45 lines
2.4 KiB
XML
45 lines
2.4 KiB
XML
<?xml version='1.0' encoding='UTF-8'?>
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<!DOCTYPE topic PUBLIC "-//OASIS//DTD DITA Topic//EN" "topic.dtd">
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<topic xml:lang="en-us" id="diskencryption-limitations">
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<title>Limitations of Disk Encryption</title>
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<body>
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<p>There are some limitations the user needs to be aware of when using this feature: </p>
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<ul>
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<li>
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<p>This feature is part of the <ph conkeyref="vbox-conkeyref-phrases/vbox-ext"/>, which needs to be installed.
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Otherwise disk encryption is unavailable. </p>
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</li>
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<li>
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<p>Since encryption works only on the stored user data, it is currently not possible to check for metadata
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integrity of the disk image. Attackers might destroy data by removing or changing blocks of data in the image
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or change metadata items such as the disk size. </p>
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</li>
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<li>
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<p>Exporting appliances which contain encrypted disk images is not possible because the OVF specification does
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not support this. All images are therefore decrypted during export. </p>
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</li>
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<li>
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<p>The DEK is kept in memory while the VM is running to be able to decrypt data read and encrypt data written by
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the guest. While this should be obvious the user needs to be aware of this because an attacker might be able
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to extract the key on a compromised host and decrypt the data. </p>
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</li>
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<li>
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<p>When encrypting or decrypting the images, the password is passed in clear text using the <ph
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conkeyref="vbox-conkeyref-phrases/product-name"/> API. This needs to be kept in mind, especially when using
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third party API clients which make use of the webservice where the password might be transmitted over the
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network. The use of HTTPS is mandatory in such a case. </p>
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</li>
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<li>
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<p>Encrypting images with differencing images is only possible if there are no snapshots or a linear chain of
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snapshots. This limitation may be addressed in a future <ph conkeyref="vbox-conkeyref-phrases/product-name"/>
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version. </p>
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</li>
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<li>
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<p>The disk encryption feature can protect the content of the disks configured for a VM only. It does not cover
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any other data related to a VM, including saved state or the configuration file itself. </p>
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</li>
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</ul>
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</body>
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</topic>
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