1tpm2_sign(1) General Commands Manual tpm2_sign(1)
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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 · ARGUMENT the command line argument specifies the file data for sign.
68 References
71 The type of a context object, whether it is a handle or file name, is
72 determined according to the following logic in-order:
73 · If the argument is a file path, then the file is loaded as a restored
75 TPM transient object.
76 · If the argument is a prefix match on one of:
78 · owner: the owner hierarchy
80 · platform: the platform hierarchy
82 · endorsement: the endorsement hierarchy
84 · lockout: the lockout control persistent object
86 · If the argument argument can be loaded as a number it will be treat
88 as a handle, e.g. 0x81010013 and used directly.OBJECT.
89
91 Authorization for use of an object in TPM2.0 can come in 3 different
92 forms: 1. Password 2. HMAC 3. Sessions
93 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
95 fied".
96 Passwords
98 Passwords are interpreted in the following forms below using prefix
99 identifiers.
100 Note: By default passwords are assumed to be in the string form when
102 they do not have a prefix.
103 String
105 A string password, specified by prefix "str:" or it's absence (raw
106 string without prefix) is not interpreted, and is directly used for au‐
107 thorization.
108 Examples
110 foobar
111 str:foobar
112 Hex-string
114 A hex-string password, specified by prefix "hex:" is converted from a
115 hexidecimal form into a byte array form, thus allowing passwords with
116 non-printable and/or terminal un-friendly characters.
117 Example
119 hex:0x1122334455667788
120 File
122 A file based password, specified be prefix "file:" should be the path
123 of a file containing the password to be read by the tool or a "-" to
124 use stdin. Storing passwords in files prevents information leakage,
125 passwords passed as options can be read from the process list or common
126 shell history features.
127 Examples
129 # to use stdin and be prompted
130 file:-
131 # to use a file from a path
133 file:path/to/password/file
134 # to echo a password via stdin:
136 echo foobar | tpm2_tool -p file:-
137 # to use a bash here-string via stdin:
139 tpm2_tool -p file:- <<< foobar
141 Sessions
143 When using a policy session to authorize the use of an object, prefix
144 the option argument with the session keyword. Then indicate a path to
145 a session file that was created with tpm2_startauthsession(1). Option‐
146 ally, if the session requires an auth value to be sent with the session
147 handle (eg policy password), then append a + and a string as described
148 in the Passwords section.
149 Examples
151 To use a session context file called session.ctx.
152 session:session.ctx
154 To use a session context file called session.ctx AND send the authvalue
156 mypassword.
157 session:session.ctx+mypassword
159 To use a session context file called session.ctx AND send the HEX auth‐
161 value 0x11223344.
162 session:session.ctx+hex:11223344
164 PCR Authorizations
166 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
167 language. The PCR minilanguage is as follows:
168 <pcr-spec>=<raw-pcr-file>
169 The PCR spec is documented in in the section "PCR bank specifiers".
171 The raw-pcr-file is an optional the output of the raw PCR contents as
173 returned by tpm2_pcrread(1).
174 PCR bank specifiers (common/pcr.md)
176 Examples
178 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
179 er of:
180 pcr:sha256:0,1,2,3
182 specifying AUTH.
184
186 Options that take algorithms support "nice-names".
187 There are two major algorithm specification string classes, simple and
189 complex. Only certain algorithms will be accepted by the TPM, based on
190 usage and conditions.
191 Simple specifiers
193 These are strings with no additional specification data. When creating
194 objects, non-specified portions of an object are assumed to defaults.
195 You can find the list of known "Simple Specifiers Below".
196 Asymmetric
198 · rsa
199 · ecc
201 Symmetric
203 · aes
204 · camellia
206 Hashing Algorithms
208 · sha1
209 · sha256
211 · sha384
213 · sha512
215 · sm3_256
217 · sha3_256
219 · sha3_384
221 · sha3_512
223 Keyed Hash
225 · hmac
226 · xor
228 Signing Schemes
230 · rsassa
231 · rsapss
233 · ecdsa
235 · ecdaa
237 · ecschnorr
239 Asymmetric Encryption Schemes
241 · oaep
242 · rsaes
244 · ecdh
246 Modes
248 · ctr
249 · ofb
251 · cbc
253 · cfb
255 · ecb
257 Misc
259 · null
260 Complex Specifiers
262 Objects, when specified for creation by the TPM, have numerous algo‐
263 rithms to populate in the public data. Things like type, scheme and
264 asymmetric details, key size, etc. Below is the general format for
265 specifying this data: <type>:<scheme>:<symmetric-details>
266 Type Specifiers
268 This portion of the complex algorithm specifier is required. The re‐
269 maining scheme and symmetric details will default based on the type
270 specified and the type of the object being created.
