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1 | <?xml version="1.0"?> |
2 | <!--*-nxml-*--> | |
3 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" | |
4 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> | |
5 | <!-- SPDX-License-Identifier: LGPL-2.1-or-later --> | |
6 | <refentry id="systemd-cryptenroll" xmlns:xi="http://www.w3.org/2001/XInclude" conditional='HAVE_LIBCRYPTSETUP'> | |
7 | ||
8 | <refentryinfo> | |
9 | <title>systemd-cryptenroll</title> | |
10 | <productname>systemd</productname> | |
11 | </refentryinfo> | |
12 | ||
13 | <refmeta> | |
14 | <refentrytitle>systemd-cryptenroll</refentrytitle> | |
15 | <manvolnum>1</manvolnum> | |
16 | </refmeta> | |
17 | ||
18 | <refnamediv> | |
19 | <refname>systemd-cryptenroll</refname> | |
20 | <refpurpose>Enroll PKCS#11, FIDO2, TPM2 token/devices to LUKS2 encrypted volumes</refpurpose> | |
21 | </refnamediv> | |
22 | ||
23 | <refsynopsisdiv> | |
24 | <cmdsynopsis> | |
38e3c61d ZJS |
25 | <command>systemd-cryptenroll</command> |
26 | <arg choice="opt" rep="repeat">OPTIONS</arg> | |
27 | <arg choice="opt">DEVICE</arg> | |
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28 | </cmdsynopsis> |
29 | </refsynopsisdiv> | |
30 | ||
31 | <refsect1> | |
32 | <title>Description</title> | |
33 | ||
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34 | <para><command>systemd-cryptenroll</command> is a tool for enrolling hardware security tokens and devices |
35 | into a LUKS2 encrypted volume, which may then be used to unlock the volume during boot. Specifically, it | |
36 | supports tokens and credentials of the following kind to be enrolled:</para> | |
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37 | |
38 | <orderedlist> | |
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39 | <listitem><para>PKCS#11 security tokens and smartcards that may carry an RSA key pair (e.g. various |
40 | YubiKeys)</para></listitem> | |
cf1e172d | 41 | |
880e1e07 ZJS |
42 | <listitem><para>FIDO2 security tokens that implement the <literal>hmac-secret</literal> extension (most |
43 | FIDO2 keys, including YubiKeys)</para></listitem> | |
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44 | |
45 | <listitem><para>TPM2 security devices</para></listitem> | |
46 | ||
a587a16a ZJS |
47 | <listitem><para>Regular passphrases</para></listitem> |
48 | ||
cf1e172d | 49 | <listitem><para>Recovery keys. These are similar to regular passphrases, however are randomly generated |
880e1e07 | 50 | on the computer and thus generally have higher entropy than user-chosen passphrases. Their character |
cf1e172d LP |
51 | set has been designed to ensure they are easy to type in, while having high entropy. They may also be |
52 | scanned off screen using QR codes. Recovery keys may be used for unlocking LUKS2 volumes wherever | |
53 | passphrases are accepted. They are intended to be used in combination with an enrolled hardware | |
54 | security token, as a recovery option when the token is lost.</para></listitem> | |
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55 | </orderedlist> |
56 | ||
57 | <para>In addition, the tool may be used to enumerate currently enrolled security tokens and wipe a subset | |
58 | of them. The latter may be combined with the enrollment operation of a new security token, in order to | |
59 | update or replace enrollments.</para> | |
60 | ||
61 | <para>The tool supports only LUKS2 volumes, as it stores token meta-information in the LUKS2 JSON token | |
62 | area, which is not available in other encryption formats.</para> | |
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63 | |
64 | <refsect2> | |
65 | <title>TPM2 PCRs and policies</title> | |
66 | ||
67 | <para>PCRs allow binding of the encryption of secrets to specific software versions and system state, | |
68 | so that the enrolled key is only accessible (may be "unsealed") if specific trusted software and/or | |
69 | configuration is used. Such bindings may be created with the option <option>--tpm2-pcrs=</option> | |
70 | described below.</para> | |
71 | ||
72 | <para>Secrets may also be bound indirectly: a signed policy for a state of some combination of PCR | |
73 | values is provided, and the secret is bound to the public part of the key used to sign this policy. | |
74 | This means that the owner of a key can generate a sequence of signed policies, for specific software | |
75 | versions and system states, and the secret can be decrypted as long as the machine state matches one of | |
76 | those policies. For example, a vendor may provide such a policy for each kernel+initrd update, allowing | |
77 | users to encrypt secrets so that they can be decrypted when running any kernel+initrd signed by the | |
78 | vendor. Such bindings may be created with the options <option>--tpm2-public-key=</option>, | |
