https://wiki.archlinux.org/api.php?hideminor=1&hidebots=1&days=7&limit=50&target=Category%3AStorage&action=feedrecentchanges&feedformat=atomArchWiki - Changes related to "Category:Storage" [en]2024-03-19T12:08:06ZRelated changesMediaWiki 1.41.0https://wiki.archlinux.org/index.php?title=Self-encrypting_drives&diff=803377&oldid=799696Self-encrypting drives2024-03-15T21:15:35Z<p><span dir="auto"><span class="autocomment">Disadvantages: </span> add short practical disadvantages (re talk) and subgroup exploits</span></p>
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 21:15, 15 March 2024</td>
</tr><tr><td colspan="4" class="diff-multi" lang="en">(One intermediate revision by the same user not shown)</td></tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l26">Line 26:</td>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Key management takes place within the disk controller and encryption keys are usually 128 or 256 bit Advanced Encryption Standard (AES).</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Key management takes place within the disk controller and encryption keys are usually 128 or 256 bit Advanced Encryption Standard (AES).</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>{{Expansion|The Opal standards are full of acronyms. The sedutil refers to them in the [https://github.com/Drive-Trust-Alliance/sedutil/wiki/FAQ FAQ] and [https://github.com/Drive-Trust-Alliance/sedutil/wiki/Command-Syntax command syntax]. It would be useful to name the important acronyms (e.g. SID, MSID, locking SP, admin SP) in this section, because they are intrinsic to the key-management defined per standard. (See also [[w:Key escrow]]).}}</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>{{Expansion|The Opal standards are full of acronyms. The sedutil refers to them in the [https://github.com/Drive-Trust-Alliance/sedutil/wiki/FAQ FAQ] and [https://github.com/Drive-Trust-Alliance/sedutil/wiki/Command-Syntax command syntax]. It would be useful to name the important acronyms (e.g. SID, MSID, locking SP, admin SP<ins style="font-weight: bold; text-decoration: none;">, MEK, DEK</ins>) in this section, because they are intrinsic to the key-management defined per standard. (See also [[w:Key escrow]]).}}</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Self-encrypting drives adhering to the TCG OPAL 2.0 standard specification (almost all modern self-encrypting drives) implement key management via an authentication key, and a 2nd-level data encryption key. The data encryption key is the key against which data on the drive is actually encrypted. The authentication key is the user-facing 1st-level passphrase which decrypts the data encryption key (which in turn decrypts the data). This approach has specific advantages:</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Self-encrypting drives adhering to the TCG OPAL 2.0 standard specification (almost all modern self-encrypting drives) implement key management via an authentication key, and a 2nd-level data encryption key. The data encryption key is the key against which data on the drive is actually encrypted. The authentication key is the user-facing 1st-level passphrase which decrypts the data encryption key (which in turn decrypts the data). This approach has specific advantages:</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In fact, in drives featuring full-disk encryption, data is ''always'' encrypted with the data encryption key when stored to disk, even if there is no password set (e.g. a new drive). Manufacturers do this to make it easier for users who do not wish to enable the security features of the self-encrypting drive. These self-encrypting drives can be thought of as having a zero-length password by default that ''always'' transparently encrypts the data (similar to how passwordless SSH keys can provide somewhat secure access without user intervention).</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>In fact, in drives featuring full-disk encryption, data is ''always'' encrypted with the data encryption key when stored to disk, even if there is no password set (e.g. a new drive). Manufacturers do this to make it easier for users who do not wish to enable the security features of the self-encrypting drive. These self-encrypting drives can be thought of as having a zero-length password by default that ''always'' transparently encrypts the data (similar to how passwordless SSH keys can provide somewhat secure access without user intervention).</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>If a user wishes to "enable" encryption at a later stage, they are able to configure an authentication key (such as a passphrase) which encrypts the existing data encryption key. The user will then be prompted for their passphrase when decrypting the data encryption key in the future. Crucially, because the existing data encryption key is not regenerated, setting a passphrase allows for the drive to be locked while preserving existing encrypted data on the disk, avoiding the need for the drive to be re-encrypted.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>If a user wishes to "enable" encryption at a later stage, they are able to configure an authentication key (such as a passphrase) which encrypts the existing data encryption key. The user will then be prompted for their passphrase when decrypting the data encryption key in the future. Crucially, because the existing data encryption key is not regenerated, setting a passphrase allows for the drive to be locked while preserving existing encrypted data on the disk, avoiding the need for the drive to be re-encrypted<ins style="font-weight: bold; text-decoration: none;">. On the flip-side, there is no way to re-encrypt the data itself, other than a secure full disk erasure</ins>.