1tpm2_import(1) General Commands Manual tpm2_import(1)
2
6 tpm2_import(1) - Imports an external key into the tpm as a TPM managed
7 key object.
8
10 tpm2_import [OPTIONS]
11
13 tpm2_import(1) - Imports an external generated key as TPM managed key
14 object. It requires that the parent key object be a RSA key. Can also
15 import a TPM managed key object created by the tpm2_duplicate tool.
16
18 These options control the key importation process:
19 • -G, --key-algorithm=ALGORITHM:
21 The algorithm used by the key to be imported. Supports:
22 • aes - AES 128, 192 or 256 key.
24 • rsa - RSA 1024 or 2048 key.
26 • ecc - ECC NIST P192, P224, P256, P384 or P521 public and private
28 key.
29 • hmac - HMAC key.
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. Algorithms should follow
36 the “formatting standards”, see section “Algorithm Specifiers”. Al‐
37 so, see section “Supported Hash Algorithms” for a list of supported
38 hash algorithms.
39 • -i, --input=FILE:
41 Specifies the filename of the key to be imported. For AES keys, this
43 file is the raw key bytes. For assymetric keys in PEM or DER format.
44 A typical file is generated with openssl genrsa.
45 • -C, --parent-context=OBJECT:
47 The parent key object.
49 • -U, --parent-public=FILE:
51 Optional. Specifies the parent key public data file input. This can
53 be read with tpm2_readpublic(1) tool. If not specified, the tool in‐
54 vokes a tpm2_readpublic on the parent object.
55 • -k, --encryption-key=FILE:
57 Optional. Specifies the file containing the symmetric algorithm key
59 that was used for the inner wrapper. If the file is specified the
60 tool assumes the algorithm is AES 128 in CFB mode otherwise none.
61 • -r, --private=FILE:
63 Specifies the file path required to save the encrypted private por‐
65 tion of the object imported as key.
66 When importing a duplicated object this option specifies the file
68 containing the private portion of the object to be imported. # Pro‐
69 tection Details
70 Objects that can move outside of TPM need to be protected (confiden‐
72 tiality and integrity). For instance, transient objects require that
73 TPM protected data (key or seal material) be stored outside of the TPM.
74 This is seen in tools like tpm2_create(1), where the -r option outputs
75 this protected data. This blob contains the sensitive portions of the
76 object. The sensitive portions of the object are protected by the par‐
77 ent object, using the parent’s symmetric encryption details to encrypt
78 the sensitive data and HMAC it.
79 In-depth details can be found in sections 23 of:
81 • https://trustedcomputinggroup.org/wp-content/up‐
83 loads/TPM-Rev-2.0-Part-1-Architecture-01.38.pdf
84 Notably Figure 20, is relevant, even though it’s specifically referring
86 to duplication blobs, the process is identical.
87 If the output is from tpm2_duplicate(1), the output will be slightly
89 different, as described fully in section 23.
90 • -u, --public=FILE:
92 Specifies the file path required to save the public portion of the
94 object imported as key
95 When importing a duplicated object this option specifies the file
97 containing the public portion of the object to be imported.
98 • -a, --attributes=ATTRIBUTES:
100 The object attributes, optional.
102 • -P, --parent-auth=AUTH:
104 The authorization value for using the parent key specified with -C.
106 • -p, --key-auth=AUTH:
108 The authorization value for the imported key, optional.
110 • -L, --policy=POLICY or HEX_STRING:
112 The policy file or policy hex string used for authorization to the
114 object.
115 • -s, --seed=FILE:
117 Specifies the file containing the encrypted seed of the duplicated
119 object.
120 In order to perform an “unencrypted import” a seed file with the con‐
122 tent 0x0000 needs to be provided (e.g. printf “0000” | xxd -r -p
123 >seed.file).
124 • --passin=OSSL_PEM_FILE_PASSWORD
126 An optional password for an Open SSL (OSSL) provided input file. It
128 mirrors the -passin option of OSSL and is known to support the pass,
129 file, env, fd and plain password formats of openssl. (see man(1)
130 openssl) for more.
131 • --cphash=FILE
133 File path to record the hash of the command parameters. This is com‐
135 monly termed as cpHash. NOTE: When this option is selected, The tool
136 will not actually execute the command, it simply returns a cpHash.
