1tpm2_create(1) General Commands Manual tpm2_create(1)
2
6 tpm2_create(1) - Create a child object.
7
9 tpm2_create [OPTIONS]
10
12 tpm2_create(1) - Create a child object. The object can either be a key
13 or a sealing object. A sealing object allows to seal user data to the
14 TPM, with a maximum size of 256 bytes. Additionally it will load the
15 created object if the -o is specified.
16
18 These options for creating the TPM entity:
19 · -C, --parent-context=OBJECT:
21 The parent of the object to be created.
23 · -P, --parent-auth=AUTH:
25 The authorization value of the parent object specified with -C.
27 · -p, --key-auth=AUTH:
29 The authorization value for the created object.
31 · -g, --hash-algorithm=ALGORITHM:
33 The hash algorithm for generating the objects name. This is optional
35 and defaults to sha256 when not specified.
36 · -G, --key-algorithm=ALGORITHM:
38 The key algorithm associated with this object. It defaults to "rsa"
40 if not specified.
41 · -a, --attributes=ATTRIBUTES:
43 The object attributes, optional. The default for created objects is:
45 TPMA_OBJECT_SIGN_ENCRYPT|TPMA_OBJECT_DECRYPT|TPMA_OB‐
47 JECT_FIXEDTPM| TPMA_OBJECT_FIXEDPARENT|TPMA_OBJECT_SENSITIVEDATAORI‐
48 GIN| TPMA_OBJECT_USERWITHAUTH
49 When -i is specified for sealing, TPMA_OBJECT_SIGN_ENCRYPT and TP‐
51 MA_OBJECT_DECRYPT are removed from the default attribute set. The
52 algorithm is set in a way where the the object is only good for seal‐
53 ing and unsealing. I.e. one cannot use an object for sealing and
54 cryptography operations.
55 · -i, --sealing-input=FILE or STDIN:
57 The data file to be sealed, optional. If file is -, read from stdin.
59 When sealing data only the TPM_ALG_KEYEDHASH algorithm with a NULL
60 scheme is allowed. Thus, -G cannot be specified.
61 · -L, --policy=FILE:
63 The input policy file, optional.
65 · -u, --public=FILE:
67 The output file which contains the public portion of the created ob‐
69 ject, optional.
70 · -r, --private=FILE:
72 The output file which contains the sensitive portion of the object,
74 optional.
75 · -c, --key-context=FILE:
77 The output file which contains the key context, optional. The key
79 context is analogous to the context file produced by tpm2_load(1),
80 however is generated via a tpm2_createloaded(1) command. This option
81 can be used to avoid the normal tpm2_create(1) and tpm2_load(1) com‐
82 mand sequences and do it all in one command, atomically.
83 · --creation-data=FILE:
85 An optional file output that saves the creation data for certifica‐
87 tion.
88 · --template-data=FILE:
90 An optional file output that saves the key template data (TPM2B_PUB‐
92 LIC) to be used in tpm2_policytemplate.
93 · -t, --creation-ticket=FILE:
95 An optional file output that saves the creation ticket for certifica‐
97 tion.
98 · -d, --creation-hash=FILE:
100 An optional file output that saves the creation hash for certifica‐
102 tion.
103 · -q, --outside-info=HEX_STR_OR_FILE:
105 An optional hex string or path to add unique data to the creation da‐
107 ta. Note that it does not contribute in creating statistically
108 unique object.
109 · -l, --pcr-list=PCR:
111 The list of PCR banks and selected PCRs' ids for each bank to be in‐
113 cluded in the creation data for certification.
114 References
117 The type of a context object, whether it is a handle or file name, is
118 determined according to the following logic in-order:
119 · If the argument is a file path, then the file is loaded as a restored
121 TPM transient object.
122 · If the argument is a prefix match on one of:
124 · owner: the owner hierarchy
126 · platform: the platform hierarchy
128 · endorsement: the endorsement hierarchy
130 · lockout: the lockout control persistent object
132 · If the argument argument can be loaded as a number it will be treat
134 as a handle, e.g. 0x81010013 and used directly.OBJECT.