79 | <option>--tpm2-public-key-pcrs=</option>, <option>--tpm2-signature=</option> described below. | |
80 | </para> | |
81 | ||
82 | <para>See <ulink url="https://uapi-group.org/specifications/specs/linux_tpm_pcr_registry/">Linux TPM | |
83 | PCR Registry</ulink> for an authoritative list of PCRs and how they are updated. The table below | |
84 | contains a quick reference, describing in particular the PCRs modified by systemd.</para> | |
85 | ||
86 | <table> | |
87 | <title>Well-known PCR Definitions</title> | |
88 | ||
89 | <!-- See: https://trustedcomputinggroup.org/resource/pc-client-specific-platform-firmware-profile-specification/ --> | |
90 | <!-- See: https://github.com/rhboot/shim/blob/main/README.tpm --> | |
91 | <!-- See: https://www.gnu.org/software/grub/manual/grub/html_node/Measured-Boot.html --> | |
92 | <!-- See: https://sourceforge.net/p/linux-ima/wiki/Home/ --> | |
93 | <!-- See: https://github.com/tianocore-docs/edk2-TrustedBootChain/blob/main/4_Other_Trusted_Boot_Chains.md --> | |
94 | <!-- See: https://wiki.archlinux.org/title/Trusted_Platform_Module#Accessing_PCR_registers --> | |
95 | ||
96 | <tgroup cols='3' align='left' colsep='1' rowsep='1'> | |
97 | <colspec colname="pcr" /> | |
98 | <colspec colname="name" /> | |
99 | <colspec colname="definition" /> | |
100 | ||
101 | <thead> | |
102 | <row> | |
103 | <entry>PCR</entry> | |
104 | <entry>name</entry> | |
105 | <entry>Explanation</entry> | |
106 | </row> | |
107 | </thead> | |
108 | ||
109 | <tbody> | |
110 | <row> | |
111 | <entry>0</entry> | |
112 | <entry>platform-code</entry> | |
113 | <entry>Core system firmware executable code; changes on firmware updates</entry> | |
114 | </row> | |
115 | ||
116 | <row> | |
117 | <entry>1</entry> | |
118 | <entry>platform-config</entry> | |
119 | <entry>Core system firmware data/host platform configuration; typically contains serial and model numbers, changes on basic hardware/CPU/RAM replacements</entry> | |
120 | </row> | |
121 | ||
122 | <row> | |
123 | <entry>2</entry> | |
124 | <entry>external-code</entry> | |
125 | <entry>Extended or pluggable executable code; includes option ROMs on pluggable hardware</entry> | |
126 | </row> | |
127 | ||
128 | <row> | |
129 | <entry>3</entry> | |
130 | <entry>external-config</entry> | |
131 | <entry>Extended or pluggable firmware data; includes information about pluggable hardware</entry> | |
132 | </row> | |
133 | ||
134 | <row> | |
135 | <entry>4</entry> | |
136 | <entry>boot-loader-code</entry> | |
137 | <entry>Boot loader and additional drivers, PE binaries invoked by the boot loader; changes on boot loader updates. <citerefentry><refentrytitle>sd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures system extension images read from the ESP here too (see <citerefentry><refentrytitle>systemd-sysext</refentrytitle><manvolnum>8</manvolnum></citerefentry>).</entry> | |
138 | </row> | |
139 | ||
140 | <row> | |
141 | <entry>5</entry> | |
142 | <entry>boot-loader-config</entry> | |
143 | <entry>GPT/Partition table; changes when the partitions are added, modified, or removed</entry> | |
144 | </row> | |
145 | ||
146 | <row> | |
147 | <entry>7</entry> | |
148 | <entry>secure-boot-policy</entry> | |
149 | <entry>Secure Boot state; changes when UEFI SecureBoot mode is enabled/disabled, or firmware certificates (PK, KEK, db, dbx, …) changes.</entry> | |
150 | </row> | |
151 | ||
152 | <row> | |
153 | <entry>9</entry> | |
154 | <entry>kernel-initrd</entry> | |
155 | <entry>The Linux kernel measures all initrds it receives into this PCR.</entry> | |
156 | <!-- Strictly speaking only Linux >= 5.17 using the LOAD_FILE2 protocol, see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f046fff8bc4c4d8f8a478022e76e40b818f692df --> | |
157 | </row> | |
158 | ||
159 | <row> | |
160 | <entry>10</entry> | |
161 | <entry>ima</entry> | |
162 | <entry>The IMA project measures its runtime state into this PCR.</entry> | |
163 | </row> | |
164 | ||
165 | <row> | |
166 | <entry>11</entry> | |
167 | <entry>kernel-boot</entry> | |
168 | <entry><citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures the ELF kernel image, embedded initrd and other payload of the PE image it is placed in into this PCR. <citerefentry><refentrytitle>systemd-pcrphase.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> measures boot phase strings into this PCR at various milestones of the boot process.</entry> | |
169 | </row> | |
170 | ||
171 | <row> | |
172 | <entry>12</entry> | |
173 | <entry>kernel-config</entry> | |
174 | <entry><citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures the kernel command line into this PCR. <citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures any manually specified kernel command line (i.e. a kernel command line that overrides the one embedded in the unified PE image) and loaded credentials into this PCR.</entry> | |
175 | </row> | |
