate status and give the user the option to continue or abort
the processing of the data, with a default option of abort.
3. Ensuring an OCSPResponse is Fresh
In order to ensure a client does not accept an out of date response
that indicates a 'good' status when in fact there is a more up to
date response that specifies the status of 'revoked', a client must
ensure the responses they receive are fresh.
In general, two mechanisms are available to clients to ensure a
response is fresh. The first uses nonces, and the second is based
on time. In order for time based mechanisms to work, both clients
and responders MUST have access to an accurate source of time.
Because this profile specifies that clients SHOULD NOT include a
requestExtensions structure in OCSPRequests (See Section 1.1)
clients MUST be able to determine OCSPResponse freshness based on an
accurate source of time. Clients that opt to include a nonce in the
request MUST NOT reject a corresponding OCSPResponse solely on the
basis of the non-existent expected nonce, but MUST fall back to
validating the OCSPResponse based on time.
Deacon Expires - April 2005 [Page 7]
Lightweight OCSP Profile October 2004
If a client includes a nonce in an OCSPRequest, and receives a nonce
in the corresponding OCSPResponse it MUST ensure that the nonce
included in the OCSPRequest matches the nonce received in the
OCSPRequest. If the nonces do not match the client MUST reject the
response as invalid. Clients that do not include a nonce in the
request MUST ignore any nonce that may be present in the response.
If there is no nonce in the OCSPResponse, clients MUST check for the
existence of the nextUpdate field and MUST ensure the current local
time falls between the thisUpdate and nextUpdate times. If the
nextUpdate field is absent, and there's no other way for the client
to determine the freshness of the response, the client MUST reject
the response.
If the nextUpdate field is present the client MUST ensure that it is
not earlier than current time. If the current local time on the
client is later than the time specified in the nextUpdate field, the
client MUST reject the response as stale. Clients MAY allow
configuration of a small tolerance period for acceptance of
responses after nextUpdate to handle minor clock differences
relative to responders and caches. This tolerance period should be
no more than a few minutes to avoid introducing increased security
risks.
See the security considerations in Section 6 for additional details
on replay and man-in-the-middle attacks.
4. Transport Profile
The OCSP responder MUST support requests and responses over HTTP.
When sending requests that are less than 255 bytes in total (after
encoding) including the method (http://), server name and base64
encoded OCSPReqeust structure, clients MUST use the GET method (to
enable for OCSP response caching). OCSP requests larger than 255
bytes SHOULD be submitted using the POST method. In all cases,
clients MUST follow the descriptions in A.1.1 of [OCSP] when
constructing these messages.
When constructing a GET message, OCSP clients MUST base64 encode the
OCSPRequest structure and append it to the URI specified in the AIA
extension [PKIX]. Clients MUST NOT include CR or LF characters in
the base64-encoded string. Clients MUST properly url-encode the
base64 encoded OCSPRequest, e.g.
http://ocsp.example.com/MEowSDBGMEQwQjAKBggqhkiG9w0CBQQQ7sp6GTKpL
2dAdeGaW267owQQqInESWQD0mGeBArSgv%2FBWQIQLJx%2Fg9xF8oySYzol80Mbpg
%3D%3D
Deacon Expires - April 2005 [Page 8]
Lightweight OCSP Profile October 2004
In response to properly formatted OCSPRequests that are cachable
(i.e. responses that contain a nextUpdate value), the responder will
include the binary value of the DER encoding of the OCSPResponse
preceded by the following HTTP headers.
content-type=application/ocsp-response
content-transfer-encoding=binary
content-length=<OCSP response length>
last-modified: <producedAt HTTP date>
expires: <nextUpdate HTTP date>
cache-control: max-age=<n>, public, no-transform, must-revalidate
date: <current HTTP date>
See Section 5.2 for details on the use of these headers.
5. Caching Recommendations
The ability to cache OCSP Responses throughout the network is an
important factor in high volume OCSP deployments. This section
discusses the recommended caching behavior of OCSP clients and HTTP
proxies and the steps that should be taken to minimize the number of
times that OCSP clients "hit the wire". In addition the concept of
including OCSP responses in protocols exchanges (aka stapling or
piggybacking), such as has been defined in TLS, is also discussed.
5.1 Caching at the Client
To minimize bandwidth usage, clients MUST locally cache
authoritative OCSP responses. (i.e. those who's signature has
successfully validated and that indicate an OCSPResponseStatus of
'successful') Once cached, the client SHOULD NOT send a new OCSP
request until the nextUpdate time in the cached response.