271 · aes - Default AES: aes128
273 · aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
275 If mode is not specified, defaults to null.
276 · aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
278 · aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
280 · ecc - Elliptical Curve, defaults to ecc256.
282 · ecc192 - 192 bit ECC
284 · ecc224 - 224 bit ECC
286 · ecc256 - 256 bit ECC
288 · ecc384 - 384 bit ECC
290 · ecc521 - 521 bit ECC
292 · rsa - Default RSA: rsa2048
294 · rsa1024 - RSA with 1024 bit keysize.
296 · rsa2048 - RSA with 2048 bit keysize.
298 · rsa4096 - RSA with 4096 bit keysize.
300 Scheme Specifiers
302 Next, is an optional field, it can be skipped.
303 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
305 Most signing schemes take a hash algorithm directly following the sign‐
306 ing scheme. If the hash algorithm is missing, it defaults to sha256.
307 Some take no arguments, and some take multiple arguments.
308 Hash Optional Scheme Specifiers
310 These scheme specifiers are followed by a dash and a valid hash algo‐
311 rithm, For example: oaep-sha256.
312 · oaep
314 · ecdh
316 · rsassa
318 · rsapss
320 · ecdsa
322 · ecschnorr
324 Multiple Option Scheme Specifiers
326 This scheme specifier is followed by a count (max size UINT16) then
327 folloed by a dash(-) and a valid hash algorithm. * ecdaa For example,
328 ecdaa4-sha256. If no count is specified, it defaults to 4.
329 No Option Scheme Specifiers
331 This scheme specifier takes NO arguments. * rsaes
332 Symmetric Details Specifiers
334 This field is optional, and defaults based on the type of object being
335 created and it's attributes. Generally, any valid Symmetric specifier
336 from the Type Specifiers list should work. If not specified, an asym‐
337 metric objects symmetric details defaults to aes128cfb.
338 Examples
340 Create an rsa2048 key with an rsaes asymmetric encryption scheme
341 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
342 Create an ecc256 key with an ecdaa signing scheme with a count of 4
344 and sha384 hash
345 /tpm2_create -C parent.ctx -G ecc256:ec‐
347 daa4-sha384 -u key.pub -r key.priv cryptographic algorithms ALGORITHM.
348
350 This collection of options are common to many programs and provide in‐
351 formation that many users may expect.
352 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
354 attempts to invoke the manpager for the tool, however, on failure
355 will output a short tool summary. This is the same behavior if the
356 "man" option argument is specified, however if explicit "man" is re‐
357 quested, the tool will provide errors from man on stderr. If the
358 "no-man" option if specified, or the manpager fails, the short op‐
359 tions will be output to stdout.
360 To successfully use the manpages feature requires the manpages to be
362 installed or on MANPATH, See man(1) for more details.
363 · -v, --version: Display version information for this tool, supported
365 tctis and exit.
366 · -V, --verbose: Increase the information that the tool prints to the
368 console during its execution. When using this option the file and
369 line number are printed.
370 · -Q, --quiet: Silence normal tool output to stdout.
372 · -Z, --enable-errata: Enable the application of errata fixups. Useful
374 if an errata fixup needs to be applied to commands sent to the TPM.
375 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
376 formation many users may expect.
377
379 The TCTI or "Transmission Interface" is the communication mechanism
380 with the TPM. TCTIs can be changed for communication with TPMs across
381 different mediums.
382 To control the TCTI, the tools respect:
384 1. The command line option -T or --tcti
386 2. The environment variable: TPM2TOOLS_TCTI.
388 Note: The command line option always overrides the environment vari‐
390 able.
391 The current known TCTIs are:
393 · tabrmd - The resource manager, called tabrmd
395 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
396 abrmd as a tcti name are synonymous.
397 · mssim - Typically used for communicating to the TPM software simula‐
399 tor.
