1tpm2_pcrallocate(1) General Commands Manual tpm2_pcrallocate(1)
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6 tpm2_pcrallocate(1) - Configure PCRs and bank algorithms.
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9 tpm2_pcrallocate [OPTIONS] [*ARGUMENT]
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12 tpm2_pcrallocate(1) - Allow the user to specify a PCR allocation for
13 the TPM. An allocation is the enabling or disabling of PCRs and it’s
14 banks. A PCR can have multiple banks, where each bank is associated
15 with a specific hashing algorithm. Allocation is specified in the ar‐
16 gument.
17 If no allocation is given, then SHA1 and SHA256 banks with PCRs 0 - 23
19 are allocated.
20 Allocation is a list of banks and selected pcrs. The values should
22 follow the pcr bank specifiers standards, see section “PCR Bank Speci‐
23 fiers”.
24 The new allocations become effective after the next reboot.
26 Note: This command requires platform authorization.
28
30 • -P, --auth=AUTH:
31 Optional authorization value. Authorization values should follow the
33 “authorization formatting standards”, see section “Authorization For‐
34 matting”.
35 • ARGUMENT the command line argument specifies the PCR allocation.
37 • --cphash=FILE
39 File path to record the hash of the command parameters. This is com‐
41 monly termed as cpHash. NOTE: When this option is selected, The tool
42 will not actually execute the command, it simply returns a cpHash.
43 References
46 The type of a context object, whether it is a handle or file name, is
47 determined according to the following logic in-order:
48 • If the argument is a file path, then the file is loaded as a restored
50 TPM transient object.
51 • If the argument is a prefix match on one of:
53 • owner: the owner hierarchy
55 • platform: the platform hierarchy
57 • endorsement: the endorsement hierarchy
59 • lockout: the lockout control persistent object
61 • If the argument argument can be loaded as a number it will be treat
63 as a handle, e.g. 0x81010013 and used directly._OBJECT_.
64
66 Authorization for use of an object in TPM2.0 can come in 3 different
67 forms: 1. Password 2. HMAC 3. Sessions
68 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
70 fied”.
71 Passwords
73 Passwords are interpreted in the following forms below using prefix
74 identifiers.
75 Note: By default passwords are assumed to be in the string form when
77 they do not have a prefix.
78 String
80 A string password, specified by prefix “str:” or it’s absence (raw
81 string without prefix) is not interpreted, and is directly used for au‐
82 thorization.
83 Examples
85 foobar
86 str:foobar
87 Hex-string
89 A hex-string password, specified by prefix “hex:” is converted from a
90 hexidecimal form into a byte array form, thus allowing passwords with
91 non-printable and/or terminal un-friendly characters.
92 Example
94 hex:1122334455667788
95 File
97 A file based password, specified be prefix “file:” should be the path
98 of a file containing the password to be read by the tool or a “-” to
99 use stdin. Storing passwords in files prevents information leakage,
100 passwords passed as options can be read from the process list or common
101 shell history features.
102 Examples
104 # to use stdin and be prompted
105 file:-
106 # to use a file from a path
108 file:path/to/password/file
109 # to echo a password via stdin:
111 echo foobar | tpm2_tool -p file:-
112 # to use a bash here-string via stdin:
114 tpm2_tool -p file:- <<< foobar
116 Sessions
118 When using a policy session to authorize the use of an object, prefix
119 the option argument with the session keyword. Then indicate a path to
120 a session file that was created with tpm2_startauthsession(1). Option‐
121 ally, if the session requires an auth value to be sent with the session
122 handle (eg policy password), then append a + and a string as described
123 in the Passwords section.
124 Examples
126 To use a session context file called session.ctx.
127 session:session.ctx
129 To use a session context file called session.ctx AND send the authvalue
131 mypassword.
132 session:session.ctx+mypassword
134 To use a session context file called session.ctx AND send the HEX auth‐
136 value 0x11223344.
137 session:session.ctx+hex:11223344
139 PCR Authorizations
141 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
142 language. The PCR minilanguage is as follows:
143 <pcr-spec>=<raw-pcr-file>
144 The PCR spec is documented in in the section “PCR bank specifiers”.
146 The raw-pcr-file is an optional argument that contains the output of
148 the raw PCR contents as returned by tpm2_pcrread(1).
149 PCR bank specifiers (pcr.md)
151 Examples
153 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
154 er of:
155 pcr:sha256:0,1,2,3
157 specifying AUTH.
159
161 Options that take algorithms support “nice-names”.
162 There are two major algorithm specification string classes, simple and
164 complex. Only certain algorithms will be accepted by the TPM, based on
165 usage and conditions.
166 Simple specifiers
168 These are strings with no additional specification data. When creating
169 objects, non-specified portions of an object are assumed to defaults.