176 | ||
177 | <row> | |
178 | <entry>13</entry> | |
179 | <entry>sysexts</entry> | |
180 | <entry><citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures any <citerefentry><refentrytitle>systemd-sysext</refentrytitle><manvolnum>8</manvolnum></citerefentry> images it passes to the booted kernel into this PCR.</entry> | |
181 | </row> | |
182 | ||
183 | <row> | |
184 | <entry>14</entry> | |
185 | <entry>shim-policy</entry> | |
186 | <entry>The shim project measures its "MOK" certificates and hashes into this PCR.</entry> | |
187 | </row> | |
188 | ||
189 | <row> | |
190 | <entry>15</entry> | |
191 | <entry>system-identity</entry> | |
94d82b59 | 192 | <entry><citerefentry><refentrytitle>systemd-cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry> optionally measures the volume key of activated LUKS volumes into this PCR. <citerefentry><refentrytitle>systemd-pcrmachine.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> measures the <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> into this PCR. <citerefentry><refentrytitle>systemd-pcrfs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> measures mount points, file system UUIDs, labels, partition UUIDs of the root and <filename>/var/</filename> filesystems into this PCR.</entry> |
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193 | </row> |
194 | ||
195 | <row> | |
196 | <entry>16</entry> | |
197 | <entry>debug</entry> | |
198 | <entry>Debug</entry> | |
199 | </row> | |
200 | ||
201 | <row> | |
202 | <entry>23</entry> | |
203 | <entry>application-support</entry> | |
204 | <entry>Application Support</entry> | |
205 | </row> | |
206 | </tbody> | |
207 | </tgroup> | |
208 | </table> | |
209 | ||
210 | <para>In general, encrypted volumes would be bound to some combination of PCRs 7, 11, and 14 (if | |
211 | shim/MOK is used). In order to allow firmware and OS version updates, it is typically not advisable to | |
212 | use PCRs such as 0 and 2, since the program code they cover should already be covered indirectly | |
213 | through the certificates measured into PCR 7. Validation through certificates hashes is typically | |
214 | preferable over validation through direct measurements as it is less brittle in context of OS/firmware | |
215 | updates: the measurements will change on every update, but signatures should remain unchanged. See the | |
216 | <ulink url="https://uapi-group.org/specifications/specs/linux_tpm_pcr_registry/">Linux TPM PCR | |
217 | Registry</ulink> for more discussion.</para> | |
218 | </refsect2> | |
cf1e172d | 219 | </refsect1> |
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220 | |
221 | <refsect1> | |
222 | <title>Limitations</title> | |
223 | ||
224 | <para>Note that currently when enrolling a new key of one of the five supported types listed above, it is | |
820c66dc PC |
225 | required to first provide a passphrase, a recovery key or a FIDO2 token. It's currently not supported to |
226 | unlock a device with a TPM2/PKCS#11 key in order to enroll a new TPM2/PKCS#11 key. Thus, if in future key | |
227 | roll-over is desired it's generally recommended to ensure a passphrase, a recovery key or a FIDO2 token | |
228 | is always enrolled.</para> | |
229 | ||
230 | <para>Also note that support for enrolling multiple FIDO2 tokens is currently limited. When multiple FIDO2 | |
231 | tokens are enrolled, <command>systemd-cryptseup</command> will perform pre-flight requests to attempt to | |
232 | identify which of the enrolled tokens are currently plugged in. However, this is not possible for FIDO2 | |
233 | tokens with user verification (UV, usually via biometrics), in which case it will fall back to attempting | |
234 | each enrolled token one by one. This will result in multiple prompts for PIN and user verification. This | |
235 | limitation does not apply to PKCS#11 tokens.</para> | |
0bada3f8 | 236 | </refsect1> |
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237 | |
238 | <refsect1> | |
239 | <title>Options</title> | |
240 | ||
241 | <para>The following options are understood:</para> | |
242 | ||
243 | <variablelist> | |
244 | <varlistentry> | |
245 | <term><option>--password</option></term> | |
246 | ||
247 | <listitem><para>Enroll a regular password/passphrase. This command is mostly equivalent to | |
248 | <command>cryptsetup luksAddKey</command>, however may be combined with | |
ec07c3c8 AK |
249 | <option>--wipe-slot=</option> in one call, see below.</para> |
250 | ||
251 | <xi:include href="version-info.xml" xpointer="v248"/></listitem> | |
cf1e172d LP |
252 | </varlistentry> |
253 | ||
254 | <varlistentry> | |
255 | <term><option>--recovery-key</option></term> | |
256 | ||
880e1e07 ZJS |
257 | <listitem><para>Enroll a recovery key. Recovery keys are mostly identical to passphrases, but are |
258 | computer-generated instead of being chosen by a human, and thus have a guaranteed high entropy. The | |
