Re: [Libvirt] VNC auth per VM

On Thu, Jun 11, 2009 at 11:45:43AM +0200, Christian Weyermann wrote: > Daniel P. Berrange schrieb: > >> On Thu, Jun 11, 2009 at 11:10:47AM +0200, Christian Weyermann wrote: >> >> >>> Daniel P. Berrange schrieb: >>> >>> >>>> On Thu, Jun 11, 2009 at 04:05:39AM -0400, Jim Paris wrote: >>>> >>>> >>>> >>>>> Daniel P. Berrange wrote: >>>>> >>>>> >>>>> >>>>>> On Mon, Jun 08, 2009 at 11:35:00AM +0200, Christian Weyermann wrote: >>>>>> >>>>>> >>>>>> >>>>>>> Hello everybody, >>>>>>> >>>>>>> I encountered the following problem. I want my users to only be able to >>>>>>> connect to their own virtual machines via VNC. Is there any way to do so? >>>>>>> >>>>>>> >>>>>>> >>>>>> The VNC authentication setup is currently being done per-host, so there >>>>>> is no way to define ACLs per-(user,vm) tuple as you describe. >>>>>> >>>>>> >>>>>> >>>>> What about the VNC password? >>>>> That's per-VM, isn't it? >>>>> >>>>> >>>>> >>>> That is true by I don't really consider VNC password to be useful. It is >>>> utterly insecure. If you want to have plain passwords, then its better to >>>> use the new SASL authentication method, with its Digest-MD5 plugin. That >>>> is still not top-grade security, but it is better then VNC password and >>>> allows configuration of arbitrary Username+pasword pairs.. At which point >>>> we just need ACLs against the usernames. SASL also provide Kerberos auth, >>>> where we can do an ACL against the Kerberos principle name. And VeNCrypt >>>> provides TLS+x509 certificates which you can either layer SASL over again, >>>> or require client x509 certs and do an ACL against the client CNAME >>>> >>>> >>> Ok, so let me sumarize: It is possible to define username+password pairs >>> via SASL. SASL can also sync with Kerberos. So the only problem left is, >>> that there is no way to assign a specific username to a VM. So, what we >>> need is a plugin, where we have an username and a virtual machine as >>> input and we need to refuse the connection, if this pair is not valid. >>> The VNC Server is part of libvirt, so the perfect method to add this >>> functionallity would be the VNC Servers authenticate or start method. >>> >>> However, a Windows user is still not able to connect as there is no >>> windows vnc client capable of doing SASL. >>> >>> >> GTK-VNC builds on Windows, and so does libvirt. So the intent was that >> we'd be able to have virt-viewer working on Windows using those two. >> Oh, when I say Windows, i mean Mingw32 >> >> > Ok, so the other part of the post is correct? So what do you think about > the effort for implementing this feature? > Well I've had the demo program from GTK-VNC working sucessfully under Wine, and had virsh successfully working under Wine. So I see no reason why we virt-viewer should be troublesome to get working. I hope it'll just be a lot of silly small bugfixes/portability fixes, rather than any large fundamental problem.