Most OCSP clients will send OCSPrequests at or near the nextUpdate
time (when the cached response expires). To avoid large spikes in
responder load that might occur when many clients refresh cached
responses for a popular certificate (e.g. www.bigecommercesite.com),
clients MAY use a locally derived value (i.e. 48 hours) to specify a
time period before nextUpdate time when a client might consider
refreshing its cached response. For example, a client can select a
random time between "nextUpdate minus locally configured value" and
"nextUpdate" at which to request a refresh of its cached
OCSPResponse.
5.2 HTTP Proxies
The responder SHOULD set the HTTP headers of the OCSP response in
such a way to allow for the intelligent use of intermediate HTTP
proxy servers.
Deacon Expires - April 2005 [Page 9]
Lightweight OCSP Profile October 2004
HTTP Header Description
=========== ====================================================
date The date and time at which the OCSP server generated
the HTTP response.
last-modified This value specifies the date and time at which the
OCSP responder last modified the response. This
date and time will be the same as the thisUpdate
timestamp in the request itself.
expires Specifies how long the response is considered fresh.
This date and time will be the same as the
nextUpdate timestamp in the OCSP response itself.
cache-control Contains a number of caching directives.
* max-age=<n>- where n is the nextUpdate time
minus the time the response is
generated (i.e. the Date header)
in seconds.
* public- makes normally uncachable response
cachable by both shared and
nonshared caches.
* no-transform-specifies that a proxy cache cannot
change the type, length , or
encoding of the object content.
* must-revalidate- prevents caches from
intentionally returning stale
responses.
OCSP responders MUST NOT include a Pragma: no-cache or
Cache-Control: no-store header in all OCSP responses.
For example, assume that an OCSP response has the following time
stamp values:
thisUpdate = May 1, 2003 01:00:00 GMT
nextUpdate = May 3, 2003 01:00:00 GMT
productedAt = May 1, 2003 01:00:00 GMT
and that an OCSP client requests the response on May 2, 2003
01:00:00 GMT. In this scenario the HTTP response will look like
this:
content-type: application/ocsp-response
content-transfer-encoding: binary
content-length: <OCSP response length>
date: Fri, 02 May 2003 01:00:00 GMT
Deacon Expires - April 2005 [Page 10]
Lightweight OCSP Profile October 2004
last-modified: Thu, 01 May 2003 01:00:00 GMT
expires: Sat, 03 May 2003 01:00:00 GMT
cache-control: max-age=86400,public,no-transform,must-revalidate
<...>
If a client encounters an expired response, it may be a result of an
intermediate proxy caching stale data, as such clients SHOULD resend
the request specifying that proxies should be bypassed by including
an appropriate HTTP header in the request (i.e. Pragma: no-cache or
Cache-Control: no-store).
5.3 Caching at Servers
In some scenarios it is advantageous to include OCSP response
information within the protocol being utilized between the client
and server. Including OCSP responses in this manner has a few
attractive effects.
First, it allows for the caching of OCSP responses on the server,
thus lowering the number of hits to the OCSP responder.
Second, it simplifies the client side OCSP implementation by
enabling a situation where the client need only the ability to parse
and recognize OCSP responses.
Third, it reduces the number of round trips the client needs to make
in order to validate a certificate.
Fourth, it enables certificate validation in the event the client is
not connected to a network and thus eliminates the need for clients
to establish a new HTTP session with the responder.
This functionality has been specified as an extension to the TLS
[TLS] protocol in Section 3.6 [TLSEXT], but can be applied to any
client-server protocol.
This profile RECOMMENDS that both TLS clients and servers implement
the certificate status request extension mechanism for TLS.
6. Security Considerations
The following considerations apply in addition to the security
consideration addressed in Section 5 of [OCSP]
6.1 Replay attacks
Because the use of nonce's in this profile is optional, there is a
possibility that an out of date OCSP response could be replayed,
thus causing a client to accept good response when in fact there is
Deacon Expires - April 2005 [Page 11]
Lightweight OCSP Profile October 2004
a more up to date response that specifies the status of revoked. In
order to mitigate this attack, clients MUST have access to an
accurate source of time and ensure that the OCSP responses they
receive are sufficiently fresh.
Required clock accuracy is relative to the validity duration of the
client's OCSP responses. A client using responses that are good for
one hour SHOULD have a clock that is within a few minutes correct
time, while a client with 24-hour responses SHOULD be within an hour
of correct time.