170 You can find the list of known “Simple Specifiers” below.
171 Asymmetric
173 • rsa
174 • ecc
176 Symmetric
178 • aes
179 • camellia
181 • sm4
183 Hashing Algorithms
185 • sha1
186 • sha256
188 • sha384
190 • sha512
192 • sm3_256
194 • sha3_256
196 • sha3_384
198 • sha3_512
200 Keyed Hash
202 • hmac
203 • xor
205 Signing Schemes
207 • rsassa
208 • rsapss
210 • ecdsa
212 • ecdaa
214 • ecschnorr
216 • sm2
218 Asymmetric Encryption Schemes
220 • oaep
221 • rsaes
223 • ecdh
225 Modes
227 • ctr
228 • ofb
230 • cbc
232 • cfb
234 • ecb
236 Misc
238 • null
239 Complex Specifiers
241 Objects, when specified for creation by the TPM, have numerous algo‐
242 rithms to populate in the public data. Things like type, scheme and
243 asymmetric details, key size, etc. Below is the general format for
244 specifying this data: <type>:<scheme>:<symmetric-details>
245 Type Specifiers
247 This portion of the complex algorithm specifier is required. The re‐
248 maining scheme and symmetric details will default based on the type
249 specified and the type of the object being created.
250 • aes - Default AES: aes128
252 • aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
254 If mode is not specified, defaults to null.
255 • aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
257 • aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
259 • sm4 - Default SM4: sm4128
261 • sm4128 or sm4_128 <mode> - 128 bit SM4 with optional mode
263 (ctr|ofb|cbc|cfb|ecb). If mode is not specified, defaults to null.
264 • ecc - Elliptical Curve, defaults to ecc256.
266 • ecc192 or ecc_nist_p192 - 192 bit ECC NIST curve
268 • ecc224 or ecc_nist_p224 - 224 bit ECC NIST curve
270 • ecc256 or ecc_nist_p256 - 256 bit ECC NIST curve
272 • ecc384 or ecc_nist_p384 - 384 bit ECC NIST curve
274 • ecc521 or ecc_nist_p521 - 521 bit ECC NIST curve
276 • ecc_sm2 or ecc_sm2_p256 - 256 bit SM2 curve
278 • rsa - Default RSA: rsa2048
280 • rsa1024 - RSA with 1024 bit keysize.
282 • rsa2048 - RSA with 2048 bit keysize.
284 • rsa3072 - RSA with 3072 bit keysize.
286 • rsa4096 - RSA with 4096 bit keysize.
288 Scheme Specifiers
290 Next, is an optional field, it can be skipped.
291 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
293 Most signing schemes take a hash algorithm directly following the sign‐
294 ing scheme. If the hash algorithm is missing, it defaults to sha256.
295 Some take no arguments, and some take multiple arguments.
296 Hash Optional Scheme Specifiers
298 These scheme specifiers are followed by a dash and a valid hash algo‐
299 rithm, For example: oaep-sha256.
300 • oaep
302 • ecdh
304 • rsassa
306 • rsapss
308 • ecdsa
310 • ecschnorr
312 • sm2
314 Multiple Option Scheme Specifiers
316 This scheme specifier is followed by a count (max size UINT16) then
317 followed by a dash(-) and a valid hash algorithm. * ecdaa For example,
318 ecdaa4-sha256. If no count is specified, it defaults to 4.
319 No Option Scheme Specifiers
321 This scheme specifier takes NO arguments. * rsaes
322 Symmetric Details Specifiers
324 This field is optional, and defaults based on the type of object being
325 created and it’s attributes. Generally, any valid Symmetric specifier
326 from the Type Specifiers list should work. If not specified, an asym‐
327 metric objects symmetric details defaults to aes128cfb.
328 Examples
330 Create an rsa2048 key with an rsaes asymmetric encryption scheme
331 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
332 Create an ecc256 key with an ecdaa signing scheme with a count of 4 and
334 sha384 hash
335 /tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
336 key.priv cryptographic algorithms ALGORITHM.
337
339 Object Attributes are used to control various properties of created ob‐
340 jects. When specified as an option, either the raw bitfield mask or
341 “nice-names” may be used. The values can be found in Table 31 Part 2
342 of the TPM2.0 specification, which can be found here:
343 <https://trustedcomputinggroup.org/wp-content/uploads/TPM-
345 Rev-2.0-Part-2-Structures-01.38.pdf>
346 Nice names are calculated by taking the name field of table 31 and re‐
348 moving the prefix TPMA_OBJECT_ and lowercasing the result. Thus, TP‐
349 MA_OBJECT_FIXEDTPM becomes fixedtpm. Nice names can be joined using
350 the bitwise or “|” symbol.
351 For instance, to set The fields TPMA_OBJECT_FIXEDTPM, TPMA_OBJECT_NODA,
353 and TPMA_OBJECT_SIGN_ENCRYPT, the argument would be:
354 fixedtpm|noda|sign specifying the object attributes ATTRIBUTES.
356
358 PCR Bank Selection lists follow the below specification:
359 <BANK>:<PCR>[,<PCR>] or <BANK>:all
361 multiple banks may be separated by `+'.