259 | key uses a character set that is easy to type in, and may be scanned off screen via a QR code. | |
ec07c3c8 AK |
260 | </para> |
261 | ||
262 | <xi:include href="version-info.xml" xpointer="v248"/></listitem> | |
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263 | </varlistentry> |
264 | ||
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265 | <varlistentry> |
266 | <term><option>--unlock-key-file=</option><replaceable>PATH</replaceable></term> | |
267 | ||
268 | <listitem><para>Use a file instead of a password/passphrase read from stdin to unlock the volume. | |
269 | Expects the PATH to the file containing your key to unlock the volume. Currently there is nothing like | |
270 | <option>--key-file-offset=</option> or <option>--key-file-size=</option> so this file has to only | |
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271 | contain the full key.</para> |
272 | ||
273 | <xi:include href="version-info.xml" xpointer="v252"/></listitem> | |
1f419024 J |
274 | </varlistentry> |
275 | ||
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276 | <varlistentry> |
277 | <term><option>--unlock-fido2-device=</option><replaceable>PATH</replaceable></term> | |
278 | ||
279 | <listitem><para>Use a FIDO2 device instead of a password/passphrase read from stdin to unlock the | |
280 | volume. Expects a <filename>hidraw</filename> device referring to the FIDO2 device (e.g. | |
281 | <filename>/dev/hidraw1</filename>). Alternatively the special value <literal>auto</literal> may be | |
282 | specified, in order to automatically determine the device node of a currently plugged in security | |
283 | token (of which there must be exactly one). This automatic discovery is unsupported if | |
ec07c3c8 AK |
284 | <option>--fido2-device=</option> option is also specified.</para> |
285 | ||
286 | <xi:include href="version-info.xml" xpointer="v253"/></listitem> | |
d8c5bd04 AAF |
287 | </varlistentry> |
288 | ||
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289 | <varlistentry> |
290 | <term><option>--pkcs11-token-uri=</option><replaceable>URI</replaceable></term> | |
291 | ||
292 | <listitem><para>Enroll a PKCS#11 security token or smartcard (e.g. a YubiKey). Expects a PKCS#11 | |
be0d27ee | 293 | smartcard URI referring to the token. Alternatively the special value <literal>auto</literal> may |
cf1e172d LP |
294 | be specified, in order to automatically determine the URI of a currently plugged in security token |
295 | (of which there must be exactly one). The special value <literal>list</literal> may be used to | |
296 | enumerate all suitable PKCS#11 tokens currently plugged in. The security token must contain an RSA | |
297 | key pair which is used to encrypt the randomly generated key that is used to unlock the LUKS2 | |
298 | volume. The encrypted key is then stored in the LUKS2 JSON token header area.</para> | |
299 | ||
300 | <para>In order to unlock a LUKS2 volume with an enrolled PKCS#11 security token, specify the | |
301 | <option>pkcs11-uri=</option> option in the respective <filename>/etc/crypttab</filename> line:</para> | |
302 | ||
303 | <programlisting>myvolume /dev/sda1 - pkcs11-uri=auto</programlisting> | |
304 | ||
305 | <para>See | |
306 | <citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry> for a | |
307 | more comprehensive example of a <command>systemd-cryptenroll</command> invocation and its matching | |
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308 | <filename>/etc/crypttab</filename> line.</para> |
309 | ||
310 | <xi:include href="version-info.xml" xpointer="v248"/></listitem> | |
cf1e172d LP |
311 | </varlistentry> |
312 | ||
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313 | <varlistentry> |
314 | <term><option>--fido2-credential-algorithm=</option><replaceable>STRING</replaceable></term> | |
315 | <listitem><para>Specify COSE algorithm used in credential generation. The default value is | |
316 | <literal>es256</literal>. Supported values are <literal>es256</literal>, <literal>rs256</literal> | |
317 | and <literal>eddsa</literal>.</para> | |
318 | ||
319 | <para><literal>es256</literal> denotes ECDSA over NIST P-256 with SHA-256. <literal>rs256</literal> | |
320 | denotes 2048-bit RSA with PKCS#1.5 padding and SHA-256. <literal>eddsa</literal> denotes | |
321 | EDDSA over Curve25519 with SHA-512.</para> | |
322 | ||
ec07c3c8 AK |
323 | <para>Note that your authenticator may not support some algorithms.</para> |
324 | ||
325 | <xi:include href="version-info.xml" xpointer="v251"/></listitem> | |
70e723c0 M |
326 | </varlistentry> |
327 | ||
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328 | <varlistentry> |
329 | <term><option>--fido2-device=</option><replaceable>PATH</replaceable></term> | |
330 | ||
331 | <listitem><para>Enroll a FIDO2 security token that implements the <literal>hmac-secret</literal> | |
