Re: HEADS UP: tls restructuring

[Philip Guenther <guenther+ldapdev@sendmail.com>]

On Tue, 12 Aug 2008, Howard Chu wrote:
> Philip Guenther wrote:
...
> > Hah.  I was going to be submitting an ITS/patch later this week to add an
> > ldap.conf option (TLS_MIN_PROTOCOL) and a slapd.conf option

Typo.  That should have been "TLS_PROTOCOL_MIN", with C option of 
LDAP_OPT_X_TLS_PROTOCOL_MIN


> > (My patch only adds this for OpenSSL)
> 
> GnuTLS doesn't implement SSLv2, so it's kind of a moot point there.

Well, would be nice to support disabling SSLv3 and require TLSv1 in case 
the day comes that someone finds an actual attack on the MAC used in the 
SSLv3 finish message.


> > > There's one user-visible change: get_option(LDAP_OPT_X_TLS_SSL_CTX) now
> > > returns a pointer to a privately defined structure. For GnuTLS this is
> > > in fact the same behavior as before. For OpenSSL this is a change; it
> > > used to return the actual (SSL *). If this is going to break something
> > > of yours, holler now...
> > 
> > Ick.  If the meaning of the option is going to change, please change the
> > name at the same time.
> 
> Yeah, it's pretty much ugly all around.
>
> It may be best to reserve the old options exclusively for OpenSSL, and 
> introduce new options for the generic/private structure. This means code 
> that doesn't expect libldap to be built with GnuTLS will get failure 
> results on those options in that situation.
> 
> That's also ugly, because there's a lot of code out there that doesn't care
> what the return structure is, because it's only being stored to be fed back
> into libldap later...

Wouldn't that sort of code be using LDAP_OPT_X_TLS_CTX instead of 
LDAP_OPT_X_TLS_SSL_CTX, as the latter can't be used with 
ldap_set_option().  LDAP_OPT_X_TLS_SSL_CTX could stay OpenSSL only and 
LDAP_OPT_X_TLS_CTX could be the 'opaque structure' one.


Philip Guenther