137 References
140 The type of a context object, whether it is a handle or file name, is
141 determined according to the following logic in-order:
142 • If the argument is a file path, then the file is loaded as a restored
144 TPM transient object.
145 • If the argument is a prefix match on one of:
147 • owner: the owner hierarchy
149 • platform: the platform hierarchy
151 • endorsement: the endorsement hierarchy
153 • lockout: the lockout control persistent object
155 • If the argument argument can be loaded as a number it will be treat
157 as a handle, e.g. 0x81010013 and used directly._OBJECT_.
158
160 Authorization for use of an object in TPM2.0 can come in 3 different
161 forms: 1. Password 2. HMAC 3. Sessions
162 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
164 fied”.
165 Passwords
167 Passwords are interpreted in the following forms below using prefix
168 identifiers.
169 Note: By default passwords are assumed to be in the string form when
171 they do not have a prefix.
172 String
174 A string password, specified by prefix “str:” or it’s absence (raw
175 string without prefix) is not interpreted, and is directly used for au‐
176 thorization.
177 Examples
179 foobar
180 str:foobar
181 Hex-string
183 A hex-string password, specified by prefix “hex:” is converted from a
184 hexidecimal form into a byte array form, thus allowing passwords with
185 non-printable and/or terminal un-friendly characters.
186 Example
188 hex:1122334455667788
189 File
191 A file based password, specified be prefix “file:” should be the path
192 of a file containing the password to be read by the tool or a “-” to
193 use stdin. Storing passwords in files prevents information leakage,
194 passwords passed as options can be read from the process list or common
195 shell history features.
196 Examples
198 # to use stdin and be prompted
199 file:-
200 # to use a file from a path
202 file:path/to/password/file
203 # to echo a password via stdin:
205 echo foobar | tpm2_tool -p file:-
206 # to use a bash here-string via stdin:
208 tpm2_tool -p file:- <<< foobar
210 Sessions
212 When using a policy session to authorize the use of an object, prefix
213 the option argument with the session keyword. Then indicate a path to
214 a session file that was created with tpm2_startauthsession(1). Option‐
215 ally, if the session requires an auth value to be sent with the session
216 handle (eg policy password), then append a + and a string as described
217 in the Passwords section.
218 Examples
220 To use a session context file called session.ctx.
221 session:session.ctx
223 To use a session context file called session.ctx AND send the authvalue
225 mypassword.
226 session:session.ctx+mypassword
228 To use a session context file called session.ctx AND send the HEX auth‐
230 value 0x11223344.
231 session:session.ctx+hex:11223344
233 PCR Authorizations
235 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
236 language. The PCR minilanguage is as follows:
237 <pcr-spec>=<raw-pcr-file>
238 The PCR spec is documented in in the section “PCR bank specifiers”.
240 The raw-pcr-file is an optional argument that contains the output of
242 the raw PCR contents as returned by tpm2_pcrread(1).
243 PCR bank specifiers (pcr.md)
245 Examples
247 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
248 er of:
249 pcr:sha256:0,1,2,3
251 specifying AUTH.
253
255 Options that take algorithms support “nice-names”.
256 There are two major algorithm specification string classes, simple and
258 complex. Only certain algorithms will be accepted by the TPM, based on
259 usage and conditions.
260 Simple specifiers
262 These are strings with no additional specification data. When creating
263 objects, non-specified portions of an object are assumed to defaults.
264 You can find the list of known “Simple Specifiers” below.
265 Asymmetric
267 • rsa
268 • ecc
270 Symmetric
272 • aes
273 • camellia
275 • sm4
277 Hashing Algorithms
279 • sha1
280 • sha256
282 • sha384
284 • sha512
286 • sm3_256
288 • sha3_256
290 • sha3_384
292 • sha3_512
294 Keyed Hash
296 • hmac
297 • xor
299 Signing Schemes
301 • rsassa
302 • rsapss
304 • ecdsa
306 • ecdaa
308 • ecschnorr
310 • sm2
312 Asymmetric Encryption Schemes
314 • oaep
315 • rsaes
317 • ecdh
319 Modes
321 • ctr
322 • ofb
324 • cbc
326 • cfb
328 • ecb
330 Misc
332 • null
333 Complex Specifiers
335 Objects, when specified for creation by the TPM, have numerous algo‐
336 rithms to populate in the public data. Things like type, scheme and
337 asymmetric details, key size, etc. Below is the general format for
338 specifying this data: <type>:<scheme>:<symmetric-details>
339 Type Specifiers
341 This portion of the complex algorithm specifier is required. The re‐
342 maining scheme and symmetric details will default based on the type
343 specified and the type of the object being created.