363 For example:
365 sha1:3,4+sha256:all
367 will select PCRs 3 and 4 from the SHA1 bank and PCRs 0 to 23 from the
369 SHA256 bank.
370 Note
372 PCR Selections allow for up to 5 hash to pcr selection mappings. This
373 is a limitation in design in the single call to the tpm to get the pcr
374 values.
375
377 This collection of options are common to many programs and provide in‐
378 formation that many users may expect.
379 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
381 attempts to invoke the manpager for the tool, however, on failure
382 will output a short tool summary. This is the same behavior if the
383 “man” option argument is specified, however if explicit “man” is re‐
384 quested, the tool will provide errors from man on stderr. If the
385 “no-man” option if specified, or the manpager fails, the short op‐
386 tions will be output to stdout.
387 To successfully use the manpages feature requires the manpages to be
389 installed or on MANPATH, See man(1) for more details.
390 • -v, --version: Display version information for this tool, supported
392 tctis and exit.
393 • -V, --verbose: Increase the information that the tool prints to the
395 console during its execution. When using this option the file and
396 line number are printed.
397 • -Q, --quiet: Silence normal tool output to stdout.
399 • -Z, --enable-errata: Enable the application of errata fixups. Useful
401 if an errata fixup needs to be applied to commands sent to the TPM.
402 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
403 formation many users may expect.
404
406 The TCTI or “Transmission Interface” is the communication mechanism
407 with the TPM. TCTIs can be changed for communication with TPMs across
408 different mediums.
409 To control the TCTI, the tools respect:
411 1. The command line option -T or --tcti
413 2. The environment variable: TPM2TOOLS_TCTI.
415 Note: The command line option always overrides the environment vari‐
417 able.
418 The current known TCTIs are:
420 • tabrmd - The resource manager, called tabrmd
422 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
423 abrmd as a tcti name are synonymous.
424 • mssim - Typically used for communicating to the TPM software simula‐
426 tor.
427 • device - Used when talking directly to a TPM device file.
429 • none - Do not initalize a connection with the TPM. Some tools allow
431 for off-tpm options and thus support not using a TCTI. Tools that do
432 not support it will error when attempted to be used without a TCTI
433 connection. Does not support ANY options and MUST BE presented as
434 the exact text of “none”.
435 The arguments to either the command line option or the environment
437 variable are in the form:
438 <tcti-name>:<tcti-option-config>
440 Specifying an empty string for either the <tcti-name> or <tcti-op‐
442 tion-config> results in the default being used for that portion respec‐
443 tively.
444 TCTI Defaults
446 When a TCTI is not specified, the default TCTI is searched for using
447 dlopen(3) semantics. The tools will search for tabrmd, device and
448 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
449 what TCTI will be chosen as the default by using the -v option to print
450 the version information. The “default-tcti” key-value pair will indi‐
451 cate which of the aforementioned TCTIs is the default.
452 Custom TCTIs
454 Any TCTI that implements the dynamic TCTI interface can be loaded. The
455 tools internally use dlopen(3), and the raw tcti-name value is used for
456 the lookup. Thus, this could be a path to the shared library, or a li‐
457 brary name as understood by dlopen(3) semantics.
458
460 This collection of options are used to configure the various known TCTI
461 modules available:
462 • device: For the device TCTI, the TPM character device file for use by
464 the device TCTI can be specified. The default is /dev/tpm0.
465 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
467 vice:/dev/tpm0”
468 • mssim: For the mssim TCTI, the domain name or IP address and port
470 number used by the simulator can be specified. The default are
471 127.0.0.1 and 2321.
472 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
474 TI=“mssim:host=localhost,port=2321”
475 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
477 ries of simple key value pairs separated by a `,' character. Each
478 key and value string are separated by a `=' character.
479 • TCTI abrmd supports two keys:
481 1. `bus_name' : The name of the tabrmd service on the bus (a
483 string).
484 2. `bus_type' : The type of the dbus instance (a string) limited to
486 `session' and `system'.
487 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
489 ample.FooBar:
490 \--tcti=tabrmd:bus_name=com.example.FooBar
492 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
494 sion:
495 \--tcti:bus_type=session
497 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
499 ules.
500
502 To allocate the two default banks (SHA1 and SHA256)
503 tpm2_pcrallocate
504 To make a custom allocation with a platform authorization
506 tpm2_pcrallocate -P abc sha1:7,8,9,10,16,17,18,19+sha256:all
507 To completly switch from SHA1 bank to SHA256 with a platform authorization
509 tpm2_pcrallocate -P abc sha1:none+sha256:all
510
512 Tools can return any of the following codes:
513 • 0 - Success.
515 • 1 - General non-specific error.
517 • 2 - Options handling error.
519 • 3 - Authentication error.
521 • 4 - TCTI related error.
523 • 5 - Non supported scheme. Applicable to tpm2_testparams.
525
527 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
528
530 See the Mailing List (https://lists.linuxfoundation.org/mailman/listin‐
531 fo/tpm2)
532tpm2-tools tpm2_pcrallocate(1)