Clients that do not have an accurate source of date and time are
vulnerable to service disruption due to rejection of fresh OCSP
responses. If this problem is not repaired, a client with a
sufficiently slow clock may also incorrectly accept expired
responses for currently revoked certificates.
6.2 Man-in-the-middle attacks
To mitigate risk associated with this class of attack, the client
must properly validate the signature on the response.
The use of signed responses in OCSP serves the purpose to
authenticate the identity of the OCSP responder that has authority
to sign request on the CA's behalf.
Clients MUST ensure that they are communicating with an authorized
responder by the rules described in [OCSP] Section 4.2.2.2.
6.3 Impersonation attacks
The use of signed responses in OCSP serves the purpose to
authenticate the identity of OCSP Responder.
Clients must properly validate the signature of the OCSP response
and the signature(s) on the OCSP response signer certificate to
ensure an authorized responder created it.
6.4 Denial of service attacks
OCSP responders should take measures to prevent or mitigate denial
of service attacks. In particular OCSP responders should not perform
an unlimited number of resource intensive operations.
In the case where client requests are not signed, as specified by
this profile, OCSP responders should take additional steps to detect
an attack of this kind.
Deacon Expires - April 2005 [Page 12]
Lightweight OCSP Profile October 2004
One such technique could be to attempt to match which response to
send based on the hash of the request, this would protect against
decode related attacks. However since extensions are supported not
all requests for the same certificate will be the same as such it
would also be necessary to support a full decode based lookup. As
such this technique would only help defend against accidental
attacks.
6.5 Modification of HTTP Headers
Values included in HTTP headers as described in Section 4 and 5, are
not cryptographically protected, they may be manipulated by an
attacker. Clients SHOULD use these values for caching guidance only
and should ultimately rely on the values present in the signed
OCSPResponse.
7. Acknowledgements
The authors wish to thank Magnus Nystrom Of RSA Security, Inc.,
Jagjeet Sondh of Vodafone Group R&D and David Engberg of CoreStreet,
Ltd. for their contributions to this specification.
8. References
8.1 Normative
[HTTP] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P. and T. Berners-Lee, "Hypertext
Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
[KEYWORDS]Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[OCSP] Myers, M., Ankney, R., Malpani, A., Galperin, S. and
C. Adams, "Internet X.509 Public Key Infrastructure:
Online Certificate Status Protocol - OCSP", RFC 2560,
June 1999.
[PKIX] Housley, R., Polk, W., Ford, W. and D. Solo, "Internet
Public Key Infrastructure - Certificate and
Certificate Revocation List (CRL) Profile", RFC 3280,
April 2002.
[TLS] Dierks, T. and C. Allen, "The TLS Protocol Version
1.0", RFC 2246, January 1999.
[TLSEXT] Blake-Wilson, et. al., "Transport Layer Security (TLS)
Extensions", RFC 3546, June 2003.
Deacon Expires - April 2005 [Page 13]
Lightweight OCSP Profile October 2004
8.2 Informative
[URI] Berners-Lee, T., Fielding, R. and L. Masinter,
"Uniform Resource Identifiers (URI): Generic Syntax",
RFC 2396, August 1998
[PKIOP]Housley, R. and P. Hoffman, "Internet X.509 Public Key
Infrastructure - Operation Protocols: FTP and HTTP",
RFC 2585, May 1999.
[OCSPMP] "OCSP Mobile Profile", OpenMobileAlliance,
www.openmobilalliance.org.
9. Author's Addresses
Alex Deacon
VeriSign, Inc.
487 E. Middlefield Road Phone: 1-650-426-3478
Mountain View, CA. USA Email: a1ex@verisign.com
Ryan Hurst
Microsoft
One Microsoft Way Phone: 1-425-707-8979
Redmond, WA. USA Email: rmh@microsoft.com
Appendix A. Useful Response Extensions
Appendix A.1. nextPublish Response Extension
Support for this extension is optional. This extension indicates the
time at which the server will be issuing new information about the
status of the certificate. If present can be used by the relying
party to determine when it is acceptable to begin attempts for new
revocationinformation.
The time specified in the nextPublish extension SHOULD be before the
time specified in the nextUpdate field.