344 • aes - Default AES: aes128
346 • aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
348 If mode is not specified, defaults to null.
349 • aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
351 • aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
353 • sm4 - Default SM4: sm4128
355 • sm4128 or sm4_128 <mode> - 128 bit SM4 with optional mode
357 (ctr|ofb|cbc|cfb|ecb). If mode is not specified, defaults to null.
358 • ecc - Elliptical Curve, defaults to ecc256.
360 • ecc192 or ecc_nist_p192 - 192 bit ECC NIST curve
362 • ecc224 or ecc_nist_p224 - 224 bit ECC NIST curve
364 • ecc256 or ecc_nist_p256 - 256 bit ECC NIST curve
366 • ecc384 or ecc_nist_p384 - 384 bit ECC NIST curve
368 • ecc521 or ecc_nist_p521 - 521 bit ECC NIST curve
370 • ecc_sm2 or ecc_sm2_p256 - 256 bit SM2 curve
372 • rsa - Default RSA: rsa2048
374 • rsa1024 - RSA with 1024 bit keysize.
376 • rsa2048 - RSA with 2048 bit keysize.
378 • rsa3072 - RSA with 3072 bit keysize.
380 • rsa4096 - RSA with 4096 bit keysize.
382 Scheme Specifiers
384 Next, is an optional field, it can be skipped.
385 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
387 Most signing schemes take a hash algorithm directly following the sign‐
388 ing scheme. If the hash algorithm is missing, it defaults to sha256.
389 Some take no arguments, and some take multiple arguments.
390 Hash Optional Scheme Specifiers
392 These scheme specifiers are followed by a dash and a valid hash algo‐
393 rithm, For example: oaep-sha256.
394 • oaep
396 • ecdh
398 • rsassa
400 • rsapss
402 • ecdsa
404 • ecschnorr
406 • sm2
408 Multiple Option Scheme Specifiers
410 This scheme specifier is followed by a count (max size UINT16) then
411 followed by a dash(-) and a valid hash algorithm. * ecdaa For example,
412 ecdaa4-sha256. If no count is specified, it defaults to 4.
413 No Option Scheme Specifiers
415 This scheme specifier takes NO arguments. * rsaes
416 Symmetric Details Specifiers
418 This field is optional, and defaults based on the type of object being
419 created and it’s attributes. Generally, any valid Symmetric specifier
420 from the Type Specifiers list should work. If not specified, an asym‐
421 metric objects symmetric details defaults to aes128cfb.
422 Examples
424 Create an rsa2048 key with an rsaes asymmetric encryption scheme
425 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
426 Create an ecc256 key with an ecdaa signing scheme with a count of 4 and
428 sha384 hash
429 /tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
430 key.priv cryptographic algorithms ALGORITHM.
431
433 Object Attributes are used to control various properties of created ob‐
434 jects. When specified as an option, either the raw bitfield mask or
435 “nice-names” may be used. The values can be found in Table 31 Part 2
436 of the TPM2.0 specification, which can be found here:
437 <https://trustedcomputinggroup.org/wp-content/uploads/TPM-
439 Rev-2.0-Part-2-Structures-01.38.pdf>
440 Nice names are calculated by taking the name field of table 31 and re‐
442 moving the prefix TPMA_OBJECT_ and lowercasing the result. Thus, TP‐
443 MA_OBJECT_FIXEDTPM becomes fixedtpm. Nice names can be joined using
444 the bitwise or “|” symbol.
445 For instance, to set The fields TPMA_OBJECT_FIXEDTPM, TPMA_OBJECT_NODA,
447 and TPMA_OBJECT_SIGN_ENCRYPT, the argument would be:
448 fixedtpm|noda|sign specifying the object attributes ATTRIBUTES.
450
452 This collection of options are common to many programs and provide in‐
453 formation that many users may expect.
454 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
456 attempts to invoke the manpager for the tool, however, on failure
457 will output a short tool summary. This is the same behavior if the
458 “man” option argument is specified, however if explicit “man” is re‐
459 quested, the tool will provide errors from man on stderr. If the
460 “no-man” option if specified, or the manpager fails, the short op‐
461 tions will be output to stdout.
462 To successfully use the manpages feature requires the manpages to be
464 installed or on MANPATH, See man(1) for more details.
465 • -v, --version: Display version information for this tool, supported
467 tctis and exit.
468 • -V, --verbose: Increase the information that the tool prints to the
470 console during its execution. When using this option the file and
471 line number are printed.
472 • -Q, --quiet: Silence normal tool output to stdout.