135
137 Authorization for use of an object in TPM2.0 can come in 3 different
138 forms: 1. Password 2. HMAC 3. Sessions
139 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
141 fied".
142 Passwords
144 Passwords are interpreted in the following forms below using prefix
145 identifiers.
146 Note: By default passwords are assumed to be in the string form when
148 they do not have a prefix.
149 String
151 A string password, specified by prefix "str:" or it's absence (raw
152 string without prefix) is not interpreted, and is directly used for au‐
153 thorization.
154 Examples
156 foobar
157 str:foobar
158 Hex-string
160 A hex-string password, specified by prefix "hex:" is converted from a
161 hexidecimal form into a byte array form, thus allowing passwords with
162 non-printable and/or terminal un-friendly characters.
163 Example
165 hex:0x1122334455667788
166 File
168 A file based password, specified be prefix "file:" should be the path
169 of a file containing the password to be read by the tool or a "-" to
170 use stdin. Storing passwords in files prevents information leakage,
171 passwords passed as options can be read from the process list or common
172 shell history features.
173 Examples
175 # to use stdin and be prompted
176 file:-
177 # to use a file from a path
179 file:path/to/password/file
180 # to echo a password via stdin:
182 echo foobar | tpm2_tool -p file:-
183 # to use a bash here-string via stdin:
185 tpm2_tool -p file:- <<< foobar
187 Sessions
189 When using a policy session to authorize the use of an object, prefix
190 the option argument with the session keyword. Then indicate a path to
191 a session file that was created with tpm2_startauthsession(1). Option‐
192 ally, if the session requires an auth value to be sent with the session
193 handle (eg policy password), then append a + and a string as described
194 in the Passwords section.
195 Examples
197 To use a session context file called session.ctx.
198 session:session.ctx
200 To use a session context file called session.ctx AND send the authvalue
202 mypassword.
203 session:session.ctx+mypassword
205 To use a session context file called session.ctx AND send the HEX auth‐
207 value 0x11223344.
208 session:session.ctx+hex:11223344
210 PCR Authorizations
212 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
213 language. The PCR minilanguage is as follows:
214 <pcr-spec>=<raw-pcr-file>
215 The PCR spec is documented in in the section "PCR bank specifiers".
217 The raw-pcr-file is an optional the output of the raw PCR contents as
219 returned by tpm2_pcrread(1).
220 PCR bank specifiers (common/pcr.md)
222 Examples
224 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
225 er of:
226 pcr:sha256:0,1,2,3
228 specifying AUTH.
230
232 Options that take algorithms support "nice-names".
233 There are two major algorithm specification string classes, simple and
235 complex. Only certain algorithms will be accepted by the TPM, based on
236 usage and conditions.
237 Simple specifiers
239 These are strings with no additional specification data. When creating
240 objects, non-specified portions of an object are assumed to defaults.
241 You can find the list of known "Simple Specifiers Below".
242 Asymmetric
244 · rsa
245 · ecc
247 Symmetric
249 · aes
250 · camellia
252 Hashing Algorithms
254 · sha1
255 · sha256
257 · sha384
259 · sha512
261 · sm3_256
263 · sha3_256
265 · sha3_384
267 · sha3_512
269 Keyed Hash
271 · hmac
272 · xor
274 Signing Schemes
276 · rsassa
277 · rsapss
279 · ecdsa
281 · ecdaa
283 · ecschnorr
285 Asymmetric Encryption Schemes
287 · oaep
288 · rsaes
290 · ecdh
292 Modes
294 · ctr
295 · ofb
297 · cbc
299 · cfb
301 · ecb
303 Misc
305 · null
306 Complex Specifiers
308 Objects, when specified for creation by the TPM, have numerous algo‐
309 rithms to populate in the public data. Things like type, scheme and
310 asymmetric details, key size, etc. Below is the general format for
311 specifying this data: <type>:<scheme>:<symmetric-details>
312 Type Specifiers
314 This portion of the complex algorithm specifier is required. The re‐
315 maining scheme and symmetric details will default based on the type
316 specified and the type of the object being created.
317 · aes - Default AES: aes128
319 · aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
321 If mode is not specified, defaults to null.
322 · aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
324 · aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
326 · ecc - Elliptical Curve, defaults to ecc256.