This profile RECOMMENDEDS this value be used by clients to determine
when it is possible to check for more up to date information.
id-msft-nextPublish OBJECT IDENTIFIER ::= {1.3.6.1.4.1.311.21.4}
nextPublish EXTENSION ::= {
SYNTAX nextPublishSyntax
IDENTIFIED BY id-msft-nextPublish
}
Deacon Expires - April 2005 [Page 14]
Lightweight OCSP Profile October 2004
nextPublishSyntax ::= Time
Time ::= CHOICE {
utcTime UTCTime,
generalTime GeneralizedTime
}
Appendix B. Example OCSP Messages
Appendix B.1: OCSP Request
SEQUENCE {
SEQUENCE {
SEQUENCE {
SEQUENCE {
SEQUENCE {
SEQUENCE {
OBJECT IDENTIFIER sha1 (1 3 14 3 2 26)
NULL
}
OCTET STRING
C0 FE 02 78 FC 99 18 88 91 B3 F2 12 E9 C7 E1 B2
1A B7 BF C0
OCTET STRING
0D FC 1D F0 A9 E0 F0 1C E7 F2 B2 13 17 7E 6F 8D
15 7C D4 F6
INTEGER
6B 26 79 83 A4 9A B7 C2 3D FF 58 E8 81 AA A5 0E
}
}
}
}
}
Appendix B.2: OCSP Response
SEQUENCE {
ENUMERATED 0
[0] {
SEQUENCE {
OBJECT IDENTIFIER ocspBasic (1 3 6 1 5 5 7 48 1 1)
OCTET STRING, encapsulates {
SEQUENCE {
SEQUENCE {
[1] {
SEQUENCE {
SET {
SEQUENCE {
Deacon Expires - April 2005 [Page 15]
Lightweight OCSP Profile October 2004
OBJECT IDENTIFIER organizationName (2 5 4 10)
PrintableString 'Example, Inc.'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER
organizationalUnitName (2 5 4 11)
PrintableString Example Trust Network'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER
organizationalUnitName (2 5 4 11)
PrintableString
'Terms of use at https://www.example.com/rpa'
'(c)02'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER commonName (2 5 4 3)
PrintableString
'Example Class 3 International Server OCSP'
'Responder'
}
}
}
}
GeneralizedTime 11/09/2003 14:55:57 GMT
SEQUENCE {
SEQUENCE {
SEQUENCE {
SEQUENCE {
OBJECT IDENTIFIER sha1 (1 3 14 3 2 26)
NULL
}
OCTET STRING
C0 FE 02 78 FC 99 18 88 91 B3 F2 12 E9 C7 E1 B2
1A B7 BF C0
OCTET STRING
0D FC 1D F0 A9 E0 F0 1C E7 F2 B2 13 17 7E 6F 8D
15 7C D4 F6
INTEGER
6B 26 79 83 A4 9A B7 C2 3D FF 58 E8 81 AA A5 0E
}
[0]
Error: Object has zero length.
Deacon Expires - April 2005 [Page 16]
Lightweight OCSP Profile October 2004
GeneralizedTime 11/09/2003 14:55:57 GMT
}
}
}
SEQUENCE {
OBJECT IDENTIFIER
sha1withRSAEncryption (1 2 840 113549 1 1 5)
}
BIT STRING
17 C3 A3 0B 87 1A A5 C9 39 D2 1E E4 49 9C 84 48
DC E7 9A 68 89 77 BE 25 60 97 D9 FB 8C D0 C5 E8
9B D2 25 F6 52 E9 BA 22 C8 FE C4 B6 B3 9F 1F 71
58 FC BE 39 DC 9D 4E 85 00 8C F1 A9 92 CD 25 CA
3C DC B9 61 46 76 87 BD A1 E9 F6 41 E2 B3 D6 7E
E1 FD A1 5D 2D 08 7C 01 3F 2C 3A 39 60 F1 53 AD
1E 81 E0 57 55 02 F7 D3 FC 9A F8 CA 09 DA 87 1E
8A 93 01 58 E0 31 72 A1 4A 05 F7 3E 21 2F D7 93
[0] {
SEQUENCE {
SEQUENCE {
SEQUENCE {
[0] {
INTEGER 2
}
INTEGER
24 D4 27 7D 62 AC 2D 92 F8 D3 4E B1 A5 19 84 78
SEQUENCE {
OBJECT IDENTIFIER
sha1withRSAEncryption (1 2 840 113549 1 1 5)
NULL
}
SEQUENCE {
SET {
SEQUENCE {
OBJECT IDENTIFIER
organizationName (2 5 4 10)
PrintableString "Example Trust Network'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER
organizationalUnitName (2 5 4 11)
