1tpm2_sign(1) General Commands Manual tpm2_sign(1)
2
6 tpm2_sign(1) - Sign a hash using the TPM.
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9 tpm2_sign [OPTIONS] [ARGUMENT]
10
12 tpm2_sign(1) - Signs an externally provided message or hash with the
13 specified symmetric or asymmetric signing key.
14 If the signing key is a restricted signing key, then validation can be
16 provided via the -t output. The ticket indicates that the TPM per‐
17 formed the hash of the message.
18
20 · -c, --key-context=OBJECT:
21 Context object pointing to the the key used for signing. Either a
23 file or a handle number. See section "Context Object Format".
24 · -p, --authAUTH:
26 Optional authorization value to use the key specified by -c. Autho‐
28 rization values should follow the "authorization formatting stan‐
29 dards", see section "Authorization Formatting".
30 · -g, --hash-algorithm=ALGORITHM:
32 The hash algorithm used to digest the message. Algorithms should
34 follow the "formatting standards", see section "Algorithm Speci‐
35 fiers". Also, see section "Supported Hash Algorithms" for a list of
36 supported hash algorithms.
37 · -s, --scheme=ALGORITHM:
39 The signing scheme used to sign the message. Optional. Signing
41 schemes should follow the "formatting standards", see section "Algo‐
42 rithm Specifiers". Also, see section "Supported Signing Schemes" for
43 a list of supported signature schemes. If specified, the signature
44 scheme must match the key type. If left unspecified, a default sig‐
45 nature scheme for the key type will be used.
46 · -d, --digest:
48 Indicate that FILE is a file containing the digest of the message.
50 When this option and -t is specified, a warning is generated and the
51 validation ticket (-t) is ignored. You cannot use this option to
52 sign a digest against a restricted signing key.
53 · -t, --ticket=FILE:
55 The ticket file, containing the validation structure, optional.
57 · -o, --signature=FILE:
59 The signature file, records the signature structure.
61 · -f, --format=FORMAT:
63 Format selection for the signature output file. See section "Signa‐
65 ture Format Specifiers".
66 · --cphash=FILE
68 File path to record the hash of the command parameters. This is com‐
70 monly termed as cpHash. NOTE: When this option is selected, The tool
71 will not actually execute the command, it simply returns a cpHash.
72 · ARGUMENT the command line argument specifies the file data for sign.
74 References
77 The type of a context object, whether it is a handle or file name, is
78 determined according to the following logic in-order:
79 · If the argument is a file path, then the file is loaded as a restored
81 TPM transient object.
82 · If the argument is a prefix match on one of:
84 · owner: the owner hierarchy
86 · platform: the platform hierarchy
88 · endorsement: the endorsement hierarchy
90 · lockout: the lockout control persistent object
92 · If the argument argument can be loaded as a number it will be treat
94 as a handle, e.g. 0x81010013 and used directly.OBJECT.
95
97 Authorization for use of an object in TPM2.0 can come in 3 different
98 forms: 1. Password 2. HMAC 3. Sessions
99 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
101 fied".
102 Passwords
104 Passwords are interpreted in the following forms below using prefix
105 identifiers.
106 Note: By default passwords are assumed to be in the string form when
108 they do not have a prefix.
109 String
111 A string password, specified by prefix "str:" or it's absence (raw
112 string without prefix) is not interpreted, and is directly used for au‐
113 thorization.
114 Examples
116 foobar
117 str:foobar
118 Hex-string
120 A hex-string password, specified by prefix "hex:" is converted from a
121 hexidecimal form into a byte array form, thus allowing passwords with
122 non-printable and/or terminal un-friendly characters.
123 Example
125 hex:0x1122334455667788
126 File
128 A file based password, specified be prefix "file:" should be the path
129 of a file containing the password to be read by the tool or a "-" to
130 use stdin. Storing passwords in files prevents information leakage,
131 passwords passed as options can be read from the process list or common
132 shell history features.
133 Examples
135 # to use stdin and be prompted
136 file:-
137 # to use a file from a path
139 file:path/to/password/file
140 # to echo a password via stdin:
142 echo foobar | tpm2_tool -p file:-
143 # to use a bash here-string via stdin:
145 tpm2_tool -p file:- <<< foobar
147 Sessions
149 When using a policy session to authorize the use of an object, prefix
150 the option argument with the session keyword. Then indicate a path to
151 a session file that was created with tpm2_startauthsession(1). Option‐
152 ally, if the session requires an auth value to be sent with the session
153 handle (eg policy password), then append a + and a string as described
154 in the Passwords section.
155 Examples
157 To use a session context file called session.ctx.
158 session:session.ctx
160 To use a session context file called session.ctx AND send the authvalue
162 mypassword.
163 session:session.ctx+mypassword
165 To use a session context file called session.ctx AND send the HEX auth‐
167 value 0x11223344.
