Re: x509

["Andersson, Mats" <mats.andersson%appgate.com@localhost>]

On Thu, 31 Jan 2002, Markus Friedl wrote:
> On Thu, Jan 31, 2002 at 11:10:48AM +0100, Markus Friedl wrote:
> > An encoding similar to
> > 	string	 "x509v3-sign-rsa"
> > 	int32	 n
> > 	byte[n]  der-encoded-x509-cert
> > would be more in line with the other encodings.
> 
> i.e.
> 	string	"x509v3-sign-rsa"
> 	string	der-encoded-x509-cert

Hi,

This is in fact inconsistent with the other encodings for keys(/certs).
For example:

   The "ssh-dss" key format has the following specific encoding:

     string    "ssh-dss"
     mpint     p
	...

It is the signature-blob that should be "enclosed" in a ssh2 string. This
is the issue, i.e. the format of the signature is not _explicitly_ defined
in the draft (hence the discussion on how it should look like I guess).

However, in rfc2459 it says:
   When signing, the DSA algorithm generates two values.  These values
   are commonly referred to as r and s.  To easily transfer these two
   values as one signature, they shall be ASN.1 encoded using the
   following ASN.1 structure:
	Dss-Sig-Value  ::=  SEQUENCE  {
                   r       INTEGER,
                   s       INTEGER  }

Which is pretty specific to me. It also refers pkcs1 for RSA which also
defines the format of the signature.

I might have missed the start of the thread but what is the issue here?  
The transport draft refers rfc2459 which states the format for both RSA
and DSA so what is it that is not clear in all this except for the detail
that it doesn't say explicitly something like:

     string    "ssh-rsa"
     string    dss_signature_value

dss_signature_value is the DER encoded value of the Dss-Sig-Value as
defined in rfc2459.

Cheers,

/Mats