332 | extension (e.g. a YubiKey). Expects a <filename>hidraw</filename> device referring to the FIDO2 | |
333 | device (e.g. <filename>/dev/hidraw1</filename>). Alternatively the special value | |
334 | <literal>auto</literal> may be specified, in order to automatically determine the device node of a | |
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335 | currently plugged in security token (of which there must be exactly one). This automatic discovery |
336 | is unsupported if <option>--unlock-fido2-device=</option> option is also specified. The special value | |
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337 | <literal>list</literal> may be used to enumerate all suitable FIDO2 tokens currently plugged in. Note |
338 | that many hardware security tokens that implement FIDO2 also implement the older PKCS#11 | |
339 | standard. Typically FIDO2 is preferable, given it's simpler to use and more modern.</para> | |
340 | ||
341 | <para>In order to unlock a LUKS2 volume with an enrolled FIDO2 security token, specify the | |
342 | <option>fido2-device=</option> option in the respective <filename>/etc/crypttab</filename> line:</para> | |
343 | ||
344 | <programlisting>myvolume /dev/sda1 - fido2-device=auto</programlisting> | |
345 | ||
346 | <para>See | |
347 | <citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry> for a | |
348 | more comprehensive example of a <command>systemd-cryptenroll</command> invocation and its matching | |
ec07c3c8 AK |
349 | <filename>/etc/crypttab</filename> line.</para> |
350 | ||
351 | <xi:include href="version-info.xml" xpointer="v248"/></listitem> | |
cf1e172d LP |
352 | </varlistentry> |
353 | ||
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354 | <varlistentry> |
355 | <term><option>--fido2-with-client-pin=</option><replaceable>BOOL</replaceable></term> | |
356 | ||
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357 | <listitem><para>When enrolling a FIDO2 security token, controls whether to require the user to enter |
358 | a PIN when unlocking the volume (the FIDO2 <literal>clientPin</literal> feature). Defaults to | |
359 | <literal>yes</literal>. (Note: this setting is without effect if the security token does not support | |
360 | the <literal>clientPin</literal> feature at all, or does not allow enabling or disabling | |
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361 | it.)</para> |
362 | ||
363 | <xi:include href="version-info.xml" xpointer="v249"/></listitem> | |
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364 | </varlistentry> |
365 | ||
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366 | <varlistentry> |
367 | <term><option>--fido2-with-user-presence=</option><replaceable>BOOL</replaceable></term> | |
368 | ||
369 | <listitem><para>When enrolling a FIDO2 security token, controls whether to require the user to | |
370 | verify presence (tap the token, the FIDO2 <literal>up</literal> feature) when unlocking the volume. | |
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371 | Defaults to <literal>yes</literal>. (Note: this setting is without effect if the security token does not support |
372 | the <literal>up</literal> feature at all, or does not allow enabling or disabling it.) | |
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373 | </para> |
374 | ||
375 | <xi:include href="version-info.xml" xpointer="v249"/></listitem> | |
06f08719 LB |
376 | </varlistentry> |
377 | ||
896cc0da LB |
378 | <varlistentry> |
379 | <term><option>--fido2-with-user-verification=</option><replaceable>BOOL</replaceable></term> | |
380 | ||
381 | <listitem><para>When enrolling a FIDO2 security token, controls whether to require user verification | |
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382 | when unlocking the volume (the FIDO2 <literal>uv</literal> feature). Defaults to |
383 | <literal>no</literal>. (Note: this setting is without effect if the security token does not support | |
ec07c3c8 AK |
384 | the <literal>uv</literal> feature at all, or does not allow enabling or disabling it.)</para> |
385 | ||
386 | <xi:include href="version-info.xml" xpointer="v249"/></listitem> | |
896cc0da LB |
387 | </varlistentry> |
388 | ||
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389 | <varlistentry> |
390 | <term><option>--tpm2-device=</option><replaceable>PATH</replaceable></term> | |
391 | ||
392 | <listitem><para>Enroll a TPM2 security chip. Expects a device node path referring to the TPM2 chip | |
393 | (e.g. <filename>/dev/tpmrm0</filename>). Alternatively the special value <literal>auto</literal> may | |
394 | be specified, in order to automatically determine the device node of a currently discovered TPM2 | |
395 | device (of which there must be exactly one). The special value <literal>list</literal> may be used to | |