328 · ecc192 - 192 bit ECC
330 · ecc224 - 224 bit ECC
332 · ecc256 - 256 bit ECC
334 · ecc384 - 384 bit ECC
336 · ecc521 - 521 bit ECC
338 · rsa - Default RSA: rsa2048
340 · rsa1024 - RSA with 1024 bit keysize.
342 · rsa2048 - RSA with 2048 bit keysize.
344 · rsa4096 - RSA with 4096 bit keysize.
346 Scheme Specifiers
348 Next, is an optional field, it can be skipped.
349 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
351 Most signing schemes take a hash algorithm directly following the sign‐
352 ing scheme. If the hash algorithm is missing, it defaults to sha256.
353 Some take no arguments, and some take multiple arguments.
354 Hash Optional Scheme Specifiers
356 These scheme specifiers are followed by a dash and a valid hash algo‐
357 rithm, For example: oaep-sha256.
358 · oaep
360 · ecdh
362 · rsassa
364 · rsapss
366 · ecdsa
368 · ecschnorr
370 Multiple Option Scheme Specifiers
372 This scheme specifier is followed by a count (max size UINT16) then
373 folloed by a dash(-) and a valid hash algorithm. * ecdaa For example,
374 ecdaa4-sha256. If no count is specified, it defaults to 4.
375 No Option Scheme Specifiers
377 This scheme specifier takes NO arguments. * rsaes
378 Symmetric Details Specifiers
380 This field is optional, and defaults based on the type of object being
381 created and it's attributes. Generally, any valid Symmetric specifier
382 from the Type Specifiers list should work. If not specified, an asym‐
383 metric objects symmetric details defaults to aes128cfb.
384 Examples
386 Create an rsa2048 key with an rsaes asymmetric encryption scheme
387 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
388 Create an ecc256 key with an ecdaa signing scheme with a count of 4
390 and sha384 hash
391 /tpm2_create -C parent.ctx -G ecc256:ec‐
393 daa4-sha384 -u key.pub -r key.priv cryptographic algorithms ALGORITHM.
394
396 Object Attributes are used to control various properties of created ob‐
397 jects. When specified as an option, either the raw bitfield mask or
398 "nice-names" may be used. The values can be found in Table 31 Part 2
399 of the TPM2.0 specification, which can be found here:
400 <https://trustedcomputinggroup.org/wp-content/uploads/TPM-
402 Rev-2.0-Part-2-Structures-01.38.pdf>
403 Nice names are calculated by taking the name field of table 31 and re‐
405 moving the prefix TPMA_OBJECT_ and lowercasing the result. Thus, TP‐
406 MA_OBJECT_FIXEDTPM becomes fixedtpm. Nice names can be joined using
407 the bitwise or "|" symbol.
408 For instance, to set The fields TPMA_OBJECT_FIXEDTPM, TPMA_OBJECT_NODA,
410 and TPMA_OBJECT_SIGN_ENCRYPT, the argument would be:
411 fixedtpm|noda|sign specifying the object attributes ATTRIBUTES.
413
415 This collection of options are common to many programs and provide in‐
416 formation that many users may expect.
417 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
419 attempts to invoke the manpager for the tool, however, on failure
420 will output a short tool summary. This is the same behavior if the
421 "man" option argument is specified, however if explicit "man" is re‐
422 quested, the tool will provide errors from man on stderr. If the
423 "no-man" option if specified, or the manpager fails, the short op‐
424 tions will be output to stdout.
425 To successfully use the manpages feature requires the manpages to be
427 installed or on MANPATH, See man(1) for more details.
428 · -v, --version: Display version information for this tool, supported
430 tctis and exit.
431 · -V, --verbose: Increase the information that the tool prints to the
433 console during its execution. When using this option the file and
434 line number are printed.
435 · -Q, --quiet: Silence normal tool output to stdout.
437 · -Z, --enable-errata: Enable the application of errata fixups. Useful
439 if an errata fixup needs to be applied to commands sent to the TPM.
440 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
441 formation many users may expect.
442
444 The TCTI or "Transmission Interface" is the communication mechanism
445 with the TPM. TCTIs can be changed for communication with TPMs across
446 different mediums.
