The _gnutls_x509_verify_certificate fix

[Simon Josefsson]

Simon Josefsson <simon at josefsson.org> writes:

> Tomas Mraz <tmraz at redhat.com> writes:
>
>> On Mon, 2008-11-10 at 21:04 +0100, Nikos Mavrogiannopoulos wrote:
>>> On Mon, Nov 10, 2008 at 2:47 PM, Tomas Mraz <tmraz at redhat.com> wrote:
>>> > Hello,
>>> > given the recent fix in the _gnutls_x509_verify_certificate I have been
>>> > looking at the function. I see there are currently some limitations in
>>> > it. For example it now doesn't allow verification of explicitely trusted
>>> > self-signed site certificate. Is there some other method how this could
>>> > be achieved?
>>> You can achieve it by associating an address of a website with the
>>> keyid of the given
>>> certificate. This is more generic of trusting a self-signed
>>> certificate. You can trust any
>>> certificate first presented when accessing a website that way (ssh security).
>>
>> But the patch should be modified anyway because in case the server
>> presents just a self-signed site certificate there will be a dereference
>> of the certificate_list[-1].
>>
>> It is also questionable whether the function should not also check for
>> clist_size of 0 before calling _gnutls_verify_certificate2().
>
> Indeed.  This may explain:
>
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=505279

On reading more code, probably not, since all calls to
_gnutls_x509_verify_certificate goes through gnutls_x509_crt_list_verify
which does check for clist_size==0.  For readability, the two functions
should probably be merged into one.

/Simon