396 | enumerate all suitable TPM2 devices currently discovered.</para> | |
397 | ||
398 | <para>In order to unlock a LUKS2 volume with an enrolled TPM2 security chip, specify the | |
399 | <option>tpm2-device=</option> option in the respective <filename>/etc/crypttab</filename> line:</para> | |
400 | ||
401 | <programlisting>myvolume /dev/sda1 - tpm2-device=auto</programlisting> | |
402 | ||
403 | <para>See | |
404 | <citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry> for a | |
405 | more comprehensive example of a <command>systemd-cryptenroll</command> invocation and its matching | |
406 | <filename>/etc/crypttab</filename> line.</para> | |
407 | ||
408 | <para>Use <option>--tpm2-pcrs=</option> (see below) to configure which TPM2 PCR indexes to bind the | |
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409 | enrollment to.</para> |
410 | ||
411 | <xi:include href="version-info.xml" xpointer="v248"/></listitem> | |
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412 | </varlistentry> |
413 | ||
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414 | <varlistentry> |
415 | <term><option>--tpm2-seal-key-handle=</option><replaceable>HANDLE</replaceable></term> | |
416 | ||
417 | <listitem><para>Configures which parent key to use for sealing, using the TPM handle (index) of the | |
418 | key. This is used to "seal" (encrypt) a secret and must be used later to "unseal" (decrypt) the | |
419 | secret. Expects a hexadecimal 32bit integer, optionally prefixed with | |
420 | <literal>0x</literal>. Allowable values are any handle index in the persistent | |
421 | (<literal>0x81000000</literal>-<literal>0x81ffffff</literal>) or transient | |
422 | (<literal>0x80000000</literal>-<literal>0x80ffffff</literal>) ranges. Since transient handles are | |
423 | lost after a TPM reset, and may be flushed during TPM context switching, they should not be used | |
424 | except for very specific use cases, e.g. testing.</para> | |
425 | ||
426 | <para>The default is the Storage Root Key (SRK) handle index <literal>0x81000001</literal>. A value | |
427 | of 0 will use the default. For the SRK handle, a new key will be created and stored in the TPM if one | |
428 | does not already exist; for any other handle, the key must already exist in the TPM at the specified | |
429 | handle index.</para> | |
430 | ||
431 | <para>This should not be changed unless you know what you are doing.</para> | |
432 | ||
433 | <xi:include href="version-info.xml" xpointer="v255"/></listitem> | |
434 | </varlistentry> | |
435 | ||
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436 | <varlistentry> |
437 | <term><option>--tpm2-pcrs=</option><arg rep="repeat">PCR</arg></term> | |
438 | ||
10fa7251 | 439 | <listitem><para>Configures the TPM2 PCRs (Platform Configuration Registers) to bind to when |
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440 | enrollment is requested via <option>--tpm2-device=</option>. Takes a list of PCR entries, where each |
441 | entry starts with a name or numeric index in the range 0…23, optionally followed by | |
442 | <literal>:</literal> and a hash algorithm name (specifying the PCR bank), optionally followed by | |
443 | <literal>=</literal> and a hash digest value. Multiple PCR entries are separated by | |
444 | <literal>+</literal>. If not specified, the default is to use PCR 7 only. If an empty string is | |
445 | specified, binds the enrollment to no PCRs at all. See the table above for a list of available | |
446 | PCRs.</para> | |
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447 | |
448 | <para>Example: <option>--tpm2-pcrs=boot-loader-code+platform-config+boot-loader-config</option> | |
449 | specifies that PCR registers 4, 1, and 5 should be used.</para> | |
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450 | <para>Example: <option>--tpm2-pcrs=7:sha256</option> specifies that PCR register 7 from the SHA256 |
451 | bank should be used.</para> | |
a11a2e05 | 452 | <para>Example: <option>--tpm2-pcrs=4:sha1=3a3f780f11a4b49969fcaa80cd6e3957c33b2275</option> |
1782b0b8 | 453 | specifies that PCR register 4 from the SHA1 bank should be used, and a hash digest value of |
a11a2e05 | 454 | 3a3f780f11a4b49969fcaa80cd6e3957c33b2275 will be used instead of reading the current PCR |
1782b0b8 | 455 | value.</para> |
ec07c3c8 AK |
456 | |
457 | <xi:include href="version-info.xml" xpointer="v248"/> | |
10fa7251 | 458 | </listitem> |
cf1e172d LP |
459 | </varlistentry> |
460 | ||
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461 | <varlistentry> |
462 | <term><option>--tpm2-with-pin=</option><replaceable>BOOL</replaceable></term> | |
463 | ||
464 | <listitem><para>When enrolling a TPM2 device, controls whether to require the user to enter a PIN | |
465 | when unlocking the volume in addition to PCR binding, based on TPM2 policy authentication. Defaults | |
