libvirt/docs/formatstorageencryption.html.in
Miloslav Trmač 05b9b8fda3 Add volume encryption information handling.
Define an <encryption> tag specifying volume encryption format and
format-depenedent parameters (e.g. passphrase, cipher name, key
length, key).

Currently the only defined parameter is a reference to a "secret"
(passphrase/key) managed using the virSecret* API.

Only the qcow/qcow2 encryption format, and a "default" format used to
let libvirt choose the format during volume creation, is currently
supported.

This patch does not add any users; the <encryption> tag is added in
the following patches to both volumes (to support encrypted volume
creation) and domains.

* docs/*.html: Re-generate
* docs/formatstorageencryption.html.in, docs/sitemap.html.in:
  Add page describing storage encryption data format
* docs/schemas/Makefile.am, docs/schemas/storageencryption.rng:
  Add RNG schema for storage encryption format
* po/POTFILES.in: Add src/storage_encryption_conf.c
* src/libvirt_private.syms: Export virStorageEncryption* functions
* src/storage_encryption_conf.h, src/storage_encryption_conf.c: Internal
  helper APIs for dealing with storage encryption format
* libvirt.spec.in, mingw32-libvirt.spec.in: Add storageencryption.rng
  RNG schema
2009-09-01 18:27:28 +01:00

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HTML

<html>
<body>
<h1>Storage volume encryption XML format</h1>
<ul id="toc"></ul>
<h2><a name="StorageEncryption">Storage volume encryption XML</a></h2>
<p>
Storage volumes may be encrypted, the XML snippet described below is used
to represent the details of the encryption. It can be used as a part
of a domain or storage configuration.
</p>
<p>
The top-level tag of volume encryption specification
is <code>encryption</code>, with a mandatory
attribute <code>format</code>. Currently defined values
of <code>format</code> are <code>default</code> and <code>qcow</code>.
Each value of <code>format</code> implies some expectations about the
content of the <code>encryption</code> tag. Other format values may be
defined in the future.
</p>
<p>
The <code>encryption</code> tag can currently contain a sequence of
<code>secret</code> tags, each with mandatory attributes <code>type</code>
and <code>uuid</code>. The only currently defined value of
<code>type</code> is <code>passphrase</code>. <code>uuid</code>
refers to a secret known to libvirt. libvirt can use a secret value
previously set using <code>virSecretSetValue()</code>, or, if supported
by the particular volume format and driver, automatically generate a
secret value at the time of volume creation, and store it using the
specified <code>uuid</code>.
<p>
<h3><a name="StorageEncryptionDefault">"default" format</a></h3>
<p>
<code>&lt;encryption type="default"/&gt;</code> can be specified only
when creating a volume. If the volume is successfully created, the
encryption formats, parameters and secrets will be auto-generated by
libvirt and the attached <code>encryption</code> tag will be updated.
The unmodified contents of the <code>encryption</code> tag can be used
in later operations with the volume, or when setting up a domain that
uses the volume.
</p>
<h3><a name="StorageEncryptionQcow">"qcow" format</a></h3>
<p>
The <code>qcow</code> format specifies that the built-in encryption
support in <code>qcow</code>- or <code>qcow2</code>-formatted volume
images should be used. A single
<code>&lt;secret type='passphrase'&gt;</code> element is expected. If
the <code>secret</code> element is not present during volume creation,
a secret is automatically generated and attached to the volume.
</p>
<h2><a name="example">Example</a></h2>
<p>
Here is a simple example, specifying use of the <code>qcow</code> format:
</p>
<pre>
&lt;encryption format='qcow'&gt;
&lt;secret type='passphrase' uuid='c1f11a6d-8c5d-4a3e-ac7a-4e171c5e0d4a' /&gt;
&lt;/encryption&gt;</pre>
</body>
</html>