400 · device - Used when talking directly to a TPM device file.
402 · none - Do not initalize a connection with the TPM. Some tools allow
404 for off-tpm options and thus support not using a TCTI. Tools that do
405 not support it will error when attempted to be used without a TCTI
406 connection. Does not support ANY options and MUST BE presented as
407 the exact text of "none".
408 The arguments to either the command line option or the environment
410 variable are in the form:
411 <tcti-name>:<tcti-option-config>
413 Specifying an empty string for either the <tcti-name> or <tcti-op‐
415 tion-config> results in the default being used for that portion respec‐
416 tively.
417 TCTI Defaults
419 When a TCTI is not specified, the default TCTI is searched for using
420 dlopen(3) semantics. The tools will search for tabrmd, device and
421 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
422 what TCTI will be chosen as the default by using the -v option to print
423 the version information. The "default-tcti" key-value pair will indi‐
424 cate which of the aforementioned TCTIs is the default.
425 Custom TCTIs
427 Any TCTI that implements the dynamic TCTI interface can be loaded. The
428 tools internally use dlopen(3), and the raw tcti-name value is used for
429 the lookup. Thus, this could be a path to the shared library, or a li‐
430 brary name as understood by dlopen(3) semantics.
431
433 This collection of options are used to configure the various known TCTI
434 modules available:
435 · device: For the device TCTI, the TPM character device file for use by
437 the device TCTI can be specified. The default is /dev/tpm0.
438 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
440 vice:/dev/tpm0"
441 · mssim: For the mssim TCTI, the domain name or IP address and port
443 number used by the simulator can be specified. The default are
444 127.0.0.1 and 2321.
445 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
447 TI="mssim:host=localhost,port=2321"
448 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
450 ries of simple key value pairs separated by a ',' character. Each
451 key and value string are separated by a '=' character.
452 · TCTI abrmd supports two keys:
454 1. 'bus_name' : The name of the tabrmd service on the bus (a
456 string).
457 2. 'bus_type' : The type of the dbus instance (a string) limited to
459 'session' and 'system'.
460 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
462 ample.FooBar:
463 \--tcti=tabrmd:bus_name=com.example.FooBar
465 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
467 sion:
468 \--tcti:bus_type=session
470 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
472 ules. # Signature Format Specifiers
473 Format selection for the signature output file. tss (the default) will
475 output a binary blob according to the TPM 2.0 specification and any po‐
476 tential compiler padding. The option plain will output the plain sig‐
477 nature data as defined by the used cryptographic algorithm.
478
480 Sign and verify with the TPM using the endorsement
481 hierarchy
482 tpm2_createprimary -C e -c primary.ctx
484 tpm2_create -G rsa -u rsa.pub -r rsa.priv -C primary.ctx
486 tpm2_load -C primary.ctx -u rsa.pub -r rsa.priv -c rsa.ctx
488 echo "my message" > message.dat
490 tpm2_sign -c rsa.ctx -g sha256 -o sig.rssa message.dat
492 tpm2_verifysignature -c rsa.ctx -g sha256 -s sig.rssa -m message.dat
494 Sign with the TPM and verify with OSSL
496 openssl ecparam -name prime256v1 -genkey -noout -out private.ecc.pem
497 openssl ec -in private.ecc.pem -out public.ecc.pem -pubout
499 # Generate a hash to sign
501 echo "data to sign" > data.in.raw
502 sha256sum data.in.raw | awk '{ print "000000 " $1 }' | \
504 xxd -r -c 32 > data.in.digest
505 # Load the private key for signing
507 tpm2_loadexternal -Q -G ecc -r private.ecc.pem -c key.ctx
508 # Sign in the TPM and verify with OSSL
510 tpm2_sign -Q -c key.ctx -g sha256 -d -f plain -o data.out.signed data.in.digest
511 openssl dgst -verify public.ecc.pem -keyform pem -sha256 \
513 -signature data.out.signed data.in.raw
514
516 Tools can return any of the following codes:
517 · 0 - Success.
519 · 1 - General non-specific error.
521 · 2 - Options handling error.
523 · 3 - Authentication error.
525 · 4 - TCTI related error.
527 · 5 - Non supported scheme. Applicable to tpm2_testparams.
529
531 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
532
534 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
535tpm2-tools tpm2_sign(1)