Subject: Online Certificate Revocation Protocol

From: Massimiliano Pala <[email-masked]>
Date: Fri, 08 Jun 2001 00:54:11 +0200

Hi all,

I am in search of some help and suggestions about certificate revocation. The
problem is that, as far as I know, no rfc covers a possible online revocation
protocol to be used to revoke a certificate.

The model I am thinking of is request-response oriented and, depending on
the policy adopted by the corresponding CA, permits a user/router/etc... to
ask for revocation of a certificate. This can help environments where
certificates from different vendors are used and we want to be able to ask
for revocation without having to follow different procedures for different
CSP -- additional steps could/shall, depending on the policy adopted,
be taken to accomplish the revocation process.

Has my problem a solution yet ??? Or can I work on a proposal to be
submitted for comments and reviews ???

Looking forwards for comments.

-- 

Best Regards,

	Massimiliano Pala

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Massimiliano Pala [OpenCA Project Manager]                [email-masked]
                                                     [email-masked]
http://www.openca.org                            Tel.:   +39 (0)59  270  094
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---

From: Hansen Wang <[email-masked]>
Date: Thu, 07 Jun 2001 17:35:57 -0700

> protocol to be used to revoke a certificate.

Isn't that what OCSP supposed to do? RFC 2560

2560 X.509 Internet Public Key Infrastructure Online Certificate
Status Protocol - OCSP. M. Myers, R. Ankney, A. Malpani, S. Galperin,
C. Adams. June 1999.

Also Certificate Revocation Status is also a per request - per response
system.

> submitted for comments and reviews ???

-
Hansen Wang
<http://members.home.net/hansen.wang/

---

From: "Carlin Covey" <[email-masked]>
Date: Thu, 7 Jun 2001 18:18:02 -0700

Massimiliano,

If you are interested in a protocol that indicates whether a
certificate has been revoked, then the OCSP document that Hansen
referred you to is appropriate.  You can get it at
http://www.ietf.org/rfc/rfc2560.txt)

Version 2 of the OCSP protocol is described in an Internet Draft
available at
http://www.ietf.org/internet-drafts/draft-ietf-pkix-ocspv2-02.txt

Simple Certificate Validation Protocol is another candidate.  You
can get the latest version of this at
http://www.ietf.org/internet-drafts/draft-ietf-pkix-scvp-05.txt

But none of these allow a certificate to be revoked. I gather that
you are interested in a protocol for requesting revocation of certificates.
Check out CMP, available at
http://www.ietf.org/internet-drafts/draft-ietf-pkix-rfc2510bis-04.txt

Regards,

Carlin

____________________________

-  Carlin Covey
   Cylink Corporation

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Hansen Wang
Sent: Thursday, June 07, 2001 5:36 PM
To: [email-masked]
Cc: [email-masked]
Subject: Re: Online Certificate Revocation Protocol

-
Hansen Wang

---

From: Massimiliano Pala <[email-masked]>
Date: Fri, 08 Jun 2001 10:48:21 +0200

Hansen Wang wrote:
[..]
> 2560 X.509 Internet Public Key Infrastructure Online Certificate
[...]
> Also Certificate Revocation Status is also a per request - per response

What I was talking about is a method to allow for standard revocation request
method to be adopted by a subject when asking the authority for revocation of
a specified certificate, not simply a method to ask for the state of a
certificate.

Let's informally call it "OCRP - Online Certificate Revocation Protocol".

-- 

C'you,

	Massimiliano Pala

---

From: Massimiliano Pala <[email-masked]>
Date: Fri, 08 Jun 2001 11:01:57 +0200

> http://www.ietf.org/internet-drafts/draft-ietf-pkix-rfc2510bis-04.txt

This could be the case, anyway I was thinking of something more "robust"
and a little bit complex -- as request/response contents -- to prevent
unauthorized revoking requesting to prevent as much as possible DoS but
allowing for a simple revocation method. This could help environments where
legal issues are also covered -- govenment PKIs, Municipalities PKIs,
etc...

The model I've been thinking of is mostly based on a structure very similar
to the model proposed in OCSP. The choosen transport mechanism could be
HTTP -- this could help browsers in adding the functionality and CSP to
implement the service.

-- 

C'you,

	Massimiliano Pala

---

From: Nada Kapidzic Cicovic <[email-masked]>
Date: Fri, 08 Jun 2001 13:21:07 +0200

>legal issues are also covered -- govenment PKIs, Municipalities PKIs,

This is exactly what CMP specifies. Many vendors already have support for 
CMP EE initiated certificate revocation. The interoperability of different 
implementations of CMP certificate revocation (among other things) has been 
conducted during PKI Forum and ICSA CMP interop testing quite successfully.

Nada

>HTTP -- this could help browsers in adding the functionality and CSP to

______________________________________________________________

Nada Kapidzic Cicovic, Ph.D.
Technical Director,   Entegrity Solutions
office: + 46 8 477 77 37,   cell: + 46 70 495 09 03,    fax: + 46 8 477 77 31

---

From: Massimiliano Pala <[email-masked]>
Date: Fri, 08 Jun 2001 15:10:42 +0200

"Hoyt L. Kesterson II" wrote:

> i don't understand. maybe i am too simpleminded. i suggest that all
[...]
> suspect the same pop is robust enough to prove right to revoke.

No, probably I am talking about something that has got already a solution,
anyway, I have not fully read the proposed rfc2510bis, anyway the pop is
left without specification. The section 2.3 describes POP of a private
key, while section 3.3.9 describe a revocation request content.

As described there:

     RevReqContent ::= SEQUENCE OF RevDetails

     RevDetails ::= SEQUENCE {
         certDetails         CertTemplate,
         -- allows requester to specify as much as they can about
         -- the cert. for which revocation is requested
         -- (e.g., for cases in which serialNumber is not available)
         crlEntryDetails     Extensions       OPTIONAL
         -- requested crlEntryExtensions
     }

Where is any POP in this structure ? Is this the right request to be
used by a client to ask for revokation ?

In section 3.3.10 there is the request response description, wich, to
me, suffers from the same problems -- it seems as the control it too
delegated to external POP. I am probably wrong, I did not had the chance
to read through the whole document -- any help ?

> if someone other than the owner can demonstrate pop, then it doesn't
> matter who issues the revocation request-the certificate should be
> revoked.

Perfectly right. If the reported revocation req/resp are the right one
to be used, I think it could be an help to develop a different protocol
extending the proposed structure allowing for extended control over
the whole revokation process ( expecially for the client point of view).

Thanks to everyone for comments sent and future.

-- 

C'you,

	Massimiliano Pala

---

From: "Paul Gogarty" <[email-masked]>
Date: Mon, 11 Jun 2001 17:08:05 +0100

Massimiliano
 Correct me if I'm wrong but I assumed the shared secret in a RevRequest
(section 5.11 draft-ietf-pkix-rfc2510bis-04.txt) would provide a system to
reduce the risk of DoS.

	Paul Gogarty
	ASN.1 Developer

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-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Massimiliano Pala
Sent: Friday, June 08, 2001 10:02 AM
To: [email-masked]
Subject: Re: Online Certificate Revocation Protocol

--

C'you,

	Massimiliano Pala