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 · --cphash=FILE
116 File path to record the hash of the command parameters. This is com‐
118 monly termed as cpHash. NOTE: When this option is selected, The tool
119 will not actually execute the command, it simply returns a cpHash.
120 References
123 The type of a context object, whether it is a handle or file name, is
124 determined according to the following logic in-order:
125 · If the argument is a file path, then the file is loaded as a restored
127 TPM transient object.
128 · If the argument is a prefix match on one of:
130 · owner: the owner hierarchy
132 · platform: the platform hierarchy
134 · endorsement: the endorsement hierarchy
136 · lockout: the lockout control persistent object
138 · If the argument argument can be loaded as a number it will be treat
140 as a handle, e.g. 0x81010013 and used directly.OBJECT.
141
143 Authorization for use of an object in TPM2.0 can come in 3 different
144 forms: 1. Password 2. HMAC 3. Sessions
145 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
147 fied".
148 Passwords
150 Passwords are interpreted in the following forms below using prefix
151 identifiers.
152 Note: By default passwords are assumed to be in the string form when
154 they do not have a prefix.
155 String
157 A string password, specified by prefix "str:" or it's absence (raw
158 string without prefix) is not interpreted, and is directly used for au‐
159 thorization.
160 Examples
162 foobar
163 str:foobar
164 Hex-string
166 A hex-string password, specified by prefix "hex:" is converted from a
167 hexidecimal form into a byte array form, thus allowing passwords with
168 non-printable and/or terminal un-friendly characters.
169 Example
171 hex:0x1122334455667788
172 File
174 A file based password, specified be prefix "file:" should be the path
175 of a file containing the password to be read by the tool or a "-" to
176 use stdin. Storing passwords in files prevents information leakage,
177 passwords passed as options can be read from the process list or common
178 shell history features.
179 Examples
181 # to use stdin and be prompted
182 file:-
183 # to use a file from a path
185 file:path/to/password/file
186 # to echo a password via stdin:
188 echo foobar | tpm2_tool -p file:-
189 # to use a bash here-string via stdin:
191 tpm2_tool -p file:- <<< foobar
193 Sessions
195 When using a policy session to authorize the use of an object, prefix
196 the option argument with the session keyword. Then indicate a path to
197 a session file that was created with tpm2_startauthsession(1). Option‐
198 ally, if the session requires an auth value to be sent with the session
199 handle (eg policy password), then append a + and a string as described
200 in the Passwords section.
201 Examples
203 To use a session context file called session.ctx.
204 session:session.ctx
206 To use a session context file called session.ctx AND send the authvalue
208 mypassword.
209 session:session.ctx+mypassword
211 To use a session context file called session.ctx AND send the HEX auth‐
213 value 0x11223344.
214 session:session.ctx+hex:11223344
216 PCR Authorizations
218 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
219 language. The PCR minilanguage is as follows:
220 <pcr-spec>=<raw-pcr-file>
221 The PCR spec is documented in in the section "PCR bank specifiers".
223 The raw-pcr-file is an optional the output of the raw PCR contents as
225 returned by tpm2_pcrread(1).
226 PCR bank specifiers (common/pcr.md)
228 Examples
230 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
231 er of:
232 pcr:sha256:0,1,2,3
234 specifying AUTH.
236
238 Options that take algorithms support "nice-names".
239 There are two major algorithm specification string classes, simple and
241 complex. Only certain algorithms will be accepted by the TPM, based on
242 usage and conditions.
243 Simple specifiers
245 These are strings with no additional specification data. When creating
246 objects, non-specified portions of an object are assumed to defaults.
247 You can find the list of known "Simple Specifiers Below".
248 Asymmetric
250 · rsa
251 · ecc
253 Symmetric
255 · aes
256 · camellia
258 Hashing Algorithms
260 · sha1
261 · sha256
263 · sha384
265 · sha512
267 · sm3_256
269 · sha3_256
271 · sha3_384
273 · sha3_512
275 Keyed Hash
277 · hmac
278 · xor
280 Signing Schemes
282 · rsassa
283 · rsapss
285 · ecdsa
287 · ecdaa
289 · ecschnorr
291 Asymmetric Encryption Schemes
293 · oaep
294 · rsaes
296 · ecdh
298 Modes
300 · ctr
301 · ofb
303 · cbc
305 · cfb
307 · ecb
309 Misc
311 · null
312 Complex Specifiers
314 Objects, when specified for creation by the TPM, have numerous algo‐
315 rithms to populate in the public data. Things like type, scheme and
316 asymmetric details, key size, etc. Below is the general format for
317 specifying this data: <type>:<scheme>:<symmetric-details>
318 Type Specifiers
320 This portion of the complex algorithm specifier is required. The re‐
321 maining scheme and symmetric details will default based on the type
322 specified and the type of the object being created.