474 • -Z, --enable-errata: Enable the application of errata fixups. Useful
476 if an errata fixup needs to be applied to commands sent to the TPM.
477 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
478 formation many users may expect.
479
481 The TCTI or “Transmission Interface” is the communication mechanism
482 with the TPM. TCTIs can be changed for communication with TPMs across
483 different mediums.
484 To control the TCTI, the tools respect:
486 1. The command line option -T or --tcti
488 2. The environment variable: TPM2TOOLS_TCTI.
490 Note: The command line option always overrides the environment vari‐
492 able.
493 The current known TCTIs are:
495 • tabrmd - The resource manager, called tabrmd
497 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
498 abrmd as a tcti name are synonymous.
499 • mssim - Typically used for communicating to the TPM software simula‐
501 tor.
502 • device - Used when talking directly to a TPM device file.
504 • none - Do not initalize a connection with the TPM. Some tools allow
506 for off-tpm options and thus support not using a TCTI. Tools that do
507 not support it will error when attempted to be used without a TCTI
508 connection. Does not support ANY options and MUST BE presented as
509 the exact text of “none”.
510 The arguments to either the command line option or the environment
512 variable are in the form:
513 <tcti-name>:<tcti-option-config>
515 Specifying an empty string for either the <tcti-name> or <tcti-op‐
517 tion-config> results in the default being used for that portion respec‐
518 tively.
519 TCTI Defaults
521 When a TCTI is not specified, the default TCTI is searched for using
522 dlopen(3) semantics. The tools will search for tabrmd, device and
523 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
524 what TCTI will be chosen as the default by using the -v option to print
525 the version information. The “default-tcti” key-value pair will indi‐
526 cate which of the aforementioned TCTIs is the default.
527 Custom TCTIs
529 Any TCTI that implements the dynamic TCTI interface can be loaded. The
530 tools internally use dlopen(3), and the raw tcti-name value is used for
531 the lookup. Thus, this could be a path to the shared library, or a li‐
532 brary name as understood by dlopen(3) semantics.
533
535 This collection of options are used to configure the various known TCTI
536 modules available:
537 • device: For the device TCTI, the TPM character device file for use by
539 the device TCTI can be specified. The default is /dev/tpm0.
540 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
542 vice:/dev/tpm0”
543 • mssim: For the mssim TCTI, the domain name or IP address and port
545 number used by the simulator can be specified. The default are
546 127.0.0.1 and 2321.
547 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
549 TI=“mssim:host=localhost,port=2321”
550 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
552 ries of simple key value pairs separated by a `,' character. Each
553 key and value string are separated by a `=' character.
554 • TCTI abrmd supports two keys:
556 1. `bus_name' : The name of the tabrmd service on the bus (a
558 string).
559 2. `bus_type' : The type of the dbus instance (a string) limited to
561 `session' and `system'.
562 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
564 ample.FooBar:
565 \--tcti=tabrmd:bus_name=com.example.FooBar
567 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
569 sion:
570 \--tcti:bus_type=session
572 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
574 ules.
575
577 To import a key, one needs to have a parent key
578 tpm2_createprimary -Grsa2048:aes128cfb -C o -c parent.ctx
579 Create your key and and import it. If you already have a key, just use
581 that and skip creating it.
582 Import an AES 128 key
584 dd if=/dev/urandom of=sym.key bs=1 count=16
585 tpm2_import -C parent.ctx -G aes -i sym.key -u key.pub -r key.priv
587 Import an RSA key
589 openssl genrsa -out private.pem 2048
590 tpm2_import -C parent.ctx -G rsa -i private.pem -u key.pub -r key.priv
592 Import an ECC key
594 openssl ecparam -name prime256v1 -genkey -noout -out private.ecc.pem
595 tpm2_import -C parent.ctx -G ecc -i private.ecc.pem -u key.pub -r key.priv
597 Import a duplicated key
599 tpm2_import -C parent.ctx -i key.dup -u key.pub -r key.priv -L policy.dat
600
602 • The TPM requires that the name algorithm of the child be smaller than
603 the parent.
604
606 Tools can return any of the following codes:
607 • 0 - Success.
609 • 1 - General non-specific error.
611 • 2 - Options handling error.
613 • 3 - Authentication error.
615 • 4 - TCTI related error.
617 • 5 - Non supported scheme. Applicable to tpm2_testparams.
619
621 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
622
624 See the Mailing List (https://lists.linuxfoundation.org/mailman/listin‐
625 fo/tpm2)
626tpm2-tools tpm2_import(1)