PrintableString 'Example, Inc.'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER
Deacon Expires - April 2005 [Page 17]
Lightweight OCSP Profile October 2004
organizationalUnitName (2 5 4 11)
PrintableString
'Example International Server CA - Class 3'
}
}
}
SEQUENCE {
UTCTime 09/07/2002 00:00:00 GMT
UTCTime 24/10/2011 23:59:59 GMT
}
SEQUENCE {
SET {
SEQUENCE {
OBJECT IDENTIFIER
organizationName (2 5 4 10)
PrintableString 'Example, Inc.'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER
organizationalUnitName (2 5 4 11)
PrintableString 'Example Trust Network'
}
}
SET {
SEQUENCE {
OBJECT IDENTIFIER commonName (2 5 4 3)
PrintableString
'Example OCSP Responder'
}
}
}
SEQUENCE {
SEQUENCE {
OBJECT IDENTIFIER
rsaEncryption (1 2 840 113549 1 1 1)
NULL
}
BIT STRING, encapsulates {
SEQUENCE {
INTEGER
00 CF 50 81 96 9A F5 D8 E2 DE 0B CF A3 A6 FB 46
3E 88 0F 34 0F 5B 28 93 6D 32 EC D1 D0 0B 9B B4
5C 9E 12 F0 22 79 1E 6E 0D C6 39 7E A8 C5 01 A7
9F D8 93 D4 48 61 19 28 9A 93 7F ED 2A C4 CA 2C
E3 47 0C 49 D6 7E D2 FB BC 2C 08 0D 9C FF 05 E6
B0 EC 4B 93 1C AF 8E A9 F3 00 07 09 CF 9B 60 F6
ED D1 B9 62 6F F1 A7 D3 61 0A 64 30 93 C9 43 4A
Deacon Expires - April 2005 [Page 18]
Lightweight OCSP Profile October 2004
0E 3E A3 3E 47 D7 B2 0D B4 65 53 CC 0A FE CF E5
[ Another 1 bytes skipped ]
INTEGER 65537
}
}
}
[3] {
SEQUENCE {
SEQUENCE {
OBJECT IDENTIFIER
basicConstraints (2 5 29 19)
OCTET STRING, encapsulates {
SEQUENCE {}
}
}
SEQUENCE {
OBJECT IDENTIFIER
certificatePolicies (2 5 29 32)
OCTET STRING, encapsulates {
SEQUENCE {
SEQUENCE {
OBJECT IDENTIFIER
'2 16 840 1 1 1 7 23 3'
SEQUENCE {
SEQUENCE {
OBJECT IDENTIFIER
cps (1 3 6 1 5 5 7 2 1)
IA5String
'https://www.example.com/rpa'
}
}
}
}
}
}
SEQUENCE {
OBJECT IDENTIFIER extKeyUsage (2 5 29 37)
OCTET STRING, encapsulates {
SEQUENCE {
OBJECT IDENTIFIER
ocspSigning (1 3 6 1 5 5 7 3 9)
}
}
}
SEQUENCE {
OBJECT IDENTIFIER keyUsage (2 5 29 15)
OCTET STRING, encapsulates {
BIT STRING 7 unused bits
'1'B (bit 0)
Deacon Expires - April 2005 [Page 19]
Lightweight OCSP Profile October 2004
}
}
SEQUENCE {
OBJECT IDENTIFIER
ocspNoCheck (1 3 6 1 5 5 7 48 1 5)
OCTET STRING, encapsulates {
NULL
}
}
}
}
}
SEQUENCE {
OBJECT IDENTIFIER
sha1withRSAEncryption (1 2 840 113549 1 1 5)
NULL
}
BIT STRING
91 C2 C6 73 75 63 9A 6E A9 A6 F1 4D 99 F6 63 93
83 78 2A DB DE 56 DE 86 B5 9A B5 E7 27 44 35 28
2E F3 62 B4 9F 17 9F 2B 21 31 90 00 B0 86 E3 AE
B6 2C 72 08 9B B8 9D A3 58 61 A8 01 35 8B 3C 6C
6A D4 FF 01 FA E7 25 0D E8 D4 A5 8D 8E DF 3A 39
11 DE 8E 7A 41 BC 56 48 98 A5 06 86 64 4E AD 0F
5B D1 C7 BB 11 57 45 D4 06 F6 FF 3C 7E C5 78 7B
68 C1 B6 71 9D 45 79 1D F7 03 0E 9E 6A 75 24 51
}
}
}
}
}
}
}
}
Full Copyright Statement
Copyright (C) The Internet Society 2004. This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
This document and the information contained herein are provided on
an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE
INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Deacon Expires - April 2005 [Page 20]
Lightweight OCSP Profile October 2004
Deacon Expires - April 2005 [Page 21]