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Advantages ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Advantages ===</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Disadvantages ===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Disadvantages ===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* Constant-power exploits</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* The configuration of [[Power management/Suspend and hibernate|suspend and hibernate]] modes is difficult and may be impossible, depending on the systems' EFI implementation.</ins></div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:Typical self-encrypting drives, once unlocked, will remain unlocked as long as power is provided. This vulnerability can be exploited by means of altering the environment external to the drive, without cutting power, in effect keeping the drive in an unlocked state. For example, it has been shown (by researchers at University of Erlangen-Nuremberg) that it is possible to reboot the computer into an attacker-controlled operating system without cutting power to the drive. The researchers have also demonstrated moving the drive to another computer without cutting power.[https://www1.cs.fau.de/sed]</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* Key-in-memory exploits</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* A re-encryption of the data is not possible without a secure disk erasure.</ins></div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:When the system is powered down into S3 ("sleep") mode, the drive is powered down, but the drive keeps access to the encryption key in its internal memory (NVRAM) to allow for a resume ("wake"). This is necessary because for system booted with an arbitrary operating system there is no standard mechanism to prompt the user to re-enter the pre-boot decryption passphrase again. An attacker (with physical access to the drive) can leverage this to access the drive. Taking together known exploits the researchers summarize "we were able to break hardware-based full-disk encryption on eleven [of twelve] of those systems provided they were running or in standby mode".[https://www1.cs.fau.de/sed] Note, however, S3 ("sleep") is '''not''' currently supported by sedutil (the current available toolset for managing a TCG OPAL 2.0 self-encrypting drives via Linux)</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>* Compromised firmware</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* Exploitations</ins></div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:The firmware of the drive may be compromised (backdoor) and data sent to it thus potentially compromised (decryptable by the malicious third party in question, provided access to physical drive is achievable). A study demonstrated methods for compromising device firmware, as well as applying invalid passwords to access data on OPAL devices.[https://www.ieee-security.org/TC/SP2019/papers/310.pdf] If data is encrypted by the operating system (e.g. dm-crypt), the encryption key is unknown to the compromised drive, thus circumventing this attack vector entirely.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:</ins>* Constant-power exploits</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:</ins>:Typical self-encrypting drives, once unlocked, will remain unlocked as long as power is provided. This vulnerability can be exploited by means of altering the environment external to the drive, without cutting power, in effect keeping the drive in an unlocked state. For example, it has been shown (by researchers at University of Erlangen-Nuremberg) that it is possible to reboot the computer into an attacker-controlled operating system without cutting power to the drive. The researchers have also demonstrated moving the drive to another computer without cutting power.[https://www1.cs.fau.de/sed]</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:</ins>* Key-in-memory exploits</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:</ins>:When the system is powered down into S3 ("sleep") mode, the drive is powered down, but the drive keeps access to the encryption key in its internal memory (NVRAM) to allow for a resume ("wake"). This is necessary because for system booted with an arbitrary operating system there is no standard mechanism to prompt the user to re-enter the pre-boot decryption passphrase again. An attacker (with physical access to the drive) can leverage this to access the drive. Taking together known exploits the researchers summarize "we were able to break hardware-based full-disk encryption on eleven [of twelve] of those systems provided they were running or in standby mode".[https://www1.cs.fau.de/sed] Note, however, S3 ("sleep") is '''not''' currently supported by sedutil (the current available toolset for managing a TCG OPAL 2.0 self-encrypting drives via Linux)</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:</ins>* Compromised firmware</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:</ins>:The firmware of the drive may be compromised (backdoor) and data sent to it thus potentially compromised (decryptable by the malicious third party in question, provided access to physical drive is achievable). A study demonstrated methods for compromising device firmware, as well as applying invalid passwords to access data on OPAL devices.[https://www.ieee-security.org/TC/SP2019/papers/310.pdf] If data is encrypted by the operating system (e.g. dm-crypt), the encryption key is unknown to the compromised drive, thus circumventing this attack vector entirely.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Linux support ==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Linux support ==</div></td></tr>
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