Re: How do I get RSA public key from X509Certificate ?

From: Allen Owen (alleno@intenda.co.za)
Date: 07/25/02 

From: "Allen Owen" <alleno@intenda.co.za>
Date: Thu, 25 Jul 2002 08:35:24 +0200

Kishore,

Yup, that's pretty much what I'm trying to do. Sorry if I didn't explain it
particularly well.

Regards
Allen

"Kishore" <kishorerc@hotmail.com> wrote in message
news:OJwaeZ2MCHA.2428@tkmsftngp12...
> Allen,
>
> I found out that the X509Certificate.GetPublicKey() actually returns the
> Modulus and Exponent in a single byte[]. The modulus starts at position 5.
> We will have to get the Modulus and Exponent from this byte[] and set it
to
> the RSAParameters object. Now the problem is how do we know how long the
> Modulus will be ? Is there a spec which defines this ?
>
> Now, for your question:
> I did not understand your question properly. But let me tell you what I am
> doing.
>
> I am playing with the SSL 3.0 specification and trying to write an SSL
> client library. The server sends all the certificates according to the
> specification. I parse the input and create X509Certificate with the
> content.
>
> Thanks,
> Kishore
>
>
> "Allen Owen" <alleno@intenda.co.za> wrote in message
> news:OZHWpZuMCHA.2244@tkmsftngp11...
> > Hi Kishore,
> >
> > I use {1,0,1} for the exponent, but I can't be 100% sure that it's the
> > correct way to go about it.
> >
> > A quick question for you though. Have you tried to retrieve the matching
> > server certificate for the X509 cert?
> > I'd imagine that you're getting your a client cert via
> > Request.ClientCertificate and I need to retreive the matching server
cert
> > and thus far can't see a way to do it :( .
> >
> > Cheers
> > Allen
> >
> >
> > "Kishore" <kishorerc@hotmail.com> wrote in message
> > news:ePCLqfsMCHA.488@tkmsftngp10...
> > > Hi Everyone,
> > > I have a X509Certificate, I want to get a RSA object using the public
> key
> > > from the cert. Is this code correct ?
> > >
> > > public RSA GetKey(X509Certificate cert)
> > > {
> > > RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
> > > RSAParameters keyInfo = new RSAParameters();
> > > keyInfo.Exponent = key;
> > > keyInfo.Modulus = key;
> > > rSA.ImportParameters(keyInfo);
> > > return rsa;
> > > }
> > >
> > > Or should I use {1,0,1} for the Exponent ?
> > > Thanks,
> > > Kishore
> > >
> > >
> >
> >
>
>