[foaf-protocols] Why exponent/modulus

Akbar Hossain akkiehossain at gmail.com
Sat Sep 18 09:32:32 CEST 2010

On Fri, Sep 17, 2010 at 11:55 PM, Mitko Iliev <imitko at openlinksw.co.uk> wrote:
> In same way as they know exponent and modulus for RSA key ;-)
> This is not a duty of the user, it is duty of the IdP.

Yes true :) Need to get with the program and forget about being my own IdP ;)

We could all agree to generate the PEM file in the one format (the
most obvious format) as per Nathans script.
Namely the one sent over the TLS connection.

However, if I put that in my foaf file I have now published other
things as well as modulus and exponent.
For example I may have published my email address. (granted that is my
choice to add it in the first place).
Having my email in my SAN in my certificate that I reveal to services
when I wish to use them and when I positively agree to reveal my email
to them is different to publishing in public. (granted I could put
this behind https with ACL)

We also all have to agree to publish our PEM (instead of or as well as
the modulus/exponent) to get any dependency reduction unless I have
missed something.  Joe seems to have the making of an ASN.1 parser in
PHP maybe an idea to complete that out (its the most advance  ASN.1
implementation in PHP I have seen - nice job). Run it over the
certificate that comes across the certificate that comes across the
TLS connection and then run the same parser over any PEM people may
add to their webid (if added to the ontology)

If optionally added not sure what we have gained. Other than perhaps
easier understanding amongst a few developers. I guess market forces
may make people move toward the PEM encoding. Getting a few more devs
onboard has got to be good thing.

So... no objection to adding PEM encoding but I'm not sure it will
simplify things unless everyone switches (ie not manadatory - as well
as or instead of). Personally I dont mind putting my certificate up
either (as is) but then I dont intend to put things in my certificate
which are not public anyway.


> On Sep 18, 2010, at 1:24 AM, Akbar Hossain wrote:
>> I am unsure how people would create the PEM file to embed in their foaf file.
> --
> Mitko Iliev
> Developer Virtuoso Team
> OpenLink Software
> http://www.openlinksw.com/virtuoso
> Cross Platform Web Services Middleware

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