466 | to <literal>no</literal>. Despite being called PIN, any character can be used, not just numbers. | |
467 | </para> | |
468 | ||
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469 | <para>Note that incorrect PIN entry when unlocking increments the TPM dictionary attack lockout |
470 | mechanism, and may lock out users for a prolonged time, depending on its configuration. The lockout | |
471 | mechanism is a global property of the TPM, <command>systemd-cryptenroll</command> does not control or | |
472 | configure the lockout mechanism. You may use tpm2-tss tools to inspect or configure the dictionary | |
473 | attack lockout, with <citerefentry | |
474 | project='mankier'><refentrytitle>tpm2_getcap</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
475 | and <citerefentry | |
476 | project='mankier'><refentrytitle>tpm2_dictionarylockout</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
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477 | commands, respectively.</para> |
478 | ||
479 | <xi:include href="version-info.xml" xpointer="v251"/></listitem> | |
caeb5604 GG |
480 | </varlistentry> |
481 | ||
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482 | <varlistentry> |
483 | <term><option>--tpm2-public-key=</option><arg>PATH</arg></term> | |
484 | <term><option>--tpm2-public-key-pcrs=</option><arg rep="repeat">PCR</arg></term> | |
485 | <term><option>--tpm2-signature=</option><arg>PATH</arg></term> | |
486 | ||
487 | <listitem><para>Configures a TPM2 signed PCR policy to bind encryption to. The | |
488 | <option>--tpm2-public-key=</option> option accepts a path to a PEM encoded RSA public key, to bind | |
489 | the encryption to. If this is not specified explicitly, but a file | |
490 | <filename>tpm2-pcr-public-key.pem</filename> exists in one of the directories | |
491 | <filename>/etc/systemd/</filename>, <filename>/run/systemd/</filename>, | |
492 | <filename>/usr/lib/systemd/</filename> (searched in this order), it is automatically used. The | |
493 | <option>--tpm2-public-key-pcrs=</option> option takes a list of TPM2 PCR indexes to bind to (same | |
494 | syntax as <option>--tpm2-pcrs=</option> described above). If not specified defaults to 11 (i.e. this | |
495 | binds the policy to any unified kernel image for which a PCR signature can be provided).</para> | |
496 | ||
497 | <para>Note the difference between <option>--tpm2-pcrs=</option> and | |
498 | <option>--tpm2-public-key-pcrs=</option>: the former binds decryption to the current, specific PCR | |
499 | values; the latter binds decryption to any set of PCR values for which a signature by the specified | |
500 | public key can be provided. The latter is hence more useful in scenarios where software updates shell | |
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501 | be possible without losing access to all previously encrypted LUKS2 volumes. Like with |
502 | <option>--tpm2-pcrs=</option>, names defined in the table above can also be used to specify the | |
503 | registers, for instance | |
504 | <option>--tpm2-public-key-pcrs=boot-loader-code+system-identity</option>.</para> | |
f0f4fcae | 505 | |
10fa7251 ZJS |
506 | <para>The <option>--tpm2-signature=</option> option takes a path to a TPM2 PCR signature file as |
507 | generated by the | |
f0f4fcae | 508 | <citerefentry><refentrytitle>systemd-measure</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
10fa7251 | 509 | tool. If this is not specified explicitly, a suitable signature file |
f0f4fcae | 510 | <filename>tpm2-pcr-signature.json</filename> is searched for in <filename>/etc/systemd/</filename>, |
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511 | <filename>/run/systemd/</filename>, <filename>/usr/lib/systemd/</filename> (in this order) and used. |
512 | If a signature file is specified or found it is used to verify if the volume can be unlocked with it | |
513 | given the current PCR state, before the new slot is written to disk. This is intended as safety net | |
514 | to ensure that access to a volume is not lost if a public key is enrolled for which no valid | |
515 | signature for the current PCR state is available. If the supplied signature does not unlock the | |
f0f4fcae | 516 | current PCR state and public key combination, no slot is enrolled and the operation will fail. If no |
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517 | signature file is specified or found no such safety verification is done.</para> |
518 | ||
519 | <xi:include href="version-info.xml" xpointer="v252"/></listitem> | |
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520 | </varlistentry> |
521 | ||
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522 | <varlistentry> |
523 | <term><option>--tpm2-pcrlock=</option><arg>PATH</arg></term> | |
524 | ||
