[ncc-services-wg] Re: [db-wg] X.509 authentication in the RIPE Database, take II

On Friday, August 15, 2003, at 04:23 PM, Shane Kerr wrote:

> Joao,
>
> Joao Luis Silva Damas wrote:
>> adding a new strong authentication method to the Database, is in my 
>> own personal opinion, a good thing(tm), particularly if the same 
>> credential can be used for other interactions with the RIPE NCC, make 
>> user's life easier.
>> I wonder however about a few questions:
>> - will this auth method be available only to RIPE NCC members? Is it 
>> not seen as a valuable general addition for non-member users of the 
>> IRR part of the RIPE DB?
>
> Initially it will only be available for RIPE NCC members.  There are 
> three ways we could extend the service to non-LIRs:
>
> 1. Accept certificates from certain "well-known" CAs, for example 
> Thawte, Verisign, etc.
>
> 2. Issue certificates from a RIPE NCC CA established for this purpose, 
> and accept them.
>
> 3. Accept all certificates, including self-signed certificates.
>
> #1 is relatively easy - the main overhead would be maintaining the 
> Certificate Revokation Lists from the CAs.  Deciding which CAs to 
> support may also be tricky.  #2 is also relatively easy, since we 
> already have the technology.  #3 is more difficult, and would require 
> a slight change of the design, and administration issues (see below).

For DB authentication purposes, why do you need to verify the 
certificate? As with the PGP model[1], the only assumption one needs to 
make is that the message issuer is the holder of the private part of 
the certificate.

If the RIPE DB is going to start making assertions about the real 
identity of the message sender, rather than just authorise or refuse 
updates, this seems to be a change in the model that warrants 
discussion in the working group.
Is this so, or am I misinterpreting your description of the mechanism?

>
>> - Why the choice of not publishing the pulic part of the certificated 
>> in the DB? The choice to have a key-cert for the PGP method was not 
>> to do with issues of web of trust but rather for purposes of helping 
>> the users with their data maintenance. As a matter of fact the 
>> recommendation regarding the use of PGP in the RIPE DB, as described 
>> in the RFC and the minutes of the DBSEC TF, was to use a PGP key for 
>> this purpose that was not used elsewhere.
>
> When you receive a PGP-signed message, you need the public key of the 
> signer to verify the signature.  The program that updates the Database 
> needs this information, and it is stored in the key-cert objects(*).
>
> With S/MIME, the certificate is sent with the message, and this 
> certificate is signed by the CA.  Since the database is configured to  
> know how to verify certificates issued by specific CAs, we can verify 
> the signature.  No key-cert is necessary.
>
> But if we decide to allow any certficate, including self-signed, then 
> we need some way to allow users to store this information in the 
> database, for example key-cert objects.  Unfortunately, this may cause 
> problems, because (for instance) someone could create a key-cert 
> object for a CA run by another organisation with bogus data, 
> preventing users from using certificates *actually* issued by that CA.
>
> We could possibly require these sort of key-cert objects be reviewed 
> by some method, for example RIPE DBM.  However, if the RIPE NCC has no 
> relationship with the CA, we have no real way to know the validity of 
> any one request.

Why do you need to verify the certificate.
Also, part of the idea of having a key-cert object was to allow users 
to check, not the DB, and to maintain DB self-consistency. Are these no 
longer desired features?

Joao

[1] RFC 2726