323 · aes - Default AES: aes128
325 · aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
327 If mode is not specified, defaults to null.
328 · aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
330 · aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
332 · ecc - Elliptical Curve, defaults to ecc256.
334 · ecc192 - 192 bit ECC
336 · ecc224 - 224 bit ECC
338 · ecc256 - 256 bit ECC
340 · ecc384 - 384 bit ECC
342 · ecc521 - 521 bit ECC
344 · rsa - Default RSA: rsa2048
346 · rsa1024 - RSA with 1024 bit keysize.
348 · rsa2048 - RSA with 2048 bit keysize.
350 · rsa4096 - RSA with 4096 bit keysize.
352 Scheme Specifiers
354 Next, is an optional field, it can be skipped.
355 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
357 Most signing schemes take a hash algorithm directly following the sign‐
358 ing scheme. If the hash algorithm is missing, it defaults to sha256.
359 Some take no arguments, and some take multiple arguments.
360 Hash Optional Scheme Specifiers
362 These scheme specifiers are followed by a dash and a valid hash algo‐
363 rithm, For example: oaep-sha256.
364 · oaep
366 · ecdh
368 · rsassa
370 · rsapss
372 · ecdsa
374 · ecschnorr
376 Multiple Option Scheme Specifiers
378 This scheme specifier is followed by a count (max size UINT16) then
379 folloed by a dash(-) and a valid hash algorithm. * ecdaa For example,
380 ecdaa4-sha256. If no count is specified, it defaults to 4.
381 No Option Scheme Specifiers
383 This scheme specifier takes NO arguments. * rsaes
384 Symmetric Details Specifiers
386 This field is optional, and defaults based on the type of object being
387 created and it's attributes. Generally, any valid Symmetric specifier
388 from the Type Specifiers list should work. If not specified, an asym‐
389 metric objects symmetric details defaults to aes128cfb.
390 Examples
392 Create an rsa2048 key with an rsaes asymmetric encryption scheme
393 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
394 Create an ecc256 key with an ecdaa signing scheme with a count of 4
396 and sha384 hash
397 /tpm2_create -C parent.ctx -G ecc256:ec‐
399 daa4-sha384 -u key.pub -r key.priv cryptographic algorithms ALGORITHM.
400
402 Object Attributes are used to control various properties of created ob‐
403 jects. When specified as an option, either the raw bitfield mask or
404 "nice-names" may be used. The values can be found in Table 31 Part 2
405 of the TPM2.0 specification, which can be found here:
406 <https://trustedcomputinggroup.org/wp-content/uploads/TPM-
408 Rev-2.0-Part-2-Structures-01.38.pdf>
409 Nice names are calculated by taking the name field of table 31 and re‐
411 moving the prefix TPMA_OBJECT_ and lowercasing the result. Thus, TP‐
412 MA_OBJECT_FIXEDTPM becomes fixedtpm. Nice names can be joined using
413 the bitwise or "|" symbol.
414 For instance, to set The fields TPMA_OBJECT_FIXEDTPM, TPMA_OBJECT_NODA,
416 and TPMA_OBJECT_SIGN_ENCRYPT, the argument would be:
417 fixedtpm|noda|sign specifying the object attributes ATTRIBUTES.
419
421 This collection of options are common to many programs and provide in‐
422 formation that many users may expect.
423 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
425 attempts to invoke the manpager for the tool, however, on failure
426 will output a short tool summary. This is the same behavior if the
427 "man" option argument is specified, however if explicit "man" is re‐
428 quested, the tool will provide errors from man on stderr. If the
429 "no-man" option if specified, or the manpager fails, the short op‐
430 tions will be output to stdout.
431 To successfully use the manpages feature requires the manpages to be
433 installed or on MANPATH, See man(1) for more details.
434 · -v, --version: Display version information for this tool, supported
436 tctis and exit.
437 · -V, --verbose: Increase the information that the tool prints to the
439 console during its execution. When using this option the file and
440 line number are printed.
441 · -Q, --quiet: Silence normal tool output to stdout.