168 session:session.ctx+hex:11223344
170 PCR Authorizations
172 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
173 language. The PCR minilanguage is as follows:
174 <pcr-spec>=<raw-pcr-file>
175 The PCR spec is documented in in the section "PCR bank specifiers".
177 The raw-pcr-file is an optional the output of the raw PCR contents as
179 returned by tpm2_pcrread(1).
180 PCR bank specifiers (common/pcr.md)
182 Examples
184 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
185 er of:
186 pcr:sha256:0,1,2,3
188 specifying AUTH.
190
192 Options that take algorithms support "nice-names".
193 There are two major algorithm specification string classes, simple and
195 complex. Only certain algorithms will be accepted by the TPM, based on
196 usage and conditions.
197 Simple specifiers
199 These are strings with no additional specification data. When creating
200 objects, non-specified portions of an object are assumed to defaults.
201 You can find the list of known "Simple Specifiers Below".
202 Asymmetric
204 · rsa
205 · ecc
207 Symmetric
209 · aes
210 · camellia
212 Hashing Algorithms
214 · sha1
215 · sha256
217 · sha384
219 · sha512
221 · sm3_256
223 · sha3_256
225 · sha3_384
227 · sha3_512
229 Keyed Hash
231 · hmac
232 · xor
234 Signing Schemes
236 · rsassa
237 · rsapss
239 · ecdsa
241 · ecdaa
243 · ecschnorr
245 Asymmetric Encryption Schemes
247 · oaep
248 · rsaes
250 · ecdh
252 Modes
254 · ctr
255 · ofb
257 · cbc
259 · cfb
261 · ecb
263 Misc
265 · null
266 Complex Specifiers
268 Objects, when specified for creation by the TPM, have numerous algo‐
269 rithms to populate in the public data. Things like type, scheme and
270 asymmetric details, key size, etc. Below is the general format for
271 specifying this data: <type>:<scheme>:<symmetric-details>
272 Type Specifiers
274 This portion of the complex algorithm specifier is required. The re‐
275 maining scheme and symmetric details will default based on the type
276 specified and the type of the object being created.
277 · aes - Default AES: aes128
279 · aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
281 If mode is not specified, defaults to null.
282 · aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
284 · aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
286 · ecc - Elliptical Curve, defaults to ecc256.
288 · ecc192 - 192 bit ECC
290 · ecc224 - 224 bit ECC
292 · ecc256 - 256 bit ECC
294 · ecc384 - 384 bit ECC
296 · ecc521 - 521 bit ECC
298 · rsa - Default RSA: rsa2048
300 · rsa1024 - RSA with 1024 bit keysize.
302 · rsa2048 - RSA with 2048 bit keysize.
304 · rsa4096 - RSA with 4096 bit keysize.
306 Scheme Specifiers
308 Next, is an optional field, it can be skipped.
309 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
311 Most signing schemes take a hash algorithm directly following the sign‐
312 ing scheme. If the hash algorithm is missing, it defaults to sha256.
313 Some take no arguments, and some take multiple arguments.
314 Hash Optional Scheme Specifiers
316 These scheme specifiers are followed by a dash and a valid hash algo‐
317 rithm, For example: oaep-sha256.
318 · oaep
320 · ecdh
322 · rsassa
324 · rsapss
326 · ecdsa
328 · ecschnorr
330 Multiple Option Scheme Specifiers
332 This scheme specifier is followed by a count (max size UINT16) then
333 folloed by a dash(-) and a valid hash algorithm. * ecdaa For example,
334 ecdaa4-sha256. If no count is specified, it defaults to 4.
335 No Option Scheme Specifiers
337 This scheme specifier takes NO arguments. * rsaes
338 Symmetric Details Specifiers
340 This field is optional, and defaults based on the type of object being
341 created and it's attributes. Generally, any valid Symmetric specifier
342 from the Type Specifiers list should work. If not specified, an asym‐
343 metric objects symmetric details defaults to aes128cfb.
344 Examples
346 Create an rsa2048 key with an rsaes asymmetric encryption scheme
347 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
348 Create an ecc256 key with an ecdaa signing scheme with a count of 4
350 and sha384 hash
351 /tpm2_create -C parent.ctx -G ecc256:ec‐
353 daa4-sha384 -u key.pub -r key.priv cryptographic algorithms ALGORITHM.
354
356 This collection of options are common to many programs and provide in‐
357 formation that many users may expect.
358 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
360 attempts to invoke the manpager for the tool, however, on failure
361 will output a short tool summary. This is the same behavior if the
362 "man" option argument is specified, however if explicit "man" is re‐
363 quested, the tool will provide errors from man on stderr. If the
364 "no-man" option if specified, or the manpager fails, the short op‐
365 tions will be output to stdout.
366 To successfully use the manpages feature requires the manpages to be
368 installed or on MANPATH, See man(1) for more details.
369 · -v, --version: Display version information for this tool, supported
371 tctis and exit.
372 · -V, --verbose: Increase the information that the tool prints to the
374 console during its execution. When using this option the file and
375 line number are printed.
376 · -Q, --quiet: Silence normal tool output to stdout.
