On 12/08/2017 05:58 AM, Daniel P. Berrange wrote: > The current docs for TLS assume only VNC is using TLS. Some of the information > is also outdated (ie lacking subject alt name info for certs). Rewrite it to > more accurately reflect the current situation. > > Signed-off-by: Daniel P. Berrange <berra...@redhat.com> > --- > qemu-doc.texi | 368 > +++++++++++++++++++++++++++++++++++++++++++--------------- > 1 file changed, 275 insertions(+), 93 deletions(-) >
> +@subsection Configuring SASL mechanisms > + > +The following documentation assumes use of the Cyrus SASL implementation on a > +Linux host, but the principals should apply to any other SASL impl. When SASL s/impl/implementation/ > +is enabled, the mechanism configuration will be loaded from system default > +SASL service config /etc/sasl2/qemu.conf. If running QEMU as an > +unprivileged user, an environment variable SASL_CONF_PATH can be used > +to make it search alternate locations for the service config. > + > +@node tls_generate_server > +@subsection Issuing server certificates > > Each server (or host) needs to be issued with a key and certificate. When > connecting > the certificate is sent to the client which validates it against the CA > certificate. > -The core piece of information for a server certificate is the hostname. This > should > -be the fully qualified hostname that the client will connect with, since the > client > -will typically also verify the hostname in the certificate. On the host > holding the > -secure CA private key: > +The core pieces of information for a server certificate are the hostnames > and/or IP > +addresses that will be used by clients when connecting. The hostname / IP > address > +that the client specifies when connecting will be validated aganist the > hostname(s) s/aganist/against/ > +and IP address(es) recorded in the server certificate, and if no match is > found > +the client will close the connection. > + > +Thus it is recommended that the server certificate include both the fully > qualfied s/qualfied/qualified/ > + > +If a single host is going to be using TLS in both a client and server > +role, it is possible to create a single certificate to cover both roles. > +This would be quite common for the migration and NBD services, where a > +QEMU be start by accepting a TLS protected incoming migration, and later s/QEMU be start/QEMU process will be started/ > +itself be migrated out to another host. To generate a single certificate, > +simply include the template data from both the client and server > +instructions in one. > > > -When not using TLS the recommended configuration is > +When copying the PEM files to the target host, save them twice > +once as @code{server-cert.pem} and @code{server-key.pem}, and s/twice/twice,/ > +against as @code{client-cert.pem} and @code{client-key.pem}. s/against/again/ > + > +@node tls_creds_setup > +@subsection TLS x509 credential configuration > + > +QEMU has a standard mechanism for loading x509 credentials that will be > +used for network services and clients. It requires specifying the > +@code{tls-creds-x509} class name to the @code{-object} command line > +argument for the system emulators. This also works for the helper tools > +like @code{qemu-nbd} and @code{qemu-img}, but is named @code{--object}. You can use '--object' with qemu as well (getopt_long_only() accepts double-dash form in addition to single dash). If it makes it any easier to only document the double-dash form, then go for it. > +Each set of credentials loaded should be given a unique string identifier > +via the @code{id} parameter. A single set of TLS credentials can be used > +for multiple network backends, so VNC, migration, NBD, character devices > +can all share the same credentials. Note, however, that credentials for > +use in a client endpoint must be loaded separately from those used in > +a server endpoint. > + > +When specifying the object, the @code{dir} parameters specifies which > +directory contains the credential files. This directory is expected to > +contain files with the names mentioned previously, @code{ca-cert.pem}, > +@code{server-key.pem}, @code{server-cert.pem}, @code{client-key.pem} > +and @code{client-cert.pem} as appropriate. It is also possible to > +include a set of pre-generated diffie-hellman parameters in a file > +@code{dh-params.pem}, which can be created using the > +@code{certtool --generate-dh-params} command. If omitted, QEMU will > +dynamically generated DH parameters when loading the credentials. s/generated/generate/ -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
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