Re: [TLS] New Cached info draft

Adam Langley <agl@imperialviolet.org> Tue, 30 March 2010 15:24 UTC

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From: Adam Langley <agl@imperialviolet.org>
To: Stefan Santesson <stefan@aaa-sec.com>
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Cc: Simon Josefsson <simon@josefsson.org>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] New Cached info draft
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On Tue, Mar 30, 2010 at 7:14 AM, Stefan Santesson <stefan@aaa-sec.com>; wrote:
> I have included your sample in draft 07.
> I think this document is done now and good to go.

For people looking to test interop I've a couple of patches:

http://www.imperialviolet.org/binary/cached-info-nss.patch (client and server)
http://www.imperialviolet.org/binary/cached-info-openssl-0.9.8n.patch  (server)

For the OpenSSL patch, it's enabled by default (probably breaking the
no-tlsext build, but that's already broken since 0.9.8m).

For NSS, you can use the selfserv and tstclnt utilities from NSS. For
tstclnt, give -I /path/to/server-certificate.pem and for selfself,
give just -I.

One last point, I think I'd like to see the ability to cache the
CertificateStatus:

enum {
  certificate_status(3)
} CachedInformationType;

4.3.  Data Substitution Syntax for certificate_status

   When a digest for an object of type certificate_status is provided in the
   client hello, the server MAY substitute the cached data with a
   matching digest value received from the client by expanding the
   CertificateStatus handshake message as follows.

   Original handshake message syntax defined in RFC 3546 [RFC3546]:

     struct {
          CertificateStatusType status_type;
          select (status_type) {
              case ocsp: OCSPResponse;
          } response;
      } CertificateStatus;

      opaque OCSPResponse<1..2^24-1>;

   The substitution syntax is defined by defining an additional
status_type which is only valid in a CertificateStatus message:

      enum { ocsp_cached(2) } CertificateStatusType;

     struct {
          CertificateStatusType status_type;
          select (status_type) {
              case ocsp: OCSPResponse;
              case ocsp_cached: opaque digest_value<0..8>;
          } response;
      } CertificateStatus;


AGL

-- 
Adam Langley agl@imperialviolet.org http://www.imperialviolet.org