378 · -Z, --enable-errata: Enable the application of errata fixups. Useful
380 if an errata fixup needs to be applied to commands sent to the TPM.
381 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
382 formation many users may expect.
383
385 The TCTI or "Transmission Interface" is the communication mechanism
386 with the TPM. TCTIs can be changed for communication with TPMs across
387 different mediums.
388 To control the TCTI, the tools respect:
390 1. The command line option -T or --tcti
392 2. The environment variable: TPM2TOOLS_TCTI.
394 Note: The command line option always overrides the environment vari‐
396 able.
397 The current known TCTIs are:
399 · tabrmd - The resource manager, called tabrmd
401 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
402 abrmd as a tcti name are synonymous.
403 · mssim - Typically used for communicating to the TPM software simula‐
405 tor.
406 · device - Used when talking directly to a TPM device file.
408 · none - Do not initalize a connection with the TPM. Some tools allow
410 for off-tpm options and thus support not using a TCTI. Tools that do
411 not support it will error when attempted to be used without a TCTI
412 connection. Does not support ANY options and MUST BE presented as
413 the exact text of "none".
414 The arguments to either the command line option or the environment
416 variable are in the form:
417 <tcti-name>:<tcti-option-config>
419 Specifying an empty string for either the <tcti-name> or <tcti-op‐
421 tion-config> results in the default being used for that portion respec‐
422 tively.
423 TCTI Defaults
425 When a TCTI is not specified, the default TCTI is searched for using
426 dlopen(3) semantics. The tools will search for tabrmd, device and
427 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
428 what TCTI will be chosen as the default by using the -v option to print
429 the version information. The "default-tcti" key-value pair will indi‐
430 cate which of the aforementioned TCTIs is the default.
431 Custom TCTIs
433 Any TCTI that implements the dynamic TCTI interface can be loaded. The
434 tools internally use dlopen(3), and the raw tcti-name value is used for
435 the lookup. Thus, this could be a path to the shared library, or a li‐
436 brary name as understood by dlopen(3) semantics.
437
439 This collection of options are used to configure the various known TCTI
440 modules available:
441 · device: For the device TCTI, the TPM character device file for use by
443 the device TCTI can be specified. The default is /dev/tpm0.
444 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
446 vice:/dev/tpm0"
447 · mssim: For the mssim TCTI, the domain name or IP address and port
449 number used by the simulator can be specified. The default are
450 127.0.0.1 and 2321.
451 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
453 TI="mssim:host=localhost,port=2321"
454 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
456 ries of simple key value pairs separated by a ',' character. Each
457 key and value string are separated by a '=' character.
458 · TCTI abrmd supports two keys:
460 1. 'bus_name' : The name of the tabrmd service on the bus (a
462 string).
463 2. 'bus_type' : The type of the dbus instance (a string) limited to
465 'session' and 'system'.
466 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
468 ample.FooBar:
469 \--tcti=tabrmd:bus_name=com.example.FooBar
471 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
473 sion:
474 \--tcti:bus_type=session
476 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
478 ules. # Signature Format Specifiers
479 Format selection for the signature output file. tss (the default) will
481 output a binary blob according to the TPM 2.0 specification and any po‐
482 tential compiler padding. The option plain will output the plain sig‐
483 nature data as defined by the used cryptographic algorithm.
484
486 Sign and verify with the TPM using the endorsement
487 hierarchy
488 tpm2_createprimary -C e -c primary.ctx
490 tpm2_create -G rsa -u rsa.pub -r rsa.priv -C primary.ctx
492 tpm2_load -C primary.ctx -u rsa.pub -r rsa.priv -c rsa.ctx
494 echo "my message" > message.dat
496 tpm2_sign -c rsa.ctx -g sha256 -o sig.rssa message.dat
498 tpm2_verifysignature -c rsa.ctx -g sha256 -s sig.rssa -m message.dat
500 Sign with the TPM and verify with OSSL
502 openssl ecparam -name prime256v1 -genkey -noout -out private.ecc.pem
503 openssl ec -in private.ecc.pem -out public.ecc.pem -pubout
505 # Generate a hash to sign
507 echo "data to sign" > data.in.raw
508 sha256sum data.in.raw | awk '{ print "000000 " $1 }' | \
510 xxd -r -c 32 > data.in.digest
511 # Load the private key for signing
513 tpm2_loadexternal -Q -G ecc -r private.ecc.pem -c key.ctx
514 # Sign in the TPM and verify with OSSL
516 tpm2_sign -Q -c key.ctx -g sha256 -d -f plain -o data.out.signed data.in.digest
517 openssl dgst -verify public.ecc.pem -keyform pem -sha256 \
519 -signature data.out.signed data.in.raw
520
522 Tools can return any of the following codes:
523 · 0 - Success.
525 · 1 - General non-specific error.
527 · 2 - Options handling error.
529 · 3 - Authentication error.
531 · 4 - TCTI related error.
533 · 5 - Non supported scheme. Applicable to tpm2_testparams.
535
537 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
538
540 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
541tpm2-tools tpm2_sign(1)