525 | <listitem><para>Configures a TPM2 pcrlock policy to bind encryption to. Expects a path to a pcrlock | |
526 | policy file as generated by the | |
527 | <citerefentry><refentrytitle>systemd-pcrlock</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
528 | tool. If a TPM2 device is enrolled and this option is not used but a file | |
529 | <filename>pcrlock.json</filename> is found in <filename>/run/systemd/</filename> or | |
530 | <filename>/var/lib/systemd/</filename> it is automatically used. Assign an empty string to turn this | |
531 | behaviour off.</para> | |
532 | ||
533 | <xi:include href="version-info.xml" xpointer="v255"/></listitem> | |
534 | </varlistentry> | |
535 | ||
cf1e172d LP |
536 | <varlistentry> |
537 | <term><option>--wipe-slot=</option><arg rep="repeat">SLOT</arg></term> | |
538 | ||
539 | <listitem><para>Wipes one or more LUKS2 key slots. Takes a comma separated list of numeric slot | |
540 | indexes, or the special strings <literal>all</literal> (for wiping all key slots), | |
541 | <literal>empty</literal> (for wiping all key slots that are unlocked by an empty passphrase), | |
542 | <literal>password</literal> (for wiping all key slots that are unlocked by a traditional passphrase), | |
543 | <literal>recovery</literal> (for wiping all key slots that are unlocked by a recovery key), | |
544 | <literal>pkcs11</literal> (for wiping all key slots that are unlocked by a PKCS#11 token), | |
545 | <literal>fido2</literal> (for wiping all key slots that are unlocked by a FIDO2 token), | |
546 | <literal>tpm2</literal> (for wiping all key slots that are unlocked by a TPM2 chip), or any | |
547 | combination of these strings or numeric indexes, in which case all slots matching either are | |
548 | wiped. As safety precaution an operation that wipes all slots without exception (so that the volume | |
549 | cannot be unlocked at all anymore, unless the volume key is known) is refused.</para> | |
550 | ||
551 | <para>This switch may be used alone, in which case only the requested wipe operation is executed. It | |
552 | may also be used in combination with any of the enrollment options listed above, in which case the | |
553 | enrollment is completed first, and only when successful the wipe operation executed — and the newly | |
554 | added slot is always excluded from the wiping. Combining enrollment and slot wiping may thus be used to | |
555 | update existing enrollments:</para> | |
556 | ||
557 | <programlisting>systemd-cryptenroll /dev/sda1 --wipe-slot=tpm2 --tpm2-device=auto</programlisting> | |
558 | ||
45861042 | 559 | <para>The above command will enroll the TPM2 chip, and then wipe all previously created TPM2 |
cf1e172d LP |
560 | enrollments on the LUKS2 volume, leaving only the newly created one. Combining wiping and enrollment |
561 | may also be used to replace enrollments of different types, for example for changing from a PKCS#11 | |
562 | enrollment to a FIDO2 one:</para> | |
563 | ||
564 | <programlisting>systemd-cryptenroll /dev/sda1 --wipe-slot=pkcs11 --fido2-device=auto</programlisting> | |
565 | ||
566 | <para>Or for replacing an enrolled empty password by TPM2:</para> | |
567 | ||
568 | <programlisting>systemd-cryptenroll /dev/sda1 --wipe-slot=empty --tpm2-device=auto</programlisting> | |
ec07c3c8 AK |
569 | |
570 | <xi:include href="version-info.xml" xpointer="v248"/> | |
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571 | </listitem> |
572 | </varlistentry> | |
573 | ||
574 | <xi:include href="standard-options.xml" xpointer="help" /> | |
575 | <xi:include href="standard-options.xml" xpointer="version" /> | |
576 | </variablelist> | |
577 | ||
578 | </refsect1> | |
579 | ||
580 | <refsect1> | |
581 | <title>Exit status</title> | |
582 | ||
583 | <para>On success, 0 is returned, a non-zero failure code otherwise.</para> | |
584 | </refsect1> | |
585 | ||
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586 | <refsect1> |
587 | <title>Examples</title> | |
588 | ||
589 | <para><citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry> and | |
590 | <citerefentry><refentrytitle>systemd-measure</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
591 | contain various examples employing <command>systemd-cryptenroll</command>.</para> | |
592 | </refsect1> | |
593 | ||
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594 | <refsect1> |
595 | <title>See Also</title> | |
596 | <para> | |
597 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
598 | <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
599 | <citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
f0f4fcae LP |
600 | <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
601 | <citerefentry><refentrytitle>systemd-measure</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
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602 | </para> |
603 | </refsect1> | |
604 | ||
605 | </refentry> |