Re: [libvirt] [PATCH 38/38] qemu: domain: Add support for TLS for NBD with default TLS env
[...]
>> +qemuProcessPrepareStorageSourceTlsNbd(virStorageSourcePtr
src,
>> + virQEMUDriverConfigPtr cfg,
>> + virQEMUCapsPtr qemuCaps)
>> +{
>> + /* XXX: for NBD we don't have the qemu.conf knobs for private TLS env
*/
>
> I believe the thought was to use the migrate ones and not default. That
> way we could modify the qemu.conf to note that the migrate environment
> would be used for NBD as it made no sense to have/use separate envs.
No. The migration environment shall be used only for NBD when migrating
disks. This is already the case by the way.
For accessing regular disks we should use the default one or a specific
one (e.g. as we do have for vxhs) if that will ever be added.
The separate environment might be wanted in the future if somebody wants
to have separate certificates for it, but it's not strictly required and
can easily be retrofitted into this optional way.
And how would anyone really know this? Why was this decision was made in
favor of creating an NBD specific set of values. Ironically not a
shortcut we've used/allowed for when adding TLS to chardev, migrate, or
vxhs.
>> + if (src->haveTLS == VIR_TRISTATE_BOOL_YES) {
>> + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_NBD_TLS)) {
>> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>> + _("this qemu does not support TLS transport for
nbd"));
>> + return -1;
>> + }
>> +
>> + if (VIR_STRDUP(src->tlsCertdir, cfg->defaultTLSx509certdir) <
0)
>> + return -1;
>> +
>> + src->tlsVerify = true;
>
> I think this is problematic for the default environment w/r/t since the
> right certs won't be present...
Please elaborate on this. I didn't quite get what you meant.
tlsVerify is what's used for the verifypeer - in order for it to be
useful, then the default environment would need:
# client-cert.pem - the client certificate signed with the ca-cert.pem
# client-key.pem - the client private key
if the default environment doesn't have those, then blindly setting this
will cause a TLS failure if the default environment doesn't have those
files.
Since you're using cfg->defaultTLSx509certdir, then this should use
cfg->defaultTLSx509verify.
John