443 · -Z, --enable-errata: Enable the application of errata fixups. Useful
445 if an errata fixup needs to be applied to commands sent to the TPM.
446 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
447 formation many users may expect.
448
450 The TCTI or "Transmission Interface" is the communication mechanism
451 with the TPM. TCTIs can be changed for communication with TPMs across
452 different mediums.
453 To control the TCTI, the tools respect:
455 1. The command line option -T or --tcti
457 2. The environment variable: TPM2TOOLS_TCTI.
459 Note: The command line option always overrides the environment vari‐
461 able.
462 The current known TCTIs are:
464 · tabrmd - The resource manager, called tabrmd
466 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
467 abrmd as a tcti name are synonymous.
468 · mssim - Typically used for communicating to the TPM software simula‐
470 tor.
471 · device - Used when talking directly to a TPM device file.
473 · none - Do not initalize a connection with the TPM. Some tools allow
475 for off-tpm options and thus support not using a TCTI. Tools that do
476 not support it will error when attempted to be used without a TCTI
477 connection. Does not support ANY options and MUST BE presented as
478 the exact text of "none".
479 The arguments to either the command line option or the environment
481 variable are in the form:
482 <tcti-name>:<tcti-option-config>
484 Specifying an empty string for either the <tcti-name> or <tcti-op‐
486 tion-config> results in the default being used for that portion respec‐
487 tively.
488 TCTI Defaults
490 When a TCTI is not specified, the default TCTI is searched for using
491 dlopen(3) semantics. The tools will search for tabrmd, device and
492 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
493 what TCTI will be chosen as the default by using the -v option to print
494 the version information. The "default-tcti" key-value pair will indi‐
495 cate which of the aforementioned TCTIs is the default.
496 Custom TCTIs
498 Any TCTI that implements the dynamic TCTI interface can be loaded. The
499 tools internally use dlopen(3), and the raw tcti-name value is used for
500 the lookup. Thus, this could be a path to the shared library, or a li‐
501 brary name as understood by dlopen(3) semantics.
502
504 This collection of options are used to configure the various known TCTI
505 modules available:
506 · device: For the device TCTI, the TPM character device file for use by
508 the device TCTI can be specified. The default is /dev/tpm0.
509 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
511 vice:/dev/tpm0"
512 · mssim: For the mssim TCTI, the domain name or IP address and port
514 number used by the simulator can be specified. The default are
515 127.0.0.1 and 2321.
516 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
518 TI="mssim:host=localhost,port=2321"
519 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
521 ries of simple key value pairs separated by a ',' character. Each
522 key and value string are separated by a '=' character.
523 · TCTI abrmd supports two keys:
525 1. 'bus_name' : The name of the tabrmd service on the bus (a
527 string).
528 2. 'bus_type' : The type of the dbus instance (a string) limited to
530 'session' and 'system'.
531 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
533 ample.FooBar:
534 \--tcti=tabrmd:bus_name=com.example.FooBar
536 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
538 sion:
539 \--tcti:bus_type=session
541 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
543 ules.
544
546 Setup
547 In order to create an object, we must first create a primary key as
548 it's parent.
549 tpm2_createprimary -c primary.ctx
551 Create an Object
553 This will create an object using all the default values and store the
554 TPM sealed private and public portions to the paths specified via -u
555 and -r respectively. The tool defaults to an RSA key.
556 tpm2_create -C primary.ctx -u obj.pub -r obj.priv
558 Seal Data to the TPM
560 Outside of key objects, the TPM allows for small amounts of user speci‐
561 fied data to be sealed to the TPM.
562 echo "my sealed data" > seal.dat
564 tpm2_create -C primary.ctx -i seal.dat -u obj.pub -r obj.priv
565 Create an EC Key Object and Load it to the TPM
567 Normally, when creating an object, only the public and private portions
568 of the object are returned and the caller needs to use tpm2_load(1) to
569 load those public and private portions to the TPM before being able to
570 use the object. However, this can be accomplished within this command
571 as well.
572 tpm2_create -C primary.ctx -G ecc -u obj.pub -r obj.priv -c ecc.ctx
574
576 Tools can return any of the following codes:
577 · 0 - Success.
579 · 1 - General non-specific error.
581 · 2 - Options handling error.
583 · 3 - Authentication error.
585 · 4 - TCTI related error.
587 · 5 - Non supported scheme. Applicable to tpm2_testparams.
589
591 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
592
594 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
595tpm2-tools tpm2_create(1)