Re: [PATCH 4/5] kerberos: Allocate a buffer for the package info structure in kerberos_SpQueryContextAttributes.

[Hans Leidekker]

On Thu, 2018-02-08 at 22:17 +0800, Dmitry Timoshkov wrote:
> Hans Leidekker  wrote:
> > static NTSTATUS NTAPI kerberos_SpQueryContextAttributes( LSA_SEC_HANDLE context, ULONG attribute, void *buffer )
> >  {
> >      TRACE( "(%lx %u %p)\n", context, attribute, buffer );
> > @@ -1104,7 +1123,7 @@ static NTSTATUS NTAPI kerberos_SpQueryContextAttributes( LSA_SEC_HANDLE context,
> >      case SECPKG_ATTR_NEGOTIATION_INFO:
> >      {
> >          SecPkgContext_NegotiationInfoW *info = (SecPkgContext_NegotiationInfoW *)buffer;
> > -
> >    info->PackageInfo      = (SecPkgInfoW *)&infoW;
> > -
> >    if (!(info->PackageInfo = build_package_info( &infoW ))) return SEC_E_INSUFFICIENT_MEMORY;
> >    info->NegotiationState = SECPKG_NEGOTIATION_COMPLETE;
> >    return SEC_E_OK;
> > }
>
> I'd assume same thing as MSDN states in the SpGetInfo() notes: the provider is
> free to return pointers to dynamic and constant data in the returned buffer,
> and it's responsibility of LSA to copy data to a flat buffer before returning
> it to a client. Same comment applies to a similar patch for the NTLM provider.

This buffer can currently be retrieved directly from NTLM, without
involving LSA. This way we can free the buffer unconditionally in the
negotiate tests. Things would change if NTLM was moved behing the LSA
interface too, but in that case it's still not wrong to do it here, as
long as the LSA wrapper and the provider agree.