447 To control the TCTI, the tools respect:
449 1. The command line option -T or --tcti
451 2. The environment variable: TPM2TOOLS_TCTI.
453 Note: The command line option always overrides the environment vari‐
455 able.
456 The current known TCTIs are:
458 · tabrmd - The resource manager, called tabrmd
460 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
461 abrmd as a tcti name are synonymous.
462 · mssim - Typically used for communicating to the TPM software simula‐
464 tor.
465 · device - Used when talking directly to a TPM device file.
467 · none - Do not initalize a connection with the TPM. Some tools allow
469 for off-tpm options and thus support not using a TCTI. Tools that do
470 not support it will error when attempted to be used without a TCTI
471 connection. Does not support ANY options and MUST BE presented as
472 the exact text of "none".
473 The arguments to either the command line option or the environment
475 variable are in the form:
476 <tcti-name>:<tcti-option-config>
478 Specifying an empty string for either the <tcti-name> or <tcti-op‐
480 tion-config> results in the default being used for that portion respec‐
481 tively.
482 TCTI Defaults
484 When a TCTI is not specified, the default TCTI is searched for using
485 dlopen(3) semantics. The tools will search for tabrmd, device and
486 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
487 what TCTI will be chosen as the default by using the -v option to print
488 the version information. The "default-tcti" key-value pair will indi‐
489 cate which of the aforementioned TCTIs is the default.
490 Custom TCTIs
492 Any TCTI that implements the dynamic TCTI interface can be loaded. The
493 tools internally use dlopen(3), and the raw tcti-name value is used for
494 the lookup. Thus, this could be a path to the shared library, or a li‐
495 brary name as understood by dlopen(3) semantics.
496
498 This collection of options are used to configure the various known TCTI
499 modules available:
500 · device: For the device TCTI, the TPM character device file for use by
502 the device TCTI can be specified. The default is /dev/tpm0.
503 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
505 vice:/dev/tpm0"
506 · mssim: For the mssim TCTI, the domain name or IP address and port
508 number used by the simulator can be specified. The default are
509 127.0.0.1 and 2321.
510 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
512 TI="mssim:host=localhost,port=2321"
513 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
515 ries of simple key value pairs separated by a ',' character. Each
516 key and value string are separated by a '=' character.
517 · TCTI abrmd supports two keys:
519 1. 'bus_name' : The name of the tabrmd service on the bus (a
521 string).
522 2. 'bus_type' : The type of the dbus instance (a string) limited to
524 'session' and 'system'.
525 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
527 ample.FooBar:
528 \--tcti=tabrmd:bus_name=com.example.FooBar
530 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
532 sion:
533 \--tcti:bus_type=session
535 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
537 ules.
538
540 Setup
541 In order to create an object, we must first create a primary key as
542 it's parent.
543 tpm2_createprimary -c primary.ctx
545 Create an Object
547 This will create an object using all the default values and store the
548 TPM sealed private and public portions to the paths specified via -u
549 and -r respectively. The tool defaults to an RSA key.
550 tpm2_create -C primary.ctx -u obj.pub -r obj.priv
552 Seal Data to the TPM
554 Outside of key objects, the TPM allows for small amounts of user speci‐
555 fied data to be sealed to the TPM.
556 echo "my sealed data" > seal.dat
558 tpm2_create -C primary.ctx -i seal.dat -u obj.pub -r obj.priv
559 Create an EC Key Object and Load it to the TPM
561 Normally, when creating an object, only the public and private portions
562 of the object are returned and the caller needs to use tpm2_load(1) to
563 load those public and private portions to the TPM before being able to
564 use the object. However, this can be accomplished within this command
565 as well.
566 tpm2_create -C primary.ctx -G ecc -u obj.pub -r obj.priv -c ecc.ctx
568
570 Tools can return any of the following codes:
571 · 0 - Success.
573 · 1 - General non-specific error.
575 · 2 - Options handling error.
577 · 3 - Authentication error.
579 · 4 - TCTI related error.
581 · 5 - Non supported scheme. Applicable to tpm2_testparams.
583
585 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
586
588 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
589tpm2-tools tpm2_create(1)