[Planetlab-devel] Re: question about certificates in SFA

[Giovanni.Gherdovich at sophia.inria.fr]

Dear Tony,

thank you for your reply.

Tony Mack wrote:
> Hi Giovanni,
>
> [...]
> When a Certifiacate or Gid object returns a keypair object, they are really just returning the public key.

Uhm.
But when, in the code below, I read

certificate.is_pubkey(gid.get_pubkey()) ,

and the implementation of "is_pubkey" is

---------------8<-------------------------------------
   def is_pubkey(self, pkey):
       return self.get_pubkey().is_same(pkey)
---------------8<-------------------------------------

which leads to the "get_pubkey" method from
sfa.trust.certificate.Keypair

---------------8<-------------------------------------
 def is_same(self, pkey):
      return self.as_pem() == pkey.as_pem()
---------------8<-------------------------------------

where "as_pem" gives the private key.

So it looks like the privare keys from the
Keypair member of the certificates are compared.

Am I wrong?

Cheers,
Giovanni


> ----- Original Message -----
> From: "Giovanni Gherdovich" <Giovanni.Gherdovich at sophia.inria.fr>
> [...]
>
> here is some pseudo-code freely inspired by
> sfa/methods/get_self_credential.py
>
> ------------8<--------------------------------------------------------
> class get_self_credential(Method):
>     [...]    
>     def call(self, cert, type, xrn):
>         [...]
>         gid = # get the gid from (type, xrn), i.e. ('user', 'plc.joe')
>         [...]
>         certificate = # get the certificate from the input arg /cert/
>         if not certificate.is_pubkey(gid.get_pubkey()):
>             raise ConnectionKeyGIDMismatch(gid.get_subject())
>
>         return manager.get_credential(self.api, xrn, type, is_self=True)
> ------------8